Bioremediation of hydrocarbon-polluted soils for improved crop performance

ABSTRACT Soil pollution arising from increasing demand for petroleum and its products has become a common problem in recent years. Soils polluted with petroleum hydrocarbons (PHCs) differ from unpolluted soils and are not able to support adequate crop growth and development. There is need to treat these soils so as to satisfy the food requirement of the ever increasing world population. Bioremediation is a cost-effective method of soil remediation which uses organisms for the treatment of polluted soils. It has been used across the globe for the treatment of a wide range of organic soil pollutants. In this paper the different approaches to bioremediation of PHC-polluted soil have been discussed. It is evident that the combined use of both microorganisms and phytoremediators improves the efficiency of bioremediation. More research on the interactions between the remediating organisms and the environment is needed for better understanding of this approach to bioremediation

Prevalence and sociodemographic determinants of adult obesity: A large representative household survey in a resource-constrained African setting with double burden of undernutrition and overnutrition

BACKGROUND The obesity epidemic has continued to spread across the globe involving even poor nations of the world. METHOD Household population survey of adults aged 20-60 years. Multistage stratified cluster randomised sampling involving both urban and rural statewide representative population samples. Anthropometric measurements were taken using standard methods. Prevalences were weighted and multinomial regression analyses were done. RESULTS A total of 6628 individuals from 2843 households were surveyed. The weighted overall prevalence for underweight was 9.1% (95% CI 8.1 to 10.1), 65.1% (95% CI 63.6 to 66.6) for normal weight, 19.0% (95% CI 17.8 to 20.3) for overweight and 6.8% (95% CI 6.0 to 7.5) for obese. Men were less likely to be overweight (adjusted OR (AOR) 0.79; 95% CI 0.68 to 0.92) and obese (AOR 0.24; 95% CI 0.19 to 0.31) than women. Urban residents were more likely to be overweight (AOR 1.42; 95% CI 1.18 to 1.71) and obese (AOR 2.09; 95% CI 1.58 to 2.76) than rural residents. Each additional 1-year increase in age increased the risk of overweight by 1.012 (AOR 1.012; 95% CI 1.005 to 1.018) and that of obesity by 1.03 (AOR 1.03; 95% CI 1.02 to 1.04). The low-income class was less likely to be overweight (AOR 0.694; 95% CI 0.507 to 0.951) and obese (AOR 0.44; 95% CI 0.28 to 0.67). CONCLUSION The prevalence of obesity and overweight in Enugu Nigeria is high and fast approaching that of underweight. Women, urban dwellers, older adults and high-income earners are at higher risk for obesity and overweight. The study provides robust information for public health policies towards the prevention of obesity in Nigeria

Moving Forward in African Economic History: Bridging the Gap Between Methods and Sources

The field of African economic history is in resurgence. This paper reviews recent and on-going research contributions and notes strengths in their wide methodological, conceptual and topical variety. In these strengths there is also a challenge: different methodological approaches may also result in divisions, particularly on the quantitative versus qualitative axis. The African Economic History Network has recently been formed to bridge the gap between methods and sources and to facilitate intellectual exchanges among the widest possible range of scholars working on Sub-Saharan economic history. This paper outlines current research projects and calls for future research as well as suggesting promising lines of enquiry in the discipline

Bioremediation of hydrocarbon-polluted soils for improved crop performance

ABSTRACT Soil pollution arising from increasing demand for petroleum and its products has become a common problem in recent years. Soils polluted with petroleum hydrocarbons (PHCs) differ from unpolluted soils and are not able to support adequate crop growth and development. There is need to treat these soils so as to satisfy the food requirement of the ever increasing world population. Bioremediation is a cost-effective method of soil remediation which uses organisms for the treatment of polluted soils. It has been used across the globe for the treatment of a wide range of organic soil pollutants. In this paper the different approaches to bioremediation of PHC-polluted soil have been discussed. It is evident that the combined use of both microorganisms and phytoremediators improves the efficiency of bioremediation. More research on the interactions between the remediating organisms and the environment is needed for better understanding of this approach to bioremediation

Physical Activity and Outdoor Leisure Time Physical Exercise: A Population Study of Correlates and Hindrances in a Resource-Constrained African Setting

Purpose: The study evaluated the burden of physical inactivity, its correlates, and the self-reported hindrances to outdoor leisure-time physical exercises in Enugu Nigeria. It also evaluated the prevalence of leisure-time outdoor physical exercise and its correlates in Enugu Nigeria. Patient and methods: This is a cross-sectional household survey involving 6628 individuals aged 20 to 60 years from 2848 households in Enugu Nigeria. Binary logistic regression and multinomial regression analyses were carried out as appropriate. Estimates were weighted to account for the actual population distribution of important sociodemographic variables and reported with the 95% confidence interval. Results: The burden of physical inactivity was 32.68% (95% CI: 31.24-34.12%). Urban dwellers were less likely to be physically active than rural dwellers (AOR = 0.477; 95% CI = 0.410-0.555). For each year increase in age, the odds of being physically active decreases by a factor of 0.993 (AOR = 0.993; 95% CI= 0.988-0.998). Gender, income level and education did not predict physical inactivity. Physical inactivity significantly increases the odds of being obese by a factor of 1.428 (AOR: 1.428; 95% CI: 1.190-1.714). Only 6.45% (95% CI: 5.82%-7.09%) participants reported at least once a week outdoor leisure-time physical exercise. The major barriers include lack of time and lack of interest in outdoor leisure-time physical exercise. Conclusion: The burden of physical inactivity is high, while the level of outdoor physical exercise is low in Enugu, Nigeria. Urban dwelling and increasing age are risk factors for physical inactivity. Living in urban areas, being less than 40 years of age, having a university education, and a high personal income are factors that positively drive outdoor leisure-time physical exercises. Policies that will promote awareness of the health benefits of physical activity and outdoor physical exercise are needed if Nigeria is to achieve the global mandate of reducing physical inactivity by 10% in the year 2025

Contributions of organic matter, clay and silt to the effective CEC of soils of different land use history

This study examined the contributions of organic matter (OM), clay and silt to the effective cation exchange capacity (ECEC) of soils of different land use history, in order to determine the influence of land use on the contributions of the various fractions to the ECEC of the soils. The land use types examined were sole cassava (C), sole pigeon pea (P), mixed cropping of cassava and pigeon pea (C + P), natural fallow land (FA) and forestland (FO). The results showed that in FA and FO, the OM fraction contributed more to the ECEC compared to the other fractions. The contribution of clay was more visible in the legume-based cropping systems, while that of silt was more pronounced in C. The average contribution of OM to ECEC was 54%, while that of silt and clay were 26% and 20%, respectively. Thus the OM fraction gave better predictions of ECEC than the particle size fractions in an Alfisol of southeastern Nigeria. The low contribution of clay to ECEC recorded in this study may be due to low activity clay dominant in the clay mineralogy of the soil