Efficacite agronomique du compost a base de la biomasse du « neem » et de l’anacarde sur des cultures maraicheres dans la zone des Niayes au Senegal

Dans la zone des Niayes au Sénégal, les sols sont pauvres en matières organiques et en éléments nutritifs nécessaires aux plantes. Les engrais chimiques utilisés pour améliorer les rendements ont engendré une forte pollution des sols et de la  nappe phréatique. L’objectif de cette étude est d’évaluer la valeur agronomique du compost fabriqué à base des feuilles de neem et d’anacarde, de fiente de volaille et de la cendre de bois. Le compost obtenu présente un rapport C/N de 15,49 et des teneurs en N - P - K de 9,1, 14,8 et 7,3 mg/kg, respectivement. Les différentes doses du compost testées  sur  des  cultures  maraichères  ont  révélé  des  performances  agronomiques  meilleures par rapport aux témoins. La dose T3 (30 t/ha) a induit les meilleurs rendements pour la tomate (27,213 t/ha) et l’oignon (105,263 t/ha). Pour le chou et la pomme de terre, la dose T1 (10 t/ha) a permis d’obtenir les meilleurs rendements (144,533 t/ha et 55,163 t/ha, respectivement). Par contre pour le poivron, la dose T2 (20 t/ha) a favorisé les meilleurs rendements (32,534 t/ha) avec un poids moyen (81,748g) et un nombre de fruits/récolte considérablement plus élevé. Ce compost pourrait constituer une alternative réelle à l’utilisation abusive de l’engrais minéral dans la zone agricole des Niayes.Mots clés : Compost, Neem, Feuilles d’anacarde, Maraichage, Sénéga

Etude de l’activité antifalcémiante d’extraits de racines de Leptadenia hastata Decne. (Asclepiadacae)

L’objectif de cette étude est d’évaluer l’activité antifalcémiante d’extraits de racines de Leptadenia hastata sur des hémoglobines falciformes et d’identifier les principes actifs à l’origine de cette activité. La méthode employée étudie la réversibilité des drépanocytes, en fonction du temps d’incubation des extraits par rapport aux témoins (eau physiologique, phénylalanine et arginine) sur des échantillons de sang de patients drépanocytaires homozygotes. Des concentrations de 0,05; 0,5; 5 et 10 mg/ml de quatre extraits (méthanol, hexane, acétate d’éthyle et méthanol résiduel) ont été mises en contact avec des drépanocytes de type SS après avoir provoqué leur falciformation avec une solution à 2% de métabisulfite de sodium. L’évaluation a été effectuée toutes les 30 minutes pendant 120 minutes. Les différents extraits ont montré une activité dosedépendante sur la réversibilité de la falciformation des globules rouges avec plus de 80% d’inversion en 120 minutes pour l’extrait méthanolique, le plus actif. Un screening phytochimique a permis de faire une corrélation entre les flavonoïdes et l’activité antifalcémiante des extraits de Leptadenia hastata.Mots clés : Drépanocytose, hémoglobine, activité antifalcémiante, Leptadenia hastata, flavonoïdes

Sensitivity of IFN-γ Release Assay to Detect Latent Tuberculosis Infection Is Retained in HIV-Infected Patients but Dependent on HIV/AIDS Progression

BACKGROUND: Detection and treatment of latent TB infection (LTBI) in HIV infected individuals is strongly recommended to decrease morbidity and mortality in countries with high levels of HIV. OBJECTIVE: To assess the validity of a newly developed in-house ELISPOT interferon-gamma release assay (IGRA) for the detection of LTBI amongst HIV infected individuals, in comparison with the Tuberculin Skin Test (TST). METHODOLOGY/PRINCIPAL FINDINGS: ESAT6/CFP10 (EC) ELISPOT assays were performed, together with a TST, in 285 HIV infected individuals recruited in HIV clinics in Dakar, Senegal, who had no signs of active TB at time of enrolment. Thirty eight of the subjects (13.3%) failed to respond to PHA stimulation and were excluded from the analysis. In the 247 remaining patients, response to PHA did not vary according to CD4 cell count categories (p = 0.51). EC ELISPOT was positive in 125 (50.6%) subjects, while 53 (21.5%) had a positive TST. Concordance between EC ELISPOT and TST was observed in 151 patients (61.1%) (kappa = 0.23). The proportion of subjects with a positive response to the EC ELISPOT assay decreased with declining CD4 counts (p trend = 0.001), but were consistently higher than the proportion of TST responders. In multivariate analysis, the risk of being EC-ELISPOT positive in HIV infected individuals was associated with age, CD4 count and HIV-1 strain. CONCLUSION: Our study indicates that IGRAs using M. tuberculosis specific antigens are likely to retain their validity for the diagnosis of LTBI among HIV positive individuals, but may be impaired by T-cell anergy in severely immuno-suppressed individuals

The Role of Health Systems Factors in Facilitating Access to Psychotropic Medicines: A Cross-Sectional Analysis of the WHO-AIMS in 63 Low- and Middle-Income Countries

In a cross-sectional analysis of WHO-AIMS data, Ryan McBain and colleagues investigate the associations between health system components and access to psychotropic drugs in 63 low and middle income countries

A Self-Assembling Lanthanide Molecular Nanoparticle for Optical Imaging

Chromophores that incorporate f-block elements have considerable potential for use in bioimaging applications because of their advantageous photophysical properties compared to organic dye, which are currently widely used. We are developing new classes of lanthanide-based self-assembling molecular nanoparticles as reporters for imaging and as multi-functional nanoprobes or nanosensors for use with biological samples. One class of these materials, which we call lanthanide "nano-drums", are homogeneous 4d-4f clusters approximately 25 to 30 angstrom in diameter. These are capable of emitting from the visible to near-infrared wavelengths. Here, we present the synthesis, crystal structure, photophysical properties and comparative cytotoxicity data for a 32 metal Eu-Cd nano-drum [Eu8Cd24L12(OAc)(48)] (1). We also explored the imaging capabilities of this nano-drum using epifluorescence, TIRF, and two-photon microscopy platforms.Welch Foundation F-816, F-1018, F1515Ministry of High Education (MOHE), Malaysia under High Impact Research (HIR) - MOHE project UM.C/625/1/HIR/MoE/CHAN/13/6 H-50001-00-A000034NIH/NIAID 1U01AI078008-3Centre for Blast Injury Study at Imperial College LondonCPRIT R1003NIH-NCI CA68682National Institutes of HealthNational Science FoundationCancer Prevention Research Institute of TexasNational Science Foundation CHE-0741973Chemistr

Evolutionary History of Helicobacter pylori Sequences Reflect Past Human Migrations in Southeast Asia

The human population history in Southeast Asia was shaped by numerous migrations and population expansions. Their reconstruction based on archaeological, linguistic or human genetic data is often hampered by the limited number of informative polymorphisms in classical human genetic markers, such as the hypervariable regions of the mitochondrial DNA. Here, we analyse housekeeping gene sequences of the human stomach bacterium Helicobacter pylori from various countries in Southeast Asia and we provide evidence that H. pylori accompanied at least three ancient human migrations into this area: i) a migration from India introducing hpEurope bacteria into Thailand, Cambodia and Malaysia; ii) a migration of the ancestors of Austro-Asiatic speaking people into Vietnam and Cambodia carrying hspEAsia bacteria; and iii) a migration of the ancestors of the Thai people from Southern China into Thailand carrying H. pylori of population hpAsia2. Moreover, the H. pylori sequences reflect iv) the migrations of Chinese to Thailand and Malaysia within the last 200 years spreading hspEasia strains, and v) migrations of Indians to Malaysia within the last 200 years distributing both hpAsia2 and hpEurope bacteria. The distribution of the bacterial populations seems to strongly influence the incidence of gastric cancer as countries with predominantly hspEAsia isolates exhibit a high incidence of gastric cancer while the incidence is low in countries with a high proportion of hpAsia2 or hpEurope strains. In the future, the host range expansion of hpEurope strains among Asian populations, combined with human motility, may have a significant impact on gastric cancer incidence in Asia

Track A Basic Science

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138319/1/jia218438.pd