Environmental Pollution from Road Transport System in Ogbomosoland, Southwestern Nigeria

Environmental pollutions from road transport system in Nigeria poses serious health hazards to the ecosystem because of presence of heavy metals and other pollutants. There are researches on assessment of heavy metals contamination of road side soils but most of them investigated the concentration of the heavy metals at the edge of the road pavements but did not considered the concentration at various distances away from the edge of the road pavement. This research therefore focussed on the investigation of the concentration of the contaminants at the edge of the road and at various distances away from the road pavement. A total of 225 soil samples were collected at three sampling depths (0, 10 and 20cm) using three sampling distances of 0.2, 1.5 and 3.0m from Federal, State and Local roads. The soil samples were digested using perchloric acid and trioxonitrate (v) acid and the resulting filterate was analysed using Atomic absorption spectrophotometer for concentrations of Lead (Pb), Copper (Cu), Zinc (Zn), Nickel (Ni) and Cadmium (Cd) at each road. The heavy metals concentration at depth 0cm and distance 0.2m show that the  Federal roads had the highest mean concentration of 154.67, 49.43, 124.71, 27.40 and 2.19µg/g for Pb, Cu, Zn, Ni and Cd respectively and the least being Local roads (110.60, 35.57, 104.26, 23.99 and 1.12µg/g). The mean heavy metals concentrations decreased with increasing soil depths and sampling distance for Federal, State and Local roads. Some of the heavy metals concentrations were above the permissible limit (Canadian Council of Ministers of the Environment, 2004). The study revealed that there are heavy metals in the road-side soils and concentrations for some of the roads were found to be above the permissible limits and this possesses serious health challenges to people around the neighbourhood. The concentrations also decreased with increasing sampling depth and distance for all the roads. Keywords: Environmental Pollution, Heavy metals, Road-side Soils, Sampling depth and distanc

Evaluation of Level of Service of Traffic at Major Road Intersections in Ibadan, Nigeria

Transportation has been of immense benefits to the social, economic and political development of communities, however, it is sometimes characterised with negative impacts such as traffic congestions, delays, environmental pollutions and crashes. In this study, the level of service of selected major road intersections in Ibadan were investigated. Traffic volume of each intersection approach was conducted from 7am - 7pm on Mondays, Wednesdays and Saturdays, delay studies were carried out during the morning, afternoon and evening peak hours and level of service for each approach was determined from the average delay per vehicle. The traffic volume reveals that passenger cars are the predominant vehicles at all the approaches and the morning and afternoon peak hours occurred between 8 to 9am and 2 to 3pm, respectively. The level of service for all the approaches is B, indicating slight reduction in capacity of the intersections. Keywords: Transport, Traffic volume, Traffic delay, Traffic congestion and Road intersection DOI: 10.7176/JIEA/9-7-05 Publication date: December 31st 201

Strength and Workability Improvement Potential of Admixture of Corn Cob Ash and Cement for Stabilizing Lateritic Soil

A natural lateritic soil classified as A-7-5 (10) and CL based on AASHTO and USCS classification systems, was stabilized with up to 5% cement admixed with up to 12% CCA to assess their effect on its basic geotechnical properties such as particle size distribution, Atterberg limits, compaction, unconfined compressive strength and California bearing ratio. The liquid limit decreased and plastic limit increased while there is a reduction in corresponding plasticity index of the clay soil. There was an increase in Maximum Dry Density (MDD) and Optimum Moisture Content (OMC) of the stabilized soil sample, which increased with the increasing content of CCA and cement. Both the Unconfined Compressive Strength (UCS) and California Bearing Ratio (CBR) of the soil increased with increasing percentage of cement and CCA. Based on the results of this study, corn cob ash (CCA) cannot be used as a stand-alone stabilizer for this lateritic soil but with a more potent stabilizer for clay soil such as lime. It is therefore recommended that the mixture of 12% CCA and 2.5% cement could be used to stabilize A-7-5 (10) lateritic soil for use as subbase material and 12% CCA and 5.0% cement could be used to stabilize A-7-5 (10) lateritic soil for use as base material for improving pavement structure in terms of strength, stability and workability. Keywords: Lateritic soil, Corn cob ash, Cement, Stabilization, Strength and Workability DOI: 10.7176/JIEA/9-7-06 Publication date: December 31st 201

Effects of Different Substrates and Temperature on the Growth and Yield of Oyster Mushroom (Lentinus sajor-caju Fr.)

The study evaluated the effects of three saw dust substrates on the growth and yield of Lentinus sajor-caju at the pathology laboratory of Forestry Research Institute of  Nigeria (FRIN) under indoor and outdoor temperatures of 28.6ºC and 29.1ºC  respectively.  The saw dust substrate includes; Triplochiton scleroxylon, Gmelina arborea, and Cordia Millenii. Wheat bran and lime (CaCo3) were incorporated to the substrates as supplements.  The mycelial growth was faster at 28.6ºC giving full colonization at 3 weeks in all the substrates, while full colonization was observed in 4 weeks at 29.1ºC. T. scleroxylon substrate recorded best heights at both indoor and outdoor temperatures with 28.1±10.2cm and 14.6±4.40 respectively.  G. arborea substrate gave the highest yield at both outdoor and indoor temperatures with 69.5±30.6 g 53.5±10.8 g respectively. There was no significant difference on the growth and yield of   L. sajor-caju at the two temperature ranges. Based on the results obtained, G. arborea saw dust was the most suitable substrate and could be recommended for the cultivation of Lentinus sajor-caju

EFFECT OF COMPACTION DELAY ON THE STRENGTH OF CEMENT STABILISED LATERITIC SOIL

Soil stabilisation is a major technique in enhancing the engineering properties of Lateritic soil. There is need to investigate the effect of scenarios when there is elapsed time between when the soil-cement is mixed and when it is spread and compacted. Therefore, this study focussed on the influence of this compaction delay on the engineering properties of cement-stabilised lateritic soil. The lateritic soil was stabilised with 1.5, 3.0, 4.5 and 6.0% cement by weight of soil. The mixture of the soil-cement was left for elapsed time of 1, 3, and 5 h. The natural, stabilised and the stabilised soils with compaction delay were subjected to Sieve analysis, LL, PL. BSL, WAS and AASHTO compaction, UCS and CBR tests. The natural soil was suitable for highway construction except for base course. The MDD of the stabilised soil decrease while the MDD, UCS and CBR increase with increase in cement content. The optimal cement content for the A-2-4(0) soil is 4.5% and the effect of the compaction delay was more prominent after 2 h elapsed time

A communal catalogue reveals Earth's multiscale microbial diversity

Our growing awareness of the microbial world's importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth's microbial diversity.Peer reviewe

A communal catalogue reveals Earth’s multiscale microbial diversity

Our growing awareness of the microbial world’s importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth’s microbial diversity

Global fertility in 204 countries and territories, 1950–2021, with forecasts to 2100: a comprehensive demographic analysis for the Global Burden of Disease Study 2021

Background Accurate assessments of current and future fertility—including overall trends and changing population age structures across countries and regions—are essential to help plan for the profound social, economic, environmental, and geopolitical challenges that these changes will bring. Estimates and projections of fertility are necessary to inform policies involving resource and health-care needs, labour supply, education, gender equality, and family planning and support. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 produced up-to-date and comprehensive demographic assessments of key fertility indicators at global, regional, and national levels from 1950 to 2021 and forecast fertility metrics to 2100 based on a reference scenario and key policy-dependent alternative scenarios. Methods To estimate fertility indicators from 1950 to 2021, mixed-effects regression models and spatiotemporal Gaussian process regression were used to synthesise data from 8709 country-years of vital and sample registrations, 1455 surveys and censuses, and 150 other sources, and to generate age-specific fertility rates (ASFRs) for 5-year age groups from age 10 years to 54 years. ASFRs were summed across age groups to produce estimates of total fertility rate (TFR). Livebirths were calculated by multiplying ASFR and age-specific female population, then summing across ages 10–54 years. To forecast future fertility up to 2100, our Institute for Health Metrics and Evaluation (IHME) forecasting model was based on projections of completed cohort fertility at age 50 years (CCF50; the average number of children born over time to females from a specified birth cohort), which yields more stable and accurate measures of fertility than directly modelling TFR. CCF50 was modelled using an ensemble approach in which three sub-models (with two, three, and four covariates variously consisting of female educational attainment, contraceptive met need, population density in habitable areas, and under-5 mortality) were given equal weights, and analyses were conducted utilising the MR-BRT (meta-regression—Bayesian, regularised, trimmed) tool. To capture time-series trends in CCF50 not explained by these covariates, we used a first-order autoregressive model on the residual term. CCF50 as a proportion of each 5-year ASFR was predicted using a linear mixed-effects model with fixed-effects covariates (female educational attainment and contraceptive met need) and random intercepts for geographical regions. Projected TFRs were then computed for each calendar year as the sum of single-year ASFRs across age groups. The reference forecast is our estimate of the most likely fertility future given the model, past fertility, forecasts of covariates, and historical relationships between covariates and fertility. We additionally produced forecasts for multiple alternative scenarios in each location: the UN Sustainable Development Goal (SDG) for education is achieved by 2030; the contraceptive met need SDG is achieved by 2030; pro-natal policies are enacted to create supportive environments for those who give birth; and the previous three scenarios combined. Uncertainty from past data inputs and model estimation was propagated throughout analyses by taking 1000 draws for past and present fertility estimates and 500 draws for future forecasts from the estimated distribution for each metric, with 95% uncertainty intervals (UIs) given as the 2·5 and 97·5 percentiles of the draws. To evaluate the forecasting performance of our model and others, we computed skill values—a metric assessing gain in forecasting accuracy—by comparing predicted versus observed ASFRs from the past 15 years (2007–21). A positive skill metric indicates that the model being evaluated performs better than the baseline model (here, a simplified model holding 2007 values constant in the future), and a negative metric indicates that the evaluated model performs worse than baseline. Findings During the period from 1950 to 2021, global TFR more than halved, from 4·84 (95% UI 4·63–5·06) to 2·23 (2·09–2·38). Global annual livebirths peaked in 2016 at 142 million (95% UI 137–147), declining to 129 million (121–138) in 2021. Fertility rates declined in all countries and territories since 1950, with TFR remaining above 2·1—canonically considered replacement-level fertility—in 94 (46·1%) countries and territories in 2021. This included 44 of 46 countries in sub-Saharan Africa, which was the super-region with the largest share of livebirths in 2021 (29·2% [28·7–29·6]). 47 countries and territories in which lowest estimated fertility between 1950 and 2021 was below replacement experienced one or more subsequent years with higher fertility; only three of these locations rebounded above replacement levels. Future fertility rates were projected to continue to decline worldwide, reaching a global TFR of 1·83 (1·59–2·08) in 2050 and 1·59 (1·25–1·96) in 2100 under the reference scenario. The number of countries and territories with fertility rates remaining above replacement was forecast to be 49 (24·0%) in 2050 and only six (2·9%) in 2100, with three of these six countries included in the 2021 World Bank-defined low-income group, all located in the GBD super-region of sub-Saharan Africa. The proportion of livebirths occurring in sub-Saharan Africa was forecast to increase to more than half of the world's livebirths in 2100, to 41·3% (39·6–43·1) in 2050 and 54·3% (47·1–59·5) in 2100. The share of livebirths was projected to decline between 2021 and 2100 in most of the six other super-regions—decreasing, for example, in south Asia from 24·8% (23·7–25·8) in 2021 to 16·7% (14·3–19·1) in 2050 and 7·1% (4·4–10·1) in 2100—but was forecast to increase modestly in the north Africa and Middle East and high-income super-regions. Forecast estimates for the alternative combined scenario suggest that meeting SDG targets for education and contraceptive met need, as well as implementing pro-natal policies, would result in global TFRs of 1·65 (1·40–1·92) in 2050 and 1·62 (1·35–1·95) in 2100. The forecasting skill metric values for the IHME model were positive across all age groups, indicating that the model is better than the constant prediction. Interpretation Fertility is declining globally, with rates in more than half of all countries and territories in 2021 below replacement level. Trends since 2000 show considerable heterogeneity in the steepness of declines, and only a small number of countries experienced even a slight fertility rebound after their lowest observed rate, with none reaching replacement level. Additionally, the distribution of livebirths across the globe is shifting, with a greater proportion occurring in the lowest-income countries. Future fertility rates will continue to decline worldwide and will remain low even under successful implementation of pro-natal policies. These changes will have far-reaching economic and societal consequences due to ageing populations and declining workforces in higher-income countries, combined with an increasing share of livebirths among the already poorest regions of the world

Strength Evaluation of Cocos nucifera Fibre Reinforced Concrete

Agro-waste can be used as raw materials for manufacturing various products after recycling. Different researches have investigated the usefulness of coconut fibers (coir) as a micro-reinforcement in concrete this research is aimed at determining properties of fresh and hardened concrete from Ordinary Portland Cement (OPC) reinforced with coconut fiber (coir) and super plasticizer admixture in the form of liquid soap. The flexural and compressive strength of the Coconut Fiber Reinforced Concrete (CRFC) were evaluated at varying percentages (0.1, 0.3 and 0.5% by weight of cement) of fiber. The optimal percentage of fiber for both compressive and flexural strength was determined. It is observed that, there is an increment in the various properties and strength of concrete by the addition of fiber as reinforcement, up to an optimum percentage where the strength starts to drop. The flexural strength was seen to increase considerably by about 17.6% while the compressive strength improved by 23%

Performance characteristics and apparent nutrient digestibility of broiler finisher fed African yam bean cake as partial replacement for soybean meal

Durante tres semanas, se realizó un estudio para evaluar las características productivas y digestibilidad aparente de los nutrientes en 150 broilers Marshal R, no sexados de 3 semanas de edad, acabados con torta de ñame africano (AYBC). Los tratamientos 1, 2, 3, 4 y 5 contenían 5, 10, 15 y 20 % de torta de ñame africano respectivamente. Los animales fueron asignados aleatoriamente a uno de los tratamientos en un diseño completamente al azar. Cada grupo estaba compuesto de 30 aves (tres repeticiones de diez aves cada una). Los animales que consumían el tratamiento 3 tuvieron mayor ganancia de peso (1430 g) pero no fue significativamente diferente de los restantes. La mejor conversión de alimento (1,57) se registró en el tratamiento 1, mientras que la peor eficiencia proteica se registró en el tratamiento 3. Por ello, las aves del tratamiento 1 presentaron la mejor utilización de nutrientes. La torta de ñame africano mejoró los rendimientos y digestibilidad aparente de los nutrientes en los broiler. Por ello debe investigarse la inclusión de torta de ñame africano por encima del 20 %