380 research outputs found

    River temperature analysis with a new way of using Independant Component Analysis

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    In the context of global warming, river management is essential to maintain favourable water temperature ranges for aquatic species. Therefore, understanding the main factors influencing the water temperature becomes a key part in the management process. In this paper, we used Independent Component Analysis (ICA) to identify these main factors and improve water temperature forecasting. The study is caried out on two rivers in Normandy (France) with quite different characteristics. Each river was equipped with several temperature sensors which series range from 2011 to 2021. The ICA analysis of the data series reveals that the thermal regime of these two rivers is mainly controlled by seasonal and daily climatic factors. The Sélune regime also turns out to be influenced by the presence of a dam, dismantled during the monitoring of the river. The temperature of the Odon appears to be clearly controlled by seasonal lightening conditions in connection with the presence of the riparian vegetation. Complementary, an innovative approach called “successive ICA” is used to reconstruct the natural thermal regime of the Sélune without the presence of the dam. Emphasis is therefore placed here on the interest of ICA in hydrology as en elementary method for extracting the main influencing factors and quantifying their importance on the thermal regime of a river. It also allows to remove the influence of a particular factor and reconstruct time series better suited for temperature forecasting. The method used here is not specific to temperature time series and can be applied to any region even with different hydrological characteristics

    Hydration with sodium bicarbonate does not prevent contrast nephropathy: a multicenter clinical trial

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    BACKGROUND: Radiographic contrast media exposition can cause acute renal function impairment. There is limited and conflicting evidence that hydration with sodium bicarbonate prevents contrast-induced nephropathy (CIN) in patients undergoing cardiac catheterization. OBJECTIVE: The present study was aimed at determining whether sodium bicarbonate is superior to hydration with saline to prevent nephropathy in patients at risk undergoing cardiac catheterization. METHODS: Three hundred and one patients undergoing coronary angiography or percutaneous coronary intervention with serum creatinine > 1.2mg/dL or glomerular filtration rate (GFR) 1,2 mg/dL ou Taxa de Filtração Glomerular (TFG) < 50 mL/min, foram randomizados para receber hidratação com bicarbonato de sódio a partir de 1 hora antes do procedimento, e 6 horas após o procedimento, ou hidratação com solução salina a 0,9%. A NIC foi definida como um aumento de 0,5 mg/dL na creatinina em 48h. RESULTADOS: Dezoito pacientes (5,9%) desenvolveram nefropatia induzida por contraste: 9 pacientes no grupo do bicarbonato (6,1%) e 9 pacientes no grupo da solução salina (6,0%), p = 0,97. A variação na creatinina sérica foi semelhante em ambos os grupos, 0,01 ± 0,26 mg/dL no grupo do bicarbonato, e 0,01 ± 0,35 mg/dL no grupo da solução salina, p = 0,9. Não foi observada diferença estatística entre a alteração na taxa de filtração glomerular (0,89 ± 9 mL/ min vs. 2,29 ± 10 mL/min, p = 0,2, grupo do bicarbonato e grupo da solução salina, respectivamente). CONCLUSÃO: A hidratação com bicarbonato de sódio não foi superior ao soro fisiológico na prevenção a nefropatia induzida pelo contraste, em pacientes de risco submetidos a cateterismo cardíaco.PUCRS Hospital São LucasUNIFESP Hospital São PauloHospital São CamiloHospital General de PueblaHospital da UnimedHospital Intercath MeridionalUFRGSUNIFESP, Hospital São PauloSciEL

    Gene clusters reflecting macrodomain structure respond to nucleoid perturbations

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    Focusing on the DNA-bridging nucleoid proteins Fis and H-NS, and integrating several independent experimental and bioinformatic data sources, we investigate the links between chromosomal spatial organization and global transcriptional regulation. By means of a novel multi-scale spatial aggregation analysis, we uncover the existence of contiguous clusters of nucleoid-perturbation sensitive genes along the genome, whose expression is affected by a combination of topological DNA state and nucleoid-shaping protein occupancy. The clusters correlate well with the macrodomain structure of the genome. The most significant of them lay symmetrically at the edges of the ter macrodomain and involve all of the flagellar and chemotaxis machinery, in addition to key regulators of biofilm formation, suggesting that the regulation of the physical state of the chromosome by the nucleoid proteins plays an important role in coordinating the transcriptional response leading to the switch between a motile and a biofilm lifestyle.Comment: Article: first 24 pages, 3 figures Supplementary methods: 1 page, 1 figure Supplementary results: 14 pages, 11 figure

    SPHERE: the exoplanet imager for the Very Large Telescope

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    Observations of circumstellar environments to look for the direct signal of exoplanets and the scattered light from disks has significant instrumental implications. In the past 15 years, major developments in adaptive optics, coronagraphy, optical manufacturing, wavefront sensing and data processing, together with a consistent global system analysis have enabled a new generation of high-contrast imagers and spectrographs on large ground-based telescopes with much better performance. One of the most productive is the Spectro-Polarimetic High contrast imager for Exoplanets REsearch (SPHERE) designed and built for the ESO Very Large Telescope (VLT) in Chile. SPHERE includes an extreme adaptive optics system, a highly stable common path interface, several types of coronagraphs and three science instruments. Two of them, the Integral Field Spectrograph (IFS) and the Infra-Red Dual-band Imager and Spectrograph (IRDIS), are designed to efficiently cover the near-infrared (NIR) range in a single observation for efficient young planet search. The third one, ZIMPOL, is designed for visible (VIR) polarimetric observation to look for the reflected light of exoplanets and the light scattered by debris disks. This suite of three science instruments enables to study circumstellar environments at unprecedented angular resolution both in the visible and the near-infrared. In this work, we present the complete instrument and its on-sky performance after 4 years of operations at the VLT.Comment: Final version accepted for publication in A&

    B cell depletion reduces the development of atherosclerosis in mice

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    B cell depletion significantly reduces the burden of several immune-mediated diseases. However, B cell activation has been until now associated with a protection against atherosclerosis, suggesting that B cell–depleting therapies would enhance cardiovascular risk. We unexpectedly show that mature B cell depletion using a CD20-specific monoclonal antibody induces a significant reduction of atherosclerosis in various mouse models of the disease. This treatment preserves the production of natural and potentially protective anti–oxidized low-density lipoprotein (oxLDL) IgM autoantibodies over IgG type anti-oxLDL antibodies, and markedly reduces pathogenic T cell activation. B cell depletion diminished T cell–derived IFN-γ secretion and enhanced production of IL-17; neutralization of the latter abrogated CD20 antibody–mediated atheroprotection. These results challenge the current paradigm that B cell activation plays an overall protective role in atherogenesis and identify new antiatherogenic strategies based on B cell modulation

    Emotional and attention-deficit/hyperactivity disorder symptoms of preterm vs. full-term children during COVID-19 pandemic restrictions

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    BACKGROUND: Preterm children are at higher risk of developing mental health problems than full-term children. Deterioration of children's mental health was observed during COVID-19 pandemic restrictive measures. Our study compared emotional and attention-deficit/hyperactivity disorder (ADHD) symptoms during school closure between preterm and full-term children. METHODS: Data from two French birth cohorts-ELFE and EPIPAGE-2-were used. In 2011, infants born ≥22 weeks' gestation were recruited. Parents completed the Strengths and Difficulties Questionnaire when the children were 9 years old and experiencing school closure. Multivariate multinomial logistic regression models were used. RESULTS: Subjects included 4164 full-term and 1119 preterm children. In univariate analyses, compared to full-term children: extremely and very preterm children more frequently had abnormal and borderline ADHD scores (odds ratio [OR] 1.86, 95% confidence interval [CI] 1.50-2.30, OR 1.42, 95% CI 1.08-1.85, respectively) and abnormal emotional scores (OR 1.86, 95% CI 1.43-2.40); moderate to late preterm children more often had abnormal ADHD scores (OR 1.33, 95% CI 1.01-1.78). The associations did not remain when previous symptoms at 5 years old were considered. CONCLUSIONS: School closure during lockdown did not appear to increase the risk of mental health problems in preterm compared to full-term children. IMPACT STATEMENT: Preterm children are at higher risk of developing mental health problems than full-term children. Deterioration in children's mental health was observed during COVID-19 pandemic restrictions. However, whether preterm children were a particularly vulnerable subgroup during school closure is unclear. In univariate analyses, extremely and very preterm children more often had abnormal and borderline ADHD symptoms and abnormal emotional symptom scores than full-term children. The associations did not remain significantly associated when previous symptoms were considered. Preterm compared to full-term children more often suffer from ADHD and emotional symptoms, but school closure during lockdown did not appear to increase this risk.Santé, perception, pratiques, relations et inégalités sociales en population générale pendant la crise COVID-1

    Thorium speciation in seawater

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    Author Posting. © The Authors, 2006. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Marine Chemistry 100 (2006): 250-268, doi:10.1016/j.marchem.2005.10.024.Since the 1960’s, thorium isotopes occupy a special place in the oceanographer’s toolbox as tracers for determining rates and mechanisms of oceanic scavenging, particle dynamics, and carbon fluxes. Due to their unique and constant production rates from soluble parent nuclides of uranium and radium, their disequilibrium can be used to calculate rates and time scales of sinking particles. In addition, by ratio-ing particulate 234Th (as well, in principle, other Thnuclides) to carbon (and other elements), and linking this ratio to the parent-daughter disequilibrium in the water column, it is possible to calculate fluxes of carbon and other elements. Most of these applications are possible with little knowledge of the dissolved chemical properties of thorium, other than its oxidation state (IV) and tendency to strongly sorb to surfaces, i.e., its “particle- or surface-activity”. However, the use of any tracer is hindered by a lack of knowledge of its chemical properties. Recent observations in the variability of carbon to 234Th ratios in different particle types, as well as of associations of Th(IV) with various marine organic biomolecules has led to the need for a review of current knowledge and what future endeavors should be taken to understand the marine chemistry of thorium.The writing of this paper was supported, in parts by NSF (OCE-0351559; OCE-0350758, and OCE 0354757)
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