367 research outputs found

    Agro-Industry and Smallholder Agriculture: Institutional Arrangements and Rural Poverty Reduction in Mozambique

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    Resultados das investigações do Departamento de Análise de Políticas MADER - Direcção de Economíafood security, food policy, Mozambique, agroindustrial, smallholder agriculture, Agribusiness, Q18,

    In-Vitro Evaluation of the Nematicidal Potential of Leaf Extracts of Commenlina benghalensis and Bidens pilosa on Root-Knot Nematode (Meloidogyne Spp)

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    The nematicidal potential of leaf extracts of Commenlina benghalensis and Bidens pilosa on Root-knot nematodes (Meloidogyne spp) was evaluated in-vitro. Four concentrations of the aqueous extracts of the leaves of each plant was used for the test. The concentration included 100mg/ml, 150mg/ml 200mg/ml and 250mg/ml while distilled water was used as control. Root-knot nematodes were sourced from susceptible plants within Jos metropolis and challenged with the different concentration of the extracts. Observation was done 24 hourly for 96 hours. Also, phytochemical analysis of the extracts was done. The results showed that all the extracts had nematicidal activities on root-knot nematodes but to varying degrees. Generally, C. benghalensis had lower nematicidal activity than B. pilosa. The result also showed that the nematicidal activities of both plant extracts increased with concentration and time of exposure. The phytochemical screening showed the presence of bioactive compounds such as Alkaloid, Saponin, Tannin, and Flavonoid among others. The findings of this work suggests that these plants have good nematicidal potentials. Keywords: Root-knot nematodes, in-vitro, Commenlina benghalensis, Bidens pilosa DOI: 10.7176/JNSR/10-4-04 Publication date: February 29th 202

    Distillery anaerobic digestion residues as fertilizers for field vegetable crops: Performance and efficiency in mid-term successions

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    Understanding nitrogen use efficiency (NUE) of crops plays an important role in achieving sustainable production. Intensive agriculture has adversely affected social and environmental issues worldwide over the past few decades. Anaerobic digested residues from the distillery industry (DADRs) can be used in agriculture, thereby recycling valuable organic materials that can supply organic N. An experiment using DADRs in horticulture was conducted to evaluate the performance of different treatments on yield and NUE. The experiment was conducted for five years, growing lettuce, cauliflower, chicory, potato, Swiss chard, catalogna chicory, tomato, pepper, and melon in two different succession schemes. Five fertilization treatments were designed, including a mineral fertilization control, in which nitrogen (N) was supplied according to standard recommendations in the area. The other treatments were an unfertilized control and three treatments in which 50%, 75%, and 100% of the N were supplied by DADRs and the remaining with common chemical fertilizer. Major findings were: (1) Spring\u2013summer crops showed the lowest N-uptake and N recovery, during this period high chemical fertilization can cause environmental problems such as N leaching, and fertilization with 100% DADRs is a viable alternative; (2) fall\u2013winter crops can be fertilized by combining 50% mineral N and 50% organic N, supplying the nutrients required by the crops during the growing cycle

    Improving the angular resolution of coded aperture instruments using a modified Lucy-Richardson algorithm for deconvolution

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    A problem with coded-mask telescopes is the achievable angular resolution. For example, with the standard cross-correlation (CC) analysis, the INTEGRAL IBIS/ISGRI angular resolution is about 13'. We are currently investigating an iterative Lucy-Richardson (LR) algorithm. The LR algorithm can be used effectively when the PSF is known, but little or no information is available for the noise. This algorithm maximizes the probability of the restored image, under the assumption that the noise is Poisson distributed, which is appropriate for photon noise in the data, and converges to the maximum likelihood solution. We have modified the classical LR algorithm, adding non-negative constraints. It doesn't take into account of the features leading to a difference in PSF depending on position in the field of view (dead pixels, gaps between modules etc), which are easily corrected for in the classical CC analysis, so we must correct for these either after the restoration of the image or by modifing the data before the sky reconstruction. We present some results using real IBIS data indicating the power of the proposed reconstruction algorithm

    Orchestrating Lightpath Recovery and Flexible Functional Split to Preserve Virtualized RAN Connectivity

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    In the next-generation radio access network (NG RAN), the next-generation evolved NodeBs (gNBs) will be, likely, split into virtualized central units (CUs) and distributed units (DUs) interconnected by a fronthaul network. Because of fronthaul latency and capacity requirements, optical metro-ring networks are among the main candidates for supporting converged 5G and non-5G services. In this scenario, a degradation in the quality of transmission of the lightpaths connecting DU and CU can be revealed (or anticipated) based on monitoring techniques. Thus, the lightpath transmission parameters can be adapted to maintain the required bit error rate (BER). However, in specific cases, the original requested capacity between DU and CU could be not guaranteed, thus impacting the service. In this case, another DU–CU connectivity should be considered, relying on a change of the so-called functional split. This study proposes a two-step recovery scheme orchestrating lightpath transmission adaptation and functional split reconfiguration to guarantee the requested connectivity in a virtualized RAN fronthaul. Results show that, for the connections that cannot be transported by the original lightpath, a graceful degradation followed by a recovery is possible within tens of seconds.This work was partly funded by the project H2020-ICT-2016-2 “5G-TRANSFORMER” (761536

    Elucidating the phylodynamics of endemic rabies virus in eastern Africa using whole-genome sequencing

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    Many of the pathogens perceived to pose the greatest risk to humans are viral zoonoses, responsible for a range of emerging and endemic infectious diseases. Phylogeography is a useful tool to understand the processes that give rise to spatial patterns and drive dynamics in virus populations. Increasingly, whole-genome information is being used to uncover these patterns, but the limits of phylogenetic resolution that can be achieved with this are unclear. Here, whole-genome variation was used to uncover fine-scale population structure in endemic canine rabies virus circulating in Tanzania. This is the first whole-genome population study of rabies virus and the first comprehensive phylogenetic analysis of rabies virus in East Africa, providing important insights into rabies transmission in an endemic system. In addition, sub-continental scale patterns of population structure were identified using partial gene data and used to determine population structure at larger spatial scales in Africa. While rabies virus has a defined spatial structure at large scales, increasingly frequent levels of admixture were observed at regional and local levels. Discrete phylogeographic analysis revealed long-distance dispersal within Tanzania, which could be attributed to human-mediated movement, and we found evidence of multiple persistent, co-circulating lineages at a very local scale in a single district, despite on-going mass dog vaccination campaigns. This may reflect the wider endemic circulation of these lineages over several decades alongside increased admixture due to human-mediated introductions. These data indicate that successful rabies control in Tanzania could be established at a national level, since most dispersal appears to be restricted within the confines of country borders but some coordination with neighbouring countries may be required to limit transboundary movements. Evidence of complex patterns of rabies circulation within Tanzania necessitates the use of whole-genome sequencing to delineate finer scale population structure that can that can guide interventions, such as the spatial scale and design of dog vaccination campaigns and dog movement controls to achieve and maintain freedom from disease

    IFNAR1 Controls Progression to Cerebral Malaria in Children and CD8+ T Cell Brain Pathology in Plasmodium berghei-Infected Mice

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    This publication hasn't any creative commons license associated. There is no public supplementary material available.Development of cerebral malaria (CM), a severe and fatal form of clinical Plasmodium falciparum infection, results from a damaging cascade of vascular, inflammatory, and immunological host responses that leads to brain injury. Progression to CM can be modified by host genetic factors. Our case-control study in Angolan children aimed at highlighting the role of IFN (α, β) receptor 1 (IFNAR1) in progression to CM. We report a robust association between IFNAR1 and CM protection, as well as detailed studies showing analogous protection from experimental CM in Ifnar1(-/-) mice infected with P. berghei ANKA. We developed a novel cell-transfer protocol that enables spleen cell priming in the absence of disease. This led to the discovery that IFNAR1 expression in CD8(+) T cells is crucial and can abrogate resistance to experimental CM in Ifnar1(-/-) mice. Splenic CD8(+) T cells from Ifnar1(-/-) mice are functionally activated upon infection, yet are unable to mediate experimental CM development within the brain tissue. Our findings prove that IFNAR1 signaling unleashes CD8(+) T cell effector capacity, which is vital for CM, and raises the hypothesis that the cohesive role of IFNAR1 in both human and mouse CM operates through CD8(+) T cell triggering.FCT fellowships: (SFRH/BD/33564/2008, SFRH/BPD/29354/2006)
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