Impact Assessment of agricultural research and development to reduce virus problems in tomato production in Mali: Farmers perceptions

Pests and diseases caused by bacteria, nematodes, fungi and viruses cause significant losses to tomato in West Africa. This study, carried-out within the framework of the IPM-CRSP implemented jointly by IITA, IER and Virginia Tech. and State University, assesses farmers’ perceptions on tomato pests and analyzes factors affecting pest management decision-making. Surveys were carried out in three tomato production areas where pests and diseases are major agricultural problems encountered by farmers. Data were collected a sample of from 343 farmers through a set of questionnaires on tomato production systems. Farmer’s decision-making in pest management was modeled using an econometrics Logit probability model. Results show that the main disease reported by most farmers is tomato leaf curl viruses transmitted by whitefly (Bemissia tabaci). The spray of chemicals was not effective on whitefly-transmitted viruses, but the observance of host free period could significantly reduce the population of whiteflies. Key factors affecting farmers’ pest management decision-making are gender; share of tomato income from household income and the level of farm income. Men are more involved in tomato production due to access to pesticide and effective demand for pesticides because of incomes (purchasing power). This paper concludes that tomato production can increase significantly if improved varieties tolerant to whitefly viruses are developed and disseminated, and farmers trained on the appropriate use of chemicals using a participatory approach to raise their level of awareness and information on effective pesticide use and pest-management decision-making.Agricultural and Food Policy, Agricultural Finance, Crop Production/Industries, Demand and Price Analysis, Environmental Economics and Policy, Farm Management, Food Consumption/Nutrition/Food Safety, Food Security and Poverty, International Relations/Trade, Marketing, Productivity Analysis, Research and Development/Tech Change/Emerging Technologies,

Caractéristiques spermatiques du taureau Baoulé (Bos taurus taurus) au Burkina Faso

Cette étude a porté sur 9 taureaux Baoulé. Une forte incidence pathologique en saison humide perturbe l'ensemble des caractéristiques spermatiques. Ces caractéristiques, pour les animaux sains, sont les suivantes : volume = 2,4 plus ou moins 1,5 ml; motilité = 3,8 plus ou moins 0,8; numération = 1,05 plus ou moins 0,40 10000000/mm3; PSI = 80 plus ou moins 23 p. 100; anomalies majeures = 3,8 plus ou moins 4,7 p. 100. Il existe une corrélation positive entre l'hygrométrie et les anomalies majeures de la tête et mineures de la tête et de la queue (p < 0,01) et une corrélation positive entre la température maximale et les anomalies majeures de la pièce intermédiaire et de la queue. Les autres caractéristiques spermatiques ne montrent pas de variations saisonnière

Behavior of unbound granular materials - Part I: isotropic case

International audienceThe paper discusses the modeling of the behavior of unbound granular materials. A representative approach that highlights some salient features of the behavior is proposed. This approach is essentially based on experimental results and the study is extended to the construction of the elastic potential from test results. to complete the analysis, two no-linear elastic models involving 3 parameters are proposed. In the construction of these models, two important aspects-the accuracy and the numerical stability-are analyzed

Behavior of unbound granular materials - Part I: isotropic case

International audienceThe paper discusses the modeling of the behavior of unbound granular materials. A representative approach that highlights some salient features of the behavior is proposed. This approach is essentially based on experimental results and the study is extended to the construction of the elastic potential from test results. to complete the analysis, two no-linear elastic models involving 3 parameters are proposed. In the construction of these models, two important aspects-the accuracy and the numerical stability-are analyzed

Comparison of data-driven methods for downscaling ensemble weather forecasts

International audienceThis study investigates dynamically different data-driven methods, specifically a statistical downscaling model (SDSM), a time lagged feedforward neural network (TLFN), and an evolutionary polynomial regression (EPR) technique for downscaling numerical weather ensemble forecasts generated by a medium range forecast (MRF) model. Given the coarse resolution (about 200-km grid spacing) of the MRF model, an optimal use of the weather forecasts at the local or watershed scale, requires appropriate downscaling techniques. The selected methods are applied for downscaling ensemble daily precipitation and temperature series for the Chute-du-Diable basin located in northeastern Canada. The downscaling results show that the TLFN and EPR have similar performance in downscaling ensemble daily precipitation as well as daily maximum and minimum temperature series whatever the season. Both the TLFN and EPR are more efficient downscaling techniques than SDSM for both the ensemble daily precipitation and temperature

Strong gametocytocidal effect of methylene blue-based combination therapy against falciparum malaria

With the availability of new preventive and curative interventions, global malaria control has been strengthened significantly in recent years. Drugs effective in reducing malaria gametocytaemia might contribute to local elimination and possible long-term eradication. We here report on the effects of methylene blue (MB)-based malaria combination therapy on gametocytaemia during a randomised-controlled trial in Burkina Faso. An open-label randomised controlled phase II study in 180 children aged 6-10 years with uncomplicated falciparum malaria was conducted in Nouna, north-western Burkina Faso. Children were randomised to MB-artesunate (AS), MB-amodiaquine (AQ), and AS-AQ (local standard of care). Overall follow-up was for 28 days, follow-up for gametocytaemia was for 14 days. The treatment groups were similar in baseline characteristics and there was only one loss to follow-up. Compared to AS-AQ, both MB-containing regimens were associated with significantly reduced gametocyte carrier rates during follow-up days 3, 7, and 14. This effect was seen both in patients with and without P. falciparum gametocytaemia at baseline. MB reveals pronounced gametocytocidal activity which appears to act against both existing and developing P. falciparum gametocytes. MB-based combination therapy thus has the potential to reduce transmission of P. falciparum malaria in endemic regions, which has important implications for future elimination and eradication strategies

Safety and efficacy of methylene blue combined with artesunate or amodiaquine for uncomplicated falciparum malaria

Besides existing artemisinin-based combination therapies, alternative safe, effective and affordable drug combinations against falciparum malaria are needed. Methylene blue (MB) was the first synthetic antimalarial drug ever used, and recent studies have been promising with regard to its revival in malaria therapy. The objective of this study was to assess the safety and efficacy of two MB-based malaria combination therapies, MB-artesunate (AS) and MB-amodiaquine (AQ), compared to the local standard of care, AS-AQ, in Burkina Faso. Open-label randomised controlled phase II study in 180 children aged 6-10 years with uncomplicated falciparum malaria in Nouna, north-western Burkina Faso. Follow-up was for 28 days and analysis by intention-to-treat. The treatment groups were similar in baseline characteristics and there was only one loss to follow-up. No drug-related serious adverse events and no deaths occurred. MB-containing regimens were associated with mild vomiting and dysuria. No early treatment failures were observed. Parasite clearance time differed significantly among groups and was the shortest with MB-AS. By day 14, the rates of adequate clinical and parasitological response after PCR-based correction for recrudescence were 87% for MB-AS, 100% for MB-AQ (p = 0.004), and 100% for AS-AQ (p = 0.003). By day 28, the respective figure was lowest for MB-AS (62%), intermediate for the standard treatment AS-AQ (82%; p = 0.015), and highest for MB-AQ (95%; p<0.001; p = 0.03). MB-AQ is a promising alternative drug combination against malaria in Africa. Moreover, MB has the potential to further accelerate the rapid parasite clearance of artemisinin-based combination therapies. More than a century after the antimalarial properties of MB had been described, its role in malaria control deserves closer attention. ClinicalTrials.gov NCT00354380

Novel Topology for Four-Quadrant Converter

Particle accelerators, like the LHC (Large Hadron Collider), make use of true bipolar power converters to feed superconducting magnets. Moreover, the LHC imposes that most converters must be installed underground. This constraint leads to the necessity of a high efficiency and a reduced volume for all the power converters. In this paper, the authors present a novel four-quadrant topology composed by an association of a ZVS-inverter and a ZCS-rectifier. This DC-AC-DC converter is fully reversible and a soft-switching operation mode is achieved for all switches over the full operating range. After a thorough analysis of the prototype design [±600A, ±10V], simulation and experimental results confirm the general performance of this power structure

Міхал Бобжинський: суспільно-політична діяльність

Розглянута суспільно-політична діяльність визначного представника краківської історичної школи М. Бобжинського. Акцентовано увагу на зв’язку наукових поглядів історика з його політичною практикою. Охарактеризовано дискусії, які досьогодні точаться серед науковців щодо оцінки результатів його діяльності.Рассмотрена общественно-политическая деятельность выдающегося представителя краковской исторической школы М. Бобжинского. Акцентировано внимание на связи научных взглядов историка с его политической практикой. Охарактеризованы дискуссии, которые досегодня ведутся среди ученых относительно оценки результатов его деятельности.The socio-political activities of M. Bobzhynski – a prominent representative of the Krakow historical school – are reviewed. Attention is given to the connection of the historian scholarly views with his political practice. The discussions that until now are going on among scholars in evaluating the results of his work are characterised