Based on a two-round household panel survey conducted in Eastern Uganda, this study shows that the analysis of the inverse scale-productivity relationship (IR) is highly sensitive to how plot-level ...maize production is measured. While farmer-reported production-based plot-level maize yield regressions consistently lend support to the IR, the comparable regressions estimated with maize yields based on sub-plot crop cutting, full-plot crop cutting, and remote sensing point towards constant returns to scale, at the mean as well as throughout the distributions. In deriving the much-debated coefficient for GPS-based plot area, the maize yield regressions control for objective measures of soil fertility and edge effects at the plot-level, as well as time-invariant household- and parcel-level unobserved heterogeneity in select specifications. The core finding appears to be driven by over-estimation of farmer-reported maize production vis-à-vis their crop cutting-based counterparts, particularly in the lower half of the plot area distribution.
•Revisits the inverse scale-productivity relationship (IR) at the plot-level using farmer-reporting, crop-cutting, and remote-sensing-based yield estimates.•Systematic measurement error in farmer-reported production generates the IR.•Regressions based on objective yield measures point to constant returns to scale.•Able to control for competing factors that have been suggested to explain the IR.•Results driven by overestimation in farmer-reported production, esp. on small plots.
Climate change impacts on food security will involve negative impacts on crop yields, and potentially on the nutritional quality of staple crops. Common bean is the most important grain legume staple ...crop for human diets and nutrition worldwide. We demonstrate by crop modeling that the majority of current common bean growing areas in southeastern Africa will become unsuitable for bean cultivation by the year 2050. We further demonstrate reductions in yields of available common bean varieties in a field trial that is a climate analogue site for future predicted drought conditions. Little is known regarding the impact of climate change induced abiotic stresses on the nutritional quality of common beans. Our analysis of nutritional and antinutritional compounds reveals that iron levels in common bean grains are reduced under future climate-scenario relevant drought stress conditions. In contrast, the levels of protein, zinc, lead and phytic acid increase in the beans under such drought stress conditions. This indicates that under climate-change induced drought scenarios, future bean servings by 2050 will likely have lower nutritional quality, posing challenges for ongoing climate-proofing of bean production for yields, nutritional quality, human health, and food security.
This study addresses important issues in infant and child mortality in Zimbabwe. The objective of the paper is to determine the impact of maternal, socioeconomic and sanitation variables on infant ...and child mortality. Results show that births of order 6+ with a short preceding interval had the highest risk of infant mortality. The infant mortality risk associated with multiple births was 2.08 times higher relative to singleton births (p<0.001). Socioeconomic variables did not have a distinct impact on infant mortality. Determinants of child mortality were different in relative importance from those of infant mortality. This study supports health policy initiatives to stimulate use of family planning methods to increase birth spacing. These and other results are expected to assist policy makers and programme managers in the child health sector to formulate appropriate strategies to improve the situation of children under 5 in Zimbabwe.
Major new opportunities abound from energy integration among regions in Africa with the sole aim of reducing transaction costs and with the role of Information Communication Technology (ICT), it ...would take energy from where it is easily affordable to places where it is needed. Given the hullabaloo over the net energy-saving impact of ICT, this study takes on a new perspective, that is, employing household energy consumption, to ascertain the use of ICT by household in accessing energy. The study reconnoiters the degree to which Energy integration among the five regional power pools in Africa can achieve ending energy poverty among regional adherents by means of three measures of energy sustainability, explicitly: energy security, energy equity and environmental sustainability. The study utilizes the Pooled Ordinary Least Squares technique on data from the SSA economies over the period 2000-2019. The study expects the results to help in suggesting the need for the acceleration of ICT development in Africa (Sub-Saharan) nations, given the universal communal mission of sustainable energy consumption.
Abstract
Unintended pregnancy is among the major challenges of public health and a major reproductive health issue, due to its implications on the health, economic and social life of a woman and her ...family mainly in low and middle-income countries, particularly sub-Saharan Africa. The study aimed to assess unintended pregnancy and associated factors among pregnant women in Ethiopia using multilevel analysis from the EDHS 2016. We used the data from the 2016 Ethiopian Demographic and Health Survey, comprised of 1122 pregnant women. The prevalence of unintended pregnancy was determined through descriptive statistics and multilevel logistic regression was performed to identify factors associated with unintended pregnancy. Variables with a p-value < 0.05 in the selected model were considered as significantly associated and an adjusted odds ratio was used to determine the strength and direction of the association. The prevalence of unintended pregnancy was 29.7% (CI 27.0%, 32.4%), of which 20.4% were mistimed and 9.3% unwanted. Being multi-para and fertility preference to have no more child were associated with a higher risk of unintended pregnancy whereas husbands' polygamy relation, having no women autonomy, and living in Afar and Somali regions showed a less likely risk of experiencing an unintended pregnancy. This study showed that the proportion of women who experienced unintended pregnancy is considerably high. Parity, fertility preference, polygamy relation, women autonomy, and region were identified factors associated with unintended pregnancy. Therefore, policymakers at all levels, reproductive health experts, and concerned organizations should emphasize minimizing unintended pregnancy targeting the regional variation at large. Researchers have to explore the regional variations through a qualitative study.
The paper analyzes the current state of plastic value chains in Africa and the potential of digital innovations adopted by African entrepreneurs to contributing to a circular plastic economy. We ...provide an overview of plastic waste trade to African countries and an assessment of existing digital solutions that can support the transition to a circular plastic economy. The findings show that various digital innovations are being applied by entrepreneurs including web-based solutions, mobile apps and 3D printing. The case studies also show that multinational companies, especially consumer facing brands, are major players in the national plastic value chains in African countries, acting as seed funders for start-ups as well as buyers of recycled plastics. Current initiatives that are underway are positive signs that changes are in progress to address the environmental and social impacts of plastics value chains in Africa. However, to achieve a transition to sustainable circular value chains, changes at policy level will be required to enable scaling-up of local start-up businesses, address regulatory barriers to digital solutions, create markets for recycled plastic materials and implement extended producer responsibility regulations.
•Barriers to green supply chains redesign (GSCR) are identified.•Relationships among identified barriers in the cashew industry are explored.•Grey DEMATEL is used to evaluate cause-effect ...relationships of barriers.•Increased collaboration in a supply chain is crucial for GSCR.•Support of government and industry organizations are vital to address barriers.
Cashew consumption has been increasing globally, but environmental issues through the whole cashew supply chain, from production, processing and transportation, have been raised. Thus, green supply chain redesign has been put forward but implementation of related practices faces many barriers. Using the case of the Africa cashew industry, which produces over half of global raw cashew nuts but only process less than 10% to kernel, this paper systematically identifies these barriers considering stakeholders through the whole cashew supply chain. Based on evaluation of four experts, results by grey Decision Making Trial and Evaluation Laboratory reveal that successful green supply chain redesign implementation needs two elementary efforts by kernel distributors. One is increased collaboration with multi-tier suppliers (producer organizations and processors) and the other is to get strategic support from industry bodies, non-governmental organizations and development agencies. Additionally, in the short-term, kernel distributors need to overcome three key operational barriers, lack of internal top-level management commitment, lack of integrated management information and traceability systems, and uncertainty of economic benefits. Furthermore, barriers such as difficulties to assess environmental sustainability performance and lack of consumer demand for green cashew should be addressed in the long-term. This study contributes to identify barriers to the successful implementation of green supply chain redesign from perspectives of both the focal enterprise and the whole supply chain. A robust multi-criteria decision making method further reveals the most important and fundamental barriers which can offer decision support for kernel distributors and policymakers in the cashew industry.
The evidence base for the benefits of urban nature for people and biodiversity is strong. However, cities are diverse and the social and environmental contexts of cities are likely to influence the ...observed effects of urban nature, and the application of evidence to differing contexts. To explore biases in the evidence base for the effects of urban nature, we text-matched city names in the abstracts and affiliations of 14 786 journal articles, from separate searches for articles on urban biodiversity, the health and wellbeing impacts of urban nature, and on urban ecosystem services. City names were found in 51% of article abstracts and 92% of affiliations. Most large cities were studied many times over, while only a small proportion of small cities were studied once or twice. Almost half the cities studied also had an author with an affiliation from that city. Most studies were from large developed cities, with relatively few studies from Africa and South America in particular. These biases mean the evidence base for the effects of urban nature on people and on biodiversity does not adequately represent the lived experience of the 41% of the world's urban population who live in small cities, nor the residents of the many rapidly urbanising areas of the developing world. Care should be taken when extrapolating research findings from large global cities to smaller cities and cities in the developing world. Future research should encourage research design focussed on answering research questions rather than city selection by convenience, disentangle the role of city size from measures of urban intensity (such as population density or impervious surface cover), avoid gross urban-rural dualisms, and better contextualise existing research across social and environmental contexts.
The radicine pond snails represent a species-rich and widely distributed group, many species of which are key vectors of human and animal trematodoses. Here we clarify the taxonomy, distribution and ...evolutionary biogeography of the radicine lymnaeids in the Old World based on the most comprehensive multi-locus molecular dataset sampled to date. We show that the subfamily Amphipepleinae is monophyletic and contains at least ten genus-level clades: Radix Montfort, 1810, Ampullaceana Servain, 1881, Peregriana Servain, 1881, Tibetoradix Bolotov, Vinarski & Aksenova gen. nov., Kamtschaticana Kruglov & Starobogatov, 1984, Orientogalba Kruglov & Starobogatov, 1985, Cerasina Kobelt, 1881, Myxas G. B. Sowerby I, 1822, Bullastra Bergh, 1901, and Austropeplea Cotton, 1942. With respect to our phylogeny, species-delimitation model and morphological data, the Old World fauna includes 35 biological species of radicines. Tibet and Eastern Europe harbor the richest faunas, while East Asia and Africa appear to be the most species-poor areas. The radicine clade could have originated near the Cretaceous - Paleocene boundary. The Miocene great lakes in Eurasia seems to be the most important evolutionary hotspots shaping spatial patterns of recent species richness. Finally, we present the first DNA barcode reference library for the reliable molecular identification of species within this group.
During copper ore smelting process, large amount of copper slag is created, which has excellent use in variance ways. In the common case, copper slag were deposited on the surface without treatment, ...which inevitably caused serious environmental problems. To deal with the pollution created and better utilize copper slag, a new controlled low strength filling material (CLSFM) was proposed for the copper slag from a mine in Africa.The filling cost of using CLSFM is equivalent to that of cement, as well as the method is more ecological and conforms to the local government environment policy. In order to study the influencing factors of this material, orthogonal test method and data visualization were used in the experiment, which make it possible to observe the effect of multifactor composite action on copper slag and the optimum ratio. The experimental results show that mechanical activation and alkali excitation can effectively activate the copper slag. Microscopic analysis shows that the main hydration product of CLSFM, C–S–H, makes the copper slag cementitious, and improves its structural strength.
•The impact of Mechanical activation and Chemical activation on the copper slag was investigated.•Orthogonal test, regression analysis and data visualization were used to optimize the ratio.•The microstructure and hydration products of copper slag after mechanical and chemical excitation were analyzed.
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