Does Automation Improve Stock Market Efficiency? Evidence from Ghana

As a burgeoning capital market in an emerging economy, automation of the stock market is regarded as a major step towards integrating the financial market as a conduit for economic growth. The automation of the Ghana Stock Exchange (GSE) in 2008 is expected among other things to improve the efficiency of the market. This paper therefore investigates the impact of the automation on the efficiency of the GSE within the framework of the weak-form Efficient Market Hypothesis (EMH) using daily market returns from the Ghana Stock Exchange All-Share index from 2006 to 2011. The Unit Root Random Walk and the GARCH models were used to analyze the efficiency of the GSE in the pre and post automation sample periods. Results show that the GSE was weakly inefficient in both pre and post automation periods, suggesting that the automation of the GSE have not yielded the needed impact towards improving the efficiency of the exchange

Clinical characteristics of COVID-19 patients admitted at the Korle-Bu Teaching Hospital, Accra, Ghana

Design: Study design was a retrospective single-center review of hospital data.Setting: The study was conducted at the COVID-19 Treatment Center of the Department of Medicine and Therapeutics of the Korle-Bu Teaching hospital in Accra, Ghana.Participants and study tools: A total of fifty patients with laboratory (rRT-PCR) confirmed COVID-19 infection were involved in the study. A chart review of the medical records of the patients was conducted and the data obtained was documented using a data extraction form.Results: The median age was 53 years and most (36% (18/50)) of the patients were at least 60 years of age. Eighty percent (40/50) of the patients were symptomatic, with cough and difficulty in breathing being the commonest presenting symptoms. The mean duration of hospitalization was 12.3 ± 7.3 days. Hypertension and Diabetes Mellitus were the commonest co-morbidities occurring in 52% (26/50) and 42% (21/50) of patients respectively. Fifty percent of patients developed COVID-19 pneumonia as a complication. The mortality rate was 12% (6/50).Conclusion: In this study, SARS-CoV2 infection affected older adults with hypertension and diabetes mellitus being the common comorbidities. Patients with these comorbid conditions should be counselled by their clinicians to strictly observe the COVID-19 prevention protocols to reduce their risk of acquiring the infection. There is a need to pay critical and prompt attention to the management of patients with COVID-19 pneumonia particularly among people with diabetes to improve outcomes

Effect of supplier appraisal on firm performance in Ghana: Views of employees of selected manufacturing firms

In Ghana, recent financial sector clean-ups and reforms have impacted the operations of several corporations in the business-to-business market. Coupled with this, several issues have been reported concerning procurement practises in the past few years. Regardless of corporate governance practises and public procurement regulations, institutions in Ghana are yet to fully realise the relevance of supplier appraisal. Grounded by the resource base theory, the study examines the effect of appraisal of suppliers’ financial stability, technical capacity to produce, adherence to systems and procedures, conformance to legislation, and suppliers’ supply chain on the performance of industrial firms in Ghana. A sample of 171 employees was drawn from a total of 250 employees. Data processing and analysis were undertaken through the partial least squares structural equation modelling (PLS-SEM) estimator. The results clearly suggest that firms’ technical capacity does not constitute firm resources that translate to firm performance. However, firms’ financial stability, adherence to systems, conformance to legislation, and supply chains are regarded as firm resources that contribute to the overall performance of the firm. We conclude that supplier evaluation is a significant predictor of manufacturing firms’ performance

Image Reconstruction using Superpixel Clustering and Tensor Completion

This paper presents a pixel selection method for compact image representation based on superpixel segmentation and tensor completion. Our method divides the image into several regions that capture important textures or semantics and selects a representative pixel from each region to store. We experiment with different criteria for choosing the representative pixel and find that the centroid pixel performs the best. We also propose two smooth tensor completion algorithms that can effectively reconstruct different types of images from the selected pixels. Our experiments show that our superpixel-based method achieves better results than uniform sampling for various missing ratios

Predicting the Potential Energy Yield of Bifacial Solar PV Systems in Low-Latitude Region

The validation of the potential energy yield of bifacial PV systems of various configurations at low latitudes under West African climatic conditions is critical for evaluating performance and for promoting market expansion of the technology since validation has mostly occurred in high-latitude regions. In this paper, the potential energy yield from an inclined south-facing bifacial PV module and a vertically mounted east–west bifacial PV module are compared to an inclined south-facing monofacial PV module using an analytical model, field-measured data, and simulations. For measured/modelled and PVsyst/modelled monofacial systems, the model predicts RMSE values of 1.49 and 9.02, respectively. An inclined bifacial PV system has RMSEs of 1.88 and 7.97 for measured/modelled and PVsyst/modelled, respectively, and a vertically installed system has RMSEs of 10.03 for measured/modelled and 3.76 for PVsyst/modelled. Monthly energy yield is predicted by the model, with deviations from measured data ranging from 0.08% to 1.41% for monofacial systems, from 0.05% to 4.06% for inclined bifacial systems, and from 4.63% to 9.61% for vertical bifacial systems. The average bifacial gains from the modelled, measured, and simulated data of an inclined south-facing stand-alone bifacial PV system over an inclined south-facing stand-alone monofacial system are 9.05%, 10.15%, and 5.65%. Finally, at 0.25 albedo, the inclined monofacial PV system outperforms and yields more energy than the vertically installed bifacial PV system

Coupling effect of waste automotive engine oil in the preparation of wood reinforced LDPE plastic composites for panels

We demonstrated the formulation of wood plastic composite (WPC) materials with flexural strength of 13.69 ± 0.09 MPa for applications in outdoor fencing using municipal waste precursors like low density polyethylene (LDPE) plastics (54.0 wt. %), sawn wood dust with particle size between 64 and 500 μm derived from variable hardwood species (36.0 wt. %) and used automotive engine oil (10 wt. %). The WPC panels were prepared by pre-compounding, extruding at a screw auger torque of 79.8 Nm and pressing through a rectangular mould of dimension 132 mm Ã 37 mm Ã 5 mm at temperature 150 °C. The efficacy of black waste oil, as a coupling agent, was demonstrated by the absence of voids and pull-outs on microscopic examination using scanning electron microscopy. No hazardous substances were exhaled during thermo-gravimetric mass spectrometry analysis. The percentage crystallinity of the LDPE in the as-prepared material determined by differential scanning calorimetry was 11.3%. Keywords: Wood plastic composites, Low density polyethylene, Wood dust, Physical, Thermal and mechanical propertie

SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study

Background: Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods: The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18-49, 50-69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results: NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion: As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population