300 research outputs found

    L'acacia au Sénégal

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    La variabilité intra et interspécifique de la fixation biologique de l'azote a été étudiée chez les acacias. Cette variabilité se manifeste d'abord dans l'aptitude des espÚces d'#Acacia à former des nodules avec des souches de #Rhizobium ou de #Bradyrhizobium. Ensuite, il a été mis en évidence une différence dans le potentiel fixateur d'azote entre les espÚces d'#Acacia : #A. mangium, #A. seyal et #A. raddiana ont un potentiel élevé alors qu'#A. senegal, #A. pellita et #Faidherbia albida ont un potentiel faible. La variabilité intraspécifique des acacias à fixer l'azote a également été observée dans le cas de #F. albida : la provenance de Kabrousse a le potentiel fixateur le plus élevé ; les provenances de Merina et Dangalma ne fixent pas d'azote. Cette diversité traduit probablement l'existence d'une variabilité génétique chez #Acacia. (Résumé d'auteur

    Un arbre au désert : Acacia raddiana

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    Biological nitrogen fixation in Crotalaria species estimated using the 15N isotope dilution method

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    A greenhouse experiment was conducted to measure nitrogen fixation in three Crotalaria species : C. ochroleuca, C. perrottetii and C. retusa growing in Senegal by using 15N direct isotope dilution technique. Two non-fixing plants, Senna obtusifolia and Senna occidentalis served as reference plants. The amount of nitrogen fixed two months after planting was obtained using the average of the two reference plants. The atom % 15N excess in the Crotalaria species was significantly lower than that of the reference plants, indicating that significant nitrogen fixation occurred in the three plants. Significant differences were observed between the Crotalaria species; C. ochroleuca yielded more dry matter weight and total nitrogen than did C. perrottetti and C. retusa. The % nitrogen derived from atmosphere (%Ndfa) in leaves and stems was also higher in C. ochroleuca. There was no significant difference in %Ndfa in the whole plant between the three Crotalaria species (47% to 53%). In contrast, interspecific variability was observed based on the %Ndfa. C. ochroleuca significantly exhibited the higher amount of total nitrogen fixed, equivalent to 83 kg of nitrogen fixed per hectare. Based on these data, it was concluded that C. ochroleuca could be used in multiple cropping systems in Senegal for making more nitrogen available to other plants. (African Journal of Biotechnology: 2002 1(1): 17-22

    The design and evaluation of a training program on culturally competent psychosocial care provision for men who have sex with men in Senegal

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    Men who have sex with men (MSM) experience a high degree of discrimination and marginalization in Senegal. Homophobia is pervasive in Senegalese society at the cultural, religious, and political levels. Its effects are reflected in the disproportionately high levels of depression, anxiety, and substance abuse among men who have sex with men when compared to the general population. Given the widespread stigma and the lack of structural support, healthcare providers play a critical role in reconciling the physical and psychological needs of men who have sex with men. This led to the design of a training program that aimed to improve the capacity of healthcare providers to deliver MSM-competent psychosocial care. The training was delivered virtually to 37 Senegal-based nurses and physicians. The program was quantitatively and qualitatively evaluated using pre- and post-testing. The findings demonstrate a general post-training increase in knowledge acquisition (9. 23%, p-value = 0.0021) and a 6.39% reduction in homophobia, which was statistically significant (p = 0.0376); with male providers outperforming female providers, and physicians outperforming nurses. This demonstrates the effectiveness and applicability of the program to support the psychosocial needs of men who have sex with men, and its capacity for future and broader implementation among healthcare providers

    Etude de l’activitĂ© antifalcĂ©miante d’extraits de racines de Leptadenia hastata Decne. (Asclepiadacae)

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    L’objectif de cette Ă©tude est d’évaluer l’activitĂ© antifalcĂ©miante d’extraits de racines de Leptadenia hastata sur des hĂ©moglobines falciformes et d’identifier les principes actifs Ă  l’origine de cette activitĂ©. La mĂ©thode employĂ©e Ă©tudie la rĂ©versibilitĂ© des drĂ©panocytes, en fonction du temps d’incubation des extraits par rapport aux tĂ©moins (eau physiologique, phĂ©nylalanine et arginine) sur des Ă©chantillons de sang de patients drĂ©panocytaires homozygotes. Des concentrations de 0,05; 0,5; 5 et 10 mg/ml de quatre extraits (mĂ©thanol, hexane, acĂ©tate d’éthyle et mĂ©thanol rĂ©siduel) ont Ă©tĂ© mises en contact avec des drĂ©panocytes de type SS aprĂšs avoir provoquĂ© leur falciformation avec une solution Ă  2% de mĂ©tabisulfite de sodium. L’évaluation a Ă©té effectuĂ©e toutes les 30 minutes pendant 120 minutes. Les diffĂ©rents extraits ont montrĂ© une activitĂ© dosedĂ©pendante sur la rĂ©versibilitĂ© de la falciformation des globules rouges avec plus de 80% d’inversion en 120 minutes pour l’extrait mĂ©thanolique, le plus actif. Un screening phytochimique a permis de faire une corrĂ©lation entre les flavonoĂŻdes et l’activitĂ© antifalcĂ©miante des extraits de Leptadenia hastata.Mots clĂ©s : DrĂ©panocytose, hĂ©moglobine, activitĂ© antifalcĂ©miante, Leptadenia hastata, flavonoĂŻdes

    Ureteroscopie Retrograde: ExpĂ©rience de l’HĂŽpital GĂ©nĂ©ral Grand Yoff de Dakar

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    But: PrĂ©senter les rĂ©sultats de la pratique de l’urĂ©tĂ©roscopie Ă  l’HĂŽpital GĂ©nĂ©ral Grand Yoff (HOGGY) de Dakar (SĂ©nĂ©gal).Sujets et mĂ©thodes: Il s’agit d’une Ă©tude descriptive de 91 urĂ©tĂ©roscopies effectuĂ©es dans le service d’Urologie de l’HĂŽpital GĂ©nĂ©ral Grand Yoff de janvier 2012 Ă  dĂ©cembre 2013. Les variables de l’étude étaient l’indication, l’ñge, la nature de l’urĂ©tĂ©roscopie associĂ©es ou non au laser, les rĂ©sultats de la lithotripsie.RĂ©sultats: Sept urĂ©tĂ©roscopies diagnostiques et 84 urĂ©tĂ©roscopies thĂ©rapeutiques ont Ă©tĂ© effectuĂ©es. L’ñge moyen des patients Ă©tait de 44,7 ans + - 13,9 ans. L’urĂ©tĂ©roscope semi rigide a Ă©tĂ© utilisĂ© dans 43 cas, l’urĂ©tĂ©roscope souple dans 15 cas, l’urĂ©tĂ©roscope rigide dans 9 cas. La topographie du calcul Ă©tait pyĂ©lique dans 30 cas, lombaire dans 28 cas, pelvienne dans 13 cas, calicielle dans 10 cas et iliaque dans 3 cas. Le nombre de calcul fragmentĂ© au laser Ă©tait de 87 calculs. Les complications Ă©taient dominĂ©es par les fausses routes dans 8 cas. Le succĂšs global de l’urĂ©tĂ©roscopie Ă©tait de 85,7%.Conclusion: La pratique courante de l’urĂ©tĂ©roscopie constitue un dĂ©fi pour l’urologue en Afrique subsaharienne. Elle est devenue le traitement de choix de la lithiase de la voie excrĂ©trice supĂ©rieure.Mots clĂ©s: ithiase; UrĂ©tĂ©roscopie; Laser; Sonde JJEnglish AbstractObjective: To present the results of the ureteroscopy at the GrandYoff General Hospital (Hoggy) in Dakar (Senegal).Subjects and methods: This is a descriptive study of 91 ureteroscopy procedures performed at the Urology department of Grand Yoff General Hospital from January 2012 to December 2013. The variables of the study were indication, age, type of ureteroscopy associate or no laser, results of lithotripsy.Results: Seven diagnostic ureteroscopy and 84 therapeutic ureteroscopy were done. The average age of the patients was 44.7 years + - 13,9 years. Semi-rigid ureteroscope was used in 43 cases, flexible ureteroscope in 15 cases and rigid ureteroscope in 9 cases. The location of the stones was renal pelvis in 30 cases, upper ureter in 28 cases, distal ureter in 13 cases, calix in 10 cases and middle ureter in 3 cases. The number of laser (Nd:Yag) fragmented stones was 87. Complications were dominated by false passages in 8 cases. The overall success of endoscopic treatment was 85.7%.Conclusion: The current practice of endoscopic treatment for upper urinary tract stone is quite challenging to the urologist practising in sub- Sahara Africa. The effectiveness and lesser morbidity of laser lithotripsy has made it the treatment of choice for upper urinary tract stones.Keywords: Lithiasis; Ureteroscopy; Laser; JJ sten

    Correlated Strength in Nuclear Spectral Function

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    We have carried out an (e,e'p) experiment at high momentum transfer and in parallel kinematics to measure the strength of the nuclear spectral function S(k,E) at high nucleon momenta k and large removal energies E. This strength is related to the presence of short-range and tensor correlations, and was known hitherto only indirectly and with considerable uncertainty from the lack of strength in the independent-particle region. This experiment confirms by direct measurement the correlated strength predicted by theory.Comment: 4 pages, 2 figures, accepted by Phys. Rev. Let
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