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Sample records for waterborne gemfibrozil challenges

  1. Waterborne Pathogens: Detection Methods and Challenges

    Science.gov (United States)

    Ramírez-Castillo, Flor Yazmín; Loera-Muro, Abraham; Jacques, Mario; Garneau, Philippe; Avelar-González, Francisco Javier; Harel, Josée; Guerrero-Barrera, Alma Lilián

    2015-01-01

    Waterborne pathogens and related diseases are a major public health concern worldwide, not only by the morbidity and mortality that they cause, but by the high cost that represents their prevention and treatment. These diseases are directly related to environmental deterioration and pollution. Despite the continued efforts to maintain water safety, waterborne outbreaks are still reported globally. Proper assessment of pathogens on water and water quality monitoring are key factors for decision-making regarding water distribution systems’ infrastructure, the choice of best water treatment and prevention waterborne outbreaks. Powerful, sensitive and reproducible diagnostic tools are developed to monitor pathogen contamination in water and be able to detect not only cultivable pathogens but also to detect the occurrence of viable but non-culturable microorganisms as well as the presence of pathogens on biofilms. Quantitative microbial risk assessment (QMRA) is a helpful tool to evaluate the scenarios for pathogen contamination that involve surveillance, detection methods, analysis and decision-making. This review aims to present a research outlook on waterborne outbreaks that have occurred in recent years. This review also focuses in the main molecular techniques for detection of waterborne pathogens and the use of QMRA approach to protect public health. PMID:26011827

  2. Gemfibrozil

    Science.gov (United States)

    (jem fi' broe zil) ... recommendations made by your doctor or dietitian. You can also visit the National Cholesterol Education Program (NCEP) ... go away: stomach pain heartburn Some side effects can be serious. If you experience any of these ...

  3. Compound list: gemfibrozil [Open TG-GATEs

    Lifescience Database Archive (English)

    Full Text Available gemfibrozil GFZ 00031 ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Human/in_vitro/gemf...ibrozil.Human.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vitro/gemf...ibrozil.Rat.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Liver/Single/gemf...archive/open-tggates/LATEST/Rat/in_vivo/Liver/Repeat/gemfibrozil.Rat.in_vivo.Liver.Repeat.zip ...

  4. SPECTROPHOTOMETRIC ESTIMATION OF GEMFIBROZIL IN BULK AND PHARMACEUTICAL DOSAGE FORMS

    OpenAIRE

    Parikh Vikas C.; Karkhanis V.V

    2011-01-01

    A simple, sensitive and accurate UV spectrophotometric method has been developed for the determination of Gemfibrozil in bulk and pharmaceutical tablet dosage formulation. This method obeys Beer’s law in the concentration range of 30-90 µg/ml. with correlation coefficient of 0.9993 and exhibiting maximum absorption at 276 nm with apparent molar absorptivity of 0.1703 × 104 L mole-1 cm-1. The method is accurate and precise and is extended to pharmaceutical tablet dosage forms and there was no ...

  5. Metagenomic sequencing for surveillance of food- and waterborne viral diseases

    NARCIS (Netherlands)

    D.F. Nieuwenhuijse (David F.); M.P.G. Koopmans D.V.M. (Marion)

    2017-01-01

    textabstractA plethora of viruses can be transmitted by the food- and waterborne route. However, their recognition is challenging because of the variety of viruses, heterogeneity of symptoms, the lack of awareness of clinicians, and limited surveillance efforts. Classical food- and waterborne viral

  6. DEVELOPMENT OF A YERSINIA RUCKERI O1 BIOTYPE 2 WATERBORNE CHALLENGE MODEL FOR FUTURE ERM VACCINE TESTING IN RAINBOW TROUT

    DEFF Research Database (Denmark)

    Kragelund Strøm, Helene; Aalbæk, Bent; Otani, Maki

    for more than 35 years. Recent years have shown ERM outbreaks caused by Y.r. O1 bt 2 reported from ERM vaccinated farmed rainbow trout stocks in both Europe and the USA. It has been suggested that Y.r. O1 bt 2 is more virulent than bt 1. In order to test this hypothesis we have collected Y.r. O1 isolates...... causing less than 50 % mortality, and a high virulence group causing more than 50 % mortality. Interestingly, all tested bt 1 isolates grouped in the low virulence group together with a few bt 2 isolates. The highly virulent strains were exclusively Y.r. O1 bt 2 strains. The most virulent strain......1 bt 2 has made it possible to develop a standardized bath challenge model which is needed in order to test and develop new experimental vaccines which are expected to induce immunity against Y.r. O1 bt 2....

  7. Comparative bioavailability study with two gemfibrozil tablet formulations in healthy volunteers.

    Science.gov (United States)

    Borges, Ney Carter do C; Mendes, Gustavo Duarte; Barrientos-Astigarraga, Rafael E; Zappi, Eduardo; Mendes, Fabiana Duarte; De Nucci, Gilberto

    2005-01-01

    To assess the bioequivalence of gemfibrozil (CAS 25812-30-0) 900 mg tablet formulation from EMS Farmaceutica as test formulation versus a 900 mg tablet formulation as reference in 36 healthy volunteers of both sexes. The study was conducted using an open, randomized, two-period crossover design with a 1-week washout interval. Plasma samples were obtained over a 24-h period. Plasma gemfibrozil concentrations were analyzed by liquid chromatography coupled to tandem mass spectrometry (LC-MS-MS) with negative ion electrospray ionization using multiple reaction monitoring (MRM). From the gemfibrozil plasma concentration vs time curves, the following pharmacokinetic parameters were obtained: AUClast, AUC(0-inf) and Cmax. The limit of quantification was 0.05 microg/mL for plasma gemfibrozil analysis. The geometric mean and respective 90% confidence interval (CI) of Test/Reference percent ratios were 90.29 (81.39-100.17) for Cmax, 96.26 (90.33-102.59) for AUClast, 96.04 (90.21-102.23) for AUC(0-24 h) and 96.62 (90.82-102.78) for AUC(0-infinity). Since the 90% CI for AUClast, AUC(0-inf) and Cmax, ratios were within the 80-125% interval proposed by the U.S. FDA, it was concluded that gemfibrozil 900 mg tablet (test formulation) was bioequivalent to the 900 mg tablet reference formulation for both rate and extent of absorption.

  8. BACTERIAL WATERBORNE PATHOGENS

    Science.gov (United States)

    Bacterial pathogens are examples of classical etiological agents of waterborne disease. While these agents no longer serve as major threats to U.S. water supplies, they are still important pathogens in areas with substandard sanitation and poor water treatment facilities. In th...

  9. Design and optimization of self-nanoemulsifying drug delivery systems (SNEDDS) for enhanced dissolution of gemfibrozil.

    Science.gov (United States)

    Villar, Ana Maria Sierra; Naveros, Beatriz Clares; Campmany, Ana Cristina Calpena; Trenchs, Monserrat Aróztegui; Rocabert, Coloma Barbé; Bellowa, Lyda Halbaut

    2012-07-15

    Self-nanoemulsifying drug delivery systems of gemfibrozil were developed under Quality by Design approach for improvement of dissolution and oral absorption. Preliminary screening was performed to select proper components combination. Box-Behnken experimental design was employed as statistical tool to optimize the formulation variables, X(1) (Cremophor(®) EL), X(2) (Capmul(®) MCM-C8), and X(3) (lemon essential oil). Systems were assessed for visual characteristics (emulsification efficacy), turbidity, droplet size, polydispersity index and drug release. Different pH media were also assayed for optimization. Following optimization, the values of formulation components (X(1), X(2), and X(3)) were 32.43%, 29.73% and 21.62%, respectively (16.22% of gemfibrozil). Transmission electron microscopy demonstrated spherical droplet morphology. SNEEDS release study was compared to commercial tablets. Optimized SNEDDS formulation of gemfibrozil showed a significant increase in dissolution rate compared to conventional tablets. Both formulations followed Weibull mathematical model release with a significant difference in t(d) parameter in favor of the SNEDDS. Equally amodelistic parameters were calculated being the dissolution efficiency significantly higher for SNEDDS, confirming that the developed SNEDDS formulation was superior to commercial formulation with respect to in vitro dissolution profile. This paper provides an overview of the SNEDDS of the gemfibrozil as a promising alternative to improve oral absorption. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Possible increased risk of rhabdomyolysis during concomitant use of simvastatin and gemfibrozil

    NARCIS (Netherlands)

    VanPuijenbroek, EP; DuBufVereijken, PWG; Spooren, PFMJ; VanDoormaal, JJ

    1996-01-01

    The occurrence of rhabdomyolysis is one of the rare side-effects of the cholesterol-lowering agent simvastatin. During the use of lovastatin, an agent related to simvastatin, the risk of this side-effect might be increased when cyclosporin or gemfibrozil are used concomitantly. It is possible that

  11. Efficacy of gemfibrozil in the primary prevention of atrial fibrillation in a large randomized controlled trial.

    Science.gov (United States)

    Adabag, A Selcuk; Mithani, Salima; Al Aloul, Basel; Collins, Dorothea; Bertog, Stefan; Bloomfield, Hanna E

    2009-05-01

    Peroxisome proliferator-activated receptor alpha (PPARalpha) activators reduce inflammation and oxidative stress. Inflammation plays an important role in the initiation and maintenance of atrial fibrillation (AF). It has been suggested that PPARalpha activators may have antiarrhythmic properties, but no clinical data exist. The objective of this study was to investigate whether the PPARalpha activator gemfibrozil prevents or delays the development of AF in patients with coronary heart disease. We retrospectively analyzed the electrocardiograms (ECGs) performed in the Veterans Affairs High-Density Lipoprotein Cholesterol Intervention Trial, a multicenter, randomized, double-blinded, secondary prevention trial of gemfibrozil and matching placebo. The ECGs were performed annually or biannually and when clinically indicated. Participants who were in AF on baseline ECG were excluded from the present analysis. Relative risk for AF was calculated from Cox regression with death as a competing risk factor. A total of 12,605 ECGs from 2,130 participants were interpreted (5.9 +/- 2.1 ECGs per participant, range 2-20). At baseline, the gemfibrozil (n = 1,070) and placebo (n = 1,060) groups were well matched. Mean age was 64.1 +/- 7.1 years. Over 4.4 +/- 1.5 years of follow-up, 123 (5.8%) participants developed new AF. There was no difference in AF incidence between the gemfibrozil and placebo groups (64/1,070 vs 59/1,060, respectively; P = .33). In Cox regression, the risk of AF was similar between the 2 study groups (hazard ratio 1.04, 95% CI 0.73-1.49, P = .82). In this post hoc analysis of a multicenter, double-blinded, randomized controlled trial, the PPARalpha activator gemfibrozil did not reduce the 4-year incidence of AF among men with coronary heart disease.

  12. Drug–drug Interaction between Pravastatin and Gemfibrozil (Antihyperlipidemic) with Gliclazide (Antidiabetic) in Rats

    Science.gov (United States)

    Sultanpur, CM; Satyanarayana, S; Reddy, NS; Kumar, KE; Kumar, S

    2010-01-01

    Diabetes mellitus is a condition of increased blood glucose level in the body. Antihyperlipidemic drugs like statins and fibrates are widely used for prophylactic treatment in dyslipideamia and atherosclerosis. Diabetic dislipidemia exists with increased triglycerides, low HDL and high LDL levels. Hence, with oral hypoglycemic drugs, the addition of a lipid-lowering drug is necessary for controlling dislipidemia. In such a situation, there may be chances of drug–drug interactions between antidiabetic and antihyperlipidemic drugs. The present study is planned to evaluate the safety of gliclazide (antidiabetic) in the presence of pravastatin and gemfibrozil (antihyperlpidemic) in rats. Studies in normal and alloxan-induced diabetic rats were conducted with oral doses of gliclazide and their combination with pravastatin and gemfibrozil, with an adequate washout period in between the treatments. Blood samples were collected in rats by retroorbital puncture at 0, 1, 2, 3, 4, 6, 8, 10 and 12 h. All the blood samples were analyzed for glucose by GOD –POD. Gliclazide (½ TD) produced hypoglycemic activity in normal and diabetic rats, with peak activity at 2 and 8 h. Pravastatin (TD) + gemfibrozil (TD) combination treatment increased the hypoglycemic effect of gliclazide in normal rats or diabetic rats when administered together. The interaction observed due to inhibition of both the enzymes (CYP 450 2C9 and CYP 450 3A4) responsible for the metabolism of gliclazide showed increased half-life, which was seen in the present study. Because concomitant administration of gliclazide with provastatin and gemfibrozil in diabetes is associated with atherosclerosis, it should be contraindicated or used with caution. PMID:21264118

  13. Drug-drug Interaction between Pravastatin and Gemfibrozil (Antihyperlipidemic) with Gliclazide (Antidiabetic) in Rats.

    Science.gov (United States)

    Sultanpur, Cm; Satyanarayana, S; Reddy, Ns; Kumar, Ke; Kumar, S

    2010-04-01

    Diabetes mellitus is a condition of increased blood glucose level in the body. Antihyperlipidemic drugs like statins and fibrates are widely used for prophylactic treatment in dyslipideamia and atherosclerosis. Diabetic dislipidemia exists with increased triglycerides, low HDL and high LDL levels. Hence, with oral hypoglycemic drugs, the addition of a lipid-lowering drug is necessary for controlling dislipidemia. In such a situation, there may be chances of drug-drug interactions between antidiabetic and antihyperlipidemic drugs. The present study is planned to evaluate the safety of gliclazide (antidiabetic) in the presence of pravastatin and gemfibrozil (antihyperlpidemic) in rats. Studies in normal and alloxan-induced diabetic rats were conducted with oral doses of gliclazide and their combination with pravastatin and gemfibrozil, with an adequate washout period in between the treatments. Blood samples were collected in rats by retroorbital puncture at 0, 1, 2, 3, 4, 6, 8, 10 and 12 h. All the blood samples were analyzed for glucose by GOD -POD. Gliclazide (½ TD) produced hypoglycemic activity in normal and diabetic rats, with peak activity at 2 and 8 h. Pravastatin (TD) + gemfibrozil (TD) combination treatment increased the hypoglycemic effect of gliclazide in normal rats or diabetic rats when administered together. The interaction observed due to inhibition of both the enzymes (CYP 450 2C9 and CYP 450 3A4) responsible for the metabolism of gliclazide showed increased half-life, which was seen in the present study. Because concomitant administration of gliclazide with provastatin and gemfibrozil in diabetes is associated with atherosclerosis, it should be contraindicated or used with caution.

  14. Waterborne outbreaks of cryptosporidiosis

    Directory of Open Access Journals (Sweden)

    Rachel M. Chalmers

    2012-12-01

    Full Text Available Water is the most commonly reported vehicle of transmission in Cryptosporidium outbreaks. While mains drinking water quality is highly regulated in industrialised countries, treated recreational water venues remain highly variable and these have emerged as important settings in the transmission of cryptosporidiosis. Epidemiological investigations of outbreaks benefit from supplementary microbiological evidence and, more recently, the application of molecular typing data to link isolates from cases to each other and to suspected sources. This article documents how waterborne Cryptosporidium outbreaks are identified and reported, how such outbreaks have acted as drivers of regulatory change, and some of the recent developments in the detection and investigation of these outbreaks and their spread, especially the application of molecular typing assays.

  15. Development of saliva-based exposure assays for detecting exposure to waterborne pathogens

    Science.gov (United States)

    Identifying which pathogens we are exposed to can be challenging because many types of pathogens can be found in water and many pathogens have similar symptoms. EPA scientists have developed a simple way to measure human exposure to waterborne pathogens.

  16. Impact of climate change on waterborne diseases

    Directory of Open Access Journals (Sweden)

    Enzo Funari

    2012-12-01

    Full Text Available Change in climate and water cycle will challenge water availability but it will also increase the exposure to unsafe water. Floods, droughts, heavy storms, changes in rain pattern, increase of temperature and sea level, they all show an increasing trend worldwide and will affect biological, physical and chemical components of water through different paths thus enhancing the risk of waterborne diseases. This paper is intended, through reviewing the available literature, to highlight environmental changes and critical situations caused by floods, drought and warmer temperature that will lead to an increase of exposure to water related pathogens, chemical hazards and cyanotoxins. The final aim is provide knowledge-based elements for more focused adaptation measures.

  17. Activation of Sterol Regulatory Element Binding Factors by Fenofibrate and Gemfibrozil Stimulate Myelination in Zebrafish

    Directory of Open Access Journals (Sweden)

    Yuhei Nishimura

    2016-07-01

    of zebrafish with another PPARα agonist, gemfibrozil, also increased expression of the mbp promoter-driven fluorescent reporter in an SREBF-dependent manner. These results suggest that activation of SREBFs by small molecular weight compounds may be a feasible therapeutic approach to stimulate myelination.

  18. Effect of gemfibrozil, rifampicin, or probenecid on the pharmacokinetics of the SGLT2 inhibitor empagliflozin in healthy volunteers.

    Science.gov (United States)

    Macha, Sreeraj; Koenen, Rüdiger; Sennewald, Regina; Schöne, Katja; Hummel, Noemi; Riedmaier, Stephan; Woerle, Hans J; Salsali, Afshin; Broedl, Uli C

    2014-02-01

    Empagliflozin is a potent, oral, selective inhibitor of sodium glucose cotransporter 2 in development for the treatment of type 2 diabetes mellitus. The goal of these studies was to investigate potential drug-drug interactions between empagliflozin and gemfibrozil (an organic anion-transporting polypeptide 1B1 [OATP1B1]/1B3 and organic anion transporter 3 [OAT3] inhibitor), rifampicin (an OATP1B1/1B3 inhibitor), or probenecid (an OAT3 and uridine diphosphate glucuronosyltransferase inhibitor). Two open-label, randomized, crossover studies were undertaken in healthy subjects. In the first study, 18 subjects received the following in 1 of 2 randomized treatment sequences: a single dose of empagliflozin 25 mg alone and gemfibrozil 600 mg BID for 5 days with a single dose of empagliflozin 25 mg on the third day. In the second study, 18 subjects received a single dose of empagliflozin 10 mg, a single dose of empagliflozin 10 mg coadministered with a single dose of rifampicin 600 mg, and probenecid 500 mg BID for 4 days with a single dose of empagliflozin 10 mg on the second day in 1 of 6 randomized treatment sequences. In the gemfibrozil study, 11 subjects were male, mean age was 35.1 years and mean body mass index (BMI) was 23.47 kg/m(2). In the rifampicin/probenecid study, 10 subjects were male, mean age was 32.7 years and mean BMI was 23.03 kg/m(2). Exposure to empagliflozin was increased by coadministration with gemfibrozil (AUC0-∞: geometric mean ratio [GMR], 158.50% [90% CI, 151.77-165.53]; Cmax: GMR, 115.00% [90% CI, 106.15-124.59]), rifampicin (AUC0-∞: GMR, 135.20% [90% CI, 129.58-141.06]; Cmax: GMR, 175.14% [90% CI, 160.14-191.56]), and probenecid (AUC0-∞: GMR, 153.47% [90% CI, 146.41-160.88]; Cmax: GMR, 125.60% [90% CI, 113.67-138.78]). All treatments were well tolerated. Increases in empagliflozin exposure were probenecid. ClinicalTrials.gov identifiers: NCT01301742 and NCT01634100. Copyright © 2014 Elsevier HS Journals, Inc. All rights reserved.

  19. Towards Actionable Waterborne and Vector-borne Disease Forecasts

    Science.gov (United States)

    Zaitchik, B. F.

    2015-12-01

    Numerous studies have shown that remote sensing (RS) and Earth System Models (ESM) can make important contributions to the analysis, monitoring and prediction of waterborne and vector-borne illnesses. Unsurprisingly, however, the great majority of these studies have been proof-of-concept investigations, and vanishingly few have been translated into operational and utilized disease early warning systems. To some extent this is simply an example of the general challenge of translating research findings into decision-relevant operations. Disease early warning, however, entails specific challenges that distinguish it from many other fields of environmental monitoring and prediction. Some of these challenges stem from predictability and data constraints, while others relate to the difficulty of communicating predictions and the particularly high price of false alarms. This presentation will review progress on the translation of analysis to decision making, identify avenues for enhancing forecast utility, and propose priorities for future RS and ESM investments in disease monitoring and prediction.

  20. Persistent Norovirus Contamination of Groundwater Supplies in Two Waterborne Outbreaks.

    Science.gov (United States)

    Kauppinen, Ari; Pitkänen, Tarja; Miettinen, Ilkka T

    2018-03-01

    Microbiological contamination of groundwater supplies causes waterborne outbreaks worldwide. In this study, two waterborne outbreaks related to microbiological contamination of groundwater supplies are described. Analyses of pathogenic human enteric viruses (noroviruses and adenoviruses), fecal bacteria (Campylobacter spp. and Salmonella spp.), and indicator microbes (E. coli, coliform bacteria, intestinal enterococci, Clostridium perfringens, heterotrophic plate count, somatic and F-specific coliphages) were conducted in order to reveal the cause of the outbreaks and to examine the effectiveness of the implemented management measures. Moreover, the long-term persistence of noro- and adenovirus genomes was investigated. Noroviruses were detected in water samples from both outbreaks after the intrusion of wastewater into the drinking water sources. In the outbreak I, the removal efficiency of norovirus genome (3.0 log 10 removal) in the sand filter of onsite wastewater treatment system (OWTS) and during the transport through the soil into the groundwater well was lower than the removal efficiencies of E. coli, coliform bacteria, intestinal enterococci, and spores of C. perfringens (6.2, 6.0, > 5.9, and > 4.8 log 10 removals, respectively). In the outbreak II, cleaning of massively contaminated groundwater well and drinking water distribution network proved challenging, and noro- and adenovirus genomes were detected up to 3 months (108 days). The long-term persistence study showed that noro- and adenovirus genomes can remain detectable in the contaminated water samples up to 1277 and 1343 days, respectively. This study highlights the transport and survival properties of enteric viruses in the environment explaining their potency to cause waterborne outbreaks.

  1. Long-term safety and efficacy of combination gemfibrozil and HMG-CoA reductase inhibitors for the treatment of mixed lipid disorders.

    Science.gov (United States)

    Murdock, D K; Murdock, A K; Murdock, R W; Olson, K J; Frane, A M; Kersten, M E; Joyce, D M; Gantner, S E

    1999-07-01

    Combinations of gemfibrozil and a 3-hydroxy-3-methylglutaryl (HMG) coenzyme A reductase inhibitor show promise in treating mixed lipid abnormalities. However, concern regarding the risk of myopathy and hepatic toxicity has limited the use of this combination. To determine the long-term safety and efficacy of this combination, we prospectively identified all patients placed on a combination of gemfibrozil and any HMG reductase inhibitor. Pravastatin, simvastatin, fluvastatin, lovastatin, or atorvastatin at incremental doses was combined with gemfibrozil (600 mg twice daily). Lipid profiles, creatine kinase levels, and aminotransferase levels were monitored. Two hundred fifty-two patients with established atherosclerosis receiving combination therapy for a mean of 2.36 +/- 1.52 years spanning a total of 593.6 patient-years were monitored. In 148 patients, gemfibrozil was started before an HMG was added. The pretreatment total cholesterol level fell from 222 +/- 34 mg/dL to 181 +/- 26 mg/dL (P <.001) on combination therapy. HDL cholesterol level rose from 30 +/- 5 mg/dL to 36 +/- 7 mg/dL (P <.01), triglyceride level fell from 361 +/- 141 mg/dL to 212 +/- 101 mg/dL (P <.03). The ratio of total cholesterol to HDL fell from 7.6 +/- 1. 7 to 5.3 +/- 1.6 (P <.001). In 104 patients an HMG was begun before gemfibrozil was added. Pretreatment total cholesterol level fell from 246 +/- 54 mg/dL to 192 +/- 40 mg/dL on combination therapy (P <.01). HDL level rose from 33 +/- 9 mg/dL to 38 +/- 9 mg/dL (P <.03) and triglyceride level fell from 314 +/- 183 mg/dL to 183 +/- 93 mg/dL (P <.001). The ratio of total cholesterol to HDL fell from 7.9 +/- 3.6 to 5.2 +/- 1.4 (P <.001). In both groups the lipid profile on combination therapy was significantly better than that obtained on single-agent therapy. One episode of myopathy (0.4%) and one episode of aminotransferase level elevation (0.4%) of greater than 3 times upper limit of normal occurred. Both resolved with cessation of therapy

  2. waterborne South Africa Canoeists and diseases in

    African Journals Online (AJOL)

    waterborne. South Africa. Canoeists and diseases in. C. c. APPLETON, I. W. BAILEY. Summary. The prevalence of urinary schistosomiasis (Schistosoma haematobium) in canoeists in South Africa was estimated from examinations of urine samples taken from participants in the 1988 and 1989 Duzi Canoe Marathons on the ...

  3. Facile approach to fabricate waterborne polyaniline nanocomposites with environmental benignity and high physical properties

    Science.gov (United States)

    Wang, Haihua; Wen, Huan; Hu, Bin; Fei, Guiqiang; Shen, Yiding; Sun, Liyu; Yang, Dong

    2017-03-01

    Waterborne polyaniline (PANI) dispersion has got extensive attention due to its environmental friendliness and good processability, whereas the storage stability and mechanical property have been the challenge for the waterborne PANI composites. Here we prepare for waterborne PANI dispersion through the chemical graft polymerisation of PANI into epichlorohydrin modified poly (vinyl alcohol) (EPVA). In comparison with waterborne PANI dispersion prepared through physical blend and in situ polymerisation, the storage stability of PANI-g-EPVA dispersion is greatly improved and the dispersion keeps stable for one year. In addition, the as-prepared PANI-g-EPVA film displays more uniform and smooth morphology, as well as enhanced phase compatibility. PANI is homogeneously distributed in the EPVA matrix on the nanoscale. PANI-g-EPVA displays different morphology at different aniline content. The electrical conductivity corresponds to 7.3 S/cm when only 30% PANI is incorporated into the composites, and then increases up to 20.83 S/cm with further increase in the aniline content. Simultaneously, the tensile strength increases from 35 MPa to 64 MPa. The as-prepared PANI-g-EPVA dispersion can be directly used as the conductive ink or coatings for cellulose fibre paper to prepare flexible conductive paper with high conductivity and mechanical property, which is also suitable for large scalable production.

  4. Rapid oxidation of ring methyl groups is the primary mechanism of biotransformation of gemfibrozil by the fungus Cunninghamella elegans.

    Science.gov (United States)

    Kang, Su-Il; Kang, Seo-Young; Kanaly, Robert A; Lee, Eunjung; Lim, Yoongho; Hur, Hor-Gil

    2009-06-01

    The hypolipidemic agent gemfibrozil (GEM), which has been studied for its metabolism in humans and animals, was investigated to elucidate its primary metabolism by Cunninghamella elegans. The fungus produced ten metabolites (FM1-FM9 and FM6') from the biotransformation of GEM. Based on LC/MS/MS and NMR analyses, a major metabolite, FM7, was identified as 2'-hydroxymethyl GEM. FM6 was considered to be 5'-hydroxymethyl GEM, after comparison of results LC/MS, LC/MS/MS, and UV absorption spectra to FM7. The combined concentration of FM6 and FM7 was found to increase up to 0.83 mM by day 2, and then decreased gradually with incubation time, followed by a noticeable increase in the biotransformation product, FM1, up to 0.86 mM by day 15. NMR analyses confirmed that FM1 was 2',5'-dihydroxymethyl GEM. Further minor oxidations of the aromatic ring and carboxylic acid intermediates were also detected. Based upon these findings, the major fungal metabolic pathway for GEM is likely to occur via production of 2',5'-dihydroxymethyl GEM from 2'-hydroxymethyl GEM. These relatively rapid and diverse biotransformations of GEM by C. elegans suggest that depending upon conditions, it may also follow a similar biodegradation fate when released into the natural environment.

  5. [Water-borne disease outbreaks in Norway].

    Science.gov (United States)

    Nygård, Karin; Gondrosen, Bjørn; Lund, Vidar

    2003-12-04

    The drinking water in Norway has traditionally been considered being of good quality. However, outbreaks related to drinking water are reported every year. We review waterborne outbreaks in Norway over the last 15 years, and describe the aetiology of and contributory factors in these outbreaks. We compiled data on waterborne outbreaks reported to the Norwegian Institute of Public Health and Norwegian Food Control Authority during 1988-2002. We included all events in which two or more people fell ill and water was the suspected source of infection. Over the 15-year period. 72 outbreaks were reported, affecting a total of 10 616 persons. Campylobacter was the cause in 26% (19/72) of the outbreaks, norovirus in 18% (13/72). The causative organism was unknown in 46% (33/72). The water came from public waterworks in 32 of the 54 outbreaks for which this information was available (59%); from a private supply in the remaining 22. For 62% (16/26) of the outbreaks related to waterworks, the water was not disinfected before distribution. None of the private water supplies were disinfected. Over the last five years, there were more outbreaks related to private supplies. The most important contributory factor to waterborne outbreaks in Norway is contamination of the raw water combined with missing or faulty disinfecting procedures. To prevent future outbreaks, a continuous upgrading of small and private water supplies is needed. Reporting of outbreaks is important for the implementation of targeted and effective preventive measures.

  6. Estimated waterborne commerce statistics for calendar year 1998 : national totals and selected inland waterways

    Science.gov (United States)

    1999-07-30

    In order to provide waterborne commerce information as soon as possible, the Waterborne Commerce Statistics Center(WCSC) has prepared this summary document of estimated waterborne commerce statistics for calendar year 1998. The foreign import and exp...

  7. Estimated waterborne commerce statistics for calendar year 1996 : national totals and selected inland waterways

    Science.gov (United States)

    1997-10-01

    In order to provide waterborne commerce information as soon as possible, the Waterborne Commerce Statistics Center (WCSC) has prepared this summary document of estimated waterborne commerce statistics for calendar year 1996. The foreign import and ex...

  8. Evaluation of an experimental and commercial state-of-the-art vaccine against enteric redmouth disease (ERM) in rainbow trout by waterborne challenge with Y. ruckeri O1 biotype 2

    DEFF Research Database (Denmark)

    Kragelund Strøm, Helene; Otani, Maki; Villumsen, Kasper Rømer

    has been compared to a state-of-the-art commercial ERM immersion vaccine (AquaVac® ReleraTM). Un-vaccinated and sham vaccinated rainbow trout were included as controls. Two months post vaccination the rainbow trout were challenged in duplicate with Y. ruckeri O1 biotype 2 by bath. No effect...... of the experimental immersion or bath vaccine was observed in the present study. However, full protection was achieved with i.p. injection of the experimental vaccine (p

  9. Interactions of triclosan, gemfibrozil and galaxolide with biosolid-amended soils: Effects of the level and nature of soil organic matter.

    Science.gov (United States)

    Usyskin, Alla; Bukhanovsky, Nadezhda; Borisover, Mikhail

    2015-11-01

    Triclosan, gemfibrozil and galaxolide, representing acidic and non-ionized hydrophobic organic compounds, are biologically active and can be accumulated during wastewater treatment in sewage sludge. The interactions of these substances with the soils amended by sewage sludge-originating biosolids may control their environmental fate. Therefore, the sorption of three organic compounds was studied in dune sand, loess soil, clay soil and mixtures of these media with three different sewage sludge-originating biosolids that were incubated under aerobic conditions for 6 months. For each compound, 15 sorption isotherms were produced at pH 7.8-8.0. The sorption of triclosan and gemfibrozil on sand-containing sorbents was examined also under acidic conditions. In some soil series, the compound's Freundlich constants (KF) are linearly related to the soil organic carbon (OC) content. Notably, for a given OC content, the sand-containing sorbents tend to demonstrate enhanced interactions with triclosan and galaxolide. This may be related with more hydrophobic and/or less rigid soil organic matter (SOM) as compared with the clay-containing soils, implying indirect effects of minerals. Generally the OC-normalized KF vary among different soil-biosolid combinations which is explained by the differences in the composition and properties of SOM, and is also contributed by the non-zero intercepts of the linear KF upon soil OC dependencies. The negative intercepts suggest that below a certain OC level no considerable organic compound-soil interactions would occur. Interactions of molecular and anionic forms of triclosan with a sand-containing sorbent may be comparable, but interactions involving gemfibrozil molecules could be stronger than interactions involving its anion. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Competence in water-borne heating systems in buildings; Kompetanse innen vannbaarene varmesystemer i bygg

    Energy Technology Data Exchange (ETDEWEB)

    Jarstein, Stig; Palm, Linn Therese; Naess, Bente Haukland; Nossum, Aase; Johnsen, Morten

    2009-01-15

    Trade participants in water-borne heating systems in buildings has experienced mistakes in all phases and of all participants of a project. When water-borne heating system functions, there is almost no follow up. This report is based on a qualitative survey where a several central participants, who on a daily basis are involved in projects with water-borne heating systems, are interviewed or have participated in focus group meetings. Following points illustrate experiences made by the operators in occasions where competence in trade is insufficiencies and mistakes occur: - Property developer lacks ordering competence and has problems in ordering quality. Consultant submit services of minor quality. Performance is of another quality than the supplier. Administration / maintenance lacks competence in how to run the system and without introduction and training in the heating system they take over a system that is over dimensioned and hard to regulate. The trade as a whole knows all the challenges, but the participants gives mainly the impression that the fault is lac of competence for all the other participants - not them self. This report points out measures and Enova can support competence improving measures which on long term will improve the quality from the participants. The trade is recommended to look into project execution, how competence is involved at the right moment, improving of control and documentation routines and at termination / hand over. (AG).14 refs., 14 figs., 2 tabs

  11. Safe drinking water and waterborne outbreaks.

    Science.gov (United States)

    Moreira, N A; Bondelind, M

    2017-02-01

    The present work compiles a review on drinking waterborne outbreaks, with the perspective of production and distribution of microbiologically safe water, during 2000-2014. The outbreaks are categorised in raw water contamination, treatment deficiencies and distribution network failure. The main causes for contamination were: for groundwater, intrusion of animal faeces or wastewater due to heavy rain; in surface water, discharge of wastewater into the water source and increased turbidity and colour; at treatment plants, malfunctioning of the disinfection equipment; and for distribution systems, cross-connections, pipe breaks and wastewater intrusion into the network. Pathogens causing the largest number of affected consumers were Cryptosporidium, norovirus, Giardia, Campylobacter, and rotavirus. The largest number of different pathogens was found for the treatment works and the distribution network. The largest number of affected consumers with gastrointestinal illness was for contamination events from a surface water source, while the largest number of individual events occurred for the distribution network.

  12. Minimizing corrosive action in timber bridges treated with waterborne preservatives

    Science.gov (United States)

    Samuel L. Zelinka; Douglas R. Rammer; James P. Wacker

    2007-01-01

    This work will briefly review published literature and current research activities on the corrosion of metals in contact with wood treated with waterborne alternatives to CCA. In addition, recommendations to minimize these corrosive effects in timber bridges will be discussed.

  13. Interaction forces between waterborne bacteria and activated carbon particles

    NARCIS (Netherlands)

    Busscher, Henk J.; Dijkstra, Rene J. B.; Langworthy, Don E.; Collias, Dimitris I.; Bjorkquist, David W.; Mitchell, Michael D.; Van der Mei, Henny C.

    2008-01-01

    Activated carbons remove waterborne bacteria from potable water systems through attractive Lifshitz-van der Waals forces despite electrostatic repulsion between negatively charged cells and carbon surfaces. In this paper we quantify the interaction forces between bacteria with negatively and

  14. Waterborne Disease Outbreaks— United States, 2009–2014

    Science.gov (United States)

    Background: The Centers for Disease Control and Prevention (CDC) has conducted national surveillance for waterborne disease outbreaks since 1971 in partnership with the Council of State and Territorial Epidemiologists and the United States Environmental Protection Agency (USEPA)....

  15. Association of water-borne diseases morbidity pattern and water ...

    African Journals Online (AJOL)

    Association of water-borne diseases morbidity pattern and water quality in ... due to unsafe water, inadequate sanitation and poor hygiene among human population. ... Provision of adequate potable water remains the most important tool for ...

  16. Genetic-based investigation of three prevalent waterborne protozoa ...

    African Journals Online (AJOL)

    SARAH

    2014-05-31

    central Côte d'Ivoire. In general, to measure water quality, microbiological analyses for bacteria such as Escherichia coli,. Clostridia perfringens and total coliforms (OMS,. 2008; Ahoussy et al, 2013) are done. Despite waterborne ...

  17. Waterborne Epoxy Nanocoatings Modified by Nanoemulsions and Nanoparticles

    National Research Council Canada - National Science Library

    Zhenyu Wang Enhou Han Fuchun Liu Zhouhai Qian Liwei Zhu

    2014-01-01

    .... In the present investigation electrically conductive nanocoatings were prepared by the incorporation of graphite, nano-SiO2 concentrate, acrylic nanoemulsion and fluorocarbon emulsion onto the waterborne epoxy polymer...

  18. Conference Report: The 6th International Symposium on Waterborne Pathogens

    Data.gov (United States)

    U.S. Environmental Protection Agency — A review of current literature on the occurrence of waterborne pathogens in DW systems. This dataset is not publicly accessible because: I am using published data...

  19. Essential veterinary education in water-borne transmission of disease.

    Science.gov (United States)

    Bowman, D D

    2009-08-01

    In this paper, the author reviews the reasons for the current interest in waterborne transmission of infectious agents in the veterinary curriculum. In addition, the paper provides short summaries of some of the major zoonotic outbreaks that have caused this new interest in water-borne diseases. Some curricular recommendations are made, including: basic training in modern methodologies in microbiology; a brief introduction to water and sewage treatment, with some discussion of pathogens in relation to the basic treatment processes of flocculation, sedimentation, filtration, disinfection, denitrification and phosphorus removal; and an introduction to the regulations being promulgated to reduce the pathogen loading of water on farms.

  20. Challenge.

    Directory of Open Access Journals (Sweden)

    René-Éric Dagorn

    2004-04-01

    Full Text Available Sous le titre « The Hispanic Challenge », Samuel P. Huntington propose dans le numéro de Foreign Policy de mars-avril 2004 une nouvelle démonstration du danger de sa pseudo-théorie du « choc des civilisations ». Quel est donc ce «  challenge  » auquel, d'après Huntington, la société américaine serait aujourd'hui confrontée ? C'est celui de l'immigration « hispanique » qui « menace l'identité américaine, ses valeurs et son mode de vie » ...

  1. Ubiquity of the water-borne pathogens, Cryptosporidium and Giardia ...

    African Journals Online (AJOL)

    The prevalence of the diarrhoea disease caused by the water-borne pathogens Cryptosporidium and Giardia in KwaZulu-Natal, was determined from pathology laboratory data. Cryptosporidium and Giardia were found to be endemic in KwaZulu-Natal with laboratory-confirmed incidences ranging from 2.9 to 3.7% and 2.9 to ...

  2. Genetic-based investigation of three prevalent waterborne protozoa ...

    African Journals Online (AJOL)

    The objective of this study was to investigate the presence of waterborne protozoa such as Cryptosporidium parvum, Giardia intestinalis, and Entamoeba histolytica in various natural water sources from Daloa city using genetic markers. Methodology and results: A total of 34 water source samples comprising 2 from springs, ...

  3. Oil-acrylic hybrid latexes as binders for waterborne coatings

    NARCIS (Netherlands)

    Hamersveld, van E.M.S.; Es, van J.; German, A.L.; Cuperus, F.P.; Weissenborn, P.; Hellgren, A.C.

    1999-01-01

    The combination of the characteristics of oil, or alkyd, emulsions and acrylic latexes in a waterborne binder has been the object of various studies in the past. Strategies for combining the positive properties of alkyds, e.g. autoxidative curing, gloss and penetration in wood, with the fast drying

  4. Water-borne protozoa parasites: The Latin American perspective.

    Science.gov (United States)

    Rosado-García, Félix Manuel; Guerrero-Flórez, Milena; Karanis, Gabriele; Hinojosa, María Del Carmen; Karanis, Panagiotis

    2017-07-01

    Health systems, sanitation and water access have certain limitations in nations of Latin America (LA): typical matters of developing countries. Water is often contaminated and therefore unhealthy for the consumers and users. Information on prevalence and detection of waterborne parasitic protozoa are limited or not available in LA. Only few reports have documented in this field during the last forty years and Brazil leads the list, including countries in South America and Mexico within Central America region and Caribbean islands. From 1979 to 2015, 16 outbreaks of waterborne-protozoa, were reported in Latin American countries. T. gondii and C. cayetanensis were the protozoa, which caused more outbreaks and Giardia spp. and Cryptosporidium spp. were the most frequently found protozoa in water samples. On the other hand, Latin America countries have not got a coherent methodology for detection of protozoa in water samples despite whole LA is highly vulnerable to extreme weather events related to waterborne-infections; although Brazil and Colombia have some implemented laws in their surveillance systems. It would be important to coordinate all surveillance systems in between all countries for early detection and measures against waterborne-protozoan and to establish effective and suitable diagnosis tools according to the country's economic strength and particular needs. Copyright © 2017 Elsevier GmbH. All rights reserved.

  5. Is Waterborne Disease Still an Issue in the US?

    Centers for Disease Control (CDC) Podcasts

    2012-08-27

    In this podcast, CDC’s Dr. Michael Beach discusses the changing face of waterborne disease in the US over the past century and how healthcare providers can apply this information to their patients.  Created: 8/27/2012 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 10/22/2012.

  6. Performance of waterborne acrylic surface coatings on wood ...

    Indian Academy of Sciences (India)

    Two waterborne acrylic coatings were applied on spruce wood, impregnated with two copperethanolamine containing preservatives (CuE and CuEQ), one of them (CuEQ) containing a boron compound, octanoic acid and a quaternary ammonium compound as additives. Lower contact angles and deeper penetration of both ...

  7. Toxicokinetics of tilapia following high exposure to waterborne and dietary copper and implications for coping mechanisms.

    Science.gov (United States)

    Tsai, Jeng-Wei; Ju, Yun-Ru; Huang, Ying-Hsuan; Deng, Yue-Sun; Chen, Wei-Yu; Wu, Chin-Ching; Liao, Chung-Min

    2013-06-01

    One of the major challenges in assessing the potential metal stress to aquatic organisms is explicitly predicting the internal dose in target organs. We aimed to understand the main sources of copper (Cu) accumulation in target organs of tilapia (Oreochromis mossambicus) and to investigate how the fish alter the process of Cu uptake, depuration, and accumulation (toxicokinetics (TK)) under prolonged conditions. We measured the temporal Cu profiles in selected organs after single and combined exposure to waterborne and dietary Cu for 14 days. Quantitative relations between different sources and levels of Cu, duration of treatment, and organ-specific Cu concentrations were established using TK modeling approaches. We show that water was the main source of Cu in the gills (>94 %), liver (>89 %), and alimentary canal (>86 %); the major source of Cu in the muscle (>51 %) was food. Cu uptake and depuration in tilapia organs were mediated under prolonged exposure conditions. In general, the uptake rate, depuration rate, and net bioaccumulation ability in all selected organs decreased with increasing waterborne Cu levels and duration of exposure. Muscle played a key role in accounting for the rapid Cu accumulation in the first period after exposure. Conversely, the liver acted as a terminal Cu storage site when exposure was extended. The TK processes of Cu in tilapia were highly changed under higher exposure conditions. The commonly used bioaccumulation model might lead to overestimations of the internal metal concentration with the basic assumption of constant TK processes.

  8. Gemfibrozil, food and drug administration-approved lipid-lowering drug, increases longevity in mouse model of late infantile neuronal ceroid lipofuscinosis.

    Science.gov (United States)

    Ghosh, Arunava; Rangasamy, Suresh Babu; Modi, Khushbu K; Pahan, Kalipada

    2017-05-01

    Late Infantile Neuronal Ceroid Lipofuscinosis (LINCL) is a rare neurodegenerative disease caused by mutations in the Cln2 gene that leads to deficiency or loss of function of the tripeptidyl peptidase 1 (TPP1) enzyme. TPP1 deficiency is known to cause the accumulation of autofluoroscent lipid-protein pigments in brain. Similar to other neurodegenerative disorders, LINCL is also associated with neuroinflammation and neuronal damage. Despite investigations, no effective therapy is currently available for LINCL. Therefore, we administered gemfibrozil (gem), an food and drug administration (FDA)-approved lipid-lowering drug, which has been shown to stimulate lysosomal biogenesis and induce anti-inflammation, orally, at a dose of 7.5 mg/kg body wt/day to Cln2((-/-)) mice. We observed that gem-fed Cln2((-/-)) mice lived longer by more than 10 weeks and had better motor activity compared to vehicle (0.1% Methyl cellulose) treatment. Gem treatment lowered the burden of storage materials, increased anti-inflammatory factors like SOCS3 and IL-1Ra, up-regulated anti-apoptotic molecule like phospho-Bad, and reduced neuronal apoptosis in the brain of Cln2((-/-)) mice. Collectively, this study reinforces a neuroprotective role of gem that may be of therapeutic interest in improving the quality of life in LINCL patients. © 2017 International Society for Neurochemistry.

  9. Viruses in recreational water-borne disease outbreaks: a review.

    Science.gov (United States)

    Sinclair, R G; Jones, E L; Gerba, C P

    2009-12-01

    Viruses are believed to be a significant cause of recreationally associated water-borne disease. However, they have been difficult to document because of the wide variety of illnesses that they cause and the limitations in previous detection methods. Noroviruses are believed to be the single largest cause of outbreaks, which have been documented in the published literature 45% (n = 25), followed by adenovirus (24%), echovirus (18%), hepatitis A virus (7%) and coxsackieviruses (5%). Just under half of the outbreaks occurred in swimming pools (49%), while the second largest outbreak occurred in lakes or ponds (40%). The number of reported outbreaks associated with noroviruses has increased significantly in recent years probably because of better methods for virus detection. Inadequate disinfection was related to 69% (n = 18) of swimming pool outbreaks. A lack of required reporting and nonuniform water quality and chlorination/disinfection standards continues to contribute to water-borne recreational disease outbreaks.

  10. The importance of waterborne disease outbreak surveillance in the United States

    Directory of Open Access Journals (Sweden)

    Gunther Franz Craun

    2012-12-01

    Full Text Available Analyses of the causes of disease outbreaks associated with contaminated drinking water in the United States have helped inform prevention efforts at the national, state, and local levels. This article describes the changing nature of disease outbreaks in public water systems during 1971-2008 and discusses the importance of a collaborative waterborne outbreak surveillance system established in 1971. Increasing reports of outbreaks throughout the early 1980s emphasized that microbial contaminants remained a health-risk challenge for suppliers of drinking water. Outbreak investigations identified the responsible etiologic agents and deficiencies in the treatment and distribution of drinking water, especially the high risk associated with unfiltered surface water systems. Surveillance information was important in establishing an effective research program that guided government regulations and industry actions to improve drinking water quality. Recent surveillance statistics suggest that prevention efforts based on these research findings have been effective in reducing outbreak risks especially for surface water systems.

  11. Excess healthcare costs of a large waterborne outbreak in Finland.

    Science.gov (United States)

    Huovinen, Elisa; Laine, Janne; Virtanen, Mikko J; Snellman, Marja; Hujanen, Timo; Kiiskinen, Urpo; Kujansuu, Eila; Lumio, Jukka; Ruutu, Petri; Kuusi, Markku

    2013-11-01

    The economic effects of waterborne outbreaks have rarely been reported. A large waterborne outbreak occurred in the town of Nokia in Finland in 2007 with half of the population in the contaminated area suffering from gastroenteritis. We studied the healthcare costs of this outbreak. Healthcare costs were studied using register data from the Nokia Health Care Centre, data collected in the regional university hospital, and data from laboratory register on stool samples. Total excess healthcare costs were EUR 354,496, which is approximately EUR 10 per resident of Nokia. There were 2052 excess visits because of gastroenteritis in Nokia Health Care Centre, 403 excess episodes in the university hospital, and altogether over 2000 excess stool samples due to the outbreak. Care in the Nokia Health Care Centre accounted for 44% and care in the university hospital for 42% of the excess healthcare costs while stool samples accounted for only 10%. Despite the high morbidity, the total cost was low because most patients had a relatively mild illness. The situation would have been worse if the microbes involved had been more hazardous or if the financial situation of the community had been worse. Prevention of waterborne outbreaks is important, as there is a risk of severe short- and long-term health effects and substantial health-economic costs.

  12. Nanoclay Dispersion and its Effect on Properties of Waterborne Polyurethanes

    Directory of Open Access Journals (Sweden)

    H. Honarkar

    2014-01-01

    Full Text Available In recent years, waterborne polyurethanes as in coatings and adhesives formulations have attracted considerable attention because they are non-toxic, non-flammable and friendly to environment. Besides environmental management, the flexibility, low temperature property, high tensile strength, good adhesion and improved rheological property are specific properties of waterborne polyurethanes. Also low production cost of water borne polyurethanes over solvent-borne polyurethanes is also a reason for their applications. However, these materials have some defects such as weak water resistance and low adhesion in the moisture environment due to sensitivity of their hydrophilic ionic bonds, ether groups, urethane and ester groups to hydrolysis which need to be improved. Also, low heat resistance of these materials is due to a relatively low crystalline melting point or glass transition temperature of hard segments. One of the ways to solve this problem and improve its properties for different applications is the addition of inorganic fillers especially nano-sized layered silicates within polyurethane matrix. In this way water resistance, heat resistance, mechanical properties and modulus increase simultaneously. In this research, waterborne polyurethane nanocomposites with PTMG polyol, IPDI, DMPA (internal emulsifier, TEA (neutralizer and 1, 3 and 5weight % of Cloisite 30B as reinforcement were synthesized and characterized. Polarity of the samples was investigated by contact angle test and dispersion of nano particles in the samples was characterized by X-Ray and TEM, Thermal properties and dynamic mechanical properties were measured by TGA and DMTA, respectively. The results showed that incorporation of clay into polyurethanes did reduce water absorption and increased heat resistance, modulus, particle size and contact angle.In recent years, waterborne polyurethanes including coatings and adhesives have attracted considerable attention because they

  13. Hydrologic, land cover and seasonal patterns of waterborne pathogens in great lakes tributaries

    Science.gov (United States)

    Great Lakes tributaries deliver waterborne pathogens from a host of sources. To examine the hydrologic, land cover, and seasonal variability of waterborne pathogens, protozoa (2), pathogenic bacteria (4) and human (8) and bovine (8) viruses from eight rivers were monitored in the Great Lakes watersh...

  14. Aeromonas and Plesiomonas as food- and waterborne pathogens.

    Science.gov (United States)

    Wadström, T; Ljungh, A

    1991-04-01

    Aeromonas and Plesiomonas have become increasingly recognized as human enteropathogens. Plesiomonas shigelloides has mainly been recovered from various sea foods, whereas Aeromonas sp. have also been cultured from pigs, broilers, eggs, milk and vegetables. Aeromonas sp. also multiply rapidly at +4 degrees C which is a significant risk in food storage. Aeromonas sp. have furthermore been recovered from fresh water sources, and some isolates are resistant to chlorination which makes it a further risk factor. No large food- or waterborne outbreaks have been reported so far with Aeromonas sp. Various virulence factors involved in intestinal infections are described such as enterotoxins, cytotoxins, and adhesins.

  15. Extreme water-related weather events and waterborne disease.

    Science.gov (United States)

    Cann, K F; Thomas, D Rh; Salmon, R L; Wyn-Jones, A P; Kay, D

    2013-04-01

    Global climate change is expected to affect the frequency, intensity and duration of extreme water-related weather events such as excessive precipitation, floods, and drought. We conducted a systematic review to examine waterborne outbreaks following such events and explored their distribution between the different types of extreme water-related weather events. Four medical and meteorological databases (Medline, Embase, GeoRef, PubMed) and a global electronic reporting system (ProMED) were searched, from 1910 to 2010. Eighty-seven waterborne outbreaks involving extreme water-related weather events were identified and included, alongside 235 ProMED reports. Heavy rainfall and flooding were the most common events preceding outbreaks associated with extreme weather and were reported in 55·2% and 52·9% of accounts, respectively. The most common pathogens reported in these outbreaks were Vibrio spp. (21·6%) and Leptospira spp. (12·7%). Outbreaks following extreme water-related weather events were often the result of contamination of the drinking-water supply (53·7%). Differences in reporting of outbreaks were seen between the scientific literature and ProMED. Extreme water-related weather events represent a risk to public health in both developed and developing countries, but impact will be disproportionate and likely to compound existing health disparities.

  16. Waterborne hyperbranched alkyd-acrylic resin obtained by miniemulsion polymerization

    Directory of Open Access Journals (Sweden)

    Edwin Murillo

    Full Text Available Abstract Four waterborne hyperbranched alkyd-acrylic resins (HBRAA were synthesized by miniemulsion polymerization from a hyperbranched alkyd resin (HBR, methyl methacrylate (MMA, butyl acrylate (BA and acrylic acid (AA, by using benzoyl peroxide (BPO and ammonium persulfate (AP as initiators. The reaction between HBR and acrylic monomers was evidenced by differential scanning calorimetric (DSC, nuclear magnetic resonance (NMR and gel permeation chromatography (GPC. The conversion percentage, glass transition temperature (Tg, content of acrylic polymer (determined by soxhlet extraction and molecular weight increased with the content of acrylic monomers used in the synthesis. The main structure formed during the synthesis was the HBRAA. The analysis by dynamic light scattering (DLS showed that the particle size distribution of HBRAA2, HBRAA3 and HBRAA4 resins were mainly monomodal. The film properties (gloss, flexibility, adhesion and drying time of the HBRAA were good.

  17. Rheological and Mechanical Behavior of Silk Fibroin Reinforced Waterborne Polyurethane

    Directory of Open Access Journals (Sweden)

    Yongzhen Tao

    2016-03-01

    Full Text Available Waterborne polyurethane (WPU is a versatile and environment-friendly material with growing applications in both industry and academia. Silk fibroin (SF is an attractive material known for its structural, biological and hemocompatible properties. The SF reinforced waterborne polyurethane (WPU is a promising scaffold material for tissue engineering applications. In this work, we report synthesis and characterization of a novel nanocomposite using SF reinforced WPU. The rheological behaviors of WPU and WPU-SF dispersions with different solid contents were investigated with steady shear and dynamic oscillatory tests to evaluate the formation of the cross-linked gel structure. The average particle size and the zeta potential of WPU-SF dispersions with different SF content were examined at 25 °C to investigate the interaction between SF and WPU. FTIR, SEM, TEM and tensile testing were performed to study the effects of SF content on the structural morphology and mechanical properties of the resultant composite films. Experimental results revealed formation of gel network in the WPU dispersions at solid contents more than 17 wt %. The conjugate reaction between the WPU and SF as well as the hydrogen bond between them helped in dispersing the SF powder into the WPU matrix as small aggregates. Addition of SF to the WPU also improved the Young’s modulus from 0.30 to 3.91 MPa, tensile strength from 0.56 to 8.94 MPa, and elongation at break from 1067% to 2480%, as SF was increased up to 5 wt %. Thus, significant strengthening and toughening can be achieved by introducing SF powder into the WPU formulations.

  18. Effects of shrimp density on transmission of penaeid acute viremia in Penaeus japonicus by cannibalism and the waterborne route.

    Science.gov (United States)

    Wu, J L; Namikoshi, A; Nishizawa, T; Mushiak, K; Teruya, K; Muroga, K

    2001-11-08

    To investigate the effects of shrimp density on mortalities of Penaeus japonicus in experimental penaeid acute viremia (= white spot syndrome), shrimp injected intramuscularly with penaeid rod-shaped DNA virus (PRDV) were reared at different densities. In Expt 1, challenged (10(-6) dilution of a PRDV preparation) shrimp were reared collectively in a tank or individually in separate chamber units. A significant difference in cumulative mortalities was found between collectively (75.6%) and individually (1.2%) reared groups after 30 d. In Expt 2, effects of density on mortality were clearly shown when challenged (10(-5) dilution) shrimp were reared collectively in tanks at high (260 shrimp m(-2)), middle (135 shrimp m(-2)) and low densities (73 shrimp m(-2)). The cumulative mortalities for 14 d in the high, middle and low density groups were 72, 46 and 18%, respectively. In Expt 3, challenged (10(-5) dilution) shrimp were reared collectively in 3 tanks (Groups A, B and C) at the same high density (260 shrimp m(-2)): Group A, dead shrimp were immediately removed to avoid transmission of the pathogen through cannibalism and the waterborne route; Group B, dead shrimp were removed at scheduled times but were separated from living shrimp by a net partition to avoid cannibalism; and Group C, dead shrimp were removed twice a day at scheduled times. Resulting cumulative mortalities for 20 d in Groups A, B and C were 4, 24 and 64 %, respectively. These results show that the higher mortalities occur in P. japonicus reared at the higher densities in experimental PRDV infection, and this phenomenon is caused mainly by a higher opportunity of horizontal transmission of the virus through cannibalism and the waterborne route.

  19. Excel file of salivary antibody analysis for Boqueron Beach study, Puerto Rico for six waterborne pathogens.

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset is the raw Luminex antibody responses to six common waterborne pathogens reported in MFI (Median Fluorescence Intensity) units. This dataset is...

  20. Quantifying the impact of climate change on enteric waterborne pathogen concentrations in surface water

    NARCIS (Netherlands)

    Hofstra, N.

    2011-01-01

    Climate change, among other factors, will impact waterborne pathogen concentrations in surface water worldwide, possibly increasing the risk of diseases caused by these pathogens. So far, the impacts are only determined qualitatively and thorough quantitative estimates of future pathogen

  1. Evaluation and specification of high build and special use waterborne pavement markings.

    Science.gov (United States)

    2014-01-01

    High build waterborne traffic paints and highly retro-reflective elements were applied at various locations to evaluate their : practicality for use by NYSDOT Maintenance forces. In addition, highly reflective elements were applied within grooved in ...

  2. Gold tailings as a source of water-borne uranium contamination of ...

    African Journals Online (AJOL)

    Gold tailings as a source of water-borne uranium contamination of streams - the Koekemoerspruit (South Africa) as a case study - part III of III: fluctuations of stream chemistry and their impacts on uranium mobility.

  3. Are soil and waterborne parasitic infections health risk for worker populations in southeast Turkey?

    OpenAIRE

    Sibel Ak; Fadime Eroğlu; Ali İhsan Nergiz; Furkan Hıyamlı

    2017-01-01

    Objective: The soil and waterborne parasitic infections rate is high degree in developed and developing countries. Migratory workers have greater exposure to these parasitic infections and a lot of morbidity due to these infections in workers. For this reason, we aimed to investigate the presence of soil and waterborne parasites in the Gaziantep Organized Industrial Zone of southeast Turkey. Methods: A total of 25 environmental samples (18 soil samples and 7 water samples) were...

  4. Leading Transportation Indicators: Forecasting Waterborne Commerce Statistics Using Lock Performance Data

    OpenAIRE

    Thoma, Mark A; Wilson, Wesley W.

    2005-01-01

    This paper develops and applies a forecasting model for transportation data based on the leading economic indicators literature. The specific application is to forecast river tonnages. Waterborne commerce data reflect tonnages of commodities moved on various rivers and in various directions. They are released after the Lock Performance Monitoring System data which reflect tonnages moving through specific locks. The model presented here forecasts waterborne commerce data from lock performance ...

  5. Water-Borne Diseases, Cost of Illness and Willingness to Pay for Diseases Interventions in Rural Communities of Developing Countries

    OpenAIRE

    Malik, A; Yasar, A; Tabinda, AB; Abubakar, M

    2012-01-01

    Background:Almost one third of the global population is living in developing South Asia where disease occurrence is high especially in rural areas and people are unaware of water-borne diseases and cost of illness.Methods:The quantitative approach involved questionnaire based study (n=50 households).The community awareness,the occurrence of water-borne diseases with related cost of illness and community participation for the introduction of health interventions for water-borne diseases were e...

  6. Detection, Diversity, and Population Dynamics of Waterborne Phytophthora ramorum Populations.

    Science.gov (United States)

    Eyre, C A; Garbelotto, M

    2015-01-01

    Sudden oak death, the tree disease caused by Phytophthora ramorum, has significant environmental and economic impacts on natural forests on the U.S. west coast, plantations in the United Kingdom, and in the worldwide nursery trade. Stream baiting is vital for monitoring and early detection of the pathogen in high-risk areas and is performed routinely; however, little is known about the nature of water-borne P. ramorum populations. Two drainages in an infested California forest were monitored intensively using stream-baiting for 2 years between 2009 and 2011. Pathogen presence was determined both by isolation and polymerase chain reaction (PCR) from symptomatic bait leaves. Isolates were analyzed using simple sequence repeats to study population dynamics and genetic structure through time. Isolation was successful primarily only during spring conditions, while PCR extended the period of pathogen detection to most of the year. Water populations were extremely diverse, and changed between seasons and years. A few abundant genotypes dominated the water during conditions considered optimal for aerial populations, and matched those dominant in aerial populations. Temporal patterns of genotypic diversification and evenness were identical among aerial, soil, and water populations, indicating that all three substrates are part of the same epidemiological cycle, strongly influenced by rainfall and sporulation on leaves. However, there was structuring between substrates, likely arising due to reduced selection pressure in the water. Additionally, water populations showed wholesale mixing of genotypes without the evident spatial autocorrelation present in leaf and soil populations.

  7. Click Cross-Linking-Improved Waterborne Polymers for Environment-Friendly Coatings and Adhesives.

    Science.gov (United States)

    Hu, Jianqing; Peng, Kaimei; Guo, Jinshan; Shan, Dingying; Kim, Gloria B; Li, Qiyao; Gerhard, Ethan; Zhu, Liang; Tu, Weiping; Lv, Weizhong; Hickner, Michael A; Yang, Jian

    2016-07-13

    Waterborne polymers, including waterborne polyurethanes (WPU), polyester dispersions (PED), and polyacrylate emulsions (PAE), are employed as environmentally friendly water-based coatings and adhesives. An efficient, fast, stable, and safe cross-linking strategy is always desirable to impart waterborne polymers with improved mechanical properties and water/solvent/thermal and abrasion resistance. For the first time, click chemistry was introduced into waterborne polymer systems as a cross-linking strategy. Click cross-linking rendered waterborne polymer films with significantly improved tensile strength, hardness, adhesion strength, and water/solvent resistance compared to traditional waterborne polymer films. For example, click cross-linked WPU (WPU-click) has dramatically improved the mechanical strength (tensile strength increased from 0.43 to 6.47 MPa, and Young's modulus increased from 3 to 40 MPa), hardness (increased from 59 to 73.1 MPa), and water resistance (water absorption percentage dropped from 200% to less than 20%); click cross-linked PED (PED-click) film also possessed more than 3 times higher tensile strength (∼28 MPa) than that of normal PED (∼8 MPa). The adhesion strength of click cross-linked PAE (PAE-click) to polypropylene (PP) was also improved (from 3 to 5.5 MPa). In addition, extra click groups can be preserved after click cross-linking for further functionalization of the waterborne polymeric coatings/adhesives. In this work, we have demonstrated that click modification could serve as a convenient and powerful approach to significantly improve the performance of a variety of traditional coatings and adhesives.

  8. Nutritional and health challenges of pastoralist populations in Kenya ...

    African Journals Online (AJOL)

    Besides experiencing chronic under-nutrition, pastoralists carry a substantial disease burden and are poorly covered by health services. The main diseases are malaria, respiratory tract infections and diarrhoea. Availability of safe drinking water is a challenge, and pastoralists are frequently affected by water-borne diseases ...

  9. Effects of wastewater disinfection on waterborne bacteria and viruses

    Science.gov (United States)

    Blatchley, E. R.; Gong, W.-L.; Alleman, J.E.; Rose, J.B.; Huffman, D.E.; Otaki, M.; Lisle, J.T.

    2007-01-01

    Wastewater disinfection is practiced with the goal of reducing risks of human exposure to pathogenic microorganisms. In most circumstances, the efficacy of a wastewater disinfection process is regulated and monitored based on measurements of the responses of indicator bacteria. However, inactivation of indicator bacteria does not guarantee an acceptable degree of inactivation among other waterborne microorganisms (e.g., microbial pathogens). Undisinfected effluent samples from several municipal wastewater treatment facilities were collected for analysis. Facilities were selected to provide a broad spectrum of effluent quality, particularly as related to nitrogenous compounds. Samples were subjected to bench-scale chlorination and dechlorination and UV irradiation under conditions that allowed compliance with relevant discharge regulations and such that disinfectant exposures could be accurately quantified. Disinfected samples were subjected to a battery of assays to assess the immediate and long-term effects of wastewater disinfection on waterborne bacteria and viruses. In general, (viable) bacterial populations showed an immediate decline as a result of disinfectant exposure; however, incubation of disinfected samples under conditions that were designed to mimic the conditions in a receiving stream resulted in substantial recovery of the total bacterial community. The bacterial groups that are commonly used as indicators do not provide an accurate representation of the response of the bacterial community to disinfectant exposure and subsequent recovery in the environment. UV irradiation and chlorination/dechlorination both accomplished measurable inactivation of indigenous phage; however, the extent of inactivation was fairly modest under the conditions of disinfection used in this study. UV irradiation was consistently more effective as a virucide than chlorination/dechlorination under the conditions of application, based on measurements of virus (phage

  10. Animal Model Reveals Potential Waterborne Transmission of Helicobacter pylori Infection.

    Science.gov (United States)

    Boehnke, Kevin F; Eaton, Kathryn A; Valdivieso, Manuel; Baker, Laurence H; Xi, Chuanwu

    2015-10-01

    Helicobacter pylori infection has been consistently associated with lack of access to clean water and proper sanitation, but no studies have demonstrated that the transmission of H. pylori can occur from drinking contaminated water. In this study, we used a laboratory mouse model to test whether waterborne H. pylori could cause gastric infection. Groups of immunocompetent C57/BL6 Helicobacter-free mice were exposed to static concentrations (1.29 × 10(5), 10(6), 10(7), 10(8), and 10(9) CFU/L) of H. pylori in their drinking water for 4 weeks. One group of Helicobacter-free mice was exposed to uncontaminated water as a negative control. H. pylori morphology changes in water were examined using microscopy Live/Dead staining. Following exposure, H. pylori infection and inflammation status in the stomach were evaluated using quantitative culture, PCR, the rapid urease test, and histology. None of the mice in the negative control or 10(5) groups were infected. One of 20 cages (one of 40 mice) of the 10(6) group, three of 19 cages (four of 38 mice) of the 10(7) CFU/L group, 19 of 20 cages (33 of 40 mice) of the 10(8) group, and 20 of 20 cages (39 of 40 mice) of the 10(9) CFU/L group were infected. Infected mice had significantly higher gastric inflammation than uninfected mice (27.86% higher inflammation, p pylori in water is infectious in mice, suggesting that humans drinking contaminated water may be at risk of contracting H. pylori infection. Much work needs to be performed to better understand the risk of infection from drinking H. pylori-contaminated water. © 2015 John Wiley & Sons Ltd.

  11. Weathering characteristics and moisture uptake properties of wood coated with water-borne sol-gel thin films

    Science.gov (United States)

    M. A. Tshabalala; C. Starr; N. R. Sutherland

    2010-01-01

    In this study, wood specimens were coated with water-borne silsesquioxane oligomers by an in situ sol-gel deposition process. The effect of these water-borne sol-gel thin films on weathering characteristics and moisture-uptake properties of the wood specimens were investigated. The weathering characteristics were investigated by exposure of the specimens to artificial...

  12. Water Safety Plan on cruise ships: A promising tool to prevent waterborne diseases

    Energy Technology Data Exchange (ETDEWEB)

    Mouchtouri, Varvara A., E-mail: mouchtourib@med.uth.gr [Department of Hygiene and Epidemiology, Faculty of Medicine, University of Thessaly, Larissa (Greece); Bartlett, Christopher L.R. [University College London, Centre for Infectious Disease Epidemiology Department of Primary Care and Population Sciences Royal Free and University College Medical School, London (United Kingdom); Diskin, Arthur [Royal Caribbean Cruise Line, Miami (United States); Hadjichristodoulou, Christos [Department of Hygiene and Epidemiology, Faculty of Medicine, University of Thessaly, Larissa (Greece)

    2012-07-01

    Background: Legionella spp. and other waterborne pathogens have been isolated from various water systems on land based premises as well as on ships and cases of Legionnaires' disease have been associated with both sites. Peculiarities of cruise ships water systems make the risk management a challenging process. The World Health Organization suggests a Water Safety Plan (WSP) as the best approach to mitigate risks and hazards such as Legionella spp. and others. Objectives: To develop WSP on a cruise ship and discuss challenges, perspectives and key issues to success. Methods: Hazards and hazardous events were identified and risk assessment was conducted of the ship water system. Ship company management, policies and procedures were reviewed, site visits were conducted, findings and observations were recorded and discussed with engineers and key crew members were interviewed. Results: A total of 53 hazards and hazardous events were taken into consideration for the risk assessment and additional essential barriers were established when needed. Most of them concerned control measures for biofilm development and Legionella spp. contamination. A total of 29 operational limits were defined. Supplementary verification and supportive programs were established. Conclusions: Application of the WSP to ship water systems, including potable water, recreational water facilities and decorative water features and fountains, is expected to improve water management on ships. The success of a WSP depends on support from senior management, commitment of the Captain and crew members, correct execution of all steps of a risk assessment and practicality and applicability in routine operation. The WSP provides to shipping industry a new approach and a move toward evidence based water safety policy. - Highlights: Black-Right-Pointing-Pointer We conducted risk assessment and developed a Water Safety Plan on a cruise ship. Black-Right-Pointing-Pointer 53 hazards and hazardous events were

  13. Use of Pathogen-Specific Antibody Biomarkers to Estimate Waterborne Infections in Population-Based Settings

    Science.gov (United States)

    Purpose of reviewThis review discusses the utility of pathogen-specific antibody biomarkers for improving estimates of the population burden of waterborne infections, assessing the fraction of infections that can be prevented by specific water treatments, and understanding transm...

  14. Waterborne toxoplasmosis investigated and analyzed under hydrogeological assessment: new data and perspectives for further research

    Science.gov (United States)

    We present a set of data on human and chicken Toxoplasma gondii seroprevalence that was investigated and analyzed in light of groundwater vulnerability information in an area of endemic waterborne toxoplasmosis in Brazil. Hydrogeological assessment was undertaken to conduct water collection from wel...

  15. Reversible assembly of magnetized particles: Application to water-borne pathogen enumeration

    Science.gov (United States)

    Ramadan, Qasem

    2009-12-01

    Reversible assembly of magnetized particles and cells has been proposed and implemented. The approach is based on magnetized particles or magnetically labeled cell immobilization in an array of individual particle/cell for optical counting. The device has been tested for few types of magnetic particles and one water-borne pathogen: Giardia Lamblia. An individual particle immobilization efficiency of 92% was achieved.

  16. A dynamic artificial clam (Corbicula fluminea) allows parsimony on-line measurement of waterborne metals

    Energy Technology Data Exchange (ETDEWEB)

    Jou, L.-J. [Ecotoxicological Modeling Center, Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan 10617 (China); Department of Biomechatronic Engineering, National Ilan University, Ilan, Taiwan 260 (China); Liao, C.-M. [Ecotoxicological Modeling Center, Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan 10617 (China)]. E-mail: cmliao@ntu.edu.tw

    2006-11-15

    We introduce a novel on-line biomonitoring system based on a valvometric conversion technique for clam Corbicula fluminea, allowing for rapid, continuous, and ecological relevant water quality control. Our model builds upon the basic principles of biological early warning system model in two ways. We first adopted a risk-based methodology to build a dynamic artificial clam for simulating how the bivalve closure rhythm in response to waterborne copper (Cu) and cadmium (Cd). Secondly, we integrated a probabilistic model associated with the time-varying dose-response relationships of valve closing behavior into the mechanisms of a dynamic artificial clam, allowing estimation of the time-varying waterborne Cu/Cd concentrations for on-line providing the outcomes of the toxicity detection technique. Measurements with Cu/Cd were performed and the calculated EC50 values were compared with published data for the valve movement test with C. fluminea. This proposed dynamic artificial clam provides a better quantitative understanding of on-line biomonitoring measurements of waterborne metals and may foster applications in clam farm management strategy and ecotoxicological risk assessment. - A dynamic artificial clam allows on-line biomonitoring waterborne metal toxicity.

  17. Mechanical and thermal properties of waterborne epoxy composites containing cellulose nanocrystals

    Science.gov (United States)

    Shanhong Xu; Natalie Girouard; Gregory Schueneman; Meisha L. Shofner; J. Carson Meredith

    2013-01-01

    Cellulose nanocrystals (CNCs) are reinforcing fillers of emerging interest for polymers due to their high modulus and potential for sustainable production. In this study, CNC-based composites with a waterborne epoxy resin matrix were prepared and characterized to determine morphology, water content, and thermal and mechanical properties. While some CNC aggregation was...

  18. Impact of food and water-borne diseases on European population health

    NARCIS (Netherlands)

    Cassini, A.; Colzani, E.; Kramarz, P.; Kretzschmar, M. E.|info:eu-repo/dai/nl/075187981; Takkinen, J.

    2016-01-01

    Composite health measures are increasingly applied in studies aiming at describing the burden of diseases, and food and water-borne diseases (FWDs) are no exception. The Burden of Communicable Diseases in Europe (BCoDE) is a project led and funded by the European Centre for Disease Prevention and

  19. Water and water-borne diseases in North Masaba District, kenya ...

    African Journals Online (AJOL)

    As a result 1.8 million people mostly in developing countries, and 90% of whom are children under 5, die every year from diarrheal diseases such as including cholera. This study was carried out with the objective of evaluating access to safe drinking water and the perceived incidence of water-borne diseases in North ...

  20. Efficacy of Copper-Silver Ionization in Controlling Biofilm- and Plankton-Associated Waterborne Pathogens▿

    Science.gov (United States)

    Shih, Hsiu-Yun; Lin, Yusen E.

    2010-01-01

    The study was to determine the efficacy of copper-silver ionization against the formation of Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and Acinetobacter baumannii in biofilms and planktonic phases. At concentrations below the EPA limits, ionization has potential to control the three waterborne pathogens, in addition to Legionella, in hospital water systems for nosocomial infection control. PMID:20080997

  1. Efficacy of Copper-Silver Ionization in Controlling Biofilm- and Plankton-Associated Waterborne Pathogens▿

    OpenAIRE

    Shih, Hsiu-Yun; Lin, Yusen E.

    2010-01-01

    The study was to determine the efficacy of copper-silver ionization against the formation of Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and Acinetobacter baumannii in biofilms and planktonic phases. At concentrations below the EPA limits, ionization has potential to control the three waterborne pathogens, in addition to Legionella, in hospital water systems for nosocomial infection control.

  2. Efficacy of copper-silver ionization in controlling biofilm- and plankton-associated waterborne pathogens.

    Science.gov (United States)

    Shih, Hsiu-Yun; Lin, Yusen E

    2010-03-01

    The study was to determine the efficacy of copper-silver ionization against the formation of Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and Acinetobacter baumannii in biofilms and planktonic phases. At concentrations below the EPA limits, ionization has potential to control the three waterborne pathogens, in addition to Legionella, in hospital water systems for nosocomial infection control.

  3. Comparing of UV and waterborne lacquers in view of amount of VOCs' emissions

    Directory of Open Access Journals (Sweden)

    Milan Meloun

    2008-01-01

    Full Text Available This contribution investigates the problematic of indoor air pollution. There were tested low emitting types of lacquers – UV and waterborne lacquers. The work has been splitted in to two parts. In the first part samples of lacquers were applied on the particle board with beech veneer on the surface. Samples of air with VOCs (Volatile Organic Compounds from lacquers were taken 3 and 24 hours after application. Tests proved that film layer of UV lacquer emit much smaller volumes of VOCs than acrylic waterborne lacquers or than 2–component epoxide waterborne lacquer. Acrylic waterborne lacquers’ materials emitted especially butoxyethylene, epoxide lacquer emitted a lot of butoxyethanol and methoxypropanol and UV lacquers particularly emitted toluene, benzene and xylene. Se­cond part of testing consists of VOCs’ measuring of chosen lacquers applied on different base materials – inertial material glass and particle board with beech veneer. Tested criterion was the impact of different base material on emitted amount of VOCs. The results showed that lacquer coated on glass emit much more chemicals than lacquer on wood material. All materials were also tested on total amount of organic compounds emitted in to the air – on the TVOC. Measuring showed the same results as the first parts of research.

  4. Global Warming and Trans-Boundary Movement of Waterborne Microbial Pathogens - Book Chapter

    Science.gov (United States)

    Subtle increases in temperature can have profound impacts on the prevalence of various waterborne microbial pathogens. Such impacts may be seen in three major areas, 1) fecally contaminated drinking water, 2) fresh produce that has been irrigated or processed with contaminated wa...

  5. Waterborne Polyurethane Coatings with Covalently Linked Black Dye Sudan Black B

    Directory of Open Access Journals (Sweden)

    Tao Wang

    2017-10-01

    Full Text Available Colored waterborne polyurethanes have been widely used in paintings, leathers, textiles, and coatings. Here, a series of black waterborne polyurethanes (WPUs with different ratios of black dye, Sudan Black B (SDB, were prepared by step-growth polymerization. WPU emulsions as obtained exhibit low particle sizes and remarkable storage stability at the same time. At different dye loadings, essential structural, statistical and thermal properties are characterized. FTIR (fourier transform infrared spectra indicate that SDB is covalently linked into waterborne polyurethane chains. All of the WPUs with covalently linked SDB show better color fastness and resistance of thermal migration than those with SDB mixed physically. Besides, WPUs incorporated SDB covalently with different polymeric diols, polytetramethylene ether glycol (PTMG, polypropylene glycol (PPG, poly-1, 4-butylene adipate glycol (PBA and polycaprolactone glycol (PCL, were prepared to obtain different properties to cater to a variety of practical demands. By a spraying method, the black WPUs can be directly used as metal coatings without complex dyeing process by simply mixing coating additive and other waterborne resins, which exhibit excellent coating performance.

  6. Structure Sensitivity Study of Waterborne Contaminant Hydrogenation Using Shape- and Size-Controlled Pd Nanoparticles

    KAUST Repository

    Shuai, Danmeng

    2013-03-01

    Catalytic reduction with Pd has emerged as a promising technology to remove a suite of contaminants from drinking water, such as oxyanions, disinfection byproducts, and halogenated pollutants, but low activity is a major challenge for application. To address this challenge, we synthesized a set of shape- and size-controlled Pd nanoparticles and evaluated the activity of three probe contaminants (i.e., nitrite, N-nitrosodimethylamine (NDMA), and diatrizoate) as a function of facet type (e.g., (100), (110), (111)), ratios of low- to high-coordination sites, and ratios of surface sites to total Pd (i.e., dispersion). Reduction results for an initial contaminant concentration of 100 μM show that initial turnover frequency (TOF0) for nitrite increases 4.7-fold with increasing percent of (100) surface Pd sites (from 0% to 95.3%), whereas the TOF0 for NDMA and for diatrizoate increases 4.5- and 3.6-fold, respectively, with an increasing percent of terrace surface Pd sites (from 79.8% to 95.3%). Results for an initial nitrite concentration of 2 mM show that TOF0 is the same for all shape- and size-controlled Pd nanoparticles. Trends for TOF0 were supported by results showing that all catalysts but one were stable in shape and size up to 12 days; for the exception, iodide liberation in diatrizoate reduction appeared to be responsible for a shape change of 4 nm octahedral Pd nanoparticles. Density functional theory (DFT) simulations for the free energy change of hydrogen (H2), nitrite, and nitric oxide (NO) adsorption and a two-site model based on the Langmuir-Hinshelwood mechanism suggest that competition of adsorbates for different Pd sites can explain the TOF0 results. Our study shows for the first time that catalytic reduction activity for waterborne contaminant removal varies with the Pd shape and size, and it suggests that Pd catalysts can be tailored for optimal performance to treat a variety of contaminants for drinking water. © 2013 American Chemical Society.

  7. Waterborne signaling primes the expression of elicitor-induced genes and buffers the oxidative responses in the brown alga Laminaria digitata.

    Directory of Open Access Journals (Sweden)

    François Thomas

    Full Text Available As marine sessile organisms, seaweeds must respond efficiently to biotic and abiotic challenges in their natural environment to reduce the fitness consequences of wounds and oxidative stress. This study explores the early steps of the defense responses of a large marine brown alga (the tangle kelp Laminaria digitata and investigates its ability to transmit a warning message to neighboring conspecifics. We compared the early responses to elicitation with oligoguluronates in laboratory-grown and harvested wild individuals of L. digitata. We followed the release of H₂O₂ and the concomitant production of volatile organic compounds. We also monitored the kinetics of expression of defense-related genes following the oxidative burst. Laboratory-grown algae were transplanted in kelp habitats to further evaluate their responses to elicitation after a transient immersion in natural seawater. In addition, a novel conditioning procedure was established to mimic field conditions in the laboratory. Our experiments showed that L. digitata integrates waterborne cues present in the kelp bed and/or released from elicited neighboring plants. Indeed, the exposure to elicited conspecifics changes the patterns of oxidative burst and volatile emissions and potentiates this kelp for faster induction of genes specifically regulated in response to oligoguluronates. Thus, waterborne signals shape the elicitor-induced responses of kelps through a yet unknown mechanism reminiscent of priming in land plants.

  8. Biomarkers of waterborne copper exposure in the guppy Poecilia vivipara acclimated to salt water

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Anderson Abel de Souza [Universidade Federal do Rio Grande, Programa de Pós-Graduação em Oceanografia Biológica, Av. Itália km 8, 96201-900 Rio Grande, Rio Grande do Sul (Brazil); Hoff, Mariana Leivas Müller [Universidade Federal do Rio Grande, Instituto de Ciências Biológicas, Av. Itália km 8, 96201-900 Rio Grande, Rio Grande do Sul (Brazil); Klein, Roberta Daniele [Universidade Federal do Rio Grande, Programa de Pós-Graduação em Ciências Fisiológicas – Fisiologia Animal Comparada, Av. Itália km 8, 96201-900 Rio Grande, Rio Grande do Sul (Brazil); Cardozo, Janaina Goulart [Universidade Federal do Rio Grande, Instituto de Ciências Biológicas, Av. Itália km 8, 96201-900 Rio Grande, Rio Grande do Sul (Brazil); Giacomin, Marina Mussoi [Universidade Federal do Rio Grande, Programa de Pós-Graduação em Ciências Fisiológicas – Fisiologia Animal Comparada, Av. Itália km 8, 96201-900 Rio Grande, Rio Grande do Sul (Brazil); Pinho, Grasiela Lopes Leães [Universidade Federal do Rio Grande, Instituto de Oceanografia, Av. Itália km 8, 96201-900 Rio Grande, Rio Grande do Sul (Brazil); and others

    2013-08-15

    Highlights: •Acute effects of waterborne copper were evaluated in the estuarine guppy Poecilia vivipara. •Fishes were acutely exposed to waterborne copper in salt water. •Waterborne copper affects the response of several biochemical and genetic endpoints. •Catalase, reactive oxygen species, antioxidant capacity and lipid peroxidation are responsive to copper exposure. •Copper exposure induces DNA damages in fish erythrocytes. -- Abstract: The responses of a large suite of biochemical and genetic parameters were evaluated in tissues (liver, gills, muscle and erythrocytes) of the estuarine guppy Poecilia vivipara exposed to waterborne copper in salt water (salinity 24 ppt). Activities of antioxidant enzymes (superoxide dismutase, catalase, glutathione reductase, and glutathione S-transferase), metallothionein-like protein concentration, reactive oxygen species (ROS) content, antioxidant capacity against peroxyl radicals (ACAP), and lipid peroxidation (LPO) were evaluated in liver, gills, and muscle. Comet assay score and nuclear abnormalities and micronucleated cell frequency were analyzed in peripheral erythrocytes. The responses of these parameters were evaluated in fish exposed (96 h) to environmentally relevant copper concentrations (5, 9 and 20 μg L{sup −1}). In control and copper-exposed fish, no mortality was observed over the experimental period. Almost all biochemical and genetic parameters proved to be affected by waterborne copper exposure. However, the response of catalase activity in liver, ROS, ACAP and LPO in muscle, gills and liver, and DNA damages in erythrocytes clearly showed to be dependent on copper concentration in salt water. Therefore, the use of these parameters could be of relevance in the scope of biomonitoring programs in salt water environments contaminated with copper.

  9. Synthesis and Characterization of Multifunctional Two-Component Waterborne Polyurethane Coatings: Fluorescence, Thermostability and Flame Retardancy

    Directory of Open Access Journals (Sweden)

    Xuan Yin

    2017-10-01

    Full Text Available Fluorescent and flame-retardant two-component waterborne polyurethane coatings were synthesized using 1,5-dihydroxy naphthalene, a halogen-free polyphosphate and a hydrophilic curing agent, and their properties were systematically characterized. The average particle sizes and zeta potential values were below 170 nm and −30 mV. Meanwhile, the multifunctional two-component waterborne polyurethane coatings had strong fluorescence intensities. When comparing with the coatings with 0.5 wt % 1,5-dihydroxy naphthalene, the coatings with 1.0 wt % 1,5-dihydroxy naphthalene had a stronger microphase separation. Interestingly, the thermostability of the multifunctional coatings was remarkably improved through 1.0 wt % 1,5-dihydroxy naphthalene, and besides it belonged to nonflammable materials. Additionally, all of the coating films passed the solvent resistance testing. These samples with different amounts of 1,5-dihydroxy naphthalene are environmental friendly, especially applications that require transparent and fluorescent coatings.

  10. Immunomagnetic separation for MEMS-based biosensor of waterborne pathogens detection

    Science.gov (United States)

    Guo, Jianjiang; Zhang, Rongbiao

    2017-07-01

    Rapid isolation and detection of special pathogens present in environmental drinking water is critical for water quality monitoring. Numerical analysis and experimental investigations on immunomagnetic capture and isolation of waterborne pathogens with magnetic nanoparticles (MNPs) in microfluidic channel are performed. A finite-element COMSOL-based model is established to demonstrate the novel method of on-chip capturing pathogens using MNPs together with periodic pulse magnetic field. Simulation results determine the optimum magnetic pole current and switching frequency for magnetic separation. With the magnetic isolation experiment platform built up, as a pathogen example of Escherichia coli O157:H7, the performance of the method is experimentally verified. Both numerical and experimental results are found to agree reasonably well. Results of these investigations show that the capture efficiency of the immunomagnetic separation method is more than 92%, which could be encouraging for the design and optimization of MEMS-based biosensor of waterborne pathogen detection.

  11. Classification and prediction of river network ephemerality and its relevance for waterborne disease epidemiology

    Science.gov (United States)

    Perez-Saez, Javier; Mande, Theophile; Larsen, Joshua; Ceperley, Natalie; Rinaldo, Andrea

    2017-12-01

    The transmission of waterborne diseases hinges on the interactions between hydrology and ecology of hosts, vectors and parasites, with the long-term absence of water constituting a strict lower bound. However, the link between spatio-temporal patterns of hydrological ephemerality and waterborne disease transmission is poorly understood and difficult to account for. The use of limited biophysical and hydroclimate information from otherwise data scarce regions is therefore needed to characterize, classify, and predict river network ephemerality in a spatially explicit framework. Here, we develop a novel large-scale ephemerality classification and prediction methodology based on monthly discharge data, water and energy availability, and remote-sensing measures of vegetation, that is relevant to epidemiology, and maintains a mechanistic link to catchment hydrologic processes. Specifically, with reference to the context of Burkina Faso in sub-Saharan Africa, we extract a relevant set of catchment covariates that include the aridity index, annual runoff estimation using the Budyko framework, and hysteretical relations between precipitation and vegetation. Five ephemerality classes, from permanent to strongly ephemeral, are defined from the duration of 0-flow periods that also accounts for the sensitivity of river discharge to the long-lasting drought of the 70's-80's in West Africa. Using such classes, a gradient-boosted tree-based prediction yielded three distinct geographic regions of ephemerality. Importantly, we observe a strong epidemiological association between our predictions of hydrologic ephemerality and the known spatial patterns of schistosomiasis, an endemic parasitic waterborne disease in which infection occurs with human-water contact, and requires aquatic snails as an intermediate host. The general nature of our approach and its relevance for predicting the hydrologic controls on schistosomiasis occurrence provides a pathway for the explicit inclusion of

  12. Water-borne hyphomycetes in tree canopies of Kaiga (Western Ghats, India

    Directory of Open Access Journals (Sweden)

    Naga M. Sudheep

    2013-12-01

    Full Text Available The canopy samples such as trapped leaf litter, trapped sediment (during summer, stemflow and throughfall (during monsoon from five common riparian tree species (Artocarpus heterophyllus, Cassia fistula, Ficus recemosa, Syzygium caryophyllatum and Xylia xylocarpa in Kaiga forest stand of the Western Ghats of southwest India were evaluated for the occurrence of water-borne hyphomycetes. Partially decomposed trapped leaf litter was incubated in bubble chambers followed by filtration to assess conidial output. Sediments accumulated in tree holes or junction of branches were shaken with sterile leaf disks in distilled water followed by incubation of leaf disks in bubble chamber and filtration to find out colonized fungi. Stemflow and throughfall samples were filtered directly to collect free conidia. From five canopy niches, a total of 29 water-borne hyphomycetes were recovered. The species richness was higher in stemflow and throughfall than trapped leaf litter and sediments (14-16 vs. 6-10 species. Although sediments of Syzygium caryophyllatum were acidic (5.1, the conidial output was higher than other tree species. Stemflow and throughfall of Xylea xylocarpa even though alkaline (8.5-8.7 showed higher species richness (6-12 species as well as conidial load than rest of the tree species. Flagellospora curvula and Triscelophorus acuminatus were common in trapped leaf litter and sediments respectively, while conidia of Anguillospora crassa and A. longissima were frequent in stemflow and throughfall. Diversity of water-borne hyphomycetes was highest in throughfall of Xylea xylocarpa followed by throughfall of Ficus recemosa. Our study reconfirms the occurrence and survival of diverse water-borne hyphomycetes in different niches of riparian tree canopies of the Western Ghats during wet and dry regimes and predicts their possible role in canopy as saprophytes, endophytes and alternation of life cycle between canopy and aquatic habitats.

  13. The design and implementation of a prototype surf-zone robot for waterborne operations

    OpenAIRE

    Ariza, Manuel

    2015-01-01

    Approved for public release; distribution is unlimited Three dimensional (3D) simulation, Fused Deposition Modeling (FDM) technology and Computer Numerical Control (CNC) milling are used to design and implement a waterborne surf-zone robot prototype. This robot is an autonomous platform meant to be a test-bed for sensors and algorithms for future developments; a key enabler is its modular design. It combines the capabilities of an untethered Remotely Operated Vehicle (ROV) and an Unmanned ...

  14. Failure Mechanisms of the Coating/Metal Interface in Waterborne Coatings: The Effect of Bonding

    OpenAIRE

    Hongxia Wan; Dongdong Song; Xiaogang Li; Dawei Zhang; Jin Gao; Cuiwei Du

    2017-01-01

    Waterborne coating is the most popular type of coating, and improving its performance is a key point of research. Cathodic delamination is one of the major modes of failure for organic coatings. It refers to the weakening or loss of adhesion between the coating and substrate. Physical and chemical characteristics of coatings have been studied via scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle measurements, Fourier transform infrared spectroscopy (FTIR), and s...

  15. Occurrence of Waterborne Pathogens and Escherichia coli at Offshore Drinking Water Intakes in Lake Ontario

    OpenAIRE

    Edge, T. A.; Khan, I. U. H.; Bouchard, R.; Guo, J.; Hill, S.; Locas, A.; Moore, L.; Neumann, N.; Nowak, E.; Payment, P.; Yang, R.; Yerubandi, R.; Watson, S.

    2013-01-01

    The occurrence of waterborne pathogens was investigated at three drinking water intakes located about 2 km offshore in Lake Ontario. Water sampling was conducted over 3 years for Campylobacter spp., Cryptosporidium spp., Giardia spp., cultivable enteric viruses, and water quality parameters. All pathogens were detected in the offshore source water for each water treatment plant (WTP1 to WTP3), although at relatively low frequencies and concentrations. Giardia was the most common pathogen, occ...

  16. River Networks As Ecological Corridors for Species, Populations and Pathogens of Water-Borne Disease

    Science.gov (United States)

    Rinaldo, A.

    2014-12-01

    River basins are a natural laboratory for the study of the integration of hydrological, ecological and geomorphological processes. Moving from morphological and functional analyses of dendritic geometries observed in Nature over a wide range of scales, this Lecture addresses essential ecological processes that take place along dendritic structures, hydrology-driven and controlled, like e.g.: population migrations and human settlements, that historically proceeded along river networks to follow water supply routes; riparian ecosystems composition that owing to their positioning along streams play crucial roles in their watersheds and in the loss of biodiversity proceeding at unprecedented rates; waterborne disease spreading, like epidemic cholera that exhibits epidemic patterns that mirror those of watercourses and of human mobility and resurgences upon heavy rainfall. Moreover, the regional incidence of Schistosomiasis, a parasitic waterborne disease, and water resources developments prove tightly related, and proliferative kidney disease in fish thrives differently in pristine and engineered watercourses: can we establish quantitatively the critical linkages with hydrologic drivers and controls? How does connectivity within a river network affect community composition or the spreading mechanisms? Does the river basin act as a template for biodiversity or for species' persistence? Are there hydrologic controls on epidemics of water-borne disease? Here, I shall focus on the noteworthy scientific perspectives provided by spatially explicit eco-hydrological studies centered on river networks viewed as ecological corridors for species, populations and pathogens of waterborne disease. A notable methodological coherence is granted by the mathematical description of river networks as the support for reactive transport. The Lecture overviews a number of topics idiosyncratically related to my own research work but ideally aimed at a coherent body of materials and methods. A

  17. Comparison of a Riverine Waterborne Transport and Dispersion Model and Yellowstone River Dye Releases

    Science.gov (United States)

    2015-01-01

    and Dispersion Model and Yellowstone River Dye Releases N. Platt, Project Leader J. L. Palguta January 2015...F E N S E A N A L Y S E S IDA Document D-5330 Comparison of a Riverine Waterborne Transport and Dispersion Model and Yellowstone ...conducted in the Yellowstone River. We selected this study because it provided all the necessary information for setting up ICWater simulations and

  18. Oncogenic Papillomavirus and Polyomavirus in Water Environments: Is There a Potential for Waterborne Transmission?

    Science.gov (United States)

    Fratini, M; Di Bonito, P; La Rosa, G

    2014-03-01

    Waterborne exposure to human viruses through contact with sewage-contaminated water environments can result in infections associated with a wide range of illnesses. Gastrointestinal symptoms are the most commonly encountered manifestations of waterborne viral illness. Respiratory diseases, neurological diseases and paralysis can also occur. Whether viral infections resulting in health outcomes like cancer might also be transmitted by the waterborne route is unknown. Recently, viruses belonging to two oncogenic groups-Human Papillomaviruses (HPVs) and Human Polyomaviruses (HPyVs)-have been detected in urban sewages worldwide. The latter have also been identified in other water environments. HPVs are epitheliotropic viruses responsible for several diseases of skin and mucosae, from common warts to squamous intraepithelial lesions that can either heal or progress to invasive carcinoma of the cervix, vulva, vagina, penis, anus or oropharynx. Human PyVs infect different tissues and organs, causing infections that are usually subclinical in immunocompetent individuals but can be serious in immunocompromised hosts. These pathogens belong to a family of DNA tumour viruses. Merkel cell polyomavirus, a HPyV identified in recent years, has attracted much attention due to its link with a rare and aggressive form of human cancer. Merkel cell carcinoma, the incidence of which has tripled over the past two decades. JC polyomavirus and BK polyomavirus are also potentially oncogenic. The observed abundance and wide dissemination of HPVs and HPyVs in water environments strongly suggest the need to shed light on the fate of these viruses in water environments and to elucidate their potential for waterborne transmission. Such information is essential for the improvement of wastewater management programs in terms of both sewage treatment and water quality surveillance.

  19. Amebae and ciliated protozoa as causal agents of waterborne zoonotic disease.

    Science.gov (United States)

    Schuster, Frederick L; Visvesvara, Govinda S

    2004-12-09

    The roles free-living amebae and the parasitic protozoa Entamoeba histolytica and Balantidium coli play as agents of waterborne zoonotic diseases are examined. The free-living soil and water amebae Naegleria fowleri, Acanthamoeba spp., and Balamuthia mandrillaris are recognized etiologic agents of mostly fatal amebic encephalitides in humans and other animals, with immunocompromised and immunocompetent hosts among the victims. Acanthamoeba spp. are also agents of amebic keratitis. Infection is through the respiratory tract, breaks in the skin, or by uptake of water into the nostrils, with spread to the central nervous system. E. histolytica and B. coli are parasitic protozoa that cause amebic dysentery and balantidiasis, respectively. Both intestinal infections are spread via a fecal-oral route, with cysts as the infective stage. Although the amebic encephalitides can be acquired by contact with water, they are not, strictly speaking, waterborne diseases and are not transmitted to humans from animals. Non-human primates and swine are reservoirs for E. histolytica and B. coli, and the diseases they cause are acquired from cysts, usually in sewage-contaminated water. Amebic dysentery and balantidiasis are examples of zoonotic waterborne infections, though human-to-human transmission can occur. The epidemiology of the diseases is examined, as are diagnostic procedures, anti-microbial interventions, and the influence of globalization, climate change, and technological advances on their spread.

  20. New hybrid latexes from a soybean oil-based waterborne polyurethane and acrylics via emulsion polymerization.

    Science.gov (United States)

    Lu, Yongshang; Larock, Richard C

    2007-10-01

    A series of new waterborne polyurethane (PU)/acrylic hybrid latexes have been successfully synthesized by the emulsion polymerization of acrylic monomers (butyl acrylate and methyl methacrylate) in the presence of a soybean oil-based waterborne PU dispersion using potassium persulfate as an initiator. The waterborne PU dispersion has been synthesized by a polyaddition reaction of toluene 2,4-diisocyanate and a soybean oil-based polyol (SOL). The resulting hybrid latexes, containing 15-60 wt % SOL as a renewable resource, are very stable and exhibit uniform particle sizes of 125 +/- 20 nm as determined by transmittance electronic microscopy. The structure, thermal, and mechanical properties of the resulting hybrid latex films have been investigated by Fourier transform infrared spectroscopy, solid state 13C NMR spectroscopy, dynamic mechanical analysis, extraction, and mechanical testing. Grafting copolymerization of the acrylic monomers onto the PU network occurs during the emulsion polymerization, leading to a significant increase in the thermal and mechanical properties of the resulting hybrid latexes. This work provides a new way of utilizing renewable resources to prepare environmentally friendly hybrid latexes with high performance for coating applications.

  1. Corrosion protection performance of waterborne epoxy coatings containing self-doped polyaniline nanofiber

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Shihui [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201 (China); Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, 315211 (China); Chen, Cheng; Cui, Mingjun [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201 (China); Li, Wei [Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, 315211 (China); Zhao, Haichao, E-mail: zhaohaichao@nimte.ac.cn [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201 (China); Wang, Liping, E-mail: wangliping@nimte.ac.cn [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201 (China)

    2017-06-15

    Highlights: • Self-dopedpolyaniline (SPANi) with good conductivity and dispersibility in water was copolymerized by aniline and its derivative. • Environmental friendly SPANi/epoxy composite coating with remarkable anti-corrosion performance was prepared. • The corrosion product of pure epoxy or composite coating was characterized by X-ray diffraction pattern and scanning electron microscope (SEM). - Abstract: Self-doped sulfonated polyaniline (SPANi) nanofiber was synthesized by the copolymerization of 2-aminobenzenesulfonic acid (ASA) and aniline via a rapid mixing polymerization approach. The chemical structure of SPANi was investigated by the Fourier-transform infrared (FT-IR), Raman, X-ray photoelectron spectroscopy (XPS), UV–vis spectra and X-ray diffraction (XRD) pattern. The as-prepared SPANi nanofibers had 45 nm average diameter and length up to 750 nm as measured by scanning electron microscope (SEM) and transmission electron microscope (TEM). The self-doped SPANi nanofiber possessed excellent aqueous solubility, good conductivity (0.11 S/cm) and reversible redox activity, making it suitable as a corrosion inhibitor for waterborne coatings. The prepared SPANi/waterborne epoxy composite coatings exhibited remarkably improved corrosion protection compared with pure waterborne epoxy coating as proved by the polarization curves and electrochemical impedance spectroscopy (EIS). The passivation effect of SPANi nanofiber and the corrosion products beneath the epoxy coatings immersed in 3.5% NaCl solution as a function of time were also investigated in this study.

  2. Water quality and occurrence of water-borne diseases in the Douala 4th District, Cameroon.

    Science.gov (United States)

    Ako, Andrew Ako; Nkeng, George Elambo; Takem, Gloria Eyong Eneke

    2009-01-01

    The monthly occurrence and mean age distribution of water-borne diseases in the Douala 4th District, Cameroon (1995-2006) were studied and probable causes of diseases spread were established. Diseases of interest included gastroenteritis, amoebic dysentery, typhoid fever and cholera. Water-borne disease occurrence was observed to follow a seasonal pattern with peaks occurring between the months of January and May followed by drops between June and October and rose again from November. Children below 5 years were found to be more vulnerable to diarrhoea, gastroenteritis, amoebic dysentery while persons between 15-44 years were more vulnerable to typhoid and cholera. Physico-chemically, water samples had turbidities varying between 5.5-86 NTU, pH values between 4.2 and 7.1 and zero residual chlorine. Bacteriological analysis showed that the total coliform count was averagely 74/100 ml, the faecal colform count was 43/100 ml and the faecal streptococci count was 27/100 ml. Lack of access to potable water, absence of sanitation facilities and environmental factors could be advanced as the probable causes of water-borne disease spread.

  3. River networks as ecological corridors for species, populations and pathogens of water-borne disease (Invited)

    Science.gov (United States)

    Rinaldo, A.; Bertuzzo, E.; Mari, L.; Suweis, S.; Ceola, S.; Carrara, F.; Rodriguez-Iturbe, I.

    2010-12-01

    Recent works at the interface of hydrology, geomorphology and ecology under an integrated framework of analysis will be reviewed with a view to a general theory for reactive transport on networks. A number of related topics will be reviewed, linked by the characters of stochastic transport, and the networked environmental matrix (including biodiversity of freshwater fish in river networks and vegetation along riparian systems, how river networks affected historic spreading of human populations, and how they influence the spreading of water-borne disease). The unique, coherent ecohydrological thread and similar mathematical methods will be exposed. Metacommunity and individual-based models will be described in the contexts of hydrochory, population and species migrations, and the spreading of infections of water-borne disease along the ecological corridors generated by the river basin. A general effect is shown to emerge on the effects of dendritic geometries on the ecological processes and dynamics operating on river basins. Insights provided by such a theory will lend themselves to issues of practical importance such as integration of riparian systems into large-scale resource management, spatial strategies to minimize loss of freshwater biodiversity, and effective prevention/vaccination campaigns against water-borne diseases.

  4. Environmental health aspects of drinking water-borne outbreak due to karst flooding: case study.

    Science.gov (United States)

    Dura, Gyula; Pándics, Tamás; Kádár, Mihály; Krisztalovics, Katalin; Kiss, Zoltánné; Bodnár, Judit; Asztalos, Agnes; Papp, Erzsébet

    2010-09-01

    Climate change may increase the incidence of waterborne diseases due to extreme rainfall events, and consequent microbiological contamination of the water source and supply. As a result of the complexity of the pathways from the surface to the consumer, it is difficult to detect an association between rainfall and human disease. The water supply of a Hungarian city, Miskolc (174,000 inhabitant), is mainly based on karstic water, a vulnerable underground water body. A large amount of precipitation fell on the catchment area of the karstic water source, causing an unusually strong karstic water flow and flooding, and subsequent microbiological contamination. The presence of several potential sources of contamination in the protective zone of the karstic water source should be emphasized. The water supplier was unprepared to treat the risk of waterborne outbreak caused by an extreme weather event. Public health intervention and hygienic measures were taken in line with epidemiological actions, focusing on the protection of consumers by providing safe drinking water. The contamination was identified, and measures were taken for risk reduction and prevention. This case study underlines the increasing importance of preparedness for extreme water events in order to protect the karstic water sources and to avoid waterborne outbreaks.

  5. Corrosion protection performance of waterborne epoxy coatings containing self-doped polyaniline nanofiber

    Science.gov (United States)

    Qiu, Shihui; Chen, Cheng; Cui, Mingjun; Li, Wei; Zhao, Haichao; Wang, Liping

    2017-06-01

    Self-doped sulfonated polyaniline (SPANi) nanofiber was synthesized by the copolymerization of 2-aminobenzenesulfonic acid (ASA) and aniline via a rapid mixing polymerization approach. The chemical structure of SPANi was investigated by the Fourier-transform infrared (FT-IR), Raman, X-ray photoelectron spectroscopy (XPS), UV-vis spectra and X-ray diffraction (XRD) pattern. The as-prepared SPANi nanofibers had 45 nm average diameter and length up to 750 nm as measured by scanning electron microscope (SEM) and transmission electron microscope (TEM). The self-doped SPANi nanofiber possessed excellent aqueous solubility, good conductivity (0.11 S/cm) and reversible redox activity, making it suitable as a corrosion inhibitor for waterborne coatings. The prepared SPANi/waterborne epoxy composite coatings exhibited remarkably improved corrosion protection compared with pure waterborne epoxy coating as proved by the polarization curves and electrochemical impedance spectroscopy (EIS). The passivation effect of SPANi nanofiber and the corrosion products beneath the epoxy coatings immersed in 3.5% NaCl solution as a function of time were also investigated in this study.

  6. Waterborne disease-related risk perceptions in the Sonora River basin, Mexico.

    Science.gov (United States)

    Morua, Agustin Robles; Halvorsen, Kathleen E; Mayer, Alex S

    2011-05-01

    Waterborne disease is estimated to cause about 10% of all diseases worldwide. However, related risk perceptions are not well understood, particularly in the developing world where waterborne disease is an enormous problem. We focus on understanding risk perceptions related to these issues in a region within northern Mexico. Our findings show how waterborne disease problems and solutions are understood in eight small communities along a highly contaminated river system. We found major differences in risk perceptions between health professionals, government officials, and lay citizens. Health professionals believed that a high level of human-waste-related risk existed within the region. Few officials and lay citizens shared this belief. In addition, few officials and lay citizens were aware of poor wastewater-management-related disease outbreaks and water contamination. Finally, aside from health professionals, a few interviewees understood the importance of basic hygiene and water treatment measures that could help to prevent disease. Our results add to the literature on environmentally-related risk perceptions in the developing world. We discuss recommendations for improving future human-wastewater-related risk communication within the region. © 2011 Society for Risk Analysis.

  7. A systematic review of nosocomial waterborne infections in neonates and mothers.

    Science.gov (United States)

    Moffa, Michelle; Guo, Wilson; Li, Trudy; Cronk, Ryan; Abebe, Lydia S; Bartram, Jamie

    2017-11-01

    Water is an important, overlooked, and controllable source of nosocomial infection. Hospitalized neonates and their mothers are particularly vulnerable to nosocomial waterborne infections. Our objectives through this systematic review were to: investigate water sources, reservoirs, and transmission routes that lead to nosocomial waterborne infections in neonates and their mothers; establish patient risk factors; compile measures for controlling outbreaks and recommended strategies for prevention; and identify information gaps to improve guidelines for reporting future outbreaks. We searched PubMed, Web of Science, Embase, and clinicaltrials.gov. Peer-reviewed studies reporting contaminated water as a route of transmission to neonates and/or their mothers were included. Twenty-five studies were included. The most common contaminated water sources in healthcare facilities associated with infection transmission were tap water, sinks, and faucets. Low birthweights, preterm or premature birth, and underlying disease increased neonatal risk of infection. Effective control measures commonly included replacing or cleaning faucets and increased or alternative methods for hand disinfection, and recommendations for prevention of future infections highlighted the need for additional surveillance. The implementation of control measures and recommended prevention strategies by healthcare workers and managing authorities of healthcare facilities and improved reporting of future outbreaks may contribute to a reduction in the incidence of nosocomial waterborne infections in neonates and their mothers. Copyright © 2017 Elsevier GmbH. All rights reserved.

  8. Upgrading a piped water supply from intermittent to continuous delivery and association with waterborne illness: a matched cohort study in urban India

    National Research Council Canada - National Science Library

    Ercumen, Ayse; Arnold, Benjamin F; Kumpel, Emily; Burt, Zachary; Ray, Isha; Nelson, Kara; Colford, Jr, John M

    2015-01-01

    ... water availability for hygiene. We assessed the association between continuous versus intermittent water supply and waterborne diseases, child mortality, and weight for age in Hubli-Dharwad, India...

  9. Climate change impacts on faecal indicator and waterborne pathogen concentrations and disease

    Science.gov (United States)

    Hofstra, Nynke; Vermeulen, Lucie C.; Wondmagegn, Berhanu Y.

    2013-04-01

    Changes in temperature and precipitation patterns may impact on the concentrations of the faecal indicator E. coli and waterborne pathogens, such as Cryptosporidium, in the surface water, and consequently - through drinking water, recreational water or consumption of irrigated vegetables - on the risk of waterborne disease. Although an increased temperature would generally increase the decline of pathogens and therefore decrease the surface water concentrations, increased precipitation and an increased incidence of extreme precipitation may increase surface water concentrations through increased (sub-)surface runoff and an increased risk of sewer overflows. And while the diluting effect of increased precipitation decreases the surface water concentration, decreased precipitation increases the percentage of sewage in the surface water and therefore increases the concentration. Moreover, (extreme) precipitation after drought may also increase the concentration. Changes in behaviour, such as increased recreation and irrigation with higher temperatures may impact on the disease risk. What the balance is between these positive and negative impacts of climate change on faecal indicator and waterborne pathogen concentrations and disease is not well known yet. A lack of available statistical or process-based models and suitable scenarios prevents quantitative analyses. We will present two examples of recent studies that aim to assess the impact of climate change on faecal indicator concentrations and waterborne disease. The first is a study on the relationship between climate variables and E. coli concentrations in the water of river systems in the Netherlands for the period 1985 - 2010. This study shows that each of the variables water temperature (negatively), precipitation and discharge (both positively) are significantly correlated with E. coli concentrations for most measurement locations. We will also present a linear regression model, including all of these

  10. Analytical studies assessing the association between extreme precipitation or temperature and drinking water-related waterborne infections: a review.

    Science.gov (United States)

    Guzman Herrador, Bernardo R; de Blasio, Birgitte Freiesleben; MacDonald, Emily; Nichols, Gordon; Sudre, Bertrand; Vold, Line; Semenza, Jan C; Nygård, Karin

    2015-03-27

    Determining the role of weather in waterborne infections is a priority public health research issue as climate change is predicted to increase the frequency of extreme precipitation and temperature events. To document the current knowledge on this topic, we performed a literature review of analytical research studies that have combined epidemiological and meteorological data in order to analyze associations between extreme precipitation or temperature and waterborne disease.A search of the databases Ovid MEDLINE, EMBASE, SCOPUS and Web of Science was conducted, using search terms related to waterborne infections and precipitation or temperature. Results were limited to studies published in English between January 2001 and December 2013.Twenty-four articles were included in this review, predominantly from Asia and North-America. Four articles used waterborne outbreaks as study units, while the remaining articles used number of cases of waterborne infections. Results presented in the different articles were heterogeneous. Although most of the studies identified a positive association between increased precipitation or temperature and infection, there were several in which this association was not evidenced. A number of articles also identified an association between decreased precipitation and infections. This highlights the complex relationship between precipitation or temperature driven transmission and waterborne disease. We encourage researchers to conduct studies examining potential effect modifiers, such as the specific type of microorganism, geographical region, season, type of water supply, water source or water treatment, in order to assess how they modulate the relationship between heavy rain events or temperature and waterborne disease. Addressing these gaps is of primary importance in order to identify the areas where action is needed to minimize negative impact of climate change on health in the future.

  11. Natural Populations of Shipworm Larvae Are Attracted to Wood by Waterborne Chemical Cues

    Science.gov (United States)

    Toth, Gunilla B.; Larsson, Ann I.; Jonsson, Per R.; Appelqvist, Christin

    2015-01-01

    The life cycle of many sessile marine invertebrates includes a dispersive planktonic larval stage whose ability to find a suitable habitat in which to settle and transform into benthic adults is crucial to maximize fitness. To facilitate this process, invertebrate larvae commonly respond to habitat-related chemical cues to guide the search for an appropriate environment. Furthermore, small-scale hydrodynamic conditions affect dispersal of chemical cues, as well as swimming behavior of invertebrate larvae and encounter with potential habitats. Shipworms within the family Teredinidae are dependent on terrestrially derived wood in order to complete their life cycle, but very little is known about the cues and processes that promote settlement. We investigated the potential for remote detection of settling substrate via waterborne chemical cues in teredinid larvae through a combination of empirical field and laboratory flume experiments. Natural populations of teredinid larvae were significantly more abundant close to wooden structures enclosed in plankton net compared to empty control nets, clearly showing that shipworm larvae can sense and respond to chemical cues associated with suitable settling substrate in the field. However, the flume experiments, using ecologically relevant flow velocities, showed that the boundary layer around experimental wooden panels was thin and that the mean flow velocity exceeded larval swimming velocity approximately 5 mm (≈ 25 larval body lengths) from the panel surface. Therefore, we conclude that the scope for remote detection of waterborne cues is limited and that the likely explanation for the higher abundance of shipworm larvae associated with the wooden panels in the field is a response to a cue during or after attachment on, or very near, the substrate. Waterborne cues probably guide the larva in its decision to remain attached and settle, or to detach and continue swimming and drifting until the next encounter with a solid

  12. Are soil and waterborne parasitic infections health risk for worker populations in southeast Turkey?

    Directory of Open Access Journals (Sweden)

    Sibel Ak

    2017-06-01

    Full Text Available Objective: The soil and waterborne parasitic infections rate is high degree in developed and developing countries. Migratory workers have greater exposure to these parasitic infections and a lot of morbidity due to these infections in workers. For this reason, we aimed to investigate the presence of soil and waterborne parasites in the Gaziantep Organized Industrial Zone of southeast Turkey. Methods: A total of 25 environmental samples (18 soil samples and 7 water samples were taken from The Gaziantep Organized Industrial Zone, in two different seasons (summer and winter. All of the samples were screened for parasites using microscopic examination and culture methods. The parasites were genotyped with polymerase chain reaction and DNA sequencing analysis. Results: The prevalence of soil and water transmitted parasites was found to be positive 52% (13/25 in summer while there is no any parasites in winter. It was found 22.3% (4/18 Acanthamoeba (genotype4, 16.6% (3/18 Ascaris lumbricoides, 11.1% (2/18 Strongoides stercoralis in soil samples and 14.3% (1/7 Acanthamoeba (genotype 4, 42.9% (3/7 Blastocystis (subtype3 in all of water samples. Conclusion: The migratory worker waves have always shaped the ethnic composition and public health problem of the province of Gaziantep. Climate change has the potential to influence prevalence of parasite and our study has shown that increased prevalence of parasite in summer. The global target for the coming years should be to remove the deaths from earth and waterborne parasitic infections in the worker populations. Thus, we prevent the distribution of parasitic infections in our country.

  13. Copper uptake kinetics and regulation in a marine fish after waterborne copper acclimation

    Energy Technology Data Exchange (ETDEWEB)

    Dang Fei; Zhong Huan [AMCE and Department of Biology, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong); Wang Wenxiong, E-mail: wwang@ust.hk [AMCE and Department of Biology, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong)

    2009-09-14

    The uptake kinetics and regulation of copper in a marine predatory fish, the black sea bream Acanthopagrus schlegeli after acclimation to waterborne Cu were examined, using radiotracer techniques. The dissolved Cu uptake followed a linear pattern during the time of exposure, and the calculated uptake rate constant was 6.24 L kg{sup -1} day{sup -1}. The efflux rate constant was 0.091 day{sup -1} following dietary uptake of Cu, and the dietary assimilation efficiency (AE) of Cu varied between 1.7% and 10.9% after the fish were fed with three types of prey (oysters, clams and brine shrimp). After the fish were acclimated at a nominal concentration of 50 {mu}g Cu L{sup -1} for 14 days, the Cu uptake rate and efflux rate constant did not change significantly, but the Cu body concentrations and metallothionein (MT) concentrations in fish tissues increased significantly. Subcellular Cu distributions were also modified. Significant MT induction was observed in response to increased Cu tissue concentrations, indicating that MT rather than the uptake kinetics may play a primary role in Cu regulation during waterborne Cu acclimation in this marine fish. Moreover, the high Cu efflux may also be important in Cu regulation during long-term exposure. Our modeling calculations indicated that dietary uptake was likely to be the main route for Cu bioaccumulation in the fish, and the relative contribution of waterborne and dietary uptake depended on the bioconcentration factor (BCF) of the prey and ingestion rate of fish.

  14. Natural populations of shipworm larvae are attracted to wood by waterborne chemical cues.

    Directory of Open Access Journals (Sweden)

    Gunilla B Toth

    Full Text Available The life cycle of many sessile marine invertebrates includes a dispersive planktonic larval stage whose ability to find a suitable habitat in which to settle and transform into benthic adults is crucial to maximize fitness. To facilitate this process, invertebrate larvae commonly respond to habitat-related chemical cues to guide the search for an appropriate environment. Furthermore, small-scale hydrodynamic conditions affect dispersal of chemical cues, as well as swimming behavior of invertebrate larvae and encounter with potential habitats. Shipworms within the family Teredinidae are dependent on terrestrially derived wood in order to complete their life cycle, but very little is known about the cues and processes that promote settlement. We investigated the potential for remote detection of settling substrate via waterborne chemical cues in teredinid larvae through a combination of empirical field and laboratory flume experiments. Natural populations of teredinid larvae were significantly more abundant close to wooden structures enclosed in plankton net compared to empty control nets, clearly showing that shipworm larvae can sense and respond to chemical cues associated with suitable settling substrate in the field. However, the flume experiments, using ecologically relevant flow velocities, showed that the boundary layer around experimental wooden panels was thin and that the mean flow velocity exceeded larval swimming velocity approximately 5 mm (≈ 25 larval body lengths from the panel surface. Therefore, we conclude that the scope for remote detection of waterborne cues is limited and that the likely explanation for the higher abundance of shipworm larvae associated with the wooden panels in the field is a response to a cue during or after attachment on, or very near, the substrate. Waterborne cues probably guide the larva in its decision to remain attached and settle, or to detach and continue swimming and drifting until the next

  15. Threat-Sensitive Behavioral Responses to Concentrations of Water-Borne Cues from Predation

    Science.gov (United States)

    Kesavaraju, Banugopan; Damal, Kavitha; Juliano, Steven A.

    2007-01-01

    Aquatic organisms often detect predators via water-borne chemical cues, and respond by showing reduced activity. Prey responses may be correlated with the concentration of predation cues, which would result in graded antipredator behavioral responses that adjust potentially costly behavioral changes to levels that are commensurate with the risk of predation. Larvae of the predatory mosquito Toxorhynchites rutilus prey upon other container-dwelling insects, including larvae of the mosquito Ochlerotatus triseriatus. Previous work has established that O. triseriatus reduce movement, foraging, and time below the surface, and increase the frequency of resting at the surface, in the presence of water-borne cues from predation by T. rutilus. We tested whether these responses by O. triseriatus are threat sensitive by recording behavior of fourth instar larvae in two runs of an experiment in which we created a series of concentrations (100, 10, 1, 0.1, and 0.01% and 100, 70, 40, 20, and 10%) of water that had held either O. triseriatus larvae alone (control) or a T. rutilus larva feeding on O. triseriatus (predation). We also tested whether associated effects on time spent feeding are threat sensitive by determining whether frequencies of filtering or browsing are also related to concentration of cues. The frequencies of resting and surface declined, whereas frequency of filtering (but not browsing) increased more rapidly with a decrease in concentration of predation cues compared with control cues. Thus, O. triseriatus shows a threat sensitive behavioral response to water-borne cues from this predator, adjusting its degree of behavioral response to the apparent risk of predation. PMID:17440601

  16. Reparation and characterization of water-borne polyurethane based on PCDL or (and) PCL prepolymer

    Science.gov (United States)

    Sun, Yenan; Zhao, Can; Xiao, Jijun

    2017-08-01

    A series of waterborne polyurethanes (WPUs) were synthesized by a pre-polymer process from isophorone diisocyanate and polycarbonatediol (PCDL), polycaprolactone (PCL). Fourier transform infrared spectroscopy, thermal gravimetric analysis, dynamic thermomechanical analysis and mechanical measurements were employed to characterize the thermal stability, physical and mechanical properties of the films derived from the emulsions. The results show that there is better mechanical properties of and thermal stability for PCL-based WPU. The thermal stability of PCDL-PCL based WPU, whichin the mass ratio of PCDL to PCL is 1 to 1 is the best. The PCDL-based WPU has the highest glass transition temperature.

  17. Preparation, thermal property and morphology analysis of waterborne polyurethane-acrylate

    Science.gov (United States)

    Zhao, Zhenyu; Jing, Zefeng; Qiu, Fengxian; Dai, Yuting; Xu, Jicheng; Yu, Zongping; Yang, Pengfei

    2017-01-01

    A series of waterborne polyurethane-acrylate (WPUA) dispersions were prepared with isophorone diisocyanate (IPDI), polyether polyol (NJ-210), dimethylol propionic acid (DMPA), hydroxyethyl methyl acrylate (HEMA), different proportions of methyl methacrylate (MMA) and ethyl acrylate (MMA and EA) and initiating agent by the emulsion co-polymerization. The structures, thermal properties and morphology of WPUA films were characterized with FT-IR, DSC, SEM and AFM. Performances of the dispersions and films were studied by means of apparent viscidity, particle size and polydispersity, surface tension and mechanical properties. The obtained WPUA have great potential application such as coatings, leather finishing, adhesives, sealants, plastic coatings and wood finishes.

  18. Risk perception and water purification practices for water-borne parasitic infections in remote Nepal.

    Science.gov (United States)

    Kovalsky, Adrienne N; Lacey, Steven E; Kaphle, Upendra Raj; Vaughn, James M

    2008-10-01

    This study assesses water-borne infection risk perception and water boiling habits in a remote Sankhuwasava region of Nepal using a brief interview-style questionnaire. All subjects were aware of the risks associated with drinking unpurified water, but a majority (65%) reported they did not boil water regularly, and almost 60% of villagers interviewed had history of infection despite their boiling practices. In contrast to reports from other communities in Nepal, risk awareness was sufficient in this region. Water boiling alone did not confer protection. Future efforts should target sanitation, screening, and other sources of contamination.

  19. Water-borne Infections, Weather Variability and Climate Change in Eastern Russia

    Science.gov (United States)

    Tirrell, A.; Naumova, E. N.; Liss, A.

    2012-12-01

    For this project, a time-series analysis of existing data will be used to assess temporal and spatial associations between long-term, seasonal and short-term weather variability and water-borne infectious diseases in several Siberian municipalities. Building on these associations, we will generate estimates of future changes in infectious disease patterns based upon existing forecasts of climate change and likely increases in extreme weather events in Eastern Russia. Finally, we will contemplate the public health implications of these findings, and offer appropriate policy recommendations.

  20. The subcellular fate of cadmium and zinc in the scallop Chlamys nobilis during waterborne and dietary metal exposure

    Energy Technology Data Exchange (ETDEWEB)

    Pan Ke [Department of Biology, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong); Wang Wenxiong [Department of Biology, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong)], E-mail: wwang@ust.hk

    2008-12-11

    Subcellular metal distribution has received increasing attention in aquatic toxicology studies, but the relationship between metal distribution and metal biokinetics remains largely unexplored. A series of short-term experiments on different concentrations of dissolved and dietary metals and on metal elimination were conducted to investigate the dynamics of subcellular distribution of Cd and Zn in the scallop Chlamys nobilis, a bivalve species that is known to accumulate very high concentrations of Cd and Zn in its tissues. Our results showed that, in general, both Cd and Zn were sequestered in insoluble forms (organelles, metal-rich granules, and cellular debris). The main binding pool for the newly acquired metals was organelles for Cd and cellular debris for Zn. Metallothionein-like protein (MTLP) was the most important storage pool for Cd in the scallops. Storage in the non-toxic form both in organelles and MTLP instead of through exocytosis was the major detoxification strategy to control Cd and accounted for the low efflux rate of Cd from scallops. In contrast to Cd, the main binding pool for Zn was cellular debris. Significant changes were found in the scallops when they were challenged with different concentrations of metals in the aqueous and food phases. Such changes provide important information on how scallops handle metals when there is increasing metal uptake. The redistribution of Zn among each subcellular compartment was much faster than the redistribution of Cd, suggesting an effective regulation mechanism for Zn in scallops. Thus, knowing subcellular metal distribution helps in studying the toxicity of both waterborne and dietborne metals.

  1. Differential effect of waterborne cadmium exposure on lipid metabolism in liver and muscle of yellow catfish Pelteobagrus fulvidraco

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Qi-Liang; Gong, Yuan [Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture of P.R.C., Fishery College, Huazhong Agricultural University, Wuhan 430070 (China); Freshwater Aquaculture Collaborative Innovative Centre of Hubei Province, Wuhan 430070 (China); Luo, Zhi, E-mail: luozhi99@mail.hzau.edu.cn [Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture of P.R.C., Fishery College, Huazhong Agricultural University, Wuhan 430070 (China); Freshwater Aquaculture Collaborative Innovative Centre of Hubei Province, Wuhan 430070 (China); Zheng, Jia-Lang; Zhu, Qing-Ling [Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture of P.R.C., Fishery College, Huazhong Agricultural University, Wuhan 430070 (China); Freshwater Aquaculture Collaborative Innovative Centre of Hubei Province, Wuhan 430070 (China)

    2013-10-15

    Highlights: •Cd triggered hepatic lipid accumulation through the improvement of lipogenesis. •Lipid homeostasis in muscle after Cd exposure derived from the down-regulation of both lipogenesis and lipolysis. •Our study determines the mechanism of waterborne Cd exposure on lipid metabolism in fish on a molecular level. •Our study indicates the tissue-specific regulatory effect of lipid metabolism under waterborne Cd exposure. -- Abstract: The present study was conducted to investigate the effect of waterborne cadmium (Cd) exposure on lipid metabolism in liver and muscle of juvenile yellow catfish Pelteobagrus fulvidraco. Yellow catfish were exposed to 0 (control), 0.49 and 0.95 mg Cd/l, respectively, for 6 weeks, the lipid deposition, Cd accumulation, the activities and expression level of several enzymes as well as the mRNA expression of transcription factors involved in lipid metabolism in liver and muscle were determined. Waterborne Cd exposure reduced growth performance, but increased Cd accumulation in liver and muscle. In liver, lipid content, the activities and the mRNA expression of lipogenic enzymes (6-phosphogluconate dehydrogenase (6PGD), glucose-6-phosphate dehydrogenase (G6PD), fatty acid synthetase (FAS)) and lipoprotein lipase (LPL) activity increased with increasing waterborne Cd concentrations. However, the mRNA expressions of LPL and peroxisome proliferators-activated receptor (PPAR) α were down-regulated by Cd exposure. Carnitine palmitoyltransferase 1 (CPT1) activity as well as the mRNA expressions of CPT1 and PPARγ showed no significant differences among the treatments. In muscle, lipid contents showed no significant differences among the treatments. The mRNA expression of 6PGD, FAS, CPT1, LPL, PPARα and PPARγ were down-regulated by Cd exposure. Thus, our study indicated that Cd triggered hepatic lipid accumulation through the improvement of lipogenesis, and that lipid homeostasis in muscle was probably conducted by the down

  2. Thermal post-treatment alters nutrient release from a controlled-release fertilizer coated with a waterborne polymer

    OpenAIRE

    Zhou, Zijun; Du, Changwen; Li, Ting; Shen, Yazhen; Zhou, Jianmin

    2015-01-01

    Controlled-release fertilizers (CRF) use a controlled-release technology to enhance the nutrient use efficiency of crops. Many factors affect the release of nutrients from the waterborne polymer-coated CRF, but the effects of thermal post-treatments remain unclear. In this study, a waterborne polyacrylate-coated CRF was post-treated at different temperatures (30 °C, 60 °C, and 80 °C) and durations (2, 4, 8, 12, and 24 h) after being developed in the Wurster fluidized bed. To characterize the ...

  3. Protection of waterborne pathogens by higher organisms in drinking water: a review.

    Science.gov (United States)

    Bichai, Françoise; Payment, Pierre; Barbeau, Benoit

    2008-07-01

    Higher organisms are ubiquitous in surface waters, and some species can proliferate in granular filters of water treatment plants and colonize distribution systems. Meanwhile, some waterborne pathogens are known to maintain viability inside amoebae or nematodes. The well-documented case of Legionella replication within amoebae is only one example of a bacterial pathogen that can be amplified inside the vacuoles of protozoa and then benefit from the protection of a resistant structure that favours its transport and persistence through water systems. Yet the role of most zooplankton organisms (rotifers, copepods, cladocerans) in pathogen transmission through drinking water remains poorly understood, since their capacity to digest waterborne pathogens has not been well characterized to date. This review aims at (i) evaluating the scientific observations of diverse associations between superior organisms and pathogenic microorganisms in a drinking water perspective and (ii) identifying the missing data that impede the establishment of cause-and-effect relationships that would permit a better appreciation of the sanitary risk arising from such associations. Additional studies are needed to (i) document the occurrence of invertebrate-associated pathogens in relevant field conditions, such as distribution systems; (ii) assess the fate of microorganisms ingested by higher organisms in terms of viability and (or) infectivity; and (iii) study the impact of internalization by zooplankton on pathogen resistance to water disinfection processes, including advanced treatments such as UV disinfection.

  4. Waterborne polyurethane-acrylic hybrid nanoparticles by miniemulsion polymerization: applications in pressure-sensitive adhesives.

    Science.gov (United States)

    Lopez, Aitziber; Degrandi-Contraires, Elise; Canetta, Elisabetta; Creton, Costantino; Keddie, Joseph L; Asua, José M

    2011-04-05

    Waterborne polyurethane-acrylic hybrid nanoparticles for application as pressure-sensitive adhesives (PSAs) were prepared by one-step miniemulsion polymerization. The addition of polyurethane to a standard waterborne acrylic formulation results in a large increase in the cohesive strength and hence a much higher shear holding time (greater than seven weeks at room temperature), which is a very desirable characteristic for PSAs. However, with the increase in cohesion, there is a decrease in the relative viscous component, and hence there is a decrease in the tack energy. The presence of a small concentration of methyl methacrylate (MMA) in the acrylic copolymer led to phase separation within the particles and created a hemispherical morphology. The tack energy was particularly low in the hybrid containing MMA because of the effects of lower energy dissipation and greater cross-linking. These results highlight the great sensitivity of the viscoelastic and adhesive properties to the details of the polymer network architecture and hence to the precise composition and synthesis conditions.

  5. Urbanization and human health in urban India: institutional analysis of water-borne diseases in Ahmedabad.

    Science.gov (United States)

    Saravanan, V S; Ayessa Idenal, Marissa; Saiyed, Shahin; Saxena, Deepak; Gerke, Solvay

    2016-10-01

    Diseases are rapidly urbanizing. Ageing infrastructures, high levels of inequality, poor urban governance, rapidly growing economies and highly dense and mobile populations all create environments rife for water-borne diseases. This article analyzes the role of institutions as crosscutting entities among a myriad of factors that breed water-borne diseases in the city of Ahmedabad, India. It applies 'path dependency' and a 'rational choice' perspective to understand the factors facilitating the breeding of diseases. This study is based on household surveys of approximately 327 households in two case study wards and intermittent interviews with key informants over a period of 2 years. Principle component analysis is applied to reduce the data and convert a set of observations, which potentially correlate with each other, into components. Institutional analyses behind these components reveal the role of social actors in exploiting the deeply rooted inefficiencies affecting urban health. This has led to a vicious cycle; breaking this cycle requires understanding the political dynamics that underlie the exposure and prevalence of diseases to improve urban health. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. A novel hydroxyl epoxy phosphate monomer enhancing the anticorrosive performance of waterborne Graphene/Epoxy coatings

    Science.gov (United States)

    Ding, Jiheng; Rahman, Obaid ur; Peng, Wanjun; Dou, Huimin; Yu, Haibin

    2018-01-01

    Herein, we report the synthesis of a novel hydroxyl epoxy phosphate monomer (PGHEP) as an efficient dispersant for graphene to enhance the compatibility of the graphene in epoxy resin. Raman spectroscopy, Ultraviolet-visible spectroscopy (UV-vis) and X-ray photoelectron spectroscopy (XPS) studies were confirmed the π-π interactions between PGHEP and graphene. Well-dispersed states of PGHEP functionalized graphene (G) sheets in water were analyzed by transmission electron microscopy (TEM), atomic force microscopy (AFM) and scanning electron microscopy (SEM). Further, microstructure of prepared G/waterborne epoxy coatings containing 0.5-1.0 wt.% of PGHEP functionalized G sheets were also observed with the help of SEM and TEM. The PGHEP functionalized G sheets dispersed composite coatings displayed enhanced corrosion resistance compared with pure epoxy resin, these coatings have higher contact angle, lower water absorption as evident from the results of electrochemical impedance spectroscopy (EIS) and salt spray tests. The superior corrosion protection performances of G/epoxy coatings were mainly attributed to the formed passive film from uniformly dispersed PGHEP functionalized G sheets which act as physical barrier on the steel surface. Therefore, this work provides a novel bio-based efficient dispersant for G sheets and an important method for preparing G/waterborne epoxy coatings with superior corrosion resistance properties.

  7. Antipredator and alarm reaction responses of silver catfish (Rhamdia quelen juveniles exposed to waterborne ammonia

    Directory of Open Access Journals (Sweden)

    Paula Weber

    Full Text Available Ammonia has relatively toxic effects on fish and other aquatic organisms. This study examined whether juvenile silver catfish exposed to alarm substances released by conspecifics and predators in water with different ammonia levels modify their behaviour in response to the perceived risk of predation. We used juvenile catfish that were naive to predators. The fish were raised from the larval stage in the laboratory and kept in 40-L aquaria at waterborne NH3 concentrations of 0, 0.05, 0.1, or 0.2 mg L-1 for 10 days. The alarm substances used were predator odour and skin extract from conspecifics. The juveniles were transferred to 2-L aquaria for the antipredator and alarm reaction behavioural tests, which were performed on days 1, 5 and 10 after initial exposure to ammonia. The test aquaria contained a shelter at one end of the tank. The trials consisted of a 10-min prestimulus and a 10-min poststimulus observation period. The results of the study suggest that naive juvenile catfish are able to identify predators and skin extract from conspecifics by odour. In addition, waterborne NH3 levels modify the antipredator response of this species.

  8. Waterborne toxoplasmosis investigated and analysed under hydrogeological assessment: new data and perspectives for further research.

    Science.gov (United States)

    Vieira, Flávia Pereira; Alves, Maria da Glória; Martins, Livia Mattos; Rangel, Alba Lucínia Peixoto; Dubey, Jitender Prakash; Hill, Dolores; Bahia-Oliveira, Lilian Maria Garcia

    2015-11-01

    We present a set of data on human and chicken Toxoplasma gondii seroprevalence that was investigated and analysed in light of groundwater vulnerability information in an area endemic for waterborne toxoplasmosis in Brazil. Hydrogeological assessment was undertaken to select sites for water collection from wells for T. gondii oocyst testing and for collecting blood from free-range chickens and humans for anti-T. gondii serologic testing. Serologic testing of human specimens was done using conventional commercial tests and a sporozoite-specific embryogenesis-related protein (TgERP), which is able to differentiate whether infection resulted from tissue cysts or oocysts. Water specimens were negative for the presence of viable T. gondii oocysts. However, seroprevalence in free-range chickens was significantly associated with vulnerability of groundwater to surface contamination (p toxoplasmosis in light of groundwater vulnerability information associated with prevalence in humans estimated by oocyst antigens recognition have implications for the potential role of hydrogeological assessment in researching waterborne toxoplasmosis at a global scale.

  9. Progression of the load of waterborne and intestinal parasitic diseases in the State of Amazonas.

    Science.gov (United States)

    Martins, Marilaine; Lacerda, Marcus Vinícius Guimarães; Monteiro, Wuelton Marcelo; Moura, Marco Antonio Saboia; Santos, Eyde Cristianne Saraiva; Saraceni, Valéria; Saraiva, Maria Graças Gomes

    2015-01-01

    In the State of Amazonas, Brazil, urban expansion together with precarious basic sanitation conditions and human settlement on river banks has contributed to the persistence of waterborne and intestinal parasitic diseases. Time series of the recorded cases of cholera, typhoid fever, hepatitis A and leptospirosis are described, using data from different levels of the surveillance systems. The sources for intestinal parasitosis prevalence data (non-compulsory reporting in Brazil) were Medical Literature Analysis and Retrieval System Online (MEDLINE), Literatura Latino-Americana (LILACS) and the annals of major scientific meetings. Relevant papers and abstracts in all languages were accessed by two independent reviewers. The references cited by each relevant paper were scrutinized to locate additional papers. Despite its initial dissemination across the entire State of Amazonas, cholera was controlled in 1998. The magnitude of typhoid fever has decreased; however, a pattern characterized by eventual outbreaks still remains. Leptospirosis is an increasing cause of concern in association with the annual floods. The overall prevalence of intestinal parasites is high regardless of the municipality and the characteristics of areas and populations. The incidence of hepatitis A has decreased over the past decade. A comparison of older and recent surveys shows that the prevalence of intestinal parasitic diseases has remained constant. The load of waterborne and intestinal parasitic diseases ranks high among the health problems present in the State of Amazonas. Interventions aiming at basic sanitation and vaccination for hepatitis A were formulated and implemented, but assessment of their effectiveness in the targeted populations is still needed.

  10. Synthesis and Optical Performances of a Waterborne Polyurethane-Based Polymeric Dye

    Directory of Open Access Journals (Sweden)

    Xianhai Hu

    2015-01-01

    Full Text Available A waterborne polyurethane-based polymeric dye (WPU-CFBB was synthesized by anchoring 1, 4-bis(methylaminoanthraquinone (CFBB to waterborne polyurethane chains. The number molecular weight, glass transition temperature, and average emulsion particle size for the polymeric dye were determined, respectively. This polymeric dye exhibited intriguing optical behaviors. The polymeric dye engendered two new absorption bands centered at about 520 nm and 760 nm if compared with CFBB in UV-vis spectra. The 760 nm peak showed hypsochromic shift with the decrease of average particle sizes. The polymeric dye dramatically demonstrated both hypsochromic and bathochromic effects with increasing temperature. The fluorescence intensity of the polymeric dye was much higher than that of CFBB. It was found that the fluorescence intensities would be enhanced from 20°C to 40°C and then decline from 40°C to 90°C. The fluorescence of the polymeric dye emulsion was very stable and was not sensitive to quenchers.

  11. Concentration of Cryptosporidium, microsporidia and other water-borne pathogens by continuous separation channel centrifugation.

    Science.gov (United States)

    Borchardt, M A; Spencer, S K

    2002-01-01

    The aim of this study was to determine the effectiveness of continuous separation channel centrifugation for concentrating water-borne pathogens of various taxa and sizes. Cryptosporidium parvum oocysts, Giardia lamblia cysts, Encephalitozoon intestinalis spores and Escherichia coli were seeded into different water matrices at densities ranging from 5 to 10 000 organisms l(-1) and recovered using continuous separation channel centrifugation. All pathogens were enumerated on membrane filters using microscopy. Recovery efficiencies were usually > 90%. Oocyst recovery did not vary with source water turbidity or with centrifuge flow rate up to 250 ml min(-1). Based on excystation, this concentration method did not alter oocyst viability. Continuous separation channel centrifugation is an effective means of concentrating water-borne pathogens. Methods are needed for detecting pathogens in drinking water to ensure public health. The first step for any pathogen detection procedure is concentration. However, this step has been problematic because recovery efficiencies of conventional methods, like filtration, are often low and variable, which may lead to false negatives. Continuous separation channel centrifugation can simultaneously concentrate multiple pathogens as small as 1 microm with high and reproducible efficiency in a variety of water matrices.

  12. Online detection of waterborne bioavailable copper by valve daily rhythms in freshwater clam Corbicula fluminea.

    Science.gov (United States)

    Jou, L J; Chen, W Y; Liao, C M

    2009-08-01

    Freshwater clam Corbicula fluminea, a surrogate species in metal toxicity testing, is a promising bioindicator of impairment in aquatic ecosystems. Little is known, however, about the relationship between clam valve daily rhythmic response and metal bioavailability related to a metal biological early warning system (BEWS) design. The purpose of this study was to link biotic ligand model (BLM)-based bioavailability and valve daily rhythm in C. fluminea to design a biomonitoring system for online in situ detection of waterborne copper (Cu). We integrated the Hill-based dose-time-response function and the fitted daily rhythm function of valve closure into a constructed programmatic mechanism. The functional presentation of the present dynamic system was completely demonstrated by employing a LabVIEW graphic control program in a personal computer. We used site-specific effect concentration causing 10% of total valve closure response (EC10) as the detection threshold to implement the proposed C. fluminea-based Cu BEWS. Here our results show that the proposed C. fluminea-based BEWS could be deliberately synthesized to online in situ transmit rapidly the information on waterborne bioavailable Cu levels under various aquatic environmental conditions through monitoring the valve daily rhythmic changes. We suggested that the developed C. fluminea-based dynamic biomonitoring system could assist in developing technically defensible site-specific water quality criteria to promote more efficient uses in water resources for protection of species health in aquatic environments.

  13. Comparative evaluation of different thermally modified wood samples finishing with UV-curable and waterborne coatings

    Science.gov (United States)

    Herrera, René; Muszyńska, Monika; Krystofiak, Tomasz; Labidi, Jalel

    2015-12-01

    Thermally modified wood has been developed as an industrial method to improve durability and dimensional stability of wood and thus extends the range of uses and service life of wood-based products. Despite the improvements gained by treatment, surface finishing using coatings prevents esthetical changes such as color degradation or occasional growth of mold adding protection in outdoor use and extending the service life of products. The wood finishing process was carried out with commercially available waterborne and UV-curable coatings on industrially modified at 192, 200, 212 °C and unmodified European ash (Fraxinus excelsior L.) wood, using an industrial rollers system and a laboratory brushing system. Changes caused by thermal treatment which could affect the surface finish were measured and compared with control samples, such as water uptake, wettability and acidity. Following the wood finishing, surface properties and esthetic changes were evaluated; as well as the coatings performance. Thermally modified wood presented improved adherence compared with unmodified wood with a significant improvement in samples modified at 212 °C, which also present the highest hardness when UV-cured. Finishes with UV-curing maintain the hydrophobic effect of thermally modified wood, whereas waterborne finishes increase the surface wettability. Thermal modification did not negatively influence on the elastic properties of the coated substrate and thus allows this material to be finished with different coating systems in the same conditions as unmodified wood.

  14. Synthesis and membrane performance characterization of self-emulsified waterborne nitrocellulose dispersion modified with castor oil

    Energy Technology Data Exchange (ETDEWEB)

    Su, Xiuxia; Zhao, Qingxiao, E-mail: 934481965@qq.com; Zhang, Dan; Dong, Wei

    2015-11-30

    Graphical abstract: - Highlights: • Waterborne nitrocellulose dispersion modified with castor oil (CWNC) was synthesized successfully. • It is a kind of environment-friendly coatings, in which volatile organic content (VOC) is near zero. • Castor oil used as an internal crosslinking agent for WNC improved the properties of the coating. • When the mass fraction of castor oil to total reactants is 7%, emulsion and the coating are of the best comprehensive performance. - Abstract: Waterborne nitrocellulose dispersion modified with castor oil (CWNC) was designed and successfully synthesized by self emulsification and reaction among isophorone diisocyanate (IPDI) trimer, dimethylol propionic acid (DMPA), nitrocellulose (NC) and castor oil (C.O.). The CWNC was characterized by transmission electron microscope (TEM), Fourier transform infrared (FTIR) spectroscopy and thermal gravimetric analysis (TGA), etc. The particle size of CWNC increased with the increase of mass fraction of castor oil to total reactants, ω (C.O.). The morphology of particles is an approximate core–shell structure indicated by TEM. FTIR confirmed that the reactions (i.e. IPDI trimer and castor oil, IPDI trimer and NC) occurred, the NCO groups of IPDI trimer were consumed totally and the backbone of NC was retained. The water contact angle measurements confirmed that introduced castor oil increased hydrophobicity of the film, thereby increasing the contact angle. TGA revealed that the CWNC film had better thermal resistance.

  15. Association of water-borne conidial fungi with epiphytic tree fern (Drynaria quercifolia

    Directory of Open Access Journals (Sweden)

    Kishore S. Karamchand

    2013-12-01

    Full Text Available The live and dead tissues, and trapped leaf litter by the epiphytic tree fern Drynaria quercifolia associated with riparian tree species of Konaje (west coast and Sampaje (Western Ghat streams of India during dry (summer and wet (monsoon seasons yielded 37 species of water-borne conidial fungi on bubble chamber incubation. Dead bracket leaves of fern possess the highest species as well as conidia in Konaje, while the trapped leaf litter in Sampaje. During summer, the diversity was highest in bracket leaves in both locations, while in monsoon season it was highest in rhizomes of Konaje and in trapped leaf litter in Sampaje. Even though the conidial output from tissues of Drynaria and trapped leaf litter were not equivalent to stream submerged leaf litter, the species richness ranged between 40% and 75% in Konaje and Sampaje streams. As stable epiphyte, Drynaria exposed to wet and dry regimes in tree canopies of west coast and Western Ghats likely to serve as host for perfect states of water-borne hyphomycetes.

  16. Sticky superhydrophobic filter paper developed by dip-coating of fluorinated waterborne epoxy emulsion

    Science.gov (United States)

    Huang, Xiangxuan; Wen, Xiufang; Cheng, Jiang; Yang, Zhuoru

    2012-09-01

    A superhydrophobic and superoleophilic coating for oil filter paper was synthesized based on waterborne bisphenol-A novolac epoxy emulsion. The benzoic acid (BA) and maleic anhydride (MA) were used as modification agents to give the epoxy resin hydrophilic groups (carboxyl) and Cdbnd C double bonds. And the fluorinated waterborne epoxy emulsion was prepared by free radical solution polymerization of dodecafluoroheptyl methacrylate (DFMA) monomer. The covalent bound low free energy fluorinated chains in the monomer reduce the surface energy of solidification polymers sufficiently to give rise to superhydrophobic behavior while conserving superoleophilicity. Surfaces prepared show a sticky property, which exhibits a static water contact angle of 152° for a 5 μL droplet that does not slid off even when the sample is held upside down. This synthetic emulsion is simple and convenient as impregnating agent for filter paper, which can be considered as a suitable candidate for various substrates such as cotton textiles, E-glass and artificial fiber, and so on.

  17. A Waterborne Gastroenteritis Outbreak Caused by Norovirus GII.17 in a Hotel, Hebei, China, December 2014.

    Science.gov (United States)

    Qin, Meng; Dong, Xiao-Gen; Jing, Yan-Yan; Wei, Xiu-Xia; Wang, Zhao-E; Feng, Hui-Ru; Yu, Hong; Li, Jin-Song; Li, Jie

    2016-09-01

    Norovirus (NoV) is responsible for an estimated 90 % of all epidemic nonbacterial outbreaks of gastroenteritis worldwide. Waterborne outbreaks of NoV are commonly reported. A novel GII.17 NoV strain emerged as a major cause of gastroenteritis outbreaks in China during the winter of 2014/2015. During this time, an outbreak of gastroenteritis occurred at a hotel in a ski park in Hebei Province, China. Epidemiological investigations indicated that one water well, which had only recently been in use, was the probable source. GII.17 NoV was detected by real-time reverse-transcription polymerase chain reaction from samples taken from cases, from concentrated water samples from water well, and from the nearby sewage settling tank. Nucleotide sequences of NoV extracted from clinical and water specimens were genetically identical and had 99 % homology with Beijing/CHN/2015. All epidemiological data indicated that GII.17 NoV was responsible for this outbreak. This is the first reported laboratory-confirmed waterborne outbreak caused by GII.17 NoV genotype in China. Strengthening management of well drinking water and systematica monitoring of NoV is essential for preventing future outbreaks.

  18. Risk of waterborne illness via drinking water in the United States.

    Science.gov (United States)

    Reynolds, Kelly A; Mena, Kristina D; Gerba, Charles P

    2008-01-01

    Outbreaks of disease attributable to drinking water are not common in the U.S., but they do still occur and can lead to serious acute, chronic, or sometimes fatal health consequences, particularly in sensitive and immunocompromised populations. From 1971 to 2002, there were 764 documented waterborne outbreaks associated with drinking water, resulting in 575,457 cases of illness and 79 deaths (Blackburn et al. 2004; Calderon 2004); however, the true impact of disease is estimated to be much higher. If properly applied, current protocols in municipal water treatment are effective at eliminating pathogens from water. However, inadequate, interrupted, or intermittent treatment has repeatedly been associated with waterborne disease outbreaks. Contamination is not evenly distributed but rather affected by the number of pathogens in the source water, the age of the distribution system, the quality of the delivered water, and climatic events that can tax treatment plant operations. Private water supplies are not regulated by the USEPA and are generally not treated or monitored, although very few of the municipal systems involved in documented outbreaks exceeded the USEPA's total coliform standard in the preceding 12 mon (Craun et al. 2002). We provide here estimates of waterborne infection and illness risks in the U.S. based on the total number of water systems, source water type, and total populations exposed. Furthermore, we evaluated all possible illnesses associated with the microbial infection and not just gastroenteritis. Our results indicate that 10.7 M infections/yr and 5.4 M illnesses/yr occur in populations served by community groundwater systems; 2.2 M infections/yr and 1.1 M illnesses/yr occur in noncommunity groundwater systems; and 26.0 M infections/yr and 13.0 M illnesses/yr occur in municipal surface water systems. The total estimated number of waterborne illnesses/yr in the U.S. is therefore estimated to be 19.5 M/yr. Others have recently estimated

  19. Removal of two waterborne pathogenic bacterial strains by activated carbon particles prior to and after charge modification

    NARCIS (Netherlands)

    Busscher, Henk J.; Dijkstra, Rene J. B.; Engels, Eefje; Langworthy, Don E.; Collias, Dimitris I.; Bjorkquist, David W.; Mitchell, Michael D.; van der Mei, Henny C.

    2006-01-01

    Waterborne diseases constitute a threat to public health despite costly treatment measures aimed at removing pathogenic microorganisms from potable water supplies. This paper compared the removal of Raoultella terrigena ATCC 33257 and Escherichia coli ATCC 25922 by negatively and positively charged

  20. Mobilizing community-based health insurance to enhance awareness & prevention of airborne, vector-borne & waterborne diseases in rural India

    NARCIS (Netherlands)

    P. Panda (Pradeep); A. Chakraborty (Arpita); D.M. Dror (David)

    2015-01-01

    textabstractBackground & objectives: Despite remarkable progress in airborne, vector-borne and waterborne diseases in India, the morbidity associated with these diseases is still high. Many of these diseases are controllable through awareness and preventive practice. This study was an attempt to

  1. Exploiting colloidal interfaces to increase dispersion, performance, and pot-life in cellulose nanocrystal/waterborne epoxy composites

    Science.gov (United States)

    Natalie Girouard; Gregory T. Schueneman; Meisha L. Shofner; J. Carson Meredith

    2015-01-01

    In this study, cellulose nanocrystals (CNCs) are incorporated into a waterborne epoxy resin following two processing protocols that vary by order of addition. The processing protocols produce different levels of CNC dispersion in the resulting composites. The more homogeneously dispersed composite has a higher storage modulus and work of fracture at temperatures less...

  2. Mechanical properties of wood from Pinus sylvestris L. treated with Light Organic Solvent Preservative and with waterborne Copper Azole

    Energy Technology Data Exchange (ETDEWEB)

    Villasante, A.; Laina, R.; Rojas, J. A. M.; Rojas, I. M.; Vignote, S.

    2013-07-01

    Aim of study: To determine the effect on wood from Pinus sylvestris of treatment with preservatives on mechanical properties and to establish the relation between the penetration and compression strenght. Area of study: Spain. Material and methods: 40 samples of defect-free wood from Pinus sylvestris L. were treated with Light Organic Solvent Preservative (Vacsol Azure WR 2601) and 50 with waterborne Copper Azole (Tanalith E 3492). 40 control samples were not treated (water or preservative). Mechanical resistance to static bending, modulus of elasticity and compression strength parallel to the grain were compared with untreated wood. Regression analysis between the penetration and compression strength parallel was done with the samples treated with waterborne preservative. Main results: The results indicate that the treated wood (with either product) presents a statistically significant increase in mechanical resistance in all three mechanical characteristics. The results obtained differ from earlier studies carried out by other authors. There was no correlation between parallel compression strength and the degree of impregnation of the wood with waterborne Copper Azole. The most probable explanation for these results concerns changes in pressure during treatment. The use of untreated control samples instead of samples treated only with water is more likely to produce significant results in the mechanical resistance studies. Research highlights: Treated wood presents a statistically significant increase in MOE, modulus of rupture to static bending and parallel compression strength. There was no correlation between parallel compression strength and the degree of impregnation with waterborne preservative. (Author)

  3. [Environmental sanitation and mortality associated with waterborne diseases in children under 5 years of age in Brazil].

    Science.gov (United States)

    Bellido, Jaime Gregorio; Barcellos, Christovam; Barbosa, Flavia dos Santos; Bastos, Francisco Inacio

    2010-08-01

    Determine and evaluate the relationship between the variables for water conditions, environmental sanitation, and mortality in children under 5 years of age associated with a group of waterborne diseases. An exploratory ecological study was conducted based on data obtained from the 2000 national demographic census and the Unified Health System for the 558 microregions of Brazil. The model used multiple linear regression analysis. Mortality associated with waterborne diseases in children under 5 years of age was considered to be the response variable. Water conditions, sanitation, and level of education were considered to be explanatory variables. A direct relationship was observed between inadequate sanitation in the dwelling (e.g., sewage disposal via rudimentary gutters and pits, the disposal of waste in uncultivated land or public areas) and mortality in children under 5 years of age associated with waterborne diseases. An inverse relationship was found between level of education and mortality associated with waterborne diseases in these children. The greatest health hazards related to poor sanitation were found in the microregions with a high concentration of low-income population with limited education. The general sanitation conditions and other factors related to dwelling quality and infrastructure are major determinants of mortality. Coverage of the water services, which reach 90% of households in Brazil, was not in itself found to be an important factor in the reduction of the mortality studied.

  4. Risk-based approach to appraise valve closure in the clam Corbicula fluminea in response to waterborne metals

    Energy Technology Data Exchange (ETDEWEB)

    Liao, C.-M. [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan 10617 (China)]. E-mail: cmliao@ntu.edu.tw; Jou, L.-J. [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan 10617 (China); Department of Biomechatronic Engineering, National Ilan University, Ilan, Taiwan 260 (China); Chen, B.-C. [Department of Post-Modern Agriculture, Mingdao University, Changhua, Taiwan 52345 (China)

    2005-05-01

    We developed a risk-based approach to assess how the valve closure behavior of Asiatic clam Corbicula fluminea responds to waterborne copper (Cu) and cadmium (Cd). We reanalyzed the valve closure response data from published literature to reconstruct the response time-dependent dose-response profiles based on an empirical three-parameter Hill equation model. We integrated probabilistic exposure profiles of measured environmental Cu and Cd concentrations in the western coastal areas of Taiwan with the reconstructed dose-response relationships at different integration times of response to quantitatively estimate the valve response risk. The risk assessment results implicate exposure to waterborne Cu and Cd may pose no significant risk to clam valve activity in the short-time response periods (e.g., <30 min), yet a relative high risk for valve closure response to waterborne Cu at response times greater than 120 min is alarming. We successfully linked reconstructed dose-response profiles and EC50-time relationships associated with the fitted daily valve opening/closing rhythm characterized by a three-parameter lognormal function to predict the time-varying bivalve closure rhythm response to waterborne metals. We parameterized the proposed predictive model that should encourage a risk-management framework for discussion of future design of biological monitoring systems. - A model was developed to link valve closure in clams to concentrations of metals in water.

  5. Risk-based approach to appraise valve closure in the clam Corbicula fluminea in response to waterborne metals.

    Science.gov (United States)

    Liao, Chung-Min; Jou, Li-John; Chen, Bo-Ching

    2005-05-01

    We developed a risk-based approach to assess how the valve closure behavior of Asiatic clam Corbicula fluminea responds to waterborne copper (Cu) and cadmium (Cd). We reanalyzed the valve closure response data from published literature to reconstruct the response time-dependent dose-response profiles based on an empirical three-parameter Hill equation model. We integrated probabilistic exposure profiles of measured environmental Cu and Cd concentrations in the western coastal areas of Taiwan with the reconstructed dose-response relationships at different integration times of response to quantitatively estimate the valve response risk. The risk assessment results implicate exposure to waterborne Cu and Cd may pose no significant risk to clam valve activity in the short-time response periods (e.g., <30 min), yet a relative high risk for valve closure response to waterborne Cu at response times greater than 120 min is alarming. We successfully linked reconstructed dose-response profiles and EC50-time relationships associated with the fitted daily valve opening/closing rhythm characterized by a three-parameter lognormal function to predict the time-varying bivalve closure rhythm response to waterborne metals. We parameterized the proposed predictive model that should encourage a risk-management framework for discussion of future design of biological monitoring systems.

  6. Effects of waterborne Fe(II) on juvenile turbot Scophthalmus maximus: analysis of respiratory rate, hematology and gill histology

    Science.gov (United States)

    Wu, Zhihao; You, Feng; Liu, Hongjun; Liu, Mengxia; Li, Jun; Zhang, Peijun

    2012-03-01

    The concentration of Fe(II) is high in some groundwater supplies used in turbot culture, and the toxicity of waterborne Fe(II) is unknown. We investigated the stress responses of juvenile turbot, Scophthalmus maximus, exposed to Fe(II) of different concentrations (0.01, 0.05, 0.1, 0.5, 1, and 2 mg/L) for 1, 7, 14, and 28 d, under the same ambient conditions of other parameters. Changes in respiratory rate, hematological parameters, and gill structure were determined. The results show that waterborne Fe(II) did not cause severe hematological perturbation to turbot. A low-medium Fe(II) concentration (lower than 0.1 mg/L) could boost the respiratory rate, and caused no or very limited damage to fish. A high Fe(II) concentration (0.1 mg/L or higher), however, caused gill damage, such as vacuoles in branchial lamellae, epithelial necrosis, and hypertrophy of epithelial cells, and even death after extended exposure time. Therefore, excess waterborne Fe(II) and long-term exposure to Fe(II) could be responsible for poor growth and high mortality of turbot in culture. The concentration of waterborne Fe(II) in turbot culture should be kept below 0.1 mg/L.

  7. The effects of ozonation on select waterborne steroid hormones in recirculation aquaculture systems containing sexually mature Atlantic salmon Salmo salar

    Science.gov (United States)

    A controlled 3-month study was conducted in 6 replicated water recirculation aquaculture systems (RAS) containing a mixture of sexually mature and immature Atlantic salmon Salmo salar to determine whether water ozonation is associated with a reduction in waterborne hormones. Post-smolt Atlantic salm...

  8. Waterborne cadmium and nickel impact oxidative stress responses and retinoid metabolism in yellow perch

    Energy Technology Data Exchange (ETDEWEB)

    Defo, Michel A. [Institut national de la recherche scientifique (INRS), Centre Eau Terre Environnement, 490 de la Couronne, Québec, Québec G1K 9A9 (Canada); Bernatchez, Louis [Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, Québec G1V 0A6 (Canada); Campbell, Peter G.C. [Institut national de la recherche scientifique (INRS), Centre Eau Terre Environnement, 490 de la Couronne, Québec, Québec G1K 9A9 (Canada); Couture, Patrice, E-mail: patrice.couture@ete.inrs.ca [Institut national de la recherche scientifique (INRS), Centre Eau Terre Environnement, 490 de la Couronne, Québec, Québec G1K 9A9 (Canada)

    2014-09-15

    Highlights: • Cd and Ni affected indicators of retinoid metabolism and oxidative stress in fish. • Liver rdh-2 transcription levels increase in fish exposed to waterborne Cd. • Liver REH and LdRAT activities increase with increasing kidney Cd concentration. • Changes at molecular levels do not always mean changes at the functional levels. • Multi-level biological approaches are needed when assessing fish metal toxicology. - Abstract: In this experiment, we studied the transcriptional and functional (enzymatic) responses of yellow perch (Perca flavescens) to metal stress, with a focus on oxidative stress and vitamin A metabolism. Juvenile yellow perch were exposed to two environmentally relevant concentrations of waterborne cadmium (Cd) and nickel (Ni) for a period of 6 weeks. Kidney Cd and Ni bioaccumulation significantly increased with increasing metal exposure. The major retinoid metabolites analyzed in liver and muscle decreased with metal exposure except at high Cd exposure where no variation was reported in liver. A decrease in free plasma dehydroretinol was also observed with metal exposure. In the liver of Cd-exposed fish, both epidermal retinol dehydrogenase 2 transcription level and corresponding enzyme activities retinyl ester hydrolase and lecithin dehydroretinyl acyl transferase increased. In contrast, muscle epidermal retinol dehydrogenase 2 transcription level decreased with Cd exposure. Among antioxidant defences, liver transcription levels of catalase, microsomal glutathione-S-transferase-3 and glucose-6-phosphate dehydrogenase were generally enhanced in Cd-exposed fish and this up-regulation was accompanied by an increase in the activities of corresponding enzymes, except for microsomal glutathione-S-transferase. No consistent pattern in antioxidant defence responses was observed between molecular and biochemical response when fish were exposed to Ni, suggesting a non-synchronous response of antioxidant defence in fish exposed to

  9. Anticorrosive performance of waterborne epoxy coatings containing water-dispersible hexagonal boron nitride (h-BN) nanosheets

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Mingjun [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); Ren, Siming [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); Chen, Jia; Liu, Shuan [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Zhang, Guangan [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Zhao, Haichao, E-mail: zhaohaichao@nimte.ac.cn [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Wang, Liping, E-mail: wangliping@nimte.ac.cn [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Xue, Qunji, E-mail: qjxue@lzb.ac.cn [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)

    2017-03-01

    Highlights: • Hexagonal boron nitride nanosheets were well dispersed by using water-soluble carboxylated aniline trimer as dispersant. • The best corrosion performance of waterborne epoxy coatings was achieved with the addition of 1 wt% h-BN. • The decrease of the pores and defects of coating matrix inhibits the diffusion and water absorption of corrosive medium in the coating. - Abstract: Homogenous dispersion of hexagonal boron nitride (h-BN) nanosheets in solvents or in the polymer matrix is crucial to initiate their many applications. Here, homogeneous dispersion of hexagonal boron nitride (h-BN) in epoxy matrix was achieved with a water-soluble carboxylated aniline trimer derivative (CAT{sup −}) as a dispersant, which was attributed to the strong π-π interaction between h-BN and CAT{sup −}, as proved by Raman and UV–vis spectra. Transmission electron microscopy (TEM) analysis confirmed a random dispersion of h-BN nanosheets in the waterborne epoxy coatings. The deterioration process of water-borne epoxy coating with and without h-BN nanosheets during the long-term immersion in 3.5 wt% NaCl solution was investigated by electrochemical measurements and water absorption test. Results implied that the introduction of well dispersed h-BN nanosheets into waterborne epoxy system remarkably improved the corrosion protection performance to substrate. Moreover, 1 wt% BN/EP composite coated substrate exhibited higher impedance modulus (1.3 × 10{sup 6} Ω cm{sup 2}) and lower water absorption (4%) than those of pure waterborne epoxy coating coated electrode after long-term immersion in 3.5 wt% NaCl solution, demonstrating its superior anticorrosive performance. This enhanced anticorrosive performance was mainly ascribed to the improved water barrier property of epoxy coating via incorporating homogeneously dispersed h-BN nanosheets.

  10. An Optimal Control Framework to Address the Relationship between Water Resource Management and Water-Borne Health Impacts: Focus on the Texas Lower Rio Grande Valley

    OpenAIRE

    Leidner, Andrew J.; Lacewell, Ronald D.; Rister, M. Edward; Sturdivant, Allen W.

    2011-01-01

    The objective of this study is develop a theoretical model that can evaluate two types of public health expenditures on water-borne health risks: water-related municipal services, an ex ante preventative measure against water-borne contamination, and medical treatment, an ex post treatment of the water-borne pollutant’s harmful effects on human health. The modeled community can allocate resources in either centralized-municipal water-services, point-of-use water-services, or medical intervent...

  11. Waterborne polyurethane single-ion electrolyte from aliphatic diisocyanate and various molecular length of polyethylene glycol

    Directory of Open Access Journals (Sweden)

    2007-03-01

    Full Text Available The waterborne polyurethane (WPU dispersions from the reaction of cycloaliphatic diisocyanates [4,4’-methylenebis(cyclohexyl isocyanate (H12MDI and isophorone diisocyanate (IPDI] and polyethylene glycol (PEG with various molecular lengths were synthesized using our modified acetone process. Differetial scanning calorimeter (DSC and Fourier transform infrared spectroscopy (FTIR were utilized to characterize WPU films for the behavior of their crystallinity and H-bonding of WPU films. The Tg value of WPU increases with increasing the molecular length of PEG, whereas the Tm of WPU decreases with increasing PEG length. Alternating current (AC impedance experiments were performed to determine the ionic conductivities of WPU films. The WPU gel electrolytes exhibits an ionic conductivity as high as ~ 10-5 S/cm at room temperature.

  12. Waterborne hyperbranched alkyd-acrylic resin obtained by mini emulsion polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Murillo, Edwin, E-mail: edwinalbertomurillo@gmail.com [Grupo de Investigacion en Materiales Polimericos (GIMAPOL), Universidad Francisco de Paula Santander, San Jose de Cucuta (Colombia); Lopez, Betty [Grupo de Investigacion en Ciencia de los Materiales, Universidad de Antioquia, Calle, Medellin (Colombia)

    2016-10-15

    Four waterborne hyper branched alkyd-acrylic resins (HBRAA) were synthesized by mini emulsion polymerization from a hyper branched alkyd resin (HBR), methyl methacrylate (MMA), butyl acrylate (BA) and acrylic acid (AA), by using benzoyl peroxide (BPO) and ammonium persulfate (AP) as initiators. The reaction between HBR and acrylic monomers was evidenced by differential scanning calorimetric (DSC), nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The conversion percentage, glass transition temperature (T{sub g}), content of acrylic polymer (determined by soxhlet extraction) and molecular weight increased with the content of acrylic monomers used in the synthesis. The main structure formed during the synthesis was the HBRAA. The analysis by dynamic light scattering (DLS) showed that the particle size distribution of HBRAA2, HBRAA3 and HBRAA4 resins were mainly mono modal. The film properties (gloss, flexibility, adhesion and drying time) of the HBRAA were good. (author)

  13. Oxyhydroxy Silicate Colloids: A New Type of Waterborne Actinide(IV) Colloids

    Science.gov (United States)

    Weiss, Stephan; Hennig, Christoph; Brendler, Vinzenz; Ikeda‐Ohno, Atsushi

    2016-01-01

    Abstract At the near‐neutral and reducing aquatic conditions expected in undisturbed ore deposits or in closed nuclear waste repositories, the actinides Th, U, Np, and Pu are primarily tetravalent. These tetravalent actinides (AnIV) are sparingly soluble in aquatic systems and, hence, are often assumed to be immobile. However, AnIV could become mobile if they occur as colloids. This review focuses on a new type of AnIV colloids, oxyhydroxy silicate colloids. We herein discuss the chemical characteristics of these colloids and the potential implication for their environmental behavior. The binary oxyhydroxy silicate colloids of AnIV could be potentially more mobile as a waterborne species than the well‐known mono‐component oxyhydroxide colloids. PMID:27957406

  14. Waterborne microorganisms and biofilms related to hospital infections: strategies for prevention and control in healthcare facilities.

    Science.gov (United States)

    Capelletti, Raquel Vannucci; Moraes, Ângela Maria

    2016-02-01

    Water is the main stimulus for the development of microorganisms, and its flow has an important role in the spreading of contaminants. In hospitals, the water distribution system requires special attention since it can be a source of pathogens, including those in the form of biofilms often correlated with resistance of microorganisms to various treatments. In this paper, information relevant to cases of nosocomial infections involving water circuits as a source of contaminants is compiled, with emphasis on the importance of microbiological control strategies to prevent the installation, spreading and growth of microorganisms in hospitals. An overview of the worldwide situation is provided, with emphasis on Brazilian hospitals. Different approaches normally used to control the occurrence of nosocomial infections due to waterborne contaminants are analyzed, and the use of the polysaccharide chitosan for this specific application is briefly discussed.

  15. A waterborne outbreak of leptospirosis among United States military personnel in Okinawa, Japan.

    Science.gov (United States)

    Corwin, A; Ryan, A; Bloys, W; Thomas, R; Deniega, B; Watts, D

    1990-09-01

    A waterborne outbreak of leptospirosis occurred among US military personnel during September 1987, on the island of Okinawa, Japan. Micro-agglutination titres for leptospiral antigen of greater than or equal to 200 were detected in hospitalized adult males averaging 22.5 years of age with symptoms compatible with leptospirosis. Epidemiological findings revealed two case clusters distinguished by time and place of exposure. The overall attack rates among recreational swimmers and combat skills training participants were 467/1000 (7/15) and 183/1000 (15/82), respectively. Swallowing of water differentiated individuals with laboratory-confirmed infection from those with no infection, while water immersion alone did not appear to result in leptospiral infection. Additionally, subnormal rainfall may have contributed to the risk of exposure associated with this outbreak.

  16. Towards chemical characterization of waterborne pheromone of amphipod crustaceanMicrodeutopus gryllotalpa.

    Science.gov (United States)

    Borowsky, B; Augelli, C E; Wilson, S R

    1987-07-01

    Previous studies demonstrated the existence of a waterborne pheromone secreted by receptive females of the amphipod crustaceanMicrodeutopus gryllotalpa which attracts males. The data were obtained by using a bioassay apparatus based on a two-choice test paradigm. The present study reports the results of additional tests employing this apparatus which have shed some light on the chemical nature of the pheromone. The bioactive substance was isolated from receptive female waters with anion exchange resin columns, but not with C-18 reverse-phase columns. This suggests that the substance is polar. Another finding of the present study was that effluents from the green algaUlva lactuca inhibit males' responses to the pheromone.

  17. Failure Mechanisms of the Coating/Metal Interface in Waterborne Coatings: The Effect of Bonding

    Directory of Open Access Journals (Sweden)

    Hongxia Wan

    2017-04-01

    Full Text Available Waterborne coating is the most popular type of coating, and improving its performance is a key point of research. Cathodic delamination is one of the major modes of failure for organic coatings. It refers to the weakening or loss of adhesion between the coating and substrate. Physical and chemical characteristics of coatings have been studied via scanning electron microscopy (SEM, atomic force microscopy (AFM, contact angle measurements, Fourier transform infrared spectroscopy (FTIR, and secondary ion mass spectrometry (SIMS. Early heterogeneous swelling at the metal-coating interface in non-defective coated metals was elucidated using frequency-dependent alternating-current scanning electrochemical microscopy. Two types of coatings (styrene-acrylic coating and terpolymer coating were compared. The effects of thickness, surface roughness, and chemical bonding on cathodic delamination were investigated.

  18. Failure Mechanisms of the Coating/Metal Interface in Waterborne Coatings: The Effect of Bonding.

    Science.gov (United States)

    Wan, Hongxia; Song, Dongdong; Li, Xiaogang; Zhang, Dawei; Gao, Jin; Du, Cuiwei

    2017-04-09

    Waterborne coating is the most popular type of coating, and improving its performance is a key point of research. Cathodic delamination is one of the major modes of failure for organic coatings. It refers to the weakening or loss of adhesion between the coating and substrate. Physical and chemical characteristics of coatings have been studied via scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle measurements, Fourier transform infrared spectroscopy (FTIR), and secondary ion mass spectrometry (SIMS). Early heterogeneous swelling at the metal-coating interface in non-defective coated metals was elucidated using frequency-dependent alternating-current scanning electrochemical microscopy. Two types of coatings (styrene-acrylic coating and terpolymer coating) were compared. The effects of thickness, surface roughness, and chemical bonding on cathodic delamination were investigated.

  19. New filtration system for efficient recovery of waterborne Cryptosporidium oocysts and Giardia cysts

    DEFF Research Database (Denmark)

    Al-Sabi, Mohammad Nafi Solaiman; Gad, J. A.; Riber, Ulla

    2015-01-01

    -)cysts (1x10(2); 10 replicates) was successfully amplified using real-time PCR.ConclusionsThe use of a metallic filter, sonication and air backwash' were key factors for creating a highly efficient system for recovery of apparently undamaged protozoa.Significance and Impact of the StudyThis reagent......AimsTo develop a filtration unit for efficient recovery of waterborne Cryptosporidium oocysts and Giardia cysts ((oo-)cysts) in drinking water.Methods and ResultsThis unit utilizes a metallic filter and an ultrasound transducer for eluting (oo-)cysts, with a fixed retentate backwash volume; approx....... 400l. Changes in the viability was evaluated by seeding wild type (oo-)cysts (1x10(4)) followed by sonication for 5, 10, 20 or 40s (five replicates for each period). Flow cytometry analysis showed negligible increase in the mortality of (oo-)cysts exposed to 5-10s of sonication. Recovery rate...

  20. SPATIAL-TEMPORAL DISTRIBUTION OF WATERBORNE INFECTIOUS DISEASE RISK USING THE HYDRAULIC MODEL AND OUTPATIENT DATA

    Science.gov (United States)

    Amano, Ayako; Sakuma, Taisuke; Kazama, So

    This study evaluated waterborne infectious diseases risk and incidence rate around Phonm Penh in Cambodia. We use the hydraulic flood simulation, coliform bacterium diffusion model, dose-response model and outpatient data for quantitative analysis. The results obtained are as follows; 1. The incidence (incidence rate) of diarrhea as water borne diseases risk is 0.14 million people (9%) in the inundation area. 2. The residents in the inundation area are exposed up to 4 times as high risk as daily mean calculated by the integrated model combined in the regional scale. 3.The infectious disease risk due to floods and inundation indicated is effective as an element to explain the risk. The scenario explains 34% number of patient estimated by the outpatient data.

  1. Synthesis and membrane performance characterization of self-emulsified waterborne nitrocellulose dispersion modified with castor oil

    Science.gov (United States)

    Su, Xiuxia; Zhao, Qingxiao; Zhang, Dan; Dong, Wei

    2015-11-01

    Waterborne nitrocellulose dispersion modified with castor oil (CWNC) was designed and successfully synthesized by self emulsification and reaction among isophorone diisocyanate (IPDI) trimer, dimethylol propionic acid (DMPA), nitrocellulose (NC) and castor oil (C.O.). The CWNC was characterized by transmission electron microscope (TEM), Fourier transform infrared (FTIR) spectroscopy and thermal gravimetric analysis (TGA), etc. The particle size of CWNC increased with the increase of mass fraction of castor oil to total reactants, ω (C.O.). The morphology of particles is an approximate core-shell structure indicated by TEM. FTIR confirmed that the reactions (i.e. IPDI trimer and castor oil, IPDI trimer and NC) occurred, the NCO groups of IPDI trimer were consumed totally and the backbone of NC was retained. The water contact angle measurements confirmed that introduced castor oil increased hydrophobicity of the film, thereby increasing the contact angle. TGA revealed that the CWNC film had better thermal resistance.

  2. Workshop on Functional Requirements for the Modeling of Fate and Transport of Waterborne CBRN Materials

    Energy Technology Data Exchange (ETDEWEB)

    Giles, GE

    2005-02-03

    The purpose of this Workshop on ''Functional Requirements for the Modeling of Fate and Transport of Waterborne CBRN Materials'' was to solicit functional requirements for tools that help Incident Managers plan for and deal with the consequences of industrial or terrorist releases of materials into the nation's waterways and public water utilities. Twenty representatives attended and several made presentations. Several hours of discussions elicited a set of requirements. These requirements were summarized in a form for the attendees to vote on their highest priority requirements. These votes were used to determine the prioritized requirements that are reported in this paper and can be used to direct future developments.

  3. Monitoring of Waterborne Parasites in Two Drinking Water Treatment Plants: A Study in Sarawak, Malaysia.

    Science.gov (United States)

    Richard, Reena Leeba; Ithoi, Init; Abd Majid, Mohamad Azlan; Wan Sulaiman, Wan Yusoff; Tan, Tian Chye; Nissapatorn, Veeranoot; Lim, Yvonne Ai Lian

    2016-06-28

    The occurrence of waterborne parasites coupled with water parameters at various processing sites of two drinking water treatment plants (A and B) and seven distribution system (DS) sites in Sarawak, Malaysia were studied. Ten liters of water underwent immunomagnetic separation (IMS) technique to detect the presence of Giardia and Cryptosporidium (oo)cysts. The remaining supernatant was used to detect other parasites whilst 50 mL of water sample was each used in the detection of free-living amoebae and fecal coliforms. Sampled water was positive for Giardia (32.9%; 28/85), Cryptosporidium (18.8%; 16/85) followed by Spirometra ova-like (25.9%; 22/85), Blastocystis-like (25.9%; 22/85), nematode larvae-like (8.2%; 7/85) and Taenia ova-like (1.2%; 1/85). Meanwhile, 90.2% (55/61) samples were positive for Acanthamoeba and Naegleria via cultivation and of these, 11 isolates were confirmed as Acanthamoeba genotype T3 (5/7) and T4 (2/7) followed by Naegleria sp. (4/11), Naegleria italica (2/11), Naegleria australiensis (1/11), Naegleria angularis (1/11) and Vahlkampfia sp. (3/11). Cryptosporidium, Acanthamoeba and Naegleria were also detected in one of the seven tested DS sites. Only Giardia and Cryptosporidium showed significant correlations with fluoride and fecal coliforms. These results describe the occurrence of waterborne parasites that will assist key stakeholders in mitigating contamination at the specific sites.

  4. Glass wool filters for concentrating waterborne viruses and agricultural zoonotic pathogens

    Science.gov (United States)

    Millen, Hana T.; Gonnering, Jordan C.; Berg, Ryan K.; Spencer, Susan K.; Jokela, William E.; Pearce, John M.; Borchardt, Jackson S.; Borchardt, Mark A.

    2012-01-01

    The key first step in evaluating pathogen levels in suspected contaminated water is concentration. Concentration methods tend to be specific for a particular pathogen group, for example US Environmental Protection Agency Method 1623 for Giardia and Cryptosporidium1, which means multiple methods are required if the sampling program is targeting more than one pathogen group. Another drawback of current methods is the equipment can be complicated and expensive, for example the VIRADEL method with the 1MDS cartridge filter for concentrating viruses2. In this article we describe how to construct glass wool filters for concentrating waterborne pathogens. After filter elution, the concentrate is amenable to a second concentration step, such as centrifugation, followed by pathogen detection and enumeration by cultural or molecular methods. The filters have several advantages. Construction is easy and the filters can be built to any size for meeting specific sampling requirements. The filter parts are inexpensive, making it possible to collect a large number of samples without severely impacting a project budget. Large sample volumes (100s to 1,000s L) can be concentrated depending on the rate of clogging from sample turbidity. The filters are highly portable and with minimal equipment, such as a pump and flow meter, they can be implemented in the field for sampling finished drinking water, surface water, groundwater, and agricultural runoff. Lastly, glass wool filtration is effective for concentrating a variety of pathogen types so only one method is necessary. Here we report on filter effectiveness in concentrating waterborne human enterovirus, Salmonella enterica, Cryptosporidium parvum, and avian influenza virus.

  5. Spread of Water-Borne Pollutants at Traffic Accidents on Roads.

    Science.gov (United States)

    Olofsson, Bo; Rasul, Hedi; Lundmark, Annika

    2017-01-01

    Traffic accidents sometimes lead to the spread of hazardous compounds to the environment. Accidental spills of hazardous compounds on roads in the vicinity of vulnerable objects such as water supplies pose a serious threat to water quality and have to be assessed. This study compared three different assessment methods, electrical resistivity measurements, analytical flow calculations, and 1D and 2D dynamic flow modeling, to describe rapid transport processes in the road shoulder and roadside verge after a major spill. The infiltration and flow paths of water-borne substances were described during simulated discharge of pollutants on different road types. Full-scale tracer tests using sodium chloride were carried out at nine different road locations in Sweden. Analysis of grain size distribution and infiltrometer tests were carried out at the road shoulder and verges. The pathways and travel times were traced using resistivity measurements and 3D inverse modeling. The resistivity measurements were compared to analytical flow calculations and 1D and 2D dynamic modeling. All measurement sites were highly heterogeneous, which caused preferential flow. Vertical flow velocities of 1.4-8.6 × 10(-4) m/s were measured. The results of the analytical calculations and flow modeling were of the same order of magnitude. The measurements showed that almost all infiltration goes directly into the road embankment, hence the composition and structure of the built-up road must be considered. The non-destructive resistivity measurements and 3D modeling provided useful information for clarifying the infiltration and flow pattern of water-borne compounds from road runoff.

  6. Hydroclimatic drivers, Water-borne Diseases, and Population Vulnerability in Bengal Delta

    Science.gov (United States)

    Akanda, A. S.; Jutla, A. S.

    2012-04-01

    Water-borne diarrheal disease outbreaks in the Bengal Delta region, such as cholera, rotavirus, and dysentery, show distinct seasonal peaks and spatial signatures in their origin and progression. However, the mechanisms behind these seasonal phenomena, especially the role of regional climatic and hydrologic processes behind the disease outbreaks, are not fully understood. Overall diarrheal disease prevalence and the population vulnerability to transmission mechanisms thus remain severely underestimated. Recent findings suggest that diarrheal incidence in the spring is strongly associated with scarcity of freshwater flow volumes, while the abundance of water in monsoon show strong positive correlation with autumn diarrheal burden. The role of large-scale ocean-atmospheric processes that tend to modulate meteorological, hydrological, and environmental conditions over large regions and the effects on the ecological states conducive to the vectors and triggers of diarrheal outbreaks over large geographic regions are not well understood. We take a large scale approach to conduct detailed diagnostic analyses of a range of climate, hydrological, and ecosystem variables to investigate their links to outbreaks, occurrence, and transmission of the most prevalent water-borne diarrheal diseases. We employ satellite remote sensing data products to track coastal ecosystems and plankton processes related to cholera outbreaks. In addition, we investigate the effect of large scale hydroclimatic extremes (e.g., droughts and floods, El Nino) to identify how diarrheal transmission and epidemic outbreaks are most likely to respond to shifts in climatic, hydrologic, and ecological changes over coming decades. We argue that controlling diarrheal disease burden will require an integrated predictive surveillance approach - a combination of prediction and prevention - with recent advances in climate-based predictive capabilities and demonstrated successes in primary and tertiary prevention

  7. Genetic diversity among food-borne and waterborne norovirus strains causing outbreaks in Sweden.

    Science.gov (United States)

    Lysén, Maria; Thorhagen, Margareta; Brytting, Maria; Hjertqvist, Marika; Andersson, Yvonne; Hedlund, Kjell-Olof

    2009-08-01

    A total of 101 food-borne and waterborne outbreaks that were caused by norovirus and that resulted in more than 4,100 cases of illness were reported to the Swedish Institute for Infectious Disease Control from January 2002 to December 2006. Sequence and epidemiological data for isolates from 73 outbreaks were analyzed. In contrast to health care-related outbreaks, no clear seasonality could be observed. Sequence analysis showed a high degree of genetic variation among the noroviruses detected. Genogroup II (GII) viruses were detected in 70% of the outbreaks, and of those strains, strains of GII.4 were the most prevalent and were detected in 25% of all outbreaks. The GII.4 variants detected in global outbreaks in health care settings during 2002, 2004, and 2006 were also found in the food-borne outbreaks. GI strains totally dominated as the cause of water-related (drinking and recreational water) outbreaks and were found in 12 of 13 outbreaks. In 14 outbreaks, there were discrepancies among the polymerase and capsid genotype results. In four outbreaks, the polymerase of the recombinant GII.b virus occurred together with the GII.1 or GII.3 capsids, while the GII.7 polymerase occurred together with the GII.6 and GII.7 capsids. Mixed infections were observed in six outbreaks; four of these were due to contaminated water, and two were due to imported frozen berries. Contaminated food and water serve as important reservoirs for noroviruses. The high degree of genetic diversity found among norovirus strains causing food-borne and waterborne infections stresses the importance of the use of broad reaction detection methods when such outbreaks are investigated.

  8. Monitoring of Waterborne Parasites in Two Drinking Water Treatment Plants: A Study in Sarawak, Malaysia

    Directory of Open Access Journals (Sweden)

    Reena Leeba Richard

    2016-06-01

    Full Text Available The occurrence of waterborne parasites coupled with water parameters at various processing sites of two drinking water treatment plants (A and B and seven distribution system (DS sites in Sarawak, Malaysia were studied. Ten liters of water underwent immunomagnetic separation (IMS technique to detect the presence of Giardia and Cryptosporidium (oocysts. The remaining supernatant was used to detect other parasites whilst 50 mL of water sample was each used in the detection of free-living amoebae and fecal coliforms. Sampled water was positive for Giardia (32.9%; 28/85, Cryptosporidium (18.8%; 16/85 followed by Spirometra ova-like (25.9%; 22/85, Blastocystis-like (25.9%; 22/85, nematode larvae-like (8.2%; 7/85 and Taenia ova-like (1.2%; 1/85. Meanwhile, 90.2% (55/61 samples were positive for Acanthamoeba and Naegleria via cultivation and of these, 11 isolates were confirmed as Acanthamoeba genotype T3 (5/7 and T4 (2/7 followed by Naegleria sp. (4/11, Naegleria italica (2/11, Naegleria australiensis (1/11, Naegleria angularis (1/11 and Vahlkampfia sp. (3/11. Cryptosporidium, Acanthamoeba and Naegleria were also detected in one of the seven tested DS sites. Only Giardia and Cryptosporidium showed significant correlations with fluoride and fecal coliforms. These results describe the occurrence of waterborne parasites that will assist key stakeholders in mitigating contamination at the specific sites.

  9. Progression of the load of waterborne and intestinal parasitic diseases in the State of Amazonas

    Directory of Open Access Journals (Sweden)

    Marilaine Martins

    2015-06-01

    Full Text Available In the State of Amazonas, Brazil, urban expansion together with precarious basic sanitation conditions and human settlement on river banks has contributed to the persistence of waterborne and intestinal parasitic diseases. Time series of the recorded cases of cholera, typhoid fever, hepatitis A and leptospirosis are described, using data from different levels of the surveillance systems. The sources for intestinal parasitosis prevalence data (non-compulsory reporting in Brazil were Medical Literature Analysis and Retrieval System Online (MEDLINE, Literatura Latino-Americana (LILACS and the annals of major scientific meetings. Relevant papers and abstracts in all languages were accessed by two independent reviewers. The references cited by each relevant paper were scrutinized to locate additional papers. Despite its initial dissemination across the entire State of Amazonas, cholera was controlled in 1998. The magnitude of typhoid fever has decreased; however, a pattern characterized by eventual outbreaks still remains. Leptospirosis is an increasing cause of concern in association with the annual floods. The overall prevalence of intestinal parasites is high regardless of the municipality and the characteristics of areas and populations. The incidence of hepatitis A has decreased over the past decade. A comparison of older and recent surveys shows that the prevalence of intestinal parasitic diseases has remained constant. The load of waterborne and intestinal parasitic diseases ranks high among the health problems present in the State of Amazonas. Interventions aiming at basic sanitation and vaccination for hepatitis A were formulated and implemented, but assessment of their effectiveness in the targeted populations is still needed.

  10. Presentation from 2016 STAR Tribal Research Meeting: Water, Our Voice to the Future: Climate Change Adaptation and Waterborne Disease Prevention on the Crow Reservation

    Science.gov (United States)

    This presentation, Water, Our Voice to the Future: Climate Change Adaptation and Waterborne Disease Prevention on the Crow Reservation, was given at the 2016 STAR Tribal Research Meeting held on Sept. 20-21, 2016.

  11. Upgrading a Piped Water Supply from Intermittent to Continuous Delivery and Association with Waterborne Illness: A Matched Cohort Study in Urban India: e1001892

    National Research Council Canada - National Science Library

    Ayse Ercumen; Benjamin F Arnold; Emily Kumpel; Zachary Burt; Isha Ray; Kara Nelson; John M Colford Jr

    2015-01-01

    ..., and limited water availability for hygiene. We assessed the association between continuous versus intermittent water supply and waterborne diseases, child mortality, and weight for age in Hubli-Dharwad, India...

  12. A Modified EPA Method 1623 that Uses Tangential Flow Hollow-Fiber Ultrafiltration and Heat Dissociation Steps to Detect Waterborne Cryptosporidum and Giardia spp.

    Science.gov (United States)

    This protocol describes the use of a tangential flow hollow-fiber ultrafiltration sample concentration system and a heat dissociation as alternative steps for the detection of waterborne Cryptosporidium and Giardia species using EPA Method 1623.

  13. Synthesis and characterization of waterborne polyurethane and polyurethane-urea towards eco-friendly materials by cellulose nanocrystals and plant extracts incorporation

    OpenAIRE

    Santamaría Echart, Arantzazu

    2017-01-01

    327 p. In this work, environmentally friendly anionic waterborne polyurethane and polyurethane-urea dispersions were synthesized in order to prepare films by casting. The effect of molar composition and synthesis route were analyzed on the waterborne polyurethane and polyurethane-urea dispersions, as well as the properties of films. Furthermore, these dispersions were used for the preparation of new eco-friendly materials. In this way, cellulose nanocrystals were isolated for the preparati...

  14. Widespread waterborne pollution in central Swedish lakes and the Baltic Sea from pre-industrial mining and metallurgy.

    Science.gov (United States)

    Bindler, Richard; Renberg, Ingemar; Rydberg, Johan; Andrén, Thomas

    2009-07-01

    Metal pollution is viewed as a modern problem that began in the 19th century and accelerated through the 20th century; however, in many parts of the globe this view is wrong. Here, we studied past waterborne metal pollution in lake sediments from the Bergslagen region in central Sweden, one of many historically important mining regions in Europe. With a focus on lead (including isotopes), we trace mining impacts from a local scale, through a 120-km-long river system draining into Mälaren--Sweden's third largest lake, and finally also the Baltic Sea. Comparison of sediment and peat records shows that pollution from Swedish mining was largely waterborne and that atmospheric deposition was dominated by long-range transport from other regions. Swedish ore lead is detectable from the 10th century, but the greatest impact occurred during the 16th-18th centuries with improvements occurring over recent centuries, i.e., historical pollution > modern industrial pollution.

  15. Unraveling novel broad-spectrum antibacterial targets in food and waterborne pathogens using comparative genomics and protein interaction network analysis.

    Science.gov (United States)

    Jadhav, Ankush; Shanmugham, Buvaneswari; Rajendiran, Anjana; Pan, Archana

    2014-10-01

    Food and waterborne diseases are a growing concern in terms of human morbidity and mortality worldwide, even in the 21st century, emphasizing the need for new therapeutic interventions for these diseases. The current study aims at prioritizing broad-spectrum antibacterial targets, present in multiple food and waterborne bacterial pathogens, through a comparative genomics strategy coupled with a protein interaction network analysis. The pathways unique and common to all the pathogens under study (viz., methane metabolism, d-alanine metabolism, peptidoglycan biosynthesis, bacterial secretion system, two-component system, C5-branched dibasic acid metabolism), identified by comparative metabolic pathway analysis, were considered for the analysis. The proteins/enzymes involved in these pathways were prioritized following host non-homology analysis, essentiality analysis, gut flora non-homology analysis and protein interaction network analysis. The analyses revealed a set of promising broad-spectrum antibacterial targets, present in multiple food and waterborne pathogens, which are essential for bacterial survival, non-homologous to host and gut flora, and functionally important in the metabolic network. The identified broad-spectrum candidates, namely, integral membrane protein/virulence factor (MviN), preprotein translocase subunits SecB and SecG, carbon storage regulator (CsrA), and nitrogen regulatory protein P-II 1 (GlnB), contributed by the peptidoglycan pathway, bacterial secretion systems and two-component systems, were also found to be present in a wide range of other disease-causing bacteria. Cytoplasmic proteins SecG, CsrA and GlnB were considered as drug targets, while membrane proteins MviN and SecB were classified as vaccine targets. The identified broad-spectrum targets can aid in the design and development of antibacterial agents not only against food and waterborne pathogens but also against other pathogens. Copyright © 2014 Elsevier B.V. All rights

  16. Water-borne diseases, cost of illness and willingness to pay for diseases interventions in rural communities of developing countries.

    Science.gov (United States)

    Malik, A; Yasar, A; Tabinda, Ab; Abubakar, M

    2012-01-01

    Almost one third of the global population is living in developing South Asia where disease occurrence is high especially in rural areas and people are unaware of water-borne diseases and cost of illness. The quantitative approach involved questionnaire based study (n=50 households). The community awareness, the occurrence of water-borne diseases with related cost of illness and community participation for the introduction of health interventions for water-borne diseases were evaluated through cross-tabulations, correlations, and ANOVA. Majority (40%) of the community had no knowledge of water-borne diseases except some had little knowledge of diarrhea and typhoid. Diarrhea followed by stomach diseases was widespread in the community. Population below poverty level was bearing the cost of illness around US$ 0.6-1.2 (Rs 50-100) per day followed by low and average income level with direct cost of US$ 2.3 (Rs 200) per day. The indirect cost of illness had showed increasing trend between US$ 2.3-4.7 (Rs 200-400) per day with increase in income levels. Maximum willingness to pay (WTP) for water supply and sewerage system was US$ 3.6 (Rs 300) and US$ 1.2 (Rs 100) per month respectively. Income and water supply demand was strongly correlated with acceptability to pay for the facilities (r = 0.319, 0.307; Pwater and sewerage system (r = 0.805, 0.797; Pwater-borne diseases can be reduced by introducing health interventions like proper water and sanitation facilities.

  17. TECHNOLOGY EVALUATION FOR WATERBORNE MERCURY REMOVAL AT THE Y12 NATIONAL SECURITY COMPLEX

    Energy Technology Data Exchange (ETDEWEB)

    He, Feng [ORNL; Liang, Liyuan [ORNL; Miller, Carrie L [ORNL

    2011-01-01

    The Hg-contaminated processing water produced at Y-12 facility is discharged through the storm drain system, merged at Outfall 200, and then discharged to EFPC. Most of the baseflow mercury at Outfall 200 arises from a small number of short sections of storm drain. This report discusses the waterborne mercury treatment technologies to decrease mercury loading to the surface water of EFPC at Y-12 NSC. We reviewed current available waterborne Hg treatment technologies based on the specific conditions of Y-12 and identified two possible options: SnCl2 reduction coupled with air stripping (SnCl2/air stripping) and sorption. The ORNL 2008 and 2009 field studies suggested that SnCl2/air stripping has the capability to remove waterborne mercury with efficiency higher than 90% at Outfall 200. To achieve this goal, dechlorination (i.e., removing residual chlorine from water) using dechlorinating agents such as thiosulfate has to be performed before the reduction. It is unclear whether or not SnCl2/air stripping can reduce the mercury concentration from ~1000 ng/L to 51 ng/L at a full-scale operation. Therefore, a pilot test is a logical step before a full-scale design to answer questions such as Hg removal efficiency, selection of dechlorinating agents, and so on. The major advantages of the SnCl2/air stripping system are: (1) expected low cost at high flow (e.g., the flow at Outfall 200); and (2) production of minimum secondary waste. However, there are many environmental uncertainties associated with this technology by introducing tin to EFPC ecosystem, for example tin methylation causing abiotic Hg methylation, which should be addressed before a full-scale implementation. Mercury adsorption by granular activated carbon (GAC) is a proven technology for treating Hg at Y-12. The ONRL 2010 lab sorption studies suggest that thiol-based resins hold the promise to combine with GAC to form a more cost-effective treatment system. To achieve a treatment goal of 51 ng/L at Outfall

  18. Spatially explicit models, generalized reproduction numbers and the prediction of patterns of waterborne disease

    Science.gov (United States)

    Rinaldo, A.; Gatto, M.; Mari, L.; Casagrandi, R.; Righetto, L.; Bertuzzo, E.; Rodriguez-Iturbe, I.

    2012-12-01

    Metacommunity and individual-based theoretical models are studied in the context of the spreading of infections of water-borne diseases along the ecological corridors defined by river basins and networks of human mobility. The overarching claim is that mathematical models can indeed provide predictive insight into the course of an ongoing epidemic, potentially aiding real-time emergency management in allocating health care resources and by anticipating the impact of alternative interventions. To support the claim, we examine the ex-post reliability of published predictions of the 2010-2011 Haiti cholera outbreak from four independent modeling studies that appeared almost simultaneously during the unfolding epidemic. For each modeled epidemic trajectory, it is assessed how well predictions reproduced the observed spatial and temporal features of the outbreak to date. The impact of different approaches is considered to the modeling of the spatial spread of V. cholera, the mechanics of cholera transmission and in accounting for the dynamics of susceptible and infected individuals within different local human communities. A generalized model for Haitian epidemic cholera and the related uncertainty is thus constructed and applied to the year-long dataset of reported cases now available. Specific emphasis will be dedicated to models of human mobility, a fundamental infection mechanism. Lessons learned and open issues are discussed and placed in perspective, supporting the conclusion that, despite differences in methods that can be tested through model-guided field validation, mathematical modeling of large-scale outbreaks emerges as an essential component of future cholera epidemic control. Although explicit spatial modeling is made routinely possible by widespread data mapping of hydrology, transportation infrastructure, population distribution, and sanitation, the precise condition under which a waterborne disease epidemic can start in a spatially explicit setting is

  19. Label-free detection and identification of waterborne parasites using a microfluidic multi-angle laser scattering system

    Science.gov (United States)

    Huang, Wei; Yang, Limei; Lei, Lei; Li, Feng

    2017-10-01

    A microfluidic-based multi-angle laser scattering (MALS) system capable of acquiring scattering patterns of a single particle is designed and demonstrated. The system includes a sheathless nozzle microfluidic glass chip, and an on-chip MALS unit being in alignment with the nozzle exit in the chip. The size and relative refractive indices (RI) of polystyrene (PS) microspheres were deduced with accuracies of 60 nm and 0.002 by comparing the experimental scattering patterns with theoretical ones. We measured scattering patterns of waterborne parasites i.e., Cryptosporidium parvum (C.parvum) and Giardia lamblia (G. lamblia), and some other representative species suspended in deionized water at a maximum flow rate of 12 μL/min, and a maximum of 3000 waterborne parasites can be identified within one minute with a mean accuracy higher than 96% by classification of distinctive scattering patterns using a support-vector-machine (SVM) algorithm. The system provides a promising tool for label-free detection of waterborne parasites and other biological contaminants.

  20. Predator faunas past and present: quantifying the influence of waterborne cues in divergent ecotypes of the isopod Asellus aquaticus.

    Science.gov (United States)

    Harris, Sanna; Karlsson Green, Kristina; Pettersson, Lars B

    2013-11-01

    Waterborne chemical cues are an important source of information for many aquatic organisms, in particular when assessing the current risk of predation. The ability to use chemical cues to detect and respond to potential predators before an actual encounter can improve prey chances of survival. We investigated predator recognition and the impact of chemical cues on predator avoidance in the freshwater isopod Asellus aquaticus. This isopod has recently colonised a novel habitat and diverged into two distinct ecotypes, which encounter different predator communities. Using laboratory-based choice experiments, we have quantified behavioural responses to chemical cues from predators typical of the two predator communities (larval dragonflies in the ancestral habitat, perch in the newly colonised habitat) in wild-caught and lab-reared Asellus of the two ecotypes. Individuals with prior experience of predators showed strong predator avoidance to cues from both predator types. Both ecotypes showed similar antipredator responses, but sexes differed in terms of threat-sensitive responses with males avoiding areas containing predator cues to a larger extent than females. Overall, chemical cues from fish elicited stronger predator avoidance than cues from larval dragonflies. Our results indicate that in these isopods, prior exposure to predators is needed to develop antipredator behaviour based on waterborne cues. Furthermore, the results emphasise the need to analyse predator avoidance in relation to waterborne cues in a sex-specific context, because of potential differences between males and females in terms of vulnerability and life history strategies.

  1. Comparison of supervised machine learning algorithms for waterborne pathogen detection using mobile phone fluorescence microscopy

    KAUST Repository

    Ceylan Koydemir, Hatice

    2017-06-14

    Giardia lamblia is a waterborne parasite that affects millions of people every year worldwide, causing a diarrheal illness known as giardiasis. Timely detection of the presence of the cysts of this parasite in drinking water is important to prevent the spread of the disease, especially in resource-limited settings. Here we provide extended experimental testing and evaluation of the performance and repeatability of a field-portable and cost-effective microscopy platform for automated detection and counting of Giardia cysts in water samples, including tap water, non-potable water, and pond water. This compact platform is based on our previous work, and is composed of a smartphone-based fluorescence microscope, a disposable sample processing cassette, and a custom-developed smartphone application. Our mobile phone microscope has a large field of view of ~0.8 cm2 and weighs only ~180 g, excluding the phone. A custom-developed smartphone application provides a user-friendly graphical interface, guiding the users to capture a fluorescence image of the sample filter membrane and analyze it automatically at our servers using an image processing algorithm and training data, consisting of >30,000 images of cysts and >100,000 images of other fluorescent particles that are captured, including, e.g. dust. The total time that it takes from sample preparation to automated cyst counting is less than an hour for each 10 ml of water sample that is tested. We compared the sensitivity and the specificity of our platform using multiple supervised classification models, including support vector machines and nearest neighbors, and demonstrated that a bootstrap aggregating (i.e. bagging) approach using raw image file format provides the best performance for automated detection of Giardia cysts. We evaluated the performance of this machine learning enabled pathogen detection device with water samples taken from different sources (e.g. tap water, non-potable water, pond water) and achieved

  2. Comparison of supervised machine learning algorithms for waterborne pathogen detection using mobile phone fluorescence microscopy

    Science.gov (United States)

    Ceylan Koydemir, Hatice; Feng, Steve; Liang, Kyle; Nadkarni, Rohan; Benien, Parul; Ozcan, Aydogan

    2017-06-01

    Giardia lamblia is a waterborne parasite that affects millions of people every year worldwide, causing a diarrheal illness known as giardiasis. Timely detection of the presence of the cysts of this parasite in drinking water is important to prevent the spread of the disease, especially in resource-limited settings. Here we provide extended experimental testing and evaluation of the performance and repeatability of a field-portable and cost-effective microscopy platform for automated detection and counting of Giardia cysts in water samples, including tap water, non-potable water, and pond water. This compact platform is based on our previous work, and is composed of a smartphone-based fluorescence microscope, a disposable sample processing cassette, and a custom-developed smartphone application. Our mobile phone microscope has a large field of view of 0.8 cm2 and weighs only 180 g, excluding the phone. A custom-developed smartphone application provides a user-friendly graphical interface, guiding the users to capture a fluorescence image of the sample filter membrane and analyze it automatically at our servers using an image processing algorithm and training data, consisting of >30,000 images of cysts and >100,000 images of other fluorescent particles that are captured, including, e.g. dust. The total time that it takes from sample preparation to automated cyst counting is less than an hour for each 10 ml of water sample that is tested. We compared the sensitivity and the specificity of our platform using multiple supervised classification models, including support vector machines and nearest neighbors, and demonstrated that a bootstrap aggregating (i.e. bagging) approach using raw image file format provides the best performance for automated detection of Giardia cysts. We evaluated the performance of this machine learning enabled pathogen detection device with water samples taken from different sources (e.g. tap water, non-potable water, pond water) and achieved a

  3. Comparison of supervised machine learning algorithms for waterborne pathogen detection using mobile phone fluorescence microscopy

    Directory of Open Access Journals (Sweden)

    Ceylan Koydemir Hatice

    2017-06-01

    Full Text Available Giardia lamblia is a waterborne parasite that affects millions of people every year worldwide, causing a diarrheal illness known as giardiasis. Timely detection of the presence of the cysts of this parasite in drinking water is important to prevent the spread of the disease, especially in resource-limited settings. Here we provide extended experimental testing and evaluation of the performance and repeatability of a field-portable and cost-effective microscopy platform for automated detection and counting of Giardia cysts in water samples, including tap water, non-potable water, and pond water. This compact platform is based on our previous work, and is composed of a smartphone-based fluorescence microscope, a disposable sample processing cassette, and a custom-developed smartphone application. Our mobile phone microscope has a large field of view of ~0.8 cm2 and weighs only ~180 g, excluding the phone. A custom-developed smartphone application provides a user-friendly graphical interface, guiding the users to capture a fluorescence image of the sample filter membrane and analyze it automatically at our servers using an image processing algorithm and training data, consisting of >30,000 images of cysts and >100,000 images of other fluorescent particles that are captured, including, e.g. dust. The total time that it takes from sample preparation to automated cyst counting is less than an hour for each 10 ml of water sample that is tested. We compared the sensitivity and the specificity of our platform using multiple supervised classification models, including support vector machines and nearest neighbors, and demonstrated that a bootstrap aggregating (i.e. bagging approach using raw image file format provides the best performance for automated detection of Giardia cysts. We evaluated the performance of this machine learning enabled pathogen detection device with water samples taken from different sources (e.g. tap water, non-potable water, pond

  4. Hydrologic, land cover, and seasonal patterns of waterborne pathogens in Great Lakes tributaries

    Science.gov (United States)

    Lenaker, Peter L.; Corsi, Steven; Borchardt, Mark A.; Spencer, Susan K.; Baldwin, Austin K.; Lutz, Michelle A.

    2017-01-01

    Great Lakes tributaries are known to deliver waterborne pathogens from a host of sources. To examine the hydrologic, land cover, and seasonal patterns of waterborne pathogens (i.e. protozoa (2), pathogenic bacteria (4) human viruses, (8) and bovine viruses (8)) eight rivers were monitored in the Great Lakes Basin over 29 months from February 2011 to June 2013. Sampling locations represented a wide variety of land cover classes from urban to agriculture to forest. A custom automated pathogen sampler was deployed at eight sampling locations which provided unattended, flow-weighted, large-volume (120–1630 L) sampling. Human and bovine viruses and pathogenic bacteria were detected by real-time qPCR in 16%, 14%, and 1.4% of 290 samples collected while protozoa were never detected. The most frequently detected pathogens were: bovine polyomavirus (11%), and human adenovirus C, D, F (9%). Human and bovine viruses were present in 16.9% and 14.8% of runoff-event samples (n = 189) resulting from precipitation and snowmelt, and 13.9% and 12.9% of low-flow samples (n = 101), respectively, indicating multiple delivery mechanisms could be influential. Data indicated human and bovine virus prevalence was different depending on land cover within the watershed. Occurrence, concentration, and flux of human viruses were greatest in samples from the three sampling locations with greater than 25% urban influence than those with less than 25% urban influence. Similarly, occurrence, concentration, and flux of bovine viruses were greatest in samples from the two sampling locations with greater than 50 cattle/km2 than those with less than 50 cattle/km2. In seasonal analysis, human and bovine viruses occurred more frequently in spring and winter seasons than during the fall and summer. Concentration, occurrence, and flux in the context of hydrologic condition, seasonality, and land use must be considered for each watershed individually to develop effective watershed management

  5. Fully glutathione degradable waterborne polyurethane nanocarriers: Preparation, redox-sensitivity, and triggered intracellular drug release.

    Science.gov (United States)

    Omrani, Ismail; Babanejad, Niloofar; Shendi, Hasan Kashef; Nabid, Mohammad Reza

    2017-01-01

    Polyurethanes are important class of biomaterials that are extensively used in medical devices. In spite of their easy synthesis, polyurethanes that are fully degradable in response to the intracellular reducing environment are less explored for controlled drug delivery. Herein, a novel glutathione degradable waterborne polyurethane (WPU) nanocarrier for redox triggered intracellular delivery of a model lipophilic anticancer drug, doxorubicin (DOX) is reported. The WPU was prepared from polyaddition reaction of isophorone diisocyanate (IPDI) and a novel linear polyester polyol involving disulfide linkage, disulfide labeled chain extender, dimethylolpropionic acid (DMPA) using dibutyltin dilaurate (DBTDL) as a catalyst. The resulting polyurethane self-assembles into nanocarrier in water. The dynamic light scattering (DLS) measurements and scanning electron microscope (SEM) revealed fast swelling and disruption of nanocarriers under an intracellular reduction-mimicking environment. The in vitro release studies showed that DOX was released in a controlled and redox-dependent manner. MTT assays showed that DOX-loaded WPU had a high in vitro antitumor activity in both HDF noncancer cells and MCF- 7 cancer cells. In addition, it is found that the blank WPU nanocarriers are nontoxic to HDF and MCF-7 cells even at a high concentration of 2mg/mL. Hence, nanocarriers based on disulfide labeled WPU have appeared as a new class of biocompatible and redox-degradable nanovehicle for efficient intracellular drug delivery. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. [Determination of three isothiazolinone biocides in water-borne adhesives by high performance liquid chromatography].

    Science.gov (United States)

    Zhou, Xiao; Li, Xiaolan; Chen, Zhiyan; Ye, Changwen; Zhou, Yun; Meng, Dongling

    2015-01-01

    A rapid high performance liquid chromatography (HPLC) method was developed for the quantitative analysis of three isothiazolinone biocides (2-methyl-4-isothiazolin-3-one (MI), 5-chloro-2-methyl-4-isothiazolin-3-one (CMI) and 1, 2-benzylisothiazolin-3-one (BIT)) in water-borne adhesives. The sample was extracted with methanol-water (1:1, v/v), and purified by centrifugation and filtration. The isothiazolones were separated on a C18 column with methanol-water as mobile phases under gradient elution and detected with a diode array detector (DAD). The pretreatment factors such as extraction solvent, extraction method, dilution ratio, extraction time were optimized. Under the optimized conditions, the targets had good linearities (r2H > or = 0.9992) in the range of 0.25-10.0 mg/L. The recoveries were between 92% and 103% with the relative standard deviations not more than 4%. The limits of detection (LODs) were between 0.43 mg/kg and 1.14 mg/kg. The limits of quantification (LOQs) were between 1.44 mg/kg and 3.81 mg/kg. The results showed that the method can achieve the purpose of quantitative detection. The analyses of real samples verified the reliability of this method.

  7. Surveillance for Waterborne Disease Outbreaks Associated with Drinking Water - United States, 2013-2014.

    Science.gov (United States)

    Benedict, Katharine M; Reses, Hannah; Vigar, Marissa; Roth, David M; Roberts, Virginia A; Mattioli, Mia; Cooley, Laura A; Hilborn, Elizabeth D; Wade, Timothy J; Fullerton, Kathleen E; Yoder, Jonathan S; Hill, Vincent R

    2017-11-10

    Provision of safe water in the United States is vital to protecting public health (1). Public health agencies in the U.S. states and territories* report information on waterborne disease outbreaks to CDC through the National Outbreak Reporting System (NORS) (https://www.cdc.gov/healthywater/surveillance/index.html). During 2013-2014, 42 drinking water-associated † outbreaks were reported, accounting for at least 1,006 cases of illness, 124 hospitalizations, and 13 deaths. Legionella was associated with 57% of these outbreaks and all of the deaths. Sixty-nine percent of the reported illnesses occurred in four outbreaks in which the etiology was determined to be either a chemical or toxin or the parasite Cryptosporidium. Drinking water contamination events can cause disruptions in water service, large impacts on public health, and persistent community concern about drinking water quality. Effective water treatment and regulations can protect public drinking water supplies in the United States, and rapid detection, identification of the cause, and response to illness reports can reduce the transmission of infectious pathogens and harmful chemicals and toxins.

  8. Advancement of high power ultrasound technology for the destruction of surface active waterborne contaminants.

    Science.gov (United States)

    Sostaric, Joe Z; Weavers, Linda K

    2010-08-01

    The current paper explores recent advances in sonochemical techniques to improve the ultrasound-mediated degradation efficiency of surface active, waterborne contaminants. Sonochemical degradation efficiency of surface active contaminants generally has a strong dependence on the concentration of contaminant at the gas/solution surface of cavitation bubbles. This in turn depends on the thermodynamic and diffusion/kinetic-controlled adsorption properties of the surfactant at the rapidly pulsating gas/solution surface of acoustic cavitation bubbles. The adsorption properties of surfactants can be exploited to enhance their sonochemical decomposition by varying ultrasound exposure parameters such that changes in the nature of the bubble population (especially the bubble life-time and rate of pulsations) cause changes in the amount of surfactant that adsorbs to the gas/solution interface of cavitation bubbles. Herein we describe recent results on the effect of ultrasound frequency and pulsing mode on sonochemical degradation of surfactants in aqueous solutions and show how the exposure parameters can be adjusted in ways to produce more efficient decomposition of contaminants, even under exposure conditions where seemingly poor sonochemical activity is detected in the bulk solution. The relevance of these results to scale-up of ultrasound decontamination processes is discussed. Copyright 2009 Elsevier B.V. All rights reserved.

  9. Climate change and waterborne diarrhoea in northern India: impacts and adaptation strategies.

    Science.gov (United States)

    Moors, Eddy; Singh, Tanya; Siderius, Christian; Balakrishnan, Sneha; Mishra, Arabinda

    2013-12-01

    Although several studies show the vulnerability of human health to climate change, a clear comprehensive quantification of the increased health risks attributable to climate change is lacking. Even more complicated are assessments of adaptation measures for this sector. We discuss the impact of climate change on diarrhoea as a representative of a waterborne infectious disease affecting human health in the Ganges basin of northern India. A conceptual framework is presented for climate exposure response relationships based on studies from different countries, as empirical studies and appropriate epidemiological data sets for India are lacking. Four climate variables are included: temperature, increased/extreme precipitation, decreased precipitation/droughts and relative humidity. Applying the conceptual framework to the latest regional climate projections for northern India shows increases between present and future (2040s), varying spatially from no change to an increase of 21% in diarrhoea incidences, with 13.1% increase on average for the Ganges basin. We discuss three types of measures against diarrhoeal disease: reactive actions, preventive actions and national policy options. Preventive actions have the potential to counterbalance this expected increase. However, given the limited progress in reducing incidences over the past decade consorted actions and effective implementation and integration of existing policies are needed. © 2013.

  10. Differential Behavioral Responses to Water-Borne Cues to Predation in Two Container-Dwelling Mosquitoes.

    Science.gov (United States)

    Kesavaraju, B; Juliano, S A

    2004-01-01

    Larvae of the mosquito Toxorhynchites rutilus (Coquillett) prey upon other container-dwelling insects, including larvae of Aedes albopictus (Skuse), which is native to Asia but was introduced into the United States, and on the native tree hole mosquito Ochlerotatus triseriatus (Say). Previous work has established that O. triseriatus adopts low-risk behaviors in the presence of predation risk from T. rutilus. It is unknown whether introduced A. albopictus show a similar response to this predator. Behavior of fourth instars of A. albopictus or O. triseriatus was recorded in water that had held either A. albopictus or O. triseriatus larvae alone (control) and in water that had held T. rutilus larvae feeding on either A. albopictus or O. triseriatus (predation). Activity and position of larvae were recorded in 30-min instantaneous scan censuses. In response to water-borne cues to predation, O. triseriatus adopted low-risk behaviors (more resting, less feeding and movement), but A. albopictus did not change its behavior. We also tested the species specificity of the cues by recording the behavior of A. albopictus in water prepared using O. triseriatus and vice versa. O. triseriatus adopted low-risk behaviors even in predation water prepared by feeding T. rutilus with A. albopictus, but A. albopictus did not alter its behavior significantly between predation and control treatments prepared using O. triseriatus. Thus, A. albopictus does not seem to respond behaviorally to cues produced by this predator and may be more vulnerable to predation than is O. triseriatus.

  11. Thermoset nanocomposites from waterborne bio-based epoxy resin and cellulose nanowhiskers.

    Science.gov (United States)

    Wu, Guo-min; Liu, Di; Liu, Gui-feng; Chen, Jian; Huo, Shu-ping; Kong, Zhen-wu

    2015-01-01

    Thermoset nanocomposites were prepared from a waterborne terpene-maleic ester type epoxy resin (WTME) and cellulose nanowhiskers (CNWs). The curing behaviors of WTME/CNWs nanocomposites were measured with rotational rheometer. The results show that the storage modulus (G') of WTME/CNWs nanocomposites increased with the increase of CNWs content. Observations by scanning electron microscopy (SEM) demonstrate that the incorporation of CNWs in WTME matrix caused microphase separation and destroyed the compactness of the matrix. This effect leads to the glass transition temperatures (Tg) of WTME/CNWs nanocomposites slightly decrease with the increase of CNWs content, which were confirmed by both DSC and DMA tests. The mechanical properties of WTME/CNWs nanocomposites were investigated by tensile testing. The Yong's modulus (E) and tensile strength (σb) of the nanocomposites were significantly reinforced by the addition of CNWs. These results indicate that CNWs exhibit excellent reinforcement effect on WTME matrix, due to the formation and increase of interfacial interaction by hydrogen bonds between CNWs nano-filler and the WTME matrix. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. PEGylated chitosan protected silver nanoparticles as water-borne coating for leather with antibacterial property.

    Science.gov (United States)

    Liu, Gongyan; Li, Kaijun; Luo, Quanqing; Wang, Haibo; Zhang, Zongcai

    2017-03-15

    Development of eco-labeled and effectively antibacterial coatings for final leather products has been desiderated both by industry and by consumers. Herein, PEGylated chitosan modified silver nanoparticles (PEG-g-CS@AgNPs) were prepared and characterized by UV-vis spectroscopy, transmission electron microscopy and dynamic light scattering. The antimicrobial activity of such silver nanoparticles was investigated against Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus), exhibiting much lower minimum inhibitory concentration (MIC) than chitosan or PEG-g-CS. Water-borne coating was formed by immobilizing the PEG-g-CS@AgNPs onto the leather surface through the electrostatic interaction between amino groups of chitosan and carboxyl groups of leather collagen. Scanning electron microscopy and water contact angle were employed to study the coating's morphology and hydrophilicity, respectively. After coating, leather samples showed significantly high bactericidal efficiency with reusability after release of dead cells from the coating by simply water washing. The excellent antibacterial property of PEG-g-CS@AgNPs coating was ascribed to the combination of bacteria-resistance and bacteria-release by PEGylation, and dual bacteria-killing based on chitosan and Ag + release. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Valve movement response of the freshwater clam Corbicula fluminea following exposure to waterborne arsenic.

    Science.gov (United States)

    Liao, Chung-Min; Jau, Sheng-Feng; Lin, Chieh-Ming; Jou, Li-John; Liu, Chen-Wuing; Liao, Vivian Hsiu-Chuan; Chang, Fi-John

    2009-07-01

    We developed an inductance-based valvometry technique as a detection system to measure the valve daily activity in freshwater clam Corbicula fluminea in response to waterborne arsenic. Our findings reveal that C. fluminea experiences a valve opening in the absence of arsenic predominantly in the morning hours (03:00-08:00) with a mean daily opening/closing period of 21.32 (95% CI: 20.58-22.05) h. Amplification of daily activity occurred in the presence of arsenic. Behavioral toxicity assays revealed arsenic detection thresholds of 0.60 (95% CI: 0.53-0.66) mg l(-1) and 0.35 (95% CI: 0.30-0.40) mg l(-1) for response times of 60 and 300 min, respectively. The proposed valve daily activity model was linked with response time-specific Hill dose-response functions to predict valve opening/closing behavior in response to arsenic. The predictive capabilities were verified satisfactory with the measurements. Our results implicate a biomonitoring system by valve daily activity in C. fluminea to identify safe water uses in areas with elevated arsenic.

  14. Manipulating Interactions in Cellulose Nanocrystal/Waterborne Epoxy Composites through Physical Mixing

    Science.gov (United States)

    Shofner, Meisha L.; Girouard, Natalie M.; Meredith, J. Carson; Schueneman, Gregory T.

    2015-03-01

    The objective of this research is to more fully understand the relationships between component interactions and processing pathways in cellulose nanocrystal (CNC)/polymer composite materials. Specifically, wood-derived CNC/waterborne epoxy composites with CNC loadings up to 15 wt.% were produced using two different protocols. Through relatively simple changes in processing, significant differences in CNC dispersion and composite physical properties were seen, and these changes were attributed to an association between the CNCs and the epoxy emulsion, similar in nature to colloidal haloing. Considering literature results available for CNC nanocomposites, as well as other types of polymer nanocomposites, these results support the assertion that the processing-structure-property relationships in such nanocomposites are diverse and can be used to design materials for a range of applications. Additionally, these results put into context the properties that can be expected in composites containing wood-based CNCs produced at a pilot scale facility as opposed to CNCs from other cellulose sources produced a few grams at a time, making these results relevant to the production of CNC-based composites at larger volumes. Research supported by the USDA Forest Service (11-JV-11111129-117).

  15. Separation and concentration of water-borne contaminants utilizing insulator-based dielectrophoresis.

    Energy Technology Data Exchange (ETDEWEB)

    Lapizco-Encinas, Blanca Hazalia; Fiechtner, Gregory J.; Cummings, Eric B.; Davalos, Rafael V.; Kanouff, Michael P.; Simmons, Blake Alexander; McGraw, Gregory J.; Salmi, Allen J.; Ceremuga, Joseph T.; Fintschenko, Yolanda

    2006-01-01

    This report focuses on and presents the capabilities of insulator-based dielectrophoresis (iDEP) microdevices for the concentration and removal of water-borne bacteria, spores and inert particles. The dielectrophoretic behavior exhibited by the different particles of interest (both biological and inert) in each of these systems was observed to be a function of both the applied electric field and the characteristics of the particle, such as size, shape, and conductivity. The results obtained illustrate the potential of glass and polymer-based iDEP devices to act as a concentrator for a front-end device with significant homeland security and industrial applications for the threat analysis of bacteria, spores, and viruses. We observed that the polymeric devices exhibit the same iDEP behavior and efficacy in the field of use as their glass counterparts, but with the added benefit of being easily mass fabricated and developed in a variety of multi-scale formats that will allow for the realization of a truly high-throughput device. These results also demonstrate that the operating characteristics of the device can be tailored through the device fabrication technique utilized and the magnitude of the electric field gradient created within the insulating structures. We have developed systems capable of handling numerous flow rates and sample volume requirements, and have produced a deployable system suitable for use in any laboratory, industrial, or clinical setting.

  16. Detection and quantification of waterborne microorganisms using an image cytometer based on angular spatial frequency processing

    CERN Document Server

    Pérez, Juan Miguel; Martínez, Pedro; Pruneri, Valerio

    2015-01-01

    We introduce a new image cytometer design for detection of very small particulate and demonstrate its capability in water analysis. The device is a compact microscope composed of off--the--shelf components, such as a light emitting diode (LED) source, a complementary metal--oxide--semiconductor (CMOS) image sensor, and a specific combination of optical lenses that allow, through an appropriate software, Fourier transform processing of the sample volume. Waterborne microorganisms, such as Escherichia coli (E. coli), Legionella pneumophila (L. pneumophila) and Phytoplankton, are detected by interrogating the volume sample either in a fluorescent or label-free mode, i.e. with or without fluorescein isothiocyanate (FITC) molecules attached to the micro-organisms, respectively. We achieve a sensitivity of 50 CFU/ml, which can be further increased to 0.2 CFU/ml by pre-concentrating an initial sample volume of 500 ml with an ad hoc fluidic system. We also prove the capability of the proposed image cytometer of diffe...

  17. New filtration system for efficient recovery of waterborne Cryptosporidium oocysts and Giardia cysts.

    Science.gov (United States)

    Al-Sabi, M N S; Gad, J A; Riber, U; Kurtzhals, J A L; Enemark, H L

    2015-09-01

    To develop a filtration unit for efficient recovery of waterborne Cryptosporidium oocysts and Giardia cysts ((oo-)cysts) in drinking water. This unit utilizes a metallic filter and an ultrasound transducer for eluting (oo-)cysts, with a fixed retentate backwash volume; approx. 400 μl. Changes in the viability was evaluated by seeding wild type (oo-)cysts (1 × 10(4)) followed by sonication for 5, 10, 20 or 40 s (five replicates for each period). Flow cytometry analysis showed negligible increase in the mortality of (oo-)cysts exposed to 5-10 s of sonication. Recovery rate was assessed by seeding ColorSeed(™) (10 replicates) into the filter unit followed by air backwash to a glass slide and counting of (oo-)cysts by epifluorescent microscopy. High recovery rates (mean ± SD) were found: 84·9% ± 4·8 for Giardia cysts and 70% ± 6·5 for Cryptosporidium oocysts. DNA of seeded wild type (oo-)cysts (1 × 10(2); 10 replicates) was successfully amplified using real-time PCR. The use of a metallic filter, sonication and 'air backwash' were key factors for creating a highly efficient system for recovery of apparently undamaged protozoa. This reagent-less system can be used for monitoring of parasite contamination in drinking water. © 2015 The Society for Applied Microbiology.

  18. Assessment of Macro-Level Socioeconomic Factors That Impact Waterborne Diseases: The Case of Jordan

    Directory of Open Access Journals (Sweden)

    John M. Polimeni

    2016-11-01

    Full Text Available The Hashemite Kingdom of Jordan is an example of a country that suffers from high water scarcity. Additionally, due to the economic drivers in the country, such as phosphate and potash extraction and pharmaceutical production, the little fresh water that remains is generally polluted. The infrastructure, often antiquated in urban areas and non-existent in rural areas, also contributes to poor water conditions and to the spread of waterborne diseases. This paper examines the socioeconomic factors that contribute to diarrhea and hepatitis A on a macro level in Jordan and discusses the public-policies that government officials could use to abate those problems. Ordinary least squares time series models are used to understand the macro-level variables that impact the incidence of these diseases in Jordan. Public health expenditure has a significant impact on reducing their incidence. Furthermore, investment in sanitation facilities in rural regions is likely to reduce the number of cases of hepatitis A. Perhaps the most surprising outcome is that importation of goods and services likely results in a decrease in cases of hepatitis A. However, income has little impact on the incidence of diarrhea and hepatitis A.

  19. Differential Behavioral Responses to Water-Borne Cues to Predation in Two Container-Dwelling Mosquitoes

    Science.gov (United States)

    KESAVARAJU, B.; JULIANO, S. A.

    2007-01-01

    Larvae of the mosquito Toxorhynchites rutilus (Coquillett) prey upon other container-dwelling insects, including larvae of Aedes albopictus (Skuse), which is native to Asia but was introduced into the United States, and on the native tree hole mosquito Ochlerotatus triseriatus (Say). Previous work has established that O. triseriatus adopts low-risk behaviors in the presence of predation risk from T. rutilus. It is unknown whether introduced A. albopictus show a similar response to this predator. Behavior of fourth instars of A. albopictus or O. triseriatus was recorded in water that had held either A. albopictus or O. triseriatus larvae alone (control) and in water that had held T. rutilus larvae feeding on either A. albopictus or O. triseriatus (predation). Activity and position of larvae were recorded in 30-min instantaneous scan censuses. In response to water-borne cues to predation, O. triseriatus adopted low-risk behaviors (more resting, less feeding and movement), but A. albopictus did not change its behavior. We also tested the species specificity of the cues by recording the behavior of A. albopictus in water prepared using O. triseriatus and vice versa. O. triseriatus adopted low-risk behaviors even in predation water prepared by feeding T. rutilus with A. albopictus, but A. albopictus did not alter its behavior significantly between predation and control treatments prepared using O. triseriatus. Thus, A. albopictus does not seem to respond behaviorally to cues produced by this predator and may be more vulnerable to predation than is O. triseriatus. PMID:17710216

  20. Comparative Study on Waterborne Parasites between Malaysia and Thailand: A New Insight

    Science.gov (United States)

    Kumar, Thulasi; Onichandran, Subashini; Lim, Yvonne A. L.; Sawangjaroen, Nongyao; Ithoi, Init; Andiappan, Hemah; Salibay, Cristina C.; Dungca, Julieta Z.; Chye, Tan Tian; Sulaiman, Wan Y. W.; Ling Lau, Yee; Nissapatorn, Veeranoot

    2014-01-01

    This study investigated the distribution of parasites as main contaminants in water environments of peninsular Malaysia (October 2011–December 2011) and the southeastern coast of Thailand (June 2012). Sixty-four water samples, 33 from Malaysia and 31 from Thailand, of various water types were examined according to U.S. Environmental Protection Agency guidelines. Drinking or household water types from both countries were free from parasitic contamination. The recreational/environmental (except a swimming pool in Malaysia) and effluent water types from these two countries were contaminated with waterborne parasites: Giardia (0.04–4 cysts/L), Cryptosporidium (0.06–2.33 oocysts/L), hookworm (6.67–350 ova/L), Ascaris (0.33–33.33 ova/L), and Schistosoma (9.25–13.33 ova/L). The most contaminated sites were recreational lake garden 3 in Malaysia and river 2 in Thailand. Higher concentrations of Giardia, Cryptosporidium, and hookworm were found in samples from Malaysia than in samples from Thailand. The presence of Giardia cysts showed a significant association with the presence of Cryptosporidium oocysts (P < 0.005). PMID:24567315

  1. A Waterborne Pursuit-Deterrent Signal Deployed by a Sea Urchin.

    Science.gov (United States)

    Sheppard-Brennand, Hannah; Poore, Alistair G B; Dworjanyn, Symon A

    2017-06-01

    Selection by consumers has led to the evolution of a vast array of defenses in animals and plants. These defenses include physical structures, behaviors, and chemical signals that mediate interactions with predators. Some of the strangest defensive structures in nature are the globiferous pedicellariae of the echinoderms. These are small venomous appendages with jaws and teeth that cover the test of many sea urchins and sea stars. In this study, we report a unique use of these defensive structures by the collector sea urchin Tripneustes gratilla. In both the laboratory and the field, globiferous pedicellariae were unpalatable to fish consumers. When subject to simulated predator attack, sea urchins released a cloud of pedicellaria heads into the water column. Flume experiments established the presence of a waterborne cue associated with this release of pedicellariae that is deterrent to predatory fish. These novel results add to our understanding of how the ecosystem-shaping sea urchin T. gratilla is able to reach high densities in many reef habitats, with subsequent impacts on algal cover.

  2. The role of cellulose nanocrystals incorporation route in waterborne polyurethane for preparation of electrospun nanocomposites mats.

    Science.gov (United States)

    Santamaria-Echart, Arantzazu; Ugarte, Lorena; Gonzalez, Kizkitza; Martin, Loli; Irusta, Lourdes; Gonzalez, Alba; Corcuera, Maria Angeles; Eceiza, Arantxa

    2017-06-15

    Electrospinning offers the possibility of obtaining fibers mats from polymer solutions. The use of environmentally-friendly waterborne polyurethane (WBPU) allows obtaining electrospun polyurethane mats in water medium. Furthermore, the incorporation of water dispersible nanoentities, like renewable cellulose nanocrystals (CNC), is facilitated. Therefore, in this work, a WBPU was synthesized and CNC were isolated for preparing WBPU-CNC dispersions nanocomposites with 1 and 3wt% of CNC following both the classical mixing by sonication, and the innovative in-situ route. The dispersions were used for obtaining electrospun mats assisted by poly(ethylene oxide) (PEO) as polymer template. Moreover, the extraction of PEO with water resulted in continuous WBPU-CNC mats, showing different properties respect to WBPU-CNC mats containing PEO. The effective addition of CNC led to more defined cylindrical morphologies and the two alternative incorporation routes induced to different CNC dispositions in the matrix, which modified fibers diameters, and thus, mats final properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Liquid based formulations of bacteriophages for the management of waterborne bacterial pathogens in water microcosms.

    Science.gov (United States)

    Ahiwale, Sangeeta; Tagunde, Sujata; Khopkar, Sushama; Karni, Mrudula; Gajbhiye, Milind; Kapadnis, Balasaheb

    2013-11-01

    Water resources are contaminated by life-threatening multidrug resistant pathogenic bacteria. Unfortunately, these pathogenic bacteria do not respond to the traditional water purification methods. Therefore, there is a need of environmentally friendly strategies to overcome the problems associated with the antimicrobial resistant bacterial pathogens. In the present study, highly potent lytic phages against multidrug-resistant Salmonella enterica serovar Paratyphi B, Pseudomonas aeruginosa and Klebsiella pneumoniae were isolated from the Pavana river water. They belonged to the Podoviridae and Siphoviridae families. These phages were purified and enriched in the laboratory. Monovalent formulations of phiSPB, BVPaP-3 and KPP phages were prepared in three different liquids viz., phage broth, saline and distilled water. The phages were stable for almost 8-10 months in the phage broth at 4 degrees C. The stability of the phages in saline and distilled water was 5-6 months at 4 degrees C. All of the phages were stable only for 4-6 months in the phage broth at 30 degrees C. The monovalent phage formulation of psiSPB was applied at MOI < 1, as disinfectant against an exponential and stationary phase cells of Salmonella enterica serovar Paratyphi B in various water microcosms. The results indicated that there was almost 80 % reduction in the log phase cells of Salmonella serovar Paratyphi B in 24 h. In stationary phase cells, the reduction was comparatively less within same period. At the same time, there was concomitant increase in the phage population by 80% in all the microcosms indicating that psiSPB phage is highly potent in killing pathogen in water. Results strongly support that the formulation of psiSPB in the phage broth in monovalent form could be used as an effective biological disinfectant for preventing transmission of water-borne bacterial pathogens, including antimicrobial resistant ones.

  4. Macroalgal Morphogenesis Induced by Waterborne Compounds and Bacteria in Coastal Seawater

    Science.gov (United States)

    Grueneberg, Jan; Engelen, Aschwin H.; Costa, Rodrigo; Wichard, Thomas

    2016-01-01

    Axenic gametes of the marine green macroalga Ulva mutabilis Føyn (Ria Formosa, locus typicus) exhibit abnormal development into slow-growing callus-like colonies with aberrant cell walls. Under laboratory conditions, it was previously demonstrated that all defects in growth and thallus development can be completely abolished when axenic gametes are inoculated with a combination of two specific bacterial strains originally identified as Roseobacter sp. strain MS2 and Cytophaga sp. strain MS6. These bacteria release diffusible morphogenetic compounds (= morphogens), which act similar to cytokinin and auxin. To investigate the ecological relevance of the waterborne bacterial morphogens, seawater samples were collected in the Ria Formosa lagoon (Algarve, Southern Portugal) at 20 sampling sites and tidal pools to assess their morphogenetic effects on the axenic gametes of U. mutabilis. Specifically the survey revealed that sterile-filtered seawater samples can completely recover growth and morphogenesis of U. mutabilis under axenic conditions. Morphogenetic activities of free-living and epiphytic bacteria isolated from the locally very abundant Ulva species (i.e., U. rigida) were screened using a multiwell-based testing system. The most represented genera isolated from U. rigida were Alteromonas, Pseudoalteromonas and Sulfitobacter followed by Psychrobacter and Polaribacter. Several naturally occurring bacterial species could emulate MS2 activity (= induction of cell divisions) regardless of taxonomic affiliation, whereas the MS6 activity (= induction of cell differentiation and cell wall formation) was species-specific and is probably a feature of difficult-to-culture bacteria. Interestingly, isolated bacteroidetes such as Algoriphagus sp. and Polaribacter sp. could individually trigger complete Ulva morphogenesis and thus provide a novel mode of action for bacterial-induced algal development. This study also highlights that the accumulation of algal growth factors in

  5. Occurrence of waterborne pathogens and Escherichia coli at offshore drinking water intakes in lake Ontario.

    Science.gov (United States)

    Edge, T A; Khan, I U H; Bouchard, R; Guo, J; Hill, S; Locas, A; Moore, L; Neumann, N; Nowak, E; Payment, P; Yang, R; Yerubandi, R; Watson, S

    2013-10-01

    The occurrence of waterborne pathogens was investigated at three drinking water intakes located about 2 km offshore in Lake Ontario. Water sampling was conducted over 3 years for Campylobacter spp., Cryptosporidium spp., Giardia spp., cultivable enteric viruses, and water quality parameters. All pathogens were detected in the offshore source water for each water treatment plant (WTP1 to WTP3), although at relatively low frequencies and concentrations. Giardia was the most common pathogen, occurring in 36% of water samples from the influent of WTP1 (n = 46), and with a maximum concentration of 0.70 cysts/liter in this influent. Cryptosporidium occurred as frequently as 15% in the WTP2 influent (n = 35), with a maximum concentration of 0.40 oocysts/liter in the WTP1 influent. The human Bacteroidales HF183 DNA marker was most common in the WTP1 influent (19%), and this was the only WTP where the Cryptosporidium hominis genotype was detected. No water quality parameter was predictive of pathogen occurrence across all three WTP influents. Escherichia coli was often below detection when pathogens were detected, and spikes in E. coli concentrations often did not coincide with pathogen occurrence. After summer rain events, river plumes had E. coli concentrations as high as 222 CFU/100 ml in surface waters 2 km offshore, without impacting drinking water intakes below the thermocline on the lake bottom. At times, prechlorination to control mussels at offshore intake cribs compromised the use of E. coli for "raw" water quality assessment, particularly for chlorine-resistant Cryptosporidium. E. coli measured by standard methods did not reliably predict pathogen occurrence at drinking water intakes in offshore ecosystems.

  6. Simultaneous quantification of multiple food- and waterborne pathogens by use of microfluidic quantitative PCR.

    Science.gov (United States)

    Ishii, Satoshi; Segawa, Takahiro; Okabe, Satoshi

    2013-05-01

    The direct quantification of multiple pathogens has been desired for diagnostic and public health purposes for a long time. In this study, we applied microfluidic quantitative PCR (qPCR) technology to the simultaneous detection and quantification of multiple food- and waterborne pathogens. In this system, multiple singleplex qPCR assays were run under identical detection conditions in nanoliter-volume chambers that are present in high densities on a chip. First, we developed 18 TaqMan qPCR assays that could be run in the same PCR conditions by using prevalidated TaqMan probes. Specific and sensitive quantification was achieved by using these qPCR assays. With the addition of two previously validated TaqMan qPCR assays, we used 20 qPCR assays targeting 10 enteric pathogens, a fecal indicator bacterium (general Escherichia coli), and a process control strain in the microfluidic qPCR system. We preamplified the template DNA to increase the sensitivity of the qPCR assays. Our results suggested that preamplification was effective for quantifying small amounts of the template DNA without any major impact on the sensitivity, efficiency, and quantitative performance of qPCR. This microfluidic qPCR system allowed us to detect and quantify multiple pathogens from fecal samples and environmental water samples spiked with pathogens at levels as low as 100 cells/liter. These results suggest that the routine monitoring of multiple pathogens in food and water samples is now technically feasible. This method may provide more reliable information for risk assessment than the current fecal contamination indicator approach.

  7. A novel spatially-explicit condition for the onset of waterborne diseases in complex environments

    Science.gov (United States)

    Mari, L.; Gatto, M.; Bertuzzo, E.; Casagrandi, R.; Righetto, L.; Rodriguez-Iturbe, I.; Rinaldo, A.

    2012-12-01

    In spatial models of waterborne infections the condition that all the local reproduction numbers be larger than one is neither necessary nor sufficient for outbreaks to occur. Here, to properly determine epidemic onset conditions, we examine the transition from stable to unstable of the disease-free equilibrium of a system of nonlinear differential equations characterizing the evolution of susceptible and infected individuals within their respective settlements, and pathogen concentration in their accessible environment. Two different network connectivity layers are assumed to link human settlements: hydrologic pathways serve as ecological corridors for pathogens, while human mobility acts as disease vehicle through susceptibles contracting the disease and asymptomatic infectives shedding bacteria at their temporary destinations. We show that an epidemic outbreak can be triggered if the dominant eigenvalue of a generalized reproduction matrix G0, suitably accounting for spatial distribution of human settlements, hydrological pathways for pathogen dispersal and pathogen redistribution mechanisms due to human mobility, is larger than unity. Matrix G0 and its dominant eigenvalue thus replace the usual reproduction number whenever spatial effects on disease propagation cannot be ignored. Conversely, our novel criterion decays into the standard onset condition based on local reproduction numbers in nonspatial settings. By analyzing realistic test cases we show that within a connected network system the disease can start even if all the local reproduction numbers are smaller than unity, or might not start even if all the local reproduction numbers are larger than unity. We also show that onset geography in complex environments is linked to the dominant eigenvector of matrix G0. Applications to cholera outbreaks in developing countries demonstrate that our approach can be successfully used for disease prediction and emergency management.

  8. Recovery of Waterborne Cryptosporidium parvum Oocysts by Freshwater Benthic Clams (Corbicula fluminea)

    Science.gov (United States)

    Graczyk, Thaddeus K.; Fayer, Ronald; Cranfield, Michael R.; Conn, David Bruce

    1998-01-01

    Asian freshwater clams, Corbicula fluminea, exposed for 24 h to 38 liters of water contaminated with infectious Cryptosporidium parvum oocysts (1.00 × 106 oocysts/liter; approximately 1.9 × 105 oocysts/clam) were examined (hemolymph, gills, gastrointestinal [GI] tract, and feces) on days 1, 2, 3, 7, and 14 postexposure (PE). No oocysts were detected in the water 24 h after the contamination event. The percentage of oocyst-containing clams varied from 20 to 100%, depending on the type of tissue examined and the technique used—acid-fast stain (AFS) or immunofluorescent antibody (IFA). The oocysts were found in clam tissues and feces on days 1 through 14 PE; the oocysts extracted from the tissues on day 7 PE were infectious for neonatal BALB/c mice. Overall, the highest number of positive samples was obtained when gills and GI tracts were processed with IFA (prevalence, 97.5%). A comparison of the relative oocyst numbers indicated that overall, 58.3% of the oocysts were found in clam tissues and 41.7% were found in feces when IFA was used; when AFS was used, the values were 51.9 and 48.1%, respectively. Clam-released oocysts were always surrounded by feces; no free oocysts or oocysts disassociated from fecal matter were observed. The results indicate that these benthic freshwater clams are capable of recovery and sedimentation of waterborne C. parvum oocysts. To optimize the detection of C. parvum oocysts in C. fluminea tissue, it is recommended that gill and GI tract samples be screened with IFA (such as that in the commercially available MERIFLUOR test kit). PMID:9464376

  9. Toxicokinetics of waterborne trivalent arsenic in the freshwater bivalve Corbicula fluminea.

    Science.gov (United States)

    Costa, Pedro M; Santos, Hugo M; Peres, Isabel; Costa, Maria H; Alves, Sheila; Capelo-Martinez, José Luís; Diniz, Mário S

    2009-08-01

    , even at exposures as high as 1000 microg L(-1) of waterborne As(III).

  10. Surveillance for waterborne disease outbreaks associated with drinking water---United States, 2007--2008.

    Science.gov (United States)

    Brunkard, Joan M; Ailes, Elizabeth; Roberts, Virginia A; Hill, Vincent; Hilborn, Elizabeth D; Craun, Gunther F; Rajasingham, Anu; Kahler, Amy; Garrison, Laurel; Hicks, Lauri; Carpenter, Joe; Wade, Timothy J; Beach, Michael J; Yoder Msw, Jonathan S

    2011-09-23

    Since 1971, CDC, the Environmental Protection Agency (EPA), and the Council of State and Territorial Epidemiologists have collaborated on the Waterborne Disease and Outbreak Surveillance System (WBDOSS) for collecting and reporting data related to occurrences and causes of waterborne disease outbreaks associated with drinking water. This surveillance system is the primary source of data concerning the scope and health effects of waterborne disease outbreaks in the United States. Data presented summarize 48 outbreaks that occurred during January 2007--December 2008 and 70 previously unreported outbreaks. WBDOSS includes data on outbreaks associated with drinking water, recreational water, water not intended for drinking (WNID) (excluding recreational water), and water use of unknown intent (WUI). Public health agencies in the states, U.S. territories, localities, and Freely Associated States are primarily responsible for detecting and investigating outbreaks and reporting them voluntarily to CDC by a standard form. Only data on outbreaks associated with drinking water, WNID (excluding recreational water), and WUI are summarized in this report. Outbreaks associated with recreational water are reported separately. A total of 24 states and Puerto Rico reported 48 outbreaks that occurred during 2007--2008. Of these 48 outbreaks, 36 were associated with drinking water, eight with WNID, and four with WUI. The 36 drinking water--associated outbreaks caused illness among at least 4,128 persons and were linked to three deaths. Etiologic agents were identified in 32 (88.9%) of the 36 drinking water--associated outbreaks; 21 (58.3%) outbreaks were associated with bacteria, five (13.9%) with viruses, three (8.3%) with parasites, one (2.8%) with a chemical, one (2.8%) with both bacteria and viruses, and one (2.8%) with both bacteria and parasites. Four outbreaks (11.1%) had unidentified etiologies. Of the 36 drinking water--associated outbreaks, 22 (61.1%) were outbreaks of

  11. Health Risk Assessment Related to Waterborne Pathogens from the River to the Tap

    Directory of Open Access Journals (Sweden)

    Pauline Jacob

    2015-03-01

    Full Text Available A two-year monitoring program of Cryptosporidium parvum oocysts, Giardia duodenalis cysts, Escherichia coli, Clostridium perfringens spores and adenovirus was conducted in three large rivers in France used for recreational activities and as a resource for drinking water production. Fifty-liter river water and one thousand-liter tap water samples were concentrated using hollow-fiber ultrafiltration and analyzed by molecular biology or laser-scanning cytometry. In order to evaluate watershed land use influence on microorganism concentration changes, occurrence and seasonality of microorganisms were studied. The highest concentrations of protozoan parasites and C. perfringens were found for one of the three sites, showing a high proportion of agricultural territories, forests and semi-natural environments, which may be partly attributable to soil leaching due to rainfall events. On the contrary, the highest concentrations of adenoviruses were found at the two other sites, probably due to strong urban activities. Health risk assessment was evaluated for each waterborne pathogen regarding exposure during recreational activities (for a single or five bathing events during the summer. The calculated risk was lower than 0.5% for parasites and varied from 1% to 42% for adenovirus. A theoretical assessment of microorganism removal during the drinking water treatment process was also performed, and it showed that an absence of microorganisms could be expected in finished drinking water. This hypothesis was confirmed since all tested tap water samples were negative for each studied microorganism, resulting in a risk for drinking water consumption lower than 0.01% for parasites and lower than 0.5% for adenovirus.

  12. A waterborne chemical cue from Gulf toadfish, Opsanus beta, prompts pulsatile urea excretion in conspecifics.

    Science.gov (United States)

    Fulton, Jeremy; LeMoine, Christophe M R; Bucking, Carol; Brix, Kevin V; Walsh, Patrick J; McDonald, M Danielle

    2017-03-15

    The Gulf toadfish (Opsanus beta) has a fully functional ornithine urea cycle (O-UC) that allows it to excrete nitrogenous waste in the form of urea. Interestingly, urea is excreted in a pulse across the gill that lasts 1-3h and occurs once or twice a day. Both the stress hormone, cortisol, and the neurotransmitter, serotonin (5-HT) are involved in the control of pulsatile urea excretion. This and other evidence suggests that urea pulsing may be linked to toadfish social behavior. The hypothesis of the present study was that toadfish urea pulses can be triggered by waterborne chemical cues from conspecifics. Our findings indicate that exposure to seawater that held a donor conspecific for up to 48h (pre-conditioned seawater; PC-SW) induced a urea pulse within 7h in naïve conspecifics compared to a pulse latency of 20h when exposed to seawater alone. Factors such as PC-SW intensity and donor body mass influenced the pulse latency response of naïve conspecifics. Fractionation and heat treatment of PC-SW to narrow possible signal candidates revealed that the active chemical was both water-soluble and heat-stable. Fish exposed to urea, cortisol or 5-HT in seawater did not have a pulse latency that was significantly different than seawater alone; however, ammonia, perhaps in the form of NH4Cl, was found to be a factor in the pulse latency response of toadfish to PC-SW and could be one component of a multi-component cue used for chemical communication in toadfish. Further studies are needed to fully identify the chemical cue as well as determine its adaptive significance in this marine teleost fish. Copyright © 2016. Published by Elsevier Inc.

  13. Waterborne outbreak among Spanish tourists in a holiday resort in the Dominican Republic, August 2002.

    Science.gov (United States)

    Páez Jiménez, A; Pimentel, R; Martínez de Aragón, M V; Hernández Pezzi, G; Mateo Ontañon, S; Martínez Navarro, J F

    2004-03-01

    On 3 September 2002, the Spanish national centre of epidemiology (Centro Nacional de Epidemiologia--CNE) was alerted to a high number of gastroenteritis cases in Spanish tourists who had travelled to a hotel in Punta Cana on different days during august 2002. Entamoeba hystolitica cysts have been visualised by microscopy in the stools of several patients that sought medical attention in the Dominican Republic. The CNE informed the health authorities in the Dominican Republic and conducted in conjunction an epidemiological investigation. A descriptive study of the 76 initial cases estimated a mean illness duration of 5.1+2.9 days and a exposure period of 3.6+2.2 days. Following a retrospective cohort study, the attack rate was found to be 32.4%. Consequently, 216 (95% CI=114.75-317.25) spanish tourists had probably developed the illness. Stool samples were collected in Spain from untreated patients who still felt unwell. None of the samples were positive for E.hystolitica. On 10 September, a hygiene inspection was undertaken at the hotel. Samples of the ice and meals served at the buffet that day, yielded coliform bacteria. Consumption of water from the resort water system was the only risk factor associated with the symptoms (RR= 3.55; 95% CI =1.13-10.99). To avoid similar outbreaks occurring again at the hotel, it is essential to regularly monitor the water quality and to improve food handling hygiene standards. Basic food hygiene training for food handlers should be mandatory. An international guideline for the management foodborne and waterborne outbreaks among tourists in holiday resorts should be drawn up, involving all competent authorities of both destination and tourist origin countries.

  14. Synthesis of waterborne polyurethane containing alkoxysilane side groups and the properties of the hybrid coating films

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qi; Guo, Longhai [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Qiu, Teng, E-mail: qiuteng@mail.buct.edu.cn [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Xiao, Weidong; Du, Dianxing [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Li, Xiaoyu, E-mail: lixy@mail.buct.edu.cn [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China)

    2016-07-30

    Highlights: • A diol with side-chain trimethoxysilane (DEA-Si) was synthesized using 3-(methacryloxypropyl)trimethoxysilane (MAPTS) and diethanolamine (DEA). • The crosslinking structure could in situ formed within the WPU matrix through sol-gel process. • The Si tends to shift to the polymer-air interface due to the flexible long alkyl-ester side chain. • The incorporation of DEA-Si enhanced mechanical and surface hydrophobic properties of WPU films. - Abstract: A series of waterborne polyurethane (WPU) containing alkoxysilane side groups were synthesized by using the dihydroxy functionalized alkoxysilane. The diol with trimethoxysilane groups at the side chains was synthesized via Michael addition between 3-(methacryloxypropyl)trimethoxysilane (MAPTS) and diethanolamine (DEA). The silane diol was applied as the chain extender for the NCO-endcapped prepolymer of isophorone diisocyanate, polycarbonate diol, 2,2-bis(hydroxymethyl) butyric acid and 1,4-butanediol. The products with the silane content varied from 1.2 to 16.5 wt% were dispersed in water after neutralization. The effect of the silane diol on the particle size and morphology of the WPU dispersion was studied by dynamic light scattering (DLS) and transmission electron microscopy (TEM), respectively. X-ray photoelectron spectroscopy (XPS) characterization was carried out on the coating film of the WPU, revealing that the long flexible side chain is favorable for the silane components to emigrate toward the film surface and crosslink during the film formation process. As a result, both the surface contact angle to water and water adsorption of the WPU coating films increased with the silane content. Furthermore, the mechanical properties including the modulus and tensile strength of the films were also improved by the incorporation of silane diol.

  15. Macroalgal Morphogenesis Induced by Waterborne Compounds and Bacteria in Coastal Seawater.

    Directory of Open Access Journals (Sweden)

    Jan Grueneberg

    Full Text Available Axenic gametes of the marine green macroalga Ulva mutabilis Føyn (Ria Formosa, locus typicus exhibit abnormal development into slow-growing callus-like colonies with aberrant cell walls. Under laboratory conditions, it was previously demonstrated that all defects in growth and thallus development can be completely abolished when axenic gametes are inoculated with a combination of two specific bacterial strains originally identified as Roseobacter sp. strain MS2 and Cytophaga sp. strain MS6. These bacteria release diffusible morphogenetic compounds (= morphogens, which act similar to cytokinin and auxin. To investigate the ecological relevance of the waterborne bacterial morphogens, seawater samples were collected in the Ria Formosa lagoon (Algarve, Southern Portugal at 20 sampling sites and tidal pools to assess their morphogenetic effects on the axenic gametes of U. mutabilis. Specifically the survey revealed that sterile-filtered seawater samples can completely recover growth and morphogenesis of U. mutabilis under axenic conditions. Morphogenetic activities of free-living and epiphytic bacteria isolated from the locally very abundant Ulva species (i.e., U. rigida were screened using a multiwell-based testing system. The most represented genera isolated from U. rigida were Alteromonas, Pseudoalteromonas and Sulfitobacter followed by Psychrobacter and Polaribacter. Several naturally occurring bacterial species could emulate MS2 activity (= induction of cell divisions regardless of taxonomic affiliation, whereas the MS6 activity (= induction of cell differentiation and cell wall formation was species-specific and is probably a feature of difficult-to-culture bacteria. Interestingly, isolated bacteroidetes such as Algoriphagus sp. and Polaribacter sp. could individually trigger complete Ulva morphogenesis and thus provide a novel mode of action for bacterial-induced algal development. This study also highlights that the accumulation of algal

  16. Macroalgal Morphogenesis Induced by Waterborne Compounds and Bacteria in Coastal Seawater.

    Science.gov (United States)

    Grueneberg, Jan; Engelen, Aschwin H; Costa, Rodrigo; Wichard, Thomas

    2016-01-01

    Axenic gametes of the marine green macroalga Ulva mutabilis Føyn (Ria Formosa, locus typicus) exhibit abnormal development into slow-growing callus-like colonies with aberrant cell walls. Under laboratory conditions, it was previously demonstrated that all defects in growth and thallus development can be completely abolished when axenic gametes are inoculated with a combination of two specific bacterial strains originally identified as Roseobacter sp. strain MS2 and Cytophaga sp. strain MS6. These bacteria release diffusible morphogenetic compounds (= morphogens), which act similar to cytokinin and auxin. To investigate the ecological relevance of the waterborne bacterial morphogens, seawater samples were collected in the Ria Formosa lagoon (Algarve, Southern Portugal) at 20 sampling sites and tidal pools to assess their morphogenetic effects on the axenic gametes of U. mutabilis. Specifically the survey revealed that sterile-filtered seawater samples can completely recover growth and morphogenesis of U. mutabilis under axenic conditions. Morphogenetic activities of free-living and epiphytic bacteria isolated from the locally very abundant Ulva species (i.e., U. rigida) were screened using a multiwell-based testing system. The most represented genera isolated from U. rigida were Alteromonas, Pseudoalteromonas and Sulfitobacter followed by Psychrobacter and Polaribacter. Several naturally occurring bacterial species could emulate MS2 activity (= induction of cell divisions) regardless of taxonomic affiliation, whereas the MS6 activity (= induction of cell differentiation and cell wall formation) was species-specific and is probably a feature of difficult-to-culture bacteria. Interestingly, isolated bacteroidetes such as Algoriphagus sp. and Polaribacter sp. could individually trigger complete Ulva morphogenesis and thus provide a novel mode of action for bacterial-induced algal development. This study also highlights that the accumulation of algal growth factors in

  17. Exposure to environmental levels of waterborne cadmium impacts corticosteroidogenic and metabolic capacities, and compromises secondary stressor performance in rainbow trout

    Energy Technology Data Exchange (ETDEWEB)

    Sandhu, Navdeep [Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); McGeer, James C. [Department of Biology, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5 (Canada); Vijayan, Mathilakath M., E-mail: matt.vijayan@ucalgary.ca [Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

    2014-01-15

    Highlights: •Low level chronic waterborne cadmium exposure did not evoke a plasma cortisol response in rainbow trout. •Chronic cadmium exposure increases liver and gill metabolic capacities. •Chronic cadmium exposure disrupts head kidney steroidogenic capacity. •Chronic cadmium exposure disrupts glucocorticoid and mineralocorticoid receptor protein expressions in target tissues. •Chronic cadmium exposure compromises physiological performances to a secondary stressor in trout. -- Abstract: The physiological responses to waterborne cadmium exposure have been well documented; however, few studies have examined animal performances at low exposure concentrations of this metal. We tested the hypothesis that longer-term exposure to low levels of cadmium will compromise the steroidogenic and metabolic capacities, and reduce the cortisol response to a secondary stressor in fish. To test this, juvenile rainbow trout (Oncorhynchus mykiss) were exposed to 0 (control), 0.75 or 2.0 μg/L waterborne cadmium in a flow-through system and were sampled at 1, 7 and 28 d of exposure. There were only very slight disturbances in basal plasma cortisol, lactate or glucose levels in response to cadmium exposure over the 28 d period. Chronic cadmium exposure significantly affected key genes involved in corticosteroidogenesis, including melanocortin 2 receptor, steroidogenic acute regulatory protein and cytochrome P450 side chain cleavage enzyme. At 28 d, the high cadmium exposure group showed a significant drop in the glucocorticoid receptor and mineralocorticoid receptor protein expressions in the liver and brain, respectively. There were also perturbations in the metabolic capacities in the liver and gill of cadmium-exposed trout. Subjecting these fish to a secondary handling disturbance led to a significant attenuation of the stressor-induced plasma cortisol, glucose and lactate levels in the cadmium groups. Collectively, although trout appears to adjust to subchronic exposure

  18. Waterborne toxicity and diet-related effects of fungicides in the key leaf shredder Gammarus fossarum (Crustacea: Amphipoda).

    Science.gov (United States)

    Zubrod, J P; Englert, D; Wolfram, J; Wallace, D; Schnetzer, N; Baudy, P; Konschak, M; Schulz, R; Bundschuh, M

    2015-12-01

    Animals involved in leaf litter breakdown (i.e., shredders) play a central role in detritus-based stream food webs, while their fitness and functioning can be impaired by anthropogenic stressors. Particularly fungicides can affect shredders via both waterborne exposure and their diet, namely due to co-ingestion of adsorbed fungicides and shifts in the leaf-associated fungal community, on which shredders' nutrition heavily relies. To understand the relevance of these effect pathways, we used a full 2×2-factorial test design: the leaf material serving as food was microbially colonized for 12 days either in a fungicide-free control or exposed to a mixture of five current-use fungicides (sum concentration of 62.5μg/L). Similarly, the amphipod shredder Gammarus fossarum was subjected to the same treatments but for 24 days. Waterborne exposure reduced leaf consumption by ∼20%, which did not fully explain the reduction in feces production (∼30%), indicating an enhanced utilization of food to compensate for detoxification mechanisms. This may also explain the reduced feces production (∼10%) of gammarids feeding on fungicide-exposed leaves. The reduction may, however, also be caused by a decreased nutritious quality of the leaves indicated by a reduced species richness (∼40%) of leaf-associated fungi. However, compensation for these effects by Gammarus was seemingly incomplete, since both waterborne exposure and the consumption of the fungicide-affected diet drastically reduced gammarid growth (∼110% and ∼40%, respectively). Our results thus indicate that fungicide mixtures have the potential for detrimental implications in aquatic ecosystem functioning by affecting shredders via both effect pathways. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Cognitive Challenges

    Science.gov (United States)

    ... Privacy Policy Sitemap Learn Engage Donate About TSC Cognitive Challenges Approximately 45% to 60% of individuals with TSC develop cognitive challenges (intellectual disabilities), although the degree of intellectual ...

  20. Synthesis and Characterization of Waterborne Fluoropolymers Prepared by the One-Step Semi-Continuous Emulsion Polymerization of Chlorotrifluoroethylene, Vinyl Acetate, Butyl Acrylate, Veova 10 and Acrylic Acid

    Directory of Open Access Journals (Sweden)

    Hongzhu Liu

    2017-01-01

    Full Text Available Waterborne fluoropolymer emulsions were synthesized using the one-step semi-continuous seed emulsion polymerization of chlorotrifluoroethylene (CTFE, vinyl acetate (VAc, n-butyl acrylate (BA, Veova 10, and acrylic acid (AA. The main physical parameters of the polymer emulsions were tested and analyzed. Characteristics of the polymer films such as thermal stability, glass transition temperature, film-forming properties, and IR spectrum were studied. Meanwhile, the weatherability of fluoride coatings formulated by the waterborne fluoropolymer and other coatings were evaluated by the quick ultraviolet (QUV accelerated weathering test, and the results showed that the fluoropolymer with more than 12% fluoride content possessed outstanding weather resistance. Moreover, scale-up and industrial-scale experiments of waterborne fluoropolymer emulsions were also performed and investigated.

  1. Synthesis and Characterization of Waterborne Fluoropolymers Prepared by the One-Step Semi-Continuous Emulsion Polymerization of Chlorotrifluoroethylene, Vinyl Acetate, Butyl Acrylate, Veova 10 and Acrylic Acid.

    Science.gov (United States)

    Liu, Hongzhu; Bian, Jiming; Wang, Zhonggang; Hou, Chuan-Jin

    2017-01-22

    Waterborne fluoropolymer emulsions were synthesized using the one-step semi-continuous seed emulsion polymerization of chlorotrifluoroethylene (CTFE), vinyl acetate (VAc), n-butyl acrylate (BA), Veova 10, and acrylic acid (AA). The main physical parameters of the polymer emulsions were tested and analyzed. Characteristics of the polymer films such as thermal stability, glass transition temperature, film-forming properties, and IR spectrum were studied. Meanwhile, the weatherability of fluoride coatings formulated by the waterborne fluoropolymer and other coatings were evaluated by the quick ultraviolet (QUV) accelerated weathering test, and the results showed that the fluoropolymer with more than 12% fluoride content possessed outstanding weather resistance. Moreover, scale-up and industrial-scale experiments of waterborne fluoropolymer emulsions were also performed and investigated.

  2. Waterfront Challenges

    DEFF Research Database (Denmark)

    Kiib, Hans

    2007-01-01

    An overall view on the waterfront transformation and the planning challenges related to this process. It contributes to the specific challenges and potentials related to Aalborg Waterfront.......An overall view on the waterfront transformation and the planning challenges related to this process. It contributes to the specific challenges and potentials related to Aalborg Waterfront....

  3. Electrochemical synthesis of multi-armed CuO nanoparticles and their remarkable bactericidal potential against waterborne bacteria

    Science.gov (United States)

    Pandey, Pratibha; Merwyn, S.; Agarwal, G. S.; Tripathi, B. K.; Pant, S. C.

    2012-01-01

    Copper (II) oxide multi-armed nanoparticles composed of 500-1000 nm long radiating nanospicules with 100-200 nm width near the base and 50-100 nm width at the tapered ends and 25 nm thickness were synthesized by electrochemical deposition in the presence of an oxidant followed by calcination at 150 °C. The nanoparticles were characterized using SEM/EDX for morphology and composition, Raman spectroscopy for compound identification, and broth culture method for antibacterial efficacy. The CuO nanoparticles have shown remarkable bactericidal efficacy against Gram-positive and -negative waterborne disease causing bacteria like Escherichia coli, Salmonella typhi, s taphylococcus aureus and Bacillus subtilis. E. coli has been chosen as representative species for waterborne disease causing bacteria. In antibacterial tests 500 μg/mL nano CuO killed 3 × 108 CFU/mL E. coli bacteria within 4 h of exposure. Moreover, 8.3 × 106 CFU/mL E. coli were killed by 100 and 10 μg/mL nano CuO within 15 min and 4 h of exposure, respectively. Antibacterial activity of nano CuO has been found many-fold compared with commercial bulk CuO. The fate of nanoparticles after antibacterial test has also been studied. The synthesized CuO nanoparticles are expected to have potential antibacterial applications in water purification and in paints and coatings used on frequently touched surfaces and fabrics in hospital settings.

  4. Exploitation of Nanotechnology for the Monitoring of Waterborne Pathogens: State-of-the-Art and Future Research Priorities.

    Science.gov (United States)

    Bridle, Helen; Balharry, Dominique; Gaiser, Birgit; Johnston, Helinor

    2015-09-15

    Contaminated drinking water is one of the most important environmental contributors to the human disease burden. Monitoring of water for the presence of pathogens is an essential part of ensuring drinking water safety. In order to assess water quality it is essential to have methods available to sample and detect the type, level and viability of pathogens in water which are effective, cheap, quick, sensitive, and where possible high throughput. Nanotechnology has the potential to drastically improve the monitoring of waterborne pathogens when compared to conventional approaches. To date, there have been no reviews that outline the applications of nanotechnology in this area despite increasing exploitation of nanotechnology for this purpose. This review is therefore the first overview of the state-of-the-art in the application of nanotechnology to waterborne pathogen sampling and detection schemes. Research in this field has been centered on the use of engineered nanomaterials. The effectiveness and limitations of nanomaterial-based approaches is outlined. A future outlook of the advances that are likely to emerge in this area, as well as recommendations for areas of further research are provided.

  5. A study of waterborne diseases during flooding using Radarsat-2 imagery and a back propagation neural network algorithm

    Directory of Open Access Journals (Sweden)

    Peera Yomwan

    2015-05-01

    Full Text Available Flood disasters are closely associated with an increased risk of infection, particularly from waterborne diseases. Most studies of waterborne diseases have relied on the direct determination of pathogens in contaminated water to assess disease risk. In contrast, this study aims to use an indirect assessment that employs a back propagation neural network (BPNN for modelling diarrheal outbreaks using data from remote sensing and dissolved-oxygen (DO measurements to reduce cost and time. Our study area is in Ayutthaya province, which was very severely affected by the catastrophic 2011 Thailand flood. BPNN was used to model the relationships among the parameters of the flood and the water quality and the risk of people becoming infected. Radarsat-2 scenes were utilized to estimate flood area and duration, while the flood water quality was derived from the interpolation of DO samples. The risk-ratio function was applied to the diarrheal morbidity to define the level of outbreak detection and the outbreak periods. Tests of the BPNN prediction model produced high prediction accuracy of diarrheal-outbreak risk with low prediction error and a high degree of correlation. With the promising accuracy of our approach, decision-makers can plan rapid and comprehensively preventive measures and countermeasures in advance.

  6. The effects of acute waterborne exposure to sublethal concentrations of molybdenum on the stress response in rainbow trout, Oncorhynchus mykiss.

    Directory of Open Access Journals (Sweden)

    Chelsea D Ricketts

    Full Text Available To determine if molybdenum (Mo is a chemical stressor, fingerling and juvenile rainbow trout (Oncorhynchus mykiss were exposed to waterborne sodium molybdate (0, 2, 20, or 1,000 mg l-1 of Mo and components of the physiological (plasma cortisol, blood glucose, and hematocrit and cellular (heat shock protein [hsp] 72, hsp73, and hsp90 in the liver, gills, heart, and erythrocytes and metallothionein [MT] in the liver and gills stress responses were measured prior to initiation of exposure and at 8, 24, and 96 h. During the acute exposure, plasma cortisol, blood glucose, and hematocrit levels remained unchanged in all treatments. Heat shock protein 72 was not induced as a result of exposure and there were no detectable changes in total hsp70 (72 and 73, hsp90, and MT levels in any of the tissues relative to controls. Both fingerling and juvenile fish responded with similar lack of apparent sensitivity to Mo exposure. These experiments demonstrate that exposure to waterborne Mo of up to 1,000 mg l(-1 did not activate a physiological or cellular stress response in fish. Information from this study suggests that Mo water quality guidelines for the protection of aquatic life are highly protective of freshwater fish, namely rainbow trout.

  7. Waterborne, all-polymeric, colloidal ‘raspberry’ particles with controllable hydrophobicity and water droplet adhesion properties

    Energy Technology Data Exchange (ETDEWEB)

    Telford, Andrew M. [School of Chemistry, The University of Sydney, NSW 2006 (Australia); Easton, Christopher D. [CSIRO Manufacturing Flagship, Clayton South, VIC 3169 (Australia); Hawkett, Brian S. [School of Chemistry, The University of Sydney, NSW 2006 (Australia); Neto, Chiara, E-mail: Chiara.neto@sydney.edu.au [School of Chemistry, The University of Sydney, NSW 2006 (Australia)

    2016-03-31

    We present a superhydrophobic coating made from waterborne, all-polymeric ‘raspberry’ particles, composed of a micrometric spherical core decorated with a corona of nanometric spherical particles. As-cast particles produced hydrophobic coatings that were highly adhesive to almost-spherical droplets of water, resembling the properties of some types of rose petals. The coatings could be made slippery to spherical water droplets, like the lotus leaf, by surface activation with air plasma followed by reaction with an alkyl-trichlorosilane. The silanisation of films of latex particles was investigated on two model surfaces (a flat polystyrene film and a monolayer of polystyrene waterborne microparticles) by X-ray photoelectron spectroscopy and water contact angle measurements, and applied to our recently-developed ‘raspberry’ particles to produce a superhydrophobic coating. - Highlights: • We have prepared superhydrophobic films using all-polymeric ‘raspberry’ particles. • We have prepared both ‘rose petal’ and ‘lotus leaf’ surfaces. • We have investigated the silanisation of complex latex particles.

  8. Characterization, validation and application of a DNA microarray for the detection of mandatory and other waterborne pathogens.

    Science.gov (United States)

    Gomes, Maria; Vieira, Helena; Vale, Filipa F

    2015-11-01

    Culture methods for the detection of indicator bacteria are currently used for detection of waterborne bacteria. The need for an increased range of analyzed bacteria coupled with the obtainment of rapid and early results justify the development of a DNA microarray for the identification of waterborne pathogens. This DNA microarray has 16 implanted probes with a median size of 147 bases, targeting 12 different parameters, including all mandatory indicator microorganisms, such as Escherichia coli, Clostridium perfringens, Pseudomonas aeruginosa, Staphylococcus aureus, total and fecal coliforms and enterococci. The validation performed with DNA extracted from pure microbial cultures showed the suitability of the probes for detection of the target microorganism. To overcome the high dilution of water samples it was included either a prior culture step of bacterial contaminants retained after filtering 100 ml of water, or a 10-fold increase in the volume of filtered water, that resulted in the increase of the detected bacteria. The analysis of complex environmental water samples using culture methods and the DNA microarray revealed that the latter detected the same parameters plus other bacteria tested only in the DNA microarray. The results show that this DNA microarray may be a useful tool for water microbiological surveillance. © The Authors 2015. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  9. Stable Photocatalytic Paints Prepared from Hybrid Core-Shell Fluorinated/Acrylic/TiO2 Waterborne Dispersions

    Directory of Open Access Journals (Sweden)

    Audrey Bonnefond

    2016-10-01

    Full Text Available The contamination of air and water is one of the major concerns towards the development of a sustainable world in the 21st century. In this context many efforts are devoted to the design of photocatalytic paints able to degrade chemical and biological impurities present in air and water. In this work, the photocatalytic activity of hybrid films formed from the blends of pure acrylic or core/shell fluorinated/acrylic waterborne dispersions and photocatalytic titanium dioxide (TiO2 nanoparticle dispersions was first assessed. The films show photocatalytic activity (inactivation of the Escherichia coli bacteria under UV irradiation at the substrate-film interface, but very reduced activity in the air-film interface due to the substantially lower amount of the TiO2 nanoparticles in the vicinity of this interface. In a second step, the fluorinated/(methacrylic core-shell hybrid dispersions were used as binders in the formulation of waterborne photocatalytic paints and the stability of the paints, in terms of gloss retain and color change, was assessed during 5000 hours of accelerated weathering tests (QUV-B. Although a decrease in gloss retention and increased color change occurs during the first 1000 hours of exposure, no further change of these properties takes place, which is an excellent indication of stable photocatalytic paints.

  10. [A water-borne tularemia outbreak caused by Francisella tularensis subspecies holarctica in Central Anatolia region].

    Science.gov (United States)

    Ulu Kılıç, Ayşegül; Kılıç, Selçuk; Sencan, Irfan; Ciçek Şentürk, Gönül; Gürbüz, Yunus; Tütüncü, Emin Ediz; Celebi, Bekir; Kıcıman, Özlem; Ergönül, Önder

    2011-04-01

    In this study, we investigated a waterborne tularemia outbreak occured in Kadiozu, a village of Cerkes county of Cankiri province (located in North-west part of central Anatolia, Turkey) between 18 November 2009-24 December 2009. Active surveillance was conducted to determine clinical characteristics and risk factors of cases after two patients from the same village had been diagnosed as oropharyngeal tularemia. All villagers were examined, and clinical specimens from cases and water samples which may be the source of outbreak in the field investigations were taken. Cases were in the form of oropharyngeal, glandular and pneumonic. Polymerase chain reaction (PCR) and cultures were conducted from lymph node aspirates, throat swabs taken from cases and samples from water sources of epidemic zone. All serum samples taken from the villagers were screened for F.tularensis antibodies with microagglutination test (MAT). Oropharyngeal tularemia was diagnosed in 11 patients, glandular form in 3 patients and pneumonic form in one patient according to clinical and laboratory results. Age of the patients ranged between 6-75 years old (mean age: 52.5 years) and thirty one of them (54.7%) were female. MAT titers ranged between 1/160 and 1/5120 in cases of tularemia. Causative agent was grown in the cultures of two patients (including a throat swab and a lymph node aspirate). F.tularensis DNA was shown by PCR in a throat swab and four lymph node aspirates. F.tularensis was also detected by PCR in the water sample obtained from one of the spring water commonly used by villagers. Only one of the lymph node samples obtained from two different patients, was positive by direct fluorescent antibody method. Causative agent was defined as F.tularensis subsp. holarctica by conventional and also molecular methods. Patients were treated with aminoglycoside (streptomycin, gentamicin, amikacin) or quinolone (ciprofloxacin, levofloxacin) antibiotics. Treatment failure was observed in five

  11. Waterborne cadmium impacts immunocytotoxic and cytogenotoxic endpoints in green-lipped mussel, Perna canaliculus

    Energy Technology Data Exchange (ETDEWEB)

    Chandurvelan, Rathishri, E-mail: rch118@uclive.ac.nz [School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand); Marsden, Islay D., E-mail: islay.marsden@canterbury.ac.nz [School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand); Gaw, Sally, E-mail: sally.gaw@canterbury.ac.nz [Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand); Glover, Chris N., E-mail: chris.glover@canterbury.ac.nz [School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand)

    2013-10-15

    Highlights: •Cadmium (Cd) significantly altered the proportional composition of haemocytes. •Subchronic exposure increased nuclear aberrations in gill cells. •Branchial nuclear aberrations correlated significantly with gill Cd accumulation. •Cd induced DNA damage in haemocytes. -- Abstract: Mussels are sentinel species that can be used to monitor coastal metal pollution through the application of biomarkers. Among the several important metal toxicants in coastal settings, cadmium (Cd) is of particular concern, being a non-essential metal that is known to cause harmful impacts in aquatic organisms at low concentrations. The aim of the present study was to examine the immunocytotoxic and cytogenotoxic effects of Cd on the green-lipped mussel, Perna canaliculus, under laboratory conditions. The acute (96 h; 0, 2000 and 4000 μg Cd L{sup −1}) and subchronic (28 d; 0, 200 and 2000 μg Cd L{sup −1}) toxic effects of waterborne Cd were measured in haemocytes and gill cells using differential haemocyte cell count, the micronucleus test and the comet assay. During subchronic exposure to Cd the relative counts of eosinophils and hyalinocytes increased significantly in Cd-exposed mussels while the proportion of basophils decreased. All of these effects were time- and concentration-dependent. Conversely, the relative numbers of basophils and eosinophils increased significantly during acute Cd exposure. Nuclear aberrations such as the formation of micronuclei, nuclear buds, fragmented-apoptotic cells and binuclei were observed in gill cells of Cd-exposed mussels. All of these parameters increased significantly at 2000 μg Cd L{sup −1} during subchronic exposure to Cd, and all showed a strong and significant correlation to gill Cd accumulation. Comet assay results demonstrated a significant increase in DNA damage in the haemocytes of mussels exposed to subchronic Cd concentrations. The results indicate that Cd has the capacity to induce immune system and genotoxic

  12. A survey of diving behaviour and accidental water ingestion among Dutch occupational and sport divers to assess the risk of infection with waterborne pathogenic microorganisms.

    NARCIS (Netherlands)

    Schijven, Jack; Roda Husman, Ana Maria de

    2006-01-01

    Divers may run a higher risk of infection with waterborne pathogens than bathers because of more frequent and intense contact with water that may not comply with microbiologic water quality standards for bathing water. In this study we aimed to estimate the volume of water swallowed during diving as

  13. The impact of meteorology on the occurrence of waterborne outbreaks of vero cytotoxin-producing Escherichia coli (VTEC): a logistic regression approach.

    Science.gov (United States)

    O'Dwyer, Jean; Morris Downes, Margaret; Adley, Catherine C

    2016-02-01

    This study analyses the relationship between meteorological phenomena and outbreaks of waterborne-transmitted vero cytotoxin-producing Escherichia coli (VTEC) in the Republic of Ireland over an 8-year period (2005-2012). Data pertaining to the notification of waterborne VTEC outbreaks were extracted from the Computerised Infectious Disease Reporting system, which is administered through the national Health Protection Surveillance Centre as part of the Health Service Executive. Rainfall and temperature data were obtained from the national meteorological office and categorised as cumulative rainfall, heavy rainfall events in the previous 7 days, and mean temperature. Regression analysis was performed using logistic regression (LR) analysis. The LR model was significant (p < 0.001), with all independent variables: cumulative rainfall, heavy rainfall and mean temperature making a statistically significant contribution to the model. The study has found that rainfall, particularly heavy rainfall in the preceding 7 days of an outbreak, is a strong statistical indicator of a waterborne outbreak and that temperature also impacts waterborne VTEC outbreak occurrence.

  14. Removal of waterborne pathogens from liver transplant unit water taps in prevention of healthcare-associated infections: a proposal for a cost-effective, proactive infection control strategy.

    Science.gov (United States)

    Zhou, Z Y; Hu, B J; Qin, L; Lin, Y E; Watanabe, H; Zhou, Q; Gao, X D

    2014-04-01

    Hospital water supplies often contain waterborne pathogens, which can become a reservoir for healthcare-associated infections (HAIs). We surveyed the extent of waterborne pathogen contamination in the water supply of a Liver Transplant Unit. The efficacy of point-of-use (POU) water filters was evaluated by comparative analysis in routine clinical use. Our baseline environmental surveillance showed that Legionella spp. (28%, 38/136), Pseudomonas aeruginosa (8%, 11/136), Mycobacterium spp. (87%, 118/136) and filamentous fungi (50%, 68/136) were isolated from the tap water of the Liver Transplant Unit. 28.9% of Legionella spp.-positive water samples (n = 38) showed high-level Legionella contamination (≥10(3) CFU/L). After installation of the POU water filter, none of these pathogens were found in the POU filtered water samples. Furthermore, colonizations/infections with Gram-negative bacteria determined from patient specimens were reduced by 47% during this period, even if only 27% (3/11) of the distal sites were installed with POU water filters. In conclusion, the presence of waterborne pathogens was common in the water supply of our Liver Transplant Unit. POU water filters effectively eradicated these pathogens from the water supply. Concomitantly, healthcare-associated colonization/infections declined after the POU filters were installed, indicating their potential benefit in reducing waterborne HAIs. © 2013 The Authors Clinical Microbiology and Infection © 2013 European Society of Clinical Microbiology and Infectious Diseases.

  15. Risk of Handling as a Route of Exposure to Infectious Waterborne Cryptosporidium parvum Oocysts via Atlantic Blue Crabs (Callinectes sapidus)▿

    Science.gov (United States)

    Graczyk, Thaddeus K.; McOliver, Cynthia; Silbergeld, Ellen K.; Tamang, Leena; Roberts, Jennifer D.

    2007-01-01

    Commercial Atlantic blue crabs (Callinectes sapidus) were exposed to 2.0 × 104 infectious waterborne oocysts of Cryptosporidium parvum. The study demonstrated that blue crabs can transfer C. parvum oocysts to persons involved in handling or preparing crabs and that they may contaminate other surfaces or products during storage. PMID:17449680

  16. Biokinetic food chain modeling of waterborne selenium pulses into aquatic food chains: Implications for water quality criteria.

    Science.gov (United States)

    DeForest, David K; Pargee, Suzanne; Claytor, Carrie; Canton, Steven P; Brix, Kevin V

    2016-04-01

    We evaluated the use of biokinetic models to predict selenium (Se) bioaccumulation into model food chains after short-term pulses of selenate or selenite into water. Both periphyton- and phytoplankton-based food chains were modeled, with Se trophically transferred to invertebrates and then to fish. Whole-body fish Se concentrations were predicted based on 1) the background waterborne Se concentration, 2) the magnitude of the Se pulse, and 3) the duration of the Se pulse. The models were used to evaluate whether the US Environmental Protection Agency's (USEPA's) existing acute Se criteria and their recently proposed intermittent Se criteria would be protective of a whole-body fish Se tissue-based criterion of 8.1 μg g(-1) dry wt. Based on a background waterborne Se concentration of 1 μg L(-1) and pulse durations of 1 d and 4 d, the Se pulse concentrations predicted to result in a whole-body fish Se concentration of 8.1 μg g(-1) dry wt in the most conservative model food chains were 144 and 35 μg L(-1), respectively, for selenate and 57 and 16 μg L(-1), respectively, for selenite. These concentrations fall within the range of various acute Se criteria recommended by the USEPA based on direct waterborne toxicity, suggesting that these criteria may not always be protective against bioaccumulation-based toxicity that could occur after short-term pulses. Regarding the USEPA's draft intermittent Se criteria, the biokinetic modeling indicates that they may be overly protective for selenate pulses but potentially underprotective for selenite pulses. Predictions of whole-body fish Se concentrations were highly dependent on whether the food chain was periphyton- or phytoplankton-based, because the latter had much greater Se uptake rate constants. Overall, biokinetic modeling provides an approach for developing acute Se criteria that are protective against bioaccumulation-based toxicity after trophic transfer, and it is also a useful tool for evaluating averaging

  17. Comparing the relative importance of water-borne cues and direct grazing for the induction of defenses in the brown seaweed Fucus vesiculosus.

    Science.gov (United States)

    Flöthe, Carla R; John, Uwe; Molis, Markus

    2014-01-01

    Some seaweed species have been shown to release water-borne cues after herbivore attack, for example, to attract natural enemies of the herbivore. These cues may also be sensed by neighboring seaweeds and used to adjust their defenses in anticipation of a possible herbivore attack. Several studies indicated information transfer between seaweed individuals in the past, including the brown seaweed Fucus vesiculosus. Previous work showed induction of defenses in F. vesiculosus in response to water-borne cues released by isopod-grazed conspecifics. In contrast, another study on induced responses after exposure to cues from isopod-grazed neighbors using the same seaweed species yielded contradictory results. This study reassessed the ability of F. vesiculosus individuals to sense water-borne cues released by isopod-grazed neighbors in a series of experiments that monitored F. vesiculosus palatability in response to direct grazing by Idotea baltica and water-borne cues from isopod-grazed neighbors relative to unmanipulated seaweed pieces. Two-choice feeding assays were conducted with both fresh and reconstituted seaweed pieces. Direct grazing by I. baltica induced a chemical defense in F. vesiculosus, confirming results of previous studies. In contrast, evidence for increased herbivore resistance in seaweed pieces that were located downstream of isopod-grazed F. vesiculosus could not be provided. The lack of defense induction in response to grazing of conspecific neighbors may be explained by the environmental conditions and the scattered distribution of F. vesiculosus individuals in the intertidal zone of Helgoland, which may render resource investment in the emission and/or response to water-borne cues at this site unprofitable.

  18. Comparing the relative importance of water-borne cues and direct grazing for the induction of defenses in the brown seaweed Fucus vesiculosus.

    Directory of Open Access Journals (Sweden)

    Carla R Flöthe

    Full Text Available Some seaweed species have been shown to release water-borne cues after herbivore attack, for example, to attract natural enemies of the herbivore. These cues may also be sensed by neighboring seaweeds and used to adjust their defenses in anticipation of a possible herbivore attack. Several studies indicated information transfer between seaweed individuals in the past, including the brown seaweed Fucus vesiculosus. Previous work showed induction of defenses in F. vesiculosus in response to water-borne cues released by isopod-grazed conspecifics. In contrast, another study on induced responses after exposure to cues from isopod-grazed neighbors using the same seaweed species yielded contradictory results. This study reassessed the ability of F. vesiculosus individuals to sense water-borne cues released by isopod-grazed neighbors in a series of experiments that monitored F. vesiculosus palatability in response to direct grazing by Idotea baltica and water-borne cues from isopod-grazed neighbors relative to unmanipulated seaweed pieces. Two-choice feeding assays were conducted with both fresh and reconstituted seaweed pieces. Direct grazing by I. baltica induced a chemical defense in F. vesiculosus, confirming results of previous studies. In contrast, evidence for increased herbivore resistance in seaweed pieces that were located downstream of isopod-grazed F. vesiculosus could not be provided. The lack of defense induction in response to grazing of conspecific neighbors may be explained by the environmental conditions and the scattered distribution of F. vesiculosus individuals in the intertidal zone of Helgoland, which may render resource investment in the emission and/or response to water-borne cues at this site unprofitable.

  19. Modeling Leptospirosis in Trinidad, West Indies: A Waterborne Zoonosis of Increasing Public Health Importance

    Science.gov (United States)

    Vega, M. C.; Opadeyi, J.

    2012-12-01

    Leptospirosis is a waterborne disease which is considered one of the most common and widely spread bacterial zoonosis and a growing global public health problem. Transmission in humans is caused by direct or indirect contact with contaminated water, soil or infected urine, blood or tissue of carrier animals. Because of the similarity with influenza, dengue and viral hepatitis symptoms it is often misdiagnosed with these diseases, but as the leptospirosis progresses, internal organs can be compromised, causing severe syndromes (e.g. Weil's disease), and potentially can cause death. In less developed countries, leptospirosis is often poorly recognized. In humid tropics and subtropics, where this disease has a high impact, climatic and environmental factors, such as rainfall, floods, land cover and their modifications have been frequently related to the occurrence of leptospirosis. In these regions one of the main problems for the study of the role of environmental factors on disease dynamics is the lack of accurate data since, in many cases, data are either unavailable or do not exist at all. Between 1980 and 2005 a total of 12,475 cases of leptospirosis were reported from all Caribbean countries, with 2,370 (19%) of these corresponding to Trinidad and Tobago, where the current average annual incidence rate is 1.84 per 100,000 population based on confirmed cases. In order to explore the underlying spatial variability of leptospirosis occurrence as related to environmental and socio-economic factors, a series of Geographically Weighted Regression (GWR) models were developed. GWR was used to examine the determinants of leptospirosis in the communities of Trinidad using a total of 1,549 reported cases and 250 confirmed cases from 1998 to 2008. MODIS satellite imagery and GIS analysis were used to develop a series of covariables for each community including land cover, vegetation indices, wetness index (ln (α/tanβ)), river length per Ha, topography, percentage of free

  20. Ultrastructural effects on gill, muscle, and gonadal tissues induced in zebrafish (Danio rerio) by a waterborne uranium exposure

    Energy Technology Data Exchange (ETDEWEB)

    Barillet, Sabrina, E-mail: sabrina.barillet@free.fr [Laboratory of Radioecology and Ecotoxicology, IRSN (Institute for Radiological Protection and Nuclear Safety), DEI/SECRE/LRE, Cadarache, Bat 186, BP 3, 13115 St-Paul-Lez-Durance cedex (France); Larno, Valerie, E-mail: valerie.larno@irsn.fr [Laboratory of Radioecology and Ecotoxicology, IRSN (Institute for Radiological Protection and Nuclear Safety), DEI/SECRE/LRE, Cadarache, Bat 186, BP 3, 13115 St-Paul-Lez-Durance cedex (France); Floriani, Magali, E-mail: magali.floriani@irsn.fr [Laboratory of Radioecology and Ecotoxicology, IRSN (Institute for Radiological Protection and Nuclear Safety), DEI/SECRE/LRE, Cadarache, Bat 186, BP 3, 13115 St-Paul-Lez-Durance cedex (France); Devaux, Alain, E-mail: alain.devaux@entpe.fr [INRA, EFPA Department, 54280, Champenoux and Environmental Science Laboratory, ENTPE, 69518 Vaulx en Velin cedex (France); Adam-Guillermin, Christelle, E-mail: christelle.adam-guillermin@irsn.fr [Laboratory of Radioecology and Ecotoxicology, IRSN (Institute for Radiological Protection and Nuclear Safety), DEI/SECRE/LRE, Cadarache, Bat 186, BP 3, 13115 St-Paul-Lez-Durance cedex (France)

    2010-11-01

    Experiments on adult zebrafish (Danio rerio) were conducted to assess histopathological effects induced on gill, muscle, and gonadal tissues after waterborne uranium exposure. Although histopathology is often employed as a tool for the detection and assessment of xenobiotic-mediated effects in aquatic organisms, few studies have been dedicated to the investigation of histopathological consequences of uranium exposure in fish. Results showed that gill tissue architecture was markedly disrupted. Major symptoms were alterations of the secondary lamellae epithelium (from extensive oedema to desquamation), hyperplasia of chloride cells, and breakdown of the pillar cell system. Muscle histology was also affected. Degeneration and disorganization of myofibrillar sarcomeric pattern as well as abnormal localization of mitochondria within muscle and altered endomysial sheaths were observed. Morphological alterations of spermatozoa within the gonadal tissue were also noticed. This study demonstrated that uranium exposure induced a variety of histological impairments in fish, supporting environmental concerns when uranium contaminates aquatic systems.

  1. A biodynamic model predicting waterborne lead bioaccumulation in Gammarus pulex: Influence of water chemistry and in situ validation.

    Science.gov (United States)

    Urien, N; Uher, E; Billoir, E; Geffard, O; Fechner, L C; Lebrun, J D

    2015-08-01

    Metals bioaccumulated in aquatic organisms are considered to be a good indicator of bioavailable metal contamination levels in freshwaters. However, bioaccumulation depends on the metal, the species, and the water chemistry that influences metal bioavailability. In the laboratory, a kinetic model was used to describe waterborne Pb bioaccumulated in Gammarus pulex. Uptake and elimination rate constants were successfully determined and the effect of Ca(2+) on Pb uptake was integrated into the model. Thereafter, accumulated Pb concentrations in organisms were predicted with the model and compared with those measured in native populations from the Seine watershed (France). The predictions had a good agreement with the bioaccumulation levels observed in native gammarids and particularly when the effect of calcium was considered. To conclude, kinetic parameters experimentally derived for Pb in G. pulex are applicable in environmental conditions. Moreover, the consideration of the water's chemistry is crucial for a reliable interpretation of bioaccumulation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. A biodynamic understanding of dietborne and waterborne Ag uptake from Ag NPs in the sediment-dwelling oligochaete, Tubifex tubifex

    DEFF Research Database (Denmark)

    Tangaa, Stine Rosendal; Selck, Henriette; Winther-Nielsen, Margrethe

    2018-01-01

    Metal nanoparticles (Me-NPs) are increasingly used in various products, such as inks and cosmetics, enhancing the likelihood of their release into aquatic environments. An understanding of the mechanisms controlling their bioaccumulation and ecotoxicity in aquatic biota will help support...... environmental risk assessment. Here we characterized unidirectional parameters for uptake and elimination of silver (Ag) in the sediment-dwelling oligochaete Tubifex tubifex after waterborne (0.01–47 nmol Ag/L) and dietborne (0.4–482 nmol Ag/g dw sed.) exposures to Ag NPs and AgNO3, respectively. Worms...... environments. However, inference of bioavailability from our estimations of Ag assimilation efficiencies (AE) suggests that Ag (AE: 3–12% for AgNO3 and 0.1–0.8% for Ag NPs) is weakly bioavailable from sediment for this species. Thus, Ag amended to sediment as NPs might not pose greater problems than...

  3. The Effect of Improved Crosslink Density on the Properties of Waterborne Polyurethanes Using Sol-Gel Process

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Ryul; Park, Jin Hwan [Pukyong National University, Busan (Korea, Republic of)

    2016-12-15

    Water-based systems are dominating the coating market because of worldwide VOCs regulations. Research is focusing especially on waterborne polyurethane (WPU) because of its unique mechanical and chemical properties. However, commercial WPU consists of linear thermoplastic polymers with polar groups on the main chain, which do not perform as well as solvent-borne PU in a two-pack system. In this study, APTES were used as a chain crosslink agent to overcome commercial WPU's limited performance. WPUs synthesized by using a sol-gel process were evaluated with FT-IR, particle analysis, TGA, tensile tests, pull-off tests, SEM, and EIS. The results showed that WPUs with added APTES had better thermal stability, mechanical properties, and water resistance than did WPUs without added APTES. Consequently, the sol-gel process increased the crosslink density of WPUs and modified the WPU's own properties.

  4. Hybrid thin films derived from UV-curable acrylate-modified waterborne polyurethane and monodispersed colloidal silica

    Directory of Open Access Journals (Sweden)

    C. H. Yang

    2012-01-01

    Full Text Available Hybrid thin films containing nano-sized inorganic domains were synthesized from UV-curable acrylate-modified waterborne polyurethane (WPU-AC and monodispersed colloidal silica with coupling agent. The coupling agent, 3-(trimethoxysilylpropyl methacrylate (MSMA, was bonded onto colloidal silica first, and then mixed with WPU-AC to form a precursor solution. This precursor was spin coated, dried and UV-cured to generate the hybrid films. The silica content in the hybrid thin films was varied from 0 to 30 wt%. Experimental results showed the aggregation of silica particles in the hybrid films. Thus, the silica domain in the hybrid films was varied from 30 to 50 nm by the different ratios of MSMAsilica to WPU-AC. The prepared hybrid films from the crosslinked WPU-AC/MSMA-silica showed much better thermal stability and mechanical properties than pure WPU-AC.

  5. Synthesis and Properties of Waterborne Polyurethane (WBPU/Modified Lignin Amine (MLA Adhesive: A Promising Adhesive Material

    Directory of Open Access Journals (Sweden)

    Mohammad Mizanur Rahman

    2016-08-01

    Full Text Available A series of waterborne polyurethane (WBPU/modified lignin amine (MLA adhesives was prepared using MLA as a chain extender by a prepolymer mixing process. A successful Mannich reaction was achieved during the synthesis of MLA by reacting lignin with bis(3-aminopropylamine. Higher tensile strength, Young’s modulus, and thermal stability were recorded for WBPU/MLA adhesives with higher MLA contents. The WBPU/MLA adhesive materials were used to coat polyvinyl chloride (PVC substrates. The adhesive strength increased with increasing MLA content. More importantly, the MLA also enhanced the WBPU/MLA coating in terms of adhesive strength at moderately high temperatures as well as under natural weather exposed conditions. The adhesive strength was essentially unaffected with 6.48 mol % MLA in the WBPU/MLA coating after exposure to natural weather conditions for 180 days.

  6. A facile one-step method for cell lysis and DNA extraction of waterborne pathogens using a microchip.

    Science.gov (United States)

    Kamat, Vivek; Pandey, Sulaxna; Paknikar, Kishore; Bodas, Dhananjay

    2018-01-15

    Globally, waterborne organisms are the primary causative agents for the transmission of various forms of diarrheal diseases. For accurate diagnosis, molecular tools have gained considerable attention in the recent past. Molecular tools require DNA as the starting material for diagnosis, and hence, a prerequisite is the quality and integrity of DNA. To obtain high quality DNA rapidly, we have fabricated a microchip in poly(dimethyl siloxane) (PDMS) by soft lithography process. The microchip facilitated in-flow coating of chitosan on the magnetic nanoparticles, which under external mechanical vibration caused cell lysis and released DNA in the supernatant. The released DNA was captured by the nanoparticles owing to its positive charge (chitosan coating). The magnetic nanoparticle-DNA complex was then isolated from the in-flow matrix using permanent magnet, Further, removal of the cell debris, proteins, and carbohydrates was done using wash buffer. DNA extracted using the microchip was pure with absorbance (260/280) ratio of 1.77±0.04, as compared to 1.79±0.03 obtained by TRIzol method. The complete isolation of the DNA using the microchip took ~ 15min as against>2h with a TRIzol method. Six gram-negative waterborne pathogens were used to demonstrate the efficacy of the microchip based DNA extraction process. The integrity of the isolated DNA was assessed by amplifying the 16S rRNA gene using Com1 and Com2 universal primers. The presence of a band at 407bp on gel electrophoresis confirmed the amplified product. Further, the gel image was used for quantification of the amplified product using ImageJ software. Higher regression values obtained using microchip confirmed better quality and integrity of the extracted DNA as opposed to the conventional method. The lower (integrity of the obtained DNA proved the simplicity, rapidity, and sensitivity of the microchip-assisted DNA extraction process. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Electrochemical synthesis of multi-armed CuO nanoparticles and their remarkable bactericidal potential against waterborne bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, Pratibha, E-mail: rkpratibha@yahoo.com; Merwyn, S.; Agarwal, G. S.; Tripathi, B. K.; Pant, S. C. [Defence Research and Development Establishment (India)

    2012-01-15

    Copper (II) oxide multi-armed nanoparticles composed of 500-1000 nm long radiating nanospicules with 100-200 nm width near the base and 50-100 nm width at the tapered ends and {approx}25 nm thickness were synthesized by electrochemical deposition in the presence of an oxidant followed by calcination at 150 Degree-Sign C. The nanoparticles were characterized using SEM/EDX for morphology and composition, Raman spectroscopy for compound identification, and broth culture method for antibacterial efficacy. The CuO nanoparticles have shown remarkable bactericidal efficacy against Gram-positive and -negative waterborne disease causing bacteria like Escherichia coli, Salmonella typhi, staphylococcus aureus and Bacillus subtilis. E. coli has been chosen as representative species for waterborne disease causing bacteria. In antibacterial tests 500 {mu}g/mL nano CuO killed 3 Multiplication-Sign 10{sup 8} CFU/mL E. coli bacteria within 4 h of exposure. Moreover, 8.3 Multiplication-Sign 10{sup 6} CFU/mL E. coli were killed by 100 and 10 {mu}g/mL nano CuO within 15 min and 4 h of exposure, respectively. Antibacterial activity of nano CuO has been found many-fold compared with commercial bulk CuO. The fate of nanoparticles after antibacterial test has also been studied. The synthesized CuO nanoparticles are expected to have potential antibacterial applications in water purification and in paints and coatings used on frequently touched surfaces and fabrics in hospital settings.

  8. Use of a passive bioreactor to reduce water-borne plant pathogens, nitrate, and sulfate in greenhouse effluent.

    Science.gov (United States)

    Gruyer, Nicolas; Dorais, Martine; Alsanius, Beatrix W; Zagury, Gérald J

    2013-01-01

    The goal of this study was to evaluate the use of passive bioreactors to reduce water-borne plant pathogens (Pythium ultimum and Fusarium oxysporum) and nutrient load (NO(-) 3 and SO(2-) 4) in greenhouse effluent. Sterilized and unsterilized passive bioreactors filled with a reactive mixture of organic carbon material were used in three replicates. After a startup period of 2 (sterilized) or 5 (unsterilized) weeks, the bioreactor units received for 14 weeks a reconstituted commercial greenhouse effluent composed of 500 mg L(-1) SO(2-) 4 and 300 mg L(-1) NO(-) 3 and were inoculated three times with P. ultimum and F. oxysporum (10(6) CFU mL(-1)). Efficacy in removing water-borne plant pathogens and nitrate reached 99.9% for both the sterilized and unsterilized bioreactors. However, efficacy in reducing the SO(2-) 4 load sharply decreased from 89% to 29% after 2 weeks of NO(-) 3-supply treatment for the unsterilized bioreactors. Although SO(2-) 4 removal efficacy for the sterilized bioreactors did not recover after 4 weeks of NO(-) 3-supply treatment, the unsterilized bioreactor nearly reached a similar level of SO(2-) 4 removal after 4 weeks of NO(-) 3-supply treatment compared with affluent loaded only with SO(2-) 4, where no competition for the carbohydrate source occurred between the denitrification process and sulfate-reducing bacteria activity. Performance differences between the sterilized and unsterilized bioreactors clearly show the predominant importance of sulfate-reducing bacteria. Consequently, when sulfate-reducing bacteria reach their optimal activity, passive bioreactors may constitute a cheap, low-maintenance method of treating greenhouse effluent to recycle wastewater and eliminate nutrient runoff, which has important environmental impacts.

  9. Dose-related carcinogenic effects of water-borne benzo(a)pyrene on livers of two small fish species

    Energy Technology Data Exchange (ETDEWEB)

    Hawkins, W.E.; Walker, W.W.; Overstreet, R.M.; Lytle, T.F.; Lytle, J.S.

    1988-12-01

    Benzo(a)pyrene (BaP) administered by water-borne exposures caused dose-related carcinogenic effects in livers of two small fish species, the Japanese medaka (Oryzias latipes) and the guppy (Poecilia reticulata). Medaka and guppies each were given two 6-h exposures. The first exposure was conducted on 6- to 10-day-old specimens. The second exposure was given 7 days later. The tests incorporated five treatment groups: (1) control, (2) carrier (dimethylformamide) control, (3) low BaP dose (not detectable--4 ppb), (4) intermediate BaP dose (about 8-47 ppb BaP), and (5) high BaP dose (200-270 ppb). Following the high-dose exposure, hepatocellular lesions classified as foci of cellular alteration (altered foci), adenomas, and hepatocellular carcinomas occurred in both species. In medaka, the lesions appeared to develop sequentially with the appearance of altered foci followed by adenomas and then hepatocellular carcinomas. Most lesions in guppies, however, were classified as altered foci although a few adenomas occurred in the early (24-week) sample and hepatocellular carcinomas occurred in the late (52-week) sample. When total lesions were combined, medaka had an 11% incidence at 24 weeks after the initial exposure and 36% incidence at 36 weeks. In guppies, 8% had liver lesions at 24 weeks, 19% at 36 weeks, and 20% at 52 weeks. A single extrahepatic neoplasm, a capillary hemangioma in a gill filament, occurred in a medaka from the 36-week high-dose sample. The results suggest that the medaka and guppy are capable of metabolizing water-borne BaP to carcinogenic metabolites which initiate hepatic tumor development.

  10. Temporal dynamics of epidermal responses of guppies Poecilia reticulata to a sublethal range of waterborne zinc concentrations.

    Science.gov (United States)

    Gheorghiu, C; Marcogliese, D J; Scott, M E

    2009-12-01

    This study assessed the histological changes in the epidermis of guppies Poecilia reticulata induced by waterborne zinc (Zn). Laboratory-reared P. reticulata fry were maintained individually in separate vessels containing artificial water (8 microg l(-1) Zn) to which 0, 15, 30, 60 or 120 microg l(-1) Zn was added. Their epidermal response to Zn was monitored regularly over 4 weeks. Compared with controls, mucus was rapidly released and mucous cell numbers decreased at all concentrations. Thereafter mucous release, epidermal thickness, numbers and size of mucous cells fluctuated at a rate that varied with Zn concentration, but fluctuations declined after day 18. Results clearly highlight the dynamic nature of the epidermal response to sublethal concentrations of waterborne Zn. In general, low concentrations of Zn induced a rapid response with reduced numbers and size of mucous cells and shift in mucin composition, and a subsequent thickening of the epidermis. Epidermal thickness and mucous cell area fluctuated over time but were normal after a month of exposure to low Zn concentrations. The number of mucous cells, however, remained low. Virtually all mucous cells from fish maintained in 15 and 60 microg l(-1) Zn contained acidic mucins throughout the month, whereas fish maintained at 30 microg l(-1) Zn responded by production of neutral mucins during the first 12 days followed by a mixture of neutral and acidic mucins. At 120 microg l(-1) Zn, the most dramatic effects were the gradual but sustained decrease in numbers and area of mucous cells, and the shift to acidic mucins in these cells. Thus, as concentration of Zn increased, the epidermal responses indicated a disturbed host response (dramatic decline in mucous cell numbers, with mixed composition of mucins), which may have been less effective in preventing Zn uptake across the epithelium.

  11. Effects of waterborne Cu and Cd on anti-oxidative response, lipid peroxidation and heavy metals accumulation in abalone Haliotis discus hannai ino

    Science.gov (United States)

    Lei, Yanju; Zhang, Wenbing; Xu, Wei; Zhang, Yanjiao; Zhou, Huihui; Mai, Kangsen

    2015-06-01

    The aim of this study was to compare the effects of waterborne copper (Cu) and cadmium (Cd) on survival, anti-oxidative response, lipid peroxidation and metal accumulation in abalone Haliotis discus hannai. Experimental animals (initial weight: 7.49 g ± 0.01 g) were exposed to graded concentrations of waterborne Cu (0.02, 0.04, 0.06, 0.08 mg L-1) or Cd (0.025, 0.05, 0.25, 0.5 mg L-1) for 28 days, respectively. Activities of the anti-oxidative enzymes (catalase, CAT; superoxide dismutase, SOD; glutathione peroxidases, GPx; glutathione S-transferase, GST), contents of the reduced glutathione (GSH) and malondiadehyde (MDA) in the hepatopancreas, and metal accumulation in hepatopancreas and muscles were analyzed after 0, 1, 3, 6, 10, 15, 21, 28 days of metal exposure, respectively. Results showed that 0.04 mg L-1, 0.06 mg L--1 and 0.08 mg L-1 Cu caused 100% death of abalone on the 21st, 10th and 6th day, respectively. However, no dead abalone was found during the 28-day waterborne Cd exposure at all experimental concentrations. Generally, activities of SOD and GST in hepatopancreas under all Cu concentrations followed a decrease trend as the exposure time prolonged. However, these activities were firstly increased and then decreased to the control level and increased again during Cd exposure. Activities of CAT in all Cu exposure treatments were higher than those in the control. These activities were firstly increased and then decreased to the control level and increased again during Cd exposure. Contents of MDA in hepatopancreas in all Cu treatments significantly increased first and then decreased to the control level. However, the MDA contents in hepatopancreas were not significantly changed during the 28-day Cd exposure. The metals accumulation in both hepatopancreas and muscles of abalone significantly increased with the increase of waterborne metals concentration and exposure time. These results indicated that H. discus hannai has a positive anti-oxidative defense

  12. Microbiological quality of water in a city with persistent and recurrent waterborne diseases under tropical sub-rural conditions: The case of Kikwit City, Democratic Republic of the Congo.

    Science.gov (United States)

    Nienie, Alexis B; Sivalingam, Periyasamy; Laffite, Amandine; Ngelinkoto, Patience; Otamonga, Jean-Paul; Matand, Alphonse; Mulaji, Crispin K; Biey, Emmanuel M; Mpiana, Pius T; Poté, John

    2017-07-01

    The availability of safe drinking water in sub-Saharan countries remains a major challenge because poor sanitation has been the cause of various outbreaks of waterborne disease due to the poor microbiological quality of water used for domestic purposes. The faecal indicator bacteria (FIB) used in the present study included Escherichia coli (E. coli) and Enterococcus (ENT). FIB and aerobic mesophilic bacteria (AMB) were quantified during July 2015 (dry season) and November 2015 (rainy season) in order to assess the quality of drinking water from wells (n=3; P1-P3), and two rivers, the River Lukemi (RLK, n=3) and River Luini (RLN, n=2) in the city of Kikwit, which is located in the province of Kwilu in the Democratic Republic of the Congo. Kikwit is well known for its outbreaks of persistent and recurrent waterborne diseases including Entamoeba, Shigella, typhoid fever, cholera, and Ebola Viral Hemorrhagic Fever. Consequently, E. coli, ENT, and AMB were quantified in water samples according to the standard international methods for water quality determination using the membrane filtration method. The FIB characterization was performed for human-specific Bacteroides by PCR using specific primers. The results obtained revealed high FIB concentrations in river samples collected during both seasons. For example, E. coli respectively reached 4.3×104 and 9.2×104 CFU 100mL-1 in the dry season and the wet season. ENT reached 5.3×103 CFU 100mL-1 during the dry season and 9.8×103 CFU 100mL-1 in the wet season. The pollution was significantly worse in the wet season compared to the dry season. Surprisingly, no faecal contamination was observed in well water samples collected in the dry season while E. coli and ENT were detected in all wells in the wet season with values of 6, 7, and 11CFUmL-1 for E. coli in wells P1-P3, respectively and 3, 5, 9 CFU mL-1for ENT in the same wells. Interestingly, the PCR assays for human-specific Bacteroides HF183/HF134 indicated that 97

  13. Challenging Identities

    DEFF Research Database (Denmark)

    , cultural, and political practices. Notions of national identity and national politics are challenged by European integration, as well as by increasing demographic heterogeneity due to migration, and migrants experience conflicts of identification stemming from clashes between cultural heritage...

  14. Food and water security issues in Russia III: food- and waterborne diseases in the Russian Arctic, Siberia and the Far East, 2000–2011

    Directory of Open Access Journals (Sweden)

    Alexey A. Dudarev

    2013-12-01

    Full Text Available Background . The food- and waterborne disease situation in Russia requires special attention. Poor quality of centralized water supplies and sewage systems, biological and chemical contamination of drinking water, as well as contamination of food products, promote widespread infectious diseases, significantly exceeding nationwide rates in the population living in the two-thirds of Russian northern territories. Objectives. The general aim was to assess the levels of food- and waterborne diseases in selected regions of Russian Arctic, Siberia and the Far East (for the period 2000–2011, and to compare disease levels among regions and with national levels in Russia. Study design and methods . This study is the first comparative assessment of the morbidity in these fields of the population of 18 selected regions of Russian Arctic, Siberia and the Far East, using official statistical sources. The incidences of infectious and parasitic food- and waterborne diseases among the general population (including indigenous peoples have been analyzed in selected regions (per 100,000 of population, averaged for 2000–2011. Results . Among compulsory registered infectious and parasitic diseases, there were high rates and widespread incidences in selected regions of shigellosis, yersiniosis, hepatitis A, tularaemia, giardiasis, enterobiasis, ascariasis, diphyllobothriasis, opistorchiasis, echinococcosis and trichinellosis. Conclusion . Incidences of infectious and parasitic food- and waterborne diseases in the general population of selected regions of the Russian Arctic, Siberia and the Far East (2000–2011 are alarmingly high. Parallel solutions must be on the agenda, including improvement of sanitary conditions of cities and settlements in the regions, modernization of the water supply and of the sewage system. Provision and monitoring of the quality of the drinking water, a reform of the general healthcare system and the epidemiological surveillance

  15. Characterization of waterborne nitrogen emissions for marine eutrophication modelling in life cycle impact assessment at the damage level and global scale

    DEFF Research Database (Denmark)

    Cosme, Nuno Miguel Dias; Hauschild, Michael Zwicky

    2017-01-01

    Current life cycle impact assessment (LCIA) methods lack a consistent and globally applicable characterization model relating nitrogen (N, as dissolved inorganic nitrogen, DIN) enrichment of coastal waters to the marine eutrophication impacts at the endpoint level. This paper introduces a method...... to calculate spatially explicit characterization factors (CFs) at endpoint and damage to ecosystems levels, for waterborne nitrogen emissions, reflecting their hypoxia-related marine eutrophication impacts, modelled for 5772 river basins of the world....

  16. Projections of Demand for Waterborne Transportation, Ohio River Basin, 1980, 1990, 2000, 2020, 2040. Volume 8. Group VI. Chemicals & Chemical Fertilizers.

    Science.gov (United States)

    1980-12-01

    the product, as well as its corrosive properties , have discouraged increases in the waterborne movements of sulfuric acid . Sulfuric acid is inorganic...bulk Acetylsalicylic acid or aspirin, in bulk Analygesics, antipyretics, and anti-inflam- matory agents, nec., in bulk Antihistamines, in bulk Anti...pure 2818 Sulfuric acid 2819 Basic chemicals and basic chemical products, not elsewhere classified (nec.) 2821 Plastic materials, regenerated cellulose

  17. Transition from the tradicional typing methods to the applications of whole genome sequencing (WGS) for surveillance of food- and waterborne diseases

    OpenAIRE

    Ferreira, Marta Patrícia Ribeiro

    2017-01-01

    Tese de mestrado, Engenharia Farmacêutica, Universidade de Lisboa, Faculdade de Farmácia, 2017 Infectious Diseases, in particular food- and waterborne diseases (FWD), are critical public health concerns nowadays, reinforcing that public health laboratories should establish accurate strategies that allow a proper epidemiological surveillance of the causative infectious agents. With the advances in the whole genome sequencing (WGS) technologies, and associated bioinformatics, genome-based ty...

  18. Effects of chronic waterborne cadmium and zinc interactions on tissue-specific metal accumulation and reproduction in fathead minnow (Pimephales promelas).

    Science.gov (United States)

    Driessnack, Melissa K; Jamwal, Ankur; Niyogi, Som

    2017-06-01

    The present study was designed to evaluate the interactive effects of chronic waterborne cadmium (Cd) and zinc (Zn) on tissue-specific metal accumulation and reproduction in fathead minnow (Pimephales promelas). Trios (1 male: 2 female; n=6-7) of fish were exposed for 21 days to: (i) control (no added Cd or Zn), (ii) waterborne Cd (7µg/L), (iii) waterborne Zn (170µg/L), and (iv) Cd and Zn in mixture (7 and 170µg/L, respectively). Exposure to Cd or Zn alone did not elicit any significant effect on reproductive output (cumulative egg production) relative to the control, however exposure to Cd and Zn in mixture resulted in a ~50% decrease in fish fecundity. Plasma estradiol in females was reduced by Cd and Zn exposures, both individually and in mixture, with the maximum reduction in the metal mixture exposure. The expression of hepatic estrogen receptor genes (ER-α and ER-β) in females was affected by exposure to Zn, alone and in mixture with Cd, but not to Cd alone, whereas hepatic vitellogenin gene expression was downregulated across all treatments. Increased follicular atresia in the ovary was also recorded, but only in fish exposed to Cd and Zn in mixture. The interactions of Cd and Zn in mixture decreased Cd accumulation in tissues (gill and liver), however no reciprocal reduction in tissue Zn accumulation was observed. In addition, the expression of the hepatic metallothionein gene was upregulated following exposure to Zn, alone and in combination with Cd, with no additive effects in the latter treatment. Overall, our findings suggest that chronic exposure to waterborne Cd and Zn in mixture may induce additive reproductive toxicity, essentially by disrupting estrogen-mediated functions in fish. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Ameliorative potential of gemfibrozil and silymarin on experimentally ...

    African Journals Online (AJOL)

    A.M. Kabel

    as vitamin E, lipoic acid and N-acetylcysteine in cisplatin-induced acute nephrotoxicity [7]. Silymarin is the active ... method of Price [17], and creatinine concentration according to the method of Henry [18]. In the following day, ..... to patients with moderate hyperlipidemia decreased plasma con- centrations of proinflammatory ...

  20. Ameliorative potential of gemfibrozil and silymarin on experimentally ...

    African Journals Online (AJOL)

    A.M. Kabel

    Abstract. Introduction: Acute nephrotoxicity is a frequent complication of critical illness especially in the inpa- tient setting. Cisplatin is one of the most active anticancer drugs. Nephrotoxicity is the most common side effect associated with cisplatin treatment. Silymarin is widely used for hepatic disorders due to its antioxidant ...

  1. Immunoprevalence to Six Waterborne Pathogens in Beachgoers at Boquerón Beach, Puerto Rico: Application of a Microsphere-Based Salivary Antibody Multiplex Immunoassay

    Directory of Open Access Journals (Sweden)

    Swinburne A. J. Augustine

    2017-05-01

    Full Text Available Waterborne infectious diseases are a major public health concern worldwide. Few methods have been established that are capable of measuring human exposure to multiple waterborne pathogens simultaneously using non-invasive samples such as saliva. Most current methods measure exposure to only one pathogen at a time, require large volumes of individual samples collected using invasive procedures, and are very labor intensive. In this article, we applied a multiplex bead-based immunoassay capable of measuring IgG antibody responses to six waterborne pathogens simultaneously in human saliva to estimate immunoprevalence in beachgoers at Boquerón Beach, Puerto Rico. Further, we present approaches for determining cutoff points to assess immunoprevalence to the pathogens in the assay. For the six pathogens studied, our results show that IgG antibodies against antigens from noroviruses GI.I and GII.4 were more prevalent (60 and 51.6%, respectively than Helicobacter pylori (21.4%, hepatitis A virus (20.2%, Campylobacter jejuni (8.7%, and Toxoplasma gondii (8% in the saliva of the study participants. The salivary antibody multiplex immunoassay can be used to examine immunoprevalence of specific pathogens in human populations.

  2. Critical comparison of intravenous injection of TiO2 nanoparticles with waterborne and dietary exposures concludes minimal environmentally-relevant toxicity in juvenile rainbow trout Oncorhynchus mykiss.

    Science.gov (United States)

    Boyle, David; Al-Bairuty, Genan A; Henry, Theodore B; Handy, Richard D

    2013-11-01

    A critical comparison of studies that have investigated tissue accumulation and toxicity of TiO2-NPs in fish is necessary to resolve inconsistencies. The present study used identical TiO2-NPs, toxicological endpoints, and fish (juvenile rainbow trout Oncorhynchus mykiss) as previous studies that investigated waterborne and dietary toxicity of TiO2-NPs, and conducted a critical comparison of results after intravenous caudal-vein injection of 50 μg of TiO2-NPs and bulk TiO2. Injected TiO2-NPs accumulated only in kidney (94% of measured Ti) and to a lesser extent in spleen; and injected bulk TiO2 was found only in kidney. No toxicity of TiO2 was observed in kidney, spleen, or other tissues. Critical comparison of these data with previous studies indicates that dietary and waterborne exposures to TiO2-NPs do not lead to Ti accumulation in internal tissues, and previous reports of minor toxicity are inconsistent or attributable to respiratory distress resulting from gill occlusion during waterborne exposure. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. One-pot synthesis and control of aqueous soluble and organic soluble carbon dots from a designable waterborne polyurethane emulsion

    Science.gov (United States)

    Gu, Jiangjiang; Hu, Donghua; Huang, Jin; Huang, Xin; Zhang, Qiuhong; Jia, Xudong; Xi, Kai

    2016-02-01

    Carbon dots (CDs) have a wide range of applications and have drawn great interest in the recent decade. The fabrication and control of CDs with different solubilities are still urgent problems for their practical use. In this paper, aqueous soluble and organic soluble CDs (ACDs, OCDs) were produced by one-pot hydrothermal treatment of a designable waterborne polyurethane (WPU) emulsion. The difference in the solubility and fluorescence of these two kinds of CDs was attributed to the various functional groups on the surface, which were derived from the different segment fragments formed by hydrothermal treatment of a block polymer. It was found that the yields of the ACDs and OCDs could be regulated by means of selecting different soft segments in WPU. The more hydrophobic soft segments could result in an increase of the OCDs and a decrease of the ACDs. While the soft segments were hydrophilic or hydrolysable under hydrothermal conditions, only ACDs were obtained. The ACDs had good fluorescence and showed low cytotoxicity for use in multicolour bio-imaging. The OCDs processed good solubility in a wide range of organic solvents and were suitable for preparing fluorescent composite films with polymers.Carbon dots (CDs) have a wide range of applications and have drawn great interest in the recent decade. The fabrication and control of CDs with different solubilities are still urgent problems for their practical use. In this paper, aqueous soluble and organic soluble CDs (ACDs, OCDs) were produced by one-pot hydrothermal treatment of a designable waterborne polyurethane (WPU) emulsion. The difference in the solubility and fluorescence of these two kinds of CDs was attributed to the various functional groups on the surface, which were derived from the different segment fragments formed by hydrothermal treatment of a block polymer. It was found that the yields of the ACDs and OCDs could be regulated by means of selecting different soft segments in WPU. The more

  4. Cholera vaccination campaign contributes to improved knowledge regarding cholera and improved practice relevant to waterborne disease in rural Haiti.

    Directory of Open Access Journals (Sweden)

    Omowunmi Aibana

    2013-11-01

    Full Text Available Haiti's cholera epidemic has been devastating partly due to underlying weak infrastructure and limited clean water and sanitation. A comprehensive approach to cholera control is crucial, yet some have argued that oral cholera vaccination (OCV might result in reduced hygiene practice among recipients. We evaluated the impact of an OCV campaign on knowledge and health practice in rural Haiti.We administered baseline surveys on knowledge and practice relevant to cholera and waterborne disease to every 10th household during a census in rural Haiti in February 2012 (N = 811. An OCV campaign occurred from May-June 2012 after which we administered identical surveys to 518 households randomly chosen from the same region in September 2012. We compared responses pre- and post-OCV campaign. Post-vaccination, there was improved knowledge with significant increase in percentage of respondents with ≥ 3 correct responses on cholera transmission mechanisms (odds ratio[OR] 1.91; 95% confidence interval[CI] 1.52-2.40, preventive methods (OR 1.83; 95% CI 1.46-2.30, and water treatment modalities (OR 2.75; 95% CI 2.16-3.50. Relative to pre-vaccination, participants were more likely post-OCV to report always treating water (OR 1.62; 95% CI 1.28-2.05. Respondents were also more likely to report hand washing with soap and water >4 times daily post-vaccine (OR 1.30; 95% CI 1.03-1.64. Knowledge of treating water as a cholera prevention measure was associated with practice of always treating water (OR 1.47; 95% CI 1.14-1.89. Post-vaccination, knowledge was associated with frequent hand washing (OR 2.47; 95% CI 1.35-4.51.An OCV campaign in rural Haiti was associated with significant improvement in cholera knowledge and practices related to waterborne disease. OCV can be part of comprehensive cholera control and reinforce, not detract from, other control efforts in Haiti.

  5. Cholera vaccination campaign contributes to improved knowledge regarding cholera and improved practice relevant to waterborne disease in rural Haiti.

    Science.gov (United States)

    Aibana, Omowunmi; Franke, Molly F; Franke, Molly; Teng, Jessica E; Teng, Jessica; Hilaire, Johanne; Raymond, Max; Ivers, Louise C

    2013-11-01

    Haiti's cholera epidemic has been devastating partly due to underlying weak infrastructure and limited clean water and sanitation. A comprehensive approach to cholera control is crucial, yet some have argued that oral cholera vaccination (OCV) might result in reduced hygiene practice among recipients. We evaluated the impact of an OCV campaign on knowledge and health practice in rural Haiti. We administered baseline surveys on knowledge and practice relevant to cholera and waterborne disease to every 10th household during a census in rural Haiti in February 2012 (N = 811). An OCV campaign occurred from May-June 2012 after which we administered identical surveys to 518 households randomly chosen from the same region in September 2012. We compared responses pre- and post-OCV campaign. Post-vaccination, there was improved knowledge with significant increase in percentage of respondents with ≥ 3 correct responses on cholera transmission mechanisms (odds ratio[OR] 1.91; 95% confidence interval[CI] 1.52-2.40), preventive methods (OR 1.83; 95% CI 1.46-2.30), and water treatment modalities (OR 2.75; 95% CI 2.16-3.50). Relative to pre-vaccination, participants were more likely post-OCV to report always treating water (OR 1.62; 95% CI 1.28-2.05). Respondents were also more likely to report hand washing with soap and water >4 times daily post-vaccine (OR 1.30; 95% CI 1.03-1.64). Knowledge of treating water as a cholera prevention measure was associated with practice of always treating water (OR 1.47; 95% CI 1.14-1.89). Post-vaccination, knowledge was associated with frequent hand washing (OR 2.47; 95% CI 1.35-4.51). An OCV campaign in rural Haiti was associated with significant improvement in cholera knowledge and practices related to waterborne disease. OCV can be part of comprehensive cholera control and reinforce, not detract from, other control efforts in Haiti.

  6. Cholera Vaccination Campaign Contributes to Improved Knowledge Regarding Cholera and Improved Practice Relevant to Waterborne Disease in Rural Haiti

    Science.gov (United States)

    Aibana, Omowunmi; Franke, Molly; Teng, Jessica; Hilaire, Johanne; Raymond, Max; Ivers, Louise C.

    2013-01-01

    Background Haiti's cholera epidemic has been devastating partly due to underlying weak infrastructure and limited clean water and sanitation. A comprehensive approach to cholera control is crucial, yet some have argued that oral cholera vaccination (OCV) might result in reduced hygiene practice among recipients. We evaluated the impact of an OCV campaign on knowledge and health practice in rural Haiti. Methodology/Principal Findings We administered baseline surveys on knowledge and practice relevant to cholera and waterborne disease to every 10th household during a census in rural Haiti in February 2012 (N = 811). An OCV campaign occurred from May–June 2012 after which we administered identical surveys to 518 households randomly chosen from the same region in September 2012. We compared responses pre- and post-OCV campaign. Post-vaccination, there was improved knowledge with significant increase in percentage of respondents with ≥3 correct responses on cholera transmission mechanisms (odds ratio[OR] 1.91; 95% confidence interval[CI] 1.52–2.40), preventive methods (OR 1.83; 95% CI 1.46–2.30), and water treatment modalities (OR 2.75; 95% CI 2.16–3.50). Relative to pre-vaccination, participants were more likely post-OCV to report always treating water (OR 1.62; 95% CI 1.28–2.05). Respondents were also more likely to report hand washing with soap and water >4 times daily post-vaccine (OR 1.30; 95% CI 1.03–1.64). Knowledge of treating water as a cholera prevention measure was associated with practice of always treating water (OR 1.47; 95% CI 1.14–1.89). Post-vaccination, knowledge was associated with frequent hand washing (OR 2.47; 95% CI 1.35–4.51). Conclusion An OCV campaign in rural Haiti was associated with significant improvement in cholera knowledge and practices related to waterborne disease. OCV can be part of comprehensive cholera control and reinforce, not detract from, other control efforts in Haiti. PMID:24278498

  7. Mitochondrial energetic metabolism perturbations in skeletal muscles and brain of zebrafish (Danio rerio) exposed to low concentrations of waterborne uranium

    Energy Technology Data Exchange (ETDEWEB)

    Lerebours, Adelaide; Adam-Guillermin, Christelle [Laboratoire de Radioecologie et d' Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire, Bat 186, BP 3, 13115 Saint-Paul-Lez-Durance Cedex (France); Brethes, Daniel [CNRS, UMR 5095, Institut de Biochimie et Genetique Cellulaires, Universite Victor Segalen-Bordeaux 2 (France); Frelon, Sandrine; Floriani, Magali; Camilleri, Virginie; Garnier-Laplace, Jacqueline [Laboratoire de Radioecologie et d' Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire, Bat 186, BP 3, 13115 Saint-Paul-Lez-Durance Cedex (France); Bourdineaud, Jean-Paul, E-mail: jp.bourdineaud@epoc.u-bordeaux1.fr [CNRS, UMR 5095, Institut de Biochimie et Genetique Cellulaires, Universite Victor Segalen-Bordeaux 2 (France)

    2010-10-01

    Anthropogenic release of uranium (U), originating from the nuclear fuel cycle or military activities, may considerably increase U concentrations in terrestrial and aquatic ecosystems above the naturally occurring background levels found throughout the environment. With a projected increase in the world-wide use of nuclear power, it is important to improve our understanding of the possible effects of this metal on the aquatic fauna at concentrations commensurate with the provisional drinking water guideline value of the World Health Organization (15 {mu}g U/L). The present study has examined the mitochondrial function in brain and skeletal muscles of the zebrafish, Danio rerio, exposed to 30 and 100 {mu}g/L of waterborne U for 10 and 28 days. At the lower concentration, the basal mitochondrial respiration rate was increased in brain at day 10 and in muscles at day 28. This is due to an increase of the inner mitochondrial membrane permeability, resulting in a decrease of the respiratory control ratio. In addition, levels of cytochrome c oxidase subunit IV (COX-IV) increased in brain at day 10, and those of COX-I increased in muscles at day 28. Histological analyses performed by transmission electron microscopy revealed an alteration of myofibrils and a dilatation of endomysium in muscle cells. These effects were largest at the lowest concentration, following 28 days of exposure.

  8. A decision support tool to compare waterborne and foodborne infection and/or illness risks associated with climate change.

    Science.gov (United States)

    Schijven, Jack; Bouwknegt, Martijn; de Roda Husman, Ana Maria; Rutjes, Saskia; Sudre, Bertrand; Suk, Jonathan E; Semenza, Jan C

    2013-12-01

    Climate change may impact waterborne and foodborne infectious disease, but to what extent is uncertain. Estimating climate-change-associated relative infection risks from exposure to viruses, bacteria, or parasites in water or food is critical for guiding adaptation measures. We present a computational tool for strategic decision making that describes the behavior of pathogens using location-specific input data under current and projected climate conditions. Pathogen-pathway combinations are available for exposure to norovirus, Campylobacter, Cryptosporidium, and noncholera Vibrio species via drinking water, bathing water, oysters, or chicken fillets. Infection risk outcomes generated by the tool under current climate conditions correspond with those published in the literature. The tool demonstrates that increasing temperatures lead to increasing risks for infection with Campylobacter from consuming raw/undercooked chicken fillet and for Vibrio from water exposure. Increasing frequencies of drought generally lead to an elevated infection risk of exposure to persistent pathogens such as norovirus and Cryptosporidium, but decreasing risk of exposure to rapidly inactivating pathogens, like Campylobacter. The opposite is the case with increasing annual precipitation; an upsurge of heavy rainfall events leads to more peaks in infection risks in all cases. The interdisciplinary tool presented here can be used to guide climate change adaptation strategies focused on infectious diseases. © 2013 Society for Risk Analysis.

  9. Present status of protozoan pathogens causing water-borne disease in northern part of El-Minia Governorate, Egypt.

    Science.gov (United States)

    Khalifa, Refaat M A; Ahmad, Azza K; Abdel-Hafeez, Ekhlas H; Mosllem, Fadia A

    2014-12-01

    Little is known about the role of different water supplies in the diversity and public health significance of pathogenic protozoan parasites. Most of these organisms have been ubiquitous in waters worldwide. The numbers of waterborne infections indicate a significant risk for their transmission even by drinking water. Hence, a total of 336 water samples were collected during 2009-2013 from different water sources from different areas of northern part of El-Minia Govemnorate, Egypt and were investigated for pathogenic protozoa. They were examined by direct microscopy followed by Modified Ziehl- Neelsen and Giemsa stains. 140 samples (41.7 %) were positive (statistically significant; P value Pwater supplies, followed by Blastocystis hominis (15.87%), Cyclospora caytenensis (11.9%), Entamoeba hiseolytica/dispar (8.73%) Giardia lamblia (6.35%() and Naegleria sp., (3.97%). Moreover, there were 14 samples with mixed parsitic infection: they were Cryptosporidium sp. and B. hominis in six samples, Cryptosporidum sp. and C. caytenenisin five samples and Cryptosporidium sp. and E histolytica/dispar in three samples. The most common contamninated water source was ponds where 32 samples (66.7%) were-positive followed by canal water 30 samples (62.5%). The results were discussed and the recommendations were offered.

  10. Water-borne diseases and extreme weather events in Cambodia: review of impacts and implications of climate change.

    Science.gov (United States)

    Davies, Grace I; McIver, Lachlan; Kim, Yoonhee; Hashizume, Masahiro; Iddings, Steven; Chan, Vibol

    2014-12-23

    Cambodia is prone to extreme weather events, especially floods, droughts and typhoons. Climate change is predicted to increase the frequency and intensity of such events. The Cambodian population is highly vulnerable to the impacts of these events due to poverty; malnutrition; agricultural dependence; settlements in flood-prone areas, and public health, governance and technological limitations. Yet little is known about the health impacts of extreme weather events in Cambodia. Given the extremely low adaptive capacity of the population, this is a crucial knowledge gap. A literature review of the health impacts of floods, droughts and typhoons in Cambodia was conducted, with regional and global information reviewed where Cambodia-specific literature was lacking. Water-borne diseases are of particular concern in Cambodia, in the face of extreme weather events and climate change, due to, inter alia, a high pre-existing burden of diseases such as diarrhoeal illness and a lack of improved sanitation infrastructure in rural areas. A time-series analysis under quasi-Poisson distribution was used to evaluate the association between floods and diarrhoeal disease incidence in Cambodian children between 2001 and 2012 in 16 Cambodian provinces. Floods were significantly associated with increased diarrhoeal disease in two provinces, while the analysis conducted suggested a possible protective effect from toilets and piped water. Addressing the specific, local pre-existing vulnerabilities is vital to promoting population health resilience and strengthening adaptive capacity to extreme weather events and climate change in Cambodia.

  11. Emerging Pathogens and Vehicles of Food- and Water-borne Disease Outbreaks in Korea, 2007-2012.

    Science.gov (United States)

    Moon, Shinje; Sohn, Il-Woong; Hong, Yeongseon; Lee, Hyungmin; Park, Ji-Hyuk; Kwon, Geun-Yong; Lee, Sangwon; Youn, Seung-Ki

    2014-02-01

    Food- and water-borne disease outbreaks (FBDOs) are an important public health problem worldwide. This study investigated the trends in FBDOs in Korea and established emerging causal pathogens and causal vehicles. We analyzed FBDOs in Korea by year, location, causal pathogens, and causal vehicles from 2007 to 2012. Information was collected from the FBDOs database in the Korean Centers for Disease Control and Prevention. During 2007-2012, a total of 1794 FBDOs and 48,897 patients were reported. After 2007, FBDOs and patient numbers steadily decreased over the next 2 years and then plateaued until 2011. However, in 2012, FBDOs increased slightly accompanied by a large increase in the number of affected patients. Our results highlight the emergence of norovirus and pathogenic Escherichia coli other than enterohemorrhagic E. coli (EHEC) in schools in 2012. We found that pickled vegetables is an emerging causal vehicle responsible for this problem. On the basis of this study we recommend intensified inspections of pickled vegetable manufacturers and the strengthening of laboratory surveillance of relevant pathogens.

  12. A waterborne outbreak of multiple diarrhoeagenic Escherichia coli infections associated with drinking water at a school camp.

    Science.gov (United States)

    Park, Jungsun; Kim, Jin Seok; Kim, Soojin; Shin, Eunkyung; Oh, Kyung-Hwan; Kim, Yonghoon; Kim, Cheon Hyeon; Hwang, Min Ah; Jin, Chan Mun; Na, Kyoungin; Lee, Jin; Cho, Enhi; Kang, Byung-Hak; Kwak, Hyo-Sun; Seong, Won Keun; Kim, Junyoung

    2017-10-11

    In June 2015, a local public health laboratory was notified that students had developed gastroenteritis symptoms after participating in a camp. An outbreak investigation was conducted to determine the extent and cause of the outbreak. We conducted a retrospective cohort study to determine the correlations between the illness and specific exposures at the school camp. All attendees were interviewed with a standard questionnaire that addressed clinical symptoms, food consumption and environmental exposures. Clinical specimens were cultured using standard microbiological methods for bacterial or viral pathogens. The genetic relationships of all isolates were determined using pulsed-field gel electrophoresis (PFGE). We identified 188 patients with symptoms of diarrhoea, abdominal pain and nausea. Their completed questionnaires suggested that the consumption of drinking water was likely to be linked to this outbreak. Using microbiological methods, we isolated enterohemorrhagic Escherichia coli, enteropathogenic E. coli and enteroaggregative E. coli, and the isolates from both patient stools and environmental water samples displayed indistinguishable XbaI-PFGE patterns. The water system in the camp used groundwater drawn from a private underground reservoir for cooking and drinking. The environmental investigation revealed some problems with the water supply system, such as the use of inappropriate filters in the water purifier and a defect in the pipeline between the reservoir and the chlorination device. This outbreak points to the importance of drinking water quality management in group facilities using underground water and emphasizes the need for periodic sanitation and inspection to prevent possible waterborne outbreaks. Copyright © 2017. Published by Elsevier Ltd.

  13. Water-Borne Diseases and Extreme Weather Events in Cambodia: Review of Impacts and Implications of Climate Change

    Science.gov (United States)

    Davies, Grace I.; McIver, Lachlan; Kim, Yoonhee; Hashizume, Masahiro; Iddings, Steven; Chan, Vibol

    2014-01-01

    Cambodia is prone to extreme weather events, especially floods, droughts and typhoons. Climate change is predicted to increase the frequency and intensity of such events. The Cambodian population is highly vulnerable to the impacts of these events due to poverty; malnutrition; agricultural dependence; settlements in flood-prone areas, and public health, governance and technological limitations. Yet little is known about the health impacts of extreme weather events in Cambodia. Given the extremely low adaptive capacity of the population, this is a crucial knowledge gap. A literature review of the health impacts of floods, droughts and typhoons in Cambodia was conducted, with regional and global information reviewed where Cambodia-specific literature was lacking. Water-borne diseases are of particular concern in Cambodia, in the face of extreme weather events and climate change, due to, inter alia, a high pre-existing burden of diseases such as diarrhoeal illness and a lack of improved sanitation infrastructure in rural areas. A time-series analysis under quasi-Poisson distribution was used to evaluate the association between floods and diarrhoeal disease incidence in Cambodian children between 2001 and 2012 in 16 Cambodian provinces. Floods were significantly associated with increased diarrhoeal disease in two provinces, while the analysis conducted suggested a possible protective effect from toilets and piped water. Addressing the specific, local pre-existing vulnerabilities is vital to promoting population health resilience and strengthening adaptive capacity to extreme weather events and climate change in Cambodia. PMID:25546280

  14. Novel microbiological and spatial statistical methods to improve strength of epidemiological evidence in a community-wide waterborne outbreak.

    Directory of Open Access Journals (Sweden)

    Katri Jalava

    Full Text Available Failures in the drinking water distribution system cause gastrointestinal outbreaks with multiple pathogens. A water distribution pipe breakage caused a community-wide waterborne outbreak in Vuorela, Finland, July 2012. We investigated this outbreak with advanced epidemiological and microbiological methods. A total of 473/2931 inhabitants (16% responded to a web-based questionnaire. Water and patient samples were subjected to analysis of multiple microbial targets, molecular typing and microbial community analysis. Spatial analysis on the water distribution network was done and we applied a spatial logistic regression model. The course of the illness was mild. Drinking untreated tap water from the defined outbreak area was significantly associated with illness (RR 5.6, 95% CI 1.9-16.4 increasing in a dose response manner. The closer a person lived to the water distribution breakage point, the higher the risk of becoming ill. Sapovirus, enterovirus, single Campylobacter jejuni and EHEC O157:H7 findings as well as virulence genes for EPEC, EAEC and EHEC pathogroups were detected by molecular or culture methods from the faecal samples of the patients. EPEC, EAEC and EHEC virulence genes and faecal indicator bacteria were also detected in water samples. Microbial community sequencing of contaminated tap water revealed abundance of Arcobacter species. The polyphasic approach improved the understanding of the source of the infections, and aided to define the extent and magnitude of this outbreak.

  15. Novel microbiological and spatial statistical methods to improve strength of epidemiological evidence in a community-wide waterborne outbreak.

    Science.gov (United States)

    Jalava, Katri; Rintala, Hanna; Ollgren, Jukka; Maunula, Leena; Gomez-Alvarez, Vicente; Revez, Joana; Palander, Marja; Antikainen, Jenni; Kauppinen, Ari; Räsänen, Pia; Siponen, Sallamaari; Nyholm, Outi; Kyyhkynen, Aino; Hakkarainen, Sirpa; Merentie, Juhani; Pärnänen, Martti; Loginov, Raisa; Ryu, Hodon; Kuusi, Markku; Siitonen, Anja; Miettinen, Ilkka; Santo Domingo, Jorge W; Hänninen, Marja-Liisa; Pitkänen, Tarja

    2014-01-01

    Failures in the drinking water distribution system cause gastrointestinal outbreaks with multiple pathogens. A water distribution pipe breakage caused a community-wide waterborne outbreak in Vuorela, Finland, July 2012. We investigated this outbreak with advanced epidemiological and microbiological methods. A total of 473/2931 inhabitants (16%) responded to a web-based questionnaire. Water and patient samples were subjected to analysis of multiple microbial targets, molecular typing and microbial community analysis. Spatial analysis on the water distribution network was done and we applied a spatial logistic regression model. The course of the illness was mild. Drinking untreated tap water from the defined outbreak area was significantly associated with illness (RR 5.6, 95% CI 1.9-16.4) increasing in a dose response manner. The closer a person lived to the water distribution breakage point, the higher the risk of becoming ill. Sapovirus, enterovirus, single Campylobacter jejuni and EHEC O157:H7 findings as well as virulence genes for EPEC, EAEC and EHEC pathogroups were detected by molecular or culture methods from the faecal samples of the patients. EPEC, EAEC and EHEC virulence genes and faecal indicator bacteria were also detected in water samples. Microbial community sequencing of contaminated tap water revealed abundance of Arcobacter species. The polyphasic approach improved the understanding of the source of the infections, and aided to define the extent and magnitude of this outbreak.

  16. Flow-through immunomagnetic separation system for waterborne pathogen isolation and detection: Application to Giardia and Cryptosporidium cell isolation

    Energy Technology Data Exchange (ETDEWEB)

    Ramadan, Qasem, E-mail: qasem.alramadan@epfl.ch [Bioelectronics Program, Institute of Microelectronics, 11 Science Park Road, Singapore 117685 (Singapore); Christophe, Lay; Teo, William; ShuJun, Li; Hua, Feng Han [Bioelectronics Program, Institute of Microelectronics, 11 Science Park Road, Singapore 117685 (Singapore)

    2010-07-12

    Simultaneous sample washing and concentration of two waterborne pathogen samples were demonstrated using a rotational magnetic system under continuous flow conditions. The rotation of periodically arranged small permanent magnets close to a fluidic channel carrying magnetic particle suspension allows the trapping and release of particles along the fluidic channel in a periodic manner. Each trapping and release event resembles one washing cycle. The performance of the magnetic separation system (MSS) was evaluated in order to test its functionality to isolate magnetic-labelled protozoan cells from filtered, concentrated tap water, secondary effluent water, and purified water. Experimental protocols described in US Environmental Protection Agency method 1623 which rely on the use of a magnetic particle concentrator, were applied to test and compare our continuous flow cell separation system to the standard magnetic bead-based isolation instruments. The recovery efficiencies for Giardia cysts using the magnetic tube holder and our magnetic separation system were 90.5% and 90.1%, respectively, from a tap water matrix and about 31% and 18.5%, respectively, from a spiked secondary effluent matrix. The recovery efficiencies for Cryptosporidium cells using the magnetic tube holder and our magnetic separation system were 90% and 83.3%, respectively, from a tap water matrix and about 38% and 36%, respectively, from a spiked secondary effluent matrix. Recoveries from all matrices with the continuous flow system were typically higher in glass tubing conduits than in molded plastic conduits.

  17. Water-Borne Diseases and Extreme Weather Events in Cambodia: Review of Impacts and Implications of Climate Change

    Directory of Open Access Journals (Sweden)

    Grace I. Davies

    2014-12-01

    Full Text Available Cambodia is prone to extreme weather events, especially floods, droughts and typhoons. Climate change is predicted to increase the frequency and intensity of such events. The Cambodian population is highly vulnerable to the impacts of these events due to poverty; malnutrition; agricultural dependence; settlements in flood-prone areas, and public health, governance and technological limitations. Yet little is known about the health impacts of extreme weather events in Cambodia. Given the extremely low adaptive capacity of the population, this is a crucial knowledge gap. A literature review of the health impacts of floods, droughts and typhoons in Cambodia was conducted, with regional and global information reviewed where Cambodia-specific literature was lacking. Water-borne diseases are of particular concern in Cambodia, in the face of extreme weather events and climate change, due to, inter alia, a high pre-existing burden of diseases such as diarrhoeal illness and a lack of improved sanitation infrastructure in rural areas. A time-series analysis under quasi-Poisson distribution was used to evaluate the association between floods and diarrhoeal disease incidence in Cambodian children between 2001 and 2012 in 16 Cambodian provinces. Floods were significantly associated with increased diarrhoeal disease in two provinces, while the analysis conducted suggested a possible protective effect from toilets and piped water. Addressing the specific, local pre-existing vulnerabilities is vital to promoting population health resilience and strengthening adaptive capacity to extreme weather events and climate change in Cambodia.

  18. Kinetics of Waterborne Alkyd/Acrylic Hybrid Resin Free Radical Polymerization by Two Systems of Redox and Thermal Initiators

    Directory of Open Access Journals (Sweden)

    shirin Madadi

    2012-12-01

    Full Text Available Kinetics of radical polymerizations of waterborne alkyd/acrylic hybrid resin via batch mini-emulsion technique was studied using redox initiators (TBHP/Fe2+/EDTA/AsAc  and  TBHP/Fe2+/EDTA/SFS at relatively low temperatures and thermal initiators (BPO, KPS and AIBN at higher temperatures to seek the most suitable initiator system. At the end of all reactions the unreacted monomer content was reduced using post-polymerization technique; consequently, leading to increased monomer conversion and flm formation with improved properties. The kinetics of mini-emulsion polymerization showed that in all redox initiator systems (Fe2+ catalyst + EDTA chelating agent, the radials are produced at relatively low temperature with more effcient control of the reactor temperature. It was found that at 45°C TBHP/Fe2+/EDTA/SFS redox initiator system leads to 98% monomer conversion, a much higher rate than that of systems involved thermal initiators.

  19. A high-efficiency denitrification bioreactor for the treatment of acrylonitrile wastewater using waterborne polyurethane immobilized activated sludge.

    Science.gov (United States)

    Dong, Honghong; Wang, Wei; Song, Zhaozheng; Dong, Hao; Wang, Jianfeng; Sun, Shanshan; Zhang, Zhongzhi; Ke, Ming; Zhang, Zhenjia; Wu, Wei-Min; Zhang, Guangqing; Ma, Jie

    2017-09-01

    The performance of a laboratory-scale, high-efficiency denitrification bioreactor (15L) using activated sludge immobilized by waterborne polyurethane in treating acrylonitrile wastewater with high concentration of nitrate nitrogen (249mg/L) was investigated. The bioreactor was operated at 30°C for 220days. Batch denitrification experiments showed that the optimal operation parameters were C/NO3(-)-N molar ratio of 2.0 using sodium acetate as electron donor and carrier filling rate of 20% (V/V) in the bioreactor. Stable performance of denitrification was observed with a hydraulic retention time of 30 to 38h. A volumetric removal rate up to 2.1kgN/m(3)·d was achieved with a total nitrogen removal efficiency of 95%. Pyrosequencing results showed that Rhodocyclaceae and Pseudomonadaceae were the dominant bacterial families in the immobilized carrier and bioreactor effluent. The overall microbial diversity declined as denitrifiers gradually dominated and the relative abundance of other bacteria decreased along with testing time. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Effects of salinity on short-term waterborne zinc uptake, accumulation and sub-lethal toxicity in the green shore crab (Carcinus maenas)

    Energy Technology Data Exchange (ETDEWEB)

    Niyogi, Som, E-mail: som.niyogi@usask.ca [Department of Biology, University of Saskatchewan, Saskatoon, SK (Canada); Toxicology Centre, University of Saskatchewan, Saskatoon, SK (Canada); Bamfield Marine Sciences Centre, Bamfield, BC (Canada); Blewett, Tamzin A. [Bamfield Marine Sciences Centre, Bamfield, BC (Canada); Department of Biological Sciences, University of Alberta, Edmonton, AB (Canada); Department of Biology, McMaster University, Hamilton, ON (Canada); Gallagher, Trevor [Toxicology Centre, University of Saskatchewan, Saskatoon, SK (Canada); Fehsenfeld, Sandra [Bamfield Marine Sciences Centre, Bamfield, BC (Canada); Department of Biological Sciences, University of Manitoba, Winnipeg, MB (Canada); Department of Zoology, University of British Columbia, Vancouver, BC (Canada); Wood, Chris M. [Bamfield Marine Sciences Centre, Bamfield, BC (Canada); Department of Biology, McMaster University, Hamilton, ON (Canada); Department of Zoology, University of British Columbia, Vancouver, BC (Canada)

    2016-09-15

    Highlights: • Zinc accumulation in the euryhaline green crab is partially salinity dependent. • Zinc accumulates mainly in the gills of green crab during acute waterborne exposure. • Branchial zinc and calcium transport in the green crab occurs via a common pathway. • Acute waterborne Zn exposure disrupts calcium and zinc homeostasis in the green crab. - Abstract: Waterborne zinc (Zn) is known to cause toxicity to freshwater animals primarily by disrupting calcium (Ca) homeostasis during acute exposure, but its effects in marine and estuarine animals are not well characterized. The present study investigated the effects of salinity on short-term Zn accumulation and sub-lethal toxicity in the euryhaline green shore crab, Carcinus maenas. The kinetic and pharmacological properties of short-term branchial Zn uptake were also examined. Green crabs (n = 10) were exposed to control (no added Zn) and 50 μM (3.25 mg L{sup −1}) of waterborne Zn (∼25% of 96 h LC{sub 50} in 100 seawater) for 96 h at 3 different salinity regimes (100%, 60% and 20% seawater). Exposure to waterborne Zn increased tissue-specific Zn accumulation across different salinities. However, the maximum accumulation occurred in 20% seawater and no difference was recorded between 60% and 100% seawater. Gills appeared to be the primary site of Zn accumulation, since the accumulation was significantly higher in the gills relative to the hepatopancreas, haemolymph and muscle. Waterborne Zn exposure induced a slight increase in haemolymph osmolality and chloride levels irrespective of salinity. In contrast, Zn exposure elicited marked increases in both haemolymph and gill Ca levels, and these changes were more pronounced in 20% seawater relative to that in 60% or 100% seawater. An in vitro gill perfusion technique was used to examine the characteristics of short-term (1–4 h) branchial Zn uptake over an exposure concentration range of 3–12 μM (200–800 μg L{sup −1}). The rate of short

  1. Microbial Diagnostic Microarrays for the Detection and Typing of Food- and Water-Borne (Bacterial) Pathogens

    Science.gov (United States)

    Kostić, Tanja; Sessitsch, Angela

    2011-01-01

    Reliable and sensitive pathogen detection in clinical and environmental (including food and water) samples is of greatest importance for public health. Standard microbiological methods have several limitations and improved alternatives are needed. Most important requirements for reliable analysis include: (i) specificity; (ii) sensitivity; (iii) multiplexing potential; (iv) robustness; (v) speed; (vi) automation potential; and (vii) low cost. Microarray technology can, through its very nature, fulfill many of these requirements directly and the remaining challenges have been tackled. In this review, we attempt to compare performance characteristics of the microbial diagnostic microarrays developed for the detection and typing of food and water pathogens, and discuss limitations, points still to be addressed and issues specific for the analysis of food, water and environmental samples. PMID:27605332

  2. CHALLENGES IN BRONCHIAL CHALLENGE TESTING

    NARCIS (Netherlands)

    Lexmond, A. J.; Hagedoorn, P.; Frijlink, H. W.; de Boer, A. H.

    2013-01-01

    Background: In the adenosine 5'-monophosphate (AMP) bronchial challenge test, AMP is usually administered according to dosing protocols developed for histamine/methacholine. It has never been thoroughly investigated whether these protocols are suitable for AMP as well. Methods: The setup of the

  3. Mobility Challenges

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Lassen, Claus

    2011-01-01

    This article takes point of departure in the challenges to understand the importance of contemporary mobility. The approach advocated is a cross-disciplinary one drawing on sociology, geography, urban planning and design, and cultural studies. As such the perspective is to be seen as a part...... mobilities. In particular the article discusses 1) the physical city, its infrastructures and technological hardware/software, 2) policies and planning strategies for urban mobility and 3) the lived everyday life in the city and the region....... of the so-called ‘mobility turn’ within social science. The perspective is illustrative for the research efforts at the Centre for Mobility and Urban Studies (C-MUS), Aalborg University. The article presents the contours of a theoretical perspective meeting the challenges to research into contemporary urban...

  4. Challenging Identities

    DEFF Research Database (Denmark)

    Identity is a keyword in a number of academic fields as well as in public debate and in politics. During the last decades, references to identity have proliferated, yet there is no simple definition available that corresponds to the use of the notion in all contexts. The significance of the notion...... depends on the conceptual or ideological constellation in which it takes part. This volume on one hand demonstrates the role of notions of identity in a variety of European contexts, and on the other hand highlights how there may be reasons to challenge the use of the term and corresponding social......, cultural, and political practices. Notions of national identity and national politics are challenged by European integration, as well as by increasing demographic heterogeneity due to migration, and migrants experience conflicts of identification stemming from clashes between cultural heritage...

  5. Challenging Identities

    DEFF Research Database (Denmark)

    , cultural, and political practices. Notions of national identity and national politics are challenged by European integration, as well as by increasing demographic heterogeneity due to migration, and migrants experience conflicts of identification stemming from clashes between cultural heritage...... Rask Madsen, JUR Center for International CourtsOrganisation ; Henning Koch, JUR Center for retskulturelle studierOrganisation ; Peter E. Nielsen ; Catharina Raudvere, Institut for Tværkulturelle og Regionale StudierOrganisation: Institut ; Barbara Törnqvist-Plewa, University of Lund, Sweden ; Karl...

  6. Hormonal and ion regulatory response in three freshwater fish species following waterborne copper exposure.

    Science.gov (United States)

    Eyckmans, Marleen; Tudorache, Christian; Darras, Veerle M; Blust, Ronny; De Boeck, Gudrun

    2010-09-01

    We evaluated effects of sublethal copper exposure in 3 different freshwater fish: rainbow trout (Oncorhynchus mykiss), common carp (Cyprinus carpio) and gibel carp (Carassius auratus gibelio). In a first experiment we exposed these fishes to an equally toxic Cu dose, a Cu level 10 times lower than their 96 h LC50 value: 20, 65, and 150 microg/L Cu. In a second series we exposed them to the same Cu concentration (50 microg/L). Na+/K+-ATPase activity in gill tissue was disturbed differently in rainbow trout then in common and gibel carp. Rainbow trout showed a thorough disruption of plasma ion levels at the beginning of both exposures, whereas common carp and gibel carp displayed effects only after 3 days. Rainbow trout and common carp thyroid hormones experienced adverse effects in the beginning of the exposure. The involvement of prolactin in handling metal stress was reflected in changes of mRNA prolactin receptor concentrations in gill tissue, with an up regulation of this mRNA in rainbow trout and a down regulation in gibel carp, which was more pronounced in the latter. Overall, rainbow trout appeared more sensitive in the beginning of the exposure, however, when it overcame this first challenge, it handled copper exposure in a better manner then common and gibel carp as they showed more long term impacts of Cu exposure. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  7. New antimicrobial contact catalyst killing antibiotic resistant clinical and waterborne pathogens

    Energy Technology Data Exchange (ETDEWEB)

    Guridi, A. [Biophysics Unit (CSIC, UPV/EHU), Department of Biochemistry and Molecular Biology, University of the Basque Country, 48940 Leioa (Spain); Diederich, A.-K. [University Medical Center Freiburg, Division of Infectious Diseases, Hugstetter Strasse 55, 79106 Freiburg (Germany); Biology II, Microbiology, Albert-Ludwigs-University Freiburg, Schänzlestrasse 1, 79104 Freiburg (Germany); Aguila-Arcos, S.; Garcia-Moreno, M. [Biophysics Unit (CSIC, UPV/EHU), Department of Biochemistry and Molecular Biology, University of the Basque Country, 48940 Leioa (Spain); Blasi, R.; Broszat, M. [University Medical Center Freiburg, Division of Infectious Diseases, Hugstetter Strasse 55, 79106 Freiburg (Germany); Biology II, Microbiology, Albert-Ludwigs-University Freiburg, Schänzlestrasse 1, 79104 Freiburg (Germany); Schmieder, W.; Clauss-Lendzian, E. [Biology II, Microbiology, Albert-Ludwigs-University Freiburg, Schänzlestrasse 1, 79104 Freiburg (Germany); Sakinc-Gueler, T. [University Medical Center Freiburg, Division of Infectious Diseases, Hugstetter Strasse 55, 79106 Freiburg (Germany); Andrade, R. [Advanced Research Facilities (SGIker), University of the Basque Country, UPV/EHU, 48940 Leioa (Spain); Alkorta, I. [Biophysics Unit (CSIC, UPV/EHU), Department of Biochemistry and Molecular Biology, University of the Basque Country, 48940 Leioa (Spain); Meyer, C.; Landau, U. [Largentec GmbH, Am Waldhaus 32, 14129 Berlin (Germany); Grohmann, E., E-mail: elisabeth.grohmann@googlemail.com [Biophysics Unit (CSIC, UPV/EHU), Department of Biochemistry and Molecular Biology, University of the Basque Country, 48940 Leioa (Spain); University Medical Center Freiburg, Division of Infectious Diseases, Hugstetter Strasse 55, 79106 Freiburg (Germany); Biology II, Microbiology, Albert-Ludwigs-University Freiburg, Schänzlestrasse 1, 79104 Freiburg (Germany)

    2015-05-01

    Microbial growth on medical and technical devices is a big health issue, particularly when microorganisms aggregate to form biofilms. Moreover, the occurrence of antibiotic-resistant bacteria in the clinical environment is dramatically growing, making treatment of bacterial infections very challenging. In search of an alternative, we studied a novel antimicrobial surface coating based on micro galvanic elements formed by silver and ruthenium with surface catalytic properties. The antimicrobial coating efficiently inhibited the growth of the nosocomial pathogens Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis and Enterococcus faecium as demonstrated by the growth inhibition on agar surface and in biofilms of antibiotic resistant clinical E. faecalis, E. faecium, and S. aureus isolates. It also strongly reduced the growth of Legionella in a drinking water pipeline and of Escherichia coli in urine. We postulate a mode of action of the antimicrobial material, which is independent of the release of silver ions. Thus, the novel antimicrobial coating could represent an alternative to combat microbial growth avoiding the toxic side effects of high levels of silver ions on eukaryotic cells. - Highlights: • The novel antimicrobial inhibits growth of clinical staphylococci and enterococci. • The novel antimicrobial inhibits growth of Legionella in drinking water. • A putative mode of action of the antimicrobial coating is presented.

  8. Challenging Identities

    DEFF Research Database (Denmark)

    , cultural, and political practices. Notions of national identity and national politics are challenged by European integration, as well as by increasing demographic heterogeneity due to migration, and migrants experience conflicts of identification stemming from clashes between cultural heritage...... and the cultures of the new habitat. European horizons—frames of mind, historical memories, and expectations at the level of groups or communities, at the national level, and at the general European level—are at odds. Analyzing a series of issues in European countries from Turkey to Spain and from Scandinavia...

  9. The challenge

    Science.gov (United States)

    Freeman, Roger L.

    1988-01-01

    Radio systems in space are on the brink of achieving throughout data rates in the hundred of megabits. At present, radio systems operate below 60 GHz and are the traditional workhorses of satellite communications. Legal constraints and the laws of physics limit data rates on the systems. It is maintained that the challenge to provide high technology tools to develop viable high-data-rate space transmission systems can be met before the next century if three optical system and technology issues are overcome. In declining order of importance, the issues are: precise optical pointing, acquisition, and tracking; efficient laser diode optical sources producing sufficient output power; and advanced optical detector technology.

  10. Challenged Pragmatism

    DEFF Research Database (Denmark)

    Christoffersen, Lisbet; Vinding, Niels Valdemar

    2013-01-01

    Against the backdrop of a well-regulated and pragmatic Danish labour market, the question of reasonable accommodation is discussed on the basis of current legislation, recent legal cases and substantial interview material drawn from the RELIGARE sociolegal research done in Denmark. Employees...... of religious faith have made religious claims and thereby challenged a secular understanding of the Danish labour market. This raises the question of the extent to which the religion of the individual can be accepted in the general public sphere. At the same time, religious ethos organisations have argued...

  11. Potential sources of bias in the use of Escherichia coli to measure waterborne diarrhoea risk in low-income settings.

    Science.gov (United States)

    Ercumen, Ayse; Arnold, Benjamin F; Naser, Abu Mohd; Unicomb, Leanne; Colford, John M; Luby, Stephen P

    2017-01-01

    Escherichia coli is the standard water quality indicator for diarrhoea risk. Yet, the association between E. coli and diarrhoea is inconsistent across studies without a systematic assessment of methodological differences behind this variation. Most studies measure water quality cross-sectionally with diarrhoea, risking exposure misclassification and reverse causation. Studies use different recall windows for self-reported diarrhoea; longer periods increase potential outcome misclassification through misrecall. Control of confounding is inconsistent across studies. Additionally, diarrhoea measured in unblinded intervention trials can present courtesy bias. We utilised measurements from a randomised trial of water interventions in Bangladesh to assess how these factors affect the E. coli-diarrhoea association. We compared cross-sectional versus prospective measurements of water quality and diarrhoea, 2-versus 7-day symptom recall periods, estimates with and without controlling for confounding and using measurements from control versus intervention arms of the trial. In the control arm, 2-day diarrhoea prevalence, measured prospectively 1 month after water quality, significantly increased with log 10 E. coli (PR = 1.50, 1.02-2.20). This association weakened when we used 7-day recall (PR = 1.18, 0.88-1.57), cross-sectional measurements of E. coli and diarrhoea (PR = 1.11, 0.79-1.56) or did not control for confounding (PR = 1.20, 0.88-1.62). Including data from intervention arms led to less interpretable associations, potentially due to courtesy bias, effect modification and/or reverse causation. By systematically addressing potential sources of bias, our analysis demonstrates a clear relationship between E. coli in drinking water and diarrhoea, suggesting that the continued use of E. coli as an indicator of waterborne diarrhoea risk is justified. © 2016 John Wiley & Sons Ltd.

  12. Effects of waterborne cadmium on metabolic rate, oxidative stress, and ion regulation in the freshwater fish, inanga (Galaxias maculatus).

    Science.gov (United States)

    McRae, Nicole K; Gaw, Sally; Glover, Chris N

    2018-01-01

    The freshwater fish Galaxias maculatus (inanga) is a widespread Southern hemisphere species, but despite its habitation of lowland near-coastal waters with a high potential for cadmium contamination, nothing is known regarding its sensitivity to this toxic trace metal. Acute (96h) exposures were therefore performed to determine sublethal responses of inanga to waterborne cadmium at a regulatory trigger value (nominally 0.2μgL-1; measured 1μgL-1), an environmental level (measured at 2.5μgL-1), and an effect level (measured at 10μgL-1). Whole body (tissue remaining following excision of kidney and liver) cadmium burden remained constant up until an exposure concentration of 10μgL-1, at which point cadmium concentration increased significantly. A transient effect of cadmium on metabolic rate was observed, with an impaired oxygen consumption noted at 2.5, but not 1 or 10, μg L-1. Cadmium did not impair influx rates of either sodium or calcium, and no effects of cadmium on oxidative stress parameters (catalase activity, lipid peroxidation) were noted in the kidney. However, at cadmium concentrations of 2.5 and 10μgL-1, lipid peroxidation in the liver increased, concomitant with a decline in hepatic catalase activity. These data indicate that there are significant differences in the mechanisms of cadmium toxicity in inanga, relative to better-studied Northern hemisphere species, especially with respect to ionoregulatory impacts. However, effects were induced at cadmium concentrations unlikely to be encountered in any but the most highly contaminated waterways, and thus our data suggest that current trigger values for cadmium concentrations in Australian and New Zealand waters are likely to be protective of inanga. Copyright © 2017. Published by Elsevier B.V.

  13. Electrical impedance sensor for quantitative monitoring of infection processes on HCT-8 cells by the waterborne parasite Cryptosporidium.

    Science.gov (United States)

    Dibao-Dina, Alfred; Follet, Jérôme; Ibrahim, Mouhamad; Vlandas, Alexis; Senez, Vincent

    2015-04-15

    Cryptosporidium is the main origin of worldwide waterborne epidemic outbreaks caused by protozoan parasites. Its resilience to water chemical treatments and the absence of therapy led to consider it as a reference pathogen to assess water quality and as a possible bioterrorism agent. We here show that an electrical impedance-based device is able to get insights on Cryptosporidium development on a cell culture and to quantify sample infectivity. HCT-8 cells were grown to confluency on Interdigitated Microelectrode Arrays (IMA's) during 76h and then infected by Cryptosporidium parvum during 60h. The impedimetric response was measured at frequencies ranging from 100Hz to 1MHz and a 7min sampling period. As the infection progresses the impedance signal shows a reproducible distinct succession of peaks at 12h post infection (PI), 23h PI and 31h PI and local minima at 9h PI, 19h PI and 28h PI. An equivalent circuit modeling-based approach indicates that these features are mostly originated from paracellular pathway modifications due to host-parasite interactions. Furthermore, our data present for the first time a real-time monitoring of early parasitic stage development with alternating zoite and meront predominances, observed respectively at peaks and local minima in the impedimetric signal. Finally, by quantifying the magnitude of the impedimetric response, we demonstrate this device can also be used as an infectivity sensor as early as 12h PI thus being at least 6 times faster than other state of the art techniques. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Waterborne cadmium and zinc uptake in a euryhaline teleost Acanthopagrus schlegeli acclimated to different salinities

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Li [Department of Biology, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong (China); Wang Wenxiong [Department of Biology, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong (China)], E-mail: wwang@ust.hk

    2007-08-30

    Metal uptake and toxicity in marine fish are usually much lower than those in freshwater fish, but the underlying mechanisms remain unclear. In this study, we investigated Cd and Zn uptake by the euryhaline black sea bream (Acanthopagrus schlegeli) over a salinity range from 0 to 35 psu. Cd and Zn uptake increased as salinity decreased. The gills were the most sensitive organs in response to salinity change, and played a more important role in Cd and Zn uptake at a lower salinity. Cd and Zn uptake in the viscera contributed to 34-36% of the overall accumulation at full salinity (35 psu), but decreased to 13-16% in freshwater despite the increase of uptake rate. Water permeability, drinking, and major ion uptake (Ca) in the fish at different salinities were also concurrently examined. The overall water uptake was comparable, whereas the drinking rate decreased at lowered salinities. In contrast, the Ca uptake increased significantly with decreasing salinity. The responses of Cd and Zn uptake to salinity challenge were correlated with the Ca uptake, suggesting that they may be taken up through the Ca uptake pathway. At a constant salinity, Cd and Zn uptake increased with reducing Ca concentration, indicating the competitive effect of Ca on metal uptake. Ca channel blockers (verapamil and lanthanum) significantly reduced the uptake of Cd, Zn, and Ca when the fish were acclimated in freshwater, but had no impact on their uptake in marine water. Furthermore, the chloride cell number in the gills could not explain the lower Cd and Zn uptake in seawater. Our results indicated that both ambient physicochemical factors and the physiological responses of fish resulted in difference of metal uptake in marine and freshwater environments.

  15. Data Challenges

    CERN Multimedia

    McCubbin, N A

    Some two years ago we planned a series of Data Challenges starting at the end of 2001. At the time, that seemed to be comfortingly far in the future... Well, as the saying goes, doesn't time fly when you are having fun! ATLAS Computing is now deep in the throes of getting the first Data Challenge (DC0) up and running. One of the main aims of DC0 is to have a software 'release' in which we can generate full physics events, track all particles through the detector, simulate the detector response, reconstruct the event, and study it, with appropriate data storage en route. As all software is "always 95% ready" (!), we have been able to do most of this, more or less, for some time. But DC0 forces us to have everything working, together, at the same time: a reality check. DC0 should finish early next year, and it will be followed almost immediately afterwards by DC1 (DC0 was foreseen as the 'check' for DC1). DC1 will last into the middle of 2002, and has two major goals. The first is generation, simulation, and r...

  16. Toxicity and trophic transfer of P25 TiO2 NPs from Dunaliella salina to Artemia salina: Effect of dietary and waterborne exposure.

    Science.gov (United States)

    Bhuvaneshwari, M; Thiagarajan, Vignesh; Nemade, Prateek; Chandrasekaran, N; Mukherjee, Amitava

    2018-01-01

    The recent increase in nanoparticle (P25 TiO2 NPs) usage has led to concerns regarding their potential implications on environment and human health. The food chain is the central pathway for nanoparticle transfer from lower to high trophic level organisms. The current study relies on the investigation of toxicity and trophic transfer potential of TiO2 NPs from marine algae Dunaliella salina to marine crustacean Artemia salina. Toxicity was measured in two different modes of exposure such as waterborne (exposure of TiO2 NPs to Artemia) and dietary exposure (NP-accumulated algal cells are used to feed the Artemia). The toxicity and accumulation of TiO2 NPs in marine algae D. salina were also studied. Artemia was found to be more sensitive to TiO2 NPs (48h LC50 of 4.21mgL-1) as compared to marine algae, D. salina (48h LC50 of 11.35mgL-1). The toxicity, uptake, and accumulation of TiO2 NPs were observed to be more in waterborne exposure as compared to dietary exposure. Waterborne exposure seemed to cause higher ROS production and antioxidant enzyme (SOD and CAT) activity as compared to dietary exposure of TiO2 NPs in Artemia. There were no observed biomagnification (BMF) and trophic transfer from algae to Artemia through dietary exposure. Histopathological studies confirmed the morphological and internal damages in Artemia. This study reiterates the possible effects of the different modes of exposure on trophic transfer potential of TiO2 NPs and eventually the consequences on aquatic environment. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. A Systematic Review of Waterborne Disease Outbreaks Associated with Small Non-Community Drinking Water Systems in Canada and the United States

    Science.gov (United States)

    Jones-Bitton, Andria; McEwen, Scott; Pintar, Katarina; Papadopoulos, Andrew

    2015-01-01

    Background Reports of outbreaks in Canada and the United States (U.S.) indicate that approximately 50% of all waterborne diseases occur in small non-community drinking water systems (SDWSs). Summarizing these investigations to identify the factors and conditions contributing to outbreaks is needed in order to help prevent future outbreaks. Objectives The objectives of this study were to: 1) identify published reports of waterborne disease outbreaks involving SDWSs in Canada and the U.S. since 1970; 2) summarize reported factors contributing to outbreaks, including water system characteristics and events surrounding the outbreaks; and 3) identify terminology used to describe SDWSs in outbreak reports. Methods Three electronic databases and grey literature sources were searched for outbreak reports involving SDWSs throughout Canada and the U.S. from 1970 to 2014. Two reviewers independently screened and extracted data related to water system characteristics and outbreak events. The data were analyzed descriptively with ‘outbreak’ as the unit of analysis. Results From a total of 1,995 citations, we identified 50 relevant articles reporting 293 unique outbreaks. Failure of an existing water treatment system (22.7%) and lack of water treatment (20.2%) were the leading causes of waterborne outbreaks in SDWSs. A seasonal trend was observed with 51% of outbreaks occurring in summer months (pwater source and whether water treatment was used (missing in 31% and 66% of reports, respectively). Conclusions More consistent reporting and descriptions of SDWSs in future outbreak reports are needed to understand the epidemiology of these outbreaks and to inform the development of targeted interventions for SDWSs. Additional monitoring of water systems that are used on a seasonal or infrequent basis would be worthwhile to inform future protection efforts. PMID:26513152

  18. [Factors associated with the quality of well water and the prevalence of waterborne diseases in the municipality of Abomey-Calavi in Benin].

    Science.gov (United States)

    Degbey, Cyriaque; Makoutode, Michel; Agueh, Victoire; Dramaix, Michele; de Brouwer, Christophe

    2011-01-01

    The objective of this work is to assess the factors associated with the water quality of household wells, suggest solutions to improve it, and study the prevalence of water-borne diseases in this community. The quality of well water and the prevalence of waterborne diseases in the municipality were studied by analysis of the microbiological indicators currently used to assess drinking-water quality and the retrospective study of waterborne diseases treated in the local health centres. The wells surveyed were contaminated by Escherichia coli, Klebsiella pneumonia, Staphylococcus aureus, Salmonella spp, Clostridium perfringens and fecal streptococci, at prevalences of 12.5, 12.2, 12.2, 12.1, 12 and 11.1%, respectively. The high rates of diarrhea, urinary infections, typhoid fever and abdominal pain found in the retrospective study were consistent with the results of the well-water quality assessment. These results showed that human activity has strongly influenced water quality, especially the lack of sanitation in the different districts and neighbourhoods. Other factors affecting the vulnerability of well water include poor waste management by households, the low depth of the water table, the nature of the soil, and the permeability of the aquifer used. Improvement in water quality, sanitation, and personal hygiene will make it possible to reduce considerably the propagation of these diseases and several others. It is therefore important to provide these populations with the necessary equipment for an adequate drinking water supply, but also to promote health education to avoid water pollution. The search for solutions to these problems will lead to a plan for future action.

  19. A Systematic Review of Waterborne Disease Outbreaks Associated with Small Non-Community Drinking Water Systems in Canada and the United States.

    Directory of Open Access Journals (Sweden)

    Wendy Pons

    Full Text Available Reports of outbreaks in Canada and the United States (U.S. indicate that approximately 50% of all waterborne diseases occur in small non-community drinking water systems (SDWSs. Summarizing these investigations to identify the factors and conditions contributing to outbreaks is needed in order to help prevent future outbreaks.The objectives of this study were to: 1 identify published reports of waterborne disease outbreaks involving SDWSs in Canada and the U.S. since 1970; 2 summarize reported factors contributing to outbreaks, including water system characteristics and events surrounding the outbreaks; and 3 identify terminology used to describe SDWSs in outbreak reports.Three electronic databases and grey literature sources were searched for outbreak reports involving SDWSs throughout Canada and the U.S. from 1970 to 2014. Two reviewers independently screened and extracted data related to water system characteristics and outbreak events. The data were analyzed descriptively with 'outbreak' as the unit of analysis.From a total of 1,995 citations, we identified 50 relevant articles reporting 293 unique outbreaks. Failure of an existing water treatment system (22.7% and lack of water treatment (20.2% were the leading causes of waterborne outbreaks in SDWSs. A seasonal trend was observed with 51% of outbreaks occurring in summer months (p<0.001. There was large variation in terminology used to describe SDWSs, and a large number of variables were not reported, including water source and whether water treatment was used (missing in 31% and 66% of reports, respectively.More consistent reporting and descriptions of SDWSs in future outbreak reports are needed to understand the epidemiology of these outbreaks and to inform the development of targeted interventions for SDWSs. Additional monitoring of water systems that are used on a seasonal or infrequent basis would be worthwhile to inform future protection efforts.

  20. Challenges in the pharmacologic management of obesity and secondary dyslipidemia in children and adolescents.

    Science.gov (United States)

    Kennedy, Mary Jayne; Jellerson, Kevin D; Snow, Michael Z; Zacchetti, Michelle L

    2013-10-01

    The rise in childhood obesity has lead to an increased number of children with lipid abnormalities and the predominance of a combined dyslipidemic pattern characterized by a moderate-to-severe elevation in triglycerides, normal-to-mild mild elevation in LDL cholesterol and reduced HDL cholesterol. Although recently published National Heart, Lung and Blood Institute (NHLBI) guidelines represent a significant step forward in managing primary dyslipidemias in pediatric patients, there is still no general consensus regarding the pharmacologic treatment of obesity-related lipid abnormalities in children. The use of early pharmacologic intervention to control dyslipidemias and reduce cardiovascular risk in young children is only expected to increase given the steady increase in obesity and emergence of atherosclerotic disease in pre-adolescents. Despite the increasing use of lipid-lowering therapy in children over the last few years, diet and lifestyle modification remain the first line therapy. Given the challenges of instituting and maintaining lifestyle modification in pediatric patients, however, it is likely that institution of drug therapy may be required in many children. Of all the medications currently available, the fibric acid derivatives have a cholesterol lowering profile that is most likely to be effective in obese children with the high TG/low HDL phenotype and data from a recently published study of gemfibrozil in children with metabolic syndrome are promising. However, additional information regarding the short and long-term safety and efficacy of fibrate therapy in children with obesity-related lipid disorders is needed before use of these agents can be recommended.

  1. Critical comparison of intravenous injection of TiO2 nanoparticles with waterborne and dietary exposures concludes minimal environmentally-relevant toxicity in juvenile rainbow trout Oncorhynchus mykiss.

    OpenAIRE

    Boyle, D; Al-Bairuty, GA; Henry, TB; Handy, RD

    2013-01-01

    A critical comparison of studies that have investigated tissue accumulation and toxicity of TiO2-NPs in fish is necessary to resolve inconsistencies. The present study used identical TiO2-NPs, toxicological endpoints, and fish (juvenile rainbow trout Oncorhynchus mykiss) as previous studies that investigated waterborne and dietary toxicity of TiO2-NPs, and conducted a critical comparison of results after intravenous caudal-vein injection of 50 μg of TiO2-NPs and bulk TiO2. Injected TiO2-NPs a...

  2. Challenging makerspaces

    DEFF Research Database (Denmark)

    Sandvik, Kjetil; Thestrup, Klaus

    . The Danish part of the project will be undertaken by a small network of partners: DOKK1, a public library and open urban space in Aarhus, that is experimenting with different kind of makerspaces, spaces and encounters between people, The LEGO-LAB situated at Computer Science, Aarhus University, that has......-8 will be developed through participation in creative activities in specially-designed spaces termed ‘makerspaces’. This paper discusses, develops and challenges this term in relation to Danish pedagogical traditions, to expanding makerspaces onto the internet and on how to combine narratives and construction...... developed a number of work space activities on children and technology and finally Katrinebjergskolen, a public school that has built a new multi-functional room, that among other things are meant for makerspaces and new combinations of media and materials. This group will work with the notion of Next...

  3. Cryptosporidium and Giardia: new challenges to the water industry

    NARCIS (Netherlands)

    Medema, Gerriet Jan

    1999-01-01

    The protozoan parasites Cryptosporidium parvum and Giardia intestinalis have emerged as significant waterborne pathogens over the past decades. Many outbreaks of waterborne cryptosporidiosis and giardiasis have been recorded,primarily in the United States and the United Kingdom.Chapter 1 gives an

  4. Scrapheap Challenge

    CERN Document Server

    2004-01-01

    Three British guys at CERN recently took a break from work to try their hand at Scrapheap Challenge. Shown on Channel 4 in the UK, it is a show where two teams must construct a machine for a specific task using only the junk they can scavenge from the scrap yard around them. And they have just 10 hours to build their contraption before it is put to the test. The first round, aired 19 September, pitted a team of three women, from the British Army's Royal Electrical and Mechanical Engineers, against the CERN guys - the Up 'n Atoms: Ali Day, David McFarlane and James Ridewood. Each team, with the help of an appointed expert, had the task of making a giant, 3-metre self-propelled "bowling ball", to roll down a 50 metre bowling alley at skittles 4 metres high. The Up 'n Atoms' contraption featured a small car with a huge wheel on its back. Once up to speed, slamming on the brakes caused the wheel to roll over and take the car with it. On their very last run they managed to take out seven pins. Luckily, though, ...

  5. [Simultaneous determination of 23 ester compounds in cigarette water-borne adhesives by liquid-liquid extraction and gas chromatography-mass spectrometry].

    Science.gov (United States)

    Gong, Shuguo; Kong, Bo; Tuo, Suxing; Dai, Yunhui; Wu, Mingjian; Tan, Liquan; Liu, Wei

    2013-10-01

    A method of gas chromatography-mass spectrometry (GC-MS) with liquid-liquid extraction has been developed for the simultaneous determination of 23 ester compounds including acetate esters, acrylic esters, metacrylic acid esters and phthalate acid esters in cigarette water-borne adhesives. After dispersed in water, the sample was extracted by n-hexane solution containing phenyl ethyl propionate as internal standard substance. Then, the solution was centrifuged and filtrated through a 0.45 microm organic membrane filter. Finally, the solution was separated on a DB-WAXETR column (60 m x 0.25 mm x 0.25 microm), and detected with MS in selected ion monitoring mode, and quantified by internal standard method. The results showed a good linear correlation in the range of 0.4-50.0 mg/L. The recoveries of the ester compounds spiked in the sample were 81.8%-109.1%, and the relative standard deviations (RSDs, n = 5) were less than 4%. The limits of detection (LODs) and limits of quantification (LOQs were in the ranges of 0.02-0.76 mg/kg and 0.04-2.52 mg/kg, respectively. The method is simple, time-saving, and has high sensitivity and good reproducibility. It can be applied to the determination of the 23 ester compounds in cigarette water-borne adhesives.

  6. Biodegradation of a biochar-modified waterborne polyacrylate membrane coating for controlled-release fertilizer and its effects on soil bacterial community profiles.

    Science.gov (United States)

    Zhou, Zijun; Du, Changwen; Li, Ting; Shen, Yazhen; Zeng, Yin; Du, Jie; Zhou, Jianmin

    2015-06-01

    Biochar-modified polyacrylate-like polymers are promising waterborne polymer-based membrane coatings for controlled-release fertilizers. However, the effect of these membrane polymers on paddy soil is unknown. A soil incubation experiment was conducted using Fourier transform infrared photoacoustic spectroscopy to monitor the changes in the polymer-coated membranes in paddy soil, and Biolog EcoPlates and polymerase chain reaction-denaturing gradient gel electrophoresis were used to detect the effects of the membranes on soil bacterial community profiles. Compared to unmodified membranes, the biodegradation rate of the biochar-modified membrane was slower, and the membrane was more intact, which improved and guaranteed the controlled release of nutrients. Compared to the soil without membranes, the biochar-modified membranes, as well as unmodified ones, showed no significant impacts on the composition diversity of soil dominant bacterial community. The activity and functional diversity of soil culturable microbial community during the early stage of incubation were reduced by biochar-modified membranes due to the release of small amount of soluble organic materials but were both recovered in the 12(th) month of the incubation period. Therefore, the biochar-modified waterborne polyacrylate was environmentally friendly, demonstrating its potential both in the development of coated controlled-release fertilizers and in the utilization of crop residue.

  7. Effects of subchronic exposure to waterborne cadmium on H-P-I axis hormones and related genes in rare minnows (Gobiocypris rarus).

    Science.gov (United States)

    Liu, Xiao-Hong; Wang, Zhi-Jian; Jin, Li; Huang, Jing; Pu, De-Yong; Wang, De-Shou; Zhang, Yao-Guang

    2017-11-01

    The H (hypothalamic)-P (pituitary)-I (interrenal) axis is critical in the stress response and other activities of fish. To further investigate cadmium (Cd) toxicity on the H-P-I axis and to identify its potential regulatory genes in fish, the adult female rare minnows (Gobiocypris rarus) were exposed to subchronic (5weeks) levels of waterborne Cd in the present study. This kind of treatment caused dose-dependent decline in fish growth, with significance in the high dose group (100μg/L). Correspondingly, low dose (5-50μg/L) waterborne Cd disrupted the endocrine system of H-P-I axis just at the secretion level, while high dose Cd disrupted both the secretion and synthesis of cortisol and its downstream signals in rare minnows, revealed by the significantly upregulation and positive correlation of corticosteroidogenic genes including MC2R, StAR, CYP11A1, and CYP11B1 in the kidney (including the interrenal tissue) (PPP-I axis in fish. The expression of FKBP5 in the intestine was positively and significantly correlated with that of Hsp90AA (PP<0.05), which indicated that Hsp90AA and Hsp90AB were more likely to serve as cofactors of GR and FKBP5 in response to Cd exposure. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Food- and water-borne disease: using case control studies to estimate the force of infection that accounts for primary, sporadic cases.

    Science.gov (United States)

    Smith, G

    2013-06-01

    Disease models which take explicit account of heterogeneities in the risk of infection offer significant advantages over models in which the risk of infection is assumed to be uniform across all hosts. However, estimating the incidence rate (force of infection) in the different at-risk (exposure) groups is no easy matter. Classically, epidemiologists differentiate groups of hosts with different infection-risks according to their exposure to putative explanatory risk factors. The importance of these risk factors is assessed by case-control studies, in which the measure of effect (the difference in disease occurrence between one population and another) is the odds ratio. This paper describes for the first time how - and under what circumstances - the incidence in these different exposure groups can be estimated from odds ratios derived from case control studies in which controls have been selected by density sampling. This new estimation technique can be applied to any transmission modality but is especially useful in the case of models of food- and water-borne disease for which the case control literature represents a vast and, as yet, untapped resource. The paper finishes with a worked example using one of the most common of all food- and water-borne pathogens, Toxoplasma gondii. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. The association of drinking water quality and sewage disposal with Helicobacter pylori incidence in infants: the potential role of water-borne transmission.

    Science.gov (United States)

    Travis, Penny B; Goodman, Karen J; O'Rourke, Kathleen M; Groves, Frank D; Sinha, Debajyoti; Nicholas, Joyce S; VanDerslice, Jim; Lackland, Daniel; Mena, Kristina D

    2010-03-01

    The mode of transmission of Helicobacter pylori, a bacterium causing gastric cancer and peptic ulcer disease, is unknown although waterborne transmission is a likely pathway. This study investigated the hypothesis that access to treated water and a sanitary sewerage system reduces the H. pylori incidence rate, using data from 472 participants in a cohort study that followed children in Juarez, Mexico, and El Paso, Texas, from April 1998, with caretaker interviews and the urea breath test for detecting H. pylori infection at target intervals of six months from birth through 24 months of age. The unadjusted hazard ratio comparing bottled/vending machine water to a municipal water supply was 0.71 (95% confidence interval (CI): 0.50, 1.01) and comparing a municipal sewer connection to a septic tank or cesspool, 0.85 (95% CI: 0.60, 1.20). After adjustment for maternal education and country, the hazard ratios decreased slightly to 0.70 (95% confidence interval: 0.49, 1.00) and 0.77 (95% confidence interval: 0.50, 1.21), respectively. These results provide moderate support for potential waterborne transmission of H. pylori.

  10. Reduction of risk of watery diarrhea with point-of-use water filters during a massive outbreak of waterborne Cryptosporidium infection in Milwaukee, Wisconsin, 1993.

    Science.gov (United States)

    Addiss, D G; Pond, R S; Remshak, M; Juranek, D D; Stokes, S; Davis, J P

    1996-06-01

    The occurrence of a massive waterborne outbreak of Cryptosporidium infection in Milwaukee, Wisconsin provided an opportunity to evaluate the effectiveness of point-of-use home water filters in preventing diarrheal illness associated with Cryptosporidium infection. Of 155 filter owners who responded to a televised request to contact the City of Milwaukee Health Department, 99 (64%) completed a self-administered questionnaire regarding their sources of drinking water, the characteristics of their home water filters, and diarrheal illness during the outbreak. Diarrhea among respondents was independently associated with residence in southern or central Milwaukee (the area served by the implicated South water treatment plant), having a home water filter with a pore diameter of greater than 1 micron, and drinking unfiltered tap water in a public building in southern Milwaukee. Among residents of southern and central Milwaukee, two (18%) of 11 persons who drank only submicron-filtered water at home and who did not drink unfiltered South plant water at work had watery diarrhea, compared with 50% (n = 2), 63% (n = 35), and 80% (n = 15) who reported drinking South plant water that was unfiltered or passed through a filter with a pore diameter > 1 micron at work only, home only, or both home and work, respectively (P = 0.02). The data indicate that use of submicron point-of-use water filters may reduce risk of waterborne cryptosporidiosis.

  11. Field evaluation of a new point-of-use faucet filter for preventing exposure to Legionella and other waterborne pathogens in health care facilities.

    Science.gov (United States)

    Baron, Julianne L; Peters, Tammy; Shafer, Raymond; MacMurray, Brian; Stout, Janet E

    2014-11-01

    Opportunistic waterborne pathogens (eg, Legionella, Pseudomonas) may persist in water distribution systems despite municipal chlorination and secondary disinfection and can cause health care-acquired infections. Point-of-use (POU) filtration can limit exposure to pathogens; however, their short maximum lifetime and membrane clogging have limited their use. A new faucet filter rated at 62 days was evaluated at a cancer center in Northwestern Pennsylvania. Five sinks were equipped with filters, and 5 sinks served as controls. Hot water was collected weekly for 17 weeks and cultured for Legionella, Pseudomonas, and total bacteria. Legionella was removed from all filtered samples for 12 weeks. One colony was recovered from 1 site at 13 weeks; however, subsequent tests were negative through 17 weeks of testing. Total bacteria were excluded for the first 2 weeks, followed by an average of 1.86 log reduction in total bacteria compared with controls. No Pseudomonas was recovered from filtered or control faucets. This next generation faucet filter eliminated Legionella beyond the 62 day manufacturers' recommended maximum duration of use. These new POU filters will require fewer change-outs than standard filters and could be a cost-effective method for preventing exposure to Legionella and other opportunistic waterborne pathogens in hospitals with high-risk patients. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  12. In situ fate and partitioning of waterborne perfluoroalkyl acids (PFAAs) in the Youngsan and Nakdong River Estuaries of South Korea

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Seongjin [School of Earth and Environmental Sciences, Seoul National University, Seoul (Korea, Republic of); Khim, Jong Seong, E-mail: jskocean@snu.ac.kr [School of Earth and Environmental Sciences, Seoul National University, Seoul (Korea, Republic of); Park, Jinsoon [School of Earth and Environmental Sciences, Seoul National University, Seoul (Korea, Republic of); Kim, Minhee; Kim, Woong-Ki; Jung, Jinho; Hyun, Seunghun; Kim, Jeong-Gyu [Division of Environmental Science and Ecological Engineering, Korea University, Seoul (Korea, Republic of); Lee, Hyojin; Choi, Heeseon J. [Department of Environmental Chemistry and Ecology, GeoSystem Research Corporation, Gunpo (Korea, Republic of); Codling, Garry [Department of Veterinary Biomedical Sciences and Toxicology Centre, University of Saskatchewan, Saskatoon, SK (Canada); Giesy, John P. [Department of Veterinary Biomedical Sciences and Toxicology Centre, University of Saskatchewan, Saskatoon, SK (Canada); Department of Zoology, Center for Integrative Toxicology, Michigan State University, East Lansing, MI (United States); Department of Biology and Chemistry and State Key Laboratory in Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong, SAR (China)

    2013-02-15

    Concentrations, distributions, fate, and partitioning of perfluoroalkyl acids (PFAAs) were investigated in surface water (n = 34) collected from the Youngsan and Nakdong River Estuaries of South Korea. Thirteen individual PFAAs in water and suspended solids (SS) were quantified by use of HPLC–MS/MS. PFAAs were detected in all samples, which indicated that they were widely distributed in the study area. Greater concentrations of PFAAs were found at some inland sites which seemed to be affected by direct input from point sources, such as wastewater treatment plants, and/or indirect diffusive sources, such as surface runoff. Spatial distributions of PFAAs in estuaries along transects toward the open sea demonstrated that these chemicals were transported to the outer region primarily by water discharged during the rainy season. Field-based partition coefficients (K{sub d}) for long-chain PFAAs (C ≥ 8) were significantly correlated with salinity (r{sup 2} = 0.48 to 0.73, p < 0.01); K{sub d} values increased exponentially as a function of salinity. Due to the ‘salting-out’ effect, PFAAs were largely scavenged by adsorption onto SS and/or sediments in estuarine environments. In addition, values for K{sub d} of those PFAAs were directly proportional to the number of carbon atoms in the PFAAs. Salting constants of selected PFAAs were notably greater than those of other environmental organic contaminants, which indicated that adsorption of PFAAs is largely associated with salinity. Overall, the results of the present study will provide better understanding of the fate and transport of PFAAs in the zone of salinity boundary that can be used for developing fate models of PFAAs in the coastal marine environment. - Highlights: ► In situ fate and partitioning of PFAAs were described along salinity gradients in estuaries. ► Salinity was found to be the key factor controlling adsorption of waterborne PFAAs. ► The K{sub d} for longer-chain PFAAs (C ≥ 8) increased as

  13. Comparison of waterborne and intraperitoneal exposure to fipronil in the Caspian white fish (Rutilus frisii on acute toxicity and histopathology

    Directory of Open Access Journals (Sweden)

    Rashid Alijani Ardeshir

    Full Text Available Fipronil is an effective insecticide widely used in agriculture with potential ecotoxicological consequences. The median lethal dose (LD50 and concentration (LC50 of fipronil in 16.3 g Caspian white fish, Rutilus frisii kutum fingerlings were determined. To determine the LD50, a total of 133 fish were assigned to 19 tanks (7 fish/tank including one control and 6 treatment groups (300, 450, 550, 650, 750, 850 mg/kg. Fish were injected intraperitoneally and monitored at 96 h. The LD50 of fipronil was 632 mg/kg suggesting it was slightly toxic to the Caspian white fish. To determine LC50, 114 fish were assigned to 19 tanks (6 fish/tank including one control and 6 treatment groups (300, 400, 500, 600, 700, 800 μg/L. The LC50 of fipronil was 572 μg/L, which was highly toxic to the fish. The degree of tissue change (DTC in vital organs from moribund fish exposed via waterborne exposure showed severe damage (DTC: 71 ± 52 for 700 μg/L in the gill, including aneurisms, extensive fusion and necrosis. The fish exposed through the intraperitoneal route seemed to have severe lesions (DTC: 66 ± 50 for 750 mg/kg in the kidney, involving hemorrhage, tubular degeneration and necrosis. The liver had no significant differences in DTC values between the two routes and showed pyknosis and sinusoid dilation. Hematoxylin and eosin staining did not show any histological alterations in the brain but nissl staining showed some alterations in distribution of purkinje cells. Generally, this study showed that the route of exposure to fipronil not only affects its acute toxicity but also determines the main target organs of toxicity and histopathological alterations in Caspian white fish. Keywords: Fipronil, Caspian white fish, Acute toxicity, Administration route

  14. Waterborne amitrole affects the predator-prey relationship between common frog tadpoles (Rana temporaria) and larval spotted salamander (Salamandra salamandra).

    Science.gov (United States)

    Mandrillon, Anne-Lise; Saglio, Philippe

    2007-08-01

    Within their aquatic habitats, larval amphibians are often subjected to multiple natural and anthropic stressors. Among these, predation and waterborne pollution represent two types of stressing factor that frequently co-occur. In this connection, the present laboratory study was designed to investigate the effects of amitrole, a commonly used triazole herbicide, on the predator-prey relationship between common frog tadpoles (Rana temporaria) and larval spotted salamander (Salamandra salamandra). Tadpoles were exposed for 3 days to 0, 0.01, 0.1, 1, and 10 mg/L amitrole, either in the absence or in the presence of larval salamanders. Tadpole behavior (refuge use, movements) was monitored every day, and the predation efficiency was assessed at the end of the experiment by counting the number of surviving tadpoles. In the absence of the predator, amitrole-exposed tadpoles (at 0.01, 0.1, and 1 mg/L) increased their refuge use and decreased their rate of movements. In the presence of the predator, amitrole contamination did not affect tadpole behavior, except on the first day, where tadpoles exposed to 10 mg/L were found to be significantly more active than unexposed control tadpoles. Throughout the experiment, control tadpoles were the only group to show significant reductions of activity and visibility in response to the predator's presence. In contrast, tadpoles exposed to 0.01 and 0.1 mg/L amitrole increased their refuge use in response to the predator, whereas their rate of movements remained unaffected. Furthermore, exposures of tadpoles to the two highest amitrole concentrations (1 and 10 mg/L) resulted in the loss of both behavioral responses to the predator's presence. Interestingly, the lack of antipredator behavior in amitrole-exposed tadpoles did not enhance their vulnerability to predation by the larval salamander. Moreover, tadpoles exposed to the two highest herbicide concentrations showed a better survival than unexposed controls, indicating that

  15. Behavioral responses of the estuarine calanoid copepod Eurytemora affinis to sub-lethal concentrations of waterborne pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Michalec, François-Gaël [Université Lille Nord de France, F-59000 Lille (France); USTL, LOG, Station Marine de Wimereux, F-62930 Wimereux (France); CNRS, UMR 8187, F-62930 Wimereux (France); National Taiwan Ocean University, Institute of Marine Biology, Keelung, Taiwan, ROC (China); Holzner, Markus [Institute of Environmental Engineering, ETH Zürich (Switzerland); Menu, Dominique [Université Lille Nord de France, F-59000 Lille (France); USTL, LOG, Station Marine de Wimereux, F-62930 Wimereux (France); CNRS, UMR 8187, F-62930 Wimereux (France); Hwang, Jiang-Shiou [National Taiwan Ocean University, Institute of Marine Biology, Keelung, Taiwan, ROC (China); Souissi, Sami, E-mail: sami.souissi@univ-lille1.fr [Université Lille Nord de France, F-59000 Lille (France); USTL, LOG, Station Marine de Wimereux, F-62930 Wimereux (France); CNRS, UMR 8187, F-62930 Wimereux (France)

    2013-08-15

    increase in speed and activity resembles an escape reaction permitting copepods to evade stressful conditions. Overall, these results indicate that environment-relevant concentrations of pollutants can induce rapid changes in copepod behavior. Since behavioral processes represent a fundamental element in the ecology of copepods, our results raise concern about the effects of background levels of pollution on a major component of the plankton community. The long-term response of copepods to waterborne pollutants, their synergistic effects and their interactions with other environmental factors need further investigation.

  16. Coordination of waterborne AGVs

    NARCIS (Netherlands)

    Zheng, H.

    2016-01-01

    The possible larger amount of container throughput and the limited handling capacities of existing infrastructures impose increasingly high pressure on large ports in improving competitiveness. Inside container terminals, land-side automated guided vehicles have been used extensively for decades to

  17. Waterborne Diseases & Illnesses

    Science.gov (United States)

    ... Information Menu Home Air Pollution Air Pollution Home Indoor Air Pollution Outdoor Air Pollution Particulate Matter Ozone Chemicals Chemicals ... Print this Page Air Pollution Air Pollution Home Indoor Air Pollution Outdoor Air Pollution Particulate Matter Ozone Chemicals Chemicals ...

  18. Waterborne diseases in Peru

    OpenAIRE

    Webb, Sheila

    1992-01-01

    The cholera epidemic in Peru brought to light the miserable state of local water and sanitation conditions. The author discusses the relationship between waterbone diseases and water and sewerage conditions in Peruvian peri-urban areas, or pueblos jovenes. These diseases are associated with poor living conditions. In 1989, only 52 percent of the population had access to piped water, and only 39 percent to sewerage. About 52 percent of schools lack light, water, and sewerage. In Lima, 2 millio...

  19. Waterborne Polymeric Films.

    Science.gov (United States)

    1979-12-01

    in the preparation of synthetic rubber for tires. Even in the modern world the term SBR rubber is a common phrase. Since the styrene-butadiene...homopolymers (TgI . . Tan).12 For applications requiring toughness and moisture barrier properties, it is frequently desirable to incorporate styrene (12a...acrylic or styrenated acrylics. Other applications may require features attributed to other vinyl containing compounds such as halides (12b), ethers

  20. Water-Borne Cues of a Non-Indigenous Seaweed Mediate Grazer-Deterrent Responses in Native Seaweeds, but Not Vice Versa

    Science.gov (United States)

    Yun, Hee Young; Engelen, Aschwin H.; Santos, Rui O.; Molis, Markus

    2012-01-01

    Plants optimise their resistance to herbivores by regulating deterrent responses on demand. Induction of anti-herbivory defences can occur directly in grazed plants or from emission of risk cues to the environment, which modifies interactions of adjacent plants with, for instance, their consumers. This study confirmed the induction of anti-herbivory responses by water-borne risk cues between adjoining con-specific seaweeds and firstly examined whether plant-plant signalling also exists among adjacent hetero-specific seaweeds. Furthermore, differential abilities and geographic variation in plant-plant signalling by a non-indigenous seaweed as well as native seaweeds were assessed. Twelve-day induction experiments using the non-indigenous seaweed Sargassum muticum were conducted in the laboratory in Portugal and Germany with one local con-familiar (Portugal: Cystoseira humilis, Germany: Halidrys siliquosa) and hetero-familiar native species (Portugal: Fucus spiralis, Germany: F. vesiculosus). All seaweeds were grazed by a local isopod species (Portugal: Stenosoma nadejda, Germany: Idotea baltica) and were positioned upstream of con- and hetero-specific seaweeds. Grazing-induced modification in seaweed traits were tested in three-day feeding assays between cue-exposed and cue-free ( = control) pieces of both fresh and reconstituted seaweeds. Both Fucus species reduced their palatability when positioned downstream of isopod-grazed con-specifics. Yet, the palatability of non-indigenous S. muticum remained constant in the presence of upstream grazed con-specifics and native hetero-specifics. In contrast, both con-familiar (but neither hetero-familiar) native species reduced palatability when located downstream of grazed S. muticum. Similar patterns of grazer-deterrent responses to water-borne cues were observed on both European shores, and were almost identical between assays using fresh and reconstituted seaweeds. Hence, seaweeds may use plant-plant signalling to

  1. Water-borne cues of a non-indigenous seaweed mediate grazer-deterrent responses in native seaweeds, but not vice versa.

    Directory of Open Access Journals (Sweden)

    Hee Young Yun

    Full Text Available Plants optimise their resistance to herbivores by regulating deterrent responses on demand. Induction of anti-herbivory defences can occur directly in grazed plants or from emission of risk cues to the environment, which modifies interactions of adjacent plants with, for instance, their consumers. This study confirmed the induction of anti-herbivory responses by water-borne risk cues between adjoining con-specific seaweeds and firstly examined whether plant-plant signalling also exists among adjacent hetero-specific seaweeds. Furthermore, differential abilities and geographic variation in plant-plant signalling by a non-indigenous seaweed as well as native seaweeds were assessed. Twelve-day induction experiments using the non-indigenous seaweed Sargassum muticum were conducted in the laboratory in Portugal and Germany with one local con-familiar (Portugal: Cystoseira humilis, Germany: Halidrys siliquosa and hetero-familiar native species (Portugal: Fucus spiralis, Germany: F. vesiculosus. All seaweeds were grazed by a local isopod species (Portugal: Stenosoma nadejda, Germany: Idotea baltica and were positioned upstream of con- and hetero-specific seaweeds. Grazing-induced modification in seaweed traits were tested in three-day feeding assays between cue-exposed and cue-free ( = control pieces of both fresh and reconstituted seaweeds. Both Fucus species reduced their palatability when positioned downstream of isopod-grazed con-specifics. Yet, the palatability of non-indigenous S. muticum remained constant in the presence of upstream grazed con-specifics and native hetero-specifics. In contrast, both con-familiar (but neither hetero-familiar native species reduced palatability when located downstream of grazed S. muticum. Similar patterns of grazer-deterrent responses to water-borne cues were observed on both European shores, and were almost identical between assays using fresh and reconstituted seaweeds. Hence, seaweeds may use plant

  2. Biochemical biomarker responses of green-lipped mussel, Perna canaliculus, to acute and subchronic waterborne cadmium toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Chandurvelan, Rathishri, E-mail: rch118@uclive.ac.nz [School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand); Marsden, Islay D., E-mail: islay.marsden@canterbury.ac.nz [School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand); Gaw, Sally, E-mail: sally.gaw@canterbury.ac.nz [Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand); Glover, Chris N., E-mail: chris.glover@canterbury.ac.nz [School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand)

    2013-09-15

    Highlights: •Biochemical biomarkers were measured to assess effects of Cd on Perna canaliculus. •Biochemical responses varied between acute and subchronic exposure to Cd. •MTLP induction correlated strongly with Cd accumulation. •Alkaline phosphatase and glycogen levels decreased during subchronic Cd exposure. •Duration of Cd exposure influenced biochemical biomarker responses in mussels. -- Abstract: The biochemical responses of the green-lipped mussel, Perna canaliculus, to waterborne cadmium (Cd) were investigated in order to delineate toxic mechanisms, and the impacts of exposure dose and duration, of this important toxicant in a potential sentinel species. Mussels were exposed for either 96 h (acute: 0, 2000, 4000 μg L{sup −1} Cd) or for 28 d (subchronic: 0, 200, 2000 μg L{sup −1} Cd), and the digestive gland, gill and haemolymph were examined for impacts. Biochemical responses measured included those associated with metal detoxification (metallothionein-like protein; MTLP), oxidative stress (catalase, lipid peroxidation), cellular homeostasis (alkaline phosphatase, Na{sup +}, K{sup +}-ATPase; NKA), and energy utilisation (glycogen, haemolymph protein). Following acute exposure, digestive gland glycogen and gill NKA activity were significantly altered by Cd exposure relative to levels in mussels exposed to Cd-free seawater. Subchronic Cd exposure resulted in a significant increase in MTLP levels in both the gill and the digestive gland. This increase was correlated strongly with the levels of Cd accumulation measured in these tissues (R = 0.957 for gill, 0.964 for digestive gland). Catalase activity followed a similar pattern, although the correlation with tissue Cd accumulation was not as strong (R = 0.907 for gill, 0.708 for digestive gland) as that for MTLP. Lipid peroxidation increased in the digestive gland at Days 7 and 14 at both subchronic Cd levels tested, but this effect had largely dissipated by Days 21 and 28 (with the exception of

  3. Heterogeneity in multiple transmission pathways: modelling the spread of cholera and other waterborne disease in networks with a common water source.

    Science.gov (United States)

    Robertson, Suzanne L; Eisenberg, Marisa C; Tien, Joseph H

    2013-01-01

    Many factors influencing disease transmission vary throughout and across populations. For diseases spread through multiple transmission pathways, sources of variation may affect each transmission pathway differently. In this paper we consider a disease that can be spread via direct and indirect transmission, such as the waterborne disease cholera. Specifically, we consider a system of multiple patches with direct transmission occurring entirely within patch and indirect transmission via a single shared water source. We investigate the effect of heterogeneity in dual transmission pathways on the spread of the disease. We first present a 2-patch model for which we examine the effect of variation in each pathway separately and propose a measure of heterogeneity that incorporates both transmission mechanisms and is predictive of R(0). We also explore how heterogeneity affects the final outbreak size and the efficacy of intervention measures. We conclude by extending several results to a more general n-patch setting.

  4. Study on Evolution of Coating State and Role of Graphene in Graphene-Modified Low-Zinc Waterborne Epoxy Anticorrosion Coating by Electrochemical Impedance Spectroscopy

    Science.gov (United States)

    Ding, Rui; Wang, Xiao; Jiang, Jianming; Gui, Taijiang; Li, Weihua

    2017-07-01

    In this paper, corrosion potential and impedance response of the graphene-modified low-zinc waterborne epoxy anticorrosion coating with different compositions were measured experimentally. Microstructure impedance analysis approach was proposed, which was applied to analyze in detail the system impedance and to clarify the variation of coating state as well as the role of graphene in the coating. Results showed that the variation course of coating state was divided into four stages: activation stage; cathodic protection stage; shielding protection stage; and failure stage. Graphene formed numerous isolation layers in the coating to hinder the diffusion of aggressive particles like water and oxygen as well as corrosion products, which played a certain shielding protective role. Moreover, graphene was a good electron conductor, which enabled the outer layer zinc to continue to constitute a galvanic couple with the iron substrate after cathodic protection stage, thereby prolonging the protective effect of the coating to some extent.

  5. Characterization of waterborne nitrogen emissions for marine eutrophication modelling in life cycle impact assessment at the damage level and global scale

    DEFF Research Database (Denmark)

    Cosme, Nuno Miguel Dias; Hauschild, Michael Zwicky

    2017-01-01

    Current life cycle impact assessment (LCIA) methods lack a consistent and globally applicable characterization model relating nitrogen (N, as dissolved inorganic nitrogen, DIN) enrichment of coastal waters to the marine eutrophication impacts at the endpoint level. This paper introduces a method ...... to calculate spatially explicit characterization factors (CFs) at endpoint and damage to ecosystems levels, for waterborne nitrogen emissions, reflecting their hypoxia-related marine eutrophication impacts, modelled for 5772 river basins of the world.......Current life cycle impact assessment (LCIA) methods lack a consistent and globally applicable characterization model relating nitrogen (N, as dissolved inorganic nitrogen, DIN) enrichment of coastal waters to the marine eutrophication impacts at the endpoint level. This paper introduces a method...

  6. A multiplex PCR/LDR assay for simultaneous detection and identification of the NIAID category B bacterial food and water-borne pathogens.

    Science.gov (United States)

    Rundell, Mark S; Pingle, Maneesh; Das, Sanchita; Hussain, Aashiq; Ocheretina, Oksana; Charles, Macarthur; Larone, Davise H; Spitzer, Eric D; Golightly, Linnie; Barany, Francis

    2014-06-01

    Enteric pathogens that cause gastroenteritis remain a major global health concern. The goal of this study was to develop a multiplex PCR/ligation detection reaction (LDR) assay for the detection of all NIAID category B bacterial food and water-borne pathogens directly from stool specimens. To validate the PCR/LDR assay, clinical isolates of Campylobacter spp., Vibrio spp., Shigella spp., Salmonella spp., Listeria monocytogenes, Yersinia enterocolitica, and diarrheagenic Escherichia coli were tested. The sensitivity and specificity of the assay were assessed using a large number of seeded culture-negative stool specimens and a smaller set of clinical specimens from Haiti. The overall sensitivity ranged from 91% to 100% (median 100%) depending on the species. For the majority of organisms, the sensitivity was 100%. The overall specificity based on initial testing ranged from 98% to 100% depending on the species. After additional testing of discordant samples, the lowest specificity was 99.4%. PCR/LDR detected additional category B agents (particularly diarrheagenic E. coli) in 11/40 specimens from Haiti that were culture-positive for V. cholerae and in approximately 1% of routine culture-negative stool specimens from a hospital in New York. This study demonstrated the ability of the PCR/LDR assay to detect a large comprehensive panel of category B enteric bacterial pathogens as well as mixed infections. This type of assay has the potential to provide earlier warnings of possible public health threats and more accurate surveillance of food and water-borne pathogens. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Detection of vitellogenin and zona radiata protein expressions in surface mucus of immature juvenile Atlantic salmon (Salmo salar) exposed to waterborne nonylphenol

    Energy Technology Data Exchange (ETDEWEB)

    Meucci, Valentina [Department of Veterinary Clinics, Section of Pharmacology and Toxicology, University of Pisa, V. le delle Piagge 2, 56124 Pisa (Italy); Arukwe, Augustine [Department of Biology, Norwegian University of Science and Technology (NTNU), Hoyskoleringen 5, 7491 Trondheim (Norway)]. E-mail: arukwe@bio.ntnu.no

    2005-06-01

    Induction of blood plasma vitellogenin (Vtg) and zona radiata proteins (Zr-proteins) in male and juvenile of oviparous vertebrates was proposed and shown to be sensitive biomarkers for exposure to estrogen mimic. The time- and dose-dependent expression of Vtg and Zr-proteins in nonylphenol (NP) exposed juvenile Atlantic salmon (Salmo salar) is reported. Fish were exposed continuously to waterborne nonylphenol at 5, 15 and 50 {mu}g/L. Blood and surface mucus samples were collected after 3 and 7 days post-exposure. Nonylphenol-induced plasma and surface mucus levels of Vtg and Zr-protein were analysed using immunochemical methods (Western blot and enzyme-linked immunosorbent assay; ELISA). Both Vtg and Zr-protein levels in plasma and surface mucus showed similar and parallel nonylphenol-induced expression patterns after waterborne nonylphenol exposure and in a concentration- and time-dependent manner. Zr-proteins were significantly induced at the lowest concentration of nonylphenol after 3 and 7 days of exposure both in plasma and in surface mucus. We conclude that the detection of Vtg and Zr-proteins directly in the surface mucus of fish, and the correlation of these values with plasma protein biomarker values in xenoestrogen-treated fish represents a sensitive non-invasive system for the detection of these known endocrine disruptor biomarkers. The demonstration of detectable Vtg and Zr-protein levels from surface mucus is a potential biomarker for estrogenic compounds, and their presence should be considered as an improvement in the methods for detection of endocrine disrupting chemicals (EDCs) and related pollutants in the environment.

  8. A hydrodynamics-based approach to evaluating the risk of waterborne pathogens entering drinking water intakes in a large, stratified lake.

    Science.gov (United States)

    Hoyer, Andrea B; Schladow, S Geoffrey; Rueda, Francisco J

    2015-10-15

    Pathogen contamination of drinking water lakes and reservoirs is a severe threat to human health worldwide. A major source of pathogens in surface sources of drinking waters is from body-contact recreation in the water body. However, dispersion pathways of human waterborne pathogens from recreational beaches, where body-contact recreation is known to occur to drinking water intakes, and the associated risk of pathogens entering the drinking water supply remain largely undocumented. A high spatial resolution, three-dimensional hydrodynamic and particle tracking modeling approach has been developed to analyze the risk and mechanisms presented by pathogen dispersion. The pathogen model represents the processes of particle release, transport and survival. Here survival is a function of both water temperature and cumulative exposure to ultraviolet (UV) radiation. Pathogen transport is simulated using a novel and computationally efficient technique of tracking particle trajectories backwards, from a drinking water intake toward their source areas. The model has been applied to a large, alpine lake - Lake Tahoe, CA-NV (USA). The dispersion model results reveal that for this particular lake (1) the risk of human waterborne pathogens to enter drinking water intakes is low, but significant; (2) this risk is strongly related to the depth of the thermocline in relation to the depth of the intake; (3) the risk increases with the seasonal deepening of the surface mixed layer; and (4) the risk increases at night when the surface mixed layer deepens through convective mixing and inactivation by UV radiation is eliminated. While these risk factors will quantitatively vary in different lakes, these same mechanisms will govern the process of transport of pathogens. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Effect of waterborne exposure to 4-tert-octylphenol and 17beta-estradiol on smoltification and downstream migration in Atlantic salmon, Salmo salar

    DEFF Research Database (Denmark)

    Bangsgaard, Karsten; Madsen, Steffen S; Korsgaard, Bodil

    2006-01-01

    in fresh water, and the effects on physiological and behavioural aspects of parr-smolt transformation were investigated. Vitellogenesis was induced by all treatments, as indicated by elevated levels of plasma vitellogenin (Vtg) and hepatosomatic index. Elevated Vtg levels were still found in OP-100 and E2...... suggests that waterborne exposure of salmon to xenoestrogens reduce both physiological and behavioural components of smoltification, even when exposure occurs several months prior to smolting....

  10. Critical body residues, Michaelis-Menten analysis of bioaccumulation, lethality and behaviour as endpoints of waterborne Ni toxicity in two teleosts.

    Science.gov (United States)

    Leonard, Erin M; Marentette, Julie R; Balshine, Sigal; Wood, Chris M

    2014-03-01

    Traditionally, water quality guidelines/criteria are based on lethality tests where results are expressed as a function of waterborne concentrations (e.g. LC50). However, there is growing interest in the use of uptake and binding relationships, such as biotic ligand models (BLM), and in bioaccumulation parameters, such as critical body residue values (e.g. CBR50), to predict metal toxicity in aquatic organisms. Nevertheless, all these approaches only protect species against physiological death (e.g. mortality, failed recruitment), and do not consider ecological death which can occur at much lower concentrations when the animal cannot perform normal behaviours essential for survival. Therefore, we investigated acute (96 h) Ni toxicity in two freshwater fish species, the round goby (Neogobius melanostomus) and rainbow trout (Oncorhynchus mykiss) and compared LC, BLM, and CBR parameters for various organs, as well as behavioural responses (spontaneous activity). In general, round goby were more sensitive. Ni bioaccumulation displayed Michaelis-Menten kinetics in most tissues, and round goby gills had lower Kd (higher binding affinity) but similar Bmax (binding site density) values relative to rainbow trout gills. Round goby also accumulated more Ni than did trout in most tissues at a given exposure concentration. Organ-specific 96 h acute CBR values tended to be higher in round goby but 96 h acute CBR50 and CBR10 values in the gills were very similar in the two species. In contrast, LC50 and LC10 values were significantly higher in rainbow trout. With respect to BLM parameters, gill log KNiBL values for bioaccumulation were higher by 0.4-0.8 log units than the log KNiBL values for toxicity in both species, and both values were higher in goby (more sensitive). Round goby were also more sensitive with respect to the behavioural response, exhibiting a significant decline of 63-75 % in movements per minute at Ni concentrations at and above only 8 % of the LC50 value

  11. Upgrading a piped water supply from intermittent to continuous delivery and association with waterborne illness: a matched cohort study in urban India.

    Science.gov (United States)

    Ercumen, Ayse; Arnold, Benjamin F; Kumpel, Emily; Burt, Zachary; Ray, Isha; Nelson, Kara; Colford, John M

    2015-10-01

    Intermittent delivery of piped water can lead to waterborne illness through contamination in the pipelines or during household storage, use of unsafe water sources during intermittencies, and limited water availability for hygiene. We assessed the association between continuous versus intermittent water supply and waterborne diseases, child mortality, and weight for age in Hubli-Dharwad, India. We conducted a matched cohort study with multivariate matching to identify intermittent and continuous supply areas with comparable characteristics in Hubli-Dharwad. We followed 3,922 households in 16 neighborhoods with children supply had no significant overall association with diarrhea (prevalence ratio [PR] = 0.93, 95% confidence interval [CI]: 0.83-1.04, p = 0.19), bloody diarrhea (PR = 0.78, 95% CI: 0.60-1.01, p = 0.06), or weight-for-age z-scores (Δz = 0.01, 95% CI: -0.07-0.09, p = 0.79) in children supply households had 37% lower prevalence of bloody diarrhea (PR = 0.63, 95% CI: 0.46-0.87, p-value for interaction = 0.03) than lower-income intermittent supply households; in higher-income households, there was no significant association between continuous versus intermittent supply and child diarrheal illnesses. Continuous supply areas also had 42% fewer households with ≥1 reported case of typhoid fever (cumulative incidence ratio [CIR] = 0.58, 95% CI: 0.41-0.78, p = 0.001) than intermittent supply areas. There was no significant association with hepatitis, cholera, or mortality of children supply areas. The major limitations of our study were the potential for unmeasured confounding given the observational design and measurement bias from differential reporting of health symptoms given the nonblinded treatment. However, there was no significant difference in the prevalence of the negative control outcomes between study groups that would suggest undetected confounding or measurement bias. Continuous water supply had no significant overall association with diarrheal

  12. Upgrading a Piped Water Supply from Intermittent to Continuous Delivery and Association with Waterborne Illness: A Matched Cohort Study in Urban India

    Science.gov (United States)

    Ercumen, Ayse; Arnold, Benjamin F.; Kumpel, Emily; Burt, Zachary; Ray, Isha; Nelson, Kara; Colford, John M.

    2015-01-01

    Background Intermittent delivery of piped water can lead to waterborne illness through contamination in the pipelines or during household storage, use of unsafe water sources during intermittencies, and limited water availability for hygiene. We assessed the association between continuous versus intermittent water supply and waterborne diseases, child mortality, and weight for age in Hubli-Dharwad, India. Methods and Findings We conducted a matched cohort study with multivariate matching to identify intermittent and continuous supply areas with comparable characteristics in Hubli-Dharwad. We followed 3,922 households in 16 neighborhoods with children supply had no significant overall association with diarrhea (prevalence ratio [PR] = 0.93, 95% confidence interval [CI]: 0.83–1.04, p = 0.19), bloody diarrhea (PR = 0.78, 95% CI: 0.60–1.01, p = 0.06), or weight-for-age z-scores (Δz = 0.01, 95% CI: −0.07–0.09, p = 0.79) in children supply households had 37% lower prevalence of bloody diarrhea (PR = 0.63, 95% CI: 0.46–0.87, p-value for interaction = 0.03) than lower-income intermittent supply households; in higher-income households, there was no significant association between continuous versus intermittent supply and child diarrheal illnesses. Continuous supply areas also had 42% fewer households with ≥1 reported case of typhoid fever (cumulative incidence ratio [CIR] = 0.58, 95% CI: 0.41–0.78, p = 0.001) than intermittent supply areas. There was no significant association with hepatitis, cholera, or mortality of children supply areas. The major limitations of our study were the potential for unmeasured confounding given the observational design and measurement bias from differential reporting of health symptoms given the nonblinded treatment. However, there was no significant difference in the prevalence of the negative control outcomes between study groups that would suggest undetected confounding or measurement bias. Conclusions Continuous water supply

  13. Early outbreak detection by linking health advice line calls to water distribution areas retrospectively demonstrated in a large waterborne outbreak of cryptosporidiosis in Sweden

    Directory of Open Access Journals (Sweden)

    Pär Bjelkmar

    2017-04-01

    Full Text Available Abstract Background In the winter and spring of 2011 a large outbreak of cryptosporidiosis occurred in Skellefteå municipality, Sweden. This study summarizes the outbreak investigation in terms of outbreak size, duration, clinical characteristics, possible source(s and the potential for earlier detection using calls to a health advice line. Methods The investigation included two epidemiological questionnaires and microbial analysis of samples from patients, water and other environmental sources. In addition, a retrospective study based on phone calls to a health advice line was performed by comparing patterns of phone calls between different water distribution areas. Results Our analyses showed that approximately 18,500 individuals were affected by a waterborne outbreak of cryptosporidiosis in Skellefteå in 2011. This makes it the second largest outbreak of cryptosporidiosis in Europe to date. Cryptosporidium hominis oocysts of subtype IbA10G2 were found in patient and sewage samples, but not in raw water or in drinking water, and the initial contamination source could not be determined. The outbreak went unnoticed to authorities for several months. The analysis of the calls to the health advice line provides strong indications early in the outbreak that it was linked to a particular water treatment plant. Conclusions We conclude that an earlier detection of the outbreak by linking calls to a health advice line to water distribution areas could have limited the outbreak substantially.

  14. An immunomagnetic separation-reverse transcription polymerase chain reaction (IMS-RT-PCR) test for sensitive and rapid detection of viable waterborne Cryptosporidium parvum.

    Science.gov (United States)

    Hallier-Soulier, Sylvie; Guillot, Emmanuelle

    2003-07-01

    The public health problem posed by the waterborne parasite Cryptosporidium parvum incited the water supply industry to develop very accurate analytical tools able to assess the presence of viable oocysts in drinking water. In this study, we report the development of a viability assay for C. parvum oocysts based on immunomagnetic separation and reverse transcription polymerase chain reaction (IMS-RT-PCR). The detection limit of the IMS-RT-PCR assay, which targets the hsp70 heat shock-induced mRNA, was in the range of ten viable oocysts per 100-l tap water samples. Purified Cryptosporidium parvum oocysts were exposed to heating, freezing and three chemical disinfection treatments namely, chlorination, chlorine dioxide treatment and ozonation under conventional doses used in water treatment plants, then detected by IMS-PCR and IMS-RT-PCR. The results obtained by IMS-PCR showed that none of the treatments had an effect on oocyst detection. The inactivation of oocysts by boiling resulted in no RT-PCR signal. Chlorine as well as chlorine dioxide did not influence oocyst viability as determined by IMS-RT-PCR. Ozone more effectively inactivated oocysts. The IMS-RT-PCR assay in conjunction with IMS-PCR marks the development of a combined detection and viability test which can be used for drinking water quality control as well as for reliable evaluation of treatment efficiency.

  15. Development of a combined in vitro cell culture--quantitative PCR assay for evaluating the disinfection performance of pulsed light for treating the waterborne enteroparasite Giardia lamblia.

    Science.gov (United States)

    Garvey, Mary; Stocca, Alessia; Rowan, Neil

    2014-09-01

    Giardia lamblia is a flagellated protozoan parasite that is recognised as a frequent cause of water-borne disease in humans and animals. We report for the first time on the use of a combined in vitro HCT-8 cell culture-quantitative PCR assay for evaluating the efficacy of using pulsed UV light for treating G. lamblia parasites. Findings showed that current methods that are limited to using vital stains before and after cyst excystation are not appropriate for monitoring or evaluating cyst destruction post PUV-treatments. Use of the human ileocecal HCT-8 cell line was superior to that of the human colon Caco-2 cell line for in vitro culture and determining PUV sensitivity of treated cysts. G. lamblia cysts were also shown to be more resistant to PUV irradiation compared to treating similar numbers of Cryptosporidium parvum oocysts. These observations also show that the use of this HCT-8 cell culture assay may replace use of animal models for determining disinfection performances of PUV for treating both C. parvum and G. lamblia. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. A waterborne outbreak and detection of cryptosporidium oocysts in drinking water of an older high-rise apartment complex in seoul.

    Science.gov (United States)

    Cho, Eun-Joo; Yang, Jin-Young; Lee, Eun-Sook; Kim, Se-Chul; Cha, So-Yang; Kim, Sung-Tek; Lee, Man-Ho; Han, Sun-Hee; Park, Young-Sang

    2013-08-01

    From May to June 2012, a waterborne outbreak of 124 cases of cryptosporidiosis occurred in the plumbing systems of an older high-rise apartment complex in Seoul, Republic of Korea. The residents of this apartment complex had symptoms of watery diarrhea and vomiting. Tap water samples in the apartment complex and its adjacent buildings were collected and tested for 57 parameters under the Korean Drinking Water Standards and for additional 11 microbiological parameters. The microbiological parameters included total colony counts, Clostridium perfringens, Enterococcus, fecal streptococcus, Salmonella, Shigella, Pseudomonas aeruginosa, Cryptosporidium oocysts, Giardia cysts, total culturable viruses, and Norovirus. While the tap water samples of the adjacent buildings complied with the Korean Drinking Water Standards for all parameters, fecal bacteria and Cryptosporidium oocysts were detected in the tap water samples of the outbreak apartment complex. It turned out that the agent of the disease was Cryptosporidium parvum. The drinking water was polluted with sewage from a septic tank in the apartment complex. To remove C. parvum oocysts, we conducted physical processes of cleaning the water storage tanks, flushing the indoor pipes, and replacing old pipes with new ones. Finally we restored the clean drinking water to the apartment complex after identification of no oocysts.

  17. Hospitalization records as a tool for evaluating performance of food- and water-borne disease surveillance systems: a Massachusetts case study.

    Directory of Open Access Journals (Sweden)

    Siobhan M Mor

    Full Text Available We outline a framework for evaluating food- and water-borne surveillance systems using hospitalization records, and demonstrate the approach using data on salmonellosis, campylobacteriosis and giardiasis in persons aged ≥65 years in Massachusetts. For each infection, and for each reporting jurisdiction, we generated smoothed standardized morbidity ratios (SMR and surveillance to hospitalization ratios (SHR by comparing observed surveillance counts with expected values or the number of hospitalized cases, respectively. We examined the spatial distribution of SHR and related this to the mean for the entire state. Through this approach municipalities that deviated from the typical experience were identified and suspected of under-reporting. Regression analysis revealed that SHR was a significant predictor of SMR, after adjusting for population age-structure. This confirms that the spatial "signal" depicted by surveillance is in part influenced by inconsistent testing and reporting practices since municipalities that reported fewer cases relative to the number of hospitalizations had a lower relative risk (as estimated by SMR. Periodic assessment of SHR has potential in assessing the performance of surveillance systems.

  18. Hospitalization records as a tool for evaluating performance of food- and water-borne disease surveillance systems: a Massachusetts case study.

    Science.gov (United States)

    Mor, Siobhan M; DeMaria, Alfred; Naumova, Elena N

    2014-01-01

    We outline a framework for evaluating food- and water-borne surveillance systems using hospitalization records, and demonstrate the approach using data on salmonellosis, campylobacteriosis and giardiasis in persons aged ≥65 years in Massachusetts. For each infection, and for each reporting jurisdiction, we generated smoothed standardized morbidity ratios (SMR) and surveillance to hospitalization ratios (SHR) by comparing observed surveillance counts with expected values or the number of hospitalized cases, respectively. We examined the spatial distribution of SHR and related this to the mean for the entire state. Through this approach municipalities that deviated from the typical experience were identified and suspected of under-reporting. Regression analysis revealed that SHR was a significant predictor of SMR, after adjusting for population age-structure. This confirms that the spatial "signal" depicted by surveillance is in part influenced by inconsistent testing and reporting practices since municipalities that reported fewer cases relative to the number of hospitalizations had a lower relative risk (as estimated by SMR). Periodic assessment of SHR has potential in assessing the performance of surveillance systems.

  19. Surveillance for waterborne disease and outbreaks associated with drinking water and water not intended for drinking--United States, 2005-2006.

    Science.gov (United States)

    Yoder, Jonathan; Roberts, Virginia; Craun, Gunther F; Hill, Vincent; Hicks, Lauri A; Alexander, Nicole T; Radke, Vince; Calderon, Rebecca L; Hlavsa, Michele C; Beach, Michael J; Roy, Sharon L

    2008-09-12

    Since 1971, CDC, the U.S. Environmental Protection Agency (EPA), and the Council of State and Territorial Epidemiologists have maintained a collaborative Waterborne Disease and Outbreak Surveillance System (WBDOSS) for collecting and reporting data related to occurrences and causes of waterborne-disease outbreaks (WBDOs) and cases of waterborne disease. This surveillance system is the primary source of data concerning the scope and effects of waterborne disease in the United States. Data presented summarize 28 WBDOs that occurred during January 2005--December 2006 and four previously unreported WBDOs that occurred during 1979--2002. The surveillance system includes data on WBDOs associated with recreational water, drinking water, water not intended for drinking (WNID) (excluding recreational water), and water use of unknown intent. Public health departments in the states, territories, localities, and Freely Associated States (FAS) (i.e., the Republic of the Marshall Islands, the Federated States of Micronesia, and the Republic of Palau, formerly parts of the U.S.-administered Trust Territory of the Pacific Islands) are primarily responsible for detecting and investigating WBDOs and voluntarily reporting them to CDC by a standard form. Only cases and outbreaks associated with drinking water, WNID (excluding recreational water), and water of unknown intent (WUI) are summarized in this report. Cases and outbreaks associated with recreational water are reported in a separate Surveillance Summary. Fourteen states reported 28 WBDOs that occurred during 2005--2006: a total of 20 were associated with drinking water, six were associated with WNID, and two were associated with WUI. The 20 drinking water-associated WBDOs caused illness among an estimated 612 persons and were linked to four deaths. Etiologic agents were identified in 18 (90.0%) of the drinking water-associated WBDOs. Among the 18 WBDOs with identified pathogens, 12 (66.7%) were associated with bacteria, three

  20. Comparison of different solar reactors for household disinfection of drinking water in developing countries: evaluation of their efficacy in relation to the waterborne enteropathogen Cryptosporidium parvum.

    Science.gov (United States)

    Gómez-Couso, H; Fontán-Sainz, M; Navntoft, C; Fernández-Ibáñez, P; Ares-Mazás, E

    2012-11-01

    Solar water disinfection (SODIS) is a type of treatment that can significantly improve the microbiological quality of drinking water at household level and therefore prevent waterborne diseases in developing countries. Cryptosporidium parvum is an obligate protozoan parasite responsible for the diarrhoeal disease cryptosporidiosis in humans and animals. Recently, this parasite has been selected by the WHO as a reference pathogen for protozoan parasites in the evaluation of household water treatment options. In this study, the field efficacy of different static solar reactors [1.5 l transparent plastic polyethylene terephthalate (PET) bottles as well as 2.5 l borosilicate glass and 25 l methacrylate reactors fitted with compound parabolic concentrators (CPC)] for solar disinfection of turbid waters experimentally contaminated with C. parvum oocysts was compared. Potential oocyst viability was determined by inclusion/exclusion of the fluorogenic vital dye propidium iodide. The results demonstrate that static solar reactors fitted with CPCs are an excellent alternative to the conventional SODIS method with PET bottles. These reactors improved the efficacy of the SODIS method by enabling larger volumes of water to be treated and, in some cases, the C. parvum oocysts were rendered totally unviable, minimising the negative effects of turbidity. Copyright © 2012 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

  1. The effect of pyrite on Escherichia coli in water: proof-of-concept for the elimination of waterborne bacteria by reactive minerals.

    Science.gov (United States)

    Friedlander, Lonia R; Puri, Neha; Schoonen, Martin A A; Wali Karzai, A

    2015-03-01

    We present proof-of-concept results for the elimination of waterborne bacteria by reactive minerals. We exposed Escherichia coli MG1655 suspended in water to the reactive mineral pyrite (FeS₂) at room temperature and ambient light. This slurry eliminates 99.9% of bacteria in fewer than 4 hours. We also exposed Escherichia coli to pyrite leachate (supernatant liquid from slurry after 24 hours), which eliminates 99.99% of bacteria over the same time-scale. Unlike SOlar water DISinfection (SODIS), our results do not depend on the presence of ultraviolet (UV) light. We confirmed this by testing proposed SODIS additive and known photo-catalyst anatase (TiO₂) for antibacterial properties and found that, in contrast to pyrite, it does not eliminate E. coli under our experimental conditions. Previous investigations of naturally antibiotic minerals have focused on the medical applications of antibiotic clays, and thus have not been conducted under experimental conditions resembling those found in water purification. In our examination of the relevant literature, we have not found previously reported evidence for the use of reactive minerals in water sanitization. The results from this proof-of-concept experiment may have important implications for future directions in household water purification research.

  2. Protective effect of high alkalinity against the deleterious effects of chronic waterborne cadmium exposure on the detection of alarm cues by juvenile silver catfish (Rhamdia quelen).

    Science.gov (United States)

    Kochhann, Daiani; Benaduce, Ana Paula S; Copatti, Carlos E; Lorenzatto, Karina R; Mesko, Márcia F; Flores, Erico M M; Dressler, Valderi L; Baldisserotto, Bernardo

    2009-05-01

    The objective of the present study was to analyze the effect of chronic cadmium (Cd) exposure at two alkalinity levels (63 and 92 mg l(-1) CaCO(3)) on the antipredatory behavior of juvenile silver catfish (Rhamdia quelen) exposed to conspecific skin extract and predator odor. At an alkalinity of 63 mg l(-1) CaCO(3), 30 days of exposure to either 4.5 or 8.0 microg l(-1) Cd impaired the catfish's antipredatory response to alarm cues. However, silver catfish exposed to 4.5 microg l(-1) Cd at an alkalinity of 92 mg l(-1) CaCO(3) responded to skin extract and predator odor. In catfish exposed to 8.0 microg l(-1) Cd at the same alkalinity, only the number of feeding bites decreased, and this occurred only for specimens exposed to predator odor. Our results show that higher alkalinity protected against the deleterious effects of Cd on alarm cue detection but only in the larvae exposed to the lowest waterborne Cd level.

  3. Comparison of phase structures and surface free energy values for the coatings synthesised from linear polyurethanes and from waterborne polyurethane cationomers.

    Science.gov (United States)

    Król, Piotr; Król, Bożena; Pielichowska, Kinga; Pikus, Stanisław

    2011-10-01

    WAXS, DSC and AFM methods were employed to compare phase structures of the coatings obtained from waterborne polyurethane cationomers which had been synthesised in the reaction of some diisocyanates (MDI, IPDI, TDI and HDI) with polyoxyethylene glycols (M = 600 and 2,000) and butane1,4-diol or N-methyl- or N-butyldiethanolamine and 2,2,3,3-tetrafluoro-1,4-butanediol. The structures were also analysed of the coatings derived from linear polyurethanes which had been synthesised on the basis of similar raw materials. Better rigidity was found for generally amorphous cationomer coats. Changes were discussed in the surface free energy (SFE) values and in their components, as calculated independently with the use of the van Oss-Good and Owens-Wendt methods. Polyurethane coats turned out more hydrophobic as compared to cationomer ones. In both coat types, fluorine incorporated into cationomers contributed to lower SFE values: from 50 down to about 30 mJ/m(2).

  4. Overcoming Breastfeeding Challenges

    Medline Plus

    Full Text Available ... Only Natural email updates. Enter email address Submit Home > It's Only Natural > Overcoming challenges Overcoming breastfeeding challenges YouTube embed video: YouTube embed video: https:// ...

  5. National Drug IQ Challenge

    Science.gov (United States)

    ... Reto nacional del coeficiente intelectual (CI) sobre las drogas y el alcohol 2016 National Drug IQ Challenge ... Reto nacional del coeficiente intelectual (CI) sobre las drogas y el alcohol 2015 National Drug IQ Challenge ...

  6. Upgrading a piped water supply from intermittent to continuous delivery and association with waterborne illness: a matched cohort study in urban India.

    Directory of Open Access Journals (Sweden)

    Ayse Ercumen

    2015-10-01

    Full Text Available Intermittent delivery of piped water can lead to waterborne illness through contamination in the pipelines or during household storage, use of unsafe water sources during intermittencies, and limited water availability for hygiene. We assessed the association between continuous versus intermittent water supply and waterborne diseases, child mortality, and weight for age in Hubli-Dharwad, India.We conducted a matched cohort study with multivariate matching to identify intermittent and continuous supply areas with comparable characteristics in Hubli-Dharwad. We followed 3,922 households in 16 neighborhoods with children <5 y old, with four longitudinal visits over 15 mo (Nov 2010-Feb 2012 to record caregiver-reported health outcomes (diarrhea, highly credible gastrointestinal illness, bloody diarrhea, typhoid fever, cholera, hepatitis, and deaths of children <2 y old and, at the final visit, to measure weight for age for children <5 y old. We also collected caregiver-reported data on negative control outcomes (cough/cold and scrapes/bruises to assess potential bias from residual confounding or differential measurement error. Continuous supply had no significant overall association with diarrhea (prevalence ratio [PR] = 0.93, 95% confidence interval [CI]: 0.83-1.04, p = 0.19, bloody diarrhea (PR = 0.78, 95% CI: 0.60-1.01, p = 0.06, or weight-for-age z-scores (Δz = 0.01, 95% CI: -0.07-0.09, p = 0.79 in children <5 y old. In prespecified subgroup analyses by socioeconomic status, children <5 y old in lower-income continuous supply households had 37% lower prevalence of bloody diarrhea (PR = 0.63, 95% CI: 0.46-0.87, p-value for interaction = 0.03 than lower-income intermittent supply households; in higher-income households, there was no significant association between continuous versus intermittent supply and child diarrheal illnesses. Continuous supply areas also had 42% fewer households with ≥1 reported case of typhoid fever (cumulative incidence

  7. Biocoatings: a new challenge for environmental biotechnology

    OpenAIRE

    Cortez, Susana; Nicolau, Ana; Michael C. Flickinger; Mota, M

    2017-01-01

    Adhesive biocatalytic coatings (biocoatings) have a nanoporous microstructure generated by partially coalesced waterborne polymer particles that entrap highly concentrated living cells in a dry state stabilized by carbohydrate osmo-protectants. Biocoatings can be deposited by high speed coating technologies, aerosol delivery or ink-jet printed in multilayered, patterned coatings on flexible nonporous or nonwoven substrates, preserving 1010 to 1012 non-growing viable microorganisms per m2 in 2...

  8. Perch, Perca fluviatilis show a directional preference for, but do not increase attacks toward, prey in response to water-borne cortisol

    Directory of Open Access Journals (Sweden)

    Lindsay J. Henderson

    2017-10-01

    Full Text Available In freshwater environments, chemosensory cues play an important role in predator-prey interactions. Prey use a variety of chemosensory cues to detect and avoid predators. However, whether predators use the chemical cues released by disturbed or stressed prey has received less attention. Here we tested the hypothesis that the disturbance cue cortisol, in conjunction with visual cues of prey, elevates predatory behavior. We presented predators (perch, Perca fluviatilis with three chemosensory choice tests and recorded their location, orientation, and aggressive behavior. We compared the responses of predators when provided with (i visual cues of prey only (two adjacent tanks containing sticklebacks; (ii visual and natural chemical cues of prey vs. visual cues only; and (iii visual cues of prey with cortisol vs. visual cues only. Perch spent a significantly higher proportion of time in proximity to prey, and orientated toward prey more, when presented with a cortisol stimulus plus visual cues, relative to presentations of visual and natural chemical cues of prey, or visual cues of prey only. There was a trend that perch directed a higher proportion of predatory behaviors (number of lunges toward sticklebacks when presented with a cortisol stimulus plus visual cues, relative to the other chemosensory conditions. But they did not show a significant increase in total predatory behavior in response to cortisol. Therefore, it is not clear whether water-borne cortisol, in conjunction with visual cues of prey, affects predatory behavior. Our results provide evidence that cortisol could be a source of public information about prey state and/or disturbance, but further work is required to confirm this.

  9. Influence of hardness on the bioavailability of silver to a freshwater snail after waterborne exposure to silver nitrate and silver nanoparticles

    Science.gov (United States)

    Stoiber, Tasha L.; Croteau, Marie-Noele; Romer, Isabella; Tejamaya, Mila; Lead, Jamie R.; Luoma, Samuel N.

    2015-01-01

    The release of Ag nanoparticles (AgNPs) into the aquatic environment is likely, but the influence of water chemistry on their impacts and fate remains unclear. Here, we characterize the bioavailability of Ag from AgNO3 and from AgNPs capped with polyvinylpyrrolidone (PVP AgNP) and thiolated polyethylene glycol (PEG AgNP) in the freshwater snail, Lymnaea stagnalis, after short waterborne exposures. Results showed that water hardness, AgNP capping agents, and metal speciation affected the uptake rate of Ag from AgNPs. Comparison of the results from organisms of similar weight showed that water hardness affected the uptake of Ag from AgNPs, but not that from AgNO3. Transformation (dissolution and aggregation) of the AgNPs was also influenced by water hardness and the capping agent. Bioavailability of Ag from AgNPs was, in turn, correlated to these physical changes. Water hardness increased the aggregation of AgNPs, especially for PEG AgNPs, reducing the bioavailability of Ag from PEG AgNPs to a greater degree than from PVP AgNPs. Higher dissolved Ag concentrations were measured for the PVP AgNPs (15%) compared to PEG AgNPs (3%) in moderately hard water, enhancing Ag bioavailability of the former. Multiple drivers of bioavailability yielded differences in Ag influx between very hard and deionized water where the uptake rate constants (kuw, l g-1 d-1 ± SE) varied from 3.1 ± 0.7 to 0.2 ± 0.01 for PEG AgNPs and from 2.3 ± 0.02 to 1.3 ± 0.01 for PVP AgNPs. Modeling bioavailability of Ag from NPs revealed that Ag influx into L. stagnalis comprised uptake from the NPs themselves and from newly dissolved Ag.

  10. Destination specific risks of acquisition of notifiable food- and waterborne infections or sexually transmitted infections among Finnish international travellers, 1995-2015.

    Science.gov (United States)

    Zöldi, Viktor; Sane, Jussi; Kantele, Anu; Rimhanen-Finne, Ruska; Salmenlinna, Saara; Lyytikäinen, Outi

    2017-10-10

    Overnight international travels made by Finns more than doubled during 1995-2015. To estimate risks and observe trends of travel-related notifiable sexually transmitted and food- and water-borne infections (STIs and FWIs) among travellers, we analysed national reports of gonorrhoea, syphilis, hepatitis A, shigellosis, campylobacteriosis and salmonellosis cases and related them to travel statistics. Cases notified as travel-related to the Finnish infectious diseases register were used as numerators and overnight stays of Statistics Finland surveys as denominator. We calculated overall risks (per 100,000 travellers) and assessed trends (using regression model) in various geographic regions. Of all travel-related cases during 1995-2015, 2304 were STIs and 70,929 FWIs. During 2012-2015, Asia-Oceania showed highest risk estimates for gonorrhoea (11.0; 95%CI, 9.5-13), syphilis (1.4; 0.93-2.1), salmonellosis (157; 151-164), and campylobacteriosis (135; 129-141), and Africa for hepatitis A (4.5; 2.5-7.9), and shigellosis (35; 28-43). When evaluating at country level, the highest risks of infections was found in Thailand, except for hepatitis A ranking Hungary the first. During 2000-2011, significantly decreasing trends occurred for most FWIs particularly in the European regions and for STIs in Russia-Baltics. Our findings can be used in targeting pre-travel advice, which should also cover those visiting Thailand or European hepatitis A risk areas. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Subcellular partitioning of cadmium in the freshwater bivalve, Pyganodon grandis, after separate short-term exposures to waterborne or diet-borne metal

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Sophie; Hare, Landis [INRS-Eau, Terre et Environnement, Universite du Quebec, 490 rue de la Couronne, Quebec, QC, G1K 9A9 (Canada); Campbell, Peter G.C., E-mail: peter.campbell@ete.inrs.ca [INRS-Eau, Terre et Environnement, Universite du Quebec, 490 rue de la Couronne, Quebec, QC, G1K 9A9 (Canada)

    2010-11-15

    The dynamics of cadmium uptake and subcellular partitioning were studied in laboratory experiments conducted on Pyganodon grandis, a freshwater unionid bivalve that shows promise as a biomonitor for metal pollution. Bivalves were collected from an uncontaminated lake, allowed to acclimate to laboratory conditions ({>=}25 days), and then either exposed to a low, environmentally relevant, concentration of dissolved Cd (5 nM; 6, 12 and 24 h), or fed Cd-contaminated algae ({approx}70 nmol Cd g{sup -1} dry weight; 4 x 4 h). In this latter case, the bivalves were allowed to depurate for up to 8 days after the end of the feeding phase. As anticipated, the gills were the main target organ during the aqueous Cd exposure whereas the intestine was the initial site of Cd accumulation during the dietary exposure; during the subsequent depuration period, the dietary Cd accumulated in both the digestive gland and in the gills. For the gills, the distribution of Cd among the subcellular fractions (i.e., granules > heat-denatured proteins (HDP) {approx} heat-stable proteins (HSP) > mitochondria {approx} lysosomes + microsomes) was insensitive to the exposure route; both waterborne and diet-borne Cd ended up largely bound to the granule fraction. The subcellular distribution of Cd in the digestive gland differed markedly from that in the gills (HDP > HSP {approx} granules {approx} mitochondria > lysosomes + microsomes), but as in the case of the gills, this distribution was relatively insensitive to the exposure route. For both the gills and the digestive gland, the subcellular distributions of Cd differed from those observed in native bivalves that are chronically exposed to Cd in the field - in the short-term experimental exposures of P. grandis, metal detoxification was less effective than in chronically exposed native bivalves.

  12. Prevalence and impact of water-borne zoonotic pathogens in water, cattle and humans in selected villages in Dodoma Rural and Bagamoyo districts, Tanzania

    Science.gov (United States)

    Kusiluka, L. J. M.; Karimuribo, E. D.; Mdegela, R. H.; Luoga, E. J.; Munishi, P. K. T.; Mlozi, M. R. S.; Kambarage, D. M.

    A study on the prevalence of water-borne zoonotic pathogens in water, cattle and humans was conducted in six villages in Dodoma Rural (5) and Bagamoyo (1) districts, Tanzania. Water sources were screened for faecal coliform organisms, thermophilic Campylobacter, Salmonella, Cryptosporidium and Giardia. Faecal samples from cattle and humans were also analysed for the above specific pathogens. Results indicate that 70.8% ( n = 48) of the water sources screened were contaminated with faecal coliform organisms. Water sources in two villages, one each in Dodoma Rural and Bagamoyo districts were also contaminated with Giardia lamblia. The overall prevalence of Campylobacter jejuni in cattle in the two study areas was 2.3% ( n = 942) and at least one animal in each village was infected with C. jejuni. Cryptosporidium parvum was detected in 0.5% ( n = 942) of the cattle examined in three villages in Dodoma district. Salmonella spp. was demonstrated in only 1.4% ( n = 144) of the cattle in Chalinze village in Dodoma Rural district while G. lamblia was only detected in 1.5% ( n = 202) of the animals examined in Chamakweza village in Bagamoyo district. Nine (1.9%) of the people screened at three heath centres in the study areas were infected with C. jejuni while 3.7% ( n = 484) of the people had C. parvum oocysts. G. lamblia was detected in 2.5% of the 202 people screened at the Chalinze health centre in Bagamoyo district. Analysis of the secondary data revealed that clinical complaints related to enteric diseases were prevalent in humans in the two areas throughout the year and the prevalence varied from about 1% to 25% in both <5 years and ⩾5 years patients. In conclusion, this study has highlighted the possible public health risks, which may be associated with keeping of animals and sharing of water sources between humans and animals.

  13. mRNA Expression and activity of ion-transporting proteins in gills of the blue crab Callinectes sapidus: effects of waterborne copper.

    Science.gov (United States)

    Martins, Camila M G; Almeida, Daniela Volcan; Marins, Luis Fernando Fernandes; Bianchini, Adalto

    2011-01-01

    Waterborne Cu effects on the transcription of genes encoding ion-transporting proteins and the activities of these proteins were evaluated in gills of the blue crab Callinectes sapidus acclimated to diluted (2‰) and full (30‰) seawater. Crabs were exposed (96 h) to an environmentally relevant concentration of dissolved Cu (0.78 µM) and had their posterior (osmoregulating) gills dissected for enzymatic and molecular analysis. Endpoints analyzed were the activity of key enzymes involved in crab osmoregulation (sodium-potassium adenosine triphosphatase [Na(+)/K(+)-ATPase], hydrogen adenosine triphosphatase [H(+)-ATPase], and carbonic anhydrase [CA]) and the mRNA expression of genes encoding these enzymes and the sodium-potassium-chloride (Na(+)/K(+)/2Cl⁻) cotransporter. Copper effects were observed only in crabs acclimated to diluted seawater (hyperosmoregulating crabs) and were associated with an inhibition of the expression of mRNA of genes encoding the Na(+)/K(+)-ATPase and the Na(+)/K(+)/2Cl⁻ cotransporter. However, Cu did not affect Na(+)/K(+)-ATPase activity, indicating that the gene transcription is downregulated before a significant inhibition of the enzyme activity can be observed. This also suggests the existence of a compensatory response of this enzyme to prevent osmoregulatory disturbances after short-term exposure to environmentally relevant Cu concentrations. These findings suggest that Cu is a potential ionoregulatory toxicant in blue crabs C. sapidus acclimated to low salinity. The lack of Cu effect on blue crabs acclimated to full seawater would be due to the reduced ion uptake needed for the regulation of the hemolymph osmotic concentration in full seawater (30‰). Also, this could be explained considering the lower bioavailability of toxic Cu (free ion) associated with the higher ionic content and dissolved organic matter concentration in high salinity (30‰) than in diluted seawater (2‰). © 2010 SETAC.

  14. The Use of Waterborne Resistivity Profiling to Quantify Hydraulic Conductivity of 150 Kilometers of Streambed in the Mississippi River Alluvial Plain

    Science.gov (United States)

    Miller, B. V.; Wallace, D. S.; Kress, W. H.

    2016-12-01

    In fresh water aquifers, the geoelectric resistivity of earth materials commonly has a positive correlation with hydraulic conducitivity. In June of 2016, the US Geological Survey used waterborne continuous-resistivity profiling to map the shallow (geoelectrical properties as a proxy for streambed hydraulic conductivity for reaches of the Tallahatchie (60km), Quiver (48km), and Sunflower (39km) Rivers in central Mississippi. Two-dimensional vertical profiles of resistivity were used to identify differences in geoelectrical structure of the streambed specifically between the larger, more-incised Tallahatchie River and the smaller, less-incised Quiver and Sunflower Rivers. Preliminary results show that mean apparent resistivity (Rhoa) on the Tallahatchie is 65 ohmm higher than on the Quiver and Sunflower Rivers. This difference in mean Rhoa is affected by lower resistivity water in the two smaller streams. However, lithologic differences among the streams are discernable in the variability of Rhoa. Distribution of Rhoa along the river profile is highly variable in the Sunflower River, with a standard deviation of 38 ohmm. This is about 52% greater than that of the Quiver at 23 ohmm and Tallahatchie at 27ohmm. Although the Tallhatchie and Quiver have significantly different water column resisitivities, the variability between the two streams is more similar than the highly variable Sunflower. In regional groundwater flow models, the hydraulic conductivity of streambed materials is typically an estimated parameter because of difficulty in obtaining a data-supported value in real-world conditions. The resistivities from this work will be used to scale streambed hydraulic conductivity for incorporation into the hydrogeological framework of a regional groundwater flow model, which may be used to guide policy decisions. Future studies will continue the development of geophysical methods to improve this model.

  15. Blastocystis infection in Malaysia: Evidence of waterborne and human-to-human transmissions among the Proto-Malay, Negrito and Senoi tribes of Orang Asli

    Directory of Open Access Journals (Sweden)

    Anuar Tengku Shahrul

    2013-02-01

    Full Text Available Abstract Background Blastocystis has been described as the most common intestinal parasite in humans and has an increased impact on public health. However, the transmission of this parasite has not been conclusively determined. Methods To contribute to a better comprehension of the epidemiology of this infection, a cross-sectional survey aimed at providing the first documented data on the prevalence and risk factors associated with Blastocystis infection was carried out among three Orang Asli tribes (Proto-Malay, Negrito and Senoi in selected villages at Negeri Sembilan, Perak and Pahang, Peninsular Malaysia. Faecal samples were examined by formalin-ether sedimentation and trichrome staining techniques. Results Of 500 individuals, 20.4% (102 were detected positive for Blastocystis; 13.3% (20/150 of Proto-Malays, 21.6% (30/139 of Negritos and 24.7% (52/211 of Senois were positive for Blastocystis, respectively. The positive cases showed a decrease with increasing age and most of the positive cases were observed in individuals less than 15 years old. Multivariate analysis confirmed that drinking untreated water and the presence of other family members infected with Blastocystis were significant risk factors of infection among the three tribes and overall population studied. Conclusion Essentially, the findings highlighted that Blastocystis infection is prevalent among Orang Asli communities in Malaysia. Further studies using molecular approaches to distinguish the subtype of Blastocystis is needed. The present study also revealed that this infection may be transmitted through waterborne and human-to-human contact. Therefore, interventions with the provision of clean water supply for the communities and health education especially to the parents are urgently required.

  16. Blastocystis infection in Malaysia: evidence of waterborne and human-to-human transmissions among the Proto-Malay, Negrito and Senoi tribes of Orang Asli.

    Science.gov (United States)

    Anuar, Tengku Shahrul; Ghani, Mohamed Kamel Abdul; Azreen, Siti Nor; Salleh, Fatmah Md; Moktar, Norhayati

    2013-02-22

    Blastocystis has been described as the most common intestinal parasite in humans and has an increased impact on public health. However, the transmission of this parasite has not been conclusively determined. To contribute to a better comprehension of the epidemiology of this infection, a cross-sectional survey aimed at providing the first documented data on the prevalence and risk factors associated with Blastocystis infection was carried out among three Orang Asli tribes (Proto-Malay, Negrito and Senoi) in selected villages at Negeri Sembilan, Perak and Pahang, Peninsular Malaysia. Faecal samples were examined by formalin-ether sedimentation and trichrome staining techniques. Of 500 individuals, 20.4% (102) were detected positive for Blastocystis; 13.3% (20/150) of Proto-Malays, 21.6% (30/139) of Negritos and 24.7% (52/211) of Senois were positive for Blastocystis, respectively. The positive cases showed a decrease with increasing age and most of the positive cases were observed in individuals less than 15 years old. Multivariate analysis confirmed that drinking untreated water and the presence of other family members infected with Blastocystis were significant risk factors of infection among the three tribes and overall population studied. Essentially, the findings highlighted that Blastocystis infection is prevalent among Orang Asli communities in Malaysia. Further studies using molecular approaches to distinguish the subtype of Blastocystis is needed. The present study also revealed that this infection may be transmitted through waterborne and human-to-human contact. Therefore, interventions with the provision of clean water supply for the communities and health education especially to the parents are urgently required.

  17. Blastocystis infection in Malaysia: Evidence of waterborne and human-to-human transmissions among the Proto-Malay, Negrito and Senoi tribes of Orang Asli

    Science.gov (United States)

    2013-01-01

    Background Blastocystis has been described as the most common intestinal parasite in humans and has an increased impact on public health. However, the transmission of this parasite has not been conclusively determined. Methods To contribute to a better comprehension of the epidemiology of this infection, a cross-sectional survey aimed at providing the first documented data on the prevalence and risk factors associated with Blastocystis infection was carried out among three Orang Asli tribes (Proto-Malay, Negrito and Senoi) in selected villages at Negeri Sembilan, Perak and Pahang, Peninsular Malaysia. Faecal samples were examined by formalin-ether sedimentation and trichrome staining techniques. Results Of 500 individuals, 20.4% (102) were detected positive for Blastocystis; 13.3% (20/150) of Proto-Malays, 21.6% (30/139) of Negritos and 24.7% (52/211) of Senois were positive for Blastocystis, respectively. The positive cases showed a decrease with increasing age and most of the positive cases were observed in individuals less than 15 years old. Multivariate analysis confirmed that drinking untreated water and the presence of other family members infected with Blastocystis were significant risk factors of infection among the three tribes and overall population studied. Conclusion Essentially, the findings highlighted that Blastocystis infection is prevalent among Orang Asli communities in Malaysia. Further studies using molecular approaches to distinguish the subtype of Blastocystis is needed. The present study also revealed that this infection may be transmitted through waterborne and human-to-human contact. Therefore, interventions with the provision of clean water supply for the communities and health education especially to the parents are urgently required. PMID:23433099

  18. Millennium Challenge Account

    National Research Council Canada - National Science Library

    Tarnoff, Curt

    2008-01-01

    .... foreign aid initiative. The Millennium Challenge Account (MCA) provides assistance through a competitive selection process to developing nations that are pursing political and economic reforms in three areas...

  19. College and University Challenge

    Science.gov (United States)

    This EPA's Green Power Partnership Challenge tracks and recognizes U.S. colleges and universities recognizes the largest single green power users within each participating collegiate athletic conferences.

  20. The significance of water-borne heating for the reduction of emission of climate gases and power peaks in the electric power system; Energihandel og klimatiltak i Nord-Europa

    Energy Technology Data Exchange (ETDEWEB)

    Alm, Leif Kristian

    2001-12-01

    This work is connected with a Nordic cooperation on the development of methods for and analyses of energy and climate issues in Northern Europe. A regression model is used to separate out the temperature-dependent electricity consumption in Norway. The regression model is used to establish a duration curve for this part of the consumption. This provides a foundation for development of improved models for the use of thermal energy. It is pointed out that existing models are inadequate for the analysis of issues relating to water-borne heating.

  1. First Aid Challenge

    Science.gov (United States)

    Roman, Harry T.

    2011-01-01

    This article describes a challenge wherein students will be asked to design a portable first aid kit that is normally carried in a recreational vehicle (RV), but can also be hand-carried or backpacked off road for distances of approximately 1-2 miles. This can be a very practical challenge for the students because it touches everyone. Everybody…

  2. Overcoming Breastfeeding Challenges

    Medline Plus

    Full Text Available ... size | Print | Skip left navigation It's Only Natural Planning ahead Overcoming challenges Overcoming breastfeeding challenges Dealing with ... it into your life My breastfeeding story Partner resources ... U.S. Department of Health and Human Services 200 Independence Avenue, S.W. • Washington, DC ...

  3. Bilingual Education: Current Challenges.

    Science.gov (United States)

    Krashen, Stephen

    2000-01-01

    Examines current controversies and challenges in bilingual education, reviewing the case for bilingual education and the research supporting it. Makes suggestions for improving bilingual education, which include enriching the print environment and using heritage language development. Discusses research findings on challenges to bilingual…

  4. Hydrodynamics challenge problem

    Energy Technology Data Exchange (ETDEWEB)

    Hornung, R. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Keasler, J. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gokhale, M. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2011-06-09

    The hydrodynamics challenge problem represents a classical HPC physics problem, namely high deformation event modeling via Lagrangian shock hydrodynamics. This challenge problem solves the Sedov blast wave problem for one material in three dimensions. The problem has an analytic solution, and can be scaled to arbitrarily large problem sizes. The reference code is drawn from a production LLNL hydrodynamics code.

  5. Dewey's Challenge to Teachers

    Science.gov (United States)

    Fishman, Stephen M.; McCarthy, Lucille

    2010-01-01

    Given the serious social problems confronting Americans and others worldwide, the authors propose that Dewey's 1932 challenge to teachers is worthy of reconsideration by educators at all levels. In times similar to our own, Dewey challenged teachers to cultivate students' capacities to identify their happiness with what they can do to improve the…

  6. Virtual Bridge Design Challenge

    Science.gov (United States)

    Mitts, Charles R.

    2013-01-01

    This design/problem-solving activity challenges students to design a replacement bridge for one that has been designated as either structurally deficient or functionally obsolete. The Aycock MS Technology/STEM Magnet Program Virtual Bridge Design Challenge is an authentic introduction to the engineering design process. It is a socially relevant…

  7. Overcoming Breastfeeding Challenges

    Medline Plus

    Full Text Available ... Health Skip Navigation En Español Skip top navigation Home A-Z Health Topics Printables and Shareables Blog ... Only Natural email updates. Enter email address Submit Home > It's Only Natural > Overcoming challenges Overcoming breastfeeding challenges ...

  8. Science Challenge Day

    Science.gov (United States)

    Siegel, Deborah

    2013-01-01

    Science fairs can be good motivators, but as extracurricular activities, they leave some students behind. However, by staging a Science Challenge Day at school, educators can involve all students in doing everything from choosing activities to judging projects. This article presents a model for running a successful Science Challenge Day. The…

  9. Employment challenges in the future

    DEFF Research Database (Denmark)

    Rimmer, Nina Roehr

    2011-01-01

    Discussion of challenges in employment challenges in Europe and a brief discription of the Danish flexicurity system......Discussion of challenges in employment challenges in Europe and a brief discription of the Danish flexicurity system...

  10. Challenges of serious games

    Directory of Open Access Journals (Sweden)

    B. Fernández-Manjón

    2015-11-01

    Full Text Available Although educational games have revealed to be a very effective focus in diverse situations, their use in education is still very limited. In this paper we analyse the main challenges concerning educational games that, from our perspective, have to be approached so that the use of this kind of games can be widespread. These challenges are classified in three main dimensions: socio-cultural, educational and technological. Once the challenges are identified, some possible measures are suggested to address or reduce these problems so that the use of educational games may be widespread.

  11. Big Data Challenges

    Directory of Open Access Journals (Sweden)

    Alexandru Adrian TOLE

    2013-10-01

    Full Text Available The amount of data that is traveling across the internet today, not only that is large, but is complex as well. Companies, institutions, healthcare system etc., all of them use piles of data which are further used for creating reports in order to ensure continuity regarding the services that they have to offer. The process behind the results that these entities requests represents a challenge for software developers and companies that provide IT infrastructure. The challenge is how to manipulate an impressive volume of data that has to be securely delivered through the internet and reach its destination intact. This paper treats the challenges that Big Data creates.

  12. Influence of hardness on the bioavailability of silver to a freshwater snail after waterborne exposure to silver nitrate and silver nanoparticles.

    Science.gov (United States)

    Stoiber, Tasha; Croteau, Marie-Noële; Römer, Isabella; Tejamaya, Mila; Lead, Jamie R; Luoma, Samuel N

    2015-01-01

    The release of Ag nanoparticles (AgNPs) into the aquatic environment is likely, but the influence of water chemistry on their impacts and fate remains unclear. Here, we characterize the bioavailability of Ag from AgNO(3) and from AgNPs capped with polyvinylpyrrolidone (PVP AgNP) and thiolated polyethylene glycol (PEG AgNP) in the freshwater snail, Lymnaea stagnalis, after short waterborne exposures. Results showed that water hardness, AgNP capping agents, and metal speciation affected the uptake rate of Ag from AgNPs. Comparison of the results from organisms of similar weight showed that water hardness affected the uptake of Ag from AgNPs, but not that from AgNO(3). Transformation (dissolution and aggregation) of the AgNPs was also influenced by water hardness and the capping agent. Bioavailability of Ag from AgNPs was, in turn, correlated to these physical changes. Water hardness increased the aggregation of AgNPs, especially for PEG AgNPs, reducing the bioavailability of Ag from PEG AgNPs to a greater degree than from PVP AgNPs. Higher dissolved Ag concentrations were measured for the PVP AgNPs (15%) compared to PEG AgNPs (3%) in moderately hard water, enhancing Ag bioavailability of the former. Multiple drivers of bioavailability yielded differences in Ag influx between very hard and deionized water where the uptake rate constants (k(uw), l g(-1) d(-1) ± SE) varied from 3.1 ± 0.7 to 0.2 ± 0.01 for PEG AgNPs and from 2.3 ± 0.02 to 1.3 ± 0.01 for PVP AgNPs. Modeling bioavailability of Ag from NPs revealed that Ag influx into L. stagnalis comprised uptake from the NPs themselves and from newly dissolved Ag.

  13. Disruption of the hypothalamic-pituitary-thyroid axis in zebrafish embryo-larvae following waterborne exposure to BDE-47, TBBPA and BPA

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Winson K. [Biochemistry Program, School of Life Sciences, Chinese University of Hong Kong, Sha Tin, Hong Kong (Hong Kong); Chan, King Ming, E-mail: kingchan@cuhk.edu.hk [Biochemistry Program, School of Life Sciences, Chinese University of Hong Kong, Sha Tin, Hong Kong (Hong Kong); Environmental Science Program, School of Life Sciences, Chinese University of Hong Kong, Sha Tin, Hong Kong (Hong Kong)

    2012-02-15

    We performed waterborne exposures of 2,2 Prime ,4,4 Prime -tetrabromodiphenyl ether (BDE-47), tetrabromobisphenol A (TBBPA) or bisphenol A (BPA) on zebrafish (Danio rerio) embryo-larvae and quantitatively measured the expression of genes belonging to the hypothalamic-pituitary-thyroid (HPT) axis to assess for adverse thyroid function. For analysis on the effects of BDE-47, TBBPA and BPA on the hypothalamic-pituitary-thyroid genes, zebrafish embryo-larvae were acutely exposed to lethal concentrations of the chemical agents in order to determine the 96 h-LC50 (96 h lethal median concentration) and 96 h-EC50 (96 h effective median concentration) values. Further exposures at sub-lethal concentrations were then carried out and total RNA samples were extracted to quantify the mRNA expression levels of the genes of interest. In larvae, BDE-47 was found to have significantly induced many genes of interest, namely thyroglobulin, thyroid peroxidase, thyroid receptors {alpha} and {beta}, thyroid stimulating hormone, and transthyretin. TBBPA only significantly induced three genes of interest (thyroid receptor {alpha}, thyroid stimulating hormone, and transthyretin) while BPA only induced thyroid stimulating hormone. In embryos, BDE-47 significantly induced the sodium iodide symporter and thyroid stimulating hormone. TBBPA significantly induced thyroid receptor {alpha} and thyroid stimulating hormone, while BPA did not significantly induce any of the genes. Most genes were only induced at the 75% 96 h-LC50 or 96 h-EC50 value; however, thyroid peroxidase and thyroid stimulating hormone demonstrated upregulation in a level as little as the 10% 96 h-LC50 value. The present study provides a new set of data on zebrafish mRNA induction of hypothalamic-pituitary-thyroid genes from exposure to BDE-47, TBBPA, or BPA. This information would serve useful for elucidating the toxicological mechanism of brominated flame retardants, assessing appropriate safety levels in the environment for

  14. Better Buildings Challenge Overview

    Energy Technology Data Exchange (ETDEWEB)

    None

    2011-06-01

    The Better Buildings Challenge is a national leadership initiative calling on corporate chief executive officers, university presidents, and state and local leaders to make a significant commitment to building energy efficiency.

  15. Overcoming Breastfeeding Challenges

    Medline Plus

    Full Text Available ... project of the U.S. Department of Health and Human Services Office on Women's Health Skip Navigation En ... breastfeeding challenges Dealing with lack of family support Is my baby getting enough milk? Breastfeeding ...

  16. 2017 TRI University Challenge

    Science.gov (United States)

    Details about the 2017 TRI University Challenge, in which EPA is looking to academic institutions to help build a diverse portfolio of practical and replicable projects that benefit communities, the environment, academic institutions, and the TRI Program.

  17. Brazil World Cup Challenges

    Directory of Open Access Journals (Sweden)

    MANSUR, R.

    2012-12-01

    Full Text Available Overcoming the productivity challenge is the main benefit of the 2014 World Cup for Brazilian people. The sustainable development of our cultural tourism industry will catapult the new middle class growing up rate.

  18. Overcoming Breastfeeding Challenges

    Medline Plus

    Full Text Available ... Overcoming breastfeeding challenges Dealing with lack of family support Is my baby getting enough milk? Breastfeeding in ... get a good latch Addressing breastfeeding myths Finding support Fitting it into your life My breastfeeding story ...

  19. The Electric Car Challenge.

    Science.gov (United States)

    Diehl, Brian E.

    1997-01-01

    Describes the Electric Car Challenge during which students applied methods of construction to build lightweight, strong vehicles that were powered by electricity. The activity required problem solving, sheet metal work, electricity, design, and construction skills. (JOW)

  20. Community Challenge Grantees

    Data.gov (United States)

    Department of Housing and Urban Development — HUD's Community Challenge Grants aim to reform and reduce barriers to achieving affordable, economically vital and sustainable communities. The funds are awarded to...

  1. Big data challenges

    DEFF Research Database (Denmark)

    Bachlechner, Daniel; Leimbach, Timo

    2016-01-01

    Although reports on big data success stories have been accumulating in the media, most organizations dealing with high-volume, high-velocity and high-variety information assets still face challenges. Only a thorough understanding of these challenges puts organizations into a position in which...... they can make an informed decision for or against big data, and, if the decision is positive, overcome the challenges smoothly. The combination of a series of interviews with leading experts from enterprises, associations and research institutions, and focused literature reviews allowed not only...... framework are also relevant. For large enterprises and startups specialized in big data, it is typically easier to overcome the challenges than it is for other enterprises and public administration bodies....

  2. The new productivity challenge.

    Science.gov (United States)

    Drucker, P F

    1991-01-01

    "The single greatest challenge facing managers in the developed countries of the world is to raise the productivity of knowledge and service workers," writes Peter F. Drucker in "The New Productivity Challenge." Productivity, says Drucker, ultimately defeated Karl Marx; it gave common laborers the chance to earn the wages of skilled workers. Now five distinct steps will raise the productivity of knowledge and service workers--and not only stimulate new economic growth but also defuse rising social tensions.

  3. 78 FR 49296 - Centennial Challenges 2014 Sample Return Robot Challenge

    Science.gov (United States)

    2013-08-13

    ... SPACE ADMINISTRATION Centennial Challenges 2014 Sample Return Robot Challenge AGENCY: National Aeronautics and Space Administration (NASA). ACTION: Notice of Centennial Challenges 2014 Sample Return Robot... Robot Challenge is scheduled and teams that wish to compete may register. Centennial Challenges is a...

  4. Surveillance for waterborne disease and outbreaks associated with drinking water and water not intended for drinking--United States, 2003-2004.

    Science.gov (United States)

    Liang, Jennifer L; Dziuban, Eric J; Craun, Gunther F; Hill, Vincent; Moore, Matthew R; Gelting, Richard J; Calderon, Rebecca L; Beach, Michael J; Roy, Sharon L

    2006-12-22

    Since 1971, CDC, the U.S. Environmental Protection Agency (EPA), and the Council of State and Territorial Epidemiologists have maintained a collaborative Waterborne Disease and Outbreaks Surveillance System for collecting and reporting data related to occurrences and causes of waterborne disease and outbreaks (WBDOs). This surveillance system is the primary source of data concerning the scope and effects of WBDOs in the United States. Data presented summarize 36 WBDOs that occurred during January 2003-December 2004 and nine previously unreported WBDOs that occurred during 1982-2002. The surveillance system includes data on WBDOs associated with drinking water, water not intended for drinking (excluding recreational water), and water of unknown intent. Public health departments in the states, territories, localities, and Freely Associated States (i.e., the Republic of the Marshall Islands, the Federated States of Micronesia, and the Republic of Palau, formerly parts of the U.S.-administered Trust Territory of the Pacific Islands) are primarily responsible for detecting and investigating WBDOs and voluntarily reporting them to CDC by using a standard form. During 2003-2004, a total of 36 WBDOs were reported by 19 states; 30 were associated with drinking water, three were associated with water not intended for drinking, and three were associated with water of unknown intent. The 30 drinking water-associated WBDOs caused illness among an estimated 2,760 persons and were linked to four deaths. Etiologic agents were identified in 25 (83.3%) of these WBDOs: 17 (68.0%) involved pathogens (i.e., 13 bacterial, one parasitic, one viral, one mixed bacterial/parasitic, and one mixed bacterial/parasitic/viral), and eight (32.0%) involved chemical/toxin poisonings. Gastroenteritis represented 67.7% of the illness related to drinking water-associated WBDOs; acute respiratory illness represented 25.8%, and dermatitis represented 6.5%. The classification of deficiencies contributing

  5. Brote de gastroenteritis por agua potable de suministro público Waterborne outbreak of gastroenteritis transmitted through the public water supply

    Directory of Open Access Journals (Sweden)

    P. Godoy

    2003-06-01

    gastroenteritis outbreaks. The aim of this study was to investigate an outbreak of waterborne disease associated with drinking water from public supplies. Methods: A historical cohort study was carried out following notification of a gastroenteritis outbreak in Baqueira (Valle de Arán, Spain. We used systematic sampling to select 87 individuals staying at hotels and 67 staying in apartments in the target area. Information was gathered on four factors (consumption of water from the public water supply, sandwiches, water and food in the ski resorts as well as on symptoms. We assessed residual chlorine in drinking water, analyzed samples of drinking water, and studied stool cultures from 4 patients. The risk associated with each water source and food type was assessed by means of relative risk (RR and 95% confidence intervals (CI. Results: The overall attack rate was 51.0% (76/149. The main symptoms were diarrhea 87.5%, abdominal pain 80.0%, nausea 50.7%, vomiting 30.3%, and fever 27.0%. The only factor associated with a statistically significant risk of disease was consumption of drinking water (RR = 11.0; 95% CI, 1.6-74.7. No residual chlorine was detected in the drinking water, which was judged acceptable. A problem associated with the location of the chlorinator was observed and corrected. We also recommended an increase in chlorine levels, which was followed by a reduction in the number of cases. The results of stool cultures of the four patients were negative for enterobacteria. Conclusions: This study highlights the potential importance of waterborne outbreaks of gastroenteritis transmitted through drinking water considered acceptableand suggests the need to improve microbiological research into these outbreaks (viruses and protozoa detection.

  6. Centennial Challenges Program

    Science.gov (United States)

    Ortega, Sam; Eberly, Eric

    2015-01-01

    NASA's Centennial Challenges Program was initiated in 2005 to directly engage the public in the process of advanced technology development. The program offers incentive prizes to generate revolutionary solutions to problems of interest to NASA and the nation. The program seeks innovations from diverse and nontraditional sources. Competitors are not supported by government funding and awards are only made to successful teams when the challenges are met. In keeping with the spirit of the Wright Brothers and other American innovators, the Centennial Challenge prizes are offered to independent inventors including small businesses, student groups, and individuals. These independent inventors are sought to generate innovative solutions for technical problems of interest to NASA and the nation and to provide them with the opportunity to stimulate or create new business ventures.

  7. Meeting the Challenge

    Directory of Open Access Journals (Sweden)

    T. Reg Bott

    2009-01-01

    Full Text Available The first Chempor Conference held in Lisbon in 1975 under the auspices of the Calouste Gulbenkian Foundation, heralded a regular wide-ranging review of research and development in Portugal and the UK Progressively in later years the Conferences have attracted contributions from other European countries and indeed further afield. There is an increasing awareness of the problems for the environment, notably global warming, brought about by human activities. Recent predictions about the future are dire, particularly regarding food and water for a rapidly growing world population. They represent a substantial challenge to the scientific and technical fraternity. In response to that challenge it is important to keep up to date with technical developments, to meet and keep in touch with coworkers in associated fields, and to cooperate wherever possible. The papers presented at the Chempor and other conferences have made and continue to make a significant contribution to that objective of meeting the challenge.

  8. Challenges facing production grids

    Energy Technology Data Exchange (ETDEWEB)

    Pordes, Ruth; /Fermilab

    2007-06-01

    Today's global communities of users expect quality of service from distributed Grid systems equivalent to that their local data centers. This must be coupled to ubiquitous access to the ensemble of processing and storage resources across multiple Grid infrastructures. We are still facing significant challenges in meeting these expectations, especially in the underlying security, a sustainable and successful economic model, and smoothing the boundaries between administrative and technical domains. Using the Open Science Grid as an example, I examine the status and challenges of Grids operating in production today.

  9. Anthropocene Age Wicked Challenges

    DEFF Research Database (Denmark)

    Edgeman, Rick; Wu, Zhaohui

    2015-01-01

    weather events, drought, and desertification; threatened food supplies; water pollution, air pollution, and soil contamination; and the connection of these to disease, violence, and terrorism. Wicked challenges are discussed in relation to enterprise excellence, sustainability, resilience and robustness...... (SEER2) where these are in part enabled by supply chain proficiency.......Grand global challenges, including wicked human caused or influenced ones key to sustainability, characterize the Anthropocene Age. Among these are climate change driven by increased methane and CO2 in the atmosphere; consequent global warming and increasing intensity and incidence of extreme...

  10. British Muslims: A Challenge

    OpenAIRE

    Abdel-Hady, Zakaryya Mohamed [زكريا محمد عبد الهادي

    2007-01-01

    The Muslim community in Britain today face multiple challenges covering a wide range of spectrum from the basic right to exists, fighting the increasing trends of Islamophobia, having equal opportunities, to participate in public life, fully integrate within the society and be a positive member of the community. The recent events of September 11th in the US, July 7th in UK and the more recent row over the ban of the headscarf in UK and other European countries have placed tremendous challenge...

  11. Electric Vehicle Battery Challenge

    Science.gov (United States)

    Roman, Harry T.

    2014-01-01

    A serious drawback to electric vehicles [batteries only] is the idle time needed to recharge their batteries. In this challenge, students can develop ideas and concepts for battery change-out at automotive service stations. Such a capability would extend the range of electric vehicles.

  12. MALL: The Pedagogical Challenges

    Science.gov (United States)

    Burston, Jack

    2014-01-01

    In this paper the development of mobile-assisted language learning (MALL) over the past 20 years is reviewed with a particular focus on the pedagogical challenges facing its exploitation. Following a consideration of the definition of mobile learning, the paper describes the dominant mobile technologies upon which MALL applications have been…

  13. Employment Challenges in Kenya

    African Journals Online (AJOL)

    Dr Kazungu

    To reverse the trend in slow employment growth, Kenya must focus on ensuring high and sustained economic growth. .... (KYEP), Youth. Employment Scheme Abroad (YESA) and Women Enterprise Fund (WEF). ..... This study undertakes a simple extrapolation exercise to examine Kenya's employment challenge over the ...

  14. The Challenge of Thor

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 3. The Challenge of Thor. Anil Kakodkar Sujata Varadarajan. Face to Face Volume 15 Issue 3 March 2010 pp 277-293. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/015/03/0277-0293 ...

  15. A Cool Challenge

    Science.gov (United States)

    Roman, Harry T.

    2012-01-01

    The world of man-made design is all around, in everyday objects and appliances people use without a second thought. In this exercise, students have an opportunity to challenge the common refrigerator's design--and improve it. This approach can be used with many other appliances.

  16. India's Higher Education Challenges

    Science.gov (United States)

    Altbach, Philip G.

    2014-01-01

    India, with the world's second largest higher education system and a rapidly growing economy as one of the BRIC nations, faces significant challenges in building both capacity and excellence in higher education. India's higher education system is characterized by "islands of excellence in a sea of mediocrity." The mainstream universities…

  17. The Store Challenge

    Science.gov (United States)

    Roman, Harry T.

    2014-01-01

    Biomedical and robotic technologies are merging to present a wonderful opportunity to develop artificial limbs and prosthetic devices for humans injured on the job, in the military, or due to disease. In this challenge, students will have the opportunity to design a store or online service that specifically dedicates itself to amputees. Described…

  18. The Better Boat Challenge

    Science.gov (United States)

    Schomburg, Aaron

    2008-01-01

    "On your mark, get set, go!" Elementary students love to hear these words as they participate in the annual Third Grade Better Boat Challenge. This highly motivational project started a few years ago as the author was developing the third-grade science curriculum to include a study that revolved around models, design, and problem solving. It has…

  19. A Challenge to Watson

    Science.gov (United States)

    Detterman, Douglas K.

    2011-01-01

    Watson's Jeopardy victory raises the question of the similarity of artificial intelligence and human intelligence. Those of us who study human intelligence issue a challenge to the artificial intelligence community. We will construct a unique battery of tests for any computer that would provide an actual IQ score for the computer. This is the same…

  20. US Cyber Challenge Research

    Science.gov (United States)

    2012-02-01

    FORCE RESEARCH LABORATORY INFORMATION DIRECTORATE US CYBER CHALLENGE RESEARCH CENTER FOR INTERNET SECURITY , INC FEBRUARY 2012...CY 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Center for Internet Security , Inc. CIS 31 Tech Valley Dr East Greenbush, NY 12061-4134 8...detect and defeat cyber threats. 15. SUBJECT TERMS Cyber Security, Information Assurance, Internet Security , Cyber Education and Training 16

  1. Microarray challenges in ecology

    NARCIS (Netherlands)

    Kammenga, Jan E.; Herman, Michael A.; Ouborg, N. Joop; Johnson, Loretta; Breitling, Rainer

    Microarrays are used to measure simultaneously the amount of mRNAs transcribed from many genes. They were originally designed for gene expression profiling in relatively simple biological systems, such as cell lines and model systems under constant laboratory conditions. This poses a challenge to

  2. University Engineering Design Challenge

    Science.gov (United States)

    2015-01-02

    shoulder strain or sprain 18 University Design Challenge 2012 –2013 Introduction Arizona State University (ASU) was contracted by the Air Force Research... causing issues with regards to lateral instability. Testing Parameters:  Amsteel purple rope, fed normally (horizontals and verticals), but then looped

  3. Kayak Design Challenge

    Science.gov (United States)

    Wood, Anson

    2011-01-01

    Living in the Adirondack Park and being an avid outdoorsman has often resulted in the author's love of the outdoors working its way into class projects. In 2010, the author gave a group of 25 students in grades 9-12 a challenge that required them to design and construct a prototype inexpensive, lightweight kayak for backpackers and fisherman. In…

  4. Challenges in data science

    DEFF Research Database (Denmark)

    Carbone, Anna; Jensen, M.; Sato, Aki-Hiro

    2016-01-01

    The ability to process and manage large data volumes has been proven to be not enough to tackle the current challenges presented by "Big Data". Deep insight is required for understanding interactions among connected systems, space- and time-dependent heterogeneous data structures. Emergence...

  5. Water Management in Africa and the Middle East: Challenges and ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    prone East Africa to the Middle East — where water is a major factor in regional conflicts — to tropical areas — where water quality is a concern and water-borne diseases are endemic. They examine the roles of governments, international ...

  6. 77 FR 70835 - Centennial Challenges 2013 Sample Return Robot Challenge

    Science.gov (United States)

    2012-11-27

    ... SPACE ADMINISTRATION Centennial Challenges 2013 Sample Return Robot Challenge AGENCY: National... in accordance with 51 U.S.C. 20144(c). The 2013 Sample Return Robot Challenge is scheduled and teams... Robot Challenge is a prize competition designed to encourage development of new technologies or...

  7. 76 FR 56819 - Centennial Challenges 2012 Sample Return Robot Challenge

    Science.gov (United States)

    2011-09-14

    ... SPACE ADMINISTRATION Centennial Challenges 2012 Sample Return Robot Challenge AGENCY: National... 42 U.S.C. 2451(314)(d). The 2012 Sample Return Robot Challenge is scheduled and teams that wish to... technologies of interest and value to NASA and the nation. The 2012 Sample Return Robot Challenge is a prize...

  8. Evaluation of the microstructure of waterborne poly(urethane-urea)s nanocomposites with hydrophilic clay (NWPUU); Avaliacao da microestrutura de nanocompositos de poli(uretano-ureia)s e argila hidrofilica obtidos como dispersoes aquosas (NWPUU)

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Gisele dos S.; Delpech, Marcia C.; Reis, Rodrigo A. dos; Pereira, Alexandre Z.I; Coelho, Aline B., E-mail: mcd@uerj.br [Universidade do Estado do Rio do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    Waterborne poly(urethane-urea)s (WPUU) and respective nanocomposites based on hydrophilic clay (NWPUU) generally show segregation between hard and soft domains, in a greater or lesser extent, which directly influences the stability of the dispersion and affect the final properties of the material. Simple characterization techniques, such as infrared spectroscopy (FTIR) and X ray diffraction (XRD), employed in this study, can generate information about the microstructure and phase miscibility, using small amounts of material. The evaluation of the results obtained from the techniques showed that increments in rigid domains content and in the amount of internal emulsifier, as well as the presence of clay, decreased the size of the crystallites (crystallinity of the soft segments). (author)'.

  9. Challenges to Resistance Welding

    DEFF Research Database (Denmark)

    Song, Quanfeng

    This report originates from the compulsory defense during my Ph.D. study at the Technical University of Denmark. Resistance welding is an old and well-proven technology. Yet the emergence of more and more new materials, new designs, invention off new joining techniques, and more stringent...... requirement in quality have imposed challenges to the resistance welding. More some research and development have to be done to adapt the old technology to the manufacturing industry of the 21st century. In the 1st part of the report, the challenging factors to the resistance welding are reviewed. Numerical...... simulation of resistance welding has been under development for many years. Yet it is no easy to make simulation results reliable and accurate because of the complexity of resistance welding process. In the 2nd part of the report numerical modeling of resistance welding is reviewed, some critical factors...

  10. Challenges in sexual medicine

    DEFF Research Database (Denmark)

    Cellek, Selim; Giraldi, Annamaria

    2012-01-01

    The sexual medicine field has been in mode of revolution until recently. Like all other fields of biomedical research, the economic situation around the world has had a negative impact on the field's momentum-research funding bodies, regulatory bodies and pharmaceutical companies seem to have...... placed sexual medicine in their low-priority list. But this is not the only challenge the field is facing. The successful development of phosphodiesterase type 5 (PDE5) inhibitors for treatment of erectile dysfunction (ED) means that research in this area seems to have slowed. However, there remain...... several unmet medical needs within sexual medicine such as premature ejaculation, severe ED and hypoactive sexual desire disorder, which await novel therapeutic approaches. Despite these challenges, research into finding and developing such therapies is likely to continue in the sexual medicine field...

  11. Diagnostic Challenges at SNS

    CERN Document Server

    Plum, M A

    2003-01-01

    The Spallation Neutron Source now being built in Oak Ridge, Tennessee, USA, accelerates an H- ion beam to 1000 MeV with an average power of 1.4 MW. The H- beam is then stripped to H+, compressed in a storage ring to a pulse length of 695 ns, and then directed onto a mercury neutron spallation target. Most of the acceleration is accomplished with superconducting rf cavities. The presence of these cavities, the high average beam power, and the large range of beam intensity in the storage ring, provide unique challenges to the beam diagnostics systems. In this talk we will discuss these challenges and some of our solutions, including the laser profile monitor system, the residual gas ionization profile monitors, and network attached devices. Measurements performed using prototype instrumentation will also be presented.

  12. Mathematical olympiad challenges

    CERN Document Server

    Andreescu, Titu

    2000-01-01

    Mathematical Olympiad Challenges is a rich collection of problems put together by two experienced and well-known professors and coaches of the U.S. International Mathematical Olympiad Team. Hundreds of beautiful, challenging, and instructive problems from algebra, geometry, trigonometry, combinatorics, and number theory were selected from numerous mathematical competitions and journals. An important feature of the work is the comprehensive background material provided with each grouping of problems. The problems are clustered by topic into self-contained sections with solutions provided separately. All sections start with an essay discussing basic facts and one or two representative examples. A list of carefully chosen problems follows and the reader is invited to take them on. Additionally, historical insights and asides are presented to stimulate further inquiry. The emphasis throughout is on encouraging readers to move away from routine exercises and memorized algorithms toward creative solutions to open-e...

  13. Challenges in Request Management

    DEFF Research Database (Denmark)

    Sommer, Anita Friis

    2014-01-01

    and its customers. The study provides an insight into a new area of supply chain management, including the process activity flow and challenges involved across the process. Furthermore, the method is dyadic including the customer in the case study, which is rare in related research....... profitability. This research study seeks to investigate the challenges of RQM in practice. Existing demand chain management literature is used as a basis for developing a RQM framework. RQM is investigated through an explorative research design in a dyadic B2B case study including a global industrial company......Request management (RQM) is a new term used for managing customer requests for new products. It is the counterpart to typical product development processes, which has no direct customer involvement. It is essential to manage customer requests in a structured and efficient way to obtain...

  14. Asia's new challenges

    DEFF Research Database (Denmark)

    Brach, Juliana; Vang, Jan

    2012-01-01

    Asian countries are currently undergoing significant changes with respect to their role in and interaction with the international economy. Despite their heterogeneity, Asian countries share the common aim to upgrade capacities, skills and capabilities. This paper aims at unpacking the challenges ...... and consequences of Asian countries' four decades of internationalisation. Special attention is granted to the current redesign of the interface with focus on the upgrading towards becoming knowledge and technology intensive nations; nations that are also exporters of FDI....

  15. Terabit Wireless Communication Challenges

    Science.gov (United States)

    Hwu, Shian U.

    2012-01-01

    This presentation briefly discusses a research effort on Terabit Wireless communication systems for possible space applications. Recently, terahertz (THz) technology (300-3000 GHz frequency) has attracted a great deal of interest from academia and industry. This is due to a number of interesting features of THz waves, including the nearly unlimited bandwidths available, and the non-ionizing radiation nature which does not damage human tissues and DNA with minimum health threat. Also, as millimeter-wave communication systems mature, the focus of research is, naturally, moving to the THz range. Many scientists regard THz as the last great frontier of the electromagnetic spectrum, but finding new applications outside the traditional niches of radio astronomy, Earth and planetary remote sensing, and molecular spectroscopy particularly in biomedical imaging and wireless communications has been relatively slow. Radiologists find this area of study so attractive because t-rays are non-ionizing, which suggests no harm is done to tissue or DNA. They also offer the possibility of performing spectroscopic measurements over a very wide frequency range, and can even capture signatures from liquids and solids. According to Shannon theory, the broad bandwidth of the THz frequency bands can be used for terabit-per-second (Tb/s) wireless communication systems. This enables several new applications, such as cell phones with 360 degrees autostereoscopic displays, optic-fiber replacement, and wireless Tb/s file transferring. Although THz technology could satisfy the demand for an extremely high data rate, a number of technical challenges need to be overcome before its development. This presentation provides an overview the state-of-the- art in THz wireless communication and the technical challenges for an emerging application in Terabit wireless systems. The main issue for THz wave propagation is the high atmospheric attenuation, which is dominated by water vapor absorption in the THz

  16. The Terawatt Challenge

    Science.gov (United States)

    Haegel, Nancy

    In response to concerns about accelerating climate change, the world is uniting to both envision and enable a global energy system that supports a sustainable environment and broad economic prosperity. Growth in the technology and the deployment of renewable energy has been dramatic. Evidence can be seen in the growth of photovoltaics (PV) and wind as contributors to worldwide electricity production over the last decade. PV and wind provided 1.2% and 3.7% of global electricity production in 2015, compared to 0.1% and 1.3% respectively in 2005. These numbers indicate both the rapid increase in the rate of deployment, as well as the remaining work to be done to extend this trend to transform a massive energy system and provide a significant fraction of the world's future energy demand with renewable energy. Based on recent trends, it is highly likely that global cumulative PV installation will reach terawatt scale in the next few decades. The challenges, as well as the resulting impact, vary greatly depending on whether we envision 1 TW ( 15% of 2015 global electricity capacity), 3 TW ( 50% of 2015 global electricity capacity) or 10 TW, a level that could drive electrification of transportation and industrial sectors and production of solar fuels. This presentation will draw upon the work of the 2016 GA-SERI (Global Alliance of Solar Energy Research Institutes) Terawatt Workshop to assess the feasibility and summarize the challenges for PV as a primary energy source. These challenges include the continuing demand for improved efficiency and reliability, the required magnitude of capital expenditure, the need for a sustainable industry (both financially and environmentally), as well as needs for grid modernization and consistent policies that support global climate goals. Physicists can play important roles in addressing this full range of challenges, from materials science to public policy, as well as in education of the public and its future leaders.

  17. Challenges in Danish VET

    DEFF Research Database (Denmark)

    Aarkrog, Vibe

    2011-01-01

    In Denmark the 95 percent target, meaning that in 2015 95 percent of a youth cohort should complete a youth education programme, is particularly challenging for the vocational educational and training (VET) system. In the article is given a short outline of the significant characteristics...... of the Danish dual VET system as well as of the current central initiatives aimed at reaching the 95 percent target....

  18. Rare cancers: Challenges & issues

    Directory of Open Access Journals (Sweden)

    Raveendran K Pillai

    2017-01-01

    Full Text Available Rare cancers account for about 22 per cent of all cancers diagnosed worldwide, disproportionately affecting some demographic groups, with an occurrence of less than 6 per 100,000 individuals annually. Many rare cancers in adults, adolescents and children are not curable, and patients and care providers have little option to take therapeutic decisions. The epidemiology of rare cancers is a challenging area of study but is inadequately addressed. Despite efforts mainly in some European nations, a few improvements have been observed in the management of rare cancers. Reasons for this obvious stagnation are multifactorial and are mainly inherent to logistical difficulties in carrying out clinical trials in very small patient populations, hesitation of the pharmaceutical industry to spend in small markets and complexity in creating adequate information for the development of cost-effective drugs. Rare cancers also face specific challenges that include late and incorrect diagnosis, lack of clinical expertise and lack of research interest and development of new therapies. The utilization of nationally representative study findings for the patients' evaluation may possibly offer chances to find out pathogenesis and prevalence, and this will eventually lead to control and prevention. Currently, advancing targeted therapies offer a great opportunity for the better management of rare cancers. Conducting clinical trials with small patient population, innovative clinical trial approach, prevailing controlling obstacles for international cooperation and financial support for research are the present challenges for rare cancers. The International Rare Cancers Initiative functions as a main platform for achieving new international clinical trials in rare tumours. This review delineates the current challenges and issues in the interpretation, management and research scenarios of rare cancers.

  19. Ireland's Competitiveness Challenge 2011

    OpenAIRE

    2012-01-01

    The NCC publishes two annual competitiveness reports. Ireland's Competitiveness Challenge focuses on the national competitiveness issues of most importance to the enterprise sector and identifies policy recommendations required to address these issues. The report focuses on pursuing policies to improve competitiveness, particularly those to reduce the cost base for enterprise, to enhance the performance of the entire education system, and to deliver meaningful public sector reform. Ireland's ...

  20. EDMS implementation challenge.

    Science.gov (United States)

    De La Torre, Marta

    2002-08-01

    The challenges faced by facilities wishing to implement an electronic medical record system are complex and overwhelming. Issues such as customer acceptance, basic computer skills, and a thorough understanding of how the new system will impact work processes must be considered and acted upon. Acceptance and active support are necessary from Senior Administration and key departments to enable this project to achieve measurable success. This article details one hospital's "journey" through design and successful implementation of an electronic medical record system.

  1. Challenges in plastics recycling

    OpenAIRE

    Pivnenko, Kostyantyn; Jakobsen, L. G.; Eriksen, Marie Kampmann; Damgaard, Anders; Astrup, Thomas Fruergaard

    2015-01-01

    Recycling of waste plastics still remains a challenging area in the waste management sector. The current and potential goals proposed on EU or regional levels are difficult to achieve, and even to partially fullfil them the improvements in collection and sorting should be considerable. A study was undertaken to investigate the factors affecting quality in plastics recycling. The preliminary results showed factors primarily influencing quality of plastics recycling to be polymer cross contamin...

  2. Rare cancers: Challenges & issues

    Science.gov (United States)

    Pillai, Raveendran K.; Jayasree, K.

    2017-01-01

    Rare cancers account for about 22 per cent of all cancers diagnosed worldwide, disproportionately affecting some demographic groups, with an occurrence of less than 6 per 100,000 individuals annually. Many rare cancers in adults, adolescents and children are not curable, and patients and care providers have little option to take therapeutic decisions. The epidemiology of rare cancers is a challenging area of study but is inadequately addressed. Despite efforts mainly in some European nations, a few improvements have been observed in the management of rare cancers. Reasons for this obvious stagnation are multifactorial and are mainly inherent to logistical difficulties in carrying out clinical trials in very small patient populations, hesitation of the pharmaceutical industry to spend in small markets and complexity in creating adequate information for the development of cost-effective drugs. Rare cancers also face specific challenges that include late and incorrect diagnosis, lack of clinical expertise and lack of research interest and development of new therapies. The utilization of nationally representative study findings for the patients’ evaluation may possibly offer chances to find out pathogenesis and prevalence, and this will eventually lead to control and prevention. Currently, advancing targeted therapies offer a great opportunity for the better management of rare cancers. Conducting clinical trials with small patient population, innovative clinical trial approach, prevailing controlling obstacles for international cooperation and financial support for research are the present challenges for rare cancers. The International Rare Cancers Initiative functions as a main platform for achieving new international clinical trials in rare tumours. This review delineates the current challenges and issues in the interpretation, management and research scenarios of rare cancers. PMID:28574010

  3. IDEOLOGICALLY CHALLENGING ENTERTAINMENT (ICE

    Directory of Open Access Journals (Sweden)

    Dana Lori Chalmers

    2015-09-01

    Full Text Available Ideologically Challenging Entertainment (ICE is entertainment that challenges ‘us vs. them’ ideologies associated with radicalization, violent conflict and terrorism. ICE presents multiple perspectives on a conflict through mainstream entertainment. This article introduces the theoretical underpinnings of ICE, the first ICE production and the audience responses to it. The first ICE production was Two Merchants: The Merchant of Venice adapted to challenge ideologies of the Arab-Israeli Conflict. A mixed-methods study of audience responses explored whether this production inspired audiences to shift their ideological views. Each performance included two versions of the adaptation: a Jewish dominated society with an Arab Muslim minority, contrasted with an Arab Muslim dominated society and a Jewish minority. A mixed-methods study of audience responses explored whether this production inspired audiences to shift their ideological views to become more tolerant of differences away from ideological radicalization. Of audience members who did not initially agree with the premise of the production, 40% reconsidered their ideological views, indicating increased tolerance, greater awareness of and desire to change their own prejudices. In addition, 86% of the audience expressed their intention to discuss the production with others, thereby encouraging critical engagement with, and broader dissemination of the message. These outcomes suggest that high quality entertainment – as defined by audience responses to it - can become a powerful tool in the struggle against radicalised ideologies.

  4. Grand Challenge Problem 10

    DEFF Research Database (Denmark)

    Dirckinck-Holmfeld, Lone; Balacheff, Nicolas; Bottino, Rosa Maria

    2016-01-01

    Small and medium sized research labs (SMLs) are dominating European TEL research. This is justified by the great numbers of countries and regions in Europe needing to develop a research and innovation competence to facilitate the diverse educational systems contextualized in various institutional...... settings across Europe. However, to strengthen the various research practices and to develop a common scientific language on TEL research the Grand Challenge Problem is to establish a vivid network and a community of practice among the research labs. TELEARC (Technology Enhanced Learning European Advanced...

  5. Semantic Web Evaluation Challenge

    CERN Document Server

    2014-01-01

    This book constitutes the thoroughly refereed post conference proceedings of the first edition of the Semantic Web Evaluation Challenge, SemWebEval 2014, co-located with the 11th Extended Semantic Web conference, held in Anissaras, Crete, Greece, in May 2014. This book includes the descriptions of all methods and tools that competed at SemWebEval 2014, together with a detailed description of the tasks, evaluation procedures and datasets. The contributions are grouped in three areas: semantic publishing (sempub), concept-level sentiment analysis (ssa), and linked-data enabled recommender systems (recsys).

  6. Challenging the Innovation Paradigm

    CERN Document Server

    Sveiby, Karl Erik; Segercrantz, Beata

    2012-01-01

    Innovation is almost always seen as a "good thing". Challenging the Innovation Paradigm is a critical analysis of the innovation frenzy and contemporary innovation research. The one-sided focus on desirable effects of innovation misses many opportunities to reduce the undesirable consequences. Authors in this book show how systemic effects outside the innovating firms reduce the net benefits of innovation for individual employees, customers, as well as for society as a whole - also the innovators' own organizations. This book analyzes the dominant discourses that construct and recons

  7. Media Challenging Status Quo

    DEFF Research Database (Denmark)

    Sandvik, Kjetil

    ). Skeptical internet sociologists such as Morozov (2011) point out that the same media which was used e.g. to mobilize the ‘Twitter revolution’ in Iran in 2009 also was used by the regime to infiltrate and strike down the democratic movement. Following such position statements, international media...... and communication research is currently engaging in a longer and deeper process of examining and assessing the cultural consequences of networked communication. One present challenge is to understand digital media and networked communication at the intersection of established and countercultural, utopian...

  8. Media challenging capitalism

    DEFF Research Database (Denmark)

    Sandvik, Kjetil

    ). Skeptical internet sociologists such as Morozov (2011) point out that the same media which was used e.g. to mobilize the ‘Twitter revolution’ in Iran in 2009 also was used by the regime to infiltrate and strike down the democratic movement. Following such position statements, international media...... and communication research is currently engaging in a longer and deeper process of examining and assessing the cultural consequences of networked communication. One present challenge is to understand digital media and networked communication at the intersection of established and countercultural, utopian...

  9. New challenges? Well, certainly!

    DEFF Research Database (Denmark)

    Lauridsen, Karen M.

    New challenges? Well, certainly! With the internationalization of European higher education, teaching and learning through the medium of a foreign language has become more and more widespread in recent years. This requires, of course, that lecturers as well as students have the necessary language......, different cultural backgrounds, different educational backgrounds and be used to a diverse set of didactic traditions and norms. Given this diversity, higher education institutions (HEIs) need to have measures in place to deal with this. Policies and practices must go hand in hand and, more often than not...

  10. Perishable Inventory Challenges

    DEFF Research Database (Denmark)

    Damgaard, Cecilie Maria; Nguyen, Vivi Thuy; Hvolby, Hans-Henrik

    2012-01-01

    The paper investigates how inventory control of perishable items is managed and line up some possible options of improvement. This includes a review of relevant literature dealing with the challenges of determining ordering policies for perishable products and a study of how the current procedures...... in the retail supply chains. The goal is to find and evaluate the parameters which affect the decision making process, when finding the optimal order quantity and order time. The paper takes a starting point in the retail industry but links to other industries....

  11. Rising to the Challenge

    Directory of Open Access Journals (Sweden)

    Xiaoping Li

    2015-06-01

    Full Text Available Writing is recognized as a vital skill in education and the workplace; students in the United States finishing K-12 schooling are expected to be competent writers. Yet, the Nation’s Report Card found that U.S. high school graduates coming into the workforce are particularly deficient in writing skills. Teachers serve as a crucial link in the move to improve literacy skills of K-12 students; however, teachers themselves are underprepared to be writers and writing teachers. Therefore, there is an urgent need to improve teachers’ writing skills and skills of teaching writing to improve K-12 students’ writing skills in the United States. This qualitative study examined the process-based writing project experienced by 22 practicing teachers through their reflective practices in a graduate capstone class. In particular, this study explored the challenges the teachers faced and the lessons they learned through the recursive phases of writing: planning, drafting, revising, editing, conferring, and publishing. The triangulation of the researchers’ field notes, teachers’ daily reflections, and informal interviews between the instructor and the teachers indicated that the challenges the teachers faced and the lesson they learned through the process-based writing project were phase specific. On the completion of the writing project, the participating teachers (a developed a deep understanding of process-based writing; (b learned new skills of planning, drafting, revising, editing, and sharing; and (c were more confident as writers themselves and as writing teachers for their students.

  12. Safeguards by Design Challenge

    Energy Technology Data Exchange (ETDEWEB)

    Alwin, Jennifer Louise [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-13

    The International Atomic Energy Agency (IAEA) defines Safeguards as a system of inspection and verification of the peaceful uses of nuclear materials as part of the Nuclear Nonproliferation Treaty. IAEA oversees safeguards worldwide. Safeguards by Design (SBD) involves incorporation of safeguards technologies, techniques, and instrumentation during the design phase of a facility, rather that after the fact. Design challenge goals are the following: Design a system of safeguards technologies, techniques, and instrumentation for inspection and verification of the peaceful uses of nuclear materials. Cost should be minimized to work with the IAEA’s limited budget. Dose to workers should always be as low are reasonably achievable (ALARA). Time is of the essence in operating facilities and flow of material should not be interrupted significantly. Proprietary process information in facilities may need to be protected, thus the amount of information obtained by inspectors should be the minimum required to achieve the measurement goal. Then three different design challenges are detailed: Plutonium Waste Item Measurement System, Marine-based Modular Reactor, and Floating Nuclear Power Plant (FNPP).

  13. Challenge Based Innovation gala

    CERN Multimedia

    CERN. Geneva; Utriainen, Tuuli Maria; Toivonen, Harri; Nordberg, Markus

    2014-01-01

    Challenge Based Innovation gala   There’s a new experiment starting in CERN called IdeaLab where we work together with detector R&D researchers to help them to bridge their knowledge into a more human, societally oriented context. Currently we are located in B153, but will move our activities to a new facility next to the Globe in May 2014. One of our first pilot projects is a 5 month course CBI (Challenge Based Innovation) where two multidisciplinary student teams join forces with Edusafe & TALENT projects at CERN. Their goal is to discover what kind of tools for learning could be created in collaboration with the two groups. After months of user interviews and low resolution prototyping they are ready to share the results with us in the form of an afternoon gala. We warmly welcome you to join us to see the students' results and experience the prototypes they have conceived. The event is in three parts, you are welcome to visit all of them,...

  14. Résultats challenge

    CERN Document Server

    Club de pétanque

    2015-01-01

    C'est avec un temps magnifique que se disputait pour la deuxième année le Challenge de notre cher ami Patrick DURAND le jeudi 30 juillet 2015. Vingt-six personnes formées en doublettes s'affrontaient pour trois parties .Après des parties très serrées le juge arbitre Claude JOUVE épaulé par Alain PHILIPONA déclarait  vainqueur l'imbattable Claude MACARI suivi de très près par Eric DARMEDRU et à la troisième place Christian JOUVE. La première féminine était Mireille ROCHE. La soirée se clôturait par une succulente paëlla préparée par Jennifer et sa maman Sylvie JOUVE. Rendez-vous à tous pour le jeudi 27 août 2015 pour le challenge Jean-Claude FROT Nos concours sont ouverts à tous les amateurs de pétanque.

  15. 75 FR 47316 - Centennial Challenges 2010 Strong Tether Challenge

    Science.gov (United States)

    2010-08-05

    ... Challenge will be conducted at the 2010 Space Elevator Conference held at the Microsoft Conference Center... SPACE ADMINISTRATION Centennial Challenges 2010 Strong Tether Challenge AGENCY: National Aeronautics and Space Administration (NASA). ACTION: Notice. SUMMARY: This notice is issued in accordance with 42 U.S.C...

  16. 76 FR 41526 - Centennial Challenges 2011 Strong Tether Challenge

    Science.gov (United States)

    2011-07-14

    ... Challenge will be conducted at the 2011 Space Elevator Conference held at the Microsoft Conference Center... SPACE ADMINISTRATION Centennial Challenges 2011 Strong Tether Challenge AGENCY: National Aeronautics and Space Administration (NASA). ACTION: Notice. SUMMARY: This notice is issued in accordance with 42 U.S.C...

  17. A brief overview of our energy challenge(s)

    Science.gov (United States)

    Rosner, Robert

    2018-01-01

    I provide an overview of the current world-wide energy generation and use, and discuss the challenge of meeting the expectations of rising standards of living in the developing world, as well as the challenge posed by ongoing climate change. I focus in particular on the possible evolution of energy systems in response to these challenges.

  18. 78 FR 19742 - Centennial Challenges: 2014 Night Rover Challenge

    Science.gov (United States)

    2013-04-02

    ... addressed to Dr. Larry Cooper, Centennial Challenges Program, NASA Headquarters, 300 E Street SW., Washington, DC 20546-0001. Email address: larry.p.cooper@nasa.gov . SUPPLEMENTARY INFORMATION: Summary Solar... Challenge will be conducted in an ambient Earth environment in a NASA test chamber. The Phase I Challenge...

  19. The challenge of conceiving

    DEFF Research Database (Denmark)

    Hansen, Claus Thorp; Jørgensen, Ulrik

    2011-01-01

    solving and optimization methods. Going back to the earlier days of engineering education problems were defined through the repertoire of existing technologies and solutions taken up and handled as given cases in the education. With the growing emphasis on scientific methods leading to a continued change...... in engineering disciplines throughout the mid 20th century the focus changed and problems were defined in more theoretical terms. Engineering education remained dominated by its introduction of a more and more dense repertoire of methods and theoretical models. In this paper we will approach this problem from...... the perspective of engineering design challenges where the need for problem identification is obvious to avoid the pitfall to reproduce and piecemeal engineer already existing product or service concepts. Problem identification is not a simple desk research task as it often involves a multitude of actors having...

  20. Hydropower Modeling Challenges

    Energy Technology Data Exchange (ETDEWEB)

    Stoll, Brady [National Renewable Energy Lab. (NREL), Golden, CO (United States); Andrade, Juan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Cohen, Stuart [National Renewable Energy Lab. (NREL), Golden, CO (United States); Brinkman, Greg [National Renewable Energy Lab. (NREL), Golden, CO (United States); Brancucci Martinez-Anido, Carlo [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-04-19

    Hydropower facilities are important assets for the electric power sector and represent a key source of flexibility for electric grids with large amounts of variable generation. As variable renewable generation sources expand, understanding the capabilities and limitations of the flexibility from hydropower resources is important for grid planning. Appropriately modeling these resources, however, is difficult because of the wide variety of constraints these plants face that other generators do not. These constraints can be broadly categorized as environmental, operational, and regulatory. This report highlights several key issues involving incorporating these constraints when modeling hydropower operations in terms of production cost and capacity expansion. Many of these challenges involve a lack of data to adequately represent the constraints or issues of model complexity and run time. We present several potential methods for improving the accuracy of hydropower representation in these models to allow for a better understanding of hydropower's capabilities.

  1. Challenges of ecological restoration

    DEFF Research Database (Denmark)

    Halme, Panu; Allen, Katherine A.; Aunins, Ainars

    2013-01-01

    The alarming rate of ecosystem degradation has raised the need for ecological restoration throughout different biomes and continents. North European forests may appear as one of the least vulnerable ecosystems from a global perspective, since forest cover is not rapidly decreasing and many...... ecosystem services remain at high level. However, extensive areas of northern forests are heavily exploited and have lost a major part of their biodiversity value. There is a strong requirement to restore these areas towards a more natural condition in order to meet the targets of the Convention...... on Biological Diversity. Several northern countries are now taking up this challenge by restoring forest biodiversity with increasing intensity. The ecology and biodiversity of boreal forests are relatively well understood making them a good model for restoration activities in many other forest ecosystems. Here...

  2. Some Challenges to Sustainability

    Directory of Open Access Journals (Sweden)

    Bruce R. Conard

    2013-08-01

    Full Text Available The word “sustainability” is often used in business in the belief that the current ways of doing things will be able to be continued with only minor changes to balance economic development with related environmental and social issues. There are, however, immense challenges that threaten the very sustainability of our global society, let alone individual businesses or developments. A few of the most important of these challenges—population growth, clean energy supply, fresh water availability, and global climate change—are discussed. As humanity forms its collective response to these threats, it is concluded that all intelligent people, but especially scientists, have important roles to play, not only in technical innovation, but also in catalyzing political action.

  3. Challenging the CSCW matrix

    DEFF Research Database (Denmark)

    Jørnø, Rasmus Leth Vergmann; Gynther, Karsten; Christensen, Ove

    2014-01-01

    of a different approach to learning situations based on the idea that tools, technology and learning environments are media through which participants simultaneously acquire proficiency to articulate and gain a perspective in order to decode what is going on. To effectively interact online, we contend that both...... teachers and students are required to modify and adapt their “perception abilities” and “enacting strategies” to appropriate a technology-mediated environment for learning purposes. The analysis illustrates the claim that particular collaborative or cooperative work practices attempt to appropriate tools......This paper challenges traditional dichotomies that identify temporal and spatial restrains as relevant defining properties of learning environments. We present a critique of the current dominant Computer Supported Cooperative Work (CSCW) taxonomy. Although we believe that the taxonomy does provide...

  4. Technology Empowerment: Security Challenges.

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Drake Edward [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Backus, George A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jones, Wendell [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Nelson, Thomas R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Skocypec, Russell D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-03-01

    “Technology empowerment” means that innovation is increasingly accessible to ordinary people of limited means. As powerful technologies become more affordable and accessible, and as people are increasingly connected around the world, ordinary people are empowered to participate in the process of innovation and share the fruits of collaborative innovation. This annotated briefing describes technology empowerment and focuses on how empowerment may create challenges to U.S. national security. U.S. defense research as a share of global innovation has dwindled in recent years. With technology empowerment, the role of U.S. defense research is likely to shrink even further while technology empowerment will continue to increase the speed of innovation. To avoid falling too far behind potential technology threats to U.S. national security, U.S. national security institutions will need to adopt many of the tools of technology empowerment.

  5. USCT data challenge

    Science.gov (United States)

    Ruiter, Nicole V.; Zapf, Michael; Hopp, Torsten; Gemmeke, Hartmut; van Dongen, Koen W. A.

    2017-03-01

    In the past years we have perceived within the USCT research community a demand for freely available USCT data sets. Inspired by the idea of Open Science, this collection of data sets could stimulate the collaboration and the exchange of ideas and experiences between USCT researchers. In addition, it may lead to comprehensive comparison of different reconstruction algorithms and their results. Finally, by collecting feedback from the users about data and system architecture, valuable information is gathered for further development of measurement setups. For the above reasons, we have initiated a digital portal with several reference data sets and access scripts under free licenses. To kick off this initiative, we organized a USCT data challenge event at SPIE Medical Imaging 2017.

  6. The Biofilm Challenge

    DEFF Research Database (Denmark)

    Alhede, Maria; Alhede, Morten

    2014-01-01

    The concept of biofilms has emerged in the clinical setting during the last decade. Infections involving biofilms have been documented in all parts of the human body, and it is currently believed that the presence of biofilm-forming bacteria is equivalent to chronic infection. A quick Pubmed search...... reveals the significance of biofilms, as evidenced by a dramatic increase in scientific publications on the topic, as well as in publications concerning wounds with biofilms, which reached 600 publications in 2013. Judged from the number of publications, it appears that biofilms play a significant role...... in wounds. However, the impact of biofilms is often debated, because infected wounds were also treated before the concept of biofilms was coined. In this short review, we will address the significance of biofilms and their role in wounds, and discuss the future tasks of the biofilm challenge....

  7. Ayurveda research: Ontological challenges

    Directory of Open Access Journals (Sweden)

    Jayakrishna Nayak

    2012-01-01

    Full Text Available Collaborative research involving Ayurveda and the current sciences is undoubtedly an imperative and is emerging as an exciting horizon, particularly in basic sciences. Some work in this direction is already going on and outcomes are awaited with bated breath. For instance the ′ASIIA (A Science Initiative In Ayurveda′ projects of Dept of Science and Technology, Govt of India, which include studies such as Ayurvedic Prakriti and Genetics. Further intense and sustained collaborative research needs to overcome a subtle and fundamental challenge-the ontologic divide between Ayurveda and all the current sciences. Ontology, fundamentally, means existence; elaborated, ontology is a particular perspective of an object of existence and the vocabulary developed to share that perspective. The same object of existence is susceptible to several ontologies. Ayurveda and modern biomedical as well as other sciences belong to different ontologies, and as such, collaborative research cannot be carried out at required levels until a mutually acceptable vocabulary is developed.

  8. Challenges of Antibacterial Discovery

    Science.gov (United States)

    Silver, Lynn L.

    2011-01-01

    Summary: The discovery of novel small-molecule antibacterial drugs has been stalled for many years. The purpose of this review is to underscore and illustrate those scientific problems unique to the discovery and optimization of novel antibacterial agents that have adversely affected the output of the effort. The major challenges fall into two areas: (i) proper target selection, particularly the necessity of pursuing molecular targets that are not prone to rapid resistance development, and (ii) improvement of chemical libraries to overcome limitations of diversity, especially that which is necessary to overcome barriers to bacterial entry and proclivity to be effluxed, especially in Gram-negative organisms. Failure to address these problems has led to a great deal of misdirected effort. PMID:21233508

  9. Challenges in plastics recycling

    DEFF Research Database (Denmark)

    Pivnenko, Kostyantyn; Jakobsen, L. G.; Eriksen, Marie Kampmann

    2015-01-01

    Recycling of waste plastics still remains a challenging area in the waste management sector. The current and potential goals proposed on EU or regional levels are difficult to achieve, and even to partially fullfil them the improvements in collection and sorting should be considerable. A study...... was undertaken to investigate the factors affecting quality in plastics recycling. The preliminary results showed factors primarily influencing quality of plastics recycling to be polymer cross contamination, presence of additives, non-polymer impurities, and polymer degradation. Deprivation of plastics quality......, with respect to recycling, has been shown to happen throughout the plastics value chain, but steps where improvements may happen have been preliminary identified. Example of Cr in plastic samples analysed showed potential spreading and accumulation of chemicals ending up in the waste plastics. In order...

  10. The Global Energy Challenge

    DEFF Research Database (Denmark)

    Connolly, David

    2011-01-01

    . Afterwards, the security of the world’s energy supply is investigated and it becomes clear that there is both an inevitable shortage of fossil fuels and a dangerous separation of supply and demand. The final topic discussed is renewable energy, since it is one sustainable solution to the global energy......This report gives a brief overview of the global energy challenge and subsequently outlines how and where renewable energy could be developed to solve these issues. The report does not go into a lot of detail on these issues and hence, it is meant as an overview only. The report begins by outlining...... the causes of global climate change, concluding that energy-related emissions are the primary contributors to the problem. As a result, global energy production is analysed in more detail, discussing how it has evolved over the last 30 years and also, how it is expected to evolve in the coming 30 years...

  11. Challenges of protection

    Directory of Open Access Journals (Sweden)

    Emma Fanning

    2010-11-01

    Full Text Available Local protection committees in North and South Kivu are tackling – with some success – a range of protection challenges.Since June 2010, Mukungu1 village in Kalehe, South Kivu, has welcomed 1,150 displaced households fleeing FDLR2 attacks during military operations in the area. A battalion of the national army arrived recently; they have set up checkpoints demanding a fee, do not speak any local language and have moved in with local families unasked. Forced labour and arbitrary arrests are widespread. Meanwhile, locals cannot farm fields near the forest as FDLR soldiers rape women who try – and have killed men who accompany them. The local community takes in IDPs but they warn that resources are limited.

  12. Huijgens' Synchronization: A Challenge

    Science.gov (United States)

    Nijmeijer, H.; Pogromsky, A. Y.

    Oscillations are common almost everywhere, be it in biology, in economics, in physics and many other fields. Everyone is familiar with the day-night rhythm, or the regular or less regular heart-beat of a human, the pig cycle in economy or the flashing of fire-flies and so on. All the above examples have in common that the oscillations seem to happen naturally, but there are also other more or less forced type of oscillations like for instance in chemistry, electrical circuits and acoustics. Probably the most basic example of an oscillator is a pendulum clock that runs at a fixed frequency and such that the exact time is given by the clock. Design and construction of a fully accurate mechanical clock is - even today - a very challenging task; the reader is referred to [Rawlings, 1994; Penman, 1998] for some background on this…

  13. Ten Challenges in Contraception.

    Science.gov (United States)

    Binette, Audrey; Howatt, Kerry; Waddington, Ashley; Reid, Robert L

    2017-01-01

    Despite the introduction of promising products into the contraceptive market, the rate of unintended pregnancies remains high. Women with underlying medical conditions should have access to safe and effective contraceptive methods for various reasons, including the potential deleterious effect of the disease on the pregnancy or the effect of the pregnancy on the disease process. Healthcare providers are often confronted with cases in which contraception counseling is problematic due to controversial evidence and persistent myths. This review will examine a number of medical conditions that often create contraception counseling challenges. It should in no way be considered as an extensive review of all contraceptive options for a given medical condition. The following topics will be explored: depression, immunosuppression, inflammatory bowel diseases, past bariatric surgery, liver diseases, family history of breast cancer, migraines, polycystic ovarian syndrome, perimenopausal state, and sickle cell disease. We advocate for improved information and accessibility to contraception as a means of decreasing the rate of unintended pregnancies.

  14. Challenging the Boundaries

    DEFF Research Database (Denmark)

    Nørgaard, Nina

    2004-01-01

    to explore in the study and teaching of foreign languages. Not only may linguistics and literature be employed to shed light on each other, the insights gained may furthermore prove useful in a broader context in our foreign language studies. The article begins with a brief introduction to literary...... linguistics in general and to Hallidayan linguistics in particular. The theoretical framework thus laid out, it is exemplified how Halliday's theory of language may be employed in the analysis of literature. The article concludes by considering the possible status of literary linguistics in a broader......To many people, challenging the boundaries between the traditional disciplines in foreign language studies means doing cultural studies. The aim of this article is to pull in a different direction by suggesting how the interface between linguistics and literature may be another fertile field...

  15. Coalition Warfare: the Leadership Challenges

    Science.gov (United States)

    2011-05-19

    multinational operations, leadership challenges, leadership attributes, unity of command. 16. SECURITY CLASSIFICATION OF: UNCLASSIFIED 17. LIMITATION OF...Approved for Public Release; Distribution is Unlimited Coalition Warfare: The leadership challenges A Monograph by Colonel Mark J Thornhill...The leadership challenges. 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Colonel Mark J. Thornhill

  16. New challenges in gas

    Energy Technology Data Exchange (ETDEWEB)

    Mandil, C. [Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France); Chabrelie, M.F. [Cedigaz, 92 - Rueil Malmaison (France); Streicher, C. [Prosernat, 92 - Paris la Defense (France)] [and others

    2003-07-01

    New developments in the area of gas treatment will be to a large extent driven by the need to find appropriate solutions to the fundamental need of sustainable development. New gas treatment processes are developed with the aim to minimise contaminant emissions and meet most stringent environmental specifications. A new major challenge for the industry will be to implement new cost effective technologies for reducing CO{sub 2} emissions. Industry has also to minimise its costs, and therefore, in order to ensure at the same time a better protection of the environment and a better safety, it is necessary to innovate. The purpose of this seminar is precisely to identify better the innovations which are required in the area of gas treatment. These proceedings comprise 8 papers and a summary of the contributions to a round-table discussion dealing with the options for CO{sub 2} capture and sequestration. The presentations treat of: the future prospects for the gas industry (M.F. Chabrelie, Cedigaz); the solutions for offshore gas treatment (C. Streicher, Prosernat); gas treatment with membranes (H. Meyer, GTI); the Axens Multibed{sub TM} technology for natural gas treatment (G. Jochem, Axens); the potentials and applications for the Propure co-current contactors (F.P. Nilsen, ProPure); the production of very-sour and super-sour large gas reserves: the new challenges (F. Lallemand, TotalFinaElf); Hybrisol, a new gas treatment process for sour natural gases (F. Lecomte, IFP); and the conception and building of large acid-gas removal units (J. Castel, Technip-Coflexip). (J.S.)

  17. Challenges in Piaget's legacy.

    Science.gov (United States)

    Bibace, Roger

    2013-03-01

    The publication of After Piaget (Martí and Rodríguez 2012) hopefully triggers a new effort to understand the richness of the efforts of that major psychologist of the 20th century. Piaget was consistently concerned with part/whole relationships throughout his life. He addressed this issue philosophically, epistemologically, and psychologically. Conceptually Piaget struggled with the issue of continuity/discontinuity in development and changed his mind about how to reconcile the discontinuities of stages with his concept of development. I also attribute his variability to the implications of his important work on perception, and to his willingness to get involved in widespread concrete applications of his approach to education including the education of children with special needs; his center for genetic epistemology, and his interest in psychoanalysis. Benefiting from all the authors of After Piaget, I want to point out that Piaget has identified many major issues that will continue to constitute challenges to psychology in this century. These include specifying terms such as 'development;' methodological issues such as sampling both quantitatively in one culture and across cultures; comprehensive inclusion of the psychological processes covered by introductory textbooks in psychology; and conceptual issues such as the relationships among all these parts within a whole. I make a distinction between an 'issue' and a 'problem'--problems have solutions; while issues refer to controversies in science generally as well as in psychology that have persisted for centuries.

  18. Challenges in Astronomy Education

    Science.gov (United States)

    De Greve, Jean-Pierre

    2010-11-01

    Astronomy is an attractive subject for education. It deals with fascination of the unknown and the unreachable, yet is uses tools, concepts and insights from various fundamental sciences such as mathematics, physics, chemistry, biology. Because of this it can be well used for introducing sciences to young people and to raise their interest in further studies in that direction. It is also an interesting subject for teaching as its different aspects (observation techniques, theory, data sampling and analysis, modelling,?) offer various didactical approaches towards different levels of pupils, students and different backgrounds. And it gives great opportunities to teach and demonstrate the essence of scientific research, through tutorials and projects. In this paper we discuss some of the challenges education in general, and astronomy in particular, faces in the coming decades, given the major geophysical and technological changes that can be deducted from our present knowledge. This defines a general, but very important background in terms of educational needs at various levels, and in geographical distribution of future efforts of the astronomical community. Special emphasis will be given to creative approaches to teaching, to strategies that are successful (such as the use of tutorials with element from computer games), and to initiatives complementary to the regular educational system. The programs developed by the IAU will be briefly highlighted.

  19. Ribosomal Antibiotics: Contemporary Challenges

    Directory of Open Access Journals (Sweden)

    Tamar Auerbach-Nevo

    2016-06-01

    Full Text Available Most ribosomal antibiotics obstruct distinct ribosomal functions. In selected cases, in addition to paralyzing vital ribosomal tasks, some ribosomal antibiotics are involved in cellular regulation. Owing to the global rapid increase in the appearance of multi-drug resistance in pathogenic bacterial strains, and to the extremely slow progress in developing new antibiotics worldwide, it seems that, in addition to the traditional attempts at improving current antibiotics and the intensive screening for additional natural compounds, this field should undergo substantial conceptual revision. Here, we highlight several contemporary issues, including challenging the common preference of broad-range antibiotics; the marginal attention to alterations in the microbiome population resulting from antibiotics usage, and the insufficient awareness of ecological and environmental aspects of antibiotics usage. We also highlight recent advances in the identification of species-specific structural motifs that may be exploited for the design and the creation of novel, environmental friendly, degradable, antibiotic types, with a better distinction between pathogens and useful bacterial species in the microbiome. Thus, these studies are leading towards the design of “pathogen-specific antibiotics,” in contrast to the current preference of broad range antibiotics, partially because it requires significant efforts in speeding up the discovery of the unique species motifs as well as the clinical pathogen identification.

  20. Constitutionality of CEPA challenged

    Energy Technology Data Exchange (ETDEWEB)

    Attaran, A.

    1997-02-24

    The Canadian Environmental Protection Act (CEPA) was challenged by Hydro-Quebec in the Supreme Court of Canada. Hydro-Quebec argued that in the absence of any explicit jurisdiction, federal environmental law must be rooted in either the Constitution`s criminal law power, or in its power to legislate for the peace, order and good government of Canada. When accused under CEPA of dumping PCBs into the the St. Maurice River in 1990, Hydro-Quebec, joined in its case by the Attorney Generals of Quebec and Saskatchewan, and IPSCO Inc., argued that the law failed to meet these criteria, and is, therefore unconstitutional and invalid. The Supreme Court case focused primarily on the validity of the Federal Government`s right to declare substances toxic in its pursuit of protecting the environment from immediate or long-term harm, in as much as the criminal law power is understood to protect human life and health, but heretofore, not the environment. Although the Justices were anxious to circumscribe the limits of federal environmental jurisdiction, they also appeared disinclined to explode all of Canada`s toxic waste laws. The most likely outcome is that the CEPA will be allowed to stand, but will be severed of the environmental protection purpose, while preserving the Federal Government`s jurisdiction over toxic substances under the protection of human life and health provisions of the Constitution.

  1. Whiplash Continues Its Challenge.

    Science.gov (United States)

    Jull, Gwendolen

    2016-10-01

    There have been many advances in the management of neck pain disorders, but a personal frustration as a clinician and researcher in the field is that the incidence of full recovery following a whiplash injury as a result of a motor vehicle crash has not increased and, subsequently, the rate of transition to chronic neck pain has not lessened. The commentaries in this special issue reflect the multifaceted nature of whiplash-associated disorders and the wide-ranging research in the field. While management of whiplash, especially the challenge of lessening the rate of transition to chronicity, has yet to be achieved, the picture is becoming clearer. This should give great confidence and some hope to individuals with whiplash-associated disorders who have long-term pain and functional disability that after the next decade of research and clinical development, the outcomes following whiplash are likely to be vastly improved. J Orthop Sports Phys Ther 2016;46(10):815-817. doi:10.2519/jospt.2016.0112.

  2. Osteomyelitis: a current challenge

    Directory of Open Access Journals (Sweden)

    Luciana Souza Jorge

    Full Text Available Over the last 30 years, the pathogenesis of osteomyelitis has almost been totally elucidated, and many factors responsible for the persistence of this infection have been identified. Numerous antimicrobial agents with distinct spectrums of action, pharmacokinetics, and pharmacodynamics have been used in its treatment. Surgical techniques, including muscle grafts, the Ilizarov technique, and antibiotic bone cements, have been applied. However, bone infections are still a challenge. Despite the importance of isolation and identification of microorganisms to determine the antimicrobial treatment of bone infections, there are few systematic national studies about the etiological profile of these diseases. This article describes the current knowledge of osteomyelitis and summarizes published national data based on the experience of different Orthopedic and Traumatology Services. In general, S. aureus was described as an important etiological agent; however, the difference in design of national studies makes a comparison between the prevalence of bone infection, the associated risk factors, and the different therapeutic approaches difficult. In conclusion, effort is necessary in order to stimulate systematic national studies in different Orthopedics and Traumatology Services to obtain a better consensus on preventive measures and therapies of bone infections.

  3. Challenges of climate change

    Science.gov (United States)

    Husaini, Amjad M

    2014-01-01

    Kashmir valley is a major saffron (Crocus sativus Kashmirianus) growing area of the world, second only to Iran in terms of production. In Kashmir, saffron is grown on uplands (termed in the local language as “Karewas”), which are lacustrine deposits located at an altitude of 1585 to 1677 m above mean sea level (amsl), under temperate climatic conditions. Kashmir, despite being one of the oldest historical saffron-producing areas faces a rapid decline of saffron industry. Among many other factors responsible for decline of saffron industry the preponderance of erratic rainfalls and drought-like situation have become major challenges imposed by climate change. Saffron has a limited coverage area as it is grown as a ‘niche crop’ and is a recognized “geographical indication,” growing under a narrow microclimatic condition. As such it has become a victim of climate change effects, which has the potential of jeopardizing the livelihood of thousands of farmers and traders associated with it. The paper discusses the potential and actual impact of climate change process on saffron cultivation in Kashmir; and the biotechnological measures to address these issues. PMID:25072266

  4. Hermes: the engineering challenges

    Science.gov (United States)

    Brzeski, Jurek; Gers, Luke; Smith, Greg; Staszak, Nicholas

    2012-09-01

    The Australian Astronomical Observatory is building a 4-channel VPH-grating High Efficiency and Resolution Multi Element Spectrograph (HERMES) for the 3.9 meter Anglo-Australian Telescope (AAT). HERMES will provide a nominal spectral resolving power of 28,000 for Galactic Archaeology with an optional high-resolution mode of 45,000 with the use of a slit mask. HERMES is fed by a fibre positioning robot called 2dF at the telescope prime focus. There are a total of 784 science fibres, which interface with the spectrograph via two separate slit body assemblies, each comprising of 392 science fibers. The slit defines the spectral lines of 392 fibres on the detector. The width of the detector determines the spectral bandwidth and the detector height determines the fibre to fibre spacing or cross talk. Tolerances that follow from this are all in the 10 micrometer range. The slit relay optics must contribute negligibly to the overall image quality budget and uniformly illuminate the spectrograph exit pupil. The latter requirement effectively requires that the relay optics provide a telecentric input at the collimator entrance slit. As a result it is critical to align the optical components to extreme precision required by the optical design. This paper discusses the engineering challenges of designing, optimising, tolerancing and manufacturing of very precise mechanical components for housing optics and the design of low cost of jigs and fixtures for alignment and assembly of the optics.

  5. IMMERSION AND BATH VACCINATION AGAINST ENTERIC REDMOUTH DISEASE (ERM) PROVIDES INSUFFICIENT PROTECTION AGAINST BATH CHALLENGE WITH YERSINIA RUCKERI O1 BIOTYPE 2

    DEFF Research Database (Denmark)

    Kragelund Strøm, Helene; Otani, Maki; Neumann, Lukas

    trout stock which had been vaccinated against both Y.r. bt 1 and 2 with a commercial “state of the art” immersion vaccine and boosted with a commercial ERM oral vaccine 4 month later. The newly isolated Y.r. bt2 strain has been used to develop a standardized challenge model which gives us...... the opportunity to test and evaluate the effect of both commercial and experimental vaccines against Y.r. bt2 in a waterborne infection experiment, mimicking a natural infection. We have developed an experimental immersion and bath vaccine containing equal amounts of the most immunogenic Y.r. bt 1 and 2 strains...... of the vaccine for 30 seconds as recommended by the manufacturer. As a positive control groups of trout were bath vaccinated for 5 minutes. Two months later was all groups bath challenged with Y.r. bt 2 in duplicate. The challenge data obtained in the present study have indicated that neither a “state of the art...

  6. DIGITAL PAKISTAN: OPPORTUNITIES & CHALLENGES

    Directory of Open Access Journals (Sweden)

    Ghulam Muhammad Kundi

    2008-10-01

    Full Text Available IT has revolutionized the social and organizational life around the globe. Given the newness of IT as a technology, there is a lot of potential that needs to be explored. It is however, argued that as IT can revolutionize the economic development, by the same coin, although its mismanagement in adoption process can end up in problems or even straight failure of the technology at the business-end. This study was conducted with reference to opportunities and challenges in the IT adoption process in Pakistan. The aim of the study was to point out the barriers that are impeding the country’s computerization process in order to provide facts to the policy makers for smooth computerization. The primary data collected through structured questionnaires was analyzed and tested through correlation, regressions analysis and t-test. Out of 10 hypotheses, 3 were accepted while in the rest null hypotheses were not substantiated. Based on primary and secondary data analysis this study has found that all independent bureaucratic, political, education and social and cultural variables are mutually correlated and have significant impact on shaping and reshaping of IT in Pakistan, while the Pakistan IT policy is inconsistent, administrative machinery attitude is negative and non cooperative, procedures are cumbersome and implementation is weak and ineffective, not to mention the lack of IT knowledge on the bureaucratic side. The political environment is instable and law and order is worse which is discouraging the investment. Moreover, physical and legal infrastructure is insufficient and the country is lacking good quality IT professionals. IT organization alignment is another serious issue in Pakistan. However, government incentives and growing interest from the private sector indicate positive attitude towards computerization of the country.

  7. The Repack Challenge

    Science.gov (United States)

    Kruse, Daniele Francesco

    2014-06-01

    Physics data stored in CERN tapes is quickly reaching the 100 PB milestone. Tape is an ever-changing technology that is still following Moore's law in terms of capacity. This means we can store every year more and more data in the same amount of tapes. However this doesn't come for free: the first obvious cost is the new higher capacity media. The second less known cost is related to moving the data from the old tapes to the new ones. This activity is what we call repack. Repack is vital for any large tape user: without it, one would have to buy more tape libraries and more floor space and, eventually, data on old non supported tapes would become unreadable and be lost forever. In this paper we describe the challenge of repacking 115 PB before LHC data taking starts in the beginning of 2015. This process will have to run concurrently with the existing experiment tape activities, and therefore needs to be as transparent as possible for users. Making sure that this works out seamlessly implies careful planning of the resources and the various policies for sharing them fairly and conveniently. To tackle this problem we need to fully exploit the speed and throughput of our modern tape drives. This involves proper dimensioning and configuration of the disk arrays and all the links between them and the tape servers, i.e the machines responsible for managing the tape drives. It is also equally important to provide tools to improve the efficiency with which we use our tape libraries. The new repack setup we deployed has on average increased tape drive throughput by 80%, allowing them to perform closer to their design specifications. This improvement in turn means a 48% decrease in the number of drives needed to achieve the required throughput to complete the full repack on time.

  8. IT Challenges for Space Medicine

    Science.gov (United States)

    Johnson-Throop, Kathy

    2010-01-01

    This viewgraph presentation reviews the various Information Technology challenges for aerospace medicine. The contents include: 1) Space Medicine Activities; 2) Private Medical Information; 3) Lifetime Surveillance of Astronaut Health; 4) Mission Medical Support; 5) Data Repositories for Research; 6) Data Input and Output; 7) Finding Data/Information; 8) Summary of Challenges; and 9) Solutions and questions.

  9. Challenges Facing Group Work Online

    Science.gov (United States)

    Chang, Bo; Kang, Haijun

    2016-01-01

    Online group work can be complicated because of its asynchronous characteristics and lack of physical presence, and its requirements for skills in handling technology, human relationships, and content-related tasks. This study focuses on the administrative, logistical and relationship-related challenges in online group work. Challenges in areas…

  10. Challenges in Delivering Distance Education

    Science.gov (United States)

    Chawdhry, Adnan A.

    2010-01-01

    Despite the challenges that exist with DE (Distance Education), university and faculty can provide a strong learning environment for their students if they understand and mitigate the challenges of the DE program. This paper describes a case study of a DE program that offers classroom instruction for multiple sites that are connected using a…

  11. Challenges in Computational Commutative Algebra

    OpenAIRE

    Abbott, John

    2006-01-01

    In this paper we consider a number of challenges from the point of view of the CoCoA project one of whose tasks is to develop software specialized for computations in commutative algebra. Some of the challenges extend considerably beyond the boundary of commutative algebra, and are addressed to the computer algebra community as a whole.

  12. Challenges When Introducing Electronic Exam

    Science.gov (United States)

    Kuikka, Matti; Kitola, Markus; Laakso, Mikko-Jussi

    2014-01-01

    Time pressures often necessitate the use of more efficient exam tools, such as electronic exams (e-exams), instead of traditional paper exams. However, teachers may face challenges when introducing e-exams in a higher education context. This paper describes what kinds of challenges teachers may face when introducing e-exams, based on experiences…

  13. Organizational leadership: meeting the challenge.

    Science.gov (United States)

    Hart, A L

    1994-06-01

    Leadership can be learned. Knowledge of leadership theories can serve as basis for developing skills and techniques. Style, trait, and transformational leadership can be applied in both health care institutions and professional associations. Organizational leadership is challenging, but those challenges can help individual nurses grow in the leadership skills that will continue to be demanded in the ever changing healthcare arena.

  14. Statistics Poster Challenge for Schools

    Science.gov (United States)

    Payne, Brad; Freeman, Jenny; Stillman, Eleanor

    2013-01-01

    The analysis and interpretation of data are important life skills. A poster challenge for schoolchildren provides an innovative outlet for these skills and demonstrates their relevance to daily life. We discuss our Statistics Poster Challenge and the lessons we have learned.

  15. Team Building through Physical Challenges.

    Science.gov (United States)

    Gibbons, Sandra L.

    The enhancement of positive self-concept has been identified as a key benefit of participation in team-building programs. This paper reviews research on the impact of team-building activities that include demanding physical challenges on the self-concept of physical education students. Team Building through Physical Challenges (TBPC) is a program…

  16. Interior Design: Challenges and Solutions.

    Science.gov (United States)

    School Planning and Management, 1999

    1999-01-01

    Presents solutions to architectural challenges in school interior design; these solutions made the indoor environments more conducive and attractive for learning. Addresses four challenges: making a long corridor look less like a tunnel; maintaining tradition and minimizing cost in a new athletic facility; designing a kindergarten that is secure…

  17. Grand Challenges facing Storage Systems

    CERN Multimedia

    CERN. Geneva

    2004-01-01

    In this talk, we will discuss the future of storage systems. In particular, we will focus on several big challenges which we are facing in storage, such as being able to build, manage and backup really massive storage systems, being able to find information of interest, being able to do long-term archival of data, and so on. We also present ideas and research being done to address these challenges, and provide a perspective on how we expect these challenges to be resolved as we go forward.

  18. Challenges in aerospace medicine education.

    Science.gov (United States)

    Grenon, S Marlene; Saary, Joan

    2011-11-01

    Aerospace medicine training and research represents a dream for many and a challenge for most. In Canada, although some opportunities exist for the pursuit of education and research in the aerospace medicine field, they are limited despite the importance of this field for enabling safe human space exploration. In this commentary, we aim to identify some of the challenges facing individuals wishing to get involved in the field as well as the causal factors for these challenges. We also explore strategies to mitigate against these.

  19. Eight challenges in phylodynamic inference

    Directory of Open Access Journals (Sweden)

    Simon D.W. Frost

    2015-03-01

    Full Text Available The field of phylodynamics, which attempts to enhance our understanding of infectious disease dynamics using pathogen phylogenies, has made great strides in the past decade. Basic epidemiological and evolutionary models are now well characterized with inferential frameworks in place. However, significant challenges remain in extending phylodynamic inference to more complex systems. These challenges include accounting for evolutionary complexities such as changing mutation rates, selection, reassortment, and recombination, as well as epidemiological complexities such as stochastic population dynamics, host population structure, and different patterns at the within-host and between-host scales. An additional challenge exists in making efficient inferences from an ever increasing corpus of sequence data.

  20. Presidential Transition. Challenges and Opportunities

    National Research Council Canada - National Science Library

    Walker, David

    2000-01-01

    .... Attention to these themes will help the new administration successfully implement its agenda and address both long-standing and newly emerging management, fiscal, and other challenges that confront...

  1. Challenging environmental mythology: wrestling Zeus

    National Research Council Canada - National Science Library

    Dini, J. W; Lehr, Jay H

    2003-01-01

    .... At a time when the public can be thoroughly confused between fact and fiction regarding our environmental concerns, this book proposes to challenge our concerns in clear, jargon free language that we can...

  2. CMS Distributed Data Analysis Challenges

    CERN Document Server

    Grandi, C

    2004-01-01

    In Spring 2004 CMS will undertake a 100 TeraByte-scale Data Challenge (DC04) as part of a series of challenges in preparation for running at CERN's Large Hadron Collider. During 1 month, DC04 must demonstrate the ability of the computing and software to cope with a sustained event data-taking rate of 25 Hz, for a total of 50 million events. The emphasis of DC04 is on the validation of the first pass reconstruction and storage systems at CERN and the streaming of events to a distributed system of Tier-1, and Tier-2 sites worldwide where typical analysis tasks will be performed. It is expected that the LHC Computing Grid project will provide a set of grid services suitable for use in a real production environment, as part of this data challenge. The results of this challenge will be used to define the CMS software and computing systems in their Technical Design Report.

  3. CHALLENGES OF PERMANENT TEACHER TRAINING

    National Research Council Canada - National Science Library

    María Manuela Valles-Ornelas; Efrén Viramontes-Anaya; Alma Delia Campos-Arroyo

    2015-01-01

    The new challenges for teachers and managers require to assume permanent formation as a tool for responding effectively and efficiently to them, different perspective to strengthen from the initial...

  4. Challenge of COPD: Getting Tested

    Science.gov (United States)

    ... please turn JavaScript on. Feature: The Challenge of COPD Getting Tested Past Issues / Fall 2014 Table of Contents Getting Tested Everyone at risk for COPD who has cough, sputum production, or shortness of ...

  5. Challenges in Designing Mechatronic Systems

    DEFF Research Database (Denmark)

    Torry-Smith, Jonas; Qamar, Ahsan; Achiche, Sofiane

    2013-01-01

    Development of mechatronic products is traditionally carried out by several design experts from different design domains. Performing development of mechatronic products is thus greatly challenging. In order to tackle this, the critical challenges in mechatronics have to be well understood and well...... supported through applicable methods and tools. This paper aims at identifying the major challenges, by conducting a systematic and thorough survey of the most relevant research work in mechatronic design. Solutions proposed in literature are assessed and illustrated through a case study in order...... to investigate if the challenges can be handled appropriately by the methods, tools, and mindsets suggested by the mechatronic community. Using a real world mechatronics case, the paper identifies the areas where further research is required, by showing a clear connection between the actual problems faced during...

  6. Refugee status determination: three challenges

    Directory of Open Access Journals (Sweden)

    Martin Jones

    2009-04-01

    Full Text Available Refugee status determination (RSD, which is vital to the protection of so many asylum seekers worldwide, is at best an imperfect, haphazard and challenging process. It merits greater attention and appropriate reform.

  7. The Cybersecurity Challenge in Acquisition

    Science.gov (United States)

    2016-04-30

    modern supply chain will add vulnerabilities to these linked supplier systems. Introduction Cyber Threat Challenges The accelerated growth in cyber...cyber challenges of their systems at the right level of detail is the only viable solution to this problem in the long run. Securing Supply Chains ...in turn introduce new vulnerabilities in the organization and must be managed by those acquisition specialists focused most on the supply chain

  8. Challenges to Nordic Police Research

    DEFF Research Database (Denmark)

    Holmberg, Lars

    2015-01-01

    The paper will cover three main points: A short description of published police research in the Nordic countries; a somewhat longer discussion of the nature of, and challenges to, Nordic police research and, finally, a critique of the homeliness of research.......The paper will cover three main points: A short description of published police research in the Nordic countries; a somewhat longer discussion of the nature of, and challenges to, Nordic police research and, finally, a critique of the homeliness of research....

  9. Stable isotope views on ecosystem function: challenging or challenged?

    Science.gov (United States)

    Resco, Víctor; Querejeta, José I.; Ogle, Kiona; Voltas, Jordi; Sebastià, Maria-Teresa; Serrano-Ortiz, Penélope; Linares, Juan C.; Moreno-Gutiérrez, Cristina; Herrero, Asier; Carreira, José A.; Torres-Cañabate, Patricia; Valladares, Fernando

    2010-01-01

    Stable isotopes and their potential for detecting various and complex ecosystem processes are attracting an increasing number of scientists. Progress is challenging, particularly under global change scenarios, but some established views have been challenged. The IX meeting of the Spanish Association of Terrestrial Ecology (AAET, Úbeda, 18–22 October 2009) hosted a symposium on the ecology of stable isotopes where the linear mixing model approach of partitioning sinks and sources of carbon and water fluxes within an ecosystem was challenged, and new applications of stable isotopes for the study of plant interactions were evaluated. Discussion was also centred on the need for networks that monitor ecological processes using stable isotopes and key ideas for fostering future research with isotopes. PMID:20015858

  10. Ecological Challenges for Closed Systems

    Science.gov (United States)

    Nelson, Mark; Dempster, William; Allen, John P.

    2012-07-01

    Closed ecological systems are desirable for a number of purposes. In space life support systems, material closure allows precious life-supporting resources to be kept inside and recycled. Closure in small biospheric systems facilitates detailed measurement of global ecological processes and biogeochemical cycles. Closed testbeds facilitate research topics which require isolation from the outside (e.g. genetically modified organisms; radioisotopes) so their ecological interactions and fluxes can be studied separate from interactions with the outside environment. But to achieve and maintain closure entails solving complex ecological challenges. These challenges include being able to handle faster cycling rates and accentuated daily and seasonal fluxes of critical life elements such as carbon dioxide, oxygen, water, macro- and mico-nutrients. The problems of achieving sustainability in closed systems for life support include how to handle atmospheric dynamics including trace gases, producing a complete human diet and recycling nutrients and maintaining soil fertility, the sustaining of healthy air and water and preventing the loss of crucial elements from active circulation. In biospheric facilities the challenge is also to produce analogues to natural biomes and ecosystems, studying processes of self-organization and adaptation in systems that allow specification or determination of state variables and cycles which may be followed through all interactions from atmosphere to soils. Other challenges include the dynamics and genetics of small populations, the psychological challenges for small isolated human groups and measures and options which may be necessary to ensure long-term operation of closed ecological systems.

  11. Challenged

    Science.gov (United States)

    Manzo, Kathleen Kennedy

    2006-01-01

    The work of librarians can be a lifeline to youths dealing with difficult personal issues, such as family strife, growing up, and sexuality. This paper presents an issue where school library books at Fayetteville High School are questioned because their books are too sexually explicit or mature for teenagers. In the midst of intense media coverage…

  12. Data challenges in ATLAS computing

    CERN Document Server

    Vaniachine, A

    2003-01-01

    ATLAS computing is steadily progressing towards a highly functional software suite, plus a World Wide computing model which gives all ATLAS equal and equal quality of access to ATLAS data. A key component in the period before the LHC is a series of Data Challenges of increasing scope and complexity. The goals of the ATLAS Data Challenges are the validation of the computing model, of the complete software suite, of the data model, and to ensure the correctness of the technical choices to be made. We are committed to 'common solutions' and look forward to the LHC Computing Grid being the vehicle for providing these in an effective way. In close collaboration between the Grid and Data Challenge communities ATLAS is testing large-scale testbed prototypes around the world, deploying prototype components to integrate and test Grid software in a production environment, and running DC1 production at 39 'tier' centers in 18 countries on four continents.

  13. Higgs Machine Learning Challenge 2014

    CERN Multimedia

    Olivier, A-P; Bourdarios, C ; LAL / Orsay; Goldfarb, S ; University of Michigan

    2014-01-01

    High Energy Physics (HEP) has been using Machine Learning (ML) techniques such as boosted decision trees (paper) and neural nets since the 90s. These techniques are now routinely used for difficult tasks such as the Higgs boson search. Nevertheless, formal connections between the two research fields are rather scarce, with some exceptions such as the AppStat group at LAL, founded in 2006. In collaboration with INRIA, AppStat promotes interdisciplinary research on machine learning, computational statistics, and high-energy particle and astroparticle physics. We are now exploring new ways to improve the cross-fertilization of the two fields by setting up a data challenge, following the footsteps of, among others, the astrophysics community (dark matter and galaxy zoo challenges) and neurobiology (connectomics and decoding the human brain). The organization committee consists of ATLAS physicists and machine learning researchers. The Challenge will run from Monday 12th to September 2014.

  14. LHC luminosity upgrade detector challenges

    CERN Multimedia

    CERN. Geneva; de Roeck, Albert; Bortoletto, Daniela; Wigmans, Richard; Riegler, Werner; Smith, Wesley H

    2006-01-01

    LHC luminosity upgrade: detector challenges The upgrade of the LHC machine towards higher luminosity (1035 cm -2s-1) has been studied over the last few years. These studies have investigated scenarios to achieve the increase in peak luminosity by an order of magnitude, as well as the physics potential of such an upgrade and the impact of a machine upgrade on the LHC DETECTORS. This series of lectures will cover the following topics: • Physics motivation and machine scenarios for an order of magnitude increase in the LHC peak luminosity (lecture 1) • Detector challenges including overview of ideas for R&D programs by the LHC experiments: tracking and calorimetry, other new detector developments (lectures 2-4) • Electronics, trigger and data acquisition challenges (lecture 5) Note: the much more ambitious LHC energy upgrade will not be covered

  15. Polymer Informatics: Opportunities and Challenges.

    Science.gov (United States)

    Audus, Debra J; de Pablo, Juan J

    2017-10-01

    We are entering an era where large volumes of scientific data, coupled with algorithmic and computational advances, can reduce both the time and cost of developing new materials. This emerging field known as materials informatics has gained acceptance for a number of classes of materials, including metals and oxides. In the particular case of polymer science, however, there are important challenges that must be addressed before one can start to deploy advanced machine learning approaches for designing new materials. These challenges are primarily related to the manner in which polymeric systems and their properties are reported. In this viewpoint, we discuss the opportunities and challenges for making materials informatics as applied to polymers, or equivalently polymer informatics, a reality.

  16. The medical leadership challenge in healthcare is an identity challenge.

    Science.gov (United States)

    Andersson, Thomas

    2015-01-01

    The purpose of this article is to describe and analyse the identity challenges that physicians with medical leadership positions face. Four qualitative case studies were performed to address the fact that identity is processual, relational and situational. Physicians with managerial roles were interviewed, as well as their peers, supervisors and subordinates. Furthermore, observations were made to understand how different identities are displayed in action. This study illustrates that medical leadership implies identity struggles when physicians have manager positions, because of the different characteristics of the social identities of managers and physicians. Major differences are related between physicians as autonomous individuals in a system and managers as subordinates to the organizational system. There are psychological mechanisms that evoke the physician identity more often than the managerial identity among physicians who are managers, which explains why physicians who are managers tend to remain foremost physicians. The implications of the findings, that there are major identity challenges by being both a physician and manager, suggest that managerial physicians might not be the best prerequisite for medical leadership, but instead, cooperative relationships between physicians and non-physician managers might be a less difficult way to support medical leadership. Acknowledging and addressing identity challenges can be important both in creating structures in organizations and designing the training for managers in healthcare (both physicians and non-physicians) to support medical leadership. Medical leadership is most often related to organizational structure and/or leadership skills, but this paper discusses identity requirements and challenges related to medical leadership.

  17. Success of Breast Cancer Startup Challenge Inspires Second Challenge | Poster

    Science.gov (United States)

    By Thomas Stackhouse, Joseph Conrad, and Michele Newton, Contributing Writers, and Rosemarie Truman, Guest Writer Sixty-one teams have been accepted into, and are now competing in, the Neuro Startup Challenge, a new collaboration established by the National Institutes of Health (NIH) with The Center for Advancing Innovation (CAI) and Heritage Provider Network, Inc.

  18. New Challenges in Model Checking

    Science.gov (United States)

    Holzmann, Gerard J.; Joshi, Rajeev; Groce, Alex

    2006-01-01

    In the last 25 years, the notion of performing software verification with logic model checking techniques has evolved from intellectual curiosity to accepted technology with significant potential for broad practical application. In this paper we look back at the main steps in this evolution and illustrate how the challenges have changed over the years, as we sharpened our theories and tools. Next we discuss a typical challenge in software verification that we face today - and that perhaps we can look back on in another 25 years as having inspired the next logical step towards a broader integration of model checking into the software development process.

  19. Grand Challenges of Enterprise Integration

    Energy Technology Data Exchange (ETDEWEB)

    Brosey, W.D; Neal, R.E.; Marks, D.

    2001-04-01

    Enterprise Integration connects and combines people, processes, systems, and technologies to ensure that the right people and the right processes have the right information and the right resources at the right time. A consensus roadmap for Technologies for Enterprise Integration was created as part of an industry/government/academia partnership in the Integrated Manufacturing Technology Initiative (IMTI). Two of the grand challenges identified by the roadmapping effort will be addressed here--Customer Responsive Enterprises and Totally Connected Enterprises. Each of these challenges is briefly discussed as to the current state of industry and the future vision as developed in the roadmap.

  20. Respiratory challenge MRI: Practical aspects

    OpenAIRE

    Moreton, Fiona C.; Dani, Krishna A.; Goutcher, Colin; O'Hare, Kevin; Muir, Keith W.

    2016-01-01

    Respiratory challenge MRI is the modification of arterial oxygen (PaO2) and/or carbon dioxide (PaCO2) concentration to induce a change in cerebral function or metabolism which is then measured by MRI. Alterations in arterial gas concentrations can lead to profound changes in cerebral haemodynamics which can be studied using a variety of MRI sequences. Whilst such experiments may provide a wealth of information, conducting them can be complex and challenging. In this paper we review the ration...