258 research outputs found

    Determination of Water Requirement and Crop Coefficient for Sorghum (Sorghum bicolor L.) at Melkassa, Ethiopia

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    Knowledge of crop evapotranspiration (ETc), the combined process of evaporation and plant transpiration, is important in agriculture for  scheduling farm  operations and designing and managing irrigation and drainage systems. Development of crop coefficient (Kc) can enhance crop evapotranspiration (ETc) estimates in specific crop growth stages. However, locally determined Kc information is not available for many important crops in Ethiopia. This research was, therefore, conducted to determine growth stage specific Kc and crop water use for sorghum (Sorghum bicolor L.) var. Gambella-1107 at the Melkassa Agricultural Research Center which is located in a semi arid climate zone in Ethiopia. Drainage type lysimeter was used to measure Gambella-1107 crop water use under water balance system on a clay loam soil and local weather data were used to determine the reference  evapotranspiration (ETo). Crop coefficient was developed from measured ETc and ETo calculated using weather data. The growth stages of the crop were assessed as the seasonal change of plant height (pH), leaf area (LA) and leaf area index (LAI). The yield obtained was 5.3 t ha-1 and the measured LAI were 0.2, 4.2, 4.9 and 1.6 at the initial, development, midseason and late season stages, respectively. The maximum LAI was achieved when the plants reach their maximum height at mid-season stage with high crop evapotranspiration due to leaf enlargement that increases transpiration. The measured ETc values were 53.8, 138.5, 214.4, and 94.0 mm during the initial, development, midseason and late-season stages, respectively, and the seasonal total value was 500.7 mm. The calculated Kc values for the crop were 0.45, 0.83, 1.18 and 0.78 during the initial, development, mid-season and late-season stages, respectively. These values were greater than those reported in FAO publication for  sorghum varieties which could be a result of soil, climate and crop genetic differences. This suggests the need for developing site-specific Kc values for proper irrigation management

    Assessment of agricultural practices by Ethiopian women farmers: existence of gender disparities in access to mycotoxins training

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    Ethiopia is one of the countries with the lowest gender-equality performance in sub-Saharan Africa being ranked 121/134 in terms of the magnitude and scope of gender disparities by the United Nations Women’s Organisation. Within the farming communities, women represent 70% of the labour force, but they are neglected from accessing training events run by Ethiopian Universities (e.g. Haramaya University). A survey to assess the existence of gender disparities among Ethiopian women farmers with respect to agricultural labour and mycotoxins knowledge was conducted on three hundred and forty-nine women from the Oromia and Amhara regions. A higher illiteracy rate was found in women compared to men from both Oromia and Amhara regions. Women played a key role in agricultural activities while having limited access to modern technologies compared to their male counterparts. Women were mainly responsible for sorting spoiled crops. Especially in Amhara, these were intended for home consumption, representing a serious health risk for local people. Overall, women from Amhara were more aware than women from Oromia about what mycotoxins are (e.g. aflatoxins), their impact and risk of occurrence in crops. Women in Amhara were also more intended to act towards mycotoxins in the future compared to women from Oromia. Only 0.24% of women have previously attended a training on mycotoxins. The radio seemed to be the most efficient way to deliver training to Ethiopian women farmers from these regions. Mycotoxins trainings were the second option of choice by all women surveyed. Such findings clearly stated the existence of gender inequality in the two Ethiopian regions considered. Empower women’s knowledge about mycotoxins will not only benefit agricultural income and the national economy, but it will also provide women the recognition they equally deserve alongside their male counterparts in future agricultural training programs and interventions.This research was supported by a Global Challenges Research Fund Quality-Research (QR-GCRF) to Cranfield University

    Screening of the Pan-African Natural Product Library Identifies Ixoratannin A-2 and Boldine as Novel HIV-1 Inhibitors

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    The continued burden of HIV in resource-limited regions such as parts of sub-Saharan Africa, combined with adverse effects and potential risks of resistance to existing antiretroviral therapies, emphasize the need to identify new HIV inhibitors. Here we performed a virtual screen of molecules from the pan-African Natural Product Library, the largest collection of medicinal plant-derived pure compounds on the African continent. We identified eight molecules with structural similarity to reported interactors of Vpu, an HIV-1 accessory protein with reported ion channel activity. Using in vitro HIV-1 replication assays with a CD4+ T cell line and peripheral blood mononuclear cells, we confirmed antiviral activity and minimal cytotoxicity for two compounds, ixoratannin A-2 and boldine. Notably, ixoratannin A-2 retained inhibitory activity against recombinant HIV-1 strains encoding patient-derived mutations that confer resistance to protease, non-nucleoside reverse transcriptase, or integrase inhibitors. Moreover, ixoratannin A-2 was less effective at inhibiting replication of HIV-1 lacking Vpu, supporting this protein as a possible direct or indirect target. In contrast, boldine was less effective against a protease inhibitor-resistant HIV-1 strain. Both ixoratannin A-2 and boldine also inhibited in vitro replication of hepatitis C virus (HCV). However, BIT-225, a previously-reported Vpu inhibitor, demonstrated antiviral activity but also cytotoxicity in HIV-1 and HCV replication assays. Our work identifies pure compounds derived from African plants with potential novel activities against viruses that disproportionately afflict resource-limited regions of the world

    NEAT: An efficient network enrichment analysis test

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    Background: Network enrichment analysis is a powerful method, which allows to integrate gene enrichment analysis with the information on relationships between genes that is provided by gene networks. Existing tests for network enrichment analysis deal only with undirected networks, they can be computationally slow and are based on normality assumptions. Results: We propose NEAT, a test for network enrichment analysis. The test is based on the hypergeometric distribution, which naturally arises as the null distribution in this context. NEAT can be applied not only to undirected, but to directed and partially directed networks as well. Our simulations indicate that NEAT is considerably faster than alternative resampling-based methods, and that its capacity to detect enrichments is at least as good as the one of alternative tests. We discuss applications of NEAT to network analyses in yeast by testing for enrichment of the Environmental Stress Response target gene set with GO Slim and KEGG functional gene sets, and also by inspecting associations between functional sets themselves. Conclusions: NEAT is a flexible and efficient test for network enrichment analysis that aims to overcome some limitations of existing resampling-based tests. The method is implemented in the R package neat, which can be freely downloaded from CRAN ( https://cran.r-project.org/package=neat )

    Genetic and phenotypic characterization of African goat populations to prioritize conservation and production efforts for small-holder farmers in sub-Saharan Africa

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    Food production systems in Africa depend heavily on the use of locally adapted animals. Goats are critical to small-holder farmers being easier to acquire, maintain, and act as scavengers in sparse pasture. Indigenous goats have undergone generations of adaptation and genetic isolation that have led to great phenotypic variation. These indigenous goats serve as a genetic reservoir for the identification of genes important to environmental adaptation, disease resistance, and improved productivity under local conditions. The immediate goal is to characterize African goat populations to prioritize conservation and production efforts and to develop genomic tools for use in selective breeding programs. We have established a standardized phenotypic scoring system to characterize goats including geographical information data, body measurements, photo characterization, and DNA. To date, 2,443 goats from 12 countries, representing 46 breeds have been sampled. Using the 50K goat beadchip, we report parameters of population structure of 620 African goats

    Back to the future : How Scenarios of future globalisation, biotechnology, disease and climate change can inform present animal genetic resources policy development

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    With the aim of assessing how exchange practices regarding Animal Genetic Resources for Food and Agriculture (AnGR) affect the various stakeholders in the livestock sector and to identify policies and regulatory options that could guide the global exchange, use and conservation of AnGR, an exploration of future scenarios was used as a complementary approach to reviewing the current situation, as well as to identify stakeholders’ views on AnGR policy development. Four 2050 future scenarios were developed and included:1. Globalization and regionalization.2. Biotechnology development.3. Climate change and environmental degradation.4. Diseases and disasters.Having developed the scenarios, these were then used as an input point for a wide range of stakeholder consultations. The findings show that such an approach has been a useful analytical tool. The ‘far’ future perspective appeared to make people less defensive, especially in a situation where current exchange problems were not yet particularly visible or well documented. Many interviewees broadly considered that it was not a question of ‘if’ the scenarios would happen, but rather a question of ‘when’. This implies that we might do well to consider the need to respond to future challenges through the proactive development of new policies or regulations. Such a finding is partly in contrast with the general perception of the current regulatory situation being broadly acceptable

    The burden of road traffic crashes, injuries and deaths in Africa:A systematic review and meta-analysis

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    Objective To estimate the burden of road traffic injuries and deaths for all road users and among different road user groups in Africa. Methods We searched MEDLINE, EMBASE, Global Health, Google Scholar, websites of African road safety agencies and organizations for registry- and population-based studies and reports on road traffic injury and death estimates in Africa, published between 1980 and 2015. Available data for all road users and by road user group were extracted and analysed. We conducted a random-effects meta-analysis and estimated pooled rates of road traffic injuries and deaths. Findings We identified 39 studies from 15 African countries. The estimated pooled rate for road traffic injury was 65.2 per 100000 population (95% confidence interval, CI: 60.8–69.5) and the death rate was 16.6 per 100 000 population (95% CI: 15.2–18.0). Road traffic injury rates increased from 40.7 per 100 000 population in the 1990s to 92.9 per 100 000 population between 2010 and 2015, while death rates decreased from 19.9 per 100 000 population in the 1990s to 9.3 per 100 000 population between 2010 and 2015. The highest road traffic death rate was among motorized four-wheeler occupants at 5.9 per 100 000 population (95% CI: 4.4–7.4), closely followed by pedestrians at 3.4 per 100 000 population (95% CI: 2.5–4.2). Conclusion The burden of road traffic injury and death is high in Africa. Since registry-based reports underestimate the burden, a systematic collation of road traffic injury and death data is needed to determine the true burden

    Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019 : a systematic analysis for the Global Burden of Disease Study 2019

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    Background In an era of shifting global agendas and expanded emphasis on non-communicable diseases and injuries along with communicable diseases, sound evidence on trends by cause at the national level is essential. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic scientific assessment of published, publicly available, and contributed data on incidence, prevalence, and mortality for a mutually exclusive and collectively exhaustive list of diseases and injuries. Methods GBD estimates incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) due to 369 diseases and injuries, for two sexes, and for 204 countries and territories. Input data were extracted from censuses, household surveys, civil registration and vital statistics, disease registries, health service use, air pollution monitors, satellite imaging, disease notifications, and other sources. Cause-specific death rates and cause fractions were calculated using the Cause of Death Ensemble model and spatiotemporal Gaussian process regression. Cause-specific deaths were adjusted to match the total all-cause deaths calculated as part of the GBD population, fertility, and mortality estimates. Deaths were multiplied by standard life expectancy at each age to calculate YLLs. A Bayesian meta-regression modelling tool, DisMod-MR 2.1, was used to ensure consistency between incidence, prevalence, remission, excess mortality, and cause-specific mortality for most causes. Prevalence estimates were multiplied by disability weights for mutually exclusive sequelae of diseases and injuries to calculate YLDs. We considered results in the context of the Socio-demographic Index (SDI), a composite indicator of income per capita, years of schooling, and fertility rate in females younger than 25 years. Uncertainty intervals (UIs) were generated for every metric using the 25th and 975th ordered 1000 draw values of the posterior distribution. Findings Global health has steadily improved over the past 30 years as measured by age-standardised DALY rates. After taking into account population growth and ageing, the absolute number of DALYs has remained stable. Since 2010, the pace of decline in global age-standardised DALY rates has accelerated in age groups younger than 50 years compared with the 1990-2010 time period, with the greatest annualised rate of decline occurring in the 0-9-year age group. Six infectious diseases were among the top ten causes of DALYs in children younger than 10 years in 2019: lower respiratory infections (ranked second), diarrhoeal diseases (third), malaria (fifth), meningitis (sixth), whooping cough (ninth), and sexually transmitted infections (which, in this age group, is fully accounted for by congenital syphilis; ranked tenth). In adolescents aged 10-24 years, three injury causes were among the top causes of DALYs: road injuries (ranked first), self-harm (third), and interpersonal violence (fifth). Five of the causes that were in the top ten for ages 10-24 years were also in the top ten in the 25-49-year age group: road injuries (ranked first), HIV/AIDS (second), low back pain (fourth), headache disorders (fifth), and depressive disorders (sixth). In 2019, ischaemic heart disease and stroke were the top-ranked causes of DALYs in both the 50-74-year and 75-years-and-older age groups. Since 1990, there has been a marked shift towards a greater proportion of burden due to YLDs from non-communicable diseases and injuries. In 2019, there were 11 countries where non-communicable disease and injury YLDs constituted more than half of all disease burden. Decreases in age-standardised DALY rates have accelerated over the past decade in countries at the lower end of the SDI range, while improvements have started to stagnate or even reverse in countries with higher SDI. Interpretation As disability becomes an increasingly large component of disease burden and a larger component of health expenditure, greater research and development investment is needed to identify new, more effective intervention strategies. With a rapidly ageing global population, the demands on health services to deal with disabling outcomes, which increase with age, will require policy makers to anticipate these changes. The mix of universal and more geographically specific influences on health reinforces the need for regular reporting on population health in detail and by underlying cause to help decision makers to identify success stories of disease control to emulate, as well as opportunities to improve
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