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598_10 | Loss of the Na+-dependent glutamate transporter EAAT2 is suspected to be associated with neurodegenerative diseases such as Alzheimer's disease, Huntington's disease, and ALS–parkinsonism dementia complex. Also, degeneration of motor neurons in the disease amyotrophic lateral sclerosis has been linked to loss of EAAT2 from patients' brains and spinal cords. |
598_11 | Addiction to certain addictive drugs (e.g., cocaine, heroin, alcohol, and nicotine) is correlated with a persistent reduction in the expression of EAAT2 in the nucleus accumbens (NAcc); the reduced expression of EAAT2 in this region is implicated in addictive drug-seeking behavior. In particular, the long-term dysregulation of glutamate neurotransmission in the NAcc of addicts is associated with an increase in vulnerability to relapse after re-exposure to the addictive drug or its associated drug cues. Drugs which help to normalize the expression of EAAT2 in this region, such as N-acetylcysteine, have been proposed as an adjunct therapy for the treatment of addiction to cocaine, nicotine, alcohol, and other drugs.
See also
Dopamine transporters
Norepinephrine transporters
Serotonin transporters
NMDA receptors
AMPA receptors
Kainate receptors
Metabotropic glutamate receptors
References
External links |
598_12 | Amphetamine
Membrane proteins
Neurotransmitter transporters
Solute carrier family
Glutamate (neurotransmitter) |
599_0 | Pang Xun (龐勛) (died October 14, 869) was the leader of a major rebellion, by soldiers from Xu Prefecture (徐州, in modern Xuzhou, Jiangsu), against the rule of Emperor Yizong of the Chinese dynasty Tang Dynasty, from 868 to 869. He was eventually defeated by the Tang general Kang Chengxun, who was assisted by the Shatuo general Zhuye Chixin.
Background of the Xu Prefecture soldiers
It is not known when Pang Xun was born, and little is known about his background other than that he was from Xu Prefecture and that his father Pang Juzhi () was still alive at the time of his eventual rebellion. |
599_1 | Xu Prefecture had a long-standing military tradition in the middle-to-late Tang Dynasty, and had long been the capital of Wuning Circuit (), which was created to control and cut off the communications between the then-rebellious Pinglu (平盧, then-headquartered in modern Tai'an, Shandong) and Zhangyi (彰義, headquartered in modern Zhumadian, Henan) Circuits. However, the soldiers from Xu Prefecture, particularly since the time of the military governor Wang Zhixing, had become arrogant and lax in discipline, such that there were frequent mutinies against military governors (Jiedushi) that the imperial government sent to govern Wuning. For the imperial government, the last straw apparently came in 862, when the soldiers of the Yindao (銀刀, "silver sword") corps mutinied and expelled the imperially-commissioned military governor Wen Zhang (). The imperial government commissioned the general Wang Shi as Wen's replacement. Wang, once he arrived at Xu Prefecture, had the soldiers that he |
599_2 | brought from Zhongwu (忠武, headquartered in modern Xuchang, Henan) and Yicheng (義成, headquartered in modern Anyang, Henan) Circuits slaughter the Yindao soldiers, killing several thousands. Then-reigning Emperor Yizong then issued an edict rebuking the people of and disbanding Wuning Circuit. Xu Prefecture was put under the jurisdiction of Yanhai Circuit (兗海, headquartered in modern Jining, Shandong); of Wuning's other prefectures, Hao Prefecture (濠州, in modern Chuzhou, Anhui) was put under the jurisdiction of Huainan Circuit (淮南, headquartered in modern Yangzhou, Jiangsu); and Su (宿州, in modern Suzhou, Anhui) and Si (泗州, in modern Huai'an, Jiangsu) Prefectures were made into a new Susi Circuit, with its capital at Su Prefecture, but with a lesser status than before—not having a military governor, but only a governor (觀察使, Guanchashi). |
599_3 | In 863, after a disturbance where bandits intruded into Xu Prefecture and killed a number of officials before the attack was repelled by the prefect Cao Qing (), the headquarters of Susi Circuit was moved back to Xu Prefecture, and thereafter it was known as Xusi Circuit, governing Xu, Hao, Su, and Si Prefectures, thus restoring the prior Wuning territory, but still under the lesser status of governance by a governor, rather than a military governor. |
599_4 | In 864, with the southwestern parts of the Tang empire dealing with frequent Dali attacks, Emperor Yizong issued an edict recounting Xu Prefecture's military tradition and ordering the military prefect (團練使, Tuanlianshi) to recruit 3,000 men from Xu Prefecture to be stationed at Yong Prefecture (邕州, in modern Nanning, Guangxi) to guard against Dali attacks; the edict promised that once the troubles with Dali were over, the soldiers would be allowed to return home. Apparently, however, only 2,000 men were actually recruited, and of those, 800 were sent to Gui Prefecture (桂州, in modern Guilin, Guangxi), with a promise that they would be allowed to return home after three years. Pang was one of these men, and he served as an assistant to the commander, in charge of food supplies. At the end of the three years, the soldiers were hoping to return home, but the governor of Xusi, Cui Yanzeng (), under the advice of his officer Yin Kan (), decided to extend their stay at Gui Prefecture, |
599_5 | because the expenses of recruiting new soldiers were considered too high. When this order reached Gui Prefecture, the Xu Prefecture soldiers were incensed. |
599_6 | Initial uprising and journey back to Xu Prefecture |
599_7 | At that time, the governor of Gui District (桂管, headquartered at Gui Prefecture), Li Cong (), had just left Gui District to take up his new position as governor of Hunan Circuit (湖南, headquartered in modern Changsha, Hunan), and the new governor of Gui had not arrived yet. The Xu Prefecture officers Xu Ji (), Zhao Keli (), Yao Zhou (), and Zhang Xingshi ()—all of whom had previously been bandits but who had submitted to the government after being given officer commissions—took the opportunity to mutiny in fall 867. They killed their commander Wang Zhongfu () and supported Pang as their leader. The mutineers pillaged the armory, seizing weapons, and began their march home; as they went, they pillaged the territory, and the local governments were unable to resist. Emperor Yizong initially sent the high-level eunuch Zhang Jingsi () to Pang and issued a pardon for Pang and his soldiers, permitting them to return to Xu Prefecture; in response, the Xu soldiers stopped their pillaging. When |
599_8 | they reached Hunan Circuit, they turned in their weapons and armor. They then went on ships and headed east on the Yangtze River. Meanwhile, Emperor Yizong also ordered Cui Yanzeng to not cause the mutineers to be alarmed, so Cui issued repeated mildly-worded orders to Pang's soldiers, trying to comfort them. In response, Pang also submitted respectfully-worded reports to Cui. |
599_9 | While the Xu soldiers were en route down the Yangtze, however, they, particularly Xu Ji, considered their situation and concluded that their crimes were even greater than those of the Yindao—and that the only reasons why the imperial government issued a pardon were to prevent them from further pillaging or becoming bandits; they came to believe that they would be slaughtered upon return to Xu. They therefore used their wealth to equip themselves with armor and weapons. When they reached Huainan Circuit, the military governor of Huainan, Linghu Tao, provided them with food, even though Linghu's officer Li Xiang () pointed out that the Xu soldiers would eventually create further disturbances, as Linghu was only interested in preserving the peace for Huainan. Meanwhile, Pang recruited those Yindao soldiers who escaped the massacre and other bandits to add to the numbers of his soldiers. |
599_10 | On October 22, Pang reached Si Prefecture. The prefect Du Tao () invited the soldiers to a feast and put on a play for entertainment. Before the start of the play, the leader of the actors, as was customary, was addressing the guests, when the Xu soldiers believed that he was parodying them, and they seized him and threatened to kill him. However, Du had prepared for this, and after this initial action, nothing else came of this. |
599_11 | On October 23, Pang reached Xucheng (徐城, near Si Prefecture). Pang and Xu Ji announced to the soldiers that it was their belief that once they arrived in Xu, the soldiers would be slaughtered or at least exiled. They announced that their plan was to attack and seize Xu Prefecture and force the imperial government to allow them to keep it. The soldiers largely agreed, and Pang executed 12 people who did not; he sent messengers with the heads of the 12 to report to Cui that those 12 had encouraged a rebellion, and that he was presenting their heads as sign of submission. When Pang's messengers reached Cui, he arrested and interrogated them and found out the truth. Meanwhile, Pang submitted another petition demanding that Cui relieve Yin Kan, as well as two other key officers, Du Zhang (), and Xu Xingjian () of their duties, and further demanding that the returning soldiers be allowed to be stationed separately from the main corps. Cui gathered his officers and discussed how to react |
599_12 | to this; most officers, by this point, realized Pang's intentions and advocated attacking Pang. As a result, Cui had the officer Yuan Mi () lead 3,000 men to attack Pang, and also ordered the Su and Si Prefectures to cut off Pang's paths as well. |
599_13 | News that Yuan was heading toward them soon reached Pang's soldiers. They quickly attacked Su Prefecture and captured it on November 4. They then gathered all of the wealth in the city and announced publicly that anyone could come and take them. Thereafter, the people in the surrounding area all swarmed to Su Prefecture. Pang's soldiers then seized the strong young men among these people and forced them to join their corps, executing anyone who refused. Several thousands were quickly added to their numbers this way. When Yuan arrived on November 6 and attacked, he could not quickly capture Su Prefecture, but the mutineers were also fearful of Yuan. They thus released Zhang Jingsi and abandoned Su on the night of November 6, intending to flee on Bian River. The morning of November 7, Yuan, realizing that the mutineers had fled, gave chase, without giving his soldiers a chance to eat. When they reached the mutineers, the mutineers used the ships that they had as defense and |
599_14 | further utilized the swamp landscape to their advantage, surprising Yuan. Yuan and most of his soldiers were killed, and the survivors surrendered to Pang. The survivors informed Pang that Xu Prefectures had virtually no defenses, and Pang thereafter resolved to attack Xu Prefecture. |
599_15 | On November 8, Pang began a rapid march toward Xu Prefecture. Not until that night did Cui receive news that Yuan's army was annihilated, and he immediately sent urgent requests for reinforcements to the nearby circuits. On November 9, the Xu city gates were closed, and the circuit government rounded up the strong young men in the city to improve the defenses, but the city lacked the will to resist. Cui refused the calls for him to flee to Yanhai's capital Yan Prefecture (), pointing out that it was his responsibility to die in the city. On November 10, Pang's soldiers arrived at Xu and comforted the people in the surrounding area, such that they joined the mutineers in large numbers as well. Within an hour, the outer city fell to the mutineers. Soon thereafter, the inner city fell as well. The mutineers put Cui under arrest and executed Yin, Du Zhang, and Xu Xingjian. It was said that 10,000 men joined the mutineer army that day. |
599_16 | Resistance against imperial forces |
599_17 | Pang Xun took control of the circuit headquarters, took the title of acting military governor (留後, Liuhou), and initially sought imperial commission to formally do so. He tried to get Cui Yanzhen's assistant, in Cui's role as the military prefect, Wen Tinghao (), to draft a petition for him requesting imperial commission, but after Wen refused, his strategist Zhou Chong () drafted a petition that was arrogantly worded, in which he threatened further military action against the imperial government if the imperial government did not commission him. Initially, though, the people in Xusi Circuit and the surrounding areas believed that the imperial government would be willing to commission Pang, and therefore, a large number of people in the surrounding origins, including agrarian rebels, went to Xu Prefecture and joined Xu's forces. Pang also sent his officer Liu Xingji () to Hao Prefecture; Li Yuan () to Si Prefecture; and Liang Pi () to Su Prefecture, to take control of those cities. |
599_18 | Liu and Liang were able to do so, but Du Tao ambushed and resisted Li, and dug in on his defenses, ready to resist Pang. When the eunuch Kang Daowei () arrived to try to placate Pang and his army, Pang made a demonstration of the strength of his force, and submitted another petition through Kang. Meanwhile, though, he attacked a number of neighboring cities, capturing a number of counties. |
599_19 | The imperial government, however, rejected Pang's overtures, as when the imperial edict arrived on December 2, all it declared were the faults of Cui and the eunuch monitor Zhang Daojin () and that they would be demoted. Pang, disappointed, arrested the eunuch delivering the edict. Meanwhile, Emperor Yizong commissioned the imperial guards general Kang Chengxun to be the military governor of Yicheng Circuit, to oversee the operations against Pang, while commissioning two other imperial guard generals, Wang Yanquan () and Dai Keshi (), to command two side armies to the north and south. At Kang's request, he was allowed to enlist the assistance of the Shatuo chieftain Zhuye Chixin, as well as those of the tribal chiefs of Tuyuhun, Tatar, and Qibi () tribes. |
599_20 | Meanwhile, Pang's forces put Si Prefecture under siege, nearly capturing it. Even though Du Shenquan the military governor of Zhenhai Circuit (鎮海, headquartered in modern Zhenjiang, Jiangsu) and Linghu Tao both sent forces to try to lift Si's siege, both circuits' armies (commanded by Zhai Xingyue () and Li Xiang, respectively) were crushed and annihilated by Pang's forces. While Pang's forces were unable to capture Si Prefecture, they were able to capture a number of other prefectures around the region, including Chu (滁洲, in modern Chuzhou) and He (和州, in modern Chaohu, Anhui). Dai tried to recapture Duliang (都梁, in modern Huai'an), where the rebels had crushed Huainan forces, before lifting Si Prefecture's siege. The rebels at Duliang feigned surrender, and then ambushed Dai. Dai's army was also crushed, and Dai was killed. LInghu, concerned that the rebels would attack Huainan next, sent messengers to Pang, offering to request imperial commission for him. Pang therefore |
599_21 | suspended further advancements on Huainan, but continued to siege Si Prefecture. To the north, Wang was also repeatedly defeated by the rebels, and was replaced by Cao Xiang () the military governor of Taining Circuit (泰寧, i.e., the new name for Yanhai). He Quanhao the military governor of Weibo Circuit (魏博, headquartered in modern Handan, Hebei), which had been ruled semi-independently from the imperial government, also sent forces to aid Cao. |
599_22 | By this point, except for their inability to capture Si Prefecture, Pang's forces were still essentially running into no opposition in their campaigns, but in spring 869, Kang began approaching Xu Prefecture with about 70,000 men, and he stationed himself near the rebel stronghold at Liuzi (柳子, in modern Suzhou). Pang, faced with this huge imperial army and the fact that his own soldiers were spread thin on various campaigns, began to be fearful, and by this point the people were no longer joining him in droves. Further, his army's attacks on Hai (海州, in modern Lianyungang, Jiangsu) and Shou (壽州, in modern Lu'an, Anhui) were repelled by forces loyal to the imperial government, at heavy losses. Meanwhile, Zhuye distinguished himself in battle, and when the rebel officer Wang Hongli (), who was instrumental in their victory at Duliang, attacked one of the imperial forces' camps at Lutang (鹿塘, in modern Shangqiu, Henan), Zhuye's Shatuo soldiers struck back, inflicting heavy losses on |
599_23 | Wang. Kang's main forces then attacked Liuzi, and when Yao Zhou tried to relieve Liuzi, Kang defeated him, and when he fled to Su Prefecture, Liang killed him due to their prior personal conflict. |
599_24 | Declaration of independence |
599_25 | Hearing news of Liuzi's fall and Yao Zhou's death, Pang Xun, in fear, considered gathering all remaining troops for a decisive battle with Kang Chengxun. Zhou Chong suggested that, in order to make it clear the decisiveness of the confrontation, that he formally declare independence from the Tang regime. At the advice of Zhou and the sorcerer Cao Junzhang (), on May 19, 869, Pang executed Cui Yanzeng, Zhang Daojin, and a number of Cui's aides. He also cut off the limbs of Li Xiang and the Huainan eunuch monitor Guo Houben (), who was captured with Li Xiang, and delivered the limbs to Kang's camp to show resolve. Pang issued a declaration stating that while he did not originally want to rebel against the Tang emperor, he was doing so at this point. A further conscription drive of the men of Xu Prefecture was carried out, gathering some 30,000 men. Xu Ji and the others offered the titles of General Tiance () and "Brilliance Prince of the Congregation" () to Pang, although Pang |
599_26 | only accepted the General Tiance title at that time. |
599_27 | Pang, leaving Xu and his father Pang Juzhi in charge at Xu Prefecture, departed Xu Prefecture on May 23, first attacking the Weibo troops, which had been attacking the rebel-controlled Feng County, Jiangsu, catching Weibo forces by surprise. He crushed the Weibo forces, and Taining forces, hearing of Weibo forces' defeat, also withdrew. Pang gathered the food that the Weibo and Taining forces left, and then prepared for a major attack on Kang's main forces. He departed Feng on June 3, and called on the other rebel forces in the vicinity to join him for an attack on Kang at Liuzi on June 12. However, some Huainan soldiers whom he had captured escaped and informed Kang of Pang's plans. When the rebels from Xiangcheng (襄城, in modern Xuchang, Henan) arrived first, Kang defeated them, and when Pang subsequently arrived, Pang's own forces collapsed without an engagement, and Kang's forces subsequently routed them. Pang fled back to Xu Prefecture. Meanwhile, Ma Ju (), who had recently |
599_28 | replaced Linghu Tao as the military governor of Huainan, attacked the rebels sieging Si Prefecture, crushing them and lifting the siege on Si. The rebels previously sieging Si Prefecture, under Wu Jiong (), withdrew to Hao Prefecture, and Ma put it under siege. |
599_29 | Meanwhile, Kang advanced on Su Prefecture, which was then defended by the rebel officers Zhang Xuanren (), Zhang Ru (), and Zhang Shi (), and put it under siege. He could not capture it quickly, however, and Zhang Shi sent a petition to Pang, suggesting that Pang should make a surprise attack on Song (宋州, in modern Shangqiu) and Bo (亳州, in modern Bozhou, Anhui) Prefectures, so that Kang would lift the siege on Su Prefecture. Kang, who had been concerned that Cao Xiang had since captured Feng County and was approaching Xu Prefecture, agreed. |
599_30 | Death |
599_31 | Unknown to Pang Xun, Zhang Xuanren had not joined him willingly, and soon, after persuading his direct subordinates to join him, made overtures to Kang Chengxun, offering to surrender Su Prefecture to Kang. On October 11, while Zhang Ru and Zhang Shi were drinking together, Zhang Xuanren had them surrounded, proclaimed that Pang had already died, and ordered that Zhang Ru and Zhang Shi be killed. The soldiers rushed in and killed Zhang Ru and Zhang Shi. Zhang Xuanren took over sole control of the city, and the next day opened the city gates and surrendered it to Kang. Kang immediately commissioned him as an imperial officer. Subsequently, under Zhang Xuanren's suggestion, Zhang Xuanren took 30,000 of his own soldiers, along with 500 imperial army soldiers, pretended to be leading a rebel army that was fleeing Su Prefecture after the imperial forces had captured it and headed for the rebel base at Fuli (), near Su Prefecture. When Fuli welcomed him, he killed the rebel commanders |
599_32 | there and took it over, and then headed toward Xu Prefecture, preparing to use the same tactics to capture it. When he reached it, however, Pang Juzhi and Xu Ji had already received the news, and therefore put up defenses. |
599_33 | On October 15, Zhang reached Xu Prefecture and surrounded it, but did not immediately attack it; rather, he announced to the defenders that the imperial government would not punish anyone who surrendered. The rebel soldiers began to surrender in droves. Pang Juzhi and Xu initially withdrew within into the inner city, but finding their own soldiers' morale failing, tried to fight out of the encirclement. Zhang intercepted and killed them. Several thousands of the rebels' family members were killed, and the imperial forces soon controlled the city. |
599_34 | Meanwhile, Kang pursued Pang, who had made a surprise attack on Song Prefecture, capturing the southern city, but with Song's prefect Zheng Chuchong () defending the northern city, Pang abandoned further attempts to capture it and continued to head west, toward Bo Prefecture. By this point, though, the Shatuo forces under Zhuye Chixin had already arrived. Pang tried to head toward back to Xu Prefecture, but when he reached Qi County (蘄縣, in modern Suzhou), the local militia leader Zhang Gun () lifted the floating bridge to stop him from crossing the Huan River (). The imperial forces then attacked and killed a large number of rebel soldiers, with the rest throwing themselves into the river and largely drowning. Pang died in the battle as well. Wu Jiong, for some time, held out at Hao Prefecture, but Hao Prefecture fell after another month, ending the rebellion. |
599_35 | In fiction
Pang Xun is a character in the 1972 Hong Kong martial arts film Trilogy of Swordsmanship where he was portrayed by Lo Lieh.
Notes and references
New Book of Tang, vol. 148.
Zizhi Tongjian, vol. 251.
9th-century births
869 deaths
Chinese military personnel killed in action
People from Xuzhou
Tang dynasty rebels |
600_0 | Precession electron diffraction (PED) is a specialized method to collect electron diffraction patterns in a transmission electron microscope (TEM). By rotating (precessing) a tilted incident electron beam around the central axis of the microscope, a PED pattern is formed by integration over a collection of diffraction conditions. This produces a quasi-kinematical diffraction pattern that is more suitable as input into direct methods algorithms to determine the crystal structure of the sample.
Overview |
600_1 | Geometry
Precession electron diffraction is accomplished utilizing the standard instrument configuration of a modern TEM. The animation illustrates the geometry used to generate a PED pattern. Specifically, the beam tilt coils located pre-specimen are used to tilt the electron beam off of the optic axis so it is incident with the specimen at an angle, φ. The image shift coils post-specimen are then used to tilt the diffracted beams back in a complementary manner such that the direct beam falls in the center of the diffraction pattern. Finally, the beam is precessed around the optic axis while the diffraction pattern is collected over multiple revolutions. |
600_2 | The result of this process is a diffraction pattern that consists of a summation or integration over the patterns generated during precession. While the geometry of this pattern matches the pattern associated with a normally incident beam, the intensities of the various reflections approximate those of the kinematical pattern much more closely. At any moment in time during precession, the diffraction pattern consists of a Laue circle with a radius equal to the precession angle, φ. It is crucial to note that these snapshots contain far fewer strongly excited reflections than a normal zone axis pattern and extend farther into reciprocal space. Thus, the composite pattern will display far less dynamical character, and will be well suited for use as input into direct methods calculations.
Advantages
PED possesses many advantageous attributes that make it well suited to investigating crystal structures via direct methods approaches: |
600_3 | Quasi-kinematical diffraction patterns: While the underlying physics of the electron diffraction is still dynamical in nature, the conditions used to collect PED patterns minimize many of these effects. The scan/de-scan procedure reduces ion channeling because the pattern is generated off of the zone axis. Integration via precession of the beam minimizes the effect of non-systematic inelastic scattering, such as Kikuchi lines. Few reflections are strongly excited at any moment during precession, and those that are excited are generally much closer to a two-beam condition (dynamically coupled only to the forward-scattered beam). Furthermore, for large precession angles, the radius of the excited Laue circle becomes quite large. These contributions combine such that the overall integrated diffraction pattern resembles the kinematical pattern much more closely than a single zone axis pattern. |
600_4 | Broader range of measured reflections: The Laue circle (see Ewald sphere) that is excited at any given moment during precession extends farther into reciprocal space. After integration over multiple precessions, many more reflections in the zeroeth order Laue zone (ZOLZ) are present, and as stated previously, their relative intensities are much more kinematical. This provides considerably more information to input into direct methods calculations, improving the accuracy of phase determination algorithms. Similarly, more higher order Laue zone (HOLZ) reflections are present in the pattern, which can provide more complete information about the three-dimensional nature of reciprocal space, even in a single two-dimensional PED pattern. |
600_5 | Practical robustness: PED is less sensitive to small experimental variations than other electron diffraction techniques. Since the measurement is an average over many incident beam directions, the pattern is less sensitive to slight misorientation of the zone axis from the optic axis of the microscope, and resulting PED patterns will generally still display the zone axis symmetry. The patterns obtained are also less sensitive to the thickness of the sample, a parameter with strong influence in standard electron diffraction patterns. |
600_6 | Very small probe size: Because x-rays interact so weakly with matter, there is a minimum size limit of approximately 5 µm for single crystals that can be examined via x-ray diffraction methods. In contrast, electrons can be used to probe much smaller nano-crystals in a TEM. In PED, the probe size is limited by the lens aberrations and sample thickness. With a typical value for spherical aberration, the minimum probe size is usually around 50 nm. However, with Cs corrected microscopes, the probe can be made much smaller. |
600_7 | Practical considerations
Precession electron diffraction is typically conducted using accelerating voltages between 100-400 kV. Patterns can be formed under parallel or convergent beam conditions. Most modern TEMs can achieve a tilt angle, φ, ranging from 0-3°. Precession frequencies can be varied from Hz to kHz, but in standard cases 60 Hz has been used. In choosing a precession rate, it is important to ensure that many revolutions of the beam occur over the relevant exposure time used to record the diffraction pattern. This ensures adequate averaging over the excitation error of each reflection. Beam sensitive samples may dictate shorter exposure times and thus, motivate the use of higher precession frequencies. |
600_8 | One of the most significant parameters affecting the diffraction pattern obtained is the precession angle, φ. In general, larger precession angles result in more kinematical diffraction patterns, but both the capabilities of the beam tilt coils in the microscope and the requirements on the probe size limit how large this angle can become in practice. Because PED takes the beam off of the optic axis by design, it accentuates the effect of the spherical aberrations within the probe forming lens. For a given spherical aberration, Cs, the probe diameter, d, varies with convergence angle, α, and precession angle, φ, as |
600_9 | Thus, if the specimen of interest is quite small, the maximum precession angle will be restrained. This is most significant for conditions of convergent beam illumination. 50 nm is a general lower limit on probe size for standard TEMs operating at high precession angles (>30 mrad), but can be surpassed in Cs corrected instruments. In principle the minimum precessed probe can reach approximately the full-width-half-max (FWHM) of the converged un-precessed probe in any instrument, however in practice the effective precessed probe is typically ~10-50x larger due to uncontrolled aberrations present at high angles of tilt. For example, a 2 nm precessed probe with >40 mrad precession angle was demonstrated in an aberration-corrected Nion UltraSTEM with native sub-Å probe (aberrations corrected to ~35 mrad half-angle). |
600_10 | If the precession angle is made too large, further complications due to the overlap of the ZOLZ and HOLZ reflections in the projected pattern can occur. This complicates the indexing of the diffraction pattern and can corrupt the measured intensities of reflections near the overlap region, thereby reducing the effectiveness of the collected pattern for direct methods calculations.
Theoretical considerations
For a cursory introduction to the theory of electron diffraction, see the theory section of the electron diffraction wiki. For a more in depth but understandable treatment, see part 2 of Williams and Carter's Transmission Electron Microscopy text |
600_11 | While it is clear that precession reduces many of the dynamical diffraction effects that plague other forms of electron diffraction, the resulting patterns cannot be considered purely kinematical in general. There are models that attempt to introduce corrections to convert measured PED patterns into true kinematical patterns that can be used for more accurate direct methods calculations, with varying degrees of success. Here, the most basic corrections are discussed. In purely kinematical diffraction, the intensities of various reflections, , are related to the square of the amplitude of the structure factor, by the equation: |
600_12 | This relationship is generally far from accurate for experimental dynamical electron diffraction and when many reflections have a large excitation error. First, a Lorentz correction analogous to that used in x-ray diffraction can be applied to account for the fact that reflections are infrequently exactly at the Bragg condition over the course of a PED measurement. This geometrical correction factor can be shown to assume the approximate form:
where g is the reciprocal space magnitude of the reflection in question and Ro is the radius of the Laue circle, usually taken to be equal to φ. While this correction accounts for the integration over the excitation error, it takes no account for the dynamical effects that are ever-present in electron diffraction. This has been accounted for using a two-beam correction following the form of the Blackman correction originally developed for powder x-ray diffraction. Combining this with the aforementioned Lorentz correction yields: |
600_13 | where , is the sample thickness, and is the wave-vector of the electron beam. is the Bessel function of zeroeth order.
This form seeks to correct for both geometric and dynamical effects, but is still only an approximation that often fails to significantly improve the kinematic quality of the diffraction pattern (sometimes even worsening it). More complete and accurate treatments of these theoretical correction factors have been shown to adjust measured intensities into better agreement with kinematical patterns. For details, see Chapter 4 of reference. |
600_14 | Only by considering the full dynamical model through multislice calculations can the diffraction patterns generated by PED be simulated. However, this requires the crystal potential to be known, and thus is most valuable in refining the crystal potentials suggested through direct methods approaches. The theory of precession electron diffraction is still an active area of research, and efforts to improve on the ability to correct measured intensities without a priori knowledge are ongoing.
Historical development |
600_15 | The first precession electron diffraction system was developed by Vincent and Midgley in Bristol, UK and published in 1994. Preliminary investigation into the Er2Ge2O7 crystal structure demonstrated the feasibility of the technique at reducing dynamical effects and providing quasi-kinematical patterns that could be solved through direct methods to determine crystal structure. Over the next ten years, a number of university groups developed their own precession systems and verified the technique by solving complex crystal structures, including the groups of J. Gjonnes (Oslo), Migliori (Bologna), and L. Marks (Northwestern). |
600_16 | In 2004, NanoMEGAS developed the first commercial precession system capable of being retrofit to any modern TEM. This hardware solution enabled more widespread implementation of the technique and spurred its more mainstream adoption into the crystallography community. Software methods have also been developed to achieve the necessary scanning and descanning using the built-in electronics of the TEM. HREM Research Inc has developed the QED plug-in for the DigitalMicrograph software. This plug-in enables the widely used software package to collect precession electron diffraction patterns without additional modifications to the microscope. |
600_17 | According to NanoMEGAS, as of June, 2015, more than 200 publications have relied on the technique to solve or corroborate crystal structures; many on materials that could not be solved by other conventional crystallography techniques like x-ray diffraction. Their retrofit hardware system is used in more than 75 laboratories across the world.
Applications
Crystallography
The primary goal of crystallography is to determine the three dimensional arrangement of atoms in a crystalline material. While historically, x-ray crystallography has been the predominant experimental method used to solve crystal structures ab initio, the advantages of precession electron diffraction make it one of the preferred methods of electron crystallography. |
600_18 | Symmetry determination
The symmetry of a crystalline material has profound impacts on its emergent properties, including electronic band structure, electromagnetic behavior, and mechanical properties . Crystal symmetry is described and categorized by the crystal system, lattice, and space group of the material. Determination of these attributes is an important aspect of crystallography.
Precession electron diffraction enables much more direct determination of space group symmetries over other forms of electron diffraction. Because of the increased number of reflections in both the zero order Laue zone and higher order Laue zones, the geometric relationship between Laue zones is more readily determined. This provides three-dimensional information about the crystal structure that can be used to determine its space group. Furthermore, because the PED technique is insensitive to slight misorientation from the zone axis, it provides the practical benefit of more robust data collection. |
600_19 | Direct methods
Direct methods in crystallography are a collection of mathematical techniques that seek to determine crystal structure based on measurements of diffraction patterns and potentially other a priori knowledge (constraints). The central challenge of inverting measured diffraction intensities (i.e. applying an inverse Fourier Transform) to determine the original crystal potential is that phase information is lost in general since intensity is a measurement of the square of the modulus of the amplitude of any given diffracted beam. This is known as the phase problem of crystallography. |
600_20 | If the diffraction can be considered kinematical, constraints may be used to probabilistically relate the phases of the reflections to their amplitudes, and the original structure can be solved via direct methods (see Sayre equation as an example). Kinematical diffraction is often the case in x-ray diffraction, and is one of the primary reasons that technique has been so successful at solving crystal structures. However, in electron diffraction, the probing wave interacts much more strongly with the electrostatic crystal potential, and complex dynamical diffraction effects can dominate the measured diffraction patterns. This makes application of direct methods much more challenging without a priori knowledge of the structure in question. |
600_21 | Ab Initio structure determination
Diffraction patterns collected through PED often agree well-enough with the kinematical pattern to serve as input data for direct methods calculations. A three-dimensional set of intensities mapped over the reciprocal lattice can be generated by collecting diffraction patterns over multiple zone axes. Applying direct methods to this data set will then yield probable crystal structures. Coupling direct methods results with simulations (e.g. multislice) and iteratively refining the solution can lead to the ab initio determination of the crystal structure.
The PED technique has been used to determine the crystal structure of many classes of materials. Initial investigations during the emergence of the technique focused on complex oxides and nano-precipitates in Aluminum alloys that could not be resolved using x-ray diffraction. Since becoming a more widespread crystallographic technique, many more complex metal oxide structures have been solved. |
600_22 | Zeolites are a technologically valuable class of materials that have historically been difficult to solve using x-ray diffraction due to the large unit cells that typically occur. PED has been demonstrated to be a viable alternative to solving many of these structures, including the ZSM-10, MCM-68, and many of the ITQ-n class of zeolite structures.
PED also enables the use of electron diffraction to investigate beam-sensitive organic materials. Because PED can reproduce symmetric zone axis diffraction patterns even when the zone axis is not perfectly aligned, it enables information to be extracted from sensitive samples without risking overexposure during a time-intensive orientation of the sample.
Automated diffraction tomography |
600_23 | Automated diffraction tomography (ADT) uses software to collect diffraction patterns over a series of slight tilt increments. In this way, a three-dimensional (tomographic) data set of reciprocal lattice intensities can be generated and used for structure determination. By coupling this technique with PED, the range and quality of the data set can be improved. The combination of ADT-PED has been employed effectively to investigate complex framework structures and beam-sensitive organic crystals
Orientation mapping |
600_24 | Mapping the relative orientation of crystalline grains and/or phases helps understand material texture at the micro and nano scales. In a transmission electron microscope, this is accomplished by recording a diffraction pattern at a large number of points (pixels) over a region of the crystalline specimen. By comparing the recorded patterns to a database of known patterns (either previously indexed experimental patterns or simulated patterns), the relative orientation of grains in the field of view can be determined. |
600_25 | Because this process is highly automated, the quality of the recorded diffraction patterns is crucial to the software's ability to accurately compare and assign orientations to each pixel. Thus, the advantages of PED are well-suited for use with this scanning technique. By instead recording a PED pattern at each pixel, dynamical effects are reduced, and the patterns are more easily compared to simulated data, improving the accuracy of the automated phase/orientation assignment.
Beyond diffraction
Although the PED technique was initially developed for its improved diffraction applications, the advantageous properties of the technique have been found to enhance many other investigative techniques in the TEM. These include bright field and dark field imaging, electron tomography, and composition-probing techniques like energy-dispersive x-ray spectroscopy (EDS) and electron energy loss spectroscopy (EELS). |
600_26 | Imaging
Though many people conceptualize images and diffraction patterns separately, they contain principally the same information. In the simplest approximation, the two are simply Fourier transforms of one another. Thus, the effects of beam precession on diffraction patterns also have significant effects on the corresponding images in the TEM. Specifically, the reduced dynamical intensity transfer between beams that is associated with PED results in reduced dynamical contrast in images collected during precession of the beam. This includes a reduction in thickness fringes, bend contours, and strain fields. While these features can often provide useful information, their suppression enables a more straightforward interpretation of diffraction contrast and mass contrast in images. |
600_27 | Tomography
In an extension of the application of PED to imaging, electron tomography can benefit from the reduction of dynamic contrast effects. Tomography entails collecting a series of images (2-D projections) at various tilt angles and combining them to reconstruct the three dimensional structure of the specimen. Because many dynamical contrast effects are highly sensitive to the orientation of the crystalline sample with respect to the incident beam, these effects can convolute the reconstruction process in tomography. Similarly to single imaging applications, by reducing dynamical contrast, interpretation of the 2-D projections and thus the 3-D reconstruction are more straightforward. |
600_28 | Investigating composition |
600_29 | Energy-dispersive x-ray spectroscopy (EDS) and electron energy loss spectroscopy (EELS) are commonly used techniques to both qualitatively and quantitatively probe the composition of samples in the TEM. A primary challenge in the quantitative accuracy of both techniques is the phenomenon of channelling. Put simply, in a crystalline solid, the probability of interaction between an electron and ion in the lattice depends strongly on the momentum (direction and velocity) of the electron. When probing a sample under diffraction conditions near a zone axis, as is often the case in EDS and EELS applications, channelling can have a large impact on the effective interaction of the incident electrons with specific ions in the crystal structure. In practice, this can lead to erroneous measurements of composition that depend strongly on the orientation and thickness of the sample and the accelerating voltage. Since PED entails an integration over incident directions of the electron probe, and |
600_30 | generally does not include beams parallel to the zone axis, the detrimental channeling effects outlined above can be minimized, yielding far more accurate composition measurements in both techniques. |
600_31 | References
External links
NanoMEGAS
System Design and Verification of the Precession Electron Diffraction Technique, Ph.D. Thesis, C.S. Own
Diffraction
Crystallography |
601_0 | Established in 1895, the Erie Yacht Club, is a private club located on the shore of Presque Isle Bay in Erie, Pennsylvania. The purpose of the Erie Yacht Club is to maintain, develop, and enlarge the facilities for yachting and boating, to encourage and develop yachting and other aquatic sports, to promote social recreational activities. To improve yachting and boating facilities at the Erie Yacht Club basin and in the area of the Erie Harbor generally.
Early history
On September 14, 1894, George T. Bliss, who served as Erie Yacht Club's Commodore from 1895 to 1903 and again from 1908 to 1910, sent out about fifty circulars, information forms and return envelopes to interested parties concerning, "a boating club in Erie that will take all kinds of boats." |
601_1 | His broadside calling for the founding of a club included his proposition that the club would have to have a clubhouse plus a low building to keep sculls, small boat, and equipment. There were many interested "Erieites" among the first to respond, so much so, that a second circular was sent out on September 20, 1894, calling for a meeting on September 20, 1894.
The organizational meeting was held in the Writing Room of the Reed House on North Park Row. The initial meeting was well attended. Forty-eight were on hand and seventeen names were sent in to the proper committee, so the organization started off with practically 65 names on the roll. While the name did not survive, Bliss originally proposed that the club be called the Keystone Yacht Club. |
601_2 | By October, 137 individuals had applied for membership. The first regular meeting was scheduled for November 14 at the Reed house. It was announced that "no charter member will have a vote unless he has paid at least $5 of the initiation, which is $15." All persons becoming members after January 1, 1895, were to be "charged $20 initiation fee and $5 semi-annual dues." |
601_3 | At this point it was time to fish or cut bait. In his May 1896, article in The Rudder, Bliss laconically noted that: "Meetings were held that were well attended until money was suggested. We couldn't get a corporal's guard together for weeks. But we kept at it, and finally on Wednesday, Nov. 14, 1894, the organization was effected." The first officers elected to serve the club were George T. Bliss (Commodore), George Berriman (Vice Commodore), C.C. Wicks (Rear Commodore), E.B. Lynch (Secretary) and Walter Reitzel, (Treasurer). The first members elected to the board of directors were: George Pratt, Charles H. Strong, William Nick, W. Boyd Hays, William P. Atkinson and W. J. Robertson. |
601_4 | The first order of business was to select a site for the new club. The City of Erie leased water lots to the Club at the foot of Myrtle Street, east of what is now the Erie Water Authority Building. After several months of work on the bidding process and construction the Erie Yacht Club's first building was dedicated on July 18, 1895. It was a beautiful two-story building with outdoor decks on the north and west side. Considerations given the ladies were a special entrance so that "they do not have to pass through the house," and the prohibition of liquor. As Bliss wrote in The Rudder: "We allow no liquor to be used or partaken of on or about the premises. This does not prohibit its being left at the club for boat owners, and being taken aboard the boats. We adopted this last rule as an experiment, and it works to perfection." |
601_5 | The fleet at the new anchorage included: Mystic, and three other small steamers, four naptha launches, three large center board sloops, four schooners, three yawls, three small sloops, two canoes, two shells and an eight oared shell. One of the latter was the Miriam, M, built and owned by W.L. Morrison, one of the club's members who achieved considerable boating fame. The Miriam's anchor is displayed in the traffic circle near our present club's entrance.
By the turn of the century, things began to change. The gasoline engine was powering launches previously driven by naphtha. Mostly crude two-cylinder affairs, they were temperamental and had a decided influence in changing the vocabulary of owners. For Club members, "gasoline was delivered in five gallon cans from wagons at ten cents a gallon and no tax." |
601_6 | Gasoline also led people away from the water. Judge Emory A. Walling was to note that there were many who were attracted "to the modern craze for bicycles and automobiles." The Club directors did everything possible to counteract this trend. They got a permit from the Coast Guard "to pull yachts out" in the winter at Crystal Point on Misery Bay where the Perry Monument was later built. |
601_7 | In addition, social events were established. The Club archives record one member's observation that in 1900, the Club "had a social urge and rented Tracy's Point", a hotel built on the site of the present Erie Water Authority Sommerheim Pumping Station. Erie Yacht Club Station No. 1, as it was known, was the focus of many social events for members and their families. Transportation was by bus, trolley car or by the motor launch, Dandy of Erie, which was termed by Bliss, "a little dude of a steam launch." The docks were repaired and the buildings painted, and the refurbished country club "became a very popular rendezvous." It burned in the winter of 1901–1902, although not all members mourned the loss. One chronicler wrote: "It was not a fundamental success and fortunately the building burned before the members drank themselves to death." |
601_8 | However, the short life of Station No. 1 pointed out the need for a larger facility. The Anchorage, as the Clubhouse at the foot of Myrtle Street was known, had become too small for the club's needs, and plans were begun to replace it with something larger. The need became more critical as the newspapers reported that the Water Supply Commission was going to reclaim the water lots used by the club to expand the Water Works.
New Location
In 1917, Commodore Henri G. Chatain negotiated with Mr. J. A. Root, president of the Kahkwa Park Realty Company, Inc., for the last remaining property on the waterfront. In a letter dated March 21, 1917, Root proposed to donate the land "west of the ravine and below the cliff" in Kahkwa Parkto the Erie Yacht Club. In return, the club was to pay $5,000 towards the road work and maintain the walls and the slope of the ravine without "marring the natural beauty of the surrounding lands." |
601_9 | With the land secured and permission granted from the Water Supply Commission of Pennsylvania "to construct a dock, retaining wall and fill" on the south shore of Presque Isle Bay, construction began. The location posed difficulties from the beginning. The beach area was made marshy by a stream which ran down the ravine. Until the creek was controlled, no road could be built, and it was necessary to lower materials by block and tackle. |
601_10 | Construction was made more difficult by the breach at the neck of Presque Isle (which remained open until 1920) and the United States' declaration of war on April 6, 1917. However, "the original clubhouse was torn down and E.H. Scott used his yacht, Roamer, to tow much of the lumber to the new location." Commodore Chatain headed a work crew which built the first road down the hill, while a temporary Clubhouse was built by Herman Lund with the help of a number of members at the south end of the newly constructed west dock. Still in use, the Canoe House now houses the office of the Dockmaster. The members constructed a stiff-legged derrick permitting launching and retrieval of their boats. |
601_11 | However, a proper Clubhouse awaited construction. Plans and specifications for a three-story building "to be done in a first-class, neat and workman-like manner" were drawn up by architect Clement S. Kirby. Kirchner Brothers submitted the winning bid for construction at $17,000, and Oscar Nick won the plumbing contract. Although they had initial problems securing payment, eventually both were paid.
The season of 1919 began under difficulties, with access to the club almost barred by muddy roads, the grounds themselves a veritable mud hole, and buildings still under construction. In spite of the open Winter and Spring, boat owners were laggard about getting their craft into the water, and the confusion and disorder of construction work made itself felt until well into the season. |
601_12 | But finally, buildings were finished, moorings installed, docks and piers constructed, grounds graded, drained, and seeded, driveway parking spaces paved and walks laid out. The marine railway was constructed, tennis courts built, a club spar erected, and later a locker house [still extant] built upon a flooring laid down as a temporary dancing pavilion. Lights, signs, screens and a hundred other refining details followed in their place, and the club was finally in shape barely in time for the formal opening on August 22, 1919. |
601_13 | On September 30, Commodore E.H. Scott and the membership closed the season with "a monster clambake", confident in their preparations for hosting the I.L.Y.A. Regatta in 1920. Less than one month later (October 28), the United States embarked upon a novel - and ultimately unsuccessful - experiment known as Prohibition. As long-time Club secretary and historian George O. Loesel wrote: "Prohibition reared its ugly head . . . and Mr. Booze was no longer the money maker [and] thus considerable revenue was denied the club."
The "Roaring Twenties", replete with gambling, prostitution, rum-running (a profitable alternative enterprise) and bootlegging "bath-tub gin", had enormous impact. John G. Carney in his, Highlights of Erie Politics, said that the "only dry thing in Erie was the inside of a light bulb." However, the Erie Yacht Club, like the rest of the country was officially dry. |
601_14 | The country club atmosphere of the new facility led to a broader membership base and activities. The Club went beyond the "manly sports" of sailing, power boat racing, ice boating, fishing and hunting, and placed recreation in a broader context. Ice skating, tobogganing, quoits, ground bowling, tennis and beach golf were available to members and their families. The new facility had a restaurant and an outdoor grill, a trap-shooting range, quoit grounds, two tennis courts and areas set aside for ground bowling and beach golf. Card parties and regularly scheduled bridge sessions, dances and Saturday night parties and dances became regular features of the club.
Hard Times
The good times ended in 1929. Winter storms ravaged Presque Isle and the bay shore, and October was to bring the stock market crash inaugurating the Great Depression. One writer recalled: |
601_15 | We have had some bad storms but none to compare with the one in 1929, which broke up our docks and front porch and carried them down the bay. A large gasoline tank in the ground broke free and was destroyed. This tragedy came close to finishing the club, for it was the year of the "Big Depression" and both members and money were scarce. Commodore Lawrence M. Nagle determined that the club should be saved and proceeded to purchase at his own expense all of the large planks from the Old Boston Store which was being dismantled. These were brought to the club, and Jerry Johnson and Joe Meisel were hired to rebuild [the] porch and docks. Mr. Nagle also paid these men, since there was no money in the Club treasury. |
601_16 | The membership roster was severely reduced, and "members dropped like flies." At the Annual Meeting of 1932, membership and morale were so low that only 12 people showed up. They met in the upstairs Dining Room, where there was a fireplace, so that they would not have to fire up the boiler.
Low membership was only one problem. Lake Erie was at one of its lowest levels ever. The water in 1931, according to Loesel, was "as low as a snake's belly". It was the determined intervention of the Harbor Commission and the Commonwealth of Pennsylvania to save yachting in the bay, which led to the state - "at its own expense" - to deepen the channel leading to the boat cranes. |
601_17 | Despite the literal and figurative low water, the Erie Yacht Club survived. Club members were among the founding fathers of the Erie Chapter of the Power Squadron. Races and regattas still went on, and social events were revived by the end of the decade as a measure of economic stability came to the club. These activities continued until the United Statesbecame involved in World War II on December 7, 1941.
The war slowed, but did not stop, Club activities. Gas rationing placed a particular burden on power-boat owners who could not get fuel for pleasure craft, which were deemed to be "non-essential" to the war effort. Most owners laid up their boats "for the duration", although a number of power boat owners volunteered themselves and their boats for the local Coast Guard Auxiliary Flotilla. |
601_18 | Sailboats took advantage of the non-rationed zephyrs. Although a number of sailboat races were cancelled because of lack of crew, many of the small boat races were held because the younger sailors were too young for the draft which sent members to war in both the European and Pacific theaters. The war ended in 1945, the same year that the Erie Yacht Club celebrated "a half Century of sport, achievement, and good fellowship in the glorious tradition of YACHTING!" |
601_19 | Recovery
The post-war period brought boom times to the Erie Yacht Club. The war had kept plans for membership and improvements on hold. Membership expanded dramatically, but low yearly budgets meant that improvements were minor and upgrading was piecemeal. The gas tank was painted blue and white, a concrete foundation along with steps was added to the Clubhouse, new lamp posts, new faucets in the lavatories and telephone lines to the west dock all marked progress. In addition, the basins were deepened and docks increased in number, so that 1954 could accommodate 200 boats. New catwalks were installed with all wooden docks replaced by 1955. But, the Clubhouse was jury-rigged and replacements were beginning to show wear. Despite paint and polish, the situation was becoming critical. |
601_20 | But, adversity had a bright side. On Memorial Day, 1953, a "Monsoon Flood" disrupted Opening Day ceremonies which were underway. The sewer viaduct, which crosses the road halfway up the ravine road, broke without warning sending tons of mud and debris down the road and into the parking lot. Those at the club were trapped by the mudslide. Some left by boat, but many seized the opportunity as a perfect excuse for an extended Club party. It was two days before cars could get up the hill. |
601_21 | Growth
By 1954, Club growth was such that the basins were deepened and docks increased in number so that 200 boats could be accommodated. The Clubhouse was renovated and plans were initiated for the building of another Clubhouse and rearrangement of Club grounds. At this time, a master plan was developed for future facilities, as the club had grown beyond the size, which permitted piecemeal decisions. The docks were expanded in 1959 and again in 1965. In 1967, plans were finalized and fund-raising began for the new Clubhouse. Commodore William Ambro and the Bridge Officers conducted the groundbreaking ceremonies in January 1968, marking a new chapter for the Erie Yacht Club. Dedication of the new Clubhouse was held on October 5, 1968, with lavish festivities presided over by the master of dedication, the Honorable Raymond Shafer, Governor of Pennsylvania. |
601_22 | Following the master plan, fill was obtained and new docks were built, which increased the basin area to triple that in use previously. New slips with steel catwalks were added, bulkheads secured the dock fill and additional boat-handling facilities were added. As of 1999, the basin capacity was approximately 400 boats.
In July 1978, Commodore Richard Waller presided over a Mortgage Burning Celebration attended by an enthusiastic membership. The next year, the club was given a long-overdue remodeling necessitated by the "bare bones" approach taken in building the new Clubhouse. For the Bridge and Board, however, major expenditures were strictly watched because of the shadow of uncertainty surrounding the title to the land. |
601_23 | Efforts to acquire the land involved long, painstaking negotiations. The sale was discussed in 1979, and again in 1980 with the Erie-Western Pennsylvania Port Authority. The issue was a crucial one for future Club development, as the EYC had signed a fifty-year lease with the Erie-Western Pennsylvania Port Authority in 1963. Negotiations continued from 1979 to 1985 with no progress reported, and the club was "in a limbo situation until [it received] a forthcoming response." The Long-Range Planning Committee kept the focus on the land as the "first priority" and the Bridge and Board worked to effect a solution. |
601_24 | Ownership
After the 1985 Annual Meeting, newly elected Rear Commodore G. "Gib" Loesel approached Commodore James Owen about his "contact" in City Hall, as his partner was advising Mayor Louis J. Tullio on insurance matters. Owen and Loesel negotiated with the Mayor and struck a deal for the purchase at a price of $550,000. At the May 24, 1986, Special Meeting, the membership voted 272–1 to purchase the property. Because of a lawsuit inaugurated by a member of City Council, the property closing was held up until February 9, 1987, at which time Commodore M. Roy Strausbaugh acquired the title on behalf of the EYC. |
601_25 | With ownership came a new master plan, which required major changes to the Clubhouse and to the yacht basin. The plan was defeated at a special membership meeting in 1991. In 1992, Commodore Robert H. Allshouse and his Bridge presented a modified plan, which called for major renovations to the Clubhouse only. The grill room used for casual dining was expanded to include a non-smoking lower level, the addition of a 45-seat private dining room named after our first commodore, George Bliss and a ballroom that accommodates 175. The plan was ratified by the membership and construction started in the winter of 1993. The construction went smoothly with the club closed for only 4 weeks. Commodore Ronald Busse dedicated the newly renovated Clubhouse in the spring of 1993. |
601_26 | Centennial
With the 100th anniversary of the club on the horizon in 1995, Commodore Allshouse appointed Fleet Captain John Ashby as chairman of the newly created Centennial Committee, with the assignment to raise money for and plan all of the centennial events.
The Centennial year started off with a bang, opening with a weekend Winter Carnival, which concluded with a fireworks display, designed specifically for the club and its celebration of 100 years. In May, the club had its official Centennial Ball. Due to the anticipated attendance, the gala was held in Rainbow Gardens rather than the Clubhouse. This evening of continuous entertainment and music was a formal event attended by more than 500 members and guests. |
601_27 | During the summer, the Club held the largest-ever Family Picnic, bringing hundreds of families together for a day full of fun. Another jumbo event of the summer was the club's raft-up. Staged immediately to the north of the basin, members circled their boats around floats "EYC" & "100". As no centennial celebration would have been complete without stories of the past, an Old Timers' Night was scheduled to professionally record and preserve the oral history and traditions of the EYC. This well-attended event allowed younger members to hear "sea stories" of the old (and not so old) days.
In the fall, the Centennial Committee arranged for first-ever Oktoberfest. This event proved to be so popular that it has now become an annual Club event. The year concluded with the burying of a time capsule, in the "round about" located just inside the Club gates. This capsule will be opened at the 200th anniversary celebrations of the club. |
601_28 | To this day the Erie Yacht Club continues the traditions set forth by the club's founding members to promote, encourage and develop activities associated with yachting and yachting activities. With a roster of over 1,300 members, the Erie Yacht Club is one of the largest and oldest privately owned clubs on the Great Lakes.
Reciprocity
Like most yacht clubs on the Lake Erie, the Erie Yacht Club is a member of the Inter-Lake Yachting Association, which provides reciprocal privileges between members of many other yacht clubs. The Erie Yacht Club has reciprocal relationships with most accredited yacht clubs and is happy to host their visiting members. When reciprocal members wish to visit the club, they must show their membership card from their Club which confirms that they are a member in good standing and are eligible to be granted guest privileges.
The Erie Yacht Club is also a member of the Yachting Club of America and offers reciprocity with their members as well. |
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