A GIS for the management of fisheries in West Africa: Preliminary application to the octopus stock in Senegal

A preliminary application of a Geographical Information System (GIS), based on a georeferenced database including data from commercial fishing and oceanographic surveys, and on geographical objects describingthe physical and juridical environment, trawl operations and artisanal fishing sites, is presented. An ArcView environment is used to show spatial and temporal phenomena. Seasonal distribution charts for Octopusvulgaris and for the main associated finfish species on the Senegalese continental shelf reveal that octopuses are particularly abundant on the deep part of the continental shelf off Casamance and the Grande Côteduring the cool season. Warm-season distribution seems to be more coastal. The results allow the interactions between artisanal and industrial fisheries and areas of potential conflicts to be identified. The intensity of these interactions for resource access and space allocation is highly correlated to season. The results also provide alternative explanations for fisheries management, e.g. on the degree of respect for or the relevance of the limitsof regulated fishing areas and spatial fishing unit strategies according to the main seasons

Chemical fluxes from time series sampling of the Irrawaddy and Salween Rivers, Myanmar

The Irrawaddy and Salween rivers in Myanmar deliver water fluxes to the ocean equal to ~ 70% of the Ganges–Brahmaputra river system. Together these systems are thought to deliver about half the dissolved load from the tectonically active Himalayan–Tibetan orogen. Previously very little data was available on the dissolved load and isotopic compositions of these major rivers. Here we present time series data of 171 samples collected fortnightly at intervals throughout 2004 to 2007 from the Irrawaddy and Salween at locations near both the river mouths, the up-stream Irrawaddy at Myitkyina, the Chindwin, a major tributary of the Irrawaddy and a set of 28 small tributaries which rise in the flood plain of the Irrawaddy between Yangon and Mandalay. The samples have been analysed for major cation, anion and 87Sr/86Sr ratios. The new data indicates that the Irrawaddy has an annual average Na concentration only a third of the widely quoted single previously published analysis. The Irrawaddy and Salween drain about 0.5% of global continental area and deliver about 3.3% of the global silicate-derived dissolved Ca + Mg fluxes and 2.6% of the global Sr riverine fluxes to the oceans. This compares with Ganges and Brahmaputra which deliver about 3.4% of the global silicate-derived dissolved Ca + Mg fluxes and 3.2% of the global Sr riverine fluxes to the oceans from about 1.1% of global continental area. The discharge-weighted mean 87Sr/86Sr ratio of the Irrawaddy is 0.71024 and the Salween 0.71466. The chemistry of the Salween and the Irrawaddy waters reflects their different bedrock geology. The catchment of the Salween extends across the Shan Plateau in Myanmar through the Eastern syntaxis of the Himalayas and into Tibet. The Irrawaddy flows over the Cretaceous and Tertiary magmatic and metamorphic rocks exposed along the western margin of the Shan Plateau and the Cretaceous to Neogene Indo-Burma ranges. The 87Sr/86Sr compositions of the Salween and Upper Irrawaddy (between 0.7128 and 0.7176) are significantly higher than the downstream Irrawaddy (0.7095 to 0.7108) and the Chindwin (0.7082 to 0.7095). The Irrawaddy and the Chindwin exhibit lower 87Sr/86Sr and Na/Ca ratios during and immediately post-monsoon, interpreted to reflect higher weathering of carbonate at high flow. The Salween exhibits higher 87Sr/86Sr ratios but lower Na/Ca ratios during the monsoon, interpreted to reflect higher inputs from the upper parts of the catchment in the Himalayas.The research was funded by the UK Natural Environmental Research Council grant NE/C513850/1.This is the final published version. It first appeared at: http://www.sciencedirect.com/science/article/pii/S0009254115000510#

Thermodynamic and Heat Transfer Properties of Al2O3 Nanolubricants

In vapor compression cycles, a small portion of the oil circulates with the refrigerant throughout the system components, while most of the oil stays in the compressors. In heat exchangers, the lubricant in excess penalizes the heat transfer and increases the pressure losses: both effects are highly undesired but yet unavoidable. Nanoparticles dispersed in the excess lubricant are expected to provide enhancements in heat transfer. While solubility and miscibility of refrigerants in polyolesters (POE) lubricant are well established knowledge there is a lack of information regarding if and how nanoparticles dispersed in the lubricant affect these two properties. This paper presents experimental data of solubility and miscibility of three types of Al2O3 nanolubricants with refrigerant R410A. The nanoparticles were dispersed in POE lubricant by using different surfactants and dispersion methods and the nanolubricants showed lower refrigerant R410A solubility than that of POE oil. High viscosity suspensions are expected to stabilize the nanoparticles and avoid clustering. This aspect was verified in the present paper for the Al2O3 nanolubricants and long term stability and the degree of agglomeration, when present, were measured. The data identified optimum combinations of surfactants to achieve stable and uniform nanolubricant dispersions for several months. Surfactants affected slightly the thermal conductivity, specific heat, viscosity, and solubility properties of the nanolubricants. The specific heats of the nanolubricants were lower than that of POE oil at temperatures from 0 to 20°C while they were similar at 40°C. Thermal conductivity ranged from 1.1 times higher at 5°C to 1.4 times higher at 40°C than that of POE lubricant. The viscosity was about 2.6 times higher at 5°C while it was similar to that of POE lubricant at 40°C. The thermal and transport properties data for three nanolubricants provided in this paper advance the basic understanding of nanoparticles interaction with R410A refrigerant and POE lubricant mixtures

1-(4-Methyl­benzo­yl)-3-{2-[3-(4-methyl­benzo­yl)thio­ureido]phen­yl}thio­urea

In the title compound, C24H22N4O2S2, the dihedral angles formed by the thio­ureido groups with the attached benzene ring are 43.81 (13) and 75.25 (13)°. The dihedral angle between the thio­ureido groups is 85.48 (10)°. The mol­ecule is stabilized by intra­molecular N—H⋯S, N—H⋯O and C—H⋯S hydrogen bonds. In the crystal, molecules are linked by intermolecular N—H⋯S hydrogen bonds together with C—H⋯π inter­actions

Rare association of Turner syndrome and Mayer-Rokitansky-Kuster Hauser syndrome

Turner syndrome and Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome is a rare association. The incidences of Turner and MRKH syndromes are estimated at 1/2000 and 1/4500 female births respectively. This is a 23-year-old patient, born of a consanguineous marriage, who was referred to us for exploration of primary amenorrhoea. The karyotype, performed three times, from peripheral blood lymphocytes was 45X0. The diagnosis of Turner syndrome associated with MRKH syndrome was retained

Etude de la variation de la végétation en milieux salé et acide au Sénégal

L’objectif de l’étude était de comprendre la variation de la végétation en milieux acide et salé. Larépartition de la végétation des sols sulfatés acides salés en fonction  de certains paramètres (pH, conductivité électrique ou CE, humidité du sol et texture des sols) a ainsi été étudiée dans les secteurs situés au Sud et au Nord du fleuve Saloum (Sénégal). Des relevés ont été effectués sur les différentes unités géomorphologiques (terrasses et dunes) suivant la méthode des grappes de superficies  graduelles. Au niveau de chaque surface de collecte, des échantillons de sol ont été prélevés à 6 cm de profondeur pour déterminer leur CE, pH, teneur en eau et texture. L’étude a mis en évidence la distribution de la végétation en fonction des unités géomorphologiques et des types de faciès ainsi que les changements des faciès écologiques à travers les distributions aires-espèces. L’analyse en composantes principales a montré le rôle important de la texture du sol sur le regroupement de la végétation en fonction des gammes de salinité, d’acidité et du taux d’humidité. La connaissance du mode de regroupement de la végétation en milieux acide et salé pourrait aider dans le choix du type d’aménagement pour régénérer les potentialités agronomiques de ces sols et leur  réintégration dans le système productif national.Mots clés: Acidité des sols, diversité biologique, humidité, salinité des sols, texture

Facteurs de risque de démence dans une population de personnes âgées sénégalaises

Description La démence est devenue un problème de santé publique. Dans le but d’une prévention, il est important de connaitre son épidémiologie au Sénégal. L’objectif de cette étude était d’identifier les facteurs de risque de démence dans une population de personnes âgées sénégalaises. MéthodesUne étude transversale a été réalisée du 01 Mars 2004 au 31 Décembre 2005 auprès d’une population de 872 personnes âgées de 55ans et plus utilisant le Centre Médicosocial et Universitaire de l’Institut de Prévoyance Retraite du Sénégal pour des soins. Par une étude en deux phases, des données sociodémographiques, sur le mode de vie, le réseau social, les antécédents ont été collectées à l’aide d’un questionnaire structuré complété par un examen clinique et une évaluation neuropsychologique. Le diagnostic de démence reposait sur des critères DSM IV-R

Imperforate hymen complicated by obstructive acute renal failure

Imperforate hymen is a rare malformation (1/ 1000 female births). It is diagnosed most often during puberty. Early diagnosis of hematocolpos and evacuation is necessary to avoid any consequences. We report a rare case of an imperforate hymen complicated with acute urinary retention,  hydronephrosis and renal failure in a 14-year-old girl to emphasize thepossible misdiagnosis and its possible consequences. This is the firstcase we encounter in our unit