76 research outputs found

    Restauration d’une zone corallienne dĂ©gradĂ©e et implantation d'un jardin corallien Ă  Bora Bora, PolynĂ©sie française

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    The restoration of coral reef habitats by coral transplantation is a hot topic in the news toda y due to the accelerating degradation of the coral reef ecosystem all over the world. There is much discussion about research programs for the transplantation of corals and about ac tuai field realizations and the motivation for coral reef restoration. But the implementation of such a project depends on a social request considering local or global cultural and economical situations . Projects are very costly and only applicable when important economical interests are involved such as the fight against erosion or tourism development. In the lagoon of Bora Bora in French Polynesia, a fringing zone, degraded by coral sand extractions, led to an erosion of the coast damaging local private property in a sec tor weil oriented toward tourism activities. The reconstruction of this degraded site (20,000 sq.m) required physically filling up holes, implementation of spurs, and putting into place artificial concrete structures to promote the natural colonization of corals and other reef organisms in order to reduce swell impacts. The creation of a coral reef garden was also part of the project with the transplantation of corals collected in the vicinity. Fifty groups of three different types of concrete blocks have been set out on the site and six others constitute the coral reef garden on which 311 coral colonies are transplanted. Two and a half years after this restoration, the project proved to be successful. The coral reef garden flourished; it showed much diversification and little mortality among the corals colonies, and the natural colonization on the concrete substrate was teeming with corals, seaurchins, mollusks, and fishes. But thirty months later, an exceptionally violent meteorological and oceanographical situation led to a catastrophic event which caused many transplanted coral as weil as natural colonies in the vicinity to be killed off. Lagoon waters temperatures were recorded as high as 34°C and of the 311 transplanted coral colonies only 119 survived, most of them bleached or partly dead. All colonies of the genus Acropora died, while those of the genus Psammocora survived. Methods for restoration and creation of coral reef gardens are highly controlled but they cannot always escape such catastrophic events such as the one in Bora Bora in December 2001. Physical restoration was successful but the biological transplantation of corals failed. Thus, when we consider how expansive a restoration project is, it is essential to conduct an historical inquiry on a potential coral transplantation site before implementing any projectLes problĂšmes de restauration de zones coralliennes, avec transplantations de coraux, sont Ă  l'ordre du jour compte tenu de la dĂ©gradation accĂ©lĂ©rĂ©e de cet Ă©cosystĂšme Ă  la surface de la planĂšte. Les motivations des recherches dans ce domaine et celles des projets de restauration sur le terrain sont Ă©voquĂ©es. Elles rĂ©pondent Ă  une demande sociale exprimĂ©e en fonction de considĂ©rations culturelles et Ă©conomiques. Les projets sont coĂ»teux et ne peuvent concerner que des cas trĂšs limitĂ©s avec des intĂ©rĂȘts Ă©conomiques importants (lutte contre l' Ă©rosion, dĂ©veloppement du tourisme). À Bora Bora, en PolynĂ©sie française, une zone lagonaire frangeante, dĂ©gradĂ©e par des extractions de sĂ©diment corallien, provoquait une Ă©rosion littorale. Son rĂ©-amĂ©nagement comporte une restauration physique des lieux (comblement des fosses, rĂ©alisation d'Ă©pis...) et la mise en place de structures artificielles pour permettre la colonisation naturelle de coraux et autres organismes, afin de jouer le rĂŽle de brise houle. Ce projet s'accompagne de la crĂ©ation d'un jardin corallien avec structures artificielles sur lesquelles sont fixĂ©s des transplants de coraux. Deux ans et demi aprĂšs la fin des travaux, le jardin corallien affiche une communautĂ© corallienne florissante et diversifiĂ©e avec trĂšs peu de mortalitĂ© des colonies transplantĂ©es, une croissance normale et la colonisation naturelle de coraux et d'autres organismes des rĂ©cifs coralliens (oursins, mollusques, poissons). Cependant, un Ă©vĂ©nement mĂ©tĂ©orologique et ocĂ©anographique exceptionnel, trente mois aprĂšs la crĂ©ation du jardin corallien, a entraĂźnĂ© une forte mortalitĂ© des coraux transplantĂ©s comme ceux naturellement en place dans le secteur. Si les techniques nĂ©cessaires Ă  la restauration de zones dĂ©gradĂ©es et Ă  la crĂ©ation de jardins coralliens sont totalement maĂźtrisĂ©es, ces rĂ©alisations n'Ă©chappent pas aux variations temporelles des conditions de milieu qui peuvent ĂȘtre catastrophiques. Dans un tel cas, comme Ă  Bora Bora en dĂ©cembre 2001, la restauration physique reste Ă  l'actif de l'opĂ©ration, mais l'Ă©chec de la restauration biologique est Ă  noter. Une Ă©tude historique, sur plusieurs dĂ©cennies, des zones sujettes Ă  des mortalitĂ©s exceptionnelles s'impose donc avant tout choix de sites pour la rĂ©alisation de jardins coralliens dont les coĂ»ts sont trĂšs Ă©levĂ©

    Peripheral Delta Opioid Receptors Mediate Formoterol Anti-allodynic Effect in a Mouse Model of Neuropathic Pain.

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    Neuropathic pain is a challenging condition for which current therapies often remain unsatisfactory. Chronic administration of ÎČ2 adrenergic agonists, including formoterol currently used to treat asthma and chronic obstructive pulmonary disease, alleviates mechanical allodynia in the sciatic nerve cuff model of neuropathic pain. The limited clinical data currently available also suggest that formoterol would be a suitable candidate for drug repurposing. The antiallodynic action of ÎČ2 adrenergic agonists is known to require activation of the delta-opioid (DOP) receptor but better knowledge of the molecular mechanisms involved is necessary. Using a mouse line in which DOP receptors were selectively ablated in neurons expressing Nav1.8 sodium channels (DOP cKO), we showed that these DOP peripheral receptors were necessary for the antiallodynic action of the ÎČ2 adrenergic agonist formoterol in the cuff model. Using a knock-in mouse line expressing a fluorescent version of the DOP receptor fused with the enhanced green fluorescent protein (DOPeGFP), we established in a previous study, that mechanical allodynia is associated with a smaller percentage of DOPeGFP positive small peptidergic sensory neurons in dorsal root ganglia (DRG), with a reduced density of DOPeGFP positive free nerve endings in the skin and with increased DOPeGFP expression at the cell surface. Here, we showed that the density of DOPeGFP positive free nerve endings in the skin is partially restored and no increase in DOPeGFP translocation to the plasma membrane is observed in mice in which mechanical pain is alleviated upon chronic oral administration of formoterol. This study, therefore, extends our previous results by confirming that changes in the mechanical threshold are associated with changes in peripheral DOP profile. It also highlights the common impact on DOP receptors between serotonin noradrenaline reuptake inhibitors such as duloxetine and the ÎČ2 mimetic formoterol.journal article20192020 02 14importe

    The antiallodynic action of pregabalin in neuropathic pain is independent from the opioid system.

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    BACKGROUND: Clinical management of neuropathic pain, which is pain arising as a consequence of a lesion or a disease affecting the somatosensory system, partly relies on the use of anticonvulsant drugs such as gabapentinoids. Therapeutic action of gabapentinoids such as gabapentin and pregabalin, which act by the inhibition of calcium currents through interaction with the α2ÎŽ-1 subunit of voltage-dependent calcium channels, is well documented. However, some aspects of the downstream mechanisms are still to be uncovered. Using behavioral, genetic, and pharmacological approaches, we tested whether opioid receptors are necessary for the antiallodynic action of acute and/or long-term pregabalin treatment in the specific context of neuropathic pain. RESULTS: Using the cuff model of neuropathic pain in mice, we show that acute pregabalin administration at high dose has a transitory antiallodynic action, while prolonged oral pregabalin treatment leads to sustained antiallodynic action, consistent with clinical observations. We show that pregabalin remains fully effective in ÎŒ-opioid receptor, in ÎŽ-opioid receptor and in Îș-opioid receptor deficient mice, either female or male, and its antiallodynic action is not affected by acute naloxone. Our work also shows that long-term pregabalin treatment suppresses tumor necrosis factor-α overproduction induced by sciatic nerve constriction in the lumbar dorsal root ganglia. CONCLUSIONS: We demonstrate that neither acute nor long-term antiallodynic effect of pregabalin in a context of neuropathic pain is mediated by the endogenous opioid system, which differs from opioid treatment of pain and antidepressant treatment of neuropathic pain. Our data are also supportive of an impact of gabapentinoid treatment on the neuroimmune aspect of neuropathic pain.journal articleresearch support, non-u.s. gov't20162016 03 29importe

    Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

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    Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≄ II, EF ≀35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure < 100 mmHg (n = 1127), estimated glomerular filtration rate < 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation

    Le traité des couleurs de Barthélemi L'Anglais (XIIIes)

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    Le xixe livre du De proprietatibus rerum rassemble les compilations de Barthélemi l'Anglais sur les couleurs, les odeurs, les saveurs et les liquides. Les trente-sept premiers chapitres sont donc un "traité des couleurs", que nous avons choisi de présenter dans la traduction achevée en 1372 par Jean Corbechon, chapelain de Charles V. Ce traité se compose, conformément au plan général adopté par Barthélemi, de deux grandes parties. Dans la premiÚre, il "parle" des couleurs en général, dans la ..

    La présentation du Diable par un encyclopédiste du xiiie siÚcle : Bartelemi l'Anglais (vers 1250)

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    Si tout au long du Moyen Age le prestige des savants fut reconnu, leur influence sur leurs contemporains resta relativement restreinte. En effet, pour Ă©clatants qu'aient Ă©tĂ© certains foyers d'Ă©tude, ils restĂšrent longtemps dispersĂ©s et mobiles au grĂ© des circonstances. De mĂȘme, le rayonnement des maĂźtres se dĂ©plaçait avec eux. Au xiiie siĂšcle, et notamment en France, une certaine stabilisation politique et Ă©conomique permit une fixation et des centralisations de la vie universitaire. Rappelon..

    Barthelemi l’Anglais, traitĂ©s du soleil et de la lune, traduits par Jean Corbechon (1372) (Ă©dition et commentaire)

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    PrĂ©sentation L’astronomie est, Ă  cĂŽtĂ© de l’arithmĂ©tique, de la musique et de la gĂ©omĂ©trie, l’un des quadrivalia dont l’enseignement est autorisĂ© Ă  la FacultĂ© des Arts de Paris, les jours de fĂȘte selon le Statut de Robert de Courçon qui date de 1215. Si, comme le remarque M. Guy Beaujouan, "il est trĂšs difficile de savoir ce qu’était, au xiiie siĂšcle, l’enseignement du Quadrivium" Ă  Paris, l’étude des manuels d’enseignement en circulation Ă  cette Ă©poque est "beaucoup plus rĂ©vĂ©latrice." En ce q..

    Un Franciscain atypique du XVIe siĂšcle : Anselme TURMEDA

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