Prévalence de la brucellose, chlamydiose et toxoplasmose chez les petits ruminants au Mali : résultats d’une enquête séro-épidemiologique

Au Mali, l’élevage des espèces à cycle court en général et celui des petits ruminants en particulier constitue une source précieuse de revenus et de protéines pour les populations. Cependant, au nombre des contraintes à l’amélioration de la productivité de cet élevage, figurent les pertes en reproduction, dont les causes demeurent mal connues. Les données relatives au rôle de certaines infections microbiennes comme la brucellose à Brucella ovis, chlamydiose et la toxoplasmose sont quasi inexistantes. L’objet de la présente étude a été d’évaluer la prévalence sérologique de ces pathologies, susceptibles de causer des pertes en reproduction chez ces espèces animales. Elle a couvert quatre sites dont Kéniébougou (Cercle de Ségou), Nioro (Cercle de Nioro), Bougouni (Cercle de Bougouni) et Briga (Cercle de Koro), choisis en collaboration étroite avec les services techniques d’encadrement et éleveurs de petits ruminants desdites localités. Au total 872 sérums (368 ovins et 504 caprins) issus des sujets présentant des signes de perte en reproduction ont été testés par la méthode Elisa indirecte. Parmi ceux-ci, 81 (9,28 %) se sont révélés positifs (1,26 % en brucellose à Brucella ovis, 3,55 % en chlamydiose à Chlamydia abortus et 4,47 % en toxoplasmose à Toxoplasma gondii). Les anticorps mis en évidence sont considérés comme d’origine infectieuse, les animaux n’ayant jamais été vaccinés contre les maladies investiguées, ce qui confirme la circulation des agents étiologiques des trois infections abortives parmi les populations de petits ruminants au Mali

Diffraction techniques and vibrational spectroscopy opportunities to characterise bones

From a histological point of view, bones that allow body mobility and protection of internal organs consist not only of different organic and inorganic tissues but include vascular and nervous elements as well. Moreover, due to its ability to host different ions and cations, its mineral part represents an important reservoir, playing a key role in the metabolic activity of the organism. From a structural point of view, bones can be considered as a composite material displaying a hierarchical structure at different scales. At the nanometre scale, an organic part, i.e. collagen fibrils and an inorganic part, i.e. calcium phosphate nanocrystals are intimately mixed to assure particular mechanical properties

High Resolution Genomic Scans Reveal Genetic Architecture Controlling Alcohol Preference in Bidirectionally Selected Rat Model

Investigations on the influence of nature vs. nurture on Alcoholism (Alcohol Use Disorder) in human have yet to provide a clear view on potential genomic etiologies. To address this issue, we sequenced a replicated animal model system bidirectionally-selected for alcohol preference (AP). This model is uniquely suited to map genetic effects with high reproducibility, and resolution. The origin of the rat lines (an 8-way cross) resulted in small haplotype blocks (HB) with a corresponding high level of resolution. We sequenced DNAs from 40 samples (10 per line of each replicate) to determine allele frequencies and HB. We achieved ~46X coverage per line and replicate. Excessive differentiation in the genomic architecture between lines, across replicates, termed signatures of selection (SS), were classified according to gene and region. We identified SS in 930 genes associated with AP. The majority (50%) of the SS were confined to single gene regions, the greatest numbers of which were in promoters (284) and intronic regions (169) with the least in exon\u27s (4), suggesting that differences in AP were primarily due to alterations in regulatory regions. We confirmed previously identified genes and found many new genes associated with AP. Of those newly identified genes, several demonstrated neuronal function involved in synaptic memory and reward behavior, e.g. ion channels (Kcnf1, Kcnn3, Scn5a), excitatory receptors (Grin2a, Gria3, Grip1), neurotransmitters (Pomc), and synapses (Snap29). This study not only reveals the polygenic architecture of AP, but also emphasizes the importance of regulatory elements, consistent with other complex traits

Spin polarization of nucleons. Limits of low and high temperatures

Section III. Theory of Atomic Nucleus and Fundamental Interaction