Semipurity of tempered Deligne cohomology

In this paper we define the formal and tempered Deligne cohomology groups, that are obtained by applying the Deligne complex functor to the complexes of formal differential forms and tempered currents respectively. We then prove the existence of a duality between them, a vanishing theorem for the former and a semipurity property for the latter. The motivation of these results comes from the study of covariant arithmetic Chow groups. The semi-purity property of tempered Deligne cohomology implies, in particular, that several definitions of covariant arithmetic Chow groups agree for projective arithmetic varieties

Propriétés d’une souche d’orthopoxvirus isolée des dromadaires du Niger

La souche de virus VD47 isolée des dromadaires du Niger possède la morphologie et les propriétés caractéristiques des camelpoxvirus : elle est thermolabile, résistante à l’éther, sensible au chloroforme et à l’IDU. Sa température limite est de 38,5 °C et elle induit la formation de syncitia et de foyers de cellules rétractées avec phénomène d’hémadsorption positif. Ce virus s’est révélé non pathogène pour les souris et très faiblement pour les lapins. Il est neutralisé par du sérum anti-vaccine. La question du pouvoir pathogène pour l’homme des camelpoxvirus et des camelparapoxvirus est débattue par les auteurs

Field desorption ion source development for neutron generators

A new approach to deuterium ion sources for deuterium-tritium neutron generators is being developed. The source is based upon the field desorption of deuterium from the surfaces of metal tips. Field desorption studies of microfabricated field emitter tip arrays have been conducted for the first time. Maximum fields of 30 V/nm have been applied to the array tip surfaces to date, although achieving fields of 20 V/nm to possibly 25 V/nm is more typical. Both the desorption of atomic deuterium ions and the gas phase field ionization of molecular deuterium has been observed at fields of roughly 20 V/nm and 20-30 V/nm, respectively, at room temperature. The desorption of common surface adsorbates, such as hydrogen, carbon, water, and carbon monoxide is observed at fields exceeding ~10 V/nm. In vacuo heating of the arrays to temperatures of the order of 800 C can be effective in removing many of the surface contaminants observed

Integral Grothendieck-Riemann-Roch theorem

We show that, in characteristic zero, the obvious integral version of the Grothendieck-Riemann-Roch formula obtained by clearing the denominators of the Todd and Chern characters is true (without having to divide the Chow groups by their torsion subgroups). The proof introduces an alternative to Grothendieck's strategy: we use resolution of singularities and the weak factorization theorem for birational maps.Comment: 24 page

Characterization of a new coronavirus strain of poultry infections bronchitis

Un coronavirus a été isolé chez des poules pondeuses présentant des signes cliniques sévères évoquant la bronchite infectieuse aviaire, maladie contre laquelle, elles avaient été immunisées avec un vaccin préparé à partir du sérotype dominant Massachusetts ; ce virus présente des dif férences antigéniques avec les sérotypes Massachusetts et Connecticut ainsi qu’avec les quatre sérotypes « variants » isolés par l’Institut de Doom aux Pays-Bas. La maladie a été reproduite chez le poulet et la poule : les symptômes respiratoires ont été sévères dans les deux cas et la chute de ponte a été intense et persistante chez les pondeuses. Le fait de développer une prophylaxie médicale adaptée est discuté.A coronavirus was isolated in an infectious bronchitis (IB) vaccinated (Massachusetts strain) layers flock showing severe IB-like clinical signs. The isolate is antigenically different from the Massachusetts and the Connecticut serotypes and from the four « variant » serotypes isolated by the Doom Institute in Holland. The disease was reproduced in chickens and layers. Respiratory signs were severe in both groups. In layers, egg drop was intense and long-lasting. The eventual need for a suitable medical prophylaxy is discussed

Equation of state and phonon frequency calculations of diamond at high pressures

The pressure-volume relationship and the zone-center optical phonon frequency of cubic diamond at pressures up to 600 GPa have been calculated based on Density Functional Theory within the Local Density Approximation and the Generalized Gradient Approximation. Three different approaches, viz. a pseudopotential method applied in the basis of plane waves, an all-electron method relying on Augmented Plane Waves plus Local Orbitals, and an intermediate approach implemented in the basis of Projector Augmented Waves have been used. All these methods and approximations yield consistent results for the pressure derivative of the bulk modulus and the volume dependence of the mode Grueneisen parameter of diamond. The results are at variance with recent precise measurements up to 140 GPa. Possible implications for the experimental pressure determination based on the ruby luminescence method are discussed.Comment: 10 pages, 6 figure

Predictive factors for concurrent deep-vein thrombosis and symptomatic venous thromboembolic recurrence in case of superficial venous thrombosis. The OPTIMEV study

Superficial venous thrombosis (SVT) prognosis is debated and its management is highly variable. It was the objective of this study to assess predictive risk factors for concurrent deep-vein thrombosis (DVT) at presentation and for three-month adverse outcome. Using data from the prospective multicentre OPTIMEV study, we analysed SVT predictive factors associated with concurrent DVT and three-month adverse outcome. Out of 788 SVT included, 227 (28.8%) exhibited a concurrent DVT at presentation. Age >75years (odds ratio [OR]=2.9 [1.5-5.9]), active cancer (OR=2.6 [1.3-5.2]), inpatient status (OR=2.3 [1.2-4.4]) and SVT on non-varicose veins (OR=1.8 [1.1-2.7]) were significantly and independently associated with an increased risk of concurrent DVT. 39.4% of SVT on non-varicose veins presented a concurrent DVT. However, varicose vein status did not influence the three-month prognosis as rates of death, symptomatic venous thromboembolic (VTE) recurrence and major bleeding were equivalent in both non-varicose and varicose SVTs (1.4% vs. 1.1%; 3.4% vs. 2.8%; 0.7% vs. 0.3%). Only male gender (OR=3.5 [1.1-11.3]) and inpatient status (OR=4.5 [1.3-15.3]) were independent predictive factors for symptomatic VTE recurrence but the number of events was low (n=15, 3.0%). Three-month numbers of deaths (n=6, 1.2%) and of major bleedings (n=2, 0.4%) were even lower, precluding any relevant interpretation. In conclusion, SVT on non-varicose veins and some classical risk factors for DVT were predictive factors for concurrent DVT at presentation. As SVT remains mostly a clinical diagnosis, these data may help selecting patients deserving an ultrasound examination or needing anticoagulation while waiting for diagnostic tests. Larger studies are needed to evaluate predictive factors for adverse outcome

Continuum-mechanical, Anisotropic Flow model for polar ice masses, based on an anisotropic Flow Enhancement factor

A complete theoretical presentation of the Continuum-mechanical, Anisotropic Flow model, based on an anisotropic Flow Enhancement factor (CAFFE model) is given. The CAFFE model is an application of the theory of mixtures with continuous diversity for the case of large polar ice masses in which induced anisotropy occurs. The anisotropic response of the polycrystalline ice is described by a generalization of Glen's flow law, based on a scalar anisotropic enhancement factor. The enhancement factor depends on the orientation mass density, which is closely related to the orientation distribution function and describes the distribution of grain orientations (fabric). Fabric evolution is governed by the orientation mass balance, which depends on four distinct effects, interpreted as local rigid body rotation, grain rotation, rotation recrystallization (polygonization) and grain boundary migration (migration recrystallization), respectively. It is proven that the flow law of the CAFFE model is truly anisotropic despite the collinearity between the stress deviator and stretching tensors.Comment: 22 pages, 5 figure