567 research outputs found

    Independent Evaluation of the BioSand Water Filter In Rural Cambodia: Sustainability, Health Impact and Water Quality Improvement

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    The United Nation's 7th Millennium Development Goal aims to reduce by half the number of people without sustainable access to safe drinking water. Safe water is critical to preventing diarrheal disease, which kills 2 million children annually. A promising household water treatment technology is the BioSand water filter (BSF), an intermittent slow sand filter that is locally made in Cambodia and several other developing countries. The BSF however, lacks adequate characterization and rigorous epidemiological evidence on its performance. The purpose of this research was to assess: (1) the factors associated with filter use and disuse by using a cross-sectional survey (2), the microbiological effectiveness of the BioSand filters still being used by reduced E. coli, and (3), the health impact of the BioSand filters as determined by a longitudinal, prospective cohort study in which diarrheal disease prevalence was measured among people in filter (intervention) households versus people in matched non-filter, control households.Master of Public Healt

    Stoichiometry and thickness dependence of superconducting properties of niobium nitride thin films

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    The current technology used in linear particle accelerators is based on superconducting radio frequency (SRF) cavities fabricated from bulk niobium (Nb), which have smaller surface resistance and therefore dissipate less energy than traditional nonsuperconducting copper cavities. Using bulk Nb for the cavities has several advantages, which are discussed elsewhere; however, such SRF cavities have a material-dependent accelerating gradient limit. In order to overcome this fundamental limit, a multilayered coating has been proposed using layers of insulating and superconducting material applied to the interior surface of the cavity. The key to this multilayered model is to use superconducting thin films to exploit the potential field enhancement when these films are thinner than their London penetration depth. Such field enhancement has been demonstrated in MgB2 thin films; here, the authors consider films of another type-II superconductor, niobium nitride (NbN). The authors present their work correlating stoichiometry and superconducting properties in NbN thin films and discuss the thickness dependence of their superconducting properties, which is important for their potential use in the proposed multilayer structure. While there are some previous studies on the relationship between stoichiometry and critical temperature T-C, the authors are the first to report on the correlation between stoichiometry and the lower critical field H-C1. (C) 2016 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)

    Experimental Correlation between Nonlinear Optical and Magnetotransport Properties Observed in Au-Co Thin Films

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    Magnetic materials where at least one dimension is in the nanometer scale typically exhibit different magnetic, magnetotransport, and magnetooptical properties compared to bulk materials. Composite magnetic thin films where the matrix composition, magnetic cluster size, and overall composite film thickness can be experimentally tailored via adequate processing or growth parameters offer a viable nanoscale platform to investigate possible correlations between nonlinear magnetooptical and magnetotransport properties, since both types of properties are sensitive to the local magnetization landscape. It has been shown that the local magnetization contrast affects the nonlinear magnetooptical properties as well as the magnetotransport properties in magnetic-metal/nonmagnetic metal multilayers; thus, nanocomposite films showcase another path to investigate possible correlations between these distinct properties which may prove useful for sensing applications

    Evaluation of the Impact of the Plastic BioSand Filter on Health and Drinking Water Quality in Rural Tamale, Ghana

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    A randomized controlled trial of the plastic BioSand filter (BSF) was performed in rural communities in Tamale (Ghana) to assess reductions in diarrheal disease and improvements in household drinking water quality. Few studies of household water filters have been performed in this region, where high drinking water turbidity can be a challenge for other household water treatment technologies. During the study, the longitudinal prevalence ratio for diarrhea comparing households that received the plastic BSF to households that did not receive it was 0.40 (95% confidence interval: 0.05, 0.80), suggesting an overall diarrheal disease reduction of 60%. The plastic BSF achieved a geometric mean reduction of 97% and 67% for E. coli and turbidity, respectively. These results suggest the plastic BSF significantly improved drinking water quality and reduced diarrheal disease during the short trial in rural Tamale, Ghana. The results are similar to other trials of household drinking water treatment technologies

    The operation, flow conditions and microbial reductions of an intermittently operated, household-scale slow sand filter

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    Nearly one-fifth of the world\u27s population lacks access to safe, reliable sources of drinking water. Point of use (POU) household water treatment technology allows people to improve the quality of their water by treating it in the home. A promising emerging POU technology is the biosand filter (BSF). The BSF is a household-scale, intermittently operated slow sand filter that maintains a wet media bed containing a schmutzdecke and allows periodic water dosing by the user. Step input chemical tracer tests indicated that the BSF operates at near-plug flow conditions. Six-to-eight week longitudinal challenge studies were conducted with daily charges of surface water spiked with E. coli strain B bacteria, coliphages MS2 and PRD-1 and human enteric virus echovirus type 12. The BSF ripened in a manner similar to conventional SSFs. Flow rate slowed and microbial reductions improved over time with ripening. E. coli reductions were ~90% following filter startup but improved to 95—99.5% over time. Microbial reductions were greater with greater residence time within the filter, especially for water retained in the filter bed overnight. E. coli and echovirus 12 reductions were greater than those of coliphages MS2 and PRD-1

    Dielectric study of electrolyzed rubber

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    Rubber was produced by placing rubber latex between two electrodes between which an external voltage was maintained. The thickness of the rubber deposited on the anode was measured as a function of time of electrolysis, voltage applied across the electrodes and distance between the electrodes. Based on the observed dielectric responses of rubber obtained through the electrolysis process, an electrical model of conductance and complex capacitance elements linked in parallel is proposed, indicating the additive nature of the individual responses in the system. Electrical representation of rubber obtained by simple drying however showed two different models. Natural rubber was found to have all the elements connected in parallel while that of vulcanized rubber was found to have a series connection of a pair of parallel connected conductance and capacitance elements

    The prediction of fatigue using speech as a biosignal

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    Automatic systems for estimating operator fatigue have application in safety-critical environments. We develop and evaluate a system to detect fatigue from speech recordings collected from speakers kept awake over a 60-hour period. A binary classification system (fatigued/not-fatigued) based on time spent awake showed good discrimination, with 80 % unweighted accuracy using raw features, and 90 % with speaker-normalized features. We describe the data collection, feature analysis, machine learning and cross-validation used in the study. Results are promising for real-world applications in domains such as aerospace, transportation and mining where operators are in regular verbal communication as part of their normal working activities

    Substance Use Patterns Among Women Living with HIV Compared with the General Female Population of Canada

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    BACKGROUND: HIV infection and substance use synergistically impact health outcomes of people with HIV. In this study, we assessed the prevalence of substance use among women living with HIV (WLWH) and compared them with expected values from general data. METHODS: Cigarette smoking, frequency of alcohol consumption, last-month non-prescribed cannabis use (vs. last-year use), and last 3 months regular (≥once/week) and occasional ( RESULTS: Compared to expected estimates from general population women, a higher proportion of WLWH reported daily cigarette smoking (SPD: 26.8% [95% CI: 23.9, 29.7]), smoking ≥20 cigarettes/day (SPD: 11.6% [9.8, 13.6]), regular non-prescribed cannabis use (SPD: 8.0% [4.1, 8.6]), regular crack/cocaine use (SPD: 16.7% [13.1, 20.9]), regular/occasional speed use (SPD: 2.4% [1.2, 4.7]), and heroin use (SPD: 11.2% [8.3, 15.0]). However, WLWH reported lower frequencies of alcohol consumption and binge drinking than their counterparts in the general population. CONCLUSIONS: Cigarette smoking and illicit drug use, but not alcohol use or binge drinking, were more prevalent in WLWH than would be expected for Canadian women with a similar age and ethnoracial group profile. These findings may indicate the need for women-centered harm reduction programs to improve health outcomes of WLWH in Canada

    Gene and protein expression of glucose transporter 1 and glucose transporter 3 in human laryngeal cancer—the relationship with regulatory hypoxia-inducible factor-1α expression, tumor invasiveness, and patient prognosis

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    Increased glucose uptake mediated by glucose transporters and reliance on glycolysis are common features of malignant cells. Hypoxia-inducible factor-1α supports the adaptation of hypoxic cells by inducing genes related to glucose metabolism. The contribution of glucose transporter (GLUT) and hypoxia-inducible factor-1α (HIF-1α) activity to tumor behavior and their prognostic value in head and neck cancers remains unclear. The aim of this study was to examine the predictive value of GLUT1, GLUT3, and HIF-1α messenger RNA (mRNA)/protein expression as markers of tumor aggressiveness and prognosis in laryngeal cancer. The level of hypoxia/metabolic marker genes was determined in 106 squamous cell laryngeal cancer (SCC) and 73 noncancerous matched mucosa (NCM) controls using quantitative realtime PCR. The related protein levels were analyzed by Western blot. Positive expression of SLC2A1, SLC2A3, and HIF-1α genes was noted in 83.9, 82.1, and 71.7 % of SCC specimens and in 34.4, 59.4, and 62.5 % of laryngeal cancer samples. Higher levels of mRNA/protein for GLUT1 and HIF-1α were noted in SCC compared to NCM (p<0.05). SLC2A1 was found to have a positive relationship with grade, tumor front grading (TFG) score, and depth and mode of invasion (p<0.05). SLC2A3 was related to grade and invasion type (p<0.05). There were also relationships of HIF-1α with pTNM, TFG scale, invasion depth and mode, tumor recurrences, and overall survival (p<0.05). In addition, more advanced tumors were found to be more likely to demonstrate positive expression of these proteins. In conclusion, the hypoxia/metabolic markers studied could be used as molecular markers of tumor invasiveness in laryngeal cancer.This work was supported, in part, by the statutory fund of the Department of Cytobiochemistry, University of Łódź, Poland (506/811), and by grant fromtheNational Science Council, Poland (N403 043 32/2326)
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