1,075 research outputs found

    Labor Camp Surveys in GCC Countries: Group Quarter Subsampling

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    The Gulf Cooperation Council is a regional cooperation of six Middle Eastern countries-Saudi Arabia, Kuwait, the United Arab Emirates, Qatar, Bahrain, and Oman. A common feature of these countries is the existence of many group quarters, usually called labor camps, a term used to refer to housing accommodations for unskilled migrants where nonrelated people live together. The camp size ranges from a few people to a few thousand people from many different countries who speak dozens of languages. Also, the camp size and the composition of residents inside the camps change relatively quickly as people move in and out of the camps as their labor contracts expire or project needs change. This article presents one way to subsample this dynamic population inside such labor camps. The technique was used in one survey conducted in Qatar, where more than half of the country's population resides in labor camps

    Effect of Deep-Fat Frying on Chemical Properties of Edible Vegetable Oils Used By Senegalese Households

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    Deep-fat frying performed at high temperatures under atmospheric pressure is a common method of preparing dishes in Senegalese culinary practices. This operation can lead to deterioration of physical, chemical, nutritional and sensory properties of oil, which affects its frying performance. It also results in the production of volatile products such as aldehydes and non volatile fraction which remains in the frying medium. Some of these remaining products have been implicated in producing adverse health effects. Highly oxidized oils may also produce polyaromatic hydrocarbons, which have carcinogenic effect. This work was intended to evaluate the effect of frying on chemical properties of edible vegetable oils. Frying process was applied to meat, fish and potatoes in Senegalese culinary conditions. Ten (10) oil samples, each of three different brands, were purchased from wholesalers and retailers in different neighborhoods of Dakar. The samples were subjected to frying at 220°C for 40 min and then oils were withdrawn in amber bottles samples of which were taken for analysis. Acid value, peroxide value and total polar components were used to evaluate the quality of these oils after initial determination of the iodine value and the moisture and volatile matter content. Acid value increased after 40 min of frying and values ranged from 0.62 to 1.08 mg/kg after frying fish, while those for meat and potatoes ranged from 0.39 to 0.73 and 0.37 to 0.51 mg/kg, respectively. Peroxide value increased slightly for peanut oil (A) and sharply for peanut oil (B) and sunflower oil (C). Frying fish led to high values of total polar components whereas those obtained after frying meat and potatoes during 40 min did not exceed 15.27% except for peanut oil (A). Therefore, frying affects chemical parameter values of edible vegetable oils, which increase at a level depending on the product to be fried. A sharp Total Polar components increase was obtained after frying fish using the three types of oil with values exceeding, sometimes, the maximum level set by the Codex Alimentarius Commission. This latter chemical parameter is considered a good indicator of overall quality of frying oil. Thus in Senegalese culinary practices where frying oil is often reused in families with low-income, such a situation may lead to significant sanitary risks. In view of these results, investigations need to be extended to other types of oil marketed in Senegal.Keywords: edible-oils, quality, frying, fish, mea

    CDS calibration under an extended JDCEV model

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    We propose a new methodology for the calibration of a hybrid credit-equity model to credit default swap (CDS) spreads and survival probabilities. We consider an extended Jump to Default Constant Elasticity of Variance model incorporating stochastic and possibly negative interest rates. Our approach is based on a perturbation technique that provides an explicit asymptotic expansion of the CDS spreads. The robustness and efficiency of the method is confirmed by several calibration tests on real market data

    Etude ethnobotanique des plantes utilisées contre la constipation chez les Malinké de la communauté rurale de Tomboronkoto, Kédougou (Sénégal)

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    La constipation est une pathologie bien connue de la médecine traditionnelle africaine. Pour la traiter, on utilise à la fois les ressources naturelles aujourd’hui fortement menacées et les savoirs traditionnels. La technique des entretiens ouverts semi-structurés a été partout utilisée. Nous avons interrogé entre 2008 et 2010 des tradithérapeutes et des chefs de ménage Malinké de la communauté rurale de Tomboronkoto. Nos investigations ont permis de recenser dix-huit espèces utilisées contre la constipation. Elles sont constituées de dix-huit genres répartis dans quatorze familles dont les mieux représentées sont les Bombacaceae (3 espèces), les Apocynaceae et les Euphorbiaceae (2 espèces chacune). Les espèces les plus citées sont successivement Combretum glutinosum Perr. ex DC, Tamarindus indica L., Adansonia digitata L., Ozoroa insignis Delile et Hibiscus sabdariffa L. Les feuilles (32%) et les racines (27%) sont les organes les plus utilisés contre la constipation. La macération est le mode de préparation le plus courant et la décoction est réservée aux feuilles. Les noms en Malinké de toutes les espèces inventoriées ont été donnés mais, l’étymologie ou la signification de 22% des noms locaux n’a pu être recueillie. Il y aurait une perte des savoirs relatifs aux noms locaux. Cette dénomination a mis en évidence plusieurs démarches utilisées par les Malinké pour nommer les plantes. Les noms des espèces recensées renvoient le plus souvent à l’écologie (29%), à la morphologie et à des anecdotes (22% chacun).Mots clés: Ethnobotanique, constipation, plantes médicinales, guérisseur traditionnel, pharmacopée sénégalais

    Unveiling induced folding of intrinsically disordered proteins – Protein engineering, frustration and emerging themes

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    Intrinsically disordered proteins (IDPs) can be generally described as a class of proteins that lack a well-defined ordered structure in isolation at physiological conditions. Upon binding to their physiological ligands, IDPs typically undergo a disorder-to-order transition, which may or may not lead to the complete folding of the IDP. In this short review, we focus on some of the key findings pertaining to the mechanisms of such induced folding. In particular, first we describe the general features of the reaction; then, we discuss some of the most remarkable findings obtained from applying protein engineering in synergy with kinetic studies to induced folding; and finally, we offer a critical view on some of the emerging themes when considering the structural heterogeneity of IDPs vis-Ă -vis to their inherent frustration

    Pan-Africanism: a contorted delirium or a pseudonationalist paradigm? Revivalist critique

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    This essaic-article goes against established conventions that there is anything ethno-cultural (and hence national) about the so-called African tribes. Drawing largely from the culture history of precolonial/prepolitical Africans—that is, the Bantu/Cushitic-Ethiopians (Azanians)—the author has demonstrated vividly that far from being distinct ethno-culture national communities, the so-called tribes of African states are better considered subculture groups, whose regional culture practices erstwhile paid tribute to their nation’s main culture center in Karnak. For example, using the culture symbols and practices of some local groups and linking them to the predynastic and dynastic Pharaonic periods, I argued that there is compelling evidence against qualifying Africa’s tribes as distinct ethno-culture national entities. In genuine culture context, I stressed that the Ritual of Resurrection and its twin culture process of the mummification of deceased indigenous Pharaohs tend to suggest that the object of the Bantu/Cushitic-Ethiopians national culture was life (in its eternal manifestation) and then resurrection later, and that there are recurring (culturally sanctioned) ethical examples among the culture custodians of these subculture groups that generally pay tribute to the overarching culture norm. Furthermore, the fact that the Ritual of Resurrection began in the Delta region and ended at the Sources of the Nile, where the spirit of the deceased indigenous Pharaohs was introduced into the spiritual world of their ancestors, contradicts conventional perceptions that ancient Egypt was a distinct national community isolated from precolonial/prepolitical Africa/Azania

    Metallization of the C-60/Rh(100) interface revealed by valence photoelectron spectroscopy and density functional theory calculations

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    The electronic structure of single and multiple layers of C(60) molecules deposited on a Rh(100) surface is investigated by means of valence photoemission spectroscopy and density functional theory calculations. The binding of the fullerene monolayer to the metal surface yields the appearance of a new state in the valence band spectrum crossing the Fermi level. Insight into the metallization of the metal/fullerene interface is provided by the calculated electronic structure that allows us to correlate the measured interface state with a strong hybridization between the Rh metal states and the highest and lowest molecular orbitals. This results in a net charge transfer of approximate to 0.5e-0.6e from the metal to the p states of the interfacial C atoms. The charge transfer is shown to be very short range, involving only the C atoms bound to the metal. The electronic structure of the second C(60) layer is already insulating and resembles the one measured for C(60) multilayers supported by the same substrate or calculated for fullerenes isolated in vacuum. The discussion of the results in the context of other C(60)/metal systems highlights the distinctive electronic properties of the molecule/metal interface determined by the Rh support

    Composition chimique et propriétés antibactériennes des huiles essentielles d’Ocimum basilicum et d’Hyptis suaveolens (L.) Poit récoltés dans la région de Dakar au Sénégal

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    Les huiles essentielles des feuilles d’Ocimum basilicumet d’Hyptis suaveolens, récoltées dans la région de Dakar au Sénégal ont été extraites par entraînement à la vapeur et analysées en CPG et CPG-SM. Les monoterpènes oxygénés dont l’estragol (38,78 %), le linalol (19,45 %) et le méthyl-eugénol (9,98 %) sont majoritaires dans l’huile essentielle d’O. basilicum. Ils sont suivis d’un sesquiterpène hydrocarboné: le bergamotène (8,48 %). Par contre, l’huile essentielle de H. suaveolensest essentiellement constituée de composés hydrocarbonés: le β-caryophyllène (16,63 %), le sabinène (11,30 %), le terpinolène (8,58 %), le limonène (8,45 %) et le bergamotène (5,26 %). Les propriétés antimicrobiennes des huiles essentielles de ces plantes ont été testées in vitro sur cinq souches bactériennes (Staphylococcus aureus, Bacillus sp.,Salmonella sp., Escherichia coli, Streptococcus sp.). Une activité inhibitrice des huiles sur les souches étudiées a été observée. Toutefois, celle d’O.basilicums’est révélée plus active, particulièrement contre Bacillus sp., Salmonella sp., et Escherichia coli.Mots-clés: Ocimum basilicum, Hyptis suaveolens, huiles essentielles, composition chimique, propriétés antimicrobiennes. Chemical composition and antimicrobial properties of the essential oils of Ocimum basilicum andHyptis suaveolensharvested from Dakar region in SenegalEssential oils of leaves from Ocimum basilicum and Hyptis suaveolens collected in the region of Dakar in Senegal have been extracted by steam distillation and analyzed by GC and GC-MS. The oxygenated monoterpenes which estragol (38.78%), linalool (19.45%) and methyl-eugenol (9.98%) constitute the major portion of the essential oils of O. basilicum followed by bergamotene (8.48%) which is a sesquiterpene hydrocarbon. Principal compounds of H.suaveolens essential oilsare: β-caryophyllene (16.63%), sabinene (11.30%), terpinolene (8.58%), limonene (8.45%) and bergamotene (5.26%).The antimicrobial properties of essential oils of these plants were tested in vitro against five bacterial strains (Staphylococcus aureus, Bacillussp, Salmonella sp., Escherichia coli, Streptococcus sp.). The inhibitory activity of the oils on the strains studied was observed. However, the essential oil of O. basilicum was more active, especially against Bacillus sp., Salmonella sp. and Escherichia coli.Keywords: Ocimum basilicum, Hyptis suaveolens, essential oils, chemical composition, antimicrobial properties
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