1,631 research outputs found
Artificial insemination in felids
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'insémination artificielle
chez le chat domestique et les félidés sauvages répond à 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 échanges géographiques de semence et donc
un brassage et une meilleure sélection génétiques. Chez les félins sauvages, elle joue un
rÎle complémentaire 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 possÚdent cependant des effets indésirables, notamment un risque
d'hyperstimulation ovarienne. La semence des mùles est généralement récoltée par
Ă©lectro-Ă©jaculation. Elle peut ĂȘtre congelĂ©e. NĂ©anmoins, un problĂšme spĂ©cifique aux fĂ©lins
tient à la tératospermie, c'est-à -dire la production de nombreux spermatozoïdes porteurs
d'anomalies morphologiques. L'insémination artificielle donne de meilleurs résultats lorsque
la semence est déposée par voie intra-utérine. Pendant longtemps, la laparoscopie a été la
technique de référence, mais récemment, des techniques de cathétérisme du col utérin par
voie vaginale ont été mises au point, aussi bien chez le chat que chez certains félidés
sauvages. Les résultats de l'insémination artificielle chez les félidés restent moyens
(souvent moins de 50 % de gestations obtenues)
French scientific names of continental molluscs of France: process for establishing a list of reference
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 biodiversité et de la prise de conscience par le grand public des enjeux environnementaux, la conservation des espÚces petites et méconnues est handicapée par le fait que ces espÚces 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 présentons les étapes qui ont permis l'établissement de cette liste. Les taxons concernés sont l'ensemble des espÚces et sous-espÚces de la faune de France, pour lesquelles nous avons recensé les noms existants, dans les textes légaux, dans l'usage
et dans la littérature scientifique des XVIIIe et XIXe siÚcles. La liste de noms obtenue étant insuffisante, nous avons dû créer de nouveaux noms, en suivant une série de recommandations adaptées de travaux similaires menés sur d'autres groupes. Enfin, nous concluons par la question de
la validité et de la légitimité d'une telle liste. La liste des noms scientifiques français est fournie en annexe et téléchargeable sur internet
Retention and Activation of Blood-Borne Proteases in the Arterial Wall Implications for Atherothrombosis
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.
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
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
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
En 2006, une fouille dâarchĂ©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 lâAntiquitĂ© il sâagit dâune zone pĂ©riurbaine situĂ©e entre la ville de Forum Iulii et le dĂ©bouchĂ© de lâArgens. Connu depuis longtemps en raison de la prĂ©sence dâun Ă©difice thermal toujours en Ă©lĂ©vation, le quartier a Ă©tĂ© fouillĂ© Ă plusieurs occasions et est interprĂ©tĂ© comme Ă©tant lâemplacement du camp de la flotte, Ă©tabli aprĂšs la bataille dâActium. 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 lâAntiquitĂ©. La fouille a permis de rĂ©vĂ©ler la prĂ©sence dâune plage amĂ©nagĂ©e. Les terrains ont ensuite Ă©tĂ© rapidement gagnĂ©s sur la mer, en raison dâune 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 lâillustration de lâexploitation de la campagne aux portes de FrĂ©jus, et cela, jusquâĂ la fin de lâAntiquitĂ©. Sâensuit une longue pĂ©riode dâabandon de plusieurs siĂšcles, avant que lâespace ne soit Ă nouveau vouĂ© Ă lâagriculture et ce jusquâĂ lâorĂ©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 lâensemble des Ă©tudes archĂ©ologiques et palĂ©oenvironnementales, rĂ©alisĂ©es Ă lâoccasion 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 dâanalyses bioarchĂ©ologiques et palĂ©oĂ©cologiques rĂ©centes. LâĂ©tude de lâensemble des mobiliers archĂ©ologiques est Ă©galement prĂ©sentĂ©e, en suivant la chronologie et lâĂ©volution de ce quartier Ă travers lâAntiquitĂ© et lâĂ©poque moderne
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