119 research outputs found

    Latest Altimetry-Based Sea Ice Freeboard and Volume Inter-Annual Variability in the Antarctic over 2003–2020

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    The relatively stable conditions of the sea ice cover in the Antarctic, observed for almost 40 years, seem to be changing recently. Therefore, it is essential to provide sea ice thickness (SIT) and volume (SIV) estimates in order to anticipate potential multi-scale changes in the Antarctic sea ice. For that purpose, the main objectives of this work are: (1) to assess a new sea ice freeboard, thickness and volume altimetry dataset over 2003–2020 and (2) to identify first order impacts of the sea ice recent conditions. To produce these series, we use a neuronal network to calibrate Envisat radar freeboards onto CryoSat-2 (CS2). This method addresses the impacts of surface roughness on Low Resolution Mode (LRM) measurements. During the 2011 common flight period, we found a mean deviation between Envisat and CryoSat-2 radar freeboards by about 0.5 cm. Using the Advanced Microwave Scanning Radiometer (AMSR) and the dual-frequency Altimetric Snow Depth (ASD) data, our solutions are compared with the Upward looking sonar (ULS) draft data, some in-situ measurement of the SIMBA campaign, the total freeboards of 6 Operation Ice Bridge (OIB) missions and ICESat-2 total freeboards. Over 2003–2020, the global mean radar freeboard decreased by about −14% per decade and the SIT and SIV by about −10% per decade (considering a snow depth climatology). This is marked by a slight increase through 2015, which is directly followed by a strong decrease in 2016. Thereafter, freeboards generally remained low and even continued to decrease in some regions such as the Weddell sea. Considering the 2013–2020 period, for which the ASD data are available, radar freeboards and SIT decreased by about −40% per decade. The SIV decreased by about −60% per decade. After 2016, the low SIT values contrast with the sea ice extent that has rather increased again, reaching near-average values in winter 2020. The regional analysis underlines that such thinning (from 2016) occurs in all regions except the Amundsen-Bellingshausen sea sector. Meanwhile, we observed a reversal of the main regional trends from 2016, which may be the signature of significant ongoing changes in the Antarctic sea ice

    Former Ă  l’écrit universitaire, un terrain pour la linguistique ?

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    Introduction Les recherches sur les littĂ©racies universitaires reprĂ©sentent aujourd’hui Ă  l’échelle internationale un champ foisonnant. Sur le terrain, la tradition des Writing Centers des universitĂ©s amĂ©ricaines sert d’exemple et la formation Ă  l’écrit se dĂ©veloppe fortement dans les universitĂ©s : formation Ă  la maĂźtrise des diffĂ©rents genres universitaires ; formation aux genres de l’écrit professionnel, dans le cadre de la professionnalisation des Ă©tudes universitaires ; et formation Ă  une..

    Former Ă  l’écrit universitaire, un terrain pour la linguistique ?

    Get PDF
    Introduction Les recherches sur les littĂ©racies universitaires reprĂ©sentent aujourd’hui Ă  l’échelle internationale un champ foisonnant. Sur le terrain, la tradition des Writing Centers des universitĂ©s amĂ©ricaines sert d’exemple et la formation Ă  l’écrit se dĂ©veloppe fortement dans les universitĂ©s : formation Ă  la maĂźtrise des diffĂ©rents genres universitaires ; formation aux genres de l’écrit professionnel, dans le cadre de la professionnalisation des Ă©tudes universitaires ; et formation Ă  une..

    Hourglass SiO2 coating increases the performance of planar patch-clamp.

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    International audienceObtaining high-throughput electrophysiological recordings is an ongoing challenge in ion channel biophysics and drug discovery. One particular area of development is the replacement of glass pipettes with planar devices in order to increase throughput. However, successful patch-clamp recordings depend on a surface coating which ideally should promote and stabilize giga-seal formation. Here, we present data supporting the use of a structured SiO(2) coating to improve the ability of cells to form a "seal" with a planar patch-clamp substrate. The method is based on a correlation study taking into account structure and size of the pores, surface roughness and chip capacitance. The influence of these parameters on the quality of the seal was assessed. Plasma-enhanced chemical vapour deposition (PECVD) of SiO(2) led to an hourglass structure of the pore and a tighter seal than that offered by a flat, thermal SiO(2) surface. The performance of PECVD chips was validated by recording recombinant potassium channels, BK(Ca), expressed in stable HEK-293 cell lines and in inducible CHO cell lines and low conductance IRK1, and endogenous cationic currents from CHO cells. This multiparametric investigation led to the production of improved chips for planar patch-clamp applications which allow electrophysiological recordings from a wide range of cell lines

    Whole-genome/exome analysis of circulating tumor DNA and comparison to tumor genomics from patients with heavily pre-treated ovarian cancer: subset analysis of the PERMED-01 trial

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    IntroductionThe poor prognosis of ovarian carcinoma (OvC) is due to the advanced stage at diagnosis, a high risk of relapse after first-line therapies, and the lack of efficient treatments in the recurrence setting. Circulating tumor DNA (ctDNA) analysis is a promising tool to assess treatment-resistant OvC and may avoid iterative tissue biopsies. We aimed to evaluate the genomic profile of recurrent heavily pre-treated OvC.MethodsWe performed tumor panel-based sequencing as well as low-coverage whole-genome sequencing (LC-WGS) of tumor and plasma collected in patients with ovarian cancer included in the PERMED-01 trial. Whole-exome sequencing (WES) data of plasma samples were also analyzed and compared to mutation and copy number alteration (CNA) tumor profiles. The prognostic value [progression-free survival (PFS)] of these alterations was assessed in an exploratory analysis.ResultsTumor and plasma genomic analyses were done for 24 patients with heavily pretreated OvC [67% high-grade serous carcinoma (HGSC)]. Tumor mutation burden was low (median 2.04 mutations/Mb) and the most frequent mutated gene was TP53 (94% of HGSC). Tumor CNAs were frequent with a median of 50% of genome altered fraction. Plasma LC-WGS and WES detected ctDNA in 21/24 cases (88%) with a median tumor fraction of 12.7%. We observed a low correlation between plasma and tumor CNA profiles. However, this correlation was significant in cases with the highest circulating tumor fraction. Plasma genome altered fraction and plasma mutation burden (p = 0.011 and p = 0.041, respectively, log-rank tests) were associated with PFS.ConclusionsCombination of LC-WGS and WES can detect ctDNA in most pre-treated OvCs. Some ctDNA characteristics, such as genome altered fraction and plasma mutation burden, showed prognostic value. ctDNA assessment with LC-WGS may be a promising and non-expansive tool to evaluate disease evolution in this disease with high genomic instability.Clinical Trial Registrationhttps://clinicaltrials.gov/ct2/show/NCT02342158, identifier NCT02342158

    Financial and relational impact of having a boy with posterior urethral valves

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    IntroductionChildhood chronic diseases affect family functioning and well-being. The aim of this study was to measure the impact of caring for a child with PUV, and the factors that most impact the burden of care.Patients and methodWe gave a questionnaire on the familial impact of having a child with posterior urethral valves to all parents of a child included in the CIRCUP trial from 2015 onwards. The questionnaire included questions about the parents' demographics, health, professional, financial and marital status and how these evolved since the child's birth as well as the “impact on family scale” (IOFS), which gives a total score ranging from 15 (no impact) to 60 (maximum impact). We then analyzed both the results of the specific demographic questions as well as the factors which influenced the IOFS score.ResultsWe retrieved answers for 38/51 families (74.5% response rate). The average IOFS score was 23.7 (15–51). We observed that the child's creatinine level had an effect on the IOFS score (p = 0.02), as did the parent's gender (p = 0.008), health status (p = 0.015), being limited in activity since the birth of the child (p = 0.020), being penalized in one's job (p = 0.009), being supported in one's job (p = 0.002), and decreased income (p = 0.004). Out of 38 mother/father binomials, 8/33 (24.2%) declared that they were no longer in the same relationship afterwards.ConclusionIn conclusion, having a boy with PUV significantly impacts families. The risk of parental separation and decrease in revenue is significant. Strategies aiming to decrease these factors should be put in place as soon as possible
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