Influence de l'état physiologique des chèvres et de saison sur la prévalence et la charge parasitaire gastro-intestinale au Bénin

Les pathologies parasitaires gastro-intestinales ont une incidence économique et zootechnique majeure qui mine la productivité des élevages caprins dans les milieux tropicaux. Cette étude a évalué l’influence de différents stades physiologiques et des saisons sur la prévalence et la charge parasitaire gastro-intestinale des chèvres en élevage traditionnel au Bénin. Pour atteindre cet objectif, des prélèvements et des analyses coproscopiques à différents stades physiologiques des caprins et à différentes saisons de l’année ont été effectués dans différents départements du Bénin. Les résultats ont montré que les chèvres étaient infestées majoritairement par les Strongles et Strongyloides spp. Les chèvres gestantes suivies de sujets en lactation étaient les plus infestées. La prévalence de ces deux parasites chez les sujets en gestation a été forte (91,7 % strongle et 88 % Strongyloides) suivi de ceux en lactation (88,4% Strongle et 87% Strongyloides) et enfin ceux en croissance (86% Strongle et 85,1% Strongyloides). Les charges parasitaires des strongles, des strongyloides, des Moniezia et des Okystes coccidiens étaient plus élevées en saison pluvieuse qu’en saison sèche. Il serait donc judicieux de veiller sur l’état sanitaire des animaux lors des stades de gestation et de lactation qui sont les plus vulnérables et de façon particulière en saison pluvieuse. Mots clés: Caprin, parasite gastro-intestinal, Strongyloides, strongles, saison, Béni

Disabled-2 (Dab2) inhibits Wnt/β-catenin signalling by binding LRP6 and promoting its internalization through clathrin

Wnt signalling requires caveolin-dependent endocytic uptake of the Fz/LRP6 receptor complex. The tumour suppressor Disabled-2 inhibits Wnt signalling by sequestering CK2-phosphorylated LRP6 into an alternative clathrin-dependent endocytic pathway

Comparative modeling of DNA and RNA polymerases from Moniliophthora perniciosa mitochondrial plasmid

<p>Abstract</p> <p>Background</p> <p>The filamentous fungus <it>Moniliophthora perniciosa </it>(Stahel) Aime & Phillips-Mora is a hemibiotrophic Basidiomycota that causes witches' broom disease of cocoa (<it>Theobroma cacao </it>L.). This disease has resulted in a severe decrease in Brazilian cocoa production, which changed the position of Brazil in the market from the second largest cocoa exporter to a cocoa importer. Fungal mitochondrial plasmids are usually invertrons encoding DNA and RNA polymerases. Plasmid insertions into host mitochondrial genomes are probably associated with modifications in host generation time, which can be involved in fungal aging. This association suggests activity of polymerases, and these can be used as new targets for drugs against mitochondrial activity of fungi, more specifically against witches' broom disease. Sequencing and modeling: DNA and RNA polymerases of <it>M. perniciosa </it>mitochondrial plasmid were completely sequenced and their models were carried out by Comparative Homology approach. The sequences of DNA and RNA polymerase showed 25% of identity to 1XHX and 1ARO (pdb code) using BLASTp, which were used as templates. The models were constructed using Swiss PDB-Viewer and refined with a set of Molecular Mechanics (MM) and Molecular Dynamics (MD) in water carried out with AMBER 8.0, both working under the ff99 force fields, respectively. Ramachandran plots were generated by Procheck 3.0 and exhibited models with 97% and 98% for DNA and RNA polymerases, respectively. MD simulations in water showed models with thermodynamic stability after 2000 ps and 300 K of simulation.</p> <p>Conclusion</p> <p>This work contributes to the development of new alternatives for controlling the fungal agent of witches' broom disease.</p

Putative tumour-suppressor gene DAB2 is frequently down regulated by promoter hypermethylation in nasopharyngeal carcinoma

<p>Abstract</p> <p>Background</p> <p>Human Disabled-2 (DAB2), is a multi-function signalling molecule that it is frequently down-regulated in human cancers. We aimed to investigate the possible tumour suppressor effect of DAB2 in nasopharyngeal carcinoma (NPC).</p> <p>Methods</p> <p>We studied the expression of DAB2 in NPC cell lines, xenografts and primary tumour samples. The status of promoter methylation was assessed by methylation specific PCR and bisulfite sequencing. The functional role of DAB2 in NPC was investigated by re-introducing DAB2 expression into NPC cell line C666-1.</p> <p>Results</p> <p>Decrease or absent of <it>DAB2 </it>transcript was observed in NPC cell lines and xenografts. Loss of DAB2 protein expression was seen in 72% (33/46) of primary NPC as demonstrated by immunohistochemistry. Aberrant <it>DAB2 </it>promoter methylation was detected in 65.2% (30/46) of primary NPC samples by methylation specific PCR. Treatment of the DAB2 negative NPC cell line C666-1 with 5-aza-2'-deoxycytidine resulted in restoration of DAB2 expression in a dose-dependent manner. Overexpression of DAB2 in NPC cell line C666-1 resulted in reduced growth rate and 35% reduction in anchorage-dependent colony formation, and inhibition of serum-induced c-Fos expression compared to vector-transfected controls. Over expression of DAB2 resulted in alterations of multiple pathways as demonstrated by expression profiling and functional network analysis, which confirmed the role of DAB2 as an adaptor molecule involved in multiple receptor-mediated signalling pathways.</p> <p>Conclusions</p> <p>We report the frequent down regulation of DAB2 in NPC and the promoter hypermethylation contributes to the loss of expression of DAB2. This is the first study demonstrating frequent DAB2 promoter hypermethylation in human cancer. Our functional studies support the putative tumour suppressor effect of DAB2 in NPC cells.</p

Oxygen Evolution from Yba 2 cu 3 o 7‐δ Superconducting Powders Generated by Aerosol Routes

The oxygen desorption kinetics of the YBa 2 Cu 3 O 7‐δ powders generated by an aerosol route was investigated and compared to that of solid state reacted powders. The oxygen content of the aerosol sample was determined using a thermogravimetric analyzer (at 990 C) and wet chemical methods, and δ was calculated to be ‐0.1. The activation energy and pre‐exponential factor were determined by regression for two peaks at 540 C and 850 C. Other activation parameters were also calculated. The calculated values of these parameters for aerosol samples and those reported for solid state reacted powders are in good agreement

Making decisions for oneself and others: How regulatory focus influences the ‘decision maker role effect' for intertemporal choices

We examined self-other differences in an intertemporal choice context, investigating whether choices vary according to different types of regulatory focus. In Study 1, the role of chronic regulatory focus on self-other intertemporal choice was investigated. In Study 2, we designed a causal chain of studies (Study 2a and 2b) to further examine the role of situational regulatory focus in the context of self-other intertemporal choice. Overall, we found a self-other difference for intertemporal choice: individuals who make choices for themselves or for an intimate friend prefer later and larger (LL) rewards than those making choices for a complete stranger, thus demonstrating a ‘decision maker role effect’. Secondly, regardless of chronic or induced regulatory focus, participants with a promotion focus preferred more immediate rewards, while participants with a prevention focus preferred deferred rewards. The self-other difference in intertemporal choice was manifested differently for those holding a chronic promotion focus versus those holding a chronic prevention focus; situationally induced regulatory focus, on the other hand, was found to play a mediating role in self-other intertemporal choice

A Neural Network Modeling Approach to Power amplifiers Taking into Account Temperature Effects

In order to analyze the behavior of PAs at different temperature, this paper propose a neural network modeling approach to predict the temperature dependence of PAs. Three different neural network modeling methods are employed to develop the behavioral models. A 0.1-1.2 GHz CMOS PA is designed and fabricated to verify the effectiveness of the modeling method. Model results agree well with the measurement results. Three different models for the fabricated PA are compared in terms of accuracy. As far as author's knowledge, this is the first time of a temperature dependent behavioral model of CMOS PA is proposed to investigate the temperature effect on the performance of a CMOS PA