Water, Sanitation and Hygiene: Interventions and Diarrhoea - A Systematic Review and Meta-analysis

This paper provides a formal systematic review and meta-analysis examining the evidence of the effectiveness of interventions intended to reduce illness through improvements in drinking water, sanitation facilities and hygiene practices. The comprehensive literature search and bibliographic review shows that in developing countries, water quality interventions, specifically point-of-use treatment, reduced diarrhea illness levels, but this effect was mainly seen with the provision of household connections and use of water without household storage. Hygiene interventions, especially those promoting hand-washing, were effective. Only limited data were available for sanitation interventions, but these suggested effectiveness in reducing diarrhea. Multifactorial interventions consisting of water supply, sanitation and hygiene education acted to reduce diarrhea but were not more effective than individual interventions

Alien Registration- Colford, Arthur (Waterville, Kennebec County)

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Friedel-Crafts Polymers Containing Thiophen

The reaction between p-di(chloromethyl) benzene (DCMB) and thiophen, catalysed by stannic chloride, has been studied with a view to elucidating the kinetics and mechanism of the reaction. In this way it was hoped to gain a clearer insight into the structure of the resultant polymer and so to account for its reported thermal stability. By studying the rate of production of involatile material it was established that the self-polymerisation of thiophen would have little or no effect on the DCMB-thiophen reaction. Analyses of these involatile materials were carried out using I.R., U-V and n. m. r. spectroscopy and molecular weight determinations. The rate of selfcondensation of DCMB was also found to be negligable, by studying the rate of evolution of HCl from DCMB-SnCl4 mixtures. Products of the DCMB-thiophen reaction, with molecular weights up to 850, have been separated using both gas liquid chromatography (GLC) and gel permeation chromatography (GPC), and identified using mass, I.R. and n. m. r. spectroscopy. A total of eight reaction products were separated and identified. However the techniques available did not permit separation and identification of products of molecular weight greater than 850 or an estimation of the extent of isomerism among the reaction products. A kinetic analysis of the reaction was carried out using both GLC and GPC for the separation and analysis of products. Using GLC the dependence of the rate of the first two reactions on the first power of the concentration of each of the reactants was established. This allowed a mechanism for the overall reaction to be proposed and rate constants and activation. energies for the first two steps in the polymerisation to be calculated. From the GPC results reaction curves for all the identified products were constructed. The extremely complex nature of the reaction and the resultant products prevented a complete kinetic analysis of the later stages of the reaction being made. It was possible, however, to arrive at semi-quantitative conclusions about the relative reactivity of the reaction products and hence construct a useful picture of the structure of the resultant polymer. Polymers were also prepared by reaction of DCMB with thiophen, 2-methyl thiophen, 3-meihyl thiophen, 2.5-dimethyl thiophen and 2-chlorothiophen and an assessment was made of their relative stabilities using both thermal gravimetric analysis and thermal volatilisation analysis. I.R. spectroscopy indicated that all the polymers had the same basic structure and so it was possible to correlate the observed degradative features with the differences in the thiophen monomers. These studies have allowed the following conclusions to be drawn concerning the reaction of DCMB with thiophen and the structure of the resultant polymer. The overall reaction may be represented by a series of competing, consecutive reactions of the type, As the reaction proceeds it rapidly becomes highly complex with a proliferation of isomers at each molecular level being brought about by the onset of branching through the disubstituted thiophen nuclei of the products The ultimate polymer has been shown to be a highly cross-linked, insoluble material which exhibits good thermal stability in vacuum, inert atmospheres and air

Deflection and frequency monitoring of the Forth Road Bridge, Scotland, by GPS

Permission is granted by ICE Publishing to print one copy for personal use. Any other use of these PDF files is subject to reprint fees. Copyright © 2012 Thomas Telford Ltd.The use of carrier phase kinematic GPS (global positioning system) has evolved into a reliable technique to measure both the three-dimensional magnitudes and frequencies of movements of structures. Techniques have been developed that tackle errors caused by multipath, tropospheric delay and issues relating to satellite geometry. GPS-derived movements compare well with data from both design predictions and structural models. Results from field trials carried out on the Forth Road Bridge are presented. This paper brings together key results that outline the procedure as well as a series of new data that indicate other potential applications. GPS data were collected continuously over a period of 46 h at a minimum rate of 10 Hz. During the trials wind speed, wind direction, relative humidity and temperature were also recorded. Frequently there was very heavy traffic flow, and at one point a special load (a 100-t lorry) passed over simultaneously to the heavy daytime flow of traffic. Data from a planned load trial during a brief bridge closure are reported and compared with the limited results available from a finite element model. Measured vibration frequencies are also computed from GPS data and compared with those given in the literature. In addition, results indicating the change in structural characteristics are also presented – in particular changes of mass associated with changes in traffic loading are observed. The results show the performance of GPS as it has developed in recent years, and that it can now reliably be used as a significant part of structural health monitoring schemes, giving both the magnitude of quasi-static deflections in known time periods and hence the frequency of dynamic movements of structures.Forth Estuary Transport Authorit

Evaluation of a pre-existing, 3-year household water treatment and handwashing intervention in rural Guatemala

Background The promotion of household water treatment and handwashing with soap has led to large reductions in child diarrhoea in randomized efficacy trials. Currently, we know little about the health effectiveness of behaviour-based water and hygiene interventions after the conclusion of intervention activities. Methods We present an extension of previously published design (propensity score matching) and analysis (targeted maximum likelihood estimation) methods to evaluate the behavioural and health impacts of a pre-existing but non-randomized intervention (a 3-year, combined household water treatment and handwashing campaign in rural Guatemala). Six months after the intervention, we conducted a cross-sectional cohort study in 30 villages (15 intervention and 15 control) that included 600 households, and 929 children <5 years of age. Results The study design created a sample of intervention and control villages that were comparable across more than 30 potentially confounding characteristics. The intervention led to modest gains in confirmed water treatment behaviour [risk difference = 0.05, 95% confidence interval (CI) 0.02-0.09]. We found, however, no difference between the intervention and control villages in self-reported handwashing behaviour, spot-check hygiene conditions, or the prevalence of child diarrhoea, clinical acute lower respiratory infections or child growth. Conclusions To our knowledge this is the first post-intervention follow-up study of a combined household water treatment and handwashing behaviour change intervention, and the first post-intervention follow-up of either intervention type to include child health measurement. The lack of child health impacts is consistent with unsustained behaviour adoption. Our findings highlight the difficulty of implementing behaviour-based household water treatment and handwashing outside of intensive efficacy trial

Incidence and public health burden of sunburn among beachgoers in the United States.

The beach environment creates many barriers to effective sun protection, putting beachgoers at risk for sunburn, a well-established risk factor for skin cancer. Our objective was to estimate incidence of sunburn among beachgoers and evaluate the relationship between sunburn incidence and sun-protective behaviors. A secondary analysis, of prospective cohorts at 12 locations within the U.S. from 2003 to 2009 (n&nbsp;=&nbsp;75,614), were pooled to evaluate sunburn incidence 10-12&nbsp;days after the beach visit. Behavioral and environmental conditions were cross-tabulated with sunburn incidence. Multivariable logistic regression was used to estimate the association between new sunburn and sun-protective behaviors. Overall, 13.1% of beachgoers reported sunburn. Those aged 13-18&nbsp;years (16.5%), whites (16.0%), and those at beach locations along the Eastern Seaboard (16.1%), had the highest incidence of sunburn. For those spending ≥5&nbsp;h in the sun, the use of multiple types of sun protection reduced odds of sunburn by 55% relative to those who used no sun protection (Odds Ratio&nbsp;=&nbsp;0.45 (95% Confidence Interval:0.27-0.77)) after adjusting for skin type, age, and race. Acute health effects of sunburn tend to be mild and self-limiting, but potential long-term health consequences are more serious and costly. Efforts to encourage and support proper sun-protective behaviors, and increase access to shade, protective clothing, and sunscreen, can help prevent sunburn and reduce skin cancer risk among beachgoers

In-house nucleic acid amplification tests for the detection of Mycobacterium tuberculosis in sputum specimens: meta-analysis and meta-regression

BACKGROUND: More than 200 studies related to nucleic acid amplification (NAA) tests to detect Mycobacterium tuberculosis directly from clinical specimens have appeared in the world literature since this technology was first introduced. NAA tests come as either commercial kits or as tests designed by the reporting investigators themselves (in-house tests). In-house tests vary widely in their accuracy, and factors that contribute to heterogeneity in test accuracy are not well characterized. Here, we used meta-analytical methods, including meta-regression, to identify factors related to study design and assay protocols that affect test accuracy in order to identify those factors associated with high estimates of accuracy. RESULTS: By searching multiple databases and sources, we identified 2520 potentially relevant citations, and analyzed 84 separate studies from 65 publications that dealt with in-house NAA tests to detect M. tuberculosis in sputum samples. Sources of heterogeneity in test accuracy estimates were determined by subgroup and meta-regression analyses. Among 84 studies analyzed, the sensitivity and specificity estimates varied widely; sensitivity varied from 9.4% to 100%, and specificity estimates ranged from 5.6% to 100%. In the meta-regression analysis, the use of IS6110 as a target, and the use of nested PCR methods appeared to be significantly associated with higher diagnostic accuracy. CONCLUSION: Estimates of accuracy of in-house NAA tests for tuberculosis are highly heterogeneous. The use of IS6110 as an amplification target, and the use of nested PCR methods appeared to be associated with higher diagnostic accuracy. However, the substantial heterogeneity in both sensitivity and specificity of the in-house NAA tests rendered clinically useful estimates of test accuracy difficult. Future development of NAA-based tests to detect M. tuberculosis from sputum specimens should take into consideration these findings in improving accuracy of in-house NAA tests