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No description available.

This investigation examined the diet, growth, movement, population genetics, and possible consumption demands of an introduced blue catfish Ictalurus furcatus population in Lake Norman, North Carolina. Clupeids, Corbicula fluminea, and Chara were the predominant food items (percent stomach contents by weight) found in blue catfish, and varied by season, lake-region, and fish size-class. Lake Norman blue catfish grow at a slower rate than has been reported for other reservoir populations, with fair to poor body conditions (Wr<85) early in life, but improving with increases in length (Wr>95). Movements and home ranges of blue catfish in Lake Norman were extremely varied, but individual blue catfish did establish specific seasonal home ranges and exhibited site fidelity. A spawning area in the upper region of the lake was identified and data suggested that blue catfish may have segregated populations within Lake Norman. The Lake Norman blue catfish population exhibited relatively little genetic variability, and was genetically differentiated from populations from Santee-Cooper, SC, and Arkansas. Genetic diversity could have been limited by a population bottleneck at the founding of the population or in subsequent generations. A consumption model indicated that 5.0 kg/ha to 8.3 kg/ha of clupeid standing stock could be eaten annually by blue catfish in Lake Norman based on percent stomach contents by weight data, and 21 kg/ha to 42 kg/ha based on percent caloric contribution calculations. This may reduce the possible production of other game fish species, including the put-grow-take striped bass Morone saxatilis fishery. / Master of Science

Biodiversity monitoring and predictions of species occurrence are essential to develop outcome-oriented conservation management plans for endangered species and assess their success over time. To assess distribution and patterns of habitat use of large mammal assemblages in Thailand, with a focus on the endangered dhole (Cuon alpinus), I first implemented a long-term camera-trapping project carried out with park rangers from October 2003 through October 2007 in Khao Yai National Park. This project was extremely successful and may serve as a regional model for wildlife conservation. I found significantly lower relative abundance indices for carnivore species, and collectively for all mammals compared to data obtained in 1999-2000, suggesting population declines resulting from increased human activity. I integrated this data into maximum entropy modeling (Maxent) to further evaluate whether ranger stations reduced poaching activity and increased wildlife diversity and abundances. I then conducted a focused camera trap survey from January 2008 through February 2010 in Khao Ang Rue Nai Wildlife Sanctuary to gather critical baseline information on dholes, one of the predator species that seemed to have declined over time and that is exposed to continued pressure from humans. Additionally, I led a collaborative effort with other colleagues in the field to collate and integrate camera trap data from 15 protected areas to build a country-wide habitat suitability map for dholes, other predators, and their major prey species. The predicted presence probability for sambar (Rusa unicolor) and leopards (Panthera pardus) were the most important variables in predicting dhole presence countrywide. Based on my experience from these different field ecological surveys and endeavors, it became clear that local people's beliefs may have a strong influence on dhole management and conservation. Thus, I conducted villager interview surveys to identify local attitudes towards dholes, document the status of dholes in wildlife sanctuaries adjacent to Cambodia, and determine the best approach to improve local support for dhole conservation before proceeding with further field studies of the species in Thailand. A photograph of a dhole was correctly identified by only 20% of the respondents. My studies provide evidence that some protected areas in Thailand continue to support a diversity of carnivore speices of conservation concern, including clouded leopards (Neofelis nebulosa), dholes, and small felids. However, dholes' impact on prey populations may be increasing as tiger (Panthera tigris) and leopards are extripated from protected areas. The next step in dhole conservation is to estimate the size and stability of their fragmented populations and also focus on maintaining adequate prey bases that would support both large felids and dholes

This project was initiated in an attempt to address the paucity of data on Asiatic black bears (Ursus thibetanus) in Mainland China. Field work was carried out from May 2004 – August 2006 within the Tangjiahe National Nature Reserve in northwestern Sichuan Province, China. Initial methodology relied on trapping and GPS radio-collaring bears, but due to extreme difficulty with capturing a sufficient sample size, I expanded the study to include reproduction, feeding analysis from scats and sign, and occupancy modeling from sign surveys. I documented the home ranges of an adult female (100% MCP = 107.5km2, n=470 locations) and a sub-adult female (100%MCP = 5.9km2, n=36 locations) Asiatic black bear. I also documented two birthing occasions with a total of four male cubs produced and eight bear den sites. I collected feeding data from 131 scat samples and 200 bear sign transects resulting in 50 identified food items consumed by Asiatic black bears. I also employed the program PRESENCE to analyze occupancy data using both a standard grid repeated sampling technique and an innovative technique of aging bear sign along strip transect surveys to represent repeated bear occupancy over time. Conservation protection patrolling and soft mast were shown to be the most important factors determining the occupancy of an area by Asiatic black bears in Tangjiahe Nature Reserve, Sichuan Province, China. / Master of Science

Admiral Thomas C. Hart And The Demise Of The Asiatic Fleet 1941 – 1942 is a chronicle of the opening days of World War II in the Pacific and the demise of the U.S. Navy’s Asiatic Fleet. Beginning with the background of Four Star Admiral Thomas Hart, this chronicle shows the history of the nearly obsolete ships that fought in the beginning of World War II. The reader will come to realize how and why this fleet ceased to exist within ninety days from the start of the war. Historical evidence will show that the damage inflicted on the Japanese was much greater than what was recorded in popular history. Hart was relieved of his command due to political considerations but not a single ship was lost while he was in command of the Asiatic Fleet. Hart fulfilled his orders to preserve the integrity and safety of the American Asiatic Fleet.

La compréhension de l'émergence des maladies infectieuses végétales causées par les bactéries passe par l'identification des populations sources, des routes d'invasion et des voies de dissémination, ainsi que par l'estimation des paramètres biotiques et abiotiques associés. Xanthomonas citri pv. citri (Xcc) est l'agent pathogène responsable du chancre Asiatique des agrumes. La bactérie est distribuée dans plusieurs pays agrumicoles du monde et listée comme organisme de quarantaine par ceux où elle est absente. Nous avons abordé l'épidémiologie moléculaire de Xcc à deux échelles spatio-temporelles grâce à un schéma de 14 microsatellites (MLVA-14) et un schéma de 31 marqueurs minisatellites (MLVA-31). Le typage MLVA-14 s'est montré adapté au génotypage d'une bactérie monomorphe comme Xcc. Le typage MLVA-31 a permis de diviser le pathovar Xcc en quatre groupes génétiques distincts correspondant aux différences de gammes d'hôtes mise en évidence chez cette bactérie. Le pathotype A (souches à large gamme d'hôtes parmi les rutacées) est séparé en deux groupes génétiques, tandis que les pathotypes A* et Aw (souches à gamme d'hôtes restreinte au limettier Mexicain et quelques espèces proches) constituent chacun un groupe génétique. Alors que l'expansion géographique de Xcc depuis son aire d'origine dans la première moitié du XXème siècle a quasi exclusivement concerné un seul groupe génétique, trois des quatre groupes décrits ont contribué à l'émergence de Xcc en Afrique au cours de la dernière décennie. La bactérie est pré-adaptée et a été introduite avec son hôte depuis sa population d'origine, faisant de la barrière migratoire la seule étape à franchir pour rencontrer un succès d'invasion. L'objectif de cette thèse a été de décrire les différentes populations émergentes grâce à des approches d'épidémiologie moléculaire et inférentielles, et identifier les différentes origines, routes et acteurs de la dissémination. Nous avons dans un premier temps montré la coexistence de deux groupes génétiques distincts au Mali : DAPC1 qui est dispersé dans quatre provinces du pays et DAPC2 qui est resté cantonné à l'espace péri-urbain de Bamako. L'analyse de l'émergence de Xcc au Sénégal a révélé le succès invasif de DAPC2 dans un autre environnement. La structure des populations DAPC1 du Mali et DAPC2 du Sénégal suggèrent que les plants de pépinières constituent une voie de dissémination majeure dans ces pays. À l'opposé, DAPC2 de Bamako n'est pas détecté en pépinières au Mali et n'a pas montré de caractère invasif. L'existence d'une population « tête de pont » invasive de souches DAPC1 au Mali donnant lieu à une épidémie au Burkina Faso a été mise en évidence par une approche ABC (calcul Bayésien approché). Les populations DAPC2 du Mali et du Sénégal ne présentent pas de lien épidémiologique direct mais partagent des liens de parenté avec des souches présentes dans le sous-continent Indien. Dans un deuxième temps, l'analyse d'une population de souches appartenant au pathotype A* en Ethiopie nous a permis de procéder à des estimations de paramètres démographiques, tels que les tailles efficaces. Nous avons montré que l'approche inférentielle nous permettait d'éclairer l'histoire démographique de Xcc dans un cas d'émergence, et de mettre en avant une dynamique saisonnière accentuant probablement le déséquilibre mutation-dérive lié à la situation d'émergence. L'émergence de Xcc en Afrique est principalement associée aux activités humaines. Sa dissémination locale et globale peut alors être considérablement limitée par des mesures de gestion plus stricte au niveau des pépinières et des flux de commerces. / Several plant emerging infectious diseases are caused by bacteria. To improve our understanding of their emergence, a description of the emerging populations, the reconstruction of invasion routes and pathways, as well as the identification of involved biotic and abiotic parameters are fundamental. The bacterium Xanthomonas citri pv. citri (Xcc) is responsible for Asiatic citrus canker. It is present in many citrus producing countries and listed as a quarantine organism in canker-free countries.Two MLVA schemes were used for molecular epidemiological analyses of Xcc. The first one, MLVA-14, targeted 14 microsatellite markers, and is useful to describe the genetic diversity of this monomorphic bacterium. The second, MLVA-31, targeted 31 minisatellite markers, is suited to global epidemiology analyses. Based on MLVA-31 data, Xcc is divided in four genetic groups (referred to as DAPC clusters) corresponding to Xcc pathotype classification based on host range. Three pathotypes were described: pathotype A strains are able to infect most citrus species, while pathotypes A* and AW strains are naturally restricted to fewer host species.DAPC 1 is responsible for almost all cases of geographical expansion of Xcc over the first half of the 20th century, we show that three Xcc genetic clusters have emerged in Africa over the last decade. Xcc is pre-adapted to its host species. Invasive success of Xcc is then mostly conditioned by migration events. Our objectives were to describe these invasive populations using a molecular epidemiology approach and to assess the origin, routes and actors of this dissemination in Africa. Two genetic clusters were found in Mali: DAPC1 is present in four provinces while DAPC2 is restricted to the Bamako urban environment. In contrast, DAPC2 emerging populations in Senegal showed an invasive succes in an other environment. Populations structures of DAPC1 in Mali and DAPC2 in Senegal highlighted the role of nurseries in Xcc dissemination. On the contrary, DAPC2 strains in Bamako were not detected in Malian nurseries and showed a limited invasive success. Approximate Bayesian Computation highlighted an invasive bridgehead scenario between DAPC1 in Mali and Burkina Faso. DAPC2 populations in Mali and Senegal were not found epidemiologically related but were genetically related to strains previously reported from the Indian subcontinent.Demographic parameters inference, such as effective population sizes, were inferred from Ethiopian pathotype A* populations. The inference approach was useful to decipher the demographic history of this emerging population, and suggested seasonal fluctuations in population sizes over time.Emergence of Xcc in Africa was found strongly related to human activities. Therefore, the local and global dispersion could be limited by a better management of nurseries and trade.

African savanna elephants (Loxodonta africana) and Asian elephants (Elephas maximus) are a focus of welfare research in zoos due to their high intelligence, complex social structure, and sheer size. Due to these challenges, some argue that zoos are inherently incapable of providing appropriate care for elephants, while others believe that zoos can fulfill the needs of these species with improved husbandry. There is a general consensus from both within and outside of zoos, however, that zoos must improve their elephant programs or cease exhibiting these animals altogether. Now more than ever, applied research on zoo elephant welfare is needed to provide context for this debate. Researchers are interested in how far zoo elephants walk due to the potential health and welfare benefits of walking in these highly mobile species. Zoo researchers recently adopted GPS technology to study elephant walking, and preliminary evidence suggests that African elephants in large zoo exhibits walk distances that correspond with wild elephants under non-extreme conditions. However, data are limited from Asian elephants and from elephants in more typically-sized exhibits. In Chapter Two, I discuss important methodological considerations of utilizing GPS in a zoo environment, including an introduction to the technology, sources of error and mitigation, methods to improve GPS performance, and possible effects of GPS device attachment on animal behavior. This review shows GPS performance is adequate for tracking zoo elephant walking when proper methodological techniques are applied, and should serve as a useful reference for zoo researchers considering using GPS. In Chapter Three, I used GPS anklets to measure outdoor daily walking distance in 56 adult female African (n = 33) and Asian (n = 23) elephants housed in 30 zoos. I collected 259 days of data and found that elephants walked an average of 5.34 km/day with no significant difference between species. Multivariate regression models predicted that elephants with more dynamic feeding regimens (more diverse feeding types and frequencies; unscheduled feeding times) will walk more. Distance walked was also predicted to be higher in elephants that spend time in a greater number of different social groups. Distance walked was predicted to decline with age. Finally, I found a significant negative correlation between distance walked and nighttime space experience. The results of the analysis suggest that zoos that want to increase walking in their elephants need not rely solely on larger exhibits, but can increase walking by adding quality and complexity to exhibits. However, my results failed to establish a definitive link between walking distance and other validated measures of elephant welfare. Thus, the direct health and welfare benefits of walking in zoo elephants remain unresolved. Resting behaviors are an essential component of animal welfare, but have received little attention in zoological research. In Chapter Four, I used accelerometers in anklets to complete the first large-scale multi-species investigation of zoo elephant recumbence. I collected 344 days of data from 72 adult female African (n = 44) and Asian (n = 28) elephants at 40 zoos. I found that African elephants are recumbent an average of 2.14 hours/day, which is significantly less than Asian elephants at 3.22 hours/day. Multivariate regression models predicted that African elephant recumbence increases when they experience more space at night, and Asian elephant recumbence increases when they spend time housed alone. Both species showed a similar response to substrate, such that African elephants spending time on all-hard substrates are predicted to be recumbent less, while Asian elephants spending time on all-soft substrates are predicted to be recumbent more. The discovery that occasional non-recumbence is a common behavior in zoo elephants also introduces a new area of research that may have important animal welfare consequences. Finally, this study established that zoos should continue their efforts to replace hard substrate with soft substrate in order to provide zoo elephants with environments that facilitate recumbence. Overall, this work assessed walking and recumbence in zoo elephants, which will allow zoos to gauge the prevalence of these behaviors in their elephants as compared to the sub-population studied here. A variety of factors that are associated with these behaviors were also identified. With this information, zoos can prioritize modifications to their facilities and animal management programs to create an environment that encourages zoo elephants to express walking and recumbence behavior, should they choose to do so. This work is one component of the Elephant Welfare Project, the largest zoo animal welfare project ever undertaken, and is unprecedented in both scope and scale. The project was funded by the Institute of Museum and Library Services (IMLS), an independent, U.S., federal, grant-making agency that supports libraries, museums, and zoos. At the time of this writing, the first manuscripts from this project are being submitted to academic journals. These papers will describe the prevalence and distribution of a variety of elephant behaviors and welfare indicators, serve as a benchmark for future elephant welfare studies, and aid in decision making with regard to best practices in elephant management.

Le cuivre, souvent utilisé pour gérer les bactérioses en agriculture, est largement utilisé dans la lutte contre Xanthomonas citri pv. citri (Xcc), agent responsable du chancre asiatique des agrumes. La récente détection d’un phénotype résistant au cuivre (CuR) chez Xcc dans deux territoires ultramarins français a motivé une étude génomique qui a révélé, dans les génomes de souches CuR, la présence d’un plasmide conjugatif portant un transposon adaptatif de type Tn3. Sa conservation chez plusieurs espèces de Xanthomonas phytopathogènes suggère le rôle des transferts horizontaux (HGT) dans l’adaptation de Xcc. Nous avons donc analysé, dans l’océan Indien, les relations phylogénétiques de souches sensibles et CuR en prenant en compte à la fois les SNP et les variations de contenu en gènes. La datation de la phylogénie a permis de formuler des scenarii d’introduction de la bactérie dans la région. La phylogénie a montré une structure géographique forte à l’échelle de l’océan Indien, qui s’estompe à l’échelle de la Réunion et disparaît à l’échelle du verger. Au sein des vergers, l’admixture est un élément favorable aux HGT entre souches génétiquement différentes. Ils sont pourtant peu caractérisés chez les bactéries du genre Xanthomonas. Nous avons ainsi analysé la dispersion de l’ensemble des gènes plasmidiques connus de la famille des Xanthomonadaceae dans l’ensemble des génomes bactériens de NCBI, mettant en évidence à la fois la forte prévalence des gènes plasmidiques au sein des Xanthomonadaceae mais aussi la limite taxonomique forte à leur échange par conjugaison. L’importance du mosaïsme plasmidique, en partie lié aux éléments mobiles a aussi été illustrée. L’ensemble de nos résultats souligne l’importance des HGT dans l’évolution des bactéries du genre Xanthomonas, et la nécessité de caractériser finement le contenu et le fonctionnement du génome environnemental des Xanthomonadaceae pour appréhender au mieux l’adaptation de ces bactéries phytopathogènes. / Copper, frequently used in agriculture to control bacterial diseases, is commonly used against Xanthomonas citri pv. citri (Xcc), the bacterial agent of Asiatic citrus canker. The recent detection of a copper-resistant phenotype in two French overseas regions motivated a genomic study which revealed, in copper-resistant (CuR) strains, a conjugative plasmid encoding an adaptive transposon of the Tn3 family. Its conservation in several Xanthomonas species suggested the role of horizontal gene transfer (HGT) in Xcc adaptation. We therefore analyzed the evolutionary history of susceptible and CuR Xcc strains in the Indian Ocean using both SNP and gene content variations. The dating of the obtained phylogeny allowed us to hypothesize the history of Xcc introduction into the region. The phylogeny showed a strong geographic structure among islands of the Indian Ocean region, which faded at the Réunion scale and disappeared at the grove scale. Among the groves, admixture is a factor favoring HGT between genetically distinct strains. This form of evolution is however largely uncharacterized in the Xanthomonas genus. To fill this gap, we searched genetic homology between the whole known plasmid gene content of the Xanthomonadaceae family and the complete set of genomes hosted in NCBI databases. We highlighted both the ubiquity of plasmid genes in the Xanthomonadaceae family and the taxonomical barrier of their sharing by conjugation. The small fraction of genes that were exchanged through the complete sharing of plasmids also revealed the importance of plasmid mosaicism, partly due to mobile genetic elements. Taken together, our results highlight the importance of bacterial communities in the evolution of phytopathogenic bacteria of the Xanthomonas genus, and the need for a precise characterization of the content and the functioning of the Xanthomonadaceae environmental genome in order to fully apprehend the adaptation of these phytopathogenic bacteria.

No description available.