ghanaopendata/ghanaian-research-english huggingface dataset:
Phosphate retention and extractability in soils of the humid zone in West Africa

Phosphate adsorption and desorption studies provide insight for developing P management strategies. Very few studies have concentrated on P desorption which provides information on the reversibility of adsorbed P. Phosphate adsorption and desorption studies were carried out on seven rice-growing soils from three countries in West Africa, with the objective of relating these processes to P management strategies for the soils. The standard P requirement (SPR) of soils, defined as the amount of P to be added to attain an equilibrium solution concentration of 0.2 mg P 1-1, varied from 42 to 175 mg P kg-1. Out of the seven soils, four required low amounts and the other three needed relatively higher P applications. The extractability of the adsorbed P in different extractants was: 0.01 M KCl 32-78%, Olsen P 21-112%, and Bray 1 P 15-40%. Differences in the amounts of P desorbed by the soils suggested that the critical P levels needed for P management must be different. Management options to increase P availability in the soils are suggested. © 2001 Elsevier Science B.V.

Source: UG
Phosphorus retention and availability in three contrasting soils amended with rice husk and corn cob biochar at varying pyrolysis temperatures

The reactive nature of phosphorus (P) leads to the formation of insoluble Fe, Al and Ca phosphates in highly weathered tropical soils, thus reducing P availability for plant uptake. Biochar with its heterogeneous surface properties as influenced by feedstock and pyrolysis temperature can affect P retention and availability in tropical soils. In the present study, incubation studies were conducted for 90 days to investigate the effect of corn cob and rice husk biochar on P sorption and desorption in two acid (Typic Plinthustult-A & Plinthic Acrudox-B) and one neutral soil (Quartzipsamment-C). The biochars were pyrolyzed at varying temperatures (300 °C, 450 °C and 650 °C) and applied at a rate of 1% (w/w) to the soils. Phosphorus sorption data were fitted to Langmuir and Freundlich models. Phosphorus desorption was done on the residual samples that received initial P concentrations of 21.5 mg L−1, 43.0 mg L−1 and 86.0 mg L−1 solution using 10 mM KCl. The P sorption capacity of the two acid soils i.e. A (395 mg kg−1) and B (296 mg kg−1) were more than two fold that of the neutral soil (C) (105 mg kg−1). Addition of the biochar types to soil A raised the equilibrium P concentration in solution at decreasing pyrolysis temperature. Similar trend was observed in soil B with the exception of corn cob and rice husk biochar at 650 °C which increased the soil's (B) P sorption capacity. In soil C, both biochar types increased P sorption capacity with increasing pyrolysis temperatures. Phosphorus desorbability increased with increasing initial P concentrations in the three soils. Generally, P desorbability increased in the acid soils but decreased in the neutral soil upon biochar amendment. Decreases in P adsorption and consequently increases in P desorption were more pronounced when the 300 °C biochar types were amended with the soils. The study thus showed that biochar pyrolyzed at 300–450 °C could be used to reduce P sorption and increase P bioavailability especially in acid soils. The addition of biochar to neutral or alkaline soils might increase P retention possibly in the short-term, reducing P bioavailability.

Source: UG
Phosphorus sorption capacity in relation to soil properties in profiles of sandy soils of the Keta sandspit in Ghana

The sandy soils of Anloga in the Volta region form part of the Keta basin. The soils are infertile and of low productivity but are intensively cultivated for vegetables such as shallot (Allium cepa). Farmers have augmented the fertility of the soils by adding cow dung and poultry manure for the past seventy years. To study the P dynamics in the soils, three profiles were dug on cultivated (F) and two on uncultivated (U) fields to study P accumulation and sorption after decades of cultivation. The results showed that total P content was 533 mg P kg-¹ at the depth of 50 cm and below in the F-profiles compared to 416 mg P kg-¹ of similar depth of the uncultivated soils, suggesting some movement of P from the surface soil into the subsoil. The maximum P sorption capacity of the U soils was low (92 6 mg kg-¹) but higher than those of the F soils (58.8 mg P kg-¹). Multiple regression analyses showed that pH and Ca were the two major determinants of P sorption in the soils. The degree of P saturation (DPS) of the surface soils of the cultivated soils was higher than the average critical value of 25% DPS of an arable land but in the lower depths of the cultivated soils, the DPS decreased tremendously below the critical level of 25% which meant that these depths were not saturated well enough to enhance leaching of P to the underground waters.

Source: UG
Photocatalytic degradation of fractionated crude oil: potential application in oil spill remediation

The current oil spill remediation strategies are costly and may be toxic to aquatic species and clean-up workers. There is, therefore, the need to look for alternative oil spill remediation strategies that are less costly and non-toxic. This paper presents the potential of TiO2 and its modified form (Fe-TiO2) to remediate crude oil fractions under the irradiation of sunlight (UV-Vis), visible (Vis) and ultraviolet (UV) lights. The TiO2 and Fe-TiO2 were synthesized by mild hydrothermal method and characterized with X-ray diffraction (XRD), Ultra-violet-visible spectroscopy (UV-Vis), Diffusion reflectance spectroscopy (DRS), Thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC), and Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDX). The DRS result of Fe-TiO2 showed an enhanced absorption in the visible light region. The estimated optical band gaps were ~3.12 and ~2.9 eV for TiO2 and Fe-TiO2, respectively. The potential application of TiO2 and Fe-TiO2 in oil spill remediation was investigated through photocatalytic degradation of benzene soluble fraction, n-hexane soluble fraction and 1:1 volume by volume methanol/benzene soluble fraction in crude oil. The degraded crude oil fractions were characterized with UV-vis, Fourier Transform Infrared (FTIR) Spectroscopy and Gas Chromatography-Mass Spectrometer (GC-MS). The FTIR and UV-vis results showed that the Fe-TiO2 was more effective in photodegrading the crude oil fractions under sunlight light irradiation than TiO2. The GCMS results showed excellent photodegradation of the various crude oil fractions with the formation of new intermediate products. The results from the study show the potential application of TiO2 and Fe-TiO2 in crude oil spills remediation.

Source: UG
Photocatalytic enhancement mechanisms for novel g-C3N4/ PVK nanoheterojunction

The interactions between monolayer graphitic carbon nitride (g-C3N4) and conjugated polymer poly(9- vinylcarbazole) (PVK) have been explored. We investigated the enhanced photocatalytic mechanisms for the novel g-C3N4/PVK nanoheterojunction covering the state-of-the-art of DFT by performing rigorous DFT calcu lations combined with van der Waals corrections (GGA + vdW). The calculated band alignment between g-C3N4 monolayer and PVK monomer clearly reveals that the conduction band minimum and the valence band maximum of g-C3N4 monolayer are higher than those of the conjugated polymer PVK. This predicted band alignment ensures the photogenerated electrons easily migrate from the g-C3N4 monolayer to the PVK monomer, and will lead to high hydrogen-evolution reaction activity. The charge transfer between g-C3N4 monolayer and PVK results in a polarized field within the interface region, which will benefit the separation of photogenerated carriers. The calculated density of electronic states, Lowdin charge transfer and charge density difference certify that this proposed layered nanoheterojunction is an excellent light-harvesting semiconductor. These findings indicate that the conjugated polymer PVK is a promising candidate as a non-noble metal co-catalyst for g-C3N4 photocatalysis. It also provides useful information for understanding the observed enhanced photocatalytic mechanisms in experiments.

Source: UG
Photosynthetic Activities, Phytohormones, and Secondary Metabolites Induction in Plants by Prevailing Compost Residue.

Compost residue enriches soil health with the potential to enhance plant metabolism and hormonal balance, but has not yet been studied. A study was performed to determine how prevailing compost residue induces tomato (Solanum lycopersicum ‘Scotia’) plant morpho-physiology, phytohormones, and secondary metabolites. Plants were grown in soils with a previous history of annual (AN) and biennial (BI) compost amendments. The controls were soil without compost (C) amendment and municipal solid waste compost (MSWC) alone. The MSWC- and AN-plants had similar and significantly (p < 0.05) highest growth and photosynthetic activities compared to the BI- or C-plants. Total phenolics and lipid peroxidase activity were significantly (p < 0.001) high in BI-plants, while hydrogen peroxide and antioxidant capacity were significantly (p < 0.001) high in AN-plants. MSWC-plants recorded the highest cis-abscisic acid, followed by AN-, and then BI- and C-plants. Cis-zeatin, trans-zeatin, and isopentenyladenine ribosides were detected in the MSWC and AN-plants but not in the BI- or C-plants. Furthermore, gibberellins GA53, GA19, and GA8 were high in the MSWC-plants, but only GA8 was detected in the AN plants and none in the others. Besides, MSWC plants exhibited the highest content of 1-aminocyclopropane-1-carboxylic acid. Conjugated salicylic acid was highest in the BI-plants, while jasmonic acid-isoleucine was highest in MSWC-plants and C plants. In conclusion, prevailing compost chemical residues upregulate plant growth, phytohormones, and metabolic compounds that can potentially increase plant growth and abiotic stress defense. Future work should investigate the flow of these compounds in plants under abiotic stress.

Source: UG
Photothermally-Heated Superparamagnetic Polymeric Nanocomposite Implants for Interstitial Thermotherapy

Photothermally-heated polymer-based superparamagnetic nanocomposite (SNC) implants have the potential to overcome limitations of the conventional inductively-heated ferromagnetic metallic alloy implants for interstitial thermotherapy (IT). This paper presents an assessment of a model SNC—poly-dimethylsiloxane (PDMS) and Fe3O4 nanoparticles (MNP)—implant for IT. First, we performed structural and optical characterization of the commercially purchased MNPs, which were added to the PDMS to prepare the SNCs (MNP weight fraction = 10 wt.%) that were used to fabricate cubic implants. We studied the structural properties of SNC and characterized the photothermal heating capabilities of the implants in three different media: aqueous solution, cell (in-vitro) suspensions and agarose gel. Our results showed that the spherical MNPs, whose optical absorbance increased with concentration, were uniformly distributed within the SNC with no new bond formed with the PDMS matrix and the SNC implants generated photothermal heat that increased the temperature of deionized water to different levels at different rates, decreased the viability of MDA-MB-231 cells and regulated the lesion size in agarose gel as a function of laser power only, laser power or exposure time and the number of implants, respectively. We discussed the opportunities it offers for the development of a smart and efficient strategy that can enhance the efficacy of conventional interstitial thermotherapy. Collectively, this proof-of-concept study shows the feasibility of a photothermally-heated polymer-based SNC implant technique.

Source: UG
Phylogenetically distinct Wolbachia gene and pseudogene sequences obtained from the African onchocerciasis vector Simulium squamosum

The Department of Parasitology conducts research into parasitic diseases of public health importance with the overall goal of reducing their transmission and the heavy disease burden that they impose on affected populations. The Department maintains focus on parasitic diseases in general. These include major diseases such as malaria, and others listed under the Neglected Tropical Diseases (NTD) control initiative such as, lymphatic filariasis, onchocerciasis, schistosomiasis, soil-transmitted helminthiasis, trypanosomiasis and leishmaniasis.

Source: UG
Phylogenomics of Mycobacterium Africanum Reveals a New Lineage and a Complex Evolutionary History

The Bacteriology Department aims to improve the quality of life first for Ghanaians and the world at large by conducting research into bacterial diseases of public health importance to Ghana and globally. In addition to working on enteric pathogens and sexually transmitted diseases, the department’s current main focus is on the two most important mycobacterial diseases of public health importance to Ghana, namely Buruli ulcer (BU) and tuberculosis (TB).

Source: UG
Physical activity and depression during the COVID 19 pandemic in Nigeria: Does age and gender make a difference?

Background There is overwhelming evidence indicating that depression may be reduced by physical activity (PA) but studies in lower- and middle-income countries and those that involved data at higher physical activity doses were underrepresented. The current study investigated the associations between PA levels (vigorous, moderate, walking and sitting) and depression, and tested whether age and gender moderates the link between PA and depression during the COVID-19 pandemic. Method Participants were 857 adults (51.0% women; aged 18–69, mean age = 29.71, SD= 10.84 years) who completed an online survey as part of the General Health, Speech and Physical Activity Relationship Assessment Study in Nigeria. Physical activity was assessed using the International Physical Activity Questionnaire (IPAQ) while depression was measured using the Patient Health Questionnaire (PHQ-9). Results Results of Hayes PROCESS macro indicated that those who engaged in vigorous PA reported lower levels of depression. Sitting, walking and moderate PA were not significantly associated with depressive symptoms. Older participants reported less symptoms of depression. Women had higher depressive symptoms compared to men. The interactions of age and gender with the PA levels were not significant, which showed that age and gender did not moderate the relationships of PA and depression. Conclusion Health practitioners should encourage people to engage in vigorous PA in order to reduce levels of depression and improve mental health in the general population.

Source: UG
Physical activity and depression during the COVID‑19 pandemic in Nigeria: does age and gender make a diference?

Background There is overwhelming evidence indicating that depression may be reduced by physical activity (PA), but studies in lower- and middle-income countries and those that involved data at higher physical activity doses were underrepresented. The current study investigated the associations between PA levels (vigorous, moderate, walking and sitting) and depression and tested whether age and gender moderate the link between PA and depression during the COVID-19 pandemic. Method The participants were 857 adults (51.0% women; aged 18–69, mean age = 29.71, SD = 10.84 years) who completed an online survey as part of the General Health, Speech, and Physical Activity Relationship Assessment Study in Nigeria. Physical activity was assessed using the International Physical Activity Questionnaire (IPAQ) short form, while depression was measured using the Patient Health Questionnaire (PHQ-9). Results The results of the Hayes PROCESS macro indicated that those who engaged in vigorous PA reported lower levels of depression (B = 0.02, p<0.01). Sitting (B = − 0.00, p = 0.050), walking (B = 0.00, p = 0.054) and moderate (B = 0.00, p = 0.054) p =.064) PA were not significantly associated with depressive symptoms. Older participants reported fewer symptoms of depression (B =0.11, p<.001). Women had higher depressive symptoms than men (B =0.91, p<0.05). The interactions of age and gender with PA levels were not significant, which showed that age and gender did not moderate the relationships between PA and depression. Conclusion Engagement in vigorous PA may be helpful to reduce levels of depression and improve mental health in the general population.

Source: UG
Physical activity of children: a global matrix of grades comparing 15 countries.

The Active Healthy Kids Canada (AHKC) Report Card on Physical Activity for Children and Youth has been effective in powering the movement to get kids moving by influencing priorities, policies, and practice in Canada. The AHKC Report Card process was replicated in 14 additional countries from 5 continents using 9 common indicators (Overall Physical Activity, Organized Sport Participation, Active Play, Active Transportation, Sedentary Behavior, Family and Peers, School, Community and Built Environment, and Government Strategies and Investments), a harmonized process and a standardized grading framework. The 15 Report Cards were presented at the Global Summit on the Physical Activity of Children in Toronto on May 20, 2014. The consolidated findings are summarized here in the form of a global matrix of grades. There is a large spread in grades across countries for most indicators. Countries that lead in certain indicators lag in others. Overall, the grades for indicators of physical activity (PA) around the world are low/poor. Many countries have insufficient information to assign a grade, particularly for the Active Play and Family and Peers indicators. Grades for Sedentary Behaviors are, in general, better in low income countries. The Community and Built Environment indicator received high grades in high income countries and notably lower grades in low income countries. There was a pattern of higher PA and lower sedentary behavior in countries reporting poorer infrastructure, and lower PA and higher sedentary behavior in countries reporting better infrastructure, which presents an interesting paradox. Many surveillance and research gaps and weaknesses were apparent. International cooperation and cross-fertilization is encouraged to tackle existing challenges, understand underlying mechanisms, derive innovative solutions, and overcome the expanding childhood inactivity crisis.

Source: UG
Physical and Mechanical Properties of Coffee Cherries and Beans in Africa: Review and the State of Arts

ABSTRACT Coffee is an important source of income for African smallholder farmers. The world is predominated by three coffee varieties, namely Arabica, Robusta, and Liberica originated in the African countries. However, the low coffee quality attributes can affect the coffee beans' price due to the improper post-harvesting processes. Therefore, this work is aimed to review the physical and mechanical properties of the African coffee cherries and beans on the country-wise level, and review the methods used to measure quality parameters and compare the key coffee quality parameters. This work was qualitatively conducted using secondary data on African Arabica and Robusta coffee from journals, conference proceedings, and reports. Methods used for determining the coffee beans' properties were explored country wise. The coffee attributes of the two coffee varieties were compared through statistical analysis using ANOVA. The review found that the coffee quality depends on geographical characteristics, agronomic factors, and post-harvesting processes. The coffee cherries de-pulping process is linked to the coffee quality to avoid the damage of parchment coffee beans based particularly on the size and shape of coffee cherries and beans. The analysed quality parameters showed that the Ethiopian Arabica coffee beans were larger than the Ghanaian Robusta coffee beans. While the size of Robusta coffee in Eastern African countries, particularly Uganda, is bigger than those in Western countries, especially Ghana. Therefore, the information on the coffee quality attributes can help to improve the performance parameters of the coffee de-pulping machine and enhance the price of African coffee.

Source: UG
Physical and social wellbeing of family caregivers of persons with hepatitis B associated chronic liver disease in Ghana: a qualitative study

Background Hepatitis B is one of the most common viral (HBV)infections that affect the liver. Infection with the virus may result in varying severity of liver disease which may be acute or chronic. Though most people recover from the infection, about 5 −10% of cases lead to chronic infection. Persons who develop HBV-related debilitating liver disease will likely require informal care from family caregivers. Aim This study sought to explore the physical and social wellbeing of family caregivers of persons with hepatitis B-associated chronic liver disease in a tertiary hospital in the Central region of Ghana. Methods This study adopted an exploratory, descriptive qualitative research design. We used a purposive sampling technique and a semi-structured interview guide to interview eighteen participants. The Quality of Life (QoL) model applied to family caregivers underpinned the study and guided the formulation of study objectives. Data analysis followed Braun and Clarke’s procedure for thematic content analysis. Similar codes were grouped into subthemes, and similar subthemes were grouped into major themes. The consolidated criteria for reporting qualitative research (coreq) checklist was used as a guide for writing the study. Results Two major themes emerged from the study: physical wellbeing and social wellbeing. Seven subthemes were also identified: physical body changes and physiological body changes (physical wellbeing) and role strain, social isolation, financial impact, affection/sexual function, and support social wellbeing). These central themes aligned with two domains of the QoL model applied to family caregivers. Conclusion Family caregivers of persons with HB-associated liver disease suffer ill health due to the burden of physical care for their sick relatives and neglect their health due to time constraints. They also experience role strain as they cannot attend to other family responsibilities and feel socially isolated since they spend all their time caring for a sick family member

Source: UG
Physical drivers of pelagic sargassum bloom interannual variability in the Central West Atlantic over 2010–2020

socioeconomic impacts for coastal populations. To investigate the role of physical drivers in post-2010 sargassum blooms in the Central West Atlantic (CWA), conditions are examined across the wider tropical North Atlantic, using ocean and atmospheric re-analyses and satellite-derived datasets. Of particular consequence for the growth and drift of sargassum are patterns and seasonality of winds and currents. Results suggest that in years of exceptionally large sargassum blooms (2015, 2018), the Intertropical Convergence Zone (ITCZ), an area of maximum wind convergence where sargassum naturally accumulates, shifted southward, towards nutrient-rich waters of the Amazon River plume and the equatorial upwelling zone further stimulating sargassum growth. These changes are associated with modes of natural variability in the tropical Atlantic, notably a negative phase of the Atlantic Meridional Mode (AMM) in 2015 and 2018, and a positive phase of the Atlantic Niño in 2018. Negative AMM in these 2 years is also associated with stronger trade winds and enhanced northwest Africa upwelling, probably resulting in stronger southwestward nutrient transport into the eastern part of CWA. Moreover, in contrast with most years, important secondary winter blooms took place in both 2015 and 2018 in the northern part of CWA, associated with excessive wind-driven equatorial upwelling and anomalously strong northwestward nutrient transport.

Source: UG