The primary purpose of this study was to investigate the history of Princess Anne County Training School and Union Kempsville High School in Princess Anne County/Virginia Beach, Virginia. The method of inquiry was qualitative, historical research that relied on oral histories to provide a cultural understanding of the school from the perspectives of its students, administrators, teachers, and staff. The school's history was reconstructed through direct engagement with individuals whose interviews recounted the establishment, growth, operation, and demise of Princess Anne County Training School/Union Kempsville High School. In order to minimize the nostalgic influence and bring greater validity to the oral histories, data were also collected from historical accounts, school board and community organization minutes, local periodicals, and school artifacts.   Segregation cultivated legally separate-but-equal schools for Blacks and Whites, with little or no attention given to actual equality. In 1925, the Black community in Princess Anne County, Virginia, mobilized to build a high school for their children who were denied an education beyond seventh grade. Princess Anne County Training School opened for Black students in 1938 and initially utilized a curriculum based on industrial education. It was the first and only Black high school in Princess Anne County/Virginia Beach, Virginia. As Princess Anne County Training School progressed, the Black community eventually repudiated the term, training school. The school's name was changed to Union Kempsville High School in the fall of 1961. Gradual desegregation inaugurated by the Brown v. Board of Education decisions led to a decline in student enrollment, and Union Kempsville High School closed in 1969. / Ph. D.

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La situation de penalty représente un moment déterminant pour l'issue d'une partie ou d'un tournoi au soccer. Seul devant un joueur, le gardien couvre le but et tente d'empêcher le ballon de traverser la ligne de but. Cependant, le ballon franchit généralement la ligne de but plus rapidement que le gardien ne peut se déplacer dans l'une des extrémités de la cage. Le gardien doit donc anticiper la trajectoire que prendra le tir. Pour ce faire, il peut s'aider d'indices biomécaniques provenant du tireur en action et d'indices liés au contexte de jeu. Les trente dernières années sont marquées par l'identification d'indices biomécaniques utiles à l'anticipation des penalties, mais peu d'études portent sur le traitement et l'utilisation des indices contextuels et, surtout, au rôle combiné des deux types d'indices pour l'anticipation. Ce mémoire a donc pour objectif d'étudier les indices contextuels utilisés lorsque les gardiens anticipent la trajectoire du ballon lors des penalties et, ensuite, d'explorer comment la prise en considération des indices biomécaniques et contextuels s'opère lors de l'anticipation. Cette étude répond à ces objectifs à l'aide d'une tâche d'anticipation informatisée basée sur les méthodes d'occlusion temporelle et spatiale, complétée par 14 gardiens et gardiennes de but (experts) et 14 individus n'ayant pratiquement aucune expérience au soccer (novices). Les résultats de la présente étude démontrent que tant les experts que les novices utilisent les indices contextuels lorsqu'ils tentent d'anticiper la trajectoire du ballon lors des penalties. Plus spécifiquement, les gardiens se basent sur la latéralité et l'angle d'approche du tireur alors que les novices utilisent seulement l'angle d'approche du tireur. Cette étude montre également que les participants utilisent simultanément les indices biomécaniques et contextuels et que l'importance accordée à chaque indice peut varier au cours de l'approche du tireur, ce qui suggère que l'anticipation est un processus dynamique basé sur le traitement et la pondération de plusieurs indices. Enfin, ce mémoire met en évidence un biais comportemental observé seulement chez les gardiens. Ce biais s'apparente au biais d'action (Bar-Eli et coll., 2007) et mène les gardiens à anticiper peu de tirs au centre du but et à croire que le ballon se dirigera plus fréquemment dans les extrémités inférieures de celui-ci. Ce biais handicape leur habileté à anticiper efficacement la trajectoire des penalties. / The penalty kick situation is a defining moment in the outcome of a soccer game or tournament. Alone in front of a player, the goalkeeper tries to prevent the ball from crossing the goal line. However, the ball usually reaches the goal line faster than the goalkeeper can move to either end of the goal. The goalkeeper must therefore anticipate the side and the height of the shot before the player touches the ball. To do so, he needs to use advance postural and contextual cues. Over the last 30 years, researchers sought to find the best postural cues to help goalkeepers to correctly anticipate the trajectory of penalty kicks. Although, only a few tried to understand the role of context in anticipation and how such information can be used in conjunction with postural cues. Hence, the current master thesis seeks to find if implicit contextual cues are used when goalkeepers anticipate penalty kicks. Moreover, this study explores how goalkeepers integrate and weight contextual and postural cues when they anticipate. The current study attempts to meet these objectives using a computerized anticipation task based on the temporal and spatial occlusion paradigms, completed by 14 goalkeepers (experts) and 14 individuals with practically no soccer experience (novices). Results show that both experts and novices use contextual cues to anticipate penalty kicks. More specifically, goalkeepers rely on the shooter's dominant foot and his approach angle while novices only rely on the shooter's approach angle. The mere presence of postural cues also affects anticipation, suggesting that both contextual and postural cues are used for penalty kicks anticipation. Furthermore, the relative importance given to each cue is not the same as the shooter approaches the ball, suggesting that anticipation is a dynamic process based on the weighting of different postural and contextual cues. Finally, this study highlights a behavioral bias, similar to the action bias (Bar-Eli et al., 2007), and leads goalkeepers to anticipate few shots in the center of the goal and to believe that the ball will go more frequently to the lower ends of the goal. This bias affects their ability to anticipate the trajectory of penalty kicks.

The opportunistic pathogen Legionella is the leading cause of reported waterborne disease outbreaks in the United States. Legionella can thrive under the warm, stagnant, low-disinfectant conditions characteristic of premise (i.e., building) plumbing systems, making it challenging to identify effective interventions for its control. Copper (Cu) is a promising antimicrobial that can be dosed directly to water via copper-silver ionization systems or released naturally via corrosion of Cu pipes to help control growth of Legionella and other pathogens. However, prior research has shown that Cu does not always reliably control Legionella and sometimes seems to even stimulate its growth. A deeper understanding of the mechanistic effects of Cu on Legionella, at both pure-culture and real-world scales, is critical in order to inform effective controls for Legionella. The overarching objective of the research embodied by this dissertation was aimed at elucidating the chemical and microbial interactions in premise plumbing that govern efficacy of Cu for Legionella control through a series of complementary bench-, pilot-, and field-scale studies. A critical review and synthesis of the literature identified important knowledge gaps in relation to antimicrobial effects of Cu. In particular, changes in the pH, phosphate corrosion control, and rising levels of natural organic matter (NOM) in distributed water are predicted to be important controlling factors. The type of sacrificial anode rod material employed in water heaters was also identified as an underappreciated factor, which directly affects pH, evolution of hydrogen gas as a microbial nutrient, and release of metals (such as aluminum) that bind copper. Microbiological factors: including growth phase of Legionella (e.g., exponential or stationary), strain-specific Cu tolerance, background microbiome composition, and the possibility that viable but non-culturable (VBNC) Legionella might still cause human disease, were also identified as major confounding factors. These knowledge gaps are addressed from various dimensions across each chapter of the dissertation. The effects of pH, orthophosphate corrosion inhibitor concentration, and NOM were examined in bench-scale pure culture experiments over a range of conditions relevant to drinking water. Cupric ions and antimicrobial effects were drastically reduced at pH >7.5, especially in the presence of phosphate, which precipitates copper, or NOM, which complexes the Cu in a form that is less bioavailable. Chick-Watson disinfection models indicated that soluble Cu was the most robust correlate with observed Cu antimicrobial effects across a range of tested waters. This new knowledge suggests that measuring soluble rather than total Cu would be much more informative to guide practitioners in dosing. The research also demonstrated that changes in pH or orthophosphate that have been made to control corrosion over the last few decades, have significantly altered Cu chemistry in buildings, undermining antimicrobial capacity and increasing likelihood of Legionella growth. Pilot-scale experiments confirmed that soluble Cu is an effective indicator of Cu antimicrobial capacity, even in more complex environments represented by realistic hot water plumbing systems. In particular, dosing of orthophosphate, which is widely added by drinking water utilities to control corrosion, directly reduces soluble copper and overall antimicrobial capacity. In some cases, Cu added together with orthophosphate apparently promoted the growth of Legionella, providing an example of at least one circumstance where Cu addition can induce interactive effects that elevate Legionella compared to a control system with trace Cu. It was also demonstrated for the first time that different water heater sacrificial anode types are subject to different corrosion processes, which indirectly influence Cu antimicrobial capacity. Specifically, aluminum ions released from aluminum anode corrosion at 1 mg/L can form an Al(OH)3 gel, which can remove >80% of the soluble Cu from water and reduce Cu antimicrobial effects by >2-log at pH=7. Corrosion from magnesium anodes was found to dramatically increase the pH from 6.8 to >8, which correspondingly reduces Cu antimicrobial capacity. Cu deposition further increased the anode corrosion rate and promoted evolution of hydrogen gas, which is a potent electron donor that stimulates autotrophic microbial growth especially with a magnesium anode. Electric powered anodes did not release metals or alter pH and thus did not diminish Cu antimicrobial capacity. Still, across the pilot-scale experiments, even very high levels of Cu (>1.2 mg/L) at low pH (<7) failed to fully eradicate culturable Legionella. The much lower than expected antimicrobial efficacy of Cu in the pilot-scale hot water plumbing systems was found to be partially explained by the properties of the strain that colonized the systems. Based on fitting the data to a Chick-Watson disinfection model, the outbreak-associated strain that was inoculated into the systems was estimated to be 7 times more tolerant to Cu compared to the common lab strain applied in the bench-scale tests. Further, exponential growth phase L. pneumophila were found to be 2.5 times more susceptible to Cu relative to early stationary phase cultures. It is important to also recognize that, in the pilot-scale systems, drinking water biofilms and the amoeba hosts that colonize them can further shield Legionella from the antimicrobial effects of Cu. Application of shotgun metagenomic sequencing offered the opportunity to more deeply examine the response of Legionella and other pathogens to Cu dosed to the pilot-scale hot water systems in the context of the broader microbiome. It was found that metagenomic analysis provided a sensitive indication of the bioavailability of Cu to the broader microbial community inhabiting the hot water systems, further confirming that the outbreak-associated strain of Legionella that colonized the rigs was relatively tolerant of Cu. Functional gene analysis provided further insight into the mechanistic action of Cu, suggesting multi-modal action of both membrane damage and interruption of nucleic acid replication. The metagenomic analysis further revealed that protozoan host numbers tended to increase in the pilot-scale systems with time, and this could also increase the potential for Legionella proliferation with time. Additional pure culture studies aiming to further assess the mechanistic action of Cu provided strong evidence that Cu can induce a VBNC state for Legionella. This is a concern, given that other studies have indicated that VBNC Legionella are still capable of causing legionellosis. However, VBNC cells are not detected by conventional culturing. Multiple lines of evidence supported the conclusion that Cu induced a VBNC state for Legionella, including membrane integrity, enzyme activity, ATP generation, and Amoebae resuscitation assays applied to two different strains of L. pneumophila. After exposure to Cu, up to a 5-log (99.999%) reduction in culturable Legionella was observed, whereas corresponding reductions in the various viability measures were only by <1-log (90%). In other words, conventional culturing may miss up to 99.99% of the Legionella that is still capable of causing disease. To our knowledge, this is the first study that has assessed the potential for Cu-induced VBNC Legionella. Additional research is needed to further quantify the contribution of VBNC status to challenges in effective Cu-based control of Legionella in premise plumbing. This research further examines, for the first time, the proteomic response of Legionella to Cu, comparing both presumably VBNC and culturable cells. Functional annotation of proteins that were differentially produced by the cells in response to Cu addition revealed that VBNC L. pneumophila modulated its proteome to favor cell membrane- and motility-related proteins, while reducing production of other proteins related to primary metabolism compared to culturable cells. These observations are consistent with the metagenomic-based observations and support the hypothesis that Cu inactivates cells by damaging the cell membrane. The findings also confirmed reduced general cell metabolism that is characteristic of a VBNC state. This dissertation highlights the important and complex effects of Cu on Legionella growth in potable water systems as modified by water chemistry, water heater anode type, characteristics of the surrounding microbiome, and Legionella strain characteristics and growth status. The findings raise important questions about how to measure disinfectant efficacy and provide fundamental new knowledge that can help to better optimize the application of Cu as an antimicrobial to drinking water systems and better protect public health. / Doctor of Philosophy / The opportunistic pathogen Legionella is the leading cause of reportable waterborne disease outbreaks in the United States. Legionella is capable of growing in drinking water plumbing systems in homes, hospitals, hotels, and other buildings. Legionella is spread by inhaling tiny droplets of water that are suspended in the air when using the water, for example when showering, resulting in a severe and deadly form of pneumonia called Legionnaires' Disease. Copper is a promising antimicrobial that can be dosed directly into a building's water system by installing a copper-silver ionization system. There is also interest in understanding whether copper released naturally from copper pipes could help control Legionella. However, prior research indicates that copper sometimes inhibits, sometimes has no effect, and sometimes even seems to stimulate Legionella growth. The purpose of this dissertation was to better understand how the chemical properties of the drinking water, such as pH, presence of corrosion inhibitors that are commonly added to the water by utilities, and natural organic matter impact the ability of copper to kill Legionella. Impacts of the design of the drinking water system were also examined, for example, the material used in the anodes of water heaters to prevent corrosive damage to other system components was hypothesized to change the water chemistry in such a way that could also interfere with copper disinfection. Finally, the effect of the strain of Legionella, its growth phase (exponential or stationary), and culturability status (culturable versus viable but non-culturable) was also examined. Experiments were conducted over a wide range of conditions, from bench-scale pure culture experiments of a few days to full-scale plumbing systems over a period of 3.5 years. The complementary approaches maximize the strength of scientific conclusions about approaches that can more effectively control Legionella. Several discoveries were made as a result of this research that can help to improve the use of copper for controlling Legionella in drinking water systems. In particular, it was found that it is best to keep the pH less than 7.5, because above pH 7.5 copper reacts with orthophosphate corrosion inhibitor or natural organic matter in the water in a manner that makes it less potent to microbes. Through disinfection modeling it was found that soluble copper was the best predictor of the ability to kill Legionella. Therefore, it is recommended from this research that practitioners should monitor soluble copper instead of total copper for the purpose of assessing Legionella control. From the pilot-scale experiments, it was further found that the type of anode installed in the water heater can affect the ability of copper to kill Legionella. Magnesium anodes performed the worst, likely because they raised the pH above the recommended level of 7.5. Aluminum anodes were also a problem because aluminum ions released form an aluminum hydroxide gel that can remove more than 80% of the soluble copper from water. Electric powered anodes did not reduce copper antimicrobial effects by raising pH or forming a gel, but they are much less commonly used. A surprising finding throughout this study was that very high levels of copper (>1.2 mg/L) were required to measurably reduce Legionella in the pilot-scale systems. In the pure culture experiments, it was found that the outbreak-associated strain from Quincy, IL, that was inoculated into the system was highly copper tolerant. This demonstrated that the strain of Legionella that colonizes a particular drinking water system could be the reason why copper is sometimes less effective. Pure culture experiments also found that stationary phase Legionella are more difficult to kill than exponential phase Legionella, which could explain some discrepancies among lab studies reported in the literature. A particularly noteworthy discovery of this research was that copper can make it appear as if Legionella have been killed, because the traditional culture media indicate that there is no growth on the Petri dish; however, they are in fact still alive and capable of causing human disease. This is referred to as a "viable but non-culturable (VBNC)" state. The VBNC state of Legionella was confirmed using an array of techniques (membrane integrity, enzyme activity, ATP generation, and amoebae resuscitation) for two strains of L. pneumophila. We also examined how VBNC Legionella cellular functions were impacted by copper using whole cell proteome, i.e., analysis of all of the proteins extracted from Legionella. Copper induced VBNC Legionella modulated its proteome to favor cell membrane and motility related proteins, and reduced others related to primary metabolism compared with culturable cells. These results were consistent with those obtained via shotgun metagenomic analysis of the microbial community DNA in the pilot-scale water systems. Given the potential for VBNC organisms to prevail in systems disinfected with copper, it is recommended to supplement culture-based monitoring with molecular-based monitoring, e.g., with quantitative polymerase chain reaction. This dissertation highlights the important and complex effects of copper on Legionella growth in potable water systems. The findings help to inform guidance on how to improve the antimicrobial effect of copper, through adjusting the water chemistry, selecting appropriate water heater anodes, and optimizing the overall hot water system design. The dissertation also helps to inform improved strategies for monitoring the efficacy of copper for killing Legionella in real-world systems. Overall, the findings can help to improve policy and practice aimed at reducing the incidence of Legionnaires' Disease and protecting public health.

Earth has its natural features; mountains, valleys, ocean, rivers, lakes, trees, plants, flowers etc. It has inhabitants; Man, animals, insects, birds etc. Man being supreme creature, introduced architecture to provide shelter for him initially and with the passage of time he brought it to the elegance where it is today. I would like to carry out his legacy with the intent of Romancing the Earth with Nothing but the Truth written in Poetic lines. My humble approach to create is to carve out the TRUTH into being from not being, to stay honest to the site and be noble in the cause. Through my investigation, my objective is to establish a life style with a serene environment. A place where one is tranquil to think about the higher values of life, A place to lose one's SELF and find HIMSELF, to serve his purpose in the universe which will bring real joy to his mind, enrichment to his soul and contentment to his body. / Master of Architecture

Les comportements orientés vers un but sont complexes et font appel à un grand nombre de processus cérébraux. Le cortex préfrontal médian (mPFC) apparaît comme une structure clef dans la réalisation de ces comportements de par son rôle dans la planification. De plus, il existe au sein du mPFC des cellules signalant les lieux à forte valeur motivationnelle. L’activité de ces neurones pourrait être essentielle à la mise en place d’un comportement spatial dirigé vers un but. S’orienter vers un but nécessite aussi la construction d’une représentation stable de l’environnement, qui repose sur l’activité de l’hippocampe (HPC). Néanmoins, peu de travaux ont analysé le rôle respectif de ces deux structures, et leurs interactions, lors de l’acquisition et de la consolidation d’une stratégie comportementale orientée vers un but. L’objectif des recherches réalisées au cours de ma thèse est donc d’étudier l’implication de l’hippocampe et du cortex préfrontal médian du rat dans ce processus. Notre première étude a montré l’existence d’un codage prospectif au sein des neurones du mPFC durant la réalisation d’une tâche de mémoire de travail.L’activité des neurones signale à la fois, la séquence temporelle comportementale, et l’anticipation de la récompense, et jouerait ainsi un rôle dans les fonctions exécutives. Dans la deuxième étude, nous nous sommes intéressés aux structures cérébrales impliquées dans la mise à jour de la valence du but ainsi que dans sa rétention à long terme. Nos résultats ont montré que l’inactivation de l’hippocampe intermédiaire provoque des déficits dans le traitement à court terme d’un changement de valence. En revanche, l’inactivation du mPFC empêche le stockage à long terme de ce changement. L’activité de ces deux structures serait donc essentielle pour effectuer une mise à jour en temps réel de la valence d’un but et pour sa consolidation en mémoire à long terme. Leur interaction permettrait d’adapter rapidement et de façon durable la stratégie comportementale de l’animal face aux changements de l’environnement. / Goal-directed behaviors are complex and involve a variety of cognitive processes. Medial prefrontal cortex (mPFC) plays a key role in behavioral planning. More over, cells in the rat mPFC show specific firing modulations at location with a high motivational value. Such neuronal activity could be essential for the setting up installation of a goal-directed behavior. Further more, navigating to a spatial goal requires the building of a stable presentation of the environment which is hippocampus-dependent. So far however, only few studies have addressed the respective role of these two structures, and their interaction, during the acquisition and the consolidation of a goal directed-behavior. The work conducted during my PhD thesis aimed at studying the role of hippocampus and prefrontal cortex in this process. In a first study,we showed the existence of a prospective coding by mPFC neurons when the rat performs a working memory task. Neuronal activity signals both, the temporal sequence of the behavior, and the prediction of reward. These neurons would play a role inexecutive functions. In a second study, we focused on cerebral structures involved in the updating of the value of a goal as well as in its long-term retention. Our results showed that the inactivation of the intermediate hippocampus causes deficit in the short-term processing of a change in the goal value. On the other hand, the inactivation of the mPFC prevents long-term consolidation of this change. Integrity of this two structures would therefore be essential to perform an on-line updating of the goal value and for its long-term consolidation. Their interaction would be necessary to rapidly adapt, and in a lasting manner, the behavioral strategy of the animal when it faces an environmental change.

Research has shown that students achieved higher standardized test scores in mathematics and gained more positive attitudes towards mathematics after learning from reform curricula. Because these studies involve actual students and teachers, there are classroom variables that are involved in these findings (Silver and Stein, 1996; Stein et al., 1996). To understand how much these curricula by themselves contribute to higher test scores, I have studied the cognitive demand of tasks in two traditional and two reform curricula. This work required the creation of a scale to categorize tasks based on their level of cognitive demand. This scale relates to those by Stein, Schoenfeld, and Bloom. Based on this task analysis, I have found that more tasks in the reform curricula require higher cognitive demand than tasks in the traditional curricula. These findings confirm other results that posing tasks with higher cognitive demand to students can lead to higher student achievement.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Quandles, which are algebraic structures related to knots, can be used to color knot diagrams, and the number of these colorings is called the quandle coloring invariant. We strengthen the quandle coloring invariant by considering a graph structure on the space of quandle colorings of a knot, and we call our graph the quandle coloring quiver. This structure is a categorification of the quandle coloring invariant. Then, we strengthen the quiver by decorating it with Boltzmann weights. Explicit examples of links that show that our enhancements are proper are provided, as well as background information in quandle theory.

In 2003 Cohn and Umans introduced a new group-theoretic framework for doing fast matrix multiplications, with several conjectures that would imply the matrix multiplication exponent $\omega$ is 2. Their methods have been used to match one of the fastest known algorithms by Coppersmith and Winograd, which runs in $O(n^{2.376})$ time and implies that $\omega \leq 2.376$. This thesis discusses the framework that Cohn and Umans came up with and presents some new results in constructing combinatorial objects called uniquely solvable puzzles that were introduced in a 2005 follow-up paper, and which play a crucial role in one of the $\omega = 2$ conjectures.