33 research outputs found
Analysis of the genetic variation for adaptation to a short thermal stress on young « Bos taurus » cattle
In the present work, an attempt was made to determine the adaptation to heat of some cattle breeds, especially French ones. A total of 582 young male and female cattle, about 14 months old and coming from 41 elementary genetic combinations analyzed in 5 different non bioclimatological experiments, were subjected to a heat stress for 8 hours during which the room temperature was increased from 18°C to 38 °C. The usual reaction were observed i.e. increase in the rectal temperature during the stress (+ 0,54 °C), increase in the respiratory rate ( X 3), increase in the sweating rate, heart rate and skin temperature. The statistical analyses were made at three stages of stress (beginning, middle, end). In all cases, a very strong environmental effect was noticed, ie effect of the year and of experimental errors in the management of the theoretical schedule involving temperature and relative hygrometry. The data adjusted for environmental effects rather clearly show the genetic variability. However, a more accurate analysis shows that it is mainly proceeded from a between group variability when defining the groups according to « animal husbandry » parameters (dairy purpose, beef purpose, and local breed group). As a matter of fact, in most cases, there was no significant variability between the reactions of the genotypes belonging to the same group, whereas this variability existed between the groups..The satisfactory performance of the local breed group clearly appeared in comparison with the group including the improved dairy or beef breeds exhibiting only minor differences in the parameters analyzed. In the discussion, emphasis in laid ov the possible influence of thermogenesis on the results. Although our findings could have been afrected by disturbing events such as emotional stress, they agree rather well with data obtained is practice on the behaviour of the local French breeds in some hot countries.Le but de ce travail est dâessayer de caractĂ©riser lâadaptation Ă la chaleur dâun certain nombre de races bovines, notamment françaises. Pour cela, 582 jeunes bovins, mĂąles et femelles, dâenviron 14 mois et issus de 41 combinaisons gĂ©nĂ©tiques Ă©lĂ©mentaires analysĂ©es dans 5 expĂ©rimentations diffĂ©rentes, Ă objectif non bioclimatologique, sont soumis en chambre chaude, Ă un stress thermique de 8 heures pendant lequel la tempĂ©rature externe a Ă©tĂ© portĂ©e de 11) De 18°C Ă 38 °C. Les rĂ©actions classiques sont observĂ©es : augmentation de la tempĂ©rature rectale au cours du stress (+ 0,54°C), augmentation du rythme respiratoire ( X 3), augmentation du taux de sudation, du rythme cardiaque, de la tempĂ©rature de la peau. Les analyses statistiques sont effectuĂ©es Ă trois stades du stress (dĂ©but, milieu, fin). Dans tous les cas, on note de trĂšs forts effets dĂ»s au milieu : effet de lâannĂ©e et des erreurs expĂ©rimentales dans la conduite du protocole thĂ©orique, concernant la tempĂ©rature et lâhygromĂ©trie relative. Sur les donnĂ©es ajustĂ©es pour les effets de milieu, la variabilitĂ© gĂ©nĂ©tique apparaĂźt assez clairement. Cependant une analyse plus fine montre quâelle provient essentiellement dâune variabilitĂ© inter groupe en dĂ©finissant le groupe dâaprĂšs des critĂšres « zootechniques » ou «fonctionnels » (groupe Ă vocation laitiĂšre, groupe Ă vocation bouchĂšre, groupe des races locales). En effet, dans la grande majoritĂ© des cas, il nâapparaĂźt pas de variabilitĂ© significative entre les rĂ©actions des gĂ©notypes rangĂ©s dans le mĂȘme groupe, alors quâelle existe entre les groupes. La bonne performance du groupe des races locales apparaĂźt en comparaison des groupes mettant en oeuvre les races amĂ©liorĂ©es, laitiĂšres ou bouchĂšres, qui diffĂšrent peu entre eux pour les critĂšres analysĂ©s. Dans la discussion, lâaccent est mis sur lâincidence probable sur les rĂ©sultats des phĂ©nomĂšnes de thermogĂ©nĂšse. Si nos rĂ©sultats ont pu ĂȘtre affectĂ©s par des phĂ©nomĂšnes parasites, notamment ceux de stress Ă©motionnel, il nâen reste pas moins quâils concordent assez bien avec lâexpĂ©rience pratique acquise sur le comportement des races locales françaises dans certains pays chauds
Near-Fatal Multiple Organ Dysfunction Syndrome Induced by Plasmodium malariae
International audienc
Comparaisons entre la race mixte normande, les races spĂ©cialisĂ©es holstein canadienne et charolaise et leurs croisements. I. â Performances de croissance des mĂąles et des femelles
International audienc
Resource-constrained scheduling of partitioned algorithms on processor arrays
International audienceno abstrac
Resource-constrained Scheduling of Partitioned Algorithms on Processor Array.
We deal with the problem of partitioning and mapping uniform loop nests onto physical processor arrays. Resource constraints are taken into account: not only we assume a limited number of available processors, but we also assume that the communication capabilities of the physical processors are restricted (in particular, the number of communication links in each direction is bounded). This paper is motivated by the recent work of Chou and Kung and of Thiele. Our main contributions are a new formulation of the complex optimization problem to be solved in terms of a single integer linear programming problem, as well as optimal scheduling algorithms and complexity results in the case of linear processor arrays.Nous étudions dans ce rapport le partitionnement et le placement de nids de boucles uniformes sur des tableaux de processeurs. les contraintes liées aux ressources sont prises en compte : non seulement nous supposons disposer d'un nombre fini de processeurs, mais également que les capacités de communication des processeurs sont limitées ( en particulier, le nombre de liens de communications dans chaque direction est bornée). les récentes travaux de Chou et Kung et de Thiele sont à l'origine de ce travail. Nos principales contributions résident dans la reformulation d'une problÚme complexe d'optimisation en un problÚme de programmation linéaire, ainsi que dans des algorithmes d'ordonnancement et des résultats de complexité dans le cas de tableaux linéaires de processeur
Resource-constrained Scheduling of Partitioned Algorithms on Processor Arrays
We deal with the problem of partitioning and mapping uniform loop nests onto physical processor arrays. Resource constraints are taken into account: not only we assume a limited number of available processors, but we also assume that the communication capabilities of the physical processors are restricted (in particular, the number of communication links in each direction is bounded). This paper is motivated by the recent work of Chou and Kung and of Thiele. Our main contributions are a new formulation of the complex optimization problem to be solved in terms of a single integer linear programming problem, as well as optimal scheduling algorithms and complexity results in the case of linear processor arrays. 1 Introduction In this paper, we deal with the problem of partitioning and mapping uniform loop nests onto physical processor arrays. Resource constraints are taken into account: not only we assume a limited number of available processors, but we also assume that the communication..