La pandémie actuelle liée à l’émergence du SARSCoV-2 en 2019 a considérablement modifié la perception des médecins de l’impact des virus respiratoires et de leur rôle dans les pneumonies aiguës ...communautaires (PAC). Alors que plus de 25 % des tableaux de PAC chez l’adulte étaient d’origine virale, les virus respiratoires étaient souvent perçus comme des agents pathogènes peu graves. Devant le défi que représente encore à nos jours la documentation microbiologique d’une PAC, l’instauration d’un traitement empirique par antibiotiques est souvent réalisée aux urgences. La pandémie de COVID-19 a surtout mis en exergue le rôle déterminant de la biologie moléculaire et du scanner thoracique dans l’algorithme diagnostique de la PAC. En effet, un diagnostic rapide et fiable est la clé pour améliorer les mesures de précaution et réduire la prescription inutile d’antibiotiques. Du fait de prises en charges très différentes, il est nécessaire de distinguer l’étiologie virale de la bactérienne d’une PAC.
The current pandemic linked to the emergence of SARS-CoV-2 in 2019 has considerably changed the perception of doctors of the impact of respiratory viruses and their role in community-acquired acute pneumonia (CAP). While more than 25% of CAP in adults were of viral origin, respiratory viruses were often perceived as harmless pathogens. Faced with the challenge that the microbiological documentation of a CAP still represents today, the establishment of empirical antibiotic treatment is often carried out in the emergency room. The COVID-19 pandemic has primarily highlighted the decisive role of molecular biology and chest CT in the diagnostic algorithm of CAP. Indeed, a rapid and reliable diagnosis is the key to improve isolation decisions and reducing the unnecessary prescription of antibiotics. Due to significantly different treatments, it is necessary to distinguish the viral etiology from the bacterial of a CAP.
We report the discovery of 1.97 ms period gamma-ray pulsations from the 75 minute orbital-period binary pulsar now named PSR J1653−0158. The associated Fermi Large Area Telescope gamma-ray source ...4FGL J1653.6−0158 has long been expected to harbor a binary millisecond pulsar. Despite the pulsar-like gamma-ray spectrum and candidate optical/X-ray associations-whose periodic brightness modulations suggested an orbit-no radio pulsations had been found in many searches. The pulsar was discovered by directly searching the gamma-ray data using the GPU-accelerated Einstein@Home distributed volunteer computing system. The multidimensional parameter space was bounded by positional and orbital constraints obtained from the optical counterpart. More sensitive analyses of archival and new radio data using knowledge of the pulsar timing solution yield very stringent upper limits on radio emission. Any radio emission is thus either exceptionally weak, or eclipsed for a large fraction of the time. The pulsar has one of the three lowest inferred surface magnetic-field strengths of any known pulsar with Bsurf 4 × 107 G. The resulting mass function, combined with models of the companion star's optical light curve and spectra, suggests a pulsar mass 2 M . The companion is lightweight with mass ∼0.01 M , and the orbital period is the shortest known for any rotation-powered binary pulsar. This discovery demonstrates the Fermi Large Area Telescope's potential to discover extreme pulsars that would otherwise remain undetected.
Résumé
Le changement climatique est à l’origine d’une augmentation, au cours des dernières décennies, des températures moyennes de la troposphère et des océans, avec des conséquences sur la fréquence ...et l’intensité de nombreux phénomènes météorologiques. Ces modifications ont un impact sur de nombreux secteurs de production agricole, élevage et sylvicole, et industrielle, ce qui entraîne des surcoûts considérables pour les nations et une diminution des revenus des ménages. Ces facteurs économiques sont responsables d’une diminution des conditions de vie et de l’accès à la santé, notamment pour les populations les plus précaires. Les risques pour la santé des populations sont considérables. Établir une cartographie des risques est une étape indispensable à la mise en place de procédures de gestion des crises sanitaires prévisibles dans le but de réduire leur fréquence et leur impact sur la population. Nous décrivons ici les risques déjà constatés et potentiels en France, sur la population générale et sur les populations les plus fragiles, notamment les risques liés aux phénomènes climatiques, les atteintes respiratoires et cardiovasculaires possibles, et les risques infectieux, notamment le risque de zoonoses.
ABSTRACT
The Fermi Large Area Telescope gamma-ray source 3FGL J2039.6–5618 contains a periodic optical and X-ray source that was predicted to be a ‘redback’ millisecond pulsar (MSP) binary system. ...However, the conclusive identification required the detection of pulsations from the putative MSP. To better constrain the orbital parameters for a directed search for gamma-ray pulsations, we obtained new optical light curves in 2017 and 2018, which revealed long-term variability from the companion star. The resulting orbital parameter constraints were used to perform a targeted gamma-ray pulsation search using the Einstein@Home-distributed volunteer computing system. This search discovered pulsations with a period of 2.65 ms, confirming the source as a binary MSP now known as PSR J2039–5617. Optical light-curve modelling is complicated, and likely biased, by asymmetric heating on the companion star and long-term variability, but we find an inclination i ≳ 60°, for a low pulsar mass between $1.1\, \mathrm{M}_{\odot } \lt M_{\rm psr} \lt $ 1.6 M⊙, and a companion mass of 0.15–$0.22\, \mathrm{M}_{\odot }$, confirming the redback classification. Timing the gamma-ray pulsations also revealed significant variability in the orbital period, which we find to be consistent with quadrupole moment variations in the companion star, suggestive of convective activity. We also find that the pulsed flux is modulated at the orbital period, potentially due to inverse Compton scattering between high-energy leptons in the pulsar wind and the companion star’s optical photon field.
We study the homogenization of Landau-Lifshitz-Gilbert equation in a ϵ-periodic composite material formed by two constituents, separated by an imperfect interface
, on which we prescribe the ...continuity of the conormal derivatives and a jump of the solution proportional to the conormal derivative, by means of a coefficient of order
. We use the periodic unfolding method together with extension operators for handling the nonlinearities to identify the limit problem when tuning up the parameter γ in
.
Ce texte décrit une étude conduite sur la zone couverte par le plan de développement de massif de la montagne thiernoise (Puy-de-Dôme) en 2007 et 2008. L'objectif était d'effectuer une évaluation ex ...ante de la mise en ½uvre d'une politique (fictive) de protection de la biodiversité ordinaire en forêt. L'évaluation permet d'anticiper les réactions possibles des acteurs locaux qui seraient confrontés à cette nouvelle politique publique, sur le périmètre d'un plan de développement de massif. / This paper presents a study carried out in the area covered by the Thiers-mountain development plan (Puy-de-Dôme department, Massif Central, France) in 2007 and 2008. The goal was to perform a prior assessment of a fictive policy for the protection of ordinary biodiversity in forests. The assessment was the means to anticipate the possible reactions of the local stakeholders who would be confronted with the new public policy in the context of the development plan.
Purpose
To describe the burden, and characteristics, of influenza-like illness (ILI) associated with non-influenza respiratory viruses (NIRV).
Methods
We performed a prospective, multicenter, ...observational study of adults admitted with ILI during three influenza seasons (2012–2015). Patients were screened for picornavirus, respiratory syncytial virus (RSV), coronavirus, human metapneumovirus, adenovirus, bocavirus, parainfluenza virus, and influenza, by PCR on nasopharyngeal samples. We excluded patients coinfected with NIRV and influenza.
Results
Among 1421 patients enrolled, influenza virus was detected in 535 (38%), and NIRV in 215 (15%), mostly picornavirus (
n
= 61), RSV (
n
= 53), coronavirus 229E (
n
= 48), and human metapneumovirus (
n
= 40). In-hospital mortality was 5% (NIRV), 4% (influenza), and 5% (no respiratory virus). As compared to influenza, NIRV were associated with age (median, 73 years vs. 68,
P
= 0.026), chronic respiratory diseases (53% vs. 45%,
P
= 0.034), cancer (14% vs. 9%,
P
= 0.029), and immunosuppressive drugs (21% vs. 14%,
P
= 0.028), and inversely associated with diabetes (18% vs. 25%,
P
= 0.038). On multivariable analysis, only chronic respiratory diseases (OR 1.5 1.1–2.0,
P
= 0.008), and diabetes (OR 0.5 0.4–0.8,
P
= 0.01) were associated with NIRV detection.
Conclusions
NIRV are common in adults admitted with ILI during influenza seasons. Outcomes are similar in patients with NIRV, influenza, or no respiratory virus.
Inhaled corticosteroids (ICS) have been associated with increased risk of pneumonia. Their impact on respiratory virus infections is unclear. We performed a post-hoc analysis of the FLUVAC cohort, a ...multicenter prospective cohort study of adults hospitalized with influenza-like illness (ILI) during six consecutive influenza seasons (2012-2018). All patients were tested for respiratory virus infection by multiplex PCR on nasopharyngeal swabs and/or bronchoalveolar lavage. Risk factors were identified by logistic regression analysis. Among the 2658 patients included, 537 (20.2%) were treated with ICS before admission, of whom 282 (52.5%, 282/537) tested positive for at least one respiratory virus. Patients on ICS were more likely to test positive for non-influenza respiratory viruses (25.1% vs. 19.5%, P = 0.004), especially for adenovirus (aOR 2.36, 95% CI 1.18-4.58), and respiratory syncytial virus (aOR 2.08, 95% CI 1.39-3.09). Complications were reported in 55.9% of patients on ICS (300/537), primarily pneumonia (171/535, 32%). Among patients on chronic ICS who tested positive for respiratory virus, 14.2% (40/282) were admitted to intensive care unit, and in-hospital mortality rate was 2.8% (8/282). Chronic use of ICS is associated with an increased risk of adenovirus or RSV infections in patients admitted for ILI.
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