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We are a family business who provide a personal service through a professional experience, with knowledge and uncomplicated easy to understand communication. We speak to clients with minimal jargon and maximum details in a friendly approachable manner to ensure you feel confidence with your financial position.
We offer a wide range of business, taxation and accounting services to individuals and businesses through efficient and reliable services. Our client base is diverse – with people from various circumstances, backgrounds, cultures, countries and occupations.
As trusted and qualified business professionals, we specialise in taxation services and financial management. With the help of our industry partners and professional affiliates we can identify opportunity, create strategies and work collaboratively towards your success. We are a registered Taxation Agent and a Member of the Institute of Public Accountants.
Kalvin White, the Practice Manager and a qualified and experienced Accountant that has lived and serviced the Gold Coast area working within and managing local firms for the last 20 years. He has over 31 years experience both in Australia and overseas in various roles within the industry.
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https://afmaccountants.com.au/about-us/
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In May 2005, the Jan van Eyck Academie in Maastricht, the Center for Contemporary Arts Estonia in Tallinn and the Salzburger Kunstverein will present the series of events called Trichtlinnburg which concern mass tourism and city development, the general public and public space. Maastricht, Tallinn and Salzburg are three typical European cities, which are among the most popular destinations for city tourism due to their ”intact“ historical city centres.
In May 2005 artists, filmmakers, architects and city developers will concentrate on the theme of the future development of European cities. They will focus on the tension between cultural heritage and mass tourism, economic interests and the urban way of life. In doing so they will pose the question about the importance of the general public and public space and there will be an attempt to address this question through the series of artistic and theoretical events carrying the title Trichtlinnburg (Maastricht, Tallinn and Salzburg).
The three cities have a certain tension in common regarding city preservation and city development. There are strict regulatory measures everywhere when there is a need to preserve historical buildings. The consequence of these attitudes towards restoration is the successive transformation of the inner cities into ”Theme Parks“. Historically grown city centres mutate into shopping malls for international fashion, fast food chains and lucrative real estate booms. Trichtlinnburg’s point of focus lies in visual arts with considerable musical input, performance, street theatre, urbanism and architecture. The discourse is centred on the role current European art can play in the debate about the public and public space. Around 30 different projects will be presented and distributed over all three cities.
Two projects will take place in all three cities: The work (If) I Lived Here by the Croatian artist Sanja Ivekovic and Love City, a DJ VJ project by the young Salzburg group gold extra. All other projects, which actively involve city inhabitants in various ways, will be realised in each respective city. The Salzburger Kunstverein is concentrating on urban structures in the city of Salzburg and how the tension between mass tourism and residents can be made into a discussion through an art project. The Jan van Eyck Academie focuses on research. The urban structures and economies of the city of Maastricht are analysed and form the basis for various performing and/or participatory artistic works in public and media space. The Center for Contemporary Arts Estonia organises an alternative source of tourist information presenting the starting point for diverse art interventions and the questioning of the official image of Tallinn.
The publication Trichtlinnburg (date of publication planned for August 2005) will contain reports by three travelling writers and two travelling photographers (amongst others), who will observe, research and document the project in all three cities. The Trichtlinnburg project will be developed and executed by all organisers, co-organisers and partners.
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https://archive.salzburger-kunstverein.at/en/whatson-news/2005/2005-05-19/trichtlinnburg
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Shadow Stories in Oral Interviews
The journal article that framed the discussion was about shadow stories – but this was not new information for the highly experienced group of practitioners gathered at the Round Table. As mental health practitioners, it is our role to ask the difficult questions in order to understand the older adults that we serve. Some settings tend to be more conducive to discovering these stories.
A therapist in private practice not only has the time and confidentiality to dig deeply, but s/he has presumably been engaged to do so. The older adult/the client has voluntarily entered into a relationship in order to sort out some troubling aspects of one’s life. In other settings, it is not always so easy. Discharge from hospital or rehab doesn’t allow for extended discussions to determine likes, dislikes, needs, or personal preferences. Group settings can be hampered by issues of group dynamics including trust and confidentiality. A care manager’s role typically assists with transitions or facilitates a discussion about care responsibilities among family members. The journal article spoke to the specific setting of a research interview and protocol which, by its very nature is limited, utilizing a prescribed set of questions and a pre-written script. However, underneath any and all of these situations is a life story that may give insight into what motivates or compels behavior.
The question was raised about the difference between narrative and reminiscence and life-review. To me reminiscence is the re-telling of life events, historical information, pleasant memories such as music and clothing and visual memories of home and place. Reminiscence can teach and convey experience and wisdom to younger generations and offer a sense of purpose and meaning – in fact it is treasured by family and younger generations. But narrative gives reminiscence depth. Narrative care lies in the hands of the listener, the receiver — not simply to hear historical events, but to frame the events and give them a context in which the person can say, “Mine has been a good life, a life well lived.”
We are narrative gerontoloigists! This was a concept written about in the editorial introduction to the special issue of the Journal of Aging Studies (Volume 34, 2015). The writers say, “The most important issue for narrative gerontologists…centers on how meaning is communicated in the stories of our lives and on how giving voice to that meaning helps to better understand how a life has been lived, is lived, and can be lived…Narrative care is core care as essential to provide as is food, or shelter, or medical care.”
And when we sit beside and are truly WITH an older adult it is easy to recognize the power of his or her life story. And isn’t that what draws us to this work?
The Round Table Discussion Group meets monthly for an interdisciplinary conversation with experienced professionals in the field of aging. Each conversation uses one or two journal articles as reference points. The articles read for this discussion were:
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https://soundaging.org/shadow-stories-oral-interviews/
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I love a great Historical Scan technique when facilitating. I was reminded of the power of the Scan when I used it recently with the board and staff of a large provincial nonprofit organization. They wanted to decide the core services to provide and the organizational model to adopt. I used the Historical Scan to:
– Allow the individuals who are new to the organization to learn its history in a fun and participatory way
– Allow the individuals who are long-term members to share their knowledge and experiences without lengthy and boring presentations
– Help them remember the significant events in their history and build upon them or avoid them
– Give context to the topics
The #HistoricalScan is also known as A Journey Wall or A Wall of Wonder. I learned it from ICA Associates https://ica-associates.ca/. This technique enables a group to review and bring forward significant events from its past, build upon the strengths of its present, and create a roadmap for its future. It typically begins with drawing a horizontal line across a surface (wall, floor) and dividing it into time periods such as years, months, or decades. I used four decades for my client organization which had formed in the early 1990s. Participants then worked in small groups of two or three people. Each group identified and wrote on large cards the events from that decade. We then placed the cards on the timeline, clustered slightly, and talked about them using a Focused Conversation.
At this stage, a group reflects on its experiences and what it learned to move into the future. In my recent facilitated session, the group was able to:
– Celebrate the successes of its first two decades of existence
– Recognize the impact of individuals and events on the third decade
– Identify the ways in the past few years that they recovered and grown.
They talked about the lessons that they learned and how these inform their strategic planning for the next five years. The revelations for this group were significant as they realized how past relationships had negatively affected their organization and how they could mitigate the negativity and build upon their current strengths.
They named the decades: Formation, Growth, Dissension, and Rebirth.
A Historical Scan can go beyond the history of the organization to include community, country, and world events. In this way, it is an excellent Environmental and Trends Scan to identify what is happening in the region and world that could impact the organization.
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https://www.barbpedersen.ca/learning-from-our-past-to-plan-our-future-a-historical-scan/
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25 September 2018
Researchers from the University of Haifa and two teams from the IMDEA Networks Institute have developed a new autonomous system to monitor schools of fish in real-time using acoustic and optical technologies.
The SYMBIOSIS system’s real-time monitoring capability will allow a more evidence-based approach to fishing policy development and enhance our ability as humans to protect the marine environment, as its optical/acoustic approach helps to prevent false alarms. Current fish monitoring methods include deploying research boats with crews within limited areas. SYMBIOSIS is designed to cover far more area without the need for a human crew —the chief expense during the assessment of marine stocks— and it also aims to enhance today’s detection capabilities.
For the researchers, led at IMDEA Networks by Dr. Paolo Casari, the SYMBIOSIS system is merely a prototype, a starting point. From that point, they hope to extend the capabilities of autonomous underwater monitoring technologies in multiple ways, including further reduction of energy consumption; miniaturization of the system; and modification of the mooring platform aboard different vessels to promote a more mobile use of the system.
An article published by the Environmental Monitor provides an in-depth look at SYMBIOSIS. You can read the full article here.
Photo caption: The team prepares to deploy SYMBIOSIS during a recent research test run.
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https://networks.imdea.org/a-deep-look-to-the-symbiosis-project/
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11.08.2020.
Junior System Engineer
We are looking for a motivated junior system engineer to join our Technical Operations Team. The candidate main responsibility will be to ensure systems are operating with optimal performance, security, and usability. In addition, the candidate will conduct all necessary activities to ensure systems are strong, robust, and perform up to standard.
Your Duties & Activities
- Monitor and analyze our systems
- Troubleshoot and resolve server, network and software issues
- Advise and work closely with other departments for collaborating IT incidents and projects
- Provide remote troubleshooting solutions for application
- Analyze complex systems, identify and troubleshoot variety of problems
- Develop and implement logical conclusions and effective solutions
- Provide timely response to all incidents, outages and performance alerts
- Categorize issues for escalation to appropriate technical/operational/development teams
- Train other staff and stakeholders on technical issues as needed
- Use a ticketing system to document and create all incoming Incident and Service Requests
- Contribute in creating general knowledge base
- Monitor production applications, servers and network using a combination of monitoring tools
The work hours for this position are based on a 24/7 shift schedule.
Our offices are located in New Belgrade.
Qualifications & Experience
- Advanced technical skills on Windows Server OS, SQL, cloud and web platforms;
- Understanding of database structure with the ability to enter, manipulate, and report data;
- Basic experience with monitoring tools like: RabbitMQ, Redis, NGINX, Azure App Insights, SQL Server;
- Network and troubleshooting skills;
- IT Security related skills (AV, encryption, firewall, etc.);
- Ability and willingness to easily adapt to and learn new technologies;
- Ability to prioritize;
- Good written and spoken English;
- Previous experience working in a similar working shifts environment would be considered as a plus
Betagy?
n. Portmanteau of the words “Better and Strategy”, also an innovative young company providing a proven, stable and ever evolving software platform.
We design, code, develop, produce and deploy our suite of software that allows clients keep abreast of their online business. Whether it’s online or land-based retail shops, our integrated platform delivers, allowing operators to focus on the running and expansion of their business.
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https://poslovi.infostud.com/posao/Junior-System-Engineer/Betagy-LTD/316063?esource=search&emedium=1&item_index=23
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AB Microfinance Bank Nigeria Limited is a member of an international network of Microfinance Banks under Access Holding Microfinance AG (www.accessholding.com), with its Head office in Berlin, Germany.
The Group provides world class banking services to micro, small and medium enterprises and private individuals in Africa and Asia. It has been spreading out to other countries across the globe rapidly.
We are recruiting to fill the position below:
Job Title: Senior System Administrator
Refcode: SSYA/IT/APR/2018
Location: Lagos
Main Responsibilities
- Plan, deploy, configure and maintain servers, administrative responsibility for server
- Implement required monitoring tools to ensure end-to-end performance management of all required infrastructures
- Maintenance of all server room equipment for all branches, HQ and datacenter
- Contribute to new project implementation with infrastructure impacts
- Monitor logging data and report system operating figures and irregularities regularly – communicate system or network events, troubleshoot problems and issues and escalate within the organization
- Monitoring of the security cameras for all branches and the smoke & Fire Detectors
- Ensure the integrity, availability and confidentiality of the recorded video on the DVR
- Working out a backup plan
- Operate and administer server and back office server (MS Win 2008/2012, MS Exchange)
- Server patch management, scripting (e.g.: log in scripts), user administration (Active Directory)
- Design server resources concept and create lifecycle plan for servers
- Document internal procedures and ensure effective monitoring
- Compliance to processes and framework in place within the department
- Mounting And Installation of Servers and rack components
- Ensure availability of infrastructure services according to required performance level
Necessary experience, skills and knowledge
- Minimum educational qualification of B.Sc. / HND in Information Technology or related discipline with cognate experience
- IT security tools and methods
- Deployment of IT infrastructure to meet changing business needs
- PowerShell scripting
- IT operations in a service-based company, preferred in the field of banking
- IT project work
- Windows batch scripting and Linux server administration
- Knowledge in operating a CBS environment is an advantage
- Openness to learning new technologies and methodologies
- Steering providers
- Analytical and problem solving skills and process-oriented approach to work
- Disciplined approach towards daily operations and documentation
- Ability to communicate effectively with colleagues in other business disciplines regarding technical issues
- At least four years of professional experience in an operational IT role as an Administrator, three years within the banking sector
- Evidence of sound experience in the following:
- Server administration (modern MS Windows server (hardware, operation system, MS Office, network connections), patch management, scripting, user administration
- Exchange Server Administration
- Advanced knowledge of Windows Active Directory Network environment, DNS and DHCP
- Backup and recovery procedures, monitoring tools
- Ability to communicate distinctly both in writing and orally in English
- Willingness to travel to bank branches throughout the country for installation and administration of server
Deadline: 16th May, 2018.
How to Apply
Interested and qualified candidates should:
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https://www.jobinformant.com/2018/04/senior-system-administrator-job-at-ab.html
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Earlier this year Australia experienced one of its deadliest and most widespread bushfire seasons. Around the globe fires engulfed areas that had never previously been burnt, such as the dense tropical Amazon and suburban Los Angeles.
One aerospace engineering graduate turned robotics visionary, Vera Somers, is hoping her research will one day help detect bushfire prone areas and survey at-risk areas by creating drones for bushfire surveillance and intervention.
“The large-scale impacts and real-world risks make bushfire research extremely important – this last bushfire season stresses how vital this research is,” said Ms Somers, who joined the University of Sydney from the Netherlands to complete a PhD at the Australian Centre for Field Robotics under the supervision of Associate Professor Ian Manchester.
Ms Somers hopes UAVs and automation can offer faster and more efficient situational awareness, potentially making firefighting efforts safer by containing fires before they become uncontrollable.“Although many fire propagation models and simulators already exist, the link connecting them to automated decision making and UAV path planning is still missing,” she said.
“We use optimisation methods to study how bushfires spread and how to control them. By creating risk maps and UAVs we can find the areas most in need of monitoring, and then use this information to deploy targeted resource allocation for both prevention and firefighting.
“We actually model and control the spread of fire in a similar way to the modelling of epidemics. It is fascinating how both bushfires and epidemics – as well as other spreading processes – have very similar underlying models.”
Ms Somers also recently assisted the post-bushfire effort by helping rebuild fences that had been lost in the January 2020 fires.
Amrit Sethi, who joined the University of Sydney from India and who is a graduate of a Bachelor of Mechatronic Engineering (Space) and a recipient of the University Medal, is working with clean energy expert and aerospace engineer from the School of Aerospace, Mechanical and Mechatronic Engineering, Associate Professor Dries Verstraete in the development of a technology that aims to extend the lifetime of hydrogen fuel cells.
“Rising pollution levels and their impact on climate change highlight the need for clean energy sources” said Mr Sethi, who is the recipient of an International Strategic Scholarship and is completing a PhD in Aerospace Engineering.
“Hydrogen fuel cells produce clean energy by combining hydrogen and oxygen with water being the only by-product, he said.
“However their short lifetimes do not justify their high costs for many real-world applications. My research focuses on developing a prognostics and health monitoring framework that can help extend the lifetime of hydrogen fuel cells to make them more efficient, hopefully leading to a wide-scale industrial adoption.
“Our research is based on the use of machine learning techniques that identify short-term and long-term fuel cell health issues, which can then be used to improve the fuel cell's lifetime.
“Tapping clean energy sources is the need of the hour, and with my research, I aspire to help the world be a little greener.”
As part of a research group focused on improving the landing operations of vertical take-off and landing aircraft led by Associate Professor Ben Thornber, Master of Aeronautical Engineering student Jack (Hee Sung) Park has developed a lightning-fast computational method to assist both manned and unmanned aircraft to operate and land on platforms such as ships, oil rigs and buildings.
“The landing of helicopters and other aircraft on platforms such as ships, oil rigs and urban buildings is inherently risky. My research aims to better understand how aircraft descend and ascend in various conditions to improve their safety and performance,” said Mr Park, who joined the University of Sydney from Handong University, South Korea in 2018.
“Previous simulations have required complex recalibration, whereas the method we have developed computes simulations in a fraction of the time.
“I hope my research results in an accurate and computationally efficient way of predicting helicopters and unmanned air vehicle aerodynamics.”
As part of the Intelligent System Transport Group led by Australian Centre for Field Robotics academic Professor Eduardo Nebot, Colombian PhD student Julie Stephany Berrio Perez is developing an algorithm that helps autonomous vehicles’ in-built mapping systems detect changes in the environment and reflect those changes into the map so they can navigate roads safely.
"One of the requirements for autonomous vehicles to be able to operate persistently in typical urban environments is to maintain high accuracy position information over time. In other words, the capability of an autonomous vehicle’s mapping and localisation system must adapt to changes in the environment,” said Ms Berrio Perez.
"A map for autonomous driving applications which is created today might not be entirely valid next month, or even next week due to changes in the environment caused by construction sites, speed zone changes, new pedestrian paths, changing signals and new road infrastructure,” she said.
"Autonomous vehicle maps require continuous updates to operate safely. An alteration of the surroundings could cause the vehicle to stop operating autonomously or even cause an accident. It is then indispensable to have an algorithm capable of reflecting environmental changes on the vehicle's map."
Ms Berrio Perez’s work has been implemented on the University of Sydney Campus Dataset, which was collected for more than a year. The autonomous, electrical vehicle was retrofitted with multiple sensors and was driven on a weekly basis around the University of Sydney campus.
A student team has created a prototype of a reusable face shield, demonstrating how to turn university resources into a rapid manufacturing solution to respond to medical emergencies, including the COVID-19 pandemic.
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https://www.sydney.edu.au/news-opinion/news/2020/06/22/meet-the-students-who-are-engineering-with-impact.html
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A new collaboration project has been initiated with the team Spirals of INRIA Lille laboratory. In this project, we want to address the steering, orchestration, and maintenance mechanisms for our applications’ packaging, delivery, and deployment activities. The lack of formalization and traceability on the actions that are carried out for the deployment of our applications, and the fact that some of them are manual or must adapt to technical or functional specificities, creates a complexity that is difficult to manage only by using traditional continuous integration and continuous deployment (CI/CD) platforms. Moreover, this lack of visibility and mastery of an automated and controlled DevOps process represents a real obstacle to our growth, as Berger-Levrault is always intending to gain clients across the world.
Therefore, and with the aim of continuously improving our level of service and our clients’ confidence in the digital resources that we provide, we are considering, in this project, the management and monitoring of our deployment activities. The aim is to harness the deployment process, facilitate its implementation, and enhance its reliability. Hereinafter are some of the considered scientific and technical approaches :
A Metamodel and a Knowledge Base for exploiting deployment elements
Multiple information depict a deployment environment: deployment modes (On-premise, SaaS, IaaS, PaaS, hybrids, or multi-cloud), clients’ operating environments, characteristics of the systems to be deployed (versions, prerequisites, OS, space, browsers, etc.), patches and updates, etc. These pieces of information should not be only known by operations teams or be stocked in configuration files. We, therefore, aim to formalize a metamodel to represent and manipulate the elements that constitute a deployment. This permits the construction of a knowledge base that can be used as an input for automated configuration management systems. Selected leads to investigate are automatic approaches to discover and catalog deployment infrastructures and infrastructure as code techniques that allow the definition and storing of deployment contexts.
Monitoring of the deployment process
The objective here is to study the possibilities of retrieving information on the actions that are carried out, trace, and collect them to have an overview of deployments status and issues. This permits to improve feedback in case of problems or suspend the process to avoid data loss or service interruption during the deployment. CI/CD pipelines can be a way to perform such monitoring, but they allow per-project monitoring. We, hence, tested monitoring tools such as the combination of Prometheus and Grafana to provide in a single view a set of indicators about several projects’ pipelines. In its current state, the tested stack allows us to gather information about project repositories, code versioning, and build status. The status of delivery and deployment actions are yet to be monitored. We also need to investigate existing correlations among the depicted indicators to help with the diagnosis in case of issues. Moreover, the link with the deployment environments and the characteristics of the deployed applications must be highlighted.
Furthermore, we project to study the possibility of using machine learning techniques to make use of the collected data to perform predictions of deployment status, detect unusual behavior and learn to continually improve delivery and deployment activities. Monitoring is also essential if we are willing to repair (or automatic repair) actions (updating configurations, infrastructures, etc.) as a reaction to events perceived by the monitoring system. This will help maintain the delivery and deployment system and ensure its reliability.
Administration means for the configuration and deployment of our applications
The goal here is to facilitate the implementation of new deployments, with administration and configuration mean. To do so, we need an approach to help specify the deployment environments and the applications to deploy and administrative means for applying the depicted elements. This can be based on the above-mentioned metamodel coupled with a DSL (Domain Specific Language). Spirals team has worked on such DSLs in their research on Model-Driven Configuration Management of Cloud Applications. Those means have to take into account :
- Packaging several of our business applications to form a software suite, while being managed by a single administrator, without having to mobilize a dedicated administrator for each application in the suite
- The distribution of our applications, where an application can consist of interconnected parts running in distributed hosts
- The deployment of a subset of the functionalities of our application in the case of product lines for instance, or a subset of components allowing to build tailored applications
Infrastructure as code has proven to be a good lead for a systematic way to create and maintain infrastructure and deploy applications. A relevant question that one can raise is: to what extent can we supply our own applications with infrastructure as code techniques?
Finally, it is important to mention that BL-Forge, a Continuous Integration Platform has been set up by BL-Tech teams, with up to date DevOps tools (GitLab, GitLab-CI, Docker registry manager, SonarQube, Nexus, Ansible, Jenkins, etc.). This work on a platform to be used by all Berger Levrault instances shows a real commitment to the modernization of our delivery and deployment methods. We will, therefore, consider the compliance of any future propositions during this project with the requirements of this platform. We can also question the use of such a “modern” platform in the context of our Legacy applications. Feasibility analysis will be necessary along with the definition of the path to set up to reach this target.
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https://www.research-bl.com/2020/07/13/devops-mde/
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Future Army missions will have autonomous agents, such as robots, embedded in human teams making decisions in the physical world. One major challenge toward this goal is maintaining performance when a robot encounters something it has not previously seen; for example, a new object or location. Robots will need to be able to learn these novel concepts on the fly in order to support the team and the mission.
Researchers have created a computational model for automated question generation and learning. The model enables a robot to ask effective clarification questions based on its knowledge of the environment and to learn from the responses. This process of learning through dialogue works for learning new words, concepts, and even actions. Researchers integrated this model into a cognitive robotic architecture.
In previous research, the team conducted an empirical study to explore and model how humans ask questions when controlling a robot. This led to the creation of the Human-Robot Dialogue Learning (HuRDL) corpus, which contains labeled dialogue data that categorizes the form of questions that study participants asked. The HuRDL corpus serves as the empirical basis for the computational model for automated question generation.
The model uses a decision network, which is a probabilistic graphical model that enables a robot to represent world knowledge from its various sensory modalities including vision and speech. It reasons over these representations to ask the best questions to maximize its knowledge about unknown concepts.
For example, if a robot is asked to pick up some object that it has never seen before, it might try to identify the object by asking a question such as, “What color is it?” or another question from the HuRDL corpus.
The question generation model was integrated into the Distributed Integrated Affect Reflection Cognition (DIARC) robot architecture originating from collaborators at Tufts University. In a proof-of-concept demonstration in a virtual Unity 3D environment, the researchers showed a robot learning through dialogue to perform a collaborative tool organization task.
While prior research on soldier-robot dialogue enabled robots to interpret soldier intent and carry out commands, there are additional challenges when operating in tactical environments. For example, a command may be misunderstood due to loud background noise or a soldier can refer to a concept with which a robot is unfamiliar. As a result, robots need to learn and adapt on the fly if they are to keep up with soldiers in these environments.
The ability to learn through dialogue is beneficial to many types of language-enabled agents, such as robots and sensors, that can use this technology to better adapt to novel environments. Such technology can be employed on robots in remote collaborative interaction tasks such as reconnaissance and search-and-rescue, or in co-located human-agent teams performing tasks such as transport and maintenance.
This research is different from existing approaches to robot learning in that the focus is on interactive human-like dialogue as a means to learn. This kind of interaction is intuitive for humans and prevents the need to develop complex interfaces to teach the robot. Another innovation of the approach is that it does not rely on extensive training data like so many deep learning approaches.
Finally, this research addresses the issue of explainability. Many commercial AI systems cannot explain why they made a decision. The new approach is inherently explainable in that questions are generated based on a robot’s representation of its own knowledge and lack of knowledge. The DIARC architecture supports this kind of introspection and can even generate explanations about its decision-making. Such explainability is critical for tactical environments, which are fraught with potential ethical concerns.
The next step is to improve the model by expanding the kinds of questions it can ask.
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https://www.techbriefs.com/component/content/article/tb/pub/briefs/machinery-and-automation/47318?m=1047
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Companies across most industries run workloads that use HPC, artificial intelligence, and machine learning to deliver real-time insights that help their businesses operate more efficiently, respond to changes faster, and innovate. The HPE Apollo 6500 Gen10 Plus System based on the latest NVIDIA A100 Tensor Core GPUs and both 2nd and 3rd Gen AMD EPYC™ processors and AMD Instinct™ MI100 accelerators deliver the needed exceptional performance, fast insights, and advanced security to fuel better business outcomes. Download this white paper to learn about the system’s capabilities, its performance in MLPerf Inference benchmarking tests, and HPE services that complement the system.
Health data capture, precise data analysis and machine assisted diagnosis are a big focus of the precision medical field. It is critical that medical organizations and researchers have a method for efficiency, simplification, and scalability to run precision medicine workloads. An optimized infrastructure is required to meet the needs of GPU systems capable of running precision medicine applications and workloads.
Read this paper now to learn the benefits for:
This paper describes how Quanta Cloud Technology (QCT) developed the QCT POD for Medical (QPM) platform specifically designed to meet the needs for life science customers. QCT provides an on-premises rack-level system for the healthcare industry. To reach greater flexibility and scaling, QPM offers common building blocks to meet different medical demands, like Next Generation Sequencing (NGS), Molecular Dynamics (MD), and Image Recognition. In addition, QCT optimized the QPM solution to automate launching the NVIDIA Clara application framework for AI-powered imaging and genomics.
Oracle’s next generation HPC architecture with Intel compute instance based on 3rd Generation Intel® Xeon® Scalable processors, code named "Ice Lake", changes the game for HPC in the Cloud. The new HPC Bare Metal instance delivers performance gains of up to 42% compared to the previous generation HPC instance. Oracle Cloud Infrastructure with Intel’s 3rd generation processors also offers the flexibility to choose the right combination of cores and memory to suit workloads. The price per core-hour stays the same as the previous HPC instance, across all Oracle Cloud regions. This combination of improved performance and flat pricing translates to faster simulations and big cost savings.
Join Oracle and Intel and learn how customers are increasing performance for HPC workloads across batch processing, video encoding, electronic design automation (EDA), distributed analytics, data science, AI, and computational fluid dynamics (CFD).
In this webinar, Intersect360 Research CEO Addison Snell will lead a discussion with AMD HPC Leaders Robert Hormuth, CVP, Architecture and Strategy, Brad McCredie, Corporate Vice President of Data Center GPU and Accelerated Processing and Brock Taylor, Global HPC Solutions Director around AMD's innovative HPC solutions and the momentum AMD has gained across all customer use cases. These AMD executives will discuss the applicability of AMD’s high-performance CPU and GPU approaches in a common environment along with the feature set that can enable small HPC clusters to the world’s most powerful supercomputers.
© 2021 HPCwire. All Rights Reserved. A Tabor Communications Publication
Reproduction in whole or in part in any form or medium without express written permission of Tabor Communications, Inc. is prohibited.
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https://www.hpcwire.com/topic/middleware/
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Conventional security mechanisms at network, host, and source code levels are no longer sufficient in detecting and responding to increasingly dynamic and sophisticated cyber threats today. Detecting malicious behavior at the application level can help better understand the intent of the threat and strengthen overall system security posture. To that end, we have developed an innovative, use case-driven framework called ARMOUR (which standards for Association Rules Mining Of Undesired behavioR) that involves mining software component interactions from system execution history and applying an adaptive detection algorithm to identify potential malicious behavior. The framework uses unsupervised learning; can perform fast, "inline" detection in near real time; and can quickly adapt to system load fluctuations and other concept drifts. Our evaluation of the approach against a real Emergency Deployment System has demonstrated very promising results.
As depicted in the diagram above, the ARMOUR framework consists of two major phases:
- The first phase is mining the usage model. In this phase, inter-component messages are captured by sensors on the target system in near real-time, stored in the event log, and then preprocessed to produce itemsets based on pre-identified use case types. Afterwards, the Apriori algorithm for association rules mining is applied on the itemsets to generate the rule base. Finally, architecture-based heuristics are leveraged to effectively prune the rule base from extraneous rules and keep the rule base within a manageable size.
- The second phase is applying the model on the current system event stream to detect anomalous behavior. We developed an efficient detection algorithm for this purpose, which produces a quantitative anomaly measure for each event. When the anomaly likelihood exceeds a certain threshold, the event is marked as suspicious and its details are recorded. As mentioned earlier, the number of simultaneously running use cases may fluctuate at runtime and adversely impact the detection accuracy. We therefore take an extra step to monitor the degree of execution concurrency and adapt the detection threshold accordingly. Once detected, the anomalous events trigger alerts to the system's security administrator or an autonomous agent that would examine them as part of the ongoing risk assessment process and deploy countermeasures to the target system such as isolating the compromised components. This last step is beyond the scope of this paper and left as an item for future research.
The contributions of our architecture-based framework, dubbed Association Rules Mining Of Undesired behavioR (ARMOUR), consist of three key elements: use case-informed monitoring of system execution history at the component level, the novel use of Association Rules mining to build a normal-use behavior model of the target system, and an efficient and adaptive algorithm that applies the model to anomaly detection. Our approach is different from many existing approaches in the following aspects:
- Most related mining efforts look at low-level datasets such as system API calls and network traffic (e.g. tcpdump) as opposed to "macro-level" system traits, such as component interactions in a large-scale software system. The former usually require specialized skills to analyze and interpret, whereas anomalous patterns at the component level can be much stronger clues for a human administrator or an autonomous agent to understand the intent of the malicious attack and deploy appropriate countermeasures.
- Many threat detection efforts rely on domain-specific knowledge (such as network protocols or OS commands) and are therefore difficult to generalize. Our approach, however, leverages architecture level abstractions such as component models and high-level use cases to inform the data mining process, which makes our approach broadly applicable to many target systems.
- Our use of the associations mining technique sets this effort apart from most other threat detection research that uses outlier detection algorithms based on distance, density, or other statistical measures.
The source code for simulating the Emergency Deployment System (EDS), a real component-based software system, can be found here.
More detailed evaluation results are also available.
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http://www.sdalab.com/projects/armour
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This exciting opportunity is within a Non-Profit organisation whose mission is the use of technology in the tracking and management of HIV youth and adolescents, and who aim at the radical reduction of HIV/Aids within this target market, particularly young women.
Your duties will be to build, test, deploy and configure the IT Systems within the organisation, and you will work at the Head Office in Tokai, reporting directly to the Head of IT.
Your skills will be necessary to :
- Set up developer environment tools that support versioning and shared repositories
- Create a pipeline to automatically build and unit test all new software in the shared repository
- Set up automated testing tools simulating the live environment.
- Determine appropriate servers and services to use based on software requirements and cost
- Set up all applications and services required for the system to function effectively Oversee/deploy upgrades to servers and ensure ongoing stability of the system
- Have roll back procedures and tools in place in case of failure or loss
- Build in redundancies to guard against single points of failure of critical services.
- Automate the deployment of fully functional services to the live environment
- Automate the upscaling or downscaling of cloud server resources in response to demand Drive deployment models that allow multiple versions of services and applications to be available
- Automate and monitor the backup procedures§ Assist the IT Helpdesk with infrastructure related issues
- Help the development team with infrastructure requests or issues
- Assist with integrating new devices into the company's systems
- Implement monitoring dashboards to give alerts on the health of all systems
- Generate reports on system performance for management.
- Other ad hoc duties as necessary.
Ideally you will have the following :-
- B.Sc in computer Science or equivalent IT Degree
- A knowledge and interest in computer systems especially the latest technologies
- An analytical mind to benefit this highly agile environment
- Solutions architect certification a bonus
- Minimum of 5 years in a software development role and at least 4 years of building IT infrastructure.
- Strong experience in Cloud Services.
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https://www.anchorexec.co.za/jobs/automate-the-building-testing-deployment-and-configuration-of-it-systems
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Research drawing upon TERN’s collection of more than 100,000 environmental samples provides new understanding on the adaptation of plants to climate change. Read on to find out which set of factors combine to create predictable relationships between plant traits and the changing environment.
Centre Spotlight: Centre for Environmental Sustainability and Remediation
This edition we highlight RMIT University’s Centre for Environmental Sustainability and Remediation (EnSuRe) and its research and work with industry to minimise the impact of land, water and air pollution.
Effective ecosystem monitoring requires a multi-scaled approach
New research has critically reviewed the main types of environmental monitoring and recommended the widespread adoption of three classifications to provide consistency and clarity. The scheme allows scientists and land managers to design programs suited to their needs that inform on multiple aspects of ecosystem change. It sets researchers in good stead to understand some of our greatest environmental challenges.
Centre Spotlight: University of New England – SMART Farms
This month we head to the Northern Tablelands region of NSW to look at the University of New England’s SMART Farms and the range of ecosystem data collected on properties used predominantly for agriculture.
Trusted environmental monitoring protocol
A detailed rationale and description of TERN’s much respected AusPlots method for environmental monitoring has been published in a peer-reviewed international science journal. With the paper’s publication, it becomes easier for researchers to access the method and its modules, adapt them for use anywhere and cite them in further research. Wider use of the protocol helps TERN to learn more about researchers’ future needs.
Centre Spotlight: University of Canberra Institute for Applied Ecology
This month we head to the nation’s capital to showcase research that’s improving our understanding of the environment and enhancing decision-making for natural resource management and sustainable development.
Centre Spotlight: Deakin University Centre for Integrative Ecology
This month we aim our spotlight on the Centre for Integrative Ecology at Deakin University and its interdisciplinary research that aims to address how life …
Extinct grass re-found
Systematic TERN monitoring in a national biodiversity hotspot has allowed identification of an exotic species of grass that nobody had seen for nearly 180 years. …
Australia’s environment in 2019
Temperatures up, rainfall down, and the destruction of vegetation and ecosystems by drought, fire and land clearing continued. That is the main conclusion from Australia’s Environment in 2019, the latest in an annual series of environmental condition reports, released today.
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https://www.tern.org.au/category/biodiversity/
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And we’re making progress: between 2007 and 2012 avoidable food waste has reduced by 21%, over 1 million tonnes.
We’re at at tipping point, but we need to capture and sustain this momentum. Here’s my thinking on the challenge ahead and 5 things we need to do about it to create a step change in how we tackle food waste:
- We need to change attitudes to what food can be distributed. Too much ‘food on the go’ i.e. sandwiches and pre-packed salads still go in the bin because of fears about food safety. We need to find ways to sensibly and safely relax internal policies. Better still, we should be producing more food on the go options with combinations of ingredients that last longer.
- What's wasted at the end of the day in supermarkets is the tip of the iceberg compared to the terrible waste of food left rotting in fields. Gleaning teams like Feedback's Gleaning Network are bringing together volunteers to rescue this food. We need a movement of gleaning volunteers in the fields, connecting membership organisations, volunteering groups and local food movements to support this nationwide.
- We need to rapidly and sustainably invest in the charities and community projects that redistribute surplus food or we’ll have plenty of supply, but lack the means to get it to the people who need it most. We need a sector wide strategy to sustainably and sufficiently fund these charities and projects, new partnerships that make collection from stores and community outreach to get the food to isolated people much easier, new ways to reduce financial and legal risk, and support to encourage many, many more people to volunteer for them.
- We need to link all parts of the effort supporting food banks to connect with local healthy eating projects, community farms, employee volunteering programmes, small businesses and producers, to link together the whole food system.
- We need to move from a discussion of tackling food waste to providing nutritious, sufficient and safe diets to everyone, tackling the causes of food inequality that mean that too many families are reliant on cheap, poor quality food.
At Neighbourly we’re working on these challenges. We're connecting youth projects like Sands End Youth Club Foodology, a project that gives young people life skills, including budgeting, healthy eating and food preparation and cooking with both volunteers to help out and food surplus to bring down their costs. We're discussing with retailers and policy experts agree how we can make policies that get more fresh surplus food to those who need it. And we’re finding new ways to create an ongoing relationship between companies and local food charities, investing in them for the long term.
It’s a once in a lifetime opportunity to tackle the scourge of hunger, under-nutrition, poor health and climate change. To seize this, we’ll all need to work together to give everyone a healthier, more sustainable and more neighbourly future.
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https://www.neighbourly.com/blog/5-things-we-need-to-do-to-create-a-step-change-in-how-we-tackle-food-waste
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July 30, 2018 (Toronto, ON): Food waste is the single largest waste stream lost to disposal and the leading cause of methane emissions from landfills. Ontario municipalities generate 55 per cent of food and organic waste annually with a recovery rate of close to 50 per cent. Comparatively, the Industrial, Commercial and Institutional (IC&I) sector generates 45 per cent of food and organic waste with a recovery rate of just 25 per cent. To trial a method to increase food and food waste recovery in the IC&I sector Recycling Council of Ontario (RCO) invites local businesses and buildings that generate any amount of surplus edible food or food waste in Oshawa to take part in an innovative food waste pilot.
RCO will be joined by a diverse group of organizations supporting the Food Waste Pilot. The Region of Durham and Miller Waste Systems host the consolidation site where source-separated and inedible packaged organics will be pre-processed prior to being sent for composting or anaerobic digestion. The City of Oshawa, in conjunction with the Downtown Oshawa Business Improvement Area, is assisting with the pilot and will collect organic waste from a number of participating members throughout the pilot. Feed the Need in Durham will rescue and redistribute edible food among its 60+ emergency food providers across the Region.
“Businesses and institutions often manage their waste, recyclables and organics location by location which can be far apart, in contrast to the standardized door-to-door collection that municipalities provide for homes. That’s why we are trialling a co-op model that mimics residential model with a smaller geographic footprint to make it simple and cost-efficient for the non-residential sector to recover food waste and rescue surplus food that would otherwise be lost to disposal,” says Jo-Anne St. Godard, Executive Director, RCO.
Collect relevant data to measure economic and environmental outcomes and advantages of a co-op model.
As part of the initiative RCO has also formed an Advisory Committee and is pleased to welcome leaders from across the waste management, property management, and food rescue industries to help guide the Food Waste Pilot: Miller Waste Systems Inc., Region of Durham, Ivanhoe Cambridge, Second Harvest, Feed the Need in Durham, StormFisher Environmental, Walker Environmental, and EcoBusiness Network.
Local businesses and buildings that generate any amount of surplus edible food or food waste in Oshawa are invited to take part in the Food Waste Pilot. For more information, visit www.rco.on.ca/foodwastepilot or contact the Project Manager, Daniel Bida – Daniel @ rco.on.ca.
This pilot project is made possible through Walmart Foundation’s $15 million USD ($19 million CAD) commitment to prevent food waste and support food banks.
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https://rco.on.ca/oshawa-action-reduce-waste-rescue-food/
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of food redistributed around the Canada thanks to donors from the Food Recovery Service in 2016.
Teamwork
Hotels, restaurants, and institutions donate their surplus food on an impromptu or recurrent basis; both options are possible.
La Tablée des Chefs oversees and coordinates the donation process, then offers an after-donation service. La Tablée des Chefs is, in a sense, the missing link that prevents edible surplus food from being wasted and thrown away.
The beneficiary organizations collect donations of surplus food, and either redistribute them to their beneficiaries, or serve meals to those in need in their own premises.
The food recovery program establishes a simple and sustainable process that sets a standard for the HRI industry; it also gives recommendations to donors and beneficiary organizations. Essentially, the program values the importance of giving safely.
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https://recuperationalimentaire.tableedeschefs.org/
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When COVID-19 first arose in the Canadian city of Lethbridge, the province of Alberta shut down all businesses, schools and non-essential operations. The severity of the outbreak was relatively low, but the restrictions affected the whole community. The “Lethbridge Helping Organizations COVID-19 Response” was launched by city authorities to strengthen collaboration by local groups to serve the needs of all residents, and ultimately helped maintain low numbers of COVID-19 cases in the city.
Community action galvanized by city authorities – to support vulnerable populations
A total of 146 members representing approximately 50 local organizations joined an online platform (called “Slack”), including not-for-profit charities, not-for-profit businesses, faith-based organizations, community-based funders, city staff, police, the public library and indigenous organizations. A University of Lethbridge funded organization, Lethbridge Public Interest Research Group (LPIRG), helped create a Facebook COVID-19 Support page where 3,000 community members offered each other help with things such as picking up medications, offering rides, lending each other house supplies, etc. This support page also included daily updates with information and support from the COVID-19 leadership group, as well as other key information from local, provincial, and federal government initiatives (e.g., about the Canada Emergency Response Benefit).
Other programmes created included volunteer wellness checks and the delivery of food bank hampers to older people. Restaurant suppliers and local hotels had a surplus of pre-ordered food that they gave to the food bank. The food banks coordinated food distribution to any social service agency that required food. Local food programmes delivered 15–25% more meals to community residents than before the pandemic. The school system worked with family organizations to provide activity packs and resources for families as well as meal and grocery deliveries where necessary. Several organizations worked together to help homeless people and our low-income population through food deliveries and setting up a clothing and furniture bank. And because there was limited mobility for people with disabilities during the pandemic, all of the services listed above were provided in partnership with disability services. It is expected that health outcomes have improved significantly due to all these organizations working together so closely.
Building future resilience: a strong local network ready to support city-wide responses
It is the first time that the social organizations in Lethbridge have worked this well together, and they have now established a long-term sustainable network for community support that can be used for future city planning and response. The City of Lethbridge now knows that community partners and stakeholders can – utilizing an online platform – respond quickly in emergencies and pandemics, and can collaborate effectively to address the needs of its most vulnerable populations.
“This new normal of community partnerships illustrates the innovation, strength, and resilience of the City of Lethbridge,”
Rob Miyashiro, City Councillor, Executive Director, Lethbridge Senior Citizens Organization, and member of the CBSS Leadership Council
City responses through COVID-19
Learn about how cities around the world have responded to the many challenges raised by COVID-19, including mobility, food security and safety, protecting older people and marginalized populations through these short case studies have been collated by the WHO. These highlight how cities have been able to build on their existing networks and partnerships with communities to best respond to the needs of their populations. Many of these initiatives are building resilience and will be important in shaping future policy on urban health.
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https://corealberta.ca/news/lethbridge-helping-organizations-covid-19-response
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The country has seen an increase in food banks and the expansion of their beneficiaries. It raises the question of “How do food banks know who is most in need of help?” Let’s talk about these people and how food banks can identify them.Who Needs the Most?You can answer this question best by knowing the economic stability of the population. You can identify it by looking at the poverty rate of a country or region. In 2020, the national poverty rate in the United States increased to 11.4 percent, up from 10.5 percent in 2019. The 0.9% difference constitutes the additional 3.3 million people to the 37.3 million American people in poverty.
There is a 2.9% drop in the median household income from $69,560 in 2019 to $67,521 for 2020. It was a clear sign of the rise of the national poverty rate. However, the actual median earnings for all workers over 15 years old decreased by 1.2%, from $42,065 to $41,535 between 2019 and 2020.
In California, the poverty rate is 11.8%, which is higher than the national average. Its household income has a median of $75,235, while the per capita income is $36,955.
These numbers show that many people need the most help from food banks and charitable organizations. Let’s now look at other reasons why these people need assistance the most.
Why Do They Need The Most?It is those who live below the poverty line who have the greatest need for help. Not only are the homeless and those scrounging for food and recyclable items to make ends meet, but they are also included in this category. People who are employed are also regarded as having the greatest need for food donations and other assistance.
Regarding food banks, those with employment are more likely to utilize their services because of low wages, delayed obtaining benefits, and changes in the number of other benefits available. These issues are exacerbated by a flawed welfare system, a substandard health care system, traumatic life experiences, and a lack of community support.
It has led to many people in need being dependent on charitable activities and organizations such as food banks and pantries, either partially or entirely.
How To Identify Them?Food banks may be a valuable resource for anybody trying to provide for their family or themselves with nutritious food. They do a better job of identifying individuals who are in the most desperate need. To identify individuals who may need food assistance, food banks have developed a screening procedure that they use. They gather demographic information from applicants and conduct interviews to evaluate whether they are eligible for food assistance.
After being accepted into the food bank program, you must complete the registration process. Some food banks only take individual registrations, while others allow both. Those who do not have children will register as single people, families with children, and families without children. Other food banks accept anybody who needs food without the requirement for an application, screening or interviewing them beforehand.
What Services Can They Expect?Food banks are facilities that store and distribute food to smaller front-line organizations that serve the community. They don’t typically hand out food to those who need it immediately. They distribute food donations via food pantries and meal programs, which are available as resources. They help the elderly, families, and others who are most in danger of going hungry.
Additionally, food banks contribute to initiatives that help those who need food to become more self-sufficient. They also work to raise awareness about hunger among the public and advocate for legislation protecting individuals from starvation. Individuals, charities, companies, and the government may all play a role in the fight against hunger, as can all other stakeholders.
Food from the industry and donation drives, food banks inventory and store the food they collect before distributing it to various organizations such as food pantries, shelters, and kitchens.
When Can They Get Their Food?It depends on which local food bank you are closest to. You may need to reserve a time for those marked “by appointment only.”
Most food banks collaborate with community organizations and healthcare professionals to identify those in need. Food banks provide various services, including bags of food for collection or delivery to people unable to collect in person. Wherever feasible, those choices will be provided so that you and your family may choose appropriate food for you.
The food bank can track who comes and goes from their facility. It helps to ensure that the food bank does everything possible to help those in the greatest need.
In the middle of this global emergency, we can be as blessed as those who have the means. We can also be as unfortunate as those who have nothing. But through working together, we can share our blessings with the unfortunate ones. And through sharing our life challenges, we can get help from those who are blessed. Become a volunteer with Second Harvest or be aided by us. We will each help one another overcome the struggles of life.
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https://localfoodbank.org/how-does-the-food-bank-know-who-needs-most/
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Where do you spend your time?
Here’s a list of some ideas where you can volunteer your time.
• The ability to read is something most of us take for granted, but can you imagine not being able to read the sports section or fill out a job application? Literacy volunteers act as tutors to adults, and in some cases, children who can’t read.
• Most animal shelters are non-profit or government organizations. Volunteers are welcome to walk the dogs, take care of the animals and clean the facilities.
• Organizations such as the Sierra Club and Friends of the Earth encourage volunteers to assist in environmental activities, like lobbying for conservation issues or leading hikes.
• Food banks work with homeless shelters, as well as poor individuals living in the area. Food banks collect and distribute food to those in need as well as manage their inventory. Volunteer opportunities may include distributing food, going to local restaurants to collect food or organizing a food drive.
• Habitat for Humanity builds and then gives homes to those in need.
Volunteers actually work on building the homes.
• Chances are there is at least one homeless shelter in your community. Most shelters have a variety of programs that would welcome your help. Tasks might include distributing meals, organizing a food drive or even working in the office answering phones and doing paperwork.
• Hospitals have volunteer programs that assist patients both in and out of the hospital. Volunteer activities may include anything from manning the information desk to delivering flowers to patients.
• Libraries always need help with running their activities, reshelving books or operating a bookmobile.
• During an election year, candidates are always looking for volunteers to mail out flyers, man the phones or organize rallies.
• There are local Red Cross affiliates across the country. They provide support in times of emergencies and hold blood drives throughout the year.
• Located all across the country, Ronald McDonald Houses provide parents and seriously ill children with a low-cost place to stay while the children are getting treated at a nearby facility. Volunteers prepare meals, talk to the families and take care of the houses.
• The Salvation Army provides social services, disaster relief, rehabilitation centers and activities for adults and children throughout the year.
• Senior Citizens Centers. These centers provide meals to seniors who are homebound, transportation that allows seniors to get to and from their doctor’s appointments and assistance for seniors in understanding their medical bills.
• The Special Olympics provides sports training and athletic competition for children and adults with mental retardation. Volunteer activities include training, fundraising, competition planning, staffing and administrative help.
• A lot of state parks have volunteer programs that include opportunities for everything from park maintenance to education.
• There are local United Way affiliates across the country. The United Way has thousands of charities affiliated with it, so volunteer opportunities are numerous.
Some of these are national organizations that may not have a chapter in your area. If an organization sounds like one you are interested in, call the national headquarters to see if there is a chapter in your area.
If not, ask for a name of a similar organization in your area. Most volunteer organizations won’t turn down help from people who seem to be genuinely interested in their cause.
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https://www.starnewsonline.com/story/news/2006/01/31/where-do-you-spend-your-time/30255918007/
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Save the World Club charity rescues surplus food from supermarkets and distributes it to vulnerable people especially those self isolating.Since the Covid19 pandemic and lockdown began in March 2020 we have shared over 125,000 kg of food saved from waste. We have expanded this service to more client groups such as the elderly, single parents and high risk individuals. We now coordinate 20+ new volunteers to provide daily food drops to people throughout the Royal Borough of Kingston. We use volunteers to collect food every evening, sort and box it, then deliver it to vulnerable homeless, refugees, elderly, disabled and low income people in need across the borough. We are working round the clock to pick up more good food and redistribute it to those self isolating. We work with local food banks, faith groups and other charities to redistribute it immediately.
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https://platform.nationalfundingscheme.org/save-the-world-club
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Through community partnerships we strive to bring awareness to the plight of homelessness and poverty in our shared communities, while providing emergency needs, such as, clothing and food for those facing sudden or unexpected financial or personal hardships. We accomplish this by building a coalition of partnerships with donors and smaller nonprofits.
WHO WE ARE
Matrix League is a 501 (c) (3) nonprofit. We partner with established nonprofit organizations in various communities to assist with immediate needs related to addressing poverty and homelessness in our community. We organize collections for individuals referred to us by other organizations, women's shelters, men's shelters, homeless individuals, and other donation driven projects.
HOW WE DO IT
We host monthly campaigns to collect various items, such as toiletries, food, gift cards, various clothing, housewares, and other supplies that help fill the continuing needs identified by our existing partner organizations. By partnering with smaller nonprofits, we can ensure that individuals receiving our assistance are properly vetted to receive goods and services. By doing this we can put goods in the hands of those in need and can achieve our mission.
Below are just a few ways you can partner with us.
To learn more about hosting a drive on our behalf contact us today!
FOOD DONATION DROP-OFF
Helping the Community
CLOTHES DROP-OFF
Clothing the Homeless
COMMUNITY OUTREACH
Helping People In Need
PARTNERSHIPS
Making Connections
"If not now, when? If not us, who?"
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https://www.matrixleague.org/
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Lethbridge COVID-19 collaboration recognized by World Health Organization
By Jensen, Randy on October 31, 2020.
LETHBRIDGE HERALD
A local community-based collaboration designed to provide a strong, unified, comprehensive COVID-19 response during the initial period of the pandemic has drawn international attention.
The “Lethbridge Helping Organizations COVID-19 Response” was launched by City authorities to strengthen collaboration by local groups to serve the needs of all residents and ultimately helped maintain low numbers of COVID-19 cases during the first wave of the global pandemic.
Rob Miyashiro, city councillor and Executive Director the Lethbridge Senior Citizens Organization, worked with Caroline Bergeron of the Public Health Agency of Canada and Lori Harasem, Community Social Pandemic Response Manager for the City of Lethbridge, to develop and submit the application to the World Health Organization. They have included it in their World Cities Day (today) publication and discussed it during a Facebook Live event early Friday morning.
“I am very proud of everything our social helping organizations have accomplished to date and I am very humbled and excited that WHO has selected our community effort to be profiled,” says Miyashiro in a news release. “This new normal of community partnerships illustrates the innovation, strength and resilience of the City of Lethbridge.”
The WHO commented on its page: “When COVID-19 first arose in the Canadian city of Lethbridge, the province of Alberta shut down all businesses, schools and non-essential operations. The severity of the outbreak was relatively low, but the restrictions affected the whole community.
“How? A total of 146 members representing approximately 50 local organizations joined an online platform (called ‘Slack’), including not-for-profit charities, not-for-profit businesses, faith-based organizations, community-based funders, City staff, police, the public library and Indigenous organizations. A University of Lethbridge-funded organization, Lethbridge Public Interest Research Group (LPIRG), helped create a Facebook COVID-19 Support page where 3,000 community members offered each other help – the mutual aid included such things as picking up medications, offering rides, lending each other house supplies, etc.
“This support page also included daily updates with information and support from the COVID-19 leadership group, as well as other key information from local, provincial, and federal government initiatives (e.g., about the Canada Emergency Response Benefit).”
Other programs created included:
– Volunteer wellness checks and the delivery of food bank hampers to older people.
– Restaurant suppliers and local hotels had a surplus of pre-ordered food that they gave to the food bank.
– The food banks co-ordinated food distribution to any social service agency that required food. Local food programs delivered between 15 and 25 per cent more meals to community residents than before the pandemic.
– Several organizations worked together to help the homeless and low-income population through food deliveries and setting up a clothing and furniture bank.
– Utilized the HelpSeeker website to assist residents to see what businesses were open and what services were being offered.
– Through a collaboration of organizations that work with families, pop-up family events in City parks took place providing information about resources, activities and allowing for socializing, following COVID guidelines, to those feeling isolated at home. More than 1,000 people attended these events and 1,785 activity kits were handed out.
– And because there was limited mobility for people with disabilities during the pandemic, all of the services listed above were provided in partnership with disability services. It is expected that health outcomes have improved significantly due to all these organizations working together so closely.
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https://ozinize.com/lethbridge-covid-19-collaboration-recognized-by-world-health-organization/
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This past summer Sustainable Connections hosted a workshop to educate restaurants and food-based businesses about ways they can reduce the amount of wasted food in their operations. One of the biggest myths we are working to overcome is that everything is hunky dory as long as we compost our wasted food. The facts remain that five times more greenhouse gases are emitted just getting food to our tables than are emitted on the disposal side of things. Therefore, if we are really going to make real progress in regards to wasted food, and recycling in general, we must have a renewed focus on reduction, and not use recycling as a crutch to continue on the same old course.
After the workshop, there was as lively discussion, ideas shared about what could be done differently, and then it was serendipity. In the face of the reality that 1 in 5 kids in Washington state lives in a household that struggles to put food on the table, there had to be an opportunity. Before you know it, plans were being hatched about how we as a community can divert perfectly edible food from the compost bin or worse the landfill–into the bellies of people who need a hot meal.
For many of the years I have been in the Toward Zero Waste realm I have always been saddened to see the vast amount of edible food discarded at restaurants, schools, campuses of all sorts, and events. For many, the writing has been on the wall, and finding a way to recover and redistribute highly perishable food items such as prepared foods in deli cases or unserved plated meals at banquets is the big gap in the Toward Zero Waste spectrum.
This is where we come back to serendipity. By happy happenstance, three people in a room sharing similar concerns was the catalyst for Sustainable Connections to seriously explore our role and opportunity to help bridge the gap between commercial entities, food recovery, and food redistribution. Armed with a new sense of purpose, we put our pens to the paper and tapped out the keystrokes that ultimately led to a successful grant application to the Washington State Department of Ecology.
We are pleased to announce a very important addition to our Toward Zero Waste campaign. The Food Redistribution Initiative (FRI) will drastically reduce food waste generated by restaurants and events in our community by redistributing unclaimed food to those in need of hot meals. Additionally, we will develop an app that allows businesses in the food industry to contact hot meal distribution organizations so the food redistribution can continue after the initial 2 year pilot. A complementary educational campaign for both businesses and the public will launch when FRI begins.
By the end of the grant period, our goal is to have 30 businesses and 8 events donating food to four recipient organizations. We estimate that this will redistribute 30,000 meals or nearly 50,000 pounds of food waste per year, keeping it out of the landfill, and feeding community members in need. Stay tuned in the coming months as we share our progress and ways you can get involved. We are beyond excited to bring this initiative to our community and we look forward to businesses, fellow non-profits, and our community helping to make it a huge success!
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https://sustainableconnections.org/serendipity-as-a-catalyst/
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My personal why is grounded in a deep appreciation of the opportunities and good fortune I’ve experienced in my own life. I had a safe, secure upbringing, followed by an affordable education and a move into the working world when times were good and there were plenty of opportunities.
In contrast, there are many people in my native Switzerland who simply haven’t had access to these opportunities, either because of their background or they’ve been derailed along the way by personal circumstances or one of life’s many curveballs.Being a citizen of one of the richest countries in the world, but not having access to basic nutrition and education is a terrible situation to be in. And so it is quality of life – or rather lack of quality of life – that is very much my personal why.
Giving something back to society is extremely important to me, and Elanco enables its employees to spend two and a half days a year to pursue their own why.
I was part of a group here in Basel who started Hunger Cause initiatives, which created regular volunteering opportunities for Basel site employees. We identified local charities engaged in collecting food with a short shelf life.
Each quarter we spend half a day (a full day in the third quarter) with these charities helping to collect, re-pack and stack food which is then distributed to people in need.
During the last volunteering activity in June, I had the opportunity to travel with a food collection team here in Basel. We collected products with a short expiry date from some 40 donors, made up of big food retailers and supermarkets but also small businesses such as bakeries and butcheries.
We re-distributed the food the same day to refugee homes, organisations that provide meals to people who receive welfare, shelters for homeless people, assisted living residences or care centers for substance abuse.
I’m always surprised at how much of this food is of impeccable quality, especially the fresh products such as fruit, salad or vegetables. When we think that every Swiss throws away an average 94kg of food every year1, there’s another very good reason to redistribute food that would otherwise go to waste.
I also realised the impact this kind of initiative can have on the overall health on hundreds of people in the area in helping ensure they had a balanced, cooked meal.
To come back to my personal why, my work needs to give me a chance to purse the opportunities to contribute to others’ quality of life – which helps me with my own.
1. Almeida 2011, FAO 2011.
Tags: Elanco Life , Our Engagement ,
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https://www.elanco360.com/authors/balz-hersberger/2016/this-is-my-why
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CalRecycle Edible Food Recovery Grant Program
The California Department of Education Nutrition Services Division is sharing information about the Edible Food Recovery Grant Program. The California Department of Resources Recycling and Recovery (CalRecycle) is offering grants to support organizations with funding new and expanded edible food recovery and food waste prevention projects. Applications are due by December 16, 2021.
This grant program provides funding to organizations that:
- Collect and redistribute edible food to people in need that would otherwise go to waste
- Help prevent the generation of food waste normally destined for landfills
This solicitation is targeting the most food insecure communities and qualifying tribal communities.
For more information, please visit the Edible Food Recovery Grant Program web page.
An informational Food Waste Prevention and Rescue Grant Program (Video; 2:28) video can also be viewed.
Contact Information
If you have any questions regarding this subject, please contact CalRecycle by email at [email protected]. Questions about school solid waste and recycling programs can be directed to [email protected].
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https://www.cde.ca.gov/ls/nu/calrecedibfoodgrantprog.asp
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SB1383, signed by Governor Brown in 2016, requires reductions in short-lived climate pollutants, similar to the way AB32, the Global Warming Solutions Act of 2006, does for greenhouse gases. SB1383 specifically targets organic waste methane emissions.
CalRecycle is developing the regulatory language to support the following targets under SB1383: a 50 percent reduction in the level of statewide disposal of organic waste from the 2014 level by 2020; a 75 percent reduction in organic waste disposal by 2025; and the recovery of 20 percent or more of edible food that is currently being disposed for human consumption by 2025.
Since the bill’s passage, CalRecycle has been holding workshops on the regulatory language. The most recent workshops were held on May 7 & 8, 2018. The following is the Table of Contents of the May 2018 proposed regulations. For more information and documents., visit the CalRecycle Public Meeting Notice.
Article 1. Definitions Article 2. Landfill Disposal and Reductions in Landfill Disposal Article 3. Organic Waste Collection Services Article 4. Education and Outreach Article 5. Generators of Organic Waste Article 6. Biosolids Generated at a Publicly Owned Treatment Works (POTW) Article 7. Regulation of Haulers Article 8. Cal-Green Building Standards Article 9. Locally Adopted Standards and Policies Article 10. Jurisdiction Edible Food Recovery Programs, Food Generators, and Food Recovery Article 11. Capacity Planning Article 12. Procurement of Recovered Organic Waste Products Article 13. Reporting Article 14. Enforcement Article 15. Enforcement Oversight by the Department Article 16. Penalties
SB1383 will require local governments to impose new levels of collection service for generators, develop new sources of organics recycling and edible food recovery capacity, and comply with new levels of state and local oversight. CalRecycle has received considerable feedback on the most recent draft, so we expect it to continue to be revised.
In 2019 CalRecycle will be networking, providing technical assistance, and developing tools, model ordinances, contracts, and case studies to support efforts at the local level to meet the organic waste reduction targets and comply with the regulatory requirements.
In the meantime, NCRA will be holding the Zero Food Waste Forum on October 16, 2018 in Berkeley focused on innovative ways local governments are implementing and can comply with Article 10, the edible food element.
A related bill, AB 1219, the California Good Samaritan Food Donation Act, adopted in 2017, should help with food recovery. It strengthens and expands liability protections for food donors. Among its provisions, the law requires health inspectors to educate businesses about the laws that exist to protect food donors from liability, which is the first time a state has done this. To assist health inspectors, staff at a number of non-profits (the Public Health Alliance of Southern California, the California Conference of the Directors of Environmental Health, and the Center for Climate Change and Health, with support from The California Endowment) produced the Safe Surplus Food Donation Toolkit, to educate food facilities about safe surplus food donation, including information on liability protections, state mandates, and safe surplus food donation practices. The Toolkit includes websites where food generators can find recipients of donated food.
If you know of any feeding organizations that are not included, please encourage them to get listed. They are: Sustainable America Feeding America and Ample Harvest
# # #
The Northern California Recycling Association and Solid Waste Association of North American are hosting the 2018 Zero Food Waste Forum on World Food Day. Tuesday, October 16th, 2018 in Berkeley, CA. The Call For Papers is now open and ends June 15.
The Forum will help local jurisdictions comply with Senate Bill 1383, which requires California to reduce edible food going to landfills by 20% by 2025. The Forum will profile successful policies and programs in food waste prevention and reduction and edible food repurposing and recovery, highlight regional and statewide examples and provide a forum for “disruptive” approaches to reduce wasted food and feed hungry people. Interested in getting involved? If you are interested in serving on the committee or being a sponsor, contact the Committee.
NORTHERN CALIFORNIA RECYCLING ASSOCIATION
BOARD MEETING – THURS May 17, 2018
Location: John Moore’s Office, 1970 Broadway St, Oakland, CA 94612
Food served at 6 pm; meeting begins at 6:30 pm.
Open to the public – all welcome to attend. Please RSVP to the NCRA Office if you wish to attend. Coming late? Let the office know so someone can be prepared to come down to let you in; the doorperson leaves at 6pm.
By NCRA Food Waste Reduction Committee
For our report, Commercial Food Waste Reduction in Alameda County, we documented the amount of surplus food that was rescued and distributed in Alameda County. We estimated that about 5.7 million pounds of surplus food that was generated within the county was redistributed to feed hungry people in Alameda County in 2016.
A major player is the Alameda County Community Food Bank. As we documented in our report, the Food Bank runs the grocery rescue or Food Recovery Program which matches grocery stores to agencies (like food pantries) that distribute the surplus food (like individually wrapped salads, sandwiches, produce and food staples). Over 3.6 million pounds of food from over 100 donors was redistributed through the grocery rescue program in 2016. This grew to over 4 million pounds in 2017.
Since we published our report in July 2017, we learned about other sources of surplus food obtained by the Food Bank.
The Food Bank receives donations from large manufacturers and retail distributors, some of which might otherwise have been disposed. The Local Donation Program from Distributors and Manufacturers accounts for over 25% of the food that they distribute. This compares to about 12% from the grocery rescue program.The Local Donation Program has grown by 2.2 million pounds over the last two years, with last fiscal year totaling 6.2 million pounds. About 40% of this product is produce, and overall, it consists of a fair mix of dry goods, fresh bread/tortillas, fresh dairy, fresh juice, frozen product (meat, meals, etc.). The Food Bank works with about 20 donation partners throughout the county weekly, and averages about 630,000 pounds of surplus food redistributed per month.
About 45% of the food that the Food Bank distributes comes from the California Association of Food Banks Farm to Family Program which distributed 164 million pounds of surplus produce to 43 food banks statewide and partnered with more than 135 farmers to access 44 different crops (which might otherwise have been wasted or ploughed under). This surplus food is generated outside of Alameda County, but feeds hungry people in county and throughout the state.
Senate Bill 1383 requires local jurisdictions to up the ante on food rescue and ensure that 20% of currently disposed edible food is recovered for human consumption in 2025. As the state identifies priorities for food rescue, it will need to consider the role of the large, traditional sources of surplus food (farms, manufacturers, and distributors) compared to the smaller, more difficult-to-address sources of surplus food (such as restaurants, schools, corporate cafeterias, and caterers).
Thank you Caroline Chow, Food Resource Development Coordinator, Alameda County Community Food Bank for contributing to this piece.
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https://ncrarecycles.org/topics/activities/committee-reports/
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Summary:
The Community Food Member Coordinator will assist in the growth and development of the organisation as a whole and especially to continue to grow the number of Community Food Members (CFMs) that we work with.
About Us:
FareShare Cymru works with charities and community organisations across South Wales helping to fight food poverty by tackling food waste. We take surplus edible food from the food and drink industry (food that would otherwise be wasted) and redistribute it to organisations in South Wales that feed people in need, turning an environmental problem into a social solution.
Over the last year we have redistributed over 1100t of surplus food, providing enough meals for over 2.8 million meals
This is a very important and exciting time for FareShare Cymru as we are about to embark on a programme of change and growth that will lead to us branching out across South Wales and into the west, recruiting more volunteers and more community food members, handling more food and expanding our base in Cardiff.
Further information on FareShare Cymru can be found on our website fareshare.cymru
Job Role:
The role will involve the recruitment of new Community Food Members ensuring that we reach more organisations and help more people, as well as ensuring that the needs of our existing CFMs continue to be met. You will develop new relationships, partnerships and projects as well as playing a role in the overall development of the organisation.
The job description can be downloaded here
Additional Information:
Interviews will be held week commencing 4th November 2021
To Apply:
Please send a copy of your CV and supporting statement to [email protected]
The closing date for applications is 09:00am Friday 31st October 2021.
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https://charityjobfinder.co.uk/en/job/community-food-member-coordinator/
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For more information contact:
Angela Blank
(502) 573-0450
FRANKFORT, Ky. — One out of every six Kentuckians – including one in four children – is food insecure. Through the Kentucky Department of Agriculture’s Hunger Initiative, farmers, businesses, charitable organizations, faith groups, community leaders, government entities, and other Kentuckians will work together to search for ways to combat hunger in the Commonwealth.
A news conference to introduce the members of the Hunger Task Force is scheduled for June 2 at 9:30 a.m. EDT at Gallrein Farms, 1029 Vigo Road, Shelbyville. The initial meeting of the task force will follow at 10 a.m.
“The members of the task force will bring their unique perspectives to this persistent problem,” Agriculture Commissioner Ryan Quarles said. “By bringing together the people who grow our food, sell our food, and distribute our food, we hope to find novel approaches that could help to alleviate the underlying issues of hunger in Kentucky.”
Map the Meal Gap 2016, an annual study by Feeding America, revealed that 17 percent of Kentucky’s population is food insecure – nearly three-quarters of a million people in all. The Kentucky Department of Agriculture works with The Kentucky Association of Food Banks and its local affiliates in the fight against hunger in Kentucky. The KAFB administers the Farms to Food Banks program, which buys surplus and Number 2 grade produce from Kentucky farmers and distributes it to local food banks.
"We applaud Commissioner Quarles’ leadership and commitment to addressing hunger in Kentucky through the formation of the Hunger Initiative,” said Tamara Sandberg, executive director of the KAFB. “Our hope is that innovative solutions to hunger can be identified and creative public partnerships can be implemented as a result of this effort.”
“Having such a dire hunger problem in Kentucky, with its rich agricultural history and abundant natural resources, is unacceptable,” Commissioner Quarles said. “Together, we can make healthy, nutritious foods accessible to more Kentuckians.”
For more information about the Hunger Task Force, go to kyagr.com/hunger. To find out more about the Kentucky Association of Food Banks, go to kafb.org.
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https://www.kyagr.com/Kentucky-AGNEWS/press-releases/Quarles-launches-Kentucky-Hunger-Initiative.html
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TRENTON, N.J. – New Jersey Department of Community Affairs (DCA) Commissioner Lori Grifa and New Jersey Department of Agriculture Secretary Douglas H. Fisher today announced a collaborative commitment that provides the five major food banks in the state with 'Jersey Fresh' fruits and vegetables for the families and organizations they assist. The announcement was made during a visit to Mercer Street Friends Food Bank. More than $147,000 in federal funding is being directed to the effort.
"By working together, the Christie Administration is giving a healthy boost to people facing hard times," said Commissioner Grifa. "We are coming together to help address the needs of families all across New Jersey; from Cape May to Sussex Counties, from Newark to Bridgeton."
The funding is made available through the DCA Division of Housing and Community Resources' administration of the Community Services Block Grant (CSBG), a federal, anti-poverty block grant which funds the operations of a state-administered network of local agencies. Five percent of the state's allocation is reserved for state priorities and special initiatives determined by the DCA Commissioner. The focus on food banks addresses the nutrition component of the CSBG program.
"Our partnership with the Department of Community Affairs helps to fulfill the mission of the Department of Agriculture to feed the hungry of our state with wholesome, nutritious foods," said Secretary Fisher. "Every citizen deserves to have access to Jersey Fresh fruits and vegetables and the CSBG funding will increase the availability of these products, grown locally by New Jersey farmers, at the 793 food pantries, soup kitchens and homeless shelters around the state."
Commissioner Jennifer Velez, Department of Human Services was also in attendance to remind everyone of the important role food banks have in providing sustenance for the indigent and working poor.
"The state's Food Banks serve as a safety net for many financially- and food-insecure families in New Jersey," said Department of Human Services Commissioner Jennifer Velez. "This partnership with the Department of Agriculture will supplement their inventory with healthy, fresh, Jersey-grown produce. Individuals who need to locate a local soup kitchen or food pantry can search online at www.endhungernj.org."
Funding to the food banks is based on the poverty level of the counties they serve. Twenty percent of the allocation to each food bank will be designated for fresh produce from New Jersey. A total of $147,462 was distributed to the following food banks, all of which were represented at today's announcement:
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Agency
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Amount
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Counties Served
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NORWESCAP
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$3,670
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Hunterdon, Sussex, Warren
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Community Food Bank
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$100,944
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North Branch: Bergen, Essex Hudson, Middlesex, Morris, Passaic, Somerset, Union
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South Branch: Atlantic, Cape May, Cumberland
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Food Bank of Ocean & Monmouth
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$16,795
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Monmouth, Ocean
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Mercer Street Friends
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$5,839
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Mercer
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Food Bank of South Jersey
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$20,214
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Burlington, Camden, Gloucester, Salem
The DCA's Division of Housing and Community Resources is committed to building neighborhoods and to providing financial and technical assistance to municipalities, community action agencies and other nonprofit organizations for community and economic development projects that improve the quality of life for low-income, disabled and disadvantaged residents.
The Department of Agriculture administers the federal Emergency Food Assistance Program which distributes United States Department of Agriculture-donated foods to the food banks and the State Food Purchase Program, which allocates funds to the food banks for the purchase of nutritious foods, including fresh New Jersey produce.
The Department of Human Services, in collaboration with the Hunger Prevention Advisory Committee, created www.endhunger.org as a resource for food-insecure residents in New Jersey to access food pantries, soup kitchens and shelters by county. People can also call 211 or go to www.nj211.org.
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https://nj.gov/dca/news/news/2011/approved/20111025.html
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Historically, religious organizations and nonprofit agencies have distributed food and meals to people in need. The sharp increases in such requests associated with high unemployment, cuts in the social safety net, decline in the value of public assistance benefits, and increases in housing and other costs has led to unprecedented growth of food banks, food pantries, soup kitchens, shelters and emergency food programs.
Below are 11 ideas for fun projects to help motivate your congregation to do food donations.
Simply choose a theme and place a large box in a convenient spot at your church so that members can deposit food items that will be delivered to the food bank or food pantry by a designated person at the church. Or encourage your members to deliver items to the food bank/pantry themselves.
1. “Plant a Row for the Hungry” – Plant an extra row in your vegetable garden and donate the harvest to the food shelters. You can also begin this project in the spring or begin to plant a container garden. Donating your extra produce will help others live better and healthier lives.
Things to note: It is important to first contact the local food pantry and make arrangements with the director or staffer at the food bank/pantry to receive your produce. Compile a list of all the government and independent food pantries in your county/community who accept donations of fresh fruits and vegetables. Circulate this list to other congregations.
If weather where you are located does not support planting a row this time of year, consider “planting a seed” by a forming a group to work your state Cooperative Extension agency to identify local Community Supported Agricultural (CSA) farms and recruit members for an early spring garden start.
2. “Casserole Wednesday” – Have your church members make Casseroles. Deliver these casseroles to local shelters and outreach centers. Volunteer at the shelter on this day by helping to serve the meal. Show extravagant hospitality by sitting down and breaking bread with community recipients.
3. Have a “Souper Day” – Ask your congregation to focus on gathering cans of soup. Soup contains many nutrients and has many health benefits. Choose soups that are lower in sodium and fat.
4. “Festive Fruity Friday” – Have everyone commit to donating fruit. Inquire if the food bank/shelter accepts fresh fruits, if not, focus on canned fruits that are packed in their own juices or have light syrup.
5. “Tasty Tuna Saturday” – Whether you’re a fisher who could provide a fresh catch or a shopper who could hook some cans, your donations will be much appreciated. Bring these items to your church to be delivered to the food bank/pantry. Fish and meats are good sources of protein and can be mixed with lots of vegetables and grains for a nice meal.
6. “Dedication and Commitment Sunday” – Choose a Sunday and ask your congregation to commit to bringing cans on that day. Designate a special time in the morning service where members may come forward with their food donations and drop them into a special basket in front of the altar. Have a special dedication and prayer over the food items. The items may be delivered to the food bank/shelter during the week.
Take it further and distribute simple “pledge” cards that members by which members of your community can pledge to donate food to pantries and food banks for an entire year. Have members drop their pledge cards into the offering plate. Print out a list of those who have pledged and post it somewhere in the church. Encourage others to pledge throughout the year.
7. “Miscellaneous Mondays” – On this day ask people to donate whatever they’ve got lying around in their house! Bring it to the church to be donated to the pantry/food bank.
8. “Cereal and Oatmeal Shoppers” – Choose a day to donate cereals that are multi-grain with low sugar content. Donate low sodium oatmeal. Cereals supply protein, vitamins and minerals.
9. “Pasta Party” – Focus on collecting all kinds of Pasta! Pasta is a food source of carbohydrates. Don’t forget to add the sauce – tomato-based sauces are good.
10. “Thankful Thursday” – Use this day to collect items for Thanksgiving dinners. Many shelters will prepare and serve thanksgiving meals. Donate turkeys that can be frozen (check to make sure that the food bank has a freezer), dry mashed potato flakes, canned vegetables, condiments, bread, etc. Don’t forget the cranberry sauce!
11. “Calling all Pet Lovers” – People are making choices between feeding their pets and feeding themselves. Many families have to give up their pets because they can no longer feed them. Give donations of pet foods to the shelter or food bank so that people can support their pets and families when they are struggling financially.
Excerpted from the Mission: 1 "Food Donation Resource"
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https://www.ucc.org/tags/mission_1
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What is the purpose of MEFP?
The purpose of the Maryland Emergency Food Program is to provide funding to assist emergency food providers (or emergency feeding organizations) in purchasing food for needy individuals and families in Maryland and to encourage self-sufficiency. MEFP grants funds to organizations that provide meals at no cost directly to individuals or households in need. These funds are utilized to purchase food items by organizations such as food pantries, soup kitchens, shelters, food banks and residential treatment programs.
What is the difference between The Emergency Food Assistance Program (TEFAP) and the Maryland Emergency Food Assistance Program (MEFP)?
TEFAP is a federally funded program that distributes food commodities and federal funds to each state. DHS is the TEFAP Administering Agency in Maryland and contracts with the Maryland Food Bank and Capital Area Food Bank to receive and store food from the United States Department of Agriculture (USDA.) MEFP grants funds directly to emergency food providing organizations such as food pantries and soup kitchens in all 24 jurisdictions in Maryland.
My family needs food. Can MEFP help me?
How much food and money can my organization receive to help feed my community?
New MEFP vendors receive a maximum of a $2000 annual grant for the first year. Allocation of grants are based upon available funding and indicators of need such as current population size, the percentage of unemployment, and the number of individuals and families living in poverty. Please see our MEFP Guidelines for additional information.
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http://dhs.maryland.gov/bureau-special-grants/maryland-emergency-food-program-mefp/faqs/
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DOVER — Kent County nonprofits are now eligible for grants in an $8 million program, created by federal funding, to aid agencies still struggling to recover from the COVID-19 pandemic.
The Kent County COVID-19 Response Programs will include two initiatives: the COVID Loss Recovery to address financial loss during the pandemic, and COVID Capital Improvement to address unmet capital needs and improve facility conditions.
The COVID Loss Recovery program will provide grants up to $100,000 to eligible nonprofits directly affected by the pandemic during 2020 and 2021. Applicants need to provide financial documentation from the last three years to compare 2019 against 2020 and 2021 to verify the economic loss of decreased revenues and increased operating costs.
The COVID Capital Improvement program is focused on nonprofit construction, expansion, and infrastructure improvement projects with grants up to $500,000, or up to 50% of project costs. Capital projects must be correlated to pandemic consequences and benefit the impacted population.
To be eligible, nonprofits must serve Kent County residents but do not have to be headquartered in Kent County. Grants will be awarded to nonprofits to serve four categories:
- Children and youth, including education, counseling, childcare, food assistance, and other child and youth support service providers.
- Disabled individuals (visual, hearing, and mobility impaired, and developmentally disabled) including education, employment assistance, transportation, food services, and other support services.
- Homeless individuals and families, including temporary housing providers (shelters), food assistance providers, guidance/counseling services, and other homeless support service providers. Food assistance may include providers such as food banks and pantries that offer food for children, their families, and the general public.
- Seniors, including senior community centers, food assistance providers, transit assistance providers, and other senior support service providers.
Kent County will use some of its share of the American Rescue Plan Act (ARPA) funds, as well as federal funding from the State and Local Financial Recovery Fund, a category of the ARPA funding specifically for small business and nonprofit recovery, among other initiatives.
County officials will allocate funds evenly to nonprofits that fit the four categories but may be reallocated funding based on demand. Additional funding may be committed if need demands, and sufficient funding remains available.
Kent County will accept applicants on a rolling basis for three months between July 28 and Oct. 28.
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https://delawarebusinesstimes.com/news/kent-county-unveils-nonprofit-grant-program/?quad_cc
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Key Concepts:
Terms in this set (47)
free verse
Poetry that does not have a regular meter or rhyme scheme
tone/mood
created by the poem's setting, tone, voice, theme and rhyme so can evoke certain emotions and feelings in the reader
stanza
A fixed number of lines of verse forming a unit of a poem
personification
A figure of speech in which an object or animal is given human feelings, thoughts, or attitudes
metaphor
A comparison that establishes a figurative identity between objects being compared.
simile
A comparison using "like" or "as"
hyperbole
A figure of speech that uses exaggeration to express strong emotion, make a point, or evoke humor
irony
A contrast between expectation and reality
situational irony
An outcome that turns out to be very different from what was expected
dramatic irony
Irony that occurs when the meaning of the situation is understood by the audience but not by the characters in the play.
verbal irony
A figure of speech in which what is said is the opposite of what is meant
oxymoron
A figure of speech that combines opposite or contradictory terms in a brief phrase
assonance
Repetition of a vowel sound within two or more words in close proximity
onomatopeia
The use of a word whose sound imitates or suggest its meaning
active voice
Expresses an action done by its subject
passive voice
The subject of the sentence receives the action.
symbolism
A device in literature where an object represents an idea
pun
A play on words. In an argument, a pun usually calls humorous attention to particular point.
juxtaposition
Placement of two things closely together to emphasize comparisons or contrasts
foreshadowing
A warning or indication of a future event
theme
an idea that the poem/story expresses about the subject or uses the subject to explore.
characterization
Actions, dialogue, and narrative description that reveal a sense of a character's personality to the reader
plot events
actions that move the conflict toward a climax
conflicts
struggles or disagreements
paradox
A statement or proposition that seems self-contradictory or absurd but in reality expresses a possible truth, contradiction or dilemma
alliteration
Repetition of consonant sounds
imagery
Description or figurative language that appeals to the senses (sight, sound, smell, touch, taste) to create sensory impressions.
author's intent
the universal message the author attempts to communicate in his or her work of literature
repetition
repeats the same words or phrases a few times to make an idea clearer
Marxist lens
connections between the content or form of a literary work and the economic, class, social or ideological factors that have shaped and determined it
Psychoanalytical lens
used to better understand human behavior and patterns in the conscious and unconscious mind of a literary character
feminist lens
reinforces the economic, political, social, and physiological oppression of women;
gender roles and patriarchy, sexism, gender vs sex, feminists
editorial
An article giving opinions or perspectives
reflection essay
Author makes a connection between a personal observation & a universal idea such as love, courage, or freedom, or makes a memory of something from the past
interview
A face-to-face or telephone questioning of a respondent to obtain desired information.
commentary
A series of notes clarifying or explaining something; an expression of opinion
journal entry
keeps records, stories, memories etc in a chronological order
expository essay
an essay that explains, informs, or presents information to prove
parallelism
Phrases or sentences of a similar construction/meaning placed side by side, balancing each other
rhetorical question
A question asked merely for rhetorical effect and not requiring an answer
antithesis
Direct opposite, sharp contrast
exclamation
An abrupt or emphatic expression of thought or of feeling
point of view
The perspective from which a story is told
omniscient person point of view
the narrator knows all the thoughts and feelings of all the characters in the story
1st person point of view
The narrator is a character in the story. ( I, me, my, we, our )
2nd person point of view
the narrator tells the story to another character using "you," so that the story is being told through the addressee's point of view
3rd person point of view
when a story is told from the perspective of a narrator that is outside the action of the story uses he she they
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https://quizlet.com/212833481/devices-for-poetry-short-story-english-final-flash-cards/
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Background:
When you see a picture of red roses growing in a garden, your eyes probably see the roses, its petals and the birds moving around. But your mind starts thinking about feelings of love and romance. This is because, over some time, roses have come to be known as a mean of expressing love for someone. Or in a way, we can say that red roses have come to symbolize love. This art style of using an object or a word to represent an abstract idea is called Symbolism.
Artists may use colours, animals, any action, person, place, word, or object to create some other abstract feeling symbolically.
Death and the Grave Digger (La Mort et le Fossoyeur) (c. 1895) by Carlos Schwabe
What is Symbolism?
When it comes to language or even art, one object, concept, or word is not limited to a single meaning. The English language has an exhaustive list of symbols, which is used to communicate the desired meaning, without saying so openly. The meaning and significance of these symbols are well known and well accepted by masses. So, when an artist wants to communicate some feeling or emotions, there are two ways of expressing it. The first way is to say it directly, but then it makes the art very simple. The other way is to hint at that same feeling through the use of symbols. For example, the use of colours. The colour black is used to symbolize sorrow, while white stand for purity.
These symbols are used indirectly to communicate the desired expression, without saying so openly. This art movement is termed Symbolism.
History of Symbolism:
Symbolism is an art movement that started in the second half of the 19th century. In literature, it all started in the year 1857, when Charles Baudelaire's published his famous work ‘Les Fleurs du mal’, where he made extensive use of symbolism. Baudelaire, who translated the great works of Edgar Allan Poe into the French language, was a great influence on Symbolism and this inspired many stock tropes and images.
However, the term "symbolist" was coined by the famous art critic Jean Moréas, who invented the term to distinguish the Symbolists from the related Decadents of literature and art. Though closely related to literature, symbolism in art was seen as being related to the gothic component of Romanticism and Impressionism.
This art movement which originated in poetry and other arts in France, Russia and Belgium attempted to represent the absolute truths symbolically through metaphorical images and language. A new generation of artists emerged on the scene, which did not have a common goal, but they were influenced by a particular style. These artists wanted to evoke certain emotions among their audiences through the use of colours, lines and forms. Though this was not a very radical shift, yet it was seen as a move towards abstraction, which is in stark contrast to Naturalism and Realism.
Use of Symbolism in past:
Symbols have been used by even primitive man in their cave paintings. Though these are bit complex. After this, the ancient Greek theatre also made us of various symbolic props to communicate some abstract idea. These props included even phallic objects to symbolize Dionysus, the god of fertility.
In literature, authors have long favoured the use of symbols among a wide range of literary devices. Many great writers and authors like William Shakespeare, Edgar Allen Poe and William Blake among others have used symbolism to create the desired effect in their work.
Symbolism in Literature:
With changing times, literature has evolved a great deal, with the subject matter it covers. However, what has not changed is the use of symbols and their definition. For ages, Symbolism is defined as a concept of a word or object representing something beyond its literal meaning. Throughout history, several poets, authors, lyricists, play writers, and painters have used certain types of symbolism in their art. Some of the major types of symbolism used are listed below:
Religious symbolism: This is perhaps the most consistent and most accepted use of Symbolism. This is because; this use of symbolism has been approved by religious authorities, who have controlled the human society for quite a long time. The major use of religious symbolism can be seen in great works like Paradise Lost by John Milton, and The Brothers Karamazov by the Russian author Fyodor Dostoevsky.
Romantic symbolism: If there is any use of another type of symbolism, which comes close to religious symbolism, it would probably be romantic symbolism. The literature, especially poetry is full of use of romantic symbols to communicate the feeling of love and romance. From sonnets of Shakespeare to the modernist stanzas of Edna St. Vincent Millay, romantic symbolism has always been popular with the poets.
Emotional symbolism: Many authors and poets have also used emotions as symbols to communicate some deeper meaning. This has been used to describe some metaphysical emotions. French language symbolists like Stéphane Mallarmé and Paul Verlaine are noted for this form of symbolism, as are English language writers like William Butler Yeats and Seamus Heaney.
How to add Symbolism:
Though it depends upon the relationship between an artist and patrons. But there are some common ways to add symbolism. This is actually like a code language between the writer and the reader. Specifically, symbolism can be used to:
Use of emotions: The correct use of symbols can create a lasting impression on a reader. For example, in William Shakespeare’s Macbeth, Lady Macbeth is shown cleaning a spat of blood, which she got after killing King Duncan. She tries a lot but is not able to clean that spat, which shows her guilt.
Use of imagery: Symbols have the power to make complex things easy by adding a visual element to the idea. For example in his poem “A Dog Was Crying To-Night in Wicklow Also, the poet, Seamus Heaney’s 1995 uses the image of “burnt wood disappearing into smoke”. This is done to symbolize the concept of dead humans drifting out of other people’s consciousness.
Use of connected themes: The green colour symbolizes money. The same symbolism has been used in The Great Gatsby, where the author F. Scott Fitzgerald’s uses green colour as a symbol for money and materialism that defines life on the North Shore of Long Island.
Define characters: Symbols can express character attributes. For example, in the Harry Potter series of books, Harry’s lightning bolt-shaped scar symbolizes the attempt on his life by Lord Voldemort and the love that saved him.
Conceal darker meaning: In The Scarlet Letter by Nathaniel Hawthorne, Hester’s seemingly feral daughter Pearl symbolizes the sin that led to her conception. Her difficult demeanour represents the secret at the heart of her existence—that her father is the prominent Reverend Arthur Dimmesdale. Only when Dimmesdale’s paternity is revealed does Pearl transition into a positive symbol: the freeing spirit of the natural world.
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A Paper on Symbolism in Novel Lord of the Flies by William Golding
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William Goldings Lord of the Flies is filled with numerous symbols The literary definition of a symbol is a person place or object that represents more than what it is physically The author uses a variety of these to assist the reader in relating aspects of the narrative to places or ideas in modern day society as well as infusing the story with greater depth and meaning Throughout the novel Golding effectively implements three distinct politically related symbols the conch Jack and Ralph On the island the conch represents law and order as well as the freedom to speak ones mind Whoever possesses the conch is the only person permitted to talk at the timeLet him have the conch shouts Piggy Let him have itpg39 Piggy is admonishing one of the older boys to let a younger boy have a chance to speak This quote show that Piggy embraces the ideology of a democracy and feels that the littleun in this case deserves the right to speak given his democratic belief that the litteuns matter just as much as the older boys do The littleuns contributed to the voting in of Ralph as their leader in the first place The idea of the conch as a device for allowing someone to have the floor or speak their mind is still utilized by some tribes around the world Instead of a conch a stick or stone can be used to control who is speaking In Lord of the Flies when the conch is blown it is a signal for the group to assemble at the platform to discuss important things such as the building and maintenance of the signal fire the pigs and the beast of which they are terrified As the island civilization deteriorates and the boys crumble into savagery the conch shell loses its power and influence among them When the conch is destroyed at Castle Rock it symbolizes the end of
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What is symbolism in literature examples?
Other Literary Examples of Symbolism
In Elie Wiesel’s novel Night, night is used throughout the book to symbolize death, darkness, and loss of faith. In Nathaniel Hawthorne’s The Scarlet Letter, the letter “A” symbolizes adultery.
How do you explain symbolism?
Symbolism is when one object or thing stands in the place of something else, such as an idea, another object, a person, or a place. For instance, all countries have flags for their own country. The flag symbolizes the country. The flag stands in place of the country.
What is the meaning of symbolist?
1: one who employs symbols or symbolism. 2: one skilled in the interpretation or explication of symbols.
How is symbolism used in writing?
Specifically, symbolism can be used in the following ways:
- Symbols help you show without telling. Writers use symbolism to convey complex ideas without using a ton of words.
- Symbols connect themes.
- Symbols add imagery.
- Symbols hint at darker meanings.
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What is another name for symbolism?
In this page you can discover 20 synonyms, antonyms, idiomatic expressions, and related words for symbolism, like: typology, relationship, metaphor, analogy, comparison, symbolisation, allegory, archetype, symbolization, iconography and mythology.
What is metaphor in literature?
A metaphor (from the Greek “metaphorá”) is a figure of speech that directly compares one thing to another for rhetorical effect. While the most common metaphors use the structure “X is Y,” the term “metaphor” itself is broad and can sometimes be used to include other literary terms, like similes.
What is the best definition of symbolism?
Symbolism is the practice or art of using an object or a word to represent an abstract idea. An action, person, place, word, or object can all have a symbolic meaning.
What is the importance of symbolism in literature?
In literature, symbolism is used to produce an impact, which it accomplishes by attaching additional meaning to an action, object, or name. Symbolism takes something that is usually concrete and associates or affixes it to something else in order to give it a new and more significant meaning.
What does metaphor mean?
A metaphor is a figure of speech that describes an object or action in a way that isn’t literally true, but helps explain an idea or make a comparison. Metaphors are used in poetry, literature, and anytime someone wants to add some color to their language.
Who started the Symbolist movement?
A group of late 19th-century French writers, including Arthur Rimbaud and Stéphane Mallarmé, who favored dreams, visions, and the associative powers of the imagination in their poetry.
Is simplistic a word?
Simplistic is sometimes used in the neutral sense of “not complicated” (in which case it is synonymous with simple) but this borders on misuse-simplistic is generally understood to be pejorative. Get Word of the Day delivered to your inbox!
How do you identify symbolism in literature?
How to Tell When Something Is Really a Symbol
- Look at descriptions. If a character is always dressed in purple clothing and wearing a crown, these items probably symbolize the character’s power, wealth, and royal status.
- Look for repetition.
- Pay attention to the turning points in a story.
What is the difference between symbolism and metaphor?
Symbol. They’re related, but generally a metaphor is used to draw a comparison between two distinct objects, whereas a symbol is used as a stand-in for a much more complex, and generally more abstract, idea.
How do you identify symbolism in a poem?
What is Symbolism? A symbol in poetry is something that is used not only literally but also as a way to represent something else. So, for example, a poem might be about an oak tree and the cycle of life of a tree. The oak itself is what the poem is about, but it might also be meant as a symbol for human life.
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Further, it highlights the significance of England. We shall go on to the end. Winston Churchill was very fond of his pet dog Rufus. I have been her kind.
When Neil Armstrong Winston churchill literary devices on the moon it might have been one small step for a man but it was one giant leap for mankind. Here is an example of an anecdote about Winston Churchill: Such a memory causes the people to become frightened that times may take a turn for the worst again, returning to those years of pain and no new ideas.
As a literary device, anaphora serves the purpose of giving artistic effect to passages of prose and poetry. The following are anaphora examples: The young writer was exited to get the reward, and he decided to celebrate the occasion in a fitting manner.
This long, seemingly interminable list with the use of asyndeton starts to numb the reader with all of the possible fatal incidences.
An allegory is a symbolism device where the meaning of a greater, Winston churchill literary devices abstract, concept is conveyed with the aid of a more corporeal object or idea being used as an example.
Hence, his question about unleashing war is asking his audience to remember that they are not attacking Hitler, only preparing to fend him off. When he uses this device, the questions cause his audience to think about the answer, which leads the people to consider more thoroughly what the consequences are.
Anthropomorphism can be understood to be the act of lending a human quality, emotion or ambition to a non-human object or being. Teachers and educators often tell classrooms of pupils anecdotes about famous people.
The whole speech is full of the anaphoric example. Gradually, Elizabethan and Romantic writers brought this device into practice. In standard parlance and writing the adjective comes before the noun but when one is employing an anastrophe the noun is followed by the adjective. Churchill also makes admirable use of imagery in this speech.
An analogy is a literary device that helps to establish a relationship based on similarities between two concepts or ideas.
The narrator of this section, a woman whose son died in Vietnam, imagines many different possible deaths in fact, there are over eighty options listed; this is just an excerpt of them. The function of asyndeton is usually to accelerate a passage and emphasize the significance of the relation between these clauses.
An allusion is a figure of speech whereby the author refers to a subject matter such as a place, event, or literary work by way of a passing reference. Not only does it show his intelligence, but also it gives his audience an idea of his true meaning.
It is up to the reader to make a connection to the subject being mentioned. Does anyone pretend that preparation for resistance to aggression is unleashing war?
The anecdotes are not always flattering, but are usually revealing of character and invariably amusing. Both lines contain asyndeton examples; in the first, the omission of a conjunction is poetic, while in the second line, the four adjectives are listed without conjunction to show their similarity.
With a mental linkage between the two, one can create understanding regarding the new concept in a simple and succinct manner. Whether using the rhetorical question or the allusion or some other device, Churchill employs it in ways that are persuasive and relatable.
The puppetry of it all. The use of asyndeton can also be to highlight the connection between words or concepts to show how they are related. They are your rallying points: The repetitive structures in the above passage suggest the importance of the war for England.
Winston churchill literary devices Caesar by William Shakespeare William Shakespeare used many examples of asyndeton in his plays and poems.
Churchill is believed to have said to Rufus: Choose rotting away in the end of it all, pishing your last in a miserable home, nothing more than an embarrassment to the selfish brats you spawned to replace yourself, choose your future. Here he asks if his audience believes he is calling them to war.
After his secret writings did indeed become public and published, the term anecdote became commonly used for similar accounts. Indeed, this statement displays how the Nazi forces are really starving for power, devouring whatever they can.
In the same way as one cannot have the rainbow without the rain, one cannot achieve success and riches without hard work. A woman like that is not a woman, quite. Example 5 I have gone out, a possessed witch, haunting the black air, braver at night; dreaming evil, I have done my hitch over the plain houses, light by light: In his court, Justinian had a historian named Procopius who was a gifted writer who wrote many witty, amusing and somewhat bawdy accounts of court life.The Literary Churchill: Author, Reader, This strikingly original book introduces a Winston Churchill we have not known before.
Award-winning author Jonathan Rose explores in tandem Churchill’s careers as statesman and author, revealing the profound influence of literature and theater on Churchill’s personal, carefully composed grand /5(13).
This extract from Winston Churchill’s speech is full of anaphoric examples in which the speaker has spoken the phrase “we shall” several As a literary device, anaphora serves the purpose of giving artistic effect to passages of prose and poetry.
As a rhetorical device, anaphora is used to appeal to the emotions of the audience, in. Winston Churchill- Rhetoric Analysis. He uses Rhetorical Devices and Persuasive Appeals to make ONE point Occasion Winston Churchill's speech 'Blood, Toil, Tears and Sweat' was given on the 13th of May and the begining of the second World War.
The occasion was very formal because Churchill was adressing his speech the population. Churchill was a prolific writer, often under the pen name "Winston S.
Churchill", which he used by agreement with the American novelist of the same name to avoid confusion between their works. His output included a novel, two biographies, three volumes of memoirs, and several histories. Winston Churchill uplifted the British people with his literary speeches during World War II.
Welcome to the website dedicated to literary devices (literary terms). Here you will find a list literary devices with definitions and examples. Please fee free to post your thoughts and vote on your favorite literary device.
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The following collection of worksheets will teach your students how to identify and use symbolism.
If you have used our activity sheet sets on similes and metaphors, then you have already introduced your students to two forms of symbolism. In many cases, authors will use symbolism to allude to real life events in a fictitious setting. This set of activity sheets covers several different types of symbolism. Answer sheets have been provided for worksheets for instructors, but please note that in some cases, your students' answers will vary.
Symbolism started as a French literary movement in the late 1800s. It later caught on in the art world and the rest is history.
Click the buttons to print each worksheet and answer key.
Study the symbols below. What does each symbol mean to you?
In each instance, the moon is being used as a symbol. Explain the symbolism.
What is the predominant symbol in the story, and what does it represent?
Consider each of the animals below. What could they symbolize? Explain. If you have seen this animal used symbolically in literature before, describe where you saw it and what it symbolized.
Symbolism is a type of figurative language. Like a metaphor, a symbol is identified with something that is very different but shares some of the same qualities. Colors are commonly used as symbols in literature.
A symbol is a thing that represents or stands for something else, especially a material object that represents something abstract.
As you read, use this sheet to take note of the symbols that you encounter.
Seasons are often used symbolically in literature to represent the different stages of life. Think about what occurs in each season of the year. Then fill in the table to explain how the four seasons might be used symbolically.
Practice identifying symbols. Read each passage. Identify the symbol, and explain what you think it means.
Many of the items below are often used symbolically in literary text. Discuss some common interpretations of these symbols.
A helpful outline for you to run along with the book.
Consider each of the abstract ideas below. Can you think of an object that could work as a symbol in a story that has this as a theme? Write your ideas on the line.
Symbolism and Allegory in "The Lottery"
Discuss how each of the items below functions as symbol or allegory in Shirley Jackson's story.
Discuss the symbolic meaning of the following items in Charles Dickens' Great Expectations.
Read the passage. Identify the symbol at work in the passage. Based on your understanding of the story so far, discuss the meaning and the importance of the symbol.
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He would be only too happy to let you make your decisions for yourselves. Most often, authors who use allegory do so in the form of an exaggerated metaphor. Some experts also consider allegory to be a type of extended metaphor which develops a particular analogy to a greater extent as opposed to a simple comparison. One person escapes the cave and is able to see reality for the first time. From the modern era, The Lord of the Rings is a classic example for the World Wars. The White represented purity or virginity which in turn represents the white heron as something that symbolized the pure and rural life. Everything from the colors on the canvas to the actual depiction tells a story and is intended to sway a mood.
An example of this occurs in Galatians 4, when Paul explains the story of Abraham, Sarah, and Hagar as an allegory for the Old and New Covenants. Soon it becomes hard to tell which characters are actors in his play from which characters are actors in the film attempting to live their lives in peace. Many allegories, like 'The Allegory of the Cave', are much more subtle and require some background knowledge to uncover their symbolic meaning. The literal level is the plot, characters and setting. It is one of the literary devices that uses objects, characters, and even actions to represent an underlying meaning that is different from what the object or character literally translates into. Allegories also help writers make their stories multidimensional.
The parables told by Jesus Christ are also fine examples of allegory, two of which are ' The Prodigal Son' and ' The Good Samaritan'. Time: 45 Minutes Grade Level: 8-12 Standards Although this lesson can be used for multiple grade levels, below are Common Core State Standards for Grades 9-10. On this wall, you see shadows of figures and objects illuminated by a fire positioned behind you. In further inspection, we see that the tesseract also uncovers the cave of knowledge. Only half awake, still unaware that those depths were sky, having no roof between those depths and me, no branches to screen them, no root to cling to, I was seized with vertigo and felt myself as if flung forth and plunging downward like a diver.
. Allegories thus can be difficult to master, as they can be pedantic when done poorly. Unlike allegory, symbolism does not depict a story. Allegory is a type of literary device that is used by writers when they would want to express and present abstract ideas and qualities through the characters and events that they write. There are also many non-literary allegorical symbols in the Bible that are brought to life through tradition and ritual. This is done so that they may stand for something much larger in meaning compared to what they are literally perceived as.
Instead, these symbols simply stand for another object to give it a particular meaning. You are trapped in a dark cave, chained up and forced to look forward onto a wall in front of you, and you have been in this position since your birth. In these texts allegory creates a critical lens to view cultural, religious, and political ideas. One instance of this is Galatians 4, where Paul interprets the story of Abraham, Hagar, and Sarah as an allegory for the Old and New Covenants. Allegory in Literature Allegory in literature abounds.
The Allegory of the Cave is a representation of how man accepts conventions and refuses to question them. Then there's the level, or the deeper meaning that all the jazz on the surface represents. The use of the allegorical literary form extends back to ancient times and the oral tradition, even before stories started being written down. Allegory is also sometimes used to explain historical events that seemingly have no previous deeper meaning. It does not describe in detail the person or thing to which it refers.
These things are being taken figuratively: The women represent two covenants. Let's take a look at some allegory examples in books. Philosophers try to explain their theories, yet many skeptics like the ones chained to the cave walls criticize their works because they fail to open their minds to the endless possibilities of the unknown. That is, in extremely simplistic terms, the use of allegory. This makes the parable much more direct than the fable, and the least veiled of all the allegories. So they pushed the tower over, with no little labour, and in order to look for hidden carvings and inscriptions, or to discover whence the man's distant forefathers had obtained their building material. It is largely believed to be written by Francesco Colonna and is the story of Poliphilo who is searching for his lover Polia.
The goal of the allegory is to make spiritual concepts more understandable. The story is a reflection of Melville's feelings about America in the time leading up to the war. So identify and understand these. But this is what makes allegories an exciting art form. The book starts with the portrayal of the animal farm wherein the animals are overworked , unhappy and underfed. We get the word 'allegory' from the Latin word 'allegoria,' taken from the Greek word for 'veiled language.
Allegorical representations are found in most mediums of expression, and therefore, language or literature is not the only way to express something that is not visibly clear to the eye. Something as basic as charity gets replaced by introspection and self-imposed spiritual flagellation. But they are assured that once they would be able to grab the interest of their readers once they would make use a literary device particularly allegory. It is unclear if Caden is able to see the world as it actually is, but it is clear that he inhibits and prevents his actors from leading normal lives and having any autonomy. Specifically, the Red-Cross Knight represents holiness, Lady Una stands for goodness and the one true faith, Una's parents symbolize the human race, and the dragon represents evil. This is clearly portrayed when he sacrifices himself to save his people, is tortured and ridiculed by traitors of his land, and is resurrected during the time that people needed him the most. Life of Pi In Life of Pi, the main character is a child who's stuck on a boat with a tiger.
For example, famous religious figures Jesus and Buddha made use of parables when imparting their beliefs to their disciples or followers. Analyzed at this level, the film seems a bit cliché, but there is much more depth. With a main character named Christian, it isn't hard to see what religion we are talking about here. While an allegory is a story, poem, or picture, it's revealing a hidden meaning or message. Another type of allegory is the parable, which has only human characters and is even more straightforward than the fable. Teddy is plagued by nightmares and migraines. An allegory is a very specific type of story, as it must stay true to the message for the entirety of the story.
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Tagore’s “60” is a prose poem, so it uses paragraphs in place of poetic stanzas. The first paragraph begins with the line: “On the seashore of endless worlds children meet.” Based on the phrase “endless worlds,” one can see that this poem may have some metaphysical, or supernatural, qualities. The idea of endless worlds suggests a universal or infinite quality of some sort. In addition, Tagore introduces the image of a seashore in this sentence. He could be talking about an actual seashore, but the metaphysical context suggests that Tagore is talking about a symbolic one. A symbol is a physical object, action, or gesture that also represents an abstract concept, without losing its original identity. Symbols appear in literature in one of two ways. They can be local symbols, meaning that their symbolism is only relevant within the context of a specific literary work. They can also be universal symbols, meaning that their significance is based on traditional associations that are widely recognized, regardless of context. In “60,” the symbols are universal. Tagore is talking about a seashore, which is the opposite of the sea. The sea traditionally represents infinity—an idea that Tagore has already suggested with “endless worlds.” Following this line of thinking, the opposite of infinity, or heaven, is the mortal, human world. So, the seashore could represent this human world.
The next line addresses the idea of infinity directly: “The infinite sky is motionless overhead and the restless water is boisterous.” Once again, Tagore could be simply describing a day at the beach, where children meet on the beach, the sky is calm, and the sea is choppy. The next line—“On the seashore of endless worlds the children meet with shouts and dances.”—certainly supports this idea of children playing by the sea. This line also repeats part of the first line, so that the paragraph is bookended by the same image—a technique that Tagore uses throughout the poem. However, looking at the poem symbolically, one can find significance in many of the images. First of all, besides the idea that the sea represents infinity, water in general is a symbol for life or creation, in a feminine sense. Likewise, the “infinite sky” traditionally symbolizes heaven, and is often associated more generally with the male forces of creation. So, taken together, the sky and sea represent male and female creation forces. Next to these two cosmic forces, the seashore, representing the human world, seems almost insignificant, except for the presence of the children.
Paragraph 2
The second paragraph describes the children in more detail. The first line notes that they “build their houses with sand and they play with empty shells.” When sand is used to build a house, it suggests impermanence, since the “vast” ocean will just wash away these sand houses with the tide. This idea of impermanence is reinforced by the idea of empty shells, since the animals that inhabited the shells have died and left only their shells behind. In general, however, shells are linked to the water from which they come, so they share water’s creation meaning, especially in the feminine sense. The second sentence notes: “With withered leaves they weave their boats and smilingly float them on the vast deep.” The withered leaves suggest death, as do the boats, since journeys across water have traditionally been associated with death. So far, Tagore’s symbolism seems to be pointing to a cycle of birth and death, although it is still too early in the poem to understand why this might be. The last sentence states: “Children have their play on the seashore of worlds.” In the first stanza, the children were meeting “with shouts and dances;” now, they are playing.
Paragraph 3
The middle paragraph gives more information about these children. “They know not how to swim, they know not how to cast nets.” The children are ignorant about the ways of the world, unlike the “Pearl fishers” and “merchants” who are forced to make a living. Instead, the children engage in idle activities that have no economic purpose: “children gather pebbles and scatter them again.” The last sentence in the paragraph reaffirms the fact that the children are not concerned about money. They do not seek “hidden treasures,” and they do not know “how to cast nets.” This is a surface reading of the middle paragraph. However, once again, when one looks at the symbolism of the paragraph, it takes on a deeper meaning. Traditionally, a “net” symbolizes the power of the gods to trap humans and hold them in the mesh of life. Since the children know nothing of nets, Tagore could be saying that they are not yet bound to life, as adults are bound. The pearls that the pearl fishers search for are also significant. Pearls have many symbolic meanings. If Tagore is indeed using pearls in a symbolic way, he is most likely including them as a sign of the permanence that is lacking elsewhere. Mortals like the pearl fishers seek out these symbols of permanence because most other aspects of their lives are not permanent. Also, at one point, pearls were thought to be the tears of the gods. Both of these interpretations fit in with the religious tone of the poem.
Paragraph 4
In the fourth paragraph, the focus shifts from the children to the sea, which is suddenly very active: “The sea surges up with laughter and pale gleams the smile of the sea beach.” Although Tagore uses terms like “laughter” and “smile,” one should not be fooled. The sea is dangerous, as the next line notes: “Death-dealing waves sing meaningless ballads to the children, even like a mother while rocking her baby’s cradle.” Once again, Tagore is giving the sea an image of feminine creation, or motherhood. However, this image has an ominous undertone because the unsuspecting children are at risk, even though they do not understand the danger of the “death-dealing waves.” As if to reinforce the juxtaposition of innocence and death, the last sentence notes: “The sea plays with children, and pale gleams the smile of the sea beach.” One can imagine the children playing in the waves of the sea, unaware that this may be dangerous and perhaps fatal.
Paragraph 5
The final paragraph repeats the first line of the poem: “On the seashore of endless worlds children meet.” Since the first line, the situation in the poem has changed drastically. The “restless water” has churned up into “death-dealing waves.” In the second sentence of this paragraph, Tagore notes: “Tempest roams in the pathless sky, ships get wrecked in the trackless water, death is abroad and children play.” In the sky, which was “motionless” in the beginning, a “tempest” now rages. It is interesting to note that the sky is “pathless.” Not even a tempest can disturb the permanent quality of the sky. Likewise, not even “wrecked ships” can leave a mark in the water, which is “trackless.” The poem does not indicate whether or not Tagore is referring to the children’s toy boats that have been wrecked or the ships of the merchants and pearl fishers. One suspects the latter, since this image is more tragic, and is consistent with the rest of the sentence, which states that “death is abroad.” Yet, the “children play.” No matter what natural catastrophes have taken place over the course of the poem, Tagore ends with the certainty that “On the seashore of endless worlds is the great meeting of children.” Given the heavy symbolism of creation, life, and death evident in the poem, Tagore seems to be underscoring the blissful ignorance of childhood, which makes children more susceptible to death, but which is more peaceful than the stressful adult world.
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Who says all good books have to be happy ones? The Grapes of Wrath certainly proves this is just not the case. It takes place during the Great Depression, so you know right away that it’s not going to be a particularly uplifting story.
But just because the story has a lot of depressing elements doesn’t mean it’s not a literary classic. In fact, it’s one of the most popular books for high school students to read because it is so rich in literary devices and potential analysis points.
If you’re having trouble figuring out just what those points of analysis are or how to write about The Grapes of Wrath, I’ve got you covered.
I’ll not only give you some tips on how to set yourself up to write a great essay, but also give you some example thesis statements you can use as inspiration for your own writing.
So let’s dive in, shall we?
Read to Analyze The Grapes of Wrath
You’re writing an analytical essay, and the first step to writing analytically is reading analytically. Some call this active reading, which basically means that you aren’t just sitting back and reading for the heck of it—you’re reading with the goal of true comprehension.
There are a few techniques that can help you become a more active reader. They all deal with making the important information from the book easily accessible for when you have to write your essay.
Highlighting
Unless you already have a prompt that asks you to write about specific elements of The Grapes of Wrath, you’re going to be pulling quite a lot of information relating to different symbols, metaphors, characters, etc.
It helps some students to have a fast way to tell which sections of text fall into which literary category. That’s where highlighting is helpful.
You can use different colors for the different categories. That way, when you do decide what you want your essay to be about, you can skim through the pages and pick out, for example, only the blue highlighted sections or only the yellow ones.
Taking notes
Note-taking can be split into several sub-categories. You can take notes on paper or on a computer, where you can write as much or as little as you want.
However, some students find annotating directly in the margins of the book to be more useful because then they can point exactly to the block of text they’re referring to without having to write or type that text.
Hybrid methods
There are various ways to combine the above methods, but my personal favorite is using different colors of sticky notes.
This way, each color can represent a symbol, a theme, or something else. You get the option to express your thoughts about the text (in detail) as you’re reading. You can collect all the sticky notes after you’re finished reading and decide the best topic to write about.
Make a Roadmap
Once you’ve gathered all your information, it can seem like a lot to sort through. But you don’t want to be like the Joads and be completely unprepared when you reach your destination (actually writing your essay).
That’s why it’s important to have a roadmap, or outline, to make it easier.
A traditional outline follows a Roman-numeral setup, where each section gets a number and the supporting information is listed underneath. This is the type of outline I’ve written below. However, if you’re a more visual person, an idea web or bubble chart may be more helpful for you.
No matter what type of outline you use, you should include some basic information. What’s your thesis statement? What are your main ideas? What’s the support for those main ideas? My The Grapes of Wrath outline would look something like this:
- Introduction
- Hook
- Thesis statement: As the story progresses, Rose of Sharon’s pregnancy and her child’s birth take on new symbolic meanings. Her pregnancy symbolizes hope, and her stillborn child represents the loss of that hope.
- Pregnancy
- Symbolizes the hope of new beginnings
- A new baby would be the start of a whole new chapter of the Joads’ lives
- Stillborn child
- Symbolizes the end of hope
- Rose of Sharon’s body still produces milk, an effect from pregnancy, meaning there’s still a small sliver of hope
- Makes the best out of a bad situation by feeding the dying man
- Conclusion
Ideas for Your The Grapes of Wrath Essay
Now that you have a few reading strategies and know how to outline, you’re probably feeling pretty ready to start writing your essay. But before you do, it might be helpful to look at some analysis ideas to get your creativity going.
The important thing to remember is that this is an analysis, not a summary. You’re not trying to paint a broad picture of what happened in the book. Rather, you’re looking at how a literary device is used. This could be discussing a theme or how symbolism is used throughout the text.
Putting too much information into your essay actually dilutes what you’re trying to say and makes your arguments much weaker. So stick to one literary device, and use as much evidence as you can muster to support it.
Here are some examples of elements you can discuss in The Grapes of Wrath:
Symbolism
Route 66
Roads in general symbolize many things in The Grapes of Wrath. Depending on the road, it can symbolize home or the great unknown. In the case of Route 66, the road symbolizes hope and opportunity.
Route 66 doesn’t intersect with any other highway, which means the Joads have to either take their chances and hope that there is prosperity in California or go back to a life of certain despair.
Here’s an example thesis statement:
In The Grapes of Wrath, roads symbolize home and unknown places, hope and despair. But the main road, Route 66, represents both the pursuit of new opportunities and the risk of returning to squalor.
Rose of Sharon’s pregnancy
Rose of Sharon is pregnant up until the very end of the book. The pregnancy symbolizes hope. A new baby could mean a new beginning.
However, Rose of Sharon delivers the baby stillborn, which dashes the dreams of a new beginning. But because of the effects the pregnancy had on her after the delivery (the ability to breastfeed), all hope is not lost.
While the end is frankly kind of weird, nursing the dying man shows that, even without a new beginning, people have to make the best out of their situations.
I’ve included the thesis statement for this symbol in the example outline above, but here it is again:
As the story progresses, Rose of Sharon’s pregnancy and her child’s birth take on new symbolic meanings. Her pregnancy symbolizes hope, and her stillborn child represents the loss of that hope.
Themes
Suffering caused by the inhumanity of others
There is a lot of pain, struggle, and hardship in The Grapes of Wrath, but it’s mostly caused by the fact that the Joads and all the other migrants are poor.
The inhumanity that the landowners (rich people) display toward the migrants stems from fear of the migrants taking over their land.
So what do the landowners do? They treat them like dogs and turn them against each other by making resources extremely scarce. The whole story stems around this division in class and shows just how much poor people suffer at the hands of the rich.
My thesis statement for an essay on this topic would look like this:
In The Grapes of Wrath, John Steinbeck explores the theme of suffering being caused by people’s inhumanity. He shows the fear of the landowners turning into anger and suppression, ultimately demonstrating how the inhumanity of the rich is what keeps them in control over the poor.
Need More Help?
There are so many other directions you could take with your The Grapes of Wrath analysis. If you need more concrete inspiration, check out the focus in each example essay on The Grapes of Wrath linked below. The essays tackle the following themes:
- Symbolism
- An analysis of right and wrong
- Character analysis of Jim Casey
- The journey theme
- The portrayal of Joads as characters of nobility
(Writing your own character analysis? Read How to Write a Character Analysis That Works.)
And if you’re still struggling to get started, here’s some extra help on writing a literary analysis:
- How to Write a Literary Analysis That Works
- 8 Components of a Smart Literary Analysis
- Literary Analysis Essay Tips from a Kibin Editor
Even though The Grapes of Wrath wasn’t the happiest book out there, by using some of the tips in this post, you can be happy about the way you write about it. The Kibin editors are always here to help as well. They’ll make sure your essay is on the road to success.
Good luck!
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https://www.kibin.com/essay-writing-blog/how-to-write-about-the-grapes-of-wrath-the-smart-way/
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9.2 What causes mental illness?
9.2.1 The biopsychosocial model
The causes of specific mental illnesses vary but most are caused by a combination of biological, psychological and social problems. Mental health professionals have developed a model of mental illness called the ‘biopsychosocial’ model (see Figure 9.8).
A model is a simplified way of describing how the different parts of a complex issue link together.
As Figure 9.8 shows, the biological, psychological and social factors often overlap. Here are some examples of biological, psychological and social causes of mental illness:
- Biological causes: genetic (inherited) causes, a chemical imbalance in the brain, head injury, alcohol or khat use, undernutrition
- Psychological causes: not loved in childhood, too many worries, the stress of somebody dying, disappointment, frustration, severe shock
- Social causes: poverty, not living in a good house, not having somebody who they can talk to about their problems, discrimination, migration.
Now read Case Study 9.1. As you do so, think about your answers to the following question:
Can you identify some possible biological, psychological and social factors contributing to Mr Hailu’s mental illness?
Case Study 9.1 Mr Hailu the farmer
A 33-year-old farmer developed mental illness after getting into a fight with one of his neighbours. For many years, the farmer had drunk araki every day to help him forget his problems. When he was drunk, he insulted his neighbour and they fought together. The neighbour hit him heavily on the head and the farmer fell to the floor for a few minutes before he was able to get up again. After that the farmer stayed in the house and then developed symptoms of mental illness. Nobody was sympathetic to the farmer because he had caused a lot of trouble in the local area. He had lost all his money because of his drinking, and his wife had gone back to her own family because she couldn’t stand it any longer. All these problems made him worry and he wished he had somebody to talk to. He couldn’t turn to his family because both parents died when he was a small child and his brothers lived far away.
Biological factors: in Mr Hailu’s case study he had a head injury and a long-term history of excessive alcohol use. Psychological factors: he had too many worries, and his parents died in childhood. Social factors: he was isolated and had nobody to talk to.
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https://www.open.edu/openlearncreate/mod/oucontent/view.php?id=296§ion=20.4.1
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The course introduces students to the art and science of Psychology. Course emphasis is on applying the "science of human behavior" to a variety of settings: vocational, personal, academic, and clinical. Course content introduces the history of psychology, major theories of personality and learning, current research and developmental issues. The course has a holistic approach and integrates the biological basis of behavior, social factors, learning and the unique coping styles of the individual to understand human behavior.
Students will be able to identify and define the key tenets and theories in the field of psychology (perceptual, cognitive, developmental, abnormal, social, and health).
Students will be able to apply basic psychological principles and theoretical concepts to their daily life, work, and relationships.
Students will be able to describe how human behavior and mental processes are affected by culture and social situations and roles.
Students will be able to apply the scientific method and research methodology to critique a simple psychological experiment.
Students will be able to identify the main symptoms and treatments for common psychological disorders.
Students will be able to describe the findings of major/critical psychological experiments and theorists in the field of psychology.
Students will be able to summarize the mind/body connection as it relates to psychological concepts.
Participation on eight weekly Forums is required. General forum posting requirements and topic-specific instructions are located on each forum.
Due in Week 3 is the Stoop Effect Assignment. Starting in Week 3 and continuing through Week 4, students collect data for their sleep journal. Due in Week 5 is the Sleep Journal and Reflection Paper. Due in Week 7 is the Prosocial Behavior Assignment.
The course Final exam is open-book and consists of short essay questions that cover all course material.
This course utilizes an adapted Learning Textbook from CogBooks. Access is through the Lessons area of the classroom.
Lindecker, C. (Ed.). (2017). Introduction to psychology. CogBooks: American Public University System.
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https://www.apu.apus.edu/course-schedule/details.html?c=PSYC101
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This course provides an overview of existing psychological and epidemiological findings on the relationship between behavior and disease. The course explores how behavior, emotion and cognition can influence disease processes and examines the impact of stress and perceived control of one’s destiny on coronary, immune and infectious diseases and symptoms. The biological processes of several relevant chronic illnesses are covered as well as related racial and social economic health disparities. Templates for understanding and treating chronic illness including social support, referral and interventions for optimal physical and mental health are discussed. The interdisciplinary theme of this course will provide an overview of extant literature on theories of health psychology within the context of critical race theory, epidemiology, research methods, philosophy of science, biological anthropology, sociology, as well as applied health/medical fields for an enriched understanding of the biopsychosocial approach to health and illness. Lectures and in-class activities as well as films, guest lecturers, and interactive computer programs make up this textbook-free course with required readings made available through CityTech’s OpenLab and Open Educational Resources (OER).
This class examines knowledge and attitudes towards human sexual behavior.
This course will explore the various critical health and safety issues and problems affecting children and adolescents. Areas to be explored will include nutrition, personal hygiene, medical care, first aid and safety, CPR, mental health, HIV and AIDS, sexually transmitted diseases, chronic and communicable diseases, sexuality and birth control.
English 1121: Composition II, Sections D400 + D431, Spring 2015, Instructed by Holly Melgard
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Essay on Addiction Is A Complex Disease
From the biopsychosocial model, we understand that addiction is a “complex disease” (Howatt 2005). It may be influenced by either biological, social or psychological factors. Some addictions are brought about by relationships we have with other people. These factors are referred to as social factors. Biological factors are those influenced by the genetic makeup. Psychological factors are those brought about by our thoughts, feelings or the environment. We shall limit our discussion to the psychological and biological theories of addiction.
The biological theory is based on the fact that when a narcotic is regularly consumed, the body eventually gets used to it and cannot do without it. It is believed that the narcotic causes readjustment of the metabolism. The narcotic has to be consumed regularly otherwise may lead to withdrawal.
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https://www.cram.com/essay/Addiction-Is-A-Complex-Disease/P35GG5AZHBWW
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Computer Science > Computer Vision and Pattern Recognition
Title:NSGA-Net: Neural Architecture Search using Multi-Objective Genetic Algorithm
(Submitted on 8 Oct 2018 (v1), last revised 18 Apr 2019 (this version, v2))
Abstract: This paper introduces NSGA-Net -- an evolutionary approach for neural architecture search (NAS). NSGA-Net is designed with three goals in mind: (1) a procedure considering multiple and conflicting objectives, (2) an efficient procedure balancing exploration and exploitation of the space of potential neural network architectures, and (3) a procedure finding a diverse set of trade-off network architectures achieved in a single run. NSGA-Net is a population-based search algorithm that explores a space of potential neural network architectures in three steps, namely, a population initialization step that is based on prior-knowledge from hand-crafted architectures, an exploration step comprising crossover and mutation of architectures, and finally an exploitation step that utilizes the hidden useful knowledge stored in the entire history of evaluated neural architectures in the form of a Bayesian Network. Experimental results suggest that combining the dual objectives of minimizing an error metric and computational complexity, as measured by FLOPs, allows NSGA-Net to find competitive neural architectures. Moreover, NSGA-Net achieves error rate on the CIFAR-10 dataset on par with other state-of-the-art NAS methods while using orders of magnitude less computational resources. These results are encouraging and shows the promise to further use of EC methods in various deep-learning paradigms.
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https://arxiv.org/abs/1810.03522
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Computer Science > Machine Learning
Title:A Constructive Approach for One-Shot Training of Neural Networks Using Hypercube-Based Topological Coverings
(Submitted on 9 Jan 2019)
Abstract: In this paper we presented a novel constructive approach for training deep neural networks using geometric approaches. We show that a topological covering can be used to define a class of distributed linear matrix inequalities, which in turn directly specify the shape and depth of a neural network architecture. The key insight is a fundamental relationship between linear matrix inequalities and their ability to bound the shape of data, and the rectified linear unit (ReLU) activation function employed in modern neural networks. We show that unit cover geometry and cover porosity are two design variables in cover-constructive learning that play a critical role in defining the complexity of the model and generalizability of the resulting neural network classifier. In the context of cover-constructive learning, these findings underscore the age old trade-off between model complexity and overfitting (as quantified by the number of elements in the data cover) and generalizability on test data. Finally, we benchmark on algorithm on the Iris, MNIST, and Wine dataset and show that the constructive algorithm is able to train a deep neural network classifier in one shot, achieving equal or superior levels of training and test classification accuracy with reduced training time.
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https://arxiv.org/abs/1901.02878v1
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7 Skills Needed to Become a Machine Learning Engineer
Do you want to transition to becoming a Machine Learning Engineer? If so, then you are not alone! Technologies like Artificial Intelligence, Machine Learning, Data Science, etc. are becoming more and more popular these days. But these technologies are also thrown about like buzz words where many people don’t know what they really mean or the skills required for learning them. That’s where this article can help you by listing all the different skills you need to bag your dream job as a Machine Learning Engineer!
Machine Learning is a technology that is focused on machines independently learning from the data without much human intervention or explicit programming. This is a complex field that is a distillation of Artificial Intelligence and interlinked with other technologies like Data Science. But this creates the question of Who is a Machine Learning Engineer. And how is he different from a Data Scientist or a Data Analyst? Let’s understand this first.
Who is a Machine Learning Engineer?
Since Machine Learning is deeply linked with Data Science, there are some overlaps in the job description of a Data Scientist, Data Analyst, or a Machine Learning Engineer. However, the main differences are what they focus on. Data Scientists and Analysts are mainly focused on obtaining insights from the data and presenting them to the higher-ups in the organization to make important decisions. This involves having some knowledge of ML algorithms. However, Machine Learning Engineers are excluding focused on Machine Learning. Their aim is to create software components that can work with minimal human supervision and help in obtaining insights from the data they are provided with. This is why there is so much focus on Computer fundamentals and software development for a Machine Learning Engineer because that is their specialization.
Now let’s see the skills you need to become a Machine Learning Engineer. While the first two of these are quite basic that you may have even learned in your high school or bachelor’s, they become more complex and domain-specific as you move through the list.
Skills Needed for Becoming a Machine Learning Engineer
1. Applied Mathematics
Maths is quite an important skill in the arsenal of a Machine Learning engineer. It is also one of the basic subjects that are taught right from school and that’s why it is the first skill on our list. But are you wondering why you need maths at all? (Especially if you don’t like it?!!) Well, maths can have many uses in ML. You can apply various mathematical formulas in selecting the correct ML algorithm for your data, you can use maths to set parameters, approximate confidence levels, Many of the ML algorithms are applications derived from statistical modeling procedures and so it’s very easy to understand them if you have a strong foundation in Maths. Some of the important topics of maths that you need to know include linear algebra, probability, statistics, multivariate calculus, distributions like Poisson, normal, binomial, etc. Apart from Maths, having some knowledge of Physics concepts can also be beneficial if you want to become a Machine Learning engineer.
2. Computer Science Fundamentals and Programming
This is another basic requirement for becoming a good machine learning engineer. You need to be familiar with different CS concepts like data structures (stack, queue, tree, graph), algorithms (searching, sorting, dynamic and greedy programming), space and time complexity, etc. The good thing is you probably know all of this if you have done your bachelor’s in computer science! You should be well versed in different programming languages like Python and R for ML and statistics, Spark and Hadoop for distributed computing, SQL for database management, Apache Kafka for data pre-processing, etc. Python is a very popular programming language especially for Machine Learning and Data Science so it’s great if you are well versed in its libraries like NumPy, Pandas, Matplotlib, Scikit-learn, TensorFlow, etc.
3. Machine Learning Algorithms
What is a very important skill in becoming a Machine Learning Engineer? Obviously, it’s very important to know all the common machine learning algorithms so that you know where to apply what algorithms. Mostly ML algorithms are divided into 3 common types namely, Supervised, Unsupervised, and Reinforcement Machine Learning Algorithms. In detail, some of the common ones include Naïve Bayes Classifier, K Means Clustering, Support Vector Machine, Apriori Algorithm, Linear Regression, Logistic Regression, Decision Trees, Random Forests, etc. So it’s good if you have a sound knowledge of all these algorithms before beginning your journey as an ML engineer.
4. Data Modeling and Evaluation
As a machine learning engineer, you should be skilled in data modeling and evaluation. After all, data is your bread and butter! Data modeling involves understanding the underlying structure of the data and then finding patterns that are not obvious to the naked eye. You also need to evaluate the data using an algorithm that is suitable for the data. For example, the type of machine learning algorithms to use such as regression, classification, clustering, dimension reduction, etc. depends on the data. A classification algorithm well suited to large data and speed may be naive beyes, or a regression algorithm for accuracy might be a random forest. Similarly, a clustering algorithm for categorical variables is k mode while for probability is k means. You need to know all these details about various algorithms to contribute to data modeling and evaluation effectively.
5. Neural Networks
Nobody can forget the importance of Neural Networks in the life of an ML engineer! These Neural Networks are modeled after the neurons in the human brain. They have multiple layers that include an input layer that receives data from the outside world which then passes through multiple hidden layers that transform the input into data that is valuable for the output layer. These demonstrate a deep insight into parallel and sequential computations that are used to analyze or learn from the data. There are many different types of neural networks like Feedforward Neural Network, Recurrent Neural Network, Convolutional Neural Network, Modular Neural Network, Radial basis function Neural Network, etc. While it’s not necessary that you understand all these neural networks in detail to become an ML engineer, it’s important that you know the core fundamentals. And you can always learn the rest on the way!
6. Natural Language Processing
Natural Language Processing is naturally quite important and a fundamental part of Machine Learning. In essence, NLP aims to teach the human language with all its complexities to computers. This is so that machines can understand and interpret the human language to eventually understand human communication in a better way. There are many different libraries that provide the foundation of Natural Language Processing. These libraries have various functions that can be used to make computers understand natural language by breaking the text according to its syntax, extracting the important phrases, removing extraneous words, etc. You can be familiar with some or even one of these libraries like the Natural Language Toolkit which is the most popular platform for creating applications relating to NLP.
7. Communication Skills
And finally, we come to a skill that is a soft skill and may not be considered that important. However, if you are good at communication skills, it can make a world of difference in your career trajectory. That’s because while you understand the data and the insights obtained using machine learning better than anyone else, it is equally important that you can convey these insights to a non-technical team, your shareholders, or clients. This can also involve data storytelling where you should be able to present your data in a storytelling format with a beginning and ending at concrete results that you have obtained from the data using machine learning. That’s because eventually, the data analysis is less important to a company than the actionable insights that can be obtained from the data. And if you are able to convey these insights, then the sky’s your limit in your profession!
Conclusion
Machine Learning is becoming more and more widespread and is used in almost every field these days. Whether it be medicine, cybersecurity, automobiles, etc. all these fields are exploring the capabilities of machine learning. It’s obvious that learning more about ML and becoming a Machine Learning Engineer is a great idea and may even be a very wise career move! So check out all these skills and start learning them so you can improve your capabilities and bag your dream job as a Machine Learning Engineer!
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https://www.geeksforgeeks.org/7-skills-needed-to-become-a-machine-learning-engineer/
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As artificial intelligence becomes more complex, evolving technologies and the jargon associated with it might sound unfamiliar or strange to you. In this article, we have compiled the most important terms that are related to AI for you to flaunt in your next meeting.
Analogical Reasoning: The term analogical generally refers to non-digital data but when it comes to the field of AI, analogical reasoning is the process where people (scientists) draw conclusions based on past results. It is more like predicting stock markets.
Autonomic computing: Refers to the self-managing characteristics of distributed computing resources, adapting to unpredictable changes while hiding intrinsic complexity to operators and users.
Backpropagation: Is a method used in artificial neural networks to calculate a gradient that is needed in the calculation of the weights to be used in the network. It is commonly used to train deep neural networks, a term referring to neural networks with more than one hidden layer.
Backward chaining: It is used in automated theorem provers, inference engines, proof assistants, and other artificial intelligence applications.
Case-based reasoning(CBR): Broadly construed, is the process of solving new problems based on the solutions of similar past problems.
Data mining: is the process of discovering patterns in large data sets involving methods at the intersection of machine learning, statistics, and database systems.
Decision boundary: In the case of backpropagation based artificial neural networks or perceptrons, the type of decision boundary that the network can learn is determined by the number of hidden layers the network has.
Decision tree learning: Uses a decision tree (as a predictive model) to go from observations about an item (represented in the branches) to conclusions about the item’s target value (represented in the leaves).
Evolutionary algorithm: Is a subset of evolutionary computation, a generic population-based metaheuristic optimization algorithm. An EA uses mechanisms inspired by biological evolution, such as reproduction, mutation, recombination, and selection.
Feature extraction: In machine learning, pattern recognition and in image processing, feature extraction starts from an initial set of measured data and builds derived values (features) intended to be informative and non-redundant, facilitating the subsequent learning and generalization steps, and in some cases leading to better human interpretations.
Feature selection: In machine learning and statistics, feature selection, also known as variable selection, attribute selection or variable subset selection, is the process of selecting a subset of relevant features (variables, predictors) for use in model construction.
Forward chaining: Or forward reasoning is one of the two main methods of reasoning when using an inference engine and can be described logically as repeated application of modus ponens. Forward chaining is a popular implementation strategy for expert systems, business and production rule systems. The opposite of forwarding chaining is backward chaining.
Generative adversarial network (GAN): Is a class of machine learning systems. Two neural networks contest with each other in a zero-sum game framework.
Graph database (GD): Is a database that uses graph structures for semantic queries with nodes, edges and properties to represent and store data.
Named-entity recognition (NER): Also known as entity identification, entity chunking and entity extraction) is a subtask of information extraction that seeks to locate and classify named entity mentions in unstructured text into pre-defined categories such as the person names, organizations, locations, medical codes, time expressions, quantities, monetary values, percentages, etc.
Pattern recognition: Is the automated recognition of patterns and regularities in data. Pattern recognition is closely related to artificial intelligence and machine learning, together with applications such as data mining and knowledge discovery in databases (KDD), and is often used interchangeably with these terms.
Spatial-temporal reasoning: Iis an area of artificial intelligence which draws from the fields of computer science, cognitive science, and cognitive psychology. The theoretic goal—on the cognitive side—involves representing and reasoning spatial-temporal knowledge in mind.
Unsupervised learning: Is a term used for Hebbian learning, associated to learning without a teacher, also known as self-organization and a method of modelling the probability density of inputs.
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https://www.analyticsindiamag.com/25-ai-terminologies-jargons-you-must-assimilate-to-sound-like-a-pro/
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Academic performance is a topic studied not only to identify those students who could drop out of their studies, but also to classify them according to the type of academic risk they could find themselves. An application has been implemented that uses academic information provided by the university and generates classification models from three different algorithms: artificial neural networks, ID3 and C4.5. The models created use a set of variables and criteria for their construction and can be used to classify student desertion and more specifically to predict their type of academic risk. The performance of these models was compared to define the one that provided the best results and that will serve to make the classification of students. Decision tree algorithms, C4.5 and ID3, presented better measurements with respect to the artificial neural network. The tree generated using the C4.5 algorithm presented the best performance metrics with correctness, accuracy, and sensitivity equal to 0.83, 0.87, and 0.90 respectively. As a result of the classification to determine student desertion it was concluded, according to the model generated using the C4.5 algorithm, that the ratio of credits approved by a student to the credits that he should have taken is the variable more significant. The classification, depending on the type of academic risk, generated a tree model indicating that the number of abandoned subjects is the most significant variable. The admission scan modality through which the student entered the university did not turn out to be significant, as it does not appear in the generated decision tree.
|Original language||English|
|Pages (from-to)||266-272|
|Number of pages||7|
|Journal||International Journal of Advanced Computer Science and Applications|
|Volume||11|
|Issue number||1|
|DOIs|
|State||Published - 2020|
Bibliographical noteFunding Information:
This work was carried out with the support of our house of studies, the National University of San Agustin, in which the Vice-Chancellor of Research channels the resources from the mining canon and convenes a set of insolvable financial schemes. It is through one that the IBA 004-2016 project was funded, "Model of Academic Performance Assessment for the Detection of Outstanding Students and Students at Academic Risk".
Publisher Copyright:
© 2013 The Science and Information (SAI) Organization.
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https://pure.unsa.edu.pe/en/publications/classification-models-for-determining-types-of-academic-risk-and--2
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Data Science Interview Guide
Data Science is quite a large and diverse field. As a result, it is really difficult to be a jack of all trades. Traditionally, Data Science would focus on mathematics, computer science and domain expertise.
While I will briefly cover some computer science fundamentals, the bulk of this blog will mostly cover the mathematical basics one might either need to brush up on (or even take an entire course).
In most data science workplaces, software skills are a must. While I understand most of you reading this are more math heavy by nature, realize the bulk of data science (dare I say 80%+) is collecting, cleaning and processing data into a useful form.
Programming Language
Python and R are the most popular ones in the Data Science space. However, I have also come across C/C++, Java and Scala. Although, I would personally recommend Python as it has all the math libraries as well as specialized libraries for querying various databases and maintaining interactive web UIs. Common Python libraries of choice are matplotlib, numpy, pandas and scikit-learn.
Database Management
It is common to see the majority of the data scientists being in one of two camps: Mathematicians and Database Architects. If you are the second one, the blog won’t help you much (YOU ARE ALREADY AWESOME!). If you are among the first group (like me), chances are you feel that writing a double nested SQL query is an utter nightmare. That being said, it is important to have some knowledge of query optimization (both for SQL and noSQL systems).
Map Reduce
Big Data technologies are a little hard to follow considering how the Apache project keeps on adding new tools all the time. However, I would recommend learning either Hadoop or Spark (though my personal recommendation is Spark). Both uses similar Map Reduce algorithms (except Hadoop does it on disk while Spark does it in memory). Common Spark wrappers are Scala, Python and Java.
Now that we have covered the software needs, we will start making a smooth transition into the mathematics domain. Around this part of the process, you generally need to have some parsing background. This might either be collecting sensor data, parsing websites or carrying out surveys. After collecting the data, it needs to be transformed into a usable form (e.g. key-value store in JSON Lines files). Once the data is collected and put in a usable format, it is essential to actual perform some quality checks. Some common quality checks are as described below:
NaN Handling
NaNs or “Not A Number” are common place holders for missing data. If the number of NaNs for the specific feature is small, it usually suffice fill in the NaNs with the average value (of the entire dataset or a window), or with 0s (for a sparse dataset).
NaNs in a dataset usually indicates:
- the data doesn’t exist
- the data does exist but we don’t know what it is
Based on the specific use case, the appropriate measures should be taken.
Class Imbalance
Specifically for supervised learning models, it is important for classes (or targets) to be balanced. However, in cases of fraud, it is very common to heave heavy class imbalance (e.g. only 2% of the dataset is actual fraud).
Such information is important to decide on the appropriate choices for feature engineering, modelling and model evaluation.
Univariate Analysis
Univariate analysis of features independently (ignoring other features) is important when trying to look for outliers and unusual spikes in the variance. Common univariate analysis of choice is the histogram.
Bivariate Analysis
In bivariate analysis, each feature is compared to other features in the dataset. This would include correlation matrix, co-variance matrix or my personal favorite, the scatter matrix.
Scatter matrices allow us to find hidden patterns such as
- features that should be engineered together
- features that may need to be eliminated to avoid multicolinearity
Multicolinearity is actually an issue for multiple models like linear regression and hence needs to be taken care of accordingly.
Once the data is collected, cleaned and analyzed, it’s time to start creating features to be used in the model. In this section, we will explore some common feature engineering tactics.
Transformation
At times, the feature by itself may not provide useful information. For example, imagine using internet usage data. You will have YouTube users going as high as Giga Bytes while Facebook Messenger users use a couple of Mega Bytes. The simplest solution here would be to take the LOG of the values. Another issue is the use of categorical values. While categorical values are common in the data science world, realize computers can only comprehend numbers. In order for the categorical values to make mathematical sense, it needs to be transformed into something numeric. Typically for categorical values, it is common to perform a One Hot Encoding. In One Hot Encoding, a new feature is created for each categorical value to state if it is present in the given record. Example of One Hot Encoding is given below:
Combination
Certain features are redundant by themselves but are useful when grouped together. For example, imagine you had a predictive model for traffic density and you had a column for each type of car. Naturally, you don’t care about the type of car but the frequency of the total number of cars. Hence, a row wise summation of all the car types can be done to create a new “all_cars” variable.
Dimensionality Reduction
At times, having too many sparse dimensions will hamper the performance of the model. For such situations (as commonly done in image recognition), dimensionality reduction algorithms are used.
A commonly used dimensionality reduction algorithm is the Principal Components Analysis or PCA. Learn the mechanics of PCA as it is also one of those topics amongst COMMON INTERVIEW QUESTIONS!!!
Now that you have engineered your list of features, it is now time to select the features that will help build the most optimum model for the use case. The common categories and their sub categories are explained in this section.
Filter Methods
Filter methods are generally used as a preprocessing step. The selection of features is independent of any machine learning algorithms. Instead, features are selected on the basis of their scores in various statistical tests for their correlation with the outcome variable. The correlation is a subjective term here. Common methods under this category are Pearson’s Correlation, Linear Discriminant Analysis, ANOVA and Chi-Square.
Wrapper Methods
In wrapper methods, we try to use a subset of features and train a model using them. Based on the inferences that we draw from the previous model, we decide to add or remove features from your subset. The problem is essentially reduced to a search problem. These methods are usually computationally very expensive. Common methods under this category are Forward Selection, Backward Elimination and Recursive Feature Elimination.
Embedded Methods
Embedded methods combine the qualities’ of filter and wrapper methods. It’s implemented by algorithms that have their own built-in feature selection methods. LASSO and RIDGE are common ones.
That being said, it is VERY IMPORTANT to understand the mechanics behind LASSO and RIDGE for interviews.
Now that we have our optimal features, it is now time to train our actual model! Machine Learning models fall into one of two camps: Supervised and Unsupervised. Supervised Learning is when the tags are available. Unsupervised Learning is when the tags are unavailable. Get it? SUPERVISE the tags! Pun intended. That being said, DO NOT MIX UP THE DIFFERENCE BETWEEN SUPERVISED AND UNSUPERVISED LEARNING!!! This mistake is enough for the interviewer to cancel the interview. Also, another noob mistake people make is not normalizing the features before running the model. While some models are resistant to this issue, a lot of models (like linear regression) is very sensitive to scaling. Hence. Rule of Thumb. ALWAYS NORMALIZE THE FEATURES BEFORE USE!!!
Linear and Logistic Regression
Linear and Logistic Regression are the most basic and commonly used Machine Learning algorithms out there. Before doing any analysis MAKE SURE YOU DO LINEAR/LOGISTIC REGRESSION FIRST AS BENCHMARK! One common interview blooper people make is starting their analysis with a more complex model like Neural Network. No doubt, Neural Network is highly accurate. However, benchmarks are important. If your simple regression model already has a 98% accuracy and really close to over-fitting, getting a more complex model is not a smart move. That being said, linear regression is used for continuous targets while logistic regression is used for binary targets (mainly because the sigmoid curve forces the feature inputs towards either 0 or 1).
I would recommend the derivation of both logistic and linear regression (both single variate and multivariate). On top of preparing for the interview, the linear regression model is used as the base of a whole range of other machine learning models out there. Hence, it is long term investment.
Decision Trees and Random Forests
A slightly more complex model than a linear regression model is the decision tree. The decision tree algorithm splits at different feature based on information gain, until it hits a pure leaf (i.e. a set of records with only 1 label). A decision tree can be made to stop after a certain number of splits to stop it from getting pure leafs (common tactic to fix over-fitting problems).
The Information Gain calculated to split the tree is important. COMMON INTERVIEW PROBLEM! ENSURE YOU KNOW HOW INFORMATION GAIN IS CALCULATED!!! The common Information Gain calculation functions are Gini and Entropy.
What is important in the above curve is that Entropy gives a higher value for Information Gain and hence cause more splitting compared to Gini.
When a Decision Tree isn’t complex enough, a Random Forest is generally used (which is nothing more than multiple Decision Trees being grown on a subset of the data and a final majority voting is done). Random Forest algorithms can over-fit if the number of trees are not determined properly.
K-Means
K-Means is an unsupervised learning model that classifies data points into clusters. The number of clusters is provided, causing the model to shift the centroid until it iteratively finds the optimal cluster centers.
The number of clusters are determined using an elbow curve.
The number of clusters may or may not be easy to find (especially if there isn’t a clear kink on the curve). Also, realize that the K-Means algorithm optimizes locally and not globally. This means that your clusters will depend on your initialization value. The most common initialization value is calculated in K-Means++, where the initial values are are far from eachother as possible.
Neural Network
Neural Network is one of those buzz word algorithms that everyone is looking towards these days. While it is not possible for me to cover the intricate details on this blog, it is important to know the basic mechanisms as well as the concept of back propagation and vanishing gradient.
It is also important to realize that a Neural Network is essentially a black box. If the case study require you to build an interpretive model, either pick a different model or be prepared to explain how you will find how the weights are contributing to the final result (e.g. the visualization of hidden layers during image recognition).
Ensemble Models
Finally, a single model may not accurately determine the target. Certain features will need special models. For such circumstances, an ensemble of multiple models are used. An example is given below:
Here, the models are in layers or stacks. The output of each layer is the input for the next layer.
Classification Score
One of the most common way of evaluating model performance is by calculating the percentage of records whose records were predicted accurately.
Learning Curve
Learning Curve is also a common method for evaluating models. Here, we are looking to see if our model is too complex or not complex enough.
If the model is not complex enough (e.g. we decided to use a linear regression when the pattern is not linear), we end up with high bias and low variance. When our model is too complex (e.g. we decided to use a deep neural network for a simple problem), we end up with low bias and high variance. High variance because the result will VARY as we randomize the training data (i.e. the model is now very stable). DO NOT MIX UP THE DIFFERENCE BETWEEN BIAS AND VARIANCE DURING THE INTERVIEW!!! Now, in order to determine the model’s complexity, we use a learning curve as shown below:
On the learning curve, we vary the train-test split on the x-axis and calculate the accuracy of the model on the training and validation datasets. If the gap between them is too wide, it’s too complex (i.e. over-fitting). If neither one of the curves is hitting the desired accuracy and the gap between the curves is too small, the dataset is highly biased.
ROC
When dealing with fraud datasets with heavy class imbalance, a classification score does not make much sense. Instead, Receiver Operating Characteristic or ROC curves offer a better alternative.
The 45 degree line is the random line, where the Area Under the Curve or AUC is 0.5 . The further the curve from this line, the higher the AUC and better the model. The highest a model can get is an AUC of 1, where the curve forms a right angled triangle. The ROC curve can also help debug a model. For example, if the bottom left corner of the curve is closer to the random line, it implies that the model is misclassifying at Y=0. Whereas, if it is random on the top right, it implies the errors are occurring at Y=1. Also, if there are spikes on the curve (as opposed to being smooth), it implies the model is not stable. When dealing with fraud models, ROC is your best friend.
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http://www.datascienceblog.pw/software-tools.html
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Large amounts of textual data, such as daily business reports, e-mail, and electronic newspapers, can be stored easily on computers, owing to the dramatic progress of computer environments and network environments. The textual data includes various kinds of knowledge. The knowledge can facilitate decision making in many situations; therefore, knowledge discovery from the textual data is significant. However, it is difficult to discover the knowledge because of the huge amounts of textual data and it is impracticable to thoroughly investigate all the textual data. Methods are needed that facilitate knowledge discovery. Thus, this chapter focuses on a method of knowledge discovery described by a rule set, that is, a rule discovery method. The rule set can classify the textual data based on viewpoints of the analysis. Also, it can reveal relationships between the features of the textual data, which constitute knowledge.
Rule discovery methods have been studied since the start of research into artificial intelligence in the field of machine learning. These studies have yielded many techniques, such as decision tree, neural network, genetic algorithm, and association rules, which acquire the rule set from the structured data. A decision tree can describe a rule set in the format of a tree structure. The tree is regarded as the set of IF-THEN rules. C4.5 (Quinlan, 1992) is one example of the algorithms that acquire a compact tree with high classification efficiency from the structured data. Each item of the data is composed of attribute values and a class. The algorithm uses an information criterion to effectively acquire the tree. A neural network can describe a rule set in the format of a network structure. The network stores the relationships between attributes and classes as weights of the arcs in the network. The weights are appropriately adjusted by the back propagation algorithm. A genetic algorithm inspired by the concept of evolution can acquire a rule set from structured data. The algorithm describes a rule or a rule set as a solution. The algorithm repeatedly improves a solution set to acquire the optimum solution by using three operations: cross-over, mutation, and selection. Association rules can describe relationships between items. If an item set is frequent, its subsets are frequent. This is called the apriori property. The association rules can be discovered by expanding small item sets to big item sets including small ones based on the property.
These techniques are important for the rule discovery, but they cannot directly deal with the textual data because the textual data is not structured. It is necessary to deal with the textual data by extracting its structured features to acquire a rule set from the textual data. A key point of the extraction is the ambiguity of textual data. That is, the same words and phrases can represent different meanings. Also, different words and phrases can represent similar meanings. In addition, even if the same textual data is given, its interpretation depends on a human. It is necessary to overcome the ambiguity. Thus, we employ fuzzy set theory, because fuzzy set theory can describe ambiguity by defining appropriate membership functions. We introduce rule discovery methods based on fuzzy set theory.
On the other hand, we need to grasp the meaning of discovered rules in order to check their validity and to gain new knowledge from them. Rules described in a visible format are required. Thus, we employ a decision tree, because the tree is an IF-THEN rule set and we intuitively grasp the meaning of rules by looking through attribute values in the IF-part and classes in the THEN-part. We introduce rule discovery methods based on the decision tree.
As anticipated in the above introduction, this chapter focuses on rule discovery methods from textual data based on a fuzzy decision tree. The tree expands the concept of the previous decision tree by incorporating the concept of fuzzy set theory. In this chapter, first, we introduce the format of the textual data. Next, we introduce the format of the fuzzy decision tree, its inductive learning method, and the inference method using it. In addition, we introduce two methods of extracting features included in the textual data and the rule discovery methods based on the features. One method is based on a key concept dictionary and the other method is based on a key phrase pattern dictionary. Lastly, this chapter introduces two application tasks based on the methods. One is an analysis system for daily business reports and the other is an e-mail analysis system.
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https://www.igi-global.com/chapter/netcube-fast-approximate-database-queries/28567
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Support vector machine (SVM) has a good application in intrusion detection, but its performance needs to be further improved. This study mainly analyzed the optimization algorithm of SVM. Firstly, the principle of SVM was introduced, then SVM was improved using whale optimization algorithm (WOA), the WOA was improved, the intrusion detection method based on IWOA-SVM was analyzed, and experiments were carried out on KDD CUP99 to verify the effectiveness of the algorithm. The results showed that the IWAO-SVM algorithm was more accurate in attack detection; compared with SVM, PSO-SVM and ACO-SVM algorithms, the performance of the IWAO-SVM algorithm was better, the detection rate was 99.89%, the precision ratio was 99.92%, the accuracy rate was 99.86%, and the detection time was 192 s, showing that it had high precision in intrusion detection. The experimental results verify the reliability of the IWAO-SVM algorithm, and it can be promoted and applied in the detection of network intrusion prevention.
Full Text:PDF
References
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Deng S, Zhou A, Yue D, Hu B, Zhu L (2017). Distributed intrusion detection based on hybrid gene expression programming and cloud computing in cyber physical power system. IET Control Theory and Applications, 11(11), pp. 1822-1829.
Chahal JK, Kaur A (2016). A Hybrid Approach based on Classification and Clustering for Intrusion Detection System. International Journal of Mathematical Sciences & Computing, 2(4), pp. 34- 40.
Modinat M, Abimbola A, Abdullateef B, Opeyemi A (2015). Gain Ratio and Decision Tree Classifier for Intrusion Detection. International Journal of Computer Applications, 126(1), pp. 975-8887.
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DOI: https://doi.org/10.31449/inf.v44i2.3195
This work is licensed under a Creative Commons Attribution 3.0 License.
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https://www.informatica.si/index.php/informatica/article/view/3195
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This paper proposes decentralized algorithms that achieve competitive performance, along with near-optimal guarantees on the incurred group regret, and presents an improved delayed-update algorithm that outperforms the existing state-of-the-art on various network topologies.
References
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Decentralized Cooperative Stochastic Bandits
- Computer ScienceNeurIPS
- 2019
A fully decentralized algorithm that uses an accelerated consensus procedure to compute (delayed) estimates of the average of rewards obtained by all the agents for each arm, and then uses an upper confidence bound (UCB) algorithm that accounts for the delay and error of the estimates.
Heterogeneous Stochastic Interactions for Multiple Agents in a Multi-armed Bandit Problem
- Computer Science, Mathematics2019 18th European Control Conference (ECC)
- 2019
An algorithm is designed for each agent to maximize its own expected cumulative reward and performance bounds that depend on the sociability of the agents and the network structure are proved.
A Dynamic Observation Strategy for Multi-agent Multi-armed Bandit Problem
- Mathematics, Computer Science2020 European Control Conference (ECC)
- 2020
A sampling algorithm and an observation protocol for each agent to maximize its own expected cumulative reward through minimizing expected cumulative sampling regret and expected cumulative observation regret is designed.
Social Imitation in Cooperative Multiarmed Bandits: Partition-Based Algorithms with Strictly Local Information
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A novel policy based on partitions of the communication graph is developed and a distributed method for selecting an arbitrary number of leaders and partitions is proposed and evaluated using Monte-Carlo simulations.
Coordinated Versus Decentralized Exploration In Multi-Agent Multi-Armed Bandits
- Computer ScienceIJCAI
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An algorithm for the decentralized setting that uses a value-ofinformation based communication strategy and an exploration-exploitation strategy based on the centralized algorithm is introduced, and it is shown experimentally that it converges rapidly to the performance of the centralized method.
Collaborative learning of stochastic bandits over a social network
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A key finding of this paper is that natural extensions of widely-studied single agent learning policies to the network setting need not perform well in terms of regret.
Optimal Algorithms for Multiplayer Multi-Armed Bandits
- Computer ScienceAISTATS
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DPE1 (Decentralized Parsimonious Exploration), a decentralized algorithm that achieves the same asymptotic regret as that obtained by an optimal centralized algorithm for Multiplayer Multi-Armed Bandit.
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A generic algorithm Decentralized Elimination is provided, which uses any best arm identification algorithm as a subroutine, and it is proved that this algorithm insures privacy, with a low communication cost, and that in comparison to the lower bound of thebest arm identification problem, its sample complexity suffers from a penalty depending on the inverse of the probability of the most frequent players.
Asymptotically efficient allocation rules for the multiarmed bandit problem with multiple plays-Part II: Markovian rewards
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At each instant of time we are required to sample a fixed number m \geq 1 out of N i.i.d, processes whose distributions belong to a family suitably parameterized by a real number \theta . The…
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This work shows that there exist differentially private variants of Upper Confidence Bound algorithms which have optimal regret, and substantially improves the bounds of previous family of algorithms which use a continual release mechanism.
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https://www.semanticscholar.org/paper/Distributed-Bandits%3A-Probabilistic-Communication-on-Madhushani-Leonard/03a9ee260ed3225485ca24326867f3be7720d1e7
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Lowton, Andrew D. (1995). A constructive learning algorithm based on back-propagation. PHD thesis, Aston University.
Abstract
There are been a resurgence of interest in the neural networks field in recent years, provoked in part by the discovery of the properties of multi-layer networks. This interest has in turn raised questions about the possibility of making neural network behaviour more adaptive by automating some of the processes involved. Prior to these particular questions, the process of determining the parameters and network architecture required to solve a given problem had been a time consuming activity. A number of researchers have attempted to address these issues by automating these processes, concentrating in particular on the dynamic selection of an appropriate network architecture.The work presented here specifically explores the area of automatic architecture selection; it focuses upon the design and implementation of a dynamic algorithm based on the Back-Propagation learning algorithm. The algorithm constructs a single hidden layer as the learning process proceeds using individual pattern error as the basis of unit insertion. This algorithm is applied to several problems of differing type and complexity and is found to produce near minimal architectures that are shown to have a high level of generalisation ability.
|Divisions:||College of Engineering & Physical Sciences > School of Informatics and Digital Engineering > Computer Science|
|Additional Information:||Department: Computer Science If you have discovered material in AURA which is unlawful e.g. breaches copyright, (either yours or that of a third party) or any other law, including but not limited to those relating to patent, trademark, confidentiality, data protection, obscenity, defamation, libel, then please read our Takedown Policy and contact the service immediately.|
|Institution:||Aston University|
|Uncontrolled Keywords:||constructive learning algorithm,back-propagation,neural networks,dynamic learning algorithm,generalisation|
|Completed Date:||1995|
|Authors:||
Lowton, Andrew D.
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https://publications.aston.ac.uk/id/eprint/10663/
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MCQ ON GAMETOGENESIS class 12 for NEET | GAMETOGENESIS class 12 | MCQ THE GAMETOGENESIS with Answer | Check the below NCERT MCQ question for class 12 Biology chapter 03 based on the with Answers.
MCQ on GAMETOGENESIS class 12 Biology with answers were prepared based on the latest pattern.We have provided class 12 Biology MCQs questions on GAMETOGENESIS with Answers to help students understand the concept very well.
MCQ ON GAMETOGENESIS is useful for NEET / CSIR / UGC / CBSE / ICSE / AIIMS / EXAM / AFMC EXAM / STATE LEVEL MEDICAL EXAM 2022-23, 2023-24
Introduction:-
Mammals are unisexual . The reproductive system of each sex consists of many organs .There is a distinct sexual dimorphism. Males visibly differ from females in physical standards, external genital organs and accessory sex characters. All you are aware , humans are sexually reproducing and viviparous. Repriductive events occur after puberty.
The female reproductive system consists of a pair of ovaries along with a pair of oviducts , uterus, cervix, vagina and the external genitalia located in the pelvic region.
MCQ ON GAMETOGENESIS class 11 for NEET
1. The primary sex organs- the testis in the males produce gametes
(a) sperms
(b) ovums
(c) germ cell
(d) immature male cells
Ans (a) sperms
2. The sex organs the ovaries in the female produce gametes
(a) sperms
(b) ovums
(c) ligament
(d) mammary lobes
Ans. (b) ovums
3. In testes, the immature male germ cells produce sperms by ……………..that begins at puberty.
(a) spermatogonia
(b) spermatogenesis
(c) primary spermatocytes
(d) secondary spermatocytes
Ans. (b) spermatogenesis
4. Each spermatogonium is
(a) haploid
(b) diploid
(c) triploid
(d) tetraploids
Ans.(b) diploid
5. Each spermatogonium contains ……. chromosomes
(a) 23
(b) 46
(c) 44
(d) 22
Ans.(b) 46
6. Each secondary spermatocytes contains only ……… chromosomes
(a) 46
(b) 23
(c) 22
(d) 24
Ans.(b) 23
7. The secondary spermatocytes undergo the second meiotic division to produce four equal , haploid
(a) spermatids
(b) spermatocytes
(c) vaginal
(d) sertoli cells
Ans.(a) spermatids
8. The The spermatids are transformed into spermatozoa (sperms) by the process called
(a) spermatocytes
(b) spermatogenesis
(c) spermiogenesis
(d) sertoli cells
Ans.(c) spermiogenesis
9. After spermiogenesis , sperm heads become embedded in the sertoli cells and are finally released from the seminiferous tubules by the process called
(a) spermiation
(b) infundibulum
(c) external genitalia
(d) spermiogenesis
Ans. (a) spermiation
10. The hormone acts at the Leydig cells and stimulates synthesis and secretion of androgens.
(a) FSH
(b) LH
(c) GnRH
(d) TH
Ans. (b) LH
11.The whole body of plasma membrane is covered by
(a) acrosome
(b) plasma membrane
(c) semen
(d) rete testis
Ans.(b) plasma membrane
12. The sperm head contains an elongated ……nucleus
(a) diploid
(b) haploid
(c) triploid
(d) all the above
Ans . (b) haploid
13.The anterior portion of head is covered by a cap- like structure
(a) ovum
(b) acrosome
(c) nucleus
(d) all of these
Ans.(b) acrosome
15. The middle piece possess numerous ……..,which produce energy for the movement of tail that facilitate sperm motility essential for fertilization.
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https://biologysir.com/mcq-on-gametogenesis-class-12-for-neet/
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Difference between Meiosis in Males and Females
Key Difference: Meiosis in males and females differ greatly in context to aspects like timing and continuity of events. The process in males and females also differ especially in terms of the actual gamete produced. Meiosis in males starts after puberty and continues throughput life. On the other hand, in females, the process begins nearly at the 12th week of fetal life and it does not resume until puberty.
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Meiosis is the specialized process through which division of cells takes place in order to form gametes. This process includes a single round of DNA replication which is followed by two rounds of cell division. The chromosome number is reduces to half during this process. It takes place in the germ line, testes and ovaries in mammals. This meiotic process is quite different from each other in context to mammal’s sexes; males and females.
Human male meiosis is termed as spermatogenesis, whereas female meiosis in female is termed as female oogenesis. In human males, it takes place in the seminiferous tubules of the testicles, whereas, it occurs in oogonia in females. The process takes place in two steps – Meiosis I and Meiosis II. Meiosis I is the process in which gametes split into two and are reduced into the two. Then crossing over of few of the chromosomes takes place which are taken from each of the parent. Finally, the chromosomes are equally distributed in these two halves. This process is called reductional division due the reduction of chromosome number into half the original number.
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In Meiosis II, internal splitting of the daughter cells takes place and results into four daughter cells with .This process is identical to mitotic division. The four haploid cells contain a single copy of each chromosome.
In males, this process occurs at puberty, whereas in females it is initialed in fetal development. In mammals, these four haploid spermatids are of similar size and are derived from each spermatogonium, whereas in females the cytoplasmic divisions are very asymmetric. The female line reduces to one enlarged haploid cell as other haploids are not able to survive. On the other hand, male line reduces to an equal number of haploid cells.
Another difference is in the terms of size of full grown ooctyes in ovary which are much larger then sperms. Eggs are non-motile and round in shape. They have yolk for nourishing the developing embryos. On the other hand, sperm are made up of a head, tail and middle-part, and they are motile.
In females, the process of completion of meiosis is delayed for months or years, on the other hand, meiosis in males is completed in days or weeks. Unlike Spermatogenesis, Oogenesis is not a continuous process throughout the life of an organism. In females, the process starts in utero where oogonia enter meiosis but are not able to enter Prophase I until ovulation. The oogonia enter the process of meiosis again before their release, and then get arrested in metaphase II. It gets completed in females only when the egg is fertilized.
Thus, there are many differences between meiosis in males and females. However, the main difference between the two is that the process of meiosis produces sperms in males and ova in females.
Comparison between Meiosis in Males and Females:
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Meiosis in Males
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Meiosis in Females
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Definition
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It is a continuous process which starts from puberty and remains throughout life. The process results into production of millions of spermatozoa daily.
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This process may take over 40 years from start to finish. Only a few oocytes reaches upto the final stages, as most of them are lost before birth.
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http://www.differencebetween.info/difference-between-meiosis-in-males-and-females
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CIB1 is a 22-kDa calcium binding, regulatory protein with ∼50% homology to calmodulin and calcineurin B. CIB1 is widely expressed and binds to a number of effectors, such as integrin αIIb, PAK1, and polo-like kinases, in different tissues. However, the in vivo functions of CIB1 are not well understood. To elucidate the function of CIB1 in whole animals, we used homologous recombination in embryonic stem cells to generate Cib1−/− mice. Although Cib1−/− mice grow normally, the males are sterile due to disruption of the haploid phase of spermatogenesis. This is associated with reduced testis size and numbers of germ cells in seminiferous tubules, increased germ cell apoptosis, and the loss of elongated spermatids and sperm. Cib1−/− testes also show increased mRNA and protein expression of the cell cycle regulator Cdc2/Cdk1. In addition, mouse embryonic fibroblasts (MEFs) derived from Cib1−/− mice exhibit a much slower growth rate compared to Cib1+/+ MEFs, suggesting that CIB1 regulates the cell cycle, differentiation of spermatogenic germ cells, and/or differentiation of supporting Sertoli cells.
Spermatogenesis is the long, complex process by which germ cells are produced through successive periods of regulated cell proliferation, meiosis, and haploid differentiation (6, 19). During spermatogenesis in the mammalian testis, stem cells proliferate to produce spermatogonia, which differentiate into primary spermatocytes. Following a prolonged meiotic prophase, the spermatocytes undergo two consecutive meiotic divisions to generate haploid spermatids. Spermatids then undergo marked morphological changes from an initially round to a progressively elongated shape with condensed nuclei, eventually forming sperm (4, 19). Mouse spermatogenesis has been well defined morphologically and is divided into 12 stages (29). The orderly progression of germ cells from spermatogonia to sperm requires the support of testis somatic cells such as Sertoli and Leydig cells (37). Sertoli cells provide structural support, create an immunological barrier, participate in germ cell movement, and nourish germ cells via secretary products (24). Although genes expressed only in the testis such as Gapdhs (glyceraldehyde 3-phosphate dehydrogenase-S) (22) and genes that are more widely expressed such as Cdk2 (cyclin-dependent kinase 2) (32) have been implicated in spermatogenesis, the regulation of this process is not fully understood due to the complex involvement and regulation of multiple gene products (21, 46). Interestingly, several genes not previously implicated in spermatogenesis were found to be essential for male mouse reproduction when specific knockout mice were generated, including Ppp1cc, which encodes the protein phosphatase 1cγ subunit (PP1cγ) (41), and NKcc2, which encodes Na+-K+-2Cl− cotransporter (34). Here, we describe another gene, Cib1, which is essential for male mouse fertility.
CIB1 was first identified as a calcium and integrin binding protein (27). It contains four EF hand motifs, two of which bind calcium (8). We previously found that CIB1 binds to the αIIb subunit of integrin αIIbβ3 and inhibits agonist-induced αIIbβ3 activation in megakaryocytes, potentially via interference with the association of talin to the integrin (48). CIB1 is widely distributed and binds to a number of potential effectors, such as the small GTPase Rac3 (11), and several serine/threonine kinases, such as the polo-like kinases Plk2 and Plk3 (12), PAK1 (p21-activated kinase) (14), and FAK (focal adhesion kinase) (26). We previously showed that CIB1 directly activates PAK1, which results in decreased cell migration via a LIM kinase- and cofilin-dependent pathway (14). Moreover, sequence analysis indicates that CIB1 may be the founding member of a distinct subfamily of EF hand-containing proteins (8). However, the role of CIB1 in vivo has never been addressed. Therefore, we generated Cib1 null mice via homologous recombination in embryonic stem (ES) cells and found that CIB1 is essential for mouse spermatogenesis.
MATERIALS AND METHODS
Generation of Cib1-deficient mice. Cib1 genomic DNA consists of seven exons and six introns and is ∼5 kb in length. A 550-bp fragment of Cib1 genomic DNA, including complete exon 4 and the majority of exon 5, was replaced with a reversed neo gene in the Cib1 knockout construct at the indicated restriction enzyme sites (Fig. 1A). The correct targeting was verified by both PCR and Southern blot analysis in the 129S6/SvEv ES cell line. The targeted cell lines were injected into C57BL/6 blastocysts, resulting in birth of chimeric mice. PCR and Southern blot analysis verified Cib1 targeting in the offspring of F1 and F2 mice (Fig. 1B). Western blotting with a chicken polyclonal antibody against CIB1 verified a lack of CIB1 protein expression in Cib1−/− mice (Fig. 1C). The housing and breeding of mice and all experiments performed with mice are in accordance with national guidelines and regulations and were approved by the University of North Carolina Institutional Animal Care and Use Committee. The mice were analyzed during the process of backcrossing the 129S6/SvEv strain onto a C57BL/6 background (three to seven generations). The protein and mRNA samples from mice of different genotypes were compared among littermates.
Generation and characterization of mouse embryonic fibroblasts (MEFs).MEFs (passage 0 [P0] cells) were generated from mouse embryos of 13.5 to 14.5 days postcoitum, resulting from the interbreeding of heterozygous Cib1+/− mice that had been backcrossed seven times (F7 generation) on a C57BL/6 background according to Ferguson et al. (7). MEFs were maintained in Dulbecco's modified Eagle medium supplemented with 10% fetal bovine serum, and P1 cells were frozen for subsequent use. MEF lysates were prepared for Western blotting as described below. For determination of MEF growth rate, passage 2, 4, and 6 MEFs from Cib1−/−, Cib1+/+, and Cib1+/− mice were plated at 0.2 × 105 cells/well in duplicate (day 0). Cells were then harvested, and the cell number was counted at the indicated days. For immunostaining, MEFs were cultured on coverslips, fixed with 3.7% paraformaldehyde, and stained with AlexaFluor488 phalloidin (Molecular Probes) and counterstained with 4′,6-diamidino-2-phenylindole (DAPI; Molecular Probes). Images were collected using a laser-scanning confocal imaging system (Fluoview 1000; Olympus) that was configured with an Olympus model IX81 fluorescence microscope fitted with a 40× objective. Images were processed using Adobe Photoshop.
Histological and TUNEL studies of Cib1−/− mouse testis sections.Mouse testes at various stages were collected and fixed for 24 h in 4% paraformaldehyde, 4% paraformaldehyde, 4% acetic acid or Bouin's solution. Testis sections were stained with hematoxylin and eosin (HE) and/or periodic acid-Schiff's reagent (PAS), and digital images were acquired with either a Nikon Eclipse TE300 microscope equipped with a Nikon D100 camera or an Olympus BH2 microscope equipped with a Spot RT Slider camera (Diagnostic Instruments, Sterling Heights, MD). To detect apoptotic cells in the adult mouse testis sections, the fluorometric terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) assay kit (Promega) was used according to the manufacturer's guidelines. The fluorometric images were acquired via the Nikon Eclipse TE300 microscope with an attached CoolSnap Photometrics HQ camera from Media Cybernetics with Image-Pro Plus 5.0 software.
RT-PCR.Total mRNA from adult, postnatal day 17, and 25-day-old Cib1+/+ and Cib1−/− mouse testes were extracted with a QIAGEN RNAeasy kit and then quantified and diluted to equivalent concentrations. One-step reverse transcription-PCR (RT-PCR) was used to amplify all the specific messages (QIAGEN). Primers for each gene were synthesized to generate DNA fragments of about 250 bp in length. To avoid possible human error, all primers were first diluted to the same concentration, and the two primers of a particular gene were then mixed. A master mix was initially made for a particular mRNA sample, including every component of the RT-PCR except the primers. An equal amount of the mix was then transferred to the PCR tubes, and equal amounts of excess primer mix were added to each reaction. The RT-PCR cycle numbers for individual genes were first tested to ensure that the PCR cycle number was in a linear amplification range. We found very consistent RT-PCR results in these experiments. The figures shown are representative of at least three independent testis samples for the same genotype and age.
Lysates preparation, Western blotting, and antibodies.All tissue and cell samples (i.e., testis tissue, purified testis cells, sperm, or MEFs) were lysed in modified 3-[(3-cholamidopropyl)-dimethylammonio]-1-propanesulfonate (CHAPS) buffer (20 mM HEPES, pH 7.4, 0.15 M NaCl, 10 mM CHAPS, 50 mM NaF, 1 mM NaVO3, 10 mM sodium pyrophosphate, 1 mM each of CaCl2 and MgCl2, and Protease Inhibitors Cocktail Set III [Calbiochem]) on ice for 30 min, and lysates were collected after centrifugation. To obtain whole-testis lysates, testes were homogenized with CHAPS lysis buffer. To obtain mixed-testis-cell lysates, the tunica albuginea was removed and the seminiferous tubules were released into, and rinsed in, phosphate-buffered saline. The tubules were then torn with forceps in RPMI 1640 media, and a mixture of cells released from tubules was filtered through a 100-μm mesh (Sigma) and collected and lysed in CHAPS buffer for blotting. Purified spermatogenic cells were isolated from CD1 mice by unit gravity sedimentation as described previously (30). Fractions were assessed for morphology and purity by light microscopy. Sertoli cells were isolated from 17-day-old mice and were then cultured for 1 week (31) before being lysed for Western analysis. The amount of protein was quantified by the bicinchoninic acid protein assay, and protein samples were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The proteins were then transferred to a polyvinylidene difluoride membrane and subjected to Western blotting. A CIB1 chicken polyclonal antibody was used to detect mouse CIB1. Antibodies against PP1cγ, PP2A, and α-tubulin were all from Santa Cruz Biotechnology. The anti-Cdc2 antibodies were from Santa Cruz Biotechnology and Calbiochem. Rabbit anti-phospho-Cdc2 (Tyr15) was from Cell Signaling. The Cdc2 expression levels in isolated testis cells of Cib1−/− and Cib1+/+ testes were quantified via densitometry with Quantity One software (Fluor-S Multimager; Bio-Rad) and adjusted with α-tubulin as a loading control (n = 4).
RESULTS
Male Cib1−/− mice are sterile.We used homologous recombination in embryonic stem cells to generate mice lacking Cib1 by deleting exon 4 and most of exon 5, which code for the third EF hand (calcium binding motif) (8) (Fig. 1A). Southern and Western blots (Fig. 1B and C) confirm that the Cib1 gene is disrupted and that these mice do not express CIB1 protein. Cib1−/− mice were born at the expected Mendelian ratios from the interbreeding of F1 heterozygous Cib1+/− mice. F2 null offspring grow normally and are macroscopically indistinguishable from their wild-type (Cib1+/+) siblings from birth to adulthood. However, we found that male Cib1−/− mice fail to reproduce despite normal mating behavior, as observed by formation of copulatory plugs (n = 10). Although Cib1 mRNA has been reported in the testis (45) and a microarray study indicated that Cib1 mRNA may be expressed in both somatic and germ cells throughout spermatogenesis (38), CIB1 has not been implicated in spermatogenesis. We therefore examined CIB1 protein expression in sperm and in different cell types isolated from Cib1+/+ mouse testes. We confirmed that CIB1 protein is present in sperm of Cib1+/+ mice (Fig. 1C, lower panel). We also found that isolated and cultured Sertoli cells express significantly more CIB1 than isolated pachytene spermatocytes, round spermatids, or condensing spermatids (Fig. 1D). The high levels of CIB1 in Sertoli cells may implicate a role of CIB1 in Sertoli cells to support spermatogenesis.
We also found that the average weight of the testis from adult Cib1−/− male mice (3 to 4 months) is ∼47.5% that of Cib1+/+ and Cib1+/− males (n = 6; P < 0.009). The weight of the Cib1−/− testis peaks at 40 days and then gradually declines, while the weight of the Cib1+/+ and Cib1+/− testis continues to increase until 60 days of age (Fig. 1E). Sperm production is undetectable upon dissection and analysis of the epididymis (n = 6) from Cib1−/− males. In contrast, male Cib1+/− and female Cib1−/− mice exhibited no obvious impairment of growth, development, or reproductive performance (data not shown). Since testosterone produced by Leydig cells is essential for male fertility and for maintenance of androgen-dependent tissues, such as the seminal vesicles (35), we measured seminal vesicle weights in adult males but found no difference between Cib1+/+, Cib1+/−, and Cib1−/− mice (3 to 4 month age; n = 6; P > 0.6; Fig. 1F). This suggests that Leydig cell function is normal in Cib1−/− males and is unlikely to contribute to the observed phenotype. Our combined results indicate that CIB1 is essential for male fertility in mice and suggest a defect in spermatogenesis per se and/or in Sertoli cells that support germ cell differentiation.
Cib1 −/− mouse embryo fibroblasts proliferate at a decreased rate.Precise cell cycle regulation and proliferation are integral for the progression of normal spermatogenesis. To better understand the potential role of CIB1 in cell cycle regulation and cell proliferation, we generated mouse embryo fibroblasts (MEFs) from embryos (13.5 to 14.5 days postcoitum) resulting from the interbreeding of heterozygous Cib1+/− mice (F7). Growth rates of Cib1+/+, Cib1+/−, and Cib1−/− MEFs were analyzed at various passages during an 8-day period. At passage 2 (P2), two separate Cib1−/− MEF cell lines proliferated at a slower rate than Cib1+/+ MEFs (Fig. 2A). At P4, Cib1−/− MEFs continued to proliferate more slowly, and by P6, Cib1−/− MEFs showed a significant delay in the rate of proliferation compared to Cib1+/+ MEFs. However, we found that early-passage Cib1−/− MEFs were morphologically indistinguishable from Cib1+/+ MEFs (Fig. 2B, P4). These data suggest that CIB1 may affect spermatogenesis by regulating cell cycle progression in germ cells and/or Sertoli cells.
Defective spermiogenesis with spermatocyte and spermatid apoptosis.Subsequent histological analysis of testes from adult mice showed profound defects in the testes of adult male Cib1−/− versus Cib1+/+ mice. Spermatogonia (black arrow heads) and primary spermatocytes (white arrow heads) appear normal in Cib1−/− testis (Fig. 3B and D) compared to Cib1+/+ testis (Fig. 3A and C). However, the layers of germ cells in the seminiferous tubules appear less organized. More importantly, postmeiotic spermatids were reduced in number in Cib1−/− seminiferous tubules (Fig. 3D), particularly in the later stage spermatids (steps 9 to 16), which are characterized by progressive elongation and condensation of the nucleus (the white arrow in Fig. 3C denotes elongated spermatids in the Cib1+/+ testis). Large, multinucleated cells (Fig. 3B and D, black arrow) containing numerous condensing spermatid nuclei were frequently observed in or near the seminiferous tubule lumen in Cib1−/− testis. In addition, there were large areas containing PAS-positive, secretory material in some seminiferous tubule cross-sections (Fig. 3B and D, black broken arrow), suggesting that Sertoli secretory processes may be altered in Cib1−/− mice. Examination of the cauda epididymis verified that sperm was absent in Cib1−/− mice (Fig. 3F), with only secretory products and dead cell bodies present, compared to abundant sperm seen in the epididymal lumen of Cib1+/+ mice (Fig. 3E, black arrow, dark blue-stained sperm head). To determine if spermatogenic cells in Cib1−/− mice undergo active apoptosis, we used a TUNEL assay to examine cross-sections of the adult testis. We observed a dramatic increase in apoptotic germ cells across the seminiferous epithelium in Cib1−/− versus Cib1+/+ mice (Fig. 3G and H). Interestingly, the multinucleated cells were generally TUNEL negative (data not shown). The increased apoptosis in Cib1−/− testis may reflect a response to defects in germ cell differentiation and/or a Sertoli cell defect similar to other reports of impaired spermatogenesis in knockout mice (15, 20, 40).
Spermatogenesis in mice begins in the neonatal period and progresses with defined kinetics, resulting in the appearance of successively more differentiated germ cells in the testis at defined intervals during prepubertal development (2). In 8-day-old mice, only spermatogonia and Sertoli cells are present in the seminiferous tubules. Meiosis begins by postnatal day 10, and round spermatids begin to appear by day 18 after completing two meiotic divisions. Spermatids require 14 additional days to complete spermatogenesis, at which time sperm are released from the seminiferous epithelium and transported to the epididymis. Sertoli cells stop dividing by approximately day 17 (44), establishing the number of Sertoli cells that remains constant throughout adult life (43). This number is critical for maintaining normal sperm production (33). With these kinetics in mind, we examined testis histology at postnatal days 20 and 25 to assess the appearance of spermatogenic defects in Cib1−/− mice. We found that the overall structure of the testis in 20-day-old mice was similar in Cib1−/− (Fig. 3J) and Cib1+/+ males (Fig. 3I), including the appearance of round spermatids in both genotypes (black star). The presence of round spermatids in Cib1−/− mice suggests that the defect develops after meiosis. By postnatal day 25, there are already several multinucleated spermatids (black asterisks) forming in the Cib1−/− testis (Fig. 3L) compared to the Cib1+/+ testis (Fig. 3K). The histology of testes from the Cib1+/− mice appeared normal compared to Cib1+/+ mice (data not shown). Our combined histological data indicate that the absence of CIB1 protein disrupts spermatogenesis during the late haploid period of germ cell differentiation. This defect may reflect a dysfunction of Sertoli cells that prevents them from nurturing the spermatids and/or defects in developing spermatogenic cells.
Cdc2 is overexpressed in Cib1−/− mice.The possible regulatory roles of CIB1 in spermatogenesis were tested first by determining which gene expression patterns were altered in the Cib1−/− testis via RT-PCR. We initially examined the expression of stage-specific marker genes that appear during meiosis, i.e., Hsp70-2 (heat shock protein, chaperone) and Sprm-1 (POU homeodomain domain [5, 15, 25, 36]) but found comparable mRNA expression levels in Cib1+/+ and Cib1−/− testis samples (Fig. 4A). Moreover, the expression patterns of all postmeiotic genes examined, such as Tp1 (transition protein 1), Tp2 (transition protein 2), Prm2 (protamine 2), Gapdhs (glyceraldehyde 3-phosphate dehydrogenase-S, testis specific), Trf2 (TBP-related factor 2), and Crem (cyclic AMP-responsive element modulator) were comparable in Cib1+/+ and Cib1−/− mice (Fig. 4A; Tp1 and Gapdhs are not shown) (1, 41, 47, 49). This is in sharp contrast to Crem knockout or mutant mice and Trf2 knockout mice, which have marked defects during the round spermatid stages and altered expression of the aforementioned genes (3, 20, 28, 41, 49). Our findings therefore indicate that the spermiogenesis defect in Cib1−/− mice is unlikely to involve changes in Crem and Trf2 transcriptional regulation.
In contrast to the mRNAs examined above, we found that mRNA and protein expression levels of the cell cycle regulator Cdc2/Cdk1 are elevated in adult Cib1−/− testis relative to Cib1+/+ testis (Fig. 4A and B). However, no consistent changes in the kinase activity of Cdc2 were observed in Cib1−/− mouse whole-testis lysates and isolated testis cell lysates (mainly germ cells and Sertoli cells) relative to Cib1+/+ mice (data not shown). When we extended our expression analysis to juvenile mice, we found that Cdc2 mRNA was also up-regulated in the testes of Cib1−/− mice at days 17 and 30 (Fig. 4A) and that Cdc2 protein was elevated as early as day 8 (Fig. 4C). Since we observed an increase in Cdc2 protein in whole-testis lysates, we asked whether Cdc2 levels in isolated testis germ cells and supporting Sertoli cells were also increased. We confirmed that Cdc2 was overexpressed in cells isolated from testis tubules of 40- and 60-day-old Cib1−/− mice (1.6- and 3.6-fold, respectively; n = 4) compared to Cib1+/+ mice (Fig. 4D). To determine whether Cdc2 overexpression was unique to the testis or a general phenomenon of Cib1−/− mice, we examined Cdc2 protein levels in MEFs and spleen (passage 4, before crisis) but found Cdc2 levels to be unaltered relative to those of Cib1+/+ (Fig. 4E and data not shown). We also observed that levels of PP1cγ protein, but not mRNA expression levels, were lower in adult Cib1−/− testis versus Cib1+/+ testis (Fig. 4B). However, PP1cc mRNA and corresponding PP1cγ protein levels were not altered in juvenile Cib1−/− testis (Fig. 4A and data not shown).
DISCUSSION
Through targeted inactivation, we have demonstrated that CIB1 is essential for spermatogenesis. Although overall growth and health seemed normal in Cib1−/− mice and spermatogenic cells can complete both mitotic and meiotic divisions, postmeiotic spermatids do not develop normally and sperm are not produced. We hypothesize that alterations in Sertoli cell function contribute to these defects, since CIB1 protein levels are higher in cultured Sertoli than in isolated pachytene spermatocytes or spermatids. Additional cell cycle defects in either germ cells or Sertoli cells, as well as specific defects in the haploid period of spermatogenesis, may also contribute to the observed infertility phenotype. Interestingly, we did not observe female fertility defects and attribute this to differences between the processes of spermatogenesis and oogenesis, as noted with several other knockout mice exhibiting male-specific phenotypes (1, 15, 20).
We observed slower growth and division of Cib1−/− MEFs before (P2 and P4) and at crisis (P6) (Fig. 2A) in the absence of overall differences in growth and weight between Cib1−/− and Cib1+/+ mice (data not shown). This result is intriguing, since CIB1 has not been previously implicated in regulating cell growth and division. Although it is apparent that CIB1 function is not essential for somatic cell growth and division, CIB1 may facilitate the regulation of cell growth and division. CIB1 binds to cell cycle-regulatory proteins such as PLK2, PLK3, and DNA-PK (12, 13, 17, 18), and thus loss of CIB1 may lead to a delay of cell growth through one or more of these proteins.
During mouse postnatal testis development, meiosis II in males first occurs around 18 days of age, and the first set of elongated spermatids do not appear until 25 to 30 days (25, 41, 49). Analysis of gene and protein expression of testis samples at different developmental stages helped us to determine where and how defects occur during Cib1−/− testis development. We found that Cdc2 protein is significantly increased in the testis before spermatids appear, whereas postmeiotic genes such as Crem and Trf2 are expressed comparably in Cib1−/− and Cib1+/+ mice. The increase in Cdc2 protein expression in Cib1−/− mice may reflect a compensatory increase that is directly related to the loss of CIB1 or a noncausal increase that is an indirect consequence of testicular defects in these mice. Thus, it is possible that CIB1 participates in the Cdc2 signaling pathway (or vice versa) and that loss of CIB1 affects the cell cycle in germ and/or Sertoli cells.
Interestingly, we observed increases in Cdc2 expression in testis as early as days 8 and 17 (Fig. 4C). Only spermatogonia and Sertoli cells are present in seminiferous tubules at day 8, and spermatogenesis progresses to the pachytene stage of meiotic prophase by day 17 (26). Since Sertoli cells represent a larger proportion of testicular cells during this juvenile period than in the adult, the observed increase in Cdc2 in the Cib1−/− testis may reflect altered expression in Sertoli cells. Such changes in the expression of Cdc2 or other cell cycle regulators could disrupt the normal interval of Sertoli cell proliferation, causing an imbalance between the number of Sertoli cells and developing germ cells (30), which can lead to increased germ cell apoptosis and defective spermatogenesis (40).
Another possibility is that loss of CIB1 leads to defects in Sertoli cell differentiation and function that are required for the maintenance of spermatogenesis. Sertoli cells secrete a variety of endocrine and paracrine factors that regulate spermatogenesis (10). In addition, they assemble and disassemble various junctions that compartmentalize the seminiferous epithelium and ensure the progressive movement of germ cells and the proper release of sperm to the lumen (16). Apical ectoplasmic specializations, which are adhesive junctions between Sertoli cells and condensing spermatids (42), may be particularly important in relation to the formation of the multinucleated spermatids seen in Cib1−/− testes. Thus, loss of CIB1 in Sertoli cells could alter junctional complexes or the microenvironment that regulates germ cell differentiation, resulting in increased germ cell apoptosis and male infertility (16, 23, 24).
The loss of CIB1 may also have direct effects on spermatogenic cells. CIB1 protein levels remain stable throughout testis development to adulthood in Cib1+/+ mice (Fig. 4C and data not shown), probably reflecting the accumulation of spermatids concomitant with a marked reduction in the proportion of Sertoli cells. Although our CIB1 antibody was not suitable for immunohistochemistry, we detected CIB1 by Western blotting in isolated round and condensing spermatids, suggesting that CIB1 may play a role in these cell types. Cdc2 has been implicated in apoptosis, although it is not universally required for apoptosis (9), and indeed we observed an increase in germ cell apoptosis in the seminiferous tubules of Cib1−/− mice. It will be interesting to determine if there is any causal relationship between increased Cdc2 and increased apoptosis in testis cells in our mouse model.
In our initial screen, we also found that PP1cγ protein is reduced in adult Cib1−/− testis (Fig. 4B). Interestingly, Ppp1cγ−/− mice show a phenotype similar to that of Cib1−/− mice (41). In addition to severe impairment of spermiogenesis beginning at the round-spermatid stage in Ppp1cγ−/− males, defects in meiosis were inferred from the presence of polyploid spermatids (42). Further studies are needed to determine if reduced levels of PP1cγ contribute to the testicular defects observed in Cib1−/− mice.
Since the initial identification of CIB1, new CIB1-interacting proteins are continually being reported. It is now clear that CIB1 is often associated with a variety of serine/threonine kinases (12, 14, 26) as well as with other molecules, such as integrin αIIb and presenilin 2 (27, 39). Therefore, CIB1 may regulate spermatogenesis via multiple kinases (identified or yet to be identified) or another mechanism(s). In initial experiments, we did not observe coimmunoprecipitation of CIB1 and Cdc2, nor did we observe altered Cdc2 kinase activity (data not shown). This may indicate that these proteins do not interact, interact very transiently, or do not act in the same signaling pathway. It should be noted that the spermatogenesis defect we observed in Cib1−/− mice could be a combined effect of CIB1-interacting proteins. We are currently investigating the potential binding partner(s) of CIB1 in order to further determine the mechanism by which CIB1 regulates spermatogenesis. Our findings here suggest that CIB1 null mice may provide a useful research model for understanding human male idiopathic infertility and thus fertility drug targets (4, 6).
ACKNOWLEDGMENTS
We thank Scott Howell for initial cloning of mouse genomic DNA fragments containing Cib1, Annette Staton for ES cell culture, Soumya Vemuganti for Western blots of isolated testicular cells, Patricia Magyar for histology studies, and the UNC animal model core laboratory for help in generating the Cib1 null mouse.
This study was supported by NIH training grant F32 HL10381 to W.Y., HL42630 to N.M., and NICHD/NIH cooperative agreement U54-HD35041 as part of the Specialized Cooperative Centers Program in Reproduction Research to D.A.O. and 2-P01-HL45100 and 2-P01-HL06350 to L.V.P.
FOOTNOTES
- Received 10 August 2006.
- Accepted 31 August 2006.
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https://mcb.asm.org/content/26/22/8507
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May present with features of testosterone deficiency and/or infertility.
When caused by pituitary macro-adenoma, patients may have additional symptoms due to mass effects, such as headaches or peripheral visual disturbance. There may also be signs and symptoms of other pituitary hormone deficiencies.
Early morning serum total testosterone level below 10.4 nanomol/L (<300 nanograms/dL) on at least two separate occasions in a symptomatic man generally confers the diagnosis of hypogonadism.
Testosterone should be measured in all men with erectile dysfunction.
Measurement of the gonadotrophins (LH and FSH) distinguishes between a primary and a secondary cause.
The aim of testosterone therapy is to achieve serum testosterone levels within the normal physiological range with dose adjustment to have the maximum effect on alleviation of symptoms.
Definition
Hypogonadism in males is a clinical syndrome that comprises symptoms and/or signs, along with biochemical evidence of testosterone deficiency.
The male gonads (testes) have 2 primary functions: testosterone production (by the Leydig cells) and spermatogenesis (by the spermatogenic and Sertoli cells in the seminiferous tubules). Hypogonadism in men occurs where there is dysfunction in the normal physiological mechanism of the hypothalamic-pituitary-gonadal axis that results in a decreased ability to carry out either of these functions.
History and exam
Key diagnostic factors
- decreased libido
- loss of spontaneous morning erections
- erectile dysfunction
- gynaecomastia
- infertility
- galactorrhoea
- micro-penis
- small testes
- bifid scrotum
- cryptorchidism
- eunuchoid proportions
- bitemporal hemianopia
- low trauma fractures
- loss of height
- anosmia
Other diagnostic factors
- decreased energy and fatigue
- delayed puberty
- lack of scrotal hyper-pigmentation and rugae
- decreased muscle mass and strength
- loss of axillary and pubic hair
- lack of facial hair
- poor concentration and memory
- depressed mood
- sleep disturbance
- hot flushes and sweats
- increasing BMI
- tall stature
- fine wrinkling of facial skin
Risk factors
- genetic anomaly
- type 2 diabetes mellitus
- use of alkylating agents, opioids, or glucocorticoids
- use of exogenous sex hormones and GnRH analogues
- hyperprolactinaemia
- pituitary tumour or apoplexy
- critical illness
- testicular damage
- varicocele
- auto-immune testicular damage
Diagnostic investigations
Treatment algorithm
Contributors
Authors
Assistant Professor of Surgery
Division of Urology
Albany Medical College
Albany
NY
Disclosures
CW has worked as a consultant for Coloplast, and as an investigator for Auxilium Pharmaceuticals, Mereo BioPharma, PROCEPT BioRobotics, and Repros; and he is a paid reviewer at Oakstone Publishing and BMJ Best Practice. CW also has a family member who is an employee at Bristol-Myers Squibb.
Dr Charles Welliver would like to gratefully acknowledge Matthew Aoun for his help with updating this topic. He would also like to acknowledge Dr T. Hugh Jones, Dr Milena Braga-Basaria, and Dr Shehzad Basaria, previous contributors to this monograph. THJ and SB are authors of references cited in this topic. MB declared that she had no competing interests.
Peer reviewers
Professor
Department of Internal Medicine
University of Texas Medical Branch
Galveston
TX
Disclosures
RJU declares that he has no competing interests.
Consultant Endocrinologist
Oxford Centre for Diabetes, Endocrinology and Metabolism
Churchill Hospital
Oxford
UK
Disclosures
NK declares that she has no competing interests.
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https://bestpractice.bmj.com/topics/en-gb/1093
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PMID:
23407454
(PubMed) - PMCID:
PMC3558145
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Volume
2
, Issue
1
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2010
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23
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35
Sunday, August 30, 2009
:Received ,
Wednesday, November 4, 2009
:Accepted
Akhondi, Mohammad Mehdi
Ph.D.,Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran, P.O. Box:19615-1177, Tel: +98 21 22432020, Fax: +98 2122432021, E-mail: [email protected]
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Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR , Tehran, Iran
Akbarzadeh Najar, Reza
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Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR , Tehran, Iran
Jeddi-Tehrani, Mahmood
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Immune and Gene Therapy Lab, Cancer Center Karolinska, Karolinska Institute , Stockholm, Sweden
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Monoclonal Antibody Research Center, Avicenna Research Institute, ACECR , Tehran, Iran
Sadeghi, Mohammad Reza
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Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR , Tehran , Iran
Zarnani, Amir-Hassan
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Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR , Tehran, Iran
Rabbani, Hodjattallah
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Immune and Gene Therapy Lab, Cancer Center Karolinska, Karolinska Institute , Stockholm, Sweden
Salehkhou, Sheida
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Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR , Tehran, Iran
Eini, Leila
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Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR , Tehran, Iran
Hoseinzadeh, Fatemeh
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Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR , Tehran, Iran
Heidari, Mahnaz
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Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR , Tehran, Iran
Abstract
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Spermatogonia are the male germ line stem cells whose life long expansion is needed for permanent production of spermatozoa. The present study was designed to examine the effect of hCG treatment on germ cell proliferation following stem cell transplantation in mice. Spermatogonial stem cells were isolated from neonatal mice testes and characterized by alkaline phosphatase, immunoreactivity and morphological analysis. hCG was injected into normal and cell transplanted mice. We then evaluated the testosterone levels and cell number in normal mice. After that, cyclin B1 gene expression was investigated in transplanted mice. Different doses of busulfan were injected to investigate the effects of chemotherapy on morphological criteria and preparation of recipient mice for transplantation. In this report we show proliferative potential of spermatogonial stem cells after cytotoxic treatment, transplantation efficiency by semi-quantitative RT-PCR, and hCG effect on stem cell regeneration in normal mice and following cell transplantation. The results indicate that spermatogonial stem cells can proliferate after transplantation, and the efficiency of their transplantation depends on hormonal treatment. Therefore, hormonal treatment after stem cell transplantation will be a powerful avenue for increasing the efficiency of transplantation and fertility restoration.
Keywords
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Busulfan
,
Cell proliferation
,
hCG
,
Transplantation
Introduction :
Proliferation and self-renewal of spermatogonial stem cells is based on the presence of hormonal support and growth factors (1). Hormonal support is very important for proliferation of germ cells (2) and can be used for increase in transplantation efficiency. It is postulated that germ cell development is controlled by the hypothalamic-pituitary-gonadal axis (3) and established that spermatogenesis is gonadotropin-dependent, and optimal function of the testis is supported by FSH and by intratesticular androgens induced by luteinizing hormone (4). Human chorionic gonadotropin (hCG) has more than 90% similarity with Luteinizing Hormone (LH) in structure and function (5) and therefore can be used alternatively. Androgen production is induced by LH and promotes germ cell proliferation and maturation. Hypophysectomy or neutralization of circulating gonadotropins increases degeneration of spermatogenic cells (6 - 8).
Spermatogonial cell transplantation is an efficient technique that can help infertility treatment and leads to restoration of spermatogenesis (9). It may be proposed to preserve a fraction of the testicular stem cell of the patient that awaits cancer chemo or radiotherapy for use as auto-transplant after treatment (9). This may be especially effective for prepubertal boys in whom spermatogenesis has not started and thus are lacking sperm.
Combining germ cell transplantation with culture and germ cell population enrichment of spermatogonia and hormonal support opens new pathways for conservation of livestock and plays important roles in medical sciences and reproduction. Events that cause an excessive loss of germ cells such as exposure to high doses of irradiation stimulate their proliferation (10, 11). Self-renewal and differentiation of the testis stem cells is dependent on their close association with Sertoli cells in the seminiferous epithelium (12). These processes are mediated by growth factors produced by the Sertoli cells, which induce or inhibit self-renewal, differentiation and further development of all germ cells (13, 14).
Hormonal environment following transplantation is an essential factor for effective proliferation of transplanted stem cells and absence of such hormonal support may lead to failure in stem cell function and transplantation efficacy. Previously the effects of hCG injection on postpubertal germ cell maturation and androgen production in rat testis was evaluated (15). However, to our knowledge, the effects of hCG treatment on germ cell status and their proliferation before and after spermatogonial stem cell transplantation has not been studied. Therefore, the aim of this study is to evaluate the effect of different doses of hCG on postnatal testicular germ cell proliferation in normal and following stem cell transplantation.
Materials and Methods :
Isolation and culture of mouse type A spermatogonia:Sequential enzymatic digestion of testicular tubules was performed essentially according to the method of Dym et al (16) with minor modifications. Briefly, testes of ten C57BL/6 3 to 6 day old mice were isolated, placed into a Petri dish, and covered with sterile Phosphate-Buffered Saline (PBS). Testes were decapsulated under a dissection microscope and were suspended in Dulbecco's Minimum Eagle's Medium (DMEM; Sigma, St Louis, MO, USA) containing 0.5 mg/ml collagenase/ dispase, 0.5 mg/ml trypsin and 0.08 mg/ml DNase (all from Sigma) supplemented with 14 mM NaHCO3 (Sigma), single-strength non-essential amino acids, 100 IU/ml penicillin, 100 µg/ml streptomycin and 40 µg/ml gentamycin (all from Invitrogen, Carlsbad, Calif, USA). They were incubated for 30 min at 37 °C on a shaker with occasional gentle pipetting to dissociate the interstitial Leydig cells from the seminiferous tubes.
After this incubation step, the tubules were allowed to settle down and the supernatant containing the Leydig cells was pipetted out. The cells were then incubated in DMEM medium containing collagenase (1.5 mg/ml), hyaluronidase (1.5 mg/ml), trypsin (0.5 mg/ml), and DNase (1 µg/ml) (all from Sigma) for 20-30 min using the conditions described above. The dispersed cells were then washed twice with DMEM medium and filtered through 70 µm nylon mesh (BD Falcon, Becton-Dickinson, USA). Isolated cells were cultured at 32 °C in 5% CO2 in air on 5 cm plastic dishes at a concentration of 10×106 cells/dish. The cells were expanded by several passages of selected cultures by digesting with trypsin and were seeded onto new dishes. They were then harvested after trypsin digestion, washed in DMEM medium by centrifugation, and resuspended in DMEM for transplantation to recipient testes. Total cell count was determined before transplantation.
Immunocytochemical localization of c-kit receptor and cytokeratin:Isolated cells were centrifuged at 30 × g for 5 min onto glass slides in a Cytospin centrifuge (Shandon, Cheshire, UK). The cells were fixed and permeabilized with ice-cold acetone for 3 min and then washed 3 times with PBS containing 0.5 % Triton X-100 and 10% rabbit serum. Endogenous peroxidase activity was blocked with 0.1 - 1% H2O2 for 5 - 10 min at room temperature. Blocking of nonspecific antibody binding was performed using 10% nonimmune rabbit serum. Cells were then incubated at 37 °C for 1 hr with 1:500 dilution of mouse monoclonal anti c-kit antibody (Santa Cruz Biotechnology, Santa Cruz, CA, USA). After washing in PBS, the cells were incubated with 1:50 dilution of Horse Radish Peroxidase (HRP)-conjugated anti mouse IgG as secondary antibody (Sigma) for 45 min. After washing with rinsing buffer, 10% 3, 3'-Diaminobenzidine (DAB) solution (Sigma) was applied for 10 min. For the negative controls, the experiments were repeated but without using the primary antibodies.
For cytokeratin immunocytochemistry, cells were fixed for 10 min in ethanol-acetone (1:1) at -20 °C rinsed with PBS and incubated for 10 min with 3% H2O2 in PBS to quench endogenous peroxidase activity. Cells were washed for 30 min with PBS containing 0.2% bovine serum albumin (BSA), followed by 30 min incubation in 1% BSA in PBS and then incubated with the primary antibody for 1 hr. Mouse monoclonal anticytokeratin Pan (Boeringer-Mannheim, Germany) antibody was used as primary antibody. The secondary antibody was a peroxidase-conjugated anti mouse IgG (Sigma) which was incubated for 90 min. After washing with rinsing buffer, 10% DAB solution was applied for 10 min. For the negative controls, the experiments were repeated but without using the primary antibody.
Cytochemical detection of alkaline phosphatase:Cells were removed from the seminiferous tubules by sequential enzymatic digestion and testis’s tissue cryosections (positive control) were evaluated for their expression of alkaline phosphatase after 3 days in culture. Briefly, th
Result :
Regeneration of spermatogenesis after busulfan injection:Morphological analysis of mouse testis structure following busulfan treatment showed that mortality was dose dependent and 90 mg/kg was the lethal dose for mice. In agreement with the results reported previously (18), injection of busulfan decreased the testis size and weight and depleted spermatogenesis in a dose-dependent manner (Figures 1a and b). Morphological evaluation at 35 days after treatment revealed that, whereas only a few of seminiferous tubules showed spermatogenesis in animals treated with busulfan at doses of 45 and 90 mg/kg, spermatogenesis was observed in 15% and 53% of the tubules of animals given busulfan at doses of 30 and 15 mg/kg, respectively (Figures 1c-e). These observations indicated that the effects of busulfan were dose dependent.
Seventy days after busulfan treatment, the increase in weight of the testis was most apparent in animals treated at a dose of 15 mg/kg, suggesting extensive regeneration of spermatogenesis at this dose. Histological analysis showed that most testes contained no germ cells in animals treated with busulfan at 45 mg/kg, and that regeneration occurred in a few tubules. On the other hand, regeneration of spermatogenesis was more significant in animals given the drug at 15 and 30 mg/kg, with averages of 80% and 35% of tubules showing spermatogenesis, respectively. Particularly in animals treated with busulfan at 15 mg/kg, virtually all seminiferous tubules showed apparently normal spermatogenesis with mature spermatozoa, and the size of the testis was almost comparable to that in uninjected controls. These results indicated that a significant proportion of spermatogonial stem cells were eliminated at 45 mg/kg, and that surviving stem cells could regenerate to show spermatogenesis following injection of 15 and 30 mg/kg of busulfan. We selected a dose of 30 mg/kg for further analysis, because the stem cell regeneration, as suggested by the testis weight and the number of repopulated tubules, occurred extensively at this dose, but there are enough spaces for cell injection.
Immunostaining:Spermatogonial stem cells express c-kit and we used it for confirmation of stem cells presence in colonies (Figure 2a). Therefore c-kit immunoreactivity as a molecular marker for spermatogonial cells was positive for the cells (Figure 2b). Figure 2c shows positive staining of Sertoli cells with anti-cytokeratin antibody throughout the cytoplasm. BrdU was added to the donor cells 2 days before transplantation and staining was examined just before transplantation. More than 80% of all the cells were labeled with BrdU before transplantation (Figure 2d). Two months after transplantation, the cells showing nuclear BrdU staining were considered as transplanted cells. Transplanted spermatogonial cells resulted in full spermatogenesis in the recipient mouse testes. The right testis served as control group.
Alkaline phosphatase is highly expressed in mouse intestine (brush border of villous), as well as in adult and neonatal testes (Figures 3a-c) that served as positive control group in our study, but it is not expressed in spermatogonial stem cells (Figure 3d).
Capsular thickness examination and spermatogenesis regeneration of the control and busulfan treated mice testes:Testis capsular thickness was evaluated by optical microscopy and was increased after busulfan treatment. Capsular thickness increase and tubular diameter reduction depended on busulfan dosage. There was no significant difference in capsular thickness and tubular diameter between doses 15, 30, and 45 mg/kg, but there was a significant difference in these parameters when the control group was compared with the experimental groups regardless of dosage of busulfan (Figures 4a-d).
Transplantation efficiency:Two months after transplantation of cells onto seminiferous tubules of left testes, spermatogenic cells, as detected by tracing BrdU incorporated cells, were found in the tu
Discussion :
Biomedical researches have been boosted after stem cell discovery. The testis is among the organs that contain adult stem cells and proliferation and differentiation of these cells play an important role in continuation of spermatogenesis (19). Research on spermatogonial stem cells can provide the scientific community with valuable information about the process of spermatogenesis. Using these cells may enlighten the future of infertility treatment (20). By time, some of the unaffected stem cells undergo spontaneous regeneration which may have important application in spermatogonial stem cell transplantation (21). This study revealed that increase in germ cell population leads to stem cell expansion that appears following busulfan treatment. Previous morphological studies have contributed to form the basic concept of stem cell self-renewal (22). Our study revealed that regeneration of spermatogonial stem cells after busulfan treatment increased the efficiency of transplantation.
The results of busulfan injection confirmed that regeneration after cytotoxic treatment is based on stem cell expansion. Removal of endogenous germ cells by busulfan treatment of recipient testes had a significant impact on donor stem cell colonization efficiency. As busulfan destroys primitive germ cells that account for less than 1% of the total number of testis cells (23, 24), most of the differentiated progenitor cells remain and continue differentiation with normal kinetics. However, the latter gradually mature and disappear by 35 days, owing to the absence of self-renewal activity (23, 24).
Therefore, as the stem cell numbers continue to recover, the number of differentiated germ cells decreases, and the ratio of stem cells to differentiated germ cells changes markedly during regeneration. Eventually, all progenitor cells must be derived from the stem cells that initially survived busulfan injection. These processes are reflected in the changes in the weight and cell recovery observed during regeneration. The renewed and the re-induction of spermatogenesis in the left testis can be used as a measure of evaluating regeneration of spermatogonial division.
In this regard spontaneous recovery of spermatogonial stem cells in the right testis makes this evaluation difficult as there is no specific markers for discrimination of the donor stem cells for the endogenous recipient stem cells which is usually performed using transgenic animals.
Since, in our study, long term analysis of spermatogonial regeneration was not necessary and the objective was to survey the effect of hormone administration as well as stem cell transplantation on cell proliferation, we chose to administer the simple and reliable technique of BrdU incorporation in spermatogonial stem cells instead of using transgenic animals.
The present study used a mouse model and demonstrated that hCG injection following stem cell transplantation and evaluation of cyclin B1 expression, has increased the efficiency of transplantation. Our results showed that hCG leads to increase in the proliferation of stem cells that may be due to increase testosterone levels shortly after injection. These results are in agreement with previous studies in rat (15).
However, hCG administration to neonate mice may have adverse effects on germ cell population, androgen secretion and probably germ cell apoptosis. Furthermore, the effects of hCG administration on the testis were time dependent, i.e. early administration of hCG in neonate mice increased testosterone levels and the number of germ cells. However, late administration of hCG showed absolutely opposite effects. The terms early and late refer to the evaluation of cell number and testosterone levels in a short and long time after hCG administration, respectively. The adverse effect of hCG on germ cells is probably due to the androgen withdrawal. Administration of hCG stimulates androgen production by the prepubertal testis (25).
Following withdra
Acknowledgement :
We greatly appreciate the collaboration of Dr. A. S. Tabatabaei Panah, Dr. E. Javadi and Dr. H. Soltanghoraee for their helpful discussions. We would also like to thank Dr. H. Zeraati for the statistical analyses and G. E. Kazemisefat, G. Ghasemi, M. Mobaraki, and M. Rashedan for their excellent technical assistance.
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Figure 1. Regeneration of spermatogenesis after busulfan injection (a) Changes in testis size after injection of busulfan. Busulfan decreased the testis size and depleted spermatogenesis. (b) Changes in testis weight after injection of busulfan at various doses. The values for each time point were determined in at least three experiments and represent data from more than six testes. The increase was most significant after busulfan injection at a dose of 15 and 30 mg/kg. Values are means±SD. Asterisks indicate significant statistical increase (p<0.01 by Kruskal-Wallis test). (c), (d), and (e) Histological changes of the testes that received busulfan injection at a dose of 30 mg/kg. (c) Wild-type B6 Testis (control). (d) Busulfan-treated B6 testis, 35 days after injection. (e) Busulfan-treated wild-type B6 testis, 70 days after injection. Note the increased number of seminiferous tubules with spermatogenesis after 70 days. Bar =30 mm
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Figure 2. Spermatogonial stem cell detection (a) The morphology of spermatogonial-derived colony and spermatogonial stem cell proliferation and colonization. (b) C-kit immunoreactivity was positive for the spermatogonial stem cells. (c) Cytokeratin was detected in the neonatal Sertoli cells. (d) Spermatogonial stem cells were positive with monoclonal anti-BrdU antibody in culture medium. Magnification: ×20 (in a), ×40 (in b and c), and ×100 (in d)
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Figure 3. Alkaline phosphatase reactivity Control groups including (a) mouse intestine, (b) adult and (c) neonatal mouse testis was alkaline phosphatase positive. (d) The colony did not show alkaline phosphatase reactivity. Magnification: × 20
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Figure 4. Histological examination of capsular thickness of mouse testes following busulfan treatment (a) Capsular thickness in normal testis (control), (b) 15 mg/kg busulfan treated testis, (c) 30 mg/kg busulfan treated testis, and (d) 45 mg/kg busulfan treated testis. The results showed that testis capsular thickness was increased after busulfan treatment in a dose-dependent manner. Magnification: × 20 (in a, b, and c) and × 40 (in d)
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Figure 5. BrdU staining was performed with anti-BrdU antibody following spermatogonial stem cell transplantation (a) Spermatogonial stem cell detection in transplanted testis cryosection staining. (b) Negative control of BrdU Staining in testis tissue. Magnification: × 60
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Figure 6. Evaluation of Oct-4, c-kit, and cyclin B1 gene expression by semi-quantitative RT-PCR (a) Oct-4, c-kit, and cyclin B1 gene expression in spermatogonial stem cells. Oct-4 was exclusively expressed in testis cells of 3-6 days old mice and adult mouse testis and busulfan treated mice did not express Oct-4. Germ cell reduction results in c-kit and cyclin B1 expression decrease in adult busulfan treated mouse testis. (b) Results revealed that cyclin B1 expression increased after hCG injection. M: Molecular marker (100 bp). (c) Busulfan eliminates most germ cells from the testis and results in c-kit and cyclin B1 expression decrease in busulfan treated testes. Three-six days old testes have minimal proliferative action and these gene expressions
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Figure 7. c-kit analysis in mouse testis (a) SDS-PAGE. Lane 1: Molecular marker, Lane2: Normal testis (control) with AgNO3 staining, Lane3: Normal testis (control) with Coomassie Blue staining, Lane4: Busulfan treated mouse testis. (b) Western blot. Lane1: Normal testis (control) Immunoblot, Lane2: Busulfan treated testis immunoblot, Lane 3 & 4: Normal & busulfan treated immunoblot synchronously. No detectable c-kit protein was seen in busulfan treated testes
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Table 1. Primer sequences and annealing temperatures used for RT-PCR Fwd, Forward; Rev, Reverse
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Table 2. Serum testosterone levels in different days and doses Serum testosterone levels on days 28. The highest testosterone values were detected in group 4, NS= Not Significant
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Table 3. Serum testosterone levels in different days and doses Serum testosterone levels on days 65. The group 4 had the lowest level of testosterone level, NS= Not Significant
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Table 4. Serum testosterone levels in different days and doses Percentage of haploid cell population of testis on days 65. DNA flow cytometric analysis revealed that the germ cell numbers had remarkably declined in the case groups in comparison with the control group on day 65. Data presented as the mean ± SD, NS= Not Significant
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Formin is one of the two major classes of actin binding proteins (ABPs) with nucleation and polymerization activity. However, despite advances in our understanding of its biochemical activity, whether and how formins generate specific architecture of the actin cytoskeleton and function in a physiological context in vivo remain largely obscure. It is also unknown how actin filaments generated by formins interact with other ABPs in the cell. Here, we combine genetic manipulation of formins mammalian diaphanous homolog1 (mDia1) and 3 (mDia3) with superresolution microscopy and single-molecule imaging, and show that the formins mDia1 and mDia3 are dominantly expressed in Sertoli cells of mouse seminiferous tubule and together generate a highly dynamic cortical filamentous actin (F-actin) meshwork that is continuous with the contractile actomyosin bundles. Loss of mDia1/3 impaired these F-actin architectures, induced ectopic noncontractile espin1-containing F-actin bundles, and disrupted Sertoli cell–germ cell interaction, resulting in impaired spermatogenesis. These results together demonstrate the previously unsuspected mDia-dependent regulatory mechanism of cortical F-actin that is indispensable for mammalian sperm development and male fertility.
Paternal genetic information is transmitted to the offspring via sperm. The unique cell morphology of the sperm plays essential roles in sperm transport through the female reproductive tract and in fertilization with oocytes. Sertoli cells are somatic cells located in the seminiferous tubules of the testis and are known to contribute to the development of sperm. While many studies have analyzed sperm development, the mechanisms underlying its morphogenesis remain obscure. In this work, we showed that the interaction between developing sperm and Sertoli cells is critical for sperm morphogenesis. We further unraveled that this interaction is strongly dependent on the cortical F-actin meshwork and contractile actomyosin bundles of Sertoli cells, and that two actin polymerization and nucleation factors of the formin family, mDia1 and mDia3, are involved in the generation of both actin-based structures. Loss of these formins in mice result in disrupted Sertoli cell actin structures, abnormal sperm morphology, and male infertility. We conclude that mDia1 and mDia3 play a role in sperm development through the regulation of the actin cytoskeletal architecture of Sertoli cells and that defects in these proteins might contribute to male infertility.
Copyright: © 2018 Sakamoto et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: Data related to this work have been deposited at the following site: http://dx.doi.org/10.17632/vczdgtsbxz.1.
Funding: Grants-in-Aid for Scientific research from the Ministry for Education, Culture, Sports, Science and Technology (MEXT) of Japan (grant number 17K08591). to DT. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Grants-in-Aid for Scientific research from the Ministry for Education, Culture, Sports, Science and Technology (MEXT) of Japan (grant number 26221302). to SN. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Research grant from Ono Medical Research Foundation (grant number 203170600055). to DT. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: DT and SN were supported by the Coordination Fund from MEXT and Astellas Pharma. SN is a scientific advisor to Astellas Pharma. Other authors declare that they have no conflicts of interest.
Filamentous actin (F-actin) nucleation and polymerization are controlled by actin nucleators, including actin-related protein2/3 (Arp2/3) and formin, in mammalian cells. Previous studies in typical cultured cell lines showed that Arp2/3 generates branched actin filaments, while formin generates straight actin filaments . However, F-actin structure and dynamics regulated by formin in a variety of mammalian cell types and their physiological roles in vivo remain largely unknown. Mammalian diaphanous homolog (mDia) proteins, mammalian homologues of Drosophila diaphanous, belong to the formin family of proteins and consist of three isoforms in mammals, namely mDia1, mDia2, and mDia3 . To unravel mDia-dependent F-actin structures in the mammalian body and explore their physiological functions in vivo, we generated mice deficient in each isoform and analyzed their phenotypes [3–5]. These studies showed the functional redundancy between mDia1 and mDia3 isoforms and demonstrated that mDia1/3-mediated F-actin is critical for neuroblast migration and neuroepithelium integrity in the developing brain, and mediates presynaptic plasticity of mature neurons in the adult brain . However, the contribution and function of mDia-mediated F-actin in other systems remain an open question.
Spermatogenesis is a process by which spermatogonial stem cells give rise to spermatozoa through spermatocytes, round spermatids, and elongated spermatids in seminiferous tubules. Besides these germ cells, the seminiferous tubule contains a somatic constituent of the seminiferous epithelium, the Sertoli cells. Sertoli cells make adhesion with developing germ cells and provide them with structural and functional supports , which are indispensable for normal spermatogenesis. Adhesion between Sertoli cells and round spermatids is mediated by the adherens junction (AJ) . In addition, a special form of cell–cell adhesion, the apical ectoplasmic specialization (ES) junction, is formed between Sertoli cells and spermatids in association with the elongation of the round spermatid [10,11]. In contrast to the AJ, which is a structure associated with contractile actomyosin bundles , the apical ES junction is typified by a layer of densely packed noncontractile F-actin bundles concentrated immediately beneath the Sertoli cell plasma membrane. It is known that these noncontractile F-actin bundles are associated with actin bundling protein espin1 and support elongated spermatid adhesion and orientation through the regulation of the apical ES junction [15,16]. Although the structure and function of AJ and ES junctions have been extensively investigated, how F-actin structures associated with these junctions in Sertoli cell are formed, interact with each other, and are maintained during spermatogenesis are largely obscure.
F-actin makes several different forms of architectures beneath the cell membrane, which are collectively termed cortical F-actin and are determined by the environment surrounding the cell. For example, in cells cultured in suspension under steady state, F-actin in the cortex makes a highly dense and fine mesh structure with a homogeneous pore size of approximately 30 nm . It was previously shown that the Arp2/3 complex dominantly nucleate these meshlike cortical actin filaments [18,19], although about 10% of the cortical F-actin of these cells was shown to be formin dependent . On the other hand, cortical F-actin structures in adherent cells are more complicated because dynamic remodeling of cortical network results in additional F-actin architectures, such as the contractile stress fibers . Stress fibers are mostly localized at the basal plane of the cell and are more visible than those finely organized filaments, making conventional imaging of cortical F-actin very challenging. Indeed, the structure and dynamics of cortical F-actin of the adherent cell remain largely unexplored to date, and how and which actin nucleators regulate them are unknown.
In this study, we show that both mDia1 and mDia3 are dominantly expressed in the Sertoli cells of mouse testes and are indispensable for sperm development and male fertility. Utilizing superresolution microscopy, we resolved the nanoscale F-actin architecture of Sertoli cells attached to the substrate and observed a previously unsuspected F-actin meshwork with a large mesh size of about 100 nm. Live imaging of F-actin has further revealed the highly dynamic nature of this cortical F-actin meshwork of the Sertoli cell. Moreover, genetic and pharmacological experiments have shown that this Sertoli cell cortical F-actin meshwork depends on actin nucleation and polymerization activity of formins, including mDia1/3, but not Arp2/3. Intriguingly, these mDia1/3-dependent actin filaments are required for the generation of contractile actomyosin bundles in Sertoli cells. Consequently, loss of mDia1/3 in Sertoli cells results in severe reduction of cortical F-actin meshwork and actomyosin bundles and, instead, unexpectedly causes ectopic formation of espin1-associated noncontractile F-actin bundles in the cell. Finally, we demonstrate that mDia-dependent cortical F-actin meshwork and contractile actomyosin in Sertoli cells are together critical for interaction with germ cells, which is required for their competency to support spermatogenesis.
When breeding mice in our colony, we found that, while mDia1 knockout (KO) male mice and mDia3 KO male mice were fully fertile, the mating of mDia1/3 double knockout (DKO) male mice yielded no offspring upon mating. The fertilization rate upon in vitro fertilization (IVF) of wild-type (WT) oocytes with mDia1/3 DKO sperms was also greatly reduced, suggesting abnormality in the sperm (S1A and S1B Fig). Analysis of the epididymis of 8-wk-old male mDia1/3 DKO mice further revealed reduced number, abnormal morphology, and impaired motility of mDia1/3 DKO sperm compared with the control WT mice (S2A–S2I Fig). These results together suggest that the male infertility phenotype of mDia1/3 DKO mice is likely due to impaired sperm development.
To investigate how mDia1/3 double deficiency causes sperm abnormalities, we next performed histological analysis on spermatogenesis in the testes of adult WT and mDia1/3 DKO mice. Paraffin sections of testis with Periodic acid-Schiff (PAS) staining revealed that, while numerous elongated spermatids aligned at the adluminal compartment of the seminiferous tubule in WT testes, the number of elongated spermatids in mDia1/3 DKO testes is extremely low compared with WT testes (Fig 1A, red boxes). Notably, the heads of mDia1/3 DKO sperm were not properly oriented toward the basal lamina of the seminiferous tubule (Fig 1A, black arrows in the lower red box). In addition, a fraction of mDia1/3 DKO elongated spermatids exhibited ectopic localization in seminiferous tubules, as evidenced by their presence at the proximity of basal lamina (Fig 1A, black boxes). Moreover, we found a significant increase in apoptotic cell number in the mDia1/3 DKO seminiferous tubule by TUNEL staining (S3A and S3B Fig). These results together suggest that mDia1/3 is indispensable for spermatogenesis.
Fig 1. mDia1 and mDia3 are dominantly expressed in Sertoli cells and indispensable for spermatogenesis.
(A) PAS-stained stage VIII seminiferous tubule sections from adult WT and mDia1/3 DKO mice. The red (apical region) and black (basal region) boxes are magnified images of the corresponding boxed areas of the lower magnification. Note that in mDia1/3 DKO mice, differentiated sperms are decreased in number and not properly orientated at the lumen of the seminiferous tubule (black arrows, red box), and elongated spermatids are ectopically localized proximal to the basal lamina (black arrow, black box). Scale bars, 50 μm (left) and 10 μm (right). (B) Immunofluorescence staining for mDia1 or mDia3 (green) and vimentin (magenta), a marker for Sertoli cells, in testis sections from WT adult mice. Note the strong mDia1 and mDia3 immunostaining signals in the cytoplasm of Sertoli cells. Scale bar, 100 μm. The red and blue boxes are magnified images of the corresponding boxed areas of the lower magnification. (C) Schematic representation of testicular germ cell suspensions from WT or mDia1/3 DKO mice transplanted into the Sertoli cell-only testes of sterile W/WV mutant mice. (D) HE-stained testis sections from W/Wv mice transplanted with WT or mDia1/3 DKO testicular germ cell suspensions. Note that the histology of W/Wv mouse testes transplanted with mDia1/3 DKO testicular cell suspensions exhibits apparently normal spermatogenesis. Scale bars, 25 μm. The red and black boxes are magnified images of the corresponding boxed areas of the lower magnification. (E) Quantification of the number of spermatozoa per seminiferous tubule in W/Wv mice transplanted with WT testicular germ cell suspensions (13 tubules of two mice) or mDia1/3 DKO testicular germ cell suspensions (17 tubules of two mice). Data are represented as mean ± SEM. (F) Schematic representation of the transplantation of testicular germ cell suspensions from acro/act-EGFP mice into the busulfan-treated Sertoli cell-only testes of WT or mDia1/3 DKO mice. (G) HE-stained testis sections from WT or mDia1/3 DKO mice transplanted with acro/act-EGFP mice-derived testicular germ cell suspensions. Note that mDia1/3 DKO mouse testis transplanted with acro/act-EGFP mice-derived testicular germ cell suspensions exhibits histologically abnormal spermatogenesis, similar to mDia1/3 DKO mouse testis. Scale bars, 25 μm. The red and black boxes are magnified images of the corresponding boxed areas of the lower magnification. Yellow arrowhead indicates ectopic localization of sperm near the basal lamina of mDia1/3 DKO seminiferous tubule. (H) Quantification of the number of spermatozoa per seminiferous tubule in busulfan-treated testes of WT mice (20 tubules of three mice) or mDia1/3 DKO mice (15 tubules of two mice) transplanted with acro/act-EGFP mice-derived testicular germ cell suspensions. Data are represented as mean ± SEM. ***P < 0.001 (Student t test). acro/act-EGFP, acrosin/actin-enhanced green fluorescent protein; DKO, double knockout; GFP, green fluorescent protein; HE, hematoxylin–eosin; mDia1, mammalian diaphanous homolog1; mDia3, mammalian diaphanous homolog3; n.s., not significant (P = 0.2675, Student t test); PAS, Periodic acid-Schiff; WT, wild-type.
We next attempted to figure out whether the mDia1/3 deficiency in germ cells or Sertoli cells is responsible for the above abnormal spermatogenesis phenotype observed in mDia1/3 DKO mice. We first examined the expression of mDia1 and mDia3 in the seminiferous tubule by immunofluorescence staining. We found positive signals for mDia1 and mDia3 in vimentin-positive Sertoli cells in the seminiferous tubule from adult WT mice (Fig 1B). These mDia1 and mDia3 signals were absent in testis sections from mDia1 or mDia3 knockout (KO) mice (S4A and S4B Fig), confirming the specificity of these signals. We also examined the expression of mDia3 in the WT seminiferous tubule during the spermatogenic cycle and compared its localization with F-actin (S5A Fig). We found that mDia3 is expressed in Sertoli cells throughout the spermatogenic cycle, though its staining intensity and localization varies in different stages. For example, in stages IV–V, although the majority of mDia3 staining localizes in the cell body, a fraction of mDia3 staining with relatively low intensity (white arrows) colocalizes with F-actin bundles associated with apical ES. Similarly, in stages VI–VII, a fraction of mDia3 staining localizes close to F-actin bundles associated with basal ESs (white arrowheads), and the mDia3 staining becomes weak in stages X–XI. Specificity of these mDia3 signals was confirmed as they were mostly absent in testis sections from mDia3 KO mice (S5B Fig).
We then examined the functional requirement of mDia1 and mDia3 expressed in Sertoli cells for spermatogenesis by germ cell transplantation (Fig 1C–1H), according to our previously established protocol . We first transplanted testicular germ cell suspensions from WT or mDia1/3 DKO mice to germ cell–free and Sertoli cell–only testes of W/Wv mice (Fig 1C), and examined spermatogenesis by hematoxylin–eosin (HE) staining of histological sections of the recipients (Fig 1D). We found that W/Wv mouse testes transplanted with mDia1/3 DKO testicular cell suspensions had normal spermatogenesis, as did W/Wv mouse testes transplanted with WT testicular cell suspensions (Fig 1D). Quantification results revealed no significant difference of the spermatozoa number per seminiferous tubule in these transplanted mice (Fig 1E). Thus, mDia1/3 expression in germ cells is dispensable for spermatogenesis. As the reciprocal approach, we depleted germ cells of WT or mDia1/3 DKO mice with busulfan treatment and transplanted testicular germ cell suspensions from acrosin/actin-enhanced green fluorescent protein (acro/act-EGFP) transgenic mice to each Sertoli cell–only testis (Fig 1F). We found that acro/act-EGFP testicular germ cells transplanted to busulfan-treated mDia1/3 DKO testes mimicked abnormal sperm phenotypes seen in mDia1/3 DKO testes, including a reduced number of elongated spermatid (Fig 1G, red box), ectopic localization near the basal lamina of the seminiferous tubule (Fig 1G, black box), and abnormal shape of the head (Fig 1G, black box, yellow arrowhead). Quantification revealed a significant decrease in the spermatozoa number per seminiferous tubule of busulfan-treated Sertoli-only mDia1/3 DKO testes compared with WT testes (Fig 1H). Therefore, mDia1/3 function in Sertoli cells is required for normal spermatogenesis.
Given the critical function of mDia1/3 expression in Sertoli cells, we then used confocal microscopy and examined F-actin structure in primary Sertoli cells cultured on gelatin-coated cover glass. We found that actin filaments in control WT Sertoli cells are composed of thick F-actin bundles and faintly stained actin filaments between these bundles (S6A Fig, left, and magenta line scanning). On the other hand, in mDia1/3 DKO Sertoli cells, F-actin bundles were apparently retained, but the staining intensity of faintly stained actin filaments between these bundles was greatly reduced (S6A Fig, right, and green line scanning). To further resolve the architecture of faintly stained actin filaments in Sertoli cells at the nanoscale level, we next examined phalloidin-stained control WT cells with total internal reflection (TIRF) three dimensional-N-stochastic optical reconstruction microscopy (3D-N-STORM) superresolution microscopy . We found that the faintly stained actin filaments between thick F-actin bundles observed in the cortices of WT cells by confocal microscope are actually a meshwork of actin filaments with a relatively large pore size of about 100 nm (Fig 2A, upper, white box). We then next examined the actin cytoskeleton organization of mDia1/3 DKO Sertoli cells and found that the above cortical F-actin meshwork was markedly sparser, and there were areas devoid of actin filaments in these cells (Fig 2A, below, white box). Quantitative analysis of STORM images revealed that the occupancy of F-actin meshwork was significantly reduced in mDia1/3 DKO Sertoli cells (Fig 2B). These results suggest that mDia1/3 contribute to the formation and maintenance of cortical F-actin meshwork in Sertoli cells.
Fig 2. mDia1/3-dependent cortical F-actin meshwork in primary cultured Sertoli cells.
(A) TIRF 3D-N-STORM imaging of the actin filaments in WT primary cultured Sertoli cells. The images on the right side are magnified images of the corresponding white boxed areas of the lower magnification. Color bar indicates the z dimension (−300 nm to 300 nm). Scale bars, 5 μm (left) and 500 nm (right). (B) Quantification of the ratio of F-actin meshwork occupancy per cell area in WT or mDia1/3 DKO primary cultured Sertoli cells. Results of eight cells for each genotype from two independent experiments. Data are represented as mean ± SEM. ***P < 0.001 (Student t test). (C) Representative images of TIRF 3D-N-STORM imaging of the actin filaments in control WT primary cultured Sertoli cells or Sertoli cells treated with 30 μM SMIFH2 or 50 μM CK-666 for 1 h. Two SMIFH2-treated Sertoli cells with different extents of impaired cortical F-actin meshwork phenotype are shown. The images on the right side are magnified images of the corresponding white boxed areas of the lower magnification. Scale bars, 5 μm (left) and 500 nm (right). (D) Quantification of the ratio of F-actin meshwork occupancy per cell area in control, 50 μM CK-666–treated, or 30 μM SMIFH2-treated primary cultured Sertoli cells. Results of nine cells for control, eight cells for CK-666–treated, and 15 cells for SMIFH2-treated primary cultured Sertoli cells from two independent experiments. *P < 0.05, ***P < 0.001 (P = 0.017 for control versus CK-666–treated cells, P < 0.001 for control versus SMIFH2-treated cells, and P < 0.001 for CK-666–treated versus SMIFH2-treated cells; one-way ANOVA with post hoc test). DKO, double knockout; F-actin, filamentous actin; mDia1/3, mammalian diaphanous homolog1/3; SMIFH2, small molecule inhibitor of formin homology 2 domain; TIRF, total internal reflection; WT, wild-type; 3D-N-STORM, three dimensional-N-stochastic optical reconstruction microscopy.
We next sought to analyze the relative contribution between formins and Arp2/3 on cortical F-actin meshwork in Sertoli cells. To this end, we utilized pharmacological inhibitors for formins and Arp2/3. We found that treatment of WT cells with small molecule inhibitor of formin homology 2 domain (SMIFH2), a formin inhibitor , reduced cortical F-actin meshwork similarly as was observed in mDia1/3 DKO cells (Fig 2C, third row). Notably, a fraction of SMIFH2-treated Sertoli cells showed total suppression of cortical F-actin meshwork with concomitant decrease in F-actin bundles (Fig 2C, fourth row). On the other hand, treatment of WT cells with CK-666, an Arp2/3 inhibitor , did not suppress the cortical F-actin meshwork (Fig 2C, second row). Quantitative analysis (Fig 2D) confirmed that treatment with SMIFH2 significantly suppressed cortical F-actin meshwork in Sertoli cells and additionally revealed that treatment of CK-666 resulted in a slight but significant increase of cortical F-actin meshwork. We speculate that the latter might be due to the increased availability of actin monomers for formins when Arp2/3-mediated actin polymerization is suppressed. These results together therefore suggest that the cortical F-actin meshwork in Sertoli cells is a structure dependent on the actin polymerization activity of formins, including mDia1 and mDia3, but not Arp2/3.
We next examined the dynamics of actin filaments in living primary cultured Sertoli cells. To this end, we introduced LifeAct-EGFP, a probe for F-actin , into primary cultured Sertoli cells. Utilizing spinning disk superresolution microscopy (SDSRM) , which allows fast image acquisition at the spatial xy-axis resolution of approximately 120 nm, we found that, while thick F-actin bundles are a relatively static structure, the cortical F-actin meshwork is an extremely dynamic structure, in which actin continually polymerizes and depolymerizes underneath the cortex of WT control cells (S1 Movie). Quantification of the dynamics of cortical meshwork actin filaments of WT Sertoli cells revealed that the F-actin elongated for a distance of several micrometers, and their extension rate was very fast, with a mean of 0.81 ± 0.06 μm/s (about 300 globular actin (G-actin) subunits incorporated per second) (Fig 3A and 3B, S2 Movie). The speed distribution further revealed at least two subpopulations of cortical meshwork actin filaments with different polymerization rates; the first subpopulation has a peak polymerization rate around 0.4 μm/s and the other subpopulation around 1.3 μm/s (Fig 3B). It should also be noted that F-actin elongation was highly straight (Fig 3C). On the other hand, in mDia1/3 DKO cells, although the straightness of elongated F-actin was not affected (Fig 3C), the subpopulation of nascent actin filament with polymerization rate peak around 1.3 μm/s was absent (Fig 3B), and the number of elongation events was significantly reduced (Fig 3D). These results together suggested that cortical F-actin meshwork is a highly dynamic structure and its formation is dependent on mDia1 and mDia3.
Fig 3. mDia1/3-dependent rapid dynamics of cortical F-actin meshwork in primary cultured Sertoli cells.
(A) Time-lapse images of WT primary cultured Sertoli cell expressing LifeAct-EGFP. Red arrows indicate the tip of the elongating F-actin in the cortical meshwork. Time is shown in seconds. The colors in the right panel indicate the elongated actin filament at each time point in the left panel. Scale bar, 2 μm. (B) Quantification of the elongation speed of LifeAct-EGFP in WT and mDia1/3 DKO Sertoli cells. Results from two independent experiments. Data are represented as mean ± SEM (n = 49 and 20 filaments from four WT and four mDia1/3 DKO Sertoli cells, respectively). **P < 0.01 (P = 0.0013, Student t test). (C) Quantification of the straightness of the elongated F-actin in WT and mDia1/3 DKO Sertoli cells. Results from two independent experiments. Data are represented as mean ± SEM (n = 49 and 20 filaments from four WT and four mDia1/3 DKO Sertoli cells, respectively). (D) Quantification of the elongation frequency of cortical F-actin meshwork. Results from two independent experiments. Data are represented as mean ± SEM (n = 9 regions from three WT and three mDia1/3 DKO Sertoli cells, respectively). ***P < 0.001 (P = 0.0002, Student t test). (E) Time-lapse images of WT primary Sertoli cell expressing EGFP-mDia3. Red boxes indicate a single molecule of EGFP-mDia3. Time is shown in seconds. Scale bar, 2 μm. (F) Kymograph of EGFP-mDia3 single molecule in Fig 3E. (G) Quantification of the processive moving speed of EGFP-mDia3 single molecules (n = 59 molecules from three cells). The result is representative of two independent experiments. (H) Quantification of the straightness of EGFP-mDia3 single molecules’ processive movement (n = 59 molecules from three cells). The result is representative of two independent experiments. (I) Quantification of the travel distance of EGFP-mDia3 single molecules (n = 59 molecules from three cells). The result is representative of two independent experiments. DKO, double knockout; EGFP, enhanced green fluorescent protein; F-actin, filamentous actin; mDia1/3, mammalian diaphanous homolog1/3; n.s., not significant (P = 0.3194, Student t test); WT, wild-type.
Given the extremely rapid rate of actin polymerization observed in the cortical F-actin meshwork area and its impairment in mDia1/3 DKO Sertoli cells, we hypothesized that actin filament polymerization in the meshwork is driven by mDia1 and mDia3. To test this hypothesis, we carried out single-molecule speckle imaging of EGFP-mDia3 in living primary cultured WT Sertoli cells. The EGFP-mDia3 used in the experiment rescued the reduced cortical actin filament meshwork phenotype of mDia1/3 DKO Sertoli cells (S7A–S7C Fig). Single-molecule speckle imaging with TIRF microscopy revealed fast and directional molecular movement of EGFP-mDia3 in the cortex of Sertoli cells (Fig 3E, S3 Movie and S4 Movie). Kymograph (Fig 3F) and quantification analyses of EGFP-mDia3 single-molecule speckles further indicated that the average speed of EGFP-mDia3 was extremely fast, with an average rate of 1.38 ± 0.06 μm/s (Fig 3G). In addition, the EGFP-mDia3 molecular movement was highly linear, similar to cortical meshwork actin filament (Fig 3H). Moreover, a single molecule of EGFP-mDia3 traveled for long distance—on average, 4.46 ± 0.40 μm (Fig 3I). Given that the spatial localization of a single molecule of EGFP-mDia3 in the cell cortex was similar to the cortical F-actin meshwork and the linear directional movement, long travel distance and fast movement speed of an EGFP-mDia3 single molecule were correlated with LifeAct-EGFP dynamics, and that the latter was diminished in the absence of mDia1 and mDia3, we concluded that cortical F-actin meshwork is an actin filament structure directly generated by mDia1/3 in primary cultured Sertoli cells. These data further substantiated that cortical F-actin meshwork is a mDia1/3-dependent structure.
In addition to the actin meshwork, thick actin bundles were seen in WT Sertoli cells and apparently similar actin bundles were observed also in mDia1/3 DKO Sertoli cells (Fig 2A). We therefore examined the origin and composition of these actin bundles. Higher magnification of TIRF-N-STORM images revealed that thick F-actin bundles of Sertoli cells are structurally continuous with the cortical F-actin meshwork both in WT and mDia1/3 DKO Sertoli cells (Fig 4A, left and middle). However, we noted that whereas these thick F-actin bundles were mostly intact in WT cells (Fig 4A, left), those in mDia1/3 DKO cells were occasionally bent (Fig 4A, right). Utilizing confocal microscopy, we found that most of F-actin bundles in primary cultured WT Sertoli cells were co-stained for phosphorylated myosin light chain (pMLC) (Fig 4B, top) and thus represent contractile actomyosin bundles . On the other hand, the pMLC staining intensity in F-actin bundles was greatly reduced in mDia1/3 DKO Sertoli cells (Fig 4B, bottom). Quantification of pMLC staining showed a significant decrease in mDia1/3 DKO cells (Fig 4C). To identify actin bundles observed in mDia1/3 DKO seminiferous tubules, we next performed immunostaining for espin1, an actin bundling protein associated with noncontractile F-actin bundles . We found that most of F-actin bundles in primary cultured Sertoli cells from mDia1/3 DKO mice were associated with espin1 (Fig 4D). Quantification further revealed that F-actin bundles associated with espin1 comprised about 50% of total F-actin bundles in mDia1/3 DKO Sertoli cells but were rarely observed in WT Sertoli cells (Fig 4E). These results together indicate that mDia1/3 are indispensable not only for the formation and maintenance of the cortical F-actin meshwork but also for the generation of contractile actomyosin bundles in Sertoli cells.
Fig 4. Loss of mDia1/3 in the Sertoli cell results in impaired actomyosin bundles and adherens junction.
(A) TIRF N-STORM imaging of F-actin bundles of primary cultured Sertoli cells. Magnified images of the corresponding white box areas are shown below. Note that the F-actin bundle is a structure continuous with cortical actin filaments meshwork. Arrows indicate the bending F-actin bundles observed in mDia1/3 DKO primary cultured Sertoli cells. Scale bars, 500 nm. (B) Primary cultured WT and mDia1/3 DKO Sertoli cells stained with phalloidin (magenta) and pMLC (green). Note the reduced and discontinuity of pMLC staining on the F-actin bundles in the mDia1/3 DKO Sertoli cell. Scale bars, 20 μm and 5 μm. White boxes are magnified and shown below the low magnification images. (C) Quantification of pMLC staining intensity. Staining intensity was normalized to the average intensity of control WT cells. Result is a sum of three independent experiments. Data are represented as mean ± SEM (n = 33 and 30 for WT cells and mDia1/3 DKO cells, respectively). ***P < 0.001 (Student t test). (D) Primary cultured WT and mDia1/3 DKO Sertoli cells stained with phalloidin (magenta) and espin1 (green). Note increased espin1 staining overlapped with F-actin staining in mDia1/3 DKO Sertoli cell. Scale bars, 20 μm and 5 μm. White boxes are magnified and shown below the low magnification images. (E) Quantification of espin1-positive actin bundles per cell. Result is a sum of three independent experiments. Data are represented as mean ± SEM (n = 25 for WT Sertoli cells and n = 2 for mDia1/3 DKO Sertoli cells). ***P < 0.001 (Student t test). (F) Schematic representation of Sertoli cell–germ cell coculture experiment. Green circle indicates germ cell isolated from 3-wk-old EGFP transgenic mouse testes, and gray ellipse indicates WT or mDia1/3 DKO Sertoli cells. Red lines indicate actin filaments of the Sertoli cell, which surround the germ cell. (G) Percentage of germ cells formed adherens junction with Sertoli cells, as judged by N-cadherin staining on WT or mDia1/3 DKO Sertoli cells in Sertoli cell–germ cell coculture experiments. Germ cells that had N-cadherin signals surrounding the germ cells were counted as adhesive cells. Result is the average of three independent experiments. Data are represented as mean ± SEM (n = 124 and 89 cells for WT and mDia1/3 DKO, respectively). *P < 0.05 (P = 0.0306, Student t test). (H) Representative images of a germ cell judged as an adhesive cell with a WT Sertoli cell. (I) SDSRM images of Sertoli cell–germ cell in cocultured experiment stained with phalloidin. Images consist of 10 pairs of serial planes (z-step = 0.5 μm from bottom to top). Note that, while the germ cell attached to WT Sertoli cell is surrounded by actin filaments, such actin filaments are impaired in the germ cell attached to mDia1/3 DKO Sertoli cell. (J) Quantification of the percentage of germ cells with actin filaments surrounding them in Sertoli cell–germ cell cocultured experiment. Result is from three independent experiments. Data are represented as mean ± SEM (n = 157 and 147 cells for WT and mDia1/3 DKO, respectively). ***P < 0.001 (P = 0.0005, Student t test). (K) Quantification of the cortical F-actin intensity underneath the germ cell of the WT or mDia1/3 DKO Sertoli cell in cocultured experiment. Staining intensity was normalized to the average intensity of control WT cells. Result is from two independent experiments. Data are represented as mean ± SEM (n = 23 and 17 cells for WT and m1/3 DKO, respectively). ***P < 0.001 (P = 0.0001, Student t test). DKO, double knockout; EGFP, enhanced green fluorescent protein; F-actin, filamentous actin; mDia1/3, mammalian diaphanous homolog1/3; N-cad, neural cadherin; N-cadherin, neural cadherin; Pha, phalloidin; pMLC, phosphorylated myosin light chain; SDSRM, spinning disk superresolution microscopy; TIRF N-STORM, total internal reflection N-stochastic optical reconstruction microscopy; WT, wild-type.
To examine how our findings on F-actin structures in Sertoli cells cultured in vitro may reflect those in vivo, we next investigated the F-actin structures in Sertoli cells in intact seminiferous tubules. To this end, we selectively fluorescently labeled Sertoli cells in vivo by microinjection of lentivirus-expressing LifeAct-EGFP to seminiferous tubules, according to our method reported previously . We then dissected and untangled the lentivirus-injected seminiferous tubules, fixed and prepared them for imaging ex vivo . Deconvoluted Z-stack images with spinning disk confocal microscopy showed that, although the morphology of intact Sertoli cells was different from that of cultured Sertoli cells, their F-actin structures imaged with LifeAct-EGFP consisted of at least two different F-actin structures, the thick F-actin bundles and thin F-actin meshwork (S8 Fig, S5 Movie). These results suggest that the overall F-actin architectures of Sertoli cells in intact seminiferous tubules are largely similar to those found in cultured Sertoli cells.
Recent studies suggested an important role of contractile actomyosin bundles in the regulation of cell–cell AJ [34,35]. Given that actomyosin bundles were impaired in primary cultured mDia1/3 DKO Sertoli cells, we next utilized an in vitro reconstitution experiment and investigated the impact of the loss of mDia1/3 on the formation of the AJ between a Sertoli cell and a round spermatid cell (Fig 4F). In this system, germ cells isolated from the approximately 3-wk-old EGFP transgenic mice testes containing mostly round spermatids were added onto the primary cultured Sertoli cells and further cocultured for 24 h to allow the formation of Sertoli cell–round spermatid AJ. Immunocytochemistry of an AJ protein, N-cadherin, revealed that while approximately 50% of the round spermatids on WT primary Sertoli cells formed N-cadherin positive cell–cell adhesion, less than 20% of germ cells formed N-cadherin positive cell–cell adhesion with mDia1/3 DKO primary Sertoli cells (Fig 4G and 4H). In addition, we found that the continuity of F-actin on the round spermatid–Sertoli cell interface was often disrupted in the mDia1/3 DKO Sertoli cell (Fig 4I and 4J). Quantitative analysis further revealed that the density of the cortical F-actin meshwork beneath the germ cell in WT Sertoli cells was compromised in mDia1/3 DKO Sertoli cells (Fig 4I and 4K). These results together suggest that mDia1/3-mediated F-actin is critical for formation of the AJ between Sertoli cells and round spermatids.
Because the above findings showed the role of mDia1/3 in the formation of AJ between Sertoli cells and germ cells in vitro, we next examined if the mDia1/3 deficiency in Sertoli cells affects these cell–cell interactions in the seminiferous tubule in vivo. To this end, we performed immunostaining for nectin-2, an adhesion molecule exclusively expressed in Sertoli cells [36,37]. Composite Z-stack images of nectin-2 in WT seminiferous tubules showed nectin-2 signals at the AJ between a Sertoli cell and a round spermatid (see the area shown by the white two-way arrow in Fig 5A, WT) and concentration of nectin-2 at the apical ES junction between Sertoli cells and elongated spermatids and basal ES between Sertoli–Sertoli cells (Fig 5A). On the contrary, nectin-2 signal at the boundary between Sertoli cells and round spermatids was significantly reduced in mDia1/3 DKO seminiferous tubules (Fig 5A, below). We also stained for nectin-2 in WT and mDia1/3 DKO seminiferous tubules throughout the spermatogenic cycles and observed consistent results (S9 Fig). Moreover, high magnification images (Fig 5B) revealed that the accumulation (Fig 5C) and the continuity (Fig 5D) of concentrated nectin-2 signals at the apical ES junction were severely impaired in the mDia1/3 DKO seminiferous tubule. These results indicate that mDia1/3 are indispensable for both AJ and apical ES junction in the seminiferous tubule.
Fig 5. Loss of mDia1/3 results in impaired Sertoli cell–germ cell adhesion and aberrant and ectopic actin bundling in seminiferous tubule.
(A) Immunofluorescence staining for nectin-2 (green) and nuclear counterstaining with DAPI (magenta). White two-way arrow indicates the area where round spermatids are located in seminiferous tubule. (B) High magnification of concentrated nectin-2 staining at apical ES junction between Sertoli cell and elongated spermatids. Note that while signals for apical ES junction nectin-2 concentrated around the head of the elongated spermatids were relatively continuous in WT seminiferous tubule, nectin-2 signal around the head of elongated spermatids is often lower than that of the WT and its continuity around the spermatids head is impaired in mDia1/3 DKO apical ES junction. Scale bars, 100 μm (A) and 2.5 μm (B). (C) Quantification of the normalized nectin-2 staining intensity at the apical ES junction. Result is a sum of three independent experiments. Data are represented as mean ± SEM (n = 35 and 39 cells for WT and mDia 1/3 DKO, respectively). ***P < 0.001 (Student t test). (D) Quantification of the coefficient of variation of nectin-2 staining intensity along the apical ES junction. Result is from three independent experiments. Data are represented as mean ± SEM (n = 35 and 39 cells for WT and mDia 1/3 DKO, respectively). ***P < 0.001 (Student t test). (E) WT (upper) and mDia1/3 DKO (lower) adult seminiferous tubule stained with phalloidin. The white two-way arrow indicates the round and elongated spermatids zone of the WT seminiferous tubule, with F-actin faintly stained. Red, yellow, and blue boxes are magnified images of the corresponding boxed areas of the lower magnification. Scale bars, 100 μm (left) and 10 μm (right). The lines (magenta and green arrows) in the blue boxes were used to calculate the fluorescence intensity. (F) Line scans of the fluorescence intensity for phalloidin staining. Fluorescence-intensity profiles along the magenta and green arrows shown in E are shown. Green asterisks indicate ectopic thick F-actin bundles observed in mDia1/3 DKO seminiferous tubule. (G) Simplified scheme summarized results of the observation in Fig 5E–5F. (H) Quantification of total F-actin staining intensity. Result is a sum of three independent experiments. Data are represented as mean ± SEM (n = 21 and 18 for WT and mDia 1/3 DKO, respectively). **P < 0.01 (P = 0.001, Student t test). (I) WT (upper) and mDia1/3 DKO (lower) adult testis immunostained for espin1 (green) and F-actin (magenta). Note that the espin1 staining in the mDia1/3 DKO seminiferous tubule was abnormally strong and colocalized to phalloidin staining of aberrant and ectopic thick F-actin bundles observed in the mDia1/3 DKO seminiferous tubule. Scale bar, 100 μm. (J) Quantification of espin1-positive actin bundles. Result is a sum of three independent experiments. Data are represented as mean ± SEM (n = 12 seminiferous tubules for WT mice and n = 17 seminiferous tubules for mDia1/3 DKO mice). ***P < 0.001 (Student t test). a.u., arbitrary unit; DKO, double knockout; ES, ectoplasmic specialization; F-actin, filamentous actin; mDia1/3, mammalian diaphanous homolog1/3; WT, wild-type.
It is known that while conventional AJs are associated with contractile actomyosin bundles [34,35], ES junctions are typified by the presence of highly dense noncontractile F-actin bundles in the Sertoli cell [13,14]. To further resolve the F-actin architecture of WT and mDia1/3 DKO seminiferous tubules, we next conducted phalloidin staining and examined F-actin structures by confocal imaging (Fig 5E). Composite Z-stack images of F-actin in WT seminiferous tubules show that, while thick F-actin bundles specifically localize to the apical ES junction along the elongated spermatid head (Fig 5E, above, red box) and basal ES at this stage (Fig 5E, above, yellow box), thick F-actin bundles were intriguingly increased in number and intensity and aberrantly distributed over the whole region of the mDia1/3 DKO seminiferous tubule (Fig 5E, below). Moreover, whereas the background F-actin staining in the area where round spermatids are located as shown by the white two-way arrow, is relatively high in WT seminiferous tubules (Fig 5E, above), they were strongly reduced between the ectopic thick F-actin bundles in mDia1/3 DKO seminiferous tubules (Fig 5E, blue box). Line scanning of the F-actin intensity in the round spermatid area (Fig 5E, blue box, magenta and green lines) clearly showed the stark difference between the faintly stained F-actin density in WT and mDia1/3 DKO Sertoli cells (Fig 5F). Based on these observations, we summarized our results in a simplified diagram (Fig 5G). Quantification revealed that the total F-actin intensity per seminiferous tubule was significantly reduced in mDia1/3 DKO seminiferous tubules compared with that of WT seminiferous tubules (Fig 5H).
To further clarify the identity of abnormal thick actin bundles specifically observed in mDia1/3 DKO seminiferous tubules, we next performed immunostaining of espin1. We found that whereas espin1 staining is relatively weak and confined to the area around the head of elongated sperm in control WT seminiferous tubules at stages X–V of the spermatogenic cycle, it showed persistent and abnormally strong signals in mDia1/3 DKO seminiferous tubules, which are mostly colocalized with ectopic F-actin bundles (Fig 5I and S10 Fig). Quantification showed that F-actin bundles associated with espin1 comprised about 60% of total F-actin bundles in mDia1/3 DKO seminiferous tubules but were rarely observed in WT seminiferous tubules (Fig 5J). These findings together suggested that the loss of mDia1/3 impaired normal F-actin structures in both AJs and apical ES junctions and induced the formation of ectopic aberrant espin1-containing F-actin bundles in seminiferous tubules.
Despite advances in our understanding of formins’ biochemical activity, how and where formins generate F-actin and what forms of F-actin structures they make in a variety of cell types and tissues remain largely unknown. Technically, the presence of abundant F-actin bundles in adherent cells makes the observation of the fine cortical actin network challenging. In this work, we found that although mDia1 KO male mice and mDia3 KO male mice were fully fertile, mDia1/3 DKO male mice were infertile, suggesting the functional redundancy between the two mDia isoforms. Starting with the Sertoli cell–intrinsic defects in spermatogenesis in mDia1/3 DKO mice, we examined how the formins mDia 1 and mDia3 contribute to actin cytoskeleton structure and dynamics in Sertoli cells and spermatogenesis. We employed superresolution microscopy, 3D-N-STORM, to unravel the nanoscale F-actin architecture in Sertoli cells and found that the actin cytoskeleton in these cells is strongly dependent on formins. We observed at least two types of actin cytoskeleton structure coexisting in primary cultured WT Sertoli cells, the thin cortical F-actin meshwork and the thick actomyosin bundles. Notably, two types of actin filaments were also seen in Sertoli cells in situ in testis tubules. High magnification superresolution images further revealed that these two types of F-actin are of continuous structure. In contrast to the previous findings on cortical F-actin meshwork in cells cultured in suspension [18, 19], we found that the cortical meshwork of Sertoli cells on the substrate has a larger pore size and is largely dependent on formin activity, including mDia1/3, but not on Arp2/3. Utilizing spinning disk superresolution live imaging , we further found that the cortical F-actin meshwork is a highly dynamic structure. Quantitative analysis of the cortical F-actin network in cultured Sertoli cells revealed two subpopulations in the cortical F-actin meshwork, the first subpopulation with the polymerization rate peak at about 0.4 μm/s and the second subpopulation with polymerization rate peak at about 1.3 μm/s. In mDia1/3 DKO Sertoli cells, the latter subpopulation was totally absent. Therefore, the subpopulation of newly polymerized actin with faster speed is dependent on mDia1/3 activity. Moreover, we found that the dynamic of a single mDia3 molecule in living Sertoli cells on a substrate is similar to that of the second subpopulation of cortical F-actin meshwork, with polymerization rate of about 1.3 μm/s. Given this correlation, it is likely that mDia1 and mDia3 generate a particular fraction of cortical F-actin meshwork with fast dynamics in Sertoli cells. We speculate that the other fraction of cortical F-actin meshwork is mediated by other formins expressed in Sertoli cells, such as formin1 , because cortical F-actin meshwork was strongly suppressed by treatment with the formin inhibitor, SMIFH2 .
Intriguingly, we also found that actomyosin bundles are impaired in mDia1/3 DKO Sertoli cells. In the absence of mDia1 and mDia3, noncontractile actin bundles containing espin1 replaced contractile actomyosin bundles in Sertoli cells. The mechanism by which mDia1/3-generated actin filaments are preferentially incorporated to actomyosin bundles and not to espin1-containing actin bundles remains unclear. We previously demonstrated that mDia1 helically rotates at the barbed end of the actin filament and proposed that it might cause the twist of F-actin . Because it was reported that the twisting of an actin filament affects its conformation and influences subsequent binding of actin binding proteins (ABPs), including myosin II , we speculate that mDia1 might affect the conformation of an actin filament that allows efficient binding of myosin II. It should also be noted that filament spacing in actin bundles is an architectural feature dependent on the actin bundling proteins. It was reported that the incorporation of small-sized (about 8 nm) espin1 molecules into F-actin results in compact F-actin bundling, which is segregated from F-actin containing contractile myosin of the larger size . We speculate that long and straight actin filaments generated by mDia1/3 in the cortical meshwork may not be favorable for espin1 binding and instead may allow larger protein cross-linking to the formation of actomyosin bundles. A previous study reported that espin-associated F-actin bundles assemble into highly ordered, densely packed bundles . On the other hand, the actomyosin bundle is a structure of parallel filaments of opposite polarity spaced apart by myosin [43,44]. Therefore, it is possible that espin-based actin bundles contain a larger number of actin filaments per bundle than actomyosin in mDia1/3 DKO Sertoli cells. Nevertheless, they are apparently more fragile than actomyosin bundles as they are occasionally bent, as observed in mDia1/3 DKO Sertoli cells in this study.
Actomyosin is a contractile structure generating force in various cellular contexts, and its importance in maintaining the cell–cell AJ has been recently reported [34,35]. Consistently, we found that formation of the AJ was impaired in the mDia1/3 DKO seminiferous tubule, as evidenced by suppressed cell adhesion between round spermatids and Sertoli cells in vitro and reduced nectin-2 staining in Sertoli cell–germ cell junction in vivo. It is plausible that mDia1/3 supply cortical actomyosin bundles to encircle spermatids that may limit the diffusion of AJ proteins and promote their clustering in Sertoli cells, as reported as a prerequisite event for cell–cell junction formation in other systems [17,45]. Notably, a small fraction of germ cells that could form cell–cell junctions with mDia1/3 DKO Sertoli cells in vitro showed impaired continuity of F-actin in the proximity of cell–cell junctions. Therefore, mDia1/3-mediated actomyosin bundles in Sertoli cells also play a role in stabilization and maintenance of cell–cell junctions. It should also be noted that in addition to AJs, apical ES junctions were also severely impaired in mDia1/3 DKO mice. As the ES junction is formed subsequent to the AJ during sperm development, we speculate that proper AJ is a prerequisite for ES junction formation. One intriguing question is how the actomyosin bundles generated by mDia1/3 localize specifically to the AJ and exert their function there. Several models were previously proposed for the generation of actomyosin bundles at the AJ [34,46]. Because we observed mDia1/3-dependent actin polymerization throughout the Sertoli cell cortex, our results support a model that mDia1/3-depedent actomyosin bundles are generated in the cortex but the localization to the AJ is mediated by other side-binding ABPs, such as α-catenin .
Sertoli cells make adhesion with developing germ cells and contribute to spermatogenesis by providing structural and functional support . Thus, proper adhesions between Sertoli cells and germ cells are indispensable for normal spermatogenesis. Involvement of F-actin in sperm development was also previously reported . However, the detailed molecular mechanism of F-actin action in spermatogenesis, especially in the supporting Sertoli cells, was largely unknown. In this work, we demonstrated that mDia1/3-dependent cortical F-actin meshwork and contractile actomyosin in Sertoli cells are critical for spermatogenesis through the regulation of Sertoli cell–germ cell adhesion.
In summary, here we have combined genetic and pharmacological manipulation of formins with superresolution and single-molecule imaging, and revealed a previously unsuspected requirement for the two formins, mDia1 and mDia3, in sperm morphogenesis and male fertility. Importantly, mDia1/3 catalyze the formation of cortical F-actin meshwork and actomyosin bundles indispensable for the formation and function of AJs and apical ES junctions essential for proper spermatogenesis (S11 Fig). The function of mDia unraveled here thus sheds a light on the importance of the F-actin structure and dynamics in Sertoli cells for spermatogenesis and paves a way for molecular dissection of its regulatory mechanisms.
Primary antibodies used were rabbit anti-mDia1 polyclonal (LifeSpan BioSciences, Seattle, WA), rabbit anti-mDia3 polyclonal (SIGMA-Aldrich, St. Louis, MO), chicken anti-vimentin polyclonal (Millipore, Burlington, MA), rabbit anti-GFP polyclonal (MBL, Nagoya, Japan), goat anti-nectin-2 polyclonal (Santa Cruz Biotechnology, Dallas, TX), rabbit anti-espin1 polyclonal (#PB538, a gift from Dr. Bechara Kachar, NIH) , mouse anti-espin1 monoclonal, mouse anti-N-cadherin monoclonal (BD Bioscience, San Jose, CA), and mouse anti-phospho-myosin light chain2 (Ser19) monoclonal (Cell Signaling, Danvers, MA). Inhibitors used were SMIFH2 (Tocris, Bristol, United Kingdom) and CK-666 (Tocris, Bristol, UK).
mDia1 KO mice were generated and backcrossed to C57BL/6N mice for more than 10 generations, as previously described . mDia3 KO mice and mDia1/mDia3 DKO were generated and backcrossed to C57BL/6N mice for more than 10 generations, as previously described . C57BL/6-Tg (CAG-EGFP) mice were purchased from the local supplier (Japanese SLC, Hamamatsu, Japan) and acro/act-EGFP [TgN(acro/act-EGFP)OsbC3-N01-FJ002] mice were kindly provided by Dr. Masaru Okabe (Osaka University). All animal care and use were in accordance with the United States National Institutes of Health Guide for the Care and Use of Laboratory Animals and were approved by the Institutional Animal Care and Use Committee of Kyoto University Graduate School of Medicine.
Testes from 12-wk-old WT or mDia1/3 DKO mice were collected in cold Hanks’ balanced salt solution (HBSS; Invitrogen, Carlsbad, CA) and placed on ice. After removal of the tunica albuginea, seminiferous tubules were dissociated from the testis and transferred immediately into 1 mL of 1 mg/mL collagenase in HBSS. Tubules were incubated for 15 min at 37°C in a water bath, then washed with HBSS three times. Collagenase-treated tubules were then dissociated in a mixture of 0.8 mL of 0.25% trypsin and 0.2 mL of 7 mg/mL DNase in HBSS for 10 min at 37°C in a water bath. A total of 5 mL of 10% FBS-contained Iscove’s modified Dulbecco’s medium (IMDM; Invitrogen, Carlsbad, CA) were subsequently added to the trypsinized cells and mixed by gently pipetting. The mixture was then centrifuged at 400g for 5 min. Cells were resuspended in 10% FBS-contained IMDM, counted, and then plated at a concentration of 8 × 105 cells/mL per well on a 0.2% gelatin-coated cover glass. Cells were allowed to settle for 24 h in 5% CO2 at 37°C. Nonattached cells were washed out with serum-free IMDM four times. Finally, 1 mL/well of IMDM containing 10% FBS was added the culture and cells were cultured for an additional 48 h in a CO2 incubator, as above.
In vitro fertilization was performed as described previously . In brief, female B6D2F1 mice were superovulated by intraperitoneal injections of equine chorionic gonadotropin (eCG; Teikoku Zoki, Tokyo, Japan) and human chorionic gonadotropin (hCG; Teikoku Zoki, Tokyo, Japan) at 48-h intervals. Ovulated eggs were recovered 13 h after the hCG injection and placed in a 200-μL drop of modified Krebs–Ringer bicarbonate solution (TYH medium) containing glucose, sodium pyruvate, bovine serum albumin, and antibiotics (0.05 mg/mL penicillin, 100 IU/mL streptomycin). Fresh spermatozoa from the cauda epididymis were dispersed in a 200-μL drop of TYH medium, diluted to 1×106 spermatozoa/mL, and incubated for 1.5 h to induce capacitation. An aliquot of capacitated spermatozoa from control WT mice and mDia1/3 DKO mice were then added to the eggs at 2×105 spermatozoa/ml for IVF. The mixture was incubated for 8 h at 37°C under 5% CO2 in air. Fertilization was confirmed by pronuclear formation. For observation of sperm–zona binding, egg masses were treated with bovine testicular hyaluronidase (175 U/mL; Sigma-Aldrich, St. Louis, MO) for 5 min to remove the cumulus cells. The cumulus-free eggs were placed in a 200-μL droplet of TYH medium and inseminated as described. After 30 min of incubation, sperm binding to the zona pellucida of the eggs was observed under an IX-70 microscope (Olympus, Tokyo, Japan).
The cauda epididymis was collected and minced with a razor blade in 1 mL PBS. The suspension was filtered through 70-μm-nylon mesh (Corning, Corning, NY). The number of spermatozoa was counted using a hemocytometer.
Cauda epididymal spermatozoa were suspended and incubated in TYH medium. Sperm motility was then measured using the CEROS sperm analysis system (software version 12.3; Hamilton Thorne Biosciences, Beverly, MA). Analysis settings were as described previously . The percentage of hyperactivated spermatozoa was analyzed as described previously .
Mature sperm were collected from cauda epididymis by pricking with a fine needle and rinsed twice with PBS. Sperms were then plated on slide glasses, air-dried, and fixed with 4% PFA/PBS for 15 min at room temperature. Sperm morphology was observed on a laser scanning confocal imaging system (Leica SP5) with an oil immersion objective lens (100×1.4 numerical aperture).
To enrich spermatogonial stem cells in donor testicular cell suspension, experimental cryptorchidism was surgically induced in donor mice . Three to six weeks after the surgery, testis cells were dissociated into single-cell suspensions by two-step enzymatic digestion using collagenase type IV and trypsin (SIGMA-Aldrich, St. Louis, MO), as described previously . The dissociated WT or mDia1/3 DKO cells were then transplanted into W/Wv recipient mice (Japan SLC, Hamamatsu, Japan) through the efferent duct. For reciprocal transplantation, testis cells from cryptorchid acro/act-EGFP transgenic mice were transplanted into busulfan-treated control WT or mDia1/3 DKO mice through the efferent duct. Approximately 5 or 10 μL was introduced into the testes, respectively. Each injection filled 75%–85% of the seminiferous tubules.
Testes or epididymides were fixed with 4% PFA at 4°C overnight. For paraffin sections, the testes or epididymides were embedded in paraffin and cut into sections at 4-μm thickness. For frozen sections, the testes were cryoprotected in 0.1 M PB containing 30% sucrose, frozen in Tissue-Tek OCT compound (Sakura-finetek, Tokyo, Japan) in dry ice, and then were cut into sections at 12-μm thickness using cryostat. HE and PAS staining were performed according to standard protocol. For immunohistochemistry, cryosections were washed with PBS three times for 5 min each. Antigen retrieval for mDia1, nectin-2, espin1, and vimentin staining was carried out by boiling the sections in 10 mM citrate buffer, pH 6.0, with a pressure cooker. Sections were incubated with the blocking buffer (PBS containing 1% normal donkey serum (Jackson laboratory, Bar Harbor, ME) or 1% normal goat serum (Jackson laboratory, Bar Harbor, ME) and 0.3% TritronX-100) for 1 h at room temperature. Sections were then incubated with the primary antibody diluted in blocking buffer. After three washes with 0.3% Triton X-100 in PBS, sections were incubated with appropriate secondary antibodies conjugated to Alexa Fluor 488, Alexa Fluor 555, Alexa Fluor 594, or Alexa Fluor 633 (Invitrogen, Carlsbad, CA). Hoechst 33342 (Invitrogen, Carlsbad, CA) or DAPI (Molecular Probes, Eugene, OR) was used for nuclear staining. Phalloidin conjugated with Alexa 488, 546, 555, or 647 (Invitrogen, Carlsbad, CA) was used for the staining of F-actin. Peanut agglutinin (PNA) conjugated with TRITC (SIGMA-Aldrich, St. Louis, MO) was used for the staining of round and early elongated spermatids acrosome. TUNEL staining was performed according to the manufacturer’s instructions using ApopTag Fluorescein Direct In Situ Apoptosis Detection Kit (Millipore, Burlington, MA). Fluorescent images were acquired with a laser scanning confocal imaging system (Leica SP5) equipped with 100× NA 1.4 HCX PL APO CS oil immersion objective lens (Leica, Wetzlar, Germany). Images were processed using Adobe Photoshop CS5 software (Adobe, San Jose, CA).
For quantification of nectin-2 intensity, nectin-2 staining signals associated with the apical ectoplasmic specialization junction were selectively visualized by setting a threshold, and then the average intensity per pixel was analyzed by ImageJ software (http://rsbweb.nih.gov/ij). For coefficient of variation of nectin-2, a line scan of the nectin-2 staining signal along the apical ectoplasmic junction was performed using ImageJ software by drawing a line, and the intensity values along the line were obtained using the Plot Profile. Coefficient of variation of nectin-2 staining intensity along the apical ectoplasmic junction were then calculated as the ratio of the standard deviation and average staining intensity. Line scan for measurement of F-actin intensity was performed using ImageJ software by drawing a line on the seminiferous tubule, and the intensity values along the line were obtained using the Plot Profile. Plots were generated based on the data obtained by ImageJ using Prism software (GraphPad Software, San Diego, CA). For quantification of seminiferous tubule F-actin intensity, region of interest (ROI) was defined to specifically include the seminiferous tubule but not the myoid cell layer, and average F-actin intensity per pixel was then analyzed by ImageJ software. Averages of F-actin intensity per pixel of WT and mDia1/3 DKO seminiferous tubules were then generated based on the data obtained by ImageJ using Prism software (GraphPad Software, San Diego, CA). For quantification of the proportion of espin1-positive actin bundles, a binary image of F-actin bundles and espin1 were generated by setting a threshold. The two images were then merged and the pixel number of total F-actin bundles and espin1 signals that are colocalized with F-actin bundles was analyzed. The proportion of espin1-positive F-actin bundles were then calculated as a ratio of the pixel number of espin1-associated F-actin bundles and total F-actin bundles for seminiferous tubules. Averages of the proportion of espin1-positive actin bundles of WT and mDia1/3 DKO seminiferous tubules were then generated using Prism software (GraphPad Software, San Diego, CA).
Sertoli cells were cultured for 72 h on 25 mm round, No. 1.5 fiducialated cover glass (Hestzig, Leesburg, VA; #600-100AuF) for TIRF 3D-N-STORM superresolution imaging. For the fixation, the cells were briefly washed with 2.5 mL of prewarmed (37°C) PBS and fixed and permeabilized with 0.3% glutaraldehyde (EM Grade; Electron Microscopy Sciences, Hatfield, PA) and 0.25% Triton X-100 in 1 mL of cytoskeleton buffer (10 mM MES, pH 6.1, 150 mM NaCl, 5 mM EGTA, 5 mM glucose, and 5 mM MgCl2) for 1.5 min. The second fixation step was performed with 2% glutaraldehyde in 1 mL of cytoskeleton buffer for 10 min. Samples were quenched with 0.1% NaBH4 (SIGMA-Aldrich, St. Louis, MO) in 2.5 mL of freshly prepared PBS for 7 min on ice to reduce autofluorescence. Finally, fixed cells were washed with PBS twice, each time for a 10-min incubation, and then kept in PBS overnight at 4°C.
Before imaging, F-actin was probed using 0.33 μM of Alexa Flour 647-conjugated phalloidin (Life Technologies, Waltham, MA) and incubated for 30 min at room temperature. The samples were imaged on a Nikon N-STORM microscope (Nikon, Tokyo, Japan) in TIRF mode. The microscope is equipped with a 100× NA 1.49 Apo TIRF objective lens, a back-illuminated EMCCD camera (Andor Ixon3, Belfast, UK), a Cy5 (excitation, 620/60; emission, 700/75) filter set (Chroma, Bellows Falls, VT), and a cylindrical lens for 3D imaging. During imaging, a 100-mW 641-nm laser (Coherent, Santa Clara, CA) and a 100-mW 405-nm laser (Coherent, Santa Clara, CA) were used to excite and photoswitch Alexa Fluor 647, respectively. In each image acquisition, a 5–10-min period of full-powered illumination by 641-nm laser was first performed to turn most Alexa Fluor 647 fluorophores into dark state to achieve a sparse distribution of single molecules. Image frames were acquired when single-molecule blinking could be observed. The intensity of 405-nm laser was periodically tuned during imaging to reactivate fluorophores to maintain sufficient fluorophore density.
For each image, 40,000 raw frames were acquired in the frame-transfer mode, with an exposure time of 50 ms, EM gain of 200, and a readout speed of 10 MHz. Fluorophore detection and localization were carried out by PeakSelector (courtesy of Harald Hess, Howard Hughes Medical Institute), a customized software developed in IDL (Exelis Vis, Boulder, CO). The centroid position of each detected fluorophore was calculated via 2D-Gaussian nonlinear least-square fitting, as described earlier . The localization precision of each centroid coordinate was computed using the Thompson-Webb formula depicted earlier . Fluorophore peaks with localization precisions smaller than 20 nm were rejected from subsequent analysis. The fiducials pre-embedded on the glass coverslips were used to correct drift. The N-STORM images were then reconstructed by representing each localization coordinate as a normalized Gaussian function whose widths depend on the localization precision . Three-dimensional data were rendered with colors encoding the z positions of fluorophores.
The N-STORM image of F-actin in Sertoli cells contains a mixture of fine meshwork and high-density bundles. To separate these two structures and analyze the density of the fine F-actin meshwork, the image was first reconstructed with a pixel size of 160 nm (an image size of 256 × 256 pixels) to blur regions of F-actin meshwork, leaving F-actin bundles as more prominent structures. The cell region was then anisotropically enhanced [58, 59] to highlight F-actin bundles, and then segmented using Otsu's method . Next, another image was reconstructed with a pixel size of 10 nm, which is sufficiently high for the F-actin network, generating an image size of 4,096×4,096 pixels. The previously segmented regions of F-actin bundles were scaled up by 16 times and used as masks to isolate regions between thick F-actin bundles from the high-resolution image. The F-actin network was segmented from the isolated areas using Otsu's method. F-actin occupancy was then computed as the ratio between the number of F-actin pixels and the total number of pixels in the binarized regions of the F-actin network.
For immunocytochemistry, cells were fixed with 4% PFA in PBS for 15 min at room temperature. The fixed cells were permeabilized with 0.1% Triton X-100 in PBS for 15 min at room temperature and then blocked with 5% skim milk in PBS for 1 h at room temperature. The cells were then stained with anti-pMLC antibodies (CST, Danvers, MA) and anti-espin1 antibodies (BD Biosciences, San Jose, CA). Secondary antibodies were Alexa Fluor 488-conjugated goat anti-mouse IgG (Molecular Probes, Eugene, OR) and Alexa Fluor 488-conjugated goat anti-rabbit IgG (Molecular Probes, Eugene, OR). F-actin was stained with Alexa Fluor 555-conjugated phalloidin (1:100; Molecular Probes, Eugene, OR). DAPI (Molecular Probes, Eugene, OR) was used for nuclear staining. Fluorescent images were acquired on a laser scanning confocal imaging system (Leica SP5) equipped with 100× NA 1.4 HCX PL APO CS oil immersion objective lens (Leica, Wetzlar, Germany). Images were processed using Adobe Photoshop CS5 software (Adobe, San Jose, CA).
ROI including a cell was defined, and average pMLC intensity per pixel was then analyzed by ImageJ software. Averages of pMLC intensity per pixel of WT and mDia1/3 DKO cells were generated based on the data obtained by ImageJ using Prism software (GraphPad Software, San Diego, CA). For quantification of the proportion of espin1-positive actin bundles, binary images of F-actin bundles and espin1 were generated by setting a threshold. The two images were then merged and the pixel number of total F-actin bundles and espin1 signals that are colocalized with F-actin bundles were analyzed. The proportion of espin1-positive F-actin bundles were then calculated as a ratio of the pixel number of espin1-associated F-actin bundles and total F-actin bundles for each cell. Averages of the proportion of espin1-positive actin bundles of WT and mDia1/3 DKO cells were then generated using Prism software (GraphPad Software, San Diego, CA).
Primary cultured Sertoli cells were transfected with pCAG-LifeAct-EGFP or pCAG-EGFP-mDia3 by electroporation using Neon Transfection System (Invitrogen, Carlsbad, CA) according to the manufacturer’s protocol. Briefly, 2×105 cells were transfected with 1.5 μg of plasmid DNA. Electroporation was performed at a single pulse of 1,350 V for 30 ms. After electroporation, cells were plated in IMDM medium containing 10% FBS for 24 h in 5% CO2 at 37°C. For observation of LifeAct-EGFP, primary cultured Sertoli cells were maintained in IMDM without phenol red containing 2% FBS. Time-lapse imaging of LifeAct-EGFP was carried out at 37°C using a SD-OSR IX83 inverted microscope (Olympus, Tokyo, Japan) equipped with a 100× NA 1.4, UPLS APO oil immersion objective (Olympus, Tokyo, Japan) and Yokogawa W1 spinning disk unit (Yokogawa, Musashino, Japan) and controlled by MetaMorph software (Universal Imaging, San Jose, CA). An area near the cell periphery was selectively illuminated. Images were recorded at a rate of 2 s/frame. Speed, straightness, and frequency measurements were performed by tracking individual actin filaments manually using ImageJ software. Graphs were generated based on the data obtained by ImageJ using Prism software (GraphPad Software, San Diego, CA). Single-molecule speckle imaging of EGFP-mDia3 was acquired using a microscope (IX81, Olympus, Tokyo, Japan) equipped with 100-W mercury illumination, a Plan-Apo 100×, 1.4 NA oil-immersion objective (Olympus, Tokyo, Japan), and a cooled EMCCD camera (Evolve 512; Photometrics, Tucson, AZ). Cells expressing a low level of EGFP-mDia3 were observed. An area near the cell periphery was selectively illuminated. Images were recorded at a rate of 200 ms/frame. Measurements of speed, straightness, and travel distance of single-molecule movement were performed by tracking individual single molecules manually using ImageJ software. Graphs were generated based on the data obtained by ImageJ using Prism software (GraphPad Software, San Diego, CA). Kymograph analysis was performed using MetaMorph software (Universal Imaging, San Jose, CA).
Testes were isolated from the 3-wk-old C57BL/6-Tg (CAG-EGFP) mice, and the tunica and blood vessels were dissected and removed by fine forceps. Isolated testes were minced in PBS using scalpel blades. The minced tissue was then transferred into 50-mL plastic tubes and centrifuged at 100g for 1 min. Supernatant was discarded and the pellet was washed twice in PBS and centrifuged at 100g for 1 min to recover germ cells. Cells were then resuspended in PBS and filtered through the 40-μm nylon mesh to remove tissue debris and cell clumps. Germ cells were then centrifuged at 500g for 10 min. The resultant cell pellet was finally resuspended in Ham's F12/DMEM containing 10% FBS .
To remove residual germ cells contaminated in the primary culture of Sertoli cells prepared as described above, the primary cultures, after 3 d of incubation, were subjected to hypotonic treatment for 2 h at room temperature with 20 mM Tris-HCl buffer, pH 7.4, for 2 min . Purified Sertoli cells were then incubated with 10% FBS in IMDM for 2 h in 5% CO2 at 37°C to recover from the hypotonic treatment. Germ cells (5×105 cells/well) isolated from testes of 3-wk-old C57BL/6-Tg (CAG-EGFP) mice were then plated onto the Sertoli cells. These cells were cocultured for 1 d, fixed with 4% PFA/PBS for 15 min at room temperature, and subjected to immunocytochemistry. Fluorescent images were acquired on a SD-OSR IX83 inverted microscope (Olympus, Tokyo, Japan) equipped with a 100× NA 1.4, UPLS APO oil immersion objective (Olympus, Tokyo, Japan) and Yokogawa W1 spinning disk unit (Yokogawa, Musashino, Japan) controlled by MetaMorph software (Universal Imaging, San Jose, CA).
Living GFP-positive germ cells with round nuclear shape, as determined by DAPI staining and continuous N-cadherin signal around the germ cells, were defined as adhesive cells. Living GFP-positive germ cells with round nuclear shape, as determined by DAPI staining and continuous phalloidin staining surrounding the germ cells, were defined as germ cells with continuous F-actin cup. Cortical F-actin meshwork density and the continuity of the F-actin cup were quantified manually using ImageJ software. Graphs, including the plot of correlation, were generated based on the data obtained by ImageJ using Prism software (GraphPad Software, San Diego, CA).
Sperms prepared from the cauda epididymis and suspended as above were fixed with an equal volume of 2% PFA and 2% GA in 0.1 M cacodylate buffer. Thereafter, they were fixed with 1% GA in 0.1 M cacodylate buffer, pH 7.4, at 4°C overnight. The samples were further fixed with 1% tannic acid in 0.1 M cacodylate buffer, pH 7.4, at 4°C for 1 h. After the fixation, the samples were washed four times with 0.1 M cacodylate buffer for 30 min each, followed by postfixation with 2% OsO4 in 0.1 M cacodylate buffer at 4°C for 2 h. The samples were dehydrated through a series of graded ethanol (50%, 70%, 90%, 100%). The samples were substituted into tert-butyl alcohol at room temperature and then frozen. The frozen samples were vacuum dried. After drying, the samples were coated with a thin layer (30 nm) of osmium by using an osmium plasma coater (NL-OPC80NS, Nippon Laser & Electronics Laboratory, Nagoya, Japan). The samples were observed by a JSM-6340F scanning electron microscope (JEOL, Akishima, Japan) at an acceleration voltage of 5.0 kV.
We constructed the pLV-LifeAct-EGFP (LV, lentivirus) by inserting a LifeAct-EGFP fragment amplified by PCR from pCAG- LifeAct-EGFP with primers LifeAct-EGFP forward (5′-GCTCTAGAATGGGCGTGGCCGACCTGAT-3′) and LifeAct-EGFP reverse (5′-CTCTCGAGTTACTTGTACAGCTCGTCCATGCC-3′) into pLV-CAG1.1 (a gift from Dr. Inder Verma, Salk Institute). Lentivirus were generated as previously reported . We injected recombinant lentivirus vectors into male C57BL6/N adult mice at 6 wk of age. Mice were anesthetized by i.p. injection of Avertin before the operation. Approximately 10 μL of lentivirus vector solution containing 0.04% trypan blue was injected into the right seminiferous tubules via the efferent ductules, according to the method described, and Sertoli cells were selectively labeled . After 1 wk, mice were humanely killed and the injected right testis was dissected and the tunica albuginea were removed. Preparation of seminiferous tubules for imaging was then performed according the previous report , with slight modifications. Seminiferous tubules were disentangled and then fixed with 4% PFA for 1 h at room temperature. Fixed seminiferous tubules were then cut into small pieces and attached to MAS-coated slide glass (Matsunami, Kishiwada, Japan) by half-drying. Specimens were mounted in antifade prolong diamond (Thermo Fisher Scientific, Waltham, MA). Samples were observed under SD-OSR IX83 inverted microscope (Olympus, Tokyo, Japan) equipped with a 100× NA 1.4, UPLS APO silicone immersion objective (Olympus, Tokyo, Japan), and Yokogawa W1 spinning disk unit (Yokogawa, Musashino, Japan) and controlled by MetaMorph software (Universal Imaging, San Jose, CA). Deconvolution processing of stacked images was performed by cellSens Dimension software (Olympus, Tokyo, Japan). Three-dimensional reconstruction of stacked images was generated by Volocity software (PerkinElmer, Waltham, MA).
Prism (GraphPad Software, San Diego, CA) and Excel (Microsoft, Redmond, WA) were used for statistical analyses. Data are presented as mean ± SEM, and were analyzed by one-way factorial ANOVA or unpaired Student t test. P < 0.05 was considered statistically significant.
S1 Fig. Male infertility of mDia1/3 DKO mice.
(A and B) Micrographs (A) and fertilization rate (B) of IVF of ZP-intact oocytes with sperms from WT or mDia1/3 DKO mice. Scale bar, 50 μm. Data represented mean ± SEM. Data are the average of three independent experiments. ***P < 0.001 (Student t test). DKO, double knockout; IVF, in vitro fertilization; mDia1/3, mammalian diaphanous homolog1/3; WT, wild-type; ZP, Zona pellucida.
S2 Fig. Reduced number, abnormal morphology, and impaired motility of mDia1/3 DKO sperm.
(A) HE-stained epididymal cross sections from adult WT or mDia1/3 DKO mice. Scale bar, 25 μm. (B) Total number of sperm per epididymis of WT or mDia1/3 DKO mice. Data represented mean ± SEM. n = 3 and 4 for WT and mDia1/3 DKO, respectively. **P < 0.01 (P = 0.0062, Student t test). (C) Bright-field micrographs of sperm isolated from cauda epididymis. Note that mDia1/3 DKO spermatozoa exhibited abnormal head (arrowhead) and tail (arrow) morphology. Scale bar, 10 μm. (D) SEM micrographs of the head of WT and mDia1/3 DKO sperm isolated from cauda epididymis. Note the abnormal shape of mDia1/3 DKO sperm head. Scale bar, 1 μm. (E) WT and mDia1/3 DKO sperm motility at 0 and 3 h after sperm suspension. Data represented mean ± SEM. n = 3 for each genotype. *P < 0.05, **P < 0.01 (P = 0.003 for 0 h and P = 0.0111 for 3 h, Student t test). (F) A cartoon depicted different parameters for sperm motility, determined by CASA. (G) Quantification of VAP (average path velocity) of sperm motility from WT (black) and mDia1/3 DKO (white) sperms isolated from cauda epididymis at 0 and 3 h after sperm suspension. Data represented mean ± SEM. n = 3 for each genotype. *P < 0.05 (P = 0.0263 for 0 h and P = 0.0138 for 3 h, Student t test). (H) Quantification of VSL (straight-line velocity) of sperm motility from WT (black) and mDia1/3 DKO (white) sperms isolated from cauda epididymis at 0 and 3 h after sperm suspension. Data represented mean ± SEM. n = 3 for each genotype. *P < 0.05 (P = 0.1569 for 0 h and P = 0.0251 for 3 h, Student t test). (I) Quantification of VCL (curvilinear velocity) of sperm motility from WT (black) and mDia1/3 DKO (white) sperms isolated from cauda epididymis at 0 and 3 h after sperm suspension. Data represented mean ± SEM. n = 3 for each genotype. *P < 0.05 (P = 0.0177 for 0 h and P = 0.0157 for 3 h, Student t test). CASA, computer-assisted sperm analysis; DKO, double knockout; HE, hematoxylin–eosin; mDia1/3, mammalian diaphanous homolog1/3; n.s., not significant; VAP, average path velocity; VCL, curvilinear velocity; VSL, straight-line velocity; WT, wild-type.
S3 Fig. Increased apoptotic cells in mDia1/3 DKO seminiferous tubule.
(A) Apoptotic cells (green) in the mDia1/3 DKO seminiferous tubules. Nuclei (magenta) were stained with Hoechst. Scale bar, 100 μm. (B) Quantification of the number of apoptotic cells per seminiferous tubule. Data represented mean ± SEM (91 seminiferous tubules from four WT mice and 99 seminiferous tubules from four mDia1/3 DKO mice). ***P < 0.001 (Student t test). DKO, double knockout; mDia1/3, mammalian diaphanous homolog1/3; WT, wild-type.
S4 Fig. Specificity of anti-mDia1 and anti-mDia3 antibodies for immunohistochemistry.
(A) Immunohistochemistry staining for mDia1 (green) and vimentin (magenta) as a marker for Sertoli cells in testis sections from WT and mDia1 KO adult mice. Positive mDia1 signals at the vimentin-positive Sertoli cells observed in WT mice were abolished in mDia1 KO mice. Scale bar, 100 μm. (B) Immunohistochemistry staining for mDia3 (green) and vimentin (magenta) as a marker for Sertoli cells in testis sections from WT and mDia3 KO adult mice. Positive mDia3 signals at the vimentin-positive Sertoli cells observed in WT mice were abolished in mDia3 KO mice. Scale bar, 100 μm. KO, knockout; mDia1, mammalian diaphanous homolog1; mDia3, mammalian diaphanous homolog3; WT, wild-type.
S5 Fig. mDia3 expression in the seminiferous tubules throughout the spermatogenic cycles.
(A) Immunohistochemistry staining for mDia3 (green) and phalloidin staining (magenta) of WT testis sections. Arrowheads indicate mDia3 staining at the basal ectoplasmic junction and arrows indicate mDia3 staining at the apical ectoplasmic junction. (B) Immunohistochemistry staining for mDia3 (green) and phalloidin staining (magenta) of mDia3 KO testis sections. Positive mDia3 signals observed in WT mice were mostly abolished in mDia3 KO seminiferous tubules, confirming the specificity of mDia3 antibodies. White asterisks indicate nonspecific staining signals in Leydig cells. Scale bars, 100 μm. KO, knockout; mDia3, mammalian diaphanous homolog3; WT, wild-type.
S6 Fig. Reduced F-actin staining of mDia1/3 DKO primary cultured Sertoli cell.
(A) Confocal images of actin filaments of WT (left) and mDia1/3 DKO (right) primary cultured Sertoli cells. The lines (magenta and green) were used to quantify the fluorescence intensity by line scan, and the fluorescence intensity profiles along these lines are shown in the right. Scale bar, 20 μm. DKO, double knockout; F-actin, filamentous actin; mDia1/3, mammalian diaphanous homolog1/3; WT, wild-type.
S7 Fig. Reduced cortical F-actin meshwork in mDia1/3 DKO Sertoli cells was rescued by expression of EGFP-mDia3.
(A) mDia1/3 DKO primary cultured Sertoli cells transfected with pEGFP-mDia3 (green) were stained with phalloidin (magenta). The cell on the right is EGFP-mDia3 positive. The magenta and green dotted line was used to quantify the fluorescence intensity of mDia1/3 DKO Sertoli cells and EGFP-mDia3 expressed mDia1/3 DKO Sertoli cells in the line scan, subsequently. Scale bar, 50 μm. (B) Fluorescence intensity profiles along the line shown in S7A Fig. (C) Quantification of average normalized F-actin intensity per cell. Data represented mean ± SEM. Data are a sum of three independent experiments. n = 19 and 20 for mDia1/3 DKO and mDia1/3 DKO + EGFP-mDia3 Sertoli cells, respectively. ***P < 0.001 (Student t test). DKO, double knockout; EGFP, enhanced green fluorescent protein; F-actin, filamentous actin; mDia1/3, mammalian diaphanous homolog1/3; pEGFP, enhanced green fluorescent protein expression plasmid.
S8 Fig. F-actin architecture of Sertoli cells in intact seminiferous tubules.
(A) Transduction of LifeAct-EGFP expressing lentivirus in the testis of WT mouse. Seminiferous tubule was microinjected with LifeAct-EGFP expressing lentivirus and analyzed at 1 wk after injection under fluorescence stereomicroscope. (B) Observation strategy of LifeAct-EGFP expressing lentivirus transduced Sertoli cells. To observe LifeAct-EGFP of Sertoli cells in intact seminiferous tubules ex vivo, seminiferous tubules of the microinjected testis were dissected and untangled under fluorescence stereomicroscope. Isolated seminiferous tubules were then cut into small pieces about 2–3 mm, fixed, and then mounted between a slide glass and cover glass. The LifeAct-EGFP–labeled Sertoli cell near the cover glass was then observed with an inverted confocal microscope equipped with a spinning disk through the peritubular myoid cell layer and basal membrane. (C) A stacked spinning disk confocal image of a LifeAct-EGFP expressing lentivirus transduced Sertoli cell. Image was processed with a deconvolution algorithm. Scale bar, 10 μm. The red and blue boxes are magnified images of the corresponding boxed areas of the lower magnification. Arrowhead indicates thick F-actin bundles and arrows indicate fine meshwork F-actin filaments. EGFP, enhanced green fluorescent protein; F-actin, filamentous actin; WT, wild-type.
S9 Fig. Nectin-2 expression in the seminiferous tubules throughout the spermatogenic cycles.
(A) Immunohistochemistry staining for nectin-2 (green) and Hoechst staining (magenta) of testis sections from WT mice. Strong nectin-2 signals were observed at the apical ectoplasmic specialization junction. In addition, nectin-2 signals were observed at the adherens junction located on the boundary between cells. (B) Immunohistochemistry staining for nectin-2 (green) and Hoechst staining (magenta) of testis sections from mDia1/3 DKO mice. Nectin-2 signals at both the apical ectoplasmic specialization junction and adherens junction were reduced. Scale bars, 100 μm. DKO, double knockout; mDia1/3, mammalian diaphanous homolog1/3; WT, wild-type.
S10 Fig. Immunohistochemistry of espin1 together with phalloidin staining in seminiferous tubule throughout spermatogenic cycles.
(A) Immunohistochemistry staining for espin1 (green) and phalloidin staining (magenta) of testis sections from WT mice. Espin1 signals were observed at the apical ES junction of elongated spermatid from stages II–V seminiferous tubules of the WT mice. (B) Immunohistochemistry staining for espin1 (green) and phalloidin staining (magenta) of testis sections from mDia1/3 DKO mice. Espin1 signals were ectopically localized to the abnormal F-actin bundles in the process of Sertoli cells throughout the spermatogenic cycle. Scale bars, 100 μm. DKO, double knockout; ES, ectoplasmic specialization; F-actin, filamentous actin; mDia1/3, mammalian diaphanous homolog1/3; WT, wild-type.
S11 Fig. Model of the molecular mechanism of mDia1/3 function in spermatogenesis through the regulation of F-actin and cell adhesions between Sertoli cell and germ cell.
F-actin, filamentous actin; mDia1/3, mammalian diaphanous homolog1/3.
S1 Movie. F-actin dynamics observed with SDSRM.
EGFP-LifeAct was expressed in primary cultured Sertoli cell from WT mouse; the images were taken every 2 s. EGFP, enhanced green fluorescent protein; F-actin, filamentous actin; SDSRM, spinning disk superresolution microscopy; WT, wild-type.
S2 Movie. Fast polymerization of cortical actin filament meshwork observed with SDSRM.
EGFP-LifeAct was expressed in primary cultured Sertoli cell from WT mouse; the images were taken every 2 s. EGFP, enhanced green fluorescent protein; SDSRM, spinning disk superresolution microscopy; WT, wild-type.
S3 Movie. Intracellular molecular movement of EGFP-mDia3 underneath the cell cortex, observed with TIRF microscopy.
EGFP-mDia3 was expressed in primary cultured Sertoli cell from WT mouse; the images were taken every 200 ms. EGFP, enhanced green fluorescent protein; mDia3, mammalian diaphanous homolog3; TIRF, total internal reflection; WT, wild-type.
S4 Movie. Single-molecule observation of fast movement of EGFP-mDia3 in a primary cultured Sertoli cell with TIRF microscopy.
S5 Movie. Three-dimensional reconstruction of deconvolution spinning disk confocal images of Sertoli cell F-actin in intact seminiferous tubule.
Z-series images of Sertoli cell transduced by LifeAct-EGFP expressing lentivirus in intact seminiferous tubule were acquired by spinning disk confocal microscopy and processed with a deconvolution algorithm. Three-dimensional reconstruction and movie were generated by Volocity software. EGFP, enhanced green fluorescent protein; F-actin, filamentous actin.
We thank M. Okabe for acro/act-EGFP [TgN(acro/act-EGFP)OsbC3-N01-FJ002] mice, I. Verma for pLV-CAG1.1, and B. Kachar for anti-espin1 polyclonal antibodies. We also thank T. Nakagawa, T. Shinohara, and S. Tsukita for advice and K. Naruo and Y. Katsura for assistance with animal experiments.
51. Toyoda Y, Yokoyama M, Hoshi T. Studies on the fertilization of mouse egg in vitro. Jpn J Anim Reprod. 1971;16: 147–151.
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https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.2004874
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In spite of the many achievements in health care delivery in the current century as evidenced by the rapid progress and expansion of orthodox medicine, people in Nigeria like in most of the developing countries lack regular access to essential medicines. For these people, faith in and popularity of traditional methods have not decreased because modern medicine is unlikely to be a tenable treatment alternative primarily because of its high cost. The cost of modern medicine is constantly increasing with improvements in modern health technology and in many cases is inappropriate to the immediate needs of people in developing and underdeveloped countries. On the other hand, medicinal herbs are widely available and affordable, even in remote areas. In addition, consumers believe that herbal medicines are safe because they are Natural. The constant resort to medical herbalism has however, thrown up certain health challenges arising from the side and unwanted effects of these herbs on the human anatomy and physiology. One such health condition is male infertility or sub-fertility as a result of the effect of medicinal herbs on the male reproductive organs. This review attempts to document those nigerian medicinal plants that possess the potentials to reduce male fertility particularly as demonstrated from the results of basic and allied medical sciences research and published in the peer reviewed scientific literature.
INTRODUCTION
Complementary and Alternative Medicine (CAM) is defined as "A group of diverse medical and health care systems, practices and products that are not presently considered to be part of conventional medicine". It interprets "Complementary" medicine as being used together with conventional medicine, whereas "Alternative" medicine is used in place of conventional medicine (Hoffman and Fox, 2006).
The CAM therapies are classified into four categories or domains (May, 2011):
Biologically based therapies in CAM use substances found in nature, such as herbs, foods and vitamins. Some examples include dietary supplements, herbal products and the use of other so-called natural but as yet scientifically unproven therapies (for example, using shark cartilage to treat cancer) (Ruggie, 2004; Shealy and Dawson, 2006).
Medical herbalism or simply, herbalism or herbology, is "The study of herbs and their medicinal uses". This definition can be extended to include the cultivation, collection or dispensing of aromatic plants, especially those considered to have medicinal properties.
Other terms substituted for medical herbalism, include herbal or botanical medicine or phytotherapy, previously defined as "The use of plant materials to prevent and treat ill health or promote wellness" (Bekalo et al., 2009).
Medicinal plants play a crucial role in health care needs of people around the world especially in developing countries (Rao et al., 2004; Bekalo et al., 2009). About 80% of the populations of most developing countries still depend on the use of traditional medicine derived from plants (Cunningham, 1993).
The African continent has a long history with the use of plants for medicinal purposes (Metz, 1991). Traditional medicine was the only source of health care in Nigeria in historical times.
Orthodox medicine was not formally introduced into Nigeria until 1860s when Sacred Heart Hospital was established by the Roman Catholic Missionaries in Abeokuta (Bekalo et al., 2009).
In the past two decades, there has been a global resurgence of interest in traditional medicine for the treatment of ailments that defile orthodox medicine principally because many diseases have defiled or developed resistance to conventional drugs as well as a health system closer to the rural poor. As a result of this renaissance in unorthodox medicine, a lot of interest and attention have been drawn to the curative claims and norms (ethics) of herbal plants in different parts of the globe especially Africa and Asia.
Characteristics of herbal medicine: Herbal medicine has some characteristics that make them unique and different from synthetic drugs (Calixto, 2000). These include:
The medical systems in developing countries involve both traditional herbal systems and orthodox medicine. Due to the economic predicament of these countries, the people resort to the traditional herbal system for primary health care. In Africa, particularly West Africa, new drugs are not often affordable thus up to 80% of the population use medicinal plants as remedies (Kirby, 1996; Hostettmann and Marston, 2002). World bank data on African development indicators 2003 revealed that the ratio of medical doctors to total population for 1990-2000 in Nigeria was 1:5208. This condition and the fact that international commercial orthodox medicines are becoming increasingly out of reach for most Nigerians have contributed to the dependence of a large percentage of the Nigerian people on local herbal medicine (Sofowora, 1992).
Treatment offered by traditional herbal healers at the primary health care leveled has greatly sustained the Nigerian Society before and after colonization.
IMPORTANCE OF MEDICAL HERBALISM IN AFRICA
World Health Organization (WHO) estimates that around 80% of the population in Africa-use traditional medicines. About 85% of traditional medicine involves use of plant extracts (Farnsworth and Soejarto, 1985). This would imply that the reliance on herbal medicine is immense. To appreciate the extent of this dependence, it is estimated that in Sub-Saharan Africa there is one traditional healer for every 500 people, whereas there is only one medical doctor for every 40,000 people. Therefore the importance of herbal medicines in the life of Africans cannot be overemphasized. The re-insurgence of interest of herbal medicines in Africa is backed by several reasons namely, the increasingly expensive and unavailability of orthodox drugs to average income earners (Sofowora, 1992). Another reason is that many ailments are developing resistance to orthodox drugs, for instance, the increasing resistance of malaria parasites to chloroquine which is the cheapest and the most commonly used drugs for treating malaria in Nigeria (Odugbemi et al., 2007). Bacterial resistance to antibiotics is another classical example. The inability of Western orthodox medicine to provide cure for some diseases and infections (e.g., HIV/AIDS) is a possible reason also. The ascendancy of the human immune deficiency virus has spurred intensive investigation into plant derivatives which may be effective especially for use in developing and underdeveloped nations. The little or no side effects with use of herbal medicines are other factors often stated in favour of herbalism.
Demand for herbal medicine: For years, public interest has increased for natural therapies (mainly herbal medicine) all over the world including Africa (Grunwald, 1995; Robbers et al., 1996; Blumenthal, 1999). According to Grunwald (1995), there are several factors that lead to the preference and growth of phytotherapeutic market worldwide and they include:
EFFECTS OF HERBAL MEDICINES ON MALE REPRODUCTIVE ANATOMY AND PHYSIOLOGY
Male reproduction anatomy is a complex structure that involves the testes, epididymis, accessory sex glands and associated hormones. Testes perform two highly organized and intricate functions, called spermatogenesis and steroidogenesis, which are crucial for the perpetuation of life. Spermatogenesis, a highly dynamic and synchronized process, takes place within the seminiferous tubules of the testis with the support of somatic Sertoli cells, leading to the formation of mature spermatozoa from undifferentiated stem cells (Hess and de Franca, 2008). The interstitial compartment, which comprises leydig cells, is the site of steroidogenesis in the testis (Osinowo, 2006).
Several plants are reported to enhance reproductive processes in laboratory animal models. This has been severally demonstrated in our laboratory. This include the findings that; grapefruit seed extract demonstrates profertility effects in male rats (Saalu et al., 2008, 2010a, b), extract of Sesame radiatum enhances fertility in male Sprague dawley rats (Ukwenya et al., 2008), Moringa oleifera lamark (drumstick) leaf extract modulates testicular toxicity in rats (Saalu et al., 2011), aqueous extract of date (Phoenix dactylifera) protects testis (Akunna et al., 2012), Laurus nobilis preserves testicular functions in crytorchid rat (Akunna et al., 2012), stem bark extract of Enantia chlorantha has testiculo-protective effect on Lead-induced toxicity in adult wistar rat (Oyewopo et al., 2012), bitter leaf has a modulating role on spermatogenic and steroidogenesis functions of the rat testis (Saalu et al., 2013), Cissus populnea extract and Jatropha curcas extract has ameliorating effect on the rat testis (Oyewopo et al., 2014) and Croton zambesicus leaf extract has ameliorating capabilities on the testis of rats exposed to pyrethroid-based insecticide (Akunna et al., 2014).
However, many basic science researches have shown several medicinal plants that hinder testicular functions.
The aim of this review is to collate all available data on nigerian medical plants with antifertility effects reported in the scientific literature.
The list of potential male antifertility Nigerian medicinal plants is presented with their photo, scientific name, common name and the local nigerian names of the country in which they are available are indicated. The description of methods used in the experiment model animals and the effect of antifertility, doses, duration of exposure, the part used, the folkloric usage and phytochemical composition are also included. Plants which did not show any significant antifertility effect were not included.
A total of 40 medical plants are reported in this review as having different antifertility activities. The collected information are given below and also summarized in Table 1 and 2.
Testicular degeneration characterized by reduced number of cells in the epithelium along with reduction in the number of sperm cells was observed when the aqueous extract of Abrus precatorious was administered to male rats at doses of 400, 800 and 1600 mg kg1 b.wt. for 18 days (Adedapo et al., 2007). The alcoholic seed extracts of Abrus precatorious at a dose of 100 mg kg1 b.wt. for 60 days significantly lowered cauda epididymal sperm motility and brought about a decrease in the levels of succinate dehydrogenase and ATPase in the sperm of albino rats. Scanning electron microscopic studies on sperm morphology revealed decapitation, acrosomal damage and formation of bulges on the mid piece region of sperms following exposure to Abrus precatorious seed extracts (Rao, 1987). Irreversible impairment of the motility of human spermatozoa at a concentration of 20 mg mL1 of the methanol extract of Abrus precatorious seed extracts was reported, which may be due to the decline in cAMP and enhanced generation of reactive oxygen species (Ratnasooriya et al., 1991).
Dose-dependent decrease in the enzyme activity of 3α, 3β, 17β-hydroxysteroid dehydrogenases and degeneration of leydig cells were reported when Abrus precatorius was administered to male rats (Sinha and Mathur, 1990).
Administration of methanolic extract of the seeds of A. precatorius (Fabaceae) (20 and 40 mg kg1 b.wt. day1) for 45 days in adult male mice caused a significant decrease in caudal sperm motility, count and viability. There was a complete suppression of fertility at 40 mg kg1 dose level. The decrease in weights of testes and Cauda epididymis of mice at 40 mg kg1 level was also observed (Bhatt et al., 2007).
Methanolic extract of A. precatorius seeds (5.0 and 20.0 mg mL1) showed inhibitory effects on the motility of washed human spermatozoa. The extract caused a concentration-related impairment of percentage sperm motility. With the highest concentration tested (20.0 mg mL1), the onset of the antimotility action was almost immediate. In addition, this concentration impaired the functional integrity of the plasma membrane (hypo-osmotic swelling test) and viability (nigrosin-eosin stain) of spermatozoa (Ratnasooriya et al., 1991).
Oral administration of crude mixture of A. precatorius seeds at dose of 50 mg kg1 b.wt., caused reduction in the epididymal sperm count and reduced level of testosterone was also observed (Gigani et al., 2012):
In male rats the methanolic extract of Albizzia lebbeck pods causes spermatogenic arrest and brought about a significant decrease in sperm motility and density. There was a marked reduction in the numbers of primary spermatocytes, secondary spermatocytes and spermatids (Gupta et al., 2004). Further, administration of saponins isolated from Albizzia lebbeck L. (50 mg kg1 b.wt. day1) for 60 days caused a significant decrease in the weights of reproductive organs of rats. The population of various spermatogenic cells in seminiferous tubules decline significantly (Gupta et al., 2005):
In male rats, triterpene extract of the bark of Acacia auriculaeformis at 20 and 50 mg kg1 b.wt., for 40 days caused a sperm immobilizing effect (Pakrashi et al., 1991):
Acacia concinna is a climbing shrub. The tree is food for the larvae of butterfly.
Methanolic extract of the bark of Acacia concinna 20 and 50 mg kg1 b.wt., for 40 days was shown to have spermicidal and semen coagulating effects in the rat (Kamboj and Dhawan, 1982):
Allamanda cathartica L. (Apocyanaceae) is widely growing perennial shrub. The leaves are smooth and thick (Islam et al., 2010).
The roots are used against jaundice, complications with malaria and enlarged spleen in traditional medicine. The flowers act as a laxative. Moreover, yellow Allamandah as also antibiotic action against Staphylococcus (Nayak et al., 2006).
All parts of the plant contain allamandin, a toxic iridoid lactone. Leaves and stems yield ursolic acid, β-amyrin and β-sitosterol. Plumericin and isoplumericin are extracted from stem and root-bark, also from leaves and roots, besides plumieride and long chain esters (Nithya and Muthumary, 2011).
The oral administration of aqueous leaf extract of A. cathartica (150 mg kg1 b.wt. day1 for 14, 28 and 42 days) induces infertility and changes in various male reproductive endpoints in Parkes strain mice. Histologically, testes in extract-treated mice showed non-uniform degenerative changes in the seminiferous. The treatment also had adverse effects on motility, viability, morphology and on number of spermatozoa in the cauda epididymidis. Fertility of the extract-treated males was also suppressed (Singh and Singh, 2008):
Allium sativum, commonly called garlic is a species in the onion genus.
The crude aqueous extract of Allium sativum bulb possesses spermicidal activity and showedthe most promising results by instantimmobilization of the epididymal sperm at 0.25 g mL1 and human ejaculated sperm at 0.5 g mL1.
More than 50% reduction in sperm viability occurred in treated sperm, indicating the possibility of plasma membrane disintegration which was further supported by the significant reduction in the activity of membrane bound nucleotidase and acrosomal acrosin (Chakrabarti et al., 2003). On the testes, use of garlic has been noted to compromise some male reproductive functions, as it affects spermatogenesis and testosterone levels, which are vital to reproduction (Hammami et al., 2008, 2009).
Administration of aqueous extract of garlic different doses (500 and 1000 mg kg1 day1) to the wistar rats caused reduction in the percentage of morphologically normal spermatozoa as well as sperm concentration (Omotoso et al., 2010):
Aloe babadensis is a succulent plant species. About 50% ethanolic extract Aloe barbadensis leaf extract 70 and 100 mg kg1 b.wt. day1 for 56 days showed antiandrogenic activity in the dog (Dixit and Joshi, 1983):
About 70 mg and 100 mg kg1 b.wt. day1 for 32 days of acqueos extract of Anethum graveolens seed extract exhibited antispermatogenic effects in the rat (Malihezaman and Sara, 2007):
Methanol leaf extract of Aspillia africana 100, 200, 400 mg kg1 b.wt. day1 for 52 days showed antispermatogenic effect in rat (Ruth et al., 2015):
Ananas comosus also called pineapple is a tropical plant with multiple fruit consisting of coalesced berries. Ethanol extract of unripe fruit of Ananas cosmosus 200 mg kg1 b.wt. day1 for 60 days showed antispermatogenic activity in rat (Satyawati, 1983):
Administration of A. indica are reduced the fertilizing activity and administration of dry powder of leaves of A. indica at the dose level of 20, 40 and 60 mg rat1 day1 results in a decrease in weight of seminal vesicle and decrease in the sperm count (Shaikh et al., 1993).
Histopathological and biochemical changes in the testis of rats treated with the leaf powder of A. indica were reported (Joshi et al., 1996). It suggested a possible reversible antiandrogenic property of the leaves of A. indica in male albino rats. Neem seed extract is reported to induce abnormality in spermatogenesis and sperms production in some of the seminiferous tubules (Meymand et al., 2002). Ultrastructural changes like intracellular spaces and vacuolization in sertoli cells and defects in the mitochondrial sheath of late spermatids were induced by leaves of A. indica (Neem) in the testis of albino rats (Kasturi et al., 2002). Neem oil proved spermicidal against rhesus monkey and human spermatozoa in vitro. Antifertility effect of neem oil has also been studied and suggested to be a novel method of contraception (Biswas et al., 2002). Contraceptive effects of A. indica leaves (500 mg kg1 b.wt. day1) on testosterone (0.25 mg kg1 b.wt. day1) were also studied in male rats (Aladakatti and Ahamed, 2005).
Inclusion of neem leaf meal up to 15% in the ration of matured rabbit bucks could cause mild supressive effect on the spermatogenesis, semen quality and seminiferous tubule diameter male albino rat treated with low dose (0.6 mL of neem oil/animal) and high dose (1.2 mL of neem oil/animal) of neem oil revealed significant decrease in the seminiferous tubular diameter and number of spermatozoa (Shaikh et al., 2009):
Bamboo buds ethanolic extract given 100 and 200 mg kg1 b.wt. daily for 60 days demonstrated impaired structural and functional activity of the epididymis in the rat (Manonayagi et al., 1989):
Also known as the porcupine flower is a species in the family Acanthaceae.
Male rats treated with isolated fractions of the B. prionitis root methanolic extract (100 mg kg1 for 60 days) showed a significant reduction on spermatogenesis without affecting general body metabolism. Sperm motility as well density in cauda epididymides was reduced significantly. The population of various spermatogenic cells such as primary spermatocytes, secondary spermatocytes and round spermatids were declined significantly in treated animals (Verma et al., 2005).
Oral administration of root extract of B. prionitis L. to male rats (100 mg rat1 day1) for the period of 60 days did not cause body weight loss. The root extract brought about an interference with spermatogenesis. The round spermatids were decreased by 73.6% (p≤0.001). The extract reduced the fertility of male rats by 100%. Cross sectional surface area of Sertoli cells and mature leydig cell numbers were significantly reduced (36.9%). Testicular glycogen contents were low. Antifertility effects of Barleria seemed to be mediated by disturbances in testicular somatic cells functions (Leydig and sertoli cells) resulting in the physio-morphological events of spermatogenesis (Gupta et al., 2000):
This plant is also popularly referred to as giant milk weed. It is used to treat headache, painful swellings and carious tooth (Iwu, 1993). It was found to decrease testicular weight and it caused testicular degenerative changes in Wistar rat (Akinloye et al., 2002):
Cannabis sativa is an annual herbaceous plant in the cannabis genus, a species of the cannabaceae family.
Methanolic leaf extract of Cannabis sativa 25 mg kg1 b.wt. day1 given for 30 days caused testicular lesion with atrophy of the leydig cells in the mouse (Sailani and Moeini, 2007):
The benzene chromatographic fractions of chloroform extract of the seeds of C. papaya possess reversible male contraception potential and the effect appears to be mediated through the testis without adverse toxicity (Pathak et al., 2000). Even aqueous extract of papaya bark has potential contraceptive activity. Further studies revealed that the inhibition of sperm motility may be due to ultrastructural changes in epididymis (Manivannan et al., 2004):
Celastrus paniculatus is a woody liana commonly known as black oil plant, climbing staff tree and intellect tree.
Ethanolic extract of Celastrus paniculatus seed 20 mg kg1 b.wt. day1 for 30 days showed antispermatogenic activity in rat (Bidwai et al., 1990):
Administration of crude 50% ethanol extract of C. colocynthis schrad roots to male albino rats at dose levels of 50, 100 and 200 mg kg1 b.wt. day1 for a period of 60 days caused a significant decreases in cauda epididymal sperm motility, density, number of pups and fertility (Mali et al., 2001). The 50% ethanolic extract of C. colocynthis extract showed an antiandrogenic nature, thereby reduced reversible infertility in male albino rats. The testes showed degenerative changes in the seminiferous epithelium and arrest of spermatogenesis at the secondary spermatocyte stage (Chaturvedi et al., 2003):
Chromolaena odorata (Asteraceae) commonly known as Siam weed is a fast-growing perennial and invasive weed.
Oral administration of aqueous extract of C. odoratum leaves (250 and 500 mg kg1 b.wt.) for 14 days in male albino rats revealed a significant reduction (p<0.05) in testicular body weight ratio and histological examination revealed disruption in the arrangement of seminiferous tubules with no distinct basement membrane. These changes were accompanied by reduction in the number of spermatozoa. All these results indicated that aqueous extract of C. odoratum leaves possesses antiandrogenic property by interfering with steroidogenesis at the testicular level and this will adversely affect the functional capacity of the testes and the fertility of the animal (Yakubu et al., 2007):
Rats fed with Curcuma longa aqueous and 70% alcoholic extract for 60 days (500 mg kg1 day1) showed a reduction in sperm motility and density. C. longa may have affected the androgen synthesis either by inhibiting the Leydig cell function or the hypothalamus pituitary axis and as a result, spermatogenesis is arrested (Ashok and Meenakshi, 2004).
Male mice of the Parkes (P) strain were orally administered aqueous rhizome extract of C. longa (600 mg kg1 b.wt. day1 for 56 and 84 days) showed adverse effect of on various male reproductive organs and fertility. The treatment had adverse effects on motility, viability, morphology and number of spermatozoa in the cauda epididymidis, serum level of testosterone and on fertility. By 56 days of treatment withdrawal, however, the above parameters recovered to control levels. The results show that C. longa treatment causes reversible suppression of spermatogenesis and fertility, thereby suggesting the potential of this plant in the regulation of male fertility (Mishra and Singh, 2009a):
Aqueous extract of Daucus carota tuber 0.5 g kg1 b.wt. day1 given for 60 days exhibited anti-spermatogenic activity in the rat (Shah and Varute, 1980):
Aqueous extract of the Fadoga agrestis stem 18, 50, 100 mg kg1 b.wt. day1 for 28 days showed reduced testicular function in rat (Yakubu et al., 2008).
Gossypol, a yellow polyphenolic compound present in the stem, seeds and roots of Gossypium species. It is known to exert unique and selective effects upon reproduction in various species such as rats, mice, hamsters, rabbits, monkeys and human beings (Coutinho, 2002). The contraceptive effect of gossypol was first discovered in China. Gossypol was reported to invoke antifertility effects in rats at 30 mg kg1 b.wt., whereas a much lesser dose, 0.3 mg kg1 b.wt., could incite infertility in humans, making the compound very efficient in humans than in rats (Udoh et al., 1992).
Several studies affirm that gossypol treatment reduced the level of serum testosterone and luteinizing hormones in dose and duration dependent manner (Zhuang et al., 1986).
Gossypol acts directly on testes and induces azoospermia or oligospermia (Zhuang et al., 1986):
Aqueous leaf and stem extract of Leptadenia hastata 100, 200, 400, 800 mg kg1 b.wt. day1 given for 60 days showed anti-spermatogenic activity in rat (Bayala et al., 2011):
Petroleum ether, benzene and alcohol extracts of the seeds of Momordica charantia tested in rats at the dose level of 25 mg/100 g b.wt. for 35 days showed antispermatogenic activity as the number of spermatocytes, spermatids and spermatozoa decreased.
Increase in cholesterol level and sudanophilic lipid accumulation indicates inhibition in the steroidogenesis. Out of the three extracts, the alcohol extract was more potent in its antispermatogenic, antisteroidogenic and androgenic activities (Naseem et al., 1998). It has been shown that oral administration of M. charantia root extract (5 mg kg1 b.wt. day1 for 60 days) showed 100% antifertility in the rats (Yama et al., 2011). There was marked decline in testicular germ cell population, leydig cell number and nuclear area as comported to controls. Serum testosterone level also reduced after extract treatment:
Morinda lucida is an evergreen shrub or small to medium-sized tree bearing a dense crow of slender, crooked branches.
Aqueous leaf extract of Morinda lucida 400 mg kg1 b.wt. day1 for 13 weeks had antispermatogenic properties on the rat (Raji et al., 2005):
Ethanolic seed extract of Mucuna urens 70, 140, 210 mg kg1 b.wt. day1 for 14 days exhibited anti-spermatogenic activity in the rat (Etta et al., 2009):
Ethanolic leaf extract of Nicotiana tabacum 100, 200 mg kg1 day1 for 60 days showed anti-androgenic effect in the rat (Londonkar et al., 1998):
Piper nigrum L. commonly known as black pepper belongs to family Piperaceae. The fruits of P. nigrum are not only important as a spice or flavoring agent but have also been prescribed for cholera, dyspepsia, diarrhea, various gastric ailments and paralytic and arthritic disorders.
Oral administration of fruit powder of P. nigrum (25 and 100 mg kg1 b.wt. day1 for 20 and 90 days) to male mice of the Parkes (P) strain adversely affects sperm parameters and also caused marked alterations in male reproductive organs (Mishra and Singh, 2009b).
Piperine (1-piperoylpiperidine) is an alkaloid present in the fruits of black pepper (Piper nigrum), long pepper (Piper longum) and other piper species. Epididymal sperm count and motility decreased at 10 and 100 mg kg1 and sperm viability decreased significantly at 100 mg kg1.
Piperine could damage the epididymal environment and sperm function (DCruz and Mathur, 2005):
Aqueous extract of Pterocarpus santalinus stem 100 mg kg1 day1 for 60 days demonstrated semen coagulating activity in mice (Dhawan et al., 1980):
Ethanolic extract of Ricinus communis seed 100 mg kg1 day1 for 60 days showed alteration in motility, mode of movement and morphology of sperms in rat (Sandhyakumary et al., 2003):
Syzygium aromaticum L. commonly known as clove belongs to family Myrtaceae. It is used as a spice to add flavor to exotic food preparations.
Oral exposure of hexane extract of flower buds of S. aromaticum in three doses (15, 30 and 60 mg kg1 b.wt.) for a single spermatogenic cycle (35 days) in Parkes (P) strain mice induced non-uniform degenerative changes in the seminiferous tubules associated with decrease in daily sperm production and depletion of round and elongated spermatids population (Mishra and Singh, 2008):
Alcohol extract of the seed of Syzygium cuminii 100 mg kg1 day1 for 60 days showed anti-spermatogenic effect in rat (Shad et al., 2014):
Ethanol leaf extract of Tecoma stans 500 mg kg1 day1 for 60 days demonstrated anti-spermatogenic effect in rat (Mathur et al., 2010):
Ethanol extract of the fruit of Terminalia superba 50 and 100 mg kg1 day1 for 60 days showed anti-androgenic effect in rat (Srivastav et al., 2010):
Methanol extract of stem bark of Thevetia peruviana 100 mg kg1 day1 for 60 days showed ant-spermatogenic effect (Gupta et al., 2011):
Tinospora cordifolia (Willd.) belongs to the Menispermaceae family. It is reported to possess anti-spasmodic, antiinflammatory, anti-allergic, anti-diabetic, antioxidant properties (Premanath and Lakshmidevi, 2010):
Trigonella foenum-graecum (Fenugreek) is a member of the Fabaceae family. Fenugreek is native to the area from the eastern Mediterranean to Central Asia and Ethiopia and much cultivated in Pakistan, India and China. Its dried ripe seeds are variously referred to as Trigonella seeds or as Fenugreek.
Trigonella foenum-graecum tends to reduce the male fertility by reducing testosterone concentration, sperms concentration and inhibiting mass and individual motility of the sperms (Kassem et al., 2006):
Aqueous extract of leaf of Vigna ungiculata 200 mg kg1 day1 for 30 days showed anti-spermatogenic effect in rat (Umapathy, 1993):
Ziziphus belongs to the kingdom; plantae, order; roasles, division; magnoliophyta, class; magnoliopsida, family; rhamnaceae, genus, Ziziphus. Z. mauritiana is a fast growing small to medium-sized, single or multi-stemmed, spiny shrub or tree, which is almost evergreen but is deciduous during the dry season. It can reach up to 12 m tall and 30 cm diameter at breast height but is highly variable in size and general appearance. The bark is dark grey, dull black or reddish with long vertical fissures, reddish and fibrous inside. The branches are spreading and droop at the ends.
Acqueous bark extract of Zizyphus mauritiana 0.1 and 0.5 mg/mL/60 days showed spermicidal properties (Dubey et al., 2011).
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https://scialert.net/fulltext/?doi=rjmp.2016.201.227
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Where is cremasteric artery?
Last Update: April 20, 2022
This is a question our experts keep getting from time to time. Now, we have got the complete detailed explanation and answer for everyone, who is interested!Asked by: Asia Russel
Score: 4.5/5 (10 votes)
The cremasteric artery is a small branch of the inferior epigastric artery that enters the deep inguinal ring of the inguinal canal and supplies the layers of the
Which artery gives rise to cremasteric artery?
The cremasteric artery (external spermatic artery) is a branch of the inferior epigastric artery which accompanies the spermatic cord, and supplies the cremaster muscle and other coverings of the cord, anastomosing with the testicular artery (internal spermatic artery in older texts).
Where are the testicular arteries located?
The testicular artery, also known as the internal spermatic artery, is a branch of the abdominal aorta. It arises in the abdomen and reaches the scrotum by traversing the spermatic cord.
What is testicular blood supply?
Vascular Supply
The main arterial supply to the testes and epididymis is via the paired testicular arteries, which arise directly from the abdominal aorta. They descend down the abdomen, and pass into the scrotum via the inguinal canal, contained within the spermatic cord.
What is inside spermatic cord?
The spermatic cord (Figs 4.10, 4.11, 4.13) contains the ductus deferens (vas deferens), the testicular artery and the pampiniform plexus of veins. Other structures in the cord are the cremasteric artery, the artery to the vas, nerve to the cremaster, sympathetic nerves and the lymphatics of the testis and epididymis.
Spermatic cord (anatomy)
Can you feel the spermatic cord?
Start by gently gripping the top of the scrotum, with your thumb on top and your fingers underneath. Pinch gently so that the testicle stays put and won't move during the exam. Between your fingers, you should feel the spermatic cord. This connects the testicle to the rest of your body.
What does spermatic cord feel like?
Normally, the testicles are smooth, and the cord holding them feels like a rope. This cord is called the spermatic cord. Any swelling or lump in or on the scrotum is called a scrotal mass (see drawing).
Is there a main artery in your balls?
The testicular artery, a branch of the abdominal aorta, descends through the inguinal ring into the cranial border of the spermatic cord in a tortuous manner and divides near the testis into several branches to supply the testis and epididymis.
What is rated testis?
The rete testis (/ˈriːti ˈtɛstɪs/ REE-tee TES-tis) is an anastomosing network of delicate tubules located in the hilum of the testicle (mediastinum testis) that carries sperm from the seminiferous tubules to the efferent ducts. It is the counterpart of the rete ovarii in females.
How do you get Spermatocele?
Spermatoceles happen when sperm builds up somewhere in the epididymis. Healthcare providers don't fully understand the factors that lead to this sperm buildup. Some medical experts point to a blockage in the epididymal duct or inflammation as potential causes.
How does blood flow to the testes?
As the name implies, the testicular artery is the blood vessel mainly responsible for supplying oxygenated blood to each of the testicles. These arteries are long, thin vessels that pass behind the peritoneum — a thin layer of tissue that lines the abdomen, rectum, and bladder. ...
Does left testicle have more veins?
Both testicles have veins that attach at different locations. The right testicular vein attaches to the inferior vena cava. The left vein drains into the left renal vein. The left testicle is bigger than the right one; therefore, the left vein is longer than the right.
What level is the testicular artery?
The testicular arteries are paired vessels that usually arise from abdominal aorta at the second lumbar vertebral level. Each artery passes retroperitonially, downward, and laterally on the posterior abdominal wall toward deep inguinal ring.
How many veins are in your balls?
Below the subcutaneous inguinal ring, they unite to form three or four veins, which pass along the inguinal canal, and, entering the abdomen through the abdominal inguinal ring, coalesce to form two veins, which ascend on the Psoas major, behind the peritoneum, lying one on either side of the internal spermatic artery.
What happens when the spermatic cord is cut?
It happens when the spermatic cord, which provides blood flow to the testicle, rotates and becomes twisted. The twisting cuts off the testicle's blood supply and causes sudden pain and swelling. Testicular torsion (also called testis torsion) requires immediate surgery to save the testicle.
What is bell clapper deformity?
Another cause of testicular torsion is a condition called “bell clapper” deformity. In most males, a testicle would not be able to twist because it is firmly attached to the scrotum. For a male who is born with bell clapper deformity, his testes are hanging in the scrotum and can swing freely, like a clapper in a bell.
What Nut produces sperm?
Testicles (testes)
The testes are responsible for making testosterone, the primary male sex hormone, and for producing sperm. Within the testes are coiled masses of tubes called seminiferous tubules. These tubules are responsible for producing the sperm cells through a process called spermatogenesis.
What is the function of the left testicle?
The main job of testicles is to make and store sperm and produce testosterone.
How much do human balls weigh?
In humans each testis weighs about 25 grams (0.875 ounce) and is 4–5 cm (1.6–2.0 inches) long and 2–3 cm (0.8–1.2 inches) in diameter.
What causes a varicose vein in the testicle?
Varicoceles are believed to be caused by defective valves in the veins within the scrotum, just above the testicles. Normally, these valves regulate the flow of blood to and from the testicles. When normal flow doesn't occur, the blood backs up, causing the veins to dilate (enlarge).
Can sperm build up cause pain?
The seminal vesicle is a gland where sperm mixes with other fluids to make semen. Problems with this gland, particularly hard growths called calculi, can make ejaculation painful.
Why do doctors make you cough when holding your balls?
A doctor can feel for a hernia by using his or her fingers to examine the area around the groin and testicles. The doctor may ask you to cough while pressing on or feeling the area. Sometimes, the hernia causes a bulge that the doctor can detect. If this happens, surgery almost always repairs the hernia completely.
Should I worry about varicocele?
Are varicoceles dangerous? Varicoceles are not life threatening, but rarely they can be associated with dangerous conditions. For example, if a varicocele forms on the right side and not the left, it is important to make sure there is no mass or other abnormality in the abdomen that might be causing it.
How do you check if your balls are healthy?
- Hold one testicle between the thumbs and fingers of both hands and roll it gently between your fingers.
- Look and feel for any hard lumps, or smooth, rounded bumps, or any change in the size, shape, or consistency of the testicles.
- Repeat with your other testicle.
Why is my left ball bigger then my right?
It's normal for guys to have one testicle a bit bigger than the other. A normal size difference is about the size of half a teaspoon —and usually the right testicle is larger than the left.
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Language teaching and learning is an extremely important process for the development of an individual. Without language learning, an individual will not be able to communicate effectively. Hence, it is important to know the factors that affect language learning and teaching.
Internal and External Factors Affecting Learning Teaching Process
The internal and external factors that affect language learning and teaching are as follows:
Motivation
Children need to be motivated a lot for them to learn a new language and develop skills effectively. It is important to motivate children to learn a new language and try new experiences.
Family Environment
The family environment a child is raised in is an important factor and it should encourage them to learn a new language.
Experiences
The experiences of learning a new language are also important for children as it affects their development. Hence, these experiences must be positive.
Learning
Learning is a continuous and lifelong process. It enables children to learn new language, knowledge, skills, and abilities which turns them into better individuals.
Heredity
Heredity refers to the transmission of physical, emotional, cognitive, and other characteristics from parents to children. Heredity is responsible for determining how fast a child can acquire a language.
Learning Opportunities
The learning environment and opportunities a child is surrounded with can have a major influence in their language and cognitive development.
Culture
The language learning and teaching is also determined by the cultural beliefs and it can influence the development of language in learners.
Conclusion
These are few of the most important external and internal factors that affect language learning and teaching.
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https://educationsummary.com/lesson/internal-and-external-factors-of-environment-affecting-language-teaching-and-learning/
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Let our instructors help you understand what constitutes normal development in children and adolescents and some of the factors that can influence it. This chapter also explores the ways chronic illness and disabilities can impact development. Educating children with special needs is discussed in several lessons. After watching these videos, you should be ready to:
- List development milestones in children and adolescents
- Explain how parenting styles can affect children with different styles of learning
- Relate how growth and development can be influenced by neglect and abuse
- Examine creativity and intelligence in children
- Describe autism and Asperger's syndrome
- Explain how to adapt instruction for children with sensory challenges and those with cognitive and social functioning delays
These lessons are developed by expert instructors, who use humor and real world examples to make the lessons come alive. The quizzes that accompany each lesson allow you to assess your knowledge and identify areas that you might want to study further.
1. Child and Adolescent Development: Developmental Milestones & Nature vs. Nurture
How does a child develop cognitively? Which influences development more - genetics or the environment? How important are early experiences in the growth and cognitive development of a child? These are some of the major questions that guide the work of researchers in the field of educational psychology. This lesson will begin to address these questions by describing the basic principles that characterize child and adolescent development.
2. Impact of Parenting Styles on Different Styles of Learners
When you got in trouble as a child, how did your parents react? This lesson covers four different parenting styles identified in educational psychology, including authoritarian, authoritative, indulgent, and neglecting. Typical results from each parenting style are discussed in terms of children's behaviors, as well as application of the styles in a classroom environment.
3. The Impact of Abuse and Neglect on Child Growth & Development
A healthy family relationship can contribute positively to the growth and development of a child. Unfortunately, unhealthy and abusive relationships do occur. This lesson will describe characteristics of abusers and the impact of abuse on a child's growth and development.
4. Child Creativity and Intelligence
What is an IQ score? What do these scores mean? What role does creativity play in a child's development? Explore these concepts with this lesson and test your knowledge with a quiz at the end.
5. Chronic Illness & Physical Disabilities: Effects on Human Development
What are chronic illnesses and physical disabilities? How do these conditions impact both the individual and society? Learn the answers to these questions in this lesson and test your knowledge with a quiz at the end.
6. Educating Students with Special Needs
In this lesson, we will explore how to educate students with special needs. We will specifically address how the educational needs of these students are best served if they are in a mainstream classroom being taught alongside their peers.
7. Behavioral Characteristics of Children with Asperger Syndrome
If you have never met a person with Asperger syndrome, you might wonder how they differ from you. In this lesson, we'll explore the behaviors common to people with Asperger and other autism spectrum disorders.
8. Cognitive & Social Functioning Delays: Adapting Instruction for Learners
When growing up, keeping pace with your classmates can be difficult, but for some it's much harder than others. In this lesson we will explore cognitive and social developmental milestones in terms of the developmental delays that affect school-age children.
9. Adapting Instruction for Learners With Sensory Challenges
In this lesson, we will discuss the general characteristics of children with sensory dysfunction and how teachers can adapt the classroom environment to accommodate these students.
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There are many influences that can affect development. These influences are termed risk factors and are often divided into biological risk and environmental risk. However, it is recognized that there is often significant overlap and influence between the two categories. Biological and environmental stresses are interactive and together have an additive effect on developmental outcome. Therefore, infants with multiple risk factors typically have a greater risk of disability than infants with single risk factors.
Biological risk factors tend to be associated with more severe developmental disability, mental retardation, and multiple handicaps. Included in this category are prenatal influences such as chromosomal disorders, congenital infections, congenital malformations (both of the brain or other organs), and intrauterine growth retardation. Maternal substance abuse during the pregnancy is also a significant prenatal, and often ongoing, risk factor. Then there are the perinatal (around birth) influences on development. Infants born prematurely are at increased risk of developmental disability. They are also at risk for chronic lung disease, deafness, and brain hemorrhages, which add to their developmental risk. Infants with severe lung disease or neonatal seizures are at increased risk. Some infants have metabolic or endocrine disorders such as hypothyroidism or phenylketonuria, which place them at increased risk without appropriate intervention. Lastly, acquired infections in infancy, particularly involving the brain, can result in compromised development. Children with developmental delay due to biological risk factors are often diagnosed in infancy.
Compromised developmental outcome is due to both biologic and environmental risk factors. Over time, environmental influences affect the development of biologically at-risk children. The environment has the potential to maximize or minimize early developmental delays. Environmental risk factors are cumulative, with each having a small incremental effect on cognitive abilities. The adverse effects of a poor environment become increasingly more evident from about two years of age onward. This influence is most strongly seen in the areas of verbal and general cognitive development. As children age, the tests used to measure intelligence place more and more emphasis on language, and therefore the environmental influences assume greater importance. The reverse is also true: A good environment can have a temporizing effect on the degree of developmental disability, but it does not determine whether the disability occurred. Environmental influence seems to be minimized when the biologic risk is severe.
Environmental risk factors are legion and varied. First, consider that the environment includes caregiver-child interactions, family resources, physical properties, and organization. Within the area of caregiver-child interaction is parenting ability. Limited parenting ability, whether due to youth, inexperience, mental retardation, illicit drug abuse, or mental illness, is a risk factor for developmental disability. Inadequate supervision can lead to accident and injury. Child neglect or abuse increases the risk of developmental compromise. Additionally, parenting ability can be limited due to physical separation because of divorce or incarceration. Caregiver-child interactions also include disciplinary techniques and the family's beliefs and attitudes. All of these can affect development.
Many children at risk of developmental disability often live in families with limited resources, frequently referred to as low socioeconomic status. Housing, financial statuses, maternal education, availability of medical insurance, and availability of appropriate play materials are all part of family resources. Homelessness, poverty, low maternal education, single parent families, and lack of medical insurance have all been associated with increased risk of developmental compromise. Unavailability of medical insurance usually means that preventative medical care, when most developmental surveillance takes place, and prenatal care are not obtained. Additionally, a family's ability to cope when suffering from stressful life events, such as divorce, loss of a job, or death, depends on their own resources and access to external sources of support.
Additional environmental influences impacting development are the physical properties of the environment, such as personal space, crowding, and excessive noise. The level of organization is also an influence. This includes the predictability, structure, and regularity of the home. Over many years, children who live in poor or disorganized families are at increased risk of slower cognitive development and diminished school performance when compared to their peers from more advantaged families.
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https://social.jrank.org/pages/301/High-Risk-Infants-Risk-Factors.html
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1. How might each of the four elements of the ecological approach influence a major developmental step, such as the decision marry or not to marry? The four elements of the ecological approaches in psychology are: the behaviourist approach, biological approach, cognitive approach and the psychodynamic approach. All these approaches help us in understanding human behaviour during the different stages of development. The behaviourist approach assumes that the behavior of living organisms is shaped through their constant interaction with the environment. Learning and experiences mainly determine how people view life.
When teenagers mature and become adults, they can then decide to marry or remain single. Through our interpersonal relationships, we learn people’s behaviour and how they view life. If two people find they are compatible and can life with each other comfortably, they can decide to get married. In the book, Approaches to Psychology, the biological approach assumes that behaviour has physiological consequences and that some human behaviors are inherited. As children grow up, they mature physically and begin releasing hormones that make them drawn to members of the opposite sex.
Sometimes these feelings are hard to control and when the age seems appropriate, individuals can decide to get married and freely engage in sexual activities. The psychodynamic approach by Sigmund Freud says that, “the personal experiences in a persons earlier years will determine their behavior, attitudes and emotions (Medcof, Roth & Emslie 134). ” If a person had healthy relationships with the opposite sex or someone they are attracted to, they will reach a point when they will decide to take it to the next level which is marriage.
On the other hand is a person has experienced a string of disappointments with the opposite sex, they may remain single as they believe that they may get disappointed. Another example is a woman who was raped; they may never trust someone hence will see no reason in courting any man. The cognitive approach dwells on the current events and does not dwell on the past. For example, if a two people think that marriage is what they need, at that point in time they will pack their things and go to Las Vegas, the next thing you know is that they wedded and their decision was not based on any past experiences.
2) Given the way the brain and nervous system develop, what sort of sensory environment would probably be most conducive to healthy neural development in the infant and why? The brain was designed by nature and genetics and is unaffected by the environment. Technology has enabled scientists to know how the brain works. An infant is born with brain cells but these brain cells need to link with things in the environments. In other words, the cells need to be activated so that the infant can do certain functions like sucking, laughing, yawn among other things.
The kind of sensory environment that will be conducive for an infant is that which allows them to connect with the environment so that they can grow, gain skills, be intelligent, interact with various things in the environment and become independent. Moreover, the physical environment is acknowledged in being instrumental in the success of learning, play, or intervention programs (Clements, Fiorentino 234). ’ 3) What does each theoretical perspective contribute to our understanding of human development? Be as concise as possible.
There are many theories that have been developed that have enabled human beings to understand their developmental process, behavior and personalities. o Freud’s Psychoanalytic Theory- “Freud assumed that all behavior is motivated and that the unconscious is a ‘starehouse’ of motives and wishes which is further shaped by person’s experiences in life (Newman 7). ” o Erikson’s Psychosocial Theory of Human development- The theory talks of 8 stages that represent the periods in a child’s development from the time they are born until they die.
It is in these stages that a person’s behavior is shaped. o Jean Piaget’s Cognitive- Developmental Theory. Piagent represented four periods when children and teenagers learn to reason and interpret things in the environment so that they can live comfortably in this life. o John Bowlby and Mary Ainsworth’s Integrated Attachment Theory- This theory focused on the relationship between parents and their children especially when they are still infants.
The relationship between children and their parents greatly shape how individuals interact with others. o Bronfenbrenner’s Ecological Theory of Development- The theory says that the different environments or surroundings of person interact with each other and an individual and contribute to the person’s development. 4) Describe an aspect of Human Development in the area of Personality and Social that is affected by both nature and nurture? Nature and nurture go hand in hand. The two can be likened to programming and reprogramming a computer.
Nurturing is bringing up a child in a certain way. Nature plays a big role in the nurturing process as it helps them discover and interpret the things around them. This can be the physical environment or hereditary traits. In the book, (Psychological Abstracts), It is stated that, developing a person’s capability is affected in many areas but the ability to regulate intense emotion for example, the likelihood of making secure relationships with others in order to develop unique personality.
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https://studyscanner.com/biological-approach/
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Attachment is the emotional bond of infant to parent or guardian. It is described as a pattern of emotional and behavioural interaction that develops over time, especially when infants express a need for attention, comfort, support or security. Parents’ ability to perceive, interpret and react promptly to their infants needs and attention, in turn influence the quality of their attachment relationships. A secure relationship results in not only positive developmental outcomes over time, but also influences the quality of future relationships with peers and partners. John Bowlby said that there is a great deal of research on the social development of children. He proposed one of the earliest theories of social development. Bowlby believed that early relationships with caregivers play a major role in child development and continue to influence social relationships throughout life.
Secure parent and child relationships help children to ;
a) regulate their emotion in stressful situations,
b) explore their environment with confidence, c) foster their cognitive, emotional and language development. Furthermore, children who are securely attached are predisposed to display positive social behaviours
Eg.) Empathy and cooperative behaviours helping them to develop future positive relationships. On the other hand, insecure and disorganized attachment put children at increasing risk of problem behaviours and psychopathologies. Examples include preschool and school-aged aggression, depression and emotional dysregulations (mood swings).
Learning to express emotions in appropriate ways begins early. Guardians promote this learning when they positively model these skills. A person’s self concept and self-esteem are also part of this area. As children have success with all skills, confidence flourishes. This leads to a healthy self-concept and sense of worth. A child’s self-concept and personal identity are closely linked to the quality of parenting in their early years. Many young people and adults who harm others or carry out serious crimes have had very negative experiences as children and often have a very poor self-concept. The physical, cognitive, and social emotional areas of development are linked to one another. Developments in one area can strongly influence another area. For instance, writing words requires fine-motor skills. It also requires cognitive development. Language, a part of cognitive development, is needed to communicate with others. It is also necessary for growing socially and emotionally. Just as research has made known the areas of development, it also shows that development follows key patterns, or principles.
Personal identity
Identity formation is the main developmental task in adolescence. Our identity is the single motivating force in life, in choosing behaviour options, and in deciding on friends. Our self-image is all that stands between action and passivity, and it will continually change for most people over the remainder of their lives, depending on intelligence, experiences, and the quality of our social network.
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https://www.majortests.com/essay/Student-Developmental-Psychology-And-Emotional-Development-544078.html
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The culture and values our family instill in us determine our characteristics initially, and as we mature through time. Our family shapes who we are at a very young age, regardless whether our family has a positive or a negative influence on us. Through our development and maturing we are
This human process is called social development. This being said, it is a continual change of human behaviors, feelings, and interpersonal thoughts; which will continue to develop over our life-span. Each phase of personal development will be essential in overall growth during childhood through adulthood. Social influences come from solitary comrade or group settings, which can have powerful effects on personal behaviors. The extent in which individuals are influences can depend on self-esteem levels, and individual strengths from moral, values to self-identity.
It is also important to ensure the safeguarding of the individual at all times. 1.2 The benefits of using person-centred thinking with individuals are the individual is always at the centre of the process. The individual will be supported in making informed choices for example being involved in the community by attending friendship groups. This will enable an individual to maintain friendships with people that are part of their circle of support. Good progress can help an individual decide what activities that they would like to participate in.
As we grow up our behaviors are modeled after who we are surrounded by, the way they act, and the environment we are introduced and exposed to on a daily basis. This brings up the question of what is a stronger influence nature or nurture to our behavioral patterns as humans. These questions can be debated both ways on many aspects of our behaviors. Nature is important to our development; it is the cause of heredity and experiences we perceive from our human surroundings. It is important to know how they will be influenced for many reasons.
The ego is always changing with new experiences and information that we get with our daily interactions. Erickson also thinks that there is a sense of competence that motivates actions and behaviours. With every stage Erickson is
They help other young people attain a higher level of Intellectual ability and to become qualified adults. Youth development is the ongoing growth process in which all youth are engaged in attempting to: “(1) Meet their basic personal and social needs to be safe, feel cared for, be valued, be useful, and be spiritually grounded, and (2) To build skills and competencies that allows them to function and contribute in their daily lives." [Karen Pittman, Co-Founder, President and CEO – The Forum For Youth Investment, USA]. This definition accurately describes youth development as a process that all young people go through on the way to adulthood. As the definition implies, it is a process or journey that automatically involves all of the people around a youth—family and community.
From the day we were born, or even earlier when we were created in the uterus, we have been constantly influenced by our surroundings, whether they are living things or nonliving objects. Parental genes and nutrition influence the development of human body. Schools, teachers, peers, and TV shows help form our perspectives of the world which we live in. Among so many sources of influence, the influence of parents and the influence of celebrities are two of the most important ones. The influence of parents and the influence of celebrities share similarities in that they influence people’s choices of lifestyle, their effectiveness through imitation, and the qualities of the influence, and contrast each other in that they differ in physical distance, the subject of being influenced by a free will, and the aspects of life that they contribute to.
These could have included the influence of a prominent adult figure or unconscious motives. In today’s day and age, Socialisation processes can be affected by biological, sociocultural, and interactive factors. Socialisation processes can also be considered to be dynamic and reciprocal, with aims and methods change and that the child is able to contribute to their own developmental outcomes (Laible and Thompson, 2007). Middle childhood shows a substantial time in which the child is able to grow in the areas of social and emotional development. It is predominantly during this time that children begin to mature, the parents still maintain a strong influence over them but there are other adults who also become influential in this period, such as teachers and peers.
ppy Be Happy – Be Youthful. The period of youth is pivotal for human development. Youth is a wonderful thing. In youth we learn; in age we understand. It is a critical period of personal change, when you consciously begin to explore and apply your knowledge, values and beliefs about individual and collective life.
We should strive to develop and sustain an educational foundation for all learners in society. Education is a fundamental right; equal opportunities should be accessible for all learners. During early childhood, children grow rapidly and are very much influenced by their environments. It is essential that young children have adequate stimulation and nutrition for development during the first few years of life. This is when the child’s brain is most influenced by the external environment; brain development affects cognitive, social and emotional growth.
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https://www.antiessays.com/free-essays/Self-Concept-Paper-8013.html
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Carbon fixation or сarbon assimilation is the process by which inorganic carbon (particularly in the form of carbon dioxide) is converted to organic compounds by living organisms. The compounds are then used to store energy and as structure for other biomolecules. Carbon is primarily fixed through photosynthesis, but some organisms use a process called chemosynthesis in the absence of sunlight.
Organisms that grow by fixing carbon are called autotrophs, which include photoautotrophs (which use sunlight), and lithoautotrophs (which use inorganic oxidation). Heterotrophs are not themselves capable of carbon fixation but are able to grow by consuming the carbon fixed by autotrophs or other heterotrophs. "Fixed carbon", "reduced carbon", and "organic carbon" may all be used interchangeably to refer to various organic compounds.
The primary form of inorganic carbon that is fixed is carbon dioxide (CO2). It is estimated that approximately 258 billion tons of carbon dioxide are converted by photosynthesis annually. The majority of the fixation occurs in terrestrial environments, especially the tropics. The gross amount of carbon dioxide fixed is much larger since approximately 40% is consumed by respiration following photosynthesis.
While carbon is primarily fixed through the 6 autotrophic pathways, there are non-autotrophic pathways as well.
Six autotrophic carbon fixation pathways are known as of 2011. The Calvin cycle fixes carbon in the chloroplasts of plants and algae, and in the cyanobacteria. It also fixes carbon in the anoxygenic photosynthesis in one type of proteobacteria called purple bacteria, and in some non-phototrophic proteobacteria.
Of the five other autotrophic pathways, two are known only in bacteria (the reductive citric acid cycle and the 3-hydroxypropionate cycle), two only in archaea (two variants of the 3-hydroxypropionate cycle), and one in both bacteria and archaea (the reductive acetyl CoA pathway).
In photosynthesis, energy from sunlight drives the carbon fixation pathway. Oxygenic photosynthesis is used by the primary producers—plants, algae, and cyanobacteria. They contain the pigment chlorophyll, and use the Calvin cycle to fix carbon autotrophically. The process works like this:
2H2O → 4e− + 4H+ + O2
CO2 + 4e− + 4H+ → CH2O + H2O
In the first step, water is dissociated into electrons, protons, and free oxygen. This allows the use of water, one of the most abundant substances on Earth, as an electron donor—as a source of reducing power. The release of free oxygen is a side-effect of enormous consequence. The first step uses the energy of sunlight to oxidize water to O2, and, ultimately, to produce ATP
ADP + Pi ATP + H2O
and the reductant, NADPH
NADP+ + 2e− + 2H+ NADPH + H+
In the second step, called the Calvin cycle, the actual fixation of carbon dioxide is carried out. This process consumes ATP and NADPH. The Calvin cycle in plants accounts for the preponderance of carbon fixation on land. In algae and cyanobacteria, it accounts for the preponderance of carbon fixation in the oceans. The Calvin cycle converts carbon dioxide into sugar, as triose phosphate (TP), which is glyceraldehyde 3-phosphate (GAP) together with dihydroxyacetone phosphate (DHAP):
3 CO2 + 12 e− + 12 H+ + Pi → TP + 4 H2OAn alternative perspective accounts for NADPH (source of e−) and ATP:
3 CO2 + 6 NADPH + 6 H+ + 9 ATP + 5 H2O → TP + 6 NADP+ + 9 ADP + 8 Pi
The formula for inorganic phosphate (Pi) is HOPO32− + 2H+. Formulas for triose and TP are C2H3O2-CH2OH and C2H3O2-CH2OPO32− + 2H+
Somewhere between 3.8 and 2.3 billion years ago, the ancestors of cyanobacteria evolved oxygenic photosynthesis, enabling the use of the abundant yet relatively oxidized molecule H2O as an electron donor to the electron transport chain of light-catalyzed proton-pumping responsible for efficient ATP synthesis. When this evolutionary breakthrough occurred, autotrophy (growth using inorganic carbon as the sole carbon source) is believed to have already been developed. However, the proliferation of cyanobacteria, due to their novel ability to exploit water as a source of electrons, radically altered the global environment by oxygenating the atmosphere and by achieving large fluxes of CO2 consumption.
Many photosynthetic organisms have not acquired CO2 concentrating mechanisms (CCMs), which increase the concentration of CO2 available to the initial carboxylase of the Calvin cycle, the enzyme RuBisCO. The benefits of a CCM include increased tolerance to low external concentrations of inorganic carbon, and reduced losses to photorespiration. CCMs can make plants more tolerant of heat and water stress.
CO2 concentrating mechanisms use the enzyme carbonic anhydrase (CA), which catalyze both the dehydration of bicarbonate to CO2 and the hydration of CO2 to bicarbonate
HCO3− + H+ CO2 + H2O
Lipid membranes are much less permeable to bicarbonate than to CO2. To capture inorganic carbon more effectively, some plants have adapted the anaplerotic reactions
HCO3− + H+ + PEP → OAA + Pi
catalyzed by PEP carboxylase (PEPC), to carboxylate phosphoenolpyruvate (PEP) to oxaloacetate (OAA) which is a C4 dicarboxylic acid.
CAM plants that use Crassulacean acid metabolism as an adaptation for arid conditions. CO2 enters through the stomata during the night and is converted into the 4-carbon compound, malic acid, which releases CO2 for use in the Calvin cycle during the day, when the stomata are closed. The dung jade plant (Crassula ovata) and cacti are typical of CAM plants. Sixteen thousand species of plants use CAM. These plants have a carbon isotope signature of −20 to −10 ‰.
C4 plants preface the Calvin cycle with reactions that incorporate CO2 into one of the 4-carbon compounds, malic acid or aspartic acid. C4 plants have a distinctive internal leaf anatomy. Tropical grasses, such as sugar cane and maize are C4 plants, but there are many broadleaf plants that are C4. Overall, 7600 species of terrestrial plants use C4 carbon fixation, representing around 3% of all species. These plants have a carbon isotope signature of −16 to −10 ‰.
The large majority of plants are C3 plants. They are so-called to distinguish them from the CAM and C4 plants, and because the carboxylation products of the Calvin cycle are 3-carbon compounds. They lack C4 dicarboxylic acid cycles, and therefore have higher CO2 compensation points than CAM or C4 plants. C3 plants have a carbon isotope signature of −24 to −33‰.
Almost all cyanobacteria and some bacteria utilize carboxysomes to concentrate carbon dioxide. Carboxysomes are protein shells filled with the enzyme RuBisCO and a carbonic anhydrase. The carbonic anhydrase produces CO2 from the bicarbonate that diffuses into the carboxysome. The surrounding shell provides a barrier to carbon dioxide loss, helping to increase its concentration around RuBisCO.
The reverse Krebs cycle, also known as reverse TCA cycle (rTCA) or reductive citric acid cycle, is an alternative to the standard Calvin-Benson cycle for carbon fixation. It has been found in strict anaerobic or microaerobic bacteria (as Aquificales) and anaerobic archea. It was discovered by Evans, Buchanan and Arnon in 1966 working with the photosynthetic green sulfur bacterium Chlorobium limicola. The cycle involves the biosynthesis of acetyl-CoA from two molecules of CO2. The key steps of the reverse Krebs cycle are:
This pathway is cyclic due to the regeneration of the oxaloacetate.
The reverse Krebs cycle is used by microorganisms in anaerobic environments. In particular, it is one of the most used pathways in hydrothermal vents by the Epsilonproteobacteria. This feature is very important in oceans. Without it, there would be no primary production in aphotic environments, which would lead to habitats without life. So this kind of primary production is called "dark primary production".
One other important aspect is the symbiosis between Gammaproteobacteria and Riftia pachyptila. These bacteria can switch from the Calvin-Benson cycle to the rTCA cycle and vice versa in response to different concentrations of H2S in the environment.
The reductive acetyl CoA pathway (CoA) pathway, also known as the Wood-Ljungdahl pathway, was discovered by Harland G. Wood and Lars G. Ljungdahl in 1965, thanks to their studies on Clostridium thermoaceticum, a Gram positive bacterium now named Moorella thermoacetica. It is an acetogen, an anaerobic bacteria that uses CO2 as electron acceptor and carbon source, and H2 as an electron donor to form acetic acid. This metabolism is wide spread within the phylum Firmicutes, especially in the Clostridia.
The pathway is also used by methanogens, which are mainly Euryarchaeota, and several anaerobic chemolithoautotrophs, such as sulfate-reducing bacteria and archaea. It is probably performed also by the Brocadiales, an order of Planctomycetes that oxidize ammonia in anaerobic condition. Hydrogenotrophic methanogenesis, which is only found in certain archaea and accounts for 80% of global methanogenesis, is also based on the reductive acetyl CoA pathway.
The Carbon Monoxide Dehydrogenase/Acetyl-CoA Synthase is the oxygen-sensitive enzyme that permits the reduction of CO2 to CO and the synthesis of acetyl-CoA in several reactions.
One branch of this pathway, the methyl branch, is similar but non-homologous between bacteria and archaea. In this branch happens the reduction of CO2 to a methyl residue bound to a cofactor. The intermediates are formate for bacteria and formyl-methanofuran for archaea, and also the carriers, tetrahydrofolate and tetrahydropterins respectively in bacteria and archaea, are different, such as the enzymes forming the cofactor-bound methyl group.
Otherwise, the carbonyl branch is homologous between the two domains and consists of the reduction of another molecule of CO2 to a carbonyl residue bound to an enzyme, catalyzed by the CO dehydrogenase/acetyl-CoA synthase. This key enzyme is also the catalyst for the formation of acetyl-CoA starting from the products of the previous reactions, the methyl and the carbonyl residues.
This carbon fixation pathway requires only one molecule of ATP for the production of one molecule of pyruvate, which makes this process one of the main choice for chemolithoautotrophs limited in energy and living in anaerobic conditions.
The 3-Hydroxypropionate bicycle, also known as 3-HP/malyl-CoA cycle, was discovered by Helge Holo in 1989. It's a pathway of carbon fixation and is utilized by green non-sulfur phototrophs of Chloroflexaceae family, including the maximum exponent of this family Chloroflexus auranticus by which this way was discovered and demonstrated.
The 3-Hydroxipropionate bicycle is composed of two cycles and the name of this way comes from the 3-Hydroxyporopionate which corresponds to an intermediate characteristic of it.
The first cycle is a way of synthesis of glycoxilate. During this cycle two bicarbonate molecules are fixed thanks to the action of two enzymes: the Acetyl-CoA carboxylase catalyzes the carboxylation of the Acetyl-CoA to Malonyl-CoA and Propionyl-CoA carboxylase catalyses the carboxylation of Propionyl-CoA to Methylamalonyl-CoA. From this point a series of reactions lead to the formation of glycoxylate which will thus become part of the second cycle.
In the second cycle, glycoxilate is approximately one molecule of Propionyl-CoA forming Methylamalonyl-CoA. This, in turn, is then converted through a series of reactions into Citramalyl-CoA. The Citramalyl-CoA is split into pyruvate and Acetyl-CoA thanks to the enzyme MMC lyase. At this point the pyruvate is released, while the Acetyl-CoA is reused and carboxylated again at Malonyl-coa thus reconstituting the cycle.
19 are the total reactions involved in 3-Hydroxypropionate bicycle and 13 are the multifunctional enzymes used. The multifunctionality of these enzymes is an important feature of this pathway which thus allows the fixation of 3 bicarbonate molecules.
It is a very expensive way: 7 ATP molecules are used for the synthesis of the new pyruvate and 3 ATP for the phosphate triose.
An important characteristic of this cycle is that it allows the co-assimilation of numerous compounds making it suitable for the mixotrophic organisms.
A variant of the 3-hydroxypropionate cycle was found to operate in the aerobic extreme thermoacidophile archaeon Metallosphaera sedula. This pathway is called the 3-hydroxypropionate/4-hydroxybutyrate cycle.
Yet another variant of the 3-hydroxypropionate cycle is the dicarboxylate/4-hydroxybutyrate cycle. It was discovered in anaerobic archaea.It was proposed in 2008 for the hyperthermophile archeon Ignicoccus hospitalis.
Chemosynthesis is carbon fixation driven by energy obtained by oxidating inorganic substances (e.g., hydrogen gas or hydrogen sulfide), rather than from sunlight. Sulfur- and hydrogen-oxidizing bacteria often use the Calvin cycle or the reductive citric acid cycle.
Although almost all heterotrophs cannot synthesize complete organic molecules from carbon dioxide, some carbon dioxide is incorporated in their metabolism. Notably pyruvate carboxylase consumes carbon dioxide (as bicarbonate ions) as part of gluconeogenesis, and carbon dioxide is consumed in various anaplerotic reactions. Recently, also 6-phosphogluconate dehydrogenase was shown to catalyze the reductive carboxylation of ribulose 5-phosphate to 6-phosphogluconate in E. coli under elevated CO2 concentrations. Considering the CO2 concentration in the habitat of E. coli (e.g. the mammalian gut), this reaction might happen also naturally. In the future, this property could be exploited for the design of synthetic carbon fixation routes.
Some carboxylases, particularly RuBisCO, preferentially bind the lighter carbon stable isotope carbon-12 over the heavier carbon-13. This is known as carbon isotope discrimination and results in carbon-12 to carbon-13 ratios in the plant that are higher than in the free air. Measurement of this ratio is important in the evaluation of water use efficiency in plants, and also in assessing the possible or likely sources of carbon in global carbon cycle studies.
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https://everything.explained.today/Carbon_fixation/
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Carbon is being continually recycled on Earth. The processes that release carbon dioxide to the atmosphere include: • combustion of fossil fuels • respiration by plants and animals • Carbon dioxide is taken in from the atmosphere by plants so that they can carry out photosynthesis Greenhouse effect on global warming.
Is carbon constantly recycled?
The carbon cycle is nature’s way of reusing carbon atoms, which travel from the atmosphere into organisms in the Earth and then back into the atmosphere over and over again. Most carbon is stored in rocks and sediments, while the rest is stored in the ocean, atmosphere, and living organisms.
How is carbon recycled?
Carbon is constantly recycled in the environment. The four main elements that make up the process are photosynthesis, respiration, decomposition and combustion. … When plants and animals die, decomposes break down the compounds in the dead matter and release carbon dioxide through respiration.
Is carbon recycled in the environment?
The carbon cycle shows how atoms of carbon can exist within different compounds at different times and be recycled between living organisms and the environment. Carbon enters the atmosphere as carbon dioxide from respiration and combustion.
Do carbon atoms recycle over and over?
The carbon cycle is the process in which carbon atoms are recycled over and over again on Earth. Carbon recycling takes place within Earth’s biosphere and between living things and the nonliving environment.
How is carbon recycled in the ground?
Background: Recycling Carbon
- Animals absorb carbon when they eat plants, or when they eat other animals that have consumed plants.
- A byproduct of photosynthesis is oxygen, lucky for us!
- When plants and animals die, they decompose and return their carbon to the soil.
Why is it necessary that earth’s carbon is recycled?
Why is recycling carbon important? Recall that carbon is the cornerstone of organic compounds, the compounds necessary for life. … Carbon must be recycled from other living organisms, from carbon in the atmosphere, and from carbon in other parts of the biosphere.
How is carbon recycled in a woodland community?
Describe how carbon is recycled in a woodland community. Plants photosynthesise and take in carbon dioxide and produce carbohydrates (/fats/proteins). Carbon compounds are transferred by feeding. Respiration breaks down carbon compounds and releases carbon dioxide.
Where do living things get their carbon?
Let’s start with how living things get carbon. Plants use carbon dioxide for photosynthesis. By doing so, they remove inorganic carbon from the atmosphere and incorporate it into the plants’ tissues in the form of organic carbon (sugar and starch). Animals get carbon by eating plants or by eating other animals.
What happens to CO2 in the atmosphere?
Carbon dioxide (CO2), after it is emitted into the atmosphere, is firstly rapidly distributed between atmosphere, the upper ocean and vegetation. Subsequently, the carbon continues to be moved between the different reservoirs of the global carbon cycle, such as soils, the deeper ocean and rocks.
How does carbon exist in the non living environment?
Carbon exists in the nonliving environment as: carbon dioxide (CO2) in the atmosphere and dissolved in water (forming HCO3−) carbonate rocks (limestone and coral = CaCO3) deposits of coal, petroleum, and natural gas derived from once-living things.
Can we recycle CO2?
CO2 recycling pathways could deliver deep emissions reductions. When supplied by low-carbon electricity and chemical feedstocks, CO2 recycling pathways have the combined potential to abate 6.8 gigatonnes of CO2 per year when displacing conventional production methods.
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https://lindsaysbackyard.com/recycling/is-carbon-continually-recycled.html
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Global Carbon Cycle
The carbon cycle is a fundamental component of the biogeochemical dynamics of Earth. Carbon is exchanged and cycled between atmosphere, ocean layers, land, and geosphere through processes such as photosynthesis, decomposition, respiration, and mineralization. In the atmosphere, carbon exists in the form of gaseous atmospheric CO2, which constitutes a small but very important portion of total terrestrial carbon.
On land, living biota and decaying organic matter are phases of the cycle. A significant fraction of carbon occurs in minerals, especially in calcium and magnesium carbonates (CaCO3). A fraction has been buried in the Earth in the form of solid coal, liquid petroleum, and natural gas by biogeochemical processes. Photosynthesis is the milestone for life on Earth. Early organisms developed the capacity, aided by sunlight, to use CO2 and water from their surroundings to build the organic molecules they required for growth. Land hosts a large percentage of the photosynthesis, and the biggest contribution comes from forests in the tropical belt. Carbon is fixed by plants as CO2 and is sooner or later returned to the air as CO2 or to the sea as organic material. This return occurs by two pathways: respiration of consuming organisms (including humans) and the action of organisms which decompose dead organic matter and eventually return it to the mineral state. Photosynthesis and respiration cause daily fluctuations of carbon dioxide in the atmospheric reservoir.
In the ocean, the carbon is dissolved as HCO3~ or exists in form of molecular CO2 or in microscopic plants such as phytoplankton. The carbon cycle is somewhat different in oceans where the agent of photosynthesis is phytoplankton. CO2 fixed in the surface layers of water initiates a downward flow of carbon. Organic sediment is used by the decomposing organisms of the ocean floor, again producing CO2 which is partly absorbed in the depths of the sea and partly released to the atmosphere. The marine reservoir absorbs CO2 from the other two systems (the Earth and atmosphere) through the rain cycle and surface absorption.
About 38 000-40 000 Gt of carbon is stored in the ocean depths, while 2000 Gt on land and in soil, 750 Gt in the atmosphere, and 800 Gt in the surface layer of the ocean.
The atmosphere, biota, soil, and surface layer of the ocean are closely linked, continuous, relatively rapid carbon exchanges of carbon occurring between them. Exchange of carbon between this fast-responding system and the ocean depths takes much longer (of the order of thousands of years). In other words, exchange with the depths of the ocean limits absorption of CO2; the overall result is accumulation of CO2 in the atmosphere. This means that the ocean depths cannot help to mitigate CO2 buildup.
Although all these fluxes, mostly driven by solar energy, are approximately balanced each year, imbalances are possible and feedbacks may occur that significantly affect atmospheric CO2 concentration in the time horizon ranging from years to centuries. This variability is mainly caused by variations in land and ocean uptake, by climatic phenomena such as El Nino, as well as by human behavior. It is often difficult to distinguish changes due to human activity from natural variations.
Human activities contribute to CO2 accumulation in two main ways: through combustion of fossil fuels (coal, oil, natural gas) and through deforestation, especially of tropical rain forests. Biomass and fossil fuels are burned to meet mankind's growing demand of energy, releasing CO2 into atmosphere. This input causes a significant perturbation in the delicate equilibria of the biosphere, especially because fossil fuels are being burned in an infinitesimal time compared to the aeons taken by slow sedimentary processes to form this resource.
Guide to Alternative Fuels
Your Alternative Fuel Solution for Saving Money, Reducing Oil Dependency, and Helping the Planet. Ethanol is an alternative to gasoline. The use of ethanol has been demonstrated to reduce greenhouse emissions slightly as compared to gasoline. Through this ebook, you are going to learn what you will need to know why choosing an alternative fuel may benefit you and your future.
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https://www.ecologycenter.us/population-dynamics-2/global-carbon-cycle.html
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Why Is Water Important to Photosynthesis? By Mike Charmaine; Updated March 13, Photosynthesis is an important biochemical pathway involving the production of sugar glucose from light, water and carbon dioxide and releasing oxygen.
The use, distribution or reproduction in other forums is permitted, provided the original author s or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice.
No use, distribution or reproduction is permitted which does not comply with these terms. Abstract Organic acids are involved in numerous metabolic pathways in all plants.
The finding that some plants, known as C4 plants, have four-carbon dicarboxylic acids as the first product of carbon fixation showed these organic acids play essential roles as photosynthetic intermediates. In this cycle, OAA is the immediate, short-lived, product of the initial CO2 fixation step in C4 leaf mesophyll cells.
The malate and Asp, resulting The significant roles of photosynthesis and the rapid conversion of OAA, are the organic acids delivered to the sites of carbon reduction in the bundle-sheath cells of the leaf, where they are decarboxylated, with the released CO2 used to make carbohydrates.
The three-carbon organic acids resulting from the decarboxylation reactions are returned to the mesophyll cells where they are used to regenerate the CO2 acceptor pool. NADP-malic enzyme-type, NAD-malic enzyme-type, and phosphoenolpyruvate carboxykinase-type C4 plants were identified, based on the most abundant decarboxylating enzyme in the leaf tissue.
The genes encoding these C4 pathway-associated decarboxylases were co-opted from ancestral C3 plant genes during the evolution of C4 photosynthesis. Malate was recognized as the major organic acid transferred in NADP-malic enzyme-type C4 species, while Asp fills this role in NAD-malic enzyme-type and phosphoenolpyruvate carboxykinase-type plants.
However, accumulating evidence indicates that many C4 plants use a combination of organic acids and decarboxylases during CO2 fixation, and the C4-type categories are not rigid. The ability to transfer multiple organic acid species and utilize different decarboxylases has been suggested to give C4 plants advantages in changing and stressful environments, as well as during development, by facilitating the balance of energy between the two cell types involved in the C4 pathway of CO2 assimilation.
The results of recent empirical and modeling studies support this suggestion and indicate that a combination of transferred organic acids and decarboxylases is beneficial to C4 plants in different light environments. C4 photosynthesis, C4 acid, malate, aspartate, NAD-malic enzyme, NADP-malic enzyme, oxaloacetate, phosphoenolpyruvate carboxykinase Introduction Organic acids are of fundamental importance in all plant species.
In addition to these varied roles, organic acids play a major part in the C4 photosynthetic pathway as the intermediates connecting CO2 uptake and fixation, and this is the focus of this review. Work on sugarcane published in the s Burr, ; Kortschak et al.
Hatch and Slack described a model of the pathway, which encompassed and extended the earlier work. The pathway is now known as the C4 pathway because of the initial fixation products, and plants using the pathway are known as C4 plants.
This seminal work Hatch and Slack, also resolved that the fourth C of oxaloacetate OAA was labeled along with those of malate and Asp.
However, OAA was short-lived, and immediately converted to malate or Asp. The label in these dicarboxylic acids was transferred to the first C of 3-PGA, which then was used for carbohydrate synthesis via the PCR cycle. Their model also included a 3-C organic acid as the acceptor molecule for atmospheric CO2 Hatch and Slack, Unlike C3 plants, most C4 species use two cell types in CO2 assimilation: The BS cells surround the vascular tissue, and are in turn surrounded by M cells, giving the characteristic wreath-like or Kranz anatomy that was first describe in the late 19th century Haberlandt, In C4 leaves, no M cell is more than two cells away from a BS cell, which facilitates rapid metabolite exchange between the two cell types.
These dicarboxylic acids move into the neighboring BS where they are decarboxylated, with the released CO2 being used for carbohydrate production by the PCR cycle, located in BS cell chloroplasts.Sep 03, · A significant amount of information on the role of seed photosynthesis for the synthesis of seed reserve compounds has In summary, in this review we discussed a number of studies that have enhanced our understanding of the parallel roles of photosynthesis and amino acid-derived respiratory catabolic processes in meeting the.
Photosynthesis is incredibly important in numerous ways. Everything in an ecosystem is a part of a food web. Trees, plants, flowers, shrubs, algae, etc.
all need the sun in order to convert the. Photosynthesis conducted by plants is also an important part of the carbon cycle. By taking carbon out of the atmosphere and converting it into glucose, plants help to preserve the delicate balance of the earth's carbon cycle.
Cellular respiration and photosynthesis have a lot of differences. They both have processes. Cellular respiration and photosynthesis are kind of like the opposite. The plants need what the animals let out and the animals need what the plants let out. The photosynthesis equation is 6Co2 +12H2O C6H12O6+ 6O2+ 6H2o.
Photosynthesis and cellular respiration play significant roles in existence of all living organisms on the planet. Supplying energy to the cells they carry out is the main process called life.
The Roles of Organic Acids in C 4 Photosynthesis. Martha Ludwig * are substrates for the C 4 acid cycle that underpins the CO 2 concentrating mechanism of C 4 photosynthesis. In this cycle, OAA is the immediate, short-lived, have been found to play significant roles in numerous metabolic processes that require or utilize PEP or OAA.
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Autotrophs generally have two modes of nutrition which are chemosynthesis and photosynthesis (holophytic).
HETEROTROPHIC NUTRITION
This is a type of nutrition in which organisms depend directly or indirectly on autotrophs for food. All animals, fungi, protozoa and some bacteria belong to this group and they are referred to as heterotrophs
HETEROTROPHIC MODES OF FEEDING
(a) Holozoic Nutrition
This is the mode of feeding in which food is ingested in the form of complex organic substances which is digested and assimilated into the body. Holozoic organisms are grouped into carnivores, herbivores, omnivores and scavengers.
(b) Parasitic Nutrition
This is the mode of feeding in which certain organisms (parasites) feed on other organisms (host). Parasites can be endoparasites (tapeworm, liver fluke) or ectoparasites (lice, ticks) depending on whether they live inside or outside the host. Plant parasites include dodder, mistletoe. Parasites have special structures such as haustoria, sucker, hooks, and muscular lips e. t. c.
(c) Saprophytic Nutrition
This is feeding process in which certain organisms (saprophytes) feed on non living organic matter i. e. plant and animal remains. Saprophytes secrete digestive enzymes into the dead organic matter to digest the food (extracellular digestion) and the soluble food substances are then absorbed into their body. Examples include fungi i.e. mucor, mushroom, yeast and some bacteria
(d) Symbiotic Nutrition
This is a mode of feeding in which two organisms of different species called symbionts live together and derive mutual benefits e.g. nutrients or food, shelter, moisture e. t. c from each other. Examples are nitrogen-fixing bacteria called Rhizobia, which live in root nodules of legumes, algae and fungi in a lichen.
(e) Carnivorous / Insectivorous Nutrition
This is a feeding process in which some plants that have special devices trap and digest insects. These plants grow in poor soil and proteins obtained from the insects are used to supplement their nitrogenous compound requirement. These plants secrete enzymes which help in digesting their victim. Examples include bladderwort (Ultricularia), Pitcher plant, sundew and venus fly trap
MODES OF AUTOTROPHIC NUTRITION
Plants are referred to as autotrophs, i.e. being able to manufacture their food (Organic compound from inorganic materials such as water, carbon dioxide)
Autotrophs generally have two modes of nutrition which are chemosynthesis and photosynthesis
PHOTOSYNTHESIS
This is the process by which green plants synthesize organic compounds from inorganic raw materials in the presence of chlorophyll and light.
light
6C02 + 6H20 C6H12O6 + 602
(Inorganic materials) Chlorophyll (organic compound) (by product)
The main product of photosynthesis is sugar (carbohydrate) while the oxygen given up is a by-product which is released into the atmosphere.
FEATURES (CHARACTERISTICS) OF PHOTOSYNTHESIS
These are as follows:
- Photosynthesis occurs in the chloroplast of cells in the presence of light.
- The raw materials required are low energy containing inorganic compound i.e. CO2 and H2O
- The final product is a high energy containing compound (C6H12O6 )n Photosynthesis, therefore is an anabolic process (metabolic building up process)
- The energy required is obtained from solar energy through the chlorophyll (the green pigment present in the chloroplast of green plants.
- The carbon dioxide and oxygen diffuse in and out (respectively) between the surrounding air and leaf passing through the stomata opening on the leaf surface. These gases are stored in insoluble form until the day is dark. Then, the sugar is converted and transported to other parts of the plants where it is needed. The movement of the sugar is called translocation.
- Leaf is the main photosynthetic organ of the plant although all green parts of a plant are photosynthetic. The main site of photosynthesis in a leaf is the pallisade mesophyll.
MECHANISM OF PHOTOSYNTHESIS
Photosynthesis involves two stages
- Light phase: it takes place during the day. It involves four stages
- Activation of chlorophyll: the chlorophyll trap light energy from the sun and get energized
- Photolysis of water: splitting of water molecules by light energy H2O H+ + OH— OH− H2O
- Hydrogen transfer by NADP (NADP + H+ NADPH2)
- Formation of ATP from ADP: this takes place to store energy for the dark phase reaction
- Dark phase: In the dark phase of photosynthesis (occurring in the stroma of chloroplast in the presence of NADPH and ATP), neither light energy nor chlorophyll is needed. This stage takes place in the dark or at night.
During this phase, hydrogen ion and carbon dioxide molecule combine chemically under the control of enzymes to form the simple sugar.
4H+ + CO2 CH2O + H2O
Simple sugar forms the chemical structural basis for other carbohydrates, lipids and proteins
IMPORTANCE OF PHOTOSYTHESIS
The enzyme-rich product of photosynthesis is used by plants and animals in the following ways:
- The source of energy for their metabolic activities
- It is needed in food cycle being the only process that can trap sun energy.
- All animals and other heterotrophic plants are directly or indirectly dependent on green plants for food.
- Photosynthesis assists in the purification of the environment by removing carbon (iv) oxide from it while oxygen is released into it.
- Basis for manufacturing other complex organic compounds such as lipids, proteins
EXPERIMENTS IN PHOTOSYNTHESIS
The occurrence of photosynthesis in plants can be shown by experiments. Experiment is carried out to show the importance of carbondioxide, sunlight energy, chlorophyll. There is the need to prove that oxygen is given off.
Testing a leaf for starch
The leaf to be tested is detached from the plant and put into boiling water for about 10-15mins. This kills the protoplasm of the leaf and makes iodine to easily penetrate the starch granules.
The boiled leaf is put into alcohol. This is to extract the chlorophyll from the leaf. The leaf becomes white and brittle. It is then dipped into hot water to soften the tissues.
The bleached leaf is spread on a white tile a few drop of iodine is added to it. The colour of the leaf is then tested against a light source.
If the leaf appears blue-black in colour, it contains starch, if the colour is yellowish-brown, it contains no starch
To show that light is necessary for photosynthesis.
Two potted plants are kept in darkness or 48-72 hours to make it starch-free or carry out the above experiment in destarching leaves. One of the potted plants remains in darkness while the other is exposed to sunlight for 4 hours. Leaves from the potted plants exposed to light turns blue-black when tested with iodine while the leaves kept in darkness remains brown. This shows that without light, photosynthesis cannot take place
To show that oxygen is given off as a by-product of photosynthesis
In this experiment, gas is collected in the test tube placed over the green plant and tested with a glowing splint. If it re-kindles the glowing splint, it shows that oxygen is given off because it is the only colourless gas that re-kindles a glowing splint.
Experiment to show that chlorophyll is necessary for photosynthesis
The same experiment in destarching a leaf is carried out here
Experiment to show that carbon (IV) oxide is necessary for photosynthesis
In this experiment, the leaves are destarched. Two potted plants are placed in two bell jars labeled A and B. Each of the potted plants is place on a Vaseline glass plate to prevent air containing carbon (iv) oxide from leaking into the bell jar. A dish containing lime water is placed in one of the jars to absorb carbon (iv) oxide. Both jars are left exposed to sunlight for about 4 hours and tested for starch.
CONDITIONS (FACTORS) FOR PHOTOSYNTHESIS
The two major conditions necessary for photosynthesis are
- External factors which include light, water, carbon (iv) oxide and mineral salt.
- Internal factors include chlorophyll and enzymes.
Temperature is partly external (from sunlight) and partly internal (from the chemical reactions taking place in plant
CHEMOSYNTHESIS
This is the process by which non-green plants (e.g. Nitrosomonas, Nitrobacter, iron bacteria etc) synthesize organic compound from inorganic materials (carbon dioxide and water). The energy used in this process is got from inorganic substances such as ammonia and by hydrogen sulphite.
H2S + O2 S + H2O + chemical energy
chemical
H2O + CO2 CH2O
energy
MINERAL REQUIREMENTS OF PLANTS
Mineral elements are required for normal growth and development of green plants. In addition to Carbon, oxygen, and hydrogen, other mineral requirements are discussed below. Unlike glucose and other carbohydrates made from carbondioxide and water by green plants, mineral salts are obtained from the soil.
Macronutrients
These are mineral nutrients that are required by plants in large quantities. They include the following;
|Macronutrients||Importance||Deficiency|
|Nitrogen(N)||1. Protein synthesis
|
2. Nucliec acid synthesis
3. Proper root development
4. Component of chlorophyll and enzymes
|1. Stunted growth and chlorosis
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2. Poor flower and fruit formation
|Phosphorus(P)||1. Formation of co-enzymes and proteins
|
2. Formation of DNA, RNA and ATP
3. Stem, root, fruit and seeds formation
|1. Poor root development
|
2. Stunted growth
|Sulphur(S)||Formation of certain proteins in the protoplasm||1. Stunted growth
|
2. Chlorosis
|Potassium(K)||1. Protein synthesis
|
2. Cell membrane formation
3. Activates respiration and photosynthesis
4. Crop maturation
|1. Premature death
|
2. Leaf margin turns yellow and brown
|Magnesium(Mg)||1. Formation of chlorophyll
|
2. Helps in cell division
3. Activates many co-enzymes
|1. Poor growth
|
2. Chlorosis
|Calcium(Ca)||1. Formation of cell wall
|
2. Helps in storage of protein and carbohydrates in roots and tubers
3. Gives rigidity to plants
|1. Death of terminal buds
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2. Roots develops poorly
3. Stunted growth
|Iron(Fe)||1. Formation of chlorophyll
|
2. Formation of protein
|1. Poor growth
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2. Yellowing of leaves
MICRO NUTRIENTS
These are mineral nutrients required by plants in small quantities. They include the following;
|Micro nutrients||Importance||Deficiency|
|Zinc(Zn)||1. Necessary for the synthesis of the starting material of auxin
|
2. Activates some enzymes
3. Plays a role in the synthesis of protein
|1. Poor growth|
|Copper(Cu)||Component of respiratory enzymes
|
|Poor growth|
|Manganese(Mn)||Activates some enzymes involved in cellular respiration||Death of shoot|
|Boron(B)||Translocation of sugar and calcium||Poor growth of pollen tubes|
|Chlorine(Cl)||Necessary for oxygen release during photosynthesis||Affects growth|
|Molybdenum(Mb)||1. Necessary for nitrogen fixation by nitrogen-fixing bacteria
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2. Activates the enzyme that reduces nitrate to nitrite
|Poor growth|
See also
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Written by:
Jennifer Chan
Soil processes are an integral part of life on Earth. With constant fluxes of carbon between plants, the atmosphere and the ground, soil also plays a vital role in the global climate.
Made up of minerals, residues from plants and animals, water, air and living organisms, the soil beneath our feet is a complex and efficient ecosystem operating at a tiny scale.Carbon cycling
Because soil organic matter contains around 60% carbon, it is the defining factor in soil’s influence on the global carbon cycle.
With around 1 500 billion tonnes of carbon found in the organic matter in soil worldwide, soils are the second largest active store of carbon after the oceans (40 000 billion tonnes). There is more carbon stored in soil than in the atmosphere (760 billion tonnes) and in vegetation (560 billion tonnes) combined.
However, as with other carbon cycles, there are constant transfers of carbon between the soil and the atmosphere and vice versa, through plants. In fact, the emissions of CO2 (carbon dioxide) from soils to the atmosphere are around ten times those from fossil fuels, but under natural conditions this is balanced by a similar flux in the other direction.
Plants absorb CO2 from the atmosphere through the process of photosynthesis and use it to build their roots, stems or leaves. Carbon is mainly transferred into the soil through the release of organic compounds into the soil by plant roots or through the decay of plant material or soil organisms when they die.
Microbial breakdown of the organic matter finally releases the nutrients which plants use to grow. During this process of decomposition, some carbon is released as carbon dioxide through soil respiration, whilst other carbon is converted into stable organic compounds that are locked into the ground. How fast this happens depends on factors including temperature and rainfall, the soil-water balance, and the composition of the organic material.
Different organic matter sources decompose at different rates. If the addition of new material is less than the rate of decomposition, soil organic matter declines and, conversely, if the rate of addition is greater than the rate of decomposition, soil organic matter will increase. However, in general the process leading to losses of carbon from the soil happens more quickly and easily than the process of rebuilding carbon stocks.
The processes that take place underground in the soil are vital in providing many of the raw materials we depend upon – from the food we eat, to the clothes we wear, to the materials we build with. Soil processes are essential for clean water and ecosystem health, without which life as we know it would be impossible.
The fertility of soil and its ability to perform its key functions depend to a large extent on the levels of organic matter within it. Humus, besides giving the soil its brownish or dark colour, is one of the most complex elements of soils. Without this mixture of different organic components, including very stable and old humified substances, as well as more changeable plant and animal residues in the process of decay, soils would not support the wide variety of organisms that live within it.
These creatures – ranging from bacteria to worms and insects – recycle organic matter and make available the nutrients that plants depend on. Organic matter is the key to healthy soil, maintaining soil structure, providing nutrients from leaching, fixing pollutants and improving water infiltration and retention.
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https://www.ifarmaissance.com/ifarmmagazine/soil%3A-the-hidden-part-of-the-climate-cycle/dec-15%2C-2020
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A function of those pigments is to absorb light energy. A more realistic and accurate definition of Biology is the reductionist definition: Carnivore Heterotrophic organism that consumes living animals or the parts of living animals for food. The major types of clouds include: First proposed by A.
This effect results in a greater range in surface air temperature at both daily and annual scales. The main organic compounds are: Learn More in these related Britannica articles: Plants absorb light primarily using the pigment chlorophyll. That photo receptor is in effect reset and is then able to repeat the absorption of another photon and the release of another photo-dissociated electron.
The outcome of this process is the local extinction the species that is a poorer competitor. The simple carbon sugars produced by photosynthesis are then used in the forming of other organic compounds, such as the building material cellulosethe precursors for lipid and amino acid biosynthesis, or as a fuel in cellular respiration.
Thickness of the continental crust varies between 20 to 75 kilometers. The sugars produced during carbon metabolism yield carbon skeletons that can be used for other metabolic reactions like the production of amino acids and lipids.
Why do you think it takes more energy shorter wavelengths, higher frequencies to excite the stretching vibration than the bending vibration. C4 carbon fixation Plants that use the C4 carbon fixation process chemically fix carbon dioxide in the cells of the mesophyll by adding it to the three-carbon molecule phosphoenolpyruvate PEPa reaction catalyzed by an enzyme called PEP carboxylasecreating the four-carbon organic acid oxaloacetic acid.
The line that separates a land surface from an ocean or sea.
The word vapor is used to describe gases that are usually liquids at room temperature. These volcanoes develop from magma of basaltic to intermediate composition. Process of grouping things into categories. Carbon Monoxide A colorless, odorless, and tasteless gas that is produced by the incomplete burning of fossil fuels.
The diagram in Figure 2 illustrates the relationships between different energy levels within a molecule. Also see maritime effect.
How are infrared spectra obtained, and what do they look like. You might have compressed air in a spray bottle or feel the carbon dioxide rush out of a can of soda.
In this way, the change will be inherited to the progeny. The light-dependent reactions are of two forms: Mostly micro-organisms and plant roots, some soil- and litter-feeding invertebrates Decomposition of organic matter Various saprophytic and litter-feeding invertebrates detritivoresfungi, bacteria, actinomycetes and other micro-organisms Suppression of pests, parasites and diseases Plants, mycorrhizae and other fungi, nematodes, bacteria and various other micro-organisms, collembola, earthworms, various predators Sources of food and medicines Plant roots, various insects crickets, beetle larvae, ants, termitesearthworms, vertebrates, micro-organisms and their by-products Symbiotic and asymbiotic relationships with plants and their roots Rhizobia, mycorrhizae, actinomycetes, diazotrophic bacteria and various other rhizosphere micro-organisms, ants Plant growth control positive and negative Direct effects: Some of these substances function as natural plant hormones auxines and gibberillins and are capable of improving seed germination, root initiation, uptake of plant nutrients and can serve as sources of N, P and S Tan, ; Schnitzer, Phenolic plastics are used in computer electronics, automobiles, machine parts, gears, fireproof coatings, waterproof binders, tools, and thousands of other commercial and household items.
Molecules differ from sets of spheres-and-springs in that the vibrational frequencies are quantized. These soils are often black in color and have a well developed A horizon rich in humus.
Coevolution The coordinated evolution of two or more species that interact and exert selective pressures on each other that can cause each species to undergo associated adaptations. Microwave radiation is even less energetic than infrared radiation. These vibrational modes, shown in Figure 4, are responsible for the "greenhouse" effect in which heat radiated from the earth is absorbed trapped by CO2 molecules in the atmosphere.
The process used to produce food by these organisms is known as chemosynthesis. Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that can later be released to fuel the organisms' activities.
This chemical energy is stored in carbohydrate molecules, such as sugars, which are synthesized from carbon dioxide and water – hence the name photosynthesis, from the Greek φῶς, phōs, "light", and σύνθεσις. Solubility rules with worked examples to decide if a precipitate will form in an aqueous solution, tutorial for chemistry students.
Soil organic matter. When plant residues are returned to the soil, various organic compounds undergo decomposition.
Decomposition is a biological process that includes the physical breakdown and biochemical transformation of complex organic molecules of dead material into simpler organic and inorganic molecules (Juma, ). Carbon dioxide (chemical formula CO 2) is a colorless gas with a density about 60% higher than that of dry air.
Carbon dioxide consists of a carbon atom covalently double bonded to two oxygen atoms. It occurs naturally in Earth's atmosphere as a trace douglasishere.com current concentration is about % ( ppm) by volume, having risen from pre-industrial levels of ppm. Glossary of Biological Terms ← BACK.
A abdomen. In vertebrates, the portion of the trunk containing visceral organs other than heart and lungs; in arthropods, the posterior portion of the body, made up of similar segments and containing the reproductive organs and part of the digestive tract.
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The carbon cycle is the biogeochemical cycle in which carbon is exchanged among the different zones like the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth.
So carbon takes various forms: glucose in plants, carbon dioxide in the air, and hydrocarbons like coal.
you can summarize the carbon cycle into the following steps……..
Here, we’ll discuss the Short-term carbon cycle that only takes days, months, or years for carbon to circulate through the environment. This involves
Carbon is generally present in the atmosphere as carbon dioxide that dissolves in water, forming the HCO3-bicarbonate group. The photosynthesis process by terrestrial plants, bacteria, and algae transforms carbon dioxide and bicarbonate into organic molecules, which in turn travel through food chains and turns organic carbon into carbon dioxide again by exhaling the cellular respiration process in living organisms.
Although carbon dioxide constitutes less than 1% of the atmosphere, it plays an important role in living things.
With CO2 and H2O in the atmosphere, photosynthesis produces sugars like glucose. This is the plant material that plants synthesize on their own.
If you have the right conditions, this process can be repeated for centuries. Photosynthesis not only extracts carbon dioxide from the atmosphere, but it feeds all living things as an energy source.
6CO2 + 6H2O ——> C6H12O6 + 6O2
Sunlight energy
By primarily using sunlight, water, and carbon dioxide, plants can grow. In turn, animals consume food for energy using O2 and emitting CO2. Alternatively, they die, decay, and decay repeating over millions of years.
Decomposition is the process of decomposition of plants. Over long periods of time, the sediment layers build up together. Due to the pressure and heat inside the Earth’s crust, this generates fossil fuels. Much of this happened during the Carboniferous Era.
For example, coal, oil, and natural gas (methane) are some of the common fossil fuels. In the long term, the decomposition of dead matter generates these fossil fuel products.
Anaerobic decomposition implies that bacteria break down organic matter like glucose into CO2 and methane (CH4). The nutrient cycle recycles inorganic and organic material in the soil through the decomposition process. Then go back through the same process again.
You and I are made of carbon. We consume plants. But we also breathe air, which has carbon in the form of carbon dioxide.
Animals depend on plants for their food, energy, and oxygen. Our cells require oxygen to break down the food we consume through cellular respiration.
Once consumed, carbon dioxide is released into the atmosphere due to cellular respiration. In turn, this CO2
produced by the cells that breathe can be used again in photosynthesis.
Our cars use carbon in the form of fossil fuels. And carbon is also a pollutant like carbon dioxide.
By extracting fossil fuels, combustion involves burning them to produce energy. But a by-product of combustion is that it releases carbon dioxide into the atmosphere. And too much CO2 increases the greenhouse effect.
And as we deplete our oil reserves by adding CO2 to the air on a daily basis, this affects the carbon cycle with an imbalance of oxygen and carbon. Carbon dioxide is one of the greenhouse gases that contribute to climate change.
But there is a limit to the amount of fossil fuel that we can extract. For millions of years, phytoplankton resting on the ocean surface photosynthesize and absorb CO2.
Using sunlight, create a molecule called glucose (C6H12O6) and sink to the bottom of the ocean. Humans discovered these fossil fuels under the ocean and began drilling into the ancient plankton that turned into oil.
In other words, plants use solar energy to break down the same carbon dioxide in the air. Through photosynthesis, it uses the same carbon for plant material and, in turn, releases oxygen again.
Carbon can move rapidly during the biological carbon cycle, especially in aquatic systems, with a total of 1,000 to 100,000 million metric tons of carbon being transported during the biological cycle each year.
In long term carbon cycle, instead of carbon being converted to sugars, carbon is reused in fossil fuels like coal. When plants are buried and compacted for millions of years, they become hydrocarbons. Volcanic activity – and more recently – human burning of fossil fuels restores this stored carbon to the carbon cycle.
The formation of fossil fuels occurs on a slow geological time scale, but humans release carbon dioxide containing it on a very fast time scale. When you drive your car on gasoline, you take advantage of the Earth’s carbon reserves deposited hundreds of millions of years ago. These fossil fuels are released into the air as carbon dioxide and water vapor.
The carbon geological cycle takes much longer than the previously described biological cycle. In fact, carbon usually takes millions of years to travel during the geological cycle. Carbon may be stored for long periods of time in air, water bodies – mostly ocean surfaces – and ocean sediments, soils, rocks, fossil fuels, and in the ground.
The level of carbon dioxide in the atmosphere is affected by the carbon stored in the ocean and vice versa. Carbon dioxide dissolves from air in water and reacts with water molecules in the following reactions:
The [CO3]2- carbonate group released from this reaction interacts with Ca+2 ions to form CaCO3 which is the main component of the shells of marine organisms. When these organisms die, their remains sink and eventually become part of the sediments on the ocean floor. Over geological time, these sediments convert to limestone, which is the largest carbon store on Earth.
Another way to get carbon into the atmosphere is through volcanic eruptions. Carbon-containing sediments at the bottom of the ocean are taken deeper into the ground in a process called tectonic slip, where a tectonic plate moves under another. This process produces carbon dioxide, which can be released into the atmosphere by volcanic eruptions or hydrothermal vents.
The distinction between the short-term carbon cycle is that this cycle takes millions of years to complete the circle.
The global demand for limited reserves of fossil fuels on Earth has increased since the beginning of the Industrial Revolution. Fossil fuel is a non-renewable resource because it is used much faster than it is produced during geological processes.
When fossil fuels are burned, carbon dioxide is released into the atmosphere. The increased use of fossil fuels has led to an increase in carbon dioxide in the atmosphere.
Deforestation (logging) is one of the factors that leads to a high level of carbon dioxide in the atmosphere. Trees and forests help absorb carbon dioxide from the air, and deforestation increases the level of carbon dioxide.
Some of the carbon dioxide produced by human activities is absorbed by plants or absorbed by ocean water, but these processes do not reduce the increase in their percentage in the air. Consequently, the proportion of carbon dioxide has increased and continues to increase.
Carbon dioxide levels naturally rise and fall during cycles for long periods of time, but they are now higher than in the past 400,000 years.
Why do we care about increasing the percentage of carbon dioxide in the air?
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https://readbiology.com/what-is-carbon-cycle/?amp=1
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Organisms acquire energy by two general methods: by light or by chemical oxidation. Productive organisms, called autotrophs, convert light or chemicals into energy-rich organic compounds beginning with energy-poor carbon dioxide (CO2). These autotrophs provide energy for the other organisms, the heterotrophs. Heterotrophs are organisms that acquire their energy by the controlled breakdown of preexisting organic molecules, or food. Human beings, like most other animals, fungi, protists, and bacteria, are heterotrophs.
Autotrophic organisms are often primary producers in their ecosystems. They acquire their useful free energy from sources other than food: either from the energy of sunlight (photoautotrophs) or from oxidative chemical reactions (chemoautotrophs). The latter mode of metabolism refers to life-forms that use inorganic materials (ammonia [NH3], methane [CH4], or hydrogen sulfide [H2S]) combined with oxygen to generate their energy. Only some bacteria are capable of obtaining energy by “burning” inorganic chemicals.
Green plants are typical photoautotrophs. Plants absorb sunlight to generate ATP and to disassociate water into oxygen and hydrogen. To break down the water molecule, H2O, into hydrogen and oxygen requires much energy. The hydrogen from water is then combined in the “dark reactions” with carbon dioxide, CO2. The result is the production of such energy-rich organic molecules as sugars, amino acids, and nucleotides. The oxygen becomes the gas O2, which is released as waste back into the atmosphere. Animals, which are strictly heterotrophs, cannot live on carbon dioxide, sunlight, and water with a few salts like plants do. They must breathe in the atmospheric oxygen. Animals combine oxygen chemically with hydrogen atoms that they remove from their food—that is, from organic materials such as sugar, protein, and amino acids. Animals release water as a waste product from the oxygen respiration. Animals, like all heterotrophs, use organic materials as their sole source of carbon. This conversion of carbon provides an example of an aspect of an ecological cycle in which a required element flows through different types of organisms as it changes its oxidation state from CO2 to (CH2O)n and back to CO2.
Metabolic cycles in general—the extraction by organisms of useful energy and food molecules from environmental source material—can be described in terms of oxidation-reduction reactions. In the case of oxygen respiration, oxygen molecules from the air accept electrons ultimately from glucose or amino acids. The oxygen, which has a great affinity for electrons, is called an electron acceptor, whereas the glucose, or other sugar or organic molecules, is an electron donor. Animal respiration is the prototype of oxidation-reduction reactions, but certainly not all oxidation-reduction reactions (or “redox reactions,” as they are often called) involve oxygen. Many other inorganic compounds are respired, or “breathed,” at the cell level. Biological electron acceptors besides oxygen include nitrate, nitrite, sulfate, carbonate, elemental sulfur, and methanol. Biological electron donors (other than sugar and amino acids) include hydrogen, nitrogen compounds (as ammonia, nitrite), sulfide, and methane. For acceptor-donor transformations to be available to chemoautotrophs and heterotrophs over sustained periods of time, ecological cycles are required. For geologically short periods of time, organisms may live off a finite supply of material; however, for any long-term continuance of life, a dynamic cycling of matter involving complementary types of organisms must prevail. If life exists on other planets, the requisite elements and liquid water must cycle. A search for such transformations provides one method of detecting extraterrestrial life.
In addition to energy, all forms of life require carbon sources. Autotrophic organisms (chemosynthetic and photosynthetic bacteria, algae, and plants) derive this essential element from carbon dioxide. Heterotrophs use preformed organic compounds as their source of carbon. Among autotrophs many types of cells do not depend on light to generate ATP; those that do without light are the chemoautotrophic bacteria, including the methanogens, ammonia oxidizers, sulfide oxidizers, hydrogen oxidizers, and a few obscure others. Indeed, at least five metabolic pathways entirely different from each other have evolved to use carbon dioxide gas. One is the oxygenic pathway described above, which is used by plants, algae, and cyanobacteria: the Calvin-Benson dark reactions. Other, more obscure pathways include phosphoenolpyruvate (PEP), succinate, and methanogen pathways. They all need to bring energy-poor carbon dioxide into the energy-rich carbon-hydrogen compound metabolism of organisms. All life on Earth depends on these autotrophic reactions that begin with carbon dioxide or its equivalent. Equivalents as carbon sources in autotrophic metabolism include the carbonate ion, bicarbonate ion, and carbon monoxide. As usual, with respect to metabolic variation and virtuosity, the bacterial repertoire is vastly more diverse than that of eukaryotes—that is, plants, animals, and other organisms composed of cells with nuclei. In general, nucleated organisms, eukaryotes, are either photolithoautotrophs (i.e., algae and plants) that derive energy from light or minerals or chemo-organoheterotrophs (animals, fungi, and most protists) that derive energy and carbon from preformed organic compounds (food).
ATP
All ATP biological electron-transfer reactions lead to the net production of ATP molecules. Two of the three phosphates (PO4) of this molecule are held by energy-rich bonds sufficiently stable to survive for long periods of time in the cell but not so strong that the cell cannot tap these bonds for energy when needed. ATP and similar molecules (such as guanosine triphosphate [GTP]) have a five-carbon sugar and three phosphates. As far as is known, such molecules are the general and unique energy currency of living systems on Earth.
No metabolic process occurs in a single step. The ordinary six-carbon sugar, glucose, does not oxidize to carbon dioxide and water in living cells in the same way that glucose in air burns. Any release of energy by burning would be too sudden and too concentrated in a small volume to happen safely inside the tiny cell. Instead, glucose is broken down at ambient (i.e., relatively cool) temperatures by a series of successive and coordinated steps. Each step is mediated by a particular and specific enzyme. In most cells that metabolize glucose, the sugar first breaks down in a set of steps that occur in the absence of oxygen. The total number of such steps in plants, animals, fungi, and protists (see below Hypotheses of origins) is about 11. Other organisms, primarily bacteria and obscure protists and fungi, are anaerobes: they do not utilize molecular oxygen in their metabolism. In anaerobes, glucose metabolism stops at compounds such as ethanol or lactic acid. Aerobic organisms, including all animals, carry the oxidation of glucose farther. They rapidly use anaerobic glucose breakdown products such as lactic acid, ethanol, or acetate with Krebs-cycle intermediates in the mitochondria. Aerobic oxidation of glucose requires an additional 60 enzyme-catalyzed steps. The anaerobic breakdown of glucose uses enzymes suspended freely in solution in the cells. The aerobic steps occur on enzymes localized in mitochondria, the “power packs” of cells where oxygen gas is used to make the energy compound ATP. The complete aerobic breakdown of sugar to carbon dioxide and water is about 10 times more efficient than the anaerobic in that 10 times as many ATP molecules are produced. (See metabolism.)
Energy made available to cells in the form of ATP is used in a variety of ways—for example, for motility. When an amoeba extends pseudopods or when a person walks, ATP molecules are tapped for their energy-rich phosphate bonds. ATP molecules are used for the synthesis of proteins that all cells require in their growth and division, amino acids, and five-carbon sugars of nucleic acids. Each synthetic process is controlled and enzymatically mediated. Each starts from an organic building-block compound available to the cell as food. The amino acid L-leucine, for example, is produced from pyruvic acid, which is itself the product of the anaerobic breakdown of glucose. Synthesis of L-leucine from pyruvic acid involves eight enzyme-mediated steps with an addition of acetic acid and water.
These exquisitely interlocked and controlled metabolic steps are not performed in a diffuse manner helter-skelter in the cell. Rather, a marvelously architectured cellular interior displays specialized regions visible at the electron-microscopic level. Particular chemical reactions are performed in association with specific structures. In aerobic eukaryotes the mitochondrion with its intricate cristate membrane (the folds in the membrane are called cristae) provides the site of pyruvate, acetate, and lactate metabolism. These molecules are transformed and passed on from one enzyme to another as through a conveyor belt in a factory. Similarly, in those eukaryotes capable of oxygenic photosynthesis (algae, plants), photosynthesis occurs only in an organelle (a cell part) called a chloroplast. Chlorophyll, carotenoids, and other pigments that absorb visible light, as well as the detailed enzymatic apparatus for the photosynthetic process, reside there.
Chloroplasts and mitochondria contain DNA. Moreover, this DNA has a sequence distribution that differs entirely from that of the nucleus and greatly resembles that of free-living photosynthetic and oxygen-respiring bacteria. The best explanation for these facts is that the ancestors to the oxygen-releasing chloroplasts and oxygen-respiring mitochondria were once free-living bacteria.
Diversity
Prokaryotes and eukaryotes
All life is composed of cells of one of two types: prokaryotes (those that lack a nucleus) or eukaryotes (those with a nucleus). Even in one-celled organisms this distinction is very clear.
All bacteria are prokaryotic, even though many, probably most, are multicelled in nature. The only other single-celled organisms that exist are fungi (one-celled fungi are called yeasts). All nucleated organisms (cells with nuclei and chromosomes in their cells) that are not animals, fungi, or plants are Protista. This huge group includes the unicellular or few-celled protists and their multicellular descendants. The large kingdom of Protista has 250,000 estimated species alive today. Some are very large, such as red algae and the kelp Macrocystis. One-celled protists include the familiar amoebas, paramecia, and euglenas as well as 50,000 less-familiar types. Scientifically speaking, no such thing as a one-celled animal exists. All animals and plants are by definition multicellular, since they all develop from multicellular embryos. Accordingly, all “protozoans” are now classified as single-celled Protista, not animals. Nor are there any one-celled plants. Organisms formerly called one-celled plants are algae and, as such, are now classified with Protista as well. If a mature organism is determined to be one-celled, then it must be either a bacterium (prokaryotic) or a fungus or protist (eukaryotic). All animals and plants develop from embryos that by definition combine two complementary sets of chromosomes (i.e., they are diploids at some stage in their development). They are all multicellular eukaryotes. But though there are no one-celled plants or animals, there are indeed myriad many-celled protists. Multicellularity evolved not only in the ancestors to the plants and the animals but also in the bacteria, the protists, and the fungi.
All eukaryotic cells undergo some form of mitosis, a sequence of cell division events that occurs after chromosomal DNA protein replication. Mitosis ensures that chromosomal DNA and protein are equally distributed to the offspring cells. Mitosis is the most distinctive activity of eukaryotic cells, which have nucleoprotein chromosomes in their nuclei and a membrane that separates the nucleus from the cytoplasm. In mitosis, mitochondria, which are usually present in the cytoplasm as well as in the chloroplasts of algae and plants, are smoothly distributed with the chromosomes to offspring cells. The Golgi apparatus and endoplasmic reticulum (ER), an intricately convoluted structure, serve to anchor many cytoplasmic enzymes excluded from mitochondria or chloroplasts. They also divide and are distributed in mitosis.
Nuclei, chromosomes, mitochondria, chloroplasts, ER, and nuclear membranes are all absent in prokaryotes. Prokaryotic cells, which include all the cyanobacteria (formerly called blue-green algae), are bacteria in every way. Division is nonmitotic in all prokaryotes. Bacteria lack nucleoprotein and a nuclear membrane, and, when chromosome stain is applied, only fuzz or nothing is seen. Whereas all eukaryotic cells have more than one chromosome and sometimes over a thousand, the genes of prokaryotic cells are organized into a single “chromoneme” or “genophore.” (The term bacterial chromosome, while still in use, is, technically speaking, inaccurate.) The genes may or may not be concentrated enough to be seen, but in any case bacterial DNA floats freely in the cytoplasm. Prokaryote cell organization is less complex than that of eukaryotes. The basic question of the evolution of prokaryotes into eukaryotes—often rated the second major evolutionary mystery, after the origin of life—is thought to involve a complex series of partnerships in which distinct strains of bacteria entered each others’ bodies, merged symbiotically, and traded genes.
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https://www.britannica.com/science/life/Energy-carbon-and-electrons
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Carbon (C) was deposited on earth from carbonaceous comets and asteroids (Anders, 1989) in both organic and inorganic forms. The extraterrestrial C contained complex compounds including hydrocarbons, organic acids, and amino compounds essential to the evolution of cellular life forms. The "carbon cycle" is the transfer of C among the atmosphere, oceans, land, and life. The C cycle is composed of both long-term and short-term cycles. The subject of this chapter is to understand the short-term C cycle, which includes the terrestrial components of plants, soil biota, and soil organic matter (SOM).
The thermal degradation of comets and asteroids entering the earth's atmosphere was presumed to be the initial source of atmospheric carbon dioxide (CO2). The accumulation of CO2 in the atmosphere resulted in the first major active component of the global C cycle: dissolved carbonates (CO3). The weathering of calcium (Ca)-magnesium (Mg)- and silicate (Si)-containing rocks dissolved by carbonic acid (HCO3) found in precipitation and other water sources consumed atmospheric CO2 (Fig. 12.1). The following describes this chemical reaction.
The overall reaction consumes atmospheric CO2 and transfers it to the near-permanent geologic reservoirs through processes encompassing terrestrial weathering and marine carbonate sedimentation (Berner, 2004). Carbonates formed during pedogenesis, termed caliche, are small in comparison to marine carbonate sedimentation.
FIGURE 12.1 The long-term C cycle (adapted from Berner, 2004).
erosive events, constantly exposing Ca-Mg Si rocks to further weathering. Following the subduction of sedimentary rock into the earth's mantle, carbonates eventually undergo thermal weathering and are released as CO2 back to the atmosphere primarily through volcanic activity (Fig. 12.1). This process represented a critical step in controlling atmospheric CO2 content of the atmosphere early in the earth's history.
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https://www.ecologycenter.us/microbiology/matter.html
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Carbon dioxide (CO2) forms approximately 0.04% of the nominal 5,000,000 gigatonnes of gas and aerosols that comprise the Earth's atmosphere. It is essential to photosynthesis in plants and other photoautotrophs, and is also a prominent greenhouse gas.
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Contents
In 2009, the CO2 global average concentration in Earth's atmosphere was about 0.0387% by volume, or 387 parts per million by volume (ppmv). This is 103 ppmv (36%) above the 1832 antarctic ice core levels of 284 ppmv. There is an annual fluctuation of about 3–9 ppmv which roughly follows the Northern Hemisphere's growing season. The Northern Hemisphere dominates the annual cycle of CO2 concentration because it has much greater land area and plant biomass than the Southern Hemisphere. Concentrations peak in May as the Northern Hemisphere spring greenup begins and reach a minimum in October when the quantity of biomass undergoing photosynthesis is greatest.
Despite its relatively small concentration overall in the atmosphere, CO2 is an important component of Earth's atmosphere because it absorbs and emits infrared radiation at wavelengths of 4.26 µm (asymmetric stretching vibrational mode) and 14.99 µm (bending vibrational mode), thereby playing a role in the greenhouse effect. See also "Carbon dioxide equivalent".
Natural sources of atmospheric carbon dioxide include volcanic outgassing, the combustion of organic matter, and the respiration processes of living aerobic organisms; man-made sources of carbon dioxide include the burning of fossil fuels for heating, power generation and transport, as well as some industrial processes such as cement making. It is also produced by various microorganisms from fermentation and cellular respiration. Plants convert carbon dioxide to carbohydrates during a process called photosynthesis. They produce the energy needed for this reaction through the photolysis of water. The resulting gas, oxygen, is released into the atmosphere by plants, which is subsequently used for respiration by heterotrophic organisms, forming a cycle.
Over 95% of total CO2 emissions are non-anthropogenic. For example, the natural decay of organic material in forests and grasslands, such as dead trees, results in the release of about 220 gigatonnes of carbon dioxide every year. In 1997, Indonesian peat fires were estimated to have released between 13% and 40% of the average carbon emissions caused by the burning of fossil fuels around the world in a single year. The initial carbon dioxide in the atmosphere of the young Earth was produced by volcanic activity, but modern volcanic activity releases only 130 to 230 teragrams (0.13-0.23 gigatonnes or 145 million to 255 million short tons) of carbon dioxide each year, which is less than 1% of the amount released by human activities.
These natural sources are nearly balanced by physical and biological processes, called natural sinks, which remove carbon dioxide from the atmosphere. For example, some carbon dioxide dissolves in sea water, and some is removed by plants during the photosynthesis.
There is a large natural flux of CO2 into and out of the biosphere and oceans. In the pre-industrial era these fluxes were largely in balance. Currently about 57% of human-emitted CO2 is removed by the biosphere and oceans. The ratio of the increase in atmospheric CO2 to emitted CO2 is known as the airborne fraction (Keeling et al., 1995); this varies for short-term averages but is typically about 45% over longer (5 year) periods.
Burning fossil fuels such as coal and petroleum is the leading cause of increased anthropogenic CO2; deforestation is the second major cause. As of 2004, around 27 gigatonnes of CO2 are released from fossil fuels per year worldwide, equivalent to about 7.4 gigatonnes of carbon (see List of countries by carbon dioxide emissions); in 2006 8.4 gigatonnes carbon were emitted .
This addition, presently about 3% of annual natural emissions, is sufficient to exceed the balancing effect of sinks. As a result, carbon dioxide has gradually accumulated in the atmosphere, until at present, its concentration is 30% above pre- industrial levels.
Various techniques have been proposed for removing excess carbon dioxide from the atmosphere in carbon dioxide sinks.
The most direct method for measuring atmospheric carbon dioxide concentrations for periods before direct sampling is to measure bubbles of air (fluid or gas inclusions) trapped in the Antarctic or Greenland ice caps. The most widely accepted of such studies come from a variety of Antarctic cores and indicate that atmospheric CO2 levels were about 260 – 280 ppmv immediately before industrial emissions began and did not vary much from this level during the preceding 10,000 years (10 ka).
The longest ice core record comes from East Antarctica, where ice has been sampled to an age of 800 ka. During this time, the atmospheric carbon dioxide concentration has varied by volume between 180 – 210 ppm during ice ages, increasing to 280 – 300 ppm during warmer interglacials.
One study disputed the claim of stable CO2 levels during the present interglacial of the last 10 ka. Based on an analysis of fossil leaves, Wagner et al. argued that CO2 levels during the period 7 – 10 ka were significantly higher (~300 ppm) and contained substantial variations that may be correlated to climate variations. Others have disputed such claims, suggesting they are more likely to reflect calibration problems than actual changes in CO2. Relevant to this dispute is the observation that Greenland ice cores often report higher and more variable CO2 values than similar measurements in Antarctica. However, the groups responsible for such measurements (e.g., Smith et al.) believe the variations in Greenland cores result from in situ decomposition of calcium carbonate dust found in the ice. When dust levels in Greenland cores are low, as they nearly always are in Antarctic cores, the researchers report good agreement between Antarctic and Greenland CO2 measurements.
On longer timescales, various proxy measurements have been used to attempt to determine atmospheric carbon dioxide levels millions of years in the past. These include boron and carbon isotope ratios in certain types of marine sediments, and the number of stomata observed on fossil plant leaves. While these measurements give much less precise estimates of carbon dioxide concentration than ice cores, there is evidence for very high CO2 volume concentrations between 200 and 150 Ma of over 3,000 ppm and between 600 and 400 Ma of over 6,000 ppm. On long timescales, atmospheric CO2 content is determined by the balance among geochemical processes including organic carbon burial in sediments, silicate rock weathering, and vulcanism. The net effect of slight imbalances in the carbon cycle over tens to hundreds of millions of years has been to reduce atmospheric CO2. The rates of these processes are extremely slow; hence they are of limited relevance to the atmospheric CO2 response to emissions over the next hundred years. In more recent times, atmospheric CO2 concentration continued to fall after about 60 Ma. About 34 Ma, when the ice sheets of Antarctica started to take their current form near the Eocene-Oligocene extinction event, CO2 has been found to be about 760 ppm, and there is geochemical evidence that volume concentrations were less than 300 ppm by about 20 Ma. Low CO2 concentrations may have been the stimulus that favored the evolution of C4 plants, which increased greatly in abundance between 7 and 5 Ma. Present carbon dioxide levels are likely higher now than at any time during the past 20 Ma and certainly higher than in the last 0.8 Ma.
The Earth's oceans contain a huge amount of carbon dioxide in the form of bicarbonate and carbonate ions — much more than the amount in the atmosphere. The bicarbonate is produced in reactions between rock, water, and carbon dioxide. One example is the dissolution of calcium carbonate:
Reactions like this tend to buffer changes in atmospheric CO2. Since the right-hand side of the reaction produces an acidic compound, adding CO2 on the left-hand side decreases the pH of sea water. Reactions between carbon dioxide and non-carbonate rocks also add bicarbonate to the seas. This can later undergo the reverse of the above reaction to form carbonate rocks, releasing half of the bicarbonate as CO2. Over hundreds of millions of years this has produced huge quantities of carbonate rocks.
Ultimately, most of the CO2 emitted by human activities will dissolve in the ocean, however the rate at which the ocean will take it up in the future is less certain.
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http://www.thefullwiki.org/Carbon_dioxide_in_Earth's_atmosphere
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Photosynthesis[α] is a process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of Bacteria, but not in Archaea. Photosynthetic organisms are called photoautotrophs, since it allows them to create their own food. In plants, algae and cyanobacteria photosynthesis uses carbon dioxide and water, releasing oxygen as a waste product. Photosynthesis is vital for life on Earth. As well as maintaining the normal level of oxygen in the atmosphere, nearly all life either depends on it directly as a source of energy, or indirectly as the ultimate source of the energy in their food.[β] The amount of energy trapped by photosynthesis is immense, approximately 100 terawatts: which is about six times larger than the power consumption of human civilization. As well as energy, photosynthesis is also the source of the carbon in all the organic compounds within organisms' bodies. In all, photosynthetic organisms convert around 100,000,000,000 tonnes of carbon into biomass per year.
Although photosynthesis can occur in different ways in different species, some features are always the same. For example, the process always begins when energy from light is absorbed by proteins called photosynthetic reaction centers that contain chlorophylls. In plants, these proteins are held inside organelles called chloroplasts, while in bacteria they are embedded in the plasma membrane. Some of the light energy gathered by chlorophylls is stored in the form of adenosine triphosphate (ATP). The rest of the energy is used to remove electrons from a substance such as water. These electrons are then used in the reactions that turn carbon dioxide into organic compounds. In plants, algae and cyanobacteria this is done by a sequence of reactions called the Calvin cycle, but different sets of reactions are found in some bacteria, such as the reverse Krebs cycle in Chlorobium. Many photosynthetic organisms have adaptations that concentrate or store carbon dioxide. This helps reduce a wasteful process called photorespiration that can consume part of the sugar produced during photosynthesis.
Photosynthesis evolved early in the evolutionary history of life, when all forms of life on Earth were microorganisms and the atmosphere had much more carbon dioxide. The first photosynthetic organisms probably evolved about 3,500 million years ago, and used hydrogen or hydrogen sulfide as sources of electrons, rather than water. Cyanobacteria appeared later, around 3,000 million years ago, and changed the Earth forever when they began to oxygenate the atmosphere, beginning about 2,400 million years ago. This new atmosphere allowed the evolution of complex life such as protists. Eventually, about 550 million years ago, one of these protists formed a symbiotic relationship with a cyanobacterium, producing the ancestor of the plants and algae. The chloroplasts in modern plants are the descendants of these ancient symbiotic cyanobacteria.
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https://phys.org/tags/photosynthesis/sort/popular/1w/?deviceType=mobile
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Biosphere and Its Units ECOLOGY The study of the relationships between organisms and their environment. Not just related to pollution Unifying factor is adaptation.
Biosphere and Its Units Biosphere Area of earth where life exists Most on or within a few meters of earth's surface. Some found 8 km high and some found 8 km below ocean surface. Smaller ecological units Population - all members of a species that live in same area and make up a breeding group Group of deer in a forest, trout in a lake. Community - All populations in an area
Biosphere and Its Units ECOSYSTEM An ecological unit that includes all interacting parts of an environment in an area. Abiotic Factors Nonliving components of an ecosystem. Biotic Factors Living components of an ecosystem.
Biosphere and Its Units ABIOTIC FACTORS Nonliving components of an ecosystem. Light, precipitation, temperature, slope/drainage of land, soil chemistry, and atmosphere. Abiotic factors may interact Stream flooding results in deposition of sediment Changing of river courses Creation of mountains or islands by volcanoes Landslides removing soil.
Biosphere and Its Units BIOTIC FACTORS Living components of an ecosystem. Plants, animals, protists, microorganisms Living things may interact Predation– predator kills prey for food. Symbiosis – relationship between two organisms Usually beneficial to one organism.
Biosphere and Its Units Abiotic and biotic factors may also interact Affect each other. Climate/soils determine type of plants in area; determines animals of area. Plants replenish oxygen - photosynthesis Overgrazing can result in loss of soil.
Ecosystem Structure HABITAT Place where an organism lives - "home" Provides food and shelter. Habitats may overlap NICHE Role or occupation; everything organism does in its habitat Organisms way of life includes habitat, feeding habits, reproductive behavior, and all other biological aspects of the organism. No two organisms can occupy the same niche Habitats overlap, niches do not.
Ecosystem Structure Trophic Levels Energy enters an ecosystem from the sun. Energy flows between organisms when one organism eats another. Trophic Levelis defined by the relationship between what organism eats and what eats it. The feeding level in an ecosystem. Comes from Greek that means "food"
Ecosystem Structure Trophic Levels Producers Autotrophic organisms that make their own food using solar or chemical energy Consumers Heterotrophic organisms that feed on producers either directly or indirectly for their energy. Decomposers Organisms that breakdown organic material and return it to the environment for use by producers Heterotrophic organisms.
Ecosystem Structure PRODUCERS Autotrophic organisms that make their own food using solar or chemical energy. Plants, algae, and photosynthetic bacteria Manufacture all organic nutrients for ecosystem Also called primary producers. Occupy the First Trophic Level Primary Productivity of an ecosystem - rate at which solar energy is converted into organic compounds Gross Primary Productivity - total amount of energy produced, includes energy used by plant for own respiration Net Primary Productivity- rate at which plants store energy not used in plant respiration.
Ecosystem Structure CONSUMERS Heterotrophs that feed on producers either directly or indirectly for their energy. Primary Consumer - feeds on producers Secondary Consumer - feeds on a primary consumer. Consumers may be classified on basis of food type Herbivore- eats primary producers; "Plant eater" Carnivore- eats other consumers; "meat eater" Omnivore– eats both primary producers and consumers; Scavenger- feeds on organisms that recently died.
Ecosystem Structure DECOMPOSERS Breakdown organic material and return it to environment for use by producers Heterotrophic organisms. Process called Decay Includes bacteria, mold, mushrooms Types Saprophytes- obtain their food from dead organisms or the waste products of living organisms Ex - molds, mushrooms Parasites- obtain their food from living organisms Ex - athlete's foot
Ecosystem Structure Energy Flow Energy flows in various patterns in ecosystem. Total energy of one trophic level never flows to next level Food Chain- specific sequence where organisms obtain energy and organic materials from one another. Food Web - interconnected food chains formed due to the complex relationships
Ecosystem Structure FOOD CHAIN Producer Primary Consumer Secondary Consumer Scavenger Grass Deer Puma Vulture
Ecosystem Structure FOOD WEB Hawk Snake Lizard Mouse Bird Grasshopper Rabbit Grass
Ecosystem Structure Ecological Pyramids Complexities of ecosystem are graphed to show the relationship between trophic levels Primary producer at the base with consumer levels above it. Common pyramid models Energy Pyramid Numbers Pyramid Biomass Pyramid
Ecosystem Structure ENERGY PYRAMID Shows that energy is lost at each level Each organism in a given trophic level uses some of energy to carry on its own life functions. Always a loss of energy as heat in any system of energy transfer. Never inverted.
Ecosystem Structure NUMBERS PYRAMID Shows number of organisms at each level Usually an increase in the size of the organisms with each level Normally producer organisms are most numerous; may be inverted Single tree may support thousands of insects and birds
Ecosystem Structure BIOMASS PYRAMID Amount of matter that can be supported at each trophic level. Biomass is the total dry weight of organisms in the ecosystem.
Ecosystem Structure BIOGEOCHEMICAL CYCLES Process where inorganic materials move from atmosphere or soil to living things and back Also called Nutrient Cycles. Water Cycle Nitrogen Cycle Oxygen-Carbon Cycle
Ecosystem Structure WATER CYCLE Movement of water from atmosphere to the earth and back again. Precipitation- movement of water to earth from atmosphere Evaporation- way most water lost from earth's surface to atmosphere. Transpiration- loss water by green plants through their leaves.
Ecosystem Structure NITROGEN CYCLE Process by which nitrogen passes from the atmosphere to organisms and back again Four major processes Nitrogen Fixation - bacteria convert nitrogen gas into ammonium compounds; live in roots of legumes Ammonification- bacteria break down nitrogen- containing amino acids from animal wastes and dead organisms to form ammonia compounds Nitrification - Bacteria oxidize ammonia compounds to produce nitrates and nitrites Denitrification- anaerobic bacteria break down nitrate releasing nitrogen gas back into the atmosphere
Ecosystem Structure OXYGEN-CARBON CYCLE Involves processes of photosynthesis and respiration Photosynthesis removes CO2 from atmosphere and fixes it as glucose and releases O2 Respiration removes O2 from atmosphere and CO2 is released. Normally processes balance each other. Levels of O2 and CO2 remain fairly constant
Ecosystem Structure Since about 1850's fossil fuels consumption has increased Fossil fuels represent stored carbon compounds Combustion of the fuels has increased the CO2 level of the atmosphere. Increased levels of CO2 increase the atmosphere’s ability to trap heat. Greenhouse Effect - an increase in atmospheric temperature due to heat being trapped by the atmosphere. Can change climates and habitats Should be called Global Warming
Terrestrial Biomes BIOME Large area identified by the presence of characteristic plants and animals. Commonly identified by dominant plant life. Don't have definite boundaries Usually have characteristic rainfall and temperatures.
Terrestrial Biomes POLAR BIOMES Surround North and South poles Receive very little precipitation - fresh water scarce Soil is sparse, low in nutrients, frozen much of the year Temperature range - -40o C to 4o C Receive virtually no sunlight for half the year. Arctic Polar Biome Lies over Arctic Ocean Plants - Some flowering plants, mosses, lichens, Animals - Gulls, Walruses, polar bears along Arctic coast. Antarctic Polar Biome Lies over landmass of the Antarctic continent. Plants - lichens, mosses, 3 types of flowering plants Animals - small insects, seals, whales, penguins.
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https://www.slideserve.com/vida/ecology
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INTERACTION OF EMR WITH ATMOSPHERE AND EARTH SURFACE 5 INTERACTIONS WITH EARTH SURFACE FEATURES Electromagnetic radiation that passes through the earths atmosphere without being absorbed or stered reaches the earths surface to interact in different ways with different materials constituting the surface.
Reconciling Carbon-Cycle Concepts, Terminology, and
2008-11-10 · 1). Carbon enters the organic component of the ecosystem as gross primary production (GPP; ecosystem-scale C fixation by all autotrophic C-fixing tissues) and is lost by respiration of autotrophs (autotrophic respiration, AR) and of heterotrophs (heterotrophic respiration, HR) such as animals and non-photosynthetic microbes.
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Carbon Capture & Storage | ECI
One way to reduce greenhouse emissions while minimising disruption to high-carbon industries is to capture the emitted carbon dioxide before it enters the atmosphere, then store it deep underground at high pressure, inside porous rocks. The successful storage of the carbon dioxide (CO2) is based on a coination of potential trapping mechanisms.
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2019-11-25 · The role of renewable energy in reducing carbon emissions is examined. and the concomitant use of fossil fuels as the main source of energy in the region has led to the release of more carbon dioxide into the atmosphere with negative consequences on the environment. The Climate Resilience Handbook (2018) reports that 2017 was a record year
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Plate tectonic controls on atmospheric CO2 levels …
2014-3-25 · Plate Tectonic Control on CO 2 Production. We now explore the use of our subduction-zone length curve to develop a fully mechanistic proxy of volcanic CO 2 degassing over the Mesozoic and Cenozoic. Upon subduction, most CO 2 is released at depths shallower than 100 km (), after which it is released to the surface within a few hundred years ().About 40–70% of the subducted C returns to the
Composition of Earth''s Atmosphere | Earth Science
Composition of Earth''s atmosphere. The early Greeks considered "air" to be one of four elementary substances; along with earth, fire, and water, air was viewed as a fundamental component of the universe.By the early 1800s, however, scientists such as John Dalton recognized that the atmosphere was in fact composed of several chemically distinct gases, which he was able to separate and …
Earth''s Atmosphere - Windows to the Universe
The atmosphere is a mixture of nitrogen (78%), oxygen (21%), and other gases (1%) that surrounds Earth. High above the planet, the atmosphere becomes thinner until it gradually reaches space. It is divided into five layers.Most of the weather and clouds are found in the first layer.. The atmosphere is an important part of what makes Earth livable. It blocks some of the Sun''s dangerous rays
What happens when there is too much carbon dioxide …
2017-6-3 · Carbon dioxide in our atmosphere is affecting our life on Earth because of the massive amounts of change we have done to cause this rise of these gases. In return, it has heated up our planet, not a terrible thing, as mentioned above, but it can be the cause of …
In climate push, Microsoft to erase its carbon footprint
2020-1-17 · Microsoft Corp. said on Thursday it aims to remove more carbon from the atmosphere than it emits by 2030 and that by 2050, it hopes to have taken out enoug
How to Reduce Carbon Dioxide in the Atmosphere
Oceans play a vital role in absorbing the carbon dioxide present in the atmosphere. As absorption of carbon dioxide by ocean is a slow process and can take hundreds of years, this process cannot keep pace with the huge amount of the gas emitted every day. However, plants and trees also use carbon dioxide during photosynthesis for sugar
Intelligent Energy Programme
2014-8-11 · ¥ Carbon Dioxide (CO2): Carbon dioxide enters the atmosphere through the burning of fossil fuels (oil, natural gas, and coal), solid waste, trees and wood products, and also as a result of other chemical reactions (e.g., manufacture of cement). Carbon dioxide is also removed from the atmosphere …
Gas Exchange in Plants - Biology Pages
2011-2-16 · Gas Exchange in Plants. In order to carry on photosynthesis, green plants need a supply of carbon dioxide and a means of disposing of oxygen.In order to carry on cellular respiration, plant cells need oxygen and a means of disposing of carbon dioxide (just as animal cells do).. Unlike animals, plants have no specialized organs for gas exchange (with the few inevitable exceptions!).
Trees Improve Our Air Quality - Urban Forestry Network
2009-1-27 · Trees Improve Our Air Quality. Urban forests help to improve our air quality. Heat from the earth is trapped in the atmosphere due to high levels of carbon dioxide (CO2) and other heat-trapping gases that prohibit it from releasing the heat into space.
The Carbon Cycle and Atmospheric Carbon Dioxide
2011-1-5 · The Carbon Cycle and Atmospheric Carbon Dioxide 2001_ 348|16 The Carbon Cycle and Atmospheric Carbon Dioxide 2001_。IPCC
ATMOSPHERE TEST REVIEW ANSWER KEY!!!!
2016-11-27 · 29. The heat from the sun that enters the earth’s atmosphere is divided in three ways: 3 Division of heat as it enter earth’s atmosphere: Absorbed or Reflected % absorbed or reflected a. Atmosphere absorbed 19 % b. Land /Water Absorbed 51 % c. Space (clouds, etc) Reflected 30 % 30.
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Atmospheric particulate matter In recent years,our country appear much haze weather,which is now often referred to PM2.5.Specifically,PM2.5 is in the atmosphere of diameter less than or equal to 2.5 micron particles,which is also known as enters the lung
Carbon neutral vs carbon negative: what’s the …
Carbon negative - also confusingly referred to as climate positive - goes one step further than carbon neutrality, aiming to remove more carbon from the atmosphere than you emit. For example, Drax - Opus Energy''s parent company - announced their goal to become carbon negative by 2030.
The ocean and the carbon cycle — Science Learning …
More carbon dioxide will mean more heat trapped, resulting in an increase in temperature. This might contribute to climate change. The ocean and carbon. The ocean plays an important part in the carbon cycle. Overall, the ocean is called a carbon ‘sink’ because it takes up more carbon from the atmosphere …
There''s so much CO2 in the atmosphere that planting …
Humans emit roughly 30 to 40 billion tons of the greenhouse gas carbon dioxide into the atmosphere each year. If we keep it up, the Earth will continue to heat up and ultimately our way of life
Atmosphere | Definition of Atmosphere by Merriam …
Atmosphere definition is - the gaseous envelope of a celestial body (such as a planet). How to use atmosphere in a sentence.
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https://www.expatbridge.nl/Jun-10+19654.html
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In research experiments, scholars can use both empirical and non-empirical methods. The type of methods used often depends on the field of science and the research outcome being analyzed. Empirical methods are objective, the results of a quantitative evaluation that produces a theory. Non-empirical methods are the opposite, using current events, personal observations, and subjectivity to draw conclusions.
Each of these evidence-gathering methods is relevant and acceptable, but when one is discounted over another, the results of the study might not be as valid as it could have been. The way to ensure a strong outcome is to include both empirical and non-empirical methods of obtaining evidence in your research.
Empirical Evidence Pros and Cons
Empirical methods are used when data must be collected in a specific, objective way. This systematic collection of data ensures that the information that was collected is free of bias and accurate.
Scholars often turn to empirical methods of evidence collection as their first course of action. This is often a good idea since there are many basic advantages to this method. Empirical studies take current knowledge bases and improve and enhance them so that the research performed has a higher impact on societal or academic issues. Because it’s basically up to the researcher to decide how to use empirical evidence, within the norms and requirements of the study, this method is also flexible, making it a preference for the scholar. He or she is able to adjust the size of the study sample, the type of sample they want to use, and how the data is collected. Then, when it’s time for the analysis, the same data can be dissected and disseminated in different ways as necessary.
The problem with empirical studies is usually found in time constraints. The type of data collected and the methods used can make empirical evidence a time-consuming endeavor. Additionally, data can’t be predicted completely, so any potential result has to be addressed and accounted for ahead of time.
Presenting empirical data is another issue entirely. You need enough information available to showcase your results and how they were achieved, but knowing what’s enough and what’s too much can be a fine line. You’ll also need to professionally display your results through graphs, tables, and whatever else it takes to prove your outcome.
Non-Empirical Pros and Cons
Non-empirical evidence has a basis in multiple types of publications. It’s used in theory articles when the author is trying to propose a new concept or further solidify the effects of those that are already in theory. Substantive review articles also are based on non-empirical evidence. In these articles, the author is trying to summarize concepts that they have significant knowledge about to display the relevance of the idea and apply it to a specific aspect of society. Critiques are another non-empirical source, in which the author tries to explain why someone else’s study was invalid or wrong.
All of these writings must be analytical with evidence-backed information instead of solely subjective discussions. Although this type of evidence is frequently connected to philosophy and arts, it has a strong place in scientific research as well. Personal observation methods, reflections, and experience can drive data in a completely different direction than solely quantitative, empirical methods would have taken it.
Using Both in Your Research
The obvious differences in data collecting between empirical and non-empirical evidence mean that each researcher has their own opinion as to which is better for their own projects. However, the hostility between those who prefer one over the other is slowly losing ground.
As scholars begin to realize the impact that all of these methods have on their work when it is put together, the debate turns to favoring both at least in part of their research. Scholars are ready to use both types of evidence gathering in order to cement their outcomes more securely, and even to test their own theories before publication.
Show Your Evidence With Impactio
Whether you need charts and tables to display your research impact data to disseminate your work to your audience, Impactio is the program for you. It’s an all-in-one platform with which expert scholars around the world compile their studies, publish them, and follow the impact of their work once it’s published.
When you’re ready to become part of a wide network of other researchers and experts in the field of academics, turn to the platform your peers are using: Impactio.
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https://www.impactio.com/blog/how-to-utilize-both-empirical-and-non-empirical-methods
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The assumption underlying tailoring is that implementation interventions are most helpful if these effectively address the most important determinants of practice for improvement in the targeted setting. The aim of the Tailored Implementation For Chronic Diseases (TICD) project is to develop valid and efficient methods of tailoring implementation interventions to determinants of practice for knowledge implementation in chronic illness care.
The TICD project has organized the planned empirical research in three work packages that follow the three main steps of tailoring: identification of determinants of healthcare practice, matching implementation interventions to identified determinants of practice, and applying and assessing the tailored implementation interventions. These three key steps of tailored implementation will be applied to targeted chronic conditions in five different healthcare systems: cardiovascular disease in the Netherlands, obesity in England, depression in Norway, chronic obstructive pulmonary disease in Poland, and multimorbidity in Germany. The design and interpretation of empirical research will be informed by systematic reviews of previous research on tailoring implementation interventions.
The TICD project will provide much needed evidence on the advantages and disadvantages of different methods of identifying important determinants of practice and selecting implementation strategies that take account of those. It will also provide five rigorous evaluations of tailored implementation interventions for five different chronic conditions.
Tailored implementation interventions are strategies that are designed to achieve desired changes in healthcare practice based on an assessment of determinants of healthcare practice . Systematic tailoring entails three key steps: identification of the determinants of healthcare practice, designing implementation interventions appropriate to the determinants, and application and assessment of implementation interventions that are tailored to the identified determinants. While the process of 'tailoring' may be used refer to the second step only, in this paper it is used in a more comprehensive way to include these three steps. 'Tailored implementation interventions' is the short phrase for implementation interventions resulting from a tailoring process. Little research evidence is available regarding how tailoring is best done in relation to implementation interventions.
Determinants of healthcare practice are factors that might prevent or enable improvements. Such factors are sometimes referred to as barriers and enablers, barriers and facilitators, problems and incentives, or as moderators and mediators. These include factors that can be modified (e.g., knowledge of health professionals) and non-modifiable factors that can be used to target interventions (e.g., wider organizational structures). Determinants of current practice are included if they are relevant to achieving change. The factors can be related to professional behaviour, organisation of healthcare, and health system arrangements. They can also be related to patient behaviours that might prevent or enable healthcare improvements and characteristics of the social and political environment, which might constrain or enable efforts to improve health services. Factors may be pragmatically defined or linked to theoretical perspectives. Healthcare improvements include improvements in any healthcare setting (including primary and secondary care) and improvements in public health services as well as clinical services.
The assumption underlying tailoring is that implementation interventions are most helpful if these effectively address the most important determinants of practice for improvement in the targeted setting. This is consistent with a rational approach to clinical practice, where a diagnosis is made in order to guide the choice of treatment. The idea is also shared with a large number of theories and models for inducing behavioural and organizational change, which have been developed in various scientific disciplines such as motivational psychology, organisational science, and educational research . Many descriptive studies of determinants of practice have been published in medical journals and an increasing number of implementation interventions have been labeled 'tailored implementation interventions.' Although tailoring implementation interventions to determinants of practice seems logical and has received growing attention, research evidence that tailored strategies are substantially more effective than other approaches is lacking .
Furthermore, it is unclear how best to identify important determinants of practice and how to match implementation interventions to those. A range of approaches is available for the different steps in tailoring, as will be outlined in the following section. It is unclear which ones are most appropriate. For example, a meta-regression analysis on 26 studies of tailored interventions did not identify impact of level of tailoring, rigour of barrier analysis, complexity of interventions, concealment of allocation, explicit utilisation of a theory when developing the intervention, and the reported presence or absence of administrative constraints . The Tailored Implementation For Chronic Diseases (TICD) project aims to address this lack of research evidence by directly comparing alternative approaches in the tailoring process and by assessing the effectiveness of resulting tailored implementation interventions.
The available research on tailored implementation interventions signals a number of challenges. Tailoring methods have been poorly described in published research. For example, a qualitative in-depth analysis of a heterogeneous set of 20 tailored interventions found that a wide variety of tailoring methods was used, methods were poorly described, and there was little matching between identified barriers for change and implementation interventions chosen . Poor documentation reduces the possibility of learning from previous studies, makes it difficult to standardize methods, and inhibits the development of a shared knowledge base.
Although many studies of determinants of practice have now been published in healthcare journals, the validation of the measurement approaches is often limited. Whether theory-based or pragmatic, non-validated measures often are used in small studies. For example, many studies were based on physician-reported barriers for change using poorly developed questionnaires. Furthermore, much research is cross-sectional and precedes the implementation process. It is possible that identified determinants of practice are not relevant to the actual implementation process, and during the implementation process determinants of practice may be present that were not identified.
The different methods and models for tailoring reflect opposing approaches to implementation science, which have been advocated by implementation scientists in the TICD consortium. Eccles et al. have argued for wider use of theory in implementation research, both for intervention development and for evaluations of intervention effectiveness . A wide range of theories is available, and personal preference rather than research evidence seems to guide the choice of theory . Theory-based approaches are explicitly linked to one or more specific theories, such as the Theory of Planned Behavior or the Diffusion of Innovation theory, and derive relevant factors and methods from such theories. Oxman et al., on the other hand, have argued for a pragmatic and empirical approach to implementation science . Pragmatic models specify a list of potentially relevant factors, but do not embed these in a comprehensive theoretical framework. Furthermore, different theory-based approaches compete with each other, just as different pragmatic approaches compete with each other. Evidence to support any approach is limited.
While there seems to be broad consensus on the value of tailoring implementation interventions to local determinants of practice, another issue is what 'local' means. Its meaning varies from 'a specific project' or 'a specific health profession' to 'a specific care provider' or 'a specific aspect of the behaviour of that care provider' (e.g., weight monitoring in diabetic patients). The appropriate aggregation level depends on the generalizability of the identified determinants of practice. The choice of aggregation level also may have implications for costs, because tailoring an implementation intervention to each individual health professional is likely to be more resource consuming than tailoring to higher aggregation levels. Tailoring to individual health professionals would be less costly if more intensive and expensive interventions were only used for individuals where they were thought to be needed, rather than for everyone.
Another area of uncertainty concerns the timing of the tailoring process. Tailoring is mostly thought of as an analysis of determinants of practice, and matching of implementation interventions to those determinants of practice, before implementation interventions are actually applied. But this may be too early in some situations, such as in the case of a very innovative technology, because the target group may have to experience the innovation first. In other situations, it may be effective to repeat the tailoring process after an implementation intervention has been started, in order to guide modifications of the implementation process.
To review research evidence regarding approaches to tailoring knowledge implementation in healthcare practice.
To test different approaches for identifying determinants of healthcare practice in chronic illness care.
To test different approaches for matching implementation interventions to identified determinants of healthcare practice in chronic illness care.
To assess the effectiveness of tailored implementation interventions in chronic illness care and the role of hypothesized determinants of healthcare practice.
The TICD project has organized the planned empirical research in three work packages that follow the three main steps of tailoring: identification of determinants of healthcare practice, matching implementation interventions to identified determinants of practice, and applying and assessing the tailored implementation interventions. These three key steps of tailored implementation will be applied to targeted chronic conditions in five different healthcare systems: cardiovascular disease in the Netherlands, obesity in England, depression in Norway, chronic obstructive pulmonary disease in Poland, and multimorbidity in Germany. The design and interpretation of empirical research will be informed by systematic reviews of previous research on tailoring implementation interventions. Ethical approval will be sought for each of the studies separately according to national regulations.
We will prepare systematic reviews of both descriptive and evaluative studies of different approaches to identifying determinants of practice, and approaches to matching implementation interventions to determinants of practice. These reviews will be undertaken the first year of the project and updated during the project.
We will include both descriptive and evaluative studies of methods that have been used to identify barriers or enablers to changing health professional practice or matching interventions to determinants of practice. We will use text words and index terms from published papers that we already have on file to construct search strategies for Medline and Embase. We will conduct citation searches (ISI and Google) and search for related articles in PubMed using key background papers and relevant included studies. We will screen the reference lists of key background documents and relevant studies, and we will contact key informants, including the authors of key background documents and included studies.
The methods for data collection were appropriate for the purpose of the study.
The sources of information were appropriate for the purpose of the study.
The methods used to analyze the data were appropriate for the purpose of the study.
The linkages are transparent between the data that were reported and inferences.
We will construct tables summarizing key advantages and disadvantages of each method to facilitate comparisons across different methods. We will summarize the strengths and weaknesses of each method, ways in which different methods complement each other and could be potentially combined, and gaps in evidence to support potential strengths and weaknesses of each method.
Terms such as checklist, framework, and taxonomy have different meanings. We use the term 'checklist' here as a generic term for any system for identifying and classifying determinants of change in practice.
We will identify checklists in papers included in the review described above. We will contact key informants, including members of an advisory group and the authors of key background documents and included articles, to identify additional checklists. We will review the advantages and disadvantages of existing checklists and compile a comprehensive list of factors included in those checklists and the ways in which factors are grouped ('dimensions'). We will add factors and dimensions that are not included in existing checklists based on input from an international advisory group. We will then organize and group factors into a draft checklist.
We will compile a list of attributes that a checklist of determinants of practice should have by circulating a draft list to the advisory group and revising it based on their input. We will ask the advisory group to appraise the draft checklist using the revised list of desirable attributes as criteria. We will revise the checklist based on their feedback and send the revised checklist with the compiled feedback to the advisory group, requesting them to appraise the revised checklist using the same criteria. The resulting checklist will be tested in work packages two through four, which are described below.
We will update the Cochrane review of tailored interventions that assessed the effectiveness of tailored implementation strategies in improving professional practice and healthcare outcomes. The review includes a comparison of interventions tailored to address identified barriers to change with no intervention or an intervention(s) not tailored to the barriers. We will undertake this analysis for two subsets of the studies, one in which the control group received no intervention and the other in which the control was a non-tailored intervention. We will also undertake an investigation of heterogeneity of the effectiveness of tailored interventions to identify factors important to consider when designing and implementing a tailored intervention. We will also compare interventions targeted at both individual and social or organisational barriers compared with interventions that are targeted at only individual barriers. This review was last updated in 2009 .
In this work package, we will evaluate different methods for identifying determinants of practice. We will first describe gaps or deficiencies in healthcare for the studied chronic conditions by drawing on publications and available datasets. Having defined the strengths and weaknesses of care, we will select up to four methods for identifying determinants of practice that appear to explain the deficiencies in care. Finally, we will compare methods and their findings to determine which methods are most appropriate to use, and to which contexts and settings they are most applicable.
Review of published observational research on adherence to guidelines or aspects of care of the targeted chronic condition, using searches in electronic bibliographic databases, national journals, and national conferences; we will apply a standardized search strategy that will ensure consistency across targeted chronic conditions, and between participant countries. Whilst the review will not be of trials of clinical interventions, we will employ systematic approaches for the searches and assessment of articles for inclusion. Data from the included articles will be extracted to a table, and the findings summarized in a narrative review that will compare evidence on what care is delivered with the prevailing guideline recommendations.
Analysis of available epidemiological or public health datasets, or data from surveillance networks that continuously collect data on disease incidence and prevalence as well as healthcare provided. For example, some practice level data on management of obesity are available in England; in different countries and for the different clinical conditions, a variety of data are available. The analyses will be descriptive, and will be used to highlight discrepancies between recommended care and actual care.
In order to check our interpretation of our evidence and data reviews, we will interview up to five key informants on each country. The informants will be selected for their knowledge of policy and practice of the targeted condition in the context of their country setting. The interview will enquire whether our interpretation of the gaps and deficiencies in performance reflect their own knowledge and experience. If differences between our interpretation and the views of the key informants are identified, we will re-visit the evidence and data to understand the inconsistencies.
We will use a structured approach to select up to four methods for identifying determinants of practice. The TICD participants and members of the scientific advisory board will be involved in this process that will employ a two- or three-stage modified Delphi procedure to identify consensus on the most appropriate methods to select. In the Delphi procedure, respondents will be asked to rate the suitability of the candidate methods using a set of criteria that will include the extent to which the methods identify a comprehensive range of determinants, whether they identify the most relevant determinants, whether there is evidence of their validity, and whether they feasible to employ and of reasonable cost. The Delphi procedure will also seek consensus on the extent to which a checklist should be used to assist in the identification of determinants, and the extent to which behavioural theory should inform the use of the methods.
Head-to-head comparisons of barrier identification methods will be conducted in each country for the targeted chronic conditions (i.e., five discrete but related studies, each addressing one of cardiovascular risk, obesity, mental health, multi-morbidity, or asthma). An internationally standardized protocol for these studies will be developed to ensure that the chosen methods are used consistently across countries. In each country, up to four methods will be used. Because there is no reference standard already known as a valid method to identify determinants of practice, we will take as the reference, for each condition, the total of all determinants identified by all methods combined. Brainstorming will be used as the reference methods involving (lowest) cost and time investment.
The setting of these studies will be dictated by the particular condition, and generally will involve primary and secondary care services. The study subjects will be clinicians, patients, managers or content experts. The number of participants in each study group is related to the method used; e.g., a survey in health professionals requires a larger sample than a brainstorming session with five to ten clinicians. Because the selected methods may be more appropriate for certain settings (for example, the team or organization level), random allocation of methods across settings would be not be helpful. Selection of methods will be made on explicit predictions of which method is likely to suit which condition and setting. For example, if care is team based, observation of teamwork, process mapping, or focus group methods may be more appropriate than individual interviews.
In each chronic condition, we aim to spread the selected methods over aggregation levels (health professional, team, organization) and orientation (explorative/pragmatic versus theory-orientated). One of the methods will be consistent across conditions, and we plan to use brainstorming in this role. A standard brainstorming session with pragmatic analysis of data represents a low cost, low intensity method. All other methods involve a greater degree of primary data collection and analysis, and therefore although brainstorming is not a no-intervention control, it offers a minimal method against which more intensive methods may be compared. Measures of process and outcomes will be standardized. The analysis will compare methods in terms of process (the time, resources, and expertise required), and outcomes (the range and completeness of determinants of practice identified, consistency of factors across methods, and whether the method highlighted the most salient determinants of practice as identified by the combined methods).
We will undertake a process evaluation in each country to describe the feasibility of use of the methods and check the fidelity of use of the methods. The research teams in each country will maintain a diary to record the required time and document any difficulties in applying the methods, any deviations from the recommended procedures for each method, and any other problems or positive experiences that occurred. The project diaries will be supplemented by interviews of each country researcher led by the lead of this work package in order to explore any emerging issues in depth. The findings of the diaries and interviews will be combined to create a report on the use of each method.
This work package focuses on the logical next step in tailoring, which is linking implementation interventions to identified determinants of practice. First, the list of determinants of practice will be standardized to set the stage for the next steps. Then, up to four methods will be selected for linking interventions to these determinants of practice. Some of these methods may be naturally linked to approaches for identifying determinants of practice, e.g., identified in the same questionnaire or focus group interview. While the strongest evidence for the usefulness of matching interventions will be provided by the planned evaluations of resulting tailored implementation interventions, this work package will examine outcomes specifically related to the matching methods.
The identified determinants of practice for knowledge implementation in the targeted chronic diseases, resulting from the different approaches in the previous work package, will be standardized. This is done to provide an equal starting point for the research planned in this work package. In this process, we will take the validity and generalizability of the findings into account.
We will select up to four methods for matching implementation interventions to identified determinants of practice identified in the previous work package. The methods will be selected for testing, using a structured process. The process will employ a two- or three-stage modified Delphi procedure to identify consensus on the most appropriate methods to test. In the Delphi procedure, respondents will be asked to rate the suitability of the candidate methods using a set of criteria that will include the extent to which the methods can be linked to specific factors, whether there is evidence of their effectiveness, and whether they are efficient and feasible to employ. Depending on the number and nature of the methods identified in the literature reviews, in the Delphi ratings process we will group the methods according to whether they are pragmatic or theory based, and whether they address individual, team, or organization levels. Consequently, it will be possible to select the most highly rated methods from these categories.
Head-to-head comparisons of barrier identification methods will be conducted in each country for the targeted chronic condition (i.e., discrete but related studies). An internationally standardized protocol for these studies will guide these studies. The comparisons will be designed as comparative evaluations. One of the methods will be consistent across conditions, and we plan to use a short brainstorming session in this role. We will take care that study groups cannot influence each other during the study (to avoid contamination), that 'interventions' to match implementation interventions are well defined and implemented, and that measures for evaluation are standardized.
The setting of these evaluation trials will be dictated by the particular condition, and generally will involve primary and secondary care services. The study subjects will be clinicians, patients, managers, or content experts. Because the selected methods may be more appropriate for specific settings (for example, the team or organization level), random allocation of methods across settings would not be helpful. Selection of methods will be made on explicit predictions of which method is likely to suit which condition and setting. In each chronic condition, we plan to test up to four different methods, spread over aggregation levels (health professional, team, organization) and orientation (explorative/pragmatic versus theory-orientated). A pragmatic brainstorm session involving experienced clinicians represents a low-cost, low-intensity method. All other methods involve a greater degree of primary data collection and analysis, and therefore although brainstorming is not a no-intervention control, it offers a minimal method against which more intensive methods will be compared.
Measures include a log of activities and time investment, and documentation on the prioritized implementation interventions. The analysis will compare methods in terms of process (the time, resources, and expertise required), and outcomes (the range and completeness of interventions identified, consistency of interventions, and whether the method highlighted the most salient interventions as compared to the combined results of the different methods). The impact of chosen interventions will be studied in the trials, which are described below.
We will undertake a process evaluation in each country to describe the feasibility of use of the methods and check the fidelity of use of the methods. The research teams in each country will maintain a diary to record the required time and document any difficulties in applying the methods, any deviations from the recommended procedures for each method, and any other problems or positive experiences that occurred. The project diaries will be supplemented by interviews of each country research led by the lead of this work package in order to explore any emerging issues in depth. The findings of the diaries and interviews will be combined to create a report on the use of each method.
In this final piece of empirical research, we will assess the effectiveness of the resulting tailored implementation interventions that were derived from the previous work package. Depending on feasibility, the studies will involve subjects who were also involved in previous work packages or newly recruited subjects. A detailed study protocol will be elaborated according to relevant guidelines, e.g., CONSORT, STROBE. Trials will be registered in an internationally recognized register. In this section an outline of the planned research is provided. First, we will make a final choice of implementation interventions and develop research protocols for each of the different (clusters) of chronic conditions. The research protocols will be internationally standardized with respect to methods and measures where possible to enhance comparability of study findings. We aim for cluster-randomized trials, when feasible. The strongest possible alternative design will be used, when cluster-randomized trials are not feasible (e.g., interrupted time series or controlled before-after comparisons). Measures related to identified determinants of practice will be included to explore their potential role in improving healthcare practice. Finally, we will apply observational and qualitative methods (surveys, interviews, focus groups) including patients and professionals as process evaluation.
Based on the results of the work package focused on matching interventions to determinants of practice, a list of implementation interventions will be made for each of the five targeted chronic conditions. Tailoring interventions implies that we cannot specify the interventions a priori in a standardized way. We expect to assess complex interventions consisting of several active components on different levels e.g., on the individual and organizational levels. Participants (practitioners and patients) may be different from those involved in the previous work packages, which may result in a different choice of implementation interventions compared to the previous work package. Furthermore, it is likely that the interventions will differ across health professionals and organizations, if these have different determinants of practice for implementation.
We will plan rigorous evaluations of tailored implementation interventions in each of the different chronic diseases. The resulting tailored interventions may differ across the targeted chronic conditions. International standardization will be sought in order to enhance the comparability of research. The size of the studies will be determined on the basis of statistical power calculations, but we expect to include large samples of patients (>100 and potentially many more) and providers (>30 and potentially many more). Baseline measurements and patient outcome measures will be included when possible. Control groups will receive minor or delayed implementation interventions (in parallel group designs), or alternative interventions (in block designs). The trials will be pragmatic, meaning that they reflect clinical reality reasonably well.
In the analysis, we will examine the influence of the hypothesized determinants of practice on implementation processes in chronic illness care, and thus provide further evidence on the validity of measures of determinants of practice. This will provide hypotheses on factors that really influence implementation processes in chronic illness care. We will also test the added value of repeated analyses of determinants of practice compared to the initial analysis of determinants of practice. The data-analysis will be based on up-to-date tools, including random coefficient regression models for longitudinal data.
Process evaluations are especially necessary in trials of complex interventions, and in multisite trials, where the same or similar interventions may be implemented. In the process evaluation, we will measure the integrity and feasibility of the implementation interventions and clinical interventions that were implemented. Furthermore, we will assess how the interventions are implemented, distinguish between components of the interventions, and identify contextual factors that may influence the content and effectiveness of the implementation intervention. For this purpose, we will keep a log and use questionnaires for participants. The process evaluation will also examine how well the interventions were tailored to the local barriers/enablers, and whether the barriers were overcome to any extent. This will be based on interviews and surveys of participants. Process evaluation will consist of qualitative and quantitative methods that will be developed with this work package. The research teams in each country will apply those methods (e.g., central questions for interviews and focus groups) for process evaluation.
An outcome evaluation will assess the effectiveness of the tailored implementation interventions and the role of the previously identified determinants of practice in the implementation process. This analysis will also provide insight into the mechanisms underlying implementation processes in chronic illness care. The evaluations will include measures regarding the following domains: (intermediate) health outcomes including clinical measures, quality of life measures, and patient reported outcomes depending on the specific disease; patient behaviours, including adherence to treatment and life style); as well as healthcare professionals' performance and processes of healthcare delivery. Furthermore, descriptive information on patients, health professionals, and practice organizations will be systematically collected using questionnaires or medical records.
Across the world, health research funders have made substantial investments in implementation programs and in implementation research . These activities should be led by the priorities in clinical practice and health policy, but it also important to invest in the assessment and innovation of approaches for implementation. The TICD project aims to contribute to the innovation of tailoring methods. The TICD project is focused on chronic illness care, which is a large and growing domain of healthcare across the world. It remains to be seen to what extent tailoring approaches are specific for this domain or can be used in other healthcare domains.
The study was conceived by MW. Writing of the paper was led by MW with all authors commenting on drafts and approving the final version.
The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 258837. We are grateful to Marion Bussemakers for administrative support. Jeremy Grimshaw holds a Canada Research Chair in Health Knowledge Transfer and Uptake.
We will seek ethical approval from recognized ethical committees within each of the countries for all research that involves participation of individuals.
Martin Eccles is Co-Editor in Chief of Implementation Science, Michel Wensing is an Associate Editor, Andy Oxman and Jeremy Grimshaw are members of the Editorial Board of Implementation Science; all decisions on this paper were made by another editor.
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https://implementationscience.biomedcentral.com/articles/10.1186/1748-5908-6-103
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The purpose of this critique is to analyze the strengths and weaknesses of the dissertation titled “Emotional Competence and Effectiveness of New Teachers” and written by Diane Wanas LeCates in 2019. This dissertation provided the findings of the study conducted on the relationship between training given to new teachers in Delaware, their emotional competence, and their effective performance. In this critique, the analysis of the problem and purpose statements, literature review topics, the research design, as well as findings and conclusions is presented.
Problem and Purpose
The introductory chapter of the dissertation presented a detailed background for the idea of developing emotional competence in novice teachers with the help of training in order to increase their effectiveness in the classroom. However, although the background information was provided effectively, the statement of the problem was not expressed clearly in one comprehensive sentence. It was stated by LeCates (2019) that there was the lack of research on the connection between teachers’ emotional competence and their performance, and there was a need for developing training for teachers to improve their emotional competence to influence their performance in the classroom. The section to present the problem statement is large, and the need for the study was described in the second part of the section: quality training programs were necessary to support new teachers to affect their emotional competence and perform effectively in the classroom. It is possible to assume with reference to the information provided in the chapter that the problem guiding the study is that modern training for new teachers did not include the development of emotional competence despite its potential impact on teachers’ effectiveness.
In comparison to the problem statement, the purpose of the research was formulated clearly: to study the relationship between training for new teachers, their emotional competence, and their effectiveness with reference to performance in the classroom. Four research questions were formulated in order to address the purpose of the research and be able to guide the researcher to find the answers and complete the purpose. Thus, the clarity of the statement was high in relation to the research purpose, but it was low when related to the formulation of the problem to address.
In order to provide the background for the study, support the problem discussion and the purpose statement, the researcher presented much evidence from prior conceptual and empirical research on related topics. It was found out that there was limited research on the topic of the relationship between teachers’ training, their emotional competence, and their effectiveness in the classroom. This conclusion provided the ground for discussing the problem statement. On the one hand, LeCates (2019) presented much evidence to support the ideas that effective training for new teachers required the inclusion of the emotional intelligence component, more research was needed for defining effective teaching, emotional competence was important to be developed, and a low number of teachers were usually involved in training. On the other hand, the findings of the prior conceptual and empirical research were not arranged effectively enough to accentuate and illustrate the problem to resolve.
In spite of some weaknesses in structuring sections and formulating the research problem, it is possible to claim that the study posed interesting and important questions to address because the determined relationship between new teachers’ training, their emotional competence and effectiveness was not researched previously. In this context, one should note that the results of the reviewed study could potentially affect important stakeholder groups. Thus, the study findings were reported to be significant for researchers interested in the topic, teachers and administrators as practitioners, and policy makers and academicians responsible for the development of training and induction programs for new teachers. The reason is that the author addressed the gap in research on explaining how the emotional competence of new teachers could be correlated with received training and then with effectiveness in the classroom.
Literature Review
The author organized the review of literature according to the concepts and topics identified in the problem and purpose statements: the emotional intelligence theory, the components of effective teaching and their relation to emotional competence, and teacher preparation and training programs. The sources for the literature review were selected depending on their ability to cover these topics, and the used sources were of the high quality. The reason is that, for presenting a historical background for the emotional intelligence theory, LeCates (2019) effectively used many seminal theoretical works to describe and support the discussion of existing theoretical models. The selection of scholarly journals and peer-reviewed articles to demonstrate researchers’ views on the correlation between the emotional competence of teachers and used methods of effective teaching was also appropriate. The analysis of the existing new teacher induction and preparation programs was efficiently based on state policies and programs, as well as previous researchers’ assessments. It is possible to state that the author demonstrated objectivity in the selection of references in order to present different perspectives regarding the identified topics.
When analyzing the thoroughness of the literature review, it is possible to state that the author mainly referred to the articles published in the period of 2000-2015 in spite of the fact that the dissertation was completed in 2019. This aspect allows for concluding that only limited research published during the period of 2016-2019 was included in the literature review, and important modern tendencies in covering the identified topics as well as some relevant literature streams could be omitted. It could be possible to focus more on the analysis of the current literature on emotional competence in training for teachers. Therefore, the provided literature review cannot be discussed as exhaustive.
Despite some issues with covering the available literature on the topic, it is possible to state that the author effectively summarized the bodies of literature. The reason is that LeCates (2019) described the most relevant models related to the emotional intelligence theory in detail. In addition, the measurement tools for emotional intelligence were also explained sufficiently. Moreover, when reviewing the research on the correlation between emotional competence and effective teaching characteristics and methods, the author presented all the required details regarding previous studies in order to summarize the information. Different frameworks of teaching and researchers’ findings were effectively introduced and explained.
It is also important to note that the author successfully analyzed the existing literature as she presented the review of topics from the perspective of different researchers and compared and opposed their ideas and conclusions where it was necessary. In the sections other than the first one with the description of theoretical models, LeCates (2019) not only presented the findings of previous researchers on issues but also concluded regarding similarities and differences, as well as strengths and weaknesses in their approaches. From this perspective, the literature review was mostly effective in terms of the presentation and analysis and fitting the problem and purpose statements formulated for the research. However, the coverage of recent studies on the problem was not appropriate and could be improved.
Research Design
In order to address the purpose of the study and answer four research questions on the types of teacher training available, on the relationship between training and self-reported emotional competence, on the relationship between training and teachers’ effectiveness, and on the relationship between teachers’ emotional competence and effectiveness, the quantitative methodology was selected in contrast to the qualitative one. This methodology was selected appropriately depending on the necessity of finding the relationship between the variables, as it is provided in the research questions. LeCates (2019) also chose a non-experimental correlation research design that is most suitable for determining the degree of relationship or correlation between variables. It is important to note that the application of the quantitative correlation research design allowed for generalizing the study results to be relevant for a wider population.
The non-random sampling approach was applied in order to recruit the participants, and this method was most effective for focusing on the population involving only new teachers enrolled in Delaware’s Comprehensive Induction Plan (CIP). This sampling allowed for selecting the teachers who directly addressed the inclusion criteria and covered the selected population of new teachers receiving specific training in Delaware according to the CIP. Thus, this successful approach allowed for inviting 143 teachers, among which 48 participants were recruited for the analyzed study. This sample size was appropriate for small quantitative studies. The author also provided the descriptive demographic data in this chapter of the dissertation in order to support the information on the sample.
The author used three instruments to collect data: the Widener Emotional Learning
Scale (WELS) as a self-administered survey for measuring teachers’ emotional competence, the Delaware Performance Appraisal System (DPAS II) survey to assess teacher effectiveness, and the new teacher training survey developed by the author. The WELS and DPAS II had the high levels of reliability and validity to provide accurate data because these instruments were actively used by other researchers, and their objectivity and validity were evaluated and supported. The WELS assessed emotional competence referring to the Tolerance of Differences or Conflict, Awareness of Emotions in Self and Others, Flexibility in Perspective Taking and Behavior, Interpersonal Relationship Skills, and Self-Management Skills using 33 items and a Likert scale.
The quality of DPAS II was supported by the fact that the survey was based on Danielson’s Framework for Teaching, and it was actively used by many researchers. Although the new teacher training survey was developed by the author of the dissertation, its validity and reliability were checked with reference to the pilot test results involving teachers who worked at a public school district in Delaware. The data were collected mainly in a digital form because the surveys were web-based, and hard copies of teaching evaluation results were provided by the participants.
The gathered data were effectively coded in order to provide information in a numerical form and analyze using descriptive and inferential statistics methods. The frequency distribution analysis was used efficiently to address the first question on the types of training that new teachers in Delaware had. The Statistical Package for Social Sciences (SPSS) software was applied for conducting ANOVA and multiple regression tests, and these tests were mentioned in the chapter on methodology. The discussed analyses were most suitable in order to test the relationship between the variables mentioned in the research questions. However, used cross-tabulation and chi-square tests were not discussed in this chapter in spite of using them for analysis and mentioning them in the abstract. From this perspective, it is possible to state that the author selected an appropriate methodology to address the research purpose and questions in order to determine the extent to which teachers’ emotional competence training was correlated with their level of competence and their effectiveness in the classroom. However, the author failed to discuss all the tests used for statistical analysis in the chapter on methodology.
Findings and Conclusions
The findings of the research were explained in a detailed but inappropriate way. There were also some weaknesses in the presentation of the results. The presentation of the findings was appropriately organized according to the research question. On the other hand, the author focused on using tables with descriptive statistics to support results instead of presenting tables with the statistical tests results, for example, for an ANOVA test, a regression test, and a chi-square test. The research questions were answered in much detail as LeCates (2019) presented the comprehensive description of findings. In response to the first research question, according to the author’s comments, it was found that 75% of new teachers received training of at least one type (courses, lessons, or professional development) on content, assessments, diversity, collaboration, adaptation of lessons, communication, and self-reflection. The author stated that most participants revealed having training on preparation, the classroom environment, responsibilities, and instruction, but according to the frequency tables, about 73% of the participants reported having no training on the management of feelings and emotions. This component was directly related to emotional competence, but it seemed not to influence the author’s conclusions.
The results of ANOVA tests were used to address the second research question. The author provided descriptive statistics tables, but not actual ANOVA table results. It was mentioned that only five of the twelve items from the new teacher training survey showed the interaction between the type of training and teachers’ emotional competence, but these results were not reflected appropriately in the abstract and concluding remarks. Thus, it was claimed that there was a significant relationship between the type of training and five emotional competencies, such as self-management skills, tolerance, interpersonal relationships, flexibility, and awareness of emotions, but other seven competencies were not discussed.
In order to address the third question, the chi-square test and cross-tabulation analysis were applied despite the fact that they were not described in the chapter on methodology. It was found that most participants had the effective performance level, but there was little differentiation between the type of training and their effective performance in the classroom (LeCates, 2019). In response to the fourth question, the author conducted a multiple regression analysis (but no illustrative table was provided) and found that all WELS components could explain 23% of the variance in teachers’ evaluation. This variance can be discussed as rather valid to claim that teachers’ emotional competence measured by the WELS could predict their performance and teaching effectiveness.
The discussion of the conclusions was directly based on the findings presented, as well as on the ideas that were found in the review of the literature. It is also important to note that the discussion of the findings addressed the gaps in the explanation presented in the chapter on findings. Furthermore, the conclusions were discussed in the context of the existing research on the topic. The concluding chapter of the dissertation included all the necessary parts of such research papers: the discussion of the findings depending on the research question and previous researchers’ results, conclusions, implications for research and practice, limitations, and recommendations for future research. It is important to note that the sub-section on recommendations was substantial, indicating the areas uncovered by the discussed study and requirement more examination.
Conclusion
The discussed dissertation addressed the important purpose, and the methodology was selected appropriately in order to answer the set research questions on the types of training and the relationship between variables. However, the dissertation had some weaknesses that influenced its quality significantly. Thus, it is possible to note that the problem statement lacked clarity, the literature review did not include most of the latest studies on the topic, the methodology chapter did not address chi-square and cross-tabulation analyses, and the interpretation of some findings required improvement. These aspects do not allow for concluding that the results of the dissertation can be widely cited and applied because of the quality issue. From this perspective, the dissertation could contribute to research and practice in the sphere of education, but some parts needed improvements.
Reference
LeCates, D. W. (2019). Emotional competence and effectiveness of new teachers (Publication No. 13860878) [Doctoral dissertation, Widener University]. ProQuest Dissertations Publishing.
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https://chalkypapers.com/emotional-competence-and-effectiveness-of-new-teachers-by-lecates/
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The module is aimed primarily at international students who often have a first degree unrelated to education and no prior teaching experience. Many international students undertake the MA Educational Studies in preparation for becoming a teacher but often lack the pedagogical and theoretical foundations that underpin teaching, learning and assessment. The introduction of a core module focused on these topics is intended to address these gaps in knowledge and understanding as well as the fragmented and uncritical view of education. The core module shoud provide a more secure foundation for choosing more specialised optional modules in the Spring Term, giving greater coherence and relevance overall. This module contributes to the achievement of all four aims of the MA in Educational Studies and provides opportunities for students to: • Engage at an advanced level with issues of significant concern to those involved in education. • Evaluate the most recent developments in research and policy initiatives on local, national and international levels. • Develop professionally by considering the implications of the module for practice, including their own practice, where appropriate. • Develop, utlilise and evaluate a range of investigation methods (by completing seminar tasks, preparatory activities and a 5,000 assignment. There are additional module-specific aims that students should: • Develop a critical understanding of theoretical and empirical research into teaching, learning and assessment. • Deepen their insights into the ‘dynamic interaction’ (Gipps, 1994) that exists between teaching, learning and assessment. • Deepen their understanding of the impact of different approaches to teaching, learning and assessment on the motivation, engagement and enjoyment of learners. • Evaluate the impact of different forms of assessment on learners: their attitudes, motivation, self esteem and approaches to learning. • Explore the relationship between formative and summative assessment and ways in which this can be enhanced. • Evaluate key theories of leadership and management in education. • Engage critically with current research on educational policy and decision-making. • Deepen their insights into school effectiveness and school improvement research.
Principal learning outcomes
Subject Knowledge By the end of the module, students should be conversant with: • Pertinent research [types of research, key findings, contribution to theory, practice and policy initiatives at (inter-)national level] • Recent theoretical developments and paradigm shifts Understanding By the end of the module students should have: • Deepened and extended their understanding of key concepts and issues in teaching, learning and assessment • Deepened their insight into the principles which inform good practice and the implications of these for professional practice Key Skills By the end of the module, students should have further developed their ability to........ • Communicate their ideas and findings effectively in various media (written, spoken and possibly graphical) • Work effectively with others • Study independently • Engage in problem-solving activities • Improve their own learning and performance by developing their study skills and academic reading and writing skills • Make an informed and effective oral presentation Cognitive Skills By the end of the module students should have further developed their ability to.... • Analyse and evaluate materials introduced during the course • Present a well-reasoned and appropriately substantiated argument, drawing on evidence from a variety of sources and synthesising ideas as appropriate • Demonstrate a critical understanding of module content in relation to professional practice Professional Skills By the end of the module students should have further developed their ability to.... • Reflect (reflection-on-action [Schön, 1983] ) • Consider, in an open-minded way, ideas and research findings which conflict with their own personal theories about teaching, learning and assessment
Timetabled teaching activities
30 (teaching hours related to assessed core module) 12 hours (structured observation progamme in HE and local schools to enhance and extend taught module content)
Departmental link
http://www2.warwick.ac.uk/fac/soc/ces/current/pgt/modules/ie9h6/
Module assessment
|Assessment group||Assessment name||Percentage|
|30 CATS (Module code: IE9H6-30)|
|A (Assessed work only)||5000 word Assignment||100%|
Module availability
This module is available on the following courses:
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https://warwick.ac.uk/services/aro/dar/quality/modules/archive201718/postgraduate-1718/postgraduate-copy/eq/ie9h6/
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This study aims at critically reviewing recently published scientific literature on the use of computer and video games in Health Education (HE) and Physical Education (PE) with a view: (a) to identifying the potential contribution of the incorporation of electronic games as educational tools into HE and PE programs, (b) to present a synthesis of the available empirical evidence on the educational effectiveness of electronic games in HE and PE, and (c) to define future research perspectives concerning the educational use of electronic games in HE and PE. After systematically searching online bibliographic databases, 34 relevant articles were located and included in the study. Following the categorization scheme proposed by [Dempsey, J., Rasmussen, K., & Lucassen, B. (1996). The instructional gaming literature: Implications and 99 sources. University of South Alabama, College of Education, Technical Report No. 96-1], those articles were grouped into the following four categories: (a) research, (b) development, (c) discussion and (d) theory. The overviewed articles suggest that electronic games present many potential benefits as educational tools for HE and PE, and that those games may improve young people’s knowledge, skills, attitudes and behaviours in relation to health and physical exercise. Furthermore, the newly emerged physically interactive electronic games can potentially enhance young people’s physical fitness, motor skills and motivation for physical exercise. The empirical evidence to support the educational effectiveness of electronic games in HE and PE is still rather limited, but the findings present a positive picture overall. The outcomes of the literature review are discussed in terms of their implications for future research, and can provide useful guidance to educators, practitioners and researchers in the areas of HE and PE, and to electronic game designers.
Papastergiou, M. (2009). Exploring the potential of computer and video games for health and physical education: A literature review. Computers & Education, 53 (3), 603-622. Elsevier Ltd. Retrieved April 23, 2019 from https://www.learntechlib.org/p/67274/.
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http://mail.editlib.org/p/67274/
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Sutherland Street Out of School Hours Care staff work to create a dynamic and engaging curriculum for all children. Based on the individual needs of each child we create experiences that are fun, educational and linked to children’s interests.
To cater for all of the children in our care we create individual plans for each child then use these to create group activities that are modified and extended upon. These group activity plans can be viewed at the entrance of each of our services and through `Childcarers’ (A link is provided by using the Childcarers App).
Below is the process of our planning cycle:
1. Observe And Review:
Assess and evaluate planned and unplanned learning – In this stage we begin to observe the children and evaluate their learning by creating learning stories on their progress and achievements. These observations then become individual learning plans and are put into the children’s files. We gather evidence and information and consider the resources, time, space and any modifications that can be made.
2. Question:
Explore knowledge and beliefs / Construct philosophy / Identify individual and group strengths and weaknesses – In this stage we question what we are doing and why, linking our answers to relevant research and theory. We look at our own knowledge of the children, families, community and our own beliefs. We look at our personal strengths, interests and what we can bring to the service. We then look at any knowledge we need to gain in order to respond to, promote and extend the children’s learning.
3. Act/Do:
Implement plans – In this stage the plan is put into action by all educators at the service. The educators actively engage with and support all children to participate in the range of experiences. We respond to the children and accommodate each of their needs. Once the experiences are implemented we begin to observe and review.
4. Plan:
Devise learning environment / define educator role / devise evaluation methods / plan experiences – During this stage the supervisors meet to plan the indoor and outdoor learning environments as well as upcoming experiences. The plan involves 6 experiences; 2 experiences aimed at younger children, 2 experiences aimed at older children and 2 experiences for outdoors only. Being child centred, the plan is developed from the recent child observations, reviews & evaluations of previous experiences. During this time we also decide upon the educator’s role and how we will evaluate our planning.
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https://ssoshc.com.au/our-approach/
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This year's report provides parents and the wider Tasmanian community with current information on the government's priority areas of the early years; literacy and numeracy; student retention; school improvement; and equity. Parents and the community can now see annual improvement achieved by our schools and can monitor progress over time as well as celebrate the improvement successes of our schools. From Department of Education's description. See also statement by State Minister for Education Lin Thorpe 29 April 2010. The full report is available online.
KLA
Subject HeadingsEducation policy
Tasmania
Developing Reading and Writing in Second-Language Learners: Lessons from the Report of the National Literacy Panel on Language-Minority Children and Youth
Routledge, August 2007
A shorter version of the full volume Developing Literacy in Second-Language Learners, this book reports the findings of the USA's National Literacy Panel on Language-Minority Children and Youth. The Panel, comprising experts in reading, language, bilingualism, research methods and education, was appointed to identify, assess and synthesise research on the literacy education of language-minority children and youth. Chapters adapted from the original report concisely summarise empirical research about the development of literacy in language-minority children and youth, including development, environment, instruction and assessment. Chapter titles include Cross-Linguistic Relationships, Sociocultural Contexts and Literacy Development, and Instruction and Professional Development. Adapted from publisher's description.
Key Learning AreasEnglish
Subject HeadingsWriting
Reading
English language teaching
English as an additional language
Our School Building Matters: How to Use Investment in the Fabric of Your School to Inspire Learning
This document is designed as a toolkit for teachers to make the most of new and refurbished school buildings. It offers a range of ways that schools can exploit the building or refurbishing process to improve opportunities for learners. A variety of activities and British case studies are included to help teachers and leaders make the most of the design and planning process. The activities range in duration and are designed to be appropriate to different contexts and situations. Chapter titles include Whole school and longer term activities; Understanding your current school building; Having a say on design decisions; Making the most of learning opportunities on campus; and Creative ways to use your completed building. The full report is available online.
KLA
Subject HeadingsSchool equipment
School grounds
School buildings
Learning Together: How Education Providers Promote Social Responsibility and Community Cohesion
OFSTED, February 2010
This document reports on a study into local education providers' knowledge of their school and community, and how they helped learners become responsible citizens. Observations were conducted of a range of learning institutions in Britain. Strategic leadership was key to identifying communities and needs, and partnerships were essential to ensuring tailored provision. Opportunities were provided for all learners to develop their skills and knowledge through appropriate curricular vision. However, the consistency and quality of these approaches varied between schools. Barriers were targeted through helping to engage the community, and through broadening students' personal horizons. The full report is available online.
KLA
Subject HeadingsSocially disadvantaged
Social life and customs
School and community
Great Britain
What Is the Effect of Block Scheduling on Academic Achievement? A Systematic Review
EPPI, 2010
Drawing on a review of the research literature, this report examines the different types of block scheduling and how they influence students' academic achievement. The research indicated that 4 x 4 block scheduling, where students attend four classes of 80–90 minutes each day, resulted in higher cross-subject achievement than traditional schedules. For science, A/B block scheduling resulted in higher results than traditional schedules, however, in mathematics and English, the evidence was unclear, with studies showing both better and worse results for block scheduling compared with traditional scheduling. The full report is available online.
KLA
Subject HeadingsSchool day
Class periods
Great Britain
The Dynamics of Educational Effectiveness: A Contribution to Policy, Practice and Theory in Contemporary Schools
Routledge Education, September 2007
Two researchers detail current thinking and evidence about educational effectiveness. The book examines definitions of educational effectiveness, and analyses the various theories and strands of research within educational effectiveness, especially with respect to the model developed by Creemers. Chapter titles include Essential Characteristics of Educational Effectiveness Research; Empirical Testing of the Comprehensive Model of Educational Effectiveness: Review of Research; The Dynamic Model: Factors Operating at School and Context Level; and Implications for the Improvement of Educational Practice. Adapted from publisher's description.
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http://cmslive.curriculum.edu.au/leader/new_publications,105.html?issueID=12111
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What are the different types of scientific evidence?
What is considered scientific evidence? Scientific evidence is information gathered from scientific research, which takes a lot of time (and patience!) to conduct. But there are a few things that all this research needs to have in common to make it possible for decision-makers, and ultimately all of us, to accept it as “evidence”.
What is type3 evidence? Type III evidence pertains to physical activity policy, i.e. studies that link policymaking to physical activity (cf. Brownson et al.
What is an example of evidence in science? In the sciences, evidence is understood as what confirms or disconfirms scientific hypotheses. The term “confirmation” is sometimes used synonymously with that of “evidential support”. Measurements of Mercury’s “anomalous” orbit, for example, are seen as evidence that confirms Einstein’s theory of general relativity.
What are the different types of scientific evidence? – Related Questions
What is object or real evidence?
OBJECT (REAL) EVIDENCE. Section 1. Object as evidence. — Objects as evidence are those addressed to the senses of the court. When an object is relevant to the fact in issue, it may be exhibited to, examined or viewed by the court. (
What type of evidence is used in evidence based practice?
Evidence from well-designed case-control or cohort studies. Evidence from systematic reviews of descriptive and qualitative studies (meta-synthesis). Evidence from a single descriptive or qualitative study. Evidence from the opinion of authorities and/or reports of expert committees.
What is an example of observational evidence?
Observational studies include cohort studies with or without a comparison group, cross-sectional studies, case series, case reports … and case-control studies’ .
What is the first step in the scientific method?
The first step in the Scientific Method is to make objective observations. These observations are based on specific events that have already happened and can be verified by others as true or false. Step 2. Form a hypothesis.
What are the 5 types of scientific journals?
These include original articles, case reports, technical notes, pictorial essays, reviews, commentaries and editorials. Authors should be aware that each type of paper is specific in nature, serve a distinct purpose, and is judged by different criteria.
What are the 4 main types of research?
There are four main types of Quantitative research: Descriptive, Correlational, Causal-Comparative/Quasi-Experimental, and Experimental Research. attempts to establish cause- effect relationships among the variables. These types of design are very similar to true experiments, but with some key differences.
What is the highest form of evidence?
Typically, systematic reviews of completed, high-quality randomized controlled trials – such as those published by the Cochrane Collaboration – rank as the highest quality of evidence above observational studies, while expert opinion and anecdotal experience are at the bottom level of evidence quality.
What is best research evidence?
Best evidence includes empirical evidence from randomized controlled trials; evidence from other scientific methods such as descriptive and qualitative research; as well as use of information from case reports, scientific principles, and expert opinion.
What is considered good evidence?
Good evidence means the recommendation considered the availability of multiple adequate scientific studies or at least one relevant high-quality scientific study, which reported that a treatment was effective.
What are the rules of evidence?
The law of evidence, also known as the rules of evidence, encompasses the rules and legal principles that govern the proof of facts in a legal proceeding. These rules determine what evidence must or must not be considered by the trier of fact in reaching its decision.
Is character evidence admissible?
The general rule: CHARACTER EVIDENCE IS NOT ADMISSIBLE. More particularly, character evidence is generally not admissible when offered for the purposes of proving conduct in conformity with the character trait offered.
What evidence is not admissible in court?
Evidence that can not be presented to the jury or decision maker for any of a variety of reasons: it was improperly obtained, it is prejudicial (the prejudicial value outweighs the probative value), it is hearsay, it is not relevant to the case, etc.
Can photographs be used as evidence?
A very important use of photographs as evidence, and probably the most common one, is the use as explanatory or illustrative evidence, and their purpose is to enable the jury to better understand the testimony of the witnesses.
What is strongest evidence-based study?
The systematic review or meta-analysis of randomized controlled trials (RCTs) and evidence-based practice guidelines are considered to be the strongest level of evidence on which to guide practice decisions.
What are the three components of evidence-based practice?
Evidence-based practice includes the integration of best available evidence, clinical expertise, and patient values and circumstances related to patient and client management, practice management, and health policy decision-making. All three elements are equally important.
What is level C evidence?
C: There is insufficient evidence to recommend for or against the inclusion of the condition in a periodic health examination, but recommendations may be made on other grounds. D: There is fair evidence to support the recommendation that the condition be excluded from consideration in a periodic health examination.
What is the most common type of observational study?
The two most common types of observational studies are cohort studies and case-control studies; a third type is cross-sectional studies. Cohort study. A cohort study is similar in concept to the experimental study.
Is Observation an evidence?
Scientific observations can be made directly with our own senses or may be made indirectly through the use of tools. In science, observations are used as evidence to help us figure out which of our explanations are correct.
What are the four steps in the scientific method?
He, as do many of his science colleagues, states that the scientific method has four steps: 1) observation and description of a phenomenon or group of phenomena; 2) formulation of a hypothesis to explain the phenomena (in physics, the hypothesis often takes the form of a causal mechanism or a mathematical relation); 3)
What is scientific method used for?
When conducting research, scientists use the scientific method to collect measurable, empirical evidence in an experiment related to a hypothesis (often in the form of an if/then statement), the results aiming to support or contradict a theory.
How do you write a scientific argument?
The figure below explains the three components of a scientific argument – the claim (or the explanation), the evidence (or the observations), and the rationale (or the reasoning). Reasoning that explains the evidence and why it supports the claim.
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https://r4dn.com/what-are-the-different-types-of-scientific-evidence/
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Education Voucher Program Review
Subject:
Education
Order Description
Education Voucher Program Review
Voucher programs are an educational privatization approach used nationally and internationally. Their use is controversial. In this assignment, you will examine the perspectives of proponents and opponents of educational vouchers, as well as examine and reflect on the empirical findings about the effectiveness of one U.S. and one international voucher program.
To prepare for this assignment, review the resources in this module, and conduct your own investigation to identify the characteristics of educational vouchers. Then, examine empirical studies about two voucher programs of your choosing, one that is national and one that is international. Suggestions are provided below, but you may identify a different program.
Note: The empirical studies included in your paper must minimally include both the effectiveness of the program relative to student achievement, as well as economic considerations.
A U.S. voucher program (e.g., D.C. Opportunity Scholarship Program (OSP), Milwaukee, Cleveland)
An international voucher program (e.g., Programa de Ampliación de Cobertura de la Educación Secundaria (PACES)* Program—Colombia, Chile)
Note: You may use the empirical studies provided in your module Learning Resources to meet the requirements of this assignment.
Develop a paper that compares one national and one international voucher program. Include the following:
Concise overview of each voucher program, meeting the following criteria:
Features and participation/qualifications information
Empirical evidence of the effectiveness of each voucher program on student achievement
Economic issues (positive and/or negative) of each voucher program
Reflection
Summarize the pros and cons about educational vouchers that emerged from your research?
What implications are there for policy based on your research?
Provide citations for each of the above areas addressed in your paper.
Use the following coupon code :
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https://www.ultimatescholars.com/education-voucher-program-review/
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This study provides a more complete examination of auditor-client pre-negotiation decisions and negotiation tactics when confronted with an ambiguous accounting issue. Because auditors and clients approach conflict resolution and make negotiation decisions in very different ways, the results should be of interest to auditors.
Bame-Aldred, C. W. and T. Kida. 2007. A Comparison of Auditor and Client Initial Negotiation Positions and Tactics. Accounting, Organizations, and Society 32 (6): 497-511.
Auditors must work with clients when forming their financial reporting decisions and the two parties may encounter situations where their reporting goals are different. This conflict can compel the auditor and client to enter into formal or informal negotiations. Various studies have previously examined auditor-client negotiation behavior, but none have directly compared the negotiation decisions of auditors and clients when faced with the same negotiation context. As such, the overall purpose of the study is to further examine the negotiation behavior of auditors and clients when facing an ambiguous revenue recognition issue. Negotiation behavior will ultimately have an impact on the firm’s financial reporting decisions. Below are the objectives that the authors address in their study:
The authors collected their evidence via research questionnaires mailed to auditors at national CPA firms and experienced financial managers at various companies during the Spring and Summer of 2002. The auditor participants included partners, senior managers, and managers. The financial managers included CFOs, controllers, accounting managers, and analysts from 38 different companies. Participants read summary financial information, a description of the auditor-client relationship, and a scenario about the proper amount of revenue recognition in a specific conflict scenario. Participants were asked questions about their initial negotiation positions, their range of acceptable amounts, their perceptions of the other party’s positions and limits, the importance of certain revenue recognition issues, and the likelihood of using specific types of negotiation tactics.
Professional skepticism is an integral component of auditing and audit quality, as evidenced by standards such as SAS 1 and SAS 109. Regulators often refer to professional skepticism as something that was missing when audit failures occur. Thus, understanding what factors influence auditors’ levels of professional skepticism is important. The author contends that this study facilitates an understanding of how audit firms can influence professional skepticism in practice via changes in such practices as hiring, training, performance appraisal, review, decision aids, incentives, and changes in tasks and institutions.
Nelson, M. W. 2009. A Model and Literature Review of Professional Skepticism in Auditing. Auditing: A Journal of Practice & Theory 28 (2): 1-34.
The purpose of this study is to review research that examines professional skepticism in auditing. Consistent with other research and recent regulatory concerns, the author defines professional skepticism as “indicated by auditor judgments and decisions that reflect a heightened assessment of the risk that an assertion is incorrect, conditional on the information available to the auditor.” Unlike the professional standards, this definition reflects more of a “presumptive doubt” view rather than a “neutral” view of professional skepticism, implying that auditors who exhibit higher levels of professional skepticism are auditors who need relatively more persuasive evidence (in terms of quality and/or quantity) to be convinced that an assertion is correct. In other words, such auditors are more likely to doubt evidence that an assertion is true than they are to doubt evidence than an assertion is false.
Drawing from prior studies, the author describes how audit evidence combines auditor knowledge, traits, and incentives to affect the level of professional skepticism exercised in auditor judgments. Further, the author describes how, given a judgment with some level of professional skepticism, the judgment combines with auditor knowledge, traits, and incentives to affect auditor actions that reflect relatively more or less degrees of professional skepticism.
The study reviews research that examines professional skepticism in auditing. The author discusses the various definitions of professional skepticism both in professional standards and academic research. The author draws on prior relevant research to explain how auditor knowledge, traits, and incentives combine to affect the level of professional skepticism in auditor judgments and auditor actions.
The results of the studies documented in this review suggest that there is a great deal of variability in the approaches taken by firms for establishing materiality. Such differences in materiality methods can affect both the effectiveness and efficiency of audits. For example, if firms differ in how they allocate materiality to financial statement accounts, then the scope of the work could differ across audits with similar characteristics. Auditors also appear to differ in terms of the factors they consider for determining the materiality of internal control weaknesses, suggesting that auditors may need more structured criteria to make materiality judgments about internal control weaknesses. Materiality judgments are influenced by authoritative guidance, suggesting that standard setters and audit firms have the ability to influence auditors’ materiality judgments by providing auditors with specific guidance.
Messier, Jr., W.F., N. Martinov-Bennie, and A. Eilifsen. 2005. A review and integration of empirical research on materiality: Two decades later. Auditing: A Journal of Practice and Theory 24 (2): 153-187.
Materiality has been and continues to be a topic of importance for auditors. There has recently been renewed interest in the concept of materiality, motivated by concerns at the Securities and Exchange Commission, and the Auditing Standards Board and as evidenced by the Sarbanes-Oxley Act and the issuance of proposed standards on materiality by the International Auditing and Assurance Standards Board. Additionally, new guidance has been issued recently in response to some of the materiality concerns, including Staff Accounting Bulletin (SAB) No. 99, Statements on Auditing Standards (SAS) No. 89, and SAS No. 90. Due to the continued importance of understanding the concept of materiality, this paper reviews and integrates the empirical research on materiality since 1982. Based on the review of the literature, the authors suggest some implications of this research for audit practice and research.
This paper reviews the literature related to materiality that has been published since 1982. The authors divide their discussion of the research into archival studies and experimental studies. Archival studies use audit firm manuals, data from auditor working papers, or published financial statement data and auditor reports to examine materiality decisions. Experimental studies examine materiality judgments and decision-making of financial statement users, auditors and others (e.g., judges/lawyers).
Archival Studies: The primary findings from archival studies are categorized based on whether they were obtained from auditor-related sources (e.g., auditor working papers) or public sources (e.g., financial statements).
Auditor Related Sources (i.e., firm manuals and working papers)
Public Sources (i.e., financial statements, disclosures, and auditors’ reports)
Experimental Studies:
The results of this study are important for audit firms to consider providing decision aids and/or on job training. The results suggest that considerable practical experience is necessary to achieve good judgment performance. In addition, the evidence indicates that auditing firms may wish to concentrate their training earlier to more quickly create a basis for high-quality auditor judgments.
Wright, William F. 2007. Academic Instruction as a Determinant of Judgment Performance. Behavioral Research in Accounting 19: 247-259.
Knowledge and personal involvement are important factors that affect auditor judgment quality. It is generally believed that sufficient knowledge can lead to good auditor judgment. Two sources of relevant knowledge are academic instruction and practical experience. Yet the relative benefits of the two sources remain unclear. The primary purpose of the study is to test for the benefit of task-specific academic instruction and practice relative to task-specific CPA training and experience in making auditor judgments.
The research evidence is collected during 1991. Three groups of people participated in the experiment: (1) graduate business students, (2) inexperienced financial institution audit seniors, and (3) experienced financial institution auditors (managers, senior managers, and junior partners). Participants were asked to complete a simulated case involving evaluating the collectability of commercial loans to a fictitious manufacturer of microcomputers.
Firms should consider the levels of accountability pressure and situations where they use them and consider how different levels of pressure may impact performance. Higher levels of accountability pressure may increase effectiveness and increase the likelihood of finding material misstatements.
On the other hand, increased effectiveness and time spent due to higher levels of accountability pressure may cause inefficiencies and result in unnecessary effort. Firms should evaluate the costs and benefits for their situations.
The authors note that this study only looks at the effect of accountability pressure from an unknown partner. In the real world, auditors have accountability pressures from many levels such as other superiors, clients, regulators, and audit committees.
Further, the auditor may have assessed things differently if they knew the partner that was performing their review.
DeZoort, T., P. Harrison, and M. Taylor. 2006. Accountability and auditors’ materiality judgments: The effects of differential pressure strength on conservatism, variability, and effort. Accounting, Organizations, and Society 31 (4-5): 373-390.
The purpose of this study is to look at how four different levels of accountability pressure (i.e. how their decisions would be reviewed) affect auditor conservatism, variability, and effort in tasks related to materiality.
The authors performed a computerized experiment using a final sample of auditors from five public accounting firms. Participants were managers, staff and senior associates. Participants were asked to review client background information, financial information, and a proposed audit adjustment for the Allowance for Doubtful Accounts balance. Participants were asked to provide a planning materiality amount for the engagement and a materiality judgment regarding the proposed audit adjustment. The auditors were put into one of four levels of accountability pressure:
In addition, about half of the participants received a “planning materiality decision aid,” which provided a range of planning materiality values.
Professional Commitment has been found to impact work behaviors. Theory indicates the three dimensions of PC can impact these behaviors in varying ways (positive or negative). Firms can influence some precursors to PC including training, organizational culture, requiring employees to complete a professional qualification, and participation in professional organizations.
Smith, D. and Hall, M. 2008. An Empirical Examination of a Three-Component Model of Professional Commitment among Public Accountants. Behavioral Research in Accounting 20 (1): 75-92.
Professional commitment (PC) refers to the attachments that individuals form to their profession. Those with strong professional commitment have been found to be less likely to leave their job and more likely to observe rules, to be involved in professional organizations, and to mentor. Three aspects of PC have been identified:
The purpose of this study is to confirm whether these three aspects of PC apply to public accountants as well as to determine whether the professional commitment questionnaire (PCQ) used in the majority of prior PC research measures only APC or all three aspects of PC.
Accountants from one big-four and six middle-tier Australian accounting firms participated in this study. Participants filled out a survey designed to assess the participants’ level of PC, and specifically their levels of APC, CPC, and NPC.
At its core, the theory proposed by the authors assumes that auditors are economic agents who provide a valuable service and can be expected to behave rationally to maximize their profits. Strategic behaviors such as under-auditing, over-auditing, or overbilling would be unobservable by an auditee in many instances. The possibility of such behaviors has important implications for the level of assurance over financial reports and can potentially affect the efficient allocation of capital resources. One of the goals of this study was to analyze how the credence aspect of audits could influence important policy decisions. Regulation may play a powerful role in mitigating the credence nature of auditing, e.g., PCAOB inspections. However, regulation can be a double-edged sword if it increases the incentive or opportunity for auditors to behave strategically. Therefore, auditors can take the theories and models presented in this study to evaluate their firms for potential profit maximizing biases that may negatively impact audit quality and efficiency. Policy makers could also use these theories and models to evaluate how new auditing policies might influence auditors’ incentives and behaviors.
For more information on this study, please contact W. Robert Knechel.
Causholli, M., and W. R. Knechel. 2012. An Examination of the Credence Attributes of an Audit. Accounting Horizons 26(4): 631-656.
The purpose of this study was to expand the understanding of the economics of auditing and audit markets by using the theory of credence goods as the basis for explaining auditors’ incentives. The idea of a credence good or service is that (1) the seller of the good or service is an expert who both recommends and provides a level of service to the buyer; (2) buyers of credence goods or services cannot assess how a service is a delivered and must rely on a seller’s recommendation; and (3) buyers cannot assess how well the service was performed. The authors suggest that the external audit is a credence good which provides auditors with incentives to under-audit, over-audit or overcharge their clients.
The authors take a purely theoretical approach to study the perspective of an audit as a credence good. The authors rely on prior research of credence goods and on the principles of Game Theory to help explain auditors’ incentives to under-audit, over-audit or overcharge clients and predict auditors’ behaviors under certain scenarios. The authors use theoretical decision trees to describe an auditor’s possible strategies for bidding for an audit, and for executing the audit. The authors also describe examples of prior auditing research that present results that support the author’s credence theory.
The authors propose that if an audit is a credence good, the auditee cannot determine any of the levels of audit effort that define the auditor’s decisions. This creates information asymmetry between the auditor and auditee both before and after the audit because the auditee cannot be sure of the true level of assurance that is necessary before the audit, and the auditee cannot be sure of the true level of assurance that is gained as a consequence of the audit. The information asymmetry goes in favor of the auditor, who can act strategically to under-audit and earn greater profits because the auditee has imperfect information about the auditor’s work and the level of assurance gained by the auditor’s efforts.
The authors also propose that there are disciplining mechanisms in the market for audit services that are in place to mitigate an auditor’s incentive to behave strategically such as an auditee’s direct knowledge, audit firm reputation and size, professional regulation, legal liability, and competition between audit firms. However, while these mechanisms may be in place, an auditor facing low penalties or risk of detection may be more likely to consider strategic actions. In environments with weak courts or regulation, auditors have more incentives to act strategically and expect to reap superior profits as a result. Similarly, changes in regulations or other structural changes in the audit market can induce changes in the incentives for auditors to behave strategically. Overall, disciplining mechanisms facilitate the operation of audit markets even though they may not completely resolve the information (credence) problem.
This study provides evidence that there were significant differences in the pre-negotiation judgments of partners and managers. Since an outcome of an auditor-client negotiation of a contentious issue may have a significant impact on financial reporting quality, the findings of the study suggest that the using partners in the negotiation process is likely to lead to improved reporting quality. The results have implications for audit firms in allocating manager and partner time to handle negotiation.
Trotman, K. T., A. M. Wright, and S.Wright. (2009). An Examination of the Effects of Auditor Rank on Pre-Negotiation Judgments. Auditing: A Journal of Practice & Theory 28(1): 191-203
Negotiations are pervasive in the auditing environment. In general, audit firms have choices over what level of staff are involved in the process of negotiation. An important issue is that differences may exist between partner and manager negotiation judgments and strategies. This study focuses on the expectations and assessments that partners and managers take into the negotiation process, specifically the pre-negotiation stage. The authors use negotiation theory as well as other general psychology findings to investigate how rank (partner versus manager) affects the pre-negotiation judgments made by auditors. The authors suggest and test the following assertions:
The research evidence was collected prior to September 2007. The authors used responses collected from a computerized case about inventory write-downs, administered to partners and managers at three Big 4 firms in Australia and the U.S.
The results should be of interest to auditing standard setters who provide guidance on the evaluation of control deficiencies as part of an integrated audit. Further, regulators inspecting public company audits may want to further review settings where control deficiencies were not evaluated as material weaknesses and assess whether the presence/absence of a financial statement misstatement was appropriately considered. The findings provide a more complete understanding of how the factors that auditors encounter during the audit engagement influence their judgment about whether identified deficiencies in ICFR are such that there is a reasonable possibility that a material misstatement of the company’s financial statements will not be prevented or detected on a timely basis (i.e., material weakness).
Gramling, A. A., E. F. O'Donnell, and S. D. Vandervelde. 2013. An Experimental Examination of Factors That Influence Auditor Assessments of a Deficiency in Internal Control over Financial Reporting. Accounting Horizons 27 (2): 249-269.
Beginning in 2004, public company auditors who opine on client financial statements also express an opinion about whether the client’s internal control over financial reporting (ICFR) is effective at year-end. In forming the ICFR opinion, auditors evaluate the severity of each identified control deficiency to determine whether the deficiency is a material weakness. When auditors conclude there is a reasonable possibility that ICFR will fail to prevent or detect a material financial misstatement (i.e., a material weakness exists), they issue an adverse opinion on the effectiveness of ICFR. This study examines how different types of audit evidence accumulated during the audit influence auditor judgment of ICFR operating effectiveness and about whether an identified control deficiency is a material weakness in ICFR.
The study is motivated by a recognition that many stakeholders, including financial statement users, company management, audit committee members, regulators, researchers, and other auditors, would benefit from an enhanced understanding of the factors an auditor considers when evaluating the effectiveness of ICFR and concluding whether identified control deficiencies represent material weaknesses.
The authors analyze responses from the submitted case materials of 138 participants, which include 44 partners, 47 senior managers, and 47 managers. On average, the participants had worked on 4.0 integrated audit engagements and had issued 1.1 adverse opinions on ICFR. For the integrated audit engagements on which the participants had worked, they reported an average of 4.1 potential material weaknesses that were ultimately deemed to be significant deficiencies. The evidence was gathered prior to June 2013.
Based on experimental results from audit managers and partners, the authors provide evidence regarding whether the following factors are significant determinants of assessed operating effectiveness of an identified control deficiency: (1) whether the client has a material weakness unrelated to the deficiency being assessed (i.e., unrelated material weakness), and (2) whether there is a known misstatement associated with the identified control deficiency (i.e., failure of the specific control to prevent a misstatement). Further, they examine whether these two factors influence the likelihood of assessing a control deficiency as a material weakness. The authors find that the presence of either an unrelated material weakness or a known misstatement influences the assessed operating effectiveness of an internal control, in addition to the likelihood of a material weakness assessment. The presence of either an unrelated material weakness or a known misstatement warrants a decreased operating effectiveness assessment and an increased likelihood of a material weakness assessment. The combination of the two factors together does not further influence those assessments.
Auditors should recognize that an implicit tradeoff exists between the availability of subsequent event evidence and timelier reporting. However, the net effect is not well understood because prior research has only focused on quantifying the benefits of timely reporting, not the costs associated with obtaining less subsequent event evidence. The low evidence discovery rate reported by participants suggests that the current audit methodology might suffer from inefficiencies. Further research should establish relative frequency information to help auditors generate hypotheses and guide audit planning.
Janvrin, D. J. and C. G. Jeffrey. 2007. An Investigation of Auditor Perceptions about Subsequent Events and Factors That Influence This Audit Task. Accounting Horizons 21 (3): 295-312
Generally accepted auditing standards require auditors to consider subsequent events by examining transactions that occur after the balance sheet date. In light of the Securities and Exchange Commission’s (SEC) decision to shorten the time between the balance sheet and report dates, this study seeks to better understand how auditors search for and discover subsequent event evidence in this new reporting environment. Prior literature on this subject is sparse. The Canadian Institute of Chartered Accountants (CICA) and the American Institute of Certified Public Accountants (AICPA) are concerned that audit quality will suffer because auditors now have less time to discover evidence of subsequent events. For example, earnings management behavior is difficult to detect without persuasive evidence. Specific study goals are as follows:
A field-based experiential questionnaire was issued to U.S. auditors from each of the Big-4 firms and one national firm over a one-year period prior to November 2004. Participants had an average of 9.6 years of experience. Participants were asked to rate how often they search for and discover subsequent event evidence both in general, and using the ten procedures found in auditing standards.
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http://commons.aaahq.org/hives/1a4d891d2d/posts?postTypeId=0&tagId=5585&view=full
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“Evidence-based” – What is it?
“Evidenced-based” has become a common adjectival term for identifying and endorsing the effectiveness of various programs and practices in fields ranging from medicine to education, from psychology to nursing, from criminal justice to psychology. The motivation for marshalling objective evidence in order to guide practices and policies in these diverse fields has been the result of the growing recognition that professional practices—whether they be doctoring or teaching, social work, or nursing—need to be based on something more sound than custom/tradition, practitioners’ habit, professional culture, received wisdom, and hearsay.
While definitions of “evidence-based” vary, the most common characteristics of evidence-based research include: objective, empirical research that is valid and replicable, whose findings are based on a strong theoretical foundation, and include high quality data and data collection procedures. The most common definition of Evidence-Based Practice (EBP) is drawn from Dr. David Sackett’s, original (1996) definition of “evidence-based” practices in medicine, i.e., “the conscientious, explicit and judicious use of current best evidence in making decisions about the care of the individual patient. It means integrating individual clinical expertise with the best available external clinical evidence from systematic research” (Sackett D, 1996). This definition was subsequently amended to, “a systematic approach to clinical problem solving which allows the integration of the best available research evidence with clinical expertise and patient values” (Sackett DL, Strauss SE, Richardson WS, et al. Evidence-based medicine: how to practice and teach EBM. London: Churchill-Livingstone,2000). (See, “Definition of Evidenced-based Medicine”).
An evidenced-based program, whether it be in youth development or education, is comprised of a set of coordinated services/activities that demonstrate effectiveness, as such effectiveness has been established by sound research, preferably, scientifically based research. (See, “Introduction to Evidence-Based Practice“).
In education, evidence-based practices are those practices that are based on sound research that shows that desired outcomes follow from the employment of such practices. “Evidence-based education is a paradigm by which education stakeholders use empirical evidence to make informed decisions about education interventions (policies, practices, and programs). ‘Evidence-based’ decision making is emphasized over ‘opinion-based’ decision making.” Additionally, “the concept behind evidence-based approaches is that education interventions should be evaluated to prove whether they work, and the results should be fed back to influence practice. Research is connected to day-to-day practice, and individualistic and personal approaches give way to testing and scientific rigor.” (See, “What is Evidence-Based Education?“).
Of course there are different kinds of evidence that can be used to show that practices, programs, and policies are effective. In a subsequent blog post I will discuss the range of evidence-based studies—from individual case studies and quasi experimental designs, to randomized controlled trials (RCT). The quality of the evidence as well as the quality of the study in which such evidence appears is a critical factor in deciding whether the practice or program is not just “evidence-based,” but in fact, effective. To learn more about our data collection and measurement click here.
What are Evidence-Based Interventions (EBI)?
Can Randomized Trials Answer the Question of What Works?
How do programs know what they should be doing— which target populations require services, the types of services programs should provide, the amounts of services, which kinds of services will be most effective, etc.? Needs assessments are the best way to determine the needs of individuals, communities, and other populations. A needs assessment is a systematic process for identifying and determining such needs. Like program evaluations, needs assessments draw on a range of social science methods—from surveys and observations, to focus groups and individual interviews.
Needs assessments assume a clear definition of “a need”. As James Altschuld and Ryan Watkins point out in New Directions in Evaluation, No. 144, Winter, 2014 “A need, in the simplest sense, is a measurable gap between two conditions: what currently is, and what should be….This requires ascertaining what the circumstances are at a point in time, what is desired in the future, and a comparison of the two.” Needs assessments don’t just exclusively focus on what is and should be, but also on gathering and synthesizing data about how to narrow the gap between the existing state and the desired state. Needs assessments also prioritize needs so that users of the assessment can address specified needs in a reasonable order, and devote appropriate resources to meeting identified needs.
By gathering data from a range of stakeholders, needs assessments are able to determine the best means to achieve the desired results. To be effective, however, needs assessments must not simply focus on deficits in individuals and communities, but must also explore existing strengths, capacities, and assets. Too narrow a focus on “what’s missing” can blind researchers and program designers to the existing assets on which effective programming can be built. Effective needs assessments therefore, ask questions about: 1) on-going needs, 2) current strengths/assets/ capacities, 3) and desired states.
Analyze data to understand the difference or “gap” between the current condition and desired condition.
With needs (and assets) in mind, design program to address (diminish or eliminate) the gap between existing needs and desired state.
When conducted in a timely and thoughtful way, needs assessments can be of substantial utility in helping programs to effectively deliver services to those who most need them. To find out more about our assessment methods visit our Impact & Assessment reporting page.
A good evaluator must, of course, be able to develop a research design, carry out research in the field, analyze data, and report findings. These technical/methodological skills, although of critical importance, are however, not the only skills that evaluators need. Effective evaluations also depend upon a range of interpersonal or relational skills that make effective and responsive interpersonal interaction possible.
I recently posted to the American Evaluation Associations listserv a query about the importance and role of the interpersonal skills in evaluation. I asked for AEA members’ opinions about the importance of interpersonal skills in conducting successful evaluations. A number of evaluators responded to my inquiry. The central theme of those responses was that successful evaluators and successful evaluation engagements require that evaluators possess and employ key interpersonal skills, and that without these, evaluation engagements are unlikely to be successful.
Among the most prominent reasons that my AEA colleagues reported for the importance of interpersonal skills were: 1) the importance of building strong, candid, and constructive relationships, on which effective data collection depends; and 2) the importance of establishing trusting and collaborative relationships between evaluators and stakeholders in order to help to ensure that evaluation findings will be utilized by clients and stakeholders. Additionally, some colleagues commented that the self-evident reason for utilizing strong interpersonal skills in evaluation engagements: these skills enhance the probability that clients and stakeholders will share information and provide insights about the program. Thus effective evaluation necessarily entails trusting, open, and amicable relationships that make access to program knowledge and information possible .
Be both socially aware and self-aware— i.e., be aware of, and manage, both one’s own and other’s emotions (including the features of emotional intelligence, i.e, capacities to accurately perceive emotions, use emotions to facilitate thinking, to understand emotional meanings, and to manage emotions).
These interpersonal skills are central to successful program evaluations. Attention to these characteristics– both by program evaluators and by those seeking to engage a program evaluator (i.e. evaluation clients)— will greatly maximize the probability of successful evaluation projects.
Interactive Evaluation Practice: Mastering the Interpersonal Dynamics of Program Evaluation J.A. King and L. Stevahn (Sage).
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https://bradroseconsulting.com/category/models_tools/
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The PRI Association, a company limited by guarantee, is governed by the PRI Association Board (the PRI Board) as set out in the Articles of Association of PRI Association. The PRI Board is collectively responsible for the long-term success of the PRI, in particular: establishing the PRI’s mission, vision and values; setting the strategy, risk appetite and structure; delegating the implementation of the strategy to the PRI Association Executive (the executive); monitoring the executive’s performance against the strategy; exercising accountability to signatories; being responsible to relevant stakeholders. The board is supported by five committees: Finance, audit, and risk; Governance; Human resources and remuneration; Policy; and Signatory status.
The Role
The role will assist the Director of Planning and Operations in supporting an effective and high-performing PRI Board, including:
- Advice on governance to the PRI Board, committees, and the leadership team.
- Coordination of the Signatory General Meeting (the PRI equivalent of an AGM).
- Reporting about the role and actions of the PRI Board and its committees, including the annual board report.
- Onboarding of new directors and UN partners.
- Annual and mid-term directors’ elections processes.
- Annual board and chair review.
- Supporting the work of the board and committees.
- Coordination of Board and committee papers, including sense-checking and proof-reading.
- Minute-taking for board and committee meetings.
- Regular review of governance related policies, rules, and procedures.
- Maintenance of the board and committee portal.
- Coordination of the annual calendar (meetings and agendas) for the PRI Board and committees.
The role will be within the Planning and Operations team but will require the individual to work with teams and individuals across the organisation.
Core Competencies:
PRI expects roles at a ‘Specialist’ level within the organisation to demonstrate skills across the following core competencies:
Analytical
- Proactively offers impartial specialist knowledge, insights or input
- Uses business/ specialist knowledge and analysis to identify issues, applying fact-based insight to develop and evaluate solutions or solve issues
- Maintains a professional and impartial stance in assessing all information which feeds into decision making
- Balances rigour with pragmatism in conducting analyses that are fit for purpose
- Effectively reviews and quality-checks all analyses
Business Awareness
Focuses on maximising Signatory or operational value and driving PRI outcomes
- Actively keeps up to date with developments both within the organisation and within area of specialism
- Balances the internal needs of the PRI and that of Signatory Organisations to deliver outputs
- Understands how own area of specialism drives value to the PRI and meets its mission
- Uses market insights and knowledge to suggest and drive strategic initiatives which will enhance signatory servicing.
Collaborative
- Builds consensus and trust with all that engage with
- Is responsive to feedback, proactively following up to ensure any issues are resolved
- Engages with colleagues to gain a broader understanding of issues and seeks to respond to or resolve them
- Provides specialist knowledge and insights to colleagues where requested
Communicative
- Translates specialist information or provides technical expertise in a clear and understandable format
- Clarifies matters by absorbing and understanding relevant information and feeding them back in concise terms
- Uses effective listening and questioning to enhance understanding of complex issues
- Engages the recipient using their language, tailoring communication style for the audience
Developmental
- Actively seeks opportunities to enhance specialist knowledge/ experience
- Constantly reviews own work with the aim of improving outputs
- Applies knowledge or experience to question practices and suggest alternatives
- Actively seeks and shares feedback wherever possible, as a means of improvement
- Uses best practice identified through external networks or evolutions in the field of specialism
Structured
- Has a strong sense of execution and delivery, working to agreed deadlines, involving relevant colleagues and allowing enough time for review and quality assurance
- Regularly monitors and reports on progress of work, providing regular updates as appropriate
- Takes a methodical approach to how specialist or technical knowledge is acquired and, distributed (where necessary)
- Captures knowledge at the end of each project/ process/activity, to use and share
Technical Competencies & Experience:
- Governance experience within a mission led or not-for-profit desirable but not mandatory.
- Partly or fully qualified Chartered Company Secretary desirable but not mandatory.
- Experience in providing advice to boards and senior executives.
- Good written communication skills (including minute-taking)
- Verbal presentation skills.
- Project management skills.
- Problem solving skills and a ‘can do’ attitude, able to take ownership of challenges and see them through to resolution.
- A collaborative and consultative approach to working with others, the ability to foster an inclusive working environment.
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https://www.unpri.org/careers/deputy-company-secretary/8395.article
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We take pride in our ability to provide clients with innovative solutions to transform their existing space into the home of their dreams. Our reputation as a reliable and reputable contractor speaks to our commitment to providing the highest quality service.
At Stuart Kitchen Bath and Flooring, we have a unique approach to remodeling and renovating your home.
Before beginning any design or construction work, our design team will meet with you to discuss your vision for your dream home. This dialogue will cover the complete aesthetic and all the finer details. Once we have adequately identified your requirements and preferences, we can set the budget and proceed to the subsequent phase.
Once the project specifications have been established, our team of professional designers will collaborate and start to create a design that meets your expectations. Aesthetics are vital; however, the design must also be practical. When confronting such matters, our designers employ creative strategies to bring forth a practical environment that does not deviate from the original idea.
Upon completion of your final design, we will arrange a meeting to receive your feedback. Any adjustments deemed necessary will be made prior to your approval. Once we have obtained your consent, the construction phase will commence.
We are committed to achieving excellence. To ensure success, we need to ensure open communication between all parties. On completion of the project, we will take you through the space and explain all functions as necessary. If any adjustments are necessary, they will be identified and implemented.
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https://stuartkitchenbathandflooring.com/home-remodel/
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In 1929 August Winter & Sons was established by August and his two sons, Wally and Roy. Family was the culture and foundation our company was built on, and this family culture is vital within our current workforce. Safety is one of our company’s core values; passed down from employee to employee similar to a family tradition. Safety is no mistake and our employees prove that every day.
On-going safety and professional training.
On-going hazard assessments with feedback.
At August Winter, we take it personally to watch out for each other and take care to ensure that safety is never missed. This is extended to all personnel on the jobsite: all contractors, clients, and visitors. We instill in every employee, at all levels, the personal responsibility to step up when there are any safety concerns. We seek input and feedback from all corners of the company to improve safety policy and procedures. Safety is the backbone that keeps the Winter family running efficiently, effectively, and productively.
I have worked with August Winter as a design/build and design/assist partner on HVAC and plumbing projects over the past eight years. They have always provided professional services and most importantly a trusted trade partner for Boldt. August Winter has always been on time with services both in the office and on the project site. If issues do arise, you can be assured August Winter will see that they are resolved in a timely and thorough manner.
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http://www.augustwinter.com/safety/
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As a Senior Research Executive, you will be responsible for the design, execution and delivery of quantitative and qualitative research projects (both adhoc and tracking) from taking a brief to presenting results. In collaboration with the Account Manager or Business Manager, the incumbent will build existing business and client relationships and contribute to the development of junior team members.
Key outcomes
Project planning and Management:
- priorities project requirements and delivery, determine tasks and actions for exec team, allocate resources effectively, schedule and meet deadlines, brief support services, manage and evaluate project progress. Supervise the work of junior team members on project preparation, execution and completion.
Project design:
- provide sound research recommendations, apply appropriate research methodology and recommend appropriate Kantar products.
Project output:
- provides sound guidance on analysis techniques, provide sound guidance on “finding the story”, finalize and ensure strategic content of conclusions and recommendations, always adding value to research results.
Client Management:
- acquire relevant client background knowledge, must have a very clear understanding of client business, relationship building, meet deadlines, manage general client expectations, responsible for liaising with client on all aspects of the study, from briefing to presentation on a project basis.
Team mentoring and training:
- Identify skills gaps and growth potential of team members, involve execs and juniors in planning and design of project, provide on the job training. Provide feedback to junior team members on challenges and successes
Quality control:
- sets standards of excellence, ensures high quality through thorough checking procedures, conduct detailed checks of proposals, questionnaires, discussion guides, presentations
Presentation:
- required to present both qualitative and quantitative studies to the marketing and research teams
Analysis:
- must be comfortable working on qualitative & quantitative projects
General:
- required to write proposals, design questionnaires, discussion guides, put together presentations with minimal input from seniors
New business:
- responsible for managing new business of existing clients where relationships sit with the senior executives.
Capabilities :
- 2 – 3 years of quantitative research experience from Market Research Agency or consumer insight from a FMCG.
- Manage day to day client liaison effectively and professionally
- Deliver accurate work under pressure
- Integrity and high ethical standards
- Courteous, respectful and professional in all communications
Brand : Kantar Millward Brown
Location : Abidjan, Cocody-Riviera Côte d’Ivoire
Kantar Rewards Statement
At Kantar we have an integrated way of rewarding our people based around a simple, clear and consistent set of principles. Our approach helps to ensure we are market competitive and also to support a pay for performance culture, where your reward and career progression opportunities are linked to what you deliver.
Join our team and you’ll be part of the 30,000 colleagues and 9 world leading research, data and insight brands that make up Kantar. At the heart of WPP, our unique consumer insight inspires clients around the globe to create and flourish in an extraordinary world.
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https://www.emploidakar.com/kantar-in-recruiting-a-senior-research-executive-codody-riviera-abidjan-cote-divoire/
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Characteristics:
Reliable, responsible and enthusiastic individual, self-motivated and conscientious. Strong interpersonal, analytical and communication skills, relating effectively with clients and colleagues at all levels. Able to work on own initiative and as part of a team.
Experience
Famous Brands
Position Held : Franchise Consultant (Debonairs Pizza)
January 2019 – June 2021
Duties and Key outputs of Franchise Consultant Role:
The role of the Franchise Consultant is to manage, develop and grow our Franchise Partners to an extent whereby they enjoy an above average return on their investment, contributing towards the brand becoming the brand of choice for both potential investors and consumers.
Key outputs of Franchise Consultant role
Assist with the development and implementation of Franchisee specific business plans and budgets
Interpret monthly management accounts, benchmark, and suggest corrective actions where necessary
Protect brand integrity via implementation and measurement of Standards of Operations Programmes
Identify and communicate formal training needs to the training department for training intervention
Monitor and feedback information about competitor activity within the region
Identify in-store training needs and implement on the job training interventions and coaching
Assist franchisees in selecting and formulating locality marketing strategies in order to increase brand awareness and grow their business turnovers
Ensure implementation of national marketing campaigns
Enforce correct use of all supporting elements i.e. point of sale, premiums etc
Act as brand custodian and ensure brand integrity is protected at all times via adherence to all requirements across key functions namely, Operations, Development, HR and Marketing
Key attributes and competencies
Strong Communication, Organisational, Operational and People Skills
Highly presentable
Developed analytical and problem-solving abilities
Strong interpersonal skills
Energetic self-starter
A hands-on approach to problem solving
Fanatical attention to detail
Strong customer service orientation
Willing to travel
Excellent telephone skills and etiquette
Brand focused attitude
Ability to reason and problem solve
Build and maintain a professional working relationship with all customers (including internal customers) at all times
Organising and planning skills
Able to operate under pressure
Self-motivator and self-starter
Able to work in teams
Persuasive
Strong achievement orientation
Self-managed
Computer literacy (MS Office, PowerPoint, Excel)
Fluent in English and other languages
Position Held : Training Consultant (Mugg and Bean
and FEGO)
January 2015 – December 2018
Duties and Key outputs of Training Consultant Role:
Their core responsibility of a Training Consultant is to facilitate and develop training programs.
They evaluate current training and educational programs and suggest ways to improve or replace existing programs and also work together with functional experts to develop programs that achieve the defined learning and business objectives.
The training consultant job description also entails modifying, revising, and updating the content of existing training programs; creating course materials and teaching aids, including graphics, visuals, and audio content to support content delivery, skill evaluations, and final assessments.
The core tasks, duties, and responsibilities of a Training Consultant:
Deliver training programs and workshops to employees or clients that motivate, improve competencies and performance, and directly impact results
Utilize individual or group performance results to check the effectiveness of training
Gather feedback on sessions from attendees for improving future content and presentation
Design a new training program and upgrade existing programs, including lesson plans and training aids as needed
Recommend resources and strategies that support and lead to market success and goal achievement
Diagnose learning issues that will help people do better and assist team members in measuring and enhancing training results
Responsible for developing consistent and positive client/learner interactions
Responsible for identifying and communicating learning gaps to the Learning Development Team
Responsible for facilitating the delivery and execution of technology-based training
Responds to student questions and augment course content as needed
Effectively utilize current learning delivery platforms and tools to deliver training
Adjust presentations to accommodate the needs of the audience
Communicate technical complexities of software in a simple manner.
SAB Ltd
Position Held : Customer Relationship Rep
May 2010 – December 2014
Duties and Key outputs of Customer Relationship Rep:
The role of a Customer Relationship Rep within SAB Ltd is to help customers with order placing, complaints and questions also provide customers with information about products and services and also process returns.
The core tasks, duties, and responsibilities of a Customer Relationship Rep:
Maintaining a positive, empathetic, and professional attitude toward customers at all times.
Responding promptly to customer inquiries.
Communicating with customers through various channels.
Acknowledging and resolving customer complaints.
Knowing our products inside and out so that you can answer questions.
Processing orders, forms, applications, and requests.
Keeping records of customer interactions, transactions, comments, and complaints.
Communicating and coordinating with colleagues as necessary.
Providing feedback on the efficiency of the customer service process.
Managing a team of junior customer service representatives.
Ensure customer satisfaction and provide professional customer support.
Dimension Data. : Mas Billing Agent
January 2008 – April 2010
Duties and Key outputs of Mas Billing Agent:
MAS Billing Agent role is to create invoices, credit memos, update accounting records, customer information, and send payment reminders, also answer any queries.
The core tasks, duties, and responsibilities of a MAS Billing Agent:
Creating and issuing invoices to customers.
Processing credit memos.
Preparing account statements for customers.
Following up on outstanding payments and answering customer queries.
Monitoring all payments and preparing monthly billing reports.
Managing account balances and resolving inconsistencies.
Assisting the accounting department with the preparation of financial reports.
Updating accounting records with issued invoices, processed payments, new balances, and customer contact information
Dimension Data. : Technical Advisor
January 2005 – December 2007
Duties and Key outputs of Technical Advisor:
Role of a Technical advisor is to assist in developing and implementing program reviews. Also, to render their knowledge and skills to customers with any technical issue they might come across.
The core tasks, duties, and responsibilities of a Technical Advisor:
Support to develop and execute all program reviews.
Provide technical advice as well as expertise to customers
Define, develop and review all existing and proposed applications for technical design plus development of all major customer or server projects.
Coordinate technical activities amongst technicians, home users, computer along with communication networks.
Present technical assistance for applications of advanced theory, principles, concepts and methods to customers.
Develop and maintain strong human relations as well as convey required skills.
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https://www.postjobfree.com/resume/ado6z2/franchise-manager-training-johannesburg
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