Nuclear Magnetic Resonance Spectroscopy Guided Biodiesel Production from Atoulfo Mango Seeds Oil and the Evaluation of Some of its Properties

Ground Atoulfo mango seeds kernel was extracted using soxhlet apparatus with hexane to give an oil yield of 22.71%. The physicochemical properties of the oil reveals; acid value (15.32±0.20 mgKOH/g), free fatty acid (7.66±0.10 mg/g), iodine value (61.31±3.70 I2g/100g) and saponification value (171.99±3.10 mgKOH/g). The production of biodiesel from the oil by transesterification reaction was monitored by proton nuclear magnetic resonance (1H NMR) spectroscopy. The percentage triacylglycerol conversion in the oil to its corresponding methyl esters (biodiesel) was calculated to be 94%. The important properties of the biodiesel studied were density (0.88 g/cm3), acid value (0.39 mg/KOH/g), kinematic viscosity (4.60 °C mm2/sec), flash point (150 °C), cetane number (65), pour point (2.1 °C), sulphur content (0.011 %) and ash content (trace) respectively. The fuel properties studied significantly agreed with the specifications of American Society for Testing and Materials (ASTM D6751), thus qualifying the seed oil as a potential ingredient for the production of biodiesel. &nbsp

Modeling the transmission dynamics of Zika with sterile insect technique

A deterministic model for the transmission dynamics of Zika is designed and rigorously analysed. A model consisting of mutually exclusive compartments representing the human and mosquito dynamics takes into account both direct (human‐human) and indirect modes of transmissions. The basic offspring number of the mosquito population is computed and condition for existence and stability of equilibria is investigated. Using the centre manifold theory, the model (with and without direct transmission) is shown to exhibit the phenomenon of backward bifurcation (where a locally asymptotically stable disease free equilibrium coexists with a locally asymptotically stable endemic equilibrium) whenever the associated reproduction number is less than unity. The study shows that the models with and without direct transmission exhibit the same qualitative dynamics with respect to the local stability of their associated disease‐free equilibrium and backward bifurcation phenomenon. The main cause of the backward bifurcation is identified as Zika induced mortality in humans. Sensitivity (local and global) analysis of the model parameters are conducted to identify crucial parameters that influence the dynamics of the disease. Analysis of the model shows that an increase in the mating rate with sterile mosquito decreases the mosquito population. Numerical simulations, using parameter values relevant to the transmission dynamics of Zika are carried out to support some of the main theoretical findings.South African DST/NRF SARChI chair on Mathematical Models and Methods in Bioengineering and Biosciences (M3B2) and DST-NRF Centre of Excellence in Mathematical and Statisti-cal Sciences (CoE-MaSS).http://wileyonlinelibrary.com/journal/mma2019-12-01hj2019Mathematics and Applied Mathematic

Lithostratigraphy and geochemical characterization of limestone deposits around Kushimaga Area in Yobe Of North-Eastern Nigeria

This study presents detailed petrographic and chemical compositional characteristic of limestone deposits for possible industrial uses and specifications. The study area falls within the Gongola basin, North-eastern Nigeria. Core limestone samples were collected from four boreholes at the depth of approximately 25 metres each in Kushimaga area around Gulani in Yobe state; north-eastern Nigeria. Lithological units were observed in the following sequence; topsoil and clay with an average thickness of 1.513m, limestone 5.553m, shale 7.853m respectively. Eleven limestone samples were selected from the boreholes for petrography and chemical analysis (Fluorescence Spectroscopy analysis). From the petrograhic studies the limestone samples are composed (visual estimate) of over 95% calcite, trace amounts of colourless already recrystallized fossil of planktonic forams and mollusc, weakly deformed greenish grains of glauconite about 0.2 to 0.3 mm in grain size, traces of opaque, isotropic, high relief iron oxide minerals with 0.03 to 0.5 mm grains sizes are present disseminated in the form of limonite. Traces of quartz and feldspar grains of silt size class were also noted in thin sections. With less than 10% grains the samples are classified as mudstone. The results of chemical analyses of limestone shows a range values of SiO2, 10.05wt% to 32.00wt% , CaO, 21.00wt% to 53.99wt%, MgO, 0.35wt% to 1.00wt%, Al2O3, 2.15wt% to 12.69wt%, Fe2O3, 1.28wt% to 4.90wt%, Na2O, 0.002wt% to 0.18wt%, K2O, 0.9wt% to 1.96wt%, TiO2, 0.21wt% to 1.00wt%, P2O5, 0.17wt% to 0.69wt%, MnO, 0.21wt% to 0.55wt%, loss on ignition, 21.98% to 36.87%, while the result of chemical classification of the limestone show a range of Ca/Mg, 23.33% to 125.68% and Mg/Ca, 0.00% to 0.04% of the Kushimaga limestone. However, the limestone beds of the research area were compared with other standard chemical industrial specifications. The study revealed that the limestone around Kushimaga area satisfies the chemical factors for Portland cement production but falls below the standard chemical specifications for other industrial uses; glass, sugar and Paint pigments and filler productions.Keywords: Argillaceous, bivariant, core, lithology, petrography and stratigraph

Detection of mycobacteria in raw cow milk sold in Bwari Area Council, Abuja FCT

Bovine tuberculosis (bTB) is an important zoonotic disease worldwide and hence it is of great public health significance. It is present in most developing countries where surveillance and control activities are often inadequate or unavailable. This study was designed to detect mycobacteria in raw milk of cows using ZN-stain, PCR, and cultural techniques to determine the prevalence of bTB in Bwari area council of FCT Abuja. Out of the 145 raw milk sampled, 6.89% tested positive by ZN-stain and culture while 1.3% were positive by PCR. The herd prevalence per satellite town based on ZN-stain technique was 8.89%, 10.0%, 3.33% and 5.00% for Bwari, Dei-Dei, Kubuwa and Ushafa respectively. While by cultural method, the prevalence was 2.22%, 10.00%, and 5.00% for Bwari, Dei-Dei, Kubuwa and Ushafa respectively. PCR revealed the prevalence of Mycobacterium species for Bwari and Dei-Dei as 2.22% and 3.33% respectively. Detection of Mycobacteria in raw (unpasteurized) pose a serious public health risk to raw milk consumers in Bwari area council.Keywords: Raw milk, bTB, ZN stain, PCR, Cultur

Global burden and strength of evidence for 88 risk factors in 204 countries and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

Background: Understanding the health consequences associated with exposure to risk factors is necessary to inform public health policy and practice. To systematically quantify the contributions of risk factor exposures to specific health outcomes, the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 aims to provide comprehensive estimates of exposure levels, relative health risks, and attributable burden of disease for 88 risk factors in 204 countries and territories and 811 subnational locations, from 1990 to 2021. Methods: The GBD 2021 risk factor analysis used data from 54 561 total distinct sources to produce epidemiological estimates for 88 risk factors and their associated health outcomes for a total of 631 risk–outcome pairs. Pairs were included on the basis of data-driven determination of a risk–outcome association. Age-sex-location-year-specific estimates were generated at global, regional, and national levels. Our approach followed the comparative risk assessment framework predicated on a causal web of hierarchically organised, potentially combinative, modifiable risks. Relative risks (RRs) of a given outcome occurring as a function of risk factor exposure were estimated separately for each risk–outcome pair, and summary exposure values (SEVs), representing risk-weighted exposure prevalence, and theoretical minimum risk exposure levels (TMRELs) were estimated for each risk factor. These estimates were used to calculate the population attributable fraction (PAF; ie, the proportional change in health risk that would occur if exposure to a risk factor were reduced to the TMREL). The product of PAFs and disease burden associated with a given outcome, measured in disability-adjusted life-years (DALYs), yielded measures of attributable burden (ie, the proportion of total disease burden attributable to a particular risk factor or combination of risk factors). Adjustments for mediation were applied to account for relationships involving risk factors that act indirectly on outcomes via intermediate risks. Attributable burden estimates were stratified by Socio-demographic Index (SDI) quintile and presented as counts, age-standardised rates, and rankings. To complement estimates of RR and attributable burden, newly developed burden of proof risk function (BPRF) methods were applied to yield supplementary, conservative interpretations of risk–outcome associations based on the consistency of underlying evidence, accounting for unexplained heterogeneity between input data from different studies. Estimates reported represent the mean value across 500 draws from the estimate's distribution, with 95% uncertainty intervals (UIs) calculated as the 2·5th and 97·5th percentile values across the draws. Findings: Among the specific risk factors analysed for this study, particulate matter air pollution was the leading contributor to the global disease burden in 2021, contributing 8·0% (95% UI 6·7–9·4) of total DALYs, followed by high systolic blood pressure (SBP; 7·8% [6·4–9·2]), smoking (5·7% [4·7–6·8]), low birthweight and short gestation (5·6% [4·8–6·3]), and high fasting plasma glucose (FPG; 5·4% [4·8–6·0]). For younger demographics (ie, those aged 0–4 years and 5–14 years), risks such as low birthweight and short gestation and unsafe water, sanitation, and handwashing (WaSH) were among the leading risk factors, while for older age groups, metabolic risks such as high SBP, high body-mass index (BMI), high FPG, and high LDL cholesterol had a greater impact. From 2000 to 2021, there was an observable shift in global health challenges, marked by a decline in the number of all-age DALYs broadly attributable to behavioural risks (decrease of 20·7% [13·9–27·7]) and environmental and occupational risks (decrease of 22·0% [15·5–28·8]), coupled with a 49·4% (42·3–56·9) increase in DALYs attributable to metabolic risks, all reflecting ageing populations and changing lifestyles on a global scale. Age-standardised global DALY rates attributable to high BMI and high FPG rose considerably (15·7% [9·9–21·7] for high BMI and 7·9% [3·3–12·9] for high FPG) over this period, with exposure to these risks increasing annually at rates of 1·8% (1·6–1·9) for high BMI and 1·3% (1·1–1·5) for high FPG. By contrast, the global risk-attributable burden and exposure to many other risk factors declined, notably for risks such as child growth failure and unsafe water source, with age-standardised attributable DALYs decreasing by 71·5% (64·4–78·8) for child growth failure and 66·3% (60·2–72·0) for unsafe water source. We separated risk factors into three groups according to trajectory over time: those with a decreasing attributable burden, due largely to declining risk exposure (eg, diet high in trans-fat and household air pollution) but also to proportionally smaller child and youth populations (eg, child and maternal malnutrition); those for which the burden increased moderately in spite of declining risk exposure, due largely to population ageing (eg, smoking); and those for which the burden increased considerably due to both increasing risk exposure and population ageing (eg, ambient particulate matter air pollution, high BMI, high FPG, and high SBP). Interpretation: Substantial progress has been made in reducing the global disease burden attributable to a range of risk factors, particularly those related to maternal and child health, WaSH, and household air pollution. Maintaining efforts to minimise the impact of these risk factors, especially in low SDI locations, is necessary to sustain progress. Successes in moderating the smoking-related burden by reducing risk exposure highlight the need to advance policies that reduce exposure to other leading risk factors such as ambient particulate matter air pollution and high SBP. Troubling increases in high FPG, high BMI, and other risk factors related to obesity and metabolic syndrome indicate an urgent need to identify and implement interventions. Funding: Bill & Melinda Gates Foundation

Influence of microclimatic elements on the early growth of jatropha (Jatropha curcas (Linn)) seedlings in Kano, Nigeria

No AbstractKeywords: Humidity, Early growth, Jatropha curcas and Temperatur