Molecular evidence of incipient speciation within Anopheles gambiae s.s. in West Africa

We karyotyped and identified by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis Anopheles gambiae s.s. samples collected in several African countries. The data show the existence of two non-panmictic molecular forms, named S and M, whose distribution extended from forest to savannahs, Mosquitoes of the S and M forms are homosequential standard for chromosome-2 inversions in forest areas. In dry savannahs, S is characterized mainly by inversion polymorphisms typical of Savanna and Bamako chromosomal forms, while M shows chromosome-2 arrangements typical of Mopti and/or Savanna and/or Bissau, depending on its geographical origin. Chromosome-2 inversions therefore seem to be involved in ecotypic adaptation rather than in mate-recognition systems. Strong support for the reproductive isolation of S and M in Ivory Coast comes from the observation that the kdr allele is found at high frequencies in S specimens and not at all in chromosomal identical M specimens. However, the kdr allele does not segregate with molecular forms in Benin

Adiponectin, in contrast to leptin, is not associated with body mass index, waist circumference and HOMA-IR in subjects of a west-African population

Factors associated with plasma levels of adiponectin and leptin were studied in adult subjects without diabetes from Cotonou in Benin (West‐Africa). Seventy (70) men and 45 women were included in the study. Anthropometric variables were measured and a venous blood sample was drawn from each subject, after an overnight fasting period, for measurement of plasma glucose, insulin, leptin, and adiponectin levels. HOMA‐IR was determined to assess insulin resistance. Adiponectin and leptin levels were higher in women than in men (with adiponectin 18.48 ± 12.77 vs.7.8 ± 10.39 μg/mL, P < 0.0001, and leptin 30.77 ± 19.16 vs. 8.66 ± 8.24 ng/mL, P < 0.0001). Fasting insulin level and HOMA‐IR were also higher in the females. Hyperleptinemia was observed in 66,96% of subjects and hypoadiponectinemia was present in 44.35% of subjects. In both men and women, leptin correlated with age (r = 0.2; P = 0.02), BMI (r = 0.572; P < 0.0001), waist circumference (r = 0.534; P < 0.0001), fasting insulin (r = 0.461; P < 0.001), and HOMA‐IR (r = 0.430; P < 0.0001). No significant correlation was observed for adiponectin levels with these variables. Only in women, adiponectin was inversely correlated with fasting glucose (r = −0.423; P < 0.004). These data confirm previous descriptions of leptin but suggest that variations in factors determining serum adiponectin levels observed between ethnicities could also been seen between populations from the same ethnicity

Some discrete exponential dispersion models : poisson-tweedie and hinde-demétrio classes

In this paper we investigate two classes of exponential dispersion models (EDMs) for overdispersed count data with respect to the Poisson distribution. The first is a class of Poisson mixture with positive Tweedie mixing distributions. As an approximation (in terms of unit variance function) of the first, the second is a new class of EDMs characterized by their unit variance functions of the form µ + µp, where p is a real index related to a precise model. These two classes provide some alternatives to the negative binomial distribution (p = 2) which is classically used in the framework of regression models for count data when overdispersion results in a lack of fit of the Poisson regression model. Some properties are then studied and the practical usefulness is also discussed

Influence of Temperature and Storage Systems on Post-Harvest Losses of Maize Varieties Cultivated at Alibori in Northern Benin

Majority of post-harvest losses of several maize varieties observed in various storage systems in northern Benin are mainly caused by storage insects due to changes in climatic parameters. The objective of this study is to evaluate the levels of insect pest infestation of three maize varieties stored in storage systems at different temperature. In 18 villages at Alibori, maize farmers were surveyed through a participatory research approach and their storage structures were also visited. The temperature of all storage structures were noted. Weight loss of samples, numbers of Prostephanus truncates, Sitophilus zeamais and perforated grains were evaluated. In total, three maize varieties and three different groups of storage systems were identified during field observations. All the three maize varieties stored in the first storage systems group built with plants were less infested and had acceptable nutritional quality than the maize grains stored in the second group built in banco and third group built with tarpaulin. In these storage systems, the yellow maize variety was the most attacked, followed by the white maize variety and finally the mixed color of yellow and white maize variety the less attacked. Effective post-harvest management of stored products requires clear monitoring criteria of climatic parameters and effective implementation of abiotic and biotic factors

Absorption enhancing proximity effects in aperiodic nanowire arrays

Aperiodic Nanowire (NW) arrays have higher absorption than equivalent periodic arrays, making them of interest for photovoltaic applications. An inevitable property of aperiodic arrays is the clustering of some NWs into closer proximity than in the equivalent periodic array. We focus on the modes of such clusters and show that the reduced symmetry associated with cluster formation allows external coupling into modes which are dark in periodic arrays, thus increasing absorption. To exploit such modes fully, arrays must include tightly clustered NWs that are unlikely to arise from fabrication variations but must be created intentionally.Comment: Accepted by Optics Expres

Effets de composts de déchets sur les propriétés chimiques du sol et la solubilité d’éléments minéraux sous deux régimes hydriques en conditions contrôlées au Togo

L'utilisation des composts de dechets en agriculture est lfune des voies principales dans la restauration de la fertilite des terres degradees. Cependant, les effets dfun compost dependent fortement de sa nature chimique et des conditions environnementales. Afin de mieux comprendre le mecanisme dfaction des composts de dechets sur les proprietes  chimiques du sol et la solubilite des ions, cinq types de composts de dechets ont ete testes selon un dispositif en blocs de Fischer repartis en trois repetitions par traitements. Les resultats obtenus revelent que les composts de dechets ont en general eleve le pH du sol de 2,13 unites et la conductivite electrique de 1301,9 µS/cm. Les traitements a engrais  synthetique NPK ont par contre reduit le pH de 0,51 unite. A lfexception du traitement a compost de dechets agroalimentaires, les traitements a compost ont en general reduit le potentiel Redox contrairement aux  traitements temoin et a engrais synthetiques. Ainsi, les traitements a engrais synthetique et a compost de dechets agroalimentaires sous deficit hydrique presentent respectivement des potentiels de 307,5 mV et 265 mV contre 262,5 mV pour le temoin absolu sous deficit hydrique. Lfetude de la fraction hydrosoluble des elements mineraux montre que la solubilite des cations essentiels (Ca, Mg et K) est liee fortement a leur concentration dans le substrat de culture contrairement aux elements traces metallique dont la solubilite depend essentiellement du pH et du potentiel Redox. Par ailleurs, le deficit hydrique a entraine lfelevation de la conductivite electrique chez les traitements a composts. Ces resultats seront utilises dans la phytoremediation des sols pollues.Mots cles : engrais organiques, amendements, parametres chimiques, ions, biodisponibilite

Évaluation Comparative De La Qualité Nutritionnelle Et Sanitaire Du Lait De Différentes Races De Vaches De Quelques Zones D’élevage Du Bénin

In this study, a comparative assessment of the nutritional quality and the safety of milk from cow breeds Girolando, Borgou, Borgou-Gir, and Lagunaire produced in Benin was carried out in the public breeding centers of Kpinnou, Bétécoucou, Okparaand in private farms in Adjohoun, respectively. Milk from the breed Borgou-Gir had the highest concentrations of macronutrients (protein and lactose) and minerals (magnesium: 197.556 ± 0.001 ppm, calcium: 2056.32 ± 0.000 ppm, and zinc: 5.522 ± 0.000 ppm). Analyzed milk samples were free of tuberculosis and brucellosis germs, and no mastitis prevalence was detected in milking cows. However, some milk samples had lead levels exceeding the maximum limit of 0.02 ppm prescribed by the Codex Alimentarius standard. In addition, milk from the breeds Borgou and Borgou-Gir contained pesticide residue levels, namely chlorpyrifos (0.12 ± 0.020 ppm) and cypermethrin (0.03 ± 0.020 ppm) higher than the Codex Alimentarius standard (0.01 ppm). Milk samples from Adjohoun and Kpinnou had an aflatoxin M1 level of 0.3 ± 0.000 ppb and 0,010 ppb ± 0.24, respectively and were not in agreement with the Codex Alimentarius standard (0, 05 ppb). Although rich in nutrients, analyzed cow’s milk may present health risks to consumers due to chemical contaminants

Double-heterostructure cavities: from theory to design

We derive a frequency-domain-based approach for radiation (FAR) from double-heterostructure cavity (DHC) modes. We use this to compute the quality factors and radiation patterns of DHC modes. The semi-analytic nature of our method enables us to provide a general relationship between the radiation pattern of the cavity and its geometry. We use this to provide general designs for ultrahigh quality factor DHCs with radiation patterns that are engineered to emit vertically