Patterns and predictors of contraceptive usage among HIV-positive women of reproductive age attending PMTCT/ART clinics in Ogbomoso, Nigeria

Objective: the objective of the study is to assess the patterns and predictors of contraceptive usage among HIV positive women of reproductive age attending PMTCT/ART clinics in Ogbomoso, Oyo state, Nigeria.Methods: it was a cross-sectional descriptive cross-sectional study conducted among HIV positive women of reproductive age group selected using multi-stage sampling technique. Data was collected using a pre-tested semi-structured interviewer administered questionnaire and analyzed using Statistical Package for Social Sciences. The questions about knowledge of and attitude towards contraception were scored, and categorized as good or poor knowledge, favourable or unfavourable attitude. Univariate, bivariate, and multivariate analyses assessed predictors of contraceptive usage. A bivariate logistic regression model which used p<0.05 as the entry criterion, was generated to calculate the odds ratios and 95% confidence intervals respectively.Results: age ranges from 16 to 48 years with mean age 31.8 + 7.8 years. Majority are within age range of 25-35 years 110 (40.7%), Christians 178 (65.9%), Yoruba 235 (87%), educated 246 (91.1%) and within monogamous settings 179 (66.3%). About half of the respondents 158 (58.5%) had favorable attitude and adequate knowledge respectively. There is a significant difference (p<0.05) between education and categorized knowledge on usage of contraception. Those who have adequate knowledge are twice more likely to use contraception compared to those with inadequate knowledge. Those who are less educated are 3.3 times less likely to use contraception compared to those that are educated.Conclusion: The findings in this study showed that about half of the respondents had high knowledge and favorable attitude on family planning.Keywords: reproduction, education, health, virus, knowledg

Age, HIV status, and research context determined attrition in a longitudinal cohort in Nigeria

Objectives: We explored determinants of attrition in a longitudinal cohort study in Nigeria. Study Design and Setting: We enrolled 1,020 women into a prospective study. Of these, 973 were eligible to return for follow-up. We investigated the determinants of attrition among eligible women using a sequential mixed methods design. We used logistic regression models to compare the baseline characteristics of responders and nonresponders. At the end of the parent study, we conducted four focus group discussions and eight key informant interviews with nonresponders. Results: Of the 973 women included in the quantitative analysis, 26% were nonresponders. From quantitative analysis, older women were less likely to drop out than younger women (reference: women ≤30 years; OR 0.46; 95% confidence interval [CI] 0.30–0.70, P < 0.001 women 31–44 years; and OR 0.31; 95% CI 0.17–0.56, P < 0.001 women ≥45 years). HIV-positive women were also less likely to drop out of the study (OR 0.45; 95% CI 0.33–0.63, P < 0.001). From qualitative analysis, contextual factors that influenced attrition were high cost of participation, therapeutic misconceptions, inaccurate expectations, spousal disapproval, unpleasant side effects, challenges in maintaining contact with participants, and participant difficulties in locating the study clinic. Conclusion: Several participant-, research-, and environment-related factors influence attrition. Retention strategies that address these barriers are important to minimize attrition

On XLE index constituents’ social media based sentiment informing the index trend and volatility prediction

Collective intelligence represented as sentiment extracted from social media mining found applications in various areas. Numerous studies involving machine learning modelling have demonstrated that such sentiment information may or may not have predictive power on the stock market trend. This research investigates the predictive information of sentiment regarding the Energy Select Sector related XLE index and of its constituents, on the index and its volatility, based on a novel robust machine learning approach. While we demonstrate that sentiment does not have any impact on any of the trend prediction scenarios investigated here related to XLE and its constituents, the sentiment’s impact on volatility predictions is significant. The proposed volatility prediction modelling approach, based on Jordan and Elman recurrent neural networks, demonstrates that the addition of sentiment or sentiment moment reduces the prediction root mean square error (RMSE) to about one third. The experiments we conducted also demonstrate that the addition of sentiment reduces the RMSE for 24 out of the 36 stocks/constituents, representing 87.9% of the index weight. This is the first study in the literature relating to the prediction of the market trend or the volatility based on an index and its constituents’ sentiment

Activated carbon derived from tree bark biomass with promising material properties for supercapacitors

Activated carbon from tree bark (ACB) has been synthesized by a facile and environmentally friendly activation and carbonization process at different temperatures (600, 700 and 800 °C) using potassium hydroxide (KOH) pellets as an activation agent with different mass loading. The physicochemical and microstructural characteristics of the as-obtained material revealed interconnected microporous/mesoporous architecture with increasing trend in specific surface area (SSA) as carbonization temperatures rises. The SSA values of up to 1018 m2 g−1 and a high pore volume of 0.67 cm3 g−1 were obtained. The potential of the ACB material as suitable supercapacitor electrode was investigated in both a three and two-electrode configuration in different neutral aqueous electrolytes. The electrodes exhibited electric double-layer capacitor (EDLC) behaviour in all electrolytes with the Na2SO4 electrolyte working reversibly in both the negative (−0.80 V to −0.20 V) and positive (0.0 V to 0.6 V) operating potentials. A specific capacitance (Cs) of up to 191 F g−1 at a current density of 1 A g−1 was obtained for the optimized ACB electrode material in 1 M Na2SO4 electrolyte. A symmetric device fabricated exhibited specific Cs of 114 F g−1 at 0.3 A g−1 and excellent stability with a coulombic efficiency of a 100 % after 5000 constant charge–discharge cycles at 5.0 A g−1 and a low capacitance loss for a floating time of 70 h.The South African Research Chairs Initiative of the Department of Science and Technology, Republic of South Africa and National Research Foundation of South Africa (Grant no. 97994).http://link.springer.com/journal/100082018-03-30hb2016Physic

Exploring the stability and electronic structure of beryllium and sulphur co-doped graphene : a first principles study

First principles density functional theory (DFT) calculations have been performed to explore the stability, structural and electronic properties of Be and S codoped graphene sheets. The band-gap of graphene has been tuned by co-doping with beryllium and sulphur at different sites. The results show that by codoping graphene with Be and S, the band-gap increases from zero up to 0.58 eV depending on the doping sites. The cohesive and the formation energies of the systems were also determined. All the isomers formed by exploring different doping sites differ notably in stability, bond length and band-gap. Nevertheless, the planar structure of all the systems investigated was preserved even after geometry optimisation. Majority of the isomers that correspond to co-doping at non-equivalent sites favour higher band-gap opening, but lesser stability, than the other set of isomers with equivalent doping sites. Bader charge analysis was adopted to account for charges distribution in the systems. As a result of the difference in electronegativity among carbon atoms and the impurities, it was observed that electrons accumulation occurred more on the carbon atoms in the proximity of Be and S than at any other position in the graphitic systems investigated.The South African Research Chairs Initiative of the Department of Science and Technology and National Research Foundation (NRF) of South Africa (Grant No. 97994). O. Okikiola acknowledges the financial support from NRF and the University of Pretoria for his PhD studies. Remove selectedhttp://www.rsc.org/journals-books-databases/about-journals/rsc-advances2017-09-30hb2017Physic

A facile hydrothermal reflux synthesis of Ni(OH)2/GF electrode for supercapacitor application

Ni(OH)2/graphene foam (GF) electrode was synthesized for electrochemical application by a facile hydrothermal reflux technique. The results obtained from the scanning electron microscopy showed that the Ni(OH)2 spheres successfully coated the entire surface area of the GF. Specific capacitance of 2420 F g-1 at a current density of 1 A g-1 was obtained for Ni(OH)2/GF composite electrode, as well as a capacitance retention of ~93% after 1000 charge-discharge cycles, demonstrating excellent cycle stability in 6.0 M KOH electrolyte. These results suggest that the composite could be a potential active material for high performance electrochemical applications.South African Research Chairs Initiative of the Department of Science and Technology, National Research Foundation of South Africa (Grant No. 97994) and University of Pretoria.http://link.springer.com/journal/108532017-06-30hb2016Physic

Effect of activated carbon on the enhancement of CO sensing performance of NiO

NiO/activated carbon (AC) composites were successfully synthesized via a hydrothermal reflux process as an electrode material for carbon monoxide (CO) gas sensor application. The X-ray diffraction (XRD) analysis was used to investigate the crystallinity of the samples while gas sorption analysis was used to probe the specific surface area of both the pristine NiO and NiO/AC composite. The sensors were subjected to continuous cycles of different CO concentrations and were purged with air after each cycle, followed by variations in a normalized resistance study. The results obtained from the gas sensing analysis disclose that the incorporation of AC into NiO increased the conductivity and surface area of NiO/ AC composite and subsequently enhancing the CO sensing performance of NiO/AC based sensor. These results imply that the NiO/AC composite could be an excellent nanomaterial for CO gas sensors.http://www.elsevier.com/locate/jalcom2018-02-28hb2017Physic

EFFECT OF DEWATERING METHOD ON SELECTED PROPERTIES OF GARI

Two of the most important steps in the ‘gari’ production process are the fermentation and dewatering steps during which the highest cyanide reduction occurs. ‘Gari’ samples were produced by dewatering the cassava mash during fermentation and after fermentation. &nbsp;The samples were analyzed for their proximate composition, cyanide content and functional properties. The moisture content, bulk density and cyanide were higher than that of the dewatering during fermentation method. Recorded functional properties suggest that the sample from dewatering after fermentation will take a longer time to cook and that the paste obtained from cooked ‘gari’ samples from the dewatering during fermentation method is firmer

EFFECT OF DRYING METHOD ON SELECTED PROPERTIES OF CASSAVA FLOUR (LAFUN)

Fermented cassava flour (lafun) is one of the products obtained from cassava processing. Traditionally, sun-drying is one of its main processing steps, but it is ineffective for large-scale production. The effect of flour needs to investigated. Sun-drying, solar drying and cabinet drying methods were used to produce fermented cassava flour. The sample were analyzed for their proximate composition, cyanide content, physico-chemical and functional properties. The moisture, bulk density and amylase contents of the sun-dried samples were higher while its protein and cyanide contents were lower than that of the other methods. Recorded functional properties of the fermented flour suggest that sun-dried samples cook faster than others and that the paste obtained from cooked sun-dried sample is firmer. However, values obtained from analysis of the different fermented cassava flours after drying were significantly different (P &lt;=0.05)