Estimation of storm runoff loads based on rainfall-related variables and power law models – Case study in Alexandra

This paper compares the use of simple regression equations of three commonly used pollutant build-up and wash-off functions, namely linear, power and exponential functions, to estimate event pollutant loads. The comparative study indicated that, event loads are better estimated as power functions of storm-related independent variables. On the notion that rainfall data are more readily available, easy and less expensive to collect than runoff data, the calibrated model was verified using rainfall volume as independent variable. The verified model was then used to develop load-duration-intensity curves to serve as predictive tools. Planners and engineers can use these predictive tools to obtain an approximate estimate of event pollutant loads in storm runoff from Alexandra (and also other townships with similar physical, land-use, climatic and hydraulic characteristics and water quality issues) for the purpose of managing or improving drainage conditions in the township. Water SA Vol.32 (2) 2006: pp.1-

INVESTIGATION OF HORIZONTAL AND VERTICAL CONTROLS ON KNUST CAMPUS

Controls are coordinated horizontal or vertical positional data for land and geographic information systems forming a framework to which surveys are started, referenced and adjusted. Controls on KNUST campus were established over three decades ago with new ones being added as and when t h e y a r e required. Conventional survey methods like trilateration, triangulation and traversing were used and are still being used for densification of controls. These approaches involve the use of low precision instruments such as analogue/optical theodolites and leveling equipment. Since the establishment of these controls, t h e y have not been investigated but t h e y are being used for p r o j e c t development. A modern method that uses satellite positioning techniques such as GPS is currently in operation and has numerous advantages in the establishmentof control networks. GPS control surveys were carried-out on seven controls and ellipsoidal coordinates were obtained in the World Geodetic System 84 reference frame. The Cartesian coordinates were projected onto the Universal Transverse Mercator frame. A two dimensional conformal transformation was done using existing KNUST boundary coordinatesto Ghana National coordinates based on the War Office ellipsoid. Precise Level routines were carried out on the seven controls for the computations of orthometric heights. The method of least squares adjustment, root mean square errors (RMSE), standard errors (SE) and residuals derived were used to analyse the differences in horizontal positions and heights of the controls.The linear displacement between the computed and the existing coordinates were within the range of 0.015m to 0.014m. The RMSE were 0.048 and 0.106, whiles the SE were also 0.057 and 0.125 for the northings and eastings respectively. The computed and existing heights differed between -0.075m and -0.004m with a mean downward movement of 0.011m.Keywords: Surveying; coordinates; control points; GPS; precise leve

Effects of farmers\' seed source on maize seed quality and crop productivity

Although farmer-saved seeds constitute about 90 per cent of maize seeds planted annually, their effects on crop performance are not well known. This study determined the seed quality and field performance of farmer-saved seeds of the most popular quality protein maize (QPM) variety, Obatanpa, compared to the certified seed of the same variety. Seed samples collected from four locations (Kwadaso, Ejura, Nkoranzah and Wenchi) showed higher percentage complete vital staining of embryos using 2, 3, 5 triphenyl tetrazolium chloride (TTC) and higher 1000-seed weight in certified seeds, indicating high vigour and complete seed development. Whereas germinating seedlings of the certified seeds did not show any fungal growth, farmersaved seeds showed profuse fungal development and stunting. Seedling counts showed 9 and 21 per cent reduction in certified and farmer-saved seeds, respectively; but plant counts before harvest showed 12 and 23 per cent reduction. Plants originating from certified seeds flowered at the predetermined date of 55 days, but the farmer-saved seeds flowered about a day or two later owing to reduced vigour. Lodging was less in plants originating from certified seeds, particularly in the trial planted at Ejura (transition zone) compared to Kwadaso (forest zone). The advantages of certified seeds reflected on increased grain yield, which was about 1.2 t ha-1, equal to ¢1,100,000.00 ($110) ha-1 or 47 per cent increases over the farmer-saved seeds. The study, therefore, showed the importance of certified seeds in increasing maize productivity and farmers' incomes. Bien que la semence gardée par l'agriculteur constitue environ 90 pour cent de graines de maïs semées annuellement, ses effets sur le rendement de culture ne sont pas bien connus. Une étude était entreprise pour déterminer la qualité de graine et le rendement sur le terrain de semence gardé par l'agriculteur de la variété la plus populaire du maïs protéique de qualité (MPQ), Obatanpa, comparé à la graine certifiée de la même variété. Les échantillons de graine recueillis de quatre emplacements (Wenchi, Nkoranzah, Ejura et Kwadaso) montraient un pourcentage plus élevé de tâches embryonnaires vitales et complétes, appliquant 2,3,5 chlorure triphényl tétrazolium (CTT), ainsi qu'un poids de 1000 graines plus élevées en semence certifiée, indiquant une vigueur élevée et un développement complet de graine. Tandis que les semis germant de semences certifiées n'ont pas montré aucune croissance fongique, les semences gardés par les agriculteurs montraient un développement fongique abondant et retardé. Les comptes de semis montraient 9 et 21 pour cent de réduction respectivement en semence certifiée et en semence gardée par l'agriculteur, tandis que les comptes de plante avant la moisson montraient 12 et 23 pour cent de réduction. Les plantes poussant de semences certifiées fleurissaient à la date déterminée de 55 jours, tandis que les semences gardées par l'agriculteur fleurissaient environ un ou deux jours plus tard à cause de vigueur réduite. Moins de la verse se produisaient chez les plantes poussant de semences certifiées, surtout dans les cultures d'essai plantées à Ejura (zone de transition) comparé à l'essai de Kwadaso (zone de forêt). Les avantages de semences certifiées se traduisaient dans l'augmentation de rendement de graine, qui étaient environ 1.2 t/ha, un équivalent de ¢1,100,000.00 ($110)/ha ou 47 pour cent d'augmentation par rapport aux semences gardées par l'agriculteur. L'étude, par conséquent, démontraient l'importance de semences certifiées à l'augmentation de la productivité de maïs et les revenus d'agriculteurs. Ghana Journal of Agricultural Science Vol. 40 (1) 2007: pp. 105-11

Food consumption pattern and dietary diversity of a vegetarian population in Ghana

Objective: This study examined the food consumption pattern and dietary diversity of a vegetarian population in the Greater Accra Region of Ghana.Methods: A cross-sectional study was employed to examine the nutritional status of four (4) vegetarian groups in the Greater Accra Region of Ghana. One hundred and twenty-two (122) vegetarians were recruited using the total enumeration technique. Food consumption pattern and dietary diversity were assessed using a validated qualitative food frequency questionnaire and a 24-hour dietary recall, respectively. Dietary diversity was calculated using the FAO guidelines.Results: Sixty eight percent (68%) of the vegetarians reported daily intakes of vegetable protein. Majority of the vegetarians (80.6%) reported daily intakes of cereals and grains while 54% reported daily intakes of tubers. Eighty two percent (82%) and 72% of the vegetarians consumed vegetables and fruits on daily basis respectively. A few ofthe vegetarians (29%) reported daily intakes of fruit juices. Soft drinks, deep fried foods and fast foods were occasionally consumed. About 40.3% of the vegetarians obtained a dietary diversity score of four (4). Majority of them (68.9%) had low dietary diversity.Conclusion: The vegetarians had low dietary diversity which may lead to inadequate nutrient intakes. Thus, there is the need for nutrition-related professionals to give appropriate information on a vegetarian diet and educate vegetarians to include a variety of foods in their diet

Genetic diversity of provitamin-A cassava (Manihot esculenta Crantz) in Sierra Leone

Open Access Article; Published online: 04 Mar 2020Understanding the genetic diversity among accessions and germplasm is an important requirement for crop development as it allows for the selection of diverse parental combinations for enhancing genetic gain in varietal selection, advancement and release. The study aimed to characterize 183 provitamin A cassava (Manihot esculenta Crantz) accessions and five Sierra Leonean varieties using morphological traits, total carotenoid content and SNP markers to develop a collection for conservation and further use in the cassava breeding program. Both morphological parameters and 5634 SNP markers were used to assess the diversity among the provitamin-A cassava accessions and varieties. Significant differences were observed among the accessions for most of the traits measured. The first five PCs together accounted for 70.44% of the total phenotypic variation based on yield and yield components among the 183 provitamin-A cassava accessions and five Sierra Leonean varieties. The present study showed that provitamin-A cassava accessions in Sierra Leone have moderate to high diversity based on morphological and molecular assessment studies. The similarity index among the 187 and 185 cassava accessions grouped them into 6 and 9 distinct clusters based on morphological and molecular analyses, respectively. A significant positive, but low correlation (r = 0.104; p\0.034), was observed between the two dendrograms. The results obtained will serve as a guide and basis of germplasm management and improvement for total carotenoid content, yield and African cassava mosaic disease resistance in Sierra Leone

Analysis of drug resistance among difficult-to-treat tuberculosis patients in Ghana identifies several pre-XDR TB cases

BACKGROUND: Resistance to tuberculosis (TB) drugs has become a major threat to global control efforts. Early case detection and drug susceptibility profiling of the infecting bacteria are essential for appropriate case management. The objective of this study was to determine the drug susceptibility profiles of difficult-to-treat (DTT) TB patients in Ghana. METHODS: Sputum samples obtained from DTT-TB cases from health facilities across Ghana were processed for rapid diagnosis and detection of drug resistance using the Genotype MTBDRplus and Genotype MTBDRsl.v2 from Hain Life science. RESULTS: A total of 298 (90%) out of 331 sputum samples processed gave interpretable bands out of which 175 (58.7%) were resistant to at least one drug (ANY(r)); 16.8% (50/298) were isoniazid-mono-resistant (INH(r)), 16.8% (50/298) were rifampicin-mono-resistant (RIF(r)), and 25.2% (75/298) were MDR. 24 (13.7%) of the ANY(r) were additionally resistant to at least one second line drug: 7.4% (2 RIF(r), 1 INH(r), and 10 MDR samples) resistant to only FQs and 2.3% (2 RIF(r), 1 INH(r), and 1 MDR samples) resistant to AMG drugs kanamycin (KAN), amikacin (AMK), capreomycin (CAP), and viomycin (VIO). Additionally, there were 4.0% (5 RIF(r) and 2 MDR samples) resistant to both FQs and AMGs. 81 (65.6%) out of 125 INH-resistant samples including INH(r) and MDR had katG-mutations (MT) whereas 15 (12%) had inhApro-MT. The remaining 28 (22.4%) had both katG and inhA MT. All the 19 FQ-resistant samples were gyrA mutants whereas the 10 AMGs were rrs (3), eis (3) as well as rrs, and eis co-mutants (4). Except for the seven pre-XDR samples, no sample had eis MT. CONCLUSION: The detection of several pre-XDR TB cases in Ghana calls for intensified drug resistance surveillance and monitoring of TB patients to, respectively, ensure early diagnosis and treatment compliance

SARS-CoV-2 detection among international air travellers to Ghana during mandatory quarantine

Objectives: To determine the prevalence of SARS-CoV-2 detection among international travellers to Ghana during mandatory quarantine.Design: A retrospective cross-sectional study.Setting: Air travellers to Ghana on 21st and 22nd March 2020.Participants: On 21st and 22nd March 2020, a total of 1,030 returning international travellers were mandatorily quarantined in 15 different hotels in Accra and tested for SARS-CoV-2. All of these persons were included in the study.Main outcome measure: Positivity for SARS-CoV-2 by polymerase chain reaction.Results: The initial testing at the beginning of quarantine found 79 (7.7%) individuals to be positive for SARS-CoV-2. In the exit screening after 12 to 13 days of quarantine, it was discovered that 26 of those who tested negative for SARS-CoV-2 in the initial screening subsequently tested positive.Conclusions: Ghana likely averted an early community spread of COVID-19 through the proactive approach to quarantine international travellers during the early phase of the pandemic

Data management during COVID-19 outbreak response in Ghana: a reference laboratory perspective on key issues and measures

The COVID-19 pandemic caused by SARS-CoV-2 is an important subject for global health. Ghana experienced lowmoderate transmission of the disease when the first case was detected in March 12, 2020 until the middle of July when the number of cases begun to drop. By August 24, 2020, the country's total number of confirmed cases stood at 43,622, with 263 deaths. By the same time, the Noguchi Memorial Institute for Medical Research (NMIMR) of the University of Ghana, the primary testing centre for COVID-19, had tested 285,501 with 28,878 confirmed cases. Due to database gaps, there were initial challenges with timely reporting and feedback to stakeholders during the peak surveillance period. The gaps resulted from mismatches between samples and their accompanying case investigation forms, samples without case investigation forms and vice versa, huge data entry requirements, and delayed test results. However, a revamp in data management procedures, and systems helped to improve the turnaround time for reporting results to all interested parties and partners. Additionally, inconsistencies such as multiple entries and discrepant patient-sample information were resolved by introducing a barcoding electronic capture system. Here, we describe the main challenges with COVID-19 data management and analysis in the laboratory and recommend measures for improvement

Molecular diagnosis for the novel coronavirus SARS-CoV-2: lessons learnt from the Ghana experience

Background: A novel coronavirus, SARS-CoV-2 is currently causing a worldwide pandemic. The first cases of SARS-CoV-2 infection were recorded in Ghana on March 12, 2020. Since then, the country has been combatting countrywide community spread. This report describes how the Virology Department, Noguchi Memorial Institute for Medical Research (NMIMR) is supporting the Ghana Health Service (GHS) to diagnose infections with this virus in Ghana.Methods: The National Influenza Centre (NIC) in the Virology Department of the NMIMR, adopted real-time Polymerase Chain Reaction (rRT-PCR) assays for the diagnosis of the SARS-CoV-2 in January 2020. Samples from suspected cases and contact tracing across Ghana were received and processed for SARS-CoV-2. Samples were ‘pooled’ to enable simultaneous batch testing of samples without reduced sensitivity.Outcomes: From February 3 to August 21, the NMIMR processed 283 946 (10%) samples. Highest number of cases were reported in June when the GHS embarked on targeted contact tracing which led to an increase in number of samples processed daily, peaking at over 7,000 samples daily. There were several issues to overcome including rapid consumption of reagents and consumables. Testing however continued successfully due to revised procedures, additional equipment and improved pipeline of laboratory supplies. Test results are now provided within 24 to 48 hours of sample submission enabling more effective response and containment.Conclusion: Following the identification of the first cases of SARS-CoV-2infection by the NMIMR, the Institute has trained other centres and supported the ramping up of molecular testing capacity in Ghana. This provides a blueprint to enable Ghana to mitigate further epidemics and pandemics

Improvement of Rice Production under Drought Conditions in West Africa: Application of QTLs in Breeding for Drought Resistance

Rice plays a paramount role in food and nutrition security in many West African countries. Despite the doubling of production during the last decade, rice consumption has grown faster, creating a deficit between the demand and supply. Although the West African sub-region remains the main rice-producing centre on the continent, production is severely hampered by biotic and abiotic stresses. Drought is one of the factors that most severely reduce grain yields of rice. Systems of production need to be established in order to mitigate yield loss as a result of drought. This review discusses the effects of drought on rice production in West Africa and its mitigation with an emphasis on the improvement of tolerance to drought stress. Yield stability can be achieved by developing drought-tolerant varieties through several processes encompassing profiling of known QTLs and identification of new ones, marker-assisted selection, genomic selection, and extensive multi-locational yield trials. We suggest a comprehensive strategy for breeding drought-tolerant rice varieties in West Africa