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- Review books or articles provide a critical and constructive analysis of existing published literature in a field, through summary, analysis, and comparison, often identifying specific gaps or problems and providing recommendations for future research. These are considered as secondary literature since they generally do not present new data from the author's experimental work. Review articles can be of three types, broadly speaking: literature reviews, systematic reviews, and meta-analyses. It also the researcher to stay abreast of new literature in the field.
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- The J. H. Kwabena Nketia Archives preserve Ghanaian and African cultural heritage through music, oral traditions, photographs, and audiovisual collections. Guided by Professor Nketia’s vision that African traditional arts must be collected, preserved, practiced, and continually inspire creative expression, the Archives serve as a living resource for scholarship, teaching, and innovation
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Item type:Item, Access status: Open Access , Evaluation of the Quality of Reclaimed Soils at Anglogold Ashanti Iduapriem Mines, Ghana(University of Ghana, 2023) Badu, J. K.The assessment of reclamation status must include soil biogeochemical indicators that are sensitive to management. This study was conducted in the Iduapriem concession, Tarkwa to determine the (a) biodiversity of the study sites, (b) characteristics of the soil profiles of the reclaimed sites and the natural forests, (c) quality of rehabilitated mined soils. Therefore, six mined sites viz B1 Pit (Site B), ITSF (Site C), OTSF (Site D), B1S/E (Site E-9), B2&3 (Site E-18), and B1N (Site E-21) under four different modes and varied ages of reclamation were selected for the study. The Neung natural forest (Site A) was used as the control site for the study. For the biodiversity assessment, the floristic and earthworm composition in each site was estimated using the Shannon-Wiener, Margalef’s, Pielou equitability, and the Czekanowski similarity coefficient indices. A 100 cm deep profile was dug at each site and samples were taken at 10 cm intervals. Each profile was described morphologically and their physicochemical characteristics were compared with the control site. Soils were also sampled from all selected sites at 0-20 cm depth using an auger for soil quality assessment. The collected soil samples were transferred to the laboratory and subjected to the physical, chemical, biological analyses and principal component analysis (PCA) to determine soil quality index. The highest Shannon-Wiener diversity index value of 3.13 was obtained at Site A (natural forest). However, at Site B had an index value of 2.64 which came close to Site A. Whereas Site C had an index value of 1.19, Site D had an index value of 1.62. Among the same mode of reclamation, Site E-9, Site E-18 and Site E-21 had an index value of 1.23, 1.82 and 1.76 respectively. Whereas a total number of 954 earthworms were collected from the study area, 30 were collected from Site A. A population of 540 earthworms were collected from Site B, 43 from Site C, while Site D recorded 129 earthworms. However, Sites E-9, E-18 and E-21 produced 6, 5 and 201 earthworms, respectively. The Shannon-Wiener earthworm diversity index was in order of Site B (0.89) > Site E-18 (0.82) > Site A (0.58) > Site D (0.57) > Site C (0.48). However, the index value for Sites E-18 and E-21 was 0 for each site. The use of heavy mining equipment in transporting, dumping and spreading the reclamation materials, compacted the soils. This resulted in higher bulk densities, poor soil structure and limited root distribution within profiles of the reclaimed sites. However, the reverse was the case in the natural forest. Except for the tailing provenance reclaimed sites (Sites C and D) that had a neutral pH, the other reclaimed soils and the natural forest soil were in the range of strongly acid to extremely acid condition. The natural forest recorded the highest soil organic matter, total carbon, total nitrogen. However, in the reclaimed sites, it occurred in the following order: Site B > Site E-21 > Site E-9 > Site E-8 > Site D > Site C. Considering the vertical cross section of the individual profiles of the reclaimed soils, it is clear to conclude that the similar and uniform properties observed from the reclaimed profiles is due to cumulative impact of anthropogenic activities rather than pedogenic. The, PCA selected bulk density, aggregate stability, CF, Exch. acidity, total P, C: N, Cmic and SFD as the final MDS. However, the SQI for the natural forest was 0.687. Whereas in the reclaimed sites, SQI was 0.527 at Site B, Site C had 0.197 and Site D had a quality index of 0.310. At Site E, the value of SQI increased with reclamation age which occurred in the following order: Site E-21 (0.589) > Site E 18 (0.424) and Site E-9 (0.320). The mode of reclamation had significant impact on the physicochemical and biological properties of the reclaimed soils than the age of reclamation. Hence a better performance of the conventionally reclaimed site (Site B) than the haphazardly reclaimed sites. The findings of the study indicate that topsoil management and replacement is very crucial in the recovery of degraded mined lands.Item type:Item, Access status: Open Access , Genetic Basis of Texture and Associated Traits in Cassava(University of Ghana, 2025) Wembabazi, E.Cassava breeding efforts in Uganda have in the past largely focused on improving agronomic traits such as yield and disease resistance but little has been done to improve consumer traits. This has limited adoption of improved varieties among consumers. In Uganda, cassava is predominantly consumed in boiled form and varieties that have a soft texture are preferred. To boost integration of texture traits in routine breeding operations, this study was conducted with specific objectives to (1) assess the phenotypic variability for texture traits (softness, toughness, stiffness) and water absorption (WAB) in a cycle 2 (C2) genomic selection diverse panel, (2) determine the prediction accuracy of Near Infrared Spectroscopy (NIRS) for phenotyping tex ture traits and WAB30 and (3) identify genomic loci and polymorphisms linked to variation for texture traits and further determine genomic prediction accuracy for these traits. From study one, significant differences (p<0.001) were observed among 250 accessions for all texture traits and WAB30, though environment effects also significantly influenced (p<0.001) the variation observed across all traits. Broad sense heritability ranged from low (Soft_p; H2 = 0.38) to moderate (Gradient; H2 = 0.62) indicating substantial genetic control of these traits. Near infrared spectroscopy (NIRS) quantitative predictions for texture traits and WAB30 based on partial least squares regression (PLSR) were all low. Using qualitative machine learning models based on binary classification with support vector machines (SVM), WAB had the high est prediction accuracy and reliability (r2cv = 0.78, ĸcv = 0.46) when spectra were pre- treated with standard normal variate (SNV) in combination with gap segment derivatization (GAP). This finding is promising for the integration of NIRS in routine phenotyping activities for consumer preferred cooking traits in cassava breeding. Through marker-trait association mapping, 24 SNPs that explained a substantial proportion of phenotypic variation were found significantly associated with textural traits and WAB in boiled cassava. Most SNPs were found on chromosomes 4, 8, 17, 18, and a survey of the cassava ge nome v7.1 positioned these SNPs in the vicinity of several genes coding for cell wall modifying proteins including Manes.04G139200 (Soft_T; Betagalactosidase 1) and Manes.18G044401 (WAB30; Glycine rich ell wall structural protein). Assessment of genomic prediction accuracy for texture traits and WAB30 found that all pre dictions across traits remained low (r2cv ≤ 0.27). Also, the Bayes A, Bayesian Ridge Regression (BRR) and Reproducing Kernel Hilbert Spaces (RKHS) models generally gave better predic tion accuracies than GBLUP model. These findings though promising, point at the need for optimal training population size and composition to achieve higher prediction accura cies. Overall, this work demonstrated that tools for improving cassava for consumer preferred traits in Uganda are available and with improvements, could be directly integrated into breeding op erations. This initiative is crucial for developing relevant cassava varieties combining end-user preferences and superior agronomic performances for the millions of actors in the cassava value chain in UgandaItem type:Item, Access status: Open Access , Immune Or Vulnerable? African Stock Markets’ Response To U.S.–China Trade Wars And Geopolitical Tensions(Future Business Journal, 2025-11-12) Korsah, D.; Danso, S.K.This study examines the dynamic impact of the U.S.–China trade war and geopolitical risks on African stock mar ket returns. Using Wavelet Coherence analysis and the Quantile Vector Autoregression (QVAR) model, we capture both time–frequency dynamics and regime-specific connectedness. Drawing on data from seven major African stock exchanges, Geopolitical Risk (GPRI) and U.S.–China Trade Tension (UCTI) indices from January 2007 to February 2024, the results reveal that African markets are not immune but exhibit state-dependent vulnerability. During calm market conditions, trade tensions dominate as the main shock transmitter, whereas geopolitical risks become more influential in crisis periods. The Johannesburg Stock Exchange (JSE) emerges as a key transmitter of shocks, while the Nigerian Exchange (NGX) remains the largest receiver. These findings underscore the need for targeted regional risk manage ment and coordinated policy responses to enhance Africa’s financial resilience against external shocks.Item type:Item, Access status: Open Access , Effect of Noni Fruit (Morinda Citrifolia) Extract on Pre-Lay Sexual Development, Egg Production Performance, and Blood Metabolite Status of Laying Birds in Ghana.(University of Ghana, 2024) Agyei-Henaku, K. A. A-O.The 2020 per capita egg consumption of Ghana was 1.07 kg. The demand for poultry products also exceeds local production, and the shortfall in animal protein intake is more of a supply problem rather than a demand problem. Commercial laying birds are popular in Ghana due to their high egg-production capabilities amongst others thus enhancing the growth and egg production of layers can have a considerable impact on the livelihoods of poultry farmers and the overall agricultural economy of the country. Disease conditions in livestock and poultry production caused stunting and delays in reaching market weight resulting in economic losses. Anti-microbials and anti-parasitic drugs or pesticides were used on farms as interventions to enhance growth and productivity but contaminated the poultry products. Ingestion of these antimicrobials in the contaminated poultry products by humans caused anti-microbial-resistant bacteria to develop in them. Therefore, those interventions using antimicrobials as therapeutic and prophylactic agents for improving health, growth and production performance in poultry are being gradually discontinued and being replaced by phytogenic feed additives, due to the increased public awareness of the risk of developing cross-resistance of pathogens to antibiotics. The method of administering feed additives to the diet of poultry could influence their performance and immune competence an indication that administering through drinking water could be superior to the more conventional in-feed supplementation. In addition, the time of administration of the additive has also not received attention, especially in Ghana, with most scientists in literature administering additives both during early lay or late lying periods and not during the entire growth and production cycle of layer-type birds. The objective of this study was to investigate the effects of noni fruit extract and physiological status on pre-lay sexual development performance, egg production performance from early to late lay, and on the overall health of layers. Four experiments were conducted involving 600 layer-type birds in two groups of 300 birds. The two groups of 300 layer-type birds were fed a regular layer ration. The first Group of 300 birds was allocated to the first three experiments, and the second group of 300 layer-type birds was used for the fourth experiment. The maximum yield and concentration of noni fruit extract used for the four experiments were determined in the laboratory. Experiment 1 had three treatments (T1, T2, and T3) with 20 pullets per treatment, respectively, that were replicated five times in a completely randomised design. Treatment one (T1) served as the control with 0 mg/ml noni fruit extract. Treatment two (T2) was composed of 20 mg/ml noni fruit extract and treatment three (T3) 40 mg/ml noni fruit extract administered through drinking water. This treatment structure was repeated for experiments 2 and 3, respectively. The treatments administered to the birds began at 16 weeks of age for experiment 1 and were run for 6 weeks. Daily feed and water consumption, as well as weight gain, were recorded. The trial for the first experiment ended at week 22 and 10 birds per treatment (2 birds per replicate) were randomly selected and euthanised. The right tibia bone (representing medullary bone), abdominal fat and reproductive tract (uterus) tissues to assess sexual development were collected at pre-lay. The age at first egg (a proxy measure of sexual maturity) was also recorded. Blood samples were collected from 10 randomly selected birds per treatment (2 birds per replicate) and analysed for their haematological and serum biochemistry. The results of the extraction and analysis of the noni fruit extract yielded 580ml/kg of fruit and an antioxidant capacity (concentration) of approximately 4.0 mg/ml at 8 weeks. The final body weight, daily weight gain, egg weight, and egg mass increased significantly in the birds that received 40 mg/ml noni fruit juice. Feed intake decreased (p < 0.05) with increasing concentration of noni fruit extract; however, water intake was similar (p > 0.05) among treatment groups. The noni fruit extract delayed the mean age at first egg, with the 20 mg/ml concentration causing the longest delay of 3.4 days compared to the 40 mg/ml concentration and the control groups. Significant reduction (p < 0.05) of abdominal fat, demonstrating anti obesity properties with dose effect of noni fruit extract was obtained. Additionally, the weight of the uterus and right tibia bone growth and mineralisation characteristics increased (p < 0.05) with increasing dose of noni fruit extract. Experiment 2 continued from week 22 using 270 layer-type birds randomly assigned to three treatments of 18 birds per treatment replicated five times in a completely randomised design. The second experiment lasted for 26 weeks and ended when the birds attained the age of 48 weeks. Eggs were collected at week 22; week 30 and week 48 representing the physiological stages (early-lay, peak-lay and late-lay) and used for internal egg quality assessments for the three physiological stages. Ten eggs per treatment were sampled to evaluate the effect of storage duration (5 different evaluation durations) on egg quality. The results of the second experiment showed that adding noni fruit extract up to 40 mg/ml to drinking water improved (p < 0.05) egg production performance indices (egg mass, %HDEP, FCR and NFEI) and the overall quality of eggs (AH, HU, yolk index, yolk colour and estimated eggshell thickness) with a dose effect. Over time, stored egg quality decreased, but noni fruit extract administered up to 40 mg/ml aided in slowing down the degradation process and preserved the yolk colour under ambient temperature. In experiment three, the application of noni fruit extract on the health status of the layers was evaluated using haematological and serum biochemical parameters. White blood cells (WBC), heterophils, lymphocytes, monocytes, eosinophils, basophils, red blood cells (RBC), haemoglobin, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC) and thrombocytes (Trb) and packed cell volume (PCV) The following biochemical profile measurements were analysed: total protein (TP), albumin (ALB), creatinine (CRE), urea, uric acid (UA), total bilirubin (TB), direct bilirubin (DB), aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT). Others were total cholesterol (TCHOL), high-density lipoprotein (HDL), low density lipoprotein (LDL), very low-density lipoprotein (VLDL), triglycerides (TG), glucose (GLU), calcium (Ca2+), sodium (Na+), chloride (CL-), and potassium (K+) ions, albumin/globulin ratio, AST/ALT ratio and globulin (GLB). Administration of noni fruit extract up to 40 mg/ml had considerable influence on the haematological and serum biochemical profile of laying hens with a dose effect. Physiological stage played a significant role in influencing these effects that were within normal reference range for chicken, demonstrating that noni fruit extract had no adverse effects on the physiology and health of the layer-type birds. In experiment four, 300 layer-type birds were used to evaluate egg production performance and quality characteristics, and health status with the administration of 40 mg/ml noni fruit extract. There were 3 treatments, each comprising of 5 replicates and 20 birds per treatment. Pullets in treatment 1 (control) received 0 mg/ml of noni extract from 16 weeks of age. Treatment 2 comprised 16-week-old pullets receiving 40 mg/ml of noni extracts in their drinking water. In treatment 3, the pullets were started on 0 mg/ml of noni fruit extract at 16 weeks of age. At 20 weeks of age, the layers were provided with 40 mg/ml of noni fruit extracts in their drinking water. At 16 weeks of age, the average body weight in all the 3 treatment groups was 1.3 ± 0.233 kg. Weekly body weights were measured in all the treatment groups from week 16 until week 22. The days at first egg (sexual maturity) were recorded. Other measurements (egg quality and haematological and serum biochemistry) were taken at 22, 30, and 48 weeks of age using the procedures outlined in experiments 2 and 3. The parameters measured were pre-lay growth and egg production performance characteristics, egg quality and blood metabolite indices as listed in experiments 1, 2, and 3. The sexual maturity of the birds that received noni fruit extract at 16 weeks was approximately 129 days compared to approximately 126 for birds that receive noni fruit extract at 20 weeks and the control group. At 22, 30 and 40 weeks of age the birds that received 40 mg/ml noni fruit extract at weeks 16 or 20 had similar (p > 0.05) body weights but higher (p < 0.05) compared to the control group. The significantly (p < 0.05) better pre-lay sexual development, egg production and performance, and egg freshness indices, as well as, reduced abdominal fat weight, and egg weight loss during storage, blood haematological indices and serum biochemical profile indicated a better health status of the birds that received 40 mg/ml noni fruit extract at 16 weeks compared to those of week 20 and control. Overall, the results from this study demonstrate the potential of noni fruit extract as a beneficial feed supplement that could enhance the productivity and health of poultry when administered at the onset of sexual development in the layer-type birds.Item type:Item, Access status: Open Access , Interactive Effects of Incubation Temperature and In Ovo Feeding on Hatchability, Organ Development, Bone Minerals and Blood Metabolites in Broiler Chicks(Veterinary Medicine and Science, 2025-11-22) Okai, M.A.; Kruenti, F.; Adjei-Mensah, B.; et al.Background: Optimal incubation temperature and in ovo feeding strategies during incubation are crucial for ideal performance and welfare of chicks. Objective: This study investigated the effects of incubation temperature and early in ovo feeding on hatchability, internal organ development, bone mineralisation and blood metabolites in broiler chicks. Methods: A total of 1200 eggs from 58-week-old Arbor Acre breeders, averaging 62 ± 1 g, were incubated in separate dual-system automatic incubators (Senjie series DZ 47-53) at specified temperatures and 60% humidity. A total of 400 eggs were randomly assigned to three incubation temperature treatments, with four replicates per treatment, based on predetermined air temperatures of 36.5◦C, 37.0◦C and 37.5◦C, maintained from embryonic day (ED) 1 until ED 18. On ED 10, eggs were candled, and each temperature group was further divided into three subgroups: the first serving as a control, where eggs were perforated but not injected; the second receiving an in ovo injection of glucose solution (5 mg/mL); and the third receiving an in ovo injection of vitamin-D3 solution (25 mg/mL). The supplements were administered 0.2 mL at egg level in the air sac. Results: Hatchability showed a clear temperature-dependent response, reaching a maximum of 89.86% in glucose-injected eggs at 37.5◦C and decreasing to 48.33% in vitamin-D3 injected eggs at 36.5◦C ( p < 0. 05). Bone mineral content was influenced by interactions between incubation temperature and feeding, with calcium highest in glucose-fed chicks incubated at 37.0◦C, while phosphorus was highest in control eggs incubated at 36.5◦C ( p < 0.05). By Day 21, chicks fed vitamin-D3 consistently demonstrated lower cholesterol levels, whereas those fed glucose and controls showed higher alkaline phosphatase activity under increased incubation temperatures ( p < 0.05). Conclusion: Optimal results were achieved with glucose injection at 37.0◦C and 37.5◦C, improving hatchability, intestinal development and bone mineralisation, whereas vitamin-D3 supplementation at lower temperatures negatively impacted hatchability and metabolic balance.