Fecal contamination of drinking-water in low- and middle-income countries: a systematic review and meta-analysis

Background: access to safe drinking-water is a fundamental requirement for good health and is also a human right. Global access to safe drinking-water is monitored by WHO and UNICEF using as an indicator “use of an improved source,” which does not account for water quality measurements. Our objectives were to determine whether water from “improved” sources is less likely to contain fecal contamination than “unimproved” sources and to assess the extent to which contamination varies by source type and setting.Methods and findings: studies in Chinese, English, French, Portuguese, and Spanish were identified from online databases, including PubMed and Web of Science, and grey literature. Studies in low- and middle-income countries published between 1990 and August 2013 that assessed drinking-water for the presence of Escherichia coli or thermotolerant coliforms (TTC) were included provided they associated results with a particular source type. In total 319 studies were included, reporting on 96,737 water samples. The odds of contamination within a given study were considerably lower for “improved” sources than “unimproved” sources (odds ratio [OR] = 0.15 [0.10–0.21], I2 = 80.3% [72.9–85.6]). However over a quarter of samples from improved sources contained fecal contamination in 38% of 191 studies. Water sources in low-income countries (OR = 2.37 [1.52–3.71]; p<0.001) and rural areas (OR = 2.37 [1.47–3.81] p<0.001) were more likely to be contaminated. Studies rarely reported stored water quality or sanitary risks and few achieved robust random selection. Safety may be overestimated due to infrequent water sampling and deterioration in quality prior to consumption.Conclusion: access to an “improved source” provides a measure of sanitary protection but does not ensure water is free of fecal contamination nor is it consistent between source types or settings. International estimates therefore greatly overstate use of safe drinking-water and do not fully reflect disparities in access. An enhanced monitoring strategy would combine indicators of sanitary protection with measures of water qualit

Improvement of propeller static thrust estimation Final report, Jul. 1, 1964 - Aug. 31, 1965

Research facility development for propeller thrust and torque measurements under static thrust condition

Causes of comorbidity among internalizing disorders of childhood and adolescence : the roles of neuroticisim, genes and environment

The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file viewed on (February 26, 2007)Vita.Thesis (Ph.D.) University of Missouri-Columbia 2006.Sources of variance and covariance among mother-reported separation anxiety disorder (SAD) and self-reported depression (DEP) and generalized anxiety disorder (GAD) were studied in a population-based sample of 4,320 female twins. The relationship of self-reported neuroticism to each of the three internalizing disorders was also examined. Correlations among the four phenotypes were computed and logistic regression was used to predict SAD, DEP and GAD from neuroticism. Structural equation modeling (SEM) was conducted to parse the causes of variation in neuroticism, SAD, DEP and GAD into additive genetic (A), shared environmental (C) and nonshared environmental (E) effects. SEM was also conducted to parse sources of covariation among the four phenotypes into A, C, and E effects. All four phenotypes were positively and significantly associated with one other. Genetic and nonshared environmental factors were important in the etiology of all four phenotypes, whereas shared environmental influences were only significant for SAD. Covariation among the phenotypes was due primarily to additive genetic and nonshared environmental effects. These results suggest a common underlying genetic liability may explain comorbidity among internalizing disorders and their association with neuroticism.Includes bibliographical reference

Tests on propellers under static thrust conditions

Dynamometer tests of propellers under static thrust condition

The origins of risk sharing: An experimental approach

Controversy exists about the act of giving as altruistic instead of self-interested behavior. Each side of this argument interprets similar results from similar experiments in diff erent ways. One side argues the results show that the appearance of altruistic behavior can be explained by self-interested motives. The other side argues these results are evidence of group selection,where a group member takes an action that is harmful to itself but benefi cial to the group. We consider this question using a novel approach. We create a rich experimental environment in which subjects have the ability to cooperate to improve the group's outcome by sharing their wealth in non-compulsory, non-enforceable risk-sharing arrangements. We find that average subject behavior appears to be motivated by self-interest more than group survival

Global assessment of exposure to faecal contamination through drinking water based on a systematic review

Objectives: To estimate exposure to faecal contamination through drinking water as indicated by levels of Escherichia coli (E. coli) or thermotolerant coliform (TTC) in water sources. Methods: We estimated coverage of different types of drinking water source based on household surveys and censuses using multilevel modelling. Coverage data were combined with water quality studies that assessed E. coli or TTC including those identified by a systematic review (n = 345). Predictive models for the presence and level of contamination of drinking water sources were developed using random effects logistic regression and selected covariates. We assessed sensitivity of estimated exposure to study quality, indicator bacteria and separately considered nationally randomised surveys. Results: We estimate that 1.8 billion people globally use a source of drinking water which suffers from faecal contamination, of these 1.1 billion drink water that is of at least 'moderate' risk (>10 E. coli or TTC per 100 ml). Data from nationally randomised studies suggest that 10% of improved sources may be 'high' risk, containing at least 100 E. coli or TTC per 100 ml. Drinking water is found to be more often contaminated in rural areas (41%, CI: 31%-51%) than in urban areas (12%, CI: 8-18%), and contamination is most prevalent in Africa (53%, CI: 42%-63%) and South-East Asia (35%, CI: 24%-45%). Estimates were not sensitive to the exclusion of low quality studies or restriction to studies reporting E. coli. Conclusions: Microbial contamination is widespread and affects all water source types, including piped supplies. Global burden of disease estimates may have substantially understated the disease burden associated with inadequate water services

Global Trends in the Status of Bird and Mammal Pollinators

Biodiversity is declining, with direct and indirect effects on ecosystem func-tions and services that are poorly quantified. Here, we develop the first globalassessment of trends in pollinators, focusing on pollinating birds and mam-mals. A Red List Index for these species shows that, overall, pollinating birdand mammal species are deteriorating in status, with more species movingtoward extinction than away from it. On average, 2.5 species per year havemoved one Red List category toward extinction in recent decades, represent-ing a substantial increase in the extinction risk across this set of species. Thismay be impacting the delivery of benefits that these species provide to people.We recommend that the index be expanded to include taxonomic groups thatcontribute more significantly to pollination, such as bees, wasps, and butter-flies, thereby giving a more complete picture of the state of pollinating speciesworldwide