42 research outputs found
Ancient DNA reveals interstadials as a driver of common vole population dynamics during the last glacial period
Aim Many species experienced population turnover and local extinction during the Late Pleistocene. In the case of megafauna, it remains challenging to disentangle climate change and the activities of Palaeolithic hunter-gatherers as the main cause. In contrast, the impact of humans on rodent populations is likely to be negligible. This study investigated which climatic and/or environmental factors affect the population dynamics of the common vole. This temperate rodent is widespread across Europe and was one of the most abundant small mammal species throughout the Late Pleistocene. Location Europe. Taxon Common vole (Microtus arvalis). Methods We generated a dataset comprised of 4.2 kb long fragment of mitochondrial DNA (mtDNA) from 148 ancient and 51 modern specimens sampled from multiple localities across Europe and covering the last 60 thousand years (ka). We used Bayesian inference to reconstruct their phylogenetic relationships and to estimate the age of the specimens that were not directly dated. Results We estimated the time to the most recent common ancestor of all last glacial and extant common vole lineages to be 90 ka ago and the divergence of the main mtDNA lineages present in extant populations to between 55 and 40 ka ago, which is earlier than most previous estimates. We detected several lineage turnovers in Europe during the period of high climate variability at the end of Marine Isotope Stage 3 (MIS 3; 57-29 ka ago) in addition to those found previously around the Pleistocene/Holocene transition. In contrast, data from the Western Carpathians suggest continuity throughout the Last Glacial Maximum (LGM) even at high latitudes. Main Conclusions The main factor affecting the common vole populations during the last glacial period was the decrease in open habitat during the interstadials, whereas climate deterioration during the LGM had little impact on population dynamics. This suggests that the rapid environmental change rather than other factors was the major force shaping the histories of the Late Pleistocene faunas.info:eu-repo/semantics/publishedVersio
Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.
RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Taphonomie des micromammifères et reconstitution paléoenvironnementale d’un site du Pléistocene superieur : l’étude de cas de Roc-en-Pail (France).
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Toxoplasmose congénitale (traitement postnatal par l'association sulfadoxine-Pyriméthamine à Rouen)
La toxoplasmose congénitale est une infection parasitaire, due à Toxoplasma gondii, qui peut contaminer le foetus par voie transplacentaire lors d'une primo-infection maternelle au cours de la grossesse. Cette foetopathie bénéficie d'un programme national de prévention en France, ce qui a permis d'améliorer le pronostic des atteintes à la naissance grâce à une prise en charge adaptée. Cependant, les thérapeutiques visant à traiter la toxoplasmose congénitale évoluent peu. L'association sulfadoxine pyriméthamine (Fansidar®) peut être utilisée pour traiter les nouveau-nés atteints. La simplicité de son administration est intéressante par rapport au schéma posologique des autres molécules utilisées, ce qui facilite une bonne observance. Le suivi des enfants infectés doit être prolongé de manière à pouvoir diagnostiquer toute complication oculaire tardive due à cette pathologie.ROUEN-BU Médecine-Pharmacie (765402102) / SudocSudocFranceF
Waziers, le Bas-Terroir : contribution des petits vertébrés à la reconstitution de l’environnement local
Taphonomic signature of Eurasian eagle owl (Bubo bubo) on fish remains
International audienc
A specific small game exploitation for Lower Paleolithic: The beaver ( Castor fiber ) exploitation at the Caune de l'Arago (Pyrénées-Orientales, France)
International audienc
Environmental context of the Caune de l'Arago Acheulean occupations (Tautavel, France), new insights from microvertebrates in Q–R levels
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Contribution of small vertebrates for the characterization of climatic variations during the last interglacial in Northern Europe
International audienceSmall vertebrates, thanks to their abundance and diversity in archaeological sites, provide a significant amount of data on the palaeoenvironmental and taphonomic context of human occupations. Moreover, the fact that they are highly habitat-dependent allows for fine palaeoenvironmental reconstructions on a local scale. It is indeed to be considered that the local environment have a direct impact on the human groups, their subsistence strategies, land use, etc. In Europe, the strong climatic variations taking place during the Late Pleistocene mark the last occupations of Neanderthal in western Europe. Following the last interglacial phase of the Eemian (MIS 5e), a climatic deterioration took place. These climatic changes had a significant impact on Neanderthal populations in Europe, their environment, and the distribution of their resources. Until now, few MIS 5 sites have yielded faunal remains, especially microfaunas, in northwestern Europe. However, recently excavated sites have yielded significant bone accumulations thanks to an exceptional depositional and preservation context. This is notably the case of four sites located in the northern half of France: Caours, Waziers, Mutzig and le Rozel. These sites allow us to apply two methods to reconstruct climatic parameters, the “bioclimatic model” and the “applied ecology” methods, which allow us to obtain notably the mean annual temperature and the summer/winter gap.The estimated temperatures correspond to a temperate environment although local specificities are present. Biodiversity is quite low, especially in the Eemian sites. This decrease in biodiversity during global warming does not correspond to what is observed in southern Europe, where palaeo-communities are well documented and where there is no significant decline in species diversity. There could therefore be a very different response to the phases of global warming between animal communities in southern and northern Europe, but more data on this latter are still required