Genome-wide association studies can identify common differences that contribute to human phenotypic diversity and disease. When genome-wide association studies are combined with approaches that test how variants alter physiology, biological insights can emerge. Here, we used such an approach to reveal regulation of cell death by the methionine salvage pathway. A common SNP associated with reduced expression of a putative methionine salvage pathway dehydratase, apoptotic protease activating factor 1 (APAF1)-interacting protein (APIP), was associated with increased caspase-1-mediated cell death in response to Salmonella. The role of APIP in methionine salvage was confirmed by growth assays with methionine-deficient media and quantitation of the methionine salvage substrate, 5'-methylthioadenosine. Reducing expression of APIP or exogenous addition of 5'-methylthioadenosine increased Salmonellae-induced cell death. Consistent with APIP originally being identified as an inhibitor of caspase-9-dependent apoptosis, the same allele was also associated with increased sensitivity to the chemotherapeutic agent carboplatin. Our results show that common human variation affecting expression of a single gene can alter susceptibility to two distinct cell death programs. Furthermore, the same allele that promotes cell death is associated with improved survival of individuals with systemic inflammatory response syndrome, suggesting a possible evolutionary pressure that may explain the geographic pattern observed for the frequency of this SNP. Our study shows that in vitro association screens of disease-related traits can not only reveal human genetic differences that contribute to disease but also provide unexpected insights into cell biology.
Social norms comparisons are tools that are being used more and more often by energy and water utilities all over the world in order to induce households to conserve resources. Such conservation programs are appealing to utilities since they are an easy-to-implement alternative to raising prices and commonly result in short-term reductions in energy and water use of about 2–5%. However, the welfare effects of social norms programs are rarely discussed and assessed, especially in the context of municipal water supply. The purpose of this paper is to identify the costs and benefits of social norms information treatments (SNITs) to all social groups and to illustrate a conceptual framework for conducting a benefit–cost analysis of social norms treatments in the municipal water sector. We provide plausible estimates for the costs and benefits of social norms treatments to different affected groups in the municipal water supply sector using current knowledge for both developing and industrialized countries in order to show how practitioners can conduct a benefit–cost analysis of an SNIT for a specific water utility. Our calculations show that the outcome of a benefit–cost analysis of an SNIT is highly location-specific and likely subject to substantial uncertainty. We also present a simple benefit–cost analysis of a price increase that would lead to an equivalent initial reduction in household water use. The latter is found to be more likely to result in net benefits to the society as a whole in low- and middle-income countries, but we show that, in this case, households would have to bear most of the costs.
This study presents a discrete choice model of households' water source choice decisions in developing countries. This model is estimated with data collected by in‐depth personal interviews with 69 households in Ukunda, Kenya, a small town south of Mombasa. The results suggest that households' source choice decisions are influenced by the time it takes to collect water from different sources, the price of water, and the number of women in a household. Household income, however, did not have a statistically significant effect. Essentially the same data were used to estimate a traditional water demand model which attempts to explain the quantity of water demanded by a household as a function of collection time, income, and other socioeconomic variables. The results of the discrete choice and traditional water demand models are compared in this paper.
The poor are most likely to suffer from a service provider that cannot reliably supply high-quality water through the piped network. Effectively assisting the poor is a key component of a successful tariff reform process. This paper provides practical, up-to-date advice that water utilities, municipalities, central governments, and donors can use to design and implement pro-poor policies for municipal water supply in low- and middle-income countries. After mapping contextual factors for a given situation and outlining the set of pro-poor policy alternatives, we use a simplified typology to diagnose common types of situations a water provider might be facing, provide policy recommendations, highlight potential policy mistakes, and discuss the challenges that policymakers are likely to face.
This paper presents the first comprehensive estimates of the economic costs experienced by households in the 2011 Greater Bangkok flood. More generally, it contributes to the literature by presenting the first estimates of flood costs based on primary data collected from respondents of flooded homes using in-person interviews. Two rounds of interviews were conducted with 469 households in three of the most heavily affected districts of greater Bangkok. The estimates of economic costs include preventative costs, ex post losses, compensation received, and any new income generated during the flood. Median household economic costs were US$3089, equivalent to about half of annual household expenditures (mean costs were US$5261). Perhaps surprisingly given the depth and duration of the flood, most houses incurred little structural damage (although furniture, appliances, and cars were damaged). Median economic costs to poor and nonpoor households were similar as a percentage of annual household expenditures (53% and 48%, respectively). Compensation payments received from government did little to reduce the total economic losses of the vast majority of households. Two flood-related deaths were reported in our sample—both in low-income neighborhoods. Overall, ex post damage was the largest component of flood costs (66% of total). These findings are new, important inputs for the evaluation of flood control mitigation and preventive measures that are now under consideration by the Government of Thailand. The paper also illustrates how detailed microeconomic data on household costs can be collected and summarized for policy purposes.
This paper examines the implications for Egypt and Sudan of the development of Blue Nile water resources by Ethiopia. The long‐term development progamme produced between 1958 and 1963 by the Ethiopian government in collaboration with the US Bureau of Reclamation is summarized. A linear programming model is used to examine the effects on Egypt and Sudan of implementing this programme. It is found that water for agricultural use in Egypt and Sudan would actually increase, though there would be some adverse consequences for Egypt.
This article employs a hydro-economic optimization model to analyze the effects of the Grand Ethiopian Renaissance Dam on the distribution and magnitude of benefits in the Eastern Nile. Scenarios are considered based on plausible institutional arrangements that span varying levels of cooperation, as well as changes in hydrological conditions (water availability). The results show that the dam can increase Ethiopia's economic benefits by a factor of 5–6, without significantly affecting or compromising irrigation and hydropower production downstream. However, increasing GERD water storage during a drought could lead to high costs not only for Egypt and Sudan, but also for Ethiopia.
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