36 research outputs found

    Performance of quality protein maize varieties and disease reaction in the derived-savanna agro-ecology of South-West Nigeria

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    Eight quality protein maize (QPM) varieties were evaluated for their agronomic performance and disease reaction in the derived savanna agro-ecology of south-west Nigeria for two years. The eightvarieties comprised of three hybrid varieties (Mama-ba, Dada-ba and CIDA-ba) and five open pollinated (OP) varieties (Obatampa, EV8363, EV8766, Pool-18-SR and Pool-15-SR). Differences among thevarieties were significant for plant and ear heights, number of days to 50% tasling and grain yield. Two hybrid varieties, Mama-ba and CIDA-ba had the highest grain yields of 4.59 and 4.20 t/ha respectively with Obatampa having the lowest yield of 2.95 t/ha. Mama-ba exhibited a yield advantage of 16.20% over the best OP variety (EV8363). All the QPM varieties were susceptible to southern leaf blight, curvelaria leaf spot and maize rust fungal diseases to varying degrees. The severity of each of these diseases onthe QPM varieties was however low less than 3.0. The implications of these findings on QPM introduction and development in Nigeria were discussed

    Variations in in vitro and in vivo indices of photoperiod sensitivity among kenaf (Hibiscus cannabinus) accessions in Nigeria

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    In equatorial climates, fibre yield is higher in photo-insensitive kenaf cultivars. To develop a rapid screening method, in vivo and in vitro indices were evaluated. Seven genotypes were grown at natural photoperiod and growth rates before and after flowering, days to flowering and fibre yield were recorded. In vitro, stem and leaf explants of genotypes Tainung and V400 which showed contrasting photoperiodic responses in vivo, were tested for callus induction at 0 and 12 h photoperiod. Calli were transferred to differentiation medium at 12 and 9 h photoperiod and numbers of green spots and embryogenic callus clusters were recorded. Flowering was delayed by at least 27 days in V400 relative to other genotypes. Growth rate reduced by 30% after flowering in all genotypes except V400 where it increased by 60%. Highest yield of 76 g / plant was recorded in V400. Eighty-four percent degree of callus formation by stem was higher than 51% by leaf explants of V400 irrespective of light regime. In Tainung, callus formation varied with explants and photoperiod. Green spots and embryogenic clusters were three times more in Tainung than V400. Both in vivo and in vitro results showed Tainung as photosensitive and V400 as photoinsenstive. Incubating kenaf callus in differentiation medium in 12 h light and evaluating for greenness was useful in screening for photoperiod sensitivity.Keywords: Kenaf, Hibiscus cannabinus, photosensitivity, in vitro screening, somatic embryogenesisAfrican Journal of Biotechnology Vol. 12(19), pp. 2581-258

    Effects of plant growth regulators on callus, shoot and root formation in fluted pumpkin (Telfairia occidentalis)

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    Root and stem explants of fluted pumpkin were cultured in medium containing different types and concentrations of plant growth regulators (PGRs). The explants were observed for callus, root and shoot formation parameters after four months. Differences among explants, plant growth regulators and their interaction were not significant for number of roots per plantlet. Callus formation was higher in stem than root explants. Stem explants formed more callus in medium containing naphthalene acetic acid than that containing indole acetic acid while the trend was opposite with root explants. Root explants did not form shoots, leaves or nodes in any of the PGR regimes, while a concentration of 1.5 mg/l benzylaminopurine (BAP) induced the highest numbers of shoots, nodes and leaves per stem explant. There was no callus, shoot, node and leaf formation by both explants when cultured in medium without PGRs while root formation was minimal

    Conservation Status and Habitat Preferences of Common Warthog ( Phacochoerus Africanus ) in Old Oyo National Park, Nigeria

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    This study assessed the conservation status and habitat preference of Common warthog in Old Oyo National Park, Nigeria using direct sighting and line transect method. The abundance estimate and encounter rate of common Warthog in the study area from 2018-2019 showed that year 2018 recorded 213 individuals at an encounter rate of 0.38/km while year 2019 recorded 184 individuals at an encounter rate of 0.32/km while the mean abundance estimate of common Warthog are 4.65\ub10.64 and 1.71\ub10.48 which represents 156 and 58 individuals at encounter rate of 0.55/km and 0.20/km in the wet season and dry season of year 2018 compared to year 2019 with average abundance estimate value of 4.00\ub10.85 and 1.41\ub10.61 which represents 135 and 48 individuals at an encounter rate of 0.47/km and 0.17/km for wet and dry season respectively. The mean age structure and sex ratio of the observed warthog population during dry and wet seasons revealed that juveniles had highest mean of age structures among the populations observed across the seasons. The habitat preference of common warthog revealed that they are mostly found in mixed woodland and open savanna with 112 observation and the lowest was recorded in the outcrop vegetation and open savanna with 21 individuals.in the wet season. During the dry season, mixed woodland/open savanna and Riparian grassland had the highest sightings of 45 and 33 individuals each. The outcrop vegetation/open savanna had the lowest observation of 1 individuals only. The study also recommends that more aspect of the ecology of the animal should be studied in details and emphasis should be placed on the habitat requirements

    QTL analysis for resistance to foliar damage caused by Thrips tabaci and Frankliniella schultzei (Thysanoptera: Thripidae) feeding in cowpea [Vigna unguiculata (L.) Walp.]

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    Three quantitative trait loci (QTL) for resistance to Thrips tabaci and Frankliniella schultzei were identified using a cowpea recombinant inbred population of 127 F2:8 lines. An amplified fragment length polymorphism (AFLP) genetic linkage map and foliar feeding damage ratings were used to identify genomic regions contributing toward resistance to thrips damage. Based on Pearson correlation analysis, damage ratings were highly correlated (r ≥ 0.7463) across seven field experiments conducted in 2006, 2007, and 2008. Using the Kruskall–Wallis and Multiple-QTL model mapping packages of MapQTL 4.0 software, three QTL, Thr-1, Thr-2, and Thr-3, were identified on linkage groups 5 and 7 accounting for between 9.1 and 32.1% of the phenotypic variance. AFLP markers ACC-CAT7, ACG-CTC5, and AGG-CAT1 co-located with QTL peaks for Thr-1, Thr-2, and Thr-3, respectively. Results of this study will provide a resource for molecular marker development and the genetic characterization of foliar thrips resistance in cowpea

    Follicular fluid content and oocyte quality: from single biochemical markers to metabolomics

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    The assessment of oocyte quality in human in vitro fertilization (IVF) is getting increasing attention from embryologists. Oocyte selection and the identification of the best oocytes, in fact, would help to limit embryo overproduction and to improve the results of oocyte cryostorage programs. Follicular fluid (FF) is easily available during oocyte pick-up and theorically represents an optimal source on non-invasive biochemical predictors of oocyte quality. Unfortunately, however, the studies aiming to find a good molecular predictor of oocyte quality in FF were not able to identify substances that could be used as reliable markers of oocyte competence to fertilization, embryo development and pregnancy. In the last years, a well definite trend toward passing from the research of single molecular markers to more complex techniques that study all metabolites of FF has been observed. The metabolomic approach is a powerful tool to study biochemical predictors of oocyte quality in FF, but its application in this area is still at the beginning. This review provides an overview of the current knowledge about the biochemical predictors of oocyte quality in FF, describing both the results coming from studies on single biochemical markers and those deriving from the most recent studies of metabolomic

    Diabetes mortality and trends before 25 years of age: an analysis of the Global Burden of Disease Study 2019

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    Background Diabetes, particularly type 1 diabetes, at younger ages can be a largely preventable cause of death with the correct health care and services. We aimed to evaluate diabetes mortality and trends at ages younger than 25 years globally using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019. Methods We used estimates of GBD 2019 to calculate international diabetes mortality at ages younger than 25 years in 1990 and 2019. Data sources for causes of death were obtained from vital registration systems, verbal autopsies, and other surveillance systems for 1990–2019. We estimated death rates for each location using the GBD Cause of Death Ensemble model. We analysed the association of age-standardised death rates per 100 000 population with the Socio-demographic Index (SDI) and a measure of universal health coverage (UHC) and described the variability within SDI quintiles. We present estimates with their 95% uncertainty intervals. Findings In 2019, 16 300 (95% uncertainty interval 14 200 to 18 900) global deaths due to diabetes (type 1 and 2 combined) occurred in people younger than 25 years and 73·7% (68·3 to 77·4) were classified as due to type 1 diabetes. The age-standardised death rate was 0·50 (0·44 to 0·58) per 100 000 population, and 15 900 (97·5%) of these deaths occurred in low to high-middle SDI countries. The rate was 0·13 (0·12 to 0·14) per 100 000 population in the high SDI quintile, 0·60 (0·51 to 0·70) per 100 000 population in the low-middle SDI quintile, and 0·71 (0·60 to 0·86) per 100 000 population in the low SDI quintile. Within SDI quintiles, we observed large variability in rates across countries, in part explained by the extent of UHC (r2=0·62). From 1990 to 2019, age-standardised death rates decreased globally by 17·0% (−28·4 to −2·9) for all diabetes, and by 21·0% (–33·0 to −5·9) when considering only type 1 diabetes. However, the low SDI quintile had the lowest decline for both all diabetes (−13·6% [–28·4 to 3·4]) and for type 1 diabetes (−13·6% [–29·3 to 8·9]). Interpretation Decreasing diabetes mortality at ages younger than 25 years remains an important challenge, especially in low and low-middle SDI countries. Inadequate diagnosis and treatment of diabetes is likely to be major contributor to these early deaths, highlighting the urgent need to provide better access to insulin and basic diabetes education and care. This mortality metric, derived from readily available and frequently updated GBD data, can help to monitor preventable diabetes-related deaths over time globally, aligned with the UN's Sustainable Development Targets, and serve as an indicator of the adequacy of basic diabetes care for type 1 and type 2 diabetes across nations.publishedVersio

    Biological versus chronological ovarian age:implications for assisted reproductive technology

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    <p>Abstract</p> <p>Background</p> <p>Women have been able to delay childbearing since effective contraception became available in the 1960s. However, fertility decreases with increasing maternal age. A slow but steady decrease in fertility is observed in women aged between 30 and 35 years, which is followed by an accelerated decline among women aged over 35 years. A combination of delayed childbearing and reduced fecundity with increasing age has resulted in an increased number and proportion of women of greater than or equal to 35 years of age seeking assisted reproductive technology (ART) treatment.</p> <p>Methods</p> <p>Literature searches supplemented with the authors' knowledge.</p> <p>Results</p> <p>Despite major advances in medical technology, there is currently no ART treatment strategy that can fully compensate for the natural decline in fertility with increasing female age. Although chronological age is the most important predictor of ovarian response to follicle-stimulating hormone, the rate of reproductive ageing and ovarian sensitivity to gonadotrophins varies considerably among individuals. Both environmental and genetic factors contribute to depletion of the ovarian oocyte pool and reduction in oocyte quality. Thus, biological and chronological ovarian age are not always equivalent. Furthermore, biological age is more important than chronological age in predicting the outcome of ART. As older patients present increasingly for ART treatment, it will become more important to critically assess prognosis, counsel appropriately and optimize treatment strategies. Several genetic markers and biomarkers (such as anti-Müllerian hormone and the antral follicle count) are emerging that can identify women with accelerated biological ovarian ageing. Potential strategies for improving ovarian response include the use of luteinizing hormone (LH) and growth hormone (GH). When endogenous LH levels are heavily suppressed by gonadotrophin-releasing hormone analogues, LH supplementation may help to optimize treatment outcomes for women with biologically older ovaries. Exogenous GH may improve oocyte development and counteract the age-related decline of oocyte quality. The effects of GH may be mediated by insulin-like growth factor-I, which works synergistically with follicle-stimulating hormone on granulosa and theca cells.</p> <p>Conclusion</p> <p>Patients with biologically older ovaries may benefit from a tailored approach based on individual patient characteristics. Among the most promising adjuvant therapies for improving ART outcomes in women of advanced reproductive age are the administration of exogenous LH or GH.</p

    Effect of plant growth regulators on indirect somatic embryogenesis of Kenaf (Hibiscus cannabinus)

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    No Abstract.Nigerian Journal of Genetics Vol. 20 2006: pp. 41-4

    Retention and loss to follow-up in antiretroviral treatment programmes in southeast Nigeria.

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    BACKGROUND: This study generated new information about the outcomes of patients enrolled in antiretroviral treatment programmes, as well as the true outcomes of those lost to follow-up (LTF). METHODS: Anonymized data were collected for patients enrolled over a 12-month period from two programmes (public and private) in southeast Nigeria. Estimates of retention, LTF, mortality and transfers were computed. All LTF enrollees (defined as patients who had missed three scheduled visits) whose contact information met pre-defined criteria were traced. RESULTS: A total of 481 (public) and 553 (private) records were included. Median duration of follow-up was about 14 months. Cumulative retention and LTF proportions were 66·5 and 32·8% (public), and 82·6 and 11·0% (private) respectively. LTF rates at third, sixth, ninth and twelfth months were 7·5, 19·3, 25·4 and 29·6% respectively (public), and 4·1, 7·1, 9·0 and 10·0% (private). LTF was higher among males, patients with CD4(+) cell count ≤200 and public programme enrollees. For the public facility, 56·7% of 104 traceable patients were dead and 38·8% were alive; the figures were 34·2 and 60·5% of 46 patients respectively for the private. Most deaths had occurred by the third month. CONCLUSION: Not all patients enrolled for treatment were retained. Though some died, many were LTF, lived within the community, and could develop and transmit resistant viral stains. Most traced patients were dead by the third month and poor contact information limited the effectiveness of tracing. Antiretroviral treatment programmes need to improve documentation processes and develop and implement tracing strategies
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