2,249 research outputs found

    On the discriminator of Lucas sequences

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    Search for Effect of Influence from Future in Large Hadron Collider

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    We propose an experiment which consists of drawing a card and using it to decide restrictions on the running of Large Hadron Collider (LHC for short) at CERN, such as luminosity, and beam energy. There may potentially occur total shut down. The purpose of such an experiment is to search for influence from the future, that is, backward causation. Since LHC will produce particles of a mathematically new type of fundamental scalars, i.e., the Higgs particles, there is potentially a chance to find unseen effects, such as on influence going from future to past, which we suggest in the present paper.Comment: 18pp, comments added, change of title and corrections of main text; v4:minor typos correcte

    L’amélioration des performances de reproduction chez le chameau: juste une question technique?

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    The question of “How to improve camel reproduction” is an age-old dilemma for scientists and veterinarians in the camel sector. In 1990, during the workshop organized in Paris, on the topic “Is it possible to improve the reproductive performance of the camel?”, Professor Musa (Sudan) said that “although the field of camel reproduction is no longer the virgin area it used to be ten years ago, there are still a lot of gaps in our knowledge concerning camel reproduction”. Among the questions, it was mentioned that infertility was still not well defined in the camel as compared with other farm animals. Knowledge has progressed over the last 25 years but, the improvement in reproductive efficiency of the camel is still limited. The improvement in reproductive efficiency has two main objectives: (i) to contribute to genetic progress, and (ii) to increase the numerical productivity of the camel herd. The main parameters contributing to this productivity are the fertility rate (number of live calves at term/mean number of adult females) of both male and female, the intercalving interval and embryo and calf survival. The main advances over the past 25 years have been due to better management regarding the diagnosis of gestation and fetus monitoring, a better understanding of mechanisms to stimulate male libido, a more rational culling policy for camels with genital abnormalities, better general hygiene of the farm at calving (distribution of colostrum) and at weaning, better health management (vaccination, parasitism prevention) and the introduction of assisted reproductive techniques such as artificial insemination and embryos transfer (AI, ET). On the other hand, advances in the organizational aspects at national level are quite insufficient. For example, no real performance control to identify the best potential genitors, no collection of data regarding reproductive performances except at some big dairy farms and even the strategy for reducing the calving interval has not really been established. In addition, the knowledge and capability of the farmers, veterinarians and technicians at the national level is still insufficient to observe progress in camel reproductive performances and even if these performances were to be improved, there is no national monitoring system to measure this improvement. A demographic model,such as the Leslie Model, could help as a first step in understanding the initial ways for improving camel productivity such as decreasing calf mortality, increasing fertility and decreasing the intercalving interval ? An example is given in the presentation. Keywords: Camel, reproduction, technical innovations, performances farmers organization.La question du “comment améliorer la reproduction chez la chamelle” est un vieux dilemme pour les chercheurs et les praticiens vétérinaires dans le secteur camelin. En 1990, au cours de l’atelier organisé à Paris, sur le thème “Est-il possible d’améliorer les performances reproductive chez le chameau ?”, le Professeur Musa (Soudan) écrivait “bien que le domaine de la reproduction cameline ne soit plus un terrain vierge depuis une dizaine d’années, il y a encore beaucoup de lacunes dans notre connaissance concernant la reproduction du chameau”. Parmi ces questions, il était mentionné que l’infertilité n’était pas encore bien définie chez le chameau, comparé à d’autres espèces de rente. Certes, les connaissances ont beaucoup progressé depuis 25 ans, mais l’amélioration de l’efficacité reproductive du chameau reste encore limitée. L’amélioration de cette efficacité a deux objectifs principaux : (i) contribuer au progrès génétique, et (ii) augmenter la productivité numérique des troupeaux camelins. Les principaux paramètres contribuant à cette productivité sont le taux de fertilité (nombre de chamelons vivants à terme/nombre moyen de femelles adultes) des mâles et des femelles, l’intervalle entre mises bas, et le taux de survie embryonnaire ou néonatal. Les principales avancées depuis 25 ans ont porté sur une meilleure gestion concernant le diagnostic de gestation et le suivi embryonnaire, une meilleure connaissance des mécanismes stimulant la libido, une meilleure politique rationnelle de réforme des chamelles avec anormalités génitales, une meilleure hygiène des fermes à la mise bas (distribution du colostrum) et au sevrage, une meilleure gestion sanitaire (vaccination, prévention parasitaire) et l’introduction des techniques de reproduction assistée telles que l’insémination artificielle et le transfert d’embryons (IA, TE). D’un autre côté, les avancées dans les aspects organisationnels aux niveaux nationaux sont tout-à-fait insuffisantes. Par exemple, il n’y a pas de réel contrôle de performances pour identifier les géniteurs à bon potentiel, aucune collecte des données concernant les performances de reproduction, à l’exception de quelques grandes fermes laitières, et même absence de stratégie de réduction de l’intervalle entre mise-bas. De plus, les connaissances des chameliers, des vétérinaires et des techniciens au niveau national sont encore insuffisantes pour observer un progrès des performances reproductives de la chamelle, et même si ces performances ont été améliorées, il n’existe aucun système de suivi national pour mesurer cette amélioration. Un modèle démographique, tel que le modèle de Leslie, peut contribuer dans une première étape à comprendre les voies initiales pour améliorer la productivité cameline en permettant de faire le choix entre diminuer la mortalité du chamelon ou augmenter la fertilité et diminuer l’intervalle entre mises bas. Un exemple est donné dans la présentation. Mots-clés: hameau, reproduction, innovations techniques, performances des organisations d’éleveurs

    New animal-based measures to assess welfare in dromedary camels

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    Reliable and measurable animal-based measures (ABMs) are essential for assessing animal welfare. This study aimed at proposing ABMs for dromedary camels identifying their possible associations with management. Data were collected at a permanent camel market; a total of 76 pens and 528 camels were evaluated. ABMs were collected for each welfare principle (i.e., good feeding, good housing, good health, appropriate behavior), while resources or management-based measures were collected at three levels of investigations (animal, herd, or caretakers). Associations were calculated by generalized linear models. Body condition score and thirst index (ABMs of good feeding) resulted negatively associated with short caretaker’s experience, dirty bedding, limited shaded space, feeding and water space, and space allowance (P < 0.05). Resting behaviors and restricted movements (ABMs of good housing) were associated with short caretaker’s experience, dirty bedding and water, rationed water distribution, water points in the sun, and presence of hobbles (P < 0.05). Disease, injury, and pain induced by management procedures (ABMs of good health) were negatively associated with short caretaker’s experience, presence of hobbles, limited space allowance and shaded space, dirty bedding, and feeding and watering practices (e.g., frequency of distribution, resource quality, location of the troughs; P < 0.05). Response to approaching test and aggressivity (ABMs of Appropriate behavior) were negatively associated with limited space allowance, shaded, feeding and water space, and rationed water distribution (P < 0.05). Overall, the proposed ABMs seems to be appropriate indicators of welfare consequences in camels being able to identify factors related to housing and management practices that may impair or improve camel welfare

    Analyse des effects de la pluviometrie sur le PIB Agricole au Senegal

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    RESUMELe secteur agricole au Sénégal est dominé par les cultures pluviales dont l’arachide et le mil qui occupent la majeure partie des terres cultivables en hivernage. Sa contribution au PIB reste faible par rapport aux secteurs tertiaire et secondaire. Une des principales raisons de cette situation est sa forte dépendance aux conditions climatiques et notamment à la pluviométrie. Dans cette recherche nous nous proposons d’étudier l’analyse des effets de la pluviométrie sur le PIB du sous- secteur agricole au Sénégal. L’étude couvre une période de 35 ans allant de 1980 à 2015 et concerne tout le territoire national. Les résultats des tests économétriques par la technique des Moindres Carrés Ordinaires (MCO) montrent que la variation pluviométrique influence les résultats économiques du secteur agricole. L’étude montre qu’à chaque fois que la pluviométrie baisse, les productions et les valeurs économiques du mil et de l’arachide suivent la même tendance. Ainsi une bonne pluviométrie a un effet positif sur la production agricole qui à son tour influence positivement le PIB agricole. ABSTRACTANALYSIS OF THE EFFECTS OF RAINFALL ON AGRICULTURAL GDP IN SENEGALThe agricultural sector in Senegal is dominated by rainfed crops, with groundnuts and millet occupying most of the land. Its contribution to GDP remains low compared to the tertiary and secondary sectors. One of the main reasons for this situation is its strong dependence on climatic conditions and in particular on rainfall. In this research we propose to study the analysis of the effects of rainfall on the GDP of the agricultural sub-sector in Senegal. The study covers a 35-year period from 1980 to 2015 and concerns the entire national territory. The results of econometric tests using the Ordinary Least Squares (OLS) technique show that rainfall variation influences the economic performance of the agricultural sector. The study shows that each time the rainfall drops, the production and economic values of millet and peanuts follow the same trend. Thus, good rainfall has a positive effect on agricultural production which in turn positively influences agricultural GDP

    ABCDs of E: Managing Metadata for E-Books and Streaming Media

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    This poster outlines the functions performed by the JMU Libraries E-Monograph Team to acquire and analyze, batch edit, check access, and distribute or delete metadata records for e-books and streaming media materials

    Estimating the burden of malaria in Senegal : Bayesian zero-inflated binomial geostatistical modeling of the MIS 2008 data

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    The Research Center for Human Development in Dakar (CRDH) with the technical assistance of ICF Macro and the National Malaria Control Programme (NMCP) conducted in 2008/2009 the Senegal Malaria Indicator Survey (SMIS), the first nationally representative household survey collecting parasitological data and malaria-related indicators. In this paper, we present spatially explicit parasitaemia risk estimates and number of infected children below 5 years. Geostatistical Zero-Inflated Binomial models (ZIB) were developed to take into account the large number of zero-prevalence survey locations (70%) in the data. Bayesian variable selection methods were incorporated within a geostatistical framework in order to choose the best set of environmental and climatic covariates associated with the parasitaemia risk. Model validation confirmed that the ZIB model had a better predictive ability than the standard Binomial analogue. Markov chain Monte Carlo (MCMC) methods were used for inference. Several insecticide treated nets (ITN) coverage indicators were calculated to assess the effectiveness of interventions. After adjusting for climatic and socio-economic factors, the presence of at least one ITN per every two household members and living in urban areas reduced the odds of parasitaemia by 86% and 81% respectively. Posterior estimates of the ORs related to the wealth index show a decreasing trend with the quintiles. Infection odds appear to be increasing with age. The population-adjusted prevalence ranges from 0.12% in Thille-Boubacar to 13.1% in Dabo. Tambacounda has the highest population-adjusted predicted prevalence (8.08%) whereas the region with the highest estimated number of infected children under the age of 5 years is Kolda (13940). The contemporary map and estimates of malaria burden identify the priority areas for future control interventions and provide baseline information for monitoring and evaluation. Zero-Inflated formulations are more appropriate in modeling sparse geostatistical survey data, expected to arise more frequently as malaria research is focused on eliminatio
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