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Solar analogues are important stars to study for understanding the properties of the Sun. Combined with seismic and spectroscopic analysis, evolutionary modelling becomes a powerful method to characterize stellar intrinsic parameters, such as mass, radius, metallicity and age. However, these characteristics, relevant for other aspects of astrophysics or exoplanetary system physics, for example, are difficult to obtain with high precision and/or accuracy. The goal of this study is to characterize the two solar analogues, HD 42618 and HD 43587, observed by CoRoT. In particular, we aim to infer their precise mass, radius and age, using evolutionary modelling constrained by spectroscopic, photometric and seismic analysis. These stars show evidence of being older than the Sun but with a relatively large lithium abundance. We present the seismic analysis of HD 42618, and the modelling of the two solar analogues, HD 42618 and HD 43587 using the cestam stellar evolution code. Models were computed to reproduce the spectroscopic (effective temperature and metallicity) and seismic (mode frequency) data, and the luminosity of the stars, based on Gaia parallaxes. We infer very similar values of mass and radius for both stars compared with the literature, within the uncertainties, and we reproduce correctly the seismic constraints. The modelling shows that HD 42618 is slightly less massive and older than the Sun, and that HD 43587 is more massive and older than the Sun, in agreement with previous results. The use of chemical clocks improves the reliability of our age estimates. [ABSTRACT FROM AUTHOR]

Les infections invasives à méningocoque (IIM) regroupent les méningites, septicémies et chocs septiques liés à Neisseiria meningitidis. En France, le sérogroupe B domine, suivi des sérogroupes C, Y et W. Leur létalité est de 10 %, voire 25 % si choc septique. Le diagnostic est évoqué devant une fièvre associée à des signes méningés (céphalée, fontanelle bombée, vomissements, raideur méningée) et/ou des signes de mauvaise perfusion périphérique (marbrures, temps de recoloration cutanée allongé, extrémités froides) et/ou des douleurs des membres, et secondairement une éruption (érythème morbilliforme ou purpura). L'évolution vers un choc septique (purpura fulminans) ou une méningite comateuse est à craindre si le traitement n'est pas instauré suffisamment tôt. Le traitement est urgent et repose sur une antibiothérapie par céphalosporine de troisième génération intraveineuse (dans l'heure qui suit le diagnostic présomptif, après hémoculture à l'hôpital) et sur un remplissage vasculaire rapide (20 ml/kg en 10 minutes), éventuellement renouvelé en fonction des objectifs thérapeutiques (diminution de la fréquence cardiaque, disparition des signes de choc, diminution du lactate). Si les objectifs ne sont pas atteints malgré deux remplissages, l'enfant doit être transféré dans un service de réanimation pédiatrique, les amines vasopressives débutées et l'intubation discutée. Le diagnostic positif d'IIM et du sérogroupe repose sur l'isolement du germe dans une hémoculture, dans le liquide céphalorachidien (la ponction lombaire étant contre-indiquée en cas de choc), ou par une polymerase chain reaction méningocoque positive dans le sang, le liquide céphalorachidien ou sur une biopsie d'un purpura nécrotique. Il s'agit d'une infection à déclaration obligatoire auprès de l'agence régionale de santé. Les mesures de prévention secondaires reposent sur une antibioprophylaxie des personnes en contact proche dans les dix jours précédant le diagnostic et une vaccination s'il s'agit d'un sérogroupe vaccinal (A, C, W, Y). La vaccination de tous les enfants de plus de 1 an et des jeunes adultes est recommandée. [ABSTRACT FROM AUTHOR]

Résumé Introduction Le pronostic des infections ostéoarticulaires (IOA) s’est amélioré depuis 20 ans mais peut encore être sévère. Le traitement s’est simplifié et raccourci. En 2008, le Groupe de pathologie infectieuse pédiatrique (GPIP) a établi de nouvelles propositions pour le standardiser en France. L’objectif de cette étude était d’analyser les pratiques dans un hôpital pédiatrique et l’efficacité de ce traitement à court et moyen termes. Matériels et méthodes Il s’est agi d’une étude rétrospective sur l’année 2012 concernant les patients de plus de 3 mois sans comorbidité, hospitalisés à l’hôpital Trousseau (Paris) pour une IOA aiguë, dont le suivi avait été d’au moins 4 semaines. Résultats Soixante-quatre enfants sur 156 ont été retenus pour l’analyse. Le diagnostic d’IOA aiguë avait été confirmé bactériologiquement (29/64) ou présumé sans preuve bactériologique (35/64). L’âge médian était de 22 mois et 78 % des patients étaient fébriles. Trente-cinq (54,7 %) enfants avaient eu une arthrite, 21 (32,8 %) une ostéomyélite aiguë (OMA), 7 (10,9 %) une ostéoarthrite, 1 une spondylodiscite. Les localisations préférentielles avaient été le genou et la hanche. Soixante et un pour cent des arthrites avaient été diagnostiquées grâce à l’échographie, 54 % des ostéomyélites par la scintigraphie. Les deux germes principaux identifiés avaient été Kingella kingae (62,1 %) et Staphylococcus aureus (24,1 %). Dans 98 % des cas, les enfants avaient reçu un traitement par céfamandole associé ou non à de la gentamicine pour une durée médiane de 3 jours (1–10) par voie intraveineuse. Il y avait eu le plus souvent un relais oral par amoxicilline-acide clavulanique pendant 6 semaines, en association avec de la rifampicine sans justification dans 40 % des cas. La durée médiane du suivi avait été de 13 semaines, et le taux de succès du traitement avait été de 86 %. Conclusion L’étude de nos pratiques a montré que les propositions du GPIP n’étaient pas appliquées strictement, le traitement oral étant trop long et non conforme aux recommandations. La tendance actuelle va vers des traitements raccourcis de 10 à 20 jours, avec une phase parentérale plus courte. Summary Introduction The prognosis of osteoarticular infections has improved over the past 20 years but it still remains potentially severe. The treatment of these infections has been simplified and shortened. In 2008, the Pediatric Infectious Disease Group (GPIP) established new therapeutic guidelines in order to standardize treatment in France. The aim of this study is to analyze practices in a Parisian hospital and assess the efficacy of this treatment in short and medium terms. Materials and methods This retrospective study focused on patients older than 3 months, without comorbidities, who were hospitalized for an acute osteoarticular infection in 2012 at Trousseau Hospital (Paris), with a follow-up of at least 4 weeks. The patients were selected from the hospital register. Results The study included 64 patients of 156, who were admitted for examination with a diagnosis of acute osteoarticular infection, bacteriologically confirmed (29/64) or presumed on the basis of bacteriological evidence (35/64). The median age of the patients was 22 months. Of the patients, 78 % were febrile; 35 patients had arthritis (54.7 %), 21 osteomyelitis (32.8 %), seven osteoarthritis (10.9 %), and one spondylitis. Preferential localizations were the knees and hips; 61 % of arthritis cases were diagnosed with ultrasound, 54 % of osteomyelitis cases with scintigraphy. The two main microorganisms found were Kingella kingae (62.1 %) and Staphylococcus aureus (24.1 %). In 98 % of cases, patients were treated by cefamandole, with or without gentamicine, for a median duration of 3 days (1–10) intravenously, with oral relay by amoxicillin-clavulanic acid, for a total duration of 6 weeks, but in association with rifampicin in 40 % of cases without explanation. The median follow-up was 13 weeks, with a treatment success rate of 86 %. Conclusion The study of local practices showed us that the GPIP guidelines are not followed, with the duration of oral treatment being too long. The trend in therapy is toward short treatments of 10–20 days, with a shorter intravenous phase. [ABSTRACT FROM AUTHOR]

Résumé Objectifs L’objectif était, dans le cadre d’une évaluation des pratiques professionnelles, de comparer la prise en charge en salle d’accueil des urgences vitales (SAUV) d’enfants gravement traumatisés dans un centre de traumatologie pour adultes à compétence pédiatrique et un centre exclusivement pédiatrique. Type d’étude Étude rétrospective monocentrique comparative sur un modèle avant-après. Patients et méthodes Cinquante-neuf enfants âgés de 1 à 15 ans, gravement traumatisés, admis dans le centre pour adultes (2005–2007) ont été comparés à 56 enfants admis dans le centre pédiatrique (2010–2012). Les données épidémiologiques et accidentologiques, les scores de gravité, le devenir et la durée en SAUV ont été recueillis et comparés. Résultats Il n’y avait pas de différence de prise en charge des enfants entre le centre pédiatrique et le centre pour adultes ayant un haut volume d’activité et une compétence pédiatrique en termes de durée en SAUV (28 min [18–40] vs 26,5 min [21–36], p = 0,89) et de mortalité précoce (8 enfants [13,5 %] vs 10 enfants [17,8 %], p = 0,35). Conclusion Ce travail a permis de valider l’organisation de notre SAUV pédiatrique. L’efficacité de la prise en charge des enfants de 1 à 15 ans en SAUV pour adultes ayant un gros volume d’activité et en SAUV pédiatrique semble similaire. Summary Objective To compare management of injured children in an adult trauma center (TC) with competencies in pediatric trauma care (2005–2007) and in a pediatric-only trauma center (2010–2012). Study design A before-after retrospective study. Patients and methods Fifty-nine children between 1 and 15 years of age admitted to the adult TC (2005–2007) were compared to 56 children admitted to the pediatric TC (2010–2012). Epidemiological data, severity scores, early outcome, and care duration in trauma resuscitation before whole-body CT were collected and compared between the two periods. Results This study found no significant differences between the two periods in terms of care duration before the whole-body CT scan (28 min [18–40] vs 26.5 min [21–36], P = 0.89) and early mortality (eight children [13.5%] vs ten children [17.8%], P = 0.35). Conclusion With no differences in early management of injured children demonstrated, this study validates the organization within our pediatric trauma center. The effectiveness of management of children between 1 and 15 years of age with severe trauma seems to be similar in the two contexts. [ABSTRACT FROM AUTHOR]

Direct metal bonding is a key technology for 3D integration that will allow semiconductor industry to go beyond predicted problems of future ICs. In this paper, for the first time, we show room temperature direct bonding of titanium layers on silicon wafers at atmospheric pressure and ambient air. Transmission electron microscopy and spreading scanning resistance microscopy are used to investigate bonding interface. Several physical mechanisms of titanium-titanium interface sealing during subsequent thermal annealing are observed and compared to copper and tungsten in terms of bonding mechanism and temperature dependence. [ABSTRACT FROM AUTHOR]

ABSTRACT Asteroseismology provides the means both to constrain the global properties and to probe the internal structures of stars. Asteroseismic data are now available on large numbers of solar-type stars, thanks in particular to the CoRoT and Kepler space missions, and automated data-analysis pipelines are needed to provide efficient and timely results. Here, we present an automated algorithm that is able to extract mode parameters under low signal-to-noise ratio conditions. We use a Bayesian framework to ensure the robustness of the algorithm. We discuss the efficiency of the method and test it using Variability of Solar Irradiance and Gravity Oscillations (VIRGO) Sun-as-a-star photometry data and the artificial Astero Fitting at Low Angular degree Group (asteroFLAG) Kepler ensemble. Analysis of the VIRGO data shows that it is possible to track variations of the individual mode parameters (frequency, height, width) through the solar cycle, using short time series (30 days). The present analysis also revealed a modulation of the degree l = 2 relative height through the solar cycle. Applied on asteroFLAG data, we show that the pipeline extracts accurately the central frequency and the large separation. It is also able to identify the degree of the modes in 78 per cent of stars. [ABSTRACT FROM AUTHOR]

Context. The advent of space-borne photometers such as CoRoT and Kepler has opened up new fields in asteroseismology. This is especially true for red giants as only a few of these stars were known to oscillate with small amplitude, solar-like oscillations before the launch of CoRoT. Aims. The G6 giant HR2582 (HD50890) was observed by CoRoT for approximately 55 days. We present here the analysis of its light curve and the characterisation of the star using different observables, such as its location in the Hertzsprung-Russell diagram and seismic observables. Methods. Mode frequencies are extracted from the observed Fourier spectrum of the light curve. Numerical stellar models are then computed to determine the characteristics of the star (mass, age, etc.) from the comparison with observational constraints. Results. We provide evidence for the presence of solar-like oscillations at low frequency, between 10 and 20 μHz, with a regular spacing of (1.7±0.1) μHz between consecutive radial orders. Only radial modes are clearly visible. From the models compatible with the observational constraints used here,We find that HR2582 (HD50890) is a massive star with a mass in the range (3-5 M☉), clearly above the red clump. It oscillates with rather low radial order (n = 5-12) modes. Its evolutionary stage cannot be determined with precision: the star could be on the ascending red giant branch (hydrogen shell burning) with an age of approximately 155 Myr or in a later phase (helium burning). In order to obtain a reasonable helium amount, the metallicity of the star must be quite subsolar. Our best models are obtained with a mixing length significantly smaller than that obtained for the Sun with the same physical description (except overshoot). The amount of core overshoot during the main-sequence phase is found to be mild, of the order of 0.1 Hp. Conclusions. HR 2582 (HD50890) is an interesting case as only a few massive stars can be observed due to their rapid evolution compared to less massive red giants. HR2582 (HD50890) is also one of the few cases that can be used to validate the scaling relations for massive red giants stars and its sensitivity to the physics of the star. [ABSTRACT FROM AUTHOR]

We present SUMER/SOHO UV measurements of chromospheric oscillations of intensity, velocity, and linewidth observed in C i, S i, O i, and C ii lines, which are formed in the altitude range from 1000 km to 2000 km above τ 500=1. Oscillations in lines originating at similar altitudes exhibit different behaviors which we discuss in terms of the formation of the lines. [ABSTRACT FROM AUTHOR]

The Middle Volgian Kashpir Oil Shales Formation, located on the Russian Platform, is a lateral equivalent of the North Sea and West Siberian petroleum source rocks. In the Volga Basin, this formation is 6 m thick and shows alternations of marls and black shales. The organic carbon content is often higher than 1%, although bioturbation and benthos are abundant, even in the black shales. In the marls, highly degraded organic matter (OM) dominates, while aliphatic, sulphur-rich OM is dominant in the black shales. The combination of sedimentological and geochemical studies allowed to determine that the redox conditions of the sediment regularly fluctuated from oxic to anoxic, under relatively productive waters, while climatic conditions were increasingly arid. It is proposed that OM deposition occurred in relation to the increasing aridity, through the combination of recurrent disruption of salinity stratification and aeolian supply of iron, which both promoted phytoplankton productivity. [Copyright &y& Elsevier]

• 28 years of sewage sludge application at low to moderate doses had a low effect on organic C concentration. • Soil organic C storage increased only at the highest dose (80 tons ha−1 y−1) • Exogenous C increased the concentration of labile fractions but accumulated mostly in mineral-associated fractions. • Rock-Eval® pyrolysis coupled to PARTY SOC model is more sensitive to the amount of sewage sludge added than other fractionations. • The response of SOC fractions did not directly correspond to that of yield of a cereal-based rotation. Soil organic matter (SOM) is a recognized carbon reservoir and paramount in soil functioning and agrosystems productivity. Different management strategies have been established to enhance SOM in arable soils, and one is the application of exogenous organic matter (EOM). Despite significant efforts in recent years, the consequences of EOM addition on increasing soil organic C (SOC) storage and stability in different pedoclimatic contexts remain incompletely understood. In this study, we evaluated the effect of long-term (28 y) sewage sludge (SS) addition to a calcareous soil supporting rainfed extensive crops in a Mediterranean sub-humid area in terms of SOC stabilization and distribution among functional fractions. To that end, we studied total SOM storage and soil fractions in a long-term experiment comparing 4 different doses of SS with mineral fertilization and no-fertilization controls. We compared the concentration, storage and distribution of C using two different fractionation methods (particulate vs. mineral-associated, defined by granulodensimetric fractionation, and active C vs. stable C defined by Rock-Eval® thermal analysis coupled to the machine learning PARTYsoc v2.0 model) on the tilled layer (0–30 cm). Three soil functioning indicators (crops yield, soil microbial biomass C and aggregate stability) were also quantified. We found that SS application, which slightly increased SOC concentration when SS was added, resulted in a net SOC stock gain only with the highest dose used (80 tons/ha), compared to mineral fertilization, suggesting that most of the C added was mineralized. An uneven response of soil fractions was however detected. The coarsest heavy physical fractions > 250 μm and 50–250 μm in size were the most enriched in their C concentration with SS addition, whereas SOC was mostly accumulated as mineral-associated C in the silt-size (2–50 μm) and the 50–250 μm fractions. Regarding thermal fractionation, SS treatments showed C gains between 57 % and 35 % in the active C pool, compared to mineral fertilization. This can be explained considering that the accumulated SOM in mineral-associated fractions corresponded to mean-residence times in the order of 20–40 years. The consequences on soil functioning indicators were not directly related to the amount of SOC stored in the soil, as the highest SOC gains corresponded to the highest dose, but not the highest yields, and some negative correlations were observed between SOC fractions and soil structural stability and microbial biomass. This can be related to some deleterious effects of excessive SS application reducing yields, the soil biological activity and soil structure, and represents an example of the need to decouple the assessment of soil health from that of SOC storage for certain soil management practices. The overall evaluation of the net consequences of long-term SS application indicated that low doses (10 tons/ha) seem a better choice, as they resulted in the highest efficiency in C incorporation, and in a slightly greater increase in SOC concentration than intermediate doses, and equal yields than mineral fertilization, but did not have the negative effects observed in soil functioning with higher doses. [ABSTRACT FROM AUTHOR]

Abstract: Thrombotic thrombocytopenic purpura (TTP) is a thrombotic microangiopathy with neurological disorder which incidence is relatively rare. Since the discovery of the ADAMTS 13 in 1996 and the changes in the treatment (plasma exchanges and rituximab), the prognosis of the TTP has considerably improved. We report the case of a 60-year-old man with a refractory TTP. The subsequent discovery of an epiglottis neoplasia and its treatment saved the patient. [Copyright &y& Elsevier]

The Indonesian Young Toba Tuff (YTT), classically dated around 74 ka BP, is considered as a short-lived explosive cataclysmic super-eruption. The huge amounts of ash and SO2 emitted are likely to have triggered a volcanic winter which accelerated the transition to the last glaciation, and may have induced a human genetic bottleneck. However, the global climatic impact of the YTT or its duration are hotly debated. The present work offers a new interpretation of the Toba volcanic complex eruptive history. Analysing the BAR94-25 marine core proximal to the Toba volcanic center and combining it with high-resolution tephrostratigraphy and δ18O stratigraphy, we show that the Toba complex produced a volcanic succession that consists of at least 17 distinct layers of tephra and cryptotephra. Textural and geochemical analyses show that the tephra layers can be divided in 3 main successive volcanic activity phases (VAP1 to VAP3) over a period of ~ 50 kyr. The main volcanic activity phase, VAP2, including the YTT, is likely composed of 6 eruptive events in an interval whose total duration is ~ 10 ka. Thus, we suggest that the eruptive model of the Toba volcano must be revised as the duration of the Toba volcanic activity was much longer than suggested by previous studies. The implications of re-estimating the emission rate and the dispersion of ashes and SO2 include global environmental reconstitutions, climate change modelling and possibly human migration and evolution. [ABSTRACT FROM AUTHOR]

Introduction La coagulation intravasculaire disséminée (CIVD) est une anomalie acquise de la coagulation relativement fréquente en réanimation, notamment lors du sepsis, et grevée d’une mortalité élevée. Le score ISTH est un score biologique permettant le diagnostic de CIVD. Il se calcule à partir de 4 paramètres biologiques : plaquettes, temps de Quick, fibrinogène et un marqueur de dégradation de la fibrine. Ce dernier est laissé au choix du laboratoire parmi les monomères de fibrine (MF), les produits de dégradation de la fibrine (PDF) ou les D-Dimères. Certaines études ont montré qu’utiliser le dosage des MF permettait d’améliorer la valeur pronostique du score ISTH [1] . Les dosages des MF et des D-Dimères se font sur des automates, alors que celui des PDF utilise une méthode manuelle. Dans un contexte de réorganisation de la biologie médicale de notre hôpital, nous avons cherché à étudier les performances diagnostiques du score ISTH en utilisant les MF et les D-Dimèrescomparativement aux PDF, méthode de référence actuelle. Matériel et méthodes Après accord du CPP, étude prospective observationnelle, incluant les patients présentant un syndrome de réponse inflammatoire systémique (SIRS) dans un service de réanimation durant 4 mois. Un bilan de coagulation était prélevé lors de l’apparition du SIRS avec comme marqueurs de dégradation de la fibrine les MF, les D-Dimères et les PDF. Pour le calcul du score ISTH, les valeurs permettant de déterminer une élévation modérée (2 points) et importante (3 points) étaient pour les D-Dimères 0,5 mg/L et 4 mg/L, pour les MF 5 mg/L et 10 mg/L et pour les PDF 10 mg/L et 20 mg/L. Les scores ISTH ont ensuite été calculés pour chaque prélèvement avec ces 3 marqueurs puis comparés. Un coefficient de corrélation de Spearman et un graphique en nuage de points étaient réalisés entre les scores ISTH calculés avec MF/D-Dimères, MF/PDF et D-Dimères/PDF ( Fig. 1 ). Résultats Ont été inclus 25 patients. Les coefficients de corrélations des scores ISTH selon le marqueur de dégradation de la fibrine utilisé sont représentés dans le Tableau 1 . Discussion Le degré de corrélation entre les scores ISTH calculés avec les 3 marqueurs est bon. Le calcul du score ISTH avec les FM et D-Dimères comme marqueurs de dégradation de la fibrine, semble au moins aussi performant que le dosage des PDF. L’utilisation de marqueurs automatisés (FM et D-Dimères) permettrait un calcul et un rendu systématique par le laboratoire, en comparaison à la technique manuelle utilisant les PDF. [ABSTRACT FROM AUTHOR]

Introduction L’optimisation du remplissage vasculaire (RV) peropératoire ajusté aux besoins du patient permet de prévenir une hyper- et une hypovolémie et de réduire l’excès de morbi-mortalité [1] . L’EtCO2 est corrélé au débit cardiaque (DC) et sa variation lors d’une épreuve de lever de jambe passif permet de prédire la réponse au remplissage chez des patients septiques de réanimation [2] . Le but de notre étude était d’évaluer la fiabilité des variations de l’EtCO2 pour déterminer la réponse à un RV de 500 mL au bloc opératoire. La prédictivité des mini-épreuves de RV de 100 et 200 mL était aussi évaluée. Matériel et méthodes Après accord du CPP, 40 patients ont été inclus prospectivement entre août et octobre 2013 au bloc d’urgence du centre hospitalier Lyon Sud. Les critères d’inclusion étaient : chirurgie digestive et orthopédique en urgence, anesthésie générale et monitorage du DC peropératoire par Doppler œsophagien. Critères d’exclusion : la chirurgie par cœlioscopie et l’hypervolémie. Les patient étaient classés en « répondeurs » si le DC était majoré de plus de 15 % avec le RV et « non-répondeurs » en cas contraire. Nous avons recueilli les valeurs de l’EtCO2, de la fréquence cardiaque (FC) de la pression artérielle moyenne (PAM), diastolique (PAD), systolique (PAS) et pulsée (PP) ainsi que le DC au début, après que 100 mL, 200 mL et 500 mL de soluté soit perfusé. Les variations de l’EtCO2 après 100 mL (varEtCO2 100 ), 200 mL (varEtCO2 200 ) et 500 mL (varEtCO2 500 ) ont été calculées et les courbes ROC réalisées. La corrélation entre les variations de l’EtCO2 et du DC. Le plus petit changement significatif était défini comme la racine de 2 multiplié par la précision. Résultats Quinze patients (36 %) ont été répondeurs. Le plus petit changement significatif de l’EtCO2 était de 3,1 %. La VarEtCO2 500 a permis de diagnostiquer les répondeurs. Le meilleur seuil était de 5,8 % (spé = 100 %, sens = 60 %). L’aire sous la courbe ROC (AUC-ROC) était de 0,82 (IC 95 % : O,67–0,97). VarEtCO2 200 était informative (AUC-ROC : 0,77 ; IC 95 % : 0,62–0,92 ; spé = 96 % ; sens = 47 %) ainsi que varEtCO2 100 (AUC-ROC = 0,74 ; IC 95 % : 0,60–0,89 ; spé = 40 % ; sens = 100 %). Les autres paramètres tels que les variations de la PAM (varPAM), de la PP ou de la FC (varFC) n’étaient pas discriminants. Les variations de l’EtCO2 étaient plus fiables dans le sous-groupe des patients ayant un sepsis pour prédire la réponse au remplissage (AUC-ROC = 0,94 ; IC 95 % 0,82–1,0 ; spé = 100 % ; sens = 84 %). La corrélation entre les variations du DC et de l’EtCO2 au cours du RV était de 0,54 ( p < 0,001). Cette corrélation était plus forte dans le sous-groupe des patients ayant un sepsis r = 0,82 ( p < 0,001) ( Fig. 1 ). Discussion L’EtCO2 est parmi les paramètres de surveillance simple utilisés quotidiennement au bloc opératoire le seul capable d’évaluer la réponse au RV dans notre étude. Cet indice semble plus fiable chez les patients septiques. En l’absence de monitorage avancé, les variations de l’EtCO2 au cours d’une mini-épreuve de remplissage permettent de prédire les patients répondeurs des patients des non-répondeurs, après 500 mL elle permet de diagnostiquer les répondeurs et non-répondeurs. [ABSTRACT FROM AUTHOR]

The presently active region of the Congo deep-sea fan (around 330,000 km 2 ), called the terminal lobes or lobe complex, covers an area of 2500 km 2 at 4700–5100 m water depth and 750–800 km offshore. It is a unique sedimentary area in the world ocean fed by a submarine canyon and a channel-levee system which presently deliver large amounts of organic carbon originating from the Congo River by turbidity currents. This particularity is due to the deep incision of the shelf by the Congo canyon, up to 30 km into the estuary, which funnels the Congo River sediments into the deep-sea. The connection between the river and the canyon is unique for major world rivers. In 2011, two cruises (WACS leg 2 and Congolobe) were conducted to simultaneously investigate the geology, organic and inorganic geochemistry, and micro- and macro-biology of the terminal lobes of the Congo deep-sea fan. Using this multidisciplinary approach, the morpho-sedimentary features of the lobes were characterized along with the origin and reactivity of organic matter, the recycling and burial of biogenic compounds, the diversity and function of bacterial and archaeal communities within the sediment, and the biodiversity and functioning of the faunal assemblages on the seafloor. Six different sites were selected for this study: Four distributed along the active channel from the lobe complex entrance to the outer rim of the sediment deposition zone, and two positioned cross-axis and at increasing distance from the active channel, thus providing a gradient in turbidite particle delivery and sediment age. This paper aims to provide the general context of this multidisciplinary study. It describes the general features of the site and the overall sampling strategy and provides the initial habitat observations to guide the other in-depth investigations presented in this special issue. Detailed bathymetry of each sampling site using 0.1–1 m resolution multibeam obtained with a remotely operated vehicle (ROV) shows progressive widening and smoothing of the channel-levees with increasing depth and reveals a complex morphology with channel bifurcations, erosional features and massive deposits. Dense ecosystems surveyed in the study area gather high density clusters of two large-sized species of symbiotic Vesicomyidae bivalves and microbial mats. These assemblages, which are rarely observed in sedimentary zones, resemble those based on chemosynthesis at cold-seep sites, such as the active pockmarks encountered along the Congo margin, and share with these sites the dominant vesicomyid species Christineconcha regab . Sedimentation rates estimated in the lobe complex range between 0.5 and 10 cm yr −1 , which is 2–3 orders of magnitude higher than values generally encountered at abyssal depths. The bathymetry, faunal assemblages and sedimentation rates make the Congo lobe complex a highly peculiar deep-sea habitat driven by high inputs of terrigenous material delivered by the Congo channel-levee system. [ABSTRACT FROM AUTHOR]

Summary: Thermococcales, a major order of archaea inhabiting the iron‐ and sulfur‐rich anaerobic parts of hydrothermal deep‐sea vents, have been shown to rapidly produce abundant quantities of pyrite FeS2 in iron–sulfur‐rich fluids at 85°C, suggesting that they may contribute to the formation of 'low temperature' FeS2 in their ecosystem. We show that this process operates in Thermococcus kodakarensis only when zero‐valent sulfur is directly available as intracellular sulfur vesicles. Whether in the presence or absence of zero‐valent sulfur, significant amounts of Fe3S4 greigite nanocrystals are formed extracellularly. We also show that mineralization of iron sulfides induces massive cell mortality but that concomitantly with the formation of greigite and/or pyrite, a new generation of cells can grow. This phenomenon is observed for Fe concentrations of 5 mM but not higher suggesting that above a threshold in the iron pulse all cells are lysed. We hypothesize that iron sulfides precipitation on former cell materials might induce the release of nutrients in the mineralization medium further used by a fraction of surviving non‐mineralized cells allowing production of new alive cells. This suggests that biologically induced mineralization of iron‐sulfides could be part of a survival strategy employed by Thermococcales to cope with mineralizing high‐temperature hydrothermal environments. [ABSTRACT FROM AUTHOR]

In order to understand the significance of the worldwide deposition of black shale facies in the Early Toarcian (∼183 Ma), considerable attention has been drawn to this Early Jurassic sub-stage over the last 3 decades. The discovery of a pronounced negative carbon isotope excursion (CIE) within the black shales disrupting the generally positive trend in carbon isotopes has stimulated many studies, particularly with a view to establish the local versus global nature of this major geochemical phenomenon. Here we document the sedimentological and chemostratigraphic evolution of a proximal environment in the Luxembourgian sedimentary area. At Bascharage, Lower Toarcian sediments record the isotopic signature of the Early Toarcian oceanic anoxic event (OAE) by a pronounced positive trend that testifies for widespread anoxia. The expression of the carbon isotope perturbation in this section, however, is unusual compared to adjacent NWEuropean sections. A first -7‰negative CIE, whose onset is recorded at the top of the tenuicostatum zone, can be assigned to the well-documented and potentially global Toarcian carbon isotope excursion (T-CIE) with confidence using the well-constrained ammonite biostratigraphic framework for this section. In this interval, facies contain only a limited amount of carbonate as a result of intense detrital supply in such a proximal and shallow environment. Stratigraphically higher in the section, the serpentinum zone records a subsequent CIE (-6 ‰) expressed as four negative steps, each being accompanied by positive shifts in the oxygen isotopic composition of carbonate. The preservation state of coccoliths and calcareous dinoflagellates in the second CIE is excellent and comparable to that observed in under- and overlying strata, so this cannot be an artefact of diagenesis. Considering the nature of this record, and the lack of such a pronounced event in the serpentinum zone in coeval sections in Europe, we hypothesise that this second CIE was caused by local factors. The geochemical record of carbonate with a relatively light carbon and relatively heavy oxygen isotopic composition is compatible with the so-called Küspert model, by which a CIE can be explained by an influx of 12C-rich and cold waters due to upwelling bottom water masses. [ABSTRACT FROM AUTHOR]

Context. The object HD43587Aa is a G0V star observed during the 145-day LRa03 run of the COnvection, ROtation and planetary Transits space mission (CoRoT), for which complementary High Accuracy Radial velocity Planet Searcher (HARPS) spectra with S/N > 300 were also obtained. Its visual magnitude is 5.71, and its effective temperature is close to 5950 K. It has a known companion in a highly eccentric orbit and is also coupled with two more distant companions. Aims. We undertake a preliminary investigation of the internal structure of HD43587Aa. Methods. We carried out a seismic analysis of the star, using maximum likelihood estimators and Markov chainMonte Carlo methods. Results. We established the first table of the eigenmode frequencies, widths, and heights for HD43587Aa. The star appears to have a mass and a radius slightly larger than the Sun, and is slightly older (5.6 Gyr). Two scenarios are suggested for the geometry of the star: either its inclination angle is very low, or the rotation velocity of the star is very low. Conclusions. A more detailed study of the rotation and of the magnetic and chromospheric activity for this star is needed, and will be the subject of a further study. New high resolution spectrometric observations should be performed for at least several months in duration. [ABSTRACT FROM AUTHOR]

Abstract: Patterns of uranium–molybdenum covariation in marine sediments have the potential to provide insights regarding depositional conditions and processes in paleoceanographic systems. Specifically, such patterns can be used to assess bottom water redox conditions, the operation of metal-oxyhydroxide particulate shuttles in the water column, and the degree of water mass restriction. The utility of this paleoenvironmental proxy is due to the differential geochemical behavior of U and Mo: (1) uptake of authigenic U by marine sediments begins at the Fe(II)–Fe(III) redox boundary (i.e., suboxic conditions), whereas authigenic Mo enrichment requires the presence of H2S (i.e., euxinic conditions), and (2) transfer of aqueous Mo to the sediment may be enhanced through particulate shuttles, whereas aqueous U is unaffected by this process. In the present study, we examine U–Mo covariation in organic-rich sediments deposited mostly in the western Tethyan region during oceanic anoxic events (OAEs) of Early Jurassic to Late Cretaceous age. Our analysis generally confirms existing interpretations of redox conditions in these formations but provides significant new insights regarding water mass restriction and the operation of particulate shuttles in depositional systems. These insights will help to address contentious issues pertaining to the character and origin of Mesozoic OAEs, such as the degree to which regional paleoceanographic factors controlled the development of the OAEs. [Copyright &y& Elsevier]

Analyses of very accurate CoRoT space photometry, past Johnson V photoelectric photometry and high-resolution echelle spectra led to the determination of improved and consistent fundamental stellar properties of both components of AU Monocerotis. We derived new, accurate ephemerides for both the orbital motion (with a period of ) and the long-term, overall brightness variation (with a period of ) of this strongly interacting Be + G semi-detached binary. It is shown that this long-term variation must be due to attenuation of the total light by some variable circumbinary material. We derived the binary mass ratio based on the assumption that the G-type secondary fills its Roche lobe and rotates synchronously. Using this value of the mass ratio as well as the radial velocities of the G-star, we obtained a consistent light curve model and improved estimates of the stellar masses, radii, luminosities and effective temperatures. We demonstrate that the observed lines of the B-type primary may not be of photospheric origin. We also discover rapid and periodic light changes visible in the high-quality residual CoRoT light curves. AU Mon is put into perspective by a comparison with known binaries exhibiting long-term cyclic light changes. [ABSTRACT FROM AUTHOR]

We report on results from the first solar Fitting at Low-Angular degree Group (solar FLAG) hare-and-hounds exercise. The group is concerned with the development of methods for extracting the parameters of low- l solar p-mode data (‘peak bagging’), collected by Sun-as-a-star observations. Accurate and precise estimation of the fundamental parameters of the p modes is a vital pre-requisite of all subsequent studies. Nine members of the FLAG (the ‘hounds’) fitted an artificial 3456-d data set. The data set was made by the ‘hare’ (WJC) to simulate full-disc Doppler velocity observations of the Sun. The rotational frequency splittings of the l= 1, 2 and 3 modes were the first parameter estimates chosen for scrutiny. Significant differences were uncovered at l= 2 and 3 between the fitted splittings of the hounds. Evidence is presented that suggests this unwanted bias had its origins in several effects. The most important came from the different way in which the hounds modelled the visibility ratio of the different rotationally split components. Our results suggest that accurate modelling of the ratios is vital to avoid the introduction of significant bias in the estimated splittings. This is of importance not only for studies of the Sun, but also of the solar analogues that will be targets for asteroseismic campaigns. [ABSTRACT FROM AUTHOR]

Thermochemolysis experiments with tetramethylammonium hydroxide (TMAH), on three Late Jurassic kerogens with contrasting features, confirmed the major role of encapsulation into aliphatic structures for the survival of proteinaceous moieties in kerogens, probably via lipid sulphurisation. It also appeared that (i) some amino acid moieties survived even in the kerogen of a sediment deposited under oxic conditions, although in lower relative abundance compared to the other two kerogens, (ii) the survival of amino acids on geological time scales, within an organic matrix, is probably rather common in kerogens, especially for glycine and alanine, and (iii) thermochemolysis of kerogen sub-units with a lower degree of cross-linking rather than direct thermochemolysis of whole kerogens is recommended to test the presence of amino acid moieties, so as to avoid dilution problems and to increase the accessibility of the TMAH. [Copyright &y& Elsevier]

Reconstitution of the geometry of sedimentary basins is fundamental to understand the nature of present sedimentary rocks and the economic potential in hydrocarbon and mineral resources. Present-day topography of southern France shows elevations growing between the Meso-Cenozoic Aquitaine Basin to the South-East Basin across the Variscan domain and the Jurassic Causses small basin with maximum relief in the Cévennes area. Present-day elevation offset is of approximately 1000 m. This geometry questions the paleogeography and dynamics of these various domains and the relative elevation of the Variscan domain during the subsidence of adjacent Aquitaine and South-East Basins. In this study, we investigate the geological history of the Variscan basement high and the Causses small basin using paleotemperatures deduced from organic matter analysis, low temperature thermochronology and regional geological constraints. Lower Jurassic (upper Pliensbachian and Toarcian) marls sampled across the area from the Aquitaine Basin to the South-East Basin have similar depositional environments containing mainly type III oganic matter, and close Tmax values ranging between 430 and 440 ± 2 °C. These data show that the entire south Massif Central has undergone a similar burial history. considering that these values are explained by burial. Low temperature thermochronology data have been acquired on basement rocks outcropping on the borders of sedimentary basins (Rouergue, Cévennes and Margeride). Fission-track ages are ranging between 74 ± 5 and 187 ± 6 Ma and track lengths between 11.5 ± 0.3 and 13.6 ± 0.1 μm; apatite (U–Th)/He corrected ages are ranging between 65 ± 5 and 184 ± 15 Ma. Data inversion with the software QTQt indicates a cooling episode starting at the end of Early Cretaceous or beginning of Late Cretaceous from maximum temperature of 100 ± 10 °C in the Rouergue and Cévennes area and from 80 ± 10 °C in most of the Margeride area. Thermal indicators are compatible with the erosion of a Middle/Upper Jurassic and Cretaceous sedimentary cover of 1400 ± 400 m assuming a thermal paleogradient of 35 °C/km. The preserved sedimentary cover attests of a Middle and Upper Jurassic – Lower Cretaceous sedimentary cover of 1000–2000m in the Aquitaine and South-East basins. This erosion phase occurred during mid-Cretaceous and is associated to a major geodynamical event characterized by large amplitude (from the Aquitaine Basin to Durancian doming in the South-East Basin) and by kilometric offset. We interpret also these data to show that marine connections have existed between the Aquitaine Basin and the South-East Basin during the Jurassic and likely Early Cretaceous. The present-day morphology of the area has then been acquired after Cretaceous times and may result from the Pyrenean orogenic event during Eocene times. • Organic matter evolution and low temperature thermochronology show high paleotemperatures for samples from southern France. • Present-day borders of the Aquitaine and South-East basins correspond to erosion limit. • A former Jurassic and Lower Cretaceous sedimentary cover has to be considered for a large area of southern France. • Erosion occurred at the end of Early Cretaceous during a major intracontinental reorganization. [ABSTRACT FROM AUTHOR]

Aims. The Spectral Imaging of the Coronal Environment (SPICE) instrument is a high-resolution imaging spectrometer operating at extreme ultraviolet wavelengths. In this paper, we present the concept, design, and pre-launch performance of this facility instrument on the ESA/NASA Solar Orbiter mission. Methods. The goal of this paper is to give prospective users a better understanding of the possible types of observations, the data acquisition, and the sources that contribute to the instrument's signal. Results. The paper discusses the science objectives, with a focus on the SPICE-specific aspects, before presenting the instrument's design, including optical, mechanical, thermal, and electronics aspects. This is followed by a characterisation and calibration of the instrument's performance. The paper concludes with descriptions of the operations concept and data processing. Conclusions. The performance measurements of the various instrument parameters meet the requirements derived from the mission's science objectives. The SPICE instrument is ready to perform measurements that will provide vital contributions to the scientific success of the Solar Orbiter mission. [ABSTRACT FROM AUTHOR]

Carbon and silicon cycles at the Earth surface are linked to long-term variations of atmospheric CO 2 and oceanic primary production. In these cycles, the river-sea interface is considered a biogeochemical hotspot, and deltas presently receive and preserve a major fraction of riverine particles in shallow water sediments. In contrast, periods of glacial maximum lowstand were characterized by massive exports of sediments to the deep-sea via submarine canyons and accumulation in deep-sea fans. Here, we calculate present-day mass balances for organic carbon (OC) and amorphous silica (aSi) in the terminal lobe complex of the Congo River deep-sea fan as an analogue for glacial periods. We show that this lobe complex constitutes a megasink with the current accumulation of 18 and 35% of the OC and aSi river input, respectively. This increases the estimates of organic carbon burial by 19% in the South Atlantic Ocean in a zone representing less than 0.01% of the basin. These megasinks might have played a role in carbon trapping in oceanic sediments during glacial times. • Sediments located at the termination of Congo Canyon are a megasink of organic carbon (0.35 TgC/yr) and aSi (0.11 TgSi/yr). • These sediments store in the deep-sea at 5 km depth 18 and 35% of Congo River OC and amorphous silica inputs, respectively. • OC burial in these sediments increases OC burial in the South Atlantic deep basin (>3000m) by 19% for a surface area <0.01%. • Burial efficiencies in this megasink are 85% for OC and 73% for aSi. [ABSTRACT FROM AUTHOR]

The carbonization process induces significant physical, elemental, and structural transformations of wood. In this study, the modification of δ18O in wood during the carbonization process was investigated in conjunction with elemental analysis, infrared spectroscopy (FTIR), and Rock-Eval thermal analysis, to explore the connection between the chemical composition of the materials and the alterations in δ18O. Quercus petraea wood samples were experimentally burned at temperatures ranging from 200 °C to 1000 °C under inert (pyrolysis) and oxidative atmospheres. The results reveal that the modification of δ18O values in charred wood can be described as a sequential two-step process. The initial step, occurring below 300 °C, involves the volatilization and preferential degradation of thermolabile compounds, leading to an increase of +1.6‰ in δ18O. The subsequent step, below 700 °C, results in a decrease in δ18O values of –21.6‰, primarily driven by the thermal degradation of cellulose and lignin, as well as the increase of aromaticity and reorganization. The components and the δ18O of wood undergo distinct changes in combustion mode, due to different carbonization kinetics as evidenced by FTIR and elemental analysis. To assess the intensity of the carbonization process, influenced by temperature, oxygen availability, and wood characteristics, the H/C atomic ratio, a good indicator of aromaticity, is used. A non-linear regression model was established, relating δ18O to the H/C atomic ratio, thereby demonstrating that δ18O values undergo changes as wood aromatization progresses, independent of the carbonization conditions. The second order model has a mean confidence interval of 1.9‰ and a prediction interval of 8.1‰. This work provides a fundamental understanding of the connection between the chemical composition of woody materials, alterations in δ18O, and the carbonization process, offering valuable insights for further studies and applications related to oxygen-related information that may be preserved in charcoals. • Quercus petraea was charred in oxidative and reducing atmospheres. • The carbonization process alters δ18O in two steps due to structural changes. • The δ18O changes follow different pathway in combustion and pyrolysis. • Key chemical parameters for identifying the wood carbonization process are provided. • A non-linear regression model links δ18O to wood aromatization via H/C ratio. [ABSTRACT FROM AUTHOR]

Abstract The mechanisms governing the development of deep-sea fans is a matter of debate and their understanding at Milankovitch and millenial time-scales is challenged by complex architectures and the lack of material suitable for establishing reliable chronostratigraphies. Based on a detailed investigation of the emplacement of channel-levee-lobe systems and their successive bifurcations and seaward-landward migrations (Picot et al., 2016), we present for the last 210 ka a detailed chronostratigraphic framework of the migration pattern based mainly on radiocarcarbon dating of channels and lobes abandonment or initiation. The comparison of architectural cycles to proxies of external factors (sea-level and climate) suggest that sea-level changes have minor impacts on the architectural evolution of the Congo Fan. In contrast, comparison with climate and environmental proxies (West African monsoon, pollen grain assemblages, Kaolinite/Smectite) evidences a major impact on the timing of the development of the architectural pattern, at least for the last 38 kyr. A general scheme of the growth pattern of the Congo Fan in link with climate evolution is proposed: the stacking pattern of the Congo Fan responds to humidity/aridity cycles that generate successive progradation and retrogradation of avulsion points. These climate changes are under the control of the West African monsoon which, by controlling the rainfall and vegetation on the watershed, ultimately impacts the composition and volume of the sediment source and the transport capacity of gravity flow generated in the canyon and flowing in the turbiditic channels. [ABSTRACT FROM AUTHOR]

Background: Fluid administration to increase stroke volume index (SVi) is a cornerstone of haemodynamic resuscitation. We assessed the accuracy of SVi variation during a calibrated abdominal compression manoeuvre (ΔSVi-CAC) to predict fluid responsiveness in children.Methods: Patients younger than 8 yr with acute circulatory failure, regardless of their ventilation status, were selected. SVi, calculated as the average of five velocity-time integrals multiplied by the left ventricular outflow tract surface area, was recorded at four different steps: baseline, after an abdominal compression with a calibrated pressure of 25 mm Hg, after return to baseline, and then after a volume expansion (VE) of 10 ml kg-1 lactated Ringer solution over 10 min. Patients were classified as responders if SVi variation after volume expansion (ΔSVi-VE) increased by at least 15%.Results: The 39 children included had a median [inter-quartile range (IQR)] age of 9 [5-31] months. Twenty patients were fluid responders and 19 were non-responders. ΔSVi-CAC correlated with ΔSVi-VE (r=0.829; P<0.001). The area under the receiver operating characteristic curve (ROCAUC) was 0.94 [95% confidence interval (CI), 0.85-0.99]. The best threshold for ΔSVi-CAC was 11% with a specificity of 95% [95% CI, 84-100] and a sensitivity of 75% [95% CI, 55-95]. ROCAUC of respiratory variation of IVC diameter (ΔIVC) was 0.53 [95% CI, 0.32-0.72].Conclusion: ΔSVi-CAC during abdominal compression was a reliable method to predict fluid responsiveness in children with acute circulatory failure regardless of their ventilation status.Clinical Trials Registration: CPP Lyon sud est II: n° ANSM 2015-A00388-41 Clinicaltrial.gov: NCT02505646. [ABSTRACT FROM AUTHOR]

Context. The space-borne missions CoRoT and Kepler have provided photometric observations of unprecedented quality. The study of solar-like oscillations observed in red giant stars by these satellites allows a better understanding of the different physical processes occurring in their interiors. In particular, the study of the mode excitation and damping is a promising way to improve our understanding of stellar physics that has, so far, been performed only on a limited number of targets. Aims. The recent asteroseismic characterization of the evolutionary status for a large number of red giants allows us to study the physical processes acting in the interior of red giants and how they are modified during stellar evolution. In this work, we aim to obtain information on the excitation and damping of pressure modes through the measurement of the stars' pressure mode widths and amplitudes and to analyze how they are modified with stellar evolution. The objective is to bring observational constraints on the modeling of the physical processes behind mode excitation and damping. Methods. We fit the frequency spectra of red giants with well-defined evolutionary status using Lorentzian functions to derive the pressure mode widths and amplitudes. To strengthen our conclusions, we used two different fitting techniques. Results. Pressure mode widths and amplitudes were determined for more than 5000 red giants. With a stellar sample two orders of magnitude larger than previous results, we confirmed that the mode width depends on stellar evolution and varies with stellar effective temperature. In addition, we discovered that the mode width depends on stellar mass. We also confirmed observationally the influence of the stellar metallicity on the mode amplitudes, as predicted by models. [ABSTRACT FROM AUTHOR]

Abstract In this preliminary study, we investigate living (stained) foraminifera from the Sea of Marmara. We focus on the faunal composition and geochemical signatures (trace elements, carbon and oxygen stable isotopes) in foraminiferal tests at two deep-sea sites (329 and ~ 1240 m depth respectively). Documented by ROV observations and sampling, both study areas are heterogeneous (including bacterial mats and carbonate concretions), proximal to cold seeps and consist of dysoxic bottom water (O 2 < 20 µmol/L). The prevailing dysoxia at both study areas restricts foraminiferal diversity to very low values (S < 9, H' < 0.97). Stress-tolerant species Bolivina vadescens and Globobulimina affinis dominate living faunas at both sites. The highest foraminiferal standing stock is recorded at the shallowest site underneath a spreading bacterial mat. No benthic foraminifera from either site possess geochemical signatures of methane seepage. Our biogeochemical results show that use of foraminiferal Mn/Ca ratios as a proxy for bottom water oxygenation depends strongly on regional physiography, sedimentary processes and water column structure. [ABSTRACT FROM AUTHOR]

Using combined asteroseismic and spectroscopic observations of 418 red-giant stars close to the Galactic disc plane (6 kpc < RGal≤ 13 kpc, &#124ZGal|< 0:3 kpc), we measure the age dependence of the radial metallicity distribution in the Milky Way's thin disc over cosmic time. The slope of the radial iron gradient of the young red-giant population (-0.058 ± 0.008 [stat.] ±0.003 [syst.] dex/kpc) is consistent with recent Cepheid measurements. For stellar populations with ages of 1-4 Gyr the gradient is slightly steeper, at a value of -0.066 ± 0.007 ± 0.002 dex/kpc, and then flattens again to reach a value of 0:03 dex/kpc for stars with ages between 6 and 10 Gyr. Our results are in good agreement with a state-of-the-art chemo-dynamical Milky-Way model in which the evolution of the abundance gradient and its scatter can be entirely explained by a non-varying negative metallicity gradient in the interstellar medium, together with stellar radial heating and migration. We also offer an explanation for why intermediate-age open clusters in the solar neighbourhood can be more metal-rich, and why their radial metallicity gradient seems to be much steeper than that of the youngest clusters. Already within 2 Gyr, radial mixing can bring metal-rich clusters from the innermost regions of the disc to Galactocentric radii of 5 to 8 kpc. We suggest that these outward-migrating clusters may be less prone to tidal disruption and therefore steepen the local intermediate-age cluster metallicity gradient. Our scenario also explains why the strong steepening of the local iron gradient with age is not seen in field stars. In the near future, asteroseismic data from the K2 mission will allow for improved statistics and a better coverage of the inner-disc regions, thereby providing tighter constraints on the evolution of the central parts of the Milky Way. [ABSTRACT FROM AUTHOR]

With the advent of the space missions CoRoT and Kepler, it has recently become feasible to determine precise asteroseismic masses and relative ages for large samples of red giant stars. We present the CoRoGEE dataset, obtained from CoRoT light curves for 606 red giants in two fields of the Galactic disc that have been co-observed by the Apache Point Observatory Galactic Evolution Experiment (APOGEE). We used the Bayesian parameter estimation code PARAM to calculate distances, extinctions, masses, and ages for these stars in a homogeneous analysis, resulting in relative statistical uncertainties of .2% in distance, ~4% in radius, ~9% in mass and ~25% in age. We also assessed systematic age uncertainties stemming from different input physics and mass loss. We discuss the correlation between ages and chemical abundance patterns of field stars over a broad radial range of the Milky Way disc (5 kpc < RGal < 14 kpc), focussing on the [ /Fe]-[Fe/H]-age plane in five radial bins of the Galactic disc. We find an overall agreement with the expectations of pure chemical-evolution models computed before the present data were available, especially for the outer regions. However, our data also indicate that a significant fraction of stars now observed near and beyond the solar neighbourhood migrated from inner regions. Mock CoRoGEE observations of a chemodynamical Milky Way disc model indicate that the number of high-metallicity stars in the outer disc is too high to be accounted for even by the strong radial mixing present in the model. The mock observations also show that the age distribution of the [ /Fe]-enhanced sequence in the CoRoGEE inner-disc field is much broader than expected from a combination of radial mixing and observational errors. We suggest that a thick-disc/bulge component that formed stars for more than 3 Gyr may account for these discrepancies. Our results are subject to future improvements due to (a) the still low statistics, because our sample had to be sliced into bins of Galactocentric distances and ages; (b) large uncertainties in proper motions (and therefore guiding radii); and (c) corrections to the asteroseismic mass-scaling relation. The situation will improve not only upon the upcoming Gaia data releases, but also with the foreseen increase in the number of stars with both seismic and spectroscopic information. [ABSTRACT FROM AUTHOR]

The Taskomirsay section (South Kazakhstan) is a unique Pliensbachian-Toarcian sequence of lignites, clayey layers and silty-sandstones deposited in a fluvial/lacustrine environment with nearby swampy areas. This period, characterized by a drastic climate change, has been particularly studied in Western Tethyan marine environments, whereas very few studies focused on continental settings. Paleoflora analyses, associated with a multi-isotope approach, based on well-preserved Type-III bulk organic nitrogen isotopes ( δ 15 N org ) and hydrogen isotopic composition ( δ 2 H) of n -alkanes, were developed to document paleoclimatic changes in the area. Sporomorph associations and fossil woods revealed a globally warm- to cool-temperate climate – characterized by Xenoxylon , a conifer morphogenus biogeographically related to cool/humid settings – apart from slightly less humid and warmer conditions in the early Toarcian. Warmer conditions are supported by reconstructed Mean Annual Air Temperatures (MAATs), based on the first branched glycerol dialkyl glycerol tetraethers (brGDGTs) ever recorded in the Early Jurassic. Nevertheless, no drastic changes were recorded in the δ 15 N org values; its signal being attributed to tenuous equilibrium between water- and nutrient-availability via intense N-recycling. Based on n -alkane distributions, sources of organic matter were separated in two pools: (i) a purely terrestrial ( n -C 27 ) and (ii) an “aquatic” pool ( n -C 23 ) constituted of vegetation that thrived under almost permanent water supply. The n -alkane δ 2 H values (− 248 to − 151‰) as well as their amounts and average chain lengths (ACL) are in agreement with cool-temperate conditions in the Pliensbachian and less humid/warmer conditions in the early Toarcian. The isotopic difference between δ 2 H values of n -C 27 and n -C 23 (Δ 2 H ter-aq ) suggests enhanced seasonality during the Pliensbachian-Toarcian transition and low seasonality in the early Toarcian, in agreement with temperate climate-regime. Finally, contrasted response to paleoclimate changes between markers suggests different spatial integration of those proxies. The role of sea-level variations for δ 2 H values might also resolve this contrasted response. [ABSTRACT FROM AUTHOR]

The Sinemurian/Pliensbachian boundary (~ 191 Ma) is acknowledged as one of the most important steps in the radiation of planktonic organisms, especially primary producers such as dinoflagellates and coccolithophores. To date, there is no detailed study documenting changes in planktonic assemblages related to palaeoceanographic changes across this boundary. The aim of this study is to characterize the palaeoenvironmental changes occurring across the Sinemurian/Pliensbachian boundary at the São Pedro de Moel section (Lusitanian Basin, Portugal) using micropalaeontology and organic geochemistry approaches. Combined calcareous nannofossil assemblage and lipid biomarker data document for a decrease in primary productivity in relation to a major sea-level rise occurring above the boundary. The Lusitanian Basin was particularly restricted during the late Sinemurian with a relatively low sea level, a configuration that led to the recurrent development of black shales. After a sharp sea-level fall, the basin became progressively deeper and more open during the earliest Pliensbachian, subsequently to a major transgression. This sea-level increase seems to have been a global feature and could have been related to the opening of the Hispanic Corridor that connected the Tethys and palaeo-Pacific oceans. The palaeoceanographic and palaeoclimatic changes induced by this opening may have played a role in the diversification of coccolithophores with the first occurrence or colonization of Tethyan waters by placolith-type coccoliths. [ABSTRACT FROM AUTHOR]

Focuses on the temporal behavior of solar activity as manifested in sunspots. Debate over sunspots; The periodicity in the total number of sunspots which is well established observationally; The occurrence of high-energy solar flares seen during cycle 21; Cause of latter periodicity; Focus on time-frequency analysis using the wavelet technique; The mechanisms used to explain solar flares; What is needed to confirm the hypothesis; What wavelet analysis shows; Effect of such flares on earth and its environment.

Highlights: [•] Clay mineralogy of the Chaotian reference section for the late Permian/Early Triassic. [•] Palaeothermicity of the Sichuan Basin using clay minerals of K-bentonites and T max data. [•] Discussion on the origin of the Wangpo Bed considered as a reworked bentonite. [Copyright &y& Elsevier]

Aims. The aim of this work was to use a multi-approach technique to derive the most accurate values possible of the physical parameters of the δ Sct star HD174966, which was observed with the CoRoT satellite. In addition, we searched for a periodic pattern in the frequency spectra with the goal of using it to determine the mean density of the star. Methods. First, we extracted the frequency content from the CoRoT light curve. Then, we derived the physical parameters of HD174966 and carried a mode identification out from the spectroscopic and photometric observations. We used this information to look for the models fulfilling all the conditions and discussed the inaccuracies of the method because of the rotation effects. In a final step, we searched for patterns in the frequency set using a Fourier transform, discussed its origin, and studied the possibility of using the periodicity to obtain information about the physical parameters of the star. Results. A total of 185 peaks were obtained from the Fourier analysis of the CoRoT light curve, all of which were reliable pulsating frequencies. From the spectroscopic observations, 18 oscillation modes were detected and identified, and the inclination angle (62.5°+7.5 -17.5) and the rotational velocity of the star (142 km s-1) were estimated. From the multi-colour photometric observations, only three frequencies were detected that correspond to the main ones in the CoRoT light curve. We looked for periodicities within the 185 frequencies and found a quasiperiodic pattern ▵ v ~ 64 μHz. Using the inclination angle, the rotational velocity, and an Echelle diagram (showing a double comb outside the asymptotic regime), we concluded that the periodicity corresponds to a large separation structure. The quasiperiodic pattern allowed us to discriminate models from a grid. As a result, the value of the mean density is achieved with a 6% uncertainty. So, the ▵ v pattern could be used as a new observable for A-F type stars. [ABSTRACT FROM AUTHOR]

Context. The CoRoT short asteroseismic runs give us the opportunity to observe a large variety of late-type stars through their solarlike oscillations. We report the observation and modeling of the F5V star HD175272. Aims. Our aim is to define a method for extracting as much information as possible from a noisy oscillation spectrum. Methods. We followed a differential approach that consists of using a well-known star as a reference to characterize another star. We used classical tools such as the envelope autocorrelation function to derive the global seismic parameters of the star. We compared HD175272 with HD181420 through a linear approach, because they appear to be asteroseismic twins. Results. The comparison with the reference star enables us to substantially enhance the scientific output for HD175272. First, we determined its global characteristics through a detailed seismic analysis of HD181420. Second, with our differential approach, we measured the difference of mass, radius and age between HD175272 and HD181420. Conclusions. We have developed a general method able to derive asteroseismic constraints on a star even in case of low-quality data. This method can be applied to stars with interesting properties but low signal-to-noise ratio oscillation spectrum, such as stars hosting an exoplanet or members of a binary system. [ABSTRACT FROM AUTHOR]

Aims. We aim to detect and interpret photometric and spectroscopic variability of the bright CoRoT B-type supergiant target HD46769 (V = 5.79). We also attempt to detect a magnetic field in the target. Methods. We analyse a 23-day oversampled CoRoT light curve after detrending and spectroscopic follow-up data using standard Fourier analysis and phase dispersion minimization methods. We determine the fundamental parameters of the star, as well as its abundances from the most prominent spectral lines. We perform a Monte Carlo analysis of spectropolarimetric data to obtain an upper limit of the polar magnetic field, assuming a dipole field. Results. In the CoRoT data, we detect a dominant period of 4.84 d with an amplitude of 87 ppm and some of its (sub-)multiples. Given the shape of the phase-folded light curve and the absence of binary motion, we interpret the dominant variability in terms of rotational modulation, with a rotation period of 9.69 d. Subtraction of the rotational modulation signal does not reveal any sign of pulsations. Our results are consistent with the absence of variability in the Hipparcos light curve. The spectroscopy leads to a projected rotational velocity of 72 ± 2 kms-1 and does not reveal periodic variability or the need to invoke macroturbulent line broadening. No signature of a magnetic field is detected in our data. A field stronger than ~500 G at the poles can be excluded, unless the possible non-detected field were more complex than dipolar. Conclusions. The absence of pulsations and macroturbulence of this evolved B-type supergiant is placed into the context of instability computations and of observed variability of evolved B-type stars. [ABSTRACT FROM AUTHOR]

We present the CoRoT light curve of the bright B2.5V star HD48977 observed during a short run of the mission in 2008, as well as a high-resolution spectrum gathered with the HERMES spectrograph at the Mercator telescope. We use several time series analysis tools to explore the nature of the variations in the light curve.We performed a detailed analysis of the spectrum of the star to determine its fundamental parameters and its element abundances. We find a large number of high-order g-modes, and one rotationally induced frequency. We find stable low-amplitude frequencies in the p-mode regime as well. We conclude that HD48977 is a new slowly pulsating B star with fundamental parameters found to be Teff = 20 000 ± 1000 K and log g = 4.2 ± 0.1. The element abundances are similar to those found for other B stars in the solar neighbourhood. HD48977 was observed during a short run of the CoRoT satellite implying that the frequency precision is insufficient to perform asteroseismic modelling of the star. Nevertheless, we show that a longer time series of this star would be promising for such modelling. Our present study contributes to a detailed mapping of the instability strips of B stars in view of the dominance of g-mode pulsations in the star, several of which occur in the gravito-inertial regime [ABSTRACT FROM AUTHOR]