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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

An Evaluation of Bull Trout Movement Dynamics in the Walla Walla River

Newlon, Courtney 01 December 2018 (has links)
Bull trout are a fish species listed as threatened under the Endangered Species Act.Historically, they ranged from Northern California at the southernmost extent, into Canada at the northern most extent, and east into Nevada and Montana. Bull trout are highly migratory and require large, unfragmented habitats to persist and are thus highly susceptible to human induced land-use practices. The goal of my thesis was to obtain a better understanding of bull trout movement patterns in the Walla Walla River, Washington using complimentary techniques; Passive Integrated Transponder (PIT)technology and otolith microchemistry. PIT tags can be injected into a fish body cavity, similar to how pets are “chipped”, and as the fish swim through antennas placed in the river, their location and movements are be documented.Otolith microchemistry is a technique that is similar to analysis of tree rings. The otolith, a hard bony structure of a fish’s ear, develops over a lifetime and as the rings of the otolith are created the chemical signature in the water in which they live is recorded and can be compared to chemical makeup of water samples collected through the river system. Using these two techniques, I found that the age or size of a fish and the season are important factors to explain both a fish’s movements and where in the river a fish might be located at a given time. Knowing at what size, age and season a fish is attempting to migrate allows managers to provide the best possible river conditions (e.g., temperatures, flow) to allow for unimpeded migrations to occur and to foster conservation and recovery of bull trout populations.
52

Modification de domaines de liaison à la choline en vue de leur utilisation comme étiquette de purification de protéines recombinantes.

DE SCHREVEL, Nathalie 21 October 2005 (has links)
Le but de ce travail consiste à créer un nouveau tag de purification d'affinité permettant la purification de protéines recombinantes sur une matrice DEAESépharose Fast Flow. Dans la nature, certaines protéines de surface de Streptococcus pneumoniae sont liées à la paroi bactérienne par des interactions non convalentes faisant intervenir des molécules de choline présentes sur les acides téichoiques et lipotéichoiques. Ces protéines de surface présentent une organisation modulaire avec le domaine catalytique et le domaine de liaison fonctionnant indépendamment l'un de l'autre. La choline étant un analogue structural du DEAE, l'étude des domaines de liaison à la choline constitue une approche de choix pour concevoir un tag de purification présentant une affinité pour le DEAE-Sépharose. Nous avons plus particulièrement travaillé sur la N-acétyl-L-alanine amidase (LytA) qui dégrade spécifiquement certaines liaisons du peptidoglycan de la paroi de Streptococcus pneumoniae. Son domaine de liaison à la choline C-terminal (ClytA) se compose de six motifs répétés imparfaits, constitué chacun d'une vingtaine de résidus. Deux stratégies ont été développées pour concevoir le tag de purification. D'une part, 126 motifs répétés de 19 domaines de liaison à la choline ont été alignés pour définir une séquence consensus. Cette approche a permis de mettre en évidence les résidus importants conservés parmi les motifs répétés. D'autre part, nous avons construit des protéines de fusion portant des fragments du domaine de liaison ClytA de longueur variable. Des expériences de chromatographies sur matrice DEAESépharose nous ont permis d'isoler un petit fragment de ClytA(L234), présentant toujours une affinité spécifique pour le DEAE Sépharose. Cette affinité est maintenue lorsque le fragment L234 est fusionné à l'extrémité C-terminale d'une autre protéine reporter. Cependant, nos résultats suggèrent que le candidat tag L234 est instable et qu'il conduit à l'insolubilisation de la protéine de fusion lors de la production de celle-ci dans Escherichia coli. Afin d'améliorer la solubilité/stabilité du fragment L234, nous avons développé trois approches bioinformatiques. Cellesci ont permis de définir trois groupes de mutations permettant d'améliorer potentiellement la solubilité et/ou la stabilité du fragment L234. Les tags mutants ont été construits et fusionnés à l'extrémité C terminale de la thiorédoxine. Le premier tag mutant, EDE-L234, est plus soluble que la version non mutante mais présente une perte d'affinité pour le DEAE Sépharose. Le second mutant, NG-L234, ne montre pas d'augmentation de solubilité et perd également une partie de son affinité pour la matrice. Le troisième tag mutant, V1V2V3-L234, présente une augmentation d'affinité pour le DEAE-Sépharose bien que sa solubilité reste inchangée.
53

Kodväxling : en studie om kodväxling i Gun-Britt Sundströms roman Maken - en förhållanderoman

Habibovic, Asima January 2012 (has links)
Syftet med denna uppsats är att undersöka hur kodväxling sker i Gun-Britt Sundströms roman Maken – en förhållanderoman. Denna lingvistiskt orienterade studie utgår från Poplacks tre stadier: tag-kodväxling, intrasentiell kodväxling och intersentiell kodväxling. Den valda metoden för denna undersökning är närläsningsmetoden, en metod som sätter texten i fokus. I forskningsbakgrunden tar jag upp olika definitioner av ordet kodväxling. Jag presenterar även tidigare forskning kring kodväxling men fokus ligger mest på Poplack och Meyers tidigare studier. Resultaten av analysen visar på att kodväxling sker ofta i Gun-Britt Sundströms roman. Dessutom är det den intrasentiella samt den intersentiella kodväxlingen som dominerar i romanen. Något exempel av tag-kodväxling kunde inte hittas i romanen. Kodväxlingen berör flera språk; norska, danska, äldre nysvenska, tyska, engelska och franska.
54

Treffpunkt Bibliothek

10 January 2013 (has links) (PDF)
In diesem Jahr wurde am 24. Oktober bereits zum fünften Mal der „Tag der Bibliotheken“ begangen. Wieder schloss sich die Aktionswoche „Treffpunkt Bibliothek – Information hat viele Gesichter“ an. In vielen Veranstaltungen präsentierten sich die Bibliotheken als Kultureinrichtungen und wiesen auf ihre vielfältigen Angebote hin.
55

Etude des systèmes RFID opérants en rétrodiffusion modulée ultra large bande

Guidi, Francesco 15 May 2013 (has links) (PDF)
Depuis quelques années le nouveau paradigme d'internet des objets, qui se traduit par la connexion des objets de la vie quotidienne à internet grâce à des dispositifs électroniques intégrés, est devenu plus qu'un simple concept et a commencé à entrer dans la réalité. Il en est ainsi des systèmes d'identification par radiofréquence (RFID), qui font partie des technologies disponibles. Lorsque le coût et la taille des tags deviennent des exigences prépondérantes, l'adoption de tags (semi-)passifs fondés sur la modulation d'un signal rétrodiffusé représente une solution attractive. En outre, l'utilisation de techniques ULB apporte des avantages propres à favoriser le remplacement d'une partie des systèmes RFID actuels qui souffrent de certains défauts tels qu'une trop forte consommation ou une faible robustesse en présence d'interférence. La thèse de doctorat se place dans ce contexte: elle a pour objectif l'étude des systèmes ULB RFID semi-passifs et se situe dans le cadre du projet européen SELECT, qui vise à développer et à évaluer un tel système. La prise de conscience qu'il était fondamental de comprendre les mécanismes électromagnétiques intrinsèques à la communication lecteur-tag, préalablement à la conception du système, s'est traduite par la mise en oeuvre d'une collaboration franco-italienne dans le cadre d'une cotutelle de thèse. C'est donc au départ autour d'une analyse fine et d'une modélisation des aspects antennaires et du canal radio entre le lecteur et le tag que la 1re partie du travail s'est construite. La 2nde partie a exploité ces travaux pour l'élaboration des schémas de modulation et de codage du lecteur et du tag pour les systèmes semi-passifs.
56

Tags: Augmenting Microkernel Messages with Lightweight Metadata

Saif Ur Rehman, Ahmad January 2012 (has links)
In this work, we propose Tags, an e cient mechanism that augments microkernel interprocess messages with lightweight metadata to enable the development of new, systemwide functionality without requiring the modi cation of application source code. Therefore, the technology is well suited for systems with a large legacy code base and for third-party applications such as phone and tablet applications. As examples, we detailed use cases in areas consisting of mandatory security and runtime veri cation of process interactions. In the area of mandatory security, we use tagging to assess the feasibility of implementing a mandatory integrity propagation model in the microkernel. The process interaction veri cation use case shows the utility of tagging to track and verify interaction history among system components. To demonstrate that tagging is technically feasible and practical, we implemented it in a commercial microkernel and executed multiple sets of standard benchmarks on two di erent computing architectures. The results clearly demonstrate that tagging has only negligible overhead and strong potential for many applications.
57

Characterization and Performance Analysis of UHF RFID Tag for Environmental Sensing Applications

Li, Zhenzhong January 2012 (has links)
Passive radio frequency identification (RFID) tag has been shown efficient in item tracking and management in the supply chain. Attracted to low weight and small size of wireless nodes, some research work was conducted to extend the RFID advantage into environmental sensing applications. The concept is to using tag frequencies as sensing parameters. When variation occurs in the surrounding environment, such as temperature and humidity level, the operation frequencies of tags would be shifted, and such shift can be used to identify the degree of variation in the environment. One challenge of RFID tag is the distortion from other surrounding objects, the existence of obstacles and metals can have greatly impact on the sensing performance in both accuracy and sensing range. This thesis work conducts an investigation of the performance of a passive radio-frequency identification (RFID) based system. The investigation systematically probed the effects of passive RFID tag orientation and obstacles (blocking line-of-sight between a reader and a tag) as well as reading period (the time required for successful detection) on the range of detection. In the absence of obstacles, optimized tag orientation improved the system reliability and range of detection. At a reading distance where tag readability became unstable, increasing the reading period led to a higher reliability. A theoretical model was also established and was in good agreement with measurement results, providing a simple guideline to the further experiments. This work would also advance the knowledge understanding on wireless sensing on metal effect, humidity and temperature.
58

Evaluation of collared peccary translocations in the Texas Hill Country

Porter, Brad Alan 17 September 2007 (has links)
Historically, the collared peccary (Tayassu tajacu) occurred throughout much of Texas including the northern portion of the Texas Hill Country. Remaining peccary populations were extirpated in much of their former range due to over harvest and habitat loss. In 2004, efforts to restore peccary populations to the Texas Hill Country began when Texas Parks and Wildlife Department biologists translocated 29 collared peccaries into the 2,157 ha, Mason Mountain Wildlife Management Area (MMWMA). I evaluated the success of peccary translocations for mixed and intact family groups by comparing survival, ranges, and dispersal of translocated, radio-tagged peccaries. In addition, I evaluated two release methods (soft versus hard) to determine differences in population demographics. I found that peccary ranges and dispersal patterns did not differ (P > 0.05) between intact and mixed groups or release method (soft versus hard). However, I did find that peccary fidelity to release sites was greater for soft releases of family groups. Individuals from the soft release group dispersed the shortest distance and stayed on MMWMA. Only 2 individuals from the hard releases stayed on MMWMA while the rest (19 individuals) dispersed 4-8 km. Future peccary translocations should emphasize the release method employed and family structure of individuals released to improve translocation effectiveness in establishing populations in target areas.
59

Studies on the migration pattern of yellowfin tuna (Thunnus albacares) around the fish aggregating devices (FADs) off South-Western Taiwan.

Hung, Mine-Kune 23 July 2008 (has links)
The spatial movements of yellowfin tunas around the fish aggregating devices which were anchored below 40 meters water with a VEMCO VR2 receiver were investigated using ultrasonic telemetry tags V9P (VEMCO VP9-2H-S256). The experiment was conducted in the Shiao-Liu-Chiu Island of Taiwan from July to September, 2007. A pair of VEMCO VR2 receivers was separated by 400 meter distances in west of south sea ,Taiwan. A total of 9 tagged fishes with different sizes were monitored for maximum 19 days. Preliminary results showed that juvenile fish stayed longer and closer within FADs than the adult fish. Fish could move vertically to as low as 160 meters at daytime. They avoid the surface water where the temperature reach 30oC. In nighttime, juvenile fish that has fork length smaller than 55cm generally moves to the surface mixed layer. On the horizontal movement, there are three types. A) fish stays at FADs site. B) Fish move in and out FADs sites for a few hours period. C) fish moves away from FADs site for a long times (maybe 2~3 days). Sometimes juvenile fish would have B) or C) moved away from the FAD devices during dawn and dusk, and back at daytime. But this would not occurred with large fish. We estimated the attraction radius of FADs at least 1 km.
60

Design of Broadband RFID Tag Antennas for Application in Near and Far Fields in the UHF Band

Lu, Yi-Sheng 24 July 2008 (has links)
In this thesis, we propose the method to design tag antennas, which are suitable for radio frequency identification system. The fact that the tag antennas design comes with single layer printed circuit board can achieve cost down of the antennas. For the tag antennas, the aim is to design the RFID tag antenna operating in 860¡V960 MHz which are suitable for both the near- and far-field operations worldwide. The method we use to design tag antenna is the dual loop form with Bow-tie antenna, and we focus on the impedance conjugate matching between the RFID strap and antenna to increase impedance bandwidth and improve reading performance. We can adjust parameter to be suitable for different RFID strap in the design framework. The dual loop structure carries out power coupling efficiently in the near field and can allow the RFID strap to work even in the weak EM wave. According to the result of power coupling simulation, we analyze and discuss which factor will affect the reliability of the identification. Such reliability will help to build RFID system.

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