STOCK MARKET EFFICIENCY, NON-LINEARITY AND THIN TRADING EFFECTS IN SOME SELECTED COMPANIES IN GHANA

This paper investigates market efficiency, non-linearity and thin trading effects in the returns of two companies listed on the Ghana Stock Exchange, namely Ghana Commercial Bank (GCB) and Transol. The Jarque-Bera and Runs tests showed that the returns of both companies deviate from normality and randomness, respectively. The returns are also non-linearly dependent using Ljung-Box and BDS tests. ARCH effects were found in the return series’ of both companies. An ARMA-GARCH model was adopted for the linearity modeling of the stock returns of GCB. The sum of the parameter estimate

Investigating Solar Street Lights in Mandi and Kamand

Solar street lights are installed throughout Himachal Pradesh, India to promote small-scale solar, but many are broken. We disassembled lights and conducted interviews with residents and experts to understand the relevant factors, finding that the street light program suffers from inadequate maintenance and that solar is often not the best lighting choice. Finally, we piloted a training program for residents to perform light diagnosis and developed an appropriate technology rubric for selecting evening lighting solutions for Mandi’s slums

Effect of Problem-Based Learning on Students’ Achievement in Chemistry

The study investigated the effect of problem-based learning on students’ achievement in chemistry.   Learners’ low achievement in Science in South Africa has been a concern to government, stakeholders, school principals and parents over the years as a result of poor teaching techniques, students’ attitudes, lack of teaching and learning materials, teachers’ pedagogical skills etc. Several studies, for instance Monitoring Learner Achievement (MLA) project conducted by UNESCO and UNICEF have shown no improvement in the performance of South African students in Mathematics and Science. Quasi-experimental design was employed for the study. 101 equivalent students were selected for the study using pre-test. The control group was taught with the traditional lecture method whiles the experimental group received instruction with PBL. Independent T-test was used for the analysis. Results showed that there was significant difference (p < 0.05) in chemistry achievement of students between control and the experimental group while there was no significant differences in the before the study. The results show that PBL is an effective way for to teach chemistry so as to improve students’ critical thinking and problem solving skills. Keywords: Chemistry, Problem-Based Learning, Critical thinking, Traditional lecture, Achievement

Effect of Locally Available Fruit Waste on Treatment of Water Turbidity

Turbidity is one of the main problems associated with surface water treatment. Chemical coagulants are already being used for treatment but their enormous cost, human and environmental issues associated with their use have led to searching for alternatives like natural coagulants (plant-based). Although the use of natural coagulants for drinking water treatment has been discussed for a long time, the practice is still not employed in most poor developing countries, probably due to availability of materials and their usage as food crops. Therefore locally available fruit waste are now being evaluated for their suitability. Laboratory scale studies using jar test experiments were performed on river water containing synthetic turbidity of kaolinite to analyze the effect of Mangifera indica (Duncan mango)  and Citrus aurantiifolia (key lime) seeds as  locally available fruit waste on treatment of water turbidity. Experiments were carried out using different turbidity levels classified as low, medium and high: 50, 100 and 150 NTU with pH kept constant at 7.25.  Results indicated that the seed extracts of Duncan mango and key lime have coagulating potential. They were very effective for treatment of medium and high water turbidity. For treatment of high water turbidity using the seed extracts of Duncan mango and key lime as primary coagulants, 92.0 % and 91.1 % turbidity removal were achieved.  Compared to alum, the turbidity removal effectiveness was: alum > Duncan mango seed extract>key lime seed extract for all water turbidity levels. The pH of the treated water were within neutral (basic) due to the buffering capacity of the seed extracts. Result further indicated that the seed extracts of Duncan mango and key lime have the potential for use as coagulant aids with alum as primary coagulant for treatment of low, medium and high water turbidity. Keywords: Mangifera indica, Citrus aurantiifolia, Turbidity, Natural coagulants, Seed extracts, Fruit wast

Contamination and Health Risk Assessment of Exposure to Heavy Metals in Soils from Informal E-Waste Recycling Site in Ghana

The objective of this study is first, to investigate the level of heavy metals in soils from Agbogbloshie e-waste processing site (AEPS), the degree at which these heavy metals contaminate the area and finally, to assess the carcinogenic and non-carcinogenic health risk of heavy metals on workers and residents in around the AEPS. 132 soil samples were collected from the study area and the samples analyzed for Ba, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn heavy metals after appropriate preparations were made. Results of the analysis showed mean concentrations of Cd, Cr and Ni considered as carcinogenic were lower than permissible levels of Dutch and Canadian soil standards. Mean concentrations however of Cu, Pb and Zn were between 100% and 500% higher than the permissible levels. Assessment of the degree of Contamination indicated Ni<Ba<Co<Cr<Zn<Hg<Cu<Cd<Pb in an increasing order as contributing to the degree of contamination with according to the degree of contamination index the burning, dismantling, residential and commercial considered as very highly contaminated. The health risk analysis of individual heavy metals in soil indicated non-carcinogenic risk of Cr, Hg and Pb with hazard index above the safe level of 1 in the burning and dismantling areas and as such could trigger neurological and developmental disorders in children less than six (6) years

ECJ judges read the morning papers. Explaining the turnaround of European citizenship jurisprudence

Recent jurisprudence of the European Court of Justice (ECJ) marks a striking shift towards a more restrictive interpretation of EU citizens’ rights. The Court's turnaround is not only highly relevant for practical debates about ‘Social Europe’ or ‘welfare migration’, but also enlightening from a more general, theoretical viewpoint. Several recent studies on the ECJ have argued that the Court is largely constrained by member state governments’ threats of legislative override and non-compliance. We show that an additional mechanism is necessary to explain the Court's turnaround on citizenship. While the ECJ extended EU citizens’ rights even against strong opposition by member state governments, its recent shift reflects changes in the broader political context, i.e., the politicization of free movement in the European Union (EU). The article theorises Court responsiveness to politicization and demonstrates empirically, how the Court's jurisprudence corresponds with changing public debates about EU citizenship

Quality assessment and refinement of chromatin accessibility data using a sequence-based predictive model

Chromatin accessibility assays are central to the genome-wide identification of gene regulatory elements associated with transcriptional regulation. However, the data have highly variable quality arising from several biological and technical factors. To surmount this problem, we developed a sequence-based machine learning method to evaluate and refine chromatin accessibility data. Our framework, gapped k-mer SVM quality check (gkmQC), provides the quality metrics for a sample based on the prediction accuracy of the trained models. We tested 886 DNase-seq samples from the ENCODE/Roadmap projects to demonstrate that gkmQC can effectively identify high-quality (HQ) samples with low conventional quality scores owing to marginal read depths. Peaks identified in HQ samples are more accurately aligned at functional regulatory elements, show greater enrichment of regulatory elements harboring functional variants, and explain greater heritability of phenotypes from their relevant tissues. Moreover, gkmQC can optimize the peak-calling threshold to identify additional peaks, especially for rare cell types in single-cell chromatin accessibility data

Evidence-based guidelines for pediatric clinical trials: focus on StaR Child Health

Clinical trials in children are challenging and filled with important ethical considerations that differ from adults. Given difficulties associated with pediatric clinical trials, off-label prescribing is a common practice in pediatrics, which can lead to adverse safety events and efficacy failures. To overcome these consequences, in the past 15 years, legislation in the USA and Europe has provided incentives to industry and increased government funding to conduct pediatric trials. Pediatric trial networks have also been formed to decrease the knowledge gap. However, challenges to performing pediatric trials and lack of standardization and guidelines regarding studies in children still exist. Standards for Research (StaR) in Child Health, begun in 2009, aims to improve the design, conduct and reporting of pediatric trials. This organization uses a consensus guideline approach involving academic, government and industry stakeholders to identify and disseminate best practices for pediatric trials. Six out of 11 planned standards are currently published

Effect of imaging and catheter characteristics on clinical outcome for patients in the PRECISE study

The PRECISE study used convection enhanced delivery (CED) to infuse IL13-PE38QQR in patients with recurrent glioblastoma multiforme (GBM) and compared survival to Gliadel Wafers (GW). The objectives of this retrospective evaluation were to assess: (1) catheter positioning in relation to imaging features and (2) to examine the potential impact of catheter positioning, overall catheter placement and imaging features on long term clinical outcome in the PRECISE study. Catheter positioning and overall catheter placement were scored and used as a surrogate of adequate placement. Imaging studies obtained on day 43 and day 71 after resection were each retrospectively reviewed. Catheter positioning scores, catheter overall placement scores, local tumor control and imaging change scores were reviewed and correlated using Generalized Linear Mixed Models. Cox PH regression analysis was used to examine whether these imaging based variables predicted overall survival (OS) and progression free survival (PFS) after adjusting for age and KPS. Of 180 patients in the CED group, 20 patients did not undergo gross total resection. Of the remaining 160 patients only 53% of patients had fully conforming catheters in respect to overall placement and 51% had adequate catheter positioning scores. Better catheter positioning scores were not correlated with local tumor control (P = 0.61) or imaging change score (P = 0.86). OS and PFS were not correlated with catheter positioning score (OS: P = 0.53; PFS: P = 0.72 respectively), overall placement score (OS: P = 0.55; PFS: P = 0.35) or imaging changes on day 43 MRI (P = 0.88). Catheter positioning scores and overall catheter placement scores were not associated with clinical outcome in this large prospective trial