743 research outputs found

    The microbiological quality of rainwater used for toilet flushing, cleaning and watering the garden- pilot study 2005

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    Regenwater opgevangen in reservoirs en toegepast voor onder andere toiletspoeling is vaak fecaal verontreinigd en bevat soms ziekteverwekkende bacterien. Om het infectierisico bij toepassing van dit water te kunnen schatten is aanvullend onderzoek nodig waarbij ziekteverwekkers worden gekwantificeerd en getypeerd en waarbij onderzocht wordt in welke mate gebruikers worden blootgesteld aan het besmette water.Regenwater is aanvankelijk onbesmet, maar bij afstromen langs oppervlakken en tijdens opslag in reservoirs kan besmetting optreden met micro-organismen die ziekte bij de mens kunnen veroorzaken. Dit kan gebeuren wanneer bijvoorbeeld vogelfeces van het dak wordt gespoeld of ratten of andere dieren toegang hebben tot het reservoir of open leidingen. Onderzoek van opgevangen hemelwater op vier verschillende locaties in Nederland toonde de aanwezigheid van de indicatoren voor fecale verontreiniging, bacterien van de coligroep, E. coli en enterococcen, in respectievelijk 28, 27 en 27 van de 28 onderzochte monsters aan. De potentieel ziekteverwekkende bacterien Campylobacter en Legionella pneumophila werden elk een maal op een locatie aangetroffen. Aeromonas en Clostridium perfringens, die ook ziekte bij de mens kunnen veroorzaken, werden in respectievelijk 20 en 23 van de 28 monsters gevonden. Salmonella en Vibrio werden op geen van de locaties aangetroffen. De aanwezigheid van ziekteverwekkende micro-organismen in regenwater toegepast voor toiletspoeling kan negatieve gevolgen voor de volksgezondheid hebben. Op basis van de verkregen resultaten is het nog niet mogelijk om het risico op het oplopen van een infectie bij blootstelling aan dit water te schatten omdat daarvoor nog aanvullende typerings- en blootstellingsgegevens nodig zijn.Rainwater collected in reservoirs and used for toilet flushing, for example, is often fecally contaminated and sometimes contains pathogenic bacteria. Estimating risk of infection caused by use of this water, will require additional research for enumerating and typing pathogens and for determining exposure to the contaminated water. Rainwater at the source is not contaminated with potential human pathogenic micro-organisms, but may become so at surface run-off and during storage in containers. This may occur when bird faeces runs off roofs, or rats or other animals have access to rainwater reservoirs or open mains. Examination of collected rainwater at four different sites in the Netherlands showed the presence of faecal indicator bacteria as total coliforms, E. coli and intestinal enterococci in 28, 27 and 27, respectively, of the 28 samples examined. Each of the potential human pathogenic bacteria, Campylobacter and Legionella pneumophila, was detected once at one sampling site. Aeromonas and Clostridium perfringens, which may also cause disease in humans, were detected in 20 and 23 of the 28 tested samples, respectively. Salmonella and Vibrio were not detected in any of the samples. The presence of potential pathogenic micro-organisms in rainwater used for toilet flushing may have adverse health effects. However, on the basis of the above results, and because additional typing and exposure data are required, it is not yet possible to estimate the risk of infection at exposure to this water.VROM Inspecti

    The microbiological quality of rainwater used for toilet flushing, cleaning and watering the garden- pilot study 2005

    Get PDF
    Rainwater collected in reservoirs and used for toilet flushing, for example, is often fecally contaminated and sometimes contains pathogenic bacteria. Estimating risk of infection caused by use of this water, will require additional research for enumerating and typing pathogens and for determining exposure to the contaminated water. Rainwater at the source is not contaminated with potential human pathogenic micro-organisms, but may become so at surface run-off and during storage in containers. This may occur when bird faeces runs off roofs, or rats or other animals have access to rainwater reservoirs or open mains. Examination of collected rainwater at four different sites in the Netherlands showed the presence of faecal indicator bacteria as total coliforms, E. coli and intestinal enterococci in 28, 27 and 27, respectively, of the 28 samples examined. Each of the potential human pathogenic bacteria, Campylobacter and Legionella pneumophila, was detected once at one sampling site. Aeromonas and Clostridium perfringens, which may also cause disease in humans, were detected in 20 and 23 of the 28 tested samples, respectively. Salmonella and Vibrio were not detected in any of the samples. The presence of potential pathogenic micro-organisms in rainwater used for toilet flushing may have adverse health effects. However, on the basis of the above results, and because additional typing and exposure data are required, it is not yet possible to estimate the risk of infection at exposure to this water.Regenwater opgevangen in reservoirs en toegepast voor onder andere toiletspoeling is vaak fecaal verontreinigd en bevat soms ziekteverwekkende bacterien. Om het infectierisico bij toepassing van dit water te kunnen schatten is aanvullend onderzoek nodig waarbij ziekteverwekkers worden gekwantificeerd en getypeerd en waarbij onderzocht wordt in welke mate gebruikers worden blootgesteld aan het besmette water.Regenwater is aanvankelijk onbesmet, maar bij afstromen langs oppervlakken en tijdens opslag in reservoirs kan besmetting optreden met micro-organismen die ziekte bij de mens kunnen veroorzaken. Dit kan gebeuren wanneer bijvoorbeeld vogelfeces van het dak wordt gespoeld of ratten of andere dieren toegang hebben tot het reservoir of open leidingen. Onderzoek van opgevangen hemelwater op vier verschillende locaties in Nederland toonde de aanwezigheid van de indicatoren voor fecale verontreiniging, bacterien van de coligroep, E. coli en enterococcen, in respectievelijk 28, 27 en 27 van de 28 onderzochte monsters aan. De potentieel ziekteverwekkende bacterien Campylobacter en Legionella pneumophila werden elk een maal op een locatie aangetroffen. Aeromonas en Clostridium perfringens, die ook ziekte bij de mens kunnen veroorzaken, werden in respectievelijk 20 en 23 van de 28 monsters gevonden. Salmonella en Vibrio werden op geen van de locaties aangetroffen. De aanwezigheid van ziekteverwekkende micro-organismen in regenwater toegepast voor toiletspoeling kan negatieve gevolgen voor de volksgezondheid hebben. Op basis van de verkregen resultaten is het nog niet mogelijk om het risico op het oplopen van een infectie bij blootstelling aan dit water te schatten omdat daarvoor nog aanvullende typerings- en blootstellingsgegevens nodig zijn

    A more active lifestyle in persons with a recent spinal cord injury benefits physical fitness and health

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    Study design:A prospective cohort study. Objectives:To study the longitudinal relationship between objectively measured everyday physical activity level, and physical fitness and lipid profile in persons with a recent spinal cord injury (SCI).Setting:A rehabilitation centre in the Netherlands and the participant's home environment. Methods:Data of 30 persons with a recent SCI were collected at the start of active rehabilitation, 3 months later, at discharge from inpatient rehabilitation, and 1 year after discharge. Physical activity level (duration of dynamic activities as % of 24 h) was measured with an accelerometry-based activity monitor. Regarding physical fitness, peak oxygen uptake (VO2peak) and peak power output (POpeak) were determined with a maximal wheelchair exercise test, and upper extremity muscle strength was measured with a handheld dynamometer. Fasting blood samples were taken to determine the lipid profile. Results:An increase in physical activity level was significantly related to an increase in VO2peak and POpeak, and an increase in physical activity level favourably affected the lipid profile. A nonsignificant relation was found with muscle strength. Conclusion:Everyday physical activity seems to have an important role in the fitness and health of persons with a recent SCI. An increase in physical activity level was associated with an increase in physical fitness and with a lower risk of cardiovascular disease.Spinal Cord advance online publication, 6 December 2011; doi:10.1038/sc.2011.152

    Metal–organic complexation in the marine environment

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    We discuss the voltammetric methods that are used to assess metal–organic complexation in seawater. These consist of titration methods using anodic stripping voltammetry (ASV) and cathodic stripping voltammetry competitive ligand experiments (CSV-CLE). These approaches and a kinetic approach using CSV-CLE give similar information on the amount of excess ligand to metal in a sample and the conditional metal ligand stability constant for the excess ligand bound to the metal. CSV-CLE data using different ligands to measure Fe(III) organic complexes are similar. All these methods give conditional stability constants for which the side reaction coefficient for the metal can be corrected but not that for the ligand. Another approach, pseudovoltammetry, provides information on the actual metal–ligand complex(es) in a sample by doing ASV experiments where the deposition potential is varied more negatively in order to destroy the metal–ligand complex. This latter approach gives concentration information on each actual ligand bound to the metal as well as the thermodynamic stability constant of each complex in solution when compared to known metal–ligand complexes. In this case the side reaction coefficients for the metal and ligand are corrected. Thus, this method may not give identical information to the titration methods because the excess ligand in the sample may not be identical to some of the actual ligands binding the metal in the sample

    Vitamin G: effects of green space on health, well-being, and social safety

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    BACKGROUND: Looking out on and being in the green elements of the landscape around us seem to affect health, well-being and feelings of social safety. This article discusses the design of a research program on the effects of green space in the living environment on health, well-being and social safety. METHODS/DESIGN: The program consists of three projects at three different scales: at a macro scale using data on the Netherlands as a whole, at an intermediate scale looking into the specific effect of green space in the urban environment, and at micro scale investigating the effects of allotment gardens. The projects are observational studies, combining existing data on land use and health interview survey data, and collecting new data through questionnaires and interviews. Multilevel analysis and GIS techniques will be used to analyze the data. DISCUSSION: Previous (experimental) research in environmental psychology has shown that a natural environment has a positive effect on well-being through restoration of stress and attentional fatigue. Descriptive epidemiological research has shown a positive relationship between the amount of green space in the living environment and physical and mental health and longevity. The program has three aims. First, to document the relationship between the amount and type of green space in people's living environment and their health, well-being, and feelings of safety. Second, to investigate the mechanisms behind this relationship. Mechanisms relate to exposure (leading to stress reduction and attention restoration), healthy behavior and social integration, and selection. Third, to translate the results into policy on the crossroads of spatial planning, public health, and safety. Strong points of our program are: we study several interrelated dependent variables, in different ordinary settings (as opposed to experimental or extreme settings), focusing on different target groups, using appropriate multilevel methods

    A flexible framework for sparse simultaneous component based data integration

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    <p>Abstract</p> <p>1 Background</p> <p>High throughput data are complex and methods that reveal structure underlying the data are most useful. Principal component analysis, frequently implemented as a singular value decomposition, is a popular technique in this respect. Nowadays often the challenge is to reveal structure in several sources of information (e.g., transcriptomics, proteomics) that are available for the same biological entities under study. Simultaneous component methods are most promising in this respect. However, the interpretation of the principal and simultaneous components is often daunting because contributions of each of the biomolecules (transcripts, proteins) have to be taken into account.</p> <p>2 Results</p> <p>We propose a sparse simultaneous component method that makes many of the parameters redundant by shrinking them to zero. It includes principal component analysis, sparse principal component analysis, and ordinary simultaneous component analysis as special cases. Several penalties can be tuned that account in different ways for the block structure present in the integrated data. This yields known sparse approaches as the lasso, the ridge penalty, the elastic net, the group lasso, sparse group lasso, and elitist lasso. In addition, the algorithmic results can be easily transposed to the context of regression. Metabolomics data obtained with two measurement platforms for the same set of <it>Escherichia coli </it>samples are used to illustrate the proposed methodology and the properties of different penalties with respect to sparseness across and within data blocks.</p> <p>3 Conclusion</p> <p>Sparse simultaneous component analysis is a useful method for data integration: First, simultaneous analyses of multiple blocks offer advantages over sequential and separate analyses and second, interpretation of the results is highly facilitated by their sparseness. The approach offered is flexible and allows to take the block structure in different ways into account. As such, structures can be found that are exclusively tied to one data platform (group lasso approach) as well as structures that involve all data platforms (Elitist lasso approach).</p> <p>4 Availability</p> <p>The additional file contains a MATLAB implementation of the sparse simultaneous component method.</p
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