1,585 research outputs found

    Artificial insemination in felids

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    Artificial insemination in the domestic cat and in wild felids has several indications. In the cat, it may replace natural reproduction when matings are unsuccessful or difficult, and it may help to perform geographical exchanges of semen and therefore enhance genetic improvement. In wild felids, it plays a complementary role inside conservation programs. However, its use is complex. First, oestrus and ovulation have to be induced. This is most often obtained using gonadotrophins, which unfortunately may induce undesirable effects, like ovarian hyperstimulation. In males, the semen is generally collected by electro-ejaculation. It may be frozen. However, teratospermia, which is the production of numerous spermatozoa showing morphological abnormalities, is a specific problem affecting felids. Intrauterine inseminations give better results. For a long period, laparoscopy was recommended in felids to perform intrauterine inseminations. Recently, new techniques consisting of catheterizing the cervix through a vaginal access have been developed in the cat as in some wild felids species. Altogether, the rate of success of artificial insemination in felids remains moderate.L'insĂ©mination artificielle chez le chat domestique et les fĂ©lidĂ©s sauvages rĂ©pond Ă  plusieurs indications. Chez le chat, elle peut notamment permettre d'aider la reproduction lorsque l'accouplement ne se produit pas ou difficilement et de favoriser les Ă©changes gĂ©ographiques de semence et donc un brassage et une meilleure sĂ©lection gĂ©nĂ©tiques. Chez les fĂ©lins sauvages, elle joue un rĂŽle complĂ©mentaire au sein des programmes de conservation. Son utilisation est cependant complexe. L'oestrus et l'ovulation sont le plus souvent induits par l'emploi de gonadotropines qui possĂšdent cependant des effets indĂ©sirables, notamment un risque d'hyperstimulation ovarienne. La semence des mĂąles est gĂ©nĂ©ralement rĂ©coltĂ©e par Ă©lectro-Ă©jaculation. Elle peut ĂȘtre congelĂ©e. NĂ©anmoins, un problĂšme spĂ©cifique aux fĂ©lins tient Ă  la tĂ©ratospermie, c'est-Ă -dire la production de nombreux spermatozoĂŻdes porteurs d'anomalies morphologiques. L'insĂ©mination artificielle donne de meilleurs rĂ©sultats lorsque la semence est dĂ©posĂ©e par voie intra-utĂ©rine. Pendant longtemps, la laparoscopie a Ă©tĂ© la technique de rĂ©fĂ©rence, mais rĂ©cemment, des techniques de cathĂ©tĂ©risme du col utĂ©rin par voie vaginale ont Ă©tĂ© mises au point, aussi bien chez le chat que chez certains fĂ©lidĂ©s sauvages. Les rĂ©sultats de l'insĂ©mination artificielle chez les fĂ©lidĂ©s restent moyens (souvent moins de 50 % de gestations obtenues)

    French scientific names of continental molluscs of France: process for establishing a list of reference

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    In the biodiversity crisis context and with the increasing general awareness on this issue, conservation of small and poorly-known species is hampered by the fact they only have latine names. In order to communicate for biodiversity conservation, having French names is an advantage which is lacking in terrestrial and freshwater molluscs from France. To remedy this problem, we propose a list of French scientific names for this group, i.e. all species and subspecies known from France. We have listed existing names in legal documents, in usage and in the 18th and 19th centuries scientific literature. The resulting list being incomplete, we had to create new French names, following a series of recommendations adapted from similar works dealing with other taxonomic groups. We conclude by dealing with the issue of the legitimacy and validity of such names. The list of French scientific names is given as an appendix and is downloadable from internetDans le contexte de la crise de la biodiversitĂ© et de la prise de conscience par le grand public des enjeux environnementaux, la conservation des espĂšces petites et mĂ©connues est handicapĂ©e par le fait que ces espĂšces ne peuvent ĂȘtre dĂ©signĂ©es que par leur nom latin. Dans une optique de communication pour la prĂ©servation de la biodiversitĂ©, disposer de nom français est un atout qui fait dĂ©faut pour les mollusques terrestres et d'eau douce de France. Pour remĂ©dier Ă  cela, nous proposons une liste de noms scientifiques français pour ce groupe, et prĂ©sentons les Ă©tapes qui ont permis l'Ă©tablissement de cette liste. Les taxons concernĂ©s sont l'ensemble des espĂšces et sous-espĂšces de la faune de France, pour lesquelles nous avons recensĂ© les noms existants, dans les textes lĂ©gaux, dans l'usage et dans la littĂ©rature scientifique des XVIIIe et XIXe siĂšcles. La liste de noms obtenue Ă©tant insuffisante, nous avons dĂ» crĂ©er de nouveaux noms, en suivant une sĂ©rie de recommandations adaptĂ©es de travaux similaires menĂ©s sur d'autres groupes. Enfin, nous concluons par la question de la validitĂ© et de la lĂ©gitimitĂ© d'une telle liste. La liste des noms scientifiques français est fournie en annexe et tĂ©lĂ©chargeable sur internet

    Retention and Activation of Blood-Borne Proteases in the Arterial Wall Implications for Atherothrombosis

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    All forms of atheroma are characterized by a risk of arterial wall rupture leading to clinical complications. This involves medial and adventitial ruptures in abdominal aortic aneurysm (AAA) and intimal cap rupture in vulnerable atherothrombotic plaques. Extracellular proteases, including metalloproteinases, locally generated plasmin, and leukocyte elastase, are important molecular mediators of atheroma progression via their matrix degradation properties. The pathological evolution of AAA is linked to the biology of its associated mural thrombus. Indeed, in aneurysmal segments lined by a thrombus, the wall is thinner, the extracellular matrix more degraded, and the adventitial inflammatory response greater than in segments that are not. Several lines of evidence highlight the role of the thrombus, in AAA, as a reservoir of blood-borne proteases that conveys them from the lumen to the diseased wall. In stenosing atheroma, both previous and recent studies provide evidence that recurrent intraplaque hemorrhages play a dominant role in the evolution of the lesion toward vulnerability. In this review, we draw a parallel between the role of protease conveyance and activation of the mural thrombus in AAA and of intraplaque hemorrhages in stenosing atheroma. We hypothesize that intraplaque hemorrhages convey blood-borne proteases into lesions, where they are retained and activated upon thrombus/hematoma formation, thus contributing significantly to their deleterious action

    Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis.

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    Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk. Modestly powered genome-wide association studies (GWAS) have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility. Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis

    Reception Test of Petals for the End Cap TEC+ of the CMS Silicon Strip Tracker

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    The silicon strip tracker of the CMS experiment has been completed and was inserted into the CMS detector in late 2007. The largest sub system of the tracker are its end caps, comprising two large end caps (TEC) each containing 3200 silicon strip modules. To ease construction, the end caps feature a modular design: groups of about 20 silicon modules are placed on sub-assemblies called petals and these self-contained elements are then mounted onto the TEC support structures. Each end cap consists of 144 such petals, which were built and fully qualified by several institutes across Europe. Fro

    Integration of the End Cap TEC+ of the CMS Silicon Strip Tracker

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    The silicon strip tracker of the CMS experiment has been completed and inserted into the CMS detector in late 2007. The largest sub-system of the tracker is its end cap system, comprising two large end caps (TEC) each containing 3200 silicon strip modules. To ease construction, the end caps feature a modular design: groups of about 20 silicon modules are placed on sub-assemblies called petals and these self-contained elements are then mounted into the TEC support structures. Each end cap consists of 144 petals, and the insertion of these petals into the end cap structure is referred to as TEC integration. The two end caps were integrated independently in Aachen (TEC+) and at CERN (TEC--). This note deals with the integration of TEC+, describing procedures for end cap integration and for quality control during testing of integrated sections of the end cap and presenting results from the testing

    Ville et campagne de Fréjus romaine

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    En 2006, une fouille d’archĂ©ologie prĂ©ventive, dĂ©signĂ©e sous le nom de « Villa Romana », a Ă©tĂ© rĂ©alisĂ©e dans le quartier de Villeneuve Ă  FrĂ©jus. Durant l’AntiquitĂ© il s’agit d’une zone pĂ©riurbaine situĂ©e entre la ville de Forum Iulii et le dĂ©bouchĂ© de l’Argens. Connu depuis longtemps en raison de la prĂ©sence d’un Ă©difice thermal toujours en Ă©lĂ©vation, le quartier a Ă©tĂ© fouillĂ© Ă  plusieurs occasions et est interprĂ©tĂ© comme Ă©tant l’emplacement du camp de la flotte, Ă©tabli aprĂšs la bataille d’Actium. Celui-ci se transforme progressivement durant le Ier siĂšcle apr. J.-C. en quartier suburbain au fur et Ă  mesure que se dĂ©veloppe Forum Iulii. Le secteur fouillĂ© se situe dans la partie sud du camp, bordĂ©e par la mer durant les premiers temps de l’AntiquitĂ©. La fouille a permis de rĂ©vĂ©ler la prĂ©sence d’une plage amĂ©nagĂ©e. Les terrains ont ensuite Ă©tĂ© rapidement gagnĂ©s sur la mer, en raison d’une avancĂ©e rapide du littoral, que des Ă©tudes rĂ©centes ont permis de bien connaitre Ă  FrĂ©jus. Des jardins y sont alors amĂ©nagĂ©s. A partir du IIe siĂšcle, cet espace est transformĂ© en zone agricole, et constitue l’illustration de l’exploitation de la campagne aux portes de FrĂ©jus, et cela, jusqu’à la fin de l’AntiquitĂ©. S’ensuit une longue pĂ©riode d’abandon de plusieurs siĂšcles, avant que l’espace ne soit Ă  nouveau vouĂ© Ă  l’agriculture et ce jusqu’à l’orĂ©e des annĂ©es soixante. Depuis, le dĂ©veloppement de la ville actuelle de FrĂ©jus a de nouveau transformĂ© ce quartier en zone urbaine. Cet ouvrage, publiĂ© quelques annĂ©es seulement aprĂšs la fouille, prĂ©sente l’ensemble des Ă©tudes archĂ©ologiques et palĂ©oenvironnementales, rĂ©alisĂ©es Ă  l’occasion de cette opĂ©ration, largement pluridisciplinaire. Elles fournissent un contexte environnemental nouveau pour ce quartier antique et permettent de redĂ©finir un paysage Ă  partir d’analyses bioarchĂ©ologiques et palĂ©oĂ©cologiques rĂ©centes. L’étude de l’ensemble des mobiliers archĂ©ologiques est Ă©galement prĂ©sentĂ©e, en suivant la chronologie et l’évolution de ce quartier Ă  travers l’AntiquitĂ© et l’époque moderne
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