310 research outputs found
Implémentation dans le code E. F. CAST3M de la méthode de changement d'échelles Transformation field analysis (TFA)
National audienceSee http://hal.archives-ouvertes.fr/docs/00/59/27/05/ANNEX/r_PN3ACFD3.pd
Optical gratings induced by field-free alignment of molecules
We analyze the alignment of molecules generated by a pair of crossed
ultra-short pump pulses of different polarizations by a technique based on the
induced time-dependent gratings. Parallel polarizations yield an intensity
grating, while perpendicular polarizations induce a polarization grating. We
show that both configurations can be interpreted at moderate intensity as an
alignment induced by a single polarized pump pulse. The advantage of the
perpendicular polarizations is to give a signal of alignment that is free from
the plasma contribution. Experiments on femtosecond transient gratings with
aligned molecules were performed in CO2 at room temperature in a static cell
and at 30 K in a molecular expansion jet.Comment: 10 pages, 5 figures, submitted to PR
SAGETTARIUS: a program to reduce the number of tags mapped to multiple transcripts and to plan SAGE sequencing stages
SAGE (Serial Analysis of Gene Expression) experiments generate short nucleotide sequences called ‘tags’ which are assumed to map unambiguously to their original transcripts (1 tag to 1 transcript mapping). Nevertheless, many tags are generated that do not map to any transcript or map to multiple transcripts. Current bioinformatics resources, such as SAGEmap and TAGmapper, have focused on reducing the number of unmapped tags. Here, we describe SAGETTARIUS, a new high-throughput program that performs successive precise Nla3 and Sau3A tag to transcript mapping, based on specifically designed Virtual Tag (VT) libraries. First, SAGETTARIUS decreases the number of tags mapped to multiple transcripts. Among the various mapping resources compared, SAGETTARIUS performed the best in this respect by decreasing up to 11% the number of multiply mapped tags. Second, SAGETTARIUS allows the establishment of a guideline for SAGE experiment sequencing efforts through efficient mapping of the CRT (Cytoplasmic Ribosomal protein Transcripts)-specific tags. Using all publicly available human and mouse Nla3 SAGE experiments, we show that sequencing 100 000 tags is sufficient to map almost all CRT-specific tags and that four sequencing stages can be identified when carrying out a human or mouse SAGE project. SAGETTARIUS is web interfaced and freely accessible to academic users
Influence of Molecular Organization on the Electrical Characteristics of {\pi}-conjugated Self-assembled Monolayers
Two new thiol compounds with {\sigma}-{\pi}-{\sigma} structure were
synthesized and self-assembled on gold substrates. The morphology and the
structural characterization of SAMs assessed by infrared spectroscopy, contact
angle, XPS, electrochemistry and scanning tunneling microscopy (STM) show the
formation of monolayers. SAMs with a terthiophene (3TSH) core as conjugated
system are much better organized compared to those with a naphthalene
carbodiimide (NaphSH) core as demonstrated by the cyclic voltammetry and STM
studies. The surface concentration of 3TSH and NaphSH is respectively three and
six times lower than ordered SAMs of pure alkyl chains. A large number of I/V
characteristics have been studied either by STS measurements on gold substrates
or by C-AFM on gold nanodots. Transition Voltage Spectroscopy (TVS) was used to
clearly identify the transport in these partially organized monolayers. The
chemical nature of the conjugated system, donor for 3TSH and acceptor for
NaphSH, involves an opposite rectification associated to the asymmetrical
coupling of the molecular orbitals and the electrodes. The conductance
histograms show that the 3TSH junctions are less dispersed than those of NaphSH
junctions. This is explained by a better control of the molecular organization
in the molecular junctions.Comment: Full paper with supporting informatio
Apports technologiques dans la prévention du risque iatrogène médicamenteux : Exemple de l'actigraphie
La santé et plus particulièrement les médicaments, sont aujourd'hui à la une de l'actualité, non seulement dans le domaine médical mais aussi sociétal et politique. Les professionnels de santé, et plus particulièrement le pharmacien et le médecin, doivent s'assurer de la qualité de leurs divers soins (pharmaceutiques et médicaux) ainsi que de la sécurité de leurs patients. Cette prévention du risque est d'autant plus importante pour certains types de populations, désignées comme populations vulnérables que représentent les personnes âgées et les patients atteints de pathologie chronique. Dans cette démarche, des nouvelles solutions technologiques commencent à apparaître présentées comme des outils d'aide prometteurs. Leur apport réel vis-à-vis du risque iatrogène médicamenteux reste à être démontré par des évaluations précises. Un exemple de protocole est présenté portant sur l'utilisation de l'actigraphie chez la personne âgée
A new polyomavirus isolated in goose: from the identification of the virus toward the development of a vaccine
Hemorrhagic nephritis enteritis of geese (HNEG) is a major disease affecting goose. We have isolated
its agent and shown that it is a novel member of Polyomavirus genus. The biology of this viral
infection has been studied, at the level of both animal and flocks, on breeders and fattening goslings.
An inactivated and adjuvanted vaccine has also been prepared and assayed on breeders and
goslings. This program should result in the control of the disease on the field. It also addresses the
question of the impact of polyomaviruses in animal and public health.La Néphrite hémorragique
entérite de l'oie (NHEO) constitue une maladie majeure de l'oie. Nous avons récemment isolé
son agent et montré qu'il s'agit d'une nouvelle espèce virale du genre Polyomavirus. La
biologie de cette infection virale a été étudiée, à l'échelle de l'animal infecté et des
populations d'oies, chez les reproducteurs et les oisons destinés au gavage. Un candidat
vaccin, inactivé et adjuvé, a été préparé et testé chez les oies reproductrices et les
oisons en croissance. Ce programme de recherche devrait permettre à terme le contrôle de
l'affection sur le terrain. Il pose aussi la question de l'impact en santé animale, voire en
santé publique, des polyomavirus
Combined spectroscopy and intensity interferometry to determine the distances of the blue supergiants P Cygni and Rigel
In this paper, we report on the spatial intensity interferometry measurements
within the H line on two stars: the Luminous Blue Variable (LBV)
supergiant \PCygni\,and the late-type B supergiant Rigel. The experimental
setup has been upgraded to allow simultaneous measurement of two polarization
channels and the zero baseline correlation function. Combined with simultaneous
spectra measurements and based on radiative transfer models calculated with the
code CMFGEN, we were able to fit our measured visibility curves to extract the
stellar distances. Our distance determinations for both \PCygni\ (1.61
0.18 kpc) and Rigel (0.26 0.02 kpc) agree very well with the values
provided by astrometry with the Gaia and Hipparcos missions, respectively. This
is the first successful step towards extending the application of the Wind
Momentum Luminosity Relation method for distance calibration from an LBV
supergiant to a more normal late-type B supergiant
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