Science & Mathematics

300 000 postes, ce chiffre à lui seul donne la démesure du défi : réaliser un Extranet fédérant l’ensemble de ces postes et le rendre accessible à tous ceux qui le désirent. Notre communauté Enseignement Supérieur Recherche est répartie administrativement en 241 établissements, physiquement sur des centaines de sites, et au niveau réseaux sur des milliers de domaines (au sens DNS). L'utilisation de Web Services a permis de réaliser une solution pertinente et élégante pouvant être appelée de partout, depuis n'importe quel serveur Web tournant sur n'importe quel système.

On présente la simulations du bilan d'énergie d'un générateur de vapeur de centrale nucléaire par des méthodes de domaine fictif. Plusieurs types de solveurs domaine fictif ont été développés pour des CL immergées générales, en EF ou en VF, avec raffinement de maillage par patchs. Le solveur est couplé à un code industriel pour la fourniture des relations de fermetures. Les gains en temps CPU et mémoires sont soulignés ainsi que les potentialités pour le calcul parallèle.

To determine the influence of elevation and year-to-year climatic fluctuations on radial growth and tree-ring properties of Abies lasiocarpa, we sampled dominant trees in 49 second-growth stands on mesic sites in British Columbia. The earlywood, latewood, and total ring width, and latewood and maximum density decreased significantly with increasing elevation. Since no significant trend was observed for latewood percentage and ring density, decline in maximum density will have minor impacts on wood quality of high and low-elevation Abies lasiocarpa. The correlation and response functions indicated that response to climatic factors changed with elevation. Although mesic sites within the study area were not expected to be water deficient, ring width decreased with the occurrence of warm and dry spring weather in low-elevation. Low summer temperature limited ring width in high-elevation and maximum latewood density and latewood width in low- and high-elevation, albeit the relationship was much stronger in high-elevation.

Rare earth elements (REEs) are increasingly accumulated in groundwater due to anthropogenic activities, but their fate, hydrogeochemical behavior, and health impacts remain poorly understood and regulated. We have systematically reviewed the scientific literature over the last decades concerning sources, geochemical processes, potential tracer, and health impacts of REEs in groundwaters. REEs in groundwaters are mainly sourced from bedrock and occasionally from anthropogenic activities. Geochemical processes, including redox processes, complexation, adsorption, and desorption, modify REE signatures in groundwater. Redox conditions can change the redox state of Ce and result in anomalies, which can reflect redox processes in groundwater systems.We systematically concluded that REE concentrations and patterns can be used to delineate sources and geochemical processes of geogenic redox-sensitive elements in groundwater (such as arsenic and uranium). Anthropogenic REEs from wastewater, fertilizer, mining, and solid waste can be introduced into groundwater systems, which disturbs the natural REE signatures. We disentangled that delineating groundwater contamination and tracing related geochemical processes can be beneficial from differentiating geogenic REE signatures from anthropogenic REE disturbance. Longterm consumption of low-dose REE-bearing drinking water is suggested to cause diverse significant damage to human health. Novel investigations are required to perform on pathways of REE intake, potential mitigation measures, and drinking water guidelines for REE concentrations to minimize their health impacts. Future studies are needed to better understand environmental behavior and epidemiological impacts of 3 anthropogenic REEs in groundwaters.

Selecting for better health has become of primary importance for the dairy industry. In France, where no national database exists for health traits (except mastitis), a collaborative project has been implemented to explore and evaluate farmer health records. Around 10% of herds record health events accurately. Genetic parameters of 4 disorders have been studied here: Displaced Abomasum (DA), Milk Fever (MF), Metritis (MET) and Retained Placenta (RP). Heritabili-ties are low (1-2%), but health traits have moderate genetic correlations with some dairy traits (0.15-0.45). Based on EBV obtained with ssGBLUP for the four health traits, the daughters’ incidence of best EBV bulls versus worst bulls is reduced by a factor of 2 minimum.

24x36 mm, gélatine plan-film.

On décrit brièvement un système d'analyse de résultats d'expériences à basse énergie. Un dialogue utilisateur-ordinateur améliore fortement la rapidité et la facilité des analyses.

The Photonic Crystal Fibers (PCFs) are microstructured waveguides currently developed in the frame of metrology, non-linear optics or coherent tomography. PCF studies are mainly focused on the improvement of dispersion property and wide spectral single-mode operating domain. Consequently, in the astronomical context, this kind of fiber is a good candidate to design a fiber linked version of stellar interferometer for aperture synthesis. In this paper, we study the potential of these fibers taking advantage of the wide spectral single-mode operation. We propose an experimental setup acting as a two-beam interferometer using PCFs to measure fringes contrasts at four different wavelengths (670nm, 980nm, 1328nm and 1543nm) corresponding to R, I, J and H astronomical bands with the same couple of PCFs. For this purpose, we implement for the first time a piezoelectric PCF optical path modulator.

A new lower bound for the maximal length of a multivector is obtained. It is much closer to the best known upper bound than previously reported lower bound estimates. The maximal length appears to be unexpectedly large for $n$-vectors, with n>2, since the few exactly known values seem to grow linearly with vector space dimension, whereas the new lower bound has a polynomial order equal to n-1 like the best known upper bound. This result has implications for quantum chemistry.

Given that (co)inductive types are naturally modelled as fixed points, it is unsurprising that fixed-point logics are of interest in the study of programming languages, via the Curry-Howard (or proofs-as-programs) correspondence. This motivates investigations of the structural proof-theory of fixedpoint logics and of their cut-elimination procedures. Among the various approaches to proofs in fixed-point logics, circular-or cyclic-proofs, are of interest in this regard but suffer from a number of limitations, most notably from a quite restricted use of cuts. Indeed, the validity condition which ensures soundness of non-wellfounded derivations and productivity of their cut-elimination prevents some computationally-relevant patterns of cuts. As a result, traditional circular proofs cannot serve as a basis for a theory of (co)recursive programming by lack of compositionality: there are not enough circular proofs and they compose badly. The present paper addresses some of these limitations by developing the circular and non-wellfounded proof-theory of multiplicative additive linear logic with fixed points (µMALL) beyond the scope of the seminal works of Santocanale and Fortier and of Baelde et al. We define bouncing-validity: a new, generalized, validity criterion for µMALL∞ , which takes axioms and cuts into account. We show soundness and cut elimination theorems for bouncing-valid non-wellfounded proofs: as a result, even though bouncing-validity proves the same sequents (or judgments) as before, we have many more valid proofs at our disposal. We illustrate the computational relevance of bouncing-validity on a number of examples. Finally, we study the decidability of the criterion in the circular case: we prove it is undecidable in general but identify a hierarchy of decidable sub-criteria.

Depuis une trentaine d’années, la confiscation est devenue l’un des instruments principaux de la lutte contre la criminalité organisée transnationale. Elle est présentée comme une sanction plus efficace que la peine privative de liberté. Elle s’est progressivement imposée comme une peine pénale obligatoire. Cependant, elle n’a cessé de se développer et de se diffuser sans pour autant aboutir à un résultat convaincant. En effet une étude d’Europol précise que seul 1% des produits tirés de la criminalité serait effectivement confisqué dans l’Union européenne. Fort de ce constat, cette recherche se propose d’analyser le cadre juridique européen en matière de confiscation et de recouvrement des produits du crime pour comprendre les sources d’un taux de recouvrement aussi faible que celui énoncé. Elle prend acte dans une première partie du renforcement des dispositifs juridiques européens adoptés depuis 1998. L’objectif européen est de garantir une confiscation aussi large que possible. Les évolutions législatives européennes se sont par conséquent inscrites dans une aggravation de la répression ou, plus exactement, dans un processus visant à faciliter le prononcé d’une sanction de confiscation. C’est ainsi que la directive 2014/42/UE et le règlement (UE) 2018/1805 ont reconnu des mécanismes de confiscation non-fondées sur une condamnation pénale. Mais cette volonté de confisquer aussi largement que possible fait peser un risque important pour les États membres, ainsi que pour l’Union européenne. Pour les premiers il s’agit d’un risque financier. Mettre en place un système efficace de confiscation implique de mettre en place les institutions nécessaires à l’exercice de cette mission. Cela représente un coût financier important. Pour l’UE, le risque est de créer des zones de forum shopping. Tous les États membres ne disposent pas des capacités institutionnelles essentielles pour mettre en œuvre les dispositifs juridiques européens de manière adéquate. Ils constituent à ce titre des espaces favorables pour accueillir les bénéfices tirés de la criminalité grave transfrontalière. La seconde partie prend ainsi acte de la nécessité de mener un travail sur la question de la mise en œuvre pratique des dispositions juridiques européennes. Un travail sur le cadre institutionnel au niveau européen doit ainsi être mené aux fins de garantir dans l’Union européenne une confiscation et un recouvrement effectif des produits du crime. Or, ce travail est encore actuellement insuffisamment traité alors même qu’il constitue le socle sur lequel s’appuient et se développent les effets voulus par les dispositifs juridiques européens adoptés.

Identifying the factors causing mortality over life is of great importance in gerontology, ecology and evolution. I first present some general methods to properly estimate age-related causes of mortality. Second, I report some of the studies that have quantified the main causes of mortality affecting wild boar over life, an emblematic game species that has dramatically increased in abundance and distribution across Europe. Hunting is the major cause of mortality, followed by natural mortality (e.g. starvation, senescence) and predation, all these factors of mortality being age- and/or sex-specific. Third, I discuss why it is important to examine how some sources of mortality can interact. Finally, I show how hunting can select for accelerated life history that allows wild boar to compensate high mortality probabilities with high reproductive output.