Petrography and Geochemistry of some Granitoids associated with Gold Mineralisation at Mpohor area in southeastern Ashanti Belt of the Birimian, Ghana

Mpohor area in Western Region of Ghana is located within the Birimian at the southeastern corridor of Ashanti belt. Diamond drilling in the area which encloses Father Brown concession intersected steeply dipping igneous rocks on which petrographic and whole rock XRF analyses were conducted to describe the rock types according to mineralogy, texture, alteration and mode of mineralisation. The study showed that gabbro and diorite are weakly deformed, partially altered and of greenschist facies metamorphism. These rocks intruded into belt granitoids which accompanied metavolcanic rocks (well exposed at a coastal region to the southeast). Subsequent tonalite and granodiorite intrusives into sheared areas of gabbro are deformed with foliation being parallel to the major foliation in the host rock. This ductile deformation was accompanied by brittle deformation and infiltrated by hydrothermal fluids leading to silicification, carbonatisation, sericitisation, pyritisation of second and third generations and gold mineralisation. On the contrary, chloritisation with fine chalcopyrite together with pyrite of first generation characterise host gabbro and diorite. Hence deformed pyrite porphyroblast of second generation is found in tonalite and partly in contact with magnetite and also associated with gold. The ore zone (Au grade between 1.78 to 48.80 g/t) in tonalite is characterised with lower TiO2 content (<0.73 wt %) in addition to Fe/Mg ratio above 2.4 and Zr values less than 100 ppm which may suggest that mineralised fluid was depleted of Ti and Zr and Mg/Fe ratio above 2.4. These probably show that hydrothermal fluid which has the potential for high sulphide-Au mineralisation accompanied more mafic host rocks. Keywords: Petrography, Geochemistry, Granitoids, Gold Mineralisation, Southeastern Ashanti bel

Ridging, a Mechanized Alternative to Mounding for Yam and Cassava Production

A cassava seedbed preparation field study was established at Fumesua in the forest and Ejura in the forest-savanna transition agroecologies of Ghana in 2004/2005. The experimental design was split plot with three seed bed preparation methods as the main plots and three nitrogen rates as sub plots, with basal application of 45-90 kg ha-1 P205 - K20 on the fertilized plots. A similar study was conducted on yam seedbed preparation in 2003/2004, with a 23 factorial design. Cassava and yams on ridges resulted in highest root and tuber yields, on both Lixisols in the coastal and forest-savanna transition and Acrisols in the forest agro-ecologies. However, yam tuber yield on mounds was not statistically different from yields on ridges. Number of roots per plant was identified as a major contributory factor to the yield increase of cassava on ridges. Seed bed preparation method was, however, not an important determinant of cassava root yield at high rates of fertilizer application of 90-45-90 kg ha-1 N-P205-K20. Planting on mounds resulted in slender, cylindrically shaped cassava roots and yam tubers, while ridging produced oblong shaped roots and tubers. Weeding and fertilizer application were easier on manual ridging than on manual mounds. The study points to ridging as a potential option to mounding for cassava and yam production, with the feasibility of mechanization of ridges to reduce drudgery associated with roots and tuber crop production in the West African sub-region

Macrosomia - maternal and fetal risk factors

Risk factors associated with fetal macrosomia were studied in 348 pregnancies resulting in the delivery of an infant weighing 4 000 g or more in a black population. Identifiable maternal risk factors included a mother in her 3rd decade of life, multiparity, maternal weight of 70 kg or more at the end of pregnancy, prolonged or post-term pregnancy, abnormal glucose tolerance and previous history of a macrosomic infant. Male infants had a higher risk of being macrosomic. Macrosomic infants accounted for 3,4% of all singleton deliveries, with their caesarean section rate of 33,9% being almost three times that of control infants. The importance of antenatal prediction of fetal weight is emphasised and suggestions for reduction of the high perinatal mortality and morbidity rates, as well as maternal morbidity, are discussed

Re-screening for syphilis at the time of delivery in areas ofhigh prevalence

Two hundred women who were screened for syphilis at their initial antenatal visit were rescreened at the time of delivery. Umbilical cord blood specimens as well as maternal sera were tested. Twenty-two (11%) women were rapid plasma reagin (RPR)-positive at booking, while a total of 23 (12%) were RPR-positive at the time of delivery, including an additional 5 (3%) who seroconverted. Four women who were RPR-positive at initial testing had become negative by the time of delivery following treatment. Of all neonates born to seropositive women, only 1 demonstrated clinical evidence of congenital syphilis. In view of the high seroconversion rate, we recommend screening for syphilis at the initial antenatal visit and rescreening at the time ofdelivery in areas such as ours

Self-reported sexually transmitted infections among sexually active men in Ghana

Background In sub-Saharan Africa, sexually transmitted infections (STIs) other than HIV are major public health problems. This study, therefore, sought to assess the prevalence and factors associated with self-reported STIsamong sexually active men in Ghana. Methods Data from the 2014 Ghana demographic and health survey wereused to conduct the study. This research included a total of 3051 sexually active men aged 15–59 years. Self-reported STI was the outcome variable. The data were analyzed using both descriptive (frequencies and percentages) and inferential (binary logistic regression) analysis. Results The prevalence of self-reported STIs in the past 12 months preceding the survey was 6.0% (CI:4.7–6.8). Compared to men aged 45-59 years, those aged 25–34 (aOR = 2.96, CI: 1.64–5.35), 15–24 (aOR = 2.19, CI: 1.13–4.26), and 35–44 (aOR = 2.29, CI: 1.23–4.24) were more likely to report an STI. Men who had 2 or more sexual partners apart from their spouse were more likely to report an STI compared to those with no other partner apart from spouse (aOR = 4.24, CI: 2.52–7.14). However, those who had their first sex when they were 20 years and above (AOR = 0.66, CI: 0.47–0.93) and men who read newspaper/magazine had lower odds (aOR = 0.53, CI: 0.37–0.77) of reporting STIs compared to those who had sex below 20 and those who did not read newspaper/magazine respectively. Conclusion The study has revealed a relatively low prevalence of self-reported STI among sexually active men in Ghana. Sexually active men aged 25–34 years, those whose age at first sex is below 20 years and those with two or more sexual partners apart from their spouse had higher odds of reporting STIs. However, reading a newspaper was found to be positive in reducing the odds of reporting STIs. To reduce STIs among sexually active men in Ghana, it is important for health systems and stakeholders to consider these factors and put in place measures to mitigate those that put men at risk of STIs and encourage the adoption of the protective factors. Mass media can be used as a useful avenue for encouraging men to report STIs in order to avoid transmitting them to their partners

Effect of Duration of Reclamation on Soil Quality Indicators of a Surface – Mined Acid Forest Oxisol in South – Western Ghana

The quality of degraded mined soils can be restored through effective reclamation practices. In this study, we evaluated the impact of varying duration of land reclamation on soil quality at AngloGold Ashanti, Iduapriem mine Ltd., Tarkwa, Ghana. Soil samples were taken from mined sites of the Company at various stages of phytoremediation: 2, 5, 9 and 11 year old reclaimed sites. The soils were analyzed for soil quality indicators. A nearby forest reserve representative of the pre-degraded condition was used as the control. Prior to phytoremediation with multipurpose agroforestry trees, the mined soils were subjected by the Company to earthworks/slope battering followed by spreading of oxide materials over the surface, construction of crest drains and cover cropping. Having determined the impact of the varying duration of reclamation on soil quality indicators, separate pot experiments involving maize and cowpea were set up using soils from the sites to assess heavy metals accumulation in the cultivated crops. Soil nutrient levels in the sites under reclamation were significantly higher (P < 0.05) than the nearby forest reserve. Soil pH though generally low, was relatively higher (P < 0.05) in sites under reclamation than in the control. Soil total nitrogen, available phosphorus and exchangeable potassium levels were highest (P < 0.05) in the 11 year old site. Zinc contents of all sites were below the maximum permissible levels. There was somewhat antagonistic interaction between zinc and phosphorus contents of maize in the unclaimed site. Though heavy metal concentrations in maize were lower than that of cowpea, the concentrations in both plants were generally beyond the permissible levels suggesting a possible transfer onto the food chain if the crops are included as part of rotation programmes from the agronomic perspective. Our results indicate that phytoremediation of mined lands using agroforestry multipurpose trees could be marginal even after a decade of reclamation

Improved prediction of clay soil expansion using machine learning algorithms and meta-heuristic dichotomous ensemble classifiers

Soil swelling-related disaster is considered as one of the most devastating geo-hazards in modern history. Hence, proper determination of a soil's ability to expand is very vital for achieving a secure and safe ground for infrastructures. Accordingly, this study has provided a novel and intelligent approach that enables an improved estimation of swelling by using kernelised machines (Bayesian linear regression (BLR) & bayes point machine (BPM) support vector machine (SVM) and deep-support vector machine (D-SVM)); (multiple linear regressor (REG), logistic regressor (LR) and artificial neural network (ANN)), tree-based algorithms such as decision forest (RDF) & boosted trees (BDT). Also, and for the first time, meta-heuristic classifiers incorporating the techniques of voting (VE) and stacking (SE) were utilised. Different independent scenarios of explanatory features’ combination that influence soil behaviour in swelling were investigated. Preliminary results indicated BLR as possessing the highest amount of deviation from the predictor variable (the actual swell-strain). REG and BLR performed slightly better than ANN while the meta-heuristic learners (VE and SE) produced the best overall performance (greatest R2 value of 0.94 and RMSE of 0.06% exhibited by VE). CEC, plasticity index and moisture content were the features considered to have the highest level of importance. Kernelized binary classifiers (SVM, D-SVM and BPM) gave better accuracy (average accuracy and recall rate of 0.93 and 0.60) compared to ANN, LR and RDF. Sensitivity-driven diagnostic test indicated that the meta-heuristic models’ best performance occurred when ML training was conducted using k-fold validation technique. Finally, it is recommended that the concepts developed herein be deployed during the preliminary phases of a geotechnical or geological site characterisation by using the best performing meta-heuristic models via their background coding resource

Critical drivers for the adoption of wearable sensing technologies (WSTs) for construction safety monitoring in Ghana: A Fuzzy Synthetic Analysis

Purpose: The construction industry is one of the most hazardous working environments globally. Studies reveal that wearable sensing technologies (WSTs) have practical applications in construction occupational health and safety management. In the global south, the adoption of WSTs in construction has been slow with few studies investigating the critical drivers for its adoption. The study therefore bridges this gap by investigating the factors driving WSTs adoption in Ghana where investments in such technologies can massively enhance health and safety through effective safety monitoring. Design/Methodology: To meet the objectives of this study, research data was drawn from 210 construction professionals. Purposive sampling technique was used to select construction professionals in Ghana and data was collected with the use of well-structured questionnaires. The study adopted the Fuzzy Synthetic Evaluation Model (FSEM) to determine the significance of the critical drivers for the adoption of WSTs. Findings: According to the findings, perceived value, technical know-how, security, top management support, competitive pressure, and trading partner readiness obtained a high model index of 4.154, 4.079, 3.895, 3.953, 3.971, and 3.969, respectively, as critical drivers for WSTs adoption in Ghana. Among the three broad factors, technological factors recorded the highest index of 3.971, followed by environmental factors and organizational factors with a model index of 3.938 and 3.916 respectively. Implications: Theoretically, findings are consistent with studies conducted in developed countries, particularly with regard to the perceived value of WSTs as a key driver in its adoption in the construction industry. This study also contributes to the subject of WSTs adoption and, in the case of emerging countries. Practically, findings from the study can be useful to technology developers in planning strategies to promote WSTs in the global south. To enhance construction health and safety in Ghana, policymakers can draw from the findings to create conducive conditions for worker acceptance of WSTs. Originality/Value: Studies investigating the driving factors for WSTs adoption have mainly centered on developed countries. This study addresses this subject in Ghana where studies on WSTs application in construction process is uncommon. It also uniquely explores the critical drivers for WSTs adoption using the Fuzzy Synthetic Evaluation Model