Yield performance of cassava genotypes in the forest and coastal ecologies of Southern Ghana

Root yield performances of 10 cassava genotypes were assessed across six environments to determine stable cassava (Manihot esculenta) cultivar(s) for root yield in southern Ghana. The assessments were carried out in the forest zone (Fumesua), coastal savanna zone (Ohawu) and coastal savanna zone (Pokuase) in the 2007-2008 and 2008-2009 growing seasons. The experimental layout was a randomized complete block design with three replications. Additive main effects and multiplicative interactions analysis (AMMI) indicated that genotype by environment interactions were significant. Genotype 6 (CR52A-25) was the highest yielding genotype with a root yield of 60.33 kg ha-1, while Genotype 9 (CR59-4) had the lowest root yield of 26.86 kg ha-1. Root yield was significantly lower (P = 0.001) at the forest zone compared to the coastal savanna zones

Social organization and reproductive behavior in southern Ghana

The objective of this research is to examine the association between social organization and reproductive behavior in one setting in sub-Saharan Africa. The particular focus is on the effects of social organization on the diffusion of innovative reproductive ideas and behaviors. Social diffusion is assumed to be strongly affected by patterns of informal social interaction, and these in turn are assumed to be determined in part by the social organization of local communities (gender relations, employment activity, voluntary organizations). The research draws on data collected in six communities in southern Ghana. The analysis reveals a weaker than expected association between the social organization of the communities and key reproductive indicators (fertility preferences, age at first marriage, postpartum practices, use of modern contraception). Closer examination of the six communities suggests that the weak association is explained by the idiosyncratic histories of several of the communities, in particular their histories of health and family planning provision. Explanations for reproductive change that place social organization on center stage must be enlarged to incorporate the potentially powerful influence of community history

Assessing Landcover Changes from Coastal Tourism Development in Ghana: Evidence from the Kokrobite-Bortianor Coastline, Accra

As a major driver of landcover change, tourism-based developments are growing rapidly along different part of Ghana’s 560 km coastline. Kokrobite and Bortianor, with their serene environment, relatively clean, and pristine sandy beaches, have become popular coastal tourism destinations for tourists, recreationist, and holiday seekers in the Greater Accra region of Ghana. This study assesses how landcover changes emanating from coastal tourism establishments such as hotels, resorts, restaurants, and recreational facilities are affecting the socio-ecological landscape of the area. In this study, we utilize the maximum likelihood supervised classification along with post classification change detection techniques to analyze Landsat images for the years 1990, 2000 and 2010. Landcover maps of the different years were created and used to analyze changes occurring along the coastline of Kokrobite and Bortianor. Assembled results showed that built-up areas associated largely with tourism-based establishments have increased substantially from 1.02 km2 (16%) to 2.20 km2 (34.6%) between 1990 and 2010. Approximately 60% of the Kokrobite and Bortianor coastline’s natural ecosystem has been converted into different forms of tourism-based facilities such as hotels, resorts and settlements. Conversely, all forms of vegetative cover–riverine, dense active, and shrub/herbaceous cover are declining significantly. Increased tourist and recreationist demands along with the rapid urban growth in Accra is a preeminent cause of the current trends of developments. Regrettably, majority of the tourism-based establishments are unplanned, lacking authorization from development institutions and agencies, a reflection of the lack of a coherent integrated coastal zone management plan and functional urban landuse policy in Ghana. The result is a significant encroachment and degradation of the coastal ecosystems. Considering the already vulnerable state of most coastal areas in Ghana including Kokrobite and Bortianor, such developments could aggravate social and ecological vulnerability if left unchecked. In line with this, this study recommends the urgent need for a functional integrated coastal zone management plan and resourced institutions and agencies to enable effective management and regulation of developments in coastal zones in Ghana. Ultimately, coastal tourism, with all its recognized and potential socio-economic benefits to local and national economies can only be sustained with an ecologically productive coastal zone. Keywords: Tourism, Coastal tourism, Landcover, Kokrobite and Bortianor, Erosio

A study of polybromide chain formation using carbon nanomaterials via density functional theory approach

\ua9 2016 The Author(s). This open access article is distributed under a Creative Commons Attribution (CC-BY) 4.0 license. We use a density functional theory approach under the local density approximation (DFT/LDA) to describe the formation of polybromide chain structures, their stretching frequency modes and charge transfer induced by the interaction of these molecules with a graphene sheet. In many cases, we find polybromides to be more thermodynamically stable than the equivalent Br2 molecular structures adsorbed on graphene sheet. This results in lower frequency stretch modes at around 170–190 cm−1. We propose that these are rarely observed experimentally due to the bromination techniques used, which introduces molecular Br2 into the carbon host material. Charge transfer with their host material means that these molecules and their associated hole charge in the neighbouring carbon materials, are then coulombically repelled from other bromine molecules which acts as a barrier to combination into polybromides. Our calculated barrier for polybromide formation (2Br2→Br4) on a graphene sheet was 0.35 eV which is an exothermic process with an enthalpy value of −0.28 eV. Therefore, thermodynamically, chain polybromide formation seems to be favourable but kinetically, is unlikely, since there is an activation barrier that needs to be overcome to give stable bromine chain structures

3層グラフェン/LiNbO3界面における音波伝搬特性

第40回超音波エレクトロニクスの基礎と応用に関するシンポジウム/The 40th Symposium on UltraSonic Electronics (USE2019), 2019年11月25日～27日, 明治大学, 東

Characterisation and identification of local kaolin clay from Ghana: A potential material for electroporcelain insulator fabrication

The aim of this work was to evaluate two kaolin clays from the southern part of Ghana, Assin-Fosu and Kumasi clays, as source clays for the fabrication of electroporcelain insulators. X-ray diffraction, differential thermal analysis, thermogravimetric analysis, chemical analyses and scanning electron microscopy observations showed the fired clay minerals have broadly similar characteristics, but with significant differences in their chemical composition. The alumina contents were determined to be 35 ± 2 wt% and 22 ± 2 wt% respectively for the two kaolins and the silica contents 49 ± 3 wt% and 58 ± 3 wt% respectively. It is concluded that Assin-Fosu kaolin is a reliable local source material for electroporcelain fabrication, while Kumasi kaolin is more suitable for making wall and floor tiles.Part of this work was undertaken at the Department of Materials Science and Metallurgy at the University of Cambridge under the Cambridge-Africa Fellowship programme, for which AY and KMK acknowledge the Cambridge African Partnership for Research Exchange (CAPREx) for funding this study. AY and EKT also acknowledge support from the Office of Research, Innovation and Development (ORID), University of Ghana, Grant #URF/7/029/2013-2014

Developmental subtypes assessed by DNA methylation-iPLEX forecast the natural history of chronic lymphocytic leukemia

© 2019 by The American Society of Hematology Alterations in global DNA methylation patterns are a major hallmark of cancer and represent attractive biomarkers for personalized risk stratification. Chronic lymphocytic leukemia (CLL) risk stratification studies typically focus on time to first treatment (TTFT), time to progression (TTP) after treatment, and overall survival (OS). Whereas TTFT risk stratification remains similar over time, TTP and OS have changed dramatically with the introduction of targeted therapies, such as the Bruton tyrosine kinase inhibitor ibrutinib. We have shown that genome-wide DNA methylation patterns in CLL are strongly associated with phenotypic differentiation and patient outcomes. Here, we developed a novel assay, termed methylation-iPLEX (Me-iPLEX), for high-throughput quantification of targeted panels of single cytosine guanine dinucleotides from multiple independent loci. Me-iPLEX was used to classify CLL samples into 1 of 3 known epigenetic subtypes (epitypes). We examined the impact of epitype in 1286 CLL patients from 4 independent cohorts representing a comprehensive view of CLL disease course and therapies. We found that epitype significantly predicted TTFT and OS among newly diagnosed CLL patients. Additionally, epitype predicted TTP and OS with 2 common CLL therapies: chemoimmunotherapy and ibrutinib. Epitype retained significance after stratifying by biologically related biomarkers, immunoglobulin heavy chain mutational status, and ZAP70 expression, as well as other common prognostic markers. Furthermore, among several biological traits enriched between epitypes, we found highly biased immunogenetic features, including IGLV3-21 usage in the poorly characterized intermediate-programmed CLL epitype. In summary, Me-iPLEX is an elegant method to assess epigenetic signatures, including robust classification of CLL epitypes that independently stratify patient risk at diagnosis and time of treatment

Artificial and Natural Radioactivity Measurements and Radiation Dose Assessment in the Vicinity of Ghana Nuclear Research Reactor-1 (GHARR-1)

Radioactivity concentrations of <sup>226</sup>Ra, <sup>232</sup>Th, <sup>40</sup>K and <sup>137</sup>Cs in soil samples and water sources around the Ghana Research Reactor-1 (GHARR-1) and the immediate surroundings have been measured using gamma spectrometry. The primary aim of the study was to establish baseline radioactivity levels in the environs of GHARR-1. The average activity concentration of <sup>226</sup>Ra, <sup>232</sup>Th, <sup>40</sup>K and <sup>137</sup>Cs were 22.3 ± 1.12 Bq kg<sup>-1</sup>, 49.8 ± 1.60Bq kg-1, 99.60 ± 5.81 Bq kg<sup>-1</sup> and 1.48 ± 0.25 Bq kg<sup>-1</sup> for soil and 0.60 ± 0.11 Bq l<sup>-1</sup>, 2.13 ± 0.21 Bq l<sup>-1</sup>, 10.75 ± 0.84 Bq l<sup>-1</sup> and 0.47 ± 0.05 Bq l<sup>-1</sup>for the water, respectively. The <sup>226</sup>Ra and <sup>232</sup>Th concentrations compare quite well with world averages, whilst the <sup>40</sup>K concentration was lower than the world average. The levels of <sup>137</sup>Cs observed in the samples are within the range of ‘background’  concentrations. The estimated average annual effective doses from external exposure to soil and ingestion of water samples were calculated to be 0.06 mSv and 0.53 mSv, respectively. The estimated outdoor  external gamma dose rate measured in air ranged from 20-430 nGy h<sup>-1</sup> with an average value of 100 nGy h<sup>-1</sup>, which is higher than the world average value of 59 nGy h<sup>-1</sup>. In the case of water samples, the average value was higher than the guidance level of 0.1 mSv y<sup>-1</sup>, as recommended by the European Union and the World Health Organization

Social networks and contraceptive dynamics in southern Ghana

There is accumulating evidence that social diffusion processes affect the pace of the adoption of modern contraception in societies undergoing fertility transition. In settings where mortality has declined and many other social and economic changes are underway, decisions about contraception are fraught with uncertainty and risk. In such circumstances, couples may rely on other persons for information and guidance. In this paper, we examine the influence of informal social networks on the contraceptive behavior of reproductive-age women, using longitudinal data collected in six communities in southern Ghana. Our results confirm the hypothesis that adoption of modern contraception is strongly affected by the reproductive attitudes and behaviors of social network partners. What might be termed “social contagion” accelerates the adoption of contraception. Finally, our data reveal that social networks are structured along the lines of social, economic, and cultural characteristics, suggesting further pathways by which socioeconomic variables can influence reproductive behavior