THE CHANGING NATURE OF UK FISH RETAILING

Resource /Energy Economics and Policy,

LONG-RUN STRIGA CONTROL BY SUBSISTENCE FARMERS IN MALI

A dynamic programming model is developed to identify barriers to the adoption of long-run control programs for the parasitic weed Striga. The model is applied to Sirakorola in northwestern Mali. The ability of national and village-level institutions to overcome the barriers to adoption is explored.Community/Rural/Urban Development, Research and Development/Tech Change/Emerging Technologies,

Characterization of maize producing households in the dry savanna of Mali

Maize is one of the three most important staple foods in Mali. Zones in the country with high potential for producing maize are limited to areas where the probability of drought risk is between 20 and 40%, meaning that recurring droughts have long handicapped maize production. In an attempt to alleviate drought stress on maize production, a household survey was conducted in the two Local Government Areas of Bougouni and Koutiala, both in the Sikasso Region, during the 2007/2008 production period. These two districts were selected following an environmental characterization of drought zones in Mali. The survey was mainly oriented towards maize based farming systems. Six sample villages were selected within each of the two districts. The sample population was defined as maize farming households. A total of 150 households were randomly selected and interviewed with structured questionnaires. Interviews were conducted by trained enumerators using a formal household survey. The purpose of the study is to provide both quantitative and qualitative feedback from farmers to researchers and to the B&MGF on the impact that improved maize varieties developed in the past have had upon the livelihoods of households and to provide a detailed database for the projection of expected outcomes with the deployment of new drought tolerant maize varieties under the B&MGF drought tolerant maize project. Both qualitative and quantitative analyses were used to extract from our set of variables those orthogonal linear combinations of the variables that best captured the common information. Most successful was the one proposed by Filmer and Pritchett (1998; 2001) called the Principal Component Analysis (PCA). To assess the variables affecting the adoption of improved maize varieties, the Tobit model was used. The results show that 99% of household heads are male. The size of a household is 22 persons, on average. About 47% of the household’s members are available for farm work. About 59% of household heads are illiterate, an important factor concerning the adoption of new technology. These household heads make decisions about 84% of farming activities; 86% of the households involved in the study belonged to at least one farmers’ organization in order to have easy access to inputs

Yield loss of Oryza glaberrima caused by grain shattering under rainfed upland conditions

The general perception of Oryza glaberrima as low yielding is a potential drawback to intraspecific breeding of this species. Yields of 21 O. glaberrima accessions were evaluated alongside four O. sativa check varieties under two conditions in which panicles were both covered by paper sacks to avoid grain shattering (potential yield plot) and also not covered (control plot) in a rainfed upland field of Benin in 2010 and 2011. Average potential yields of O. glaberrima with panicles covered were 2.42 and 3.65 t ha-1 in 2010 and 2011, respectively, while those of O. sativa were respectively 2.99 and 3.49 t ha-1. Although there was no significant difference between potential yield and control yield in O. sativa, 19 O. glaberrima accessions showed significant yield reduction by grain shattering — the average percentages of lost yield by shattering were 57.88% in 2010 and 66.76% in 2011. These results suggest that low yield of O. glaberrima is due to grain shattering and that its potential yield would not be inferior to O. sativa if the grain shattering problems were overcome. Two O. glaberrima accessions, TOG 12303 and TOG 9300, possessing strong resistance to grain shattering comparable to O. sativa checks, were identified.Keywords: Panicles, paper sacks, potential yield, yield reduction

Activités antimicrobiennes des huiles essentielles de Eucalyptus citriodora Hook et Eucalyptus houseana W.Fitzg. ex Maiden

Les huiles essentielles de Eucalyptus citriodora et Eucalyptus houseana récoltées à N’Débougou (Mali) ont été testées sur les bactéries Escherichia coli, Staphylococcus aureus et le champignon Candida albicans. Nous avons utilisé la méthode de diffusion en Agar pour de la détermination des activités antibactériennes. La plus grande activité a été notée avec l’huile essentielle de Eucalyptus houseana sur Staphylococcus aureus. L’activité antifongique a été déterminée par chromatographie sur couche mince (CCM). Les deux huiles essentielles ont été actives sur Candida albicans.Mots clés: Antibactérienne, antifongique, Escherichia coli, Staphylococcus aureus, Candida albicans

Synthesis of Perfectly Oriented MAPb0.93Cr0.07Br3 Perovskite Crystals for Thin-Film Photovoltaic Applications

[EN] Wide band gap methylammonium lead halide perovskites (CH3NH3PbX3, X=halogen; CH3NH3: MA) are interesting materials for photovoltaic applications. They have recently gained substantial attention because of their high efficiency, low cost, superior optical properties. The most attractive and representative perovskites are methylammonium lead halides (CH3NH3PbX3,) denoted as MAPbX3, X = Br, Cl, I. usually the optical and structural properties of CH3NH3PbBr3 can be adjusted by introducing other extrinsic ions such as chloride and bromide. In this work, instead of replacing the halogens I or Cl with bromine (Br) as usual, we preferred to act on the post-transition metal (Pb). To this end, we replaced lead with chromium (Cr) which is a transition metal and may have the same oxidation state (+2) as lead. MAPb0.93Cr0.07Br3 thin films were deposited on ITO substrate by the spin coating process. X-ray diffraction analyses indicated the formation of a cubic perovskite with space group Pm3 m. The structural analysis reveals films with (110) and (220) as main peaks. Deposited films showed a strong absorbance in the UV¿vis range. The band gap values were estimated from absorbance measurements. It was found between 1.60 and 1.80 eV. SEM analysis shows a morphology with good coverage and no apparent crystal orientation.Soro, D.; Sidibé, M.; Fassinou, W.; Marí, B.; Sall, T.; Fofana, B.; Boko, A.... (2017). Synthesis of Perfectly Oriented MAPb0.93Cr0.07Br3 Perovskite Crystals for Thin-Film Photovoltaic Applications. International Journal of Innovative Research in Science, Engineering and Technology. IJIRSET (Online). 6(6):10170-10176. doi:10.15680/IJIRSET.2017.0606007S10170101766

Hepatitis C virus cell-cell transmission and resistance to direct-acting antiviral agents

Hepatitis C virus (HCV) is transmitted between hepatocytes via classical cell entry but also uses direct cell-cell transfer to infect neighboring hepatocytes. Viral cell-cell transmission has been shown to play an important role in viral persistence allowing evasion from neutralizing antibodies. In contrast, the role of HCV cell-cell transmission for antiviral resistance is unknown. Aiming to address this question we investigated the phenotype of HCV strains exhibiting resistance to direct-acting antivirals (DAAs) in state-of-the-art model systems for cell-cell transmission and spread. Using HCV genotype 2 as a model virus, we show that cell-cell transmission is the main route of viral spread of DAA-resistant HCV. Cell-cell transmission of DAA-resistant viruses results in viral persistence and thus hampers viral eradication. We also show that blocking cell-cell transmission using host-targeting entry inhibitors (HTEIs) was highly effective in inhibiting viral dissemination of resistant genotype 2 viruses. Combining HTEIs with DAAs prevented antiviral resistance and led to rapid elimination of the virus in cell culture model. In conclusion, our work provides evidence that cell-cell transmission plays an important role in dissemination and maintenance of resistant variants in cell culture models. Blocking virus cell-cell transmission prevents emergence of drug resistance in persistent viral infection including resistance to HCV DAAs

Species-Specific Activity of HIV-1 Vpu and Positive Selection of Tetherin Transmembrane Domain Variants

Tetherin/BST-2/CD317 is a recently identified antiviral protein that blocks the release of nascent retrovirus, and other virus, particles from infected cells. An HIV-1 accessory protein, Vpu, acts as an antagonist of tetherin. Here, we show that positive selection is evident in primate tetherin sequences and that HIV-1 Vpu appears to have specifically adapted to antagonize variants of tetherin found in humans and chimpanzees. Tetherin variants found in rhesus macaques (rh), African green monkeys (agm) and mice were able to inhibit HIV-1 particle release, but were resistant to antagonism by HIV-1 Vpu. Notably, reciprocal exchange of transmembrane domains between human and monkey tetherins conferred sensitivity and resistance to Vpu, identifying this protein domain as a critical determinant of Vpu function. Indeed, differences between hu-tetherin and rh-tetherin at several positions in the transmembrane domain affected sensitivity to antagonism by Vpu. Two alterations in the hu-tetherin transmembrane domain, that correspond to differences found in rh- and agm-tetherin proteins, were sufficient to render hu-tetherin completely resistant to HIV-1 Vpu. Interestingly, transmembrane and cytoplasmic domain sequences in primate tetherins exhibit variation at numerous codons that is likely the result of positive selection, and some of these changes coincide with determinants of HIV-1 Vpu sensitivity. Overall, these data indicate that tetherin could impose a barrier to viral zoonosis as a consequence of positive selection that has been driven by ancient viral antagonists, and that the HIV-1 Vpu protein has specialized to target the transmembrane domains found in human/chimpanzee tetherin proteins

Étude de la variabilité agromorphologique de la collection nationale de mils locaux du Sénégal

Objectif : Le mil est la première culture vivrière au Sénégal. Il joue un rôle capital dans la vie des populations rurales qui en dépendent pour leur survie (STAT/FAO/SENEGAL, 2010). Il est cultivé sur plus 60% des terres arables. Les variétés locales étaient les plus utilisées mais depuis quelques années leur survie est menacée par l'introduction des variétés améliorées.Methodology et application des résultats : Pour éviter l'érosion génétique, des missions de collecte ont été organisées en 1994 et 2006 dans les principales zones de culture du mil. Le matériel collecté est caractérisé pour faciliter leur utilisation dans les programmes de création variétale. L'objectif du présent travail est caractériser le germoplasme national mil du Sénégal pour les rendre utilisables par les sélectionneurs pour la création de nouvelles variétés hautement productives pour l'augmentation de la production céréalière et l'atteinte de la sécurité alimentaire. Pour caractériser les accessions, 12 variables sélectionnées à partir du Descripteur du mil IPGRI/ICRISAT, 1993 ont été utilisées. Un dispositif expérimental en blocs complets randomisés avec 3 répétitions a été choisi et les sites d'essais étaient Bambey, Nioro et Darou pendant les hivernages 2011 et 2012. Les analyses descriptives ou qualitatives ; statistiques simples (ANOVA) ; de la diversité (phénologique ; génétique avec la méthode de la classification ascendante (CAH), avec les composantes principales (ACP) et l'analyse factorielle discriminante (AFD)) ont été réalisées avec les logiciels Genstat Discovery4 et R. Les analyses descriptives ont montré l'existence d'une grande variabilité entre les accessions pour les caractères qualitatifs comme l'architecture de l'épi et la couleur des grains. Les analyses statistiques simples (ANOVA) ont montré qu'il existe une différence hautement significative entre les entrées et les sites. Cependant, les interactions étaient non significatives à l'exception de la floraison, de l'indice de récolte et des rendements en grains et en matière sèche. Les analyses de la diversité phénologique a permis de classer les variétés en trois groupes selon le cycle végétatif (G1 des variétés extra-précoces, G2 des cycles courts et G3 des cycles longs). La classification ascendante hiérarchique (CAH) suivant la méthode de Ward a permis d'identifier la valeur des axes et les compositions des 3 groupes y découlant (le groupe G1 compte 106 accessions, le G2 compte 129 accessions et le G3 compte 8 accessions) et de tracer le dendrogramme de filiations. L'analyse de la diversité génétique par les composantes principales (ACP) a permis de déterminer la position des accessions par rapport aux axes expliquant les variabilités inter-accessions. L'analyse de la diversité génétique par la méthode factorielle discriminante a permis de déterminer la structuration de la diversité agromorphologique et la représentation graphique des accessions suivant un plan factoriel. Les groupes ainsi formés seront convertis en des entités hétérotiques constituées de pools de gènes différents où les sélectionneurs et autres scientifiques vont puiser pour créer des variétés hautement productives et résistantes aux stress bio et abiotiques afin de nourrir les populations et de lutter contre la faim et la malnutrition