Bien que le lithium soit le traitement de première ligne pour la prévention des rechutes dans le trouble bipolaire seuls 30 % des patients sont de bons répondeurs. Ainsi, un sous-groupe important des patients, traités avec du lithium, présente des taux élevés de rechute. En l’absence de marqueurs cliniques prédictifs de réponse il reste difficile de prédire avec précision quels patients répondront en évitant de les soumettre à de longues périodes de traitements au lithium. L’identification de biomarqueurs prédictifs est donc un enjeu majeur pour améliorer la prise en charge des patients bipolaires. Le mécanisme d’action du lithium est complexe car il exerce une action inhibitrice ou activatrice sur plusieurs voies de signalisation cellulaires. L’ensemble de ces cibles et effecteurs contribuent aux effets neuroprotecteurs dans le cerveau et de stabilisation de l’humeur et complexifient la compréhension de la réponse prophylactique au lithium. Les études visant à identifier une corrélation entre la réponse au lithium et des mutations de gènes ont produit des résultats controversés. Afin de mieux comprendre la variabilité de la réponse au lithium, une approche complémentaire aux études génétiques, consiste à étudier les effets moléculaires induits par un traitement aigu ou chronique au lithium. Il a ainsi été montré que le lithium module les niveaux d’expression de gènes au niveau des ARN messagers, des protéines aussi des miRNA dans plusieurs modèles in vivo et in vitro. Ces études ouvrent de nouvelles voies de recherche pour identifier des biomarqueurs de la réponse prophylactique au lithium pouvant être transférés en clinique afin d’éviter de longues périodes de traitement inefficace au lithium et élaborer des stratégies de traitement plus personnalisées.

Climate change affects the livestock populations. As temperature increases, the rainfall distribution patterns shifts. These indirectly change the ecosystems like changes in crop yield, alter the distribution of animal diseases, geographically restriction of rare breed populations and increased competition for resources. Therefore, the objective of the study was to quantify impacts of climate variability on livestock population dynamics and breed distribution patterns. The study was conducted in Gondar Zuria, Farta and Bahir Dar Zuria districts. The sites were selected based on agro-ecology and livestock distribution potential. Data were collected through desk reviews of different documents and studies, focused group discussions, key informants interviews and different projection models. The results revealed that 70 percent of respondents believed that the trends of livestock breed distribution varied from year to year and from agro-ecology to agro-ecology. The number of cattle and equines are decreasing from year to year due to climate variability. Particularly, the crossbred cattle population decreased in 1998, 2002 and 2008 due to shortage of rainfall, increments of temperature and feed shortage. A correlation analysis was used to quantify impacts of temperature and rainfall on livestock population dynamics and breed distribution. The analyses revealed that sheep (r = −0.535, P < 0.05) and cattle (r = −0. 512, P < 0.05) were negatively affected by climate variability. Whereas goats were having positive relationship (r = 0.345, P < 0.001). As the average maximum temperature steadily increases, the population dynamics of ruminant livestock fluctuated after the year 1996. About 92.2, 78 and 83.3 percent respondents in Farta, Gondar Zuria and Bahir Dar Zuria districts, respectively, stated that there is a fluctuation in amount of rainfall distribution during the main rainy seasons. About 84.5 percent of respondent of the three districts also believed that climate change made variation in rainfall distribution. About 52 percent of the respondents also suggested that if livestock is to be protected from climate change and related effects, changing the farming system with appropriate breed is important and can be achieved with the zero-grazing system. The farmers also recommended with stocking climate change adaptive and productive breeds. In conclusion, climate variability affected livestock population dynamics and breed distribution pattern negatively.

Echo sounder data were used to investigate the spatio-temporal variability of shoal behaviour in the Bay of Biscay. Data collected from annual surveys were processed using MOVIES-B software in order to mcasure this variability. The software was designed to measure morphological, energetic and space-time distribution descriptors from the acoustic signal received from fish shoals. Two surveys, DAAG 90 and DAAG 91, provided the appropriate characteristics for such an analysis. The survey's objective was to obtain relative abundance indices for the anchovy (Engraulis encrasicolus) biomass in the Bay of Biscay. The surveys were carried out in the same area (southern Bay of Biscay), at the same period (April) within one year interval (1990 and 1991), using the same equipment (vessel, acoustic system, fishing gear) in a multispecies environment. Frequency distributions for every descriptor were obtained and used to describe the acoustic detection of fish shoals. The analysis of frequency distributions of space-time descriptors (year, day-hour and bottom depth) allowed the construction of derived discrete variables, which defined new subsets of detections. The subsets were then described by the continuous variables. A principal components analysis was used to describe the multidimensional data structure and to describe behaviour patterns. The size and external outline unevenness are correlated groups of shoal descriptors, but are independent of the water column shoal position and the degree of internal shoal structure. An important feature is shoal size variability between years. Significant differences in shoal characteristics were found between bathymetric zones of the same region and the pattern was similar between years. This spatial wariability is related to the distribution of different species between bathymetric zones. Although it was not possible to explain size variability between years, this will be necessary to improve shoal characterization. More knowledge about oceanographic conditions, the productivity level and availability of food, predator pressure and accurate identification of shoal speeies is required, in order to study the spatial or temporal variability in size and behaviour of shoals.

Within the distributional range of a species the number of self-sustaining populations can vary, from one population for panmictic species such as American eel to many populations as observed in Atlantic salmon. This "species-level" characteristic is defined here as "population richness". Aspects of geographic patterns in population richness in the northern Atlantic for Atlantic salmon, American shad, rainbow smelt, Atlantic herring, Atlantic cod, haddock, winter flounder, yellowtail flounder, Atlantic mackerel, and European eel are described. It is concluded that events at the early life-history stages, involving "retention" of the eggs and larvae in relation to particular physical oceanographic features, are involved in the definition of population richness.