Climate change impact on waves in the Bay of Biscay, France

International audienceThe knowledge of offshore and coastal wave climate evolution towards the end of the twenty-first century is particularly important for human activities in a region such as the Bay of Biscay and the French Atlantic coast. Using dynamical downscaling, a high spatial resolution dataset of wave conditions in the Bay of Biscay is built for three future greenhouse gases emission scenarios. Projected wave heights, periods and directions are analysed at regional scale and more thoroughly at two buoys positions, offshore and along the coast. A general decrease of wave heights is identified (up to -20 cm during summer within the Bay of Biscay), as well as a clockwise shift of summer waves and winter swell coming from direction. The relation between those changes and wind changes is investigated and highlights a complex association of processes at several spatial scales. For instance, the intensification and the north-eastward shift of strong wind core in the North Atlantic Ocean explain the clockwise shift of winter swell directions. During summer, the decrease of the westerly winds in the Bay of Biscay explains the clockwise shift and the wave height decrease of wind sea and intermediate waves. Finally, the analysis reveals that the offshore changes in the wave height and the wave period as well as the clockwise shift in the wave direction continue toward the coast. This wave height decrease result is consistent with other regional projections and would impact the coastal dynamics by reducing the longshore sediment flux

Mantle upwellings and convective instabilities revealed by seismic tomography and helium isotope geochemistry beneath eastern Africa

International audienceThe relationship between intraplate volcanism and continental tectonics has been investigated for North and East Africa using a high resolution three-dimensional anisotropic tomographic model derived from seismic data of a French experiment ''Horn of Africa'' and existing broadband data. The joint inversion for seismic velocity and anisotropy of the upper 400 km of the mantle, and geochemical data reveals a complex interaction between mantle upwellings, and lithosphere. Two kinds of mantle upwellings can be distinguished: The first one, the Afar ''plume'' originates from deeper than 400 km and is characterized by enrichment in primordial 3 He and 3 He/ 4 He ratios higher than those along mid-ocean ridges (MOR). The second one, associated with other Cenozoic volcanic provinces (Darfur, Tibesti, Hoggar, Cameroon), with 3 He/ 4 He ratios similar to, or lower than MOR, is a consequence of shallower upwelling. The presumed asthenospheric convective instabilities are oriented in an east-west direction, resulting from interaction between south-north asthenospheric mantle flow, main plume head and topography on the base of lithosphere

MARINE-EXPRESS: taking advantage of high throughput cloning and expression strategies for the post-genomic analysis of marine organisms

Background: The production of stable and soluble proteins is one of the most important steps prior to structural and functional studies of biological importance. We investigated the parallel production in a medium throughput strategy of genes coding for proteins from various marine organisms, using protocols that involved recombinatorial cloning, protein expression screening and batch purification. This strategy was applied in order to respond to the need for post-genomic validation of the recent success of a large number of marine genomic projects. Indeed, the upcoming challenge is to go beyond the bioinformatic data, since the bias introduced through the genomes of the so called model organisms leads to numerous proteins of unknown function in the still unexplored world of the oceanic organisms. Results: We present here the results of expression tests for 192 targets using a 96-well plate format. Genes were PCR amplified and cloned in parallel into expression vectors pFO4 and pGEX-4T-1, in order to express proteins N-terminally fused to a six-histidine-tag and to a GST-tag, respectively. Small-scale expression and purification permitted isolation of 84 soluble proteins and 34 insoluble proteins, which could also be used in refolding assays. Selected examples of proteins expressed and purified to a larger scale are presented. Conclusions: The objective of this program was to get around the bottlenecks of soluble, active protein expression and crystallization for post-genomic validation of a number of proteins that come from various marine organisms. Multiplying the constructions, vectors and targets treated in parallel is important for the success of a medium throughput strategy and considerably increases the chances to get rapid access to pure and soluble protein samples, needed for the subsequent biochemical characterizations. Our set up of a medium throughput strategy applied to genes from marine organisms had a mean success rate of 44% soluble protein expression from marine bacteria, archaea as well as eukaryotic organisms. This success rate compares favorably with other protein screening projects, particularly for eukaryotic proteins. Several purified targets have already formed the base for experiments aimed at post-genomic validation

Pyruvate dehydrogenase fuels a critical citrate pool that is essential for Th17 cell effector functions

Pyruvate dehydrogenase (PDH) is the central enzyme connecting glycolysis and the tricarboxylic acid (TCA) cycle. The importance of PDH function in T helper 17 (Th17) cells still remains to be studied. Here, we show that PDH is essential for the generation of a glucose-derived citrate pool needed for Th17 cell proliferation, survival, and effector function. In vivo, mice harboring a T cell-specific deletion of PDH are less susceptible to developing experimental autoimmune encephalomyelitis. Mechanistically, the absence of PDH in Th17 cells increases glutaminolysis, glycolysis, and lipid uptake in a mammalian target of rapamycin (mTOR)-dependent manner. However, cellular citrate remains critically low in mutant Th17 cells, which interferes with oxidative phosphorylation (OXPHOS), lipid synthesis, and histone acetylation, crucial for transcription of Th17 signature genes. Increasing cellular citrate in PDH-deficient Th17 cells restores their metabolism and function, identifying a metabolic feedback loop within the central carbon metabolism that may offer possibilities for therapeutically targeting Th17 cell-driven autoimmunity

Fratura periprotética de quadril - Vancouver tipo A: Periprosthetic hip fracture - Vancouver type A

Introdução: As  fraturas  periprotéticas  de  quadril  são uma  complicação  grave e com elevado índice de morbimortalidade observadas  após abordagens   cirúrgicas,   como   artroplastia   de   quadril   e  cirurgias   de   revisão. Ocorrem mais frequentemente ao redor do componente femoral em relação ao acetabular. Essa complicação  está  relacionada  a  fatores  que  são  avaliados  por  meio  do  sistema  de Vancouver,   possibilitando   definir   a   melhor   forma   de   abordagem   e   cuidados   da complicação. Apresentação do caso: Paciente do sexo feminino, 60 anos de idade, admitida no Hospital Universitário Risoleta Tolentino Neves (UFMG), com uma fratura tipo A, que tem localização trocantérica e pode se manifestar no trocanter femoral maior ou menor. Discussão: Com o aumento da longevidade, a idade média da população vem aumentando, e com isso o número de intervenções cirúrgicas também aumentam, principalmente as artroplastias de quadril. O que leva a um maior número de situações que envolvem complicações pós-cirúrgicas. Com mais episódios de fraturas periprotéticas, torna-se importante uma melhor avaliação dos quadros para melhor conduta e elucidação de eventuais complicações. Conclusão: Ao se constatar uma fratura periprotética de quadril, deve-se classificar a mesma seguindo o sistema de Vancouver que é dividido em três tipos A, B e C. Essa classificação vai ditar como será a abordagem mais assertiva para  resolução do quadro do pacient

Síndrome de Dubowitz: Dubowitz syndrome

Introdução: a síndrome de Dubowitz é uma síndrome rara herdada de forma autossômica recessiva e o diagnóstico é realizado por exclusão, foi primeiramente descrita no ano de 1965 e possui um grande espectro fenótico, podendo afetar inúmeros  sistemas. Apresentação do caso: paciente do sexo masculino, branco, sete anos, admitido no Hospital das Clínicas da UFG, após encaminhamento de UB. Nasceu de parto normal a termo, sem intercorrências, pesando 2.200 g, PIG (pequeno para idade gestacional), estatura de 46 cm, Apgar de 9 e 10. A mãe relata ter realizado todas consultas de pré-natal e nega qualquer infecção, uso de bebida alcoólica, cigarro ou drogas ilícitas durante a gravidez. Discussão: a apresentação  clínica mais comumente encontrada está relacionada ao retardo do crescimento, baixo peso ao nascer, microcefalia, alterações faciais e físicas características, desempenho intelectual diminuído, oligofrenia discreta. Conclusão: a Síndrome de Dubowitz ainda é bastante desconhecida. Com base nas bibliografias pesquisadas percebeu-se que há muito para ser explorado

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/)