220 research outputs found

    Sensitivity kernels for time-distance helioseismology: efficient computation for spherically-symmetric solar models

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    The interpretation of helioseismic measurements, such as wave travel-time, is based on the computation of kernels that give the sensitivity of the measurements to localized changes in the solar interior. These are computed using the ray or the Born approximation. The Born approximation is preferable as it takes finite-wavelength effects into account, but can be computationally expensive. We propose a fast algorithm to compute travel-time sensitivity kernels under the assumption that the background solar medium is spherically symmetric. Kernels are typically expressed as products of Green's functions that depend upon depth, latitude and longitude. Here, we compute the spherical harmonic decomposition of the kernels and show that the integrals in latitude and longitude can be performed analytically. In particular, the integrals of the product of three associated Legendre polynomials can be computed thanks to the algorithm of Dong and Lemus (2002). The computations are fast and accurate and only require the knowledge of the Green's function where the source is at the pole. The computation time is reduced by two orders of magnitude compared to other recent computational frameworks. This new method allows for flexible and computationally efficient calculations of a large number of kernels, required in addressing key helioseismic problems. For example, the computation of all the kernels required for meridional flow inversion takes less than two hours on 100 cores

    Cenozoic intracontinental dextral motion in the Okhotsk-Japan Sea Region

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    Laurent Jolivet est Professeur à l'Université d'Orléans au 1er Septembre 2009International audienceA right-lateral shear zone trending northerly along more than 2000 km is recognized from central Japan to northern Sakhalin. It was active mainly during the Neogene and has accommodated several hundreds of kilometers of displacement. The whole structure of Sakhalin is built on this shear zone. En échelon sigmoidal folds and thrusts, en échelon narrow Miocene basins, and a major discontinuity which is observed along more than 600 km, the Tym-Poronaisk fault, characterize the deformation there. In Hokkaido, en échelon folds and thrusts and a ductile shear zone with high-temperature metamorphism constitute the southern extension of this transpressional shear zone. It continues to the south as a zone of transtensional deformation along the eastern margin of Japan Sea, as en échelon basins and dextral transfer faults observed as far south as Noto peninsula and Yatsuo basin. The style of the shear zone thus evolves from transpressional in the north far from the subduction zone, to transtensional in the south in the back-arc region. Strike-slip motion along this shear zone was primarily responsible for the dextral pull-apart opening of Japan Sea during the early and middle Miocene. Dextral motion is still active in the north along the Tym-Poronaisk fault in Sakhalin as well as on the continental margin of Japan Sea (Korea and Asia mainland). Active E-W compression replaced the dextral motion along the eastern margin of Japan Sea in late Miocene time, and incipient subduction began in the early Quaternary

    Circulating adrenomedullin estimates survival and reversibility of organ failure in sepsis: the prospective observational multinational Adrenomedullin and Outcome in Sepsis and Septic Shock-1 (AdrenOSS-1) study

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    Background: Adrenomedullin (ADM) regulates vascular tone and endothelial permeability during sepsis. Levels of circulating biologically active ADM (bio-ADM) show an inverse relationship with blood pressure and a direct relationship with vasopressor requirement. In the present prospective observational multinational Adrenomedullin and Outcome in Sepsis and Septic Shock 1 (, AdrenOSS-1) study, we assessed relationships between circulating bio-ADM during the initial intensive care unit (ICU) stay and short-term outcome in order to eventually design a biomarker-guided randomized controlled trial. Methods: AdrenOSS-1 was a prospective observational multinational study. The primary outcome was 28-day mortality. Secondary outcomes included organ failure as defined by Sequential Organ Failure Assessment (SOFA) score, organ support with focus on vasopressor/inotropic use, and need for renal replacement therapy. AdrenOSS-1 included 583 patients admitted to the ICU with sepsis or septic shock. Results: Circulating bio-ADM levels were measured upon admission and at day 2. Median bio-ADM concentration upon admission was 80.5 pg/ml [IQR 41.5-148.1 pg/ml]. Initial SOFA score was 7 [IQR 5-10], and 28-day mortality was 22%. We found marked associations between bio-ADM upon admission and 28-day mortality (unadjusted standardized HR 2.3 [CI 1.9-2.9]; adjusted HR 1.6 [CI 1.1-2.5]) and between bio-ADM levels and SOFA score (p < 0.0001). Need of vasopressor/inotrope, renal replacement therapy, and positive fluid balance were more prevalent in patients with a bio-ADM > 70 pg/ml upon admission than in those with bio-ADM ≤ 70 pg/ml. In patients with bio-ADM > 70 pg/ml upon admission, decrease in bio-ADM below 70 pg/ml at day 2 was associated with recovery of organ function at day 7 and better 28-day outcome (9.5% mortality). By contrast, persistently elevated bio-ADM at day 2 was associated with prolonged organ dysfunction and high 28-day mortality (38.1% mortality, HR 4.9, 95% CI 2.5-9.8). Conclusions: AdrenOSS-1 shows that early levels and rapid changes in bio-ADM estimate short-term outcome in sepsis and septic shock. These data are the backbone of the design of the biomarker-guided AdrenOSS-2 trial. Trial registration: ClinicalTrials.gov, NCT02393781. Registered on March 19, 2015

    Acute tubulointerstitial nephritis complicating Legionnaires' disease: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Legionnaires' disease is recognized as a multi-systemic illness. Afflicted patients may have pulmonary, renal, gastrointestinal tract and central nervous system complications. However, renal insufficiency is uncommon. The spectrum of renal involvement may range from a mild and transient elevation of serum creatinine levels to anuric renal failure requiring dialysis and may be linked to several causes. In our present case report, we would like to draw attention to the importance of the pathological documentation of acute renal failure by reporting a case of a patient with acute tubulointerstitial nephritis complicating Legionnaires' disease.</p> <p>Case presentation</p> <p>A 55-year-old Caucasian man was admitted to our hospital for community-acquired pneumonia complicated by acute renal failure. <it>Legionella pneumophila </it>serogroup type 1 was diagnosed. Although the patient's respiratory illness responded to intravenous erythromycin and ofloxacin therapy, his renal failure worsened, he became anuric, and hemodialysis was started. A renal biopsy was performed, which revealed severe tubulointerstitial nephritis. After initiation of steroid therapy, his renal function improved dramatically.</p> <p>Conclusions</p> <p>This case highlights the importance of kidney biopsies in cases where acute renal failure is a complicating factor in Legionnaires' disease. If the presence of acute tubulointerstitial nephritis can be confirmed, it will likely respond favorably to steroidal treatment and thus irreversible renal damage and chronic renal failure will be avoided.</p

    Global Analysis of Circulating Immune Cells by Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry

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    Background: MALDI-TOF mass spectrometry is currently used in microbiological diagnosis to characterize bacterial populations. Our aim was to determine whether this technique could be applied to intact eukaryotic cells, and in particular, to cells involved in the immune response. Methodology/Principal Findings: A comparison of frozen monocytes, T lymphocytes and polymorphonuclear leukocytes revealed specific peak profiles. We also found that twenty cell types had specific profiles, permitting the establishment of a cell database. The circulating immune cells, namely monocytes, T lymphocytes and polymorphonuclear cells, were distinct from tissue immune cells such as monocyte-derived macrophages and dendritic cells. In addition, MALDI-TOF mass spectrometry was valuable to easily identify the signatures of monocytes and T lymphocytes in peripheral mononuclear cells. Conclusions/Significance: This method was rapid and easy to perform, and unlike flow cytometry, it did not require any additional components such as specific antibodies. The MALDI-TOF mass spectrometry approach could be extended t

    Neogene strike-slip faulting in Sakhalin and the Japan Sea opening

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    Laurent Jolivet est Professeur à l'Université d'Orléans au 1er Septembre 2009International audienceWe describe structural data from a 2000 km N-S dextral strike-slip zone extending from northern Sakhalin to the southeast corner of the Japan Sea. Satellite images, field data, and focal mechanisms of earthquakes in Sakhalin are included in the interpretation. Since Miocene time the deformation in Sakhalin has been taken up by N-S dextral strike-slip faults with a reverse component and associated en e'chelon folds. Narrow en échelon Neogene basins were formed along strike-sup faults and were later folded in a second stage of deformation. We propose a model of basin formation along extension al faults delimitating dominos between two major strike-slip faults, and subsequent counterclockwise rotation of the dominos in a dextral transpressional regime, basins becoming progressively oblique to the direction of maximum horizontal compression and undergoing shortening. The association of both dextral and compressional focal mechanisms of earthquakes indicates that the same transpressional regime still prevails today in Sakhalin. We present fault set measurements undertaken in Noto Peninsula and Yatsuo Basin at the southern end of the Sakhalin-East Japan Sea strike-slip zone. Early and middle Miocene formations recorded the same transtensional regime as observed along the west coast of NE Honshu. During the early and middle Miocene the strike-slip regime was transpressional to the north in Sakhalin and Hokkaido, and transtensional to the south along the west coast of NE Honshu as far as Noto Peninsula and Yatsuo basin. Dextral motion accommodated the opening of the Japan Sea as a pull-apart basin, with the Tsushima fault to the west. The opening of the Japan Sea ceased at the end of the middle Miocene when transtension started to change to E-W compression in the Japan arc. Subduction of the Japan Sea lithosphere under the Japan arc started 1.8 Ma ago. The evolution of the stress regime from transtensional to compressional in the southern part of the strike-slip zone is related to the inception of the subduction of the young Philippine Sea Plate lithosphere under the Japan arc during the late Miocene. Subduction related extension is a necessary condition for the opening of the Japan Sea. Two possible mechanisms can account for dextral shear in this area: (1) counterclockwise rotation of crustal blocks due to the collision of India with Asia, (2) extrusion of the Okhotsk Sea block squeezed between the North America and Eurasia plates

    Repertoire of Intensive Care Unit Pneumonia Microbiota

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    Despite the considerable number of studies reported to date, the causative agents of pneumonia are not completely identified. We comprehensively applied modern and traditional laboratory diagnostic techniques to identify microbiota in patients who were admitted to or developed pneumonia in intensive care units (ICUs). During a three-year period, we tested the bronchoalveolar lavage (BAL) of patients with ventilator-associated pneumonia, community-acquired pneumonia, non-ventilator ICU pneumonia and aspiration pneumonia, and compared the results with those from patients without pneumonia (controls). Samples were tested by amplification of 16S rDNA, 18S rDNA genes followed by cloning and sequencing and by PCR to target specific pathogens. We also included culture, amoeba co-culture, detection of antibodies to selected agents and urinary antigen tests. Based on molecular testing, we identified a wide repertoire of 160 bacterial species of which 73 have not been previously reported in pneumonia. Moreover, we found 37 putative new bacterial phylotypes with a 16S rDNA gene divergence ≥98% from known phylotypes. We also identified 24 fungal species of which 6 have not been previously reported in pneumonia and 7 viruses. Patients can present up to 16 different microorganisms in a single BAL (mean ± SD; 3.77±2.93). Some pathogens considered to be typical for ICU pneumonia such as Pseudomonas aeruginosa and Streptococcus species can be detected as commonly in controls as in pneumonia patients which strikingly highlights the existence of a core pulmonary microbiota. Differences in the microbiota of different forms of pneumonia were documented

    Transposable Elements Are a Major Cause of Somatic Polymorphism in Vitis vinifera L.

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    Through multiple vegetative propagation cycles, clones accumulate mutations in somatic cells that are at the origin of clonal phenotypic diversity in grape. Clonal diversity provided clones such as Cabernet-Sauvignon N°470, Chardonnay N° 548 and Pinot noir N° 777 which all produce wines of superior quality. The economic impact of clonal selection is therefore very high: since approx. 95% of the grapevines produced in French nurseries originate from the French clonal selection. In this study we provide the first broad description of polymorphism in different clones of a single grapevine cultivar, Pinot noir, in the context of vegetative propagation. Genome sequencing was performed using 454 GS-FLX methodology without a priori, in order to identify and quantify for the first time molecular polymorphisms responsible for clonal variability in grapevine. New generation sequencing (NGS) was used to compare a large portion of the genome of three Pinot noir clones selected for their phenotypic differences. Reads obtained with NGS and the sequence of Pinot noir ENTAV-INRA® 115 sequenced by Velasco et al., were aligned on the PN40024 reference sequence. We then searched for molecular polymorphism between clones. Three types of polymorphism (SNPs, Indels, mobile elements) were found but insertion polymorphism generated by mobile elements of many families displayed the highest mutational event with respect to clonal variation. Mobile elements inducing insertion polymorphism in the genome of Pinot noir were identified and classified and a list is presented in this study as potential markers for the study of clonal variation. Among these, the dynamic of four mobile elements with a high polymorphism level were analyzed and insertion polymorphism was confirmed in all the Pinot clones registered in France

    LiverScreen project: study protocol for screening for liver fibrosis in the general population in European countries

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    Background: The development of liver cirrhosis is usually an asymptomatic process until late stages when complications occur. The potential reversibility of the disease is dependent on early diagnosis of liver fibrosis and timely targeted treatment. Recently, the use of non-invasive tools has been suggested for screening of liver fibrosis, especially in subjects with risk factors for chronic liver disease. Nevertheless, large population-based studies with cost-effectiveness analyses are still lacking to support the widespread use of such tools. The aim of this study is to investigate whether non-invasive liver stiffness measurement in the general population is useful to identify subjects with asymptomatic, advanced chronic liver disease. Methods: This study aims to include 30,000 subjects from eight European countries. Subjects from the general population aged ≥ 40 years without known liver disease will be invited to participate in the study either through phone calls/letters or through their primary care center. In the first study visit, subjects will undergo bloodwork as well as hepatic fat quantification and liver stiffness measurement (LSM) by vibration-controlled transient elastography. If LSM is ≥ 8 kPa and/or if ALT levels are ≥1.5 x upper limit of normal, subjects will be referred to hospital for further evaluation and consideration of liver biopsy. The primary outcome is the percentage of subjects with LSM ≥ 8kPa. In addition, a health economic evaluation will be performed to assess the cost-effectiveness and budget impact of such an intervention. The project is funded by the European Commission H2020 program. Discussion: This study comes at an especially important time, as the burden of chronic liver diseases is expected to increase in the coming years. There is consequently an urgent need to change our current approach, from diagnosing the disease late when the impact of interventions may be limited to diagnosing the disease earlier, when the patient is asymptomatic and free of complications, and the disease potentially reversible. Ultimately, the LiverScreen study will serve as a basis from which diagnostic pathways can be developed and adapted to the specific socio-economic and healthcare conditions in each country
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