ghanaopendata/ghanaian-research-english huggingface dataset:
Stroke in Indigenous Africans, African Americans, and European Americans Interplay of Racial and Geographic Factors

Background and Purpose—The relative contributions of racial and geographic factors to higher risk of stroke in people of African ancestry have not been unraveled. We compared stroke type and contributions of vascular risk factors among indigenous Africans (IA), African Americans (AA), and European Americans (EA). Methods—SIREN (Stroke Investigative Research and Educational Network) is a large multinational case–control study in West Africa—the ancestral home of 71% AA—whereas REGARDS (Reasons for Geographic and Racial Differences in Stroke) is a cohort study including AA and EA in the United States. Using harmonized assessments and standard definitions, we compared data on stroke type and established risk factors for stroke in acute stroke cases aged ≥55 years in both studies. Results—There were 811 IA, 452 AA, and 665 EA stroke subjects, with mean age of 68.0±9.3, 73.0±8.3, and 76.0±8.3 years, respectively (P<0.0001). Hemorrhagic stroke was more frequent among IA (27%) compared with AA (8%) and EA (5.4%; P<0.001). Lacunar strokes were more prevalent in IA (47.1%), followed by AA (35.1%) and then EA (21.0%; P<0.0001). The frequency of hypertension in decreasing order was IA (92.8%), followed by AA (82.5%) and then EA (64.2%; P<0.0001) and similarly for diabetes mellitus IA (38.3%), AA (36.8%), and EA (21.0%; P<0.0001). Premorbid sedentary lifestyle was similar in AA (37.7%) and EA (34.0%) but lower frequency in IA (8.0%). Conclusions—Environmental risk factors such as sedentary lifestyle may contribute to the higher proportion of ischemic stroke in AA compared with IA, whereas racial factors may contribute to the higher proportion of hypertension and diabetes mellitus among stroke subjects of African ancestry.

Source: KNUST
Structural and optoelectronic properties of copper, zinc, cadmium and lead chalcogenide nanocrystalline thin films deposited at the water-toluene interface

Nanostructured thin films of CuE (E=S, Se, Te) have been prepared at the water-toluene interface by reacting toluene solutions of copper cupferronates with aqueous chalcogenide ions obtained by the borohydride reduction of sulphur, selenium and tellurium powder. The thin film deposits were characterized by powder X-ray crystallography, scanning electron microscopy and absorption spectroscopy. The influence of deposition conditions such as precursor concentrations, temperature as well as deposition times were studied. The average crystallite sizes of the as-prepared nanoparticles at different temperatures, concentrations and deposition times ranged from 3.4 to 4.3 nm for CuS, 5.1 to 5.7 nm for CuSe and 1.4 to 4.5 nm for CuTe. The dislocation densities ranged from 5.46 to 8.85 x 1017 lines/m for CuS and 2.32 to 3.86 x 1017 lines/m for CuSe, 5.0 to 47.91 x 1017 lines/m for CuTe. The shape of the as-prepared nanoparticles at different temperatures was studied by SEM and gave morphologies from cubes to rods. The band gaps obtained for CuS ranged from 3.6 to 3.9 eV and CuSe ranged from 3.53 to 3.96 eV

Source: KNUST
Structural analysis of stock prices and some macroeconomic indicators in Ghana

Capital markets play a significant role in the financial sector of every economy. Through stabilization of the financial sector and the provision of important investment channels that contribute to attract domestic and foreign capital, an efficient market can promote economic growth and prosperity. This study investigates the relationship between stock prices and macroeconomic factors in Ghana using monthly data covering the period November, 1990 to June, 2011. The study employed the celebrated multivariate Vector Auto regression (VAR) models to establish the linkage between stock prices and macroeconomic factors. Additionally, the Granger causality analysis was used to examine the direction of causality between stock prices and the various macroeconomic factors. It was found that interest rate and inflation are the key macroeconomic factors that determine stock prices in Ghana within the period. Furthermore, it was found that with the exception of inflation and interest rate, no other macroeconomic variable specified in the model Granger causes stock prices. Indeed, causality does not also run from stock prices to these variables. Additionally, forecasting GSE index using macroeconomic variables was somewhat difficult since they are affected considerably by economic policies. . The immediate corollary of the results therefore is that, perhaps the Ghana Stock market might be sensitive to global macroeconomic factors other than the internal ones. Thus the economic policies of Ghana need to be properly and utterly synchronized thus brought to line with global macroeconomic and financial conditions. Incidentally, this policy direction would mean that, controlling domestic policies alone is not enough for the determination of stock prices in Ghana.

Source: KNUST
“Structural properties of masonry bricks manufactured from clay deposits in Ghana”

In the past, there has been very little use of burnt clay bricks for constructional purposes in Ghana. This situation is viewed as an anomaly since all the raw material requirements for their production are locally obtainable. Rather, the preference, to date, has been for sandcrete blocks whose production is heavily dependent on the availability of imported cement. The need to conserve our limited foreign exchange in the face of the country’s present economic situation has been reiterated on numerous occasions by the government. It is anticipated that the use of burnt clay bricks will be promoted vigorously as the government continues the search for solutions to the housing deficit problem. The situation therefore calls for an engineering investigation into our abundant clay deposits as well as the bricks that can be manufactured from these clays. The database that can be derived from this investigation will, needless to say, provide invaluable information for engineering design purposes. The present study attempts to fulfil this national need. Experiments were conducted to establish the suitability or otherwise, of selected clay deposits for brick manufacture in the country. Next, burnt clay bricks manufactured from these clays were used to make model brickwork panels meant for structural (uniaxial) testing. The results indicate that, firstly, the clay deposits are very suitable for the manufacture of burnt bricks. Secondly, and more importantly, the finding was made that under the application of uniaxial compressive loading, structural brickwork obeys the single plane of weakness theory, which was originally proposed by J.C. Jaeger to explain the failure mode of sedimentary rocks. This finding will, doubtlessly, throw more light on design principles involving brick masonry structures.

Source: KNUST
Structural properties of ground palm kernel shell (GPKS) masonry units

The study aims to assess how the partial replacement of sand with Ground Palm Kernel Shell (GPKS) affects the physical and other properties of masonry units. The experiment showed, the acceptable GPKS aggregate percentage that can be used for the production of masonry units, 10% - 30% GPKS aggregate replacement is acceptable for the production of 150mm thick solid masonry units and 10% - 40% GPKS aggregate replacement is acceptable for the 125mm thick solid masonry units, 150mm and 125mm thick cellular masonry unit. Also it showed that, the increasing quantity of GPKS aggregate increases the water demand of the mix and this often increased the porosity and water absorption rate of the masonry unit with 40% GPKS aggregate. Generally, porosity, water absorption and capillary action decreased with increasing sand quantity and the water absorption rate of the masonry unit with GPKS aggregate was much slower than that of masonry unit with 0% GPKS aggregate (Control sample). Again it was revealed that, the increase in water demand was as a result of the increase in GPKS aggregate which reduced the workability, hence the demand for more water. Increasing GPKS aggregate content measuring above 30% also reduced the mechanical properties of 150mm and 125mm solid masonry units with GPKS aggregate type A at the 28 days curing period. The increasing GPKS aggregate content also demand increase in water/cement ratio. The 40% GPKS aggregate type was seen to have influenced the 28 days compressive strength of 150mm and 125mm cellular masonry units. In addition, the compressive strength of all the GPKS aggregate masonry units decreased with the increase of GPKS aggregate replacement percentages as compared to the control samples (0% GPKS). With these finding, it was recommended that, GPKS aggregate percentage content of 10% is optimum as partial replacement for masonry unit production, the grinding of GPKS aggregate should be controlled in the way that the particle size distribution curve would fall within the upper and lower limits in relation to standard grading requirement and the best standard sizes that can withstand all the adverse condition was 150mm and 125mm, both solid and cellular with GPKS aggregate type B percentage content of 10%, 20% 30% and 40%

Source: KNUST
A structuralist interpretation of Ayi Kwei Armah’s novels (using the genette schema of time in the presentation of narrative events)

This dissertation is a structuralist study and the aim is to apply a structuralist theory to an interpretation of the novels of Ayi Kwei Armah. In all, to date, Ayi Kwei Armah has five novels to his credit. These novels, in chronological order, are The Beautiful Ones Are Not Yet Born (1968), Fragments (1969), Why Are We So Blest? (1972), To Thousand Season (1973) end The Healers (1978). All the five novels were produced within a span of ten years and in a literary epoch that has seen phenomenal changes in literary discourse. One of such changes is the emergence of Modernism which began comparatively recently, in fact, toward the end of the nineteenth century. The term modernism describes works of art which show a marked tendency to flout conventions in literary expression. Such works have been in existence since the later part of the nineteenth century. Professor Jeremy Hawthorn has explained the texture of modernist works. According to him, “modernist works tend to be self—conscious in v:ays that vary according to the genre and art form in question: they deliberately remind the reader or observer that they are art works, rather than seeking to serve as ‘windows on reality’”.1 What this means is that a modernist novel consistently invites the reader more to it own artistic edifice than to its inner substance. In other words, a modernist novel does not just aim to reflect reality but rather to express itself as a pure work of art thereby divorcing itself from veridical reality. That is to say that in a modernist novel the focus is on the structures of the work more then on the author or the society or on the substance of the work. Hence, there is, in the modernist novel, a shift from content to form and Conrad was one of the first to observe this tendency.

Source: KNUST
Structure and physicochemical properties of Ghanaian grewia gum

Grewia polysaccharides were isolated using sodium metabisulphite and phosphate buffers and the influence of the different extraction techniques on the chemical composition and structural characteristics of the extracts were determined. Structure and chemical composition of the resulting polysaccharide extracts were determined using FT-IR and NMR spectroscopy, neutral sugar analysis, size exclusion chromatography coupled to multi-angle light scattering (SEC-MALS), dilute solution viscometry and steady shear rheology. Chemical composition was similar irrespectively of the extraction solvent used and ranged between 11.1 and 16.5% for protein, 53.4 and 66.9% for total carbohydrate, 18.5 and 35.1% for total uronic acid and 23.5 and 28.6% for rhamnose. Predominate sugars in the extracts were rhamnose and uronic acids with spectroscopy showing the presence of esterified groups. Intrinsic viscosity varied between 6.5 and 9.1 dL g−1 and related with molar mass (754–2778 × 103 g mol−1 ). Grewia polysaccharide dispersions at 1 g dL−1 exhibited a shear thinning flow behaviour with crude and sodium metabisulphite extracts having higher viscosities. Overall, differences in extraction techniques produced grewia samples with tailored bulk properties for use in the food and pharmaceutical industries.

Source: KNUST
Structure of district finances and its implications for local based development - a case study of the Bosomtwi-Atwima-Kwanwoma District

The government of Ghana created 110 Assemblies as part of its decentralization policy. These Assemblies are the political decision-makers and implementers at the sub national level. The government has transferred to the Assemblies the power and authority to perform the tasks assigned them. To make the transfer of functions meaningful and efficient the Assemblies have been given the Authority to generate revenue from sources prescribed by law. In addition the government supplements their income with funds from what is commonly referred to as the District Assemblies Common Fund (DACF). Most of the Assemblies derive revenue from other sources such as NGO’s and Bilateral Agencies among others. Despite the provisions made for Assemblies to generate their own revenue and use it at their own discretion, most are not able to generate enough revenue from these sources for which the Bosomtwe-Atwima-Kwaawoma District BAKD) is no exception. In view of this they rely considerably on external funding for their activities. This funding comes with it strings which direct the Assemblies as to how the funds should be utilized. This defeats the essence of the decentralization programme for which local-based decision making is the prime factor. Districts can therefore perform better if they are able to generate much revenue from their own sources. This study was therefore conducted in BAKD in the Ashanti region with the objective of assessing the structure of its revenue and the implication for local based development. It seeks to determine the extent to which the district exercises discretional authority in the use of its revenue and makes appropriate recommendations accordingly. Both qualitative and quantitative data was collected by means of structured questionnaires and discussions with staff of the Assembly and people in some selected settlements of the District. Simple analytical tools such as percentages, trend analysis, measurement of variations and associations and discounting techniques were adopted for the analysis. The work has demonstrated that the district relies so much on the DACF for the implementation of development projects. This fund comes with its guidelines which limits the district in exercising discretional authority in its, spending. Even though revenue from own sources tends to increase in nominal values, it is not enough to meet its recurrent expenditure let alone fund capital projects. This is because the implementation of the DACF projects has expenditure implications and yet the fund is only applicable to development expenditure only. In this respect the Assembly is compelled to follow the guidelines in the utilization of the fund, and this restricts its discretional authority. It would therefore be mutually beneficial if the assembly strengthens its revenue mobilization machinery for which it can have discretionary authority to spend according to its own priorities but within broad Government goals.

Source: KNUST
The structure and function of the land and tree tenure systems and Agroforestry in the Brong Ahafo Region of Ghana

Increasing population in the country has led to pressure on land in some parts of the country which has resulted in short fallow periods and low crop yields. Agroforestry has the potential to solve some of the land use problems faced by farmers in the Brong Ahafo Region, yet its adoption depends on several factors of which important ones are land and tree tenure. A study was therefore conducted in 1995. The aim of the study was to provide information which could assist the development of new policies to encourage agroforestry adoption. The results of the study indicate that natives have no difficulty acquiring land for farming since they can cultivate family or stool lands. Tenants on the other hand do not have permanent interest in their farmlands and cannot adopt agroforestry without the prior knowledge and consent of the landowner. Some farmers were prepared to integrate fruit and nut trees like cashew on their farms. Many farmers would not adopt introduced agroforestry technologies which were new to them. The Ministry of Food and Agriculture (MOFA) has not been able to reach out to most rural areas on agroforestry due to perhaps shortage of extension personnel. The results suggest that there is the need to formulate laws to protect the interest of tenant farmers and to regulate land prices to encourage tenants to purchase land for agroforestry. The MOFA should engage the services of more extension personnel to reach out to farmers with new technologies.

Source: KNUST
Structure-Function Relationships in Pectin Emulsification

The emulsifying characteristics of pectins isolated from six different okra genotypes were investigated and their structurefunction relationships have been evaluated. Emulsion formation and stabilization of acidic oil-in-water emulsions (pH 2.0, φ = 0.1) were studied by means of droplet size distribution, ζ-potential measurements, viscometry, interfacial composition analysis and fluorescence microscopy. Fresh and aged emulsions differed in terms of droplet size distribution, interfacial protein and pectin concentrations (Γ) depending on the molecular properties of pectin that was used. Specifically, pectins with intermediate length of RG-I branching with molar ratio of (Ara + Gal)/Rha between 2 and 3 exhibit the optimum emulsification capacity whereas samples with the molar ratio outside this range do not favour emulsification. Additionally, low amounts of RG-I segments (HG/RG-I > 2) improve long term stability of emulsions as opposed to the samples that contain high amounts of RG-I (HG/RG-I < 2) which lead to long term instability. Protein was not found to be the controlling factor for the stability of the dispersions. The present results show that rational design of pectin should be sought before application as functional ingredient in food and/or pharmaceutical systems.

Source: KNUST
Structure-Function Relationships in Pectin Emulsification

The emulsifying characteristics of pectins isolated from six different okra genotypes were investigated and their structure function relationships have been evaluated. Emulsion formation and stabilization of acidic oil-in-water emulsions (pH 2.0,φ = 0.1) were studied by means of droplet size distribution, ζ-potential measurements, viscometry, interfacial composition analysis and fluorescence microscopy. Fresh and aged emulsions differed in terms of droplet size distribution, interfacial protein and pectin concentrations (Γ) depending on the molecular properties of pectin that was used. Specifically, pectins with intermediate length of RG-I branching with molar ratio of (Ara + Gal)/Rha between 2 and 3 exhibit the optimum emulsification capacity whereas samples with the molar ratio outside this range do not favour emulsification. Additionally, low amounts of RG-I segments (HG/RG-I > 2) improve long term stability of emulsions as opposed to the samples that contain high amounts of RG-I (HG/RG-I < 2) which lead to long term instability. Protein was not found to be the controlling factor for the stability of the dispersions. The present results show that rational design of pectin should be sought before application as functional ingredient in food and/or pharmaceutical systems.

Source: KNUST
Students’ abandonment of the Visual Arts programme in Senior High Schools: Ejisu-Juaben Municipality Senior High Schools as a case study

The focus of this study was to investigate students’ abandonment of the Visual Arts programme in Senior High Schools within the Ejisu-Juaben Municipality of the Ashanti Region of Ghana. The study employed both qualitative and quantitative methods of research and questionnaire to gather data from Visual Arts teachers and Visual Arts students. Other data were collected from some Non-Visual Arts students, around the schools’ environment, the Visual Arts departments, Heads of Visual Arts departments, Assistant Headmasters/mistresses and Headmasters, through the use of observations and interviews. A triangulation of these indicated that some SHS Visual Arts students who are enrolled onto the programme swap to other programmes. Majority of these students who abandon the Visual Arts programme have initial interest but lose interest in the programme along their line of academic pursuance due to multiples of challenges confronting the Visual Arts programme such as; Lack of proper orientation, Lack of practical working studios in some schools, Lack of adequate funds for tools and materials even for practical demonstration lessons, Negative comments about the Visual Arts programme from non-Visual Arts teachers and students as well as Lack of administrative interest and support. Some of the data collected were quantitatively tabled and organized in charts for partial statistical analysis. Again, it was found that, though some of the schools organize orientations for their fresh students in general, there is no properly organized departmental orientation for newly admitted Visual Arts students specifically to properly root them in the department to stand firm against all odds. The researcher through this study recommends that, apart from the general orientations organized by the schools at large, the Visual Arts departments must also organize well-structured orientations, pregnant with detailed but specific information about the Visual Arts programme, for its fresh students. These departmental orientations could even be periodically organized to involve continuing students as refresher courses to firmly root the Visual Arts student in what he/she has originally set out to pursue. Again, the Visual Arts programmes are generally practically oriented: Visual Arts teachers and their Heads of Departments are therefore entreated to adopt more practical innovative approaches in their pedagogical deliveries in order to make what they teach become more interesting and attractive. This will help to win the trust and confidence of their school administrators as well as their students and the school community at large, thereby retaining students who are originally enrolled onto the Visual Arts programme to reduce the abandonment menace.

Source: KNUST
Studies into the manufacture of water-base (emulsion) paint using local extenders

Water base paint was manufactured by using local clay and local lime as extender in place of imported ones. Three different clays from Moseaso, Abompe and Kwahu Nsaba, and local calcium carbonate (CaCO3) and local Calcium hydroxide (Ca (OH)2) from BRRI Kumasi were used with two different formulations to manufacture water-base paint. The properties of the different formulation of the paint manufactured such as pH, viscosity, specific gravity, drying time, fineness, durability, brushability, flow and hiding power were determined. It was observed that local clay and local calcium carbonate (CaCO3) may be used as extenders in water-base paints.

Source: KNUST