Physicochemical Characterization of Limestone Deposits at Ewekoro, Ogun State, South-West of Nigeria and the Environment Impact

Limestone is the primary constituent raw material for cement manufacture. While most limestone deposits are suitable for cement making, there are some characteristics of limestone which need to be defined in order to establish a usable raw material supply.  These relate to compositional requirements and also the consistency of the deposit in chemical and physical terms. Limestone makes up about 10% of the total volume of all sedimentary rocks. The solubility of limestone in water and weak acid solutions leads to karst landscapes, in which water erodes the limestone over thousands to millions of years. The density and porosity of samples from the various locations vary from 2.61g/cm3 to 2.72g/cm3 and 2.70% to 3.80%. The Schmidt hammer rebound number of samples from Ewekoro quarry varies from 32.1 to 33.6. The uniaxial compressive strength of samples from Ewekoro quarry varies from 60.5 MPa to 63.5 MPa thereby classifying the rock as moderate to high strength. The point load strength index is obtained from the LAFARGE laboratory results and varies from 1.239 MPa to 2.185 MPa. The strength classifications fall within the range of moderate to high strength class. Also, the tensile strength, obtained from point load strength ranges from 1.862 MPa to 3.086 MPa. The staining process induces a reaction on the surface of a particular mineral species which results in coloured precipitate characteristic of that mineral. Alizarin red S in NaOH stained the samples purple indicating the presence of magnesium in the carbonate while Alizarin red S in HCL stained the samples red. Physical observation of Ewekoro limestone deposit reveal the rock is highly fossiliferous with the identified fossils indicating deposition in an open shelf environment. Moreover, the limestone deposit was equally observed to be principally mud supported which is indicative of rocks deposited in quiet water and a low energy environment. Keywords: Limestone, Solubility, Ewekoro, Physical and Chemical

The impact of adjusting for baseline in pharmacogenomic genome-wide association studies of quantitative change.

In pharmacogenomic studies of quantitative change, any association between genetic variants and the pretreatment (baseline) measurement can bias the estimate of effect between those variants and drug response. A putative solution is to adjust for baseline. We conducted a series of genome-wide association studies (GWASs) for low-density lipoprotein cholesterol (LDL-C) response to statin therapy in 34,874 participants of the Genetic Epidemiology Research on Adult Health and Aging (GERA) cohort as a case study to investigate the impact of baseline adjustment on results generated from pharmacogenomic studies of quantitative change. Across phenotypes of statin-induced LDL-C change, baseline adjustment identified variants from six loci meeting genome-wide significance (SORT/CELSR2/PSRC1, LPA, SLCO1B1, APOE, APOB, and SMARCA4/LDLR). In contrast, baseline-unadjusted analyses yielded variants from three loci meeting the criteria for genome-wide significance (LPA, APOE, and SLCO1B1). A genome-wide heterogeneity test of baseline versus statin on-treatment LDL-C levels was performed as the definitive test for the true effect of genetic variants on statin-induced LDL-C change. These findings were generally consistent with the models not adjusting for baseline signifying that genome-wide significant hits generated only from baseline-adjusted analyses (SORT/CELSR2/PSRC1, APOB, SMARCA4/LDLR) were likely biased. We then comprehensively reviewed published GWASs of drug-induced quantitative change and discovered that more than half (59%) inappropriately adjusted for baseline. Altogether, we demonstrate that (1) baseline adjustment introduces bias in pharmacogenomic studies of quantitative change and (2) this erroneous methodology is highly prevalent. We conclude that it is critical to avoid this common statistical approach in future pharmacogenomic studies of quantitative change

The prospects of E-Examination Implementation in Nigeria

The massive examination leakages, demand for gratification by teachers, bribe-taking by supervisors and invigilators of examinations have become a global phenomenon. This menace has resulted to general fallen standards of education and Nigeria is no exception, particularly among developing nations. Consequent upon this, all Nigerian universities have resorted to conducting post-entrance “Post-JAMB” examination/screening because of lack of confidence in the conduct of the entrance examinations. This paper proposes a model for e-Examination in Nigeria where all applicants are subjected to online entrance examination as a way of curbing the irregularities as proposed by the Joint Admissions Matriculation Board (JAMB), the body saddled with the responsibility of conducting entrance examinations into all the Nigerian universities. This model was designed and tested in Covenant University, one of the private universities in Nigeria. There were 120 questions drawn from English (30), Mathematics (30), General Science (20), Commercial Courses (20), and Religion Knowledge (20), all for one hour duration. Questionnaires were administered to the applicants at the end of the examination to assess their level of ICT literacy, ease of use of the system and the difficulties encountered. Findings revealed that the system has the potentials to eliminate some of the problems that are associated with the traditional methods of examination such as impersonation and other forms of examination malpractices. The system is easy to use and candidates can get use to it with time. The timing of examination can be spaced without compromising the quality and integrity of the examination. However, much is still desired if the system were to be adopted on a national scale, particularly in terms of infrastructural and manpower development. Similarly, the quest for e-Examination can fast track the development of e-Learning facilities in the country with improved access to education

Assessment of Background Radioactivity of Surface Soils in Ondo City, Ondo State, Nigeria

The natural radioactivity of surface soils collected from various locations in Ondo City were measured by means of well calibrated High Purity Germanium (HPGe) detector, Canberra model coupled to a versatile Canberra Multichannel Analyzer, at the Centre for Energy Research and Development of Obafemi Awolowo University. Ile Ife. The soil samples were collected from the fourteen zones that constituted the town with four samples taken from each zone. The emission line spectra used in identifying the natural radioisotopes belong to 238U and 232Th decay series and that of naturally occurring 40K. The gamma activity obtained for 40K ranged from 212.1 Bq/kg to 895.7 Bq/kg with a mean value of 470.4 ± 26.8 Bq/kg. For 232Th, the gamma activity ranged from 30.2 Bq/kg to 72.4 Bq/kg with a mean value of 48.8 ± 8.4 Bq/kg, and from 3.6 Bq/kg to 14.2 Bq/kg with a mean value of 6.9 ± 1.2 Bq/kg for 238U. The mean absorbed dose rate in these locations amounts to 45.36 nGy/h which by approximate conversion gives an indoor annual effective dose of 0.223 mSv/year and outdoor annual effective dose of 0.056 mSv/year. These values constitute the baseline dose equivalent, which is below the 1.0 mSv/year recommended by the International Commission for Radiological Protection (ICRP, 1990) as the maximum permissible dose equivalent for members of public. The results obtained showed that the study area is free from radiological contamination. Keywords: Radioactivity, Absorbed dose, Radioisotopes, Environment

Linking dynamic phenotyping with metabolite analysis to study natural variation in drought responses of Brachypodium distachyon

Drought is an important environmental stress limiting the productivity of major crops worldwide. Understanding drought tolerance and possible mechanisms for improving drought resistance is therefore a prerequisite to develop drought-tolerant crops that produce significant yields with reduced amounts of water. Brachypodium distachyon (Brachypodium) is a key model species for cereals, forage grasses and energy grasses. In this study, initial screening of a Brachypodium germplasm collection consisting of 138 different ecotypes exposed to progressive drought, highlighted the natural variation in morphology, biomass accumulation and responses to drought stress. A core set of ten ecotypes, classified as being either tolerant, susceptible or intermediate, in response to drought stress, were exposed to mild or severe (respectively 15% and 0% soil water content) drought stress and phenomic parameters linked to growth and colour changes were assessed. When exposed to severe drought stress, phenotypic data and metabolite profiling combined with multivariate analysis revealed a remarkable consistency in separating the selected ecotypes into their different pre-defined drought tolerance groups. Increases in several metabolites, including for the phytohormones jasmonic acid and salicylic acid, and TCA-cycle intermediates, were positively correlated with biomass yield and with reduced yellow pixel counts; suggestive of delayed senescence, both key target traits for crop improvement to drought stress. While metabolite analysis also separated ecotypes into the distinct tolerance groupings after exposure to mild drought stress, similar analysis of the phenotypic data failed to do so, confirming the value of metabolomics to investigate early responses to drought stress. The results highlight the potential of combining the analyses of phenotypic and metabolic responses to identify key mechanisms and markers associated with drought tolerance in both the Brachypodium model plant as well as agronomically important crops

How Reliable is the Cuprates System to Recent Technology?

The emergence of cuprates as a high Tc superconductor gave high hopes in the discovery of a room temperature superconductor. It is almost three decades and the highest critical temperature attained on the cuprates is about 135K. A brief overview was conducted on the progress made so far on the cuprates. A mathematical approach was used to design a formula which could determine the experimental results of critical temperature of versed cuprates superconductors. The result of our findings shows that the possibility of attaining the experimental room temperature cuprates superconductor seems very narrow. The study recommended an elaborate approach on the hybridization of cuprates for future research. Hence, there is possibility of having cuprates with wide engineering applicatio

Advancing Stroke Genomic Research in the Age of Trans-Omics Big Data Science: Emerging Priorities and Opportunities

Background—We systematically reviewed the genetic variants associated with stroke in genome-wide association studies (GWAS) and examined the emerging priorities and opportunities for rapidly advancing stroke research in the era of Trans-Omics science. Methods—Using the PRISMA guideline, we searched PubMed and NHGRI- EBI GWAS catalog for stroke studies from 2007 till May 2017. Results—We included 31 studies. The major challenge is that the few validated variants could not account for the full genetic risk of stroke and have not been translated for clinical use. None of the studies included continental Africans. Genomic study of stroke among Africans presents a unique opportunity for the discovery, validation, functional annotation, trans-omics study and translation of genomic determinants of stroke with implications for global populations. This is because all humans originated from Africa, a continent with a unique genomic architecture and a distinctive epidemiology of stroke; as well as substantially higher heritability and resolution of fine mapping of stroke genes. Conclusion—Understanding the genomic determinants of stroke and the corresponding molecular mechanisms will revolutionize the development of a new set of precise biomarkers for stroke prediction, diagnosis and prognostic estimates as well as personalized interventions for reducing the global burden of stroke

TRENDS, DRIVERS AND HEALTH RISKS OF ADOLESCENT FATHERHOOD IN SUB-SAHARAN AFRICA

The study examined the trends, determinants and health risks of adolescent fatherhood in countries where adolescent-girl pregnancy/motherhood are decried but with permissive male sexual latitude. Male-recode datasets of Demographic Health Survey (2000-2014) for Nigeria, Ethiopia and Zambia were used. The surveys were grouped into 3-Waves: Wave 1 (2000 and 2004); Wave 2 (2005 to 2009) and waves 3 (2010 to 2014). Ethiopia data consisted of 2000, 2005 and 2011 datasets; Nigeria‘s datasets included 2003, 2008 and 2013 while Zambia set of data featured 2002, 2007 and 2014. Wave-1 consists of 2000, 2002 and 2003 datasets; Wave-2 has 2005, 2007 and 2008 datasets while 2011, 2013 and 2014 data were used for Wave- 3. These files in each wave were grouped together and then combined into a single file. All data were weighted to ensure representation and analyses were split by countries and by waves to show the trends across .the years and for different countries. The study employed univariate, bivariate analysis and binary logistics that tested the log-odds of adolescent fatherhood with respect to selected sexual behaviour indices, individual and shared demographic variables. The results, among others, indicated that more than one out of every five adolescents has had two or more sexual partners. The likelihood of adolescent fatherhood is inversely related to condom use, but positively associated with increasing age at first cohabitation and higher number of multiple sexual partnerships (≥ 2) at odd-ratio of 1.673 and 1.769 in 2005/2009 and 2010/2014, respectively. Adolescents that have attained primary and tertiary education, and who are professionals and skilled labourers were 0.379, 0.313, 0.213 and 0.403 times (respectively) less likely to father a child as adolescent. The positive association between rural place of residence and adolescent fatherhood in the past shifted to urban residents in 2010/2014. The study concludes that enlightenment on the use of condom and testing for STIs/HIV and AIDS should be intensified. Increasing access to higher formal education including job opportunities is crucial to interventions towards boys’ vulnerability to fatherhood. The authors recommend support from policy-takers, governments and other stakeholders towards male adolescent access to higher education, skills acquisition, and campaigns against boys and girls cohabitations in the study locations and by extension sub-Saharan Africa in general

Exploring Overlaps Between the Genomic and Environmental Determinants of LVH and Stroke: A Multicenter Study in West Africa

Background Whether left ventricular hypertrophy (LVH) is determined by similar genomic and environmental risk factors with stroke, or is simply an intermediate stroke marker, is unknown. Objectives We present a research plan and preliminary findings to explore the overlap in the genomic and environmental determinants of LVH and stroke among Africans participating in the SIREN (Stroke Investigative Research and Education Network) study. Methods SIREN is a transnational, multicenter study involving acute stroke patients and age-, ethnicity-, and sex-matched control subjects recruited from 9 sites in Ghana and Nigeria. Genomic and environmental risk factors and other relevant phenotypes for stroke and LVH are being collected and compared using standard techniques. Results This preliminary analysis included only 725 stroke patients (mean age 59.1 ± 13.2 years; 54.3% male). Fifty-five percent of the stroke subjects had LVH with greater proportion among women (51.6% vs. 48.4%; p \u3c 0.001). Those with LVH were younger (57.9 ± 12.8 vs. 60.6 ± 13.4; p = 0.006) and had higher mean systolic and diastolic blood pressure (167.1/99.5 mm Hg vs 151.7/90.6 mm Hg; p \u3c 0.001). Uncontrolled blood pressure at presentation was prevalent in subjects with LVH (76.2% vs. 57.7%; p \u3c 0.001). Significant independent predictors of LVH were age \u3c45 years (adjusted odds ratio [AOR]: 1.91; 95% confidence interval [CI]: 1.14 to 3.19), female sex (AOR: 2.01; 95% CI: 1.44 to 2.81), and diastolic blood pressure \u3e 90 mm Hg (AOR: 2.10; 95% CI: 1.39 to 3.19; p \u3c 0.001). Conclusions The prevalence of LVH was high among stroke patients especially the younger ones, suggesting a genetic component to LVH. Hypertension was a major modifiable risk factor for stroke as well as LVH. It is envisaged that the SIREN project will elucidate polygenic overlap (if present) between LVH and stroke among Africans, thereby defining the role of LVH as a putative intermediate cardiovascular phenotype and therapeutic target to inform interventions to reduce stroke risk in populations of African ancestry

Trends, Determinants and Health Risks of Adolescent Fatherhood in Sub-Saharan Africa

BACKGROUND: This study examined the trends, determinants and health risks of adolescent fatherhood in three selected African countries where adolescent-girl pregnancy/motherhood are decried but with permissive male sexual latitude.METHODS: Adolescent male data were extracted from the malerecodedatasets of Demographic Health Survey (2000-2014) for Nigeria, Ethiopia and Zambia. The surveys were grouped into 3-Waves: (2000-2004); (2005-2008) and (2011-2014). The study employed descriptive and binary logistics that tested the log-odds of adolescent fatherhood with respect to selected sexual behaviour indices, and individual and shared demographic variables.RESULTS: The results revealed that the number of lifetimesexual-partners among the boys is ≥2. The likelihood of adolescent fatherhood is positively associated with increasing age at first cohabitation and multiple sexual partnerships (≥2) having OR=1.673 and OR=1.769 in 2005/2008 and 2011/2014 respectively. Adolescents who had attained tertiary education, and engaged in professional and skilled jobs were 0.313, 0.213 and 0.403 times (respectively) less likely to have ever-fathered a child. The positive association between rural place of residence and adolescent fatherhood in the past shifted to urban residents in 2011/2014.CONCLUSION: The study concludes that early sexual activities and cohabitation are common among male adolescents among the countries of study. The authors recommend discouragement of boy-girl cohabitation, increasing access to higher education and job opportunities in order to stem boy-fatherhood incidence in the study locations and, by extension, other countries in sub-Saharan Africa.KEYWORDS: Adolescent fatherhood, sexual behaviour, trends, determinants, health risks, lifetime-sexual-partner