Isotope shift in the Sulfur electron affinity: observation and theory

The electron affinities eA(S) are measured for the two isotopes 32S and 34S (16752.9753(41) and 16752.9776(85) cm-1, respectively). The isotope shift in the electron affinity is found to be positive, eA(34S)-eA(32S) = +0.0023(70) cm-1, but the uncertainty allows for the possibility that it may be either "normal" (eA(34S) > eA(32S)) or "anomalous" (eA(34S) < eA(32S)). The isotope shift is estimated theoretically using elaborate correlation models, monitoring the electron affinity and the mass polarization term expectation value. The theoretical analysis predicts a very large specific mass shift that counterbalances the normal mass shift and produces an anomalous isotope shift, eA(34S)-eA(32S) = - 0.0053(24) cm-1. The observed and theoretical residual isotope shifts agree with each other within the estimated uncertainties.Comment: 15 pages, 4 figure

Productive re-use of CSCL data and analytic tools to provide a new perspective on group cohesion

The goals of this paper are twofold: (1) to demonstrate how previously published data can be re-analyzed to gain a new perspective on CSCL dynamics and (2) to propose a new measure of social cohesion that was developed through improvements to existing analytic tools. In this study, we downloaded the Simuligne corpus from the publicly available Mulce repository. We improved the Knowledge Space Visualizer (KSV) to deepen the notion of cohesion by using a dynamic representation of sociograms. The Calico tools have been used and extended to complete this cohesion measure by analyzing lexical markers. These complementary analyses of cohesion, based on clique sizes and communication intensity on the one hand, and lexical markers on the other hand, offer more detailed information on (a) the relationships between participants and (b) the structure and intensity of communication. In particular, the analyses highlight strong convergences that were not visible in the previous analysis

Microscopie et spectroscopie de photodétachement; mesure de la section efficace de photodétachement de H- à 1064 nm par observation du comportement asymptotique du régime saturé

Dans cette thèse, nous initions la démonstration, à échelle réduite, de la faisabilité du photodétachement presque total, par laser, d un jet d'ions négatifs d'hydrogène en cavité optique Fabry-Perot pour les futurs injecteurs de neutres destinés au chauffage des plasmas des réacteurs de fusion nucléaire.Nous élaborons une nouvelle méthode de mesure d une section efficace de photodétachement, dont la connaissance à la longueur d onde d excitation est requise pour le dimensionnement de la cavité Fabry-Perot, basée sur l observation de la saturation en régime d éclairement impulsionnel. Le calcul analytique de l accroissement du signal de détachement produit lors de l éclairement d un jet d ions par une impulsion laser supposée gaussienne, fait apparaître une contrainte mathématique sur le flux requis pour transiter vers le régime saturé. Cette contrainte est une caractéristique de la transition vers la saturation pour toutes les expériences réalisées en faisceau gaussien et pour tous les processus d interaction lumière-matière linéaires. Avec cette méthode, nous déduisons une section efficace de photodétachement de H- à 1064 nm longueur d onde sélectionnée pour les futurs injecteurs de neutres en léger désaccord avec les prédictions théoriques.Pour réduire les exigences technologiques sur la cavité et le laser, nous étudions les résonances de Landau qui apparaissent dans le spectre de photodétachement en champ magnétique. S asservir sur l une de ces résonances permettrait d augmenter la probabilité de photodétachement à un flux donné.Par ailleurs, nous présentons nos mesures des affinités électroniques du phosphore, du sélénium et de l étain, réalisées avec le microscope de photodétachement. L'expérience de microscopie de photodétachement du phosphore est la première où l atome neutre est laissé dans un terme excité.In this thesis, we initiate the demonstration, at a reduced scale, of the feasibility of the almost-complete laser photodetachment of negative hydrogen ion beams in a Fabry-Perot optical cavity for future neutral beam injectors for the heating of fusion power plants plasmas.We develop a new method to measure a photodetachement cross section, the knowledge of which at the exciting wavelength is needed to scale the Fabry-Perot cavity, based on the observation of the saturation in a pulsed lighting regime. The analytical calculus of the detachment signal growth produced while illuminating a negative ion beam with a Gaussian laser pulse bring out a mathematical constraint on the required flux to pass through the saturated regime. This constraint is the signature of the transition toward the saturation for all experiment carried out in Gaussian beam and for all linear light-matter interaction processes. With this method, we measure the photodetachement cross section of H- at 1064 nm selected wavelength for future neutral beam injectors in slight disagreement with theoretical predictions.To reduce the technological requirement on the Fabry-Perot cavity and the laser, we study Landau resonances which appear in the photodetachement spectrum. Locking the laser on one of these resonances would allow increasing the photodetachment probability at a given flux.We also present our phosphorus, selenium and tin electron affinity measurements carried out with the photodetachment microscope. The photodetachment microscopy experiment of phosphorus is the first one where the neutral atom is left in an excited term.PARIS11-SCD-Bib. électronique (914719901) / SudocSudocFranceF

Reconstruction of Coronary Arteries from One Rotational X-Ray Projection Sequence

Cardiovascular diseases remain the first death cause in developed countries. In most cases, exploration of possibly underlying coronary artery pathologies is performed using injected X-ray coronary angiography imaging modality. Current clinical routine in coronary angiography is directly conducted in 2-D from angiograms acquired from several static points of view. However, for diagnosis and treatment purposes, coronary arteries reconstruction is highly suitable. In this report, we propose a novel method to reconstruct coronary arteries from one single rotational X-ray projection sequence. The purpose of this study is to provide physicians with a 3-D model of coronary arteries, e.g. for absolute tridimensional measures for lesion assessment, instead of direct projective measures deducted from the images, which are highly dependent on the point of view. Our method is split in 3 sequential steps: (1) 3-D stereoscopic reconstruction of coronary arteries centerlines, including respiratory motion compensation, (2) coronary arteries 4-D motion computation, and (3) 3-D tomographic reconstruction of coronary arteries, involving compensation for respiratory and cardiac motions. We have successfully tested it on the datasets from a synthetic phantom and16 patients

Evaluation du devenir des produits phytopharmaceutiques en plein champ en fonction des pratiques culturales pour le développement d’une agriculture éco responsable (Sol-Phy-Ly). Rapport d’activités final 2018-2021.

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Evaluation du devenir des produits phytopharmaceutiques en plein champ en fonction des pratiques culturales : Sol-Phy-Ly

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Geographical dispersal of mobile communication networks

In this paper, we analyze statistical properties of a communication network constructed from the records of a mobile phone company. The network consists of 2.5 million customers that have placed 810 millions of communications (phone calls and text messages) over a period of 6 months and for whom we have geographical home localization information. It is shown that the degree distribution in this network has a power-law degree distribution $k^{-5}$ and that the probability that two customers are connected by a link follows a gravity model, i.e. decreases like $d^{-2}$, where $d$ is the distance between the customers. We also consider the geographical extension of communication triangles and we show that communication triangles are not only composed of geographically adjacent nodes but that they may extend over large distances. This last property is not captured by the existing models of geographical networks and in a last section we propose a new model that reproduces the observed property. Our model, which is based on the migration and on the local adaptation of agents, is then studied analytically and the resulting predictions are confirmed by computer simulations.Comment: 17 pages, 8 figure

How did episiotomy rates change from 2007 to 2014? Population-based study in France

International audienceBACKGROUND: Since the 2000s, selective episiotomy has been systematically recommended worldwide. In France, the recommended episiotomy rate in vaginal deliveries is less than 30%. The aims of this study were to describe the evolution of episiotomy rates between 2007 and 2014, especially for vaginal deliveries without instrumental assistance and to assess individual characteristics and birth environment factors associated with episiotomy.METHODS: This population-based study included all hospital discharge abstracts for all deliveries in France from 2007 to 2014. The use of episiotomy in vaginal deliveries was identified by one code in the French Common Classification of Medical Procedures. The episiotomy rate per department and its evolution is described from 2007 to 2014. A mixed model was used to assess associations with episiotomy for non-operative vaginal deliveries and the risk factors related to the women's characteristics and the birth environment.RESULTS: There were approximately 540,000 non-operative vaginal deliveries per year, in the study period. The national episiotomy rate for vaginal deliveries overall significantly decreased from 26.7% in 2007 to 19.9% in 2014. For non-operative deliveries, this rate fell from 21.1% to 14.1%. For the latter, the use of episiotomy was significantly associated with breech vaginal delivery (aOR = 1.27 [1.23-1.30]), epidural analgesia (aOR = 1.45 [1.43-1.47]), non-reassuring fetal heart rate (aOR = 1.47 [1.47-1.49]), and giving birth for the first time (aOR = 3.85 [3.84-4.00]).CONCLUSIONS: The episiotomy rate decreased throughout France, for vaginal deliveries overall and for non-operative vaginal deliveries. This decrease is probably due to proactive changes in practices to restrict the number of episiotomies, which should be performed only if beneficial to the mother and the infant

K63-linked ubiquitin chains as a specific signal for protein sorting into the multivesicular body pathway

A growing number of yeast and mammalian plasma membrane proteins are reported to be modified with K63-linked ubiquitin (Ub) chains. However, the relative importance of this modification versus monoubiquitylation in endocytosis, Golgi to endosome traffic, and sorting into the multivesicular body (MVB) pathway remains unclear. In this study, we show that K63-linked ubiquitylation of the Gap1 permease is essential for its entry into the MVB pathway. Carboxypeptidase S also requires modification with a K63-Ub chain for correct MVB sorting. In contrast, monoubiquitylation of a single target lysine of Gap1 is a sufficient signal for its internalization from the cell surface, and Golgi to endosome transport of the permease requires neither its ubiquitylation nor the Ub-binding GAT (Gga and Tom1) domain of Gga (Golgi localizing, gamma-ear containing, ARF binding) adapter proteins, the latter being crucial for subsequent MVB sorting of the permease. Our data reveal that K63-linked Ub chains act as a specific signal for MVB sorting, providing further insight into the Ub code of membrane protein trafficking

Outbreak of Leishmania braziliensis cutaneous leishmaniasis, Saül, French Guiana [letter]

New World cutaneous leishmaniasis (CL), a zoonotic disease, is increasingly seen among travelers returning from Latin American countries, particularly from Bolivia, Belize, and French Guiana (1). The epidemiology of CL in the Americas is heterogeneous and has complex variations in transmission cycles, reservoir hosts, and sandfly vectors. Changing human activities that affect these factors may have resulted in the emergence of species with distinct pathogenic potentials and responses to therapy. In the Guianan ecoregion complex, leishmaniasis is endemic, and 5 coexisting Leishmania parasite species are known to infect humans: L. guyanensis, L. braziliensis, L. amazonensis, L. naiffi, and L. lainsoni. Among these species, L. guyanensis accounts for ≈85% of CL cases (2). We report an outbreak of 7 cases of L. braziliensis CL that occurred among 24 scientists who participated in a field mission at Limonade Creek in Saül, French Guiana, during October 10–25, 2013. Saül is an isolated village in the Amazonian rainforest (3°55′18′′N, 53°18′02′′W)