822 research outputs found

    Molecular characterization and expression of DERL1 in bovine ovarian follicles and corpora lutea

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    The endoplasmic reticulum (ER) is a major site of protein synthesis and facilitates the folding and assembly of newly synthesized proteins. Misfolded proteins are retrotranslocated across the ER membrane and destroyed at the proteasome. DERL1 is an important protein involved in the retrotranslocation and degradation of a subset of misfolded proteins from the ER. We characterized a 2617 bp cDNA from bovine granulosa cells that corresponded to bovine DERL1. Two transcripts of 3 and 2.6 kb were detected by Northern blot analysis, and showed variations in expression among tissues. During follicular development, DERL1 expression was greater in day 5 dominant follicles compared to small follicles, ovulatory follicles, or corpus luteum (CL). Within the CL, DERL1 mRNA expression was intermediate in midcycle, and lowest in late cycle as compared to early in the estrous cycle. Western blot analyses demonstrated the presence of DERL1 in the bovine CL at days 5, 11, and 18 of the estrous cycle. Co-immunoprecipitation using luteal tissues showed that DERL1 interacts with class I MHC but not with VIMP or p97 ATPase. The interaction between DERL1 and MHC I suggests that, in the CL, DERL1 may regulate the integrity of MHC I molecules that are transported to the ER membrane. Furthermore, the greater expression of DERL1 mRNA is associated with the active follicular development and early luteal stages, suggesting a role of DERL1 in tissue remodeling events and maintenance of function in reproductive tissues

    Risk Factors for Dementia in a Senegalese Elderly Population Aged 65 Years and Over

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    Background: With the aging of the population, dementia is increasing worldwide. The objective of this study was to identify risk factors for dementia in an elderly population utilizing a primary health care service in Dakar, Senegal. Methods: Through a cross-sectional study conducted from March 2004 to December 31, 2005, 507 elderly patients aged ≥65 years who came to the Social and Medical Center of IPRES, Dakar, Senegal, were first screened with the screening interview questionnaire ‘Aging in Senegal’. Those who were cognitively impaired underwent a clinical examination to detect dementia. Univariate, bivariate, and multivariate logistic regression analyses were done. Results: The whole population had a mean age of 72.4 years (±5.2) and was mostly male, married, and non-educated. Hypertension, arthritis, and gastrointestinal diseases were the main health conditions reported in the past medical history. Smoking was important while alcohol consumption was rare. Social network was high. Forty-five patients (8.87%) had dementia. In the multivariate model, only advanced age, education, epilepsy, and family history of dementia were independently associated with dementia. Conclusion: The risk factors identified are also found in developed countries confirming their role in dementia. It is important to take dementia into consideration in Senegal and to sensitize the community for prevention

    The Special Atom Space and Haar Wavelets in Higher Dimensions

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    In this note, we will revisit the special atom space introduced in the early 1980s by Geraldo De Souza and Richard O\u27Neil. In their introductory work and in later additions, the space was mostly studied on the real line. Interesting properties and connections to spaces such as Orlicz, Lipschitz, Lebesgue, and Lorentz spaces made these spaces ripe for exploration in higher dimensions. In this article, we extend this definition to the plane and space and show that almost all the interesting properties such as their Banach structure, Hölder\u27s-type inequalities, and duality are preserved. In particular, dual spaces of special atom spaces are natural extension of Lipschitz and generalized Lipschitz spaces of functions in higher dimensions. We make the point that this extension could allow for the study of a wide range of problems including a connection that leads to what seems to be a new definition of Haar functions, Haar wavelets, and wavelets on the plane and on the space

    Surveying the field

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    Three-dimensional arrangement of β-tricalcium phosphate granules evaluated by microcomputed tomography and fractal analysis.

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    The macrophysical properties of granular biomaterials used to fill bone defects have rarely been considered. Granules of a given biomaterial occupy three-dimensional (3-D) space when packed together and create a macroporosity suitable for the invasion of vascular and bone cells. Granules of β-tricalcium phosphate were prepared using polyurethane foam technology and increasing the amount of material powder in the slurry (10, 11, 15, 18, 21 and 25g). After sintering, granules of 1000-2000μm were prepared by sieving. They were analyzed morphologically by scanning electron microscopy and placed in polyethylene test tubes to produce 3-D scaffolds. Microcomputed tomography (microCT) was used to image the scaffolds and to determine porosity and fractal dimension in three dimensions. Two-dimensional sections of the microCT models were binarized and used to compute classical morphometric parameters describing porosity (interconnectivity index, strut analysis and star volumes) and fractal dimensions. In addition, two newly important fractal parameters (lacunarity and succolarity) were measured. Compression analysis of the stacks of granules was done. Porosity decreased as the amount of material in the slurry increased but non-linear relationships were observed between microarchitectural parameters describing the pores and porosity. Lacunarity increased in the series of granules but succolarity (reflecting the penetration of a fluid) was maximal in the 15-18g groups and decreased noticeably in the 25g group. The 3-D arrangement of biomaterial granules studied by these new fractal techniques allows the optimal formulation to be derived based on the lowest amount of material, suitable mechanical resistance during crushing and the creation of large interconnected pores

    Cordyla pinnata améliore les propriétés du sol et la productivité des cultures

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    Dans les systèmes agroforestiers, les cultures sous le couvert des arbres (SC) bénéficient de plus de nutriments, après décomposition et minéralisation des litières, que celles hors de leur couvert (HC). La fertilité des sols et la productivité du mil et de l’arachide ont été évaluées sur des sols prélevés à différentes distances de Cordyla pinnata, une légumineuse arborée qui forme un parc agroforestier au Sénégal. Les analyses de sols ont montré des valeurs plus élevées pour N total, Ca échangeable et CEC sous le couvert de l’espèce. Pour le mil, la hauteur, les biomasses aérienne et racinaire ont également été plus élevées sur les sols SC. Par conséquent, la biomasse totale du mil a fortement augmenté (+ 90%) sur les sols SC. Pour l’arachide, la longueur totale, les biomasses (tiges, feuilles, gousses, racines) ont été supérieures sur les sols SC. Comme pour le mil, la biomasse totale de l’arachide a augmenté (+ 94%) sur les sols SC par rapport au découvert. La plupart des variables des cultures ont été plus élevées sur les sols SC, probablement à cause de leur meilleur statut nutritif. L’introduction des arbres dans les systèmes de production au Sahel pourrait ainsi constituer une bonne stratégie pour améliorer la fertilité des sols et contribuer au développement d’une agriculture durable.Mots clés: Arachide, Fertilité des sols, Mil, Parc agroforestier, Sénéga

    Efficiency of Traditional Maize Storage and Control Methods in Rural Grain Granaries: a Case Study from Senegal

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    Maize storage and pest control method as practiced in traditional clay granaries in the Kédougou region in eastern Senegal were evaluated under rural conditions during two successive years. Three storage modes, i.e. maize cobs, winnowed and non-winnowed maize grains, were tested in seven granaries where the insecticidal plants Hyptis spicigera or H. suaveolens were either incorporated in the store structure or deposited as layers intermittently with maize. At the beginning of the storage period, all granaries were artificially infested with 7 pairs Tribolium castaneum and Sitophilus zeamais. No damage, losses or live insects were observed during 7 months of storage when maize cobs were placed between layers of H. spicigera. Compared with the control, incorporation of insecticidal plants within the granary bottom had no significant effect on the damage and loss level irrespective of the storage mode. Non-winnowed maize always suffered less damage and losses than the winnowed variant. In all granaries depredation, insect abundance and moisture content were highest toward the end of storage period between June and July

    Assessment of Rice Inbred Lines and Hybrids under Low Fertilizer Levels in Senegal

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    This research was conducted at the Africa Rice Sahel Regional Station (near Saint Louis, Senegal) during two wet seasons (i.e., July to November) in 2010 and 2011 with the aim of assessing the performances of introduced hybrid cultivars along with an inbred check cultivar under low input fertilizer levels. The five treatments used in this study were (a) the control (without any fertilizer application), (b) 37.5-4.4-8.3 kg N-P-K ha(-1), (c) half of recommend application in Senegal (75-8.75-16.5 kg N-P-K ha(-1)), (d) 112.5-13.3-24.8 kg N-P-K ha(-1), and (e) the recommended application in the country (150-17.5-33 kg N-P-K ha(-1)). There were significant year and cultivar effects for all traits. The fertilizer levels affected significantly most traits except panicle length and 1000-grain weight. The year x fertilizer level and year x cultivar interactions were significant for most traits, but the fertilizer level x cultivar and year x fertilizer level x cultivar interactions were not significant. Days to maturity, plant height, panicle per m2, and grain yield increased with increasing fertilizer levels during the two wet seasons. The grain yield of rice hybrids (bred by the International Rice Research Institute) was not significantly higher than that of the check cultivar widely grown in Senegal. The assessment of other rice hybrid germplasm showing more adaptability to low fertilizer levels will facilitate further hybrid cultivar development in Africa

    Etude clinique et épidémiologique du paludisme en zone urbaine d'Afrique soudano-sahélienne (Pikine-Sénégal)

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    Pour des raisons de coût et de tolérance, la chimiothérapie présomptive repose toujours essentiellement sur la chloroquine, malgré l'apparition, il y a dix ans en Afrique de l'Est, de souches de #Plasmodium falciparum$ résistantes à la chloroquine et leur extension à l'ensemble de l'Afrique intertropicale. Dans le cas des zones urbaines, plusieurs particularités épidémiologiques du paludisme suggèrent qu'à partir de certains niveaux de chimiorésistance d'autres stratégies de lutte anti paludique pourraient être développées avec un meilleur rapport coût/efficacité. Dans une première approche de cette question, une recherche a été faite à Pikine, à savoir s'il existait des paramètres cliniques ou épidémiologiques, faciles à obtenir chez un enfant consultant pour fièvre, qui permettraient de choisir entre trois attitudes possibles : abstention thérapeutique, traitement présomptif, confection d'une goutte épaiss
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