50 research outputs found

    Livestock waste-menace: Fish wealth-solution

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    A review of the use of livestock wastes for sustainable fish wealth creation was done, using information from literature and data from field observation and experimentation. Livestock wastes including animal manure and poultry by-products, which are a menace to the environment, are sources of wealth creation in fish farming. In Nigeria, about 932.5 metric tonnes of manure is produced annually from the well established livestock industries which keep expanding at the rate of 8% year-1. Nigeria is the largest importer of frozen fish in the world with a fish demand of between 106,200 - 128,052 metric tonnes year-1. This situation calls for increased fish production which can be achieved through the effective utilization of livestock wastes. Properly treated animal manure can serve as organic fertilizer/feed component. Consequently, there is enhanced fish farming profitability, efficient resources utilization and conservation of environment due to waste management.Key words: Wastes, manure, fish, plankton, livestock, fertilizer, fee

    Framework for assessing the viability of implementing dual water reticulation systems in South Africa

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    In many settlements across the world (e.g. Pimpama Coomera and Mawson Lakes – Australia, Hong Kong – China, Majuro – Marshall Islands, Tarawa – Kiribati, and Windhoek – Namibia), dual water reticulation systems have been implemented in response to increasing water demands and decreasing freshwater availability. A dual water reticulation system comprises separate pipes that supply different water qualities to the end consumer. A set of pipes supply potable water while another set of pipes supply non-potable water. The non-potable water is targeted at meeting water requirements traditionally met using potable water (e.g. toilet and urinal flushing, landscaping irrigation, and industrial cooling). This therefore frees potable water to be used for previously unmet or increasing potable water requirements. For several reasons including the dearth of relevant national regulatory and guideline documents, consumer and decision-maker perceptions, ignorance, and appropriate decision-making tools, the use of dual water reticulation systems in South Africa has been limited. The aim of this study was therefore to develop a decision-making framework, using robust criteria, for assessing the viability of implementing dual systems in South Africa. This aim was achieved through undertaking literature reviews on the subject, an investigation of non-potable water consumers’ and decision-makers’ perceptions using questionnaires, and the actual development of a framework using data obtained from the literature review and questionnaires. The questionnaires were developed using seven key issues i.e. public health and safety, economics, technical feasibility, legislation/regulations and guidelines, organisational capacity, social acceptance, and public education. The various aspects of the Triple Bottom Line of sustainability (i.e. economic, environmental and social) provided structure to the framework while the Triple Bottom Line approach was utilised in the assessment of the different criteria

    Assessment of groundwater contamination by leachate near a municipal solid waste landfill

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    Physico-chemical and microbiological parameters were analyzed in leachate and groundwater samples obtained at different locations adjacent to a municipal solid waste landfill in order to assess the impact of leachate percolation on groundwater quality. Total dissolved solids (TDS), electrical conductivity (EC), and Na+ exceeded the World Health Organization (WHO) tolerance levels for drinking water in 62.5, 100, and 37.5% of the groundwater samples, respectively with pH and Fe exceeding WHO limits in 75% of the samples. Significant negative correlations of -0.839, -0.590, and -0.590 were shown by Na+, TDS, and EC respectively to distance from landfill. A high population of Enterobacteriaceae ranging from 4.0 × 103 ± 0 to 1.0575 × 106 ± 162,705 CFU/ml was also detected in the groundwater samples, indicating contamination. The results show that the leachate from the landfill has a minimal impact on the groundwater resource and this can be attributed to the existing soil stratigraphy at the site consisting of clay which is deduced to have a significant influence on the natural attenuation of leachate into groundwater.Keywords: Groundwater, correlation, percolation, landfill, leachate, municipal solid waste, natural attenuation, Enterobacteriaceae

    Carbon stock in topsoil, standing floor litter and above ground biomass in Tectona grandis plantation 10-years after establishment in Ile-Ife, Southwestern Nigeria

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    This paper provides information on carbon stock at the habitat level in the above ground biomass (ABG), standing floor litter and soils in a 10 year-old Tectona grandis plantation following restoration of a degraded secondary forest at Obafemi Awolowo University, Ile-Ife Nigeria. Four sample plots 25 m x 25 m, two in Tectona grandis plantation and two in a nearby degraded secondary forest were studied. Soil samples were randomly collected at 0-20 cm and bulk density determined. Standing floor litter was randomly collected at five points every three months for one year, sorted into different litter components. Soil and standing floor litters carbon concentration and C stock were determined. Above ground biomass (ABG) and carbon stock were significantly (p=0.003 and p=0.0001) higher in the plantation, the order is ABG > soil > standing floor leaf litter > standing floor wood litter. Soil C stock varies from 10.47 t ha-1 in the plantation to 10.58 t ha-1 C in the forest. Above ground biomass, standing leaf and wood litter were estimated as 18.26-5.81, 0.49-0.36, 0.06-0.08 t ha-1 C, respectively (plantation to secondary forest). Reforestation after 10 years has increased C stocks by 45% in ABG in the plantations.Keywords: Carbon stock, degraded forest, plantation, reforestation, standing litter

    Economic, nutritional and medicinal values of African walnut (Tetracarpidium conophorum) in Nigeria (Hutch. & Dalziel): a review

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    The Nigeria Walnut (Tetracarpidium conophorum) is a climber crop species that help in poverty reduction through improvement of the purchasing power of families and their standard of living. African walnut has proven evidence that leads to general acceptability to its protective effects against certain diseases majorly the cardiovascular disease (CDV). It has many other medicinal values such as treatment of Diabetic, maintenance of healthy bone, Anti-malarial, diseases prevention, pregnancy protection and sperm improvement, weight management and so on. The consumption of this fruit is not only effective for the health of man but contributes to other lifestyles characteristics backed up by evidence from certain scientific investigations. However, the challenges facing its year round availability have not been fully documented and data related to its contributions to livelihoods of rural farmers and it nutritional value is not readily available to the populace, thereby places the plant in danger of genetic extinction and disappearance which have the potential to restrict its development options. Therefore, this paper reviewed the monetary contribution of African Walnut, its potential roles in poverty reduction, commitment to national advancement and value added exports from Nigeria, hence the investigation is expected to bridge some of this gap, giving an overview of the present information encompassing the economic commitment of Walnut, it nutritional and medicinal values in Nigeria. Key words: Economics, Nutrition, Medicinal Benefits, Chemical composition, Walnu

    Serum testosterone levels of HbSS (sickle cell disease) male subjects in Lagos, Nigeria

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    <p>Abstract</p> <p>Background</p> <p>Infertility is a major problem in sickle cell disease patients, especially in males. In addition to low serum testosterone, other abnormalities involving the accessory sex organs, such as the seminal vesicles and the prostate gland, as well as marked decrease in ejaculate volume may be observed in male HbSS patients. Hence, the need to study the role of sex hormones as a cause of infertility in male HbSS patients.</p> <p>Methods</p> <p>An unmatched case-control study was performed using seventy-five consenting subjects from Lagos University Teaching Hospital. These included 47 patients with haemoglobin phenotype SS from the Sickle cell clinic and 28 volunteered medical students and members of staff with haemoglobin phenotype AA. Demographic data were obtained using a self-administered questionnaire. A total of 5 mls of blood was collected from each subject between 9.00 am & 11.am, and assayed for serum testosterone concentration.</p> <p>Results</p> <p>The concentrations of serum testosterone in HbSS patients ranged from 0.2 to 4.3 ng/ml with a mean of 1.28 ± 0.72 ng/ml whilst the values in HbAA controls ranged from 1.2 to 6.9 ng/ml with a mean of 2.63 ± 1.04 ng/ml. Seven (25.0%) of the 28 controls had serum testosterone concentration lower than the quoted reference (normal) range whereas 44 (93.6%) of the 47 HbSS subjects had serum testosterone concentration lower than the reference range.</p> <p>Conclusion</p> <p>Overall, subjects with HbSS have significantly lower mean serum testosterone than HbAA controls.</p

    MasakhaNER 2.0: Africa-centric Transfer Learning for Named Entity Recognition

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    African languages are spoken by over a billion people, but are underrepresented in NLP research and development. The challenges impeding progress include the limited availability of annotated datasets, as well as a lack of understanding of the settings where current methods are effective. In this paper, we make progress towards solutions for these challenges, focusing on the task of named entity recognition (NER). We create the largest human-annotated NER dataset for 20 African languages, and we study the behavior of state-of-the-art cross-lingual transfer methods in an Africa-centric setting, demonstrating that the choice of source language significantly affects performance. We show that choosing the best transfer language improves zero-shot F1 scores by an average of 14 points across 20 languages compared to using English. Our results highlight the need for benchmark datasets and models that cover typologically-diverse African languages

    Prevalence and burden of HBV co-infection among people living with HIV:A global systematic review and meta-analysis

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    Globally, in 2017 35 million people were living with HIV (PLHIV) and 257 million had chronic HBV infection (HBsAg positive). The extent of HIV-HBsAg co-infection is unknown. We undertook a systematic review to estimate the global burden of HBsAg co-infection in PLHIV. We searched MEDLINE, Embase and other databases for published studies (2002-2018) measuring prevalence of HBsAg among PLHIV. The review was registered with PROSPERO (#CRD42019123388). Populations were categorized by HIV-exposure category. The global burden of co-infection was estimated by applying regional co-infection prevalence estimates to UNAIDS estimates of PLHIV. We conducted a meta-analysis to estimate the odds of HBsAg among PLHIV compared to HIV-negative individuals. We identified 506 estimates (475 studies) of HIV-HBsAg co-infection prevalence from 80/195 (41.0%) countries. Globally, the prevalence of HIV-HBsAg co-infection is 7.6% (IQR 5.6%-12.1%) in PLHIV, or 2.7 million HIV-HBsAg co-infections (IQR 2.0-4.2). The greatest burden (69% of cases; 1.9 million) is in sub-Saharan Africa. Globally, there was little difference in prevalence of HIV-HBsAg co-infection by population group (approximately 6%-7%), but it was slightly higher among people who inject drugs (11.8% IQR 6.0%-16.9%). Odds of HBsAg infection were 1.4 times higher among PLHIV compared to HIV-negative individuals. There is therefore, a high global burden of HIV-HBsAg co-infection, especially in sub-Saharan Africa. Key prevention strategies include infant HBV vaccination, including a timely birth-dose. Findings also highlight the importance of targeting PLHIV, especially high-risk groups for testing, catch-up HBV vaccination and other preventative interventions. The global scale-up of antiretroviral therapy (ART) for PLHIV using a tenofovir-based ART regimen provides an opportunity to simultaneously treat those with HBV co-infection, and in pregnant women to also reduce mother-to-child transmission of HBV alongside HIV

    Systems biology discoveries using non-human primate pluripotent stem and germ cells: novel gene and genomic imprinting interactions as well as unique expression patterns

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    The study of pluripotent stem cells has generated much interest in both biology and medicine. Understanding the fundamentals of biological decisions, including what permits a cell to maintain pluripotency, that is, its ability to self-renew and thereby remain immortal, or to differentiate into multiple types of cells, is of profound importance. For clinical applications, pluripotent cells, including both embryonic stem cells and adult stem cells, have been proposed for cell replacement therapy for a number of human diseases and disorders, including Alzheimer's, Parkinson's, spinal cord injury and diabetes. One challenge in their usage for such therapies is understanding the mechanisms that allow the maintenance of pluripotency and controlling the specific differentiation into required functional target cells. Because of regulatory restrictions and biological feasibilities, there are many crucial investigations that are just impossible to perform using pluripotent stem cells (PSCs) from humans (for example, direct comparisons among panels of inbred embryonic stem cells from prime embryos obtained from pedigreed and fertile donors; genomic analysis of parent versus progeny PSCs and their identical differentiated tissues; intraspecific chimera analyses for pluripotency testing; and so on). However, PSCs from nonhuman primates are being investigated to bridge these knowledge gaps between discoveries in mice and vital information necessary for appropriate clinical evaluations. In this review, we consider the mRNAs and novel genes with unique expression and imprinting patterns that were discovered using systems biology approaches with primate pluripotent stem and germ cells

    Microfluidics: reframing biological enquiry

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    The underlying physical properties of microfluidic tools have led to new biological insights through the development of microsystems that can manipulate, mimic and measure biology at a resolution that has not been possible with macroscale tools. Microsystems readily handle sub-microlitre volumes, precisely route predictable laminar fluid flows and match both perturbations and measurements to the length scales and timescales of biological systems. The advent of fabrication techniques that do not require highly specialized engineering facilities is fuelling the broad dissemination of microfluidic systems and their adaptation to specific biological questions. We describe how our understanding of molecular and cell biology is being and will continue to be advanced by precision microfluidic approaches and posit that microfluidic tools - in conjunction with advanced imaging, bioinformatics and molecular biology approaches - will transform biology into a precision science
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