518 research outputs found

    Biological effects of Physalis peruviana L. (Solanaceae) crude extracts and its major withanolides on Ceratitis capitata Wiedemann (Diptera: Tephritidae)

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    Biological effects of Physalis peruviana crude extracts and its major withanolides (withanolide E and 4-ß-hydroxywithanolide E) were investigated on larvae and adults of the fruit fly Ceratitis capitata. High concentrations of crude extracts (10000 and 35000 ppm) in larval diet caused 100% mortality while low concentration (1000 ppm) caused significative differences in larval mortality, development delay and puparia length. Withanolide E and 4-ß-hydroxywithanolide E (500 ppm) also produced significative mortality on larvae. The application of crude extracts to adults drinking vessels caused significative lethal effects at 10000 and 35000 ppm. These data indicate that P. peruviana crude extracts and its two major withanolides could be used to develop baits to control C.capitata.EEA ChubutFil: Cirigliano, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Orgánica; ArgentinaFil: Colamarino, I. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Zoología Agrícola; ArgentinaFil: Mareggiani, G. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Zoología Agrícola; ArgentinaFil: Bado, Silvina Graciela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Chubut; Argentin

    Involving Stakeholders in Crop-Livestock Systems Analysis: Innovation Platforms in Burkina Faso and Niger, West Africa

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    The development of markets and agricultural productivity need participative research approaches that involve farmers, stakeholders and actors in the value chains of agricultural products and inputs. This study illustrates the use of multi-stakeholder platforms to address critical issues that often curtail effective implementation of development strategies and achievement of objectives. The process used to facilitate stakeholder participation and achieve enhanced understanding of collective actions to achieve objectives is illustrated by case studies in Niger and Burkina Faso. The process that determines the causal relationships among the various problems is also presented; results from the process can be used to determine entry points for addressing system challenges. Finally, the study offers specific insights and analysis related to small-ruminant and feed value chains within Niger and Burkina Faso. The strengths and weaknesses of each node of the value chain are assessed and appropriate upgrading, management, and development strategies suggested. Entry points for action and strategies for intervention are identified to improve functioning of the crop-livestock value chain and the productivity of agro-pastoral farming systems. Participative analysis and understanding of the functioning of agricultural value chains enable farmers and actors to improve agricultural productivity and marketing. The multi-stakeholder platform approach is a more suitable tool for socio-economic analysis of integrated systems, and identification and implementation of development strategies, than traditional disciplinary research approaches

    Integrated Management of Soil Fertility and Land Resources in Sub-Saharan Africa: Involving Local Communities

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    The soils of sub-Saharan Africa are characterized by their poverty in nutrients along with low clay and organic carbon content and low exchange capacity. There is high pressure on land resources with the quick growth of population and demand for food. Maintaining the fertility of cultivated soils and land resources is a challenge. Since the paradigm of “external input” in the 1960s and 1970s, to the latest concept of integrated soil fertility management, most of the approaches remain crop oriented or livestock oriented with less attention to local communities (LC), which are at the heart of land resource management. This chapter suggests a new integrated and holistic approach involving LC for land resources management, including cultivated soils and rangelands. A global framework is proposed for development of management options of land resources with LC. It is a dynamic process of participative management of lands as providers of services for the entire community

    Evaluation of the feed quality of six dual purpose pearl millet varieties and growth performance of sheep fed their residues in Niger

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    Pearl millet (Pennisetum glaucum) is a staple food popularly cultivated by small farmers in Niger. The stover are also used as feeds for livestock (small ruminant) as basal diet, especially during the cold dry season. ICRISAT has developed many dualpurpose millet varieties that aim to increase feeds for livestock while providing grain as food to farmers. But the nutritional quality of Stover of these varieties for livestock are not known. This research aims to assess the quality of residues of the dual-purpose varieties and their effect on feed intake and live weight changes of young sheep

    Effet de la combinaison des fumures organo-minérales et de la rotation niébé-mil sur la nutrition azotée et les rendements du mil au sahel

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    Peu de données existent sur la contribution en azote des légumineuses, et leurs impacts en présence des fumures sur la nutrition azotée des  céréales. Ainsi, pour évaluer les effets du niébé et des fumures organo-minérales sur la nutrition azotée et les rendements du mil subséquent, une expérimentation a été conduite de 2008 à 2009 à Sadoré au Niger. Dans un dispositif en split-plot, trois doses de résidus, de fumier et d’engrais minéraux ont été appliquées dans une rotation niébé-mil. La méthode isotopique de 15N a été utilisée pour déterminer le coefficient réel d’utilisation d’engrais azoté (CRU). En présence de résidus, le CRU a varié de 16 à 23%. Les doses du fumier ont entraîné sa variation de 16 à 22%. Le CRU du mil subséquent était de 30% contre 22% pour le mil en monoculture. Le mil subséquent a prélevé du sol 54 kg N ha-1 contre 38 kg N ha-1 pour le mil en continu. Les doses des fumures et leur  combinaison dans les systèmes de culture, ont augmenté les rendements du mil de 17 à 272%. La nutrition azotée et la productivité des systèmes peuvent donc être améliorées en combinant les fumures organo-minérales et les rotations avec légumineuses.Mots clés : Céréale, légumineuse, rotation, azote, dilution isotopique, Niger

    Women's education and health inequalities in under-five mortality in selected sub-Saharan African countries, 1990–2015

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    The aim of the study was to analyse trends in the relationship between mother’s educational level and mortality of children under the year of five in Sub-Saharan Africa, from 1990 to 2015.Data used in this study came from different waves of Demographic and Health Surveys (DHS) of Sub-Saharan countries. Logistic regression and Buis’s decomposition method were used to explore the effect of mother’s educational level on the mortality of children under five years

    H3-receptor regulation of vascular gastrin and somatostatin releases by the isolated rat stomach.

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    We have studied the effects of the H3-receptor agonist (R) alpha-methylhistamine [(R) alpha-MeHA] and the H3-receptor antagonist thioperamide (Thiop) on basal- and carbachol-stimulated vascular gastrin release (GR) and somatostatin release (SR) by the isolated rat stomach. Carbachol dose-dependently stimulated and inhibited GR and SR, respectively. Maximal stimulation of GR (500 +/- 112 percent of basal; p < .01), and maximal inhibition of SR (-62 +/- 9 percent under basal; p < .01) were obtained with 1 micron carbachol. Neither (R)alpha-MeHA nor Thiop, up to 10 microns, affected GR. However, SR was dose-dependently enhanced by Thiop (25 +/- 8 percent for 10 microns). Carbachol stimulation of GR was strongly inhibited by Thiop (30 +/- 7 percent for 100 nM and 73 +/- 14 percent for 1 microgram), whereas it was potentiated by (R)alpha-MeHA. Carbachol inhibition of SR was reversed by Thiop and (R)alpha-MeHA. However, the reversal effect of (R)alpha-MeHA was prevented by the CCKB/gastrin receptor antagonist PD134308. These results support H3-receptor regulation of basal and cholinergically-stimulated GR and SR

    Luminal leptin inhibits L-glutamine transport in rat small intestine: involvement of ASCT2 and B0AT1.

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    L-glutamine is the primary metabolic fuel for enterocytes. Glutamine from the diet is transported into the absorptive cells by two sodium-dependent neutral amino acid transporters present at the apical membrane: ASCT2/SLC1A5 and B(0)AT1/SLC6A19. We have demonstrated that leptin is secreted into the stomach lumen after a meal and modulates the transport of sugars after binding to its receptors located at the brush border of the enterocytes. The present study was designed to address the effect of luminal leptin on Na(+)-dependent glutamine (Gln) transport in rat intestine and identify the transporters involved. We found that 0.2 nM leptin inhibited uptake of Gln and phenylalanine (Phe) (substrate of B(0)AT1) using everted intestinal rings. In Ussing chambers, 10 mM Gln absorption followed as Na(+)-induced short-circuit current was inhibited by leptin in a dose-dependent manner (maximum inhibition at 10 nM; I(C50) = approximately 0.1 nM). Phe absorption was also decreased by leptin. Western blot analysis after 3-min incubation of the intestinal loops with 10 mM Gln, showed marked increase of ASCT2 and B(0)AT1 protein in the brush-border membrane that was reduced by rapid preincubation of the intestinal lumen with 1 nM leptin. Similarly, the increase in ASCT2 and B(0)AT1 gene expression induced by 60-min incubation of the intestine with 10 mM Gln was strongly reduced after a short preincubation period with leptin. Altogether these data demonstrate that, in rat, leptin controls the active Gln entry through reduction of both B(0)AT1 and ASCT2 proteins traffic to the apical plasma membrane and modulation of their gene expression
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