Disposal frequencies of selected recyclable wastes in Dar es Salaam

A statistical survey of households based upon questionnaires distributed via primary schools has been carried out in five wards of Dar es Salaam, Tanzania, to estimate disposal frequencies (number of items disposed per week) for newsprint, metal cans, glass and plastic containers and plastic shopping bags. Plastic shopping bags are disposed most frequently while glass containers are disposed least frequently. The statistical distribution of disposal frequencies, which seems to be influenced by household income, is well described by Poisson distribution. Disposal frequencies are mutually correlated at 95% level of probability despite the differences in disposal patterns of individual households.     

Awareness of sea-level response under climate change on the coast of Ghana

In response to climate change, coastal communities are expected to experience increasing coastal impacts of sea-level rise (SLR). Strategies formulated and implemented to curb these impacts can thus be more effective if scientific findings on the response to climate change and SLR impacts on coastal communities are taken into consideration and not based merely on the need for coastal protection due to physical coastal erosion. There is also the need to determine the level of awareness of sea-level rise and responses in coastal communities to improve adaptation planning. This study assesses the impact of future erosion on the coastal land cover of Ghana. This assessment estimates approximately 2.66 km², 2.77 km², and 3.24 km² of coastal settlements, 2.10 km², 2.20 km² and 2.58 km² of lagoons, 1.39 km², 1.46 km² and 1.71 km² of wetlands to be at risk of inundation by the year 2050 based on coastal erosion estimates for the 2.6, 4.5 and 8.5 Representative Concentration Pathways (RCPs) used in the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC). This study also assesses the level of awareness of respondents to SLR on the coast of Ghana and explores the availability and level of integration of scientific knowledge of SLR into coastal adaptation strategies in Ghana. Assessment of the awareness of SLR responses to the changing climate in Ghana is made through semi-structured interviews at national, municipal/district and coastal community scales. Although settlements may be inundated based on the coastal erosion estimates, coastal dwellers interviewed cherish their proximity to the sea and are determined to maintain their occupancy close to the sea as spatial location influences their source of livelihood (fishing). Respondents lack knowledge/understanding of SLR, as the majority of household interviewees attributed the rise or fall in sea level to God. Respondents from Ngiresia alleged that the ongoing coastal sea defence project in their community has led to increased malaria cases.     

Toxicity of cadmium to Parachanna obscura : As evidenced by alterations in hematology,histology, and behavior

Fish of species Parachanna obscura are exposed to four concentrations of cadmium (Cd) (0.02, 0.06, 0.18, or 0.54?mg?L^?1). Acute toxicity test results after 96?h showed marked hematological, histological, and behavioral changes. Quantitative blood analysis revealed that white blood cell (WBC), packed cell volume (PCV), and platelets counts were linearly correlated with increasing Cd concentrations; however, blood haemoglobin (Hb) showed an inverse relationship, with higher Hb levels at lower Cd concentrations. Histological changes of the liver showed hepatic separation, bloody appearance, and deposition of a brownish-yellow substance, which increased with rising concentrations of metal. Behavioral changes observed included reduced activity, avoidance response, and deposition of a slimy-whitish film on the body of the fish, which increased with concentration and exposure time.     

Crop biodiversity,productivity and production risk: Panel data micro‐evidence from Ethiopia

This paper uses data from the Central Highlands of Ethiopia to assess the productivity and production risk impacts of crop diversification. Using count index as a measure of crop biodiversity, results show that increasing crop biodiversity contributes positively to farm level productivity. In addition, the findings suggest that the level of production risk significantly responds to the level of diversity, with the effect highly conditional on the skewness. The major contribution of the paper is that, unlike previous similar studies that tended to focus on intra‐crop diversity, it incorporates the mutual interdependencies across crops within a farm by focusing on inter‐crop diversity. Hence the study adds to the growing empirical literature, particularly in Africa, that tests empirical relationships between productivity, risk and crop diversity. An important policy implication for a diversity rich country such as Ethiopia is that agro‐biodiversity can be used to improve agricultural productivity while promoting in situ conservation.