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The gabT gene encodes for GABA transaminase, an enzyme that catalyzes the conversion of GABA and 2-oxoglutarate into succinate semialdehyde and glutamate. Succinate semialdehyde is then oxidized into succinate by succinate semialdehyde dehydrogenase which is encoded by the gabP gene, thereby entering the TCA cycle as a usable source of energy. The gab operon contributes to homeostasis of polyamines such as putrescine, during nitrogen-limited growth. It is also known to maintain high internal glutamate concentrations under stress conditions.

Gene expression + Signal Transduction

The sigma-2 receptor is located in the lipid raft. The sigma-2 receptor is found in several areas of the brain, including high densities in the cerebellum, motor cortex, hippocampus, and substantia nigra. It is also highly expressed in the lungs, liver, and kidneys.

Gene expression + Signal Transduction

When the ribosome movement on the mRNA is not linear, the ribosome gets paused at different regions without a precise reason. The ribosome pause position will help to identify the mRNA sequence features, structure, and the transacting factor that modulates this process. The advantage of ribosomal pause sites that are located at protein domain boundaries are aiding the folding of a protein. There are times when the ribosomal pause does not cause an advantage and it needs to be restricted. In translation, elF5A inhibits ribosomal pausing for translation to function better. Ribosomal pausing can cause more non-canonical start codons without elF5A in eukaryotic cells. When there is a lack of elF5A in the eukaryotic cell, it can cause an increase in ribosomal pausing. The ribosomal pausing process can also be used by amino acids to control translation.

Gene expression + Signal Transduction

* geWorkbench is open-source software that can be downloaded and installed locally. A zip file of the released version Java source is also available. * Prepackaged installer versions also exist for Windows, Macintosh, and Linux.

Gene expression + Signal Transduction

Since the Civil War, North Alabama became one of the countrys leading iron and steel manufacturers. The Birmingham District was particularly well positioned to be an iron-and-steel production centre in the southern United States. The development of Alabamas iron and steel industry was primarily stimulated by the abundance of raw materials; coal, iron ore, limestone, and dolomite. The most powerful and profitable companies in North Alabama were those which had direct control over mines, as well as other facilities necessary for extracting and assembling raw materials, such as blast furnaces. Being dependent on raw materials and relevant infrastructural facilities, iron and steel makers expanded the furnaces in Alabama. Those manufacturers also attempted to incorporate new charging machines to increase the overall production of iron. Since iron and steel production was a resource-intensive industry this required powerful iron and steel manufacturing enterprises to hold a control over the regional railroads in Alabama. A typical example was the Woodward Iron Company whose holdings were mostly linked by a company-owned railroad. This railroad originally measured 12 miles in length but the company extended it outward from its blast furnaces, to its quarries of limestone and dolomite, and further to its coal mines and ore mines.

Metallurgy

Chemokine (C-C motif) ligand 7 (CCL7) is a small cytokine that was previously called monocyte-chemotactic protein 3 (MCP3). CCL7 is a small protein that belongs to the CC chemokine family and is most closely related to CCL2 (previously called MCP1).

Gene expression + Signal Transduction

It can be synthesised in the following ways: * as an intermetallic compound, by direct fusion of pure components according to stoichiometric calculations: * by reduction of uranium dioxide with hydrogen in the presence of platinum:

Metallurgy

Magnetic roasting involves controlled roasting of the ore to convert it into a magnetic form, thus enabling easy separation and processing in subsequent steps. For example, controlled reduction of haematite (non magnetic FeO) to magnetite (magnetic FeO).

Metallurgy

Non-ferrous metals are used in residential, commercial and industrial applications. Material selection for a mechanical or structural application requires some important considerations, including how easily the material can be shaped into a finished part and how its properties can be either intentionally or inadvertently altered in the process. Depending on the end use, metals can be simply cast into the finished part, or cast into an intermediate form, such as an ingot, then worked, or wrought, by rolling, forging, extruding, or other deformation process. Although the same operations are used with ferrous as well as nonferrous metals and alloys, the reaction of nonferrous metals to these forming processes is often more severe. Consequently, properties may differ considerably between the cast and wrought forms of the same metal or alloy.

Metallurgy

Plasma transferred wire arc (PTWA) is another form of wire arc spray which deposits a coating on the internal surface of a cylinder, or on the external surface of a part of any geometry. It is predominantly known for its use in coating the cylinder bores of an engine, enabling the use of Aluminum engine blocks without the need for heavy cast iron sleeves. A single conductive wire is used as "feedstock" for the system. A supersonic plasma jet melts the wire, atomizes it and propels it onto the substrate. The plasma jet is formed by a transferred arc between a non-consumable cathode and the type of a wire. After atomization, forced air transports the stream of molten droplets onto the bore wall. The particles flatten when they impinge on the surface of the substrate, due to the high kinetic energy. The particles rapidly solidify upon contact. The stacked particles make up a high wear resistant coating. The PTWA thermal spray process utilizes a single wire as the feedstock material. All conductive wires up to and including 0.0625" (1.6mm) can be used as feedstock material, including "cored" wires. PTWA can be used to apply a coating to the wear surface of engine or transmission components to replace a bushing or bearing. For example, using PTWA to coat the bearing surface of a connecting rod offers a number of benefits including reductions in weight, cost, friction potential, and stress in the connecting rod.

Metallurgy

Although the classification of tumor suppressor genes into these categories is helpful to the scientific community, the potential role of many genes cannot be reliably identified as the functions of many genes are rather ill-defined. In some contexts, genes exhibit discrete caretaker function while in other situations gatekeeper characteristics are recognized. An example of one such gene is p53. Patients with Li-Fraumeni syndrome, for example, have mutations in the p53 gene that suggest caretaker function. p53 has an identified role, however, in regulating the cell cycle as well, which is an essential gatekeeper function.

Gene expression + Signal Transduction

A regulatory DNA sequence does not regulate unless it is activated. Different regulatory sequences are activated and then implement their regulation by different mechanisms.

Gene expression + Signal Transduction

RNA Pol II elongation promoters can be summarised in three classes: # Drug/sequence-dependent arrest affected factors, e.g., SII (TFIIS) and P-TEFb protein families. # Chromatin structure oriented factors. Based on histone post translational modifications – phosphorylation, acetylation, methylation and ubiquination. #: See: chromatin, histone, and nucleosome # RNA Pol II catalysis improving factors. Improve the Vmax or Km of RNA Pol II, so improving the catalytic quality of the polymerase enzyme. E.g. TFIIF, Elongin and ELL families. #: See: Enzyme kinetics, Henri–Michaelis–Menten kinetics, Michaelis constant, and Lineweaver–Burk plot As for initiation, protein interference, seen as the "drug/sequence-dependent arrest affected factors" and "RNA Pol II catalysis improving factors" provide a very rapid response and is used for fine level individual gene control. Elongation downregulation is also possible, in this case usually by blocking polymerase progress or by deactivating the polymerase. Chromatin structure-oriented factors are more complex than for initiation control. Often the chromatin-altering factor becomes bound to the polymerase complex, altering the histones as they are encountered and providing a semi-permanent memory of previous promotion and transcription.

Gene expression + Signal Transduction

Froth flotation is one of the processes used to recover recycled paper. In the paper industry this step is called deinking or just flotation. The target is to release and remove the hydrophobic contaminants from the recycled paper. The contaminants are mostly printing ink and stickies. Normally the setup is a two-stage system with 3,4 or 5 flotation cells in series. * pH control: sodium silicate and sodium hydroxide * Calcium ion source: hard water, lime or calcium chloride * Collector: fatty acid, fatty acid emulsion, fatty acid soap and/or organo-modified siloxane

Metallurgy

Continuous casting is a refinement of the casting process for the continuous, high-volume production of metal sections with a constant cross-section. Its primarily used to produce a semi-finished products for further processing. Molten metal is poured into an open-ended, water-cooled mold, which allows a skin' of solid metal to form over the still-liquid center, gradually solidifying the metal from the outside in. After solidification, the strand, as it is sometimes called, is continuously withdrawn from the mold. Predetermined lengths of the strand can be cut off by either mechanical shears or traveling oxyacetylene torches and transferred to further forming processes, or to a stockpile. Cast sizes can range from strip (a few millimeters thick by about five meters wide) to billets (90 to 160 mm square) to slabs (1.25 m wide by 230 mm thick). Sometimes, the strand may undergo an initial hot rolling process before being cut. Continuous casting is used due to the lower costs associated with continuous production of a standard product, and also increased quality of the final product. Metals such as steel, copper, aluminum and lead are continuously cast, with steel being the metal with the greatest tonnages cast using this method.

Metallurgy

Hardenability is the depth to which a steel is hardened after putting it through a heat treatment process. It should not be confused with hardness, which is a measure of a sample's resistance to indentation or scratching. It is an important property for welding, since it is inversely proportional to weldability, that is, the ease of welding a material.

Metallurgy

Nickel aluminide refers to either of two widely used intermetallic compounds, NiAl or NiAl, but the term is sometimes used to refer to any nickel–aluminium alloy. These alloys are widely used because of their high strength even at high temperature, low density, corrosion resistance, and ease of production. NiAl is of specific interest as a precipitate in nickel-based superalloys, where it is called the γ' (gamma prime) phase. It gives these alloys high strength and creep resistance up to 0.7–0.8 of its melting temperature. Meanwhile, NiAl displays excellent properties such as lower density and higher melting temperature than those of NiAl, and good thermal conductivity and oxidation resistance. These properties make it attractive for special high-temperature applications like coatings on blades in gas turbines and jet engines. However, both these alloys have the disadvantage of being quite brittle at room temperature, with NiAl remaining brittle at high temperatures as well. To address this problem, has been shown that NiAl can be made ductile when manufactured in single-crystal form rather than in polycrystalline form.

Metallurgy

E. coli produces a second protein responsible for degradation of (p)ppGpp, SpoT. When the amino acid balance in the cell is restored, (p)ppGpp is hydrolyzed by SpoT and returned to a more energetically favorable state. This protein also has the capacity to synthesize (p)ppGpp, and seems to be the primary synthase under certain conditions of stress. Most other bacteria encode a single protein that is responsible for both synthesis and degradation of (p)ppGpp, generally homologs of SpoT.

Gene expression + Signal Transduction

This book is extensively illustrated and describes the tools and machinery associated with mining. Handtools and different sorts of buckets, wheelbarrows and trucks on wooded plankways are described. Packs for horses and sledges are used to carry loads above ground. Agricola then provides details of various kinds of machines for lifting weights. Some of these are man-powered and some powered by up to four horses or by waterwheels. Horizontal drive shafts along tunnels allow lifting in shafts not directly connected to the surface. If this is not possible, treadmills will be installed underground. Instead of lifting weights, similar machines use chains of buckets to lift water. Agricola also describes several designs of piston force pumps, which are either man or animal-powered, or powered by water wheels. Because these pumps can only lift water about 24 feet, batteries of pumps are required for the deepest mines. Water pipe designs are also covered in this section. Designs of wind scoop for ventilating shafts or forced air using fans or bellows are also described. Finally, ladders and lifts using wicker cages are used to get miners up and down shafts.

Metallurgy

PERK (encoded in humans by the gene EIF2AK3) responds mainly to endoplasmic reticulum stress and has two modes of activation. This kinase has a unique luminal domain that plays a role in activation. The classical model of activation states that the luminal domain is normally bound to 78-kDa glucose-regulated protein (GRP78). Once there is a buildup of unfolded proteins, GRP78 dissociates from the luminal domain. This causes PERK to dimerize, leading to autophosphorylation and activation. The activated PERK kinase will then phosphorylate eIF2α, causing a cascade of events. Thus, the activation of this kinase is dependent on the aggregation of unfolded proteins in the endoplasmic reticulum. PERK has also been observed to activate in response to activity of the proto-oncogene MYC. This activation causes ATF4 expression, resulting in tumorigenesis and cellular transformation.

Gene expression + Signal Transduction

In general, in prokaryotes the lifetime of mRNA is much shorter than in eukaryotes. Prokaryotes degrade messages by using a combination of ribonucleases, including endonucleases, 3 exonucleases, and 5 exonucleases. In some instances, small RNA molecules (sRNA) tens to hundreds of nucleotides long can stimulate the degradation of specific mRNAs by base-pairing with complementary sequences and facilitating ribonuclease cleavage by RNase III. It was recently shown that bacteria also have a sort of 5 cap consisting of a triphosphate on the 5 end. Removal of two of the phosphates leaves a 5 monophosphate, causing the message to be destroyed by the exonuclease RNase J, which degrades 5 to 3'.

Gene expression + Signal Transduction

Oxidizing roasting, the most commonly practiced roasting process, involves heating the ore in excess of air or oxygen, to burn out or replace the impurity element, generally sulfur, partly or completely by oxygen. For sulfide roasting, the general reaction can be given by: :2MS (s) + 3O (g) -> 2MO (s) + 2SO (g) Roasting the sulfide ore, until almost complete removal of the sulfur from the ore, results in a dead roast.

Metallurgy

Three prime untranslated regions (3UTRs) of messenger RNAs (mRNAs) often contain regulatory sequences that post-transcriptionally cause RNA interference. Such 3-UTRs often contain both binding sites for microRNAs (miRNAs) as well as for regulatory proteins. By binding to specific sites within the 3-UTR, miRNAs can decrease gene expression of various mRNAs by either inhibiting translation or directly causing degradation of the transcript. The 3-UTR also may have silencer regions that bind repressor proteins that inhibit the expression of a mRNA. The 3-UTR often contains microRNA response elements (MREs). MREs are sequences to which miRNAs bind. These are prevalent motifs within 3-UTRs. Among all regulatory motifs within the 3'-UTRs (e.g. including silencer regions), MREs make up about half of the motifs. As of 2014, the miRBase web site, an archive of miRNA sequences and annotations, listed 28,645 entries in 233 biologic species. Of these, 1,881 miRNAs were in annotated human miRNA loci. miRNAs were predicted to have an average of about four hundred target mRNAs (affecting expression of several hundred genes). Freidman et al. estimate that >45,000 miRNA target sites within human mRNA 3'UTRs are conserved above background levels, and >60% of human protein-coding genes have been under selective pressure to maintain pairing to miRNAs. Direct experiments show that a single miRNA can reduce the stability of hundreds of unique mRNAs. Other experiments show that a single miRNA may repress the production of hundreds of proteins, but that this repression often is relatively mild (less than 2-fold). The effects of miRNA dysregulation of gene expression seem to be important in cancer. For instance, in gastrointestinal cancers, nine miRNAs have been identified as epigenetically altered and effective in down regulating DNA repair enzymes. The effects of miRNA dysregulation of gene expression also seem to be important in neuropsychiatric disorders, such as schizophrenia, bipolar disorder, major depression, Parkinsons disease, Alzheimers disease and autism spectrum disorders.

Gene expression + Signal Transduction

Shape-memory coupling is a system for connecting pipes using shape-memory alloys. In its typical form the technique uses an internally ribbed sleeve of alloy such as Tinel(see Nitinol) that is slightly smaller in diameter than the pipes it is to connect. The sleeve is cooled in liquid nitrogen then, in this low-temperature state, mechanically expanded with a mandrel to fit easily over the two pipe ends to be joined. After fitting, it is allowed to rewarm, when the memory effect causes the sleeve to shrink back to its original smaller size, creating a tight joint. It was first produced in the late 1960s or early 1970s by the Raychem Corporation under the trade name CryoFit. Manufacture of these couplings for aerospace hydraulic connections was later transferred to AMCI (Advanced Metal Components Inc.) and then later to [http://www.aerofit.com Aerofit Products Inc.] Additional products using the same shape-memory alloy technology are produced under Cryolive and CryoFlare trade names.

Metallurgy

Salt spray testing is popular because it is relatively inexpensive, quick, well standardized, and reasonably repeatable. Although there may be a weak correlation between the duration in salt spray test and the expected life of a coating in certain coatings such as hot-dip galvanized steel, this test has gained worldwide popularity due to low cost and quick results. Most Salt Spray Chambers today are being used NOT to predict the corrosion resistance of a coating, but to maintain coating processes such as pre-treatment and painting, electroplating, galvanizing, and the like, on a comparative basis. For example, pre-treated + painted components must pass 96 hours Neutral Salt Spray, to be accepted for production. Failure to meet this requirement implies instability in the chemical process of the pre-treatment, or the paint quality, which must be addressed immediately so that the upcoming batches are of the desired quality. The longer the accelerated corrosion test, the longer the process remains out of control, and larger is the loss in the form of non-conforming batches. The principal application of the salt spray test is, therefore, enabling quick comparisons to be made between actual and expected corrosion resistance. Most commonly, the time taken for oxides to appear on the samples under test is compared to expectations, to determine whether the test is passed or failed. For this reason, the salt spray test is most often deployed in a quality audit role, where, for example, it can be used to check the effectiveness of a production process, such as the surface coating of a metallic part. The salt spray test has little application in predicting how materials or surface coatings will resist corrosion in the real world, because it does not create, replicate or accelerate real-world corrosive conditions. Cyclic corrosion testing is better suited to this.

Metallurgy

Rotavirus mRNAs are capped but not polyadenylated, and viral proteins are translated by the cellular translation machinery. This is accomplished through the action of the viral Nonstructural Protein NSP3 which specifically binds the 3' consensus sequence of viral mRNAs and interacts with the eukaryotic translation initiation factor eIF4G I. RoXaN (rotavirus X protein associated with NSP3) is 110-kDa cellular protein that contains a minimum of three regions predicted to be involved in protein–protein or nucleic acid–protein interactions. A tetratricopeptide repeat region, a protein–protein interaction domain most often found in multiprotein complexes, is present in the amino-terminal region. In the carboxy terminus, at least five zinc finger motifs are observed, further suggesting the capacity of RoXaN to bind other proteins or nucleic acids. Between these two regions exists a paxillin leucine-aspartate repeat (LD) motif which is involved in protein–protein interactions.

Gene expression + Signal Transduction

Artists and metalworkers often deliberately add patinas as a part of the original design and decoration of art and furniture, or to simulate antiquity in newly made objects. The process is often called distressing. A wide range of chemicals, both household and commercial, can give a variety of patinas. They are often used by artists as surface embellishments either for color, texture, or both. Patination composition varies with the reacted elements and these will determine the color of the patina. For copper alloys, such as bronze, exposure to chlorides leads to green, while sulfur compounds (such as "liver of sulfur") tend to brown. The basic palette for patinas on copper alloys includes chemicals like ammonium sulfide (blue-black), liver of sulfur (brown-black), cupric nitrate (blue-green), and ferric nitrate (yellow-brown). For artworks, patination is often deliberately accelerated by applying chemicals with heat. Colors range from matte sandstone yellow to deep blues, greens, whites, reds, and various blacks. Some patina colors are achieved by the mixing of colors from the reaction with the metal surface with pigments added to the chemicals. Sometimes the surface is enhanced by waxing, oiling, or other types of lacquers or clear-coats. More simply, the French sculptor Auguste Rodin used to instruct assistants at his studio to urinate over bronzes stored in the outside yard. A patina can be produced on copper by the application of vinegar (acetic acid). This patina is water-soluble and will not last on the outside of a building like a "true" patina. It is usually used as pigment. Patina is also found on slip rings and commutators. This type of patina is formed by corrosion, what elements the air might hold, residue from the wear of the carbon brush, and moisture; thus, the patina needs special conditions to work as intended. Patinas can also be found in woks or other metal baking dishes. The process of applying patinas to cookware is known as seasoning. The patina on a wok is a dark coating of oils that have been polymerized onto it to prevent food from sticking. Scrubbing or using soap on a wok or other dishware could damage the patina and possibly allow rust. Knife collectors that own carbon steel blades sometimes force a patina onto the blade to help protect it and give it a more personalized look. This can be done using various chemicals and substances such as muriatic acid, apple cider vinegar, or mustard. It can also be done by sticking the blade into any acidic vegetable or fruit such as an orange or an apple.

Metallurgy

For superalloys operating at high temperatures and exposed to corrosive environments, oxidation behavior is a concern. Oxidation involves chemical reactions of the alloying elements with oxygen to form new oxide phases, generally at the alloy surface. If unmitigated, oxidation can degrade the alloy over time in a variety of ways, including: * sequential surface oxidation, cracking, and spalling, eroding the alloy over time * surface embrittlement through the introduction of oxide phases, promoting crack formation and fatigue failure * depletion of key alloying elements, affecting mechanical properties and possibly compromising performance Selective oxidation is the primary strategy used to limit these deleterious processes. The ratio of alloying elements promotes formation of a specific oxide phase that then acts as a barrier to further oxidation. Most commonly, aluminum and chromium are used in this role, because they form relatively thin and continuous oxide layers of alumina (AlO) and chromia (CrO), respectively. They offer low oxygen diffusivities, effectively halting further oxidation beneath this layer. In the ideal case, oxidation proceeds through two stages. First, transient oxidation involves the conversion of various elements, especially the majority elements (e.g. nickel or cobalt). Transient oxidation proceeds until the selective oxidation of the sacrificial element forms a complete barrier layer. The protective effect of selective oxidation can be undermined. The continuity of the oxide layer can be compromised by mechanical disruption due to stress or may be disrupted as a result of oxidation kinetics (e.g. if oxygen diffuses too quickly). If the layer is not continuous, its effectiveness as a diffusion barrier to oxygen is compromised. The stability of the oxide layer is strongly influenced by the presence of other minority elements. For example, the addition of boron, silicon, and yttrium to superalloys promotes oxide layer adhesion, reducing spalling and maintaining continuity. Oxidation is the most basic form of chemical degradation superalloys may experience. More complex corrosion processes are common when operating environments include salts and sulfur compounds, or under chemical conditions that change dramatically over time. These issues are also often addressed through comparable coatings.

Metallurgy

The majority of these twintrons have been characterized within the Euglena chloroplast genome but these elements have also been found in cryptomonad algae (Pyrenomonas salina), and group I intron based twintrons (group I inserted within a group I intron) have been described in Didymium iridis. Since the discovery of the psbF twintron, several categories of twintrons have been characterized. A twintron can be simple (external intron interrupted by 1 internal intron), or complex (external intron interrupted by multiple internal introns). Most probably, the internal and external introns comprising the twintron element are from the same category; group I internal to group I, group II internal to group II, and group III internal to group III. Mixed twintrons (consisting of introns belonging to different categories) were characterized from the Euglena gracilis rps3 gene in which an internal group II intron is found to interrupt an external group III intron. In Rhodomonas salina (=Pyrenomonas salina) twintrons (nested group II/group III introns) were identified where the internal intron lost its splicing capacity, essentially merging with the outer intron forming one splicing unit. Recently, two novel twintrons have been uncovered within the fungal mitochondrial genome, one at position mS917 of the Cryphonectria parasitica mt-rns gene, where a group ID intron encoding a LAGLIDADG ORF invaded another ORF-less group ID intron. Another twintron complex was detected at position mS1247 of the Chaetomium thermophilumhere mt-rns gene, a group IIA1 intron invaded the open reading frame embedded within a group IC2 intron. The mS1247 twintron represents the first recorded fungal mitochondrial mixed twintron consisting of group II intron as an internal intron and a group I intron as an external intron. In mS1247 twintron, splicing of the internal group IIA1 intron reconstitutes the open reading frame encoded within the group IC2 intron and thus facilitates the expression of the encoded homing endonuclease. The mS1247 twintron encod ORF have been biochemically characterized and the results showed that it is an active homing endonuclease that could potentially mobilize the twintron to rns genes that have not yet been invaded by this mobile composite element.

Gene expression + Signal Transduction

The initiation of the transcription is a multistep sequential process that involves several mechanisms: promoter location, initial reversible binding of RNA polymerase, conformational changes in RNA polymerase, conformational changes in DNA, binding of nucleoside triphosphate (NTP) to the functional RNA polymerase-promoter complex, and nonproductive and productive initiation of RNA synthesis. The promoter binding process is crucial in the understanding of the process of gene expression. Tuning synthetic genetic systems relies on precisely engineered synthetic promoters with known levels of transcription rates.

Gene expression + Signal Transduction

Pure calcium carbide is a colourless solid. The common crystalline form at room temperature is a distorted rock-salt structure with the C</sup> units lying parallel. There are three different polymorphs which appear at room temperature: the tetragonal structure and two different monoclinic structures.

Metallurgy

Promoters reside at the beginning of the gene and serve as the site where the transcription machinery assembles and transcription of the gene begins. Enhancers turn on the promoters at specific locations, times, and levels and can be simply defined as the “promoters of the promoter.” Silencers are thought to turn off gene expression at specific time points and locations. Insulators, also called boundary elements, are DNA sequences that create cis-regulatory boundaries that prevent the regulatory elements of one gene from affecting neighboring genes. The general dogma is that these regulatory elements get activated by the binding of transcription factors, proteins that bind to specific DNA sequences, and control mRNA transcription. There could be several transcription factors that need to bind to one regulatory element in order to activate it. In addition, several other proteins, called transcription cofactors, bind to the transcription factors themselves to control transcription.

Gene expression + Signal Transduction

Hammond married Ellen Sarah Sophia Clarke (1833–1905), the sister-in-law of Samuel Warren, in 1874. Hammond survived her by three years upon her death in 1905. Along with New York architect Alexander Twombly, who was the engineer and draftsman of Forest Paper Company, Hammond designed what is today known as Camp Hammond, set back from Yarmouths Main Street and from which Hammond could see his mill. Twombly also designed several buildings in Boston. Frederick Law Olmsted, who designed Central Park in New York City, designed the gardens of the property. With the Hammonds splitting their time between Boston and Yarmouth, the property became known as the Camp'. The Hammonds also formed the Antiquarian Society in order to facilitate the 1890 purchase of the North Yarmouth and Freeport Baptist Meetinghouse on Yarmouth's Hillside Street. It became a library and museum, known as the Hillside Library. Among the many roles Hammond took on without payment was as president of the Yarmouth Water Committee, established in 1895, which sourced its water supply from Hammond Spring on the property of Forest Paper Company. Hammond donated Forest Paper Company land for the 1903 construction of Merrill Memorial Library, on Main Street, which was designed by Alexander Longfellow, a nephew of the poet Henry Wadsworth Longfellow. Hammond served in the Maine Legislature between 1868 and 1870, was on the Maine Board of Agriculture and the board of trustees of North Yarmouth Academy, was a member of the American Association for the Advancement of Science, the Society of Chemical Industry, the American Institute of Mining, Metallurgical, and Petroleum Engineers, The Society of Arts and Crafts of Boston, the Massachusetts Historical Society, the New England Historic Genealogical Society (from January 1876), The Bostonian Society and the Franklin Institute. He was also a Freemason. A member of the American Horticultural Society, he was a keen arborist, and his knowledge of trees and plants earned him a place on the Overseers Committee at Harvard Universitys Gray Herbarium between 1888 and the time of his death. The Hammonds were members of Yarmouths First Parish Congregational Church and Bostons Trinity Church.

Metallurgy

Inverse agonists differ from regular agonists in that they effect receptors to which a regular agonist binds such that the bound receptors demonstrate reduced activity compared to when they are normally inactive. In other words, inverse antagonists limit the efficacy of the bound receptor in some way. This is noted to be beneficial in instances wherein expression of receptors or up-regulated receptor sensitivity could be detrimental, thus making suppression of response the best recourse. A handful of examples of inverse agonist use in therapy include β-blockers, antihistamines, ACP-103 to treat Parkinson's disease, hemopressin, drugs to treat obesity, and more besides.

Gene expression + Signal Transduction

A common concept in materials science is that, at ambient conditions, smaller features (like grain size or absolute size) generally lead to stronger materials (see Hall-Petch strengthening, Weibull statistics). However, due to the high-level of porosity in the dealloyed materials, their strengths and stiffnesses are relatively low compared to the bulk counterparts. The decrease in strength due to porosity can be described with the Gibson-Ashby (GA) relations, which give the yield strength and Young's modulus of a foam according to the following equations: where and <math>C_E and <math>n_E is the relative density of the foam. The GA relations can be used to estimate the strength and stiffness of a given dealloyed, porous material, but more extensive study has revealed an additional factor: ligament size. When the ligament diameter is greater than 100 nm, increasing ligament size leads to greater agreement between GA predictions and experimental measurements of yield stress and Young's modulus. However, when the ligament size is under 100 nm, which is very common in many dealloying processes, there is an addition to the GA strength that looks similar to Hall-Petch strengthening of bulk polycrystalline metals (i.e., the yield stress increases with the inverse square root of grain size). Combining this relationship with the GA relation from before, an expression for the yield stress of dealloyed materials with ligaments smaller than 100 nm can be determined: where A and m are empirically determined constants, and is the ligament size. The represents the Hall-Petch-like contribution. There are two theories for why this increase in strength occurs: 1) dislocations are less common in smaller sample volumes, so deformation requires activation of sources (which is a more difficult process), or 2) dislocations pile-up, which strengthens the material. Either way, there would be significant surface and small volume effects in the ligaments <100 nm, which lead to this increase in yield stress. A relationship between ligament size and Young's modulus has not been studied past the GA relation. Occasionally, the metastable nature of these materials means that ligaments in the structure may "pinch off" due to surface diffusion, which decreases the connectivity of the structure, and reduces the strength of the dealloyed material past what would be expected from simply porosity (as predicted by the Gibson-Ashby relations).

Metallurgy

Chemistry determines the optimum relationship between the fuel and the material, among other variables. The reverberatory furnace can be contrasted on the one hand with the blast furnace, in which fuel and material are mixed in a single chamber, and, on the other hand, with crucible, muffling, or retort furnaces, in which the subject material is isolated from the fuel and all of the products of combustion including gases and flying ash. There are, however, a great many furnace designs, and the terminology of metallurgy has not been very consistently defined, so it is difficult to categorically contradict other views. The applications of these devices fall into two general categories, metallurgical melting furnaces, and lower temperature processing furnaces typically used for metallic ores and other minerals. A reverberatory furnace is at a disadvantage from the standpoint of efficiency compared to a blast furnace due to the separation of the burning fuel and the subject material, and it is necessary to effectively utilize both reflected radiant heat and direct contact with the exhaust gases (convection) to maximize heat transfer. Historically these furnaces have used solid fuel, and bituminous coal has proven to be the best choice. The brightly visible flames, due to the substantial volatile component, give more radiant heat transfer than anthracite coal or charcoal. Contact with the products of combustion, which may add undesirable elements to the subject material, is used to advantage in some processes. Control of the fuel/air balance can alter the exhaust gas chemistry toward either an oxidizing or a reducing mixture, and thus alter the chemistry of the material being processed. For example, cast iron can be puddled in an oxidizing atmosphere to convert it to the lower-carbon mild steel or bar iron. The Siemens-Martin oven in open hearth steelmaking is also a reverberatory furnace. Reverberatory furnaces (in this context, usually called air furnaces) were formerly also used for melting brass, bronze, and pig iron for foundry work. They were also, for the first 75 years of the 20th century, the dominant smelting furnace used in copper production, treating either roasted calcine or raw copper sulfide concentrate. While they have been supplanted in this role, first by flash furnaces and more recently also by the Ausmelt and ISASMELT furnaces, they are very effective at producing slags with low copper losses.

Metallurgy

Unlike in protein coding regions, where the assumption of sequence conservation of functionally homologous genes have been frequently proved, there is not a clear relationship of conservation between sequences and their functions for regulatory regions. The transcriptional promoters regions are under less stringent selection, then have a higher substitutions rates, allowing transcription factor binding sites to be replaced easily be new ones arising from random mutations. Notwithstanding the sequence changes, mainly the functions of regulatory sequences remain conserved. In recents years with the increase of availability of genome sequences, phylogenetic footprinting open the possibility to identify cis-elements, and then study their evolution processes. In this sense, Raijman et al., Dermitzakis et al. have developed techniques for analyzing evolutionary processes in transcription factor regions in Saccharomyces species promoters and mammalian regulatory networks respectively. The basis for many of these evolutionary changes in nature are probably related with events within the cis-regulatory regions involve in gene expression. The impact of variation in regulatory regions is important for disease risk due their impact in the gene expression level. Furthermore, perturbations in the binding properties of proteins encoded by regulatory genes have been linked with phenotypes effects such as, duplicated structures, homeotic transformations and novel morphologies.

Gene expression + Signal Transduction

The strip mill was a major innovation, with the first being erected at Ashland, Kentucky in 1923. This provided a continuous process, eliminating the need to pass the plates over the rolls and to double them. At the end the strip was cut with a guillotine shear or rolled into a coil. Early (hot rolling) strip mills did not produce strip suitable for tinplate, but in 1929 cold rolling began to be used to reduce the gauge further. The first strip mill in Great Britain was opened at Ebbw Vale in 1938 with an annual output of 200,000 tons. The strip mill had several advantages over pack mills: * It was cheaper due to having all parts of the process, starting with blast furnaces, on the same site. * Softer steel could be used. * Larger sheets could be produced at lower cost; this reduced cost and enabled tinplate and steel sheet to be used for more purposes. * It was capital-intensive, rather than labour-intensive.

Metallurgy

An RA plot, like its cousin, the MA plot, is a re-scaled and (45-degree) rotated version of a simple two-dimensional scatter plot of a versus b where a and b are equal-length vectors of positive measurements. This rescaling and rotation allows for better visibility and emphasis of important outliers points that vary between the two measurement conditions. Essentially it is a plot of the log ratio [R] vs the average log [A] of each pairing of the elements of a and b. Unlike an MA plot, however, because the RA plot takes non-negative integer counts as input, it must employ work-arounds to include mathematically invisible points (such as points where one or both element(s) of the pair is zero). If we modify our original a (or b) vector via: where then R and A can be defined as: R, like M, is plotted on the y-axis and represents a log (fold change) ratio between a and b. A is plotted on the x-axis and represents the average abundance for a coordinate pair. The RA plot provides a quick overview of the distribution and size of a dataset consisting of non-zero counts.

Gene expression + Signal Transduction

The environmental bacterium and opportunistic pathogen Pseudomonas aeruginosa uses quorum sensing to coordinate the formation of biofilm, swarming motility, exopolysaccharide production, virulence, and cell aggregation. These bacteria can grow within a host without harming it until they reach a threshold concentration. Then they become aggressive, developing to the point at which their numbers are sufficient to overcome the hosts immune system, and form a biofilm, leading to disease within the host as the biofilm is a protective layer encasing the bacterial population. The relative ease of growth, handling, and genetic manipulation of Pseudomonas aeruginosa has lent much research effort to the quorum sensing circuits of this relatively common bacterium. Quorum sensing in Pseudomonas aeruginosa typically encompasses two complete AHL synthase-receptor circuits, LasI-LasR and RhlI-RhlR, as well as the orphan receptor-regulator QscR, which is also activated by the LasI-generated signal. Together, the multiple AHL quorum sensing circuits of Pseudomonas aeruginosa' influence regulation of hundreds of genes. Another form of gene regulation that allows the bacteria to rapidly adapt to surrounding changes is through environmental signaling. Recent studies have discovered that anaerobiosis can significantly impact the major regulatory circuit of quorum sensing. This important link between quorum sensing and anaerobiosis has a significant impact on the production of virulence factors of this organism. There is hope among some humans that the therapeutic enzymatic degradation of the signaling molecules will be possible when treating illness caused by biofilms, and prevent the formation of such biofilms and possibly weaken established biofilms. Disrupting the signaling process in this way is called quorum sensing inhibition.

Gene expression + Signal Transduction

Primary role of EpoR is to promote proliferation of erythroid progenitor cells and rescue erythroid progenitors from cell death. EpoR induced Jak2-Stat5 signaling, together with transcriptional factor GATA-1, induces the transcription of pro-survival protein Bcl-xL. Additionally, EpoR has been implicated in suppressing expression of death receptors Fas, Trail and TNFa that negatively affect erythropoiesis. Based on current evidence, it is still unknown whether Epo/EpoR directly cause "proliferation and differentiation" of erythroid progenitors in vivo, although such direct effects have been described based on in vitro work.

Gene expression + Signal Transduction

The JAK-STAT signaling pathway is instrumental in the development of limbs, specifically in its ability to regulate bone growth through paracrine signaling of cytokines. However, mutations in this pathway have been implicated in severe forms of dwarfism: thanatophoric dysplasia (lethal) and achondroplasic dwarfism (viable). This is due to a mutation in a Fgf gene, causing a premature and constitutive activation of the Stat1 transcription factor. Chondrocyte cell division is prematurely terminated, resulting in lethal dwarfism. Rib and limb bone growth plate cells are not transcribed. Thus, the inability of the rib cage to expand prevents the newborn's breathing.

Gene expression + Signal Transduction

Due to the very small electrical fields produced by neurons, mathematical models are often used in order to test a number of manipulations. Cable theory is one of the most important mathematical equations in neuroscience. It calculates electric current using capacitance and resistance as variables and has been the main basis for many predictions about ephaptic coupling in neurons. However, many authors have worked to create more refined models in order to more accurately represent the environments of the nervous system. For example, many authors have proposed models for cardiac tissue that includes additional variables that account for the unique structure and geometry of cardiac cells varying scales of size, or three-dimensional electrodiffusion.

Gene expression + Signal Transduction

FAHFAs (fatty acid esters of hydroxy fatty acids) are formed in adipose tissue, improve glucose tolerance and also reduce adipose tissue inflammation. Palmitic acid esters of hydroxy-stearic acids (PAHSAs) are among the most bioactive members able to activate G-protein coupled receptors 120. Docosahexaenoic acid ester of hydroxy-linoleic acid (DHAHLA) exert anti-inflammatory and pro-resolving properties.

Gene expression + Signal Transduction

TFA is a heterodimer with two subunits: one large unprocessed (subunit 1, or alpha/beta; gene name ) and one small (subunit 2, or gamma; gene name ). It was originally believed to be a heterotrimer of an alpha (p35), a beta (p19) and a gamma subunit (p12). In humans, the sizes of the encoded proteins are approximately 55 kD and 12 kD. Both genes are present in species ranging from humans to yeast, and their protein products interact to form a complex composed of a beta barrel domain and an alpha helical bundle domain. It is the N-terminal and C-terminal regions of the large subunit that participate in interactions with the small subunit. These regions are separated by another domain whose sequence is always present in large subunits from various species but whose size varies and whose sequence is poorly conserved. A second gene encoding a large TFA subunit has been found in some higher eukaryotes. This gene, ALF/TFIIAtau (gene name ) is expressed only in oocytes and spermatocytes, suggesting it has a TFA-like regulatory role for gene expression only in germ cells.

Gene expression + Signal Transduction

Bases: adenine (A), cytosine (C), guanine (G) and thymine (T) or uracil (U). Amino acids: Alanine (Ala, A), Arginine (Arg, R), Asparagine (Asn, N), Aspartic acid (Asp, D), Cysteine (Cys, C), Glutamic acid (Glu, E), Glutamine (Gln, Q), Glycine (Gly, G), Histidine (His, H), Isoleucine (Ile, I), Leucine (Leu, L), Lysine (Lys, K), Methionine (Met, M), Phenylalanine (Phe, F), Proline (Pro, P), Serine (Ser, S), Threonine (Thr, T), Tryptophan (Trp, W), Tyrosine (Tyr, Y), Valine (Val, V)

Gene expression + Signal Transduction

Hydrogen gas porosity is an aluminium casting defect in the form of a porosity or void in an aluminium casting caused by a high level of hydrogen gas (H) dissolved in the aluminium at liquid phase. The solubility of hydrogen in solid aluminium is much smaller than in liquid aluminium. As the aluminium freezes, some of the hydrogen comes out of solution and forms bubbles, creating porosity in the solid aluminium. Aluminium foundries want to produce high-quality aluminum castings with minimum porosity. Hydrogen porosity can be reduced by reducing the amount of hydrogen in the liquid aluminium alloy, by degassing or sparging. (Sometimes a small hydrogen concentration is intentionally maintained; some very fine hydrogen porosity can be preferable to internal voids caused by shrinkage.) Directional solidification can drive impurities to one end of the casting.

Metallurgy

PELP1 is a proto-oncogene that provides cancer cells with a distinct growth and survival advantage. PELP1 overexpression has been reported in many cancers. PELP1 expression is an independent prognostic predictor of shorter breast cancer–specific survival and disease free interval. Patients whose tumors had high levels of cytoplasmic PELP1 exhibited a tendency to respond poorly to tamoxifen and PELP1 deregulated tumors respond to Src kinase and mTOR inhibitors. Treatment of breast and ovarian cancer xenografts with liposomal PELP1–siRNA–DOPC formulations revealed that knockdown of PELP1 significantly reduce the tumor growth. These results provided initial proof that PELP1 is a bonafide therapeutic target. Emerging data support a central role for PELP1 and its direct protein–protein interactions in cancer progression. Since PELP1 lacks known enzymatic activity, drugs that target PELP1 interactions with other proteins should have clinical utility. Recent studies described an inhibitor (D2) that block PELP1 interactions with AR. Since PELP1 interacts with histone modifications and epigenetic enzymes, drugs targeting epigenetic modifier enzymes may be useful in targeting PELP1 deregulated tumors.

Gene expression + Signal Transduction

Smelting is a process of applying heat and a chemical reducing agent to an ore to extract a desired base metal product. It is a form of extractive metallurgy that is used to obtain many metals such as iron, copper, silver, tin, lead and zinc. Smelting uses heat and a chemical reducing agent to decompose the ore, driving off other elements as gases or slag and leaving the metal behind. The reducing agent is commonly a fossil fuel source of carbon, such as carbon monoxide from incomplete combustion of coke—or, in earlier times, of charcoal. The oxygen in the ore binds to carbon at high temperatures as the chemical potential energy of the bonds in carbon dioxide () is lower than that of the bonds in the ore. Sulfide ores such as those commonly used to obtain copper, zinc or lead, are roasted before smelting in order to convert the sulfides to oxides, which are more readily reduced to the metal. Roasting heats the ore in the presence of oxygen from air, oxidizing the ore and liberating the sulfur as sulfur dioxide gas. Smelting most prominently takes place in a blast furnace to produce pig iron, which is converted into steel. Plants for the electrolytic reduction of aluminium are referred to as aluminium smelters.

Metallurgy

*The G complexes sometimes also have active functions. Examples include coupling to and activating G protein-coupled inwardly-rectifying potassium channels.

Gene expression + Signal Transduction

Tarnish is a product of a chemical reaction between a metal and a nonmetal compound, especially oxygen and sulfur dioxide. It is usually a metal oxide, the product of oxidation; sometimes it is a metal sulfide. The metal oxide sometimes reacts with water to make the hydroxide, or with carbon dioxide to make the carbonate. It is a chemical change. There are various methods to prevent metals from tarnishing.

Metallurgy

Amorphous metal is usually an alloy rather than a pure metal. The alloys contain atoms of significantly different sizes, leading to low free volume (and therefore up to orders of magnitude higher viscosity than other metals and alloys) in molten state. The viscosity prevents the atoms moving enough to form an ordered lattice. The material structure also results in low shrinkage during cooling, and resistance to plastic deformation. The absence of grain boundaries, the weak spots of crystalline materials, leads to better resistance to wear and corrosion. Amorphous metals, while technically glasses, are also much tougher and less brittle than oxide glasses and ceramics. Amorphous metals can be grouped in two categories, as either non-ferromagnetic, if they are composed of Ln, Mg, Zr, Ti, Pd, Ca, Cu, Pt and Au, or ferromagnetic alloys, if they are composed of Fe, Co, and Ni. Thermal conductivity of amorphous materials is lower than that of crystalline metal. As formation of amorphous structure relies on fast cooling, this limits the maximum achievable thickness of amorphous structures. To achieve formation of amorphous structure even during slower cooling, the alloy has to be made of three or more components, leading to complex crystal units with higher potential energy and lower chance of formation. The atomic radius of the components has to be significantly different (over 12%), to achieve high packing density and low free volume. The combination of components should have negative heat of mixing, inhibiting crystal nucleation and prolonging the time the molten metal stays in supercooled state. As temperatures change, the electrical resistivity of amorphous metals behaves very different than that of regular metals. While the resistivity in regular metals generally increases with temperature, following the Matthiessens rule, the resistivity in a large number of amorphous metals is found to decrease with increasing temperature. This is effect can be observed in amorphous metals of high resistivities between 150 and 300 microohm-centimeters. In these metals, the scattering events causing the resistivity of the metal can no longer be considered statistically independent, thus explaining the breakdown of the Matthiessens rule. The fact that the thermal change of the resistivity in amorphous metals can be negative over a large range of temperatures and correlated to their absolute resistivity values was first observed by Mooij in 1973, hence coining the term "Mooij-rule". The alloys of boron, silicon, phosphorus, and other glass formers with magnetic metals (iron, cobalt, nickel) have high magnetic susceptibility, with low coercivity and high electrical resistance. Usually the electrical conductivity of a metallic glass is of the same low order of magnitude as of a molten metal just above the melting point. The high resistance leads to low losses by eddy currents when subjected to alternating magnetic fields, a property useful for e.g. transformer magnetic cores. Their low coercivity also contributes to low loss. The superconductivity of amorphous metal thin films was discovered experimentally in the early 1950s by Buckel and Hilsch. For certain metallic elements the superconducting critical temperature T can be higher in the amorphous state (e.g. upon alloying) than in the crystalline state, and in several cases T increases upon increasing the structural disorder. This behavior can be understood and rationalized by considering the effect of structural disorder on the electron-phonon coupling. Amorphous metals have higher tensile yield strengths and higher elastic strain limits than polycrystalline metal alloys, but their ductilities and fatigue strengths are lower. Amorphous alloys have a variety of potentially useful properties. In particular, they tend to be stronger than crystalline alloys of similar chemical composition, and they can sustain larger reversible ("elastic") deformations than crystalline alloys. Amorphous metals derive their strength directly from their non-crystalline structure, which does not have any of the defects (such as dislocations) that limit the strength of crystalline alloys. One modern amorphous metal, known as Vitreloy, has a tensile strength that is almost twice that of high-grade titanium. However, metallic glasses at room temperature are not ductile and tend to fail suddenly when loaded in tension, which limits the material applicability in reliability-critical applications, as the impending failure is not evident. Therefore, there is considerable interest in producing metal matrix composites consisting of a metallic glass matrix containing dendritic particles or fibers of a ductile crystalline metal. Perhaps the most useful property of bulk amorphous alloys is that they are true glasses, which means that they soften and flow upon heating. This allows for easy processing, such as by injection molding, in much the same way as polymers. As a result, amorphous alloys have been commercialized for use in sports equipment, medical devices, and as cases for electronic equipment. Thin films of amorphous metals can be deposited via high velocity oxygen fuel technique as protective coatings.

Metallurgy

Both prokaryotic and eukarotic genomes are organized into large loops of protein-bound DNA. In eukaryotes, the bases of the loops are called scaffold attachment regions (SARs) and they consist of stretches of DNA that bind an RNA/protein complex to stabilize the loop. There are about 100,000 loops in the human genome and each one consists of about 100 bp of DNA. The total amount of DNA devoted to SARs accounts for about 0.3% of the human genome.

Gene expression + Signal Transduction

Antiquarian interest in the gold artefacts of prehistory emerged in the British Isles during the Early Modern period. In 1696, the Ashmolean Museum in Oxford, southern England obtained the Ballyshannon Disk, the first such artefact of its type in their collection, although in ensuing centuries they would gain a number of other items to accompany it. The British Museum in London would follow suit almost a century later, gaining its first Bronze Age gold artefact, a disk from Kirk Andrews on the Isle of Man, in 1782.

Metallurgy

Depending on the environment developed in the crevice and the nature of the metal, the crevice corrosion can take a form of: * pitting (i.e., formation of pits), but note pitting and crevice corrosion are not the same phenomenon, * filiform corrosion (this type of crevice corrosion that may occur on a metallic surface underneath an organic coating), * intergranular attack, or, * stress corrosion cracking.

Metallurgy

In base and precious metals flotation, the Jameson Cell has established itself as being particularly useful in several applications in flotation circuits that also use other types of flotation cells, such as mechanical cells. These applications include: * preflotation roughers for removing naturally hydrophobic gangue materials (such as carbon, talc and elemental sulfur), where the Jameson Cell minimises the entrainment of the valuable minerals while eliminating naturally floating gangue minerals that would otherwise contaminate the concentrate * rougher-scalper and roughing duties where selectivity and froth washing produce high-grade concentrate. In this application, the recovery in one Jameson Cell is normally equivalent to several mechanical cells, and where the feed contains fast-floating liberated particles, the Cell can produce final-grade product, thus reducing the number of mechanical cells required in a flotation circuit * cleaner-scalper duties, in which the Jameson Cell recovers fast floating minerals to produce a final-grade concentrate, thus reducing the load on the rest of the cleaning circuit and reducing its size. In this application, it can also be used as a low-cost way of expanding the capacity of an existing cleaner circuit * final cleaning duties where mechanical cleaning circuits are unable to consistently produce final grade concentrate because of entrained gangue, the Jameson Cell with its enhanced selectivity and froth washing, is able to remove the gangue

Metallurgy

As PA is rapidly converted to DAG, it is very short-lived in the cell. This means that it is difficult to measure PA production and therefore to study the role of PA in the cell. However, PLD activity can be measured by the addition of primary alcohols to the cell. PLD then carries out a transphosphatidylation reaction, instead of hydrolysis, producing phosphatidyl alcohols in place of PA. The phosphatidyl alcohols are metabolic dead-ends, and can be readily extracted and measured. Thus PLD activity and PA production (if not PA itself) can be measured, and, by blocking the formation of PA, the involvement of PA in cellular processes can be inferred.

Gene expression + Signal Transduction

Nahal Mishmar (Hebrew:נחל משמר) or Wadi Mahras (Arabic:مَحْرَس) is a small seasonal stream in the Judean Desert in Israel. A hoard of rare Chalcolithic artifacts (the Nahal Mishmar hoard) was discovered in a cave near the stream bed which was dubbed the "Treasure Cave".

Metallurgy

After getting out of the promoter region, the RNAP moves into the elongation state, where it keeps growing the new RNA strand in a processive process. Double stranded DNA that enters from the front of the enzyme is unzipped to avail the template strand for RNA synthesis. For every DNA base pair separated by the advancing polymerase, one hybrid RNA:DNA base pair is immediately formed. DNA strands and nascent RNA chain exit from separate channels; the two DNA strands reunite at the trailing end of the transcription bubble while the single strand RNA emerges alone. A number of elongation factors help with the rate and processivity of the RNAP. Factors of the Spt4/Spt5 family (bacterial homolog of Spt5 is called NusG) stimulate transcription by binding to the RNAP clamp on one side of the DNA channel and to the gate loop on the other. The resultant DSIF locks the clamp into a closed state to prevent the elongation complex (EC) from dissociating. Spt5 also has a NGN domain that helps the two strands separate. A KOW domain probably hooks the RNAP up to a ribosome so that translation and transcription happen together. Some archaea have an Elf1 homolog that might also act as an elongation factor.

Gene expression + Signal Transduction

The gene for the LHCGR is found on chromosome 2 p21 in humans, close to the FSH receptor gene. It consists of 70 kbp (versus 54 kpb for the FSHR). The gene is similar to the gene for the FSH receptor and the TSH receptor.

Gene expression + Signal Transduction

The shutter is fitted to the dimensions of the masonry opening. The pintle is embedded or surface mounted to the structure itself. The pintle pin is positioned on the outside corner of the masonry. This approach can be seen on brick structures, especially post-civil war commercial multi-story buildings. Also common in the south of Europe, France, Italy, and Austria, it allows the shutter to sit almost fully parallel to the structure. The European structures are typically stucco coated, with a drive type pintle built diagonally into the masonry prior to stucco finish. A lag screw pintle can be substituted for the drive pintle. Brick structures can employ a similar embedded pintle, or a surface mounted pintle. Storm type strap hinges are typically in Europe. American examples are often tapered.

Metallurgy

Potassium ethyl xanthate is used in the mining industry as flotation agent for extraction of the ores of copper, nickel, and silver. The method exploits the affinity of these "soft" metals for the organosulfur ligand. Potassium xanthate is a useful reagent for preparing xanthate esters from alkyl and aryl halides. The resulting xanthate esters are useful intermediates in organic synthesis.

Metallurgy

Distribution of stop codons within the genome of an organism is non-random and can correlate with GC-content. For example, the E. coli K-12 genome contains 2705 TAA (63%), 1257 TGA (29%), and 326 TAG (8%) stop codons (GC content 50.8%). Also the substrates for the stop codons release factor 1 or release factor 2 are strongly correlated to the abundance of stop codons. Large scale study of bacteria with a broad range of GC-contents shows that while the frequency of occurrence of TAA is negatively correlated to the GC-content and the frequency of occurrence of TGA is positively correlated to the GC-content, the frequency of occurrence of the TAG stop codon, which is often the minimally used stop codon in a genome, is not influenced by the GC-content.

Gene expression + Signal Transduction

The compound with empirical formula FeSn is the first known kagome magnet. It is an intermetallic compound composed of iron (Fe) and tin (Sn), with alternating planes of FeSn and Sn.

Metallurgy

Most materials shrink as they solidify, but, as the adjacent table shows, a few materials do not, such as gray cast iron. For the materials that do shrink upon solidification the type of shrinkage depends on how wide the freezing range is for the material. For materials with a narrow freezing range, less than , a cavity, known as a pipe, forms in the center of the casting, because the outer shell freezes first and progressively solidifies to the center. Pure and eutectic metals usually have narrow solidification ranges. These materials tend to form a skin in open air molds, therefore they are known as skin forming alloys. For materials with a wide freezing range, greater than , much more of the casting occupies the mushy or slushy zone (the temperature range between the solidus and the liquidus), which leads to small pockets of liquid trapped throughout and ultimately porosity. These castings tend to have poor ductility, toughness, and fatigue resistance. Moreover, for these types of materials to be fluid-tight, a secondary operation is required to impregnate the casting with a lower melting point metal or resin. For the materials that have narrow solidification ranges, pipes can be overcome by designing the casting to promote directional solidification, which means the casting freezes first at the point farthest from the gate, then progressively solidifies toward the gate. This allows a continuous feed of liquid material to be present at the point of solidification to compensate for the shrinkage. Note that there is still a shrinkage void where the final material solidifies, but if designed properly, this will be in the gating system or riser.

Metallurgy

The process of mechanical alloying involves the production of a composite powder particles by: # Using a high energy mill to favor plastic deformation required for cold welding and reduce the process times # Using a mixture of elemental and master alloy powders (the latter to reduce the activity of the element, since it is known that the activity in an alloy or a compound could be orders of magnitude less than in a pure metal) # Eliminating the use of surface-active agents which would produce fine pyrophoric powder as well as contaminate the powder # Relying on a constant interplay between welding and fracturing to yield a powder with a refined internal structure, typical of very fine powders normally produced, but having an overall particle size which was relatively coarse, and therefore stable.

Metallurgy

An unspliced form of SFRP1 is the dominant form in the lung and liver, leading to an extended protein. This extended sequence contains a hydrophobic region that may act as a transmembrane anchor, modifying the localization of the protein. This may then influence the function of SFRP1 in different tissues because an untethered protein may be more effective in antagonizing Wnt signaling to tumor cells than would a membrane-bound form.

Gene expression + Signal Transduction

The definition of a coil coating process according to EN 10169:2010 is a ‘process in which an (organic) coating material is applied on rolled metal strip in a continuous process which includes cleaning, if necessary, and chemical pre-treatment of the metal surface and either one-side or two-side, single or multiple application of (liquid) paints or coating powders which are subsequently cured or/and laminating with permanent plastic films’. The metal substrate (steel or aluminum) is delivered in coil form from the rolling mills. Coil weights vary from 5-6 tons for aluminum and up to about 25 tons for steel. The coil is positioned at the beginning of the line, then unwound at a constant speed, passing through the various pre-treatment and coating processes before being recoiled. Two strip accumulators at the beginning and the end of the line enable the work to be continuous, allowing new coils to be added (and finished coils removed) by a metal stitching process without slowing down or stopping the line.

Metallurgy

GABA degradation pathways exists in almost all eukaryotic organisms and takes place by the action of similar enzymes. Although, GABA in E.coli is predominantly used as an alternative source of energy through GABA degradation pathways, GABA in higher eukaryotic organisms acts as an inhibitory neurotransmitter and also as regulator of muscle tone. GABA degradation pathways in eukaryotes are responsible for the inactivation of GABA.

Gene expression + Signal Transduction

The Takehara copper refinery of the Mitsui Mining & Smelting Company Limited of Japan commissioned a BBOC in its precious metals department in 1993. Prior to the installation of the BBOC, the Takehara refinery refined a mixture of copper and lead anode slimes in a three reverberatory furnaces (two operating and one being rebricked) in a process that had a cycle time of 104 hours for refining 6 t of bullion. The reverberatory furnaces were replaced with a single BBOC with a charge capacity of 6 t of feed. The cycle time was reduced to 50 hours. The use of the BBOC reduced the energy consumption from 74 GJ/t to 27 GJ/t and also had better bismuth elimination than the reverberatory furnaces.

Metallurgy

Ephaptic coupling is a form of communication within the nervous system and is distinct from direct communication systems like electrical synapses and chemical synapses. The phrase may refer to the coupling of adjacent (touching) nerve fibers caused by the exchange of ions between the cells, or it may refer to coupling of nerve fibers as a result of local electric fields. In either case ephaptic coupling can influence the synchronization and timing of action potential firing in neurons. Research suggests that myelination may inhibit ephaptic interactions.

Gene expression + Signal Transduction

Genuine alternative splicing occurs in both protein-coding genes and non-coding genes to produce multiple products (proteins or non-coding RNAs). External information is needed in order to decide which product is made, given a DNA sequence and the initial transcript. Since the methods of regulation are inherited, this provides novel ways for mutations to affect gene expression. Alternative splicing may provide evolutionary flexibility. A single point mutation may cause a given exon to be occasionally excluded or included from a transcript during splicing, allowing production of a new protein isoform without loss of the original protein. Studies have identified intrinsically disordered regions (see Intrinsically unstructured proteins) as enriched in the non-constitutive exons suggesting that protein isoforms may display functional diversity due to the alteration of functional modules within these regions. Such functional diversity achieved by isoforms is reflected by their expression patterns and can be predicted by machine learning approaches. Comparative studies indicate that alternative splicing preceded multicellularity in evolution, and suggest that this mechanism might have been co-opted to assist in the development of multicellular organisms. Research based on the Human Genome Project and other genome sequencing has shown that humans have only about 30% more genes than the roundworm Caenorhabditis elegans, and only about twice as many as the fly Drosophila melanogaster. This finding led to speculation that the perceived greater complexity of humans, or vertebrates generally, might be due to higher rates of alternative splicing in humans than are found in invertebrates. However, a study on samples of 100,000 expressed sequence tags (EST) each from human, mouse, rat, cow, fly (D. melanogaster), worm (C. elegans), and the plant Arabidopsis thaliana found no large differences in frequency of alternatively spliced genes among humans and any of the other animals tested. Another study, however, proposed that these results were an artifact of the different numbers of ESTs available for the various organisms. When they compared alternative splicing frequencies in random subsets of genes from each organism, the authors concluded that vertebrates do have higher rates of alternative splicing than invertebrates.

Gene expression + Signal Transduction

When a neurotransmitter is released at a synapse, it reaches its highest concentration inside the narrow space of the synaptic cleft, but some of it is certain to diffuse away before being reabsorbed or broken down. If it diffuses away, it has the potential to activate receptors that are located either at other synapses or on the membrane away from any synapse. The extrasynaptic activity of a neurotransmitter is known as volume transmission. It is well established that such effects occur to some degree, but their functional importance has long been a matter of controversy. Recent work indicates that volume transmission may be the predominant mode of interaction for some special types of neurons. In the mammalian cerebral cortex, a class of neurons called neurogliaform cells can inhibit other nearby cortical neurons by releasing the neurotransmitter GABA into the extracellular space. Along the same vein, GABA released from neurogliaform cells into the extracellular space also acts on surrounding astrocytes, assigning a role for volume transmission in the control of ionic and neurotransmitter homeostasis. Approximately 78% of neurogliaform cell boutons do not form classical synapses. This may be the first definitive example of neurons communicating chemically where classical synapses are not present.

Gene expression + Signal Transduction

The non-pathogenic and gram-negative bacteria, Pseudomonas fluorescens, is used for high level production of recombinant proteins; commonly for the development bio-therapeutics and vaccines. P. fluorescens is a metabolically versatile organism, allowing for high throughput screening and rapid development of complex proteins. P. fluorescens is most well known for its ability to rapid and successfully produce high titers of active, soluble protein.

Gene expression + Signal Transduction

In 1783, Carl Wilhelm Scheele discovered that gold dissolved in aqueous solutions of cyanide. Through the work of Bagration (1844), Elsner (1846), and Faraday (1847), it was determined that each atom of gold required two cyanide ions, i.e. the stoichiometry of the soluble compound.

Metallurgy

* Advantages ** By using uniform droplets to deliver therapeutic payloads to specific locations in the body, researchers can achieve greater precision and control over drug delivery while also minimizing toxicity and harmful side effects. For example, these droplets can be quickly loaded during the polymerization process and can be varied in porosity to control the time it takes to release a drug. Microdroplets-based drug delivery also has a significant advantage over traditional systems in that they can minimize side effects, reduce the need for invasive procedures, and even improve a drug's efficacy. Overall, microdroplet-based drug delivery systems show great promise for revolutionizing medicine with significant potential for targeted drug delivery. * Limitations ** Nevertheless, it is essential to note some common challenges associated with microdroplet-based drug delivery systems, including their biocompatibility, toxicity, and scalability. The biocompatibility and toxicity of Microdroplets are essential to consider because these can affect a drug's safety and overall efficacy, causing unwanted side effects and possibly death. On the other hand, scalability is another crucial challenge to consider because this aspect can lead to increased manufacturing costs, problems with quality control, and limitations in equipment used. All in all, even with great promise to revolutionize targeted drug delivery, researchers must keep in mind the biocompatibility, toxicity, and scalability of microdroplet-based drug delivery systems when using them.

Gene expression + Signal Transduction

There are certain advantages of using sinters as opposed to using other materials which include recycling the fines and other waste products, to include flue dust, mill scale, lime dust and sludge. Processing sinter helps eliminate raw flux, which is a binding material used to agglomerate materials, which saves the heating material, coke, and improves furnace productivity. Improvements and efficiency can be gained from higher softening temperature and narrower softening in the melting zone, which increases the volume of the granular zone and shrinks the width of the cohesive zone. A lower silica content and higher hot metal temperature contributes to more sulphur removal.

Metallurgy

hnRNP serves a variety of processes in the cell, some of which include: # Preventing the folding of pre-mRNA into secondary structures that may inhibit its interactions with other proteins. # Possible association with the splicing apparatus. # Transport of mRNA out of the nucleus. The association of a pre-mRNA molecule with a hnRNP particle prevents formation of short secondary structures dependent on base pairing of complementary regions, thereby making the pre-mRNA accessible for interactions with other proteins.

Gene expression + Signal Transduction

Signal peptides are not to be confused with the leader peptides sometimes encoded by leader mRNA, although both are sometimes ambiguously referred to as "leader peptides." These other leader peptides are short polypeptides that do not function in protein localization, but instead may regulate transcription or translation of the main protein, and are not part of the final protein sequence. This type of leader peptide primarily refers to a form of gene regulation found in bacteria, although a similar mechanism is used to regulate eukaryotic genes, which is referred to as uORFs (upstream open reading frames).

Gene expression + Signal Transduction

Also in 1989, Peko Mines, then a division of North Broken Hill Peko Limited, also engaged Jameson to undertake test work in its Warrego concentrator near Tennant Creek in Australias Northern Territory. The objective was to determine the Jameson Cells performance in cleaning copper concentrate to improve its grade by removing gangue minerals, including pyrite, magnetite, hematite and quartz. Peko Mines personnel also tested a conventional flotation column for comparison. Following the test work, Peko Mines installed two full-scale, 1.4 m diameter Jameson Cells in the concentrator, each with three downcomers. Peko Mines' decision was based on: * metallurgical performance during pilot plant test work * lower capital expenditure and installation costs * shorter construction and installation times * ease of operation and lower expected maintenance costs. Peko Mines reported a payback on the investment in the Cells of two months.

Metallurgy

All STAT molecules are phosphorylated by receptor associated kinases, that causes activation, dimerization by forming homo- or heterodimers and finally translocate to nucleus to work as transcription factors. Specifically STAT1 can be activated by several ligands such as Interferon alpha (IFNα), Interferon gamma (IFNγ), Epidermal Growth Factor (EGF), Platelet Derived Growth Factor (PDGF), Interleukin 6 (IL-6), or IL-27. Type I interferons (IFN-α, IFN-ß) bind to receptors, cause signaling via kinases, phosphorylate and activate the Jak kinases TYK2 and JAK1 and also STAT1 and STAT2. STAT molecules form dimers and bind to ISGF3G/IRF-9, which is Interferon stimulated gene factor 3 complex with Interferon regulatory Factor 9. This allows STAT1 to enter the nucleus. STAT1 has a key role in many gene expressions that cause survival of the cell, viability or pathogen response. There are two possible transcripts (due to alternative splicing) that encode 2 isoforms of STAT1. STAT1α, the full-length version of the protein, is the main active isoform, responsible for most of the known functions of STAT1. STAT1ß, which lacks a portion of the C-terminus of the protein, is less-studied, but has variously been reported to negatively regulate activation of STAT1 or to mediate IFN-γ-dependent anti-tumor and anti-infection activities. STAT1 is involved in upregulating genes due to a signal by either type I, type II, or type III interferons. In response to IFN-γ stimulation, STAT1 forms homodimers or heterodimers with STAT3 that bind to the GAS (Interferon-Gamma-Activated Sequence) promoter element; in response to either IFN-α or IFN-β stimulation, STAT1 forms a heterodimer with STAT2 that can bind the ISRE (Interferon-Stimulated Response Element) promoter element. In either case, binding of the promoter element leads to an increased expression of ISG (Interferon-Stimulated Genes). Expression of STAT1 can be induced with diallyl disulfide, a compound in garlic.

Gene expression + Signal Transduction

This type of equipment has an eccentric drive or weights that causes the shaker to travel in an orbital path. The material rolls over the screen and falls with the induction of gravity and directional shifts. Rubber balls and trays provide an additional mechanical means to cause the material to fall through. The balls also provide a throwing action for the material to find an open slot to fall through. The shaker is set a shallow angle relative to the horizontal level plane. Usually, no more than 2 to 5 degrees relative to the horizontal level plane. These types of shakers are used for very clean cuts. Generally, a final material cut will not contain any oversize or any fines contamination. These shakers are designed for the highest attainable quality at the cost of a reduced feed rate.

Metallurgy

In the finery, a workman known as the "finer" remelted pig iron so as to oxidise the carbon (and silicon). This produced a lump of iron (with some slag) known as a bloom. This was consolidated using a water-powered hammer (see trip hammer) and returned to the finery. The next stages were undertaken by the "hammerman", who in some iron-making areas such as South Yorkshire was also known as the "stringsmith", who heated his iron in a string-furnace. Because the bloom is highly porous, and its open spaces are full of slag, the hammermans or stringsmiths tasks were to beat (work) the heated bloom with a hammer to drive the molten slag out of it, and then to draw the product out into a bar to produce what was known as anconies or bar iron. In order to do this, he had to reheat the iron, for which he used the chafery. The fuel used in the finery had to be charcoal (later coke), as impurities in any mineral fuel would affect the quality of the iron.

Metallurgy

Mouza Sulaiman Mohamed Al-Wardi (Arabic: موزة سليمان محمد الوردي) is a curator and historian from Oman, who is Director of the Collections Department at the National Museum. She specialises in the history of silverworking in the Oman region.

Metallurgy

In molecular biology, the single-domain protein SUI1 is a translation initiation factor often found in the fungus, Saccharomyces cerevisiae (Bakers yeast) but it is also found in other eukaryotes and prokaryotes as well as archaea. It is otherwise known as Eukaryotic translation initiation factor 1 (eIF1) in eukaryotes or YciH' in bacteria.

Gene expression + Signal Transduction

Archaea have a preinitiation complex resembling that of a minimized Pol II PIC, with a TBP and an Archaeal transcription factor B (TFB, a TFIIB homolog). The assembly follows a similar sequence, starting with TBP binding to the promoter. An interesting aspect is that the entire complex is bound in an inverse orientation compared to those found in eukaryotic PIC. They also use TFE, a TFIIE homolog, which assists in transcription initiation but is not required.

Gene expression + Signal Transduction

Example phases are: *β-MgAl: 1168 atoms per unit cell, face-centred cubic, atoms arranged in Friauf polyhedra. *ξ'–AlPdMn: 318 atoms per unit cell, face-centred orthorhombic, atoms arranged in Mackay-type clusters. * (Bergman phase): 163 atoms per unit cell, body centred cubic, atoms arranged in Bergman clusters. * (Taylor phase): 204 atoms per unit cell, face-centred orthorhombic, atoms arranged in Mackay-type clusters.

Metallurgy

The Falcon Ultra-Fine (UF) centrifugal concentrator is primarily used for the separation of heavy minerals which occur in ore concentrations above 0.1% by weight, such as cassiterite, tantalum and scheelite when the majority of the particles are smaller than 75 µm. The machine generates forces up to 600 times the force of gravity (600 G's) and uses a smooth-walled bowl for particle stratification with a pneumatically controlled rubber lip for heavy material collection. The machine is stopped periodically to rinse and collect the valuable concentrate from the bowl. Studies have found that the deposition of heavy material within the bowl can be predicted by a hindered settling model. The Falcon UF concentrator is used in a number of process plants around the world such as the Tanco mine in Canada and the Bluestone tin mine in Tasmania.

Metallurgy

While arsenic was most likely originally mixed with copper as a result of the ores already containing it, its use probably continued for a number of reasons. First, it acts as a deoxidizer, reacting with oxygen in the hot metal to form arsenous oxides which vaporize from the liquid metal. If a great deal of oxygen is dissolved in liquid copper, when the metal cools the copper oxide separates out at grain boundaries, and greatly reduces the ductility of the resulting object. However, its use can lead to a greater risk of porous castings, owing to the solution of hydrogen in the molten metal and its subsequent loss as a bubble (although any bubbles could be forge-welded and still leave the mass of the metal ready to be work-hardened). Second, the alloy is capable of greater work-hardening than is the case with pure copper, so that it performs better when used for cutting or chopping. An increase in work-hardening capability arises with an increasing percentage of arsenic, and the bronze can be work-hardened over a wide range of temperatures without fear of embrittlement. Its improved properties over pure copper can be seen with as little as 0.5 to 2 wt% As, giving a 10-to-30% improvement in hardness and tensile strength. Third, in the correct percentages, it can contribute a silvery sheen to the article being manufactured. There is evidence of arsenical bronze daggers from the Caucasus and other artifacts from different locations having an arsenic-rich surface layer which may well have been produced deliberately by ancient craftsmen, and Mexican bells were made of copper with sufficient arsenic to color them silver.

Metallurgy

The first step in the investigation of archaeometallurgical slag is the identification and macro-analysis of slag in the field. Physical properties of slag such as shape, colour, porosity and even smell are used to make a primary classification to ensure representative samples from slag heaps are obtained for future micro-analysis. For example, tap slag usually has a wrinkled upper face and a flat lower face due to contact with soil. Furthermore, the macro-analysis of slag heaps can prove an estimated total weight which in turn can be used to determine the scale of production at a particular smelting location.

Metallurgy

* In the manga and anime series JoJos Bizarre Adventure, the Diamond is Unbreakable and Golden Wind' story arcs prominently feature a set of six arrows which are made out of meteoric iron sourced from the Cape York meteorite.

Metallurgy

Small impurity interstitial atoms are usually on true interstitial sites between the lattice atoms. Large impurity interstitials can also be in split interstitial configurations together with a lattice atom, similar to those of the self-interstitial atom.

Metallurgy

Knowles began his career in 1991 with a research fellowship at St Catharines College, Cambridge, before moving to New Zealand to work as a research and consultancy metallurgist for Industrial Research Ltd between 1993 and 1995. He then returned to the University of Cambridge in 1995 to take up a post as lecturer in Mechanical Properties of Materials, and was also appointed assistant director of Research of the Rolls-Royce University Technology Centre. His research at that time focussed on fatigue and creep in nickel based superalloys including high stress low' temperature creep anisotropy in single crystals. In 2001 Knowles returned to New Zealand to take up the role of CTO at MPT Solutions, where he continued to publish academic papers with a developing interest in crystal plasticity. In 2006 he was appointed Global Research Leader for Materials at Shell Global Solutions, based in Amsterdam looking into materials for LNG and gas to liquid technologies. In 2010, he moved to Atkins as their materials authority in the energy sector, focussing on offshore wind turbine foundations and nuclear Advanced Gas Reactors. In 2016 he took up a post at the University of Bristol as Professor of Nuclear Engineering, and co-director of the South West Nuclear Hub. Knowles was named Chief Executive of the Henry Royce Institute for advanced materials research in 2019. He has continued his research as the principal investigator on the Sindri prosperity partnership EPSRC project, working with a number of university partners alongside EDF and UKAEA, which is focussed on characterising and modelling the meso to macro scale mechanics of alloys. In particular, he is interested in researching the use of data-centric methods to interrogate and describe material mechanical behaviour which can then be used to predict the condition of components of nuclear power plants.

Metallurgy

Currently, there are two main types of silencers in DNA, which are the classical silencer element and the non-classical negative regulatory element (NRE). In classical silencers, the gene is actively repressed by the silencer element, mostly by interfering with general transcription factor (GTF) assembly. NREs passively repress the gene, usually by inhibiting other elements that are upstream of the gene. Of the NREs, there are certain silencers that are orientation-dependent meaning that the binding factor binds in a particular direction relative to other sequences. Promoter-dependent silencers are understood to be silencer elements because they are position and orientation-dependent but must also use a promoter-specific factor. There has been a recent discovery of Polycomb-group Response Elements (PREs), which can allow and inhibit repression depending on the protein bound to it, and the presence of non-coding transcription.

Gene expression + Signal Transduction

Some of the best-known examples of quorum sensing come from studies of bacteria. Bacteria use quorum sensing to regulate certain phenotype expressions, which in turn, coordinate their behavio rs. Some common phenotypes include biofilm formation, virulence factor expression, and motility. Certain bacteria are able to use quorum sensing to regulate bioluminescence, nitrogen fixation and sporulation. The quorum-sensing function is based on the local density of the bacterial population in the immediate environment. It can occur within a single bacterial species, as well as between diverse species. Both gram-positive and gram-negative bacteria use quorum sensing, but there are some major differences in their mechanisms.

Gene expression + Signal Transduction

Niobium anodizes in a similar fashion to titanium with a range of attractive colors being formed by interference at different film thicknesses. Again the film thickness is dependent on the anodizing voltage. Uses include jewelry and commemorative coins.

Metallurgy

The Swedish Lancashire hearth consisted of a rectangular closed furnace with a chimney (8 metres high) at one end and a working arch in front of the hearth proper at the other. Pig iron was charged through a door at the foot of the chimney and stacked on an iron-clad bridge so that it could be heated by the waste gases from the hearth. The hearth was blown through a single water-cooled tuyere with pre-heated air. The hearth consisted of a rectangular box of iron plates, the bottom plate being water-cooled. Surplus slag was removed with a shovel between finings, but some was left to help the process. Pig stacked on the bridge at the back of the hearth was then pulled forward with a hook and charcoal added. The blast was then turned on and fining began. When the pigs began to melt, rabelling began (as in the Walloon process) using two bars of iron one to stir the iron and the other to lift it back into the blast. Periodically the tuyere had to be cleaned of matter adhering to it with a third bar. Finally, the iron was gathered into a loop which was lifted out of the hearth with a heavier bar and tongs, and taken to the shingling hammer. The process was more fuel-efficient and more productive than its predecessors.

Metallurgy

Sulfuric acid is the most widely used solution to produce an anodized coating. Coatings of moderate thickness 1.8 μm to 25 μm (0.00007" to 0.001") are known as Type II in North America, as named by MIL-A-8625, while coatings thicker than 25 μm (0.001") are known as Type III, hard-coat, hard anodizing, or engineered anodizing. Very thin coatings similar to those produced by chromic anodizing are known as Type IIB. Thick coatings require more process control, and are produced in a refrigerated tank near the freezing point of water with higher voltages than the thinner coatings. Hard anodizing can be made between 13 and 150 μm (0.0005" to 0.006") thick. Anodizing thickness increases wear resistance, corrosion resistance, ability to retain lubricants and PTFE coatings, and electrical and thermal insulation. Sealing Type III will improve corrosion resistance at the cost of reducing abrasion resistance. Sealing will reduce this greatly. Standards for thin (Soft/Standard) sulfuric anodizing are given by MIL-A-8625 Types II and IIB, AMS 2471 (undyed), and AMS 2472 (dyed), BS EN ISO 12373/1 (decorative), BS 3987 (Architectural). Standards for thick sulphuric anodizing are given by MIL-A-8625 Type III, AMS 2469, BS ISO 10074, BS EN 2536 and the obsolete AMS 2468 and DEF STAN 03-26/1.

Metallurgy

Small-scale cupellation is based on the same principle as the one done in a cupellation hearth; the main difference lies in the amount of material to be tested or obtained. The minerals have to be crushed, roasted and smelted to concentrate the metallic components to separate the noble metals. By the Renaissance the use of the cupellation processes was diverse: assay of ores from the mines, testing the amount of silver in jewels or coins or for experimental purposes. It was carried out in small shallow recipients known as cupels. As the main purpose of small-scale cupellation was to assay and test minerals and metals, the matter to be tested must be carefully weighed. The assays were made in the cupellation or assay furnace, which needs to have windows and bellows to ascertain that the air oxidises the lead, as well as to be sure and prepared to take away the cupel when the process is complete. Pure lead must be added to the matter being tested to guarantee the further separation of the impurities. After the litharge has been absorbed by the cupel, buttons of silver were formed and settled in the middle of the cupel. If the alloy also contained a certain amount of gold, it settled with the silver, and both had to be separated by parting.

Metallurgy

In metallurgy, a flux () is a chemical cleaning agent, flowing agent, or purifying agent. Fluxes may have more than one function at a time. They are used in both extractive metallurgy and metal joining. Some of the earliest known fluxes were sodium carbonate, potash, charcoal, coke, borax, lime, lead sulfide and certain minerals containing phosphorus. Iron ore was also used as a flux in the smelting of copper. These agents served various functions, the simplest being a reducing agent, which prevented oxides from forming on the surface of the molten metal, while others absorbed impurities into slag, which could be scraped off molten metal. Fluxes are also used in foundries for removing impurities from molten nonferrous metals such as aluminium, or for adding desirable trace elements such as titanium. As cleaning agents, fluxes facilitate soldering, brazing, and welding by removing oxidation from the metals to be joined. In some applications molten flux also serves as a heat-transfer medium, facilitating heating of the joint by the soldering tool or molten solder.

Metallurgy