La région étudiée est un fragment du bassin molassique périalpin cénozoique. Dans le bas Dauphiné affleurent uniquement des terrains néogènes et quaternaires. Le Miocène et le Pliocène sont étudiés.

A dor orofacial compreende todas as dores que envolvem os tecidos moles e mineralizados da cavidade oral e da face, pode ser referida na região da cabeça e/ou pescoço. A etiologia da disfunção temporomandibular (DTM) é multifatorial, são distúrbios musculoesqueléticos que afetam o sistema estomatognático, os músculos mastigatórios e/ou estruturas associadas. Uma disfunção muito prevalente é a dor miofascial. O front-plateau é um dispositivo de resina acrílica instalado nos dentes superiores anteriores, que desoclui os dentes posteriores, proporcionando desprogramação neuromuscular. O objetivo deste estudo foi avaliar a atividade eletromiográfica, o limiar de dor à pressão (LDP) dos músculos temporal e masseter, e a força de mordida molar máxima de participantes com dor miofascial, antes e após a instalação da placa anterior \"front-plateau\". As participantes foram recrutadas e atendidas na Clínica de Dor Orofacial do DAPE da FORP-USP. Para tanto, foram avaliadas 22 mulheres entre 20 e 60 anos. As participantes foram submetidas inicialmente aos exames de eletromiografia (EMG), eletromiógrafo MyoSystem-Br1, limiar de dor a pressão (LDP) algômetro Kratos® e foi aferida força de mordida molar máxima (FMM) por meio do dinamômetro Kratos® IDDK. Foram formados dois grupos, no grupo 1 (G1) 11 participantes usaram o front-plateau por sete dias, 16 horas nos três primeiros dias e por oito horas nos próximos quatro dias, sendo que o tratamento foi interrompido após este período. O grupo 2 (G2), com 11 participantes, iniciou o tratamento idem ao G1 e após sete dias continuaram usando o front-plateau por oito horas diárias por mais três semanas, totalizando 1 mês de uso. Após o tratamento, as participantes dos dois grupos foram novamente avaliadas quatro semanas após a primeira avaliação. Os dados foram analisados com auxílio do software R (R® Foundation for Statistical Computing, Áustria). Os valores reais ou transformados das variáveis foram comparados entre os tratamentos, dias de avaliação e sua interação pela Analise de Variância (ANOVA) em um delineamento interamente casualizado com medidas repetidas no tempo. Para as variáveis que apresentaram diferença estatística, as médias foram comparadas pelo pós-teste de Tukey (p<0,05) e os dados apresentados como a média ± o erro padrão (EP). Foi encontrado relevância estatística em todas as variáveis das análises feitas pelo algômetro durante a utilização do front-plateau, havendo diminuição da sensibilidade dolorosa e aumento do LDP em todos os músculos analisados. Não houve qualquer alteração estatisticamente significativa na FMM no período de utilização do front plateau. Na eletromiografia foi encontrados valores significativos nos padrões posturais de lateralidade direita (LD) e lateralidade esquerda (LE) e mastigação de uva-passa (MU) entre os grupos. Podemos concluir que durante o período de uso do front-plateau houve elevação do LDP (reduzindo a sensibilidade à dor) sendo que após a interrupção do tratamento essa variável retornou às condições iniciais; Na EMG foi observado diminuição do estímulo elétrico para padrões posturais de LD, LE e MU. Porém a FMM não foi modificada durante a utilização do dispositivo. / Orofacial pain comprises all pains involving the soft and mineralized tissues of the oral cavity and face, it can be felt in the region of the head and/or neck. The etiology of temporomandibular dysfunction (TMD) is multifactorial. Its defined as musculoskeletal disorders that affect the stomatognathic system, the masticatory muscles and/or associated structures. A very prevalent dysfunction is myofascial pain. Front-plateau is an acrylic resin device installed in the anterior superior teeth, which separates the posterior teeth, providing neuromuscular deprogramming. The purpose of this study was to assess the electromyographic activity, the pain threshold at the temporal and masseter muscles, and the maximum molar bite strength of participants with myofascial pain, before and after the installation of the front-plateau. Participants were recruited and cared at the FORP-USP DAPE Orofacial Pain Clinic. Twenty two women between 20 and 60 years old were evaluated. The participants were initially submitted to electromyography (EMG) tests, MyoSystem-Br1 electromyograph, pressure pain threshold (PPT), Kratos® algometer, and maximal molar bite force (MMB), Kratos® IDDK dynamometer. Two groups were formed, in group 1 (G1) 11 participants used the front-plateau for seven days, 16 hours on the first three days and for eight hours on the next four days, and treatment was stopped after this period. Group 2 (G2), with 11 participants, started the treatment identical to G1 and after seven days they continued using the front-plateau for eight hours daily for another three weeks, totaling one month of use. After treatment, participants from both groups were reassessed four weeks after the first evaluation. The data were analyzed using R software (R® Foundation for Statistical Computing, Austria). The real or transformed values of the variables were compared between the treatments, evaluation days and their interaction by the Analysis of Variance (ANOVA) in an inter randomized design with repeated measures in time. For the variables that presented statistical difference, the means were compared by Tukey\'s post-test (p <0.05) and the data presented as the mean ± standard error (SE). A statistically significant value was found in all the variables analyzed by the algometer. There was a decrease in pain sensitivity and an increase in the pressure pain threshold (PPT) in all muscles analyzed. There was no statistically significant change in the maximum bite force during the period of use of the front-plateau. In electromyography, significant values were found in the postural patterns of right laterality (RL) and left laterality (LL) and chewing of raisins (CR). We can conclude that during the period of use of the front-plateau there was elevation of the PPT (reducing the sensitivity to pain) returning to the initial conditions after removal of the device; It was observed a decrease in the electrical stimulus for postural patterns of RL, LL and CR. However, the MMB was not modified during the use of the device.

Spatial and temporal temperature and moisture patterns across the Tibetan Plateau are very complex. The onset and magnitude of the Holocene climate optimum in the Asian monsoon realm, in particular, is a subject of considerable debate as this time period is often used as an analogue for recent global warming. In the light of contradictory inferences regarding past climate and environmental change on the Tibetan Plateau, I have attempted to explain mismatches in the timing and magnitude of change. Therefore, I analysed the temporal variation of fossil pollen and diatom spectra and the geochemical record from palaeo-ecological records covering different time scales (late Quaternary and the last 200 years) from two core regions in the NE and SE Tibetan Plateau. For interpretation purposes I combined my data with other available palaeo-ecological data to set up corresponding aquatic and terrestrial proxy data sets of two lake pairs and two sets of sites. I focused on the direct comparison of proxies representing lacustrine response to climate signals (e.g., diatoms, ostracods, geochemical record) and proxies representing changes in the terrestrial environment (i.e., terrestrial pollen), in order to asses whether the lake and its catchments respond at similar times and magnitudes to environmental changes. Therefore, I introduced the established numerical technique procrustes rotation as a new approach in palaeoecology to quantitatively compare raw data of any two sedimentary records of interest in order to assess their degree of concordance. Focusing on the late Quaternary, sediment cores from two lakes (Kuhai Lake 35.3°N; 99.2°E; 4150 m asl; and Koucha Lake 34.0°N; 97.2°E; 4540 m asl) on the semi-arid northeastern Tibetan Plateau were analysed to identify post-glacial vegetation and environmental changes, and to investigate the responses of lake ecosystems to such changes. Based on the pollen record, five major vegetation and climate changes could be identified: (1) A shift from alpine desert to alpine steppe indicates a change from cold, dry conditions to warmer and more moist conditions at 14.8 cal. ka BP, (2) alpine steppe with tundra elements points to conditions of higher effective moisture and a stepwise warming climate at 13.6 cal. ka BP, (3) the appearance of high-alpine meadow vegetation indicates a further change towards increased moisture, but with colder temperatures, at 7.0 cal. ka BP, (4) the reoccurrence of alpine steppe with desert elements suggests a return to a significantly colder and drier phase at 6.3 cal. ka BP, and (5) the establishment of alpine steppe-meadow vegetation indicates a change back to relatively moist conditions at 2.2 cal. ka BP. To place the reconstructed climate inferences from the NE Tibetan Plateau into the context of Holocene moisture evolution across the Tibetan Plateau, I applied a five-scale moisture index and average link clustering to all available continuous pollen and non-pollen palaeoclimate records from the Tibetan Plateau, in an attempt to detect coherent regional and temporal patterns of moisture evolution on the Plateau. However, no common temporal or spatial pattern of moisture evolution during the Holocene could be detected, which can be assigned to the complex responses of different proxies to environmental changes in an already very heterogeneous mountain landscape, where minor differences in elevation can result in marked variations in microenvironments. Focusing on the past 200 years, I analysed the sedimentary records (LC6 Lake 29.5°N, 94.3°E, 4132 m asl; and Wuxu Lake 29.9°N, 101.1°E, 3705 m asl) from the southeastern Tibetan Plateau. I found that despite presumed significant temperature increases over that period, pollen and diatom records from the SE Tibetan Plateau reveal only very subtle changes throughout their profiles. The compositional species turnover investigated over the last 200 years appears relatively low in comparison to the species reorganisations during the Holocene. The results indicate that climatically induced ecological thresholds are not yet crossed, but that human activity has an increasing influence, particularly on the terrestrial ecosystem. Forest clearances and reforestation have not caused forest decline in our study area, but a conversion of natural forests to semi-natural secondary forests. The results from the numerical proxy comparison of the two sets of two pairs of Tibetan lakes indicate that the use of different proxies and the work with palaeo-ecological records from different lake types can cause deviant stories of inferred change. Irrespective of the timescale (Holocene or last 200 years) or region (SE or NE Tibetan Plateau) analysed, the agreement in terms of the direction, timing, and magnitude of change between the corresponding terrestrial data sets is generally better than the match between the corresponding lacustrine data sets, suggesting that lacustrine proxies may partly be influenced by in-lake or local catchment processes whereas the terrestrial proxy reflects a more regional climatic signal. The current disaccord on coherent temporal and spatial climate patterns on the Tibetan Plateau can partly be ascribed to the complexity of proxy response and lake systems on the Tibetan Plateau. Therefore, a multi-proxy, multi-site approach is important in order to gain a reliable climate interpretation for the complex mountain landscape of the Tibetan Plateau. / Die räumlichen und zeitlichen Temperatur- und Feuchtigkeitsmuster auf dem Tibet-Plateau sind sehr komplex. Im Einzugsbereich der asiatischen Monsune sind insbesondere der Beginn und das Ausmaß des Klimaoptimums während des Holozäns von wissenschaftlichem Interesse, da diese Periode oft als Analogie für die derzeitige globale Klimaerwärmung herangezogen wird. In Hinblick auf sich teilweise widersprechende Paläoklima- und Umweltrekonstruktionen für das Tibet-Plateau, ist es mein Ziel, die bestehenden Unstimmigkeiten bezüglich des Zeitpunktes und des Ausmaßes des Umweltwandels zu erklären. Dafür wurden von mir zeitliche Variationen fossiler Pollen- und Diatomeenspektren und geochemische Untersuchungen an Seesedimenten unterschiedlicher Zeitskalen (Spätquartär und die letzten 200 Jahre) aus zwei Kernregionen auf dem NO und SO Tibet-Plateau analysiert. Zur Unterstützung der Interpretation wurden die hier erhobenen Daten mit bereits vorhandenen paläoökologischen Aufzeichnungen der Lokalitäten kombiniert, um Datensätze der entsprechenden aquatischen und terrestrischen Proxy-Daten (Stellvertreterdaten) zweier Seenpaare aus den beiden Regionen gegenüberstellen zu können. Hierbei konzentrierte ich mich auf den direkten Vergleich von Proxies, die die Seenentwicklung reflektieren (z.B. Diatomeen, Ostracoden, geochemische Eigenschaften), mit Proxies, die Veränderungen der terrestrischen Umgebung des Sees beschreiben (terrestrische Pollen). Durch diesen Vergleich lässt sich beurteilen, ob Veränderungen im See selbst mit Umweltveränderungen in dem jeweiligen Einzugsgebiet zeitlich übereinstimmen. Dafür habe ich die bereits etablierte numerische Methode Procrustes-Rotation als neuen Ansatz in der Paläoökologie eingeführt. Damit ist ein quantitativer Vergleich von Rohdaten zweier beliebiger sedimentärer Datensätze möglich, um den Grad der Übereinstimmung zu prüfen. Um die in dieser Arbeit rekonstruierten Umwelt- und Klimaereignisse des nordöstlichen Tibet-Plateaus in einen größeren Zusammenhang hinsichtlich holozäner Klimaentwicklung des gesamten Plateaus setzen zu können, und um schlüssige zeitliche und räumliche Klimatrends auf dem Plateau erkennen zu können, habe ich auf alle vorhandenen Paläoklimadatensätze einen Fünf-Skalen Feuchtigkeitsindex und eine Clusteranalyse angewandt. Es konnten jedoch keine einheitlichen zeitlichen und räumlichen Trends der holozänen Klimaentwicklung nachgewiesen werden, was meiner Analyse entsprechend, auf die komplexen Reaktionen verschiedener Proxies auf Umweltveränderungen in einer ohnehin sehr heterogen Berglandschaft, zurückgeführt werden kann. Die Ergebnisse des numerischen Proxy-Vergleichs beider Seenpaare zeigen, dass die Verwendung von verschiedenen Proxies und die Arbeit mit paläo-ökologischen Datensätzen unterschiedlicher See-Typen zu abweichenden Klimaableitungen führen können. Unabhängig vom untersuchten Zeitraum (Holozän oder die letzten 200 Jahren) oder der Region (SO oder NO Tibet-Plateau), ist die Übereinstimmung zweier Datensätze hinsichtlich der Richtung, des Zeitpunktes und des Ausmaßes der abgeleiteten Paläo-Umweltverhältnisse in der Regel zwischen den entsprechenden terrestrischen Datensätzen besser als zwischen den entsprechenden lakustrinen Datensätzen. Die derzeitige Uneinigkeit über stimmige zeitliche und räumliche Klimatrends auf dem Tibet-Plateau kann daher teilweise der Komplexität der verschieden Proxies und ihrer individuellen Empfindlichkeiten gegenüber Umweltveränderungen sowie der unterschiedlichen Reaktionsweise verschiedenartiger See-Systeme auf dem Plateau zugeschrieben werden. Meine Ergebnisse zeigen, dass ein „Multi-Proxy-Multi-Site-Ansatz“ für zuverlässige Paläoklimaableitungen für das Tibet-Plateau von zentraler Bedeutung ist.

In this paper, we mainly discuss the transport properties of the two-dimensional gas of a high-mobility GaAs/AlGaAs semiconductor heterostructure in high magnetic fields and low temperatures. We analyzed the measured longitudinal resistivity and Hall resistivity at the five different temperatures. We observed that the classical Hall effect is valid when the magnetic field is less than 0.25 Tesla; and the quantum Hall plateaux appeared obviously when the magnetic field is larger than 1.6 Tesla. We proceeded to analyze the longitudinal resistivity oscillation occurred in the magnetic fields between 0.477 Tesla and 1.483 Tesla. According to the Lifshitz-Kosevich (LK) formula, we can get the two-dimensional electron concentration, effective mass, and quantum scattering time from the quantum magnetoresistivity oscillation measurement. Our results suggested that the applicable range of the LK formula could be broader than the generally-assumed one. In quantum Hall effect regime at high magnetic field, we can calculate the h/e2 value from the quantum Hall plateaux value. In classical Hall effect regime, the three-dimensional electron concentration and classical mobility (classical scattering time) can be obtained. However, we find out that the zero-field Hall resistivity experimental value is not equal to zero, and this is not conformed to the standard theory. We tried to use the magnetic field shift and Hall resistivity shift to solve the problem, and compared both advantages of them. Finally, we observed the plateau-plateau phase transitions of the two-dimensional electron system

A dor orofacial compreende todas as dores que envolvem os tecidos moles e mineralizados da cavidade oral e da face, pode ser referida na região da cabeça e/ou pescoço. A etiologia da disfunção temporomandibular (DTM) é multifatorial, são distúrbios musculoesqueléticos que afetam o sistema estomatognático, os músculos mastigatórios e/ou estruturas associadas. Uma disfunção muito prevalente é a dor miofascial. O front-plateau é um dispositivo de resina acrílica instalado nos dentes superiores anteriores, que desoclui os dentes posteriores, proporcionando desprogramação neuromuscular. O objetivo deste estudo foi avaliar a atividade eletromiográfica, o limiar de dor à pressão (LDP) dos músculos temporal e masseter, e a força de mordida molar máxima de participantes com dor miofascial, antes e após a instalação da placa anterior \"front-plateau\". As participantes foram recrutadas e atendidas na Clínica de Dor Orofacial do DAPE da FORP-USP. Para tanto, foram avaliadas 22 mulheres entre 20 e 60 anos. As participantes foram submetidas inicialmente aos exames de eletromiografia (EMG), eletromiógrafo MyoSystem-Br1, limiar de dor a pressão (LDP) algômetro Kratos® e foi aferida força de mordida molar máxima (FMM) por meio do dinamômetro Kratos® IDDK. Foram formados dois grupos, no grupo 1 (G1) 11 participantes usaram o front-plateau por sete dias, 16 horas nos três primeiros dias e por oito horas nos próximos quatro dias, sendo que o tratamento foi interrompido após este período. O grupo 2 (G2), com 11 participantes, iniciou o tratamento idem ao G1 e após sete dias continuaram usando o front-plateau por oito horas diárias por mais três semanas, totalizando 1 mês de uso. Após o tratamento, as participantes dos dois grupos foram novamente avaliadas quatro semanas após a primeira avaliação. Os dados foram analisados com auxílio do software R (R® Foundation for Statistical Computing, Áustria). Os valores reais ou transformados das variáveis foram comparados entre os tratamentos, dias de avaliação e sua interação pela Analise de Variância (ANOVA) em um delineamento interamente casualizado com medidas repetidas no tempo. Para as variáveis que apresentaram diferença estatística, as médias foram comparadas pelo pós-teste de Tukey (p<0,05) e os dados apresentados como a média ± o erro padrão (EP). Foi encontrado relevância estatística em todas as variáveis das análises feitas pelo algômetro durante a utilização do front-plateau, havendo diminuição da sensibilidade dolorosa e aumento do LDP em todos os músculos analisados. Não houve qualquer alteração estatisticamente significativa na FMM no período de utilização do front plateau. Na eletromiografia foi encontrados valores significativos nos padrões posturais de lateralidade direita (LD) e lateralidade esquerda (LE) e mastigação de uva-passa (MU) entre os grupos. Podemos concluir que durante o período de uso do front-plateau houve elevação do LDP (reduzindo a sensibilidade à dor) sendo que após a interrupção do tratamento essa variável retornou às condições iniciais; Na EMG foi observado diminuição do estímulo elétrico para padrões posturais de LD, LE e MU. Porém a FMM não foi modificada durante a utilização do dispositivo. / Orofacial pain comprises all pains involving the soft and mineralized tissues of the oral cavity and face, it can be felt in the region of the head and/or neck. The etiology of temporomandibular dysfunction (TMD) is multifactorial. Its defined as musculoskeletal disorders that affect the stomatognathic system, the masticatory muscles and/or associated structures. A very prevalent dysfunction is myofascial pain. Front-plateau is an acrylic resin device installed in the anterior superior teeth, which separates the posterior teeth, providing neuromuscular deprogramming. The purpose of this study was to assess the electromyographic activity, the pain threshold at the temporal and masseter muscles, and the maximum molar bite strength of participants with myofascial pain, before and after the installation of the front-plateau. Participants were recruited and cared at the FORP-USP DAPE Orofacial Pain Clinic. Twenty two women between 20 and 60 years old were evaluated. The participants were initially submitted to electromyography (EMG) tests, MyoSystem-Br1 electromyograph, pressure pain threshold (PPT), Kratos® algometer, and maximal molar bite force (MMB), Kratos® IDDK dynamometer. Two groups were formed, in group 1 (G1) 11 participants used the front-plateau for seven days, 16 hours on the first three days and for eight hours on the next four days, and treatment was stopped after this period. Group 2 (G2), with 11 participants, started the treatment identical to G1 and after seven days they continued using the front-plateau for eight hours daily for another three weeks, totaling one month of use. After treatment, participants from both groups were reassessed four weeks after the first evaluation. The data were analyzed using R software (R® Foundation for Statistical Computing, Austria). The real or transformed values of the variables were compared between the treatments, evaluation days and their interaction by the Analysis of Variance (ANOVA) in an inter randomized design with repeated measures in time. For the variables that presented statistical difference, the means were compared by Tukey\'s post-test (p <0.05) and the data presented as the mean ± standard error (SE). A statistically significant value was found in all the variables analyzed by the algometer. There was a decrease in pain sensitivity and an increase in the pressure pain threshold (PPT) in all muscles analyzed. There was no statistically significant change in the maximum bite force during the period of use of the front-plateau. In electromyography, significant values were found in the postural patterns of right laterality (RL) and left laterality (LL) and chewing of raisins (CR). We can conclude that during the period of use of the front-plateau there was elevation of the PPT (reducing the sensitivity to pain) returning to the initial conditions after removal of the device; It was observed a decrease in the electrical stimulus for postural patterns of RL, LL and CR. However, the MMB was not modified during the use of the device.

abstract: The plateau pika (Ochotona curzoniae), a small burrowing lagomorph that occupies the high alpine grassland ecosystems of the Qinghai-Tibetan Plateau in western China, remains a controversial subject among policymakers and researchers. One line of evidence points to pikas being a pest, which has led to massive attempts to eradicate pika populations. Another point of view is that pikas are a keystone species and an ecosystem engineer in the grassland ecosystem of the QTP. The pika eradication program raises a difficult ethical and religious dilemma for local pastoralists, and is criticized for not being supported by scientific evidence. Complex interactions between pikas, livestock, and habitat condition are poorly understood. My dissertation research examines underpinning justifications of the pika poisoning program leading to these controversies. I investigated responses of pikas to habitat conditions with field experimental manipulations, and mechanisms of pika population recovery following pika removal. I present policy recommendations based on an environmental ethics framework and findings from the field experiments. After five years of a livestock grazing exclusion experiment and four years of pika monitoring, I found that grazing exclusion resulted in a decline of pika habitat use, which suggests that habitat conditions determine pika population density. I also found that pikas recolonized vacant burrow systems following removal of residents, but that distances travelled by dispersing pikas were extremely short (~50 m). Thus, current pika eradication programs, if allowed to continue, could potentially compromise local populations as well as biodiversity conservation on the QTP. Lethal management of pikas is a narrowly anthropocentric-based form of ecosystem management that has excluded value-pluralism, such as consideration of the intrinsic value of species and the important ecological role played by pikas. These conflicting approaches have led to controversies and policy gridlock. In response, I suggest that the on-going large-scale pika eradication program needs reconsideration. Moderation of stocking rates is required in degraded pika habitats, and Integrated Pest Management may be required when high stocking rate and high pika density coexist. A moderate level of livestock and pika density can be consistent with maintaining the integrity and sustainability of the QTP alpine steppe ecosystem. / Dissertation/Thesis / Doctoral Dissertation Biology 2016

Les Eaux Atlantiques (AW) sont cruciales pour le budget de sel et de chaleur de l'Arctique. Ce doctorat apporte de nouvelles informations sur l'entrée des AW dans la région du nord Svalbard. Les plateformes IAOOS ont collecté pendant la campagne N-ICE2015 les premières données hydrographiques d'hiver de la région. Elles ont documentées des eaux chaudes peu profondes sur le talus continental du Svalbard qui ont généré des flux de chaleur océan-glace atteignant 400 W/m2 et faisant fondre la glace. Cette chaleur est amenée des AW vers la surface par des ondes quasi-inertielles causées par des tempêtes hivernales, de grandes marées barotropes sur des pentes raides et/ou des ajustements géostrophiques. Les extensions de glace sont très différentes entre 2015 et 2016. Les sorties du modèle opérationnel de Mercator Ocean (1/12°) suggèrent que les flux de chaleur orientés vers la surface et induits par la convection expliquent ces différences. En plus de la Svalbard Branch et de la Yermak Branch, le modèle présente un chemin robuste l'hiver à travers le plateau du Yermak: la Yermak Pass Branch. Enfin, le modèle suggère une activité méso-échelle importante le long du courant des AW. Les propriétés de la Yermak Pass sont examinées avec un an de données ADCP (2007-2008) dans la Yermak Pass. Le courant est dominé par la marée. En hiver, des tourbillons baroclines d'AW avec une périodicité de 5-10 jours et des entrées sporadiques d'AW tous les un/deux mois sont observés, transportant les AW vers l'Est. Le modèle suggère que la Yermak Pass Branch est une structure robuste d'hiver les 10 dernières années et transporte en moyenne 31% du transport volumique du West Spitsbergen Current. / The Atlantic Water (AW) inflow is crucial for the heat and salt budget of the Arctic. This PhD thesis brings new insights to the inflow of AW in the area north of Svalbard. The IAOOS (Ice Atmosphere Ocean Observing System) platforms were deployed during the N-ICE2015 expedition which gathered the first winter hydrographic data in the area. They document shallow warm water over the Svalbard continental slope that melts sea ice with ice-ocean heat fluxes reaching up to 400W.m-2. Heat is brought from the AW layer up to the surface through near-inertial waves generated by winter storms, large barotropic tides over steep topography and/or geostrophic adjustments. Sea ice extent largely differs between winters 2015 and 2016. 1/12° operational model outputs from Mercator-Ocean suggest that convection-induced upward heat fluxes explain the differences. Model outputs are also used to examine the AW inflow pathways : besides the Svalbard Branch and the Yermak Branch, the model shows an AW winter pathway not much documented before : the Yermak Pass Branch across the Yermak Plateau. Finally, the model suggests an important mesoscale activity throughout the AW flow. The Yermak Pass Branch properties are examined using one-year (2007-2008) of moored ADCP data in the Yermak Pass. The flow is largely dominated by tides. In winter, baroclinic eddies of AW with a periodicity of 5 to 10 days and pulses of AW monthly/bimonthly are found, carrying AW eastward through the Pass. Model outputs suggest that the Yermak Pass Branch is a robust winter pattern over the last 10 years, carrying on average 31% of the volume transport of the West Spitsbergen Current.

Nous étudions expérimentalement différentes configurations du transport de particules solide dans le réseau de canaux fluides (bords de Plateau) d’une mousse liquide. Dans un premier temps, la perméabilité de la mousse est mesurée à l’échelle d’un canal fluide puis de l’ensemble du réseau de canaux pour deux solutions moussantes conférant des mobilités interfaciales significativement différentes. Un modèle d’écoulement, basé sur une description fine de la géométrie des canaux de la mousse ainsi que sur un nombre de Boussinesq constant pour une solution donnée, permet de rendre compte de tous les résultats expérimentaux sur une large gamme de fraction volumique de liquide. Dans un second temps nous mesurons, à l’échelle d’un canal fluide, la vitesse d’une particule convectée par le liquide pour différents rapports d’aspect particule / canal. Pour des petits rapports d’aspects, nous mesurons des vitesses de particules anormalement faibles. Ces mesures nous permettent de mettre en évidence des contre-écoulement à la jonction du bord de Plateau et des films. Pour expliquer cet effet, nous proposons un modèle de recirculation du tensioactif faisant intervenir l’élasticité de Gibbs. Nous abordons ensuite le cas d’une particule piégée dans le réseau de canaux de la mousse. Nous abordons ensuite le cas d’une particule piégée dans le réseau de canaux de la mousse. Nous montrons que le seuil de rétention de la particule est déterminé par l’équilibre des forces hydrodynamique et capillaire. Finalement, le cas du colmatage d’un nœud de mousse est abordé / We study experimentally different particle transport configurations in fluid microchannels network (Plateau borders) of aqueous foams. At first, foams permeability is measured at the scale of a single channel and of the whole foam network for two soap solutions known for their significant different interface mobility. Experimental data are well described by a model that takes into account the real geometry of the foam and by considering a constant value of the Boussinesq number for each soap solutions. Secondly, the velocity of one particle convected in a single foam channel is measured for different particle / channel aspect ratio. For small aspect ratio, counterflows that are taking place at the channel’s corners slow down the particle. A recirculation model in the channel foam films is developed to describe this effect. To do this, the Gibbs elasticity is introduced. Then, the threshold between trapped and released of one particle in liquid foam are carried out. This threshold is deduced from hydrodynamic and capillary forces equilibrium. Finally, the case of a clog foam node is adressed

The area of land farmed in Africa is predicted to double by the year 2050 yet very few African studies have investigated the impact of different farming intensities and regimes on bird communities. This study examined avian species richness and diversity along with the densities of some common bird species on the Jos Plateau, Nigeria, in relation to habitat features on farmland over a gradient of differing farming intensities. The study area exhibited a variety of different levels of farming which differed in the habitat available for birds. Birds normally associated with savanna woodland were more associated with less intensive farming, and open-country birds were more associated with more intensive sites, with more species of birds observed where farming was less intensive. Common species of birds using cultivated land associated with different crops, with acha and millet being the most commonly used. Tree density was the most important variable predicting avian species richness and diversity, with medium tree density predicting the highest species richness and diversity. The densities of two common farmland birds were predicted best by tree density, but varied in their responses to the habitat variables, with common bulbul, a savanna generalist, associating more with less intensive, wooded areas and red-cheeked cordon-bleu, an open savanna granivore, associating with medium intensity, more open farmland. Whinchats were common in open, intensively farmed areas with few trees and good herbaceous vegetation cover. The data presented indicates the importance of retaining natural features of savanna habitat in farmland in order to maintain high avian diversity on farmland. More detailed studies are needed in order to determine the mechanisms involved in the associations observed and collaborations between ecologists and social scientists will be necessary to develop effective policies to limit the impact of the intensification of agriculture in Africa on avian biodiversity.

The aim of this study is to examine conflict and how it impinges on development. Conflict is an inevitable element of human existence since creation and has always affected human activities and endeavors in several ways. Understanding the dimensions of human conflict therefore provides blueprints on how to manage and resolve conflicts. This makes this study timely. In this research, some relevant related to conflict management approaches were examined. The research adopted a case study approach using the Jos Plateau conflict in the Plateau State of the Federal Republic of Nigeria. Data was collected and analyzed using a mixed research methods approach. The findings show several causes of this conflict among which are differences in religious beliefs among the people of the area, socio-economic causes, political tensions and land disputes. The consequences of the conflict identified are: it retards development in the area, creates fear and feelings of insecurity, destruction of property and loss of human lives. This study also examined how the conflict impinges on people-cantered development. In terms of how the conflict can be mitigated, respondents think education, creation of employment opportunities, the administration of justice and the practice of tolerance values is going to promote a spirit of coexistence and eventually result in a more peaceful and stable environment.