Dans cette étude, nous examinons la trajectoire d’un migrant canadien-français au XIXe siècle, Sam Gravel, ainsi que les changements identitaires qu’il subit en fonction des lieux de migration qu’il atteint. Sam se rend en Nouvelle-Angleterre en 1882 pendant quelques mois. Il revient brièvement au Québec puis immigre dans l’Ouest canadien en 1883 et y demeurera jusqu’en 1891. Il s’établira ensuite dans le Midwest américain jusqu’en 1897. Il rentrera finalement au Québec et s’installera dans le village de Somerset en 1897. Il décède en 1899 d’une noyade à Québec. C’est en analysant son parcours migratoire, son mode d’établissement et son discours que nous pouvons déterminer comment s’insère sa migration dans les courants de migration du XIXe siècle. Est-ce que ses choix sont représentatifs de la majorité des migrants de l’époque ? Comment ces choix influencent-ils sa perception des autres groupes ethniques ainsi que ses valeurs religieuses et familiales? Sam tient un discours qui se rapproche beaucoup de celui des Canadiens français de l’époque alors qu’il se trouve dans l’Ouest canadien et tend à s’en dégager alors qu’il atteint le Midwest américain.

This thesis investigates three different surface modifications, and the route to design and synthesize them. The thesis is therefore divided into three sub- projects. (i.) Design and synthesis of a peptide which secondary structure could be controlled by a negatively charged surface. (ii.) Design and synthesis of a cyclic peptide, that would self-organize prior to surface interaction, using the type I anti-freeze protein of a winter flounder as template. (iii.) The use of solid-phase synthesis to make the synthesis of SAM-molecules easier.

The Antarctic Circumpolar Current (ACC) is well known for its multiple bands with large meridional property gradients in the upper waters, each associated with a deep-reaching current core. A revised nineteen-year time series (1992?2011) of altimeter data from the CNES/CLS AVISO is analyzed to identify and trace the spatial distribution of ACC fronts. Specific contours of sea surface height (SSH) are selected within narrow continuous bands of relative maxima SSH slope in the Southwest Atlantic Ocean sector, where they closely follow the distribution of ACC fronts derived from inspection of concurrent high-resolution profile data at hydrographic stations. When applied to the full circumpolar belt, the frontal distribution derived from these new altimeter-based indicators also agrees well with the traces of current jets and in-situ dynamic height fields calculated from concurrent Argo profile data. The temporal variability of ACC fronts is analyzed in relation to dominant modes of atmospheric forcing variability in the Southern Ocean. All three ACC fronts have experienced large seasonal to decadal variability throughout the satellite altimetry era. The general seasonal tendency for each of these jets, with respect to long-term mean positions, is to be located farther to the south during the austral summer and to north in the winter. Circumpolar-mean annual frontal locations show a consistent linear trend of southward migration. However, the estimated decadal variability of the frontal distributions is highly localized, and due to selective response mechanisms to atmospheric variability. A persistent poleward drift of ACC fronts is observed in the Indian sector consistent with increasing sea surface temperature trends. In contrast, a vacillation in the meridional location of ACC fronts is observed in the Pacific sector in association to minor sea surface cooling trends. Therefore, unlike in the Indian sector, the regional Pacific Ocean response is significantly sensitive to dominant atmospheric forcing indices. Mesoscale eddies derived from instabilities at strong current cores are successfully identified with specific SSH gradient criteria. The new estimates of rings population in the Southern Ocean are tightly linked to interannual to decadal atmospheric variability. Increased number of mesoscale eddies correlate with positive SAM forcing about two years earlier, or negative ENSO forcing two to three months earlier. These cross-correlations might explain a prominent peak in rings abundance estimated during 2000 and 2001, and the short-lived maximum that appeared in 2010. There are no persistent trends in the estimated sea surface slope across Drake Passage, and therefore neither in the transport of the ACC. High cross-correlation between the abundance of mesoscale eddies and atmospheric forcing suggests that the overall ACC system is in an eddy-saturated state. However, Drake Passage positive sea level slope anomalies were two-year lagged with negative SAM forcing and with positive ENSO events. These regional responses are characteristic of eastward-propagating signals from a buoyancy-dominated Pacific sector of the Southern Ocean.

Soils in many agricultural areas have high pH, resulting in low availability of zinc and iron. Plants grown on such soils suffer from either Zn or Fe deficiency or both. The efficient plant genotypes grown normally in calcerous soils were found to evolve some strategies to acquire the iron which is in insoluble form. Iron efficient graminaceous monocots release iron chelating substances, mugineic acid family phytosiderophores (MAs), in response to iron deficiency stress. Several researchers have suggested that phytosiderophores also can play role in grass Zn nutrition and thus it may be possible that it is the uptake mechanism for Zn efficiency. Several possible genes that take role in phytosiderophore synthesis or found to be induced under iron deficient conditions were identified in several organisms but not on wheat. In this study, the efficient barley cultivar Tokak-157, efficient wheat cultivar Kira&ccedil / -66 and relatively less efficient wheat cultivar BDMM-19 were grown in normal growth conditions for 1 week and transfered to zinc deficient, iron deficient and both zinc and iron deficient nutrient solutions. After growing 1 week on these conditions, plants grown on both zinc and iron deficient nutrient solutions were retransfered to zinc and iron sufficient conditions. Degenerate primers were designed for the conserved regions of previously identified genes that take role in phytosiderophore synthesis or induced under iron deficient conditions and RT-PCRs were performed. The complete open reading frame of IDI-1(Iron deficiency induced-1) gene and the putative gene fragment for SAM-s (S-adenosylmethionine synthetase) were identified.

Observations of Antarctic sea ice thickness are sporadic in space and time, hindering knowledge of its variability. A proxy based on stage of development data from the National Ice Center (NIC) weekly operational charts is used to create a high-resolution time series of sea ice concentration, thickness and volume for 2000-2009. Record-length mean thickness and volume of Antarctic sea ice are 66.7 cm and 7.7 x10^3 km^3. The mean growth and decay seasons in the Southern Ocean and in the Ross sector are 210 days and 155 days, but at least at least one week shorter (growth) and longer (decay) in the Amundsen/Bellingshausen sector. Over 90% of the Antarctic continental shelf is covered with sea ice for 3-5 months, and for 2 to 4 months longer periods in the Amundsen/Bellingshausen and Ross sectors. Yearly mean sea ice area (extent) in the Southern Ocean increased at a rate of 0.71 x 10^6 km^2/decade (0.70 x 10^6 km^2/decade), equivalent to a 7.7 %/decade (6.3 %/decade) rise. A comparable trend of 9.1 %/decade (8.5 %/decade) is estimated in the Ross sector, at 0.21 x 10^6 km2/decade (0.23 x 10^6 km2/decade). The opposite trend is found in the Amundsen/Bellingshausen sector: a -0.15 x 10^6 km^2/decade (-0.17 x 10^6 km^2/decade) decline, or -14.6 %/decade (-13.4 %/decade). The estimated annual increase of Antarctic sea ice thickness is 22.6 cm/decade (49.2 %/decade) and of volume is 3.78 x 10^3 km^3/decade (68.3 %/decade). The Ross sector showed similar trends for thickness, at 23.8 cm/decade (47.0 %/decade), and volume, at 1.11 x 10^3 km^3/decade (75.8 %/decade). Thickness has increased in the Amundsen/Bellingshausen sector, 20.7 cm/decade (44.8 %/decade), but with a less pronounced volume rise of 0.17 x10^3 km^3/decade (26.0 %/decade). Monthly sea ice thickness anomalies show a weak response to the El Nino Southern Oscillation (ENSO) index. A strong positive response is observed in 2008 when a negative a negative ENSO index compounded to a positive Southern Annular Mode (SAM) index. Therefore the estimated increase of sea ice thickness in the Southern Ocean could be attributed to the prevailing atmospheric conditions with a positive SAM phase over the past decade.

The goal of this work has been to improve the accuracy of a pre-existing algorithm for vehicle pose estimation, which uses intrinsic measurements of vehicle motion and measurements derived from far infrared images. Estimating the pose of a vehicle, based on images from an on-board camera and intrinsic measurements of vehicle motion, is a problem of simultanoeus localization and mapping (SLAM), and it can be solved using the extended Kalman filter (EKF). The EKF is a causal filter, so if the pose estimation problem is to be solved off-line acausal methods are expected to increase estimation accuracy significantly. In this work the EKF has been compared with an acausal method for solving the SLAM problem called smoothing and mapping (SAM) which is an optimization based method that minimizes process and measurement noise. Analyses of how improvements in the vehicle motion model, using a number of different model extensions, affects accuracy of pose estimates have also been performed.

Plants are exposed to a variety of environmental stresses, ranging from insects and phytopathogens known as biotic stressors, to edaphic stressors including drought and salinity - clustered under the group of abiotic stresses. Facing these pernicious risks, plants have adopted several strategies to survive in stressful environments. With contemporary advances in technology and scientific research, it is possible to insert a specific gene or trait into a plant in order to confer salt tolerance. For example, a thiol methyltransferase enzyme in cabbage converts Cl¯ and other halide ions into their corresponding methyl halides, which are released directly into the air. Cloning the TMT1 gene and functionally expressing this gene into tobacco plants conferred salt tolerance on these plants. Although increased salt tolerance is a favourable and beneficial trait for plant productivity, the emission of methyl halides into the atmosphere can be noxious for the environment. Indeed, methyl halides are some of the factors contributing to climate change, widely believed to be the foremost environmental problem of the twenty-first century. Climate change is affecting all forms of life on earth and its impacts are often severe and irreversible. For that reason, it has been placed at the forefront of the international political agenda. The present study focused on two main physiological traits of stress resistance in tobacco plants which have been genetically engineered with the cabbage TMT1 gene: The production of methyl halides, particularly methyl chloride, as a way to confer salt tolerance; and synthesis of the stress hormone, ethylene. Both pathways share a common metabolite, S-adenosyl-L-methionine (SAM), for the synthesis of the final products. SAM, derived from the amino acid methionine (Met), is a universal methyl group donor. It plays essential roles in plant metabolism, by acting as a precursor for ethylene, polyamines, and vitamin B1 synthesis, and as a source of atmospheric dimethylsulphides. Therefore, it is important that the plant maintains the SAM pool at a level sufficient to serve all the different metabolic pathways. The present work set out to determine whether addition of another SAM-dependent pathway through TMT insertion in tobacco plants would negatively affect ethylene synthesis by lessening the amount of SAM available for ethylene biosynthesis. Detailed experimental studies were conducted, including in vitro and in vivo experiments, to examine the potential effect of TMT gene insertion on SAM availability for ethylene synthesis in tobacco plants. Three series of in vitro tests, differing by the number of leaf discs used, the final headspace volume in each flask, the incubation period in the different solutions and the time of introducing salt solutions, were carried out. Data obtained from two series of in vitro experiments revealed a decrease in ethylene emission when salt solutions were added at the beginning of the experiment and when leaves where incubated overnight in the presence of 0.1 M NaBr, coupled with the production of methyl halides, whereas the other series of in vitro tests as well as the in vivo results showed no alteration in ethylene accumulation because of TMT insertion when tobacco leaves were exposed to salt treatments. According to the results presented in this study, the amounts of available SAM in transformed tobacco are likely sufficient to serve both ethylene and methyl halides biosynthetic pathways. Besides, in vivo results indicate that inserting the TMT1 gene that improves salt stress resistance in tobacco should not dramatically alter ethylene synthesis, and therefore, would be unlikely to affect any physiological trait associated with ethylene production if this gene is used to engineer salt tolerance in high-value crops. Although TMT insertion does not alter ethylene emission in transgenic plants and tends to be an efficient tool to confer salt tolerance in halo-intolerant crops, its environmental cost is of great concern and, therefore, should be taken into consideration to mitigate the amounts of methyl halides emitted into the atmosphere because of this insertion.

Methods for conditional Poisson sampling (CP-sampling) and Sampford sampling are compared and the focus is on the efficiency of the methods. The efficiency is investigated by simulation in different sampling situations. It was of interest to compare methods since new methods for both CP-sampling and Sampford sampling were introduced by Bondesson, Traat & Lundqvist in 2004. The new methods are acceptance rejection methods that use the efficient Pareto sampling method. They are found to be very efficient and useful in all situations. The list sequential methods for both CP-sampling and Sampford sampling are other methods that are found to be efficient, especially if many samples are to be generated.

Tomato has been genetically modified for providing properties such as insect-resistance or delayed-ripening. Tomato seeds purchased from several bazaars and markets were screened for the presence of genetic modification by targeting NptII kanamycin resistance, Nos terminator, and 35S promoter gene regions which are the most commonly transformed gene regions in transgenic plants, and then ripening-delayed tomato seeds were tried to be identified in this study. F type truncated-PG gene and Sam-k gene were selected as the indicator of genetically modified ripening delayed tomatoes. DNAs of 25 seed samples were isolated by CTAB method and examined with several primer pairs, and the primer sets that provided consistent results were selected to conduct routine testing by PCR analysis of the samples. In screening analysis via conventional PCR, 4 samples were amplified with 35S, Nos and NptII primer sets. Among other samples, 3 of them were amplified with 35S and Nos primer sets and 2 of them were amplified only with 35S primer set. The amplification was observed with Nos, NptII and Sam-k primers in one sample and this sample was identified as 35 1 N, since the sequence result of the PCR product amplified with Sam-k primers showed high homology with the Samase gene of T3 Coliphage. F type truncated PG gene was not observed in any of the samples. Although this study demonstrates the presence of commonly used gene regions in genetically modified tomatoes, further analysis of the genetically modified ripening delayed tomato seeds via construct specificor event specific PCR techniques is needed for confirmation.

Es werden Probleme der Langzeitarchivierung diskutiert, sowohl aus Anwendersicht als auch Betreibersicht. Konkret wird das Speicherungskonzept von MONARCH vorgestellt, mit dem versucht wird, die aufgeworfenen Probleme der Langzeitarchivierung zu loesen.