20,032 research outputs found

    An integrated molecular and conventional breeding scheme for enhancing genetic gain in maize in Africa

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    Open Access Journal; Published online: 06 Nov 2019Maize production in West and Central Africa (WCA) is constrained by a wide range of interacting stresses that keep productivity below potential yields. Among the many problems afflicting maize production in WCA, drought, foliar diseases, and parasitic weeds are the most critical. Several decades of efforts devoted to the genetic improvement of maize have resulted in remarkable genetic gain, leading to increased yields of maize on farmers’ fields. The revolution unfolding in the areas of genomics, bioinformatics, and phenomics is generating innovative tools, resources, and technologies for transforming crop breeding programs. It is envisaged that such tools will be integrated within maize breeding programs, thereby advancing these programs and addressing current and future challenges. Accordingly, the maize improvement program within International Institute of Tropical Agriculture (IITA) is undergoing a process of modernization through the introduction of innovative tools and new schemes that are expected to enhance genetic gains and impact on smallholder farmers in the region. Genomic tools enable genetic dissections of complex traits and promote an understanding of the physiological basis of key agronomic and nutritional quality traits. Marker-aided selection and genome-wide selection schemes are being implemented to accelerate genetic gain relating to yield, resilience, and nutritional quality. Therefore, strategies that effectively combine genotypic information with data from field phenotyping and laboratory-based analysis are currently being optimized. Molecular breeding, guided by methodically defined product profiles tailored to different agroecological zones and conditions of climate change, supported by state-of-the-art decision-making tools, is pivotal for the advancement of modern, genomics-aided maize improvement programs. Accelerated genetic gain, in turn, catalyzes a faster variety replacement rate. It is critical to forge and strengthen partnerships for enhancing the impacts of breeding products on farmers’ livelihood. IITA has well-established channels for delivering its research products/technologies to partner organizations for further testing, multiplication, and dissemination across various countries within the subregion. Capacity building of national agricultural research system (NARS) will facilitate the smooth transfer of technologies and best practices from IITA and its partners

    Extension and adoption of biofortified crops: Quality protein maize in East Africa

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    Biofortified crops, bred for improved nutritional quality, can alleviate nutritional deficiencies if they are produced and consumed in sufficient quantities. These varieties can be promoted based on their agronomic performance or based on their nutritional qualities. Quality protein maize (QPM) was the first biofortified crop and has been disseminated in Africa using both approaches. To study their effectiveness, a survey of rural households was conducted in the maize-growing areas of East Africa, comparing communities with access to QPM extension activities to control communities. The results show that a third to one half of the farmers in project communities participated in extension activities in all countries except Kenya. In these communities, familiarity with QPM was high (74-80% of farmers), again except for Kenya (19%), but understanding of their nutritional benefits was much lower (47-55%, with 7% in Kenya). In all countries, farmers evaluated QPM varieties as good or better than conventional varieties (CV) for post-harvest characteristics. For agronomic characteristics, however, QPM varieties scored better than CV in Uganda, about the same in Tanzania, but less in Ethiopia. Adoption patterns differed widely between the countries: in the project areas it varied from 70% in Uganda, 30% in Tanzania to none in Kenya. In the control areas, adoption was only observed in Uganda (45% of farmers). Factors that significantly influenced adoption were farmers’ participation in extension activities, farmers’ agronomic and post-harvest evaluation of QPM vs. CM, and their understanding of the nutritional benefits of QPM. Evaluation for agronomic performance was found to be more important than knowledge of nutritional benefits, thus favoring the first approach. A reliable seed supply was, however, found to be a basic condition for adoption.Teaching/Communication/Extension/Profession,

    Taking boys seriously: a longitudinal study of adolescent male school-life experiences in Northern Ireland

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    This report presents the findings of a five year longitudinal study (2006-2011) carried out by The Centre for Young Men’s Studies at the University of Ulster and funded by the Department of Education and the Department of Justice. The research was initiated in response to concerns about boys’ educational underachievement and wider concerns about boys’ health and well-being. The study annually tracked the same 378 adolescent boys aged 11-16 across nine post-primary schools in Northern Ireland

    How To Strengthen Youth-Serving Nonprofits?: Experiences of the James Irvine Foundation's Youth Development Initiative

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    Examines how Irvine's initiative to strengthen the management and organizational capacities of youth-serving nonprofits in Fresno and Los Angeles changed budgets, staff, numbers served, funding sources, and practices. Discusses the role of intermediaries

    Strategies for adapting to climate change in rural Sub-Saharan Africa

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    The ten ASARECA member countries (Burundi, Democratic Republic of Congo, Eritrea, Ethiopia, Kenya, Madagascar, Rwanda, Sudan, Tanzania, and Uganda) have adopted, or are planning to adopt, a range of climate change adaptation strategies in agriculture (see Table 1 for a summary). Of the 26 strategies mentioned, only two are common to all 10 countries, while five more are common to five or more. The strategies common to all member countries include the development and promotion of drought-tolerant and early-maturing crop species and exploitation of new and renewable energy sources. Most countries have areas that are classifiable as arid or semiarid, hence the need to develop drought-tolerant and early-maturing crops. Strangely, only one country recognizes the conservation of genetic resources as an important strategy although this is also potentially important for dealing with drought. Biomass energy resources account for more than 70 percent of total energy consumption in ASARECA member countries. To mitigate the potential adverse effects of biomass energy depletion, ASARECA countries plan to harness new and renewable energy sources, including solar power, wind power, hydro and geothermal sources, and biofuels. Eight of the 10 countries cite the promotion of rainwater harvesting as an important adaptation strategy, either small scale with small check dams or large scale with large dam projects. The five measures that are common to more than five countries are (a) the conservation and restoration of vegetative cover in degraded and mountain areas; (b) reduction of overall livestock numbers through sale or slaughter; (c) cross-breeding, zero-grazing, and acquisition of smaller livestock (for example, sheep or goats); (d) adoption of traditional methods of natural forest conservation and food use; and (e) community-based management programs for forests, rangelands, and national parks. The promotion of environmentally friendly investments and Clean Development Mechanism (CDM) projects that can be funded through carbon trading is a feature of only one country. Three examples of strategies that warrant greater region wide collaboration are the conservation of genetic materials, development and promotion of drought-tolerant species, and soil conservation. To date, the national adaptation policies of only three countries have indicated that they carry out these strategies.Adaptation, ASARECA, Climate change, NAPA, Natural resource management, PRSP,

    Conservation Agriculture as Practised in Ghana

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    This case study presents the status of conservation agriculture in Ghana. It is one in a series of eight case studies about conservation agriculture in Africa, which were developed within the framework of a collaboration between CIRAD (French Agricultural Research Centre for International Development), FAO (Food and Agriculture Organization of the United Nations), RELMA-in-ICRAF (Regional Land Management Unit of the World Agroforestry Centre) and ACT (African Conservation Tillage Network)

    Adapting integrated agriculture aquaculture for HIV and AIDS-affected households: the case of Malawi

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    The WorldFish Center in conjunction with World Vision Malawi carried out a project to improve income and nutrition status of households affected by HIV and AIDS with funding from the World Bank. The project was implemented in Southern Malawi particularly in the West of Zomba District from July 2005 to June 2006. Through participatory approaches, the project identified constraints that limit HIV and AIDS affected households’ realisation of the benefits from fish farming and adapted technologies and practices for the affected beneficiaries to boost fish production and utilization. Specifically, the project sought (1) to identify the constraints that limit HIV and AIDS affected households to realise the benefits from fish farming and based on the constraints, (2) to adapt technologies and practices for use by the affected beneficiaries to boost fish production and utilization. (PDF cotains 17 pages

    Single needle hemodialysis : is the past the future?

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    Whereas the usual way to gain access to the vascular bed for hemodialysis is by inserting two needles, an alternative option based on the introduction of only one needle has been available for several decades. Although single needle hemodialysis gradually lost popularity in the early nineties of last century, this option now seems to make a come-back, with the current change in patient mix towards more elderly and cardio-vascular disease and the appearance of more flexible hardware. Single needle hemodialysis offers several advantages, such as the possibility to puncture small or maturing access systems, a decrease in number of punctures with less potential access damage and subsequent complications, the avoidance of central vein catheter use, and an improved quality of life by reducing puncture-related pain, stress and complications. The main drawback is recirculation which however can be overcome (if considered necessary) by making dialysis somewhat longer and in addition has more impact on removal of small water soluble compounds than on clearance of the more toxic difficult to remove solutes (middle molecules and protein bound compounds). Effective dialyzer blood flow with single needle dialysis cannot be much higher than 300 mL/min, which however also offers advantages by making short dialysis sessions less feasible and thus reducing the likelihood of intradialytic blood pressure falls, organ stunning and other negative outcomes of shorter dialysis. Direct outcome comparisons between single and double needle dialysis are not available but indirect data suggest no differences, in as far as efficient enough access perfusion can keep dialyzer blood flow adequate. The single needle method seems especially suited for the elderly and for home hemodialysis. Recent technological improvements have made the system more accessible and adequate, but further studies are needed to assess with modern methodologies the clearance kinetics of these systems, which could emanate in further technological fine-tuning
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