Dynamics of plasma blobs in a shear flow

The global dynamic of plasma blobs in a shear flow is investigated in a simple magnetized torus using the spatial Fourier harmonics (k-space) framework. Direct experimental evidence of a linear drift in k space of the density fluctuation energy synchronized with blob events is presented. During this drift, an increase of the fluctuation energy and a production of the kinetic energy associated with blobs are observed. The energy source of the blob is analyzed using an advection-dissipation-type equation that includes blob-flow exchange energy, linear drift in k space, nonlinear processes, and viscous dissipations. We show that blobs tap their energy from the dominant E B vertical background flow during the linear drift stage. The exchange of energy is unidirectional as there is no evidence that blobs return energy to the flow

Caractérisation agropédologique des sols de mboltime dans la zone des niayes (Sénégal)

L'objectif de cette étude était de faire une évaluation de la fertilité physico-chimique de différents sols du village de Mboltime et de déterminer les similarités relatives. Les horizons de cinq fosses pédologiques (P1 , P2, P3, P4 et P5) ouvertes dans les zones dunaires et inter-dunaires ont servi à cet effet. Les résultats obtenus ont montré que les horizons de surface sont sableux à sablo-limoneux avec des pH et conductivité électrique variant selon les profils et les horizons. Seul le profil P4 a montré des sols acides et salés au niveau des horizons P4H1, P4H3 et P4H5. Les autres profils ont montré des sols neutres à légèrement alcalins et non salins. Les teneurs en matière organique et azote total ont été assez faibles dans les profils 1, 2, 3 et 5, et moyens dans le profil 4 avec un rapport C/N variant de 2,72 à 16,50. Les teneurs en Ca2+, Mg2+, Na+ et K+ varient suivant le C et N. Le cation le plus abondant dans les sols a été le Ca2+; suivi du Mg2+ et du Na+ alors que K+ a été le cation le moins abondant. L'analyse factorielle des correspondances (AFC) a permis de mettre en évidence deux groupes de sols en fonction de la salinité et de l'acidité. Un groupe I constitué de sols très salins et un groupe II constitué de sols non salins. Cette étude a mis en évidence deux contraintes majeures à la production végétale dans le village de Mboltime que sont la salinité et l'acidité des sols.Mots clés : Sol, Profil pédologique, Niayes, salinite ; Sénégal AGROPEDOLOGICAL CARACTERIZATION OF MBOLTIME SOILS IN NIAYES AREA (SENEGAL)The objective of this study was to evaluate physico - chemical properties of different soils from Mboltime village and relevant similarities. Horizons of five soil profiles (P1, P2, P3, P4 and P5) in the dune and inter-dune areaswere used for that purpose. The results showed variance in topsoil contents of sand with silt- loam, pH and electric conductivity according to the  profiles. Only the P4 profile presents acid and salty soil to the level asof horizons P4H1, P4H3 and P4H5. The other profiles presented neutral to slightly alkaline soil pH with limited salinity. The soil contents of organic matter, and total nitrogen were rather weak in the profiles 1, 2, 3 and 5, and moderate in profile 4. The C/N ratio values varied from 2.72 to 16.50 while soil contents of Ca2+, Mg2+, Na+ and K+ variations were according to C and N. The most abundant cations in land was Ca2+; followed by Mg2+, Na+ and K+ was the least abundant cationin soils. The factorial  correspondence analysis (FCA) showed two groups of soil according to  salinity and acidity mainly depending to high and low salinity respectively. This study showed two major constraints to land productivity in the village of Mboltime which are the salinity and the acidity of soils.Keywords : Soil, soil profile, salinity, Niayes, Senega

Marker assisted introgression of opaque2 gene into herbicide resistant elite maize inbred lines

Marker assisted selection in combination with conventional breeding can greatly accelerate the introgression of modified opaque2 genotype into herbicide resistant maize. By combining these two approaches, time and costs are greatly minimized. The application of opaque2 allele specific SSR markers was done on materials already undergoing selection in a breeding program for converting herbicide resistant maize lines into quality protein maize (QPM) which is the equivalent of modified opaque2 phenotype. The breeder had selected QPM lines using the light table in the previous cycle and we used leaf samples to extract DNA for analysis of the presence of the opaque2 gene using SSR markers. Two co-dominant SSR markers phi057 and umc1066 and a dominant marker phi112 were used. Umc1216, a modifier marker was also tested in combination with the opaque2 markers with theobjective of using the marker to select for modifiers for the opaque2 phenotype. The modified FTA paper technology protocol was applied in field sampling. The results showed 97% of the lines wereopaque2 while 3% were non-opaque2. Both methods of conventional breeding using light table and marker assisted selection (MAS) were comparable. However, the application of SSR markers and theFTA technology offers the breeder a fast, time saving, reliable and less labour intensive method of screening QPM maize during the early growing stages instead of having to wait to screen the kernels onthe light table after harvesting. Moreover, the routine biochemical analysis for high lysine and tryptophan levels need not be carried out at each backcross since the presence of the opaque2 gene is confirmed with markers

Evaluation des modes de preparation et de consommation de la tisane de kinkeliba et du cafe touba consommes dans la ville de Dakar au Senegal

As a consequence of societies’ evolution, food habits are changing and resulting in serious issues. Consumers are experiencing new foods and new ways of consuming traditional ones. Café Touba and kinkeliba are important beverages in Senegalese diet. Kinkeliba herbal tea is made of a decoction of dry leaves of Combretum micranthum. Café Touba is made by pouring hot water over roasted, ground coffee (Coffea robusta) and Xylopia aethiopica beans through a filter container. Sugar is added to the beverages, which are generally consumed in breakfast or sold in the streets or in small restaurants called Tangana. Many Senegalese, especially the young, are involved into the business. In this study, a survey was conducted in houses, streets and Tangana where the Café Touba and kinkeliba are prepared, consumed or sold. The objective of the survey was to determine methods of preparation and consumption of two local brews in Dakar. Sixty (60) questionnaires were given to the target people to assess the preparation methods and the amount of drinks consumed. Standard methods of preparation of Café Touba and kinkeliba were defined. From these methods, drinks were prepared and used to determine the tannins contents. The added sugar and energy taken for one portion size were also determined. The results showed differences in preparing methods and drinking habits of Café Touba and kinkeliba. The house-made Café Touba was more concentrated than the one prepared and sold in streets or in Tangana. Total dry leaves used for preparing the house-made kinkeliba or sold in streets or in Tangana were similar. Unlike the kinkeliba, the amount of Café Touba consumed in houses for one serving was higher than that in Tangana or in streets. These drinks could be good sources of tannins which have important therapeutic proprieties. However, Café Touba and kinkeliba drinkers could be exposed to an excessive added sugar consumption. In conclusion, Café Touba and kinkeliba are drinks that are well consumed by Senegalese. Promoting these local brews could improve nutrition and health of consumers. However, the high amount of added sugar in these drinks could increase the risk of chronic diseases.Keywords: Café Touba, Kinkeliba, Tannins, Household, Sellers, Cups, Drinks, Breakfast, Suga

Caractérisation des peuplements ligneux de la zone Cayor Baol (Thiès-Sénégal)

Cette étude se propose de déterminer la composition floristique et la structure des peuplements ligneux dans trois localités de la région de Thiès (Fandène, Mont Rolland et Sessène). Sur un transect orienté Nord/Sud, partant de Mont Rolland à Sessène, un inventaire floristique et des relevés dendrométriques ont été effectués en fonction des unités morphopédologiques. Le traitement statistique des données recueillies a montré que la flore ligneuse, dans ces 3 sites, est riche de 35 espèces réparties en 30 genres appartenant à 20 familles. La famille des  Mimosaceae est la mieux représentée, suivie des Caesalpiniaceae, des Combretaceae et des Anacardiaceae. La richesse floristique varie suivant les sites. La surface terrière est plus élevée au Mont Rolland, le  recouvrement et la densité sont plus importants à Fandène. La distribution du peuplement selon la circonférence est homogène à Fandène,  contrairement à Sessène et à Mont Rolland. Quant à la distribution selon la hauteur des individus, elle montre une prédominance de la strate arbustive dans les 3 sites. Les analyses de régression ont montré une corrélation entre la circonférence et la hauteur. La pression anthropiquesur la strate ligneuse est plus importante à Sessène, moyenne au Mont Rolland et faible à Fandène. L’AFC montre une forte hétérogénéité des peuplements ligneux. Elle a révélé l’existence de 3 groupements en  étroite relation avec les facteurs édaphologiques.© 2013 International Formulae Group. All rights reserved.Mot clés : Thiès, ligneux, flore, structure, groupement

Addition of H_2O and O_2 to Acetone and Dimethylsulfoxide Ligated Uranyl(V) Dioxocations

Gas-phase complexes of the formula [UO_2(lig)]^+ (lig = acetone (aco) or dimethylsulfoxide (dmso)) were generated by electrospray ionization (ESI) and studied by tandem ion-trap mass spectrometry to determine the general effect of ligand charge donation on the reactivity of UO_2^+ with respect to water and dioxygen. The original hypothesis that addition of O_2 is enhanced by strong σ-donor ligands bound to UO_2^+ is supported by results from competitive collision-induced dissociation (CID) experiments, which show near exclusive loss of H_2O from [UO_2(dmso)(H_2O)(O_2)]^+, whereas both H_2O and O_2 are eliminated from the corresponding [UO_2(aco)(H_2O)(O_2)]^+ species. Ligand-addition reaction rates were investigated by monitoring precursor and product ion intensities as a function of ion storage time in the ion-trap mass spectrometer: these experiments suggest that the association of dioxygen to the UO_2^+ complex is enhanced when the more basic dmso ligand was coordinated to the metal complex. Conversely, addition of H_2O is favored for the analogous complex ion that contains an aco ligand. Experimental rate measurements are supported by density function theory calculations of relative energies, which show stronger bonds between UO_2^+ and O_2 when dmso is the coordinating ligand, whereas bonds to H_2O are stronger for the aco complex

Effet protecteur des feuilles de Opilia celtidifolia contre l’ulcère induit par l’éthanol chez le rat

Opilia celtidifolia est une plante traditionnellement utilisée contre les plaies et l’ulcère gastro duodénal. Le but de ce travail était d’étudier l’activité antiulcéreuse des extraits aqueux de cette de la plante. Des extraits aqueux, total et épuisé, ont été préparés par décoction. Le décoté total a été testé à 100 et 200 mg/kg et le décocté épuisé à100 mg/kg. Le Sucralfate a été utilisé comme témoin positif à la dose de 1000 mg/kg et le groupe non traité a reçu de l’eau distillée à10 ml/kg. Les extraits ont été administrés par voie intragastrique, une heure après, 0,5 ml d’éthanol à 90% a été administré aux animaux pour provoquer l’ulcère pendant une heure. Après ce temps, les rats ont été sacrifiés. L’estomac de chaque rat a été ouvert pour observer et compter les ulcères. L’indice d’ulcère a été exprimé et le pourcentage de protection a été calculé. A 100mg/kg, le décocté épuisé a induit une protection de la muqueuse de 75%, contre 31% pour le décocté total. Le Sucralfate, utilisé comme témoin a présenté une protection de 87,50%. Ces résultats démontrent que les feuilles de Opilia celtidifolia peuvent intervenir dans le traitement de l’ulcère gastrique. La mise au point d’un phytomédicament contre l’ulcère gastrique à base des feuilles de cette plante est donc envisageable.Mots clés : Opilia celtidifolia, protection, ulcère gastrique

Cetacean research in Senegal 1995-97, an overview. Scientific Committee document SC/49/SM10, International Whaling Commission, Bournemouth, UK

Historically Senegal is the West-African nation with the best kept faunistical records for cetaceans. We found verifiable evidence for at least 18 species, but limited life history data. Quantified information on interactions with soaring coastal fisheries is wanting. Here we present preliminary results of recent field work in central and central-south Senegal, which aim was to help design a long-term research plan with Senegalese scientists, offer training and reinitiate data collecting.With limited monitoring we encountered evidence of dolphin by-catches but no wide-spread directed dolphin fishery. However the presence of tell-tale conditions including spreading acceptance for consumption of dolphin meat and indications of overexploitation of some fish stocks are known warning signs. Future efforts should cover larger areas and generally be more intensive. Three carcasses of Atlantic hump-backed dolphin Sousa teuszii found on Sangomar island had rope tied around the tailstock. Fishermen at Djifer and Joal-Fadiouth confirmed regular incidental takes and landings. In the Siné-Saloum delta, inshore S. teuszii and T. truncatus are probably the most affected species. Senegal’s EEZ waters support large industrial fisheries which may constitute an additional source of by-caught small cetaceans. We here document 21 new specimen records and a series of sightings. Dolphins occurring in the Casamance river and upstream in the salt-water canals of the Saloum delta are identified as T. truncatus