126 research outputs found

    The Cave of Fouvent, also called Abri Cuvier (Fouvent-le-Bas, Haute-Saône, France): Taphonomical analysis of a Late Pleistocene Hyena Den (OIS3)

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    Le gisement paléontologique de Fouvent (Fouvent-le-Bas, Haute-Saône, France) est une accumulation osseuse karstique connue depuis le début du XIXe siècle. Ce site est à l’origine de nombreuses avancées paléontologiques (reconnaissance de l’hyène fossile par Cuvier, première mention du glouton en France) et taphonomique (caractérisation du repaire de carnivore). Le présent article porte sur l’analyse de 14 977 restes osseux issus à la fois de la collection historique (fouilles de 1842) et des fouilles récentes (1989-1992). Une liste faunique de 19 taxons de grands mammifères a été établie : 11 carnivores (Crocuta crocuta spelaea, Panthera (Leo) spelaea, Ursus spelaeus, Canis lupus, Vulpes vulpes, cf. Alopex, Gulo gulo, Meles meles, Martes sp., Mustela eversmanii, Mustela sp.) et 8 ongulés (Mammuthus primigenius, Coelodonta antiquitatis, Megaloceros giganteus, Cervus elaphus, Rangifer tarandus, Equus germanicus, Bos primigenius et/ou Bison priscus). L’étude des hyènes des cavernes permet de préciser les caractères d’une population du stade isotopique 3 et de discuter de sa composition. Quant au spectre d’ongulés, son identification permet de préciser la diversité des proies de l’hyène (en termes d’espèces et d’âges individuels). Les interactions entre le prédateur et ses proies sont caractérisées grâce à l’étude de la distribution squelettique, de la fragmentation osseuse, des morphologies des restes consommés et des traces de dents. L’examen détaillé de l’ensemble des éléments taphonomiques de l’accumulation osseuse de Fouvent permet de discuter et de préciser la spécificité d’un repaire d’hyènes pléistocène.The palaeontological site of Fouvent (Fouvent-le-Bas, Haute-Saône, France) is a fissure-filling bone accumulation known from the beginning of the XIXth century. This assemblage is at the origin of palaeontological (description of fossil hyena by Cuvier, first record of French wolverine) and taphonomical advances (first carnivore den characterization). This paper presents the analysis of 14 977 bone remains from both the historical collection (1842) and recent excavations (between 1989 and 1992). A faunal list of 19 mammalian species has been identified: 11 carnivore species (Crocuta crocuta spelaea, Panthera (Leo) spelaea, Ursus spelaeus, Canis lupus, Vulpes vulpes, cf. Alopex, Gulo gulo, Meles meles, Martes sp., Mustela eversmanii, Mustela sp.) and 8 large ungulate species (Mammuthus primigenius, Coelodonta antiquitatis, Megaloceros giganteus, Cervus elaphus, Rangifer tarandus, Equus germanicus, Bos primigenius and/or Bison priscus). The analysis of cave hyenas from Fouvent allows us to precise characteristics of an OIS3 population and to discuss population structure. The study of ungulate populations allows us to describe prey diversity (in terms of species and individual age). Prey skeletal part distribution, bone fragmentation, consumption morphotypes and tooth marks are observed to point out predator-prey interactions. The detailed analysis of taphonomical aspects of Fouvent bone accumulation allows also to discuss and to give criteria about hyena den characterization grids

    Le lynx Lynx pardinus spelaeus Boule, 1910 du Pléistocène moyen de la grotte de l'Escale (Bouches-du-Rhône, France) : données paléontologiques et taphonomiques

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    Les lynx sont rares dans le registre paléontologique quaternaire. Fouillée dans les années 1960 par Eugène et Marie-Françoise Bonifay, la grotte de l’Escale, dans le Sud-Est de la France (Bouches-du-Rhône), renferme un puissant remplissage, daté de la première moitié du Pléistocène moyen. La présente étude dresse un inventaire actualisé des restes crâniens et postcrâniens de lynx identifiés dans les différents niveaux et livre un corpus ostéométrique pour l’ensemble des éléments squelettiques. Le nombre de restes attribués à cette espèce est de 435, le nombre minimal d’individus de 15, faisant de la grotte de l’Escale l’un des plus riches gisements à lynx des cavernes d’Europe. Par ses caractéristiques morphologiques dentaires, ce lynx appartient au lynx pardelle, dont il constitue une sous-espèce évolutive en raison de la fréquence élevée du métaconide sur la carnassière inférieure. Les données ostéométriques pour chaque dent / os, mises en ligne sur internet, permettent de décrire une « population » de lynx homogène avec un faible dimorphisme sexuel. Des données taphonomiques (fragmentation osseuse in situ, quasi absence de traces de prédation) et paléobiologiques (population composée d’individus adultes) suggèrent un piégeage des lynx dans les remplissages verticaux (dolines, cheminées) du site.Lynx are rare in the Quaternary paleontological record. Excavated in the 1960s by Eugène Bonifay and Marie-Françoise Bonifay, the Escale cave, in southeastern France (Bouches du Rhône), yields an important sedimentary filling, dated to the first half of the Middle Pleistocene. The present study provides an updated inventory of the cranial and post-cranial remains of lynx identified in the different levels and an osteometrical dataset on all teeth and bones as well. The number of idendified specimens (NISP) attributed to the lynx is based on 435 teeth and bones, the minimum number of individuals (MNI), based on right calcaneus reach 15 adult individuals. The Escale cave is one of the richest deposits yielding lynx remains in Europe. Morphological characteristics noticed on teeth allow to identify undoubtedly this lynx to the Iberian lynx (Lynx pardinus spelaeus) and can be seen as an evolutionary chronoform (high frequency of the metaconid on the lower carnassial). The osteometrical data for each bone, available online, allow to describe an homogeneous «population» of lynx, with a low sexual dimorphism. Taphonomical and paleobiological data (bone fragmentation in situ, almost no toothmarks on bones, only young adult individuals) suggest that lynxes were trapped in the vertical fillings (sinkholes, chimneys) of the site

    Norepinephrine weaning in septic shock patients by closed loop control based on fuzzy logic

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    International audienceABSTRACT: INTRODUCTION: The rate of weaning of vasopressors drugs is usually an empirical choice made by the treating in critically ill patients. We applied fuzzy logic principles to modify intravenous norepinephrine (noradrenaline) infusion rates during norepinephrine infusion in septic patients in order to reduce the duration of shock. METHODS: Septic patients were randomly assigned to norepinephrine infused either at the clinician's discretion (control group) or under closed-loop control based on fuzzy logic (fuzzy group). The infusion rate changed automatically after analysis of mean arterial pressure in the fuzzy group. The primary end-point was time to cessation of norepinephrine. The secondary end-points were 28-day survival, total amount of norepinephine infused and duration of mechanical ventilation. RESULTS: Nineteen patients were randomly assigned to fuzzy group and 20 to control group. Weaning of norepinephrine was achieved in 18 of the 20 control patients and in all 19 fuzzy group patients. Median (interquartile range) duration of shock was significantly shorter in the fuzzy group than in the control group (28.5 [20.5 to 42] hours versus 57.5 [43.7 to 117.5] hours; P < 0.0001). There was no significant difference in duration of mechanical ventilation or survival at 28 days between the two groups. The median (interquartile range) total amount of norepinephrine infused during shock was significantly lower in the fuzzy group than in the control group (0.6 [0.2 to 1.0] mug/kg versus 1.4 [0.6 to 2.7] mug/kg; P < 0.01). CONCLUSIONS: Our study has shown a reduction in norepinephrine weaning duration in septic patients enrolled in the fuzzy group. We attribute this reduction to fuzzy control of norepinephrine infusion. TRIAL REGISTRATION: Trial registration: Clinicaltrials.gov NCT00763906

    Structural determinants of TAR RNA-DNA annealing in the absence and presence of HIV-1 nucleocapsid protein

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    Annealing of the TAR RNA hairpin to the cTAR DNA hairpin is required for the minus-strand transfer step of HIV-1 reverse transcription. HIV-1 nucleocapsid protein (NC) plays a crucial role by facilitating annealing of the complementary hairpins. To gain insight into the mechanism of NC-mediated TAR RNA–DNA annealing, we used structural probes (nucleases and potassium permanganate), gel retardation assays, fluorescence anisotropy and cTAR mutants under conditions allowing strand transfer. In the absence of NC, cTAR DNA-TAR RNA annealing depends on nucleation through the apical loops. We show that the annealing intermediate of the kissing pathway is a loop–loop kissing complex involving six base-pairs and that the apical stems are not destabilized by this loop–loop interaction. Our data support a dynamic structure of the cTAR hairpin in the absence of NC, involving equilibrium between both the closed conformation and the partially open ‘Y’ conformation. This study is the first to show that the apical and internal loops of cTAR are weak and strong binding sites for NC, respectively. NC slightly destabilizes the lower stem that is adjacent to the internal loop and shifts the equilibrium toward the ‘Y’ conformation exhibiting at least 12 unpaired nucleotides in its lower part

    Mammouths et Eléphants : un bestiaire du Pléistocène

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    L'INFLUENCE DE L'ETAT DE SANTE ANTERIEUR SUR LA PREDICTION DE MORTALITE LIEE A LA GRAVITE A L'ADMISSION EN REANIMATION

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    PARIS13-BU Serge Lebovici (930082101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

    Les lagomorphes de Romain-la-Roche (Doubs, France)

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    International audience127 restes de lagomorphes ont été recueillis à Romain-la-Roche. En raison de l'état de fragmentation du matériel, seuls 20 % des échantillons ont été déterminés. Si la présence seule du genre Lepus est avérée, la distinction L. europeaus / L. timidus n'a pu être précisée. Mots-clés Romain-la-Roche, lagomorphes, Lepus, Lepus cf. timidus, Lepus cf. europaeus

    Les mustélidés de Romain-la-Roche (Doubs, France)

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