36 research outputs found

    Evaluation of Selected Cowpea Lines and Cultivars for Inherent Resistance against Cowpea Seed Beetle, Callosobruchus maculatus Fabricius (Coleoptera: Chrysomelidae: Bruchinae)

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    Four cowpea lines (IT99K-494-6, IT97K-390-2, IT84S-2246-4 and IT06K-141) obtained from the Genetic Resources Centre, International Institute of Tropical Agriculture (IITA), Ibadan Nigeria, one cultivar (Ife Brown) obtained from Institute of Agricultural Research and Training (IAR&T), Obafemi Awolowo University, Ibadan and two cultivars (Drum and Oloyin) obtained from Wazobia Market, Ogbomoso, Nigeria were screened for comparative susceptibility to the infestation of cowpea seed bruchid, Callosobruchus maculatus. The number of eggs laid on IT99K-494-6 (20.05) was significantly (p < 0.05) lower than the number laid on all the local cultivars (56.33-78.83). First filial progeny emergence (0.71) observed in IT99K-494-6 was significantly (p < 0.05) lower than 2.06 and 1.65 observed in Ife Brown and Drum cowpea cultivars, respectively. Percentage seed damage for 1T99k-49-6 (10.14) was significantly lower than the value obtained in 1T06K-141 (49.93) and Drum (47.74). Alkaloids content was significantly higher in IT06K–141 (31.67 mg/100 g) than in other lines and cultivars. Oloyin had the highest flavonoid (51.7 mg/100 g), tannins (43.3 mg/100 g) whereas 1T84S-2246-4 had the highest saponins (61.7 mg/100 g) Drum had the highest terpenoid (33.33 mg/100 g). Steroid was highest in Oloyin and 1T84S-2246-4 (11.67 mg/100 g). Reducing sugar was highest in Oloyin (5.33 mg/100 g) followed by 1T84S-2246–4 (4.3 mg/100 g) and IT06K–141 (4.0 mg/100 g). Significant and positive relationship exists between saponins content and the number of grains without exit holes (r = 0.46, p = 0.04), suggesting that high saponins was contributory to cowpea host plant resistance to the cowpea seed bruchid, C. maculatus. Keywords: cowpea cultivars, Drum, Oloyin, host plant resistanc

    Performance-based grouping of adapted and exotic drought-tolerant maize (Zea mays L) inbred lines under stressed and non-stressed conditions

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    Knowledge of the heterotic responses of elite adapted and exotic maize inbred lines can facilitate their utilization for population improvement and hybrid development. In the present study, a line x tester mating design was used to determine the combining ability of 20 elite drought-tolerant maize inbred lines developed at CIMMYT and IITA and to classify them into heterotic groups under diverse growing conditions. The 20 lines were crossed each with two inbred line testers representing the tropical and temperate heterotic pattern established in West and Cental Africa (WCA), to generate 40 testcrosses. A trial comprising the 40 testcrosses along with the cross between the two testers and three hybrid checks were evaluated at two environments in the dry season and at six environments in the rainy season. GCA effects were more important than SCA effects in controlling grain yield in both seasons. Two exotic lines in the dry season and four exotic lines in the rainy season had significantly positive GCA effects. Only EXL22 was identified as a superior line in the two seasons. Only two adapted lines had significantly positive GCA effects in either or both seasons while three adapted lines consistently had significantly negative GCA effects in both seasons. Hybrid between EXL22 and tester 9071 showed broad adaptation to all test environments. The two testers separated some of the lines into two main heterotic groups. the lines in each heterotic group and the good combiners will be utilized for developing populations for extracting new improved inbred lines

    Effect of Population Growth on Human Capital Development in Nigeria

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    Despite several studies on the impact of human capital development on economic development and studies on the impact of population growth on economic development, only a few studies have directly linked the impact of population growth on human capital development. In view of this, this study analyzes the causal relationship between population growth and human capital development from the period of 1970-2020. The primary school enrolment rate was set as a proxy for human development capital and the population growth rate used to measure population growth. In carryout the study, the Augmented Dicker Fuller test, was used to test for stationarity. The two variables were stationary at levels. The granger causality test was then carried out and results revealed bi-directional causality in that population growth granger caused human capital development and vice versa. This is a preliminary study that hopes to spur up more studies in this direction with specific interest to Nigeria. The policy recommendation is for massive investment in human capital along Lucas postulation and UNESCO education policy for developing nations like Nigeria

    STRENGTH CHARACTERISTICS OF CONCRETE MADE WITH RECYCLED CONCRETE AGGREGATE (RCA), MICRO-SILICA AND POLYPROPYLENE FIBRE

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    Recycled concrete aggregate has been widely researched to be capable of replacing natural coarse aggregate in concrete, however, with some inadequacies in its concrete’s ability to attain the same feat in mechanical properties as normal concrete. This research work attempts to improve the strength characteristics of concrete containing recycled coarse aggregate with the addition of admixtures (Micro-Silica and Superplasticizer) and Polypropylene fibre. Results showed that admixtures significantly improved the workability and mechanical properties of CRCA at all RCA replacement levels. Addition of PPF had significant effect on the flexural and splitting tensile strengths of CRCA, but not much impact on the compressive strength

    STRENGTH CHARACTERISTICS OF CONCRETE MADE WITH RECYCLED CONCRETE AGGREGATE (RCA), MICRO-SILICA AND POLYPROPYLENE FIBRE

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    Recycled concrete aggregate has been widely researched to be capable of replacing natural coarse aggregate in concrete, however, with some inadequacies in its concrete’s ability to attain the same feat in mechanical properties as normal concrete. This research work attempts to improve the strength characteristics of concrete containing recycled coarse aggregate with the addition of admixtures (Micro-Silica and Superplasticizer) and Polypropylene fibre. Results showed that admixtures significantly improved the workability and mechanical properties of CRCA at all RCA replacement levels. Addition of PPF had significant effect on the flexural and splitting tensile strengths of CRCA, but not much impact on the compressive strength

    Subnational mapping of HIV incidence and mortality among individuals aged 15–49 years in sub-Saharan Africa, 2000–18 : a modelling study

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    Background: High-resolution estimates of HIV burden across space and time provide an important tool for tracking and monitoring the progress of prevention and control efforts and assist with improving the precision and efficiency of targeting efforts. We aimed to assess HIV incidence and HIV mortality for all second-level administrative units across sub-Saharan Africa. Methods: In this modelling study, we developed a framework that used the geographically specific HIV prevalence data collected in seroprevalence surveys and antenatal care clinics to train a model that estimates HIV incidence and mortality among individuals aged 15–49 years. We used a model-based geostatistical framework to estimate HIV prevalence at the second administrative level in 44 countries in sub-Saharan Africa for 2000–18 and sought data on the number of individuals on antiretroviral therapy (ART) by second-level administrative unit. We then modified the Estimation and Projection Package (EPP) to use these HIV prevalence and treatment estimates to estimate HIV incidence and mortality by second-level administrative unit. Findings: The estimates suggest substantial variation in HIV incidence and mortality rates both between and within countries in sub-Saharan Africa, with 15 countries having a ten-times or greater difference in estimated HIV incidence between the second-level administrative units with the lowest and highest estimated incidence levels. Across all 44 countries in 2018, HIV incidence ranged from 2 ·8 (95% uncertainty interval 2·1–3·8) in Mauritania to 1585·9 (1369·4–1824·8) cases per 100 000 people in Lesotho and HIV mortality ranged from 0·8 (0·7–0·9) in Mauritania to 676· 5 (513· 6–888·0) deaths per 100 000 people in Lesotho. Variation in both incidence and mortality was substantially greater at the subnational level than at the national level and the highest estimated rates were accordingly higher. Among second-level administrative units, Guijá District, Gaza Province, Mozambique, had the highest estimated HIV incidence (4661·7 [2544·8–8120·3]) cases per 100000 people in 2018 and Inhassunge District, Zambezia Province, Mozambique, had the highest estimated HIV mortality rate (1163·0 [679·0–1866·8]) deaths per 100 000 people. Further, the rate of reduction in HIV incidence and mortality from 2000 to 2018, as well as the ratio of new infections to the number of people living with HIV was highly variable. Although most second-level administrative units had declines in the number of new cases (3316 [81· 1%] of 4087 units) and number of deaths (3325 [81·4%]), nearly all appeared well short of the targeted 75% reduction in new cases and deaths between 2010 and 2020. Interpretation: Our estimates suggest that most second-level administrative units in sub-Saharan Africa are falling short of the targeted 75% reduction in new cases and deaths by 2020, which is further compounded by substantial within-country variability. These estimates will help decision makers and programme implementers expand access to ART and better target health resources to higher burden subnational areas

    Mapping geographical inequalities in access to drinking water and sanitation facilities in low-income and middle-income countries, 2000-17

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    Background: Universal access to safe drinking water and sanitation facilities is an essential human right, recognised in the Sustainable Development Goals as crucial for preventing disease and improving human wellbeing. Comprehensive, high-resolution estimates are important to inform progress towards achieving this goal. We aimed to produce high-resolution geospatial estimates of access to drinking water and sanitation facilities. Methods: We used a Bayesian geostatistical model and data from 600 sources across more than 88 low-income and middle-income countries (LMICs) to estimate access to drinking water and sanitation facilities on continuous continent-wide surfaces from 2000 to 2017, and aggregated results to policy-relevant administrative units. We estimated mutually exclusive and collectively exhaustive subcategories of facilities for drinking water (piped water on or off premises, other improved facilities, unimproved, and surface water) and sanitation facilities (septic or sewer sanitation, other improved, unimproved, and open defecation) with use of ordinal regression. We also estimated the number of diarrhoeal deaths in children younger than 5 years attributed to unsafe facilities and estimated deaths that were averted by increased access to safe facilities in 2017, and analysed geographical inequality in access within LMICs. Findings: Across LMICs, access to both piped water and improved water overall increased between 2000 and 2017, with progress varying spatially. For piped water, the safest water facility type, access increased from 40·0% (95% uncertainty interval [UI] 39·4–40·7) to 50·3% (50·0–50·5), but was lowest in sub-Saharan Africa, where access to piped water was mostly concentrated in urban centres. Access to both sewer or septic sanitation and improved sanitation overall also increased across all LMICs during the study period. For sewer or septic sanitation, access was 46·3% (95% UI 46·1–46·5) in 2017, compared with 28·7% (28·5–29·0) in 2000. Although some units improved access to the safest drinking water or sanitation facilities since 2000, a large absolute number of people continued to not have access in several units with high access to such facilities (>80%) in 2017. More than 253 000 people did not have access to sewer or septic sanitation facilities in the city of Harare, Zimbabwe, despite 88·6% (95% UI 87·2–89·7) access overall. Many units were able to transition from the least safe facilities in 2000 to safe facilities by 2017; for units in which populations primarily practised open defecation in 2000, 686 (95% UI 664–711) of the 1830 (1797–1863) units transitioned to the use of improved sanitation. Geographical disparities in access to improved water across units decreased in 76·1% (95% UI 71·6–80·7) of countries from 2000 to 2017, and in 53·9% (50·6–59·6) of countries for access to improved sanitation, but remained evident subnationally in most countries in 2017. Interpretation: Our estimates, combined with geospatial trends in diarrhoeal burden, identify where efforts to increase access to safe drinking water and sanitation facilities are most needed. By highlighting areas with successful approaches or in need of targeted interventions, our estimates can enable precision public health to effectively progress towards universal access to safe water and sanitation

    Meningococcus serogroup C clonal complex ST-10217 outbreak in Zamfara State, Northern Nigeria.

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    After the successful roll out of MenAfriVac, Nigeria has experienced sequential meningitis outbreaks attributed to meningococcus serogroup C (NmC). Zamfara State in North-western Nigeria recently was at the epicentre of the largest NmC outbreak in the 21st Century with 7,140 suspected meningitis cases and 553 deaths reported between December 2016 and May 2017. The overall attack rate was 155 per 100,000 population and children 5-14 years accounted for 47% (3,369/7,140) of suspected cases. The case fatality rate (CFR) among children 5-9 years was 10%, double that reported among adults ≥ 30 years (5%). NmC and pneumococcus accounted for 94% (172/184) and 5% (9/184) of the laboratory-confirmed cases, respectively. The sequenced NmC belonged to the ST-10217 clonal complex (CC). All serotyped pneumococci were PCV10 serotypes. The emergence of NmC ST-10217 CC outbreaks threatens the public health gains made by MenAfriVac, which calls for an urgent strategic action against meningitis outbreaks

    Global age-sex-specific fertility, mortality, healthy life expectancy (HALE), and population estimates in 204 countries and territories, 1950-2019 : a comprehensive demographic analysis for the Global Burden of Disease Study 2019

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    Background: Accurate and up-to-date assessment of demographic metrics is crucial for understanding a wide range of social, economic, and public health issues that affect populations worldwide. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 produced updated and comprehensive demographic assessments of the key indicators of fertility, mortality, migration, and population for 204 countries and territories and selected subnational locations from 1950 to 2019. Methods: 8078 country-years of vital registration and sample registration data, 938 surveys, 349 censuses, and 238 other sources were identified and used to estimate age-specific fertility. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate age-specific fertility rates for 5-year age groups between ages 15 and 49 years. With extensions to age groups 10–14 and 50–54 years, the total fertility rate (TFR) was then aggregated using the estimated age-specific fertility between ages 10 and 54 years. 7417 sources were used for under-5 mortality estimation and 7355 for adult mortality. ST-GPR was used to synthesise data sources after correction for known biases. Adult mortality was measured as the probability of death between ages 15 and 60 years based on vital registration, sample registration, and sibling histories, and was also estimated using ST-GPR. HIV-free life tables were then estimated using estimates of under-5 and adult mortality rates using a relational model life table system created for GBD, which closely tracks observed age-specific mortality rates from complete vital registration when available. Independent estimates of HIV-specific mortality generated by an epidemiological analysis of HIV prevalence surveys and antenatal clinic serosurveillance and other sources were incorporated into the estimates in countries with large epidemics. Annual and single-year age estimates of net migration and population for each country and territory were generated using a Bayesian hierarchical cohort component model that analysed estimated age-specific fertility and mortality rates along with 1250 censuses and 747 population registry years. We classified location-years into seven categories on the basis of the natural rate of increase in population (calculated by subtracting the crude death rate from the crude birth rate) and the net migration rate. We computed healthy life expectancy (HALE) using years lived with disability (YLDs) per capita, life tables, and standard demographic methods. Uncertainty was propagated throughout the demographic estimation process, including fertility, mortality, and population, with 1000 draw-level estimates produced for each metric. Findings: The global TFR decreased from 2·72 (95% uncertainty interval [UI] 2·66–2·79) in 2000 to 2·31 (2·17–2·46) in 2019. Global annual livebirths increased from 134·5 million (131·5–137·8) in 2000 to a peak of 139·6 million (133·0–146·9) in 2016. Global livebirths then declined to 135·3 million (127·2–144·1) in 2019. Of the 204 countries and territories included in this study, in 2019, 102 had a TFR lower than 2·1, which is considered a good approximation of replacement-level fertility. All countries in sub-Saharan Africa had TFRs above replacement level in 2019 and accounted for 27·1% (95% UI 26·4–27·8) of global livebirths. Global life expectancy at birth increased from 67·2 years (95% UI 66·8–67·6) in 2000 to 73·5 years (72·8–74·3) in 2019. The total number of deaths increased from 50·7 million (49·5–51·9) in 2000 to 56·5 million (53·7–59·2) in 2019. Under-5 deaths declined from 9·6 million (9·1–10·3) in 2000 to 5·0 million (4·3–6·0) in 2019. Global population increased by 25·7%, from 6·2 billion (6·0–6·3) in 2000 to 7·7 billion (7·5–8·0) in 2019. In 2019, 34 countries had negative natural rates of increase; in 17 of these, the population declined because immigration was not sufficient to counteract the negative rate of decline. Globally, HALE increased from 58·6 years (56·1–60·8) in 2000 to 63·5 years (60·8–66·1) in 2019. HALE increased in 202 of 204 countries and territories between 2000 and 2019

    Adolescent transport and unintentional injuries: a systematic analysis using the Global Burden of Disease Study 2019

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    Background: Globally, transport and unintentional injuries persist as leading preventable causes of mortality and morbidity for adolescents. We sought to report comprehensive trends in injury-related mortality and morbidity for adolescents aged 10–24 years during the past three decades. Methods: Using the Global Burden of Disease, Injuries, and Risk Factors 2019 Study, we analysed mortality and disability-adjusted life-years (DALYs) attributed to transport and unintentional injuries for adolescents in 204 countries. Burden is reported in absolute numbers and age-standardised rates per 100 000 population by sex, age group (10–14, 15–19, and 20–24 years), and sociodemographic index (SDI) with 95% uncertainty intervals (UIs). We report percentage changes in deaths and DALYs between 1990 and 2019. Findings: In 2019, 369 061 deaths (of which 214 337 [58%] were transport related) and 31·1 million DALYs (of which 16·2 million [52%] were transport related) among adolescents aged 10–24 years were caused by transport and unintentional injuries combined. If compared with other causes, transport and unintentional injuries combined accounted for 25% of deaths and 14% of DALYs in 2019, and showed little improvement from 1990 when such injuries accounted for 26% of adolescent deaths and 17% of adolescent DALYs. Throughout adolescence, transport and unintentional injury fatality rates increased by age group. The unintentional injury burden was higher among males than females for all injury types, except for injuries related to fire, heat, and hot substances, or to adverse effects of medical treatment. From 1990 to 2019, global mortality rates declined by 34·4% (from 17·5 to 11·5 per 100 000) for transport injuries, and by 47·7% (from 15·9 to 8·3 per 100 000) for unintentional injuries. However, in low-SDI nations the absolute number of deaths increased (by 80·5% to 42 774 for transport injuries and by 39·4% to 31 961 for unintentional injuries). In the high-SDI quintile in 2010–19, the rate per 100 000 of transport injury DALYs was reduced by 16·7%, from 838 in 2010 to 699 in 2019. This was a substantially slower pace of reduction compared with the 48·5% reduction between 1990 and 2010, from 1626 per 100 000 in 1990 to 838 per 100 000 in 2010. Between 2010 and 2019, the rate of unintentional injury DALYs per 100 000 also remained largely unchanged in high-SDI countries (555 in 2010 vs 554 in 2019; 0·2% reduction). The number and rate of adolescent deaths and DALYs owing to environmental heat and cold exposure increased for the high-SDI quintile during 2010–19. Interpretation: As other causes of mortality are addressed, inadequate progress in reducing transport and unintentional injury mortality as a proportion of adolescent deaths becomes apparent. The relative shift in the burden of injury from high-SDI countries to low and low–middle-SDI countries necessitates focused action, including global donor, government, and industry investment in injury prevention. The persisting burden of DALYs related to transport and unintentional injuries indicates a need to prioritise innovative measures for the primary prevention of adolescent injury. Funding: Bill & Melinda Gates Foundation
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