Highly sensitive frequency metrology for optical anisotropy measurements

In this paper we present a novel apparatus aimed at measuring very small birefringences and anisotropies, based on frequency metrology and not on polarimetry as usual. In our experiment, a very high finesse resonant cavity is used to convert the phase difference into a resonance frequency difference, which can then be measured with very high accuracy. We describe the set-up and present the results of experimental tests which exhibited a sensitivity dn ~ 2 x 10?18, allowing for the measurement of long-predicted magneto-electro-optical effects in gases. Since the shotnoise limited sensitivity of our apparatus lies well below the state-of-the-art sensitivity, frequency metrology appears as a promising technique for small birefringence measurements.Comment: Accepted for publication in Review of Scientific Instrument

Status of the BMV experiment

In this contribution we present the status of the BMV experiment whose goal is to measure the vacuum magnetic birefringence

Differential permissivity of human cerebrovascular endothelial cells to enterovirus infection and specificities of enterovirus 71 in crossing an in vitro model of human blood brain barrier

Human cerebral microvascular endothelial cells (hCMEC/D3 cell line) form a steady polarized barrier when cultured in vitro on a permeable membrane. Their susceptibility to enterovirus (EV) strains was analysed to investigate how these viruses may cross the blood-brain barrier. A sample of 88 virus strains was selected on phylogenetic features among 44 epidemiologically relevant types of the four EV species A-D. The EV-A71 genome was replicated at substantial rates while the infectious virus was released at extremely low but sustained rates at both barrier sides for at least 4 days. EV-A71 antigens were detected in a limited number of cells. The properties of the endothelial barrier (structure and permeability) remained intact throughout infection. The chronic EV-A71 infection was in sharp contrast with the productive infection of cytolytic EVs (e.g. echoviruses 6 and 30). The hCMEC/D3 barriers infected with the latter EVs exhibited elevated proportions of apoptotic and necrotic cells, which resulted in major injuries to the endothelial barriers with dramatic increase of paracellular permeability and virus crossing to the abluminal side. The following intracellular rearrangements were also seen: early destruction of the actin cytoskeleton, remodelling of intracellular membranes, and reorganization of the mitochondrion network in a small cluster near the perinuclear space

GEN1 from a thermophilic fungus is functionally closely similar to non-eukaryotic junction-resolving enzymes

AbstractProcessing of Holliday junctions is essential in recombination. We have identified the gene for the junction-resolving enzyme GEN1 from the thermophilic fungus Chaetomium thermophilum and expressed the N-terminal 487-amino-acid section. The protein is a nuclease that is highly selective for four-way DNA junctions, cleaving 1nt 3′ to the point of strand exchange on two strands symmetrically disposed about a diagonal axis. CtGEN1 binds to DNA junctions as a discrete homodimer with nanomolar affinity. Analysis of the kinetics of cruciform cleavage shows that cleavage of the second strand occurs an order of magnitude faster than the first cleavage so as to generate a productive resolution event. All these properties are closely similar to those described for bacterial, phage and mitochondrial junction-resolving enzymes. CtGEN1 is also similar in properties to the human enzyme but lacks the problems with aggregation that currently prevent detailed analysis of the latter protein. CtGEN1 is thus an excellent enzyme with which to engage in biophysical and structural analysis of eukaryotic GEN1

Bibliothèques et publics handicapés visuels

Il y a, en France, quelque 1 500 000 mal-voyants et 70 000 aveugles pour qui l'accès à l'information et à l'écrit constitue un véritable parcours du combattant. Les bibliothèques ont un rôle primordial à jouer vis-à-vis de ces publics. Depuis l'ouverture en 1984 de la salle Borges par la Bibliothèque publique d'information, suivie par celle de l'espace Louis Braille à la Médiathèque de la Cité des sciences et de l'industrie en 1986, les bibliothèques publiques et universitaires sont de plus e..

L'intérêt d'une lettre d'admission aux urgences

Objectif : évaluer l'impact de la lettre d'admission aux urgences médicales du CHU de Grenoble. Population et méthodes : pendant une semaine, tous les sujets admis dans le service des urgences ont été inclus, le recueil des données a été réalisé à l'aide d'un questionnaire. Les deux critères de jugement étaient : le délai de prise en charge et la concordance de diagnostics entre le médecin traitant, le service des urgences et le service hospitalier. Résultats : l'étude inclut 435 dossiers, dont 233 avec une lettre d'admission. La probabilité que les patients soient adressés avec un courrier augmente avec l'âge et la gravité de l'état clinique. La présence d'une lettre n'influence pas significativement le délai de prise en charge. Conclusion : la communication médicale est essentielle, surtout pour la prise en charge de patient âgé. Le médecin adressant doit communiquer les éléments pertinents du dossier médical de ses patients. Le courrier est le support le plus utilisé.Objective: investigate the impact of General Practitioners' referral letters on the management's efficiency at the emergency department of the Grenoble Hospital. Population and methods : this survey includes all admitted patients to the emergency department during one week. The patients filled in a questionnaire, to evaluate the quality of the letter. The two criteria for evaluation are the waiting time and the concordance of diagnosis between the GPs and the consultants of emergency. Results : the survey includes 435 patients, among whom 233 had a letter. More a patient is old or in a critical condition, more he comes with a letter. The referral letter doesn't affect the patients' waiting time in the department. Conclusion : the communication between GPs and consultants is the most important item, mainly for old patients. Letters are an objective, efficient and practical way for the GP to communicate the information from the medical files. They are the most common means of communication.GRENOBLE1-BU Médecine pharm. (385162101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Using scattered hyperspectral imagery data to map the soil properties of a region

Airborne hyperspectral imagery has been recently proved to be a successful technique for predicting soil properties of the bare soil surfaces that are usually scattered in the landscape. This new soil covariate could much improve the digital soil mapping (DSM) of soil properties over larger areas. To illustrate this, we experimented with digital soil mapping in a 24.6-km2 area located in the vineyard plain of Languedoc. As input data, we used 200 points with clay content measurements and 192 bare soil fields representing 3.5% of the total area in which the clay contents of the soil surface were successfully mapped at 5-m resolution by hyperspectral remote sensing. The clay contents were estimated from CR2206, a spectrometric indicator that quantifies specific absorption features of clay at 2206 nm. We demonstrated by cross-validation that the co-kriging procedure based on our co-regionalization model provided accurate error estimates at the clay measurement sites. Then, we applied a block co-kriging model to map the mean clay content at increasing resolutions (50 , 100, 250 and 500 m). The results showed the following: (i) using hyperspectral data significantly increased the accuracy of the mean clay content estimations; (ii) a block co-kriging procedure with reliable estimates of error variance can be used to estimate mean clay contents over larger areas and at coarser resolutions with acceptable and predictable errors and (iii) various maps can be produced that represent different compromises between prediction accuracy and spatial resolution