Prototypentheorie und Flexionsmorphologie

This article presents an application of the theory of prototypes to the field of inflectional morphology and especially to the treatment of exceptions. From the assumption that the handling of irregular facts is basically ruled by the same principles of categorization as the handling of regular facts, the article shows on concrete examples of German nouns - weak masculine nouns, feminine nouns with inflected e-plural and er-plural - that the principle of the motivation of inflection by other properties of lexical items (phonological, semantic, syntactic properties) also works in inflectional classes with few elements. This type of analysis leads to the hypothesis of much more complex categorial structures, which includes subcategories with very few elements, instead of the traditional dichotomy between regular and irregular or a simple continuum prototypical - non prototypical

Identities for field extensions generalizing the Ohno-Nakagawa relations

In previous work, Ohno conjectured, and Nakagawa proved, relations between the counting functions of certain cubic fields. These relations may be viewed as complements to the Scholz reflection principle, and Ohno and Nakagawa deduced them as consequences of `extra functional equations' involving the Shintani zeta functions associated to the prehomogeneous vector space of binary cubic forms. In the present paper we generalize their result by proving a similar identity relating certain degree l fields with Galois groups D_l and F_l respectively, for any odd prime l, and in particular we give another proof of the Ohno-Nakagawa relation without appealing to binary cubic forms.Comment: Version 2, 16 pages, to appear in Compositi

Modelling the palaeo-evolution of the geodynamo

International audienceAlthough it is known that the geodynamo has been operating for at least 3.2 Ga, it remains difficult to infer the intensity, dipolarity and stability (occurrence of reversals) of the Precam-brian magnetic field of the Earth. In order to assist the interpretation of palaeomagnetic data, we produce models for the long-term evolution of the geodynamo by combining core ther-modynamics with a systematic scaling analysis of numerical dynamo simulations. We update earlier dynamo scaling results by exploring a parameter space, which has been extended in order to account for core aspect ratios and buoyancy source distributions relevant to Earth in the Precambrian. Our analysis highlights the central role of the convective power, which is an output of core thermodynamics and the main input of our updated scalings. As the thermal evolution of the Earth's core is not well known, two end-member models of heat flow evolution at the core–mantle boundary (CMB) are used, respectively, terminating at present heat flows of 11 TW (high-power scenario) and 3 TW (low power scenario). The resulting models predict that until the appearance of the inner core, a thermal dynamo driven only by secular cooling, and without any need for radioactive heating, can produce a dipole moment of strength comparable to that of the present field, thus precluding an interpretation of the oldest palaeomagnetic records as evidence of the inner core presence. The observed lack of strong long-term trends in palaeointensity data throughout the Earth's history can be rationalized by the weakness of palaeointensity variations predicted by our models relatively to the data scatter. Specifically, the most significant internal magnetic field increase which we predict is associated to the sudden power increase resulting from inner core nucleation, but the dynamo becomes deeper-seated in the core, thus largely cancelling the increase at the core and Earth surface, and diminishing the prospect of observing this event in palaeointensity data. Our models additionally suggest that the geodynamo has lied close to the transition to polarity reversals throughout its history. In the Precambrian, we predict a dynamo with similar dipolarity and less frequent reversals than at present times, due to conditions of generally lower convective forcing. Quantifying the typical CMB heat flow variation needed for the geodynamo to cross the transition from a reversing to a non-reversing state, we find that it is unlikely that such a variation may have caused superchrons in the last 0.5 Ga without shutting down dynamo action altogether

Développement d'un code éléments finis pour simuler le soudage par ultrasons de matériaux composites = Development of a Finite element code for simulating the ultrasonic welding of composite materials

National audienceLe développement récent des matériaux composites à matrices thermoplastiques c'est accompagné de nouveaux moyens d'assemblages. Nous nous concentrons ici sur le soudage par ultrasons. Afin d'étudier l'influence des paramètres procédé sur la qualité d'une soudure, nous proposons une modélisation puis une simulation du procédé. La modélisation se fait à l'aide de deux problèmes mécaniques et d'un problème thermique. Un code de simulation multiphysique a été développé afin de résoudre ces trois problèmes. L'évolution que subit l'interface est simulé à l'aide d'une méthode de level-set et de contact unilatéral par pénalité. Les simulations en 2D sans modélisation du contact montrent que des porosités sont piégées à l'interface. Ceci est confirmé par les essais de soudage statique (sans mouvement de l'outil). Les simulations avec modélisation du contact permettent de mieux décrire l'écrasement à l'interface mais montrent des lacunes physiques. Le soudage dynamique avec avance de l'outil est un variant du procédé permettant de limiter les porosités à l'interface. La simulation de l'écoulement tridimensionnel qui en résulte est en cours. Elle devrait permettre d'expliquer la meilleure qualité de la soudure

Statistical Interpretation of Joint Multiplicity Distributions of Neutrons and Charged Particles

Experimental joint multiplicity distributions of neutrons and charged particles emitted in complex nuclear reactions provide an important test of theoretical models. The method is applied to test three different theoretical models of nuclear multi-fragmentation, two of which fail the test. The measurement of neutrons is decisive in distinguishing between the Berlin and Copenhagen models of nuclear multi-fragmentation and challenges the interpretation of pseudo- Arrhenius plots. Statistical-model evaporation calculations with GEMINI give a good reproduction first and second moments of the experimental multiplicity correlations.Comment: 12 pages, 3 figures Added GEMINI calculations of multiplicity correlations Added brief discussion of how neutron emission is treated in MMM

Prescribing the behaviour of geodesics in negative curvature

Given a family of (almost) disjoint strictly convex subsets of a complete negatively curved Riemannian manifold M, such as balls, horoballs, tubular neighborhoods of totally geodesic submanifolds, etc, the aim of this paper is to construct geodesic rays or lines in M which have exactly once an exactly prescribed (big enough) penetration in one of them, and otherwise avoid (or do not enter too much in) them. Several applications are given, including a definite improvement of the unclouding problem of [PP1], the prescription of heights of geodesic lines in a finite volume such M, or of spiraling times around a closed geodesic in a closed such M. We also prove that the Hall ray phenomenon described by Hall in special arithmetic situations and by Schmidt-Sheingorn for hyperbolic surfaces is in fact only a negative curvature property.Comment: 89 page

The energy dependence of flow in Ni induced collisions from 400 to 1970A MeV

We study the energy dependence of collective (hydrodynamic-like) nuclear matter flow in 400-1970 A MeV Ni+Au and 1000-1970 A MeV Ni+Cu reactions. The flow increases with energy, reaches a maximum, and then gradually decreases at higher energies. A way of comparing the energy dependence of flow values for different projectile-target mass combinations is introduced, which demonstrates a common scaling behaviour among flow values from different systems.Comment: 12 pages, 3 figures. Submitted to Physical Review Letter

Marine Strategy Framework Directive - Task Group 10 Report Marine Litter

The Marine Strategy Framework Directive (2008/56/EC) (MSFD) requires that the European Commis-sion (by 15 July 2010) should lay down criteria and methodological standards to allow consistency in approach in evaluating the extent to which Good Environmental Status (GES) is being achieved. ICES and JRC were contracted to provide scientific support for the Commission in meeting this obligation. A total of 10 reports have been prepared relating to the descriptors of GES listed in Annex I of the Directive. Eight reports have been prepared by groups of independent experts coordinated by JRC and ICES in response to this contract. In addition, reports for two descriptors (Contaminants in fish and other seafood and Marine Litter) were written by expert groups coordinated by DG SANCO and IFREMER respectively. A Task Group was established for each of the qualitative Descriptors. Each Task Group consisted of selected experts providing experience related to the four marine regions (the Baltic Sea, the North-east Atlantic, the Mediterranean Sea and the Black Sea) and an appropriate scope of relevant scien-tific expertise. Observers from the Regional Seas Conventions were also invited to each Task Group to help ensure the inclusion of relevant work by those Conventions. This is the report of Task Group 10 Marine litter.JRC.DDG.H.5-Rural, water and ecosystem resource

Adipocyte ATP-binding cassette G1 promotes triglyceride storage, fat mass growth, and human obesity

The role of ATP-binding Cassette G1 (ABCG1) transporter in human pathophysiology is still largely unknown. Indeed, beyond its role in mediating free cholesterol efflux to HDL, ABCG1 transporter equally promotes lipid accumulation in a triglyceride (TG)-rich environment through regulation of the bioavailability of Lipoprotein Lipase (LPL).As both ABCG1 and LPL are expressed in adipose tissue, we hypothesize that ABCG1 is implicated in adipocyte TG storage and could be then a major actor in adipose tissue fat accumulation.Silencing of Abcg1 expression by RNAi in 3T3-L1 preadipocytes compromised LPL-dependent TG accumulation during initial phase of differentiation. Generation of stable Abcg1 Knockdown 3T3-L1 adipocytes revealed that Abcg1 deficiency reduces TG storage and diminishes lipid droplet size through inhibition of Pparγ expression. Strikingly, local inhibition of adipocyte Abcg1 in adipose tissue from mice fed a high fat diet led to a rapid decrease of adiposity and weight gain. Analysis of two frequent ABCG1 SNPs (rs1893590 (A/C) and rs1378577 (T/G)) in morbidly obese individuals indicated that elevated ABCG1 expression in adipose tissue was associated with an increased PPARγ expression and adiposity concomitant to an increased fat mass and BMI (haplotype AT>GC). The critical role of ABCG1 regarding obesity was further confirmed in independent populations of severe obese and diabetic obese individuals.For the first time, this study identifies a major role of adipocyte ABCG1 in adiposity and fat mass growth and suggests that adipose ABCG1 might represent a potential therapeutic target in obesity