419 research outputs found

    Renoval Charge Technic Applied To A Bifacial Solar Cell Under Constant Magnetic Field

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    An n+-p-p+ bifacial solar cell under constant magnetic field is placed in a fast-switch-interrupted circuit and submitted to a constant multi-spectral illumination. The transient decay occurs between two steady states throughoperating points depending on two variable resistors; this allows us to obtain a transient decay at any operating point of the I-V curve of the solar cell, from the short circuit to the open one. The influence of magnetic field on the transient photocurrent has been studied using Matlab Simulink simulations.These simulations lead to an equivalent circuit of the bifacial cell in transient state assuming that the photocurrent is the diffused

    Developpement des systemes de production innovants d’association mais/legumineuses dans la zone subhumide du Mali

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    Parmi les 3 piliers de l’intégration agriculture-élevage (traction animale, fumure organique, cultures fourragères) diffusés en Afrique de l’Ouest, seules les cultures fourragères ont été peu adoptées. Pourtant, les associations maïs/légumineuses ont l’avantage d’améliorer la production et l’alimentation animale. Elles représentent une alternative dans la gestion des risques et des incertitudes pour les agro-éleveurs, confrontés aux changements globaux (climatiques, pression foncière, dégradation des ressources naturelles). L’objectif de cette étude est de déterminer la contribution des associations maïs/légumineuses dans l’amélioration de la production de maïs grain et le bilan fourrager des exploitations agricoles. Le dispositif en blocs dispersés chez 10 producteurs, a consisté en 3 traitements, T1 (maïs seul), T2 (maïs/ niébé) et T3 (maïs/mucuna) durant 2 campagnes agricoles. En 2013 - 2014, les rendements de maïs grain ont été de 2433 kg/ha et en biomasse 2597 kgMS/ha. Par contre, en 2014 - 2015 les rendements ont été de 1932 kg/ha de maïs grain et de 5134 kgMS/ha de biomasse. Les besoins en matière sèche pour 90 jours de supplémentation ont été de 4,62 UBT en 2013 - 2014 et de 9,13 UBT en 2014 - 2015. Ces résultats montrent la contribution des associations maïs/légumineuses dans l’amélioration du rendement de maïs grain et de fourrages dans la zone subhumide au Mali.Mots clés : légumineuses, maïs, fourrage, Mal

    The Coxsackievirus B 3Cpro Protease Cleaves MAVS and TRIF to Attenuate Host Type I Interferon and Apoptotic Signaling

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    The host innate immune response to viral infections often involves the activation of parallel pattern recognition receptor (PRR) pathways that converge on the induction of type I interferons (IFNs). Several viruses have evolved sophisticated mechanisms to attenuate antiviral host signaling by directly interfering with the activation and/or downstream signaling events associated with PRR signal propagation. Here we show that the 3Cpro cysteine protease of coxsackievirus B3 (CVB3) cleaves the innate immune adaptor molecules mitochondrial antiviral signaling protein (MAVS) and Toll/IL-1 receptor domain-containing adaptor inducing interferon-beta (TRIF) as a mechanism to escape host immunity. We found that MAVS and TRIF were cleaved in CVB3-infected cells in culture. CVB3-induced cleavage of MAVS and TRIF required the cysteine protease activity of 3Cpro, occurred at specific sites and within specialized domains of each molecule, and inhibited both the type I IFN and apoptotic signaling downstream of these adaptors. 3Cpro-mediated MAVS cleavage occurred within its proline-rich region, led to its relocalization from the mitochondrial membrane, and ablated its downstream signaling. We further show that 3Cpro cleaves both the N- and C-terminal domains of TRIF and localizes with TRIF to signalosome complexes within the cytoplasm. Taken together, these data show that CVB3 has evolved a mechanism to suppress host antiviral signal propagation by directly cleaving two key adaptor molecules associated with innate immune recognition

    Examining the Gender Productivity Gap among Farm Households in Mali

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    AbstractThis paper decomposes the gender agricultural productivity gap and measures the factors that influence the gap between male and female agricultural plot managers in Mali. The Oaxaca–Blinder approach and the recentred influence function (RIF) decompositionmethodology are applied to a nationally representative survey of Mali. The results show that the agricultural productivity of female plot managers is 20.18%lower than that of male plot managers. Additionally, while more than half (56%) of the agricultural productivity gap is influenced by female-specific structural disadvantages, 44% of the gap is due to an endowment effect. Socioeconomic characteristics such as the educational level and age of the plot manager, environmental factors and agricultural production practices, i.e., the differential use of inputs (organic or inorganic fertiliser and improved seeds) and the use of hired female workers seem to affect the female-specific structural disadvantages. To reduce or close the gender productivity gap, the underlying causes of femalespecific structural disadvantages must be addressed to enable female farmers to obtain the same returns as men. Traditional means of addressing the gender gap, such as providing education for women in rural areas and facilitating rural women’ access to extension services and improved seeds, can mitigate the endowment deficit. This paper highlights the need to develop a better understanding of the factors influencing the structural disadvantages faced by female farmers inMali that could feed into the development ofmore effective policies to address the gender gap in agricultural productivity, improving productivity and gender equity and reducing poverty

    Genetic Diversification and Selection Strategies for Improving Sorghum Grain Yield Under Phosphorous-Deficient Conditions in West Africa

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    Sorghum, a major crop for income generation and food security in West and Central Africa, is predominantly grown in low-input farming systems with serious soil phosphorus (P) deficiencies. This study (a) estimates genetic parameters needed to design selection protocols that optimize genetic gains for yield under low-phosphorus conditions and (b) examines the utility of introgressed backcross nested association mapping (BCNAM) populations for diversifying Malian breeding materials. A total of 1083 BC1F5 progenies derived from an elite hybrid restorer “Lata-3” and 13 diverse donor accessions were evaluated for yield and agronomic traits under contrasting soil P conditions in Mali in 2013. A subset of 298 progenies were further tested under low-P (LP) and high-P (HP) conditions in 2014 and 2015. Significant genetic variation for grain yield was observed under LP and HP conditions. Selection for grain yield under LP conditions was feasible and more efficient than the indirect selection under HP in all three years of testing. Several of the BCNAM populations exhibited yields under LP conditions that were superior to the elite restorer line used as a recurrent parent. The BCNAM approach appears promising for diversifying the male parent pool with introgression of diverse materials using both adapted Malian breed and unadapted landrace material from distant geographic origins as donors

    Sélection participative des variétés de sorgho à l’aide d’essais multilocaux dans deux zones cibles

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    Variety development for sorghum requires multi-location testing for yielding ability. In West-Africa, where adaptation to specific zones of rainfall distribution is crucial for the success of a variety, these multi-location trials need to be conducted within any specific zone of adaptation. As most West-African countries lack sufficient research station capacity for this type of yield testing, we have developed a trial design and experiments with a sharing of roles and responsibilities between farmers, NGO's and researchers that allow for effective varietal differentiation in the target environment across a wide range of production conditions within a zone. The added advantage of farmer participation in this early stage of variety evaluation is that farmers also evaluate a wide range of other traits that are essential for making a variety a success
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