Le saumon Atlantique fait partie du patrimoine écologique et économique du bassin de l’Adour. Dans le cadre de la gestion actuelle du saumon dans ce bassin, l’origine natale des géniteurs, le taux de retour des individus d’origine piscicole, le taux de homing sur chaque sous-bassin ou encore le soutient par des géniteurs extérieurs au bassin de l’Adour sont des thématiques qui restent sans réponses. Ce projet propose donc de tester le potentiel de la géochimie des otolithes sur le saumon Atlantique du bassin de l’Adour. Nos travaux démontrent que la variation géographique de la composition chimique de l’eau dans 12 rivières colonisées par le saumon, associée à un enregistrement dans l’otolithe proportionnel à la signature géochimique du milieu de vie, permettent de discriminer l’origine géographique des individus. La combinaison des signatures élémentaires (Sr:Ca et Ba:Ca) et surtout l’isotopie du Sr (temporellement plus stable et sans fractionnement biologique) dans les otolithes améliore la précision du classement à l’échelle de la rivière de développement. En se basant sur la transmission de signatures géochimiques (élémentaires et isotopiques) transgénérationelles entre la femelle reproductrice et les otolithes des embryons produits par cette dernière, nous avons discriminé avec succès les individus nés en rivière de ceux nés en pisciculture. Le classement des géniteurs (180 individus) selon leur rivière natale a confirmé que le sous bassin du gave d’Oloron, et plus particulièrement le gave d’Ossau, reste le lieu qui produit le plus de saumon de retour. De façon non négligeable, le gave de Pau contribue lui aussi au renouvellement de la population (10 d’origine piscicole et 6 d’origine naturelle). 18 saumons sur 180 sont issus de l’alevinage (soit 10%); la majorité s’étant développée dans le sous-bassin du gave de Pau. Par ailleurs, nous avons mis à jour l’existence de périodes au cours de la vie des juvéniles (changements de milieu: sac vitellin—milieu extérieur et pisciculture—rivière) durant lesquelles l’enregistrement du Ba dans l’otolithe n’est pas en relation avec la chimie de l’eau. L’originalité de notre approche est d’avoir étudié l’influence des facteurs endogènes et environnementaux chez des poissons ayant vécu dans le milieu naturel ou ayant séjourné en milieu naturel contrôlé. Nos travaux mettent l’accent sur la complexité de l’intégration du rapport Ba:Ca dans l’otolithe et démontrent l’utilité des éléments traces et des isotopes du Sr comme « tag naturel » pour distinguer l’origine natale du saumon Atlantique. / The Adour basin holds one of the largest populations of Atlantic salmon in southern Europe exploited by commercial and sport fisheries. Determining the relative contributions of individual rivers and hatcheries to the Adour basin populations becomes crucial to understand key sources that contribute the most to its persistence. We successfully used Sr:Ca, Ba:Ca and 87Sr:86Sr ratios as natural tags for determining the natal origins of adults from 12 tributaries. Success in discriminating between fish from different sites was greatest using Sr isotopes since the latter remained relatively constant across years at a given location. Geochemical signatures from core regions of the otolith were also used to identify fish from hatchery or naturally spawned sources. The predominance of adults spawned in the Ossau River among returning adults corresponded with long-term juvenile production trends in the Ossau River. Despite the limited upstream accessibility of the Pau River, our study demonstrated that Atlantic salmon recruits can successfully leave this river to join the adult population in the Adour basin. We observed relatively clear separation between hatchery and wild juveniles using both Sr:Cacore (wild > 2.5 and hatchery < 0.80) and 87Sr:86Srcore (wild < 0.710 and hatchery > 0.710). The return of hatchery reared fish as adult spawners represented 10% of the total sampled fish we analyzed. Almost all adults, previously identified as belonging to the Ouzom River, were hatchery produced. Adults originated from the Pau River were either wild or hatchery reared fish. We also conducted field controlled experiments that characterized the elemental uptake process in juvenile Atlantic salmon otoliths during freshwater residency. Physiological effects influenced Ba deposition. Ba:Ca otolith profiles from hatchery-reared and field collected fish were characterised by a peak at yolk absorption mark. Hatchery-reared fish stocked in a river also displayed a peak of Ba:Ca following transfer which was not related to the water chemistry. Our experiment revealed a 20-day lag time between initial Ba:Cawater changes and Ba:Caotolith saturation. Results suggested that such effects should be considered during any attempts to determine rivers of origin of Atlantic salmon based on otolith elemental composition or reconstruct the movement of individual fish among and within streams.

Ce travail de thèse a porté sur de nouveaux implants intervertébraux en céramique. Au cours du projet dans son ensemble (projet européen Longlife), un nouveau matériau et de nouveaux designs d’implants ont été développés, ainsi qu’un nouveau test destiné à simuler les sollicitations subies in vivo par les implants afin d’estimer leur durée de vie. Le nouveau matériau développé est un composite triphasé composé d’une matrice de zircone dopée à l’oxyde de cérium (pour sa résistance au vieillissement), d’une phase globulaire d’alumine α (pour affiner la microstructure) et d’une phase allongée composée d’aluminates de strontium (pour augmenter la ténacité). La première partie du travail a consisté à caractériser ce matériau afin de connaître son comportement en termes de résistance mécanique, stabilité thermique, et de résistance à la stérilisation. Une deuxième partie a été consacrée au développement d’un test multiphysique regroupant les différentes sollicitations attendues par une prothèse in vivo (fatigue axiale, micro-séparation, vieillissement et usure). Il a fallu pour cela s’appuyer sur des simulations numériques qui ont permis de développer le système. Les données de la littérature ont été utilisées afin de choisir les paramètres du test (durée, fréquence, milieu d’essai). Enfin, la dernière partie de ce travail a été la mise à l’épreuve de différents prototypes à travers le test multiphysique et leur caractérisation en cours d’essai. Les principaux résultats de ce travail de thèse sont les suivants : le composite montre un comportement pseudo-plastique sous charge, avec une nette transformation de phase avant rupture, ce qui est positif dans le cadre de son utilisation. De plus, il ne semble pas affecté par la stérilisation. Du point de vue des implants développés, peu passent le test multiphysique. Le design, ainsi que la géométrie (notamment la clearance des échantillons) sont des leviers d’amélioration qui permettront d’augmenter la fiabilité des implants. / This work deals with the development of new intervertebral prostheses, made with ceramics. A whole European project, Longlife, was dedicated to the development of such implants. To achieve this goal, several axes have been followed: the synthesis of a new material, the development of new designs of intervertebral bodies, and the set-up of a new test aimed at reproducing in vitro the different solicitations undergone by an intervertebral implant in vivo. The new material developed is a triphasic composite composed of a matrix of ceria-doped zirconia (insensitive to ageing), a secondary globular phase of α-alumina (to reduce the grain size), and a third, elongated phase composed of strontium aluminates platelets (in order to improve fracture toughness). The first part of this work was to characterize this new material in order to forecast its behaviour under mechanical solicitation, thermal stability and resistance to sterilization. Secondly, the set-up of the new test is exposed. Different steps were chosen (axial fatigue, micro-separation, ageing and wear) in order to reproduce the “real-life” solicitations. To achieve this goal, Finite Elements simulations were performed, allowing the development of specific specimen holders that mimic the fixation of the implants in the vertebrae. The parameters of the test (duration, frequency, medium) were chosen after a details survey of the literature and of standards. At the end, we tested different prototypes trough this new multiphysic assessment set up. As a main result of this thesis, the chosen ceramic composite exhibits a pseudo-plastic behaviour, with a large deformation due to phase transformation before fracture, which is a positive result in the framework of the forecast applications. Moreover, the material doesn’t seem degraded by the sterilization processes. Concerning the multiphysic test, only a few implants resisted it. The design of the implants is a key-point, as well as the geometry (in particular, clearance seems to be critical).

Communication and reconnaissance systems are requiring increasing flexibility concerning functionality and efficiency for multiband and broadband frequency applications. Circuit-based reconfiguration mechanisms continue to promote radio frequency (RF) application flexibility; however, increasing limitations have resulted in hindering performance. Therefore, the implementation of a "wireless" reconfiguration mechanism provides the required agility and amicability for microwave circuits and antennas without local overhead. The wireless reconfiguration mechanism in this thesis integrates dynamic, fluidic-based material systems to achieve electromagnetic agility and reduce the need for "wired" reconfiguration technologies. The dynamic material system component has become known as electromagnetically functionalized colloidal dispersions (EFCDs). In a microfluidic reconfiguration system, they provide electromagnetic agility by altering the colloidal volume fraction of EFCDs - their name highlights the special considerations we give to material systems in applied electromagnetics towards lowering loss and reducing system complexity. Utilizing EFCDs at the RF device-level produced the first circuit-type integration of this reconfiguration system; this is identified as the coaxial stub microfluidic impedance transformer (COSMIX). The COSMIX is a small hollowed segment of transmission line with results showing a full reactive loop (capacitive to inductive tuning) around the Smith chart over a 1.2 GHz bandwidth. A second microfluidic application demonstrates a novel antenna reconfiguration mechanism for a 3 GHz microstrip patch antenna. Results showed a 300 MHz downward frequency shift by dielectric colloidal dispersions. Magnetic material produced a 40 MHz frequency shift. The final application demonstrates the dynamically altering microfluidic system for a 3 GHz 1x2 array of linearly polarized microstrip patch antennas. The parallel microfluidic capillaries were imbedded in polydimethylsiloxane (PDMS). Both E- and H-plane designs showed a 250 MHz frequency shift by dielectric colloidal dispersions. Results showed a strong correlation between decreasing electrical length of the elements and an increase of the volume fraction, causing frequency to decrease and mutual coupling to increase. Measured, modeled, and analytical results for impedance, voltage standing wave ratio (VSWR), and radiation behavior (where applicable) are provided.

Communication and reconnaissance systems are requiring increasing flexibility concerning functionality and efficiency for multiband and broadband frequency applications. Circuit-based reconfiguration mechanisms continue to promote radio frequency (RF) application flexibility; however, increasing limitations have resulted in hindering performance. Therefore, the implementation of a "wireless" reconfiguration mechanism provides the required agility and amicability for microwave circuits and antennas without local overhead. The wireless reconfiguration mechanism in this thesis integrates dynamic, fluidic-based material systems to achieve electromagnetic agility and reduce the need for "wired" reconfiguration technologies. The dynamic material system component has become known as electromagnetically functionalized colloidal dispersions (EFCDs). In a microfluidic reconfiguration system, they provide electromagnetic agility by altering the colloidal volume fraction of EFCDs - their name highlights the special considerations we give to material systems in applied electromagnetics towards lowering loss and reducing system complexity. Utilizing EFCDs at the RF device-level produced the first circuit-type integration of this reconfiguration system; this is identified as the coaxial stub microfluidic impedance transformer (COSMIX). The COSMIX is a small hollowed segment of transmission line with results showing a full reactive loop (capacitive to inductive tuning) around the Smith chart over a 1.2 GHz bandwidth. A second microfluidic application demonstrates a novel antenna reconfiguration mechanism for a 3 GHz microstrip patch antenna. Results showed a 300 MHz downward frequency shift by dielectric colloidal dispersions. Magnetic material produced a 40 MHz frequency shift. The final application demonstrates the dynamically altering microfluidic system for a 3 GHz 1x2 array of linearly polarized microstrip patch antennas. The parallel microfluidic capillaries were imbedded in polydimethylsiloxane (PDMS). Both E- and H-plane designs showed a 250 MHz frequency shift by dielectric colloidal dispersions. Results showed a strong correlation between decreasing electrical length of the elements and an increase of the volume fraction, causing frequency to decrease and mutual coupling to increase. Measured, modeled, and analytical results for impedance, voltage standing wave ratio (VSWR), and radiation behavior (where applicable) are provided.

Ceramics are distinguished from metals and polymers by their inorganic nature and lack of metallic properties. They can be highly crystalline to amorphous, and their physical and chemical properties can vary widely. Ceramics can, for instance, be made to resemble the mineral phase in bone and are therefore an excellent substitute for damaged hard tissue. They can also be made porous, surface active, chemically inert, mechanically strong, optically transparent or biologically resorbable, and all these properties are of interest in the development of new materials intended for a wide variety of applications. In this thesis, the focus was on the development of different ceramics for use in the controlled release of drugs and ions. These concepts were developed to obtain improved therapeutic effects from orally administered opioid drugs, and to reduce the number of implant-related infections as well as to improve the stabilization of prosthetic implants in bone. Geopolymers were used to produce mechanically strong and chemically inert formulations intended for oral administration of opioids. The carriers were developed to allow controlled release of the drugs over several hours, in order to improve the therapeutic effect of the substances in patients with severe chronic pain. The requirement for a stable carrier is a key feature for these drugs, as the rapid release of the entire dose, due to mechanical or chemical damage to the carrier, could have lethal effects on the patient because of the narrow therapeutic window of opioids. It was found that it was possible to profoundly retard drug release and to achieve almost linear release profiles from mesoporous geopolymers when the aluminum/silicon ratio of the precursor particles and the curing temperature were tuned. Ceramic implant coatings were produced via a biomimetic mineralization process and used as carriers for various drugs or as an ion reservoir for local release at the site of the implant. The formation and characteristics of these coatings were examined before they were evaluated as potential drug carriers. It was demonstrated that these coatings were able to carry antibiotics, bisphosphonates and bone morphogenetic proteins to obtain a sustained local effect, as they were slowly released from the coatings. / <p>Felaktigt tryckt som Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 710</p>

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Call number: LD2668 .T4 1986 C52 / Master of Science / Geology

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In this thesis the enriched stable isotope marking technique was examined to determine its validity and effectiveness in marking of Lake Sturgeon fin rays. The enriched stable isotope marking technique uses stable isotopes of elements that replace calcium in boney tissue, which are fixed in nature, however in laboratory settings can be easily manipulated. Manipulated ratios of naturally occurring isotopes can be determined from a small sample of the fin ray, thus allowing for the discrimination of fish stocks. Further, the thesis examined the underlying assumptions for strontium and barium into the Lake Sturgeon. For the marking technique to work, strontium and barium must be taken up from the environment and accumulated long-term in boney tissue. Net flux and tissue retention of strontium is reported and the research has demonstrated that enriched stable isotopes can be successfully used to mark the fin ray of Lake Sturgeon for long-term stock discrimination. / October 2015

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