ghanaopendata/ghanaian-research-english huggingface dataset:
Modelling Volatility and the Risk-return Relationship of Selected Equities on the Ghana Stock Exchange

The volatility and the risk-return trade o of equities or stock markets play essential role in investment, decision making, fi nancial stability among others. This study used secondary data of 35 equities from the Ghana Stock Exchange (GSE) and Annual Report Ghana databases comprising the daily closing prices from the period 02/01/2004 to 16/01/2015. Principal component analysis was used in selecting equities that characterized each sector. The results revealed that, for the Finance sector, CAL, ETI and GCB were selected, the Distribution sector had PBC and TOTAL selected, the Food and Beverage sector had FML selected, the Information Communication Technology sector had CLYD selected, the Insurance sector had EGL selected, the Manufacturing and Mining sectors had PZC, UNIL and TLW, AGA selected respectively. The symmetry and asymmetry of the daily returns of the selected equities as well as the risk-return relationship was investigated using the univariate GARCH-M (1, 1), EGARCH-M (1, 1) and TGARCH-M (1, 1) models and the results indicated the existence of positive risk premium meaning investors were compensated for holding risky assets. The results also showed that, the asymmetry models gave a better t than the symmetry model indicating the presence of leverage e ect among the selected equities. TGARCH-M (1, 1) model with the student-t distribution was the appropriate model selected. It was revealed that, volatility was persistent (explosive process) in most of the selected equities with the three distributional assumptions. The persistence in volatility was extended in investigating the half-life measure of the selected equities. It was revealed that most of the equities had strong mean reversion and short half-life measure. The long-run trends in volatility was investigated by regressing the conditional variance against a time variable. The results showed that, most of the equities exhibited increasing volatility over the sample period.

Source: KNUST
Modification and evaluation of a groundnut cracker for cracking Jatropha Curcas seeds

Jatropha curcas L. is a multipurpose drought-resistant plant with numerous attributes and considerable potentials. The most valuable aspect of the plant is the oil content of its seed kernel. In the extraction of the oil, the seeds are either cracked to obtain the kernels or used without cracking. Using uncracked nuts produce oil at low recovery and quality, whiles cracking manually involves so much labour and time. The objective of the study was to modify an existing motorised Groundnut Cracker with a winnower for cracking Jatropha curcas seeds and to evaluate its performance. The physical dimensions of seeds and kernels were determined for the design of the sieve of the cracker. The cracker was evaluated using 3 kg seed samples at cracking drum speeds of 140, 150, 160, 170 and 180 rpm and feed gate openings of 32, 48 and 64 mm. Chemical extraction of Jatropha curcas oil for kernel samples with 0 %, 20 %, 40 %, and 100 % husk contents was done. A sieve with hole diameter 10 mm was selected and designed for the cracker. At 140 rpm and 48 mm feed gate opening, the cracker had a capacity of 1037.90 kg/h, blower loss of 2.76 %, cleanliness of 88.65 %, uncracked seeds of 3.32 %, kernel recovery of 48.57 %, cracking efficiency of 96.68 % and machine efficiency of 90.84 %. Chemical oil extraction gave the lowest oil yield from the sample with 100 % husk at 66.7 % of oil extraction and highest oil yield from the sample with 0 % husk content at 93.5 % of oil extraction, an increase of 40.1 % in oil yield due to seed cracking.

Source: KNUST
Modern depositional environment in Lake Bosumtwi, mapped by the spatial relationships of bulk sediment and magnetic mineral grain size.

A study of the modern depositional environment mapped by the spatial relationships of bulk sediment and magnetic mineral grain size has been conducted at Lake Bosumtwi. A total of 134 sediment samples were collected from specific locations over the entire lake with sampling depths ranging from 2 cm to 8 cm using the Ekman dredge. Sample measurements include magnetic susceptibility, anhysteretic remanent magnetization, isothermal remanent magnetization, saturation isothermal remanent magnetization, loss- on-ignition as well as the determination of magnetic hysteretic parameters such as coercive force (Hc) and the remanent coercivity (Hcr). In addition, grain size analysis was performed on selected samples using the Rotap sieving method. The analysis of the measured results shows an increase in the magnetic concentration of the samples with increasing lake water depth. Coercivity values measured reveals that samples contain high proportions of magnetic minerals with low coercivity. The magnetic mineral grain size analyzed shows a decrease in size as lake water depth increases and bulk sediment grain size decreases with increasing water depth. The ratio of saturation remanent magnetization to saturation magnetization (Mrs/Ms) for selected samples were calculated. This ratio was observed to lie in the range of values, 0.21 – 0.31 indicating the presence of pseudo – single domain magnetic mineral grain size. Similarly, the percentage of organic content of the samples was found to increase with increasing lake water depth. From the results above, it can be concluded that, the uppermost 8 cm of surface sediment possibly accumulated under wet climatic conditions, which allowed the settling of sediments of reduced dust flux. The magnetic minerals present in the lake could be more of an authigenic and diagenetic origin than from allogenic origin.

Source: KNUST
Modification of Bambara Groundnuts Starch, Composited With Defatted Bambara Groundnut Flour for Noodle Formulation

Bambara groundnut legume is neglected and underutilized because its industrial potential has not been fully exploited. This work was carried out to phosphorylate starch from the legume which was used as its flour binder for noodles preparation. Four different factors namely; reaction time, % Sodium hexametaphosphate (SHMP) and starch solids were varied at 130 oC and optimized to obtain 1.6 h, 0.163 % SHMP, 33 g starch solids for the preparation of phosphorylated starch. The modified starch gave optimized responses of degree of substitution of 0.0042 and specific volume of 1.48 cm3/ g. An optimum binder to flour ratio of 1.41 g to 19.95 g gave flour composite with least gelation concentration of 0.246 g per ml. When pasted it showed a peak viscosity of 177 BU with relatively small breakdown of 26 BU and increased viscosity during cooling at setback of 172 BU. This observation suggests the modified starch as a potential component for viscoelastic food products. Three sample noodles; alkaline, Udon and control were prepared from the composited flour. From the sensory evaluation studies, the alkaline noodle was the most preferred and gave the best sensory characteristic scores for aroma, texture, colour, mouth feel and after taste as 3.59, 5.74, 7.55, 9.88 and 8.57 respectively. The utilization of Bambara groundnut flour in the food industry especially when composited with the starch binder is therefore recommended for the preparation of noodles.

Source: KNUST
Modification of bitumen with waste plastics for road construction

The absence of efficient management of municipal solid waste (MSW), with regards to used plastic components, which have overwhelmed our major cities and towns, is a growing challenge for developing countries including Ghana. Another challenge is the deformation of our roads due to excessive traffic and binder quality used; thus, new technologies need to be adopted to improve road construction. This study examines the effect of blending waste thermoplastic polymers, namely high density polyethylene (HDPE) and polypropylene (PP) in conventional AC-20 graded bitumen, at different plastic compositions. The plastics were chopped and blended with the bitumen ‘in-situ’, with a shear mixer at a temperature range of 160 ºC-170 ºC. Basic rheological parameters such as penetration, ring and ball softening point and viscosity test were employed to determine the resulting changes from the base bitumen. FTIR spectroscopy was also employed to study the chemical functionalities present in the bitumen composite. Three prominent peaks were identified in the spectrum of the unmodified bitumen, occurring at the 3000-2850cm-1 IR frequency range, typical of aliphatic –C-H symmetrical and asymmetrical stretches in alkanes. CH2 and CH3 bends were also observed at the characteristic frequencies of 1465cm-1 and 1375cm-1 respectively. A low intensity peak was observed within the 2400 cm-1-2100cm-1 range, indicating the presence of a very weak -C≡C- or -C≡N group with an absorbance of precisely 0.12. The properties of the unmodified bitumen were found to be enhanced with the changes in the rheological properties of the polymer modified bitumen (PMB). The viscosity of unmodified bitumen was enhanced with the addition of the polymers and thixotropic effect was observed for both HDPE and PP at 60°C. For all modified binders prepared, the penetration values decrease as polymer ratio increases whilst, softening temperature generally increases as polymer ratio increases. The most compatible and incompatible blends for HDPE were respectively observed at 2% and 3% polymer loading. The most enhanced, homogenous blend is achieved with PP at 3% polymer loading. The use of waste commodity plastics in binder modification carries the advantage of a cheap and effective means of enhancing conventional binder performance and is an alternative way to utilise plastic waste.

Source: KNUST
Modified Condensation Method for Evaluating the determinant of a 3 × 3 matrix

We observed that when the pivot entry is zero, both the Dodgson and Chio condensation methods fail. Thus, these condensation methods cannot be used for evaluating the determinants of a 3×3 matrix and higher dimension matrices. In order to overcome this shortcoming of the condensation methods, we introduce the modified condensation method (MCM) for evaluating the determinant of a 3 × 3 matrix. The MCM involves finding the supremum of the row or column that contains the zero entry and then interchanging this row or column with a row or column without any zero entry. In addition, unlike the Laplace expansion method (LEM), the Dodgson’s condensation method (DCM), the Chio’s condensation method (CCM) and the diagonal rearrangement (DRM), the MCM has the highest computational speed.

Source: KNUST
Modified Holling Tanner diffusive and non-diffusive predator–prey models: The impact of prey refuge and fear effect

The secondary consequences of predator species on prey species have substantial implications for population dynamics. A deeper comprehension of the dynamics between prey and predator can be achieved through the examination of indirect consequences. This work examines the dynamic behavior of a modified Holling-Tanner model. The interactions between the species are characterized by a functional response of the Beddington– DeAngelis type. Factors such as prey refuge, fear factor, disturbance intensity, and cross diffusion have been taken into account. The boundedness, feasibility of equilibrium points, their stability and restrictions for Hopf bifurcation of non-spatial model system are derived. The study explores the combined effects of prey refuge presence and fear factors on population dynamics. Furthermore, the investigation focuses on the stability of spatial self-diffusion and cross-diffusion model systems, as well as the specific conditions that lead to Turing instability. Ultimately, it has been shown that in the context of self-diffusion, a moderate level of fear promotes the survival of prey, whereas an excessive level of dread hinders the survival of prey. Concurrently, the mean density of prey exhibited a gradual decline as the refuge parameters increased. The spatial patterns of the population have also been investigated. As the mutual interference between prey populations intensifies, the spatial distribution of the prey population transitions from a clustered pattern to a combination of striped and clustered patterns, ultimately settling into a striped pattern. With the gradual growth of the half saturation constant, the prey population reached a state of uniform distribution. In the scenario of cross diffusion, when the prey is heavily impacted by the pursuit of predators, the fear effect, when appropriately used, did not have a significant impact on the survival of the prey. This work adds to the existing body of knowledge by revealing novel insights into the influence of indirect factors on the behavior of predator and prey populations.

Source: KNUST
Mokwe Marina Village - Tema

There is no Marina in Ghana, despite the enormous water resources available in the country, both inland and along the coast stretching 365 rniles. Water resources all over the world have been and can be tapped for recreational purposes, then bringing enormous revenue to the beneficiary country. The question is why Ghana at this stage of her development, has such great potential to bring variety into the lives of individuals, interms of recreation. There are estimated over 64 marinas in England alone which generators revenue to the country sculpts the landscape and increase variety in recreation. Attempts being made by individual, companies in the country to own and maintain boats and chalets on the volta lake as well as water fronts under scores the need for the tapping of this sleeping giant resource. The time to act is now, because resources are not, they become. 2. OBJECTIVES Realising there is no such purpose built facility in the country the following objective were set out. 1. Study the potential and development of water front facilities for recreational purposes. 2. To encourage water sports activities i.e. Boating rowing, skiing, hydroplaning, sailing, canoeing and other related water sports in the country. 3. To provide an avenue for the encouragement of Ghanaian to own maintain pleasure boats. 4. Broaden the Scope of recreation in Ghana by the introduction of this all important activity to the holiday maker. 5. To unify the tentative water clubs that have been formed into formidable clubs to, compete in international competitions and to bring them under one umbrella facility. 6. Extend the season: this would be achieved by introducing a varied scope of activities so the facility is busy all year round. 7. Provide mooring for boat owners where they can service and maintain their boats. 8. Develop the facility with associated facilities like accommodation eating, swimming and conference facility. 9. To hire boats for the purpose of cruising at a fee to interested individuals and groups of people. 10. Objective of Thesis The main objective of this Thesis is to design a comprehensive marina village. where holiday maker can move from the bustling city to a quiet and restful environment and engage in active and passive leisure. 4. Scope The design embraces all aspects of a state of the art marina. Chapter 2 gives a fairer idea of the scope.

Source: KNUST
MODIS NDVI trends and fractional land cover change for improved assessments of vegetation degradation in Burkina Faso, West Africa

Reduction of natural vegetation cover in the savannah of West Africa constitutes a pressing environmental concern that may lead to soil degradation. With the aim to assess the degradation of natural vegetation in the savannah of Burkina Faso, this study combined NDVI trends and fractional Land Use/Cover Change (LULCC). Fractional LULCC maps, derived from the aggregation of a 30 m Landsat LULCC map (1999–2011) to 250 m resolution of MODIS, were used to assess natural vegetation conversions in the small-scale spatial patterns of savannah landscapes. Mann-Kendall's monotonic trend test was applied to 250 m MODIS NDVI time series (2000–2011) to assess modifications of natural vegetation cover. Finally, the Spearman's correlation was employed to determine the relationship of natural vegetation degradation with environmental factors. The study revealed a vast conversion of natural vegetation into agriculture (15.9%) and non-vegetated area (1.8%) between 1999 and 2011. Significant decreasing NDVI trends (p < .05) indicated negative modifications of natural vegetation (2000–2011 period) occurring along the protected areas borders and in fragmented landscapes characterized by disruption of continuity in natural vegetation. Spearman's correlation showed that accessibility, climatic and topographic conditions favored natural vegetation degradation. The results can enable the development of efficient land degradation policies.

Source: KNUST
Modulation of Carbon Tetrachloride (CCL4) and Acetaminophen induced liver damage in rats by Morinda Lucida Benth. (Rubiaceae).

Morinda lucida is a tropical West Africa rainforest tree also called Brimstone tree. The plant is employed in the traditional settings for the treatment of malaria and severe jaundice. The alcoholic leaf extract of the plant was investigated for its possible toxicity in experimental rats and its hepatoprotective activity against carbon tetrachloride and acetaminophen-induced liver damage, also in rats. Administration of Morinda lucida extract (MLE) (250, 500, 1000, 2000, and 4000 mg/kg) to rats daily for two weeks did not cause significant changes in most of the haematological parameters assessed between the MLE treated groups and the control except for a significant increase in the mean corpuscular volume (MCV) at the 250 mg/kg. Also, there were no significant changes in the biochemical parameters assessed as well as the body weight and the selected organ weights (heart, spleen, liver and kidney). In the pentobarbitone-induced sleeping time assessment, pentobarbitone at 50 mg/kg, administered one hour after the oral administration of MLE (250, 1000 and 4000 mg/kg) caused a dose dependent decrease (P < 0.05) in the rat sleeping time. The hepatoprotective effect of the extract was assessed using two widely used models, CCl4 and acetaminophen. Intraperitoneal administration of CCl4 to rats caused severe liver damage as was indicated by the elevation of serum enzymes, bilirubin levels as well as the reduction in the protein levels. These effects were attenuated by the pre and post treatments with MLE and the effects were comparable to that of silymarin, used as the positive standard drug. A histopathology study of the liver samples from the MLE treated rats showed recovery from the injury caused by CCl4 to the toxin control group of rats whereas samples from the CCl4 did not. In the acetaminophen-induced liver damage, the effect of a single dose and multiple doses of the acetaminophen caused extensive liver damage, resulting in the elevation of the serum enzymes, bilirubin and a decrease in protein levels as well as damage to the hepatocytes as seen in the histopathology of the liver. Treatment with MLE assuaged this injurious effect caused by pre- and post-administration of acetaminophen by reducing the levels of the serum enzymes and bilirubin levels as well as increasing the protein levels. This effect was comparable to silymarin the standard positive drug used in the study. Overall, this study has shown that leaves of Morinda lucida is safe up to a dose of 4000 mg/kg in rats, does not interfere with the normal functioning of the hepatic microsomal drug metabolizing enzymes (MDME) and also protects the liver from injury caused by CCl4 and acetaminophen.

Source: KNUST
Molecular basis of glucose-6-phosphate dehydrogenase deficiency in Cape Coast, Ghana

Glucose-6-phosphate dehydrogenase (G6PD) is a cytoplastic enzyme that is essential for a cell's capacicity to withstand oxidant stress. (G6PD)-deficiency is the commonest enzymopathy of humans with a worldwide distribution. The geographical correlation of its distribution with the historical endemicity of malaria suggests that the defect has risen in frequency through natural selection by malaria.This study was carried out to ascertain the molecular basis of G6PD-deficiency in Cape Coast in the Central Region of Ghana. Two hundred (200) unrelated persons...............................................

Source: KNUST
Molecular characterization of interactions between the D614G variant of SARS-CoV-2 S-protein and neutralizing antibodies: A computational approach

The D614G variant of SARS-CoV-2 S-protein emerged in early 2020 and quickly became the dominant circulating strain in Europe and its environs. The variant was characterized by the higher viral load, which is not associated with disease severity, higher incorporation into the virion, and high cell entry via ACE-2 and TMPRSS2. Previous strains of the coronavirus and the current SARS-CoV-2 have demonstrated the selection of mutations as a mechanism of escaping immune responses. In this study, we used molecular dynamics simulation and MM-PBSA binding energy analysis to provide insights into the behaviour of the D614G S-protein at the molecular level and describe the neutralization mechanism of this variant. Our results show that the D614G S-protein adopts distinct conformational dynamics which is skewed towards the open-state conformation more than the closed-state conformation of the wild-type S-protein. Residue-specific variation of amino acid flexibility and domain specific RMSD suggest that the mutation causes an allosteric conformational change in the RBD. Evaluation of the interaction energies between the S-protein and neutralizing antibodies show that the mutation may enhance, reduce or not affect the neutralizing interactions depending on the neutralizing antibody, especially if it targets the RBD. The results of this study have shed insights into the behaviour of the D614G S-protein at the molecular level and provided a glimpse of the neutralization mechanism of this variant.

Source: KNUST
Molecular characterization of mycobacterial species isolated from tuberculosis lesions seen in bovine carcasses at post mortem: a case study of three abattoirs in the Accra Region of Ghana.

Tuberculosis in cattle poses a serious public health threat and yet there is very little information on its extent in Ghana. A study to screen and characterize suspicious carcasses at post-mortem in three selected abattoirs in Accra was conducted. A total of 2,886 cattle slaughtered between June and October, 2009 were examined at post-mortem. One hundred and fifty five (155) suspicious tissue samples were taken from 145 bovines and subjected to Ziehl-Neelsen (ZN) microscopy and subsequently cultured on Löwenstein-Jensen (L-J) media. Isolates were harvested and subjected to ZN microscopy and then screened with the Capilia TB-Neo test and also characterized by a 13-probe Multiplex Ligation-dependent Probe Amplification assay (MLPA). The results revealed an apparent lesion prevalence of 5.0%. ZN microscopy indicated that 32.3% (50/155) of tissues were acid fast. Culture on L-J yielded 85.8% (133/155) isolates. One hundred and twenty-nine out of one hundred and fifty-five (129/155 or 97%) of these were acid fast by ZN microscopy. The Capilia TB-Neo test was performed on 93 of the isolates. Capilia TB-Neo test identified 11.8% (11/ 93) as members of the Mycobacterium tuberculosis Complex (MTBC) and 88.2% (82/93) as Non tuberculous mycobacteria (NTM). A further characterization of isolates using MLPA revealed that 3.8% (5/130) were M. africanum and 6.2% (8/130) were M. bovis. Surprisingly, 38.5 % (50/130) were classified as MTB (not M. bovis or M. africanum). Mixed infection was also identified in 42.9% (3/7) bovines. A comparison of MLPA and Capilia TB-Neo tests using the latter as a “Gold Standard” revealed that MLPA has a sensitivity and specificity of 72.7% and 39.7% respectively. The positive predictive value (PPV) and negative predictive value (NPV) were 16.3% and 90.0% respectively. The data obtained indicates that contamination of beef by TB is prevalent and therefore could pose a serious health threat. More stringent management and control methods should be put in place to improve beef quality.

Source: KNUST