ghanaopendata/ghanaian-research-english huggingface dataset:
Genotype by environment interaction in groundnut genotypes for yield and other agronomic traits in two locations in Ghana

Groundnut productivity in Ghana is generally low when compared to yields obtained in developed countries. The low yields can be partly attributed to unstable rainfall patterns, pest and disease infestation, and the low yielding varieties cultivated by farmers. Over the past years, a number of improved disease resistant cultivars have been released to boost local production. These improved varieties are however late maturing, and as such adoption rate among small-holder farmers is very low. To address the problem, 39 improved hybrid lines were developed from crosses between three farmers‟ preferred early maturing but low yielding varieties and two improved varieties, which are high yielding and late maturing. The development of improved lines which are both high yielding and early maturing is considered the most viable solution. The objective of the study was to evaluate 49 groundnut genotypes for yield and stability performances and to identify high yielding early maturing genotypes with superior agronomic performances. Forty-nine groundnut genotypes (39 improved lines and 10 checks) were evaluated at two locations (Fumesua and Ejura), representing two agro-ecological zones of Ghana during the major and minor cropping seasons of 2014. The trial was laid out in Lattice Square (7x7) Design with three replications per location. Significant variations (p<0.05) were observed among genotypes and highly significant variations (p<0.01) between locations, and their interaction with genotypes for pod yield. The combined mean square analysis for pod yield revealed that location main effects accounted for 97.22% of the total variation; while genotypes and genotype by environment interaction accounted for 0.58% and 0.61% of the total variation, respectively. Positive correlations were observed between pod yield and the following traits: pod yield per plant, number of pods per plant, 100-pod weight, shelling percentage, number of seeds per pod, and number of branches per plant. CRG-AP x AZ-14-13 emerged as the second highest performer across locations and the best genotype among the improved hybrid lines. The genotype is early maturing, a trait preferred by groundnut farmers in Ghana; and was also identified as the ideal genotype in terms of stability and yield performance. Overall, ten improved lines were selected based on both yield performance and early maturity, ranging from 89.0 to 92.0 days to maturity

Source: KNUST
Genotypic characterisation of human papillomavirus infections among persons living with HIV infection; a case–control study in Kumasi, Ghana

The objective of this study is to describe the burden of human papillomavirus (HPV) infection among women living with HIV and non-infected women in Ghana. methods A case–control study was conducted involving 107 women living with HIV aged between 18 and 59 years (cases) and 100 non-HIV-infected apparently healthy women (controls) who were recruited from the Kumasi South Hospital, from July to December, 2014. Cervicovaginal swabs were taken from study participants to characterise 28 high- and low-risk HPV genotypes using a multiplex real-time PCR. results The overall mean age for the participants was 40.10 9.76 years. The prevalence of high risk (hr)-HPV genotypes was significantly higher among the cases than the controls (77.4% vs. 41.6%, P < 0.0001). Overall, HPV 58 and 54 were the most predominant high-risk (18.8%) and low-risk (15.0%) genotypes detected. The two most common hr-HPV genotype isolates were 58 (18.8%) and 35 (15.9%) with 58 being the most prevalent among age group 35–44 years compared with hr-HPV 16, 18, 35 and 45, found predominantly among 18–34 age group. conclusions Significant variations exist in HPV genotypes among HIV-infected and uninfected women.

Source: KNUST
Genotypic variation for phosphorus uptake and dinitrogen fixation in cowpea on low-phosphorus soils of southern Cameroon

In cowpea, efficient N2-fixing genotypes are being selected to promote sustainable cropping systems in southern Came roon (SC). However, N2 fixation and growth of these geno types are largely hampered by low levels of soil plant-avail able P. To evaluate the genotypic variation in N2 fixation and P uptake among cowpea (Vigna unguiculata L.) genotypes, field experiments were conducted over two years on two acid soils low in available P. The experiments were laid out in a split-block design with four replications on typic (TK) and rhodic (RK) Kandiudult soils with seven cowpea genotypes. Phosphorus (P) fertilizers were applied on the main plots with 0 kg P, 30 kg P ha–1 as triple superphosphate (TSP) and 90 kg P ha–1 as Togo phosphate rock (PR). Nodule dry matter(DM), shoot DM, grain yield, and P uptake of cowpea significantly varied with site, P application, and genotype (p < 0.05). The N2 fixation of the cowpea genotypes ranged from 29 to 51 kg N ha–1 on both TK and RK soils and was sig nificantly increased with P application. Significant genotypic variations in N2 fixation were observed with superior ability of the genotypes IT89KD-391 and IT90K-59 to fix N2. The harvest index (HI) did not significantly differ between soils and P application levels (p > 0.05). Four genotypes were selected to investigate root mechanisms responsible for effi cient P acquisition in pot experiments. The results suggest that a better root infection by arbuscular mycorrhizal fungi (AMF) in genotype IT90K-59 and root morphological and phy siological characteristics in IT89KD-391 were the most impor tant factors for inc

Source: KNUST
Geodesics in (2 + 1)-dimensions

The geodesics in (2+1) dimensional spacetime should be the same as the geodesics in (3+1) dimensional spacetime, since the two dimensional surface on which these geodesics lie should be embeddable 3-dimensional co-ordinate space. In the present thesis, we show precisely that .We demonstrate that the plane, the spherical surface, the ellipsoidal surface and the surface of a saddle on which these geodesics lie are embeddable in 3-dimensional co-ordinate space. We then go ahead and fine these geodesics. And clearly, the determination of the geodesics in (2+1) dimensional spacetime should be easier than in 3-dimensional spacetime since the number of equations involved in (2+1) dimensional spacetime is much smaller than in (3+1) dimensional spacetime. We talk about (2+1) and (3+1) dimensional spacetime because it is easier and more elegant to use the techniques of general relativity in the determination of these curves. After showing that the surfaces indicated above are embeddable in 3-dimensional co-ordinate space, we go ahead and construct the 3-dimensional equivalent of the Robertson-Walker metric. The equation for the geodesics in general relativity is well known, and using our 3-dimensional metric, we compute all the geodesics on these surfaces which turn out to be the surfaces of zero, positive and negative curvatures Not surprisingly, the geodesics in the plane and spherical surface were found to be straight line and great circles respectively. What can apparently be considered to be new results are the geodesics on ellipsoidal surface and the surface of a saddle which can really be described as 2-dimensional hyperbolic space. The geodesic on these last two surfaces were found to ellipses and hyperbolae. But it should be emphasized that in the relativistic language, curves are the geodesics in curved space and it is perhaps worth nothing that these curves are the trajectories of bodies attracted or repelled in force fields of the inverse square law

Source: KNUST
Geographical Information Systems (GIS) and the Environment: the Case of Mine Waste Management

The importance of Geographical Information Systems (GIS) in environmental studies is being recognised worldwide. GIS is especially useful in waste management, where analysis of the spatial locations, dimensions, and inter-relationships between waste facilities and other mining activities, infrastructural facilities, water bodies, farmlands, forest, animal habitat, human settlements, and other objects or activities of interest, are essential for assessing impacts and control measures. This thesis examined the GIS technology and its application in mine waste management. Main areas of the technology explored were its capabilities and usefulness for integrating the large spatial and non-spatial environmental data sets involved, and for performing the spatial analysis necessary for addressing all the factors for effective management of the waste, including meeting regulatory requirements and the concerns of all stake-holders in the selection of dumping sites. Key features, operations, principles and potential applications of the technology in mining have also been covered. Detailed environmental review of the past and present mine waste disposal in Ghana has been addressed, identifying the problems thereof, the causes, and what can be done to improve the situation, including the use of GIS. One critical source of the problems is the location of dumping sites within the environment — for which the usefulness of applying GIS has been practically demonstrated in this thesis, using the Arcinfo and ArcView GIS software. The steps involved building a GIS database and applying it for analysis that included map extraction, buffering, overlaying, combination and spatial queries. A set of application methodology and procedures has also been developed for use in applying the GIS technology to solving waste management problems. The results, analysis and evaluations of the research prove that GIS will be a versatile tool for quick but effective studies and decision-making on mine waste management problems in Ghana It is therefore recommended for use by the mining companies, research institutions and the regulatory bodies like the Environmental Protection Agency (EPA), Minerals Commission and Mines Department in their operations.

Source: KNUST
Geochemical and statistical investigations into quality control management of samples in a mine within the Sefwi Bibian gold belt

The problem of data analysis is a combination of philosophy of approach, clear understanding of the quality and nature of the data to be investigated. To attempt to carry out blind evaluation of data by submitting the data set to any one of the ever increasing number of packaged software systems and expect the computer to do the thinking is patently wrong. Generally, sample data is usually collected with specific goals. The collection procedure ideally should incorporate an element of rigorous statistical design that provides efficiency in the accumulation of data. Representativeness of the data relative to the source, monitoring during data collection and analysis are vital in providing a reasonable measure of quality. The research is based on gold assay results from three analytical laboratories referred to as laboratories ‘K’, ‘L’ and ‘M’ in the text. The data sets were subjected to the chi-test, the student’s t-test and linear correlation coefficient to ascertain measure of similarity between the original and duplicate samples from the laboratories. Laboratories ‘K’ and ‘L’ registered near perfect positive correlation of 0.998 and 0.992, respectively, between original and duplicate samples while laboratory ‘M’ recorded reasonably good positive correlation of 0.723. However, the 27.7% bias registered by laboratory ‘M’ fell out of the 95% confident limit set for the laboratories. All the data sets failed the goodness-fit test. The samples showed a rather positive skew owing to excess of low grade values, a situation attributed to a batch effect. From the statistical deduction made from the geochemical data, It is recommended that samples from anomalously high and low grade zones may not have to be lumped together as one batch to the laboratory.

Source: KNUST
Geological and Structural Interpretation of part of the Buem Formation, Ghana, using Aerogeophysical Data

Airborne magnetic and radiometric datasets were processed to interpret the geology of part of the Buem formation and estimate the depth to basement of magnetic source in the area. The study was aimed at mapping lithology, delineating structural lineaments and their trends as well as estimating the depth to magnetic source bodies of the area. The data processing steps involved enhancement filters such as reduction to the pole, analytic signal and first vertical derivative, Tilt angle derivative and these helped delineate geological structures and lithology within the Buem formation. The radiometric datasets displaying the geochemical information on potassium, thorium and uranium concentrations within the study area proved valuable in delineating the Buem shales, sandstones, basalts and part of the Voltaian sediments that underlie the Buem formation. Lineament analysis using the rose diagram showed that the area is dominated by north-south (NS) and east-west (EW) trending lineaments. Depths to the magnetic source bodies were estimated using Werner deconvolution method, indicating two depth source models. The depth of the magnetic body produced from the dike model ranged from 101.15 m to 1866.34 m and that of the contact model ranged from 100.36 m to 983.709 m.

Source: KNUST
Geological and structural interpretation of the Beposo area in the Ashanti region of Ghana, using aeromagnetic and radiometric data-sets

Aeromagnetic and radiometric data-sets, acquired over the Beposo area in the Ashanti region of Ghana, were used to come out with an integrated geological and structural map, that will help in delineating possible gold mineralisation zones. Important new information on the extent of the lithology and structure which led to a more comprehensive understanding of areas of poor outcrop or under cover were obtained through the use of magnetic enhancement transforms such as analytical signal, first vertical derivative, horizontal derivative and tilt derivative on the magnetic dataset. The first vertical derivative and tilt derivative together with the horizontal derivative map helped in tracing out geological structures such as the Ashanti shear and faults which probably served as conduits for hydrothermal fluids and their resulting gold concentration. A rose diagram of the strike of geological structures in the area indicated that most of these structures are striking between 00 and 900 in the NE-SW direction and dipping to the NE. Granitoid intrusions which probably caused isoclinal folds in the Birimian were clearly defined by the aeromagnetic and radiometric data-sets. The radiometric dataset provided geochemical (K, eTh, eU) information that helped in interpreting surface lithology and possible hydrothermal alteration zones.

Source: KNUST
Geological and structural interpretation of South–East Voltaian basin, Ghana, using airborne gravity and magnetic datasets

Airborne gravity and magnetic methods were used to interpret the geology of the south eastern Voltaian, Ghana. The study was aimed at mapping lithologies and geological structures responsible for any observed anomaly in the Area. The enhancement filters applied were used to reduce signal–to–noise ratio. The high-resolution airborne gravity and magnetic data delineated the Densubon Sandstone Formation which was permeated by a Mafic subvolcanic intrusion and the Bimbila Formation which was also permeated by a felsic granitic intrusion. The Densubon Sandstone Formation, located at the southern part of the study area and the Bimbila formation also located at the northern part of the basin, were separated by a geological contact which trended NE–SW. The results show that the Voltaian Basin is underlain by the Proterozoic Birimian Supergroup which could be the reason for both the high gravity and magnetic signatures.

Source: KNUST
Geological and Structural Interpretation of the Konongo Area of the Ashanti Gold Belt Using Airborne Magnetic and Radiometric Data

Integrated airborne geophysical methods namely magnetic and radiometric were used to investigate the Konongo mining area located at the north-eastern boundary of the prospective Ashanti Gold Belt in south-eastern Ghana. These datasets provided useful information on the lithology and geological structures within the area. The geophysics data processing approach employed concentrated on enhancing the geophysical data quality and this aided in tracing accurate positioning of geological boundaries, the responses related to mineralization and geological structures that may be of vital economic importance. The magnetic image enhancing technique such as reduction to the pole, analytic signal and first vertical derivative helped delineate folds, fractures, tectonic boundaries and the D 1-NE /D2-NNW structural deformation events which are potential hydrothermal fluid traps. The Birimian Meta-sedimentary and meta-volcanic rocks noted to host gold mineralization and other metal ores in the Belt were also delineated. The radiometric data provided geochemical information of potassium (K), thorium (Th) and uranium (U) that proved valuable in delineating bedrock lithology of the area such as the Banso Batholith, Birimian meta-volcanics, Tarkwaian Formation and alteration zones within the area and contact zones. High K, Th and U concentration were mapped in the meta-sediments and the Banso Batholith. The high-resolution airborne magnetic and radiometric data of the study area resulted in better definition of both geological structures and lithological boundaries. This project shows the usefulness of geophysical data in mapping possible geological structures that host hydrothermal gold mineralization.

Source: KNUST
Geometrical methods for the solution of a class of convex programming problems

In this thesis, we suggest geometrical methods for the solution of convex programming problems with linear objective functions, with special emphasis on linear programming problems defined on Euclidean space. One method that we propose is based on a rigid rotation of Cartesian coordinates and a second method uses orthogonal projections to generate a monotonic sequence which is induced by an optimal sequence. It is found that these methods enrich the theory of convex optimization and also simplify the process of solving the class of problems studied. For purposes of demonstrating the comparative efficiency of these methods relative to some traditional ones, sample problems in 2 and 3 dimensional Euclidean space are solved in detail and some algorithms and computer codes for implementing the methods are also provided. It is found that in many cases our method is easier to implement. We find that for the particular case of low dimensional linear programming problems with a large number of constraints, our optimal sequence method is more efficient than the simplex algorithm.

Source: KNUST
Geomechanical Characteristics of Natural and Stabilised Black Cotton Soils from the Accra Plains of Ghana

Black cotton soils or tropical black earths or black clays are potentially expansive soils which classify as vertisols in pedological parlance and have been found to occur in all major climatic zones of the world. These soils are considered ―problematic‖ and sometimes as ―potential natural hazard‖ because they are susceptible to seasonal volumetric changes, exhibit severe cracking when dry, swell and yield low bearing strengths when wet, etc. These problems cause extensive damage to light structures founded on them and estimated cost of damage due to expansive soils in general runs into billions of dollars annually. Considering the widespread prevalence of these soils and the problems they pose to structures founded on them, there is the need to conduct studies into the geological and geomechanical characteristics of the black cotton soils to enable effective utilization. Although some works have been done globally on these soils, these rather useful information are scattered in various publications. The need to collect these scattered information, synthesize them and present a hands-on-information regarding the nature, distribution, physical and engineering properties of the black cotton soils for the benefit of the construction industry has long been felt. Secondly, it has also become necessary to conduct studies with the view to enhancing knowledge on the geology and geomechanics of these soils. This study has attempted to address the above mentioned problems through a review of literature on the mode of formation, nature, as well as distribution of these soils around the world and secondly, presents studies on typical black cotton soils from the Accra plains of Ghana. Soil samples were collected from Tsopoli and Doryumu, both in the Accra plains of Ghana and subjected to physical, chemical and mineralogical as well as geomechanical studies. Results of the study reveal that the black cotton soils are formed over the Garnet-Amphibolites Gneisses of the Dahomeyan Supergroup. The chemical compositions of the soils indicate iii that the most abundant oxides are silica, alumina and iron oxide. The mineralogy of the two soils from X-Ray Diffraction analyses are similar and are composed of Quartz and montmorillonite. The geomechanical studies also suggest that the natural black cotton soils are unsuitable for subgrade construction and hence require improvement through stabilization. Attempts at stabilising the soils with quarry dust, pozzolana and pozzolana-cement which are readily available local materials, reveal that although the three stabilizing agents improved some geomechanical parameters of the soils the pozzolana-cement appears to be the most effective for stabilising the black cotton soils.

Source: KNUST
Geophagia, Nutrient Intakes and Possible Health Outcome of Women with Pregnancy-Induced Hypertension - A Case-Control Study

Calcium is a major nutrient implicated in pregnancy-induced hypertension (PIH). Aside dietary sources of calcium and other essential nutrients required to prevent adverse pregnancy outcomes, the practice of geophagia (consumption of soil/clay) has been reported to provide calcium needed to prevent hypertension during pregnancy. These soils are shown to also contain significant amount of lead and other heavy metals which have been associated with hypertension. The aim of this study was to determine the relationship between geophagia and hypertensive disorders of pregnancy, and assess the dietary intakes and health outcomes in participants. This study was a case-control involving 30 women with PIH without proteinuria and 70 normotensive pregnant women. Percentage intakes of macronutrients for normotensives were within the Adequate Macronutrient Distribution Range and PIH group recorded higher intakes of carbohydrate (72.75±16.16 %), lower intakes of protein (9.77±5.61 %) and fat (17.15±11.99%). Sources of protein among PIH were mainly from cereal based products. Dietary calcium intakes in both groups were lower than recommended (˂1,000 mg/day). Geophagia and energy drink intake was not significantly associated with PIH. Coffee intake significantly increased the risk of hypertension (OR, 4.10; 95% CI 2.10-8.00; p=0.004) while food supplementation during pregnancy significantly reduced the risk of PIH (OR, 0.33; 95% CI 0.17-0.61; p=0.017). Hypertensives recorded impaired fasting blood glucose (5.77±1.71 mmol/L, p=0.051) higher levels of urea (3.60±1.29 mmol/L, p=0.000) and creatinine (382.67±11.17 μmol/L, p=0.000). There was no significant difference in serum calcium and ferritin levels in both groups. Women with PIH practicing geophagia recorded significantly low levels of haemoglobin (8.35±1.91 g/dL, p=0.026), calcium (7.05±1.05 mg/dL, p=0.047) and ferritin (14.89±3.73 ng/dL, p=0.000) than those who did not. The population of pregnant women in this study had considerably low intakes of energy and nutrients. There is the need for measures to ensure adequate maternal nutrition for a positive health and pregnancy outcome.

Source: KNUST