WorldWideScience

Sample records for water links gaps

  1. Kinetic multi-layer model of gas-particle interactions in aerosols and clouds (KM-GAP: linking condensation, evaporation and chemical reactions of organics, oxidants and water

    Directory of Open Access Journals (Sweden)

    M. Shiraiwa

    2011-12-01

    Full Text Available We present a novel kinetic multi-layer model for gas-particle interactions in aerosols and clouds (KM-GAP that treats explicitly all steps of mass transport and chemical reaction of semi-volatile species partitioning between gas phase, particle surface and particle bulk. KM-GAP is based on the PRA model framework (Pöschl-Rudich-Ammann, 2007, and it includes gas phase diffusion, reversible adsorption, surface reactions, bulk diffusion and reaction, as well as condensation, evaporation and heat transfer. The size change of atmospheric particles and the temporal evolution and spatial profile of the concentration of individual chemical species can be modeled along with gas uptake and accommodation coefficients. Depending on the complexity of the investigated system, unlimited numbers of semi-volatile species, chemical reactions, and physical processes can be treated, and the model shall help to bridge gaps in the understanding and quantification of multiphase chemistry and microphysics in atmospheric aerosols and clouds.

    In this study we demonstrate how KM-GAP can be used to analyze, interpret and design experimental investigations of changes in particle size and chemical composition in response to condensation, evaporation, and chemical reaction. For the condensational growth of water droplets, our kinetic model results provide a direct link between laboratory observations and molecular dynamic simulations, confirming that the accommodation coefficient of water at ~270 K is close to unity. Literature data on the evaporation of dioctyl phthalate as a function of particle size and time can be reproduced, and the model results suggest that changes in the experimental conditions like aerosol particle concentration and chamber geometry may influence the evaporation kinetics and can be optimized for efficient probing of specific physical effects and parameters. With regard to oxidative aging of organic aerosol particles, we illustrate how the

  2. Kinetic multi-layer model of gas-particle interactions in aerosols and clouds (KM-GAP: linking condensation, evaporation and chemical reactions of organics, oxidants and water

    Directory of Open Access Journals (Sweden)

    M. Shiraiwa

    2012-03-01

    Full Text Available We present a novel kinetic multi-layer model for gas-particle interactions in aerosols and clouds (KM-GAP that treats explicitly all steps of mass transport and chemical reaction of semi-volatile species partitioning between gas phase, particle surface and particle bulk. KM-GAP is based on the PRA model framework (Pöschl-Rudich-Ammann, 2007, and it includes gas phase diffusion, reversible adsorption, surface reactions, bulk diffusion and reaction, as well as condensation, evaporation and heat transfer. The size change of atmospheric particles and the temporal evolution and spatial profile of the concentration of individual chemical species can be modeled along with gas uptake and accommodation coefficients. Depending on the complexity of the investigated system and the computational constraints, unlimited numbers of semi-volatile species, chemical reactions, and physical processes can be treated, and the model shall help to bridge gaps in the understanding and quantification of multiphase chemistry and microphysics in atmospheric aerosols and clouds.

    In this study we demonstrate how KM-GAP can be used to analyze, interpret and design experimental investigations of changes in particle size and chemical composition in response to condensation, evaporation, and chemical reaction. For the condensational growth of water droplets, our kinetic model results provide a direct link between laboratory observations and molecular dynamic simulations, confirming that the accommodation coefficient of water at ~270 K is close to unity (Winkler et al., 2006. Literature data on the evaporation of dioctyl phthalate as a function of particle size and time can be reproduced, and the model results suggest that changes in the experimental conditions like aerosol particle concentration and chamber geometry may influence the evaporation kinetics and can be optimized for efficient probing of specific physical effects and parameters. With regard to oxidative

  3. Bridging the Gap: Linking Simulation and Testing

    Energy Technology Data Exchange (ETDEWEB)

    Krajewski, Paul E.; Carsley, John; Stoudt, Mark R.; Hovanski, Yuri

    2012-09-01

    The Materials Genome Initiative (MGI) which is a key enabler for the Advanced Manufacturing Partnership, announced in 2011 by U.S. President Barack Obama, was established to accelerate the development and deployment of advanced materials. The MGI is driven by the need to "bridge the gap" between (I) experimental results and computational analysis to enable the rapid development and validation of new mateirals, and (II) the processes required to convert these materials into useable goods.

  4. Water limits to closing yield gaps

    Science.gov (United States)

    Davis, Kyle Frankel; Rulli, Maria Cristina; Garrassino, Francesco; Chiarelli, Davide; Seveso, Antonio; D'Odorico, Paolo

    2017-01-01

    Agricultural intensification is often seen as a suitable approach to meet the growing demand for agricultural products and improve food security. It typically entails the use of fertilizers, new cultivars, irrigation, and other modern technology. In regions of the world affected by seasonal or chronic water scarcity, yield gap closure is strongly dependent on irrigation (blue water). Global yield gap assessments have often ignored whether the water required to close the yield gap is locally available. Here we perform a gridded global analysis (10 km resolution) of the blue water consumption that is needed annually to close the yield gap worldwide and evaluate the associated pressure on renewable freshwater resources. We find that, to close the yield gap, human appropriation of freshwater resources for irrigation would have to increase at least by 146%. Most study countries would experience at least a doubling in blue water requirement, with 71% of the additional blue water being required by only four crops - maize, rice, soybeans, and wheat. Further, in some countries (e.g., Algeria, Morocco, Syria, Tunisia, and Yemen) the total volume of blue water required for yield gap closure would exceed sustainable levels of freshwater consumption (i.e., 40% of total renewable surface and groundwater resources).

  5. Subharmonic energy-gap structure in superconducting weak links

    DEFF Research Database (Denmark)

    Flensberg, K.; Hansen, Jørn Bindslev; Octavio, M.

    1988-01-01

    We present corrected calculations of the subharmonic energy-gap structure using the model of Octavio, Tinkham, Blonder, and Klapwijk, which includes the effect of normal scattering in the weak link. We show that while the overall predictions of this model do not change qualitatively, the details ...

  6. The missing link : bridging the gap between science and conservation

    NARCIS (Netherlands)

    Hoeven, van der C.A.

    2007-01-01

    Conservation biology is faced with an implementation crisis. This crisis is the result of a “knowledge-doing” or “assessment-planning” gap. One reason for this is that there is a discrepancy between systematic classical scientific assessments or surveys, and actual implementation in the field. This

  7. The missing link : bridging the gap between science and conservation

    NARCIS (Netherlands)

    Hoeven, van der C.A.

    2007-01-01

    Conservation biology is faced with an implementation crisis. This crisis is the result of a “knowledge-doing” or “assessment-planning” gap. One reason for this is that there is a discrepancy between systematic classical scientific assessments or surveys, and actual implementation in the field. This

  8. The missing link : bridging the gap between science and conservation

    OpenAIRE

    Hoeven, van der, J.J.M.

    2007-01-01

    Conservation biology is faced with an implementation crisis. This crisis is the result of a “knowledge-doing” or “assessment-planning” gap. One reason for this is that there is a discrepancy between systematic classical scientific assessments or surveys, and actual implementation in the field. This thesis explores the state of conservation biology by discussing the practicality of several research activities that are needed in most biodiversity conservation projects. Classical conservation sc...

  9. Bridging the Gap between Linked Data and the Semantic Desktop

    Science.gov (United States)

    Groza, Tudor; Drăgan, Laura; Handschuh, Siegfried; Decker, Stefan

    The exponential growth of the World Wide Web in the last decade brought an explosion in the information space, which has important consequences also in the area of scientific research. Finding relevant work in a particular field and exploring the links between publications is currently a cumbersome task. Similarly, on the desktop, managing the publications acquired over time can represent a real challenge. Extracting semantic metadata, exploring the linked data cloud and using the semantic desktop for managing personal information represent, in part, solutions for different aspects of the above mentioned issues. In this paper, we propose an innovative approach for bridging these three directions with the overall goal of alleviating the information overload problem burdening early stage researchers. Our application combines harmoniously document engineering-oriented automatic metadata extraction with information expansion and visualization based on linked data, while the resulting documents can be seamlessly integrated into the semantic desktop.

  10. A methodology to bridge the water information gap

    NARCIS (Netherlands)

    Timmerman, J.G.; Beinat, E.; Termeer, C.J.A.M.; Cofino, W.P.

    2010-01-01

    The metaphor of the water information gap is used to describe the discontent between information users and information producers about the use of and need for specific information. This paper describes the rugby-ball methodology for specification of information needs that was developed on the basis

  11. Linking water resources to food security through virtual water

    Science.gov (United States)

    Tamea, Stefania

    2014-05-01

    interdisciplinary topic. Virtual water and water footprint accounting provide the tools for understanding such implications and to describe, quantify, and investigate the inextricable link existing between water resources and food security.

  12. Gap junctions linking the dendritic network of GABAergic interneurons in the hippocampus.

    Science.gov (United States)

    Fukuda, T; Kosaka, T

    2000-02-15

    The network of GABAergic interneurons connected by chemical synapses is a candidate for the generator of synchronized oscillations in the hippocampus. We present evidence that parvalbumin (PV)-containing GABAergic neurons in the rat hippocampal CA1 region, known to form a network by mutual synaptic contacts, also form another network connected by dendrodendritic gap junctions. Distal dendrites of PV neurons run parallel to the alveus (hippocampal white matter) and establish multiple contacts with one another at the border between the stratum oriens and the alveus. In electron microscopic serial section analysis, gap junctions could be identified clearly at 24% of these contact sites. A dendrodendritic chemical synapse and a mixed synapse also were found between PV-immunoreactive dendrites. Three-dimensional reconstruction of the dendritic arborization revealed that both PV neurons of the well known vertical type (presumptive basket cells and axoaxonic cells) and those of another horizontal type constitute the dendritic network at the light microscopic level. The extent of dendritic fields of single PV neurons in the lateral direction was 538 +/- 201 micrometer (n = 5) in the vertical type and 838 +/- 159 micrometer (n = 6) in the horizontal type. Our previous and present observations indicate that PV-containing GABAergic neurons in the hippocampus form the dual networks connected by chemical and electrical synapses located at axosomatic and dendrodendritic contact sites, respectively. Gap junctions linking the dendritic network may mediate coherent synaptic inputs to distant interneurons and thereby facilitate the synchronization of oscillatory activities generated in the interneuron network.

  13. Bridging the gap between data acquisition and inference ontologies: toward ontology-based link discovery

    Science.gov (United States)

    Goldstein, Michel L.; Morris, Steven A.; Yen, Gary G.

    2003-09-01

    Bridging the gap between low level ontologies used for data acquisition and high level ontologies used for inference is essential to enable the discovery of high-level links between low-level entities. This is of utmost importance in many applications, where the semantic distance between the observable evidence and the target relations is large. Examples of these applications would be detection of terrorist activity, crime analysis, and technology monitoring, among others. Currently this inference gap has been filled by expert knowledge. However, with the increase of the data and system size, it has become too costly to perform such manual inference. This paper proposes a semi-automatic system to bridge the inference gap using network correlation methods, similar to Bayesian Belief Networks, combined with hierarchical clustering, to group and organize data so that experts can observe and build the inference gap ontologies quickly and efficiently, decreasing the cost of this labor-intensive process. A simple application of this method is shown here, where the co-author collaboration structure ontology is inferred from the analysis of a collection of journal publications on the subject of anthrax. This example uncovers a co-author collaboration structures (a well defined ontology) from a scientific publication dataset (also a well defined ontology). Nevertheless, the evidence of author collaboration is poorly defined, requiring the use of evidence from keywords, citations, publication dates, and paper co-authorship. The proposed system automatically suggests candidate collaboration group patterns for evaluation by experts. Using an intuitive graphic user interface, these experts identify, confirm and refine the proposed ontologies and add them to the ontology database to be used in subsequent processes.

  14. Water2Invest: Global facility for calculating investments needed to bridge the climate-induced water gap

    Science.gov (United States)

    Straatsma, Menno; Droogers, Peter; Brandsma, Jairus; Buytaert, Wouter; Karssenberg, Derek; Meijer, Karen; van Aalst, Maaike; van Beek, Rens; Wada, Yoshihide; Bierkens, Marc

    2013-04-01

    Decision makers responsible for climate change adaptation investments are confronted with large uncertainties regarding future water availability and water demand, as well as the investment cost required to reduce the water gap. Moreover, scientists have worked hard to increase fundamental knowledge on climate change and its impacts (climate services), while practical use of this knowledge is limited due to a lack of tools for decision support under uncertain long term future scenarios (decision services). The Water2Invest project aims are to (i) assess the joint impact of climate change and socioeconomic change on water scarcity, (ii) integrate impact and potential adaptation in one flow, (iii) prioritize adaptation options to counteract water scarcity on their financial, regional socio-economic and environmental implications, and (iv) deliver all this information in an integrated user-friendly web-based service. Global water availability is computed between 2006 and 2100 using the PCR-GLOBWB water resources model at a 6 minute spatial resolution. Climate change scenarios are based on the fifth Assessment Report (AR5) of the IPCC Coupled Model Intercomparison Project (CMIP5) that defines four CO2 emission scenarios as representative concentration pathways. Water demand is computed for agriculture, industry, domestic, and environmental requirements based on socio-economic scenarios of increase in population and gross domestic product. Using a linear programming algorithm, water is allocated on a monthly basis over the four sectors. Based on these assessments, the user can evaluate various technological and infrastructural adaptation measures to assess the investments needed to bridge the future water gap. Regional environmental and socioeconomic effects of these investments are evaluated, such as environmental flows or downstream effects. A scheme is developed to evaluate the strategies on robustness and flexibility under climate change and scenario uncertainty

  15. Recurrent Anion Gap Acidosis: An Unusual Presentation of X-Linked Adrenoleukodystrophy in a Five-year-old Male.

    Science.gov (United States)

    Schwab, Joel; Pena, Loren; Sigman, Laura; Waggoner, Darrel

    2010-01-01

    We are presenting a five-year-old male with recurrent anion gap acidosis. During his last admission, it was detected that he had elevated VLCFA and the evaluation discovered that he had X-linked Adrenooleukodystrophy. He had the Addisonian only phenotype without any clinical or radiographic CNS findings. We were unable to find any other reports of this presentation of ALD. If the work-up of recurrent anion gap acidosis does not uncover an etiology, X-linked ALD should be considered in the differential diagnosis.

  16. Link prediction in the network of global virtual water trade

    Science.gov (United States)

    Tuninetti, Marta; Tamea, Stefania; Laio, Francesco; Ridolfi, Luca

    2016-04-01

    Through the international food-trade, water resources are 'virtually' transferred from the country of production to the country of consumption. The international food-trade, thus, implies a network of virtual water flows from exporting to importing countries (i.e., nodes). Given the dynamical behavior of the network, where food-trade relations (i.e., links) are created and dismissed every year, link prediction becomes a challenge. In this study, we propose a novel methodology for link prediction in the virtual water network. The model aims at identifying the main factors (among 17 different variables) driving the creation of a food-trade relation between any two countries, along the period between 1986 and 2011. Furthermore, the model can be exploited to investigate the network configuration in the future, under different possible (climatic and demographic) scenarios. The model grounds the existence of a link between any two nodes on the link weight (i.e., the virtual water flow): a link exists when the nodes exchange a minimum (fixed) volume of virtual water. Starting from a set of potential links between any two nodes, we fit the associated virtual water flows (both the real and the null ones) by means of multivariate linear regressions. Then, links with estimated flows higher than a minimum value (i.e., threshold) are considered active-links, while the others are non-active ones. The discrimination between active and non-active links through the threshold introduces an error (called link-prediction error) because some real links are lost (i.e., missed links) and some non-existing links (i.e., spurious links) are inevitably introduced in the network. The major drivers are those significantly minimizing the link-prediction error. Once the structure of the unweighted virtual water network is known, we apply, again, linear regressions to assess the major factors driving the fluxes traded along (modelled) active-links. Results indicate that, on the one hand

  17. Material gap membrane distillation: A new design for water vapor flux enhancement

    KAUST Repository

    Francis, Lijo

    2013-08-19

    A new module design for membrane distillation, namely material gap membrane distillation (MGMD), for seawater desalination has been proposed and successfully tested. It has been observed that employing appropriate materials between the membrane and the condensation plate in an air gap membrane distillation (AGMD) module enhanced the water vapor flux significantly. An increase in the water vapor flux of about 200-800% was observed by filling the gap with sand and DI water at various feed water temperatures. However, insulating materials such as polypropylene and polyurethane have no effect on the water vapor flux. The influence of material thickness and characteristics has also been investigated in this study. An increase in the water gap width from 9. mm to 13. mm increases the water vapor flux. An investigation on an AGMD and MGMD performance comparison, carried out using two different commercial membranes provided by different manufacturers, is also reported in this paper. © 2013 Elsevier B.V.

  18. Water service delivery - the weakest link

    CSIR Research Space (South Africa)

    Wall, K

    2009-05-01

    Full Text Available and operators • There are ~ 2000 plumbers and other water service men in local government, but ~ 1100 vacancies. Plus more posts required – largely for maintenance • The majority of the 3 000 to 5 000 operators working in the 2 000+ water and wastewater... and systems (e.g. procurement processes) that could enable more assistance than they do; – poor operation and maintenance: the services have been delivered, yes, in the sense that the pipe is in the ground -- but operation and maintenance...

  19. Bridging the Gap: Ideas for water sustainability in the western United States

    Science.gov (United States)

    Tidwell, V. C.; Passell, H. D.; Roach, J. D.

    2012-12-01

    Incremental improvements in water sustainability in the western U.S. may not be able to close the growing gap between increasing freshwater demand, climate driven variability in freshwater supply, and growing environmental consciousness. Incremental improvements include municipal conservation, improvements to irrigation technologies, desalination, water leasing, and others. These measures, as manifest today in the western U.S., are successful in themselves but limited in their ability to solve long term water scarcity issues. Examples are plainly evident and range from the steady and long term decline of important aquifers and their projected inability to provide water for future agricultural irrigation, projected declines in states' abilities to meet legal water delivery obligations between states, projected shortages of water for energy production, and others. In many cases, measures that can close the water scarcity gap have been identified, but often these solutions simply shift the gap from water to some other sector, e.g., economics. Saline, brackish or produced water purification, for example, could help solve western water shortages in some areas, but will be extremely expensive, and so shift the gap from water to economics. Transfers of water out of agriculture could help close the water scarcity gap in other areas; however, loss of agriculture will shift the gap to regional food security. All these gaps, whether in water, economics, food security, or other sectors, will have a negative impact on the western states. Narrowing these future gaps requires both technical and policy solutions as well as tools to understand the tradeoffs. Here we discuss several examples from across the western U.S. that span differing scales and decision spaces. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear

  20. A mechanism of gap junction docking revealed by functional rescue of a human-disease-linked connexin mutant.

    Science.gov (United States)

    Gong, Xiang-Qun; Nakagawa, So; Tsukihara, Tomitake; Bai, Donglin

    2013-07-15

    Gap junctions are unique intercellular channels formed by the proper docking of two hemichannels from adjacent cells. Each hemichannel is a hexamer of connexins (Cxs) - the gap junction subunits, which are encoded by 21 homologous genes in the human genome. The docking of two hemichannels to form a functional gap junction channel is only possible between compatible Cxs, but the underlying molecular mechanism is unclear. On the basis of the crystal structure of the Cx26 gap junction, we developed homology models for homotypic and heterotypic channels from Cx32 and/or Cx26; these models predict six hydrogen bonds at the docking interface of each pair of the second extracellular domain (E2). A Cx32 mutation N175H and a human-disease-linked mutant N175D were predicted to lose the majority of the hydrogen bonds at the E2 docking-interface; experimentally both mutations failed to form morphological and functional gap junctions. To restore the lost hydrogen bonds, two complementary Cx26 mutants - K168V and K168A were designed to pair with the Cx32 mutants. When docked with Cx26K168V or K168A, the Cx32N175H mutant was successfully rescued morphologically and functionally in forming gap junction channels, but not Cx32 mutant N175Y. By testing more homotypic and heterotypic Cx32 and/or Cx26 mutant combinations, it is revealed that a minimum of four hydrogen bonds at each E2-docking interface are required for proper docking and functional channel formation between Cx26 and Cx32 hemichannels. Interestingly, the disease-linked Cx32N175D could be rescued by Cx26D179N, which restored five hydrogen bonds at the E2-docking interface. Our findings not only provide a mechanism for gap junction docking for Cx26 and Cx32 hemichannels, but also a potential therapeutic strategy for gap junction channelopathies.

  1. Linking water treatment practices and fish welfare

    DEFF Research Database (Denmark)

    Zubiaurre, Claire; Pedersen, Lars-Flemming

    2016-01-01

    Peracetic acids can be used as sanitizers to control water quality in aquaculture systems. As an alternative to formalin, chloramine-T or copper sulphate, PAA has strong anti-microbial effects, degrades quickly and is relatively safe to use. Its mode of action and associated rapid decay can make...

  2. Linking water treatment practices and fish welfare

    DEFF Research Database (Denmark)

    Zubiaurre, Claire; Pedersen, Lars-Flemming

    2016-01-01

    Peracetic acids can be used as sanitizers to control water quality in aquaculture systems. As an alternative to formalin, chloramine-T or copper sulphate, PAA has strong anti-microbial effects, degrades quickly and is relatively safe to use. Its mode of action and associated rapid decay can make...... optimizing treatment protocols a challenge. Continuous low-dose applications seem to be a promising solution. In this preliminary study behavioral response was used to assess potential correlations with PAA dosage. A behavioral change or response is not necessarily an indication of compromised welfare....... Supportive enzymatic, biochemical and physiological biomarkers can be used along with gill and epidermal histological measures to evaluate the effects on water treatment regimens. The ultimate goal is to define the therapeutic window where fish welfare is not compromised.PAA is among the few disinfectants...

  3. Robust Decision Making and Info-Gap Decision Theory for water resource system planning

    Science.gov (United States)

    Matrosov, Evgenii S.; Woods, Ashley M.; Harou, Julien J.

    2013-06-01

    Stationarity assumptions of linked human-water systems are frequently invalid given the difficult-to-predict changes affecting such systems. In this case water planning occurs under conditions of deep or severe uncertainty, where the statistical distributions of future conditions and events are poorly known. In such situations predictive system simulation models are typically run under different scenarios to evaluate the performance of future plans under different conditions. Given that there are many possible plans and many possible futures, which simulations will lead to the best designs? Robust Decision Making (RDM) and Info-Gap Decision Theory (IGDT) provide a structured approach to planning complex systems under such uncertainty. Both RDM and IGDT make repeated use of trusted simulation models to evaluate different plans under different future conditions. Both methods seek to identify robust rather than optimal decisions, where a robust decision works satisfactorily over a broad range of possible futures. IGDT efficiently charts system performance with robustness and opportuneness plots summarising system performance for different plans under the most dire and favourable sets of future conditions. RDM samples a wider range of dire, benign and opportune futures and offers a holistic assessment of the performance of different options. RDM also identifies through ‘scenario discovery' which combinations of uncertain future stresses lead to system vulnerabilities. In our study we apply both frameworks to a water resource system planning problem: London's water supply system expansion in the Thames basin, UK. The methods help identify which out of 20 proposed water supply infrastructure portfolios is the most robust given severely uncertain future hydrological inflows, water demands and energy prices. Multiple criteria of system performance are considered: service reliability, storage susceptibility, capital and operating cost, energy use and environmental flows

  4. Transport of Antarctic bottom water through the Kane Gap, tropical NE Atlantic Ocean

    NARCIS (Netherlands)

    Morozov, E.G.; Tarakanov, R.Y.; van Haren, H.

    2013-01-01

    We study low-frequency properties of the Antarctic Bottom Water (AABW) flow through the Kane Gap (9° N) in the Atlantic Ocean. The measurements in the Kane Gap include five visits with CTD (Conductivity-Temperature-Depth) sections in 2009–2012 and a year-long record of currents on a mooring using th

  5. Transport of Antarctic bottom water through the Kane Gap, tropical NE Atlantic Ocean

    NARCIS (Netherlands)

    Morozov, E.G.; Tarakanov, R.Y.; van Haren, H.

    2013-01-01

    We study low-frequency properties of the Antarctic Bottom Water (AABW) flow through the Kane Gap (9° N) in the Atlantic Ocean. The measurements in the Kane Gap include five visits with CTD (Conductivity-Temperature-Depth) sections in 2009–2012 and a year-long record of currents on a mooring using th

  6. Mind the Gap: Persistent and Mobile Organic Compounds-Water Contaminants That Slip Through.

    Science.gov (United States)

    Reemtsma, Thorsten; Berger, Urs; Arp, Hans Peter H; Gallard, Hervé; Knepper, Thomas P; Neumann, Michael; Quintana, José Benito; Voogt, Pim de

    2016-10-04

    The discharge of persistent and mobile organic chemicals (PMOCs) into the aquatic environment is a threat to the quality of our water resources. PMOCs are highly polar (mobile in water) and can pass through wastewater treatment plants, subsurface environments and potentially also drinking water treatment processes. While a few such compounds are known, we infer that their number is actually much larger. This Feature highlights the issue of PMOCs from an environmental perspective and assesses the gaps that appear to exist in terms of analysis, monitoring, water treatment and regulation. On this basis we elaborate strategies on how to narrow these gaps with the intention to better protect our water resources.

  7. Accuracy Assessment Points Modified for Delaware Water Gap National Recreation Area Vegetation Mapping Project

    Data.gov (United States)

    National Park Service, Department of the Interior — Location of thematic accuracy assessment sampling points used in the vegetation and fire fuel model mapping in Delaware Water Gap National Recreation Area. In this...

  8. Field Plot Points Modified for Delaware Water Gap National Recreation Area Vegetation Mapping Project

    Data.gov (United States)

    National Park Service, Department of the Interior — Location of vegetation sampling plots use to collect data for vegetation classification and mapping at Delaware Water Gap National Recreation Area. In this data set,...

  9. The reparative response to cross-linked collagen-based scaffolds in a rat spinal cord gap model.

    Science.gov (United States)

    Cholas, Rahmatullah H; Hsu, Hu-Ping; Spector, Myron

    2012-03-01

    Prior work demonstrated the improvement of peripheral nerve regeneration in gaps implanted with collagen scaffold-filled collagen tubes, compared with nerve autografts, and the promise of such implants for treating gaps in spinal cord injury (SCI) in rats. The objective of this study was to investigate collagen implants alone and incorporating select therapeutic agents in a 5-mm full-resection gap model in the rat spinal cord. Two studies were performed, one with a 6-week time point and one with a 2-week time point. For the 6-week study the groups included: (1) untreated control, (2) dehydrothermally (DHT)-cross-linked collagen scaffold, (3) DHT-cross-linked collagen scaffold seeded with adult rat neural stem cells (NSCs), and (4) DHT-cross-linked collagen scaffold incorporating plasmid encoding glial cell line-derived neurotropic factor (pGDNF). The 2-week study groups were: (1) nontreated control, (2) DHT-cross-linked collagen scaffold; (3) DHT-cross-linked collagen scaffold containing laminin; and (4) carbodiimide-cross-linked collagen scaffold containing laminin. The tissue filling the defect of all groups at 6 weeks was largely composed of fibrous scar; however, the tissue was generally more favorably aligned with the long axis of the spinal cord in all of the treatment groups, but not in the control group. Quantification of the percentage of animals per group containing cystic cavities in the defect showed a trend toward fewer rats with cysts in the groups in which the scaffolds were implanted compared to control. All of the collagen implants were clearly visible and mostly intact after 2 weeks. A band of fibrous tissue filling the control gaps was not seen in the collagen implant groups. In all of the groups there was a narrowing of the spinal canal within the gap as a result of surrounding soft tissue collapse into the defect. The narrowing of the spinal canal occurred to a greater extent in the control and DHT scaffold alone groups compared to the DHT

  10. The gender gap reloaded: are school characteristics linked to labor market performance?

    Science.gov (United States)

    Konstantopoulos, Spyros; Constant, Amelie

    2008-06-01

    This study examines the wage gender gap of young adults in the 1970s, 1980s, and 2000 in the US. Using quantile regression we estimate the gender gap across the entire wage distribution. We also study the importance of high school characteristics in predicting future labor market performance. We conduct analyses for three major racial/ethnic groups in the US: Whites, Blacks, and Hispanics, employing data from two rich longitudinal studies: NLS and NELS. Our results indicate that while some school characteristics are positive and significant predictors of future wages for Whites, they are less so for the two minority groups. We find significant wage gender disparities favoring men across all three surveys in the 1970s, 1980s, and 2000. The wage gender gap is more pronounced in higher paid jobs (90th quantile) for all groups, indicating the presence of a persistent and alarming "glass ceiling."

  11. Linking the HOMO-LUMO gap to torsional disorder in P3HT/PCBM blends

    Science.gov (United States)

    McLeod, John A.; Pitman, Amy L.; Kurmaev, Ernst Z.; Finkelstein, Larisa D.; Zhidkov, Ivan S.; Savva, Achilleas; Moewes, Alexander

    2015-12-01

    The electronic structure of [6,6]-phenyl C61 butyric acid methyl ester (PCBM), poly(3-hexylthiophene) (P3HT), and P3HT/PCBM blends is studied using soft X-ray emission and absorption spectroscopy and density functional theory calculations. We find that annealing reduces the HOMO-LUMO gap of P3HT and P3HT/PCBM blends, whereas annealing has little effect on the HOMO-LUMO gap of PCBM. We propose a model connecting torsional disorder in a P3HT polymer to the HOMO-LUMO gap, which suggests that annealing helps to decrease the torsional disorder in the P3HT polymers. Our model is used to predict the characteristic length scales of the flat P3TH polymer segments in P3HT and P3HT/PCBM blends before and after annealing. Our approach may prove useful in characterizing organic photovoltaic devices in situ or even in operando.

  12. Linking global water demand and supply using remote sensing products

    Science.gov (United States)

    Poortinga, A.; Thanh Ha, L.; Phuong Vu, N.; Saah, D. S.; Cutter, P. G.; Troy, A.; Ganz, D.

    2016-12-01

    Due to increasing pressures on water resources and changing population dynamics, there is a need to monitor regional water resource availability in a spatially and temporally explicit manner. However, for many parts of the world, there is insufficient data to quantify stream flow in river basins or potential ground water infiltration rates. Often water resource managers use sophistic hydrology models that require complex data sets to generate estimations, but the results of these efforts lack confidence due to the absence of accurate input data or validation methods. Global open access remote sensing derived data products offer exciting new opportunities to study spatial-temporal water dynamics in a way directly relevant to managers. We present the results of an elegant pixel-based water balance formulation to partition rainfall into evapotranspiration, surface water runoff and potential ground water. The method provides a rapid, accurate, and cost-effective solution to mapping water resource availability in basins with no gauges or monitoring infrastructure. The presented method provides important new insights into the spatial and temporal water supply and demand dynamics. The preliminary result of an application of the model build for the Mekong region will be presented, where quantitative water supply estimations are linked with demand patterns. It will be demonstrated that global freely available remote sensing products can be used to produce significant and operational results for water resource managers. We demonstrate that space based technologies and their applications play a key role to optimize the planning, implementation, and monitoring of projects.

  13. Size Reduction of a DC Link Choke Using Saturation Gap and Biasing with Permanent Magnets

    DEFF Research Database (Denmark)

    Aguilar, Andres Revilla; Munk-Nielsen, Stig; Zuccherato, Marco;

    2014-01-01

    This document describes the design procedure of permanent magnet biased DC inductors using the Saturation-gap technique [1]. This biasing configuration can provide a 50% reduction in either the core volume or the number of turns, while meeting its current and inductance requirements. A design exa...

  14. Xylobolus subpileatus, a specialized basidiomycete functionally linked to old canopy gaps

    DEFF Research Database (Denmark)

    Taudiere, A.; Bellanger, J. M.; Moreau, P. A.

    2017-01-01

    treefall. In contrast, the abundance and the richness of saprobic and ectomycorrhizal fruitbodies decrease as canopy gaps age. Our results emphasize the high ecological specialization of X. subpileatus. They also highlight the imperative need to conserve the last patches of old-growth Mediterranean forests...

  15. Integrated crop water management might sustainably halve the global food gap

    Science.gov (United States)

    Jägermeyr, J.; Gerten, D.; Schaphoff, S.; Heinke, J.; Lucht, W.; Rockström, J.

    2016-02-01

    As planetary boundaries are rapidly being approached, humanity has little room for additional expansion and conventional intensification of agriculture, while a growing world population further spreads the food gap. Ample evidence exists that improved on-farm water management can close water-related yield gaps to a considerable degree, but its global significance remains unclear. In this modeling study we investigate systematically to what extent integrated crop water management might contribute to closing the global food gap, constrained by the assumption that pressure on water resources and land does not increase. Using a process-based bio-/agrosphere model, we simulate the yield-increasing potential of elevated irrigation water productivity (including irrigation expansion with thus saved water) and optimized use of in situ precipitation water (alleviated soil evaporation, enhanced infiltration, water harvesting for supplemental irrigation) under current and projected future climate (from 20 climate models, with and without beneficial CO2 effects). Results show that irrigation efficiency improvements can save substantial amounts of water in many river basins (globally 48% of non-productive water consumption in an ‘ambitious’ scenario), and if rerouted to irrigate neighboring rainfed systems, can boost kcal production significantly (26% global increase). Low-tech solutions for small-scale farmers on water-limited croplands show the potential to increase rainfed yields to a similar extent. In combination, the ambitious yet achievable integrated water management strategies explored in this study could increase global production by 41% and close the water-related yield gap by 62%. Unabated climate change will have adverse effects on crop yields in many regions, but improvements in water management as analyzed here can buffer such effects to a significant degree.

  16. Structural analysis of key gap junction domains--Lessons from genome data and disease-linked mutants.

    Science.gov (United States)

    Bai, Donglin

    2016-02-01

    A gap junction (GJ) channel is formed by docking of two GJ hemichannels and each of these hemichannels is a hexamer of connexins. All connexin genes have been identified in human, mouse, and rat genomes and their homologous genes in many other vertebrates are available in public databases. The protein sequences of these connexins align well with high sequence identity in the same connexin across different species. Domains in closely related connexins and several residues in all known connexins are also well-conserved. These conserved residues form signatures (also known as sequence logos) in these domains and are likely to play important biological functions. In this review, the sequence logos of individual connexins, groups of connexins with common ancestors, and all connexins are analyzed to visualize natural evolutionary variations and the hot spots for human disease-linked mutations. Several gap junction domains are homologous, likely forming similar structures essential for their function. The availability of a high resolution Cx26 GJ structure and the subsequently-derived homology structure models for other connexin GJ channels elevated our understanding of sequence logos at the three-dimensional GJ structure level, thus facilitating the understanding of how disease-linked connexin mutants might impair GJ structure and function. This knowledge will enable the design of complementary variants to rescue disease-linked mutants. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Desalination and Water Recycling by Air Gap Membrane Distillation

    NARCIS (Netherlands)

    Meindersma, G.W.; Guijt, C.M.; de Haan, A.B.

    2006-01-01

    Membrane distillation (MD) is an emerging technology for desalination. Membrane distillation differs from other membrane technologies in that the driving force for desalination is the difference in vapour pressure of water across the membrane, rather than total pressure. The membranes for MD are

  18. Water recycling and desalination by air gap membrane distillation

    NARCIS (Netherlands)

    Meindersma, G.W.; Guijt, C.M.; Haan, de A.B.

    2005-01-01

    Because salt and other small components are the most common compounds in wastewater from the process industry, desalination techniques are likely to be suitable as treatment processes in many cases. Although membrane distillation (MD) is a well-known technology for desalination and water treatment,

  19. Desalination and water recycling by air gap membrane distillation

    NARCIS (Netherlands)

    Meindersma, G.W.; Guijt, C.M.; Haan, de A.B.

    2006-01-01

    Membrane distillation (MD) is an emerging technology for desalination. Membrane distillation differs from other membrane technologies in that the driving force for desalination is the difference in vapour pressure of water across the membrane, rather than total pressure. The membranes for MD are hyd

  20. Linking the HOMO-LUMO gap to torsional disorder in P3HT/PCBM blends

    Energy Technology Data Exchange (ETDEWEB)

    McLeod, John A., E-mail: jmcleod@suda.edu.cn [College of Nano Science and Technology, Soochow University, 199 Ren-Ai Rd., Suzhou, Jiangsu 215123 (China); Pitman, Amy L.; Moewes, Alexander [Department of Physics and Engineering Physics, University of Saskatchewan, 116 Science Place, Saskatoon, Saskatchewan S7N 5E2 (Canada); Kurmaev, Ernst Z.; Finkelstein, Larisa D. [Institute of Metal Physics, Russian Academy of Sciences–Ural Division, 620990 Yekaterinburg (Russian Federation); Zhidkov, Ivan S. [Ural Federal University, 620002 Yekaterinburg (Russian Federation); Savva, Achilleas [Molecular Electronics and Photonics Research Unit, Department of Mechanical Engineering and Materials Science and Engineering, Cyprus University of Technology, Kitiou Kiprianou St. 45, 3603 Limassol (Cyprus)

    2015-12-14

    The electronic structure of [6,6]-phenyl C{sub 61} butyric acid methyl ester (PCBM), poly(3-hexylthiophene) (P3HT), and P3HT/PCBM blends is studied using soft X-ray emission and absorption spectroscopy and density functional theory calculations. We find that annealing reduces the HOMO-LUMO gap of P3HT and P3HT/PCBM blends, whereas annealing has little effect on the HOMO-LUMO gap of PCBM. We propose a model connecting torsional disorder in a P3HT polymer to the HOMO-LUMO gap, which suggests that annealing helps to decrease the torsional disorder in the P3HT polymers. Our model is used to predict the characteristic length scales of the flat P3TH polymer segments in P3HT and P3HT/PCBM blends before and after annealing. Our approach may prove useful in characterizing organic photovoltaic devices in situ or even in operando.

  1. Jumpstarting post-conflict strategic water resources protection from a changing global perspective: gaps and prospects in Afghanistan.

    Science.gov (United States)

    Habib, H; Anceno, A J; Fiddes, J; Beekma, J; Ilyuschenko, M; Nitivattananon, V; Shipin, O V

    2013-11-15

    Notwithstanding ambiguities, long-term economic resurgence in Afghanistan amidst water insecurity exacerbated by climate change decisively requires a water protection strategy that will complement a multitude of agroindustrial and socioeconomic activities in an environmentally sustainable and climate resilient manner. In this paper, we begin with a perspective on institutions, legislation, and key issues in the water sector of Afghanistan. We then embark on linking the integrated water resources management (IWRM) and strategic environmental assessment (SEA) approaches as a novel framework for strategic water management and subsequently propose a strategy for post-conflict water protection based on the coalesced IWRM and SEA. Context relevant good practices worldwide are presented to provide empirical evidence for this approach whereas perceived opportunities and vulnerabilities in the Afghan context are discussed. Examination of post-conflict water sector initiatives in Afghanistan reveals the critical role of foreign assistance in both water infrastructure rehabilitation and modernization of the institutional aspect of water management. The introduction of IWRM as the basis for a progressive water sector strategy has been seen as a major milestone which is detrimentally matched by substantial deficiency in national capacity for implementation. Concurrently, the role of extra-national actors in relevant policy interventions has been considered catalytic despite criticisms of proposed regulations as being anachronistic to field realities. Therefore the view is maintained to practicable policies by accelerating policy learning in the country's water and environment sectors to encourage homegrown water strategy innovations. Demonstratively, mainstreaming IWRM-SEA coalescence will bridge institutional gaps for better feedback between local and national water stakeholders, providing a venue for improved delivery of water services to sustain post-conflict socioeconomic

  2. The gender gap reloaded: is school quality linked to labor market performance?

    OpenAIRE

    Konstantopoulos, Spyros; Constant, Amelie F.

    2005-01-01

    This study examines the gender gap in wages of young adults in the late 1970s, mid 1980s, and 2000, in the middle and the tails of the wage distribution using quantile regression. We also examine the importance of school quality indicators in predicting future labor market performance. We conduct analyses for three major racial groups in the US: Whites, Blacks, and Hispanics. We employ base year and follow up data from two rich longitudinal studies: the National Longitudinal Study (NLS) of hi...

  3. Single-Crystal Semiconductors with Narrow Band Gaps for Solar Water Splitting.

    Science.gov (United States)

    Wang, Tuo; Gong, Jinlong

    2015-09-07

    Solar water splitting provides a clean and renewable approach to produce hydrogen energy. In recent years, single-crystal semiconductors such as Si and InP with narrow band gaps have demonstrated excellent performance to drive the half reactions of water splitting through visible light due to their suitable band gaps and low bulk recombination. This Minireview describes recent research advances that successfully overcome the primary obstacles in using these semiconductors as photoelectrodes, including photocorrosion, sluggish reaction kinetics, low photovoltage, and unfavorable planar substrate surface. Surface modification strategies, such as surface protection, cocatalyst loading, surface energetics tuning, and surface texturization are highlighted as the solutions.

  4. A Linked Hydro-Economic Model to Examine the Effects of Water Policy on Rural Poverty

    Science.gov (United States)

    Maneta, M. P.; Torres, M.; Vosti, S. A.; Wallender, W. W.; Howitt, R.; Rodrigues, L. N.; Bassoi, L. H.; Pfeiffer, L.; Young, J.

    2006-12-01

    The sustainable intensification of small-scale agriculture is a necessary condition for reducing rural poverty in developing countries. Increasing the amount of irrigated cropland and the economic efficiency of irrigation are two key components of most intensification strategies. Improved access to water generally increases farm income but richer farmers use a disproportionate share of the available water, decreasing the chances of poor farmers to meet their water needs. Furthermore, water and poverty have strong spatial components that have so far been neglected in water planning. In that sense, too little is known about the short and long term hydrological effects, especially the externality effects of changes in on-farm water use and its implications to nearby farmers. To address this gap in knowledge, a spatially distributed and transient description of changes in surface and groundwater allocation under different agricultural management scenarios is needed. We propose a hydro-economic model providing a realistic spatio-temporal description of the linkages between the economic and hydrologic subsystems. This hydro-economic model is composed of a basin-level 3D spatially distributed transient hydrologic model (MOD-HMS) and a farm-level, spatially distributed agricultural production model. Both models are explicitly linked through the boundary conditions of the hydrologic model. The linkage will account for the spatial and temporal impact of different crop mixes, irrigation techniques and groundwater pumpage on water availability at farm level to assess the effects of policy action on the hydro-economic components of the system.

  5. Healthier students are better learners: a missing link in school reforms to close the achievement gap.

    Science.gov (United States)

    Basch, Charles E

    2011-10-01

    This article provides an introduction to the October 2011 special issue of the Journal of School Health on "Healthier Students Are Better Learners." Literature was reviewed and synthesized to identify health problems affecting school-aged youth that are highly prevalent, disproportionately affect urban minority youth, directly and indirectly causally affect academic achievement, and can be feasibly and effectively addressed through school health programs and services. Based on these criteria, 7 educationally relevant health disparities were selected as strategic priorities to help close the achievement gap: (1) vision, (2) asthma, (3) teen pregnancy, (4) aggression and violence, (5) physical activity, (6) breakfast, and (7) inattention and hyperactivity. Research clearly shows that these health problems influence students' motivation and ability to learn. Disparities among urban minority youth are outlined, along with the causal pathways through which each adversely affects academic achievement, including sensory perceptions, cognition, school connectedness, absenteeism, and dropping out. Evidence-based approaches that schools can implement to address these problems are presented. These health problems and the causal pathways they influence have interactive and a synergistic effect, which is why they must be addressed collectively using a coordinated approach. No matter how well teachers are prepared to teach, no matter what accountability measures are put in place, no matter what governing structures are established for schools, educational progress will be profoundly limited if students are not motivated and able to learn. Particular health problems play a major role in limiting the motivation and ability to learn of urban minority youth. This is why reducing these disparities through a coordinated approach warrants validation as a cohesive school improvement initiative to close the achievement gap. Local, state, and national policies for implementing this

  6. A vital link: water and vegetation in the Anthropocene

    Directory of Open Access Journals (Sweden)

    D. Gerten

    2013-10-01

    Full Text Available This paper argues that the interplay of water, carbon and vegetation dynamics fundamentally links some global trends in the current and conceivable future Anthropocene, such as cropland expansion, freshwater use, and climate change and its impacts. Based on a review of recent literature including geographically explicit simulation studies with the process-based LPJmL global biosphere model, it demonstrates that the connectivity of water and vegetation dynamics is vital for water security, food security and (terrestrial ecosystem dynamics alike. The water limitation of net primary production of both natural and agricultural plants – already pronounced in many regions – is shown to increase in many places under projected climate change, though this development is partially offset by water-saving direct CO2 effects. Natural vegetation can to some degree adapt dynamically to higher water limitation, but agricultural crops usually require some form of active management to overcome it – among them irrigation, soil conservation and eventually shifts of cropland to areas that are less water-limited due to more favourable climatic conditions. While crucial to secure food production for a growing world population, such human interventions in water–vegetation systems have, as also shown, repercussions on the water cycle. Indeed, land use changes are shown to be the second-most important influence on the terrestrial water balance in recent times. Furthermore, climate change (warming and precipitation changes will in many regions increase irrigation demand and decrease water availability, impeding rainfed and irrigated food production (if not CO2 effects counterbalance this impact – which is unlikely at least in poorly managed systems. Drawing from these exemplary investigations, some research perspectives on how to further improve our knowledge of human–water–vegetation interactions in the Anthropocene are outlined.

  7. Identifying the Gaps in Practice for Combating Lead in Drinking Water in Hong Kong.

    Science.gov (United States)

    Lee, Wai Ling; Jia, Jie; Bao, Yani

    2016-09-30

    Excessive lead has been found in drinking water in Hong Kong in tests carried out in 2015. Investigations have identified that the problem in public rental housing estates was caused by the problematic solders used in the plumbing, and recommendations on enhancing the quality control system and strengthening the relevant water quality standards have been proposed. The cause for the same problem happening in other premises where soldering has not been adopted for water pipe connections is left unidentified. Considering the unidentified cause and the recommendations made, this study aims to identify the gaps in practice followed in Hong Kong for safeguarding the water quality of new installations. A holistic review of governing ordinances and regulations, products and materials used and the testing and commissioning requirements adopted in Hong Kong and elsewhere in the world were conducted. Based on international practices and parametric analysis, it was found that there are gaps in practices followed in Hong Kong, which are directly and indirectly leading to the lead-in-water crisis. Recommendations for improvement in the quality control system, and the water quality standards including the allowable lead content and leaching limit for products and materials and the testing and commissioning requirements on plumbing installations have been made. The review and the identified gaps would become useful reference for countries in strengthening their relevant water quality standards.

  8. Identifying the Gaps in Practice for Combating Lead in Drinking Water in Hong Kong

    Directory of Open Access Journals (Sweden)

    Wai Ling Lee

    2016-09-01

    Full Text Available Excessive lead has been found in drinking water in Hong Kong in tests carried out in 2015. Investigations have identified that the problem in public rental housing estates was caused by the problematic solders used in the plumbing, and recommendations on enhancing the quality control system and strengthening the relevant water quality standards have been proposed. The cause for the same problem happening in other premises where soldering has not been adopted for water pipe connections is left unidentified. Considering the unidentified cause and the recommendations made, this study aims to identify the gaps in practice followed in Hong Kong for safeguarding the water quality of new installations. A holistic review of governing ordinances and regulations, products and materials used and the testing and commissioning requirements adopted in Hong Kong and elsewhere in the world were conducted. Based on international practices and parametric analysis, it was found that there are gaps in practices followed in Hong Kong, which are directly and indirectly leading to the lead-in-water crisis. Recommendations for improvement in the quality control system, and the water quality standards including the allowable lead content and leaching limit for products and materials and the testing and commissioning requirements on plumbing installations have been made. The review and the identified gaps would become useful reference for countries in strengthening their relevant water quality standards.

  9. Modelling global freshwater resources using WaterGAP 2.2 - model overview, selected results and applications

    Science.gov (United States)

    Müller Schmied, Hannes; Adam, Linda; Döll, Petra; Eisner, Stephanie; Flörke, Martina; Güntner, Andreas; Kynast, Ellen; Portmann, Felix T.; Riedel, Claudia; Schneider, Christoph; Song, Qi; Wattenbach, Martin; Zhang, Jing

    2014-05-01

    The estimation of global freshwater flows and storages and their dynamics is essential for the assessment of historical and future water availability both for mankind and ecosystems. WaterGAP 2 is a state-of-the-art water model covering the entire global land area (except Antarctica) on a 0.5° by 0.5° grid. WaterGAP consists of a set of water use models and a hydrological model. Five global water use models representing the sectors irrigation, domestic water demand, manufacturing industries, livestock farming and cooling of thermal power plants inform the sub-model GWSWUSE which calculates net water abstractions distinguishing surface water and groundwater sources. Water flows and storages are simulated by the WaterGAP Global Hydrology Model (WGHM). WGHM is calibrated against measured discharge for basins covering around 50 % of global land area. Since the original development of WaterGAP in the late 1990s, new input data and refined process algorithms have led to a significant improvement of the results. We present the current version WaterGAP 2.2 including selected results (e.g. discharge seasonality, water storage) and the global water balance for the time period 1971-2000. In addition, some examples of the application of WaterGAP output, e.g. within the GRACE community and for global environmental assessments are shown, reflecting the importance of global hydrology modeling in our globalized world.

  10. Monitoring hemlock crown health in Delaware Water Gap National Recreation Area

    Science.gov (United States)

    Michael E. Montgomery; Bradley Onken; Richard A. Evans; Richard A. Evans

    2005-01-01

    Decline of the health of hemlocks in Delaware Water Gap National Recreation Area was noticeable in the southern areas of the park by 1992. The following year, a series of plots were established to monitor hemlock health and the abundance of hemlock woolly adelgid. This poster examines only the health rating of the hemlocks in the monitoring plots.

  11. Bridging the climate-induced water gap in the twenty-first century: adaptation support based on water supply, demand, adaptation and financing.

    Science.gov (United States)

    Straatsma, Menno; Droogers, Peter; Brandsma, Jaïrus; Buytaert, Wouter; Karssenberg, Derek; Van Beek, Rens; Wada, Yoshihide; Sutanudjaja, Edwin; Vitolo, Claudia; Schmitz, Oliver; Meijer, Karen; Van Aalst, Maaike; Bierkens, Marc

    2014-05-01

    realistic combinations of a shared socio-economic pathways (SSPs) and RCPs. Our Water And Climate Adaptation Model (WatCAM) was used to compute the water gap based on reservoir capacity, water supply, and water demand. WatCam is based on the existing ModSim (Labadie, 2010) water allocation model, and facilitated the evaluation of nine technological and infrastructural adaptation measures to assess the investments needed to bridge the future water gap. Regional environmental and socio-economic effects of these investments, such as environmental flows or downstream effects, were evaluated. A scheme was developed to evaluate the strategies on robustness and flexibility under climate change and scenario uncertainty, and each measure was linked to possibilities for investment and financing mechanisms. The WatCAM is available as a web modeling service from www.water2invest.com, and enables user specified adaptation measures and the creation of an ensemble of water gap forecasts.

  12. Linking Europa's plume activity to tides, tectonics, and liquid water

    CERN Document Server

    Rhoden, Alyssa R; Roth, Lorenz; Retherford, Kurt

    2015-01-01

    Much of the geologic activity preserved on Europa's icy surface has been attributed to tidal deformation, mainly due to Europa's eccentric orbit. Although the surface is geologically young (30 - 80 Myr), there is little information as to whether tidally-driven surface processes are ongoing. However, a recent detection of water vapor near Europa's south pole suggests that it may be geologically active. Initial observations indicated that Europa's plume eruptions are time-variable and may be linked to its tidal cycle. Saturn's moon, Enceladus, which shares many similar traits with Europa, displays tidally-modulated plume eruptions, which bolstered this interpretation. However, additional observations of Europa at the same time in its orbit failed to yield a plume detection, casting doubt on the tidal control hypothesis. The purpose of this study is to analyze the timing of plume eruptions within the context of Europa's tidal cycle to determine whether such a link exists and examine the inferred similarities and...

  13. Bridging the gap between marine biogeochemical and fisheries sciences; configuring the zooplankton link

    DEFF Research Database (Denmark)

    Mitra, Aditee; Castellani, Claudia; Gentleman, Wendy

    2014-01-01

    phytoplankton- dominated biogeochemistry or on aspects of fisheries regulation. In consequence the roles of zooplankton communities (protists and metazoans) linking phytoplankton and fish communities are typically under-represented if not (especially in fisheries models) ignored. Where represented in ecosystem...... models, zooplankton are usually incorporated in an extremely simplistic fashion, using empirical descriptions merging various interacting physiological functions governing zooplankton growth and development, and thence ignoring physiological feedback mechanisms. Here we demonstrate, within a modelled...... plankton food-web system, how trophic dynamics are sensitive to small changes in parameter values describing zooplankton vital rates and thus the importance of using appropriate zooplankton descriptors. Through a comprehensive review, we reveal the mismatch between empirical understanding and modelling...

  14. Sustainable Water Infrastructure Asset Management: A Gap Analysis of Customer and Service Provider Perspectives

    Directory of Open Access Journals (Sweden)

    Sangjong Han

    2015-09-01

    Full Text Available The ultimate goal of urban water infrastructure asset management may be sustainable water supply with satisfaction for customers. In this work, we attempted to evaluate the gaps between the perspectives of customers and service providers in Korea’s water infrastructure asset management. To evaluate the customers’ perspective, a hierarchical questionnaire survey was conducted to estimate the weights of influence for six customer values and their attributes on Korean water utility management. To evaluate the service providers’ perspective, an AHP (Analytic Hierarchy Process analysis was performed to estimate the weights of influence for the customer values and their PIs (performance indicators. The gap analysis results show that customers place higher value on customer service satisfaction (emotion and information than do the service providers (managers, whereas the managers place more value on affordability than do the customers. The findings from this work imply that improving customer service is effective in satisfying the desirable water LOS (level of service for customers. Recommendations have also been provided for administrators and engineers to develop integrated decision-making systems that can reflect customer needs regarding the improvement of their water infrastructure asset management. The findings from this work may be helpful for the Korean government and water supply utilities in improving the sustainability of their water infrastructure asset management.

  15. Linking economic water use, freshwater ecosystem impacts, and virtual water trade in a Great Lakes watershed

    Science.gov (United States)

    Mubako, S. T.; Ruddell, B. L.; Mayer, A. S.

    2013-12-01

    The impact of human water uses and economic pressures on freshwater ecosystems is of growing interest for water resource management worldwide. This case study for a water-rich watershed in the Great Lakes region links the economic pressures on water resources as revealed by virtual water trade balances to the nature of the economic water use and the associated impacts on the freshwater ecosystem. A water accounting framework that combines water consumption data and economic data from input output tables is applied to quantify localized virtual water imports and exports in the Kalamazoo watershed which comprises ten counties. Water using economic activities at the county level are conformed to watershed boundaries through land use-water use relationships. The counties are part of a region implementing the Michigan Water Withdrawal Assessment Process, including new regulatory approaches for adaptive water resources management under a riparian water rights framework. The results show that at local level, there exists considerable water use intensity and virtual water trade balance disparity among the counties and between water use sectors in this watershed. The watershed is a net virtual water importer, with some counties outsourcing nearly half of their water resource impacts, and some outsourcing nearly all water resource impacts. The largest virtual water imports are associated with agriculture, thermoelectric power generation and industry, while the bulk of the exports are associated with thermoelectric power generation and commercial activities. The methodology is applicable to various spatial levels ranging from the micro sub-watershed level to the macro Great Lakes watershed region, subject to the availability of reliable water use and economic data.

  16. The Energy-Water Nexus: Managing the Links between Energy and Water for a Sustainable Future

    Science.gov (United States)

    Hussey, Karen; Petit, Carine

    2010-05-01

    Water and energy are both indispensable inputs to modern economies but currently both resources are under threat owing to the impacts of an ever-increasing population and associated demand, unsustainable practices in agriculture and manufacturing, and the implications of a changing climate. However, it is where water and energy rely on each other that pose the most complex challenges for policy-makers. Water is needed for mining coal, drilling oil, refining gasoline, and generating and distributing electricity; and, conversely, vast amounts of energy are needed to pump, transport, treat and distribute water, particularly in the production of potable water through the use of desalination plants and waste water treatment plants. Despite the links, and the urgency in both sectors for security of supply, in existing policy frameworks energy and water policies are developed largely in isolation from one another. Worse still, some policies designed to encourage alternative energy supplies give little thought to the resultant consequences on water resources, and, similarly, policies designed to secure water supplies pay little attention to the resultant consequences on energy use. The development of new technologies presents both opportunities and challenges for managing the energy-water nexus but a better understanding of the links between energy and water is essential in any attempt to formulate policies for more resilient and adaptable societies. The energy-water nexus must be adequately integrated into policy and decision-making or governments run the risk of contradicting their efforts, and therefore failing in their objectives, in both sectors. A series of COST Exploratory Workshops, drawing on on-going research in the energy-water nexus from a number of international teams, identified the implications of the energy-water nexus on the development of (i) energy policies (ii) water resource management policies and (iii) climate adaptation and mitigation policies. A

  17. Plasmon-enhanced water splitting on TiO2-passivated GaP photocatalysts.

    Science.gov (United States)

    Qiu, Jing; Zeng, Guangtong; Pavaskar, Prathamesh; Li, Zhen; Cronin, Stephen B

    2014-02-21

    Integrating plasmon resonant nanostructures with photocatalytic semiconductors shows great promise for high efficiency photocatalytic water splitting. However, the electrochemical instability of most III-V semiconductors severely limits their applicability in photocatalysis. In this work, we passivate p-type GaP with a thin layer of n-type TiO2 using atomic layer deposition. The TiO2 passivation layer prevents corrosion of the GaP, as evidenced by atomic force microscopy and photoelectrochemical measurements. In addition, the TiO2 passivation layer provides an enhancement in photoconversion efficiency through the formation of a charge separating pn-region. Plasmonic Au nanoparticles deposited on top of the TiO2-passivated GaP further increases the photoconversion efficiency through local field enhancement. These two enhancement mechanisms are separated by systematically varying the thickness of the TiO2 layer. Because of the tradeoff between the quickly decaying plasmonic fields and the formation of the pn-charge separation region, an optimum performance is achieved for a TiO2 thickness of 0.5 nm. Finite difference time domain (FDTD) simulations of the electric field profiles in this photocatalytic heterostructure corroborate these results. The effects of plasmonic enhancement are distinguished from the natural catalytic properties of Au by evaluating similar photocatalytic TiO2/GaP structures with catalytic, non-plasmonic metals (i.e., Pt) instead of Au. This general approach of passivating narrower band gap semiconductors enables a wider range of materials to be considered for plasmon-enhanced photocatalysis for high efficiency water splitting.

  18. Water exchange through the Kerama Gap estimated with a 25-year Pacific HYbrid Coordinate Ocean Model

    Science.gov (United States)

    Zhou, Wenzheng; Yu, Fei; Nan, Feng

    2017-03-01

    V ariations in water exchange through the Kerama Gap (between Okinawa Island and Miyakojima Island) from 1979 to 2003 were estimated with the 0.08° Pacific HYbrid Coordinate Ocean Model (HYCOM). The model results show that the mean transport through the Kerama Gap (KGT) from the Pacific Ocean to the East China Sea (ECS) was 2.1 Sv, which agrees well with the observed mean KGT (2.0 Sv) for 2009-2010. Over the time period examined, the monthly KGT varied from -10.9 Sv to 15.8 Sv and had a standard deviation of ± 5.0 Sv. The water mainly enters the ECS via the subsurface layer (300-500 m) along the northeastern slope of the Kerama Gap and mainly flows out of the ECS into the southwest of the Kerama Gap. The seasonal and interannual variations of the KGT and the Kuroshio upstream transport were negatively correlated. The Kuroshio upstream transport was largest in summer and smallest in autumn while the KGT was smallest in summer (1.02 Sv) and largest in spring (2.94 Sv) and autumn (2.44 Sv). The seasonal and interannual variations in the Kuroshio downstream (across the PN-line) transport differed significantly from the Kuroshio upstream transport but corresponded well with the KGT and the sum of the transport through the Kerama Gap and the Kuroshio upstream, which indicates that information about variation in the KGT is important for determining variation in the Kuroshio transport along the PN-line.

  19. Linking Atomistic and Mesoscale Simulations of Water Soluble Polymers

    Science.gov (United States)

    Jones, J. L.

    2003-03-01

    There exist a range of techniques for studying surfactants and polymers in the mesoscale regime. One of the challenges is to link mesoscale theories and simulations to other calculation methods which address different length scales of the system. We introduce some mesoscale methods of calculation for polymers and surfactants and then present a case study of where mesoscale modelling is used for mechanistic understanding, by linking the method to high throughput in-silico screening methods. We look at the adsorption onto silica of ethylene oxide (EO)/ propylene oxide (PO) block copolymers (lutrols) which have been modified by end-grafting of short, cationic dimethylamino ethyl methacrylate (DMAEMA)chains. Given that the silica surface is negatively charged, it is remarkable that in some circumstances, polymers with longercationic chains have a lower adsorption. The effect is attributed to a competition between strong adsorption of the cationic DMAEMA groups driven by electrostatics, and weaker adsorption of the more numerous EO groups. This then raises the question of how we produce the values for the mesoscale parameters in these models and in the second part of the talk we describe a calculation method for doing this for water soluble polymers. The most promising route, but notoriously costly, is based on free energy calculations at the atomistic level. Free energy calculations are computationally intensive in general, but in an aqueous system one is also faced with the additional problem of using complex continuum models and/or accurate interaction potentials for water. Here we show how potential of mean force (PMF)calculations offer a practical alternative which avoids these drawbacks, though one is still faced with extremely long simulations.

  20. Linking integrated water resources management and integrated coastal zone management.

    Science.gov (United States)

    Rasch, P S; Ipsen, N; Malmgren-Hansen, A; Mogensen, B

    2005-01-01

    Some of the world's most valuable aquatic ecosystems such as deltas, lagoons and estuaries are located in the coastal zone. However, the coastal zone and its aquatic ecosystems are in many places under environmental stress from human activities. About 50% of the human population lives within 200 km of the coastline, and the population density is increasing every day. In addition, the majority of urban centres are located in the coastal zone. It is commonly known that there are important linkages between the activities in the upstream river basins and the environment conditions in the downstream coastal zones. Changes in river flows, e.g. caused by irrigation, hydropower and water supply, have changed salinity in estuaries and lagoons. Land use changes, such as intensified agricultural activities and urban and industrial development, cause increasing loads of nutrients and a variety of chemicals resulting in considerable adverse impacts in the coastal zones. It is recognised that the solution to such problems calls for an integrated approach. Therefore, the terms Integrated Water Resources Management (IWRM) and Integrated Coastal Zone Management (ICZM) are increasingly in focus on the international agenda. Unfortunately, the concepts of IWRM and ICZM are mostly being developed independently from each other by separate management bodies using their own individual approaches and tools. The present paper describes how modelling tools can be used to link IWRM and ICZM. It draws a line from the traditional sectoral use of models for the Istanbul Master Planning and assessment of the water quality and ecological impact in the Bosphorus Strait and the Black Sea 10 years ago, to the most recent use of models in a Water Framework Directive (WFD) context for one of the selected Pilot River Basins in Denmark used for testing of the WFD Guidance Documents.

  1. Root-soil air gap and resistance to water flow at the soil-root interface of Robinia pseudoacacia.

    Science.gov (United States)

    Liu, X P; Zhang, W J; Wang, X Y; Cai, Y J; Chang, J G

    2015-12-01

    During periods of water deficit, growing roots may shrink, retaining only partial contact with the soil. In this study, known mathematical models were used to calculate the root-soil air gap and water flow resistance at the soil-root interface, respectively, of Robinia pseudoacacia L. under different water conditions. Using a digital camera, the root-soil air gap of R. pseudoacacia was investigated in a root growth chamber; this root-soil air gap and the model-inferred water flow resistance at the soil-root interface were compared with predictions based on a separate outdoor experiment. The results indicated progressively greater root shrinkage and loss of root-soil contact with decreasing soil water potential. The average widths of the root-soil air gap for R. pseudoacacia in open fields and in the root growth chamber were 0.24 and 0.39 mm, respectively. The resistance to water flow at the soil-root interface in both environments increased with decreasing soil water potential. Stepwise regression analysis demonstrated that soil water potential and soil temperature were the best predictors of variation in the root-soil air gap. A combination of soil water potential, soil temperature, root-air water potential difference and soil-root water potential difference best predicted the resistance to water flow at the soil-root interface.

  2. A novel mutation of gap junction protein β 1 gene in X-linked Charcot-Marie-Tooth disease.

    Science.gov (United States)

    Chen, Sheng Dong; Li, Zheng Xi; Guan, Yang Tai; Zhou, Xia Jun; Jiang, Jian Ming; Hao, Yong

    2011-06-01

    In this study we report a novel mutation in the gap junction protein beta 1 (GJB1) gene of a Chinese X-linked Charcot-Marie-Tooth disease (CMTX1) family, which has specific electrophysiological characteristics. Twenty members in the family were studied by clinical neurological examination and GJB1 gene mutation analysis, and 3 patients were studied electrophysiologically. The proband and his mother also underwent sural nerve biopsy. All patients have the CMT phenotype, except for 2 asymptomatic carriers. Electrophysiological examinations showed non-uniform slowing of motor conduction velocities and partial motor conduction blocks and temporal dispersion. Sural nerve biopsy confirmed a predominantly demyelinating neuropathy, and an Asn2Lys mutation in the amino-terminal domain was found in 9 members of this family, but not in 25 normal controls in the family. This family represents a novel mutation in the GJB1 form of CMTX1. The mutation in the amino-terminus has an impact on the electrophysiological characteristics of the disease. Copyright © 2011 Wiley Periodicals, Inc.

  3. A Framework for Developing Indicators Linking Socio-Economic and Ecological Impacts of Water Funds

    Science.gov (United States)

    Bremer, L.; Game, E.; Calvache, A.; Moreno, P.; Morales, A.; Rivera, B.; Rodriguez, L. M.

    2014-12-01

    Growing interest in the equity and sustainability of water funds and other investment in watershed services programs has spurred interest in evaluation of program impacts on ecosystem services and human well-being. Yet, programs often lack a systematic framework to select indicators that are both important to stakeholders and relevant to hypothesized program impact. To fill this gap, we developed a participatory indicator selection methodology and piloted it in Fondo Agua por La Vida y la Sostenibilidad in the East Cauca Valley Colombia. We started by linking program activities to anticipated ecological and socio-economic impacts through stakeholder developed results chains. Using results chains as the framework, we constructed fuzzy cognitive models to explore the relative impact of program activities on social and ecological attributes. To prioritize indicators to monitor, we combined our fuzzy modelling results with an assessment of the perceived importance of different attributes for stakeholders in the water fund. We used the selected indicators to design a monitoring program that will allow the water fund to track and communicate its impact over the long-term.

  4. Scotland's Water Map: Understanding water sector links to support decision making for the Hydro Nation Agenda

    Science.gov (United States)

    Falconer, Ruth E.; Gilmour, Daniel; Duffy, Alison; Isaacs, John; Stojanovic, Vladeta; O'Keeffe, Juliette; Blackwood, David

    2015-04-01

    The value of Scotland's water and sewerage market is projected to grow to £1.24bn by 2016/17. Developing future opportunities must take place alongside maintaining current service provision; however the demand on water and waste water services is constantly evolving. An integrated approach to water management requires an understanding of complex interactions that exist between key actors in the sector to allow water management strategies to exploit inter-sectorial links. Successful integrated analysis of the water sector in Scotland will support management activities key to responding to the Hydro Nation themes of 1) Governance and international development 2) Environmental protection 3) Economic opportunities 4) Research development. In order to deliver on these objectives an approach is required to capture and communicate the scope and scale of the water sector and its interconnectedness. The methodology required to determine scope, scale and interconnectedness of water sector involved the identification and application of an appropriate range of techniques from the Information and Knowledge Management disciplines combined with the Information Visualisation field. Scope and scale of the water sector was identified by a desk based study and this data was visualized using a geographic map. Sector interconnectedness was determined by interviewing key actors. The interviews identified the stakeholders associated with information flows, and the purpose of the information transfer through Reporting/Managing (R/M), Influence and Information sharing (I) or Control (C) activities. Primary information flows were also scored with respect to importance against the 4 key Hydro Nation agenda themes. Many organisations were identified who interact within Scotland's water sector including the Scottish Government and Ministers, the Regulators (WICS, DWQR, SEPA), Scottish Water (core and non-core functions), plus many other stakeholders ranging from research institutions to

  5. Water desalination by air-gap membrane distillation using meltblown polypropylene nanofiber membrane

    Science.gov (United States)

    Rosalam, S.; Chiam, C. K.; Widyaparamitha, S.; Chang, Y. W.; Lee, C. A.

    2016-06-01

    This paper presents a study of air gap membrane distillation (AGMD) using meltblown polypropylene (PP) nanofiber membrane to produce fresh water via desalination process. PP nanofiber membranes with the effective area 0.17 m2 are tested with NaCl solutions (0.5 - 4.0 wt.%) and seawater as the feed solutions (9400 - 64800 μS/cm) in a tubular membrane module. Results show that the flux decreases with increasing the membrane thickness from 547 to 784 μm. The flux increases with the feed flow rate and temperature difference across the membrane. The feed concentration affects the flux insignificantly. The AGMD system can reject the salts at least 96%. Water vapor permeation rate is relatively higher than solute permeation rate resulting in the conductivity value of permeate decreases when the corresponding flux increases. The AGMD system produces the fresh water (200 - 1520 μS/cm) that is suitable for drinking, fisheries or irrigation.

  6. Effects of Hydroxyl Radicals on Introduced Organisms of Ship's Ballast Water Based Micro-Gap Discharge

    Institute of Scientific and Technical Information of China (English)

    BAI Mindong; ZHANG Zhitao; BAI Mindi; YANG Bo; BAI Xiyao

    2007-01-01

    With the physical method of micro-gap gas discharge,OH.radicals were produced by the ionization of O2 in air and H2O in the gaseous state,in order to explore more effective method totreat the ship's ballast water.The surface morphology of A1203 dielectric layer was analysed using Atomic Force Microscopy (AFM),where the size of A1203 particles was in the range of 2 μm to 5 μm.At the same time,the biochemical effect of hydroxyl radicals on the introduced organisms and the quality of ship's ballast water were studied.The results indicate that the main reasons of cell death are lipid peroxide and damage of the antioxidant enzyme system in Catalase (CAT),Peroxidase (POD) and Superoxide dismutase (SOD).In addition,the quality of the ballast water was greatly improved.

  7. Linking fractional wettability and contact angle dynamics in water repellent soils

    Science.gov (United States)

    Beatty, Sarah; Smith, James

    2016-04-01

    Dynamic soil water repellency has become a highly documented soil phenomenon across a range of environmental conditions and investigated within a range of disciplines. With global climate change at the environmental science fore, there is growing concern and need for accurate quantification of fundamental soil hydraulic properties and model parameterization. In the presence of soil water repellency, however, substantial unknowns remain in terms of characterizing repellency and drawing linkages to fundamental hydraulic parameters. This is often related to the complexity of investigating soil water repellency, which is often a challenging environment because of its spatially and temporally variable nature. To help bridge this gap, this work reports on different approaches using various technologies to explore opportunities that yield greater quantification and parametrization of soil water repellency in natural hydrologic systems at different scales. These approaches include X-ray microtomography (μXCT), Axisymmetric Drop Shape Analysis (ADSA), Drop Penetration tests (MED/WDPT), and Tension Infiltrometry. This work has shown the strength of conceptually linking contact angle dynamics and fractional wettability as a means to understand the nature of infiltration in water repellent soils and provide a mechanistic foundation upon which repellency can be quantified and related to fundamental hydraulic properties. Contact angle dynamics and fractional wettability are complimentary terminology that appear in the multiphase flow and soil physics literature, but have largely/essentially only been applied in synthetic systems. Their utility in natural environments is potentially significant and conceptually useful since they can readily incorporate existing characterizations while providing greater opportunity for articulating and defining specific behaviours in systems with high spatial and temporal heterogeneity.

  8. Effect of nitrogen and water deficit type on the yield gap between the potential and attainable wheat yield

    Directory of Open Access Journals (Sweden)

    Jiangang Liu

    2015-12-01

    Full Text Available Water deficit and N fertilizer are the two primary limiting factors for wheat yield in the North China plain, the most important winter wheat (Triticum aestivum L. production area in China. Analyzing the yield gap between the potential yield and the attainable yield can quantify the potential for increasing wheat production and exploring the limiting factors to yield gap in the high-yielding farming region of North China Plain. The Decision Support System for Agrotechnology Transfer (DSSAT model was used to identify methods to increase the grain yield and decrease the gap. In order to explore the impact of N and cultivars on wheat yield in the different drought types, the climate conditions during 1981 to 2011 growing seasons was categorized into low, moderate, and severe water deficit classes according to the anomaly percentage of the water deficit rate during the entire wheat growing season. There are differences (P < 0.0001 in the variations of the potential yields among three cultivars over 30 yr. For all three water deficit types, the more recent cultivars Jimai22 and Shijiazhuang8 had higher yields compared to the older 'Jinan17'. As the N fertilizer rate increased, the yield gap decreased more substantially during the low water deficit years because of the significant increase in attainable yield. Overall, the yield gaps were smaller with less water stress. Replacement of cultivars and appropriate N fertilizer application based on the forecasted drought types can narrow the yield gap effectively.

  9. Natural convection heat transfer of water in a horizontal circular gap

    Institute of Scientific and Technical Information of China (English)

    SU Guanghui; Kenichiro Sugiyama; WU Yingwei

    2007-01-01

    An experimental study on the natural convection heat transfer on a horizontal downward facing heated surface in a water gap was carried out under atmospheric pressure conditions. A total of 700 experimental data points were correlated using Rayleigh versus Nusselt number in various forms, based on different independent variables. The effects of different characteristic lengths and film temperatures were discussed. The results show that the buoyancy force acts as a resistance force for natural convecti on beat transfer ona downward facing horizontal heated surface in a confined space. For the estimation of the natural convection heat transfer under the present conditions, empirical correlations in which Nusselt number is expressed as a function of the Rayleigh number, or both Rayleigh and Prandtl numbers, may be used. When it is accurately predicted, the Nusselt number is expressed as a function of the Rayleigh and Prandtl numbers, as well as the gap width-to-heated surface diameter ratio; and uses the temperature difference between the heated surface and the ambient fluid in the definition of Rayleigh number. The characteristic length is the gap size and the film temperature is the average fluid temperature.

  10. Linking International Development Actors to Geophysical Infrastructure: Exploring an IRIS Community Role in Bridging a Communications Gap

    Science.gov (United States)

    Lerner-Lam, A.; Aster, R.; Beck, S.; Ekstrom, G.; Fisher, K.; Meltzer, A.; Nyblade, A.; Sandvol, E.; Willemann, R.

    2008-12-01

    Over the past quarter century, national investments in high-fidelity digital seismograph networks have resulted in a global infrastructure for real-time in situ earthquake monitoring. Many network operators adhere to community-developed standards, with the result that there are few technical impediments to data sharing and real-time information exchange. Two unanswered questions, however, are whether the existing models of international collaboration will ensure the stability and sustainability of global earthquake monitoring, and whether the participating institutions can work with international development agencies and non- governmental organizations in meeting linked development and natural hazard risk reduction goals. Since the 2004 Indian Ocean tsunami, many of these actors are enlarging their commitments to natural hazard risk reduction and building national technical capacities, among broader programs in poverty alleviation and adaptation to environmental stress. Despite this renewed commitment, international development organizations, with notable exceptions, have been relatively passive in discussions of how the existing earthquake monitoring infrastructure could be leveraged to support risk-reduction programs and meet sustainable development goals. At the same time, the international seismological community - comprising universities and government seismological surveys - has built research and education initiatives such as EarthScope, AfricaArray, and similar programs in China, Europe and South America, that use innovative instrumentation technologies and deployment strategies to enable new science and applications, and promote education and training in critical sectors. Can these developments be combined? Recognizing this communication or knowledge gap, the IRIS International Working Group (IWG) explores the link between the activities of IRIS Members using IRIS facilities and the missions of international development agencies, such as US AID, the World

  11. Semi-Arid Water Resource Challenges - Can Water Harvesting Close the Gap?

    Science.gov (United States)

    Meixner, T.; Niraula, R.; Norman, L.; Pivo, G.; Gerlak, A.; Pavao-Zuckerman, M.; Henry, A.

    2015-12-01

    Water resource availability restricts development in arid and semi-arid regions of world. Past observations show that urban areas can increase stream discharge at least on a local scale. These results suggest that urbanization may increase the availability of wet water capable of being used by urban society. Here we present a combination of observational work demonstrating the increase of available water in urban areas of southern Arizona; and a modelling study demonstrating that future land use change may significantly increase river discharge across the Santa Cruz watershed which is ~12% urban. The observational data comes from over 30 watersheds varying in cover from undeveloped to highly urban and in spatial scale from a few square meters to thousands of square kilometers. The modelling study includes a conservation (~35% urban), megalopolitan (~34% urban) and business as usual scenario (~38% urban) for land use change due to regional population growth. All land use change scenarios result in significant increases in watershed streamflow. Depending upon pattern of urbanization, streamflow increased as much 88% in some watershed locations; demonstrating the potential to partially meet water resources demands in the region with water produced by the urbanization process. This water could be used regionally or locally, and significant efforts at implementing water harvesting in the region have been pursued. However, the ability to scale such implementation and overcome the physical, and social barriers to implementation are currently unquantified.

  12. Catalyzed Water Oxidation by Solar Irradiation of Band-Gap-Narrowed Semiconductors (Part 1. Overview).

    Energy Technology Data Exchange (ETDEWEB)

    Fujita,E.; Khalifah, P.; Lymar, S.; Muckerman, J.T.; Rodgriguez, J.

    2008-03-18

    The objectives of this report are: (1) Investigate the catalysis of water oxidation by cobalt and manganese hydrous oxides immobilized on titania or silica nanoparticles, and dinuclear metal complexes with quinonoid ligands in order to develop a better understanding of the critical water oxidation chemistry, and rationally search for improved catalysts. (2) Optimize the light-harvesting and charge-separation abilities of stable semiconductors including both a focused effort to improve the best existing materials by investigating their structural and electronic properties using a full suite of characterization tools, and a parallel effort to discover and characterize new materials. (3) Combine these elements to examine the function of oxidation catalysts on Band-Gap-Narrowed Semiconductor (BGNSC) surfaces and elucidate the core scientific challenges to the efficient coupling of the materials functions.

  13. Links between climate change, water-table depth, and water chemistry in a mineralized mountain watershed

    Science.gov (United States)

    Manning, Andrew H.; Verplanck, Philip L.; Caine, Jonathan S.; Todd, Andrew S.

    2013-01-01

    Recent studies suggest that climate change is causing rising solute concentrations in mountain lakes and streams. These changes may be more pronounced in mineralized watersheds due to the sensitivity of sulfide weathering to changes in subsurface oxygen transport. Specific causal mechanisms linking climate change and accelerated weathering rates have been proposed, but in general remain entirely hypothetical. For mineralized watersheds, a favored hypothesis is that falling water tables caused by declining recharge rates allow an increasing volume of sulfide-bearing rock to become exposed to air, thus oxygen. Here, we test the hypothesis that falling water tables are the primary cause of an increase in metals and SO4 (100-400%) observed since 1980 in the Upper Snake River (USR), Colorado. The USR drains an alpine watershed geologically and climatologically representative of many others in mineralized areas of the western U.S. Hydrologic and chemical data collected from 2005 to 2011 in a deep monitoring well (WP1) at the top of the USR watershed are utilized. During this period, both water table depths and groundwater SO4 concentrations have generally increased in the well. A numerical model was constructed using TOUGHREACT that simulates pyrite oxidation near WP1, including groundwater flow and oxygen transport in both saturated and unsaturated zones. The modeling suggests that a falling water table could produce an increase in metals and SO4 of a magnitude similar to that observed in the USR (up to 300%). Future water table declines may produce limited increases in sulfide weathering high in the watershed because of the water table dropping below the depth of oxygen penetration, but may continue to enhance sulfide weathering lower in the watershed where water tables are shallower. Advective air (oxygen) transport in the unsaturated zone caused by seasonally variable recharge and associated water table fluctuations was found to have little influence on pyrite

  14. Cross-linking of dermal sheep collagen using a water-soluble carbodiimide

    NARCIS (Netherlands)

    Olde Damink, L.H.H.; Dijkstra, P.J.; Luyn, van M.J.A.; Wachem, van P.B.; Nieuwenhuis, P.; Feijen, J.

    1996-01-01

    A cross-linking method for collagen-based biomaterials was developed using the water-soluble carbodiimide 1-ethyl-3-(3-dimethyl aminopropyl)carbodiimide hydrochloride (EDC). Cross-linking using EDC involves the activation of carboxylic acid groups to give O-acylisourea groups, which form cross-links

  15. Variable conformation of GAP junctions linking bone cells: a transmission electron microscopic study of linear, stacked linear, curvilinear, oval, and annular junctions.

    Science.gov (United States)

    Shapiro, F

    1997-10-01

    There is a marked variability in the conformation of bone cell gap junctions in newborn murine cortical bone as defined by transmission electron microscopy (TEM). Studies were done in newborn BALB/c mouse and Sprague-Dawley rat femurs and tibias. Femoral and tibial cortices were dissected into 1 mm3 fragments and prepared in standardized fashion using modified Karnovsky fixation, 7.5% EDTA decalcification, 1% osmium tetroxide-sym collidine buffer with 1% lanthanum nitrate postfixation, Epon resin, 60 nm sections, lead citrate/uranyl acetate staining, and examination at 60 kV. Previous TEM descriptions of bone junctions have, with rare exceptions, noted only isolated linear or mildly curvilinear structures. In this study we noted gap junctional shapes on thin-section TEM preparations of osteoblasts and osteocytes to be extremely variable and complex encompassing linear, curvilinear, stacked linear, oval, and annular conformations. Multiple observations revealed linear gap junctions linking surface osteoblast cell bodies; linear, curvilinear, stacked linear, and oval junctions linking osteoblast processes in osteoid; linear and curvilinear junctions where cell processes joined with osteocyte cell bodies and each of the five conformations linking osteocyte processes within canaliculi. The annular junctions were found within osteoblast and osteocyte cytoplasm and in osteocyte cell processes within canaliculi. The annular junctions are intracellular, degenerating structures which appear as ultrastructural markers of gap junction involution. The more complex shapes reported here must be considered in (1) interpreting quantitative studies using freeze-fracture replicas, thin sections, and confocal microscopy immunolabeled junction connexin-43 components and (2) assessing gap junction biogenesis and turnover. 3-D reconstruction of bone junctions will enhance our understanding of these complex conformations.

  16. Urban water metabolism indicators derived from a water mass balance - Bridging the gap between visions and performance assessment of urban water resource management.

    Science.gov (United States)

    Renouf, M A; Serrao-Neumann, S; Kenway, S J; Morgan, E A; Low Choy, D

    2017-10-01

    Improving resource management in urban areas has been enshrined in visions for achieving sustainable urban areas, but to date it has been difficult to quantify performance indicators to help identify more sustainable outcomes, especially for water resources. In this work, we advance quantitative indicators for what we refer to as the 'metabolic' features of urban water management: those related to resource efficiency (for water and also water-related energy and nutrients), supply internalisation, urban hydrological performance, sustainable extraction, and recognition of the diverse functions of water. We derived indicators in consultation with stakeholders to bridge this gap between visions and performance indicators. This was done by first reviewing and categorising water-related resource management objectives for city-regions, and then deriving indicators that can gauge performance against them. The ability for these indicators to be quantified using data from an urban water mass balance was also examined. Indicators of water efficiency, supply internalisation, and hydrological performance (relative to a reference case) can be generated using existing urban water mass balance methods. In the future, indicators for water-related energy and nutrient efficiencies could be generated by overlaying the urban water balance with energy and nutrient data. Indicators of sustainable extraction and recognising diverse functions of water will require methods for defining sustainable extraction rates and a water functionality index. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Living waters: Linking cultural knowledge, ecosystem services, and wilderness

    Science.gov (United States)

    Linda Moon Stumpff

    2013-01-01

    American Indian tribes value pristine water sources that often originate in wilderness areas to support provisioning and cultural benefits. Based on interviews with four traditional leaders, this article focuses on the concept of living waters in ways that connect ecosystem service benefits to wilderness. Cultural knowledge connects indigenous water stewardship and...

  18. Using info-Gap Decision Theory for Water Resources Planning Under Severe Uncertainty

    Science.gov (United States)

    Korteling, B.; Brazier, R.; Kapelan, Z.; Dessai, S.

    2012-12-01

    Water resource managers are required to develop comprehensive water resource plans based on severely uncertain information of the effects of climate change on local hydrology and future socio-economic changes on localised demand. In England and Wales, current water resource planning methodologies include a headroom estimation process that quantifies uncertainty based on only one point of an assumed range of deviations from the expected climate and projected demand 25 years into the future. There are many situations where there is not enough knowledge to be able to estimate a representative probability of occurrence, or to be confident that the tails of an assumed probability distribution will not exhibit unexpected skewness, or that the kurtosis of a distribution differs from the norm. These situations can be considered severely uncertain. Information-Gap decision theory offers a method to sample a wider range of uncertainty than with traditional methods, and as a result, compare the robustness of various water resource management options under conditions of severe uncertainty. A more robust management option is one that delivers the same level of performance as other options at higher levels of uncertainty. A case study is based on a Water Supply Area that encompasses the county of Cornwall in southwest England containing 17 reservoirs and 19 demand nodes. The performance success of management options are evaluated primarily by measures of water availability including a reservoir risk measure that tests the probability and magnitude that strategic reservoir storage levels fall below the drought management curve under adverse conditions and also a safety margin deficit that tests how quickly reservoir levels can return to optimum operating levels in favourable conditions. Multi-Criteria Decision Analysis (MCDA) is used to test the effectiveness of different management options with different weightings for metrics other than water availability including; capital and

  19. Linking ceragenins to water-treatment membranes to minimize biofouling.

    Energy Technology Data Exchange (ETDEWEB)

    Hibbs, Michael R.; Altman, Susan Jeanne; Feng, Yanshu (Brigham Young University, Provo, Utah); Savage, Paul B. (Brigham Young University, Provo, Utah); Pollard, Jacob (Brigham Young University, Provo, Utah); Branda, Steven S.; Goeres, Darla (Montana State University, Bozeman, MT); Buckingham-Meyer, Kelli (Montana State University, Bozeman, MT); Stafslien, Shane (North Dakota State University, Fargo, ND); Marry, Christopher; Jones, Howland D. T.; Lichtenberger, Alyssa; Kirk, Matthew F.; McGrath, Lucas K. (LMATA, Albuquerque, NM)

    2012-01-01

    Ceragenins were used to create biofouling resistant water-treatment membranes. Ceragenins are synthetically produced antimicrobial peptide mimics that display broad-spectrum bactericidal activity. While ceragenins have been used on bio-medical devices, use of ceragenins on water-treatment membranes is novel. Biofouling impacts membrane separation processes for many industrial applications such as desalination, waste-water treatment, oil and gas extraction, and power generation. Biofouling results in a loss of permeate flux and increase in energy use. Creation of biofouling resistant membranes will assist in creation of clean water with lower energy usage and energy with lower water usage. Five methods of attaching three different ceragenin molecules were conducted and tested. Biofouling reduction was observed in the majority of the tests, indicating the ceragenins are a viable solution to biofouling on water treatment membranes. Silane direct attachment appears to be the most promising attachment method if a high concentration of CSA-121a is used. Additional refinement of the attachment methods are needed in order to achieve our goal of several log-reduction in biofilm cell density without impacting the membrane flux. Concurrently, biofilm forming bacteria were isolated from source waters relevant for water treatment: wastewater, agricultural drainage, river water, seawater, and brackish groundwater. These isolates can be used for future testing of methods to control biofouling. Once isolated, the ability of the isolates to grow biofilms was tested with high-throughput multiwell methods. Based on these tests, the following species were selected for further testing in tube reactors and CDC reactors: Pseudomonas ssp. (wastewater, agricultural drainage, and Colorado River water), Nocardia coeliaca or Rhodococcus spp. (wastewater), Pseudomonas fluorescens and Hydrogenophaga palleronii (agricultural drainage), Sulfitobacter donghicola, Rhodococcus fascians, Rhodobacter

  20. Characteristic of hyaluronic acid derivative films cross-linked by polyethylene glycol of low water content

    Institute of Scientific and Technical Information of China (English)

    Chen Jinghua; Chen Jingtao; Xu Zheng; Gu Qisheng

    2008-01-01

    Objective: To test the characteristics of byaluronic acid (HA) derivative cross-linked by polyethylene glycol films of low water content. Methods: The cross-linked HA film with 200 μm thickness was got at atmospheric pressure at 25℃ for 5 d. After dried, cross-linked films of 10 mm×10 mm were weighed and immersed in phosphate buffered saline (PBS pH 7.45) at 37℃ for 24 h. Then the solution fraction and water content were estimated. Meanwhile, cross-linked HA derivative films were immersed in phosphate buffered saline (PBS: pH 7.45) at 37℃ for determined time and then implanted subcutaneously in the back of white rats to test in vitro or in vivo degradation characteristic. Results and Conclusion: HA hydrogel cross-linked by polyethylene glycol with water content is as low as 60% and this kind of HA derivative has a slow degradation rate.

  1. Links between river water acidity, land use and hydrology

    Energy Technology Data Exchange (ETDEWEB)

    Saarinen, T.; Celebi, A.; Kloeve, B. [Oulu Univ. (Finland). Water Resources and Environmental Eng. Lab.], Email: tuomas.saarinen@oulu.fi

    2013-11-01

    In western Finland, acid leaching to watercourses is mainly due to drainage of acid sulphate (As) soils. This study examined how different land-use and land-cover types affect water acidity in the northwestern coastal region of Finland, which has abundant drained AS soils and peatlands. Sampling conducted in different hydrological conditions in studied river basins revealed two different catchment types: catchments dominated by drained forested peatlands and catchments used by agriculture. Low pH and high electric conductivity (EC) were typical in rivers affected by agriculture. In rivers dominated by forested peatlands and wetlands, EC was considerably lower. During spring and autumn high runoff events, water quality was poor and showed large spatial variation. Thus it is important to ensure that in river basin status assessment, sampling is carried out in different hydrological situations and in also water from some tributaries is sampled. (orig.)

  2. Linking Fish Habitat Modelling and Sediment Transport in Running Waters

    Institute of Scientific and Technical Information of China (English)

    Andreas; EISNER; Silke; WIEPRECHT; Matthias; SCHNEIDER

    2005-01-01

    The assessment of ecological status for running waters is one of the major issues within an integrated river basin management and plays a key role with respect to the implementation of the European Water Frame- work Directive (WFD).One of the tools supporting the development of sustainable river management is physi- cal habitat modeling,e.g.,for fish,because fish population are one of the most important indicators for the e- colngical integrity of rivers.Within physical habitat models hydromorphological ...

  3. Structurally Distinct Bacterial TBC-like GAPs Link Arf GTPase to Rab1 Inactivation to Counteract Host Defenses

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Na; Zhu, Yongqun; Lu, Qiuhe; Hu, Liyan; Zheng, Yuqing; Shao, Feng (NIBS-China); (Zhejiang)

    2012-10-10

    Rab GTPases are frequent targets of vacuole-living bacterial pathogens for appropriate trafficking of the vacuole. Here we discover that bacterial effectors including VirA from nonvacuole Shigella flexneri and EspG from extracellular Enteropathogenic Escherichia coli (EPEC) harbor TBC-like dual-finger motifs and exhibits potent RabGAP activities. Specific inactivation of Rab1 by VirA/EspG disrupts ER-to-Golgi trafficking. S. flexneri intracellular persistence requires VirA TBC-like GAP activity that mediates bacterial escape from autophagy-mediated host defense. Rab1 inactivation by EspG severely blocks host secretory pathway, resulting in inhibited interleukin-8 secretion from infected cells. Crystal structures of VirA/EspG-Rab1-GDP-aluminum fluoride complexes highlight TBC-like catalytic role for the arginine and glutamine finger residues and reveal a 3D architecture distinct from that of the TBC domain. Structure of Arf6-EspG-Rab1 ternary complex illustrates a pathogenic signaling complex that rewires host Arf signaling to Rab1 inactivation. Structural distinctions of VirA/EspG further predict a possible extensive presence of TBC-like RabGAP effectors in counteracting various host defenses.

  4. Modification of Wide-Band-Gap Oxide Semiconductors with Cobalt Hydroxide Nanoclusters for Visible-Light Water Oxidation.

    Science.gov (United States)

    Maeda, Kazuhiko; Ishimaki, Koki; Tokunaga, Yuki; Lu, Daling; Eguchi, Miharu

    2016-07-11

    Cobalt-based compounds, such as cobalt(II) hydroxide, are known to be good catalysts for water oxidation. Herein, we report that such cobalt species can also activate wide-band-gap semiconductors towards visible-light water oxidation. Rutile TiO2 powder, a well-known wide-band-gap semiconductor, was capable of harvesting visible light with wavelengths of up to 850 nm, and thus catalyzed water oxidation to produce molecular oxygen, when decorated with cobalt(II) hydroxide nanoclusters. To the best of our knowledge, this system constitutes the first example that a particulate photocatalytic material that is capable of water oxidation upon excitation by visible light can also operate at such long wavelengths, even when it is based on earth-abundant elements only.

  5. Self-assembly made durable: water-repellent materials formed by cross-linking fullerene derivatives.

    Science.gov (United States)

    Wang, Jiaobing; Shen, Yanfei; Kessel, Stefanie; Fernandes, Paulo; Yoshida, Kaname; Yagai, Shiki; Kurth, Dirk G; Möhwald, Helmuth; Nakanishi, Takashi

    2009-01-01

    Fullerene flakes: A diacetylene-functionalized fullerene derivative self-organizes into flakelike microparticles (see picture). Both the diacetylene and C(60) moieties can be effectively cross-linked, which leads to supramolecular materials with remarkable resistivity to solvent, heat, and mechanical stress. Moreover, the surface of the cross-linked flakelike objects is highly durable and water-repellent.

  6. Linking smallholder agriculture and water to household food security ...

    African Journals Online (AJOL)

    Multidisciplinary team: Partners with complementary skills should work together towards a common goal. When working ... on the NWP figures of Table 3, the theoretical water require- .... BOYLE MA (2003) Community Nutrition in Action – An Entrepreneur- ... DÜVEL GH and AFFUL DB (1997) Towards an understanding of.

  7. Closing the gaps in knowledge, policy and action to address water issues in forests

    Science.gov (United States)

    Adams, Paul W.

    1993-10-01

    Water issues on forest lands involve many human elements and needs that are not addressed by advanced physical and biological research and technology. Major gaps in our knowledge of important patterns of climate, soils, and terrain can be filled by relatively basic data collection and monitoring programs. Careful analysis of existing data and field experience also can reveal appropriate directions for management. A focus on problem-solving can direct research more effectively towards the resolution of key issues. Despite their impact, resource policies have widely varying scientific foundations. Policy-makers need sound processes for policy development, including timely technical input that is clear, objective, and related to socio-economic considerations. Resource polices should be consistent and include not only regulation, but also research, education, assistance, and incentives. Knowledge and sound policies still may not produce the desired on-the-ground actions, however, because of variable awareness, understanding, skill, or supervision in the field. Education and training programs are important not only for resource technicians, but also for contractors, operators, and other forest workers. Good planning, communication, and field coordination further insure that problems are avoided and new opportunities for effective actions are identified.

  8. Bridging "The Gap"--Linking Workplace-Based and University-Based Learning in Preschool Teacher Education in Sweden

    Science.gov (United States)

    Karlsson Lohmander, Maelis

    2015-01-01

    Professional experience in preschool settings comprises an important part of the education of preschool teachers. During their placements, students are expected to link theory to practice, to integrate university-based knowledge with workplace-based knowledge and skills essential for their future profession. They often refer to a perceived gap…

  9. On the Links Between Photosynthesis and Soil Water Balance

    Science.gov (United States)

    Daly, E.; Porporato, A.; Rodriguez-Iturbe, I.

    2002-12-01

    The equations of soil moisture dynamics and a model of leaf gas exchange and water transport through the Soil-Plant-Atmosphere Continuum (SPAC) are coupled to explore the dependence of plant CO2 assimilation on soil moisture. The model is also coupled with a daily growing boundary layer model, that gives the values of air specific humidity and potential temperature during the day. Two different approaches for modeling stomatal conductance gs are implemented and compared. One is the mixed-empirical formulation of stomatal conductance used by Jarvis (1976), who assumed a multiplicative relationship among the main environmental factors affecting stomatal movement; the other one is the empirical relationship between stomatal conductance and assimilation introduced by Ball et al. (1987) and modified by Leuning (1990, 1995), that assume a direct dependence of stomatal movement on the assimilation rate. This second approach is extended to include drought conditions and the common bases underlying the two approaches are elucidated. The model also gives the soil moisture value below which plants are under stress and the moisture content at the wilting point. These are used to evaluate the probability distribution of soil moisture, carbon assimilation by photosynthesis and plant water stress, thus providing a more physical basis to a previous stochastic model of soil moisture by the authors.

  10. Linking water age and solute dynamics in streamflow at the Hubbard Brook Experimental Forest, NH, USA

    Science.gov (United States)

    Paolo Benettin; Scott W. Bailey; John L. Campbell; Mark B. Green; Andrea Rinaldo; Gene E. Likens; Kevin J. McGuire; Gianluca Botter

    2015-01-01

    We combine experimental and modeling results from a headwater catchment at the Hubbard Brook Experimental Forest (HBEF), New Hampshire, USA, to explore the link between stream solute dynamics and water age. A theoretical framework based on water age dynamics, which represents a general basis for characterizing solute transport at the catchment scale, is here applied to...

  11. What drives the gender gap in STEM? The SAGA Science, Technology and Innovation Gender Objectives List (STI GOL) as a new approach to linking indicators to STI policies

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, E.; Schaaper, M.; Bello, A.

    2016-07-01

    There is a large imbalance in the participation of women in Science, Technology, Engineering and Mathematics (STEM) fields across all of Latin American countries despite the fact that the region has one of the highest proportions of female researchers worldwide (44% according to UIS statistics). Female researchers face persisting institutional and cultural barriers, which limit the development of their careers and constrains their access to decision-making positions. In this framework, UNESCO has launched the STEM and Gender Advancement (SAGA) project, which has for objective to address the gender gap in STEM fields in all countries at all levels of education and research as well as to promote women’s participation in science. SAGA is a global UNESCO project with the support of the Swedish Government through the Swedish International Development Cooperation Agency (Sida). One of the outcomes of this project is the SAGA Science, Technology and Innovation Gender Objectives List (STI GOL), which is an innovative tool that aids in the identification of gaps in the policy mix. Additionally, the STI GOL configures the conceptual backbone of the SAGA project, by linking gender equality STI policy instruments with indicators. By using the STI GOL, and identifying the gender gaps, policy-makers will be able to implement evidence-based policies in STEM fields. The SAGA STI GOL is a new and innovative way of contributing to the development of effective gender sensitive policies in STI fields, both in education and in the workplace. Likewise, it enables the categorization of STI policies and instruments, with the objective of identifying gaps in the policy mix and aid in the creation and design of evidence-based public policies to promote gender equality. (Author)

  12. Modeling water quality, temperature, and flow in Link River, south-central Oregon

    Science.gov (United States)

    Sullivan, Annett B.; Rounds, Stewart A.

    2016-09-09

    The 2.1-km (1.3-mi) Link River connects Upper Klamath Lake to the Klamath River in south-central Oregon. A CE-QUAL-W2 flow and water-quality model of Link River was developed to provide a connection between an existing model of the upper Klamath River and any existing or future models of Upper Klamath Lake. Water-quality sampling at six locations in Link River was done during 2013–15 to support model development and to provide a better understanding of instream biogeochemical processes. The short reach and high velocities in Link River resulted in fast travel times and limited water-quality transformations, except for dissolved oxygen. Reaeration through the reach, especially at the falls in Link River, was particularly important in moderating dissolved oxygen concentrations that at times entered the reach at Link River Dam with marked supersaturation or subsaturation. This reaeration resulted in concentrations closer to saturation downstream at the mouth of Link River.

  13. Missing Links in Global Water Governance: a Processes-Oriented Analysis

    Directory of Open Access Journals (Sweden)

    Claudia Pahl-Wostl

    2013-06-01

    Full Text Available Over the past decade, the policy and scholarly communities have increasingly recognized the need for governance of water-related issues at the global level. There has been major progress in the achievement of international goals related to the provision of basic water and some progress on sanitation services. However, the water challenge is much broader than securing supply. Doubts have been raised about the effectiveness of some of the existing governance processes, in the face of trends such as the unsustainable use of water resources, the increasing pressure imposed by climate change, or the implications of population growth for water use in food and energy production. Conflicts between different water uses and users are increasing, and the state of the aquatic environment is further declining. Inequity in access to basic water and sanitation services is still an issue. We argue that missing links in the trajectories of policy development are one major reason for the relative ineffectiveness of global water governance. To identify these critical links, a framework is used to examine how core governance processes are performed and linked. Special attention is given to the role of leadership, representativeness, legitimacy, and comprehensiveness, which we take to be critical characteristics of the processes that underpin effective trajectories of policy development and implementation. The relevance of the identified categories is illustrated with examples from three important policy arenas in global water governance: the effort to address access to water and sanitation, currently through the Millennium Development Goals; the controversy over large dams; and the links between climate change and water resources management. Exploratory analyses of successes and failures in each domain are used to identify implications and propose improvements for more effective and legitimate action.

  14. Sorption of substituted indoles on highly cross-linked polystyrene from water-acetonitrile solutions

    Science.gov (United States)

    Shafigulin, R. V.; Myakishev, A. A.; Il'Ina, E. A.; Il'in, M. M.; Davankov, V. A.; Bulanova, A. V.

    2011-07-01

    The sorption of first synthesized indole derivatives by highly cross-linked polystyrenes from water-acetonitrile solutions was studied by high-performance liquid chromatography. The retention factors and differences in the Gibbs energy of adsorption from infinite diluted solutions were calculated, and the applicability of the Snyder-Soczewinski and Scott-Kucera models for describing the chromatographic retention of sorbates on a polymer network of highly cross-linked polystyrene was shown.

  15. The missing link in the history of urology: A call for more efforts to bridge the gap

    Directory of Open Access Journals (Sweden)

    Abdel-Halim Rabie

    2009-01-01

    Full Text Available With few exceptions, most of the current publications on history of urology still ignore the scientific and technological events of the more than a thousand years between the Greco-Roman times and the modern era. This has broken an important link in the globally continuous line of progress and evolution of world civilizations. Another aggravation of that missing-link problem in the history of urology, and history of medicine, in general, is the large number of articles based, only, on copying from secondary sources without checking the primary sources (the edited and published original manuscripts. Such articles easily propagate omissions, deficiencies, misunderstandings, distortions, and unfounded claims. On the other hand, in the Arabic and Islamic world, though many original authentic medical manuscripts written by famous scholars of the Islamic era were authoritatively edited and published during the twentieth century, the number of primary source studies based on them by historians or medical researchers remained few and were limited to individual efforts. Therefore, we focused on this missing-link era and performed several primary source studies of the published medical works of eleven scholars who lived and practiced between the ninth and the thirteenth centuries and whose Latinized books were available in Europe as early as the twelfth century with their influence lasting until the eighteenth century. Our results confirm that those scholars of the Islamic era were not mere compilers or sheer transmitters of Greco-Roman medical literature. On the contrary, they critically reviewed the translated heritage of previous civilizations rejecting what is superfluous and accepting only what proves to be true. They added original contributions to the progress of urology and pioneered new fields of medical knowledge and practice such as medical ethics, medical education, medical certification, health education, preventive medicine, hospitals and

  16. Water-Food-Nutrition-Health Nexus: Linking Water to Improving Food, Nutrition and Health in Sub-Saharan Africa

    OpenAIRE

    Tafadzwanashe Mabhaudhi; Tendai Chibarabada; Albert Modi

    2016-01-01

    Whereas sub-Saharan Africa’s (SSA) water scarcity, food, nutrition and health challenges are well-documented, efforts to address them have often been disconnected. Given that the region continues to be affected by poverty and food and nutrition insecurity at national and household levels, there is a need for a paradigm shift in order to effectively deliver on the twin challenges of food and nutrition security under conditions of water scarcity. There is a need to link water use in agriculture...

  17. Band-gap determination from diffuse reflectance measurements of semiconductor films, and application to photoelectrochemical water-splitting

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, A.B. [CSIRO Industrial Physics, P.O. Box 218, Lindfield, NSW 2070 (Australia); CSIRO Energy Transformed National Research Flagship, PO Box 330, Newcastle, NSW 2300 (Australia)

    2007-09-06

    Measurements of the diffuse reflectance of TiO{sub 2} semiconductor coatings, such as are used for water splitting, are analysed using the Kubelka-Munk radiative transfer model. The widely used practice of determining the band gap of the coating directly from the diffuse reflectance is found to be inaccurate, since the diffuse reflectance depends on parameters such as the thickness, refractive index and surface roughness of the coating. However, it is shown that the absorption coefficient can be derived from the diffuse reflectance using an inversion method; the band gap can then be obtained from the absorption coefficient. Finally, the diffuse reflectance of carbon-doped TiO{sub 2} presented by Khan et al. [Science 297 (2002) 2243-2245] is analysed; it is found that while the band-gap wavelength is extended into the visible region, it is overestimated. Moreover, light at visible wavelengths is only very weakly absorbed, and is expected to make only a minor contribution to the water-splitting efficiency. (author)

  18. Climate Change and European Water Bodies, a Review of Existing Gaps and Future Research Needs: Findings of the ClimateWater Project.

    Science.gov (United States)

    Garnier, Monica; Harper, David M; Blaskovicova, Lotta; Hancz, Gabriella; Janauer, Georg A; Jolánkai, Zsolt; Lanz, Eva; Lo Porto, Antonio; Mándoki, Monika; Pataki, Beata; Rahuel, Jean-Luc; Robinson, Victoria J; Stoate, Chris; Tóth, Eszter; Jolánkai, Géza

    2015-08-01

    There is general agreement among scientists that global temperatures are rising and will continue to increase in the future. It is also agreed that human activities are the most important causes of these climatic variations, and that water resources are already suffering and will continue to be greatly impaired as a consequence of these changes. In particular, it is probable that areas with limited water resources will expand and that an increase of global water demand will occur, estimated to be around 35-60% by 2025 as a consequence of population growth and the competing needs of water uses. This will cause a growing imbalance between water demand (including the needs of nature) and supply. This urgency demands that climate change impacts on water be evaluated in different sectors using a cross-cutting approach (Contestabile in Nat Clim Chang 3:11-12, 2013). These issues were examined by the EU FP7-funded Co-ordination and support action "ClimateWater" (bridging the gap between adaptation strategies of climate change impacts and European water policies). The project studied adaptation strategies to minimize the water-related consequences of climate change and assessed how these strategies should be taken into consideration by European policies. This article emphasizes that knowledge gaps still exist about the direct effects of climate change on water bodies and their indirect impacts on production areas that employ large amounts of water (e.g., agriculture). Some sectors, such as ecohydrology and alternative sewage treatment technologies, could represent a powerful tool to mitigate climate change impacts. Research needs in these still novel fields are summarized.

  19. Effective Ecological Restoration of Collapsed Ecosystems - Linking Soil, Water and Society

    Science.gov (United States)

    Petursdottir, Thorunn; Finger, David

    2014-05-01

    All natural resources, utilized by humans are embedded in complex social-ecological systems (SESs). To maintain the systems' sustainability, the SESs needs to be managed within their resilience optimum, considering both social and ecological elements. Throughout the centuries the humankind has often failed in doing so. Overexploitation of natural resources has thus widely disrupted equilibrium within the respective SESs, driving unforeseen changes of ecosystems worldwide. Anthropogenic factors such as poor institutional structure on resource utilization and weak policies in combination to environmental factors like droughts, fires or other unpredictable events have ruptured ecosystems' resilience and caused global degradation on a scale that currently threatens the Earth's welfare. As an example it's worth to mention that up to 40% of the world's agricultural land is severely degraded mainly due to unsustainable landuse. Once an ecosystem, or part/s of it, have collapsed, ecological restoration is almost always necessary to overcome the threshold/s that may prevent the system from self-recovering. It also re-activates the system's environmental cycles like the water, carbon and nutrient circulation. Although soil is the fundamental body of terrestrial ecosystems, water availability is of equal importance and should be taken more into consideration in restoration than currently is done. Based on that, we will focus on how to best manage effective large-scale ecological restoration (LSER) of collapsed ecosystems and link it to water catchment areas. LSER is a fundamental social-ecological activity that substantially can improve ecosystem condition, human livelihood and if well organized, facilitate improved management of natural resources. By definition, restoration of ecological integrity and functions is the fundamental basis for all restoration activities. But to achieve long-term sustainability of LSER activities the initial set of rules/policies established by

  20. Linking poverty levels to water resource use and conflicts in rural Tanzania

    Science.gov (United States)

    Madulu, Ndalahwa F.

    Water scarcity is an important environmental constraint to development. Water availability is closely linked to human welfare and health by affecting nutrition status and quantity of drinking water especially for the poor. It has impacts on household labour because of the time and energy spent in obtaining it. These problems are more keenly felt among the poor households and in the agricultural subsistence economy. In many areas, the demand for water has been increasing due to rapid population growth, economic development, and climatic change. Water scarcity also stimulates social conflicts between various water users: individuals, communities, industries, livestock, wildlife, agriculture etc. Consequently, local communities have evolved strategies for coping with water stress and drought. These strategies include use of various sources of water, inaction to strict bye-laws regarding the use of water, crop diversification, wage labour, and possibly seasonal migration. The available strategies are likely to vary from one area to another. Some of these actions have measurable longterm demographic consequences, particularly if water stress is severe or repetitive. Although most governments and donor organizations often put much emphasis on the provision of water for drinking purposes, there is clear evidence that the supply of water for other uses has equal importance especially among rural communities. This observation suggests that putting too much emphasis on drinking water needs, addresses a rather insignificant part of the problem of water resources and biases the range of solutions which are likely to be proposed for perceived shortages. The presence of other water uses necessitates the provision of multi-purpose water sources that can serve a number of contrasting functions. This demand-responsive approach can enable the local communities and the poor households to choose the type of services they require on the basis of perceived needs and their ability to

  1. Aggregating land use quantity and intensity to link water quality in upper catchment of Miyun Reservoir

    Science.gov (United States)

    Xu, E.

    2015-12-01

    Land use is closely related to hydrological and biochemical processes influencing the water quality. Quantifying relationship between both of them can help effectively manage land use to improve water quality. Previous studies majorly utilized land use quantity as an indicator to link water quality parameters, which lacked an insight to the influence of land use intensity. Taking upper catchment of Miyun Reservoir as a case study, we proposed a method of aggregating land use quantity and intensity to build a new land use indicator and investigated its explanation empower on water quality. Six nutrient concentrations from 52 sub-watersheds covering the whole catchment were used to characterize spatial distributions of water eutrophication. Based on spatial techniques and empirical conversion coefficients, combined remote sensing with socio-economic statistical data, land use intensity was measured and mapped visually. Then the new land use indicator was calculated and linked to nutrient concentrations by Pearson correlation coefficients. Results demonstrated that our new land use indicator incorporating intensity information can quantify the potential different nutrients exporting abilities from land uses. Comparing to traditional indicators only characterized by land use quantity, most Pearson correlation coefficients between new indicator and water nutrient concentrations increased. New information enhanced the explanatory power of land use on water nutrient concentrations. Then it can help better understand the impact of land use on water quality and guide land use management for supporting decision making.

  2. Error Analysis of Clay-Rock Water Content Estimation with Broadband High-Frequency Electromagnetic Sensors—Air Gap Effect

    Directory of Open Access Journals (Sweden)

    Thierry Bore

    2016-04-01

    Full Text Available Broadband electromagnetic frequency or time domain sensor techniques present high potential for quantitative water content monitoring in porous media. Prior to in situ application, the impact of the relationship between the broadband electromagnetic properties of the porous material (clay-rock and the water content on the frequency or time domain sensor response is required. For this purpose, dielectric properties of intact clay rock samples experimental determined in the frequency range from 1 MHz to 10 GHz were used as input data in 3-D numerical frequency domain finite element field calculations to model the one port broadband frequency or time domain transfer function for a three rods based sensor embedded in the clay-rock. The sensor response in terms of the reflection factor was analyzed in time domain with classical travel time analysis in combination with an empirical model according to Topp equation, as well as the theoretical Lichtenecker and Rother model (LRM to estimate the volumetric water content. The mixture equation considering the appropriate porosity of the investigated material provide a practical and efficient approach for water content estimation based on classical travel time analysis with the onset-method. The inflection method is not recommended for water content estimation in electrical dispersive and absorptive material. Moreover, the results clearly indicate that effects due to coupling of the sensor to the material cannot be neglected. Coupling problems caused by an air gap lead to dramatic effects on water content estimation, even for submillimeter gaps. Thus, the quantitative determination of the in situ water content requires careful sensor installation in order to reach a perfect probe clay rock coupling.

  3. Error Analysis of Clay-Rock Water Content Estimation with Broadband High-Frequency Electromagnetic Sensors--Air Gap Effect.

    Science.gov (United States)

    Bore, Thierry; Wagner, Norman; Lesoille, Sylvie Delepine; Taillade, Frederic; Six, Gonzague; Daout, Franck; Placko, Dominique

    2016-04-18

    Broadband electromagnetic frequency or time domain sensor techniques present high potential for quantitative water content monitoring in porous media. Prior to in situ application, the impact of the relationship between the broadband electromagnetic properties of the porous material (clay-rock) and the water content on the frequency or time domain sensor response is required. For this purpose, dielectric properties of intact clay rock samples experimental determined in the frequency range from 1 MHz to 10 GHz were used as input data in 3-D numerical frequency domain finite element field calculations to model the one port broadband frequency or time domain transfer function for a three rods based sensor embedded in the clay-rock. The sensor response in terms of the reflection factor was analyzed in time domain with classical travel time analysis in combination with an empirical model according to Topp equation, as well as the theoretical Lichtenecker and Rother model (LRM) to estimate the volumetric water content. The mixture equation considering the appropriate porosity of the investigated material provide a practical and efficient approach for water content estimation based on classical travel time analysis with the onset-method. The inflection method is not recommended for water content estimation in electrical dispersive and absorptive material. Moreover, the results clearly indicate that effects due to coupling of the sensor to the material cannot be neglected. Coupling problems caused by an air gap lead to dramatic effects on water content estimation, even for submillimeter gaps. Thus, the quantitative determination of the in situ water content requires careful sensor installation in order to reach a perfect probe clay rock coupling.

  4. Error Analysis of Clay-Rock Water Content Estimation with Broadband High-Frequency Electromagnetic Sensors—Air Gap Effect

    Science.gov (United States)

    Bore, Thierry; Wagner, Norman; Delepine Lesoille, Sylvie; Taillade, Frederic; Six, Gonzague; Daout, Franck; Placko, Dominique

    2016-01-01

    Broadband electromagnetic frequency or time domain sensor techniques present high potential for quantitative water content monitoring in porous media. Prior to in situ application, the impact of the relationship between the broadband electromagnetic properties of the porous material (clay-rock) and the water content on the frequency or time domain sensor response is required. For this purpose, dielectric properties of intact clay rock samples experimental determined in the frequency range from 1 MHz to 10 GHz were used as input data in 3-D numerical frequency domain finite element field calculations to model the one port broadband frequency or time domain transfer function for a three rods based sensor embedded in the clay-rock. The sensor response in terms of the reflection factor was analyzed in time domain with classical travel time analysis in combination with an empirical model according to Topp equation, as well as the theoretical Lichtenecker and Rother model (LRM) to estimate the volumetric water content. The mixture equation considering the appropriate porosity of the investigated material provide a practical and efficient approach for water content estimation based on classical travel time analysis with the onset-method. The inflection method is not recommended for water content estimation in electrical dispersive and absorptive material. Moreover, the results clearly indicate that effects due to coupling of the sensor to the material cannot be neglected. Coupling problems caused by an air gap lead to dramatic effects on water content estimation, even for submillimeter gaps. Thus, the quantitative determination of the in situ water content requires careful sensor installation in order to reach a perfect probe clay rock coupling. PMID:27096865

  5. Exploring the link between meteorological drought and streamflow to inform water resource management

    Science.gov (United States)

    Lennard, Amy; Macdonald, Neil; Hooke, Janet

    2015-04-01

    Drought indicators are an under-used metric in UK drought management. Standardised drought indicators offer a potential monitoring and management tool for operational water resource management. However, the use of these metrics needs further investigation. This work uses statistical analysis of the climatological drought signal based on meteorological drought indicators and observed streamflow data to explore the link between meteorological drought and hydrological drought to inform water resource management for a single water resource region. The region, covering 21,000 km2 of the English Midlands and central Wales, includes a variety of landscapes and climatological conditions. Analysis of the links between meteorological drought and hydrological drought performed using streamflow data from 'natural' catchments indicates a close positive relationship between meteorological drought indicators and streamflow, enhancing confidence in the application of drought indicators for monitoring and management. However, many of the catchments in the region are subject to modification through impoundments, abstractions and discharge. Therefore, it is beneficial to explore how climatological drought signal propagates into managed hydrological systems. Using a longitudinal study of catchments and sub-catchments that include natural and modified river reaches the relationship between meteorological and hydrological drought is explored. Initial statistical analysis of meteorological drought indicators and streamflow data from modified catchments shows a significantly weakened statistical relationship and reveals how anthropogenic activities may alter hydrological drought characteristics in modified catchments. Exploring how meteorological drought indicators link to streamflow across the water supply region helps build an understanding of their utility for operational water resource management.

  6. Linking water quality and well-being for improved assessment and valuation of ecosystem services.

    Science.gov (United States)

    Keeler, Bonnie L; Polasky, Stephen; Brauman, Kate A; Johnson, Kris A; Finlay, Jacques C; O'Neill, Ann; Kovacs, Kent; Dalzell, Brent

    2012-11-06

    Despite broad recognition of the value of the goods and services provided by nature, existing tools for assessing and valuing ecosystem services often fall short of the needs and expectations of decision makers. Here we address one of the most important missing components in the current ecosystem services toolbox: a comprehensive and generalizable framework for describing and valuing water quality-related services. Water quality is often misrepresented as a final ecosystem service. We argue that it is actually an important contributor to many different services, from recreation to human health. We present a valuation approach for water quality-related services that is sensitive to different actions that affect water quality, identifies aquatic endpoints where the consequences of changing water quality on human well-being are realized, and recognizes the unique groups of beneficiaries affected by those changes. We describe the multiple biophysical and economic pathways that link actions to changes in water quality-related ecosystem goods and services and provide guidance to researchers interested in valuing these changes. Finally, we present a valuation template that integrates biophysical and economic models, links actions to changes in service provision and value estimates, and considers multiple sources of water quality-related ecosystem service values without double counting.

  7. 36 CFR 7.71 - Delaware Water Gap National Recreation Area.

    Science.gov (United States)

    2010-07-01

    ..., carabiners or snap links, ropes, expansion bolts, or other mechanical equipment are used to make the climb... otherwise designated, fishing in any manner authorized under applicable State law is allowed....

  8. Mutation Analysis of Gap Junction Protein Beta 1 and Genotype-Phenotype Correlation in X-linked Charcot-Marie-Tooth Disease in Chinese Patients.

    Science.gov (United States)

    Sun, Bo; Chen, Zhao-Hui; Ling, Li; Li, Yi-Fan; Liu, Li-Zhi; Yang, Fei; Huang, Xu-Sheng

    2016-05-05

    Among patients with Charcot-Marie-Tooth disease (CMT), the X-linked variant (CMTX) caused by gap junction protein beta 1 (GJB1) gene mutation is the second most frequent type, accounting for approximately 90% of all CMTX. More than 400 mutations have been identified in the GJB1 gene that encodes connexin 32 (CX32). CX32 is thought to form gap junctions that promote the diffusion pathway between cells. GJB1 mutations interfere with the formation of the functional channel and impair the maintenance of peripheral myelin, and novel mutations are continually discovered. We included 79 unrelated patients clinically diagnosed with CMT at the Department of Neurology of the Chinese People's Liberation Army General Hospital from December 20, 2012, to December 31, 2015. Clinical examination, nerve conduction studies, and molecular and bioinformatics analyses were performed to identify patients with CMTX1. Nine GJB1 mutations (c.283G>A, c.77C>T, c.643C>T, c.515C>T, c.191G>A, c.610C>T, c.490C>T, c.491G>A, and c.44G>A) were discovered in nine patients. Median motor nerve conduction velocities of all nine patients were T, c.191G>A, and c.610C>T, were revealed and bioinformatics analyses indicated high pathogenicity. The three novel missense mutations within the GJB1 gene broaden the mutational diversity of CMT1X. Molecular analysis of family members and bioinformatics analyses of the afflicted patients confirmed the pathogenicity of these mutations.

  9. Mutation Analysis of Gap Junction Protein Beta 1 and Genotype-Phenotype Correlation in X-linked Charcot-Marie-Tooth Disease in Chinese Patients

    Institute of Scientific and Technical Information of China (English)

    Bo Sun; Zhao-Hui Chen; Li Ling; Yi-Fan Li; Li-Zhi Liu; Fei Yang; Xu-Sheng Huang

    2016-01-01

    Background:Among patients with Charcot-Marie-Tooth disease (CMT),the X-linked variant (CMTX) caused by gap junction protein beta 1 (GJB1) gene mutation is the second most frequent type,accounting for approximately 90% of all CMTX.More than 400 mutations have been identified in the GJB1 gene that encodes connexin 32 (CX32).CX32 is thought to form gap junctions that promote the diffusion pathway between cells.GJB1 mutations interfere with the formation of the functional channel and impair the maintenance of peripheral myelin,and novel mutations are continually discovered.Methods:We included 79 unrelated patients clinically diagnosed with CMT at the Department of Neurology of the Chinese People's Liberation Army General Hospital from December 20,2012,to December 31,2015.Clinical examination,nerve conduction studies,and molecular and bioinformatics analyses were performed to identify patients with CMTX 1.Results:Nine GJB1 mutations (c.283G>A,c.77C>T,c.643C>T,c.515C>T,c.191G>A,c.610C>T,c.490C>T,c.491G>A,and c.44G>A) were discovered in nine patients.Median motor nerve conduction velocities of all nine patients were < 38 m/s,resembling CMT Type 1.Three novel mutations,c.643C>T,c.191G>A,and c.610C>T,were revealed and bioinformatics analyses indicated high pathogenicity.Conclusions:The three novel missense mutations within the GJB1 gene broaden the mutational diversity of CMT 1 X.Molecular analysis of family members and bioinformatics analyses of the afflicted patients confirmed the pathogenicity of these mutations.

  10. Acanthamoeba Species Keratitis in a Soft Contact Lens Wearer Molecularly Linked to Well Water

    Directory of Open Access Journals (Sweden)

    Samira Mubareka

    2006-01-01

    Full Text Available Acanthamoeba species keratitis has been associated with soft contact lens wear. In the present report, an epidemiological link was established between the patient's isolate and well water from the home using molecular methods. To the authors' knowledge, this is the first case in Canada where such a link has been established. Primary care practitioners and specialists, including ophthalmologists and infectious diseases specialists, must maintain a high degree of clinical suspicion in soft contact lens wearers with keratitis unresponsive to conventional topical and systemic treatment.

  11. Reinforced films based on cross-linked water-soluble sulfonated carbon nanotubes with sulfonated polystyrene.

    Science.gov (United States)

    Dai, Ying; Haiping, Hong; Guiver, Michael; Welsh, Jeffry S

    2009-09-01

    Reinforced films based on sulfonated polystyrene cross-linked with water-soluble sulfonated carbon nanotubes were fabricated using a free-standing film-making method. Transmission and scanning electron microscopy (TEM and SEM), and X-ray photoelectron spectroscopy (XPS) were used to verify the cross-linking reaction. The mechanical properties of these films demonstrated that the tensile strength increases with an increase in the sulfonated nanotube concentration. At 5 wt% nanotube loading, the tensile strength increased 84% compared with polymer containing no nanotube loading. The relationships between structure and mechanical properties are discussed and a possible direction for making ultra thin and ultra lightweight film is proposed.

  12. The Joint Front Range Climate Change Vulnerability Study: Closing the Gap between Science and Water Management Decisions

    Science.gov (United States)

    Kaatz, L.; Yates, D.; Woodbury, M.

    2008-12-01

    There is increasing concern among metropolitan water providers in Colorado's Front Range about the possible impacts of global and regional climate changes on their future water supply. This is of particular worry given that recent studies indicate global warming may lead to unprecedented drought conditions in the Southwest U.S. (IPCC 2007). The City of Aurora, City of Boulder, Colorado Springs Utilities, Denver Water, City of Ft. Collins, and Northern Colorado Water Conservancy District, along with additional water agencies including the Colorado Water Conservation Board, the Water Research Foundation (formerly AwwaRF), and the NOAA-CIRES Western Water Assessment, have come together to participate in a study intended to provide the education, tools, and methodology necessary to examine possible effects of climate change on several common watersheds. The central objective of this project is to assess possible changes in the timing and volume of hydrologic runoff from selected climate change scenarios centered about the years 2040 and 2070. Two hydrologic models will be calibrated and implemented in the study for this purpose. The future temperature and precipitation scenarios used to generate corresponding future streamflow are based on regionally downscaled temperature and precipitation projections. The projected streamflow obtained by running varied sequences of temperature and precipitation through the hydrologic models, will be compared to historic streamflow to estimate the sensitivity of water supplies to climate change. This regional unified approach is intended to help Colorado water providers communicate with their customers and the media cohesively, by working with the same historic and projected hydrometeorological data, historic natural streamflow, and methodology. Lessons learned from this collaborative approach can be used to encourage and establish other regional efforts throughout the country. Furthermore, this study will set the stage for future

  13. Water-Food-Nutrition-Health Nexus: Linking Water to Improving Food, Nutrition and Health in Sub-Saharan Africa.

    Science.gov (United States)

    Mabhaudhi, Tafadzwanashe; Chibarabada, Tendai; Modi, Albert

    2016-01-06

    Whereas sub-Saharan Africa's (SSA) water scarcity, food, nutrition and health challenges are well-documented, efforts to address them have often been disconnected. Given that the region continues to be affected by poverty and food and nutrition insecurity at national and household levels, there is a need for a paradigm shift in order to effectively deliver on the twin challenges of food and nutrition security under conditions of water scarcity. There is a need to link water use in agriculture to achieve food and nutrition security outcomes for improved human health and well-being. Currently, there are no explicit linkages between water, agriculture, nutrition and health owing to uncoordinated efforts between agricultural and nutrition scientists. There is also a need to develop and promote the use of metrics that capture aspects of water, agriculture, food and nutrition. This review identified nutritional water productivity as a suitable index for measuring the impact of a water-food-nutrition-health nexus. Socio-economic factors are also considered as they influence food choices in rural communities. An argument for the need to utilise the region's agrobiodiversity for addressing dietary quality and diversity was established. It is concluded that a model for improving nutrition and health of poor rural communities based on the water-food-nutrition-health nexus is possible.

  14. Water-Food-Nutrition-Health Nexus: Linking Water to Improving Food, Nutrition and Health in Sub-Saharan Africa

    Directory of Open Access Journals (Sweden)

    Tafadzwanashe Mabhaudhi

    2016-01-01

    Full Text Available Whereas sub-Saharan Africa’s (SSA water scarcity, food, nutrition and health challenges are well-documented, efforts to address them have often been disconnected. Given that the region continues to be affected by poverty and food and nutrition insecurity at national and household levels, there is a need for a paradigm shift in order to effectively deliver on the twin challenges of food and nutrition security under conditions of water scarcity. There is a need to link water use in agriculture to achieve food and nutrition security outcomes for improved human health and well-being. Currently, there are no explicit linkages between water, agriculture, nutrition and health owing to uncoordinated efforts between agricultural and nutrition scientists. There is also a need to develop and promote the use of metrics that capture aspects of water, agriculture, food and nutrition. This review identified nutritional water productivity as a suitable index for measuring the impact of a water-food-nutrition-health nexus. Socio-economic factors are also considered as they influence food choices in rural communities. An argument for the need to utilise the region’s agrobiodiversity for addressing dietary quality and diversity was established. It is concluded that a model for improving nutrition and health of poor rural communities based on the water-food-nutrition-health nexus is possible.

  15. A linked hydrodynamic and water quality model for the Salton Sea

    Science.gov (United States)

    Chung, E.G.; Schladow, S.G.; Perez-Losada, J.; Robertson, D.M.

    2008-01-01

    A linked hydrodynamic and water quality model was developed and applied to the Salton Sea. The hydrodynamic component is based on the one-dimensional numerical model, DLM. The water quality model is based on a new conceptual model for nutrient cycling in the Sea, and simulates temperature, total suspended sediment concentration, nutrient concentrations, including PO4-3, NO3-1 and NH4+1, DO concentration and chlorophyll a concentration as functions of depth and time. Existing water temperature data from 1997 were used to verify that the model could accurately represent the onset and breakup of thermal stratification. 1999 is the only year with a near-complete dataset for water quality variables for the Salton Sea. The linked hydrodynamic and water quality model was run for 1999, and by adjustment of rate coefficients and other water quality parameters, a good match with the data was obtained. In this article, the model is fully described and the model results for reductions in external phosphorus load on chlorophyll a distribution are presented. ?? 2008 Springer Science+Business Media B.V.

  16. Leaf photosynthetic rate of tropical ferns is evolutionarily linked to water transport capacity.

    Science.gov (United States)

    Zhang, Shi-Bao; Sun, Mei; Cao, Kun-Fang; Hu, Hong; Zhang, Jiao-Lin

    2014-01-01

    Ferns usually have relatively lower photosynthetic potential than angiosperms. However, it is unclear whether low photosynthetic potential of ferns is linked to leaf water supply. We hypothesized that there is an evolutionary association of leaf water transport capacity with photosynthesis and stomatal density in ferns. In the present study, a series of functional traits relating to leaf anatomy, hydraulics and physiology were assessed in 19 terrestrial and 11 epiphytic ferns in a common garden, and analyzed by a comparative phylogenetics method. Compared with epiphytic ferns, terrestrial ferns had higher vein density (Dvein), stomatal density (SD), stomatal conductance (gs), and photosynthetic capacity (Amax), but lower values for lower epidermal thickness (LET) and leaf thickness (LT). Across species, all traits varied significantly, but only stomatal length (SL) showed strong phylogenetic conservatism. Amax was positively correlated with Dvein and gs with and without phylogenetic corrections. SD correlated positively with Amax, Dvein and gs, with the correlation between SD and Dvein being significant after phylogenetic correction. Leaf water content showed significant correlations with LET, LT, and mesophyll thickness. Our results provide evidence that Amax of the studied ferns is linked to leaf water transport capacity, and there was an evolutionary association between water supply and demand in ferns. These findings add new insights into the evolutionary correlations among traits involving carbon and water economy in ferns.

  17. Integrated Water Flow Model (IWFM), A Tool For Numerically Simulating Linked Groundwater, Surface Water And Land-Surface Hydrologic Processes

    Science.gov (United States)

    Dogrul, E. C.; Brush, C. F.; Kadir, T. N.

    2006-12-01

    The Integrated Water Flow Model (IWFM) is a comprehensive input-driven application for simulating groundwater flow, surface water flow and land-surface hydrologic processes, and interactions between these processes, developed by the California Department of Water Resources (DWR). IWFM couples a 3-D finite element groundwater flow process and 1-D land surface, lake, stream flow and vertical unsaturated-zone flow processes which are solved simultaneously at each time step. The groundwater flow system is simulated as a multilayer aquifer system with a mixture of confined and unconfined aquifers separated by semiconfining layers. The groundwater flow process can simulate changing aquifer conditions (confined to unconfined and vice versa), subsidence, tile drains, injection wells and pumping wells. The land surface process calculates elemental water budgets for agricultural, urban, riparian and native vegetation classes. Crop water demands are dynamically calculated using distributed soil properties, land use and crop data, and precipitation and evapotranspiration rates. The crop mix can also be automatically modified as a function of pumping lift using logit functions. Surface water diversions and groundwater pumping can each be specified, or can be automatically adjusted at run time to balance water supply with water demand. The land-surface process also routes runoff to streams and deep percolation to the unsaturated zone. Surface water networks are specified as a series of stream nodes (coincident with groundwater nodes) with specified bed elevation, conductance and stage-flow relationships. Stream nodes are linked to form stream reaches. Stream inflows at the model boundary, surface water diversion locations, and one or more surface water deliveries per location are specified. IWFM routes stream flows through the network, calculating groundwater-surface water interactions, accumulating inflows from runoff, and allocating available stream flows to meet specified or

  18. Planning water supply under uncertainty - benefits and limitations of RDM, Info-Gap, economic optimization and many-objective optimization

    Science.gov (United States)

    Matrosov, E.; Padula, S.; Huskova, I.; Harou, J. J.

    2012-12-01

    Population growth and the threat of drier or changed climates are likely to increase water scarcity world-wide. A combination of demand management (water conservation) and new supply infrastructure is often needed to meet future projected demands. In this case system planners must decide what to implement, when and at what capacity. Choices can range from infrastructure to policies or a mix of the two, culminating in a complex planning problem. Decision making under uncertainty frameworks can be used to help planners with this planning problem. This presentation introduces, applies and compares four decision making under uncertainty frameworks. The application is to the Thames basin water resource system which includes the city of London. The approaches covered here include least-economic cost capacity expansion optimization (EO), Robust Decision Making (RDM), Info-Gap Decision Theory (Info-gap) and many-objective evolutionary optimization (MOEO). EO searches for the least-economic cost program, i.e. the timing, sizing, and choice of supply-demand management actions/upgrades which meet projected water demands. Instead of striving for optimality, the RDM and Info-gap approaches help build plans that are robust to 'deep' uncertainty in future conditions. The MOEO framework considers multiple performance criteria and uses water systems simulators as a function evaluator for the evolutionary algorithm. Visualizations show Pareto approximate tradeoffs between multiple objectives. In this presentation we detail the application of each framework to the Thames basin (including London) water resource planning problem. Supply and demand options are proposed by the major water companies in the basin. We apply the EO method using a 29 year time horizon and an annual time step considering capital, operating (fixed and variable), social and environmental costs. The method considers all plausible combinations of supply and conservation schemes and capacities proposed by water

  19. Increase in outbreaks of gastroenteritis linked to bathing water in Finland in summer 2014

    Science.gov (United States)

    Kauppinen, Ari; Al-Hello, Haider; Zacheus, Outi; Kilponen, Jaana; Maunula, Leena; Huusko, Sari; Lappalainen, Maija; Miettinen, Ilkka; Blomqvist, Soile; Rimhanen-Finne, Ruska

    2017-01-01

    An increased number of suspected outbreaks of gastroenteritis linked to bathing water were reported to the Finnish food- and waterborne outbreak (FWO) registry in July and August 2014. The investigation reports were assessed by a national outbreak investigation panel. Eight confirmed outbreaks were identified among the 15 suspected outbreaks linked to bathing water that had been reported to the FWO registry. According to the outbreak investigation reports, 1,453 persons fell ill during these outbreaks. Epidemiological and microbiological data revealed noroviruses as the main causative agents. During the outbreaks, exceptionally warm weather had boosted the use of beaches. Six of eight outbreaks occurred at small lakes; for those, the investigation strongly suggested that the beach users were the source of contamination. In one of those eight outbreaks, an external source of contamination was identified and elevated levels of faecal indicator bacteria (FIB) were noted in water. In the remaining outbreaks, FIB analyses were insufficient to describe the hygienic quality of the water. Restrictions against bathing proved effective in controlling the outbreaks. In spring 2015, the National Institute for Health and Welfare (THL) and the National Supervisory Authority for Welfare and Health (Valvira) published guidelines for outbreak control to prevent bathing water outbreaks. PMID:28251888

  20. Remote field eddy current technique for gap measurement of horizontal flux detector guide tube in pressurized heavy water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Hoon; Jung, Hyun Kyu; Yang, Dong Ju; Cheong, Yong Moo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2004-11-15

    The fuel channels including the pressure tube(PT) and the calandria tube(CT) are important components of the pressurized heavy water reactor(PHWR). A sagging of fuel channel increases by heat and radiation exposure with the increasing operation time. The contact of fuel channel to the Horizontal flux Detector(HFD) guide tube is needed for the power plant safety. In order to solve this safety issue, the electromagnetic technique was applied to measure the status of the guide tube. The Horizontal flux Detector(HFD) guide tube and the Calandria tube(CT) in the Pressurized Heavy Water Reactor(PHWR) are cross-aligned horizontally. The remote field eddy current(RFEC) technology is applied for gap measurement between the HFD guide tube and the CT HFD guide tube can be detected by inserting the RFEC probe into pressure tube(PT) at the crossing point directly. The RFEC signals using the volume integral method(VIM) were simulated for obtaining the optimal inspection parameters. This paper shows that the simulated eddy current signals and the experimental results in variance with the CT/HFD gap.

  1. AFLP marker linked to water-stress-tolerant bulks in barley (Hordeum vulgare L.

    Directory of Open Access Journals (Sweden)

    A. Altinkut

    2003-01-01

    Full Text Available The amplified fragment length polymorphism (AFLP assay is an efficient method for the identification of molecular markers, useful in the improvement of numerous crop species. Bulked Segregant Analysis (BSA was used to identify AFLP markers associated with water-stress tolerance in barley, as this would permit rapid selection of water-stress tolerant genotypes in breeding programs. AFLP markers linked to water-stress tolerance was identified in two DNA pools (tolerant and sensitive, which were established using selected F2 individuals resulting from a cross between water-stress-tolerant and sensitive barley parental genotypes, based on their paraquat (PQ tolerance, leaf size, and relative water content (RWC. All these three traits were previously shown to be associated with water-stress tolerance in segregating F2 progeny of the barley cross used in a previous study. AFLP analysis was then performed on these DNA pools, using 40 primer pairs to detect AFLP fragments that are present/absent, respectively, in the two pools and their parental lines. One separate AFLP fragment, which was present in the tolerant parent and in the tolerant bulk, but absent in the sensitive parent and in the sensitive bulk, was identified. Polymorphism of the AFLP marker was tested among tolerant and sensitive F2 individuals. The presence of this marker that is associated with water-stress tolerance will greatly enhance selection for paraquat and water-stress tolerant genotypes in future breeding programs.

  2. Sorption of adamantane phenylamide derivatives on hyper-cross-linked polystyrene from water-acetonitrile eluents

    Science.gov (United States)

    Shafigulin, R. V.; Konstantinov, A. V.; Bulanova, A. V.; Il'in, M. M.; Davankov, V. A.

    2016-11-01

    Study of the main physicochemical features of the sorption of phenylamide adamantane derivatives on hyper-cross-linked polystyrene from water-acetonitrile solutions shows that both hydrophobic and electronic interactions make a large contribution to retention, especially for a chlorine-containing derivative in which there are π- p and π- d interactions between the outer-shell electrons of the chlorine atom in addition to π- π interactions between aromatic fragments of the sorbate and sorbent.

  3. Source Water Flow Pathways In Forested, Mountain, Headwater Streams: A Link Between Sediment Movement Patterns And Stream Water Chemistry.

    Science.gov (United States)

    Martin, S.; Conklin, M. H.; Liu, F.

    2015-12-01

    Three years of continuous and discrete sediment and water quality data, from four forested, mountain, headwater catchments in the Sierra Nevada, is used to identify water sources, determine the importance of sub-surface flow pathways, detect any changes in source waters due to seasonal variation or drought, and link flow pathways with observed patterns of in-channel sediment movement within the study watersheds. Patterns in stream chemistry and turbidity point to infiltration as the dominant flow pathway within these catchments. Data support a flow pathway conceptual model in which precipitation water infiltrates into the shallow or deeper subsurface, increasing the hydraulic head of the water table and pushing pre-event water into the stream ahead of event water. Study catchments contain perennial streams and are characterized by a Mediterranean climate with a distinct wet and dry season. Sites are located in the rain-snow transition zone with snow making up 40 to 60 percent of average annual precipitation. Barring human disturbances such as logging/grazing (compaction) or fire (hydrophobicity), catchment soils have high infiltration capacities. Springs and seeps maintain baseflow during the summer low-flow season, and shifting chemical signals within the streams indicate the increased importance of sub-surface water sources during drought years. End-member mixing analysis was conducted to identify possible water end members. Turbidity hysteresis patterns described by previous studies show in-channel sources are dominant for discharge events year round, and there is no difference in fine sediment delivery to streams with or without a soil protecting layer of snow on the land surface. The dominance of sub-surface water sources and evidence for infiltration flow fits with turbidity data, as little material is reaching the stream due to erosive overland flow. An understanding of flow pathways provides a foundation for sustainable land use management in forested

  4. Bridging the Gap: The 'Soft Path' for Improving Resilience and Adaptability of Water Systems (Invited)

    Science.gov (United States)

    Gleick, P. H.

    2010-12-01

    The failure of traditional water management systems in the 20th century -- what I call the "hard path for water" -- is evident in several ways, including the persistent inability to meet basic human needs for safe water and adequate sanitation for vast populations, ongoing and accelerating aquatic ecosystem collapses , and growing political disputes over water allocation, management, and use, even in regions where substantial investment in water has been made. Progress in resolving these problems, especially in the face of unavoidable climate changes, growing populations, and constrained financial systems, will require bridging hydrologic and social sciences in new ways. Integrating social and cultural knowledge with new economic and technological tools and classical hydrologic and climatological sciences can produce a new “soft path for water” that offers the opportunity to move toward sustainable water systems. This talk will define the soft path for water and offer examples of innovative steps already being taken along that path in the western United States, South Africa, India, and elsewhere.

  5. GAP Analysis Program (GAP)

    Data.gov (United States)

    Kansas Data Access and Support Center — The Kansas GAP Analysis Land Cover database depicts 43 land cover classes for the state of Kansas. The database was generated using a two-stage hybrid classification...

  6. A synthesis of atmospheric mercury depletion event chemistry linking atmosphere, snow and water

    Directory of Open Access Journals (Sweden)

    A. Steffen

    2007-07-01

    Full Text Available It was discovered in 1995 that, during the spring time, unexpectedly low concentrations of gaseous elemental mercury (GEM occurred in the Arctic air. This was surprising for a pollutant known to have a long residence time in the atmosphere; however conditions appeared to exist in the Arctic that promoted this depletion of mercury (Hg. This phenomenon is termed atmospheric mercury depletion events (AMDEs and its discovery has revolutionized our understanding of the cycling of Hg in Polar Regions while stimulating a significant amount of research to understand its impact to this fragile ecosystem. Shortly after the discovery was made in Canada, AMDEs were confirmed to occur throughout the Arctic, sub-Artic and Antarctic coasts. It is now known that, through a series of photochemically initiated reactions involving halogens, GEM is converted to a more reactive species and is subsequently associated to particles in the air and/or deposited to the polar environment. AMDEs are a means by which Hg is transferred from the atmosphere to the environment that was previously unknown. In this article we review the history of Hg in Polar Regions, the methods used to collect Hg in different environmental media, research results of the current understanding of AMDEs from field, laboratory and modeling work, how Hg cycles around the environment after AMDEs, gaps in our current knowledge and the future impacts that AMDEs may have on polar environments. The research presented has shown that while considerable improvements in methodology to measure Hg have been made the main limitation remains knowing the speciation of Hg in the various media. The processes that drive AMDEs and how they occur are discussed. As well, the roles that the snow pack, oceans, fresh water and the sea ice play in the cycling of Hg are presented. It has been found that deposition of Hg from AMDEs occurs at marine coasts and not far inland and that a fraction of the deposited Hg does not

  7. Accurate Linking of Lake Erie Water Level with Shoreline Datum Using GPS Buoy and Satellite Altimetry

    Directory of Open Access Journals (Sweden)

    Kai-Chien Cheng

    2008-01-01

    Full Text Available There is a need to accurately link the water level to the shoreline vertical datum for various applications including coastal management, lake/river/estuary/wetland hydrological or storm surge modeling/forecasting. Coastal topography is historically surveyed and referenced to the predetermined vertical datum in terms of orthometric heights, or the heights above the geoid, which is poorly known in terms of accuracy and lack of adequate spatial resolution for coastal applications such as estuary or storm surge modeling. We demonstrate an accurate linking of the lake surface to a shoreline datum using satellite techniques, including GPS buoy and satellite altimetry, water level gauges, and local geoid and lake circulation models. The possible error sources are analyzed and an error budget is reported in this study. An innovated method to estimate geoid height near the water level gauge using a GPS buoy is proposed. It is found that at a 95% confidence interval, the method is consistent with the National Geodetic Survey GEOID03 geoid model. The lake surface represented using a lake circulation model provided by the Great Lakes Forecasting Systems is also verified with kriging based on the data (1999 - 2001 from the water level gauge, and TOPEX/POSEIDON altimeter. Mean discrepancies of 2.7 and 7.2 cm are found with the data from the gauges around Lake Erie, and from the combination of the gauges and the altimeter, respectively. It reveals that the current dominant limitation of more accurate linking of water surface to shoreline is the insufficient knowledge of geoid in the current models. Further improvement is feasible through more accurate and higher resolution modeling of the lake geoid.

  8. A gap analysis of the South African innovation system for water

    African Journals Online (AJOL)

    2015-04-03

    failure' linear model of innovation, and the more complex ... between users and researchers, and to involve the private sector much more strongly in water innovation. ... of its impacts on macroeconomic performance and on the.

  9. Meeting report: knowledge and gaps in developing microbial criteria for inland recreational waters

    Science.gov (United States)

    Dorevitch, Samuel; Ashbolt, Nicholas J.; Ferguson, Christobel M.; Fujioka, Roger; McGee, Charles D.; Soller, Jeffrey A.; Whitman, Richard L.

    2010-01-01

    The U.S. Environmental Protection Agency (EPA) has committed to issuing in 2012 new or revised criteria designed to protect the health of those who use surface waters for recreation. For this purpose, the U.S. EPA has been conducting epidemiologic studies to establish relationships between microbial measures of water quality and adverse health outcomes among swimmers. New methods for testing water quality that would provide same-day results will likely be elements of the new criteria. Although the epidemiologic studies upon which the criteria will be based were conducted at Great Lakes and marine beaches, the new water quality criteria may be extended to inland waters (IWs). Similarities and important differences between coastal waters (CWs) and IWs that should be considered when developing criteria for IWs were the focus of an expert workshop. Here, we summarize the state of knowledge and research needed to base IWs microbial criteria on sound science. Two key differences between CWs and IWs are the sources of indicator bacteria, which may modify the relationship between indicator microbes and health risk, and the relationship between indicators and pathogens, which also may vary within IWs. Monitoring using rapid molecular methods will require the standardization and simplification of analytical methods, as well as greater clarity about their interpretation. Research needs for the short term and longer term are described.

  10. AWRA-G: A continental scale groundwater component linked to a land surface water balance model

    Science.gov (United States)

    Joehnk, Klaus; Crosbie, Russell; Peeters, Luk; Doble, Rebecca

    2013-04-01

    The Australian Water Resources Assessment (AWRA) system is a combination of models, data sources and analysis techniques that together will describe the water balance of Australia's landscapes, rivers and groundwater systems. It is a grid based water balance model that has lumped representation of the water balance of the soil, groundwater and surface water stores for each cell. The purpose of AWRA is to operationally provide up to date, credible, comprehensive, and accurate information about the history, present state and future trajectory of the water balance across Australia with sufficient spatial and temporal detail and enable water resources management for undertaking annual water resource assessments and national water accounts. AWRA is developed to link three major components: a landscape water balance model (AWRA-L), a river routing model (AWRA-R), and a groundwater component model (AWRA-G). These three component models combined are expected to be able to model the fluxes and stores of water throughout the landscape. The groundwater component (AWRA-G) addresses an improved representation of groundwater in the AWRA system to describe basic aquifer dynamics and groundwater-surface water processes. While most continental scale land surface models do not have the capacity to allow water to flow between cells and thus ignore this element of the water balance, AWRA-G does account for lateral flows. In general, AWRA-G provides estimates of groundwater fluxes that are not incorporated into either AWRA-L and its modifications to in-cell soil and groundwater processes, or AWRA-R. The processes integrated into AWRA-G thus are lateral groundwater flow between cells in regional and intermediate groundwater flow systems, groundwater discharge to the ocean, groundwater extraction and infiltration, river losses to groundwater, recharge from overbank flooding, and interactions between deep confined systems and surficial groundwater systems. Basis of AWRA-G is a good

  11. Dehydration of an ethanol/water azeotrope through alginate-DNA membranes cross-linked with metal ions by pervaporation.

    Science.gov (United States)

    Uragami, Tadashi; Banno, Masashi; Miyata, Takashi

    2015-12-10

    To obtain high dehydration membranes for an ethanol/water azeotrope, dried blend membranes prepared from mixtures of sodium alginate (Alg-Na) and sodium deoxyribonucleate (DNA-Na) were cross-linked by immersing in a methanol solution of CaCl2 or MaCl2. In the dehydration of an ethanol/water azeotropic mixture by pervaporation, the effects of immersion time in methanol solution of CaCl2 or MaCl2 on the permeation rate and water/ethanol selectivity through Alg-DNA/Ca(2+) and Alg-DNA/Mg(2+) cross-linked membranes were investigated. Alg-DNA/Mg(2+) cross-linked membrane immersed for 12h in methanol solution of MaCl2 exhibited the highest water/ethanol selectivity. This results from depressed swelling of the membranes by formation of a cross-linked structure. However, excess immersion in solution containing cross-linker led to an increase in the hydrophobicity of cross-linked membrane. Therefore, the water/ethanol selectivity of Alg-DNA/Mg(2+) cross-linked membranes with an excess immersion in cross-linking solution was lowered. The relationship between the structure of Alg-DNA/Ca(2+) and Alg-DNA/Mg(2+) cross-linked membranes and their permeation and separation characteristics during pervaporation of an ethanol/water azeotropic mixture is discussed in detail.

  12. Electron binding energies and the fundamental gap of a push-pull dye in a polar environment: p-nitroaniline in liquid water

    Science.gov (United States)

    Cabral, Benedito J. C.

    2017-01-01

    The outer valence electron binding energies and the fundamental gap of p-nitroaniline (PNA) in water were determined by electron propagator theory. The adopted methodology relies on the calculation of electron binding energies by using configurations generated by Born-Oppenheimer molecular dynamics of PNA in water. The fundamental gap (Eg) of PNA in water was estimated from the first ionisation energy (IE) and the first vertical electron affinity VEA (Eg = IE-VEA). In liquid water Eg is predicted to be 6.5 ± 0.5 eV (OVGF), which is ∼3.3 eV greater than the experimental optical gap (3.25 eV).

  13. Gastrointestinal illness linked to incidents in drinking water distribution networks in Sweden.

    Science.gov (United States)

    Säve-Söderbergh, Melle; Bylund, John; Malm, Annika; Simonsson, Magnus; Toljander, Jonas

    2017-10-01

    During recent years, knowledge gaps on drinking water-related gastrointestinal illness have been identified, especially for non-epidemic cases. Pathogen contamination of drinking water during distribution has been suggested to contribute to these cases, but the risk factors are not yet fully understood. During 2014-2015, we conducted an epidemiological study in five municipalities in Sweden, to assess whether incidents in the drinking water distribution system influence the risk of gastrointestinal illness. Telephone interviews were conducted in the affected areas and in reference areas 7-14 days after a reported incident. Symptoms of gastrointestinal illness occurring during the period were documented for each household member. The results showed a significantly elevated risk of vomiting and acute gastrointestinal illness (AGI) in the affected areas, compared to the reference areas (ORvom. = 2.0, 95% CI: 1.2-3.3; ORAGI = 1.9, 95% CI: 1.2-3.0). Certain conditions, or risk factors, during the incidents, such as sewage and drinking water pipelines at the same level in the trench, were associated with an elevated risk of AGI and vomiting. Safety measures taken during repair work, like flushing, were also associated with an elevated risk of AGI and vomiting. These results show that incidents in the drinking water distribution network contribute to endemic gastrointestinal illness, especially AGI and vomiting, and that external pathogen contamination of the drinking water is a likely cause of these cases of gastrointestinal illness. The results also indicate that safety measures used today may not be sufficient for eliminating the risk of gastrointestinal illness. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. Bridging the gap between uncertainty analysis for complex watershed models and decision-making for watershed-scale water management

    Science.gov (United States)

    Zheng, Y.; Han, F.; Wu, B.

    2013-12-01

    Process-based, spatially distributed and dynamic models provide desirable resolutions to watershed-scale water management. However, their reliability in solving real management problems has been seriously questioned, since the model simulation usually involves significant uncertainty with complicated origins. Uncertainty analysis (UA) for complex hydrological models has been a hot topic in the past decade, and a variety of UA approaches have been developed, but mostly in a theoretical setting. Whether and how a UA could benefit real management decisions remains to be critical questions. We have conducted a series of studies to investigate the applicability of classic approaches, such as GLUE and Markov Chain Monte Carlo (MCMC) methods, in real management settings, unravel the difficulties encountered by such methods, and tailor the methods to better serve the management. Frameworks and new algorithms, such as Probabilistic Collocation Method (PCM)-based approaches, were also proposed for specific management issues. This presentation summarize our past and ongoing studies on the role of UA in real water management. Challenges and potential strategies to bridge the gap between UA for complex models and decision-making for management will be discussed. Future directions for the research in this field will also be suggested. Two common water management settings were examined. One is the Total Maximum Daily Loads (TMDLs) management for surface water quality protection. The other is integrated water resources management for watershed sustainability. For the first setting, nutrients and pesticides TMDLs in the Newport Bay Watershed (Orange Country, California, USA) were discussed. It is a highly urbanized region with a semi-arid Mediterranean climate, typical of the western U.S. For the second setting, the water resources management in the Zhangye Basin (the midstream part of Heihe Baisn, China), where the famous 'Silk Road' came through, was investigated. The Zhangye

  15. Enzyme-linked immunosorbent assay (ELISA) for the anthropogenic marker isolithocholic acid in water.

    Science.gov (United States)

    Baldofski, Stefanie; Hoffmann, Holger; Lehmann, Andreas; Breitfeld, Stefan; Garbe, Leif-Alexander; Schneider, Rudolf J

    2016-11-01

    Bile acids are promising chemical markers to assess the pollution of water samples with fecal material. This study describes the optimization and validation of a direct competitive enzyme-linked immunosorbent assay for the bile acid isolithocholic acid (ILA). The quantification range of the optimized assay was between 0.09 and 15 μg/L. The assay was applied to environmental water samples. Most studies until now were focused on bile acid fractions in the particulate phase of water samples. In order to avoid tedious sample preparation, we undertook to evaluate the dynamics and significance of ILA levels in the aqueous phase. Very low concentrations in tap and surface water samples made a pre-concentration step necessary for this matrix as well as for wastewater treatment plant (WWTP) effluent. Mean recoveries for spiked water samples were between 97% and 109% for tap water and WWTP influent samples and between 102% and 136% for WWTP effluent samples. 90th percentiles of intra-plate and inter-plate coefficients of variation were below 10% for influents and below 20% for effluents and surface water. ILA concentrations were quantified in the range of 33-72 μg/L in influent, 21-49 ng/L in effluent and 18-48 ng/L in surface water samples. During wastewater treatment the ILA levels were reduced by more than 99%. ILA concentrations of influents determined by ELISA and LC-MS/MS were in good agreement. However, findings in LC-ELISA experiments suggest that the true ILA levels in concentrated samples are lower due to interfering effects of matrix compounds and/or cross-reactants. Yet, the ELISA will be a valuable tool for the performance check and comparison of WWTPs and the localization of fecal matter input into surface waters.

  16. An improved water footprint methodology linking global consumption to local water resources: a case of Spanish tomatoes.

    Science.gov (United States)

    Chapagain, A K; Orr, S

    2009-02-01

    A water footprint (WF) measures the total water consumed by a nation, business or individual by calculating the total water used during the production of goods and services. This paper extends the existing methods for WF to more localised levels for crops grown partly in open systems and partly in plastic-covered houses with multi-seasonal harvesting, such as the horticulture industry in Spain. This improvement makes it possible to visualise the links of EU tomato consumption to precise production sites in Spain and opens a debate to the usefulness of such findings. This paper also compares existing ecological methodologies with WF and argues that both life cycle analysis (LCA) and ecological footprint (EF) models could benefit from WF methods. Our results show that the EU consumes 957,000 tons of Spanish fresh tomatoes annually, which evaporates 71 Mm(3)/yr of water and would require 7 Mm(3)/yr of water to dilute leached nitrates in Spain. In Spain, tomato production alone evaporates 297 Mm(3)/yr and pollutes 29 Mm(3)/yr of freshwater. Depending upon the local agro-climatic character, status of water resources, total tomato production volumes and production system, the impact of EU consumption of fresh tomatoes on Spanish freshwater is very location specific. The authors suggest that business now seek to report and address negative impacts on the environment. WF opens the door to complex water relationships and provides vital information for policy actors, business leaders, regulators and managers to their draw, dependence and responsibilities on this increasingly scarce resource.

  17. The effects of gaseous bubble composition and gap distance on the characteristics of nanosecond discharges in distilled water

    Science.gov (United States)

    Hamdan, Ahmad; Cha, Min Suk

    2016-06-01

    Electric discharge in liquids with bubbles can reduce the energy consumption, which increases treatment efficiency. We present an experimental study of nanosecond discharges in distilled water bubbled with the monoatomic gas argon and with the polyatomic gases methane, carbon dioxide, and propane. We monitor the time evolution of the voltage and current waveforms, and calculate the injected charges to characterize the discharge. We establish a relationship between the injected charges and the shape of the plasma by time-resolved imaging to find that increasing the size of the gap reduces the injected charges. Moreover, we determine the plasma characteristics, including electron density, excitation temperatures (for atoms and ions), and rotational temperature of the OH and C2 radicals found in the plasma. Our space- and time-averaged measurements allow us to propose a spatial distribution of the plasma that is helpful for understanding the plasma dynamics necessary to develop and optimize applications based on nanosecond discharges in bubbled liquids.

  18. Zero-Gap Alkaline Water Electrolysis Using Ion-Solvating Polymer Electrolyte Membranes at Reduced KOH Concentrations

    DEFF Research Database (Denmark)

    Kraglund, Mikkel Rykær; Aili, David; Jankova Atanasova, Katja;

    2016-01-01

    Membranes based on poly(2,2'-(m-phenylene)-5,5-bibenzimidazole) (m-PBI) can dissolve large amounts of aqueous KOH to give electrolyte systems with ion conductivity in a practically useful range. The conductivity of the membrane strongly depends on the concentration of the aqueous KOH phase......, reaching about 10-1 S cm-1 or higher in 15-25 wt% KOH. Herein, m-PBI membranes are systematically characterized with respect to performance and short-term stability as electrolyte in a zero-gap alkaline water electrolyzer at different KOH concentrations. Using plain uncatalyzed nickel foam electrodes...... exclusion chromatography and spectroscopy reveal evidence of oxidative degradation of the base polymer at KOH concentrations of 15 wt% and higher....

  19. Linking carbon and water relations to drought-induced mortality in Pinus flexilis seedlings.

    Science.gov (United States)

    Reinhardt, Keith; Germino, Matthew J; Kueppers, Lara M; Domec, Jean-Christophe; Mitton, Jeffry

    2015-07-01

    Survival of tree seedlings at high elevations has been shown to be limited by thermal constraints on carbon balance, but it is unknown if carbon relations also limit seedling survival at lower elevations, where water relations may be more important. We measured and modeled carbon fluxes and water relations in first-year Pinus flexilis seedlings in garden plots just beyond the warm edge of their natural range, and compared these with dry-mass gain and survival across two summers. We hypothesized that mortality in these seedlings would be associated with declines in water relations, more so than with carbon-balance limitations. Rather than gradual declines in survivorship across growing seasons, we observed sharp, large-scale mortality episodes that occurred once volumetric soil-moisture content dropped below 10%. By this point, seedling water potentials had decreased below -5 MPa, seedling hydraulic conductivity had decreased by 90% and seedling hydraulic resistance had increased by >900%. Additionally, non-structural carbohydrates accumulated in aboveground tissues at the end of both summers, suggesting impairments in phloem-transport from needles to roots. This resulted in low carbohydrate concentrations in roots, which likely impaired root growth and water uptake at the time of critically low soil moisture. While photosynthesis and respiration on a leaf area basis remained high until critical hydraulic thresholds were exceeded, modeled seedling gross primary productivity declined steadily throughout the summers. At the time of mortality, modeled productivity was insufficient to support seedling biomass-gain rates, metabolism and secondary costs. Thus the large-scale mortality events that we observed near the end of each summer were most directly linked with acute, episodic declines in plant hydraulic function that were linked with important changes in whole-seedling carbon relations.

  20. Linking carbon and water limitations to drought-induced mortality of Pinus flexilis seedlings

    Science.gov (United States)

    Reinhardt, Keith; Germino, Matthew J.; Kueppers, Lara M.; Domec, Jean-Christophe; Mitton, Jeffry

    2015-01-01

    Survival of tree seedlings at high elevations has been shown to be limited by thermal constraints on carbon balance, but it is unknown if carbon relations also limit seedling survival at lower elevations, where water relations may be more important. We measured and modeled carbon fluxes and water relations in first-year Pinus flexilis seedlings in garden plots just beyond the warm edge of their natural range, and compared these with dry-mass gain and survival across two summers. We hypothesized that mortality in these seedlings would be associated with declines in water relations, more so than with carbon-balance limitations. Rather than gradual declines in survivorship across growing seasons, we observed sharp, large-scale mortality episodes that occurred once volumetric soil-moisture content dropped below 10%. By this point, seedling water potentials had decreased below −5 MPa, seedling hydraulic conductivity had decreased by 90% and seedling hydraulic resistance had increased by >900%. Additionally, non-structural carbohydrates accumulated in aboveground tissues at the end of both summers, suggesting impairments in phloem-transport from needles to roots. This resulted in low carbohydrate concentrations in roots, which likely impaired root growth and water uptake at the time of critically low soil moisture. While photosynthesis and respiration on a leaf area basis remained high until critical hydraulic thresholds were exceeded, modeled seedling gross primary productivity declined steadily throughout the summers. At the time of mortality, modeled productivity was insufficient to support seedling biomass-gain rates, metabolism and secondary costs. Thus the large-scale mortality events that we observed near the end of each summer were most directly linked with acute, episodic declines in plant hydraulic function that were linked with important changes in whole-seedling carbon relations.

  1. Linking knowledge with action in the pursuit of sustainable water-resources management.

    Science.gov (United States)

    Jacobs, Katharine; Lebel, Louis; Buizer, James; Addams, Lee; Matson, Pamela; McCullough, Ellen; Garden, Po; Saliba, George; Finan, Timothy

    2016-04-26

    Managing water for sustainable use and economic development is both a technical and a governance challenge in which knowledge production and sharing play a central role. This article evaluates and compares the role of participatory governance and scientific information in decision-making in four basins in Brazil, Mexico, Thailand, and the United States. Water management institutions in each of the basins have evolved during the last 10-20 years from a relatively centralized water-management structure at the state or national level to a decision structure that involves engaging water users within the basins and the development of participatory processes. This change is consistent with global trends in which states increasingly are expected to gain public acceptance for larger water projects and policy changes. In each case, expanded citizen engagement in identifying options and in decision-making processes has resulted in more complexity but also has expanded the culture of integrated learning. International funding for water infrastructure has been linked to requirements for participatory management processes, but, ironically, this study finds that participatory processes appear to work better in the context of decisions that are short-term and easily adjusted, such as water-allocation decisions, and do not work so well for longer-term, high-stakes decisions regarding infrastructure. A second important observation is that the costs of capacity building to allow meaningful stakeholder engagement in water-management decision processes are not widely recognized. Failure to appreciate the associated costs and complexities may contribute to the lack of successful engagement of citizens in decisions regarding infrastructure.

  2. Filling environmental data gaps with QSPR for ionic liquids: Modeling n-octanol/water coefficient.

    Science.gov (United States)

    Rybinska, Anna; Sosnowska, Anita; Grzonkowska, Monika; Barycki, Maciej; Puzyn, Tomasz

    2016-02-13

    Ionic liquids (ILs) form a wide group of compounds characterized by specific properties that allow using ILs in different fields of science and industry. Regarding that the growing production and use of ionic liquids increase probability of their emission to the environment, it is important to estimate the ability of these compounds to spread in the environment. One of the most important parameters that allow evaluating environmental mobility of compound is n-octanol/water partition coefficient (KOW). Experimental measuring of the KOW values for a large number of compounds could be time consuming and costly. Instead, computational predictions are nowadays being used more often. The paper presents new Quantitative Structure-Property Relationship (QSPR) model that allows predicting the logarithmic values of KOW for 335 ILs, for which the experimentally measured values had been unavailable. We also estimated bioaccumulation potential and point out which group of ILs could have negative impact on environment.

  3. Linking High Frequency Variations in Stream Water DOC to Ages of Water Sources in Peat-Dominated Montane Watersheds

    Science.gov (United States)

    Tunaley, C.; Tetzlaff, D.; Lessels, J. S.; Soulsby, C.

    2015-12-01

    We combined time series of inferred DOC (from optical sensors) and stable isotopes in streams and watershed source areas to assess the link between water age and C fluxes. We monitored temporal dynamics of FDOM for 2 yrs at nested scales (0.9, 3.0 and 30km2) in a montane Scottish watershed. FDOM was strongly correlated (r2 ~ 0.8) with DOC allowing inference of 15 min timeseries. Marked seasonality was observed, with highest DOC concentrations (~25 mg l-1) in summer events and lower concentrations (~5mg l-1) in winter. During events, anticlockwise hysteresis was observed; consistent with expansion of the riparian saturation zone, increasing hydrological connectivity across peat soils and mobilizing DOC. Lag times for peak discharge and DOC were 1-12 hrs depending on event characteristics and antecedent conditions. Isotope time series from precipitation, streams and catchment source waters (overland flow and hillslope drainage) were also generated. These allowed us to model the non-stationary characteristics of their ages. Stream water age ranges from 3 months at high flows when overland flow dominates runoff to 4 yrs under baseflow. Overland flow age was a dominant influence on DOC transport. Highest concentrations occurred in small summer events with relatively young (strategies.

  4. Transient, recurrent, white matter lesions in x-linked Charcot-Marie-tooth disease with novel mutation of gap junction protein beta 1 gene in China: a case report.

    Science.gov (United States)

    Zhao, Yuan; Xie, Yanchen; Zhu, Xiaoquan; Wang, Huigang; Li, Yao; Li, Jimei

    2014-08-03

    Transient white matter lesions have been rarely reported in X-linked Charcot-Marie-Tooth disease type 1. We describe a 15-year-old boy who presented transient and recurrent weakness of the limbs for 5 days. His mother, his mother's mother and his mother's sister presented pes cavus. MRI and electrophysiology were performed in the proband. Gap junction protein beta l gene was analyzed by PCR-sequencing in the proband and his parents. The electrophysiological studies showed a mixed demyelinating and axonal sensorimotor neuropathy. MRI showed white matter lesions in the internal capsule, corpus callosum and periventricular areas, which showed almost complete resolution after two months. T278G mutation in Gap junction protein beta l gene was detected in the proband and his mother. This case report highlights that the novel T278G mutation of Gap junction protein beta l maybe could result in X-linked Charcot-Marie-Tooth disease type 1 with predominant leucoencephalopathy. The white matter changes in MRI of X-linked Charcot-Marie-Tooth disease type 1 patient are reversible.

  5. River temperature processes under contrasting riparian land cover: linking microclimate, heat exchange and water thermal dynamics

    Science.gov (United States)

    Hannah, D. M.; Kantola, K.; Malcolm, I.

    2012-12-01

    River temperature influences strongly growth and survival in salmonid fish, which are often the target of river management strategies. Temperature is controlled by transfers of heat and water to/ from the river system, with land and water management modifying exchanges and consequently thermal regime. In the UK, fisheries managers are promoting riparian forest planting as a climate change adaption measure to reduce water temperature extremes. However, scientific understanding lags behind management and policy needs. Specifically, there is an urgent requirement to determine planting strategies that maximise expected benefits of riparian forest in terms of reduction in maximum water temperature. Scientific knowledge is necessary to underpin conceptual and deterministic models to inform management. To address this research gap, this paper analyses high resolution (15 minute) hydrometeorological data collected over a calendar year in the western Scottish Highlands (Loch Ard) to understand the controls and processes determining river temperature dynamics under open moorland (control), semi-natural woodland and commercial forest. The research programme aims: (1) to characterise spatial and temporal variability in riparian microclimate and stream water temperature regime across forest treatments; (2) to identify the hydrological, climatological and site-specific factors affecting stream temperature; (3) to estimate the energy balance at sites representative of each forest treatment and, thus, yield physical process understanding about dominant heat exchanges driving thermal variability; and (4) to use 1-3 to predict stream temperature sensitivity under different forestry and hydroclimatological scenarios. Results indicated that inter-treatment differences in mean and maximum daily water column temperature were ordered open > semi-natural > commercial during summer, but semi-natural > commercial > open during winter. Minimum water temperature was ordered commercial > semi

  6. Linking water age and solute dynamics in streamflow at the Hubbard Brook Experimental Forest, NH, USA

    Science.gov (United States)

    Benettin, Paolo; Bailey, Scott W.; Campbell, John L.; Green, Mark B.; Rinaldo, Andrea; Likens, Gene E.; McGuire, Kevin J.; Botter, Gianluca

    2015-11-01

    We combine experimental and modeling results from a headwater catchment at the Hubbard Brook Experimental Forest (HBEF), New Hampshire, USA, to explore the link between stream solute dynamics and water age. A theoretical framework based on water age dynamics, which represents a general basis for characterizing solute transport at the catchment scale, is here applied to conservative and weathering-derived solutes. Based on the available information about the hydrology of the site, an integrated transport model was developed and used to compute hydrochemical fluxes. The model was designed to reproduce the deuterium content of streamflow and allowed for the estimate of catchment water storage and dynamic travel time distributions (TTDs). The innovative contribution of this paper is the simulation of dissolved silicon and sodium concentration in streamflow, achieved by implementing first-order chemical kinetics based explicitly on dynamic TTD, thus upscaling local geochemical processes to catchment scale. Our results highlight the key role of water stored within the subsoil glacial material in both the short-term and long-term solute circulation. The travel time analysis provided an estimate of streamflow age distributions and their evolution in time related to catchment wetness conditions. The use of age information to reproduce a 14 year data set of silicon and sodium stream concentration shows that, at catchment scales, the dynamics of such geogenic solutes are mostly controlled by hydrologic drivers, which determine the contact times between the water and mineral interfaces. Justifications and limitations toward a general theory of reactive solute circulation at catchment scales are discussed.

  7. Inter-Basin Water Transfer Impact Assessment on Environment of Pennar to Cauvery Link Canal

    Science.gov (United States)

    Rajesh, S. V. J. S. S.; Prakasa Rao, B. S.; Niranjan, K.

    2016-07-01

    Owing to its striking differences in its climatic conditions, India is frequently facing with extremities such as heavy rain fall in some regions where as some other regions endure little rainfall. The regions receiving heavy precipitation are facing floods resulting in huge amount of water runs into the sea. Contrarily, the regions, without adequate rainfall are suffering from persistent droughts. To overcome such disparities in the distribution of water, National Water Development Agency (NWDA) put a proposal to transfer water through link canals between rivers. The current study is limited to two river basins, Pennar and Cauvery. The present study is confined to Pennar (somasila) to Cauvery (Grand Anicut) whose length is 483 km. The study consist of10 km. buffer on either side of the canal and it occupies 17,215.68 sq. km. out of these 10,105.96 sq.km.is proposed command area which falls in Chittoor, Chengalpattu, North Arcott and South Arcott districts. Using IRS-P6, LISS-III data the characteristics of the rocks, lineaments, drainage, settlements and land use/land cover are mapped for better analysis and the environmental impact. The study indicated that Current fallow land of 5340.14 km2 and 6307.98 km2 of cropland will be brought under cultivation which is more than what is NWDA estimated land that will be benefited. The canal will provide water for irrigation and drinking to 4597 villages and 244 villages to be rehabilitated. 119 culverts/canal bridges and 24 aqueducts have to be constructed across the canal.

  8. Health-risk market garden production linked to heavy metals in irrigation water in Benin.

    Science.gov (United States)

    Koumolou, Luc; Edorh, Patrick; Montcho, Sabine; Aklikokou, Kodjo; Loko, Frédéric; Boko, Michel; Creppy, Edmond E

    2013-01-01

    Heavy metals in the Benin market garden products: is irrigation water the first factor in question, and what is the level of health risk linked to the consumption of these vegetables? Such are the essential problems that this survey attempts to solve. Comparison of the level of lead (Pb), cadmium (Cd) and arsenic (As) pollution shows that all the vegetables taken from three market sites are differently contaminated, as well as their irrigation water and the soil. But establishing that water is the first factor responsible for the presence of heavy metals in market garden products is not so obvious. Otherwise, the health risk assessment revealed that the total daily exposure dose (DED) of Cd, namely 8.05μg/kg/day, is high compared to the daily dose defined by the WHO, which is 1μg/kg/day. Also, the ensuing quotient of danger (QD) is 8.05; such a value poses public health risks for the consumer. Copyright © 2013 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  9. The accurate calculation of the band gap of liquid water by means of GW corrections applied to plane-wave density functional theory molecular dynamics simulations

    NARCIS (Netherlands)

    Fang, Changming; Li, Wun Fan; Koster, Rik S.; Klimeš, Jiří; Van Blaaderen, Alfons; Van Huis, Marijn A.

    2015-01-01

    Knowledge about the intrinsic electronic properties of water is imperative for understanding the behaviour of aqueous solutions that are used throughout biology, chemistry, physics, and industry. The calculation of the electronic band gap of liquids is challenging, because the most accurate ab initi

  10. Water, sanitation, and hygiene (WASH), environmental enteropathy, nutrition, and early child development: making the links.

    Science.gov (United States)

    Ngure, Francis M; Reid, Brianna M; Humphrey, Jean H; Mbuya, Mduduzi N; Pelto, Gretel; Stoltzfus, Rebecca J

    2014-01-01

    There is scarce research and programmatic evidence on the effect of poor water, sanitation, and hygiene (WASH) conditions of the physical environment on early child cognitive, sensorimotor, and socioemotional development. Furthermore, many common WASH interventions are not specifically designed to protect babies in the first 3 years of life, when gut health and linear growth are established. We review evidence linking WASH, anemia, and child growth, and highlight pathways through which WASH may affect early child development, primarily through inflammation, stunting, and anemia. Environmental enteropathy, a prevalent subclinical condition of the gut, may be a key mediating pathway linking poor hygiene to developmental deficits. Current early child development research and programs lack evidence-based interventions to provide a clean play and infant feeding environment in addition to established priorities of nutrition, stimulation, and child protection. Solutions to this problem will require appropriate behavior change and technologies that are adapted to the social and physical context and conducive to infant play and socialization. We propose the concept of baby WASH as an additional component of early childhood development programs.

  11. Ecosystem-groundwater interactions under changing land uses: Linking water, salts, and carbon across central Argentina

    Science.gov (United States)

    Jobbagy, E. G.; Nosetto, M. D.; Santoni, C. S.; Jackson, R. B.

    2007-05-01

    Although most ecosystems display a one-way connection with groundwater based on the regulation of deep water drainage (recharge), this link can become reciprocal when the saturated zone is shallow and plants take up groundwater (discharge). In what context is the reciprocal link most likely? How is it affected by land use changes? Has it consequences on salt and carbon cycling? We examine these questions across a precipitation gradient in the Pampas and Espinal of Argentina focusing on three vegetation change situations (mean annual rainfall): afforestation of humid (900-1300 mm) and subhumid grassland (700-900 mm/yr of rainfall), annual cultivation of subhumid grasslands (700-800 mm/yr), and annual cultivation of semiarid forests (500-700 mm). Humid and subhumid grasslands have shallow (salinity of tree species. Cultivation with corn and soybean can lead to groundwater consumption in the driest belt of subhumid grassland. Up to five-fold yield increases in lowlands vs. uplands during the driest years indicate a dramatic impact of groundwater use on carbon uptake and groundwater salinization suggests a recharge-to- discharge switch. In dry forests groundwater is not accessible (> 15 m deep) and recharge under natural conditions is null. The establishment of crops, however, triggers the onset of recharge, as evidenced by vadose zones getting wetter and leached of atmospheric chloride. Cropping may cause water table raises leading to a two-way coupling of ecosystems and groundwater in the future, as it has been documented for similar settings in Australia and the Sahel. In the Pampas land use change interacts with groundwater consumption leading to higher carbon uptake (humid and subhumid grasslands) and salt accumulation (subhumid grasslands). In the Espinal (semiarid forest) land use change currently involves a one-way effect on groundwater recharge that may switch to a reciprocal connection if regional water table raises occur. Neglecting the role of groundwater

  12. Klamath River Water Quality Data from Link River Dam to Keno Dam, Oregon, 2008

    Science.gov (United States)

    Sullivan, Annett B.; Deas, Michael L.; Asbill, Jessica; Kirshtein, Julie D.; Butler, Kenna D.; Vaughn, Jennifer

    2009-01-01

    This report documents sampling and analytical methods and presents field data from a second year of an ongoing study on the Klamath River from Link River Dam to Keno Dam in south central Oregon; this dataset will form the basis of a hydrodynamic and water quality model. Water quality was sampled weekly at six mainstem and two tributary sites from early April through early November, 2008. Constituents reported herein include field-measured water-column parameters (water temperature, pH, dissolved oxygen concentration, specific conductance); total nitrogen and phosphorus; particulate carbon and nitrogen; total iron; filtered orthophosphate, nitrite, nitrite plus nitrate, ammonia, organic carbon, and iron; specific UV absorbance at 254 nanometers; chlorophyll a; phytoplankton and zooplankton enumeration and species identification; and bacterial abundance and morphological subgroups. Sampling program results indicated: *Most nutrient and carbon concentrations were lowest in spring, increased starting in mid-June, remained elevated in the summer, and decreased in fall. Dissolved nitrite plus nitrate had a different seasonal cycle and was below detection or at low concentration in summer. *Although total nitrogen and total phosphorus concentrations did not show large differences from upstream to downstream, filtered ammonia and orthophosphate concentrations increased in the downstream direction and particulate carbon and particulate nitrogen generally decreased in the downstream direction. *Large bacterial cells made up most of the bacteria biovolume, though cocci were the most numerous bacteria type. Cocci, with diameters of 0.1 to 0.2 micrometers, were smaller than the filter pore sizes used to separate dissolved from particulate matter. *Phytoplankton biovolumes were dominated by diatoms in spring and by the blue-green alga Aphanizomenon flos-aquae after mid-June. Another blue-green, Anabaena flos-aquae, was noted in samples from late May to late June. Phytoplankton

  13. Water and energy link in the cities of the future - achieving net zero carbon and pollution emissions footprint.

    Science.gov (United States)

    Novotny, V

    2011-01-01

    This article discusses the link between water conservation, reclamation, reuse and energy use as related to the goal of achieving the net zero carbon emission footprint in future sustainable cities. It defines sustainable ecocities and outlines quantitatively steps towards the reduction of energy use due to water and used water flows, management and limits in linear and closed loop water/stormwater/wastewater management systems. The three phase water energy nexus diagram may have a minimum inflection point beyond which reduction of water demand may not result in a reduction of energy and carbon emissions. Hence, water conservation is the best alternative solution to water shortages and minimizing the carbon footprint. A marginal water/energy chart is developed and proposed to assist planners in developing future ecocities and retrofitting older communities to achieve sustainability.

  14. Effect of operating parameters and membrane characteristics on air gap membrane distillation performance for the treatment of highly saline water

    KAUST Repository

    Xu, Jingli

    2016-04-07

    In this study, ten different commercially available PTFE, PP and PVDF membranes were tested in desalination of highly saline water by air gap membrane distillation (AGMD). Process performance was investigated under different operating parameters, such as feed temperatures, feed flow velocities and salt concentrations reaching 120 g/L, and different membrane characteristics, such as membrane material, thickness, pore size and support layer, using a locally designed and fabricatd AGMD module and spacer. Results showed that increasing feed temperature increases permeate flux regardless of the feed concentration. However, feed flow velocity does not significantly affect the flux, especially at low feed temperatures. The PP membrane showed a better performance than the PVDF and PTFE membranes. Permeate flux decreases with the increase of salt concentration of feed solution, especially at higher concentrations above 90 g/L. The existence of membrane support layer led to a slight decrease of permeate flux. Membranes with pore sizes of 0.2 and 0.45 μm gave the best performance. Smaller pore size led to lower flux and larger pore size led to pore wetting due to lower LEP values. The effect of concentration polarization and temperature polarization has also been studied and compared.

  15. The effects of gaseous bubble composition and gap distance on the characteristics of nanosecond discharges in distilled water

    KAUST Repository

    Hamdan, Ahmad

    2016-05-17

    Electric discharge in liquids with bubbles can reduce the energy consumption, which increases treatment efficiency. We present an experimental study of nanosecond discharges in distilled water bubbled with the monoatomic gas argon and with the polyatomic gases methane, carbon dioxide, and propane. We monitor the time evolution of the voltage and current waveforms, and calculate the injected charges to characterize the discharge. We establish a relationship between the injected charges and the shape of the plasma by time-resolved imaging to find that increasing the size of the gap reduces the injected charges. Moreover, we determine the plasma characteristics, including electron density, excitation temperatures (for atoms and ions), and rotational temperature of the OH and C2 radicals found in the plasma. Our space- and time-averaged measurements allow us to propose a spatial distribution of the plasma that is helpful for understanding the plasma dynamics necessary to develop and optimize applications based on nanosecond discharges in bubbled liquids. © 2016 IOP Publishing Ltd.

  16. An atrial-fibrillation-linked connexin40 mutant is retained in the endoplasmic reticulum and impairs the function of atrial gap-junction channels

    Directory of Open Access Journals (Sweden)

    Yiguo Sun

    2014-05-01

    Full Text Available Connexin40 (Cx40-containing gap-junction channels are expressed in the atrial myocardium and provide a low-resistance passage for rapid impulse propagation. A germline mutation in the GJA5 gene, which encodes Cx40, resulting in a truncated Cx40 (Q49X was identified in a large Chinese family with lone (idiopathic atrial fibrillation (AF. This mutation co-segregated with seven AF probands in an autosomal-dominant way over generations. To test the hypothesis that this Cx40 mutant affects the distribution and function of atrial gap junctions, we studied the Q49X mutant in gap-junction-deficient HeLa and N2A cells. The Q49X mutant, unlike wild-type Cx40, was typically localized in the cytoplasm and failed to form gap-junction plaques at cell-cell interfaces. When the Q49X mutant was co-expressed with Cx40 or Cx43, the mutant substantially reduced the gap-junction plaque formation of Cx40 and Cx43. Electrophysiological studies revealed no electrical coupling of cell pairs expressing the mutant alone and a significant decrease in the coupling conductance when the mutant was co-expressed with Cx40 or Cx43. Further colocalization experiments with the organelle residential proteins indicate that Q49X was retained in the endoplasmic reticulum. These findings provide evidence that the Q49X mutant is capable of impairing gap-junction distribution and function of key atrial connexins, which might play a role in the predisposition to and onset of AF.

  17. Nuclear Quantum Effects in Water at the Triple Point: Using Theory as a Link Between Experiments.

    Science.gov (United States)

    Cheng, Bingqing; Behler, Jörg; Ceriotti, Michele

    2016-06-16

    One of the most prominent consequences of the quantum nature of light atomic nuclei is that their kinetic energy does not follow a Maxwell-Boltzmann distribution. Deep inelastic neutron scattering (DINS) experiments can measure this effect. Thus, the nuclear quantum kinetic energy can be probed directly in both ordered and disordered samples. However, the relation between the quantum kinetic energy and the atomic environment is a very indirect one, and cross-validation with theoretical modeling is therefore urgently needed. Here, we use state of the art path integral molecular dynamics techniques to compute the kinetic energy of hydrogen and oxygen nuclei in liquid, solid, and gas-phase water close to the triple point, comparing three different interatomic potentials and validating our results against equilibrium isotope fractionation measurements. We will then show how accurate simulations can draw a link between extremely precise fractionation experiments and DINS, therefore establishing a reliable benchmark for future measurements and providing key insights to increase further the accuracy of interatomic potentials for water.

  18. Extreme diving behaviour in devil rays links surface waters and the deep ocean.

    Science.gov (United States)

    Thorrold, Simon R; Afonso, Pedro; Fontes, Jorge; Braun, Camrin D; Santos, Ricardo S; Skomal, Gregory B; Berumen, Michael L

    2014-07-01

    Ecological connections between surface waters and the deep ocean remain poorly studied despite the high biomass of fishes and squids residing at depths beyond the euphotic zone. These animals likely support pelagic food webs containing a suite of predators that include commercially important fishes and marine mammals. Here we deploy pop-up satellite archival transmitting tags on 15 Chilean devil rays (Mobula tarapacana) in the central North Atlantic Ocean, which provide movement patterns of individuals for up to 9 months. Devil rays were considered surface dwellers but our data reveal individuals descending at speeds up to 6.0 m s(-1) to depths of almost 2,000 m and water temperatures <4 °C. The shape of the dive profiles suggests that the rays are foraging at these depths in deep scattering layers. Our results provide evidence of an important link between predators in the surface ocean and forage species occupying pelagic habitats below the euphotic zone in ocean ecosystems.

  19. Extreme diving behaviour in devil rays links surface waters and the deep ocean

    KAUST Repository

    Thorrold, Simon R.

    2014-07-01

    Ecological connections between surface waters and the deep ocean remain poorly studied despite the high biomass of fishes and squids residing at depths beyond the euphotic zone. These animals likely support pelagic food webs containing a suite of predators that include commercially important fishes and marine mammals. Here we deploy pop-up satellite archival transmitting tags on 15 Chilean devil rays (Mobula tarapacana) in the central North Atlantic Ocean, which provide movement patterns of individuals for up to 9 months. Devil rays were considered surface dwellers but our data reveal individuals descending at speeds up to 6.0 ms-1 to depths of almost 2,000 m and water temperatures <4 C. The shape of the dive profiles suggests that the rays are foraging at these depths in deep scattering layers. Our results provide evidence of an important link between predators in the surface ocean and forage species occupying pelagic habitats below the euphotic zone in ocean ecosystems. 2014 Macmillan Publishers Limited. All rights reserved.

  20. Linking water quality and quantity in environmental flow assessment in deteriorated ecosystems: a food web view.

    Science.gov (United States)

    Chen, He; Ma, Lekuan; Guo, Wei; Yang, Ying; Guo, Tong; Feng, Cheng

    2013-01-01

    Most rivers worldwide are highly regulated by anthropogenic activities through flow regulation and water pollution. Environmental flow regulation is used to reduce the effects of anthropogenic activities on aquatic ecosystems. Formulating flow alteration-ecological response relationships is a key factor in environmental flow assessment. Traditional environmental flow models are characterized by natural relationships between flow regimes and ecosystem factors. However, food webs are often altered from natural states, which disturb environmental flow assessment in such ecosystems. In ecosystems deteriorated by heavy anthropogenic activities, the effects of environmental flow regulation on species are difficult to assess with current modeling approaches. Environmental flow management compels the development of tools that link flow regimes and food webs in an ecosystem. Food web approaches are more suitable for the task because they are more adaptive for disordered multiple species in a food web deteriorated by anthropogenic activities. This paper presents a global method of environmental flow assessment in deteriorated aquatic ecosystems. Linkages between flow regimes and food web dynamics are modeled by incorporating multiple species into an ecosystem to explore ecosystem-based environmental flow management. The approach allows scientists and water resources managers to analyze environmental flows in deteriorated ecosystems in an ecosystem-based way.

  1. The accurate calculation of the band gap of liquid water by means of GW corrections applied to plane-wave density functional theory molecular dynamics simulations.

    Science.gov (United States)

    Fang, Changming; Li, Wun-Fan; Koster, Rik S; Klimeš, Jiří; van Blaaderen, Alfons; van Huis, Marijn A

    2015-01-07

    Knowledge about the intrinsic electronic properties of water is imperative for understanding the behaviour of aqueous solutions that are used throughout biology, chemistry, physics, and industry. The calculation of the electronic band gap of liquids is challenging, because the most accurate ab initio approaches can be applied only to small numbers of atoms, while large numbers of atoms are required for having configurations that are representative of a liquid. Here we show that a high-accuracy value for the electronic band gap of water can be obtained by combining beyond-DFT methods and statistical time-averaging. Liquid water is simulated at 300 K using a plane-wave density functional theory molecular dynamics (PW-DFT-MD) simulation and a van der Waals density functional (optB88-vdW). After applying a self-consistent GW correction the band gap of liquid water at 300 K is calculated as 7.3 eV, in good agreement with recent experimental observations in the literature (6.9 eV). For simulations of phase transformations and chemical reactions in water or aqueous solutions whereby an accurate description of the electronic structure is required, we suggest to use these advanced GW corrections in combination with the statistical analysis of quantum mechanical MD simulations.

  2. Linking high-frequency DOC dynamics to the age of connected water sources

    Science.gov (United States)

    Tunaley, C.; Tetzlaff, D.; Lessels, J.; Soulsby, C.

    2016-07-01

    We combined high-frequency dissolved organic matter fluorescence (FDOM) data with stable isotope observations to identify the sources and ages of runoff that cause temporal variability in dissolved organic carbon (DOC) within a peat-dominated Scottish catchment. FDOM was strongly correlated (r2 ˜ 0.8) with DOC, allowing inference of a 15 min time series. We captured 34 events over a range of hydrological conditions. Along with marked seasonality, different event responses were observed during summer depending on dry or wet antecedent conditions. The majority of events exhibited anticlockwise hysteresis as a result of the expansion of the riparian saturation zone, mobilizing previously unconnected DOC sources. Water ages from the main runoff sources were extracted from a tracer-aided hydrological model. Particularly useful were ages of overland flow, which were negatively correlated with DOC concentration. Overland flow age, which ranged between 0.2 and 360 days, reflected antecedent conditions, with younger water generally mobilizing the highest DOC concentrations in summer events. During small events with dry antecedent conditions, DOC response was proportionally higher due to the displacement and mixing of small volumes of previously unconnected highly concentrated riparian soil waters by new precipitation. During large events with wet antecedent conditions, the riparian saturation zone expands to organic layers on the hillslopes causing peaks in DOC. However, these peaks were limited by dilution and supply. This study highlights the utility of linking high-frequency DOC measurements with other tracers, allowing the effects of hydrologic connectivity and antecedent conditions on delivery of DOC to streams to be assessed.

  3. Small-Gap Flows

    Science.gov (United States)

    1984-04-01

    34’OF CALIFORNIA# BERKELEY, CA 5.1720 ft (45 642-141 SMALL- GAP FLOWS BY E. 0. TUCK REPORT No. NAUE 84-1 CONTRACT N00014-84-K-OU26 APRIL i984...Mechanics, 41 (1970) 769-792. 11 3. Shallow-Water Waves at Discontinuities Shallow-water waves represent perhaps the prototype small- gap flow , the...solving (4.4) we need "initial" conditions at the starting station z = 0, and "exit" conditions at the station z = L where the gap flow merges with the

  4. Studies on Structure and Properties of Water Soluble Polysaccharide from Fruiting Body of Cordyceps Militarvs(L.) Link

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A water soluble crude polysaccharide has been isolated from the fruiting body of cultivated Cordyceps militarvs(L.) Link. The GC analysis indicated that it contained the monosaccharides of Gal, Man, Glc and GlcA. Their molar ratio is 1.00∶1.58∶7.89∶0.19. The crude polysaccharide was fractionated with ethanol to get three fractions, which were CM-Ⅰ, CM-Ⅱ and CM-Ⅲ. CM-Ⅱ was further purified to get one homogeneous fraction named CMB. The molecular weight was estimated to be 60000 by means of gel filtration. CMB is a greyish white powder. The GC analysis indicated that it was composed of Gal, Man, Glc and the molar ratio is 1.00∶1.38∶5.10. Partial hydrolysis with an acid, periodate oxidation, Smith degradation, IR, GC and methylation analyses, GC/MS analyses were used for the structure analyses of CMB. The results reveal that CMB is of a lower branched structure. The main chain is composed of (1→6)-linked-Man, (1→6)-linked-Glc, (1→4)-linked-Glc and (1→4)-linked-Gal. Some of (1→4)-linked-Glc and all (1→4)-linked-Gal residues are substituted at 3-O and 6-O respectively. (1→4)-Linked-Glc residues without branch probably exist with other monosaccharides alternately. On an average, there is one branch every ten hexose residues. The side chain is composed of major (1→4)-linked-Glc and minor (1→6)-linked-Glc. The nonreduced end is composed of Gal and Glc. The main glycosidic link of CMB is α configuration.

  5. Water Vapor Feedback and Links to Mechanisms of Recent Tropical Climate Variations

    Science.gov (United States)

    Robertson, F. R.; Miller, Tim L.

    2008-01-01

    Recent variations of tropical climate on interannual to near-decadal scales have provided a useful target for studying feedback processes. A strong warm/cold ENSO couplet (e.g. 1997-2000) along with several subsequent weaker events are prominent interannual signals that are part of an apparent longer term strengthening of the Walker circulation during the mid to late1990 s with some weakening thereafter. Decadal scale changes in tropical SST structure during the 1990s are accompanied by focusing of precipitation over the Indo-Pacific warm pool and an increase in tropical ocean evaporation of order 1.0 %/decade. Here we use a number of diverse satellite measurements to explore connections between upper-tropospheric humidity (UTH) variations on these time scales and changes in other water and energy fluxes. Precipitation (GPCP, TRMM), turbulent fluxes (OAFlux), and radiative fluxes (ERBE / CERES, SRB) are use to analyze vertically-integrated divergence of moist static energy, divMSE, and its dry and moist components. Strong signatures of MSE flux transport linking ascending and descending regions of tropical circulations are found. Relative strengths of these transports compared to radiative flux changes are interpreted as a measure of efficiency in the overall process of heat rejection during episodes of warm or cold SST forcing. In conjunction with the diagnosed energy transports we explore frequency distributions of upper-tropospheric humidity as inferred from SSM/T-2 and AMSU-B passive microwave measurements. Relating these variations to SST changes suggests positive water vapor feedback, but at a level reduced from constant relative humidity.

  6. Preparation of new hyper cross-linked chelating resin for adsorption of Cu2+ and Ni2+ from water

    Institute of Scientific and Technical Information of China (English)

    Cheng Cheng; Jin Nan Wang; Li Xu; Ai Min Li

    2012-01-01

    The new hyper cross-linked chelating resin NDWJN2 modified with carboxyl groups was prepared for removal of Cu2+ and Ni2+ from water.NDWJN2 was characterized using BET,SEM and FT-IR spectroscopy.Comparing with commercial resins D113 and IRC84,NDWJN2 could remove Cu2+ and Ni2+ from water more effectively.Langmuir model could fit adsorption isotherms well.

  7. Detection of Campylobacter jejuni and Campylobacter coli in Environmental Waters by PCR Enzyme-Linked Immunosorbent Assay

    OpenAIRE

    Sails, A. D.; Bolton, F. J.; Fox, A. J.; Wareing, D. R. A.; Greenway, D. L. A.

    2002-01-01

    A PCR enzyme-linked immunosorbent assay (ELISA) assay was applied to the detection of Campylobacter jejuni and Campylobacter coli in environmental water samples after enrichment culture. Bacterial cells were concentrated from 69 environmental water samples by using filtration, and the filtrates were cultured in Campylobacter blood-free broth. After enrichment culture, DNA was extracted from the samples by using a rapid-boiling method, and the DNA extracts were used as a template in a PCR ELIS...

  8. Comparative studies on performance of radiation-induced and thermal cross-linked ion-exchange membrane for water electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Chakrabarty, Tina; Jasti, Amaranadh [Electro-Membrane Processes Division, Central Salt and Marine Chemicals Research Institute, Council of Scientific and Industrial Research (CSIR), G. B. Marg, Bhavnagar 364002, Gujarat (India); Goel, N.K. [Radiation Technology Division, Bhabha Atomic Research Center, Trombay, Mumbai (India); Shahi, Vinod K., E-mail: vkshahi@csmcri.or [Electro-Membrane Processes Division, Central Salt and Marine Chemicals Research Institute, Council of Scientific and Industrial Research (CSIR), G. B. Marg, Bhavnagar 364002, Gujarat (India); Sabharwal, Sunil [Radiation Technology Division, Bhabha Atomic Research Center, Trombay, Mumbai (India)

    2011-07-15

    Radiation-induced and thermal cross-linked sulfonated poly(ether sulfone) (SPS)-sulfonated poly(ether ether ketone) (SPK) composite ion-exchange membranes (SPS/SPK({gamma}) and SPS/SPK(T), respectively) were prepared. Their performances for water electrolysis were comparatively assessed. Thermal cross-linked membrane (SPS/SPK(T)) showed cross-linking of part functional groups (-SO{sub 3}H) and thus deterioration in membrane conductivity. While, radiation-induced cross-linked membrane (SPS/SPK({gamma})) avoided any cross-linking between functional groups and thus conductivity. Electrolysis performances of these membranes were evaluated in comparison with Nafion117 membrane. Relatively low current efficiency (CE) for SPS/SPK and SPS/SPK(T) membranes was due to their high mass transfer (water) via electro-osmotic drag, which was negligible for SPS/SPK({gamma}) membrane. SPS/SPK({gamma}) membrane exhibited comparable stabilities and water splitting performance with Nafion117 membrane, which revealed its suitability as substitute for electrochemical applications.

  9. Comparative studies on performance of radiation-induced and thermal cross-linked ion-exchange membrane for water electrolysis

    Science.gov (United States)

    Chakrabarty, Tina; Jasti, Amaranadh; Goel, N. K.; Shahi, Vinod K.; Sabharwal, Sunil

    2011-07-01

    Radiation-induced and thermal cross-linked sulfonated poly(ether sulfone) (SPS)-sulfonated poly(ether ether ketone) (SPK) composite ion-exchange membranes (SPS/SPK(γ) and SPS/SPK(T), respectively) were prepared. Their performances for water electrolysis were comparatively assessed. Thermal cross-linked membrane (SPS/SPK(T)) showed cross-linking of part functional groups (-SO 3H) and thus deterioration in membrane conductivity. While, radiation-induced cross-linked membrane (SPS/SPK(γ)) avoided any cross-linking between functional groups and thus conductivity. Electrolysis performances of these membranes were evaluated in comparison with Nafion117 membrane. Relatively low current efficiency (CE) for SPS/SPK and SPS/SPK(T) membranes was due to their high mass transfer (water) via electro-osmotic drag, which was negligible for SPS/SPK(γ) membrane. SPS/SPK(γ) membrane exhibited comparable stabilities and water splitting performance with Nafion117 membrane, which revealed its suitability as substitute for electrochemical applications.

  10. Critical body residues linked to octanol-water partitioning, organism composition, and LC50 QSARs: Meta-analysis and model

    NARCIS (Netherlands)

    Hendriks, A.J.; Traas, T.P.; Huijbregts, M.A.J.

    2005-01-01

    To protect thousands of species from thousands of chemicals released in the environment, various risk assessment tools have been developed. Here, we link quantitative structure-activity relationships (QSARs) for response concentrations in water (LC50) to critical concentrations in organisms (C-50) b

  11. Evolution of Microbial Quorum Sensing to Human Global Quorum Sensing: An Insight into How Gap Junctional Intercellular Communication Might Be Linked to the Global Metabolic Disease Crisis.

    Science.gov (United States)

    Trosko, James E

    2016-06-15

    The first anaerobic organism extracted energy for survival and reproduction from its source of nutrients, with the genetic means to ensure protection of its individual genome but also its species survival. While it had a means to communicate with its community via simple secreted molecules ("quorum sensing"), the eventual shift to an aerobic environment led to multi-cellular metazoan organisms, with evolutionary-selected genes to form extracellular matrices, stem cells, stem cell niches, and a family of gap junction or "connexin" genes. These germinal and somatic stem cells responded to extracellular signals that triggered intra-cellular signaling to regulate specific genes out of the total genome. These extra-cellular induced intra-cellular signals also modulated gap junctional intercellular communication (GJIC) in order to regulate the new cellular functions of symmetrical and asymmetrical cell division, cell differentiation, modes of cell death, and senescence. Within the hierarchical and cybernetic concepts, differentiated by neurons organized in the brain of the Homo sapiens, the conscious mind led to language, abstract ideas, technology, myth-making, scientific reasoning, and moral decision-making, i.e., the creation of culture. Over thousands of years, this has created the current collision between biological and cultural evolution, leading to the global "metabolic disease" crisis.

  12. Evolution of Microbial Quorum Sensing to Human Global Quorum Sensing: An Insight into How Gap Junctional Intercellular Communication Might Be Linked to the Global Metabolic Disease Crisis

    Directory of Open Access Journals (Sweden)

    James E. Trosko

    2016-06-01

    Full Text Available The first anaerobic organism extracted energy for survival and reproduction from its source of nutrients, with the genetic means to ensure protection of its individual genome but also its species survival. While it had a means to communicate with its community via simple secreted molecules (“quorum sensing”, the eventual shift to an aerobic environment led to multi-cellular metazoan organisms, with evolutionary-selected genes to form extracellular matrices, stem cells, stem cell niches, and a family of gap junction or “connexin” genes. These germinal and somatic stem cells responded to extracellular signals that triggered intra-cellular signaling to regulate specific genes out of the total genome. These extra-cellular induced intra-cellular signals also modulated gap junctional intercellular communication (GJIC in order to regulate the new cellular functions of symmetrical and asymmetrical cell division, cell differentiation, modes of cell death, and senescence. Within the hierarchical and cybernetic concepts, differentiated by neurons organized in the brain of the Homo sapiens, the conscious mind led to language, abstract ideas, technology, myth-making, scientific reasoning, and moral decision–making, i.e., the creation of culture. Over thousands of years, this has created the current collision between biological and cultural evolution, leading to the global “metabolic disease” crisis.

  13. Evolution of Microbial Quorum Sensing to Human Global Quorum Sensing: An Insight into How Gap Junctional Intercellular Communication Might Be Linked to the Global Metabolic Disease Crisis

    Science.gov (United States)

    Trosko, James E.

    2016-01-01

    The first anaerobic organism extracted energy for survival and reproduction from its source of nutrients, with the genetic means to ensure protection of its individual genome but also its species survival. While it had a means to communicate with its community via simple secreted molecules (“quorum sensing”), the eventual shift to an aerobic environment led to multi-cellular metazoan organisms, with evolutionary-selected genes to form extracellular matrices, stem cells, stem cell niches, and a family of gap junction or “connexin” genes. These germinal and somatic stem cells responded to extracellular signals that triggered intra-cellular signaling to regulate specific genes out of the total genome. These extra-cellular induced intra-cellular signals also modulated gap junctional intercellular communication (GJIC) in order to regulate the new cellular functions of symmetrical and asymmetrical cell division, cell differentiation, modes of cell death, and senescence. Within the hierarchical and cybernetic concepts, differentiated by neurons organized in the brain of the Homo sapiens, the conscious mind led to language, abstract ideas, technology, myth-making, scientific reasoning, and moral decision–making, i.e., the creation of culture. Over thousands of years, this has created the current collision between biological and cultural evolution, leading to the global “metabolic disease” crisis. PMID:27314399

  14. Knowledge Gaps

    DEFF Research Database (Denmark)

    Lyles, Marjorie; Pedersen, Torben; Petersen, Bent

    2003-01-01

    The study explores what factors influence the reduction of managers' perceivedknowledge gaps in the context of the environments of foreign markets. Potentialdeterminants are derived from traditional internationalization theory as well asorganizational learning theory, including the concept......, assimilating, and utilizing knowledge - are crucial determinants ofknowledge gap elimination. In contrast, the two factors deemed essential in traditionalinternationalization process theory - elapsed time of operations and experientiallearning - are found to have no or limited effect.Key words......: Internationalization, knowledge gap, absorptive capacity, learning box....

  15. Remote field Eddy Current Technique Development for Gap Measurement of Neighboring Tubes of Nuclear Fuel Channel in Pressurized Heavy Water Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jung, H. K.; Lee, D. H.; Lee, Y. S.; Huh, H.; Cheong, Y. M. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2004-04-15

    Liquid Injection Nozzle(LIN) tube and Calandria tube(CT) in pressurized Heavy Water Reactor (PHWR) are cross-aligned horizontally. These neighboring tubes can contact each other due to the sag of the calandria tube resulting from the irradiation creep and thermal creep, and fuel load, etc. In order to judge the contact which might be the safety concern, the remote field eddy current (RFEC) technology is applied for the gap measurement in this paper. LIN can be detected by inserting the RFEC probe into pressure tube (PT) at the crossing point directly. To obtain the optimal conditions of the RFEC inspection, the sensitivity, penetration and noise signals are considered simultaneously. The optimal frequency and coil spacing are 1kHz and 200mm respectively. Possible noises during LIN signal acquisition are caused by lift-off, PT thickness variation, and gap variation between PT and CT. The simulated noise signals were investigated by the Volume Integral Method(VIM). Signal analysis on the voltage plane describes the amplitude and shape of LIN and possible defects at several frequencies. All the RFEC measurements in the laboratory were done in variance with the CT/LIN gap and showed the relationship between the LIN gap and the signal parameters by analyzing the voltage plane signals

  16. Ground water security and drought in Africa: linking availability, access, and demand.

    Science.gov (United States)

    Calow, Roger C; Macdonald, Alan M; Nicol, Alan L; Robins, Nick S

    2010-01-01

    Drought in Africa has been extensively researched, particularly from meteorological, agricultural, and food security perspectives. However, the impact of drought on water security, particularly ground water dependent rural water supplies, has received much less attention. Policy responses have concentrated on food needs, and it has often been difficult to mobilize resources for water interventions, despite evidence that access to safe water is a serious and interrelated concern. Studies carried out in Ghana, Malawi, South Africa, and Ethiopia highlight how rural livelihoods are affected by seasonal stress and longer-term drought. Declining access to food and water is a common and interrelated problem. Although ground water plays a vital role in buffering the effects of rainfall variability, water shortages and difficulties in accessing water that is available can affect domestic and productive water uses, with knock-on effects on food consumption and production. Total depletion of available ground water resources is rarely the main concern. A more common scenario is a spiral of water insecurity as shallow water sources fail, additional demands are put on remaining sources, and mechanical failures increase. These problems can be planned for within normal development programs. Water security mapping can help identify vulnerable areas, and changes to monitoring systems can ensure early detection of problems. Above all, increasing the coverage of ground water-based rural water supplies, and ensuring that the design and siting of water points is informed by an understanding of hydrogeological conditions and user demand, can significantly increase the resilience of rural communities to climate variability.

  17. Linking water and energy objectives in lowland areas through the application of model predictive control

    NARCIS (Netherlands)

    Van Overloop, P.J.A.T.M.; Negenborn, R.R.; Weijs, S.V.; Malda, W.; Bruggers, M.R.; De Schutter, B.

    2010-01-01

    Unlike mountainous areas, lowland areas have limited potential to generate energy from water flows. Instead, for water systems in lowland areas that continuously need to pump water out of the system, the focus should be set to saving energy in the present water management. This paper gives an introd

  18. Gap Resolution

    Energy Technology Data Exchange (ETDEWEB)

    2017-04-25

    Gap Resolution is a software package that was developed to improve Newbler genome assemblies by automating the closure of sequence gaps caused by repetitive regions in the DNA. This is done by performing the follow steps:1) Identify and distribute the data for each gap in sub-projects. 2) Assemble the data associated with each sub-project using a secondary assembler, such as Newbler or PGA. 3) Determine if any gaps are closed after reassembly, and either design fakes (consensus of closed gap) for those that closed or lab experiments for those that require additional data. The software requires as input a genome assembly produce by the Newbler assembler provided by Roche and 454 data containing paired-end reads.

  19. Two-photon excitation of surface plasmon and the period-increasing effect of low spatial frequency ripples on a GaP crystal in air/water

    Science.gov (United States)

    Liu, Jukun; Jia, Tianqing; Zhao, Hongwei; Huang, Yaoqing

    2016-11-01

    We report the period-increasing effect of low spatial frequency ripples on a GaP crystal irradiated by 1 kHz, 50 fs, 800 nm femtosecond laser pulses. Massive free electrons are excited by a two-photon absorption process and surface plasmon is excited. The Drude model is used to estimate the changing of the dielectric constant of the GaP crystal. The period-increasing effects of low spatial frequency laser-induced ripples are theoretically predicted in air/water, and the experimental results agree well. The experimental and theoretical results indicate that surface plasmon excited by two-photon absorption plays a key role in the formation of low spatial frequency ripples.

  20. The Gap in the Current Research on the Link between Health Locus of Control and Multiple Sclerosis: Lessons and Insights from a Systematic Review.

    Science.gov (United States)

    Bragazzi, Nicola Luigi

    2013-01-01

    Multiple sclerosis (MS) is a chronic neurological disease whose etiology has not been fully understood yet in detail. Empirical findings show how psychosocial symptoms are very important features of the clinical presentation of MS, having a deep impact on patient's quality of life, and thus psychological coping strategies may play a central role in reducing the burden of the disease and improving patient's satisfaction of life. MS progression and relapses/exacerbations are unpredictable and may depend on factors such as stressor chronicity, frequency, severity, type, and individual patient characteristics such as depression, personality, locus of control (LOC), optimism, and perceived social support. Due to its importance for health-care delivery, rehabilitation, and nursing, here, we make a systematic review on the current state-of-the-art studies concerning the relationship between LOC and MS, according to the PRISMA guidelines, and we assess the quality and the completeness of the studies using the CONSORT instrument, underpinning their limitations, and suggesting how to fill the gap in this research field.

  1. The Gap in the Current Research on the Link between Health Locus of Control and Multiple Sclerosis: Lessons and Insights from a Systematic Review

    Directory of Open Access Journals (Sweden)

    Nicola Luigi Bragazzi

    2013-01-01

    Full Text Available Multiple sclerosis (MS is a chronic neurological disease whose etiology has not been fully understood yet in detail. Empirical findings show how psychosocial symptoms are very important features of the clinical presentation of MS, having a deep impact on patient's quality of life, and thus psychological coping strategies may play a central role in reducing the burden of the disease and improving patient's satisfaction of life. MS progression and relapses/exacerbations are unpredictable and may depend on factors such as stressor chronicity, frequency, severity, type, and individual patient characteristics such as depression, personality, locus of control (LOC, optimism, and perceived social support. Due to its importance for health-care delivery, rehabilitation, and nursing, here, we make a systematic review on the current state-of-the-art studies concerning the relationship between LOC and MS, according to the PRISMA guidelines, and we assess the quality and the completeness of the studies using the CONSORT instrument, underpinning their limitations, and suggesting how to fill the gap in this research field.

  2. Cross-linked PEG via degradable phosphate ester bond: synthesis, water-swelling, and application as drug carrier.

    Science.gov (United States)

    Liu, Zhaoxing; Wang, Lei; Bao, Chunyan; Li, Xinxin; Cao, Lei; Dai, Kerong; Zhu, Linyong

    2011-06-13

    A new series of degradable and water-swellable cross-linked PEG phosphoester polymers (CPPs) based on a facile cross-linked reaction between diphosphoesters of polyethylene glycol (P-PEG-P) and diglycidyl ether of polyethylene glycol (E-PEG-E) has been prepared and characterized. The molecular weights and ratios of the prepolymers played an important role for the properties of CPPs polymers, such as mechanical property, swelling, and degradation rates. In the curing process, the glycidyl ether was consumed by both hydroxyl of the phosphoester (P-OH) and hydroxyl generated from the opened glycidyl ethers (C-OH) with the presence of acid, which generated degradable phosphate esters as cross-linked points and ether bonds as the short branches, respectively. Drug entrapment and release test and biological cytotoxicity studies in vitro suggested that the polymers and generated hydrogels have great potential applications in drug delivery system and biological materials.

  3. Progress in the Efficiency of Wide-Gap Cu(In1-xGax)Se2 Solar Cells Using CIGSe Layers Grown in Water Vapor

    Science.gov (United States)

    Ishizuka, Shogo; Sakurai, Keiichiro; Yamada, Akimasa; Shibata, Hajime; Matsubara, Koji; Yonemura, Minoru; Nakamura, Satoshi; Nakanishi, Hisayuki; Kojima, Takeshi; Niki, Shigeru

    2005-05-01

    Progress in the performance of wide-gap Cu(In1-xGax)Se2 (CIGSe) solar cells for x values around 0.5 has been demonstrated using CIGSe layers grown in the presence of water vapor. While CIGSe thin films deposited in the presence of water vapor showed variations in electrical properties such as increases in hole carrier density and a consequent enhancement of p-type conductivity, no significant changes in the morphology and growth orientation were observed. Both the open circuit voltages and current densities of the CIGSe solar cells were improved using CIGSe layers grown in water vapor. An 18.1%-efficient cell with an open circuit voltage of 0.744 V, a current density of 32.4 mA/cm2 and a fill factor of 0.752 was fabricated from a 1.3 eV-CIGSe (x ˜ 0.48) layer.

  4. Gap Junctions

    Science.gov (United States)

    Nielsen, Morten Schak; Axelsen, Lene Nygaard; Sorgen, Paul L.; Verma, Vandana; Delmar, Mario; Holstein-Rathlou, Niels-Henrik

    2013-01-01

    Gap junctions are essential to the function of multicellular animals, which require a high degree of coordination between cells. In vertebrates, gap junctions comprise connexins and currently 21 connexins are known in humans. The functions of gap junctions are highly diverse and include exchange of metabolites and electrical signals between cells, as well as functions, which are apparently unrelated to intercellular communication. Given the diversity of gap junction physiology, regulation of gap junction activity is complex. The structure of the various connexins is known to some extent; and structural rearrangements and intramolecular interactions are important for regulation of channel function. Intercellular coupling is further regulated by the number and activity of channels present in gap junctional plaques. The number of connexins in cell-cell channels is regulated by controlling transcription, translation, trafficking, and degradation; and all of these processes are under strict control. Once in the membrane, channel activity is determined by the conductive properties of the connexin involved, which can be regulated by voltage and chemical gating, as well as a large number of posttranslational modifications. The aim of the present article is to review our current knowledge on the structure, regulation, function, and pharmacology of gap junctions. This will be supported by examples of how different connexins and their regulation act in concert to achieve appropriate physiological control, and how disturbances of connexin function can lead to disease. © 2012 American Physiological Society. Compr Physiol 2:1981-2035, 2012. PMID:23723031

  5. Gap junctions.

    Science.gov (United States)

    Nielsen, Morten Schak; Axelsen, Lene Nygaard; Sorgen, Paul L; Verma, Vandana; Delmar, Mario; Holstein-Rathlou, Niels-Henrik

    2012-07-01

    Gap junctions are essential to the function of multicellular animals, which require a high degree of coordination between cells. In vertebrates, gap junctions comprise connexins and currently 21 connexins are known in humans. The functions of gap junctions are highly diverse and include exchange of metabolites and electrical signals between cells, as well as functions, which are apparently unrelated to intercellular communication. Given the diversity of gap junction physiology, regulation of gap junction activity is complex. The structure of the various connexins is known to some extent; and structural rearrangements and intramolecular interactions are important for regulation of channel function. Intercellular coupling is further regulated by the number and activity of channels present in gap junctional plaques. The number of connexins in cell-cell channels is regulated by controlling transcription, translation, trafficking, and degradation; and all of these processes are under strict control. Once in the membrane, channel activity is determined by the conductive properties of the connexin involved, which can be regulated by voltage and chemical gating, as well as a large number of posttranslational modifications. The aim of the present article is to review our current knowledge on the structure, regulation, function, and pharmacology of gap junctions. This will be supported by examples of how different connexins and their regulation act in concert to achieve appropriate physiological control, and how disturbances of connexin function can lead to disease. © 2012 American Physiological Society. Compr Physiol 2:1853-1872, 2012.

  6. An enzyme-linked immunosorbent assay (ELISA) for the identification of Naegleria fowleri in environmental water samples.

    Science.gov (United States)

    Reveiller, Fabienne L; Varenne, Marie-Pierre; Pougnard, Claire; Cabanes, Pierre-Andre; Pringuez, Emmanuelle; Pourima, Benedicte; Legastelois, Stephane; Pernin, Pierre

    2003-01-01

    Naegleria fowleri, a free-living amoeba, is the causative agent of primary amoebic meningoencephalitis, a fatal human disease of the central nervous system often contracted after swimming in fresh water. Identifying sites contaminated by N. fowleri is important in order to prevent the disease. An Enzyme-Linked ImmunoSorbent Assay (ELISA) has been developed for the specific identification of N. fawleri in primary cultures of environmental water samples. Of 939 samples isolated from artificially heated river water and screened by ELISA, 283 were positive. These results were subsequently confirmed by isoelectric focusing, the established reference method. A sensitivity of 97.4% and a specificity of 97% were obtained. These results indicate that this ELISA method is reliable and can be considered as a powerful tool for the detection of N. fowleri in environmental water samples.

  7. Linking levels of societal and ecosystems metabolism of water in a Mediterranean watershed

    Science.gov (United States)

    Cabello, V.

    2014-12-01

    Water resources degradation is a complex environmental problem that involves multiple dimensions and scales of analysis. The Socio-Ecological Systems Water Metabolism has been proposed as a general holistic framework to deal with integrated analysis of water use sustainability (Madrid and Giampietro 2014). The innovation of the approach is that it sets the research focus beyond the classical supply-demand modeling to societal integrity and ecosystems integrity. To do so, it integrates quantitative grammars of water use (relating water exchange to societal and ecosystems organization) and qualitative methods (discourse analysis). This work presents the first case study focused at a river basin extent: the Upper Andarax, in South-East Spain. Water metabolism is indicated at multiple levels for ecosystems and society. To deal with the interfaces among them, relational indicators of water exploitation, water use and impact over ecosystems are used alongside policies and narratives analysis.While being a rather not intensively exploited river basin (year Water Exploitation Index~0.3 blue water,~0.15 green water), impacts over water bodies are yet important (periodic aquifer overdraft, biological degradation of the river) especially during dry season. Perceived mayor problems of water sustainability are generated by the not integration of different policies at European, national and regional scales: while the water authority establishes a compulsory reduction over water withdrawal to attend environmental flows, agricultural markets force to raise productivity increasing water demands. Adaptation strategies are divided among irrigation efficiency improvement and a reorientation of the economy towards touristic activities. Both of them entail specific trade-offs to be deemed. Aquifer-river interactions and climate change impacts are yet mayor research challenges.

  8. Chemo-Enzymatic Synthesis of Ester-Linked Docetaxel-Monosaccharide Conjugates as Water-Soluble Prodrugs

    OpenAIRE

    Naoji Kubota; Kei Shimoda

    2011-01-01

    Three new docetaxel prodrugs, i.e., 7-propionyldocetaxel 3''-O-b-D-glycopyranosides, which contain ester-linked monosaccharides, were synthesized by a chemo-enzymatic procedure involving enzymatic transglycosylations with lactase, b-galactosidase, or b-xylosidase. The water-solubility of 7-propionyldocetaxel 3''-O-b-D-glucopyranoside was 52-fold higher than that of docetaxel. 7-Propionyldocetaxel 3''-O-b-D-glucopyranoside and 7-propionyldocetaxel 3''-O-b-D-xylopyranoside were effectively hydr...

  9. Coastal upwelling linked to toxic Pseudo-nitzschia australis blooms in Los Angeles coastal waters, 2005-2007

    KAUST Repository

    Schnetzer, Astrid

    2013-06-10

    Harmful algal blooms dominated by the diatom Pseudo-nitzschia spp. have become a perennial but variable event within surface waters near the greater Los Angeles area. Toxic blooms during spring seasons from 2005 to 2007 varied strongly in their overall toxicity and duration. Differences in bloom dynamics were linked to differences in storm-induced river discharge following episodic rain events and coastal upwelling, both major coastal processes that led to the injection of nutrients into coastal surface waters. Heavy river runoff during early 2005, a record-rainfall year, favored a phytoplankton community mainly comprised of algal taxa other than Pseudo-nitzschia. The spring bloom during 2005 was associated with low domoic acid surface concentrations and minor contributions of (mainly) P. delicatissima to the diatom assemblage. In contrast, highly toxic P. australis-dominated blooms during spring seasons of 2006 and 2007 were linked to strong upwelling events. River discharge quotas in 2006 and 2007, in contrast to 2005, fell well below annual averages for the region. Surface toxin levels were linked to colder, more saline (i.e. upwelled) water over the 3-year study, but no such consistent relationship between domoic acid levels and other physiochemical parameters, such as macronutrient concentrations or nutrient ratios, was observed. © The Author 2013. Published by Oxford University Press. All rights reserved.

  10. Analysis of environmental setting, surface-water and groundwater data, and data gaps for the Citizen Potawatomi Nation Tribal Jurisdictional Area, Oklahoma, through 2011

    Science.gov (United States)

    Andrews, William J.; Harich, Christopher R.; Smith, S. Jerrod; Lewis, Jason M.; Shivers, Molly J.; Seger, Christian H.; Becker, Carol J.

    2013-01-01

    in more urbanized areas. Much of the water in the area is of good quality, though some parts of this area have water quality impaired by very hard surface water and groundwater; large chloride concentrations in some smaller streams; relatively large concentrations of nutrients and counts of fecal-indicator bacteria in the North Canadian River; and chloride, iron, manganese, and uranium concentrations that exceed primary or secondary drinking-water standards in water samples collected from small numbers of wells. Substantial amounts of hydrologic and water-quality data have been collected in much of this area, but there are gaps in those data caused by relatively few streamflow-gaging stations, uneven distribution of surface-water quality sampling sites, lack of surface-water quality sampling at high-flow and low-flow conditions, and lack of a regularly measured and sampled groundwater network. This report summarizes existing water-use, climatic, geographic, hydrologic, and water-quality data and describes several means of filling gaps in hydrologic data for this area.

  11. Picosecond laser generation of Ag-TiO2 nanoparticles with reduced energy gap by ablation in ice water and their antibacterial activities

    Science.gov (United States)

    Hamad, Abubaker; Li, Lin; Liu, Zhu; Zhong, Xiang Li; Wang, Tao

    2015-06-01

    Ag-TiO2 nanoparticles were synthesised in ice water using a picosecond laser with a 1064-nm wavelength, at a 200-kHz repetition rate, a laser pulse energy of 42-43.79 µJ, and laser fluences of 0.342-0.357 J/cm2, by ablation of solid Ag and Ti targets. The absorption spectra and size distribution of the colloidal nanoparticles were obtained by UV-Vis spectroscopy and transmission electron microscopy, respectively. The morphology and chemical composition of the nanoparticles were characterised using high-angle annular dark-field-scanning transmission electron microscope and energy-dispersive X-ray spectroscopy. The results show that the sizes of the Ag-TiO2 nanoparticles range from less than 10-130 nm, with some large particles above 130 nm, of which the predominant size is 20 nm. A significant reduction in the energy gap of TiO2 nanoparticles was obtained to 1.75 eV after the modification with Ag nanoparticles during co-ablation. The role of Ag nanoparticles in the reduction in the energy band gap of the TiO2 nanoparticles can only be seen during laser ablation in an ice environment but not in deionised water at room temperature. Furthermore, the TiO2 nanoparticles were produced in ice and deionised water under the same laser and experimental conditions; the results show that the nanoparticles in both media have the same energy gap (about 2.4 eV). The antibacterial activity of the Ag-TiO2 nanoparticles generated was then tested against E. coli bacteria under standard laboratory light conditions. The results show that the nanoparticles can effectively kill E. coli bacteria much more effectively than laser-generated TiO2 nanoparticles.

  12. Mythic gaps

    Directory of Open Access Journals (Sweden)

    William Hansen

    2014-11-01

    Full Text Available Different kinds of omissions sometimes occur, or are perceived to occur, in traditional narratives and in tradition-inspired literature. A familiar instance is when a narrator realizes that he or she does not fully remember the story that he or she has begun to tell, and so leaves out part of it, which for listeners may possibly result in an unintelligible narrative. But many instances of narrative gap are not so obvious. From straightforward, objective gaps one can distinguish less-obvious subjective gaps: in many cases narrators do not leave out anything crucial or truly relevant from their exposition, and yet readers perceive gaps and take steps to fill them. The present paper considers four examples of subjective gaps drawn from ancient Greek literature (the Pandora myth, ancient Roman literature (the Pygmalion legend, ancient Hebrew literature (the Joseph legend, and early Christian literature (the Jesus legend. I consider the quite varied ways in which interpreters expand the inherited texts of these stories, such as by devising names, manufacturing motives, creating backstories, and in general filling in biographical ellipses. Finally, I suggest an explanation for the phenomenon of subjective gaps, arguing that, despite their variety, they have a single cause.

  13. Bacterial diversity and antibiotic resistance in water habitats: searching the links with the human microbiome.

    Science.gov (United States)

    Vaz-Moreira, Ivone; Nunes, Olga C; Manaia, Célia M

    2014-07-01

    Water is one of the most important bacterial habitats on Earth. As such, water represents also a major way of dissemination of bacteria between different environmental compartments. Human activities led to the creation of the so-called urban water cycle, comprising different sectors (waste, surface, drinking water), among which bacteria can hypothetically be exchanged. Therefore, bacteria can be mobilized between unclean water habitats (e.g. wastewater) and clean or pristine water environments (e.g. disinfected and spring drinking water) and eventually reach humans. In addition, bacteria can also transfer mobile genetic elements between different water types, other environments (e.g. soil) and humans. These processes may involve antibiotic resistant bacteria and antibiotic resistance genes. In this review, the hypothesis that some bacteria may share different water compartments and be also hosted by humans is discussed based on the comparison of the bacterial diversity in different types of water and with the human-associated microbiome. The role of such bacteria as potential disseminators of antibiotic resistance and the inference that currently only a small fraction of the clinically relevant antibiotic resistome may be known is discussed.

  14. Ecohydrology of managed ecosystems: Linking rainfall unpredictability, agronomic performance, and sustainable water use

    Science.gov (United States)

    Vico, Giulia; Porporato, Amilcare

    2014-05-01

    The field of ecohydrology, traditionally focusing on natural ecosystems, can offer the necessary quantitative tools to assess and compare the sustainability of agriculture across climates, soil types, crops, and irrigation strategies, including rainfall unpredictability. In particular, irrigation is one of the main strategies to enhance and stabilize agricultural productivity, but represents a cost in terms of often scarce water resources. Here, the sustainability of irrigated and rainfed agriculture is assessed by means of water productivity (defined as the ratio between yield and total supplied water), yields, water requirements, and their variability. These indicators are quantified using a probabilistic description of the soil water balance and crop development. Employing this framework, we interpret changes in water productivity as total water input is altered, in two staple crops (maize and wheat) grown under different soils, climates, and irrigation strategies. Climate change scenarios are explored by using the same approach and altering the rainfall statistics. For a given irrigation strategy, intermediate rainfall inputs leads to the highest variability in yield and irrigation water requirement - it is under these conditions that water management is most problematic. When considering the contrasting needs of limiting water requirements while ensuring adequate yields, micro-irrigation emerges as the most sustainable strategy at the field level, although consideration should be given to its profitability and long-term environmental implications.

  15. Reducing water scarcity possible by 2050: Linking global assessments to policy dimensions

    Science.gov (United States)

    Wada, Y.; Gleeson, T.; Esnault, L.

    2015-12-01

    Water scarcity is not a problem just for the developing world. In California, legislators are currently proposing a $7.5 billion emergency water plan to their voters; and U.S. federal officials last year warned residents of Arizona and Nevada that they could face cuts in Colorado River water deliveries in 2016. Irrigation techniques, industrial and residential habits combined with climate change lie at the root of the problem. But despite what appears to be an insurmountable problem, it is possible to turn the situation around and significantly reduce water scarcity in over next 35 years. We identify outline strategies in six key areas that they believe can be combined in different ways in different parts of the world in order to effectively reduce water stress. (Water stress occurs in an area where more than 40% of the available water from rivers is unavailable because it is already being used - a situation that currently affects about a third of the global population, and may affect as many as half the people in the world by the end of the century if the current pattern of water use continues). We separate six key strategy areas for reducing water stress into "hard path" measures, involving building more reservoirs and increasing desalination efforts of sea water, and "soft path" measures that focus on reducing water demand rather than increasing water supply thanks to community-scale efforts and decision-making, combining efficient technology and environmental protection. While there are some economic, cultural and social factors that may make certain of the "soft path" measures such as population control difficult, the "soft path" measures offer the more realistic path forward in terms of reducing water stress by 2050.

  16. Systems Biology for Smart Crops and Agricultural Innovation: Filling the Gaps between Genotype and Phenotype for Complex Traits Linked with Robust Agricultural Productivity and Sustainability

    Science.gov (United States)

    Pathak, Rajesh Kumar; Gupta, Sanjay Mohan; Gaur, Vikram Singh; Pandey, Dinesh

    2015-01-01

    Abstract In recent years, rapid developments in several omics platforms and next generation sequencing technology have generated a huge amount of biological data about plants. Systems biology aims to develop and use well-organized and efficient algorithms, data structure, visualization, and communication tools for the integration of these biological data with the goal of computational modeling and simulation. It studies crop plant systems by systematically perturbing them, checking the gene, protein, and informational pathway responses; integrating these data; and finally, formulating mathematical models that describe the structure of system and its response to individual perturbations. Consequently, systems biology approaches, such as integrative and predictive ones, hold immense potential in understanding of molecular mechanism of agriculturally important complex traits linked to agricultural productivity. This has led to identification of some key genes and proteins involved in networks of pathways involved in input use efficiency, biotic and abiotic stress resistance, photosynthesis efficiency, root, stem and leaf architecture, and nutrient mobilization. The developments in the above fields have made it possible to design smart crops with superior agronomic traits through genetic manipulation of key candidate genes. PMID:26484978

  17. Systems Biology for Smart Crops and Agricultural Innovation: Filling the Gaps between Genotype and Phenotype for Complex Traits Linked with Robust Agricultural Productivity and Sustainability.

    Science.gov (United States)

    Kumar, Anil; Pathak, Rajesh Kumar; Gupta, Sanjay Mohan; Gaur, Vikram Singh; Pandey, Dinesh

    2015-10-01

    In recent years, rapid developments in several omics platforms and next generation sequencing technology have generated a huge amount of biological data about plants. Systems biology aims to develop and use well-organized and efficient algorithms, data structure, visualization, and communication tools for the integration of these biological data with the goal of computational modeling and simulation. It studies crop plant systems by systematically perturbing them, checking the gene, protein, and informational pathway responses; integrating these data; and finally, formulating mathematical models that describe the structure of system and its response to individual perturbations. Consequently, systems biology approaches, such as integrative and predictive ones, hold immense potential in understanding of molecular mechanism of agriculturally important complex traits linked to agricultural productivity. This has led to identification of some key genes and proteins involved in networks of pathways involved in input use efficiency, biotic and abiotic stress resistance, photosynthesis efficiency, root, stem and leaf architecture, and nutrient mobilization. The developments in the above fields have made it possible to design smart crops with superior agronomic traits through genetic manipulation of key candidate genes.

  18. Linking knowledge with action in the pursuit of sustainable water-resources management

    OpenAIRE

    Jacobs, Katharine; Lebel, Louis; De Buizer, James; Addams, Lee; Matson, Pamela; McCullough, Ellen; Garden, Po; Saliba, George; Finan, Timothy

    2010-01-01

    Managing water for sustainable use and economic development is both a technical and a governance challenge in which knowledge production and sharing play a central role. This article evaluates and compares the role of participatory governance and scientific information in decision-making in four basins in Brazil, Mexico, Thailand, and the United States. Water management institutions in each of the basins have evolved during the last 10–20 years from a relatively centralized water-management s...

  19. Afloat in a Boat: Linking Land Use / Land Cover to the Spatial Evolution of Water Quality along a Blackwater Stream

    Science.gov (United States)

    Neville, J.; Vose, J. M.; Nichols, E. G.; Jass, T. L.; Emanuel, R. E.; McRae, J.

    2016-12-01

    Water quality and land use/land cover (LULC) are linked intimately in many watersheds, although exact relationships are often nonlinear and sometimes complex. Together with watershed topography, LULC can affect water quality in various ways. As such, attributing water quality characteristics to LULC variations (either in space or time) can be difficult. Many studies seek to understand these relationships from a Eulerian reference frame, which typically involves many samples or observations through time at a fixed location. Here we explore an alternative approach to understanding relationships between LULC and water quality that relies on a Lagrangian, or moving, reference frame, in which the effects of LULC and watershed topography on water quality can be observed through a different lens. We studied three reaches of the Lumber River, a blackwater stream in North Carolina's Coastal Plain, to assess relationships between LULC and water quality in a watershed that is a patchwork of agriculture, forests, wetlands and developed land. Our study combines spatially intensive water quality measurements (temperature, specific conductance, dissolved oxygen, pH and nitrate concentration), collected by boat, with geospatial analyses of LULC to understand influences on the spatial evolution of reach-scale water quality. In particular, we investigate relationships between spatial patterns in nitrate and the changing spatial characteristics of the watershed integrated at sampling points along each reach. We also assess relationships between nitrate and other water quality variables, such as pH, temperature, and dissolved oxygen to better understand the potential role of in-stream nutrient processing in observed spatial patterns. This work has implications for the regulation and management of agriculture, wetlands, and forests in a region that has long struggled to balance agriculture, a major economic driver, with water quality, a major concern for recreation and cultural

  20. GAP Analysis Program (GAP) Raster

    Data.gov (United States)

    Kansas Data Access and Support Center — The Kansas GAP Land Cover database depicts 43 land cover classes for the state of Kansas. The database was generated using a two-stage hybrid classification of...

  1. Resin bond strength to water versus ethanol-saturated human dentin pretreated with three different cross-linking agents

    Science.gov (United States)

    Venigalla, Bhuvan Shome; Jyothi, Pinnamreddy; Kamishetty, Shekhar; Reddy, Smitha; Cherukupalli, Ravi Chandra; Reddy, Depa Arun

    2016-01-01

    Context: Resin-dentin bonds are unstable owing to hydrolytic and enzymatic degradation. Several approaches such as collagen cross-linking and ethanol-wet bonding (EWB) have been developed to overcome this problem. Collagen cross-linking improves the intrinsic properties of the collagen matrix. However, it leaves a water-rich collagen matrix with incomplete resin infiltration making it susceptible to fatigue degradation. Since EWB is expected to overcome the drawbacks of water-wet bonding (WWB), a combination of collagen cross-linking with EWB was tested. Aim: The aim of this study was to compare the effect of pretreatment with different cross-linking agents such as ultraviolet A (UVA)-activated 0.1% riboflavin, 1 M carbodiimide, and 6.5 wt% proanthocyanidin on the immediate and long-term bond strengths of an etch and rinse adhesive system to water- versus ethanol-saturated dentin within clinically relevant application time periods. Settings and Design: Long-term in vitro study evaluating the microtensile bond strength of adhesive-dentin interface after different surface pretreatments. Subjects and Methods: Eighty freshly extracted human molars were prepared to expose dentin, etched with 37% phosphoric acid for 15 s rinsed, and grouped randomly. They were blot-dried and pretreated with different cross-linkers: 0.1% riboflavin for 2 min followed by UVA activation for 2 min; 1 M carbodiimide for 2 min; 6.5 wt% proanthocyanidin for 2 min and rinsed. They were then bonded with Adper Single Bond Adhesive (3M ESPE), by either WWB or EWB, followed by resin composite build-ups (Filtek Z350, 3M ESPE). Bonded specimens in each group were then sectioned and divided into two halves. Microtensile bond strength was tested in one half after 24 h and the other after 6 months storage in artificial saliva. Statistical Analysis Used: Analysis was done using SPSS version 18 software (SPSS Inc., Chicago, IL, USA). Intergroup comparison of bond strength was done using ANOVA with post hoc

  2. Water-energy links in cities: the urban metabolism of London

    Science.gov (United States)

    Mijic, A.; Ruiz Cazorla, J.; Keirstead, J.

    2014-12-01

    Rapid urbanisation results in increased water consumption in cities, requiring improved tools for understanding adaptive measures for water resources management under climate change. The energy sector is facing the same challenges and requires equally comprehensive solutions. More frequent water shortages due to climate and land use changes and potential limits on CO2 emissions from fossil fuels that science demands indicate clearly that the next step in the sustainable city development will be to look for the most efficient use of these highly interdependent resources. One of the concepts that could be used for quantifying fundamental flows in an urban environment such as water and energy is the urban metabolism framework. This paper will examine the concept of urban metabolism by quantifying amounts and trends of water and energy consumed in London by four main sectors: residential, industrial, commercial and public. Key data requirements at the sector level will be identified and initial mapping of critical factors for urban sustainability will be provided. Finally, the work will examine the potential of urban metabolism framework to provide data and information for implementing water, energy and greenhouse emissions trade-off 'fit-for-purpose' strategy for water supply security. The paper is a part of the Panta Rhei Research Initiative of the International Association of Hydrological Sciences (IAHS) under the working group of Energy and Food Impacts on Water.

  3. Towards reflexive land and water management in Iran : linking technology, governance and culture

    NARCIS (Netherlands)

    Balali, M.R.

    2009-01-01

    Key words: Qanat, land and water, sustainability, Industrial and reflexive modernity This PhD thesis is concerned with the causes and consequences of the environmental crisis and explores possible trajectories towards sustainable land and water management in Iran and other countries of the Middle

  4. MRI links stem water content to stem diameter variations in transpiring trees

    NARCIS (Netherlands)

    Schepper, De V.; Dusschoten, van D.; Copini, P.; Jahnke, S.; Steppe, K.

    2012-01-01

    In trees, stem diameter variations are related to changes in stem water content, because internally stored water is depleted and replenished over a day. To confirm this relationship, non-invasive magnetic resonance imaging (MRI) was combined with point dendrometer measurements in three actively

  5. MRI links stem water content to stem diameter variations in transpiring trees

    NARCIS (Netherlands)

    Schepper, De V.; Dusschoten, van D.; Copini, P.; Jahnke, S.; Steppe, K.

    2012-01-01

    In trees, stem diameter variations are related to changes in stem water content, because internally stored water is depleted and replenished over a day. To confirm this relationship, non-invasive magnetic resonance imaging (MRI) was combined with point dendrometer measurements in three actively tran

  6. Compensatory Water Effects Link Yearly Global Land CO2 Sink Changes to Temperature

    Science.gov (United States)

    Jung, Martin; Reichstein, Markus; Tramontana, Gianluca; Viovy, Nicolas; Schwalm, Christopher R.; Wang, Ying-Ping; Weber, Ulrich; Weber, Ulrich; Zaehle, Soenke; Zeng, Ning; hide

    2017-01-01

    Large interannual variations in the measured growth rate of atmospheric carbon dioxide (CO2) originate primarily from fluctuations in carbon uptake by land ecosystems13. It remains uncertain, however, to what extent temperature and water availability control the carbon balance of land ecosystems across spatial and temporal scales314. Here we use empirical models based on eddy covariance data15 and process-based models16,17 to investigate the effect of changes in temperature and water availability on gross primary productivity (GPP), terrestrial ecosystem respiration (TER) and net ecosystem exchange (NEE) at local and global scales. We find that water availability is the dominant driver of the local interannual variability in GPP and TER. To a lesser extent this is true also for NEE at the local scale, but when integrated globally, temporal NEE variability is mostly driven by temperature fluctuations. We suggest that this apparent paradox can be explained by two compensatory water effects. Temporal water-driven GPP and TER variations compensate locally, dampening water-driven NEE variability. Spatial water availability anomalies also compensate, leaving a dominant temperature signal in the year-to-year fluctuations of the land carbon sink. These findings help to reconcile seemingly contradictory reports regarding the importance of temperature and water in controlling the interannual variability of the terrestrial carbon balance36,9,11,12,14. Our study indicates that spatial climate covariation drives the global carbon cycle response.

  7. Towards reflexive land and water management in Iran : linking technology, governance and culture

    NARCIS (Netherlands)

    Balali, M.R.

    2009-01-01

    Key words: Qanat, land and water, sustainability, Industrial and reflexive modernity This PhD thesis is concerned with the causes and consequences of the environmental crisis and explores possible trajectories towards sustainable land and water management in Iran and other countries of the Middle

  8. Productivity Amelioration of Solar Water Distillator Linked with Salt Gradient Pond

    Directory of Open Access Journals (Sweden)

    Miqdam Miqdam Tariq Chaichan

    2013-04-01

    Full Text Available There is a great need for fresh water in many developing countries. Water sources from, e.g., lakes; rivers and groundwater are often brackish or contain harmful bacteria and should therefore not be used for drinking or irrigation.In this work a simple solar double sloped basin type still was connected to a solar salt gradient pond. The salinity-gradient solar pond is constructed in such a manner that the convective circulation in the pond is prohibited by making the bottom water much denser than the surface water. In doing so, the solar radiation absorbed in the deep water can be stored; the hot water from the salt pond was used to heat salt water in the stiller, at daylight and night.The tests were conducted in September and October in autumn season in Baghdad city-Iraq in 2009. The results show development in stiller productivity at daylight and larger productivity increase at night. The stiller productivity increased also with cooling the glass cover from the still outside. 

  9. The cross-linking influence of electromagnetic radiation on water-soluble polyacrylan compositions with biopolymers

    Directory of Open Access Journals (Sweden)

    B. Grabowska

    2009-01-01

    Full Text Available The results of examinations of the cross-linking influence of electromagnetic radiation - in a microwave range – on polyacrylancompositions with biopolymers, are presented in the hereby paper. The cross-linking process of the tested compositions was determined on the basis of the FT-IR spectroscopic methods. It was shown that microwave operations can lead to the formation of new cross-linkedstructures with strong covalent bonds. The adsorption process and formation of active centres in polymer molecules as well as in highsilica sand were found due to microwave radiations. In this process hydroxyl groups (-OH - present in a polymer - and silane groups (Si- O-H - present in a matrix - are mainly taking part. Spectroscopic and strength tests performed for the system: biopolymer binding agent – matrix indicate that the microwave radiation can be applied for hardening moulding sands with biopolymer binders.

  10. Knowledge Gaps

    DEFF Research Database (Denmark)

    Lyles, Marjorie; Pedersen, Torben; Petersen, Bent

    2003-01-01

    of absorptive capacity. Building onthese literature streams a conceptual model is developed and tested on a set of primarydata of Danish firms and their foreign market operations. The empirical study suggeststhat the factors that pertain to the absorptive capacity concept - capabilities ofrecognizing......, assimilating, and utilizing knowledge - are crucial determinants ofknowledge gap elimination. In contrast, the two factors deemed essential in traditionalinternationalization process theory - elapsed time of operations and experientiallearning - are found to have no or limited effect.Key words......: Internationalization, knowledge gap, absorptive capacity, learning box....

  11. Effect of hardening method and structure of linking bridges on strength of water glass moulding sands

    Directory of Open Access Journals (Sweden)

    M. Stachowicz

    2010-04-01

    Full Text Available The paper presents examination results of the effect of four hardening methods on structure of linking bridges in sandmixes containing hydrated sodium silicate. Test pieces prepared of the moulding sands containing 2.5 % of a binder with molar module between 2.4 and 2.6 were hardened with carbon dioxide, dried traditionally in an oven and hardened with microwaves at 2.54 GHz or using a combination of the CO2 process and microwave heating. It was revealed that the hardening method influences structure of linking bridges and is correlated with mechanical properties of the hardened moulding sands. It was found that strength of the moulding sands microwave-heated for 240 s is approximate to that measured after traditional drying for 120 min at 110 °C. So, the microwave hardening permits significant reduction of the process time, comparable to the CO2 hardening, at the same time guaranteeing over 10 times higher mechanical properties. Analysis of SEM photographs of the moulding sands hardened with the mentioned methods allow explaining differences in qualitative parameters of the moulding sands and their relation to structures of the created linking bridges.

  12. Reflexive Land and Water Management in Iran: Linking Technology, Governance and Culture. Part 1: Land and Water Management Paradigms

    NARCIS (Netherlands)

    Balali, M.R.; Keulartz, F.W.J.; Korthals, M.J.J.A.A.

    2011-01-01

    In order to examine the possibilities for sustainable land and water management in Iran, this research was carried out with two types of research and their combinations, i.e. theoretical and empirical research during 2005- 2009. In the theoretical part, which is the scope of this paper, the co-evolu

  13. Reflexive Land and Water Management in Iran: Linking Technology, Governance and Culture. Part 1: Land and Water Management Paradigms

    NARCIS (Netherlands)

    Balali, M.R.; Keulartz, F.W.J.; Korthals, M.J.J.A.A.

    2011-01-01

    In order to examine the possibilities for sustainable land and water management in Iran, this research was carried out with two types of research and their combinations, i.e. theoretical and empirical research during 2005- 2009. In the theoretical part, which is the scope of this paper, the

  14. Modeling stomatal conductance in the Earth system: linking leaf water-use efficiency and water transport along the soil-plant-atmosphere continuum

    Directory of Open Access Journals (Sweden)

    G. B. Bonan

    2014-05-01

    Full Text Available The empirical Ball–Berry stomatal conductance model is commonly used in Earth system models to simulate biotic regulation of evapotranspiration. However, the dependence of stomatal conductance (gs on vapor pressure deficit (Ds and soil moisture must both be empirically parameterized. We evaluated the Ball–Berry model used in the Community Land Model version 4.5 (CLM4.5 and an alternative stomatal conductance model that links leaf gas exchange, plant hydraulic constraints, and the soil–plant–atmosphere continuum (SPA to numerically optimize photosynthetic carbon gain per unit water loss while preventing leaf water potential dropping below a critical minimum level. We evaluated two alternative optimization algorithms: intrinsic water-use efficiency (Δ An/Δ gs, the marginal carbon gain of stomatal opening and water-use efficiency (Δ An/Δ El, the marginal carbon gain of water loss. We implemented the stomatal models in a multi-layer plant canopy model, to resolve profiles of gas exchange, leaf water potential, and plant hydraulics within the canopy, and evaluated the simulations using: (1 leaf analyses; (2 canopy net radiation, sensible heat flux, latent heat flux, and gross primary production at six AmeriFlux sites spanning 51 site–years; and (3 parameter sensitivity analyses. Without soil moisture stress, the performance of the SPA stomatal conductance model was generally comparable to or somewhat better than the Ball–Berry model in flux tower simulations, but was significantly better than the Ball–Berry model when there was soil moisture stress. Functional dependence of gs on soil moisture emerged from the physiological theory linking leaf water-use efficiency and water flow to and from the leaf along the soil-to-leaf pathway rather than being imposed a priori, as in the Ball–Berry model. Similar functional dependence of gs on Ds emerged from the water-use efficiency optimization. Sensitivity analyses showed that two

  15. Linking the mobilization of dissolved organic matter in catchments and its removal in drinking water treatment to its molecular characteristics.

    Science.gov (United States)

    Raeke, Julia; Lechtenfeld, Oliver J; Tittel, Jörg; Oosterwoud, Marieke R; Bornmann, Katrin; Reemtsma, Thorsten

    2017-04-15

    Drinking water reservoirs in the Northern Hemisphere are largely affected by the decadal-long increase in riverine dissolved organic carbon (DOC) concentrations. The removal of DOC in drinking water treatment is costly and predictions are needed to link DOC removal efficiency to its mobilization in catchments, both of which are determined by the molecular composition. To study the effect of hydrological events and land use on the molecular characteristics of dissolved organic matter (DOM), 36 samples from three different catchment areas in the German low mountain ranges, with DOC concentrations ranging from 3 to 32 mg L(-1), were examined. Additionally, nine pairs of samples from downstream drinking water reservoirs were analyzed before and after flocculation. The molecular composition and the age of DOM were analyzed using ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) and radiocarbon ((14)C) analysis. At elevated discharge in a forested catchment comparatively younger, more oxygenated and unsaturated molecules of higher molecular weight were preferentially mobilized, likely linked to the reductive mobilization of iron. DOM with highly similar molecular characteristics (O/C ratio > 0.5, m/z > 500) could also be efficiently removed through flocculation in drinking water treatment. The proportion of DOM removed through flocculation ranged between 43% and 73% of DOC and was highest at elevated discharge. In catchment areas with a higher percentage of grassland and agriculture a higher proportion of DOM molecules containing sulfur and nitrogen was detected, which in turn could be less efficiently flocculated. Altogether, it was shown that DOM that is released during large hydrological events can be efficiently flocculated again, suggesting a reversal of similar chemical mechanisms in both processes. Since the occurrence of heavy rainfall events is predicted to increase in the future, event-driven mobilization of DOC

  16. Precipitation isotopes link regional climate patterns to water supply in a tropical mountain forest, eastern Puerto Rico

    Science.gov (United States)

    Scholl, Martha A.; Murphy, Sheila F.

    2014-01-01

    Like many mountainous areas in the tropics, watersheds in the Luquillo Mountains of eastern Puerto Rico have abundant rainfall and stream discharge and provide much of the water supply for the densely populated metropolitan areas nearby. Projected changes in regional temperature and atmospheric dynamics as a result of global warming suggest that water availability will be affected by changes in rainfall patterns. It is essential to understand the relative importance of different weather systems to water supply to determine how changes in rainfall patterns, interacting with geology and vegetation, will affect the water balance. To help determine the links between climate and water availability, stable isotope signatures of precipitation from different weather systems were established to identify those that are most important in maintaining streamflow and groundwater recharge. Precipitation stable isotope values in the Luquillo Mountains had a large range, from fog/cloud water with δ2H, δ18O values as high as +12 ‰, −0.73 ‰ to tropical storm rain with values as low as −127 ‰, −16.8 ‰. Temporal isotope values exhibit a reverse seasonality from those observed in higher latitude continental watersheds, with higher isotopic values in the winter and lower values in the summer. Despite the higher volume of convective and low-pressure system rainfall, stable isotope analyses indicated that under the current rainfall regime, frequent trade -wind orographic showers contribute much of the groundwater recharge and stream base flow. Analysis of rain events using 20 years of 15 -minute resolution data at a mountain station (643 m) showed an increasing trend in rainfall amount, in agreement with increased precipitable water in the atmosphere, but differing from climate model projections of drying in the region. The mean intensity of rain events also showed an increasing trend. The determination of recharge sources from stable isotope tracers indicates that water

  17. Abundance and physiology of dominant soft corals linked to water quality in Jakarta Bay, Indonesia

    Directory of Open Access Journals (Sweden)

    Gunilla Baum

    2016-11-01

    Full Text Available Declining water quality is one of the main reasons of coral reef degradation in the Thousand Islands off the megacity Jakarta, Indonesia. Shifts in benthic community composition to higher soft coral abundances have been reported for many degraded reefs throughout the Indo-Pacific. However, it is not clear to what extent soft coral abundance and physiology are influenced by water quality. In this study, live benthic cover and water quality (i.e. dissolved inorganic nutrients (DIN, turbidity (NTU, and sedimentation were assessed at three sites (< 20 km north of Jakarta in Jakarta Bay (JB and five sites along the outer Thousand Islands (20–60 km north of Jakarta. This was supplemented by measurements of photosynthetic yield and, for the first time, respiratory electron transport system (ETS activity of two dominant soft coral genera, Sarcophyton spp. and Nephthea spp. Findings revealed highly eutrophic water conditions in JB compared to the outer Thousand Islands, with 44% higher DIN load (7.65 μM/L, 67% higher NTU (1.49 NTU and 47% higher sedimentation rate (30.4 g m−2 d−1. Soft corals were the dominant type of coral cover within the bay (2.4% hard and 12.8% soft coral cover compared to the outer Thousand Islands (28.3% hard and 6.9% soft coral cover. Soft coral abundances, photosynthetic yield, and ETS activity were highly correlated with key water quality parameters, particularly DIN and sedimentation rates. The findings suggest water quality controls the relative abundance and physiology of dominant soft corals in JB and may thus contribute to phase shifts from hard to soft coral dominance, highlighting the need to better manage water quality in order to prevent or reverse phase shifts.

  18. An indirect competitive enzyme-linked immunosorbent assay for determination of norfloxacin in waters using a specific polyclonal antibody.

    Science.gov (United States)

    Cui, Jianlan; Zhang, Kun; Huang, Qiuxin; Yu, Yiyi; Peng, Xianzhi

    2011-02-28

    A specific polyclonal anti-norfloxacin antibody was obtained, and a sensitive indirect competitive enzyme-linked immunosorbent assay (icELISA) was developed for determining trace amounts of norfloxacin in various waters. Good linearity was achieved in the range from 0.1 to 10 μg L(-1). The average IC(50) value was determined to be 2.2 μg L(-1) and the limit of detection was 0.016 μg L(-1) at a signal-to-noise ratio of 3 in phosphate-buffered saline buffer. Recoveries of norfloxacin at various spiking levels ranged from 74 to 105% in groundwater, surface water, treated and untreated wastewater samples, with relative standard deviations of 3-5%. The assay was applied for determining norfloxacin in municipal wastewater, surface water, and groundwater collected in a metropolis of China. Raw wastewater samples were only submitted to filtration and pH adjustment while the other water samples were pre-concentrated by solid phase extraction prior to the icELISA assay. Good agreement of the results obtained by the icELISA and liquid chromatography tandem mass spectrometry further confirmed the reliability and accuracy of the icELISA for rapid detection of norfloxacin in waters. Copyright © 2010 Elsevier B.V. All rights reserved.

  19. Modeling Sustainability of Water, Environment, Livelihood, and Culture in Traditional Irrigation Communities and Their Linked Watersheds

    Directory of Open Access Journals (Sweden)

    Kenneth Boykin

    2012-11-01

    Full Text Available Water scarcity, land use conversion and cultural and ecosystem changes threaten the way of life for traditional irrigation communities of the semi-arid southwestern United States. Traditions are strong, yet potential upheaval is great in these communities that rely on acequia irrigation systems. Acequias are ancient ditch systems brought from the Iberian Peninsula to the New World over 400 years ago; they are simultaneously gravity flow water delivery systems and shared water governance institutions. Acequias have survived periods of drought and external shocks from changing economics, demographics, and resource uses. Now, climate change and urbanization threaten water availability, ecosystem functions, and the acequia communities themselves. Do past adaptive practices hold the key to future sustainability, or are new strategies required? To explore this issue we translated disciplinary understanding into a uniform format of causal loop diagrams to conceptualize the subsystems of the entire acequia-based human-natural system. Four subsystems are identified in this study: hydrology, ecosystem, land use/economics, and sociocultural. Important linkages between subsystems were revealed as well as variables indicating community cohesion (e.g., total irrigated land, intensity of upland grazing, mutualism. Ongoing work will test the conceptualizations with field data and modeling exercises to capture tipping points for non-sustainability and thresholds for sustainable water use and community longevity.

  20. Method of cross-linking polyvinyl alcohol and other water soluble resins

    Science.gov (United States)

    Phillipp, W. H.; May, C. E.; Hsu, L. C.; Sheibley, D. W. (Inventor)

    1980-01-01

    A self supporting sheet structure comprising a water soluble, noncrosslinked polymer such as polyvinyl alcohol which is capable of being crosslinked by reaction with hydrogen atom radicals and hydroxyl molecule radicals is contacted with an aqueous solution having a pH of less than 8 and containing a dissolved salt in an amount sufficient to prevent substantial dissolution of the noncrosslinked polymer in the aqueous solution. The aqueous solution is then irradiated with ionizing radiation to form hydrogen atom radicals and hydroxyl molecule radicals and the irradiation is continued for a time sufficient to effect crosslinking of the water soluble polymer to produce a water insoluble polymer sheet structure. The method has particular application in the production of battery separators and electrode envelopes for alkaline batteries.

  1. Linking glacially modified waters to catchment-scale subglacial discharge using autonomous underwater vehicle observations

    Science.gov (United States)

    Stevens, Laura A.; Straneo, Fiamma; Das, Sarah B.; Plueddemann, Albert J.; Kukulya, Amy L.; Morlighem, Mathieu

    2016-02-01

    Measurements of near-ice (autonomous underwater vehicle as close as 150 m from the ice-ocean interface of the Saqqarliup sermia-Sarqardleq Fjord system, West Greenland, with modeled and observed subglacial discharge locations and magnitudes. We find evidence of two main types of subsurface glacially modified water (GMW) with distinct properties and locations. The two GMW locations also align with modeled runoff discharged at separate locations along the grounded margin corresponding with two prominent subcatchments beneath Saqqarliup sermia. Thus, near-ice observations and subglacial discharge routing indicate that runoff from this glacier occurs primarily at two discrete locations and gives rise to two distinct glacially modified waters. Furthermore, we show that the location with the largest subglacial discharge is associated with the lighter, fresher glacially modified water mass. This is qualitatively consistent with results from an idealized plume model.

  2. Linking carbon and water cycles using stable isotopes across scales: progress and challenges

    Directory of Open Access Journals (Sweden)

    C. Werner

    2011-03-01

    Full Text Available Stable isotope analysis is a powerful tool for tracing biogeochemical processes in the carbon and water cycles. One particularly powerful approach is to employ multiple isotopes where the simultaneous assessment of the D/H,18O/16O and/or 13C/12C in different compounds provide a unique means to investigate the coupling of water and carbon fluxes at various temporal and spatial scales. Here, we present a research update on recent advances in our process-based understanding of the utilization of carbon, oxygen and hydrogen isotopes to lend insight into carbon and water cycling. We highlight recent technological developments and approaches, their strengths and methodological precautions with examples covering scales from minutes to centuries and from the leaf to the globe.

  3. Effect of hardening method and structure of linking bridges on strength of water glass moulding sands

    OpenAIRE

    Stachowicz, M.; K. Granat

    2010-01-01

    The paper presents examination results of the effect of four hardening methods on structure of linking bridges in sandmixes containing hydrated sodium silicate. Test pieces prepared of the moulding sands containing 2.5 % of a binder with molar module between 2.4 and 2.6 were hardened with carbon dioxide, dried traditionally in an oven and hardened with microwaves at 2.54 GHz or using a combination of the CO2 process and microwave heating. It was revealed that the hardening method influences s...

  4. Link between DOC in near surface peat and stream water in an upland catchment.

    Science.gov (United States)

    Clark, Joanna M; Lane, Stuart N; Chapman, Pippa J; Adamson, John K

    2008-10-15

    Hydrologic transport of dissolved organic carbon (DOC) from peat soils may differ to organo-mineral soils in how they responded to changes in flow, because of differences in soil profile and hydrology. In well-drained organo-mineral soils, low flow is through the lower mineral layer where DOC is absorbed and high flow is through the upper organic layer where DOC is produced. DOC concentrations in streams draining organo-mineral soils typically increase with flow. In saturated peat soils, both high and low flows are through an organic layer where DOC is produced. Therefore, DOC in stream water draining peat may not increase in response to changes in flow as there is no switch in flow path between a mineral and organic layer. To verify this, we conducted a high-resolution monitoring study of soil and stream water at an upland peat catchment in northern England. Our data showed a strong positive correlation between DOC concentrations at -1 and -5 cm depth and stream water, and weaker correlations between concentrations at -20 to -50 cm depth and stream water. Although near surface organic material appears to be the key source of stream water DOC in both peat and organo-mineral soils, we observed a negative correlation between stream flow and DOC concentrations instead of a positive correlation as DOC released from organic layers during low and high flow was diluted by rainfall. The differences in DOC transport processes between peat and organo-mineral soils have different implications for our understanding of long-term changes in DOC exports. While increased rainfall may cause an increase in DOC flux from peat due to an increase in water volume, it may cause a decrease in concentrations. This response is contrary to expected changes in DOC exports from organo-mineral soils, where increase rainfall is likely to result in an increase in flux and concentration.

  5. Linking ecosystem services and water resources: landscape-scale hydrology of the Little Karoo

    CSIR Research Space (South Africa)

    Le Maitre, David C

    2007-07-01

    Full Text Available relatively high rainfall (> 900 mm per year), but the Little Karoo is in a rain shadow and receives only 150–350 mm annually. The rainfall season occurs in summer in the east and in winter in the west. Most of the water in the major river systems... infiltration and overland flow determines the amount of water and waterborne materials that are retained or exported from a patch and, ultimately, a hillslope, to river systems and the ocean. The responses of large spatial units may not simply be the sum...

  6. Aquastress D2.2.3 - Key research priorities for and major knowledge gaps in Water Stress mitigation

    OpenAIRE

    Moors, E; Manez, M.; Van den Wyngaert, I.; Bauer, M; Inman, D.; Koundouri, P.; Loubier, S.; Preziosi, E.; Tarnacki, K.

    2008-01-01

    In this report the factual analysis is compared with the stakeholder perceptions for different test sites. Based on these findings the following general conclusions could be drawn. To obtain a good insight in the bio-geophysical system as well as the socio-economic setting often data were inadequate. This made it difficult to assess the water stress. It also stresses the need for a good monitoring network. A number of sites indicated that the distribution of the amount of water over the diffe...

  7. Combining integrated models and participatory methods to quantify water and agricultural trade-offs linked to different rural development scenarios

    Science.gov (United States)

    Rivas, David; Willaarts, Barbara; García, Ángel de Miguel; Tarquis, Ana Maria

    2017-04-01

    This study explores the water and agricultural tradeoffs linked to three different rural development scenarios in the Cega-Eresma-Adaja basin (CEA) in Central Spain. Agriculture is a key socioeconomic activity in CEA, and nearly 44% of the basin is devoted to croplands and pastures. Irrigated agriculture accounts for 12% of the cropland area and is currently using over 84% of available water resources. To define the three scenarios for CEA, we conducted a workshop with local stakeholders to infer how contrasting evolutions of EU agricultural, water and environmental policies could affect the local land use and agricultural management using participatory mapping techniques. The three scenarios reflect 1) a business as usual (BAU) rural development; 2) a land sharing strategy (LSH); and 3) a land sparing (LSP) situation. The integrated Soil Water Assessment Tool (SWAT) was used to model the changes in water use (hm^3/year) and agricultural productivity (ton/year) under each scenario. To account for changes in agricultural land use and management, the model integrates a large set of agricultural patterns obtained from combining high resolution remote sensing images (20m x 20m) for the years 2011-2015, agricultural productivity from survey by municipality and land use information obtained from the national map SIOSE2011 (1:50.000). Model calibration and sensitivity analysis were performed using SWAT-CUP/SUFI2 The period of the years 2005 to 2008 were used for parameter calibration and validation period extending between 2009 and 2014. The predicted daily streamflow presents a correlation coefficient of 0.76 and a NS coefficient of 0.81. The preliminary results reveal that under a BAU and a LSP scenario agricultural production and water demand will increase significantly (>25%) despite the improvements in water use efficiency and agricultural productivity. Under these scenarios, allocated water is likely to exceed the natural renewable water resources compromising the

  8. Applications of Crown Ether Cross-Linked Chitosan for the Analysis of Lead and Cadmium in Environmental Water Samples

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new type of crown ether cross-linked chitosan was synthesized by the reaction of chitosan with 4,4'-dibromodibenzo-18-crown-6 (Br-DBC). Its token structure was analyzed with FT-IR and NMR and the adsorption behaviors for lead and cadmium in environmental water samples by FAAS were studied. In addition the best analysis conditions were discussed and the adsorption mechanism was explained. As the enrichment factor is above 100, both recoveries are 94%-106%, the detection limits of lead and cadmium are 0.5μg*L-1and 0.04 μg*L-1 and the relatively standard deviations of lead and cadmium are 3.1% and 2.8% respectively, this new method was successfully applied to the determination of environmental water samples. This method is fast and simple and it greatly enhances the determination ability of FAAS for lead and cadmium.

  9. The link between water quality and tidal marshes in a highly impacted estuary.

    Science.gov (United States)

    Meire, Patrick; Maris, Tom; van Damme, Stefan; Jacobs, Sander; Cox, Tom; Struyf, Eric

    2010-05-01

    The Schelde estuary is one of the most heavily impacted estuaries in Europe. During several decades, untreated waste water from large cities (e.g. Brussels, Antwerp, Valenciennes, Lille) and industries was discharged in the river. As a result, the Schelde estuary has the reputation of being one of the most polluted estuaries in Europe. For a long time (approx. 1950 - 1995) all forms of higher life (macro-invertebrates and fish) were absent in the fresh and brackish parts of the estuary. Due to European legislation, a large part of the sewage water is now treated resulting in a significant recovery of water quality in the estuary. However, next to water quality, the estuary also suffered serious habitat losses during the last decades, mostly due to economic development and changing hydrological conditions causing more erosion. Over the last fifteen years, the management of the estuary has changed fundamentally. It is now more and more focused on the restoration of ecosystem services. In this presentation we will document the changes in water quality over the last 50 years and summarize recent work on the role of tidal marshes on water quality within the freshwater part of the Schelde estuary. Our results stress the important of taking into account ecosystem services and habitat restoration for long-term estuarine management. .After decades of high inorganic nutrient concentrations and recurring anoxia and hypoxia, we observed a paradoxical increase in chlorophyll-a concentrations with decreasing nutrient inputs, indicating a regime shift. Our results indicate that the recovery of a hypereutrophied systems towards a classical eutrophied state, needs the reduction of waste loads below certain thresholds. Paradoxically, phytoplankton production was inhibited by high ammonia or low oxygen concentrations. The system state change is accompanied by large fluctuations in oxygen concentrations. The improved water quality resulted in a remarkable recovery of different groups

  10. Surface effects on phase distributions of a fast-quenched miscibility gap type system - Succinonitrile-water

    Science.gov (United States)

    Frazier, D. O.; Facemire, B. R.; Fanning, U. S.

    1986-01-01

    If a binary homogeneous melt is cooled into an immiscible region, the newly formed second phase will generally have a density different from the parent phase, and will separate readily by sedimentation. Observation of solidification processes in microgravity indicates that outside of sedimentation, at least two other important effets can separate the phases: (1) preferential wetting, and (2) thermal migration of second-phase droplets due to interfacial tension gradients. The latter effect would drive the minority phase along the thermal gradient toward the hottest part (assuming the interfacial tension decreases with increasing temperature), which is usually away from the crucible wall. On the other hand, if the minority phase preferentially wets the crucible, a minority phase layer which thickens as initial solution compositions approach critical, will form adjacent to the solid surface and remain in the coldest region of the ingot. This study presents compelling preliminary evidence that these two effects do exist and that they compete with one another. However, the temperature dependence of preferential wetting below T(c) for the current system of study is, as yet, undetermined. These effects are sensitive to the initial concentration of a hypermonotectic solution cooling through a miscibility gap.

  11. Links Between Flood Frequency and Annual Water Balance Behaviors: A Basis for Similarity and Regionalization

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Jiali; Li, Hongyi; Leung, Lai-Yung R.; Guo, Shenglian; Liu, Pan; Sivapalan, Murugesu

    2014-03-28

    This paper presents the results of a data based comparative study of several hundred catchments across continental United States belonging to the MOPEX dataset, which systematically explored the connection between the flood frequency curve and measures of mean annual water balance. Two different measures of mean annual water balance are used: (i) a climatic aridity index, AI, which is a measure of the competition between water and energy availability at the annual scale; and, (ii) baseflow index, BFI, the ratio of slow runoff to total runoff also at the annual time scale, reflecting the role of geology, soils, topography and vegetation. The data analyses showed that the aridity index, AI, has a first order control on both the mean and Cv of annual maximum floods. While mean annual flood decreases with increasing aridity, Cv increases with increasing aridity. BFI appeared to be a second order control on the magnitude and shape of the flood frequency curve. Higher BFI, meaning more subsurface flow and less surface flow leads to a decrease of mean annual flood whereas lower BFI leads to accumulation of soil moisture and increased flood magnitudes that arise from many events acting together. The results presented in this paper provide innovative means to delineate homogeneous regions within which the flood frequency curves can be assumed to be functionally similar. At another level, understanding the connection between annual water balance and flood frequency will be another building block towards developing comprehensive understanding of catchment runoff behavior in a holistic way.

  12. In vitro degradation of dermal sheep collagen cross-linked using a water-soluble carbodiimide

    NARCIS (Netherlands)

    Olde damink, L.H.H.; Olde Damink, L.H.H.; Dijkstra, Pieter J.; van Luyn, M.J.A.; van Wachem, P.B.; Nieuwenhuis, P.; Feijen, Jan

    1996-01-01

    Bacterial collagenase was used to study the susceptibility of dermal sheep collagen (DSC) crosslinked with a mixture of the water-soluble carbodiimide 1-ethyl-3-(3-dimethyl aminopropyl)-carbodiimide hydrochloride and N-hydroxysuccinimide (E/N-DSC) towards enzymatic degradation. Contrary to

  13. In vitro degradation of dermal sheep collagen cross-linked using a water-soluble carbodiimide

    NARCIS (Netherlands)

    Damink, LHHO; Dijkstra, PJ; vanLuyn, MJA; vanWachem, PB; Nieuwenhuis, P; Feijen, J

    Bacterial collagenase was used to study the susceptibility of dermal sheep collagen (DSC) cross-inked with a mixture of the water-soluble carbodiimide 1-ethyl-3-(3-dimethyl aminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide (EIN-DSC) towards enzymatic degradation. Contrary to

  14. In vitro degradation of dermal sheep collagen cross-linked using a water-soluble carbodiimide

    NARCIS (Netherlands)

    Damink, LHHO; Dijkstra, PJ; vanLuyn, MJA; vanWachem, PB; Nieuwenhuis, P; Feijen, J

    1996-01-01

    Bacterial collagenase was used to study the susceptibility of dermal sheep collagen (DSC) cross-inked with a mixture of the water-soluble carbodiimide 1-ethyl-3-(3-dimethyl aminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide (EIN-DSC) towards enzymatic degradation. Contrary to non-cross-

  15. In vitro degradation of dermal sheep collagen cross-linked using a water-soluble carbodiimide

    NARCIS (Netherlands)

    Olde Damink, L.H.H.; Dijkstra, P.J.; Luyn, van M.J.A.; Wachem, van P.B.; Nieuwenhuis, P.; Feijen, J.

    1996-01-01

    Bacterial collagenase was used to study the susceptibility of dermal sheep collagen (DSC) crosslinked with a mixture of the water-soluble carbodiimide 1-ethyl-3-(3-dimethyl aminopropyl)-carbodiimide hydrochloride and N-hydroxysuccinimide (E/N-DSC) towards enzymatic degradation. Contrary to non-cross

  16. Comment on 'Water footprint of marine protein consumption—aquaculture's link to agriculture'

    NARCIS (Netherlands)

    Troell, M.; Metian, M.; Beveridge, M.; Verdegem, M.C.J.; Deutsch, L.

    2014-01-01

    In their article ‘Freshwater savings from marine protein consumption’ (2014 Environ. Res. Lett. 9 014005), Gephart and her colleagues analyzed how consumption of marine animal protein rather than terrestrial animal protein leads to reduced freshwater allocation. They concluded that future water savi

  17. Linking Health Concepts in the Assessment and Evaluation of Water Distribution Systems

    Science.gov (United States)

    Karney, Bryan W.; Filion, Yves R.

    2005-01-01

    The concept of health is not only a specific criterion for evaluation of water quality delivered by a distribution system but also a suitable paradigm for overall functioning of the hydraulic and structural components of the system. This article views health, despite its complexities, as the only criterion with suitable depth and breadth to allow…

  18. The `seafood gap' in the food-water nexus literature-issues surrounding freshwater use in seafood production chains

    NARCIS (Netherlands)

    Gephart, Jessica A.; Troell, Max; Henriksson, Patrik J.G.; Beveridge, Malcolm C.M.; Verdegem, Marc; Metian, Marc; Mateos, Lara D.; Deutsch, Lisa

    2017-01-01

    Freshwater use for food production is projected to increase substantially in the coming decades with population growth, changing demographics, and shifting diets. Ensuring joint food-water security has prompted efforts to quantify freshwater use for different food products and production methods.

  19. Physiological plasticity to water flow habitat in the damselfish, Acanthochromis polyacanthus: linking phenotype to performance.

    Directory of Open Access Journals (Sweden)

    Sandra A Binning

    Full Text Available The relationships among animal form, function and performance are complex, and vary across environments. Therefore, it can be difficult to identify morphological and/or physiological traits responsible for enhancing performance in a given habitat. In fishes, differences in swimming performance across water flow gradients are related to morphological variation among and within species. However, physiological traits related to performance have been less well studied. We experimentally reared juvenile damselfish, Acanthochromis polyacanthus, under different water flow regimes to test 1 whether aspects of swimming physiology and morphology show plastic responses to water flow, 2 whether trait divergence correlates with swimming performance and 3 whether flow environment relates to performance differences observed in wild fish. We found that maximum metabolic rate, aerobic scope and blood haematocrit were higher in wave-reared fish compared to fish reared in low water flow. However, pectoral fin shape, which tends to correlate with sustained swimming performance, did not differ between rearing treatments or collection sites. Maximum metabolic rate was the best overall predictor of individual swimming performance; fin shape and fish total length were 3.3 and 3.7 times less likely than maximum metabolic rate to explain differences in critical swimming speed. Performance differences induced in fish reared in different flow environments were less pronounced than in wild fish but similar in direction. Our results suggest that exposure to water motion induces plastic physiological changes which enhance swimming performance in A. polyacanthus. Thus, functional relationships between fish morphology and performance across flow habitats should also consider differences in physiology.

  20. Linking Water Table Dynamics to Carbon Cycling in Artificial Soil Column Incubations

    Science.gov (United States)

    Geertje, Pronk; Adrian, Mellage; Tatjana, Milojevic; Fereidoun, Rezanezhad; Cappellen Philippe, Van

    2016-04-01

    The biogeochemistry of wetlands soils is closely tied to their hydrology. Water table fluctuations that cause flooding and drying of these systems may lead to enhanced degradation of organic matter and release of greenhouse gasses (e.g. CO2, CH4) to the atmosphere. However, predicting the influence of water table fluctuations on the biogeochemical functioning of soils requires an understanding of the interactions of soil hydrology with biogeochemical and microbial processes. To determine the effects of water table dynamics on carbon cycling, we are carrying out state-of-the-art automated soil column experiments with fully integrated monitoring of hydro-bio-geophysical process variables under both constant and oscillating water table conditions. An artificial, homogeneous mixture consisting of minerals and organic matter is used to provide a well-defined starting material. The artificial soils are composed of quartz sand, montmorillonite, goethite and humus from a forested riparian zone, from which we also extracted the microbial inoculum added to the soil mixture. The artificial soils are packed into 60 cm high, 7.5 cm wide columns. In the currently ongoing experiment, three replicate columns are incubated while keeping the water table constant water at mid-depth, while another three columns alternate between drained and saturated conditions. Micro-sensors installed at different depths below the soil surface record time-series redox potentials (Eh) varying between oxidizing (~+700 mV) and reducing (~-200 mV) conditions. Continuous O2 levels throughout the soil columns are monitored using high-resolution, luminescence-based, Multi Fiber Optode (MuFO) microsensors. Pore waters are collected periodically with MicroRhizon samplers from different depths, and analyzed for pH, EC, dissolved inorganic and organic carbon and ion/cation compositions. These measurements allow us to track the changes in pore water geochemistry and relate them to differences in carbon cycling

  1. Coupling solid-phase extraction and enzyme-linked immunosorbent assay for ultratrace determination of herbicides in pristine water

    Science.gov (United States)

    Aga, D.S.; Thurman, E.M.

    1993-01-01

    Solid-phase extraction (SPE) and enzyme-linked immunosorbent assay (ELISA) were coupled for automated trace analysis of pristine water samples containing 2-chloro-4-ethylamino-6-isopropylamine-s-triazine (atrazine) and 2-chloro-2???,6???-diethyl-N-(methoxymethyl)acetanilide (alachlor). The isolation of the two herbicides on a C18-resin involved the selection of an elution solvent that both removes interfering substances and is compatible with ELISA. Ethyl acetate was selected as the elution solvent followed by a solvent exchange with methanol/water (20/80, % v/v). The SPE-ELISA method has a detection limit of 5.0 ng/L (5 ppt), >90% recovery, and a relative standard deviation of ??10%. The performance of a microtiter plate-based ELISA and a magnetic particle-based ELISA coupled to SPE was also evaluated. Although the sensitivity of the two ELISA methods was comparable, the precision using magnetic particles was improved considerably (??10% versus ??20%) because of the faster reaction kinetics provided by the magnetic particles. Finally, SPE-ELISA and isotope dilution gas chromatography/ mass spectrometry correlated well (correlation coefficient of 0.96) for lake-water samples. The SPE-ELISA method is simple and may have broader applications for the inexpensive automated analysis of other contaminants in water at trace levels.

  2. From microbes to water districts: Linking observations across scales to uncover the implications of riparian and channel management on water quality in an irrigated agricultural landscape

    Science.gov (United States)

    Webster, A.; Cadenasso, M. L.

    2016-12-01

    Interactions among runoff, riparian and stream ecosystems, and water quality remain uncertain in many settings, particularly those heavily impacted by human activities. For example, waterways in the irrigated agricultural landscape of California's Central Valley are seasonally disconnected from groundwater tables and are extensively modified by infrastructure and management. These conditions make the impact of riparian and channel management difficult to predict across scales, which hinders efforts to promote best management practices to improve water quality. We seek to link observations across catchment, reach, and patch scales to understand patterns of nitrate and turbidity in waterways draining irrigated cropland. Data was collected on 80 reaches spanning two water management districts. At the catchment scale, water districts implemented waterway and riparian management differently: one water district had a decentralized approach, allowing individual land owners to manage their waterway channels and banks, while the other had a centralized approach, in which land owners defer management to a district-run program. At the reach scale, riparian and waterway vegetation, geomorphic complexity, and flow conditions were quantified. Reach-scale management such as riparian planting projects and channel dredging frequency were also considered. At the patch scale, denitrification potential and organic matter were measured in riparian toe-slope soils and channel sediments, along with associated vegetation and geomorphic features. All factors were tested for their ability to predict water quality using generalized linear mixed effects models and the consistency of predictors within and across scales was evaluated. A hierarchy of predictors emerges: catchment-scale management regimes predict reach-scale geomorphic and vegetation complexity, which in turn predicts sediment denitrification potential - the patch-scale factor most associated with low nitrate. Similarly

  3. Absorbed Pb2+ and Cd2+ Ions in Water by Cross-Linked Starch Xanthate

    Directory of Open Access Journals (Sweden)

    Kai Feng

    2017-01-01

    Full Text Available A cross-linked starch xanthate was prepared by graft copolymerization of acrylamide and sodium acrylate onto starch xanthate using potassium persulfate and sodium hydrogen sulfite initiating system and N,N′-methylenebisacrylamide as a cross-linker. As this kind of cross-linked potato starch xanthate can effectively absorb heavy metal ions, it was dispersed in aqueous solutions of divalent heavy metal ions (Pb2+ and Cd2+ to investigate their absorbency by the polymer. Factors that can influence absorbency were investigated, such as the ratio of matrix to monomers, the amount of initiator and cross-linker, pH, and the concentration of metal ions. Results were reached and conclusion was drawn that the best synthetic conditions for the polymer adsorbing Pb2+ and Cd2+ were as follows: the quality ratio of matrix to monomers was 1 : 12 and 1 : 11, the amount of initiator was 2.4% and 3.2% of matrix, and the amount of cross-linker was 12 mg and 13 mg. When the initial concentration of ions was 10 mg/L, the highest quantities of adsorption of Pb2+ and Cd2+ were 47.11 mg/g and 36.55 mg/g. Adsorption mechanism was discussed by using Fourier transform infrared (FTIR spectroscopy, X-ray diffraction (XRD, scanning electron microscope (SEM, Energy Dispersive X-Ray Spectroscopy (EDS test, and adsorption kinetic simulation.

  4. Water-Responsive Shape Recovery Induced Buckling in Biodegradable Photo-Cross-Linked Poly(ethylene glycol) (PEG) Hydrogel.

    Science.gov (United States)

    Salvekar, Abhijit Vijay; Huang, Wei Min; Xiao, Rui; Wong, Yee Shan; Venkatraman, Subbu S; Tay, Kiang Hiong; Shen, Ze Xiang

    2017-02-21

    -responsive shape memory embolization plug for temporary vascular occlusion. The plug consists of a composite with a poly(dl-lactide-co-glycolide) (PLGA) core (loaded with radiopaque filler) and cross-linked poly(ethylene glycol) (PEG) hydrogel outer layer. The device can be activated by body fluid (or water) after about 2 min of immersion in water. The whole occlusion process is completed within a few dozens of seconds. The underlying mechanism is water-responsive shape recovery induced buckling, which occurs in an expeditious manner within a short time period and does not require complete hydration of the whole hydrogel. In this paper, we experimentally and analytically investigate the water-activated shape recovery induced buckling in this biodegradable PEG hydrogel to understand the fundamentals in precisely controlling the buckling time. The molecular mechanism responsible for the water-induced SME in PEG hydrogel is also elucidated. The original diameter and amount of prestretching are identified as two influential parameters to tailor the buckling time between 1 and 4 min as confirmed by both experiments and simulation. The phenomenon reported here, chemically induced buckling via a combination of the SME and swelling, is generic, and the study reported here should be applicable to other water- and non-water-responsive gels.

  5. Measuring Jupiter's water abundance by Juno: the link between interior and formation models

    CERN Document Server

    Helled, Ravit

    2014-01-01

    The JUNO mission to Jupiter is planned to measure the water abundance in Jupiter's atmosphere below the cloud layer. This measurement is important because it can be used to reveal valuable information on Jupiter's origin and its composition. In this paper we discuss the importance of this measurement, the challenges in its interpretation, and address how it can be connected to interior and formation models of Jupiter.

  6. Identifying factors linked to the occurrence of alien gastropods in isolated woodland water bodies.

    Science.gov (United States)

    Spyra, Aneta; Strzelec, Małgorzata

    2014-03-01

    Biological invasions are a significant component of human-caused global change and is widely regarded as one of the main threats to natural biodiversity. Isolated anthropogenic water bodies created in the areas that are deprived of natural freshwater habitats allow the survival and reproduction of alien species on newly settled sites. They are often small with water level fluctuations causing frequent environmental disturbances. The colonisation success may be the result of the rate of their degradation. The aims of the study were to determine the environmental conditions that affect the existence of alien species of gastropods in this type of aquatic environment and to examine whether the occurrence of non-native species affects the community structure of the native species. This study made it possible to group woodland ponds according to the occurrence of the three invasive species in snail communities and discuss the environmental conditions present in these pond types. Analysis of water properties emphasised the distinctiveness of the selected pond types. In ponds of the Potamopyrgus antipodarum type, we found the highest values of some parameters mainly hardness, conductivity, and content of calcium and chlorides, in contrast with the Physella acuta type, which were characterised by the lowest values except for phosphates and nitrites. In the Ferrissia fragilis type, we found the highest nitrate content. Data on the occurrence of alien species in different water environments play an important role in actions which are taken to prevent new invasions and spread of non-native species as well as to reduce future impacts of invaders.

  7. Growth decline linked to warming-induced water limitation in hemi-boreal forests.

    Science.gov (United States)

    Wu, Xiuchen; Liu, Hongyan; Guo, Dali; Anenkhonov, Oleg A; Badmaeva, Natalya K; Sandanov, Denis V

    2012-01-01

    Hemi-boreal forests, which make up the transition from temperate deciduous forests to boreal forests in southern Siberia, have experienced significant warming without any accompanying increase in precipitation during the last 80 years. This climatic change could have a profound impact on tree growth and on the stability of forest ecosystems in this region, but at present evidence for these impacts is lacking. In this study, we report a recent dramatic decline in the growth of hemi-boreal forests, based on ring width measurements from three dominant tree-species (Pinus sylvestris, Larix sibirica and Larix gmelinii), sampled from eight sites in the region. We found that regional tree growth has become increasingly limited by low soil water content in the pre- and early-growing season (from October of the previous year to July of the current year) over the past 80 years. A warming-induced reduction in soil water content has also increased the climate sensitivity of these three tree species. Beginning in the mid-1980s, a clear decline in growth is evident for both the pine forests and the larch forests, although there are increasing trends in the proxy of soil water use efficiencies. Our findings are consistent with those from other parts of the world and provide valuable insights into the regional carbon cycle and vegetation dynamics, and should be useful for devising adaptive forest management strategies.

  8. Growth decline linked to warming-induced water limitation in hemi-boreal forests.

    Directory of Open Access Journals (Sweden)

    Xiuchen Wu

    Full Text Available Hemi-boreal forests, which make up the transition from temperate deciduous forests to boreal forests in southern Siberia, have experienced significant warming without any accompanying increase in precipitation during the last 80 years. This climatic change could have a profound impact on tree growth and on the stability of forest ecosystems in this region, but at present evidence for these impacts is lacking. In this study, we report a recent dramatic decline in the growth of hemi-boreal forests, based on ring width measurements from three dominant tree-species (Pinus sylvestris, Larix sibirica and Larix gmelinii, sampled from eight sites in the region. We found that regional tree growth has become increasingly limited by low soil water content in the pre- and early-growing season (from October of the previous year to July of the current year over the past 80 years. A warming-induced reduction in soil water content has also increased the climate sensitivity of these three tree species. Beginning in the mid-1980s, a clear decline in growth is evident for both the pine forests and the larch forests, although there are increasing trends in the proxy of soil water use efficiencies. Our findings are consistent with those from other parts of the world and provide valuable insights into the regional carbon cycle and vegetation dynamics, and should be useful for devising adaptive forest management strategies.

  9. Forecasting recreational water quality standard violations with a linked hydrologic-hydronamic modeling system

    Science.gov (United States)

    Gronewold, A. D.; Ritzenthaler, A.; Fry, L. M.; Anderson, E. J.

    2012-12-01

    There is a clear need in the water resource and public health management communities to develop and test modeling systems which provide robust predictions of water quality and water quality standard violations, particularly in coastal communities. These predictions have the potential to supplement, or even replace, conventional human health protection strategies which (in the case of controlling public access to beaches, for example) are often based on day-old fecal indicator bacteria monitoring results. Here, we present a coupled modeling system which builds upon recent advancements in watershed-scale hydrological modeling and coastal hydrodynamic modeling, including the evolution of the Huron-Erie Connecting Waterways Forecasting System (HECWFS), developed through a partnership between NOAA's Great Lakes Environmental Research Laboratory (GLERL) and the University of Michigan Cooperative Institute for Limnology and Ecosystems Research (CILER). Our study is based on applying the modeling system to a popular beach in the metro-Detroit (Michigan, USA) area and implementing a routine shoreline monitoring program to help assess model forecasting skill. This research presents an important stepping stone towards the application of similar modeling systems in frequently-closed beaches throughout the Great Lakes region.

  10. Linking low- to high-mass young stellar objects with Herschel-HIFI observations of water

    Science.gov (United States)

    San José-García, I.; Mottram, J. C.; van Dishoeck, E. F.; Kristensen, L. E.; van der Tak, F. F. S.; Braine, J.; Herpin, F.; Johnstone, D.; van Kempen, T. A.; Wyrowski, F.

    2016-01-01

    Context. Water probes the dynamics in young stellar objects (YSOs) effectively, especially shocks in molecular outflows. It is therefore a key molecule for exploring whether the physical properties of low-mass protostars can be extrapolated to massive YSOs, an important step in understanding the fundamental mechanisms regulating star formation. Aims: As part of the WISH key programme, we investigate excited water line properties as a function of source luminosity, in particular the dynamics and the excitation conditions of shocks along the outflow cavity wall. Methods: Velocity-resolved Herschel-HIFI spectra of the H2O 202-111 (988 GHz), 211-202 (752 GHz) and 312-303 (1097 GHz) lines were analysed, together with 12CO J = 10-9 and 16-15, for 52 YSOs with bolometric luminosities ranging from 105 L⊙. The H2O and 12CO line profiles were decomposed into multiple Gaussian components which are related to the different physical structures of the protostellar system. The non-LTE radiative transfer code radex was used to constrain the excitation conditions of the shocks along the outflow cavity. Results: The profiles of the three excited water lines are similar, indicating that they probe the same gas. Two main emission components are seen in all YSOs: a broad component associated with non-dissociative shocks in the outflow cavity wall ("cavity shocks") and a narrow component associated with the quiescent envelope material. More than 60% of the total integrated intensity in the excited water lines comes from the broad cavity shock component, while the remaining emission comes mostly from the envelope for low-mass Class I, intermediate- and high-mass objects, and dissociative "spot shocks" for low-mass Class 0 protostars. The widths of the water lines are surprisingly similar from low- to high-mass YSOs, whereas 12CO J = 10-9 line widths increase slightly with Lbol. The excitation analysis of the cavity shock component shows stronger 752 GHz emission for high-mass YSOs

  11. Linking hydrology of traditional irrigation canals and socio-economic aspects of agricultural water use around Mt. Kilimanjaro

    Science.gov (United States)

    Kimaro, Jerome; Scharsich, Valeska; Huwe, Bernd; Bogner, Christina

    2017-04-01

    Traditional irrigation network around Mt. Kilimanjaro has been an important resource for both ecosystem functioning and agricultural production. However, a number of irrigation furrows can no longer maintain their discharge throughout the year and their future sustainability is uncertain. The actual efforts to improve the water supply were unsuccessful. We attribute this failure to a lack of information about the actual causes and extent of the problem. We suppose that there is a strong link between the socio-economic aspects like institutional and community management of the furrows and conflicts about water use. Therefore, we conducted a study to determine the relationship between current hydrological patterns and socio-economic aspects of agricultural water use. We measured discharge at 11 locations along an altitudinal gradient on the southern slopes of Mt. Kilimanjaro. Additionally, we conducted focus group discussions with participants from 15 villages and key informants interviews (n = 15). We found that the mean discharge did not differ significantly between dry and rainy seasons (ANOVA, p = 0.17). The overall discharge pattern indicated that furrows located in lower altitude had higher mean monthly discharge rate of 65 l s-1 compared to 11.5 l s-1 at the source area of the canals. This is due to the convergence of canals downstream. 41% of furrows were seasonal, 22% dry and only 37% perennial. Despite of a seemingly better water resource availability downstream, water conflicts are a major challenge across the whole mountain communities. Key informants and group discussions reported poor management of water on the district level. The Rural Moshi and Hai District Councils operate on a top down approach that give less power to the local water management committees. However, the latter have been an important part of the traditional management system for decades. Since 1990, the district authorities are using 65% of springs from the catchment to abstract water

  12. Simulated nutrient dissolution of Asian aerosols in various atmospheric waters: Potential links to marine primary productivity

    Science.gov (United States)

    Wang, Lingyan; Bi, Yanfeng; Zhang, Guosen; Liu, Sumei; Zhang, Jing; Xu, Zhaomeng; Ren, Jingling; Zhang, Guiling

    2017-09-01

    To probe the bioavailability and environmental mobility of aerosol nutrient elements (N, P, Si) in atmospheric water (rainwater, cloud and fog droplets), ten total suspended particulate (TSP) samples were collected at Fulong Mountain, Qingdao from prevailing air mass trajectory sources during four seasons. Then, a high time-resolution leaching experiment with simulated non-acidic atmospheric water (non-AAW, Milli-Q water, pH 5.5) and subsequently acidic atmospheric water (AAW, hydrochloric acid solution, pH 2) was performed. We found that regardless of the season or source, a monotonous decreasing pattern was observed in the dissolution of N, P and Si compounds in aerosols reacted with non-AAW, and the accumulated dissolved curves of P and Si fit a first-order kinetic model. No additional NO3- + NO2- dissolved out, while a small amount of NH4+ in Asian dust (AD) samples was released in AAW. The similar dissolution behaviour of P and Si from non-AAW to AAW can be explained by the Transition State Theory. The sources of aerosols related to various minerals were the natural reasons that affected the amounts of bioavailable phosphorus and silicon in aerosols (i.e., solubility), which can be explained by the dissolution rate constant of P and Si in non-AAW with lower values in mineral aerosols. The acid/particle ratio and particle/liquid ratio also have a large effect on the solubility of P and Si, which was implied by Pearson correlation analysis. Acid processing of aerosols may have great significance for marine areas with limited P and Si and post-acidification release increases of 1.1-10-fold for phosphorus and 1.2-29-fold for silicon. The decreasing mole ratio of P and Si in AAW indicates the possibility of shifting from a Si-limit to a P-limit in aerosols in the ocean, which promotes the growth of diatoms prior to other algal species.

  13. Surface-water quantity and quality, aquatic biology, stream geomorphology, and groundwater-flow simulation for National Guard Training Center at Fort Indiantown Gap, Pennsylvania, 2002-05

    Science.gov (United States)

    Langland, Michael J.; Cinotto, Peter J.; Chichester, Douglas C.; Bilger, Michael D.; Brightbill, Robin A.

    2010-01-01

    Base-line and long-term monitoring of water resources of the National Guard Training Center at Fort Indiantown Gap in south-central Pennsylvania began in 2002. Results of continuous monitoring of streamflow and turbidity and monthly and stormflow water-quality samples from two continuous-record long-term stream sites, periodic collection of water-quality samples from five miscellaneous stream sites, and annual collection of biological data from 2002 to 2005 at 27 sites are discussed. In addition, results from a stream-geomorphic analysis and classification and a regional groundwater-flow model are included. Streamflow at the facility was above normal for the 2003 through 2005 water years and extremely high-flow events occurred in 2003 and in 2004. Water-quality samples were analyzed for nutrients, sediments, metals, major ions, pesticides, volatile and semi-volatile organic compounds, and explosives. Results indicated no exceedances for any constituent (except iron) above the primary and secondary drinking-water standards or health-advisory levels set by the U.S. Environmental Protection Agency. Iron concentrations were naturally elevated in the groundwater within the watershed because of bedrock lithology. The majority of the constituents were at or below the method detection limit. Sediment loads were dominated by precipitation due to the remnants of Hurricane Ivan in September 2004. More than 60 percent of the sediment load measured during the entire study was transported past the streamgage in just 2 days during that event. Habitat and aquatic-invertebrate data were collected in the summers of 2002-05, and fish data were collected in 2004. Although 2002 was a drought year, 2003-05 were above-normal flow years. Results indicated a wide diversity in invertebrates, good numbers of taxa (distinct organisms), and on the basis of a combination of metrics, the majority of the 27 sites indicated no or slight impairment. Fish-metric data from 25 sites indicated results

  14. U.S. Navy Regional Climatic Study of the Greenland-Iceland-United Kingdom Gap and Associated Waters

    Science.gov (United States)

    1992-02-01

    Associated Waters 6. AUTHOR(S) William A. Brower, Jr., William 0. Brown, Ronald G. Baldwin, and Phala L. Franks 7. PERFORMING ORGANIZATION NAME(S) AND...meteorologists of the NCDC’s Global Climate Laboratory (GCL): William A. Brower, Jr., for serving as project leader and chief climatic analyst; William 0. Brown...ITOTI REAN NO. OF DAYS 4ITR (LI EANS I EATAEREIPERCENTIPP IP.I ALTI I I𔄂𔃻 TEMP IDEG F, I PRECIPITATION i OBSTR TO VISION I I I I ILST1 I.4.1 I

  15. Mercury in southeastern U.S. riverine fish populations linked to water body type.

    Science.gov (United States)

    Rypel, Andrew L; Arrington, D Albrey; Findlay, Robert H

    2008-07-15

    We compared Hg concentrations in fishes from the regulated Black Warrior River and the unregulated Sipsey River in west Alabama whose neighboring watersheds receive equivalent atmospheric Hg deposition. Average fish fillet Hg concentrations were 3-fold higher in the unregulated river compared to the regulated river. Between river differences in Hg fish concentrations likely originate from structural (e.g., species composition) and functional (e.g., energy flow pathways) differences between the two ecosystems. We tested the generality of these findings by comparing largemouth bass Hg concentrations among unregulated rivers (n=6) and reservoirs (n=11) throughout the southern Coastal Plain geologic region. ANCOVA revealed that at a given bass length, Hg concentrations were approximately 1.75 times higher in unregulated rivers compared to regulated rivers. Aerial deposition of Hg was not correlated to largemouth bass Hg concentrations. We suggest that the link between atmospheric Hg deposition and fish Hg concentrations is significantly modulated by the structure and function of aquatic ecosystems and this accounts for much of the variation in fish Hg concentrations among systems. Unregulated floodplain-rivers in the south have some of the highest fish Hg concentrations on record and should be intensely monitored to establish human consumption risks.

  16. Urban Stormwater Quality: Linking Pesticide Variability To Our Sustainable Water Future

    Science.gov (United States)

    Rippy, M.; Deletic, A.; Gernjak, W.

    2015-12-01

    Climate change and global population growth demand creative, multidisciplinary, and multi-benefit approaches for sustaining adequate fresh water resources and protecting ecosystem health. Currently, a driving factor of aquatic ecosystem degradation (stormwater) is also one of the largest untapped urban freshwater resources. This suggests that ecosystem protection and potable water security might both be achieved via treating and capturing stormwater for human use (e.g., potable substitution). The viability of such a scheme, however, depends on 1) initial stormwater quality (e.g., the contaminants present and their associated human/environmental health risks), 2) the spatial and temporal variability of contaminants in stormwater, and 3) the capacity of existing technologies to treat those contaminants to fit for purpose standards. Here we present results from a four year study of urban stormwater conducted across ten catchments and four states in Australia that addresses these three issues relative to stormwater pesticides. In total, 19 pesticides were detected across all sites and times. In general, pesticide concentrations were lower than has been reported in other countries, including the United States, Canada and Europe. This is reflected in few exceedences of public health (map closely to co-occurrence patterns in registered Australian products. Importantly, the presence of catchment-specific pesticide variability has clear management implications; namely, urban stormwater must be managed at the catchment level and target local contaminant suites in order to best achieve desired human use and environmental protection standards.

  17. Linking in Vitro Effects and Detected Organic Micropollutants in Surface Water Using Mixture-Toxicity Modeling.

    Science.gov (United States)

    Neale, Peta A; Ait-Aissa, Selim; Brack, Werner; Creusot, Nicolas; Denison, Michael S; Deutschmann, Björn; Hilscherová, Klára; Hollert, Henner; Krauss, Martin; Novák, Jiří; Schulze, Tobias; Seiler, Thomas-Benjamin; Serra, Helene; Shao, Ying; Escher, Beate I

    2015-12-15

    Surface water can contain countless organic micropollutants, and targeted chemical analysis alone may only detect a small fraction of the chemicals present. Consequently, bioanalytical tools can be applied complementary to chemical analysis to detect the effects of complex chemical mixtures. In this study, bioassays indicative of activation of the aryl hydrocarbon receptor (AhR), activation of the pregnane X receptor (PXR), activation of the estrogen receptor (ER), adaptive stress responses to oxidative stress (Nrf2), genotoxicity (p53) and inflammation (NF-κB) and the fish embryo toxicity test were applied along with chemical analysis to water extracts from the Danube River. Mixture-toxicity modeling was applied to determine the contribution of detected chemicals to the biological effect. Effect concentrations for between 0 to 13 detected chemicals could be found in the literature for the different bioassays. Detected chemicals explained less than 0.2% of the biological effect in the PXR activation, adaptive stress response, and fish embryo toxicity assays, while five chemicals explained up to 80% of ER activation, and three chemicals explained up to 71% of AhR activation. This study highlights the importance of fingerprinting the effects of detected chemicals.

  18. Linking hydraulic properties of fire-affected soils to infiltration and water repellency

    Science.gov (United States)

    Moody, J.A.; Kinner, D.A.; Ubeda, X.

    2009-01-01

    Heat from wildfires can produce a two-layer system composed of extremely dry soil covered by a layer of ash, which when subjected to rainfall, may produce extreme floods. To understand the soil physics controlling runoff for these initial conditions, we used a small, portable disk infiltrometer to measure two hydraulic properties: (1) near-saturated hydraulic conductivity, Kf and (2) sorptivity, S(??i), as a function of initial soil moisture content, ??i, ranging from extremely dry conditions (??i capillarity, and adsorption in a transitional domain corresponding to extremely dry soil, and moreover, it may explain the observed non-linear behavior, and the critical soil-moisture threshold of water repellent soils. Laboratory measurements of Kf and S(??i) are the first for ash and fire-affected soil, but additional measurements are needed of these hydraulic properties for in situ fire-affected soils. They provide insight into water repellency behavior and infiltration under extremely dry conditions. Most importantly, they indicate how existing rainfall-runoff models can be modified to accommodate a possible two-layer system in extremely dry conditions. These modified models can be used to predict floods from burned watersheds under these initial conditions.

  19. The association between fluoride in drinking water and dental caries in Danish children. Linking data from health registers, environmental registers and administrative registers

    DEFF Research Database (Denmark)

    Kirkeskov, Lilli; Kristiansen, Eva; Bøggild, Henrik

    2010-01-01

    Dent Oral Epidemiol 2010. (c) 2010 John Wiley & Sons A/S Abstract - Objectives: To study the association between fluoride concentration in drinking water and dental caries in Danish children. Methods: The study linked registry data on fluoride concentration in drinking water over a 10-year period...

  20. Biomass Assessment. Assessment of global biomass potentials and their links to food, water, biodiversity, energy demand and economy. Inventory and analysis of existing studies. Supporting document

    Energy Technology Data Exchange (ETDEWEB)

    Dornburg, V.; Faaij, A.; Verweij, P. [Utrecht University, Utrecht (Netherlands); Banse, M.; Van Diepen, K.; Van Keulen, H.; Langeveld, H.; Meeusen, M.; Van de Ven, G.; Wester, F. [Wageningen UR, Wageningen (Netherlands); Alkemade, R.; Ten Brink, B.; Van den Born, G.J.; Van Oorschot, M.; Ros, J.; Smout, F.; Van Vuuren, D.; Van den Wijngaart, R. [Netherlands Environmental Assessment Agency NMP, Bilthoven (Netherlands); Aiking, H. [Vrije Universiteit, Amsterdam (Netherlands); Londo, M.; Mozaffarian, H.; Smekens, K. [ECN Policy Studies, Petten (Netherlands); Lysen, E. (ed.); Van Egmond, S. (ed.) [Utrecht Centre for Energy research UCE, Utrecht University, Utrecht (Netherlands)

    2008-01-15

    This supporting document contains the result from the inventory phase of the biomass assessment of global biomass potentials and their links to food, water, biodiversity, energy demand and economy. This study provides a comprehensive assessment of global biomass potential estimates, focusing on the various factors affecting these potentials, such as food supplies, water use, biodiversity, energy demands and agro-economics.

  1. Linking hydraulic properties of fire-affected soils to infiltration and water repellency

    Science.gov (United States)

    Moody, John A.; David Kinner,; Xavier Úbeda,

    2009-01-01

    Heat from wildfires can produce a two-layer system composed of extremely dry soil covered by a layer of ash, which when subjected to rainfall, may produce extreme floods. To understand the soil physics controlling runoff for these initial conditions, we used a small, portable disk infiltrometer to measure two hydraulic properties: (1) near-saturated hydraulic conductivity, Kf and (2) sorptivity, S(θi), as a function of initial soil moisture content, θi, ranging from extremely dry conditions (θi water repellency that influences Kf and S(θi).Values of Kf ranged from 4.5 × 10−3 to 53 × 10−3 cm s−1 for ash; from 0.93 × 10−3 to 130 × 10−3 cm s−1 for reference soils; and from 0.86 × 10−3 to 3.0 × 10−3 cm s−1, for soil unaffected by fire, which had the lowest values of Kf. Measurements indicated that S(θi) could be represented by an empirical non-linear function of θi with a sorptivity maximum of 0.18–0.20 cm s−0.5, between 0.03 and 0.08 cm3 cm−3. This functional form differs from the monotonically decreasing non-linear functions often used to represent S(θi) for rainfall–runoff modeling. The sorptivity maximum may represent the combined effects of gravity, capillarity, and adsorption in a transitional domain corresponding to extremely dry soil, and moreover, it may explain the observed non-linear behavior, and the critical soil-moisture threshold of water repellent soils. Laboratory measurements of Kf and S(θi) are the first for ash and fire-affected soil, but additional measurements are needed of these hydraulic properties for in situ fire-affected soils. They provide insight into water repellency behavior and infiltration under extremely dry conditions. Most importantly, they indicate how existing rainfall–runoff models can be modified to accommodate a possible two-layer system in extremely dry conditions. These modified models can be used to predict floods from burned watersheds

  2. Arcobacter in Lake Erie beach waters: an emerging gastrointestinal pathogen linked with human-associated fecal contamination.

    Science.gov (United States)

    Lee, Cheonghoon; Agidi, Senyo; Marion, Jason W; Lee, Jiyoung

    2012-08-01

    The genus Arcobacter has been associated with human illness and fecal contamination by humans and animals. To better characterize the health risk posed by this emerging waterborne pathogen, we investigated the occurrence of Arcobacter spp. in Lake Erie beach waters. During the summer of 2010, water samples were collected 35 times from the Euclid, Villa Angela, and Headlands (East and West) beaches, located along Ohio's Lake Erie coast. After sample concentration, Arcobacter was quantified by real-time PCR targeting the Arcobacter 23S rRNA gene. Other fecal genetic markers (Bacteroides 16S rRNA gene [HuBac], Escherichia coli uidA gene, Enterococcus 23S rRNA gene, and tetracycline resistance genes) were also assessed. Arcobacter was detected frequently at all beaches, and both the occurrence and densities of Arcobacter spp. were higher at the Euclid and Villa Angela beaches (with higher levels of fecal contamination) than at the East and West Headlands beaches. The Arcobacter density in Lake Erie beach water was significantly correlated with the human-specific fecal marker HuBac according to Spearman's correlation analysis (r = 0.592; P Arcobacter sequences were closely related to Arcobacter cryaerophilus, which is known to cause gastrointestinal diseases in humans. Since human-pathogenic Arcobacter spp. are linked to human-associated fecal sources, it is important to identify and manage the human-associated contamination sources for the prevention of Arcobacter-associated public health risks at Lake Erie beaches.

  3. Reactivity of the Bacteria-Water Interface: Linking Nutrient Availability to Bacteria-Metal Interactions

    Science.gov (United States)

    Fowle, D. A.; Daughney, C. J.; Riley, J. L.

    2002-12-01

    Identifying and quantifying the controls on metal mobilities in geologic systems is critical in order to understand processes such as global element cycling, metal transport in near-surface water-rock systems, sedimentary diagenesis, and mineral formation. Bacteria are ubiquitous in near-surface water-rock systems, and numerous laboratory and field studies have demonstrated that bacteria can facilitate the formation and dissolution of minerals, and enhance or inhibit contaminant transport. However, despite the growing evidence that bacteria play a key role in many geologic processes in low temperature systems, our understanding of the influence of the local nutrient dynamics of the system of interest on bacteria-metal interactions is limited. Here we present data demonstrating the effectiveness of coupling laboratory experiments with geochemical modeling to isolate the effect of nutrient availability on bacterially mediated proton and metal adsorption reactions. Experimental studies of metal-bacteria interactions were conducted in batch reactors as a function of pH, and solid-solute interactions after growth in a variety of defined and undefined media. Media nutrient composition (C,N,P) was quantified before and after harvesting the cells. Surface complexation models (SCM) for the adsorption reactions were developed by combining sorption data with the results of acid-base titrations, and in some cases zeta potential titrations of the bacterial surface. Our results indicate a clear change in both buffering potential and metal binding capacity of the cell walls of Bacillus subtilis as a function of initial media conditions. Combining current studies with our past studies on the effects of growth phase and others work on temperature dependence on metal adsorption we hope to develop a holistic surface complexation model for quantifying bacterial effects on metal mass transfer in many geologic systems.

  4. Organic compounds in water extracts of coal: links to Balkan endemic nephropathy.

    Science.gov (United States)

    Maharaj, S V M; Orem, W H; Tatu, C A; Lerch, H E; Szilagyi, D N

    2014-02-01

    The Pliocene lignite hypothesis is an environmental hypothesis that has been proposed to explain the etiology of Balkan endemic nephropathy (BEN). Aqueous leaching experiments were conducted on a variety of coal samples in order to simulate groundwater leaching of organic compounds, and to further test the role of the Pliocene lignite hypothesis in the etiology of BEN. Experiments were performed on lignite coal samples from endemic BEN areas in Romania and Serbia, and lignite and bituminous coals from nonendemic regions in Romania and the USA. Room temperature, hot water bath, and Soxhlet aqueous extraction experiments were conducted between 25 and 80 °C, and from 5 to 128 days in duration. A greater number of organic compounds and in higher concentrations were present in all three types of leaching experiments involving endemic area Pliocene lignite samples compared to all other coals examined. A BEN causing molecule or molecules may be among phenols, PAHs, benzenes, and/or lignin degradation compounds. The proposed transport pathway of the Pliocene lignite hypothesis for organic compound exposure from endemic area Pliocene lignite coals to well and spring drinking water, is likely. Aromatic compounds leached by groundwater from Pliocene lignite deposits in the vicinity of endemic BEN areas may play a role in the etiology of the disease. A better understanding of organic compounds leached by groundwater from Pliocene lignite deposits may potentially lead to the identification and implementation of effective strategies for the prevention of exposure to the causative agent(s) for BEN, and in turn, prevention of the disease.

  5. Minding the Gap

    Energy Technology Data Exchange (ETDEWEB)

    Firestone, Millicent Anne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-23

    Neutron & X-ray scattering provides nano- to meso-scale details of complex fluid structure; 1D electronic density maps dervied from SAXS yield molecular level insights; Neutron reflectivity provides substructure details of substrate supported complex fluids; Complex fluids composition can be optimized to support a wide variety of both soluble and membrane proteins; The water gap dimensions can be finely tuned through polymer component.

  6. Chemo-Enzymatic Synthesis of Ester-Linked Docetaxel-Monosaccharide Conjugates as Water-Soluble Prodrugs

    Directory of Open Access Journals (Sweden)

    Naoji Kubota

    2011-08-01

    Full Text Available Three new docetaxel prodrugs, i.e., 7-propionyldocetaxel 3''-O-b-D-glycopyranosides, which contain ester-linked monosaccharides, were synthesized by a chemo-enzymatic procedure involving enzymatic transglycosylations with lactase, b-galactosidase, or b-xylosidase. The water-solubility of 7-propionyldocetaxel 3''-O-b-D-glucopyranoside was 52-fold higher than that of docetaxel. 7-Propionyldocetaxel 3''-O-b-D-glucopyranoside and 7-propionyldocetaxel 3''-O-b-D-xylopyranoside were effectively hydrolyzed by the relevant enzyme(s of human cancer cells to release docetaxel, whereas 7-propionyldocetaxel 3''-O-b-D-galactopyranoside was relatively resistant under similar conditions. 7-Propionyldocetaxel 3''-O-b-D-glucopyranoside and 7-propionyldocetaxel 3''-O-b-D-xylopyranoside showed in vitro cytotoxic activity against human cancer cells, whereas 7-propionyldocetaxel 3''-O-b-D-galactopyranoside exerted low cytotoxicity.

  7. Modeling stomatal conductance in the earth system: linking leaf water-use efficiency and water transport along the soil-plant-atmosphere continuum

    Science.gov (United States)

    Bonan, G. B.; Williams, M.; Fisher, R. A.; Oleson, K. W.

    2014-09-01

    The Ball-Berry stomatal conductance model is commonly used in earth system models to simulate biotic regulation of evapotranspiration. However, the dependence of stomatal conductance (gs) on vapor pressure deficit (Ds) and soil moisture must be empirically parameterized. We evaluated the Ball-Berry model used in the Community Land Model version 4.5 (CLM4.5) and an alternative stomatal conductance model that links leaf gas exchange, plant hydraulic constraints, and the soil-plant-atmosphere continuum (SPA). The SPA model simulates stomatal conductance numerically by (1) optimizing photosynthetic carbon gain per unit water loss while (2) constraining stomatal opening to prevent leaf water potential from dropping below a critical minimum. We evaluated two optimization algorithms: intrinsic water-use efficiency (ΔAn /Δgs, the marginal carbon gain of stomatal opening) and water-use efficiency (ΔAn /ΔEl, the marginal carbon gain of transpiration water loss). We implemented the stomatal models in a multi-layer plant canopy model to resolve profiles of gas exchange, leaf water potential, and plant hydraulics within the canopy, and evaluated the simulations using leaf analyses, eddy covariance fluxes at six forest sites, and parameter sensitivity analyses. The primary differences among stomatal models relate to soil moisture stress and vapor pressure deficit responses. Without soil moisture stress, the performance of the SPA stomatal model was comparable to or slightly better than the CLM Ball-Berry model in flux tower simulations, but was significantly better than the CLM Ball-Berry model when there was soil moisture stress. Functional dependence of gs on soil moisture emerged from water flow along the soil-to-leaf pathway rather than being imposed a priori, as in the CLM Ball-Berry model. Similar functional dependence of gs on Ds emerged from the ΔAn/ΔEl optimization, but not the ΔAn /gs optimization. Two parameters (stomatal efficiency and root hydraulic

  8. Linking low- to high-mass YSOs with Herschel-HIFI observations of water

    CERN Document Server

    Jose-Garcia, I San; van Dishoeck, E F; Kristensen, L E; van der Tak, F F S; Braine, J; Herpin, F; Johnstone, D; van Kempen, T A; Wyrowski, F

    2016-01-01

    Water probes the dynamics in young stellar objects (YSOs) effectively, especially shocks in molecular outflows. It is a key molecule for exploring whether the physical properties of low-mass protostars can be extrapolated to massive YSOs. As part of the WISH key programme, we investigate the dynamics and the excitation conditions of shocks along the outflow cavity wall as function of source luminosity. Velocity-resolved Herschel-HIFI spectra of the H2O 988, 752, 1097 GHz and 12CO J=10-9, 16-15 lines were analysed for 52 YSOs with bolometric luminosities (L_bol) ranging from 10^5 L_sun. The profiles of the H2O lines are similar, indicating that they probe the same gas. We see two main Gaussian emission components in all YSOs: a broad component associated with non-dissociative shocks in the outflow cavity wall (cavity shocks) and a narrow component associated with quiescent envelope material. More than 60% of the total integrated intensity of the H2O lines (L_H2O) comes from the cavity shock component. The H2O ...

  9. Linking Assessment to Decision Making in Water Resources Planning - Decision Making Frameworks and Case Study Evaluations

    Science.gov (United States)

    Broman, D.; Gangopadhyay, S.; Simes, J.

    2015-12-01

    Climate assessments have become an accepted and commonly used component of long term water management and planning. There is substantial variation in the methods used in these assessments; however, managers and decision-makers have come to value their utility to identify future system limitations, and to evaluate future alternatives to ensure satisfactory system performance. A new set of decision-making frameworks have been proposed, including robust decision making (RDM), and decision scaling, that directly address the deep uncertainties found in both future climate, and non-climatic factors. Promising results have been obtained using these new frameworks, offering a more comprehensive understanding of future conditions leading to failures, and identification of measures to address these failures. Data and resource constraints have limited the use of these frameworks within the Bureau of Reclamation. We present here a modified framework that captures the strengths of previously proposed methods while using a suite of analysis tool that allow for a 'rapid climate assessment' to be performed. A scalable approach has been taken where more complex tools can be used if project resources allow. This 'rapid assessment' is demonstrated through two case studies on the Santa Ana and Colorado Rivers where previous climate assessments have been completed. Planning-level measures are used to compare how decision making is affected when using this new decision making framework.

  10. Detection of Campylobacter jejuni and Campylobacter coli in environmental waters by PCR enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Sails, A D; Bolton, F J; Fox, A J; Wareing, D R A; Greenway, D L A

    2002-03-01

    A PCR enzyme-linked immunosorbent assay (ELISA) assay was applied to the detection of Campylobacter jejuni and Campylobacter coli in environmental water samples after enrichment culture. Bacterial cells were concentrated from 69 environmental water samples by using filtration, and the filtrates were cultured in Campylobacter blood-free broth. After enrichment culture, DNA was extracted from the samples by using a rapid-boiling method, and the DNA extracts were used as a template in a PCR ELISA assay. A total of 51 samples were positive by either PCR ELISA or culture; of these, 43 were found to be positive by PCR ELISA and 43 were found to be positive by culture. Overall, including positive and negative results, 59 samples were concordant in both methods. Several samples were positive in the PCR ELISA assay but were culture negative; therefore, this assay may be able to detect sublethally damaged or viable nonculturable forms of campylobacters. The method is rapid and sensitive, and it significantly reduces the time needed for the detection of these important pathogens by 2 to 3 days.

  11. Human cell toxicogenomic analysis links reactive oxygen species to the toxicity of monohaloacetic acid drinking water disinfection byproducts

    Science.gov (United States)

    Pals, Justin; Attene-Ramos, Matias S.; Xia, Menghang; Wagner, Elizabeth D.; Plewa, Michael J.

    2014-01-01

    Chronic exposure to drinking water disinfection byproducts has been linked to adverse health risks. The monohaloacetic acids (monoHAAs) are generated as byproducts during the disinfection of drinking water and are cytotoxic, genotoxic, mutagenic, and teratogenic. Iodoacetic acid toxicity was mitigated by antioxidants, suggesting the involvement of oxidative stress. Other monoHAAs may share a similar mode of action. Each monoHAA generated a significant concentration-response increase in the expression of a β-lactamase reporter under the control of the Antioxidant Response Element (ARE). The monoHAAs generated oxidative stress with a rank order of IAA > BAA >> CAA; this rank order was observed with other toxicological endpoints. Toxicogenomic analysis was conducted with a non-transformed human intestinal epithelial cell line (FHs 74 Int). Exposure to the monoHAAs altered the transcription levels of multiple oxidative stress responsive genes, indicating that each exposure generated oxidative stress. The transcriptome profiles showed an increase in TXNRD1 and SRXN1, suggesting peroxiredoxin proteins had been oxidized during monoHAA exposures. Three sources of reactive oxygen species were identified, the hypohalous acid generating peroxidase enzymes LPO and MPO, NADPH-dependent oxidase NOX5, and PTGS2 (COX-2) mediated arachidonic acid metabolism. Each monoHAA exposure caused an increase in COX-2 mRNA levels. These data provide a functional association between monoHAA exposure and adverse health outcomes such as oxidative stress, inflammation, and cancer. PMID:24050308

  12. Legionellaceae in the hospital water-supply. Epidemiological link with disease and evaluation of a method for control of nosocomial legionnaires' disease and Pittsburgh pneumonia.

    Science.gov (United States)

    Best, M; Yu, V L; Stout, J; Goetz, A; Muder, R R; Taylor, F

    1983-08-06

    An epidemiological link was found between contamination of a hospital water-supply by Legionella pneumophila and by Pittsburgh pneumonia agent (PPA) and subsequent cases of nosocomial legionnaires' disease and Pittsburgh pneumonia. The extent of L pneumophila isolation from the water-supply paralleled the occurrence of disease. Whenever L pneumophila was isolated from more than 30% of ten selected water sites, nosocomial legionellosis occurred. The temperature of the hot water tanks was raised to 60-77 degrees C for 72 h, and water outlets were flushed for 30 min with hot water. A decline in numbers of L pneumophila and PPA in the water-supply was followed by a fall in the incidence of legionnaires' disease and Pittsburgh pneumonia. In addition, intermittent raising of the temperature in the hot water system decreased both the number of months in which disease occurred and the proportion of nosocomial pneumonias caused by these organisms.

  13. Klamath River Water Quality and Acoustic Doppler Current Profiler Data from Link River Dam to Keno Dam, 2007

    Science.gov (United States)

    Sullivan, Annett B.; Deas, Michael L.; Asbill, Jessica; Kirshtein, Julie D.; Butler, Kenna D.; Stewart, Marc A.; Wellman, Roy W.; Vaughn, Jennifer

    2008-01-01

    In 2007, the U.S. Geological Survey, Watercourse Engineering, and the Bureau of Reclamation began a project to construct and calibrate a water quality and hydrodynamic model of the 21-mile reach of the Klamath River from Link River Dam to Keno Dam. To provide a basis for this work, data collection and experimental work were planned for 2007 and 2008. This report documents sampling and analytical methods and presents data from the first year of work. To determine water velocities and discharge, a series of cross-sectional acoustic Doppler current profiler (ADCP) measurements were made on the mainstem and four canals on May 30 and September 19, 2007. Water quality was sampled weekly at five mainstem sites and five tributaries from early April through early November, 2007. Constituents reported here include field parameters (water temperature, pH, dissolved oxygen concentration, specific conductance); total nitrogen and phosphorus; particulate carbon and nitrogen; filtered orthophosphate, nitrite, nitrite plus nitrate, ammonia, organic carbon, iron, silica, and alkalinity; specific UV absorbance at 254 nm; phytoplankton and zooplankton enumeration and species identification; and bacterial abundance and morphological subgroups. The ADCP measurements conducted in good weather conditions in May showed that four major canals accounted for most changes in discharge along the mainstem on that day. Direction of velocity at measured locations was fairly homogeneous across the channel, while velocities were generally lowest near the bottom, and highest near surface, ranging from 0.0 to 0.8 ft/s. Measurements in September, made in windy conditions, raised questions about the effect of wind on flow. Most nutrient and carbon concentrations were lowest in spring, increased and remained elevated in summer, and decreased in fall. Dissolved nitrite plus nitrate and nitrite had a different seasonal cycle and were below detection or at low concentration in summer. Many nutrient and

  14. Analysis of drought and desertification by means of aridity indices and the estimation of water gap in Baja California Sur, Northwest Mexico

    Directory of Open Access Journals (Sweden)

    Enrique Troyo Diéguez

    2013-10-01

    Full Text Available In Baja California Sur (BCS, Mexico, dry-semi warm and warm climates prevail associated to an extreme trend of diurnal temperatures and the environmental dryness. In this State, the maximum summer t exceeds 40° C and the minimum varies from 5 to 12° C, with a minimal for the State of 2° C in winter, at the top of the Sierra de La Laguna; only Los Cabos region has a warm humid climate. Because precipitation in the state is low, oscillating from 310 mm in the southern area of the state to 120 mm per year in the northern portion, predictions and scenarios under climate conditions point to an intensification of droughts. The aim of this work was to carry out a comparative analysis of trends of temperature, precipitation and hydro-environmental aridity among contrasting localities of BCS, by means of the application of Aridity Indexes and the determination of the Standardized Water Gap (BHE, through a numerical scale modification of the De Martonne Index. With the values of temperature and precipitation for the different climate change scenarios for four weather stations, the indicators Hydro Environmental Availability Index (IDHA and Hydro Environmental Drought Index (ISHA were calculated to determine their trend and the consequent BHE, an innovative quantification of wáter deficit, which is proposed in this paper. The máximum value of BHE (10 units, indicating prevalence of drought, is observed from February to June in almost the entire state.

  15. Chemical thermodynamics of the system Cs--U--Zr--H--I--O in the light water reactor fuel-cladding gap

    Energy Technology Data Exchange (ETDEWEB)

    Besmann, T.M.; Lindemer, T.B.

    1978-10-01

    Equilibrium thermodynamic calculations were performed on the Cs-U-Zr-H-I-O system that is assumed to exist in the fuel-cladding gap of light water reactor fuel under in-reactor, steam, and 50% steam--50% air conditions. The in-reactor oxygen potential is assumed to be controlled by either UO/sub 2+x/ + Cs/sub 2/UO/sub 4/ or Zr + ZrO/sub 2/. The important condensed phases in-reactor are UO/sub 2+x/, Cs/sub 2/UO/sub 4/, and CsI, and the major gaseous species are Cs, Cs/sub 2/, CsI, and Cs/sub 2/I/sub 2/. The presence of steam does not alter these species, although CsOH also becomes a major gaseous species. In a 50% steam--50% air mixture, the equilibrium condensed phases are U/sub 3/O/sub 8/ or UO/sub 3/ and Cs/sub 2/U/sub 15/O/sub 46/. Under a nonequilibrium situation where zirconium metal can react with iodine, ZrO/sub 3/ or liquid ZrI/sub 2/ is present, and the gaseous species ZrI/sub 3/ and ZrI/sub 4/ have large partial pressures.

  16. Differential growth responses to water balance of coexisting deciduous tree species are linked to wood density in a Bolivian tropical dry forest.

    Science.gov (United States)

    Mendivelso, Hooz A; Camarero, J Julio; Royo Obregón, Oriol; Gutiérrez, Emilia; Toledo, Marisol

    2013-01-01

    A seasonal period of water deficit characterizes tropical dry forests (TDFs). There, sympatric tree species exhibit a diversity of growth rates, functional traits, and responses to drought, suggesting that each species may possess different strategies to grow under different conditions of water availability. The evaluation of the long-term growth responses to changes in the soil water balance should provide an understanding of how and when coexisting tree species respond to water deficit in TDFs. Furthermore, such differential growth responses may be linked to functional traits related to water storage and conductance. We used dendrochronology and climate data to retrospectively assess how the radial growth of seven coexisting deciduous tree species responded to the seasonal soil water balance in a Bolivian TDF. Linear mixed-effects models were used to quantify the relationships between basal area increment and seasonal water balance. We related these relationships with wood density and sapwood production to assess if they affect the growth responses to climate. The growth of all species responded positively to water balance during the wet season, but such responses differed among species as a function of their wood density. For instance, species with a strong growth response to water availability averaged a low wood density which may facilitate the storage of water in the stem. By contrast, species with very dense wood were those whose growth was less sensitive to water availability. Coexisting tree species thus show differential growth responses to changes in soil water balance during the wet season. Our findings also provide a link between wood density, a trait related to the ability of trees to store water in the stem, and wood formation in response to water availability.

  17. Differential growth responses to water balance of coexisting deciduous tree species are linked to wood density in a Bolivian tropical dry forest.

    Directory of Open Access Journals (Sweden)

    Hooz A Mendivelso

    Full Text Available A seasonal period of water deficit characterizes tropical dry forests (TDFs. There, sympatric tree species exhibit a diversity of growth rates, functional traits, and responses to drought, suggesting that each species may possess different strategies to grow under different conditions of water availability. The evaluation of the long-term growth responses to changes in the soil water balance should provide an understanding of how and when coexisting tree species respond to water deficit in TDFs. Furthermore, such differential growth responses may be linked to functional traits related to water storage and conductance. We used dendrochronology and climate data to retrospectively assess how the radial growth of seven coexisting deciduous tree species responded to the seasonal soil water balance in a Bolivian TDF. Linear mixed-effects models were used to quantify the relationships between basal area increment and seasonal water balance. We related these relationships with wood density and sapwood production to assess if they affect the growth responses to climate. The growth of all species responded positively to water balance during the wet season, but such responses differed among species as a function of their wood density. For instance, species with a strong growth response to water availability averaged a low wood density which may facilitate the storage of water in the stem. By contrast, species with very dense wood were those whose growth was less sensitive to water availability. Coexisting tree species thus show differential growth responses to changes in soil water balance during the wet season. Our findings also provide a link between wood density, a trait related to the ability of trees to store water in the stem, and wood formation in response to water availability.

  18. Human cell toxicogenomic analysis linking reactive oxygen species to the toxicity of monohaloacetic acid drinking water disinfection byproducts.

    Science.gov (United States)

    Pals, Justin; Attene-Ramos, Matias S; Xia, Menghang; Wagner, Elizabeth D; Plewa, Michael J

    2013-01-01

    Chronic exposure to drinking water disinfection byproducts has been linked to adverse health risks. The monohaloacetic acids (monoHAAs) are generated as byproducts during the disinfection of drinking water and are cytotoxic, genotoxic, mutagenic, and teratogenic. Iodoacetic acid toxicity was mitigated by antioxidants, suggesting the involvement of oxidative stress. Other monoHAAs may share a similar mode of action. Each monoHAA generated a significant concentration-response increase in the expression of a β-lactamase reporter under the control of the antioxidant response element (ARE). The monoHAAs generated oxidative stress with a rank order of iodoacetic acid (IAA) > bromoacetic acid (BAA) ≫ chloroacetic acid (CAA); this rank order was observed with other toxicological end points. Toxicogenomic analysis was conducted with a nontransformed human intestinal epithelial cell line (FHs 74 Int). Exposure to the monoHAAs altered the transcription levels of multiple oxidative stress responsive genes, indicating that each exposure generated oxidative stress. The transcriptome profiles showed an increase in thioredoxin reductase 1 (TXNRD1) and sulfiredoxin (SRXN1), suggesting peroxiredoxin proteins had been oxidized during monoHAA exposures. Three possible sources of reactive oxygen species were identified, the hypohalous acid generating peroxidase enzymes lactoperoxidase (LPO) and myeloperoxidase (MPO), nicotinamide adenine dinucleotide phosphate (NADPH)-dependent oxidase 5 (NOX5), and PTGS2 (COX-2) mediated arachidonic acid metabolism. Each monoHAA exposure caused an increase in COX-2 mRNA levels. These data provide a functional association between monoHAA exposure and adverse health outcomes such as oxidative stress, inflammation, and cancer.

  19. Critical body residues linked to octanol-water partitioning, organism composition, and LC50 QSARs: meta-analysis and model.

    Science.gov (United States)

    Hendriks, A Jan; Traas, Theo P; Huijbregts, Mark A J

    2005-05-01

    To protect thousands of species from thousands of chemicals released in the environment, various risk assessment tools have been developed. Here, we link quantitative structure-activity relationships (QSARs) for response concentrations in water (LC50) to critical concentrations in organisms (C50) by a model for accumulation in lipid or non-lipid phases versus water Kpw. The model indicates that affinity for neutral body components such as storage fat yields steep Kpw-Kow relationships, whereas slopes for accumulation in polar phases such as proteins are gentle. This pattern is confirmed by LC50 QSARs for different modes of action, such as neutral versus polar narcotics and organochlorine versus organophosphor insecticides. LC50 QSARs were all between 0.00002 and 0.2Kow(-1). After calibrating the model with the intercepts and, for the first time also, with the slopes of the LC50 QSARs, critical concentrations in organisms C50 are calculated and compared to an independent validation data set. About 60% of the variability in lethal body burdens C50 is explained by the model. Explanations for differences between estimated and measured levels for 11 modes of action are discussed. In particular, relationships between the critical concentrations in organisms C50 and chemical (Kow) or species (lipid content) characteristics are specified and tested. The analysis combines different models proposed before and provides a substantial extension of the data set in comparison to previous work. Moreover, the concept is applied to species (e.g., plants, lean animals) and substances (e.g., specific modes of action) that were scarcely studied quantitatively so far.

  20. The Optimal Gap between Small Gear's Addendum and Crescent Shaped Link of the Internal Involute Gear Pump%内啮合渐开线齿轮泵小齿轮齿顶与月牙板间的间隙优化

    Institute of Scientific and Technical Information of China (English)

    吴军强; 廖敏

    2011-01-01

    介绍内啮合渐开线齿轮泵的结构原理,从减小功率损失的角度出发,利用最优化设计理论、径向间隙泄漏理论和缝隙流量理论对内啮合渐开线齿轮泵小齿轮齿顶与月牙板间的间隙进行优化研究,推导出间隙优化模型,并求出最佳间隙解.%The structure and principle of internal involute gear pump were introduced. In purpose of reducing the power loss, the optimal gap between small gear's addendum and crescent shaped link of the internal involute gear pump was researched, by using the optimization theory and method, the radial gap leakage theory and the gap flow theory. The mathematical model of the optimal gap was concluded, and the optimal gap was calculated.

  1. Modulation of proton transfer in the water wire of dioxolane-linked gramicidin channels by lipid membranes.

    Science.gov (United States)

    de Godoy, C M; Cukierman, S

    2001-09-01

    Proton conductance (g(H)) in single SS stereoisomers of dioxolane-linked gramicidin A (gA) channels were measured in different phospholipid bilayers at different HCl concentrations. In particular, measurements were obtained in bilayers made of 1,2-diphytanoyl 3-phosphocholine (DiPhPC) or its ethylated derivative 1,2-diphytanoyl 3-ethyl-phosphocholine (et-DiPhPC,). The difference between these phospholipids is that in et-DiPhPC one of the phosphate oxygens is covalently linked to an ethyl group and cannot be protonated. In relatively dilute acid solutions, g(H) in DiPhPC is significantly higher than in et-DiPhPC. At high acid concentrations, g(H) is the same in both diphytanoyl bilayers. Such differences in g(H) can be accounted for by surface charge effects at the membrane/solution interfaces. In the linear portion of the log g(H)-log [H] relationship, g(H) values in diphytanoyl bilayers were significantly larger (approximately 10-fold) than in neutral glyceryl monooleate (GMO) membranes. The slopes of the linear log-log relationships between g(H) and [H] in diphytanoyl and GMO bilayers are essentially the same (approximately 0.76). This slope is significantly lower than the slope of the log-log plot of proton conductivity versus proton concentration in aqueous solutions (approximately 1.00). Because the chemical composition of the membrane-channel/solution interface is strikingly different in GMO and diphytanoyl bilayers, the reduced slope in g(H)-[HCl] relationships may be a characteristic of proton transfer in the water wire inside the SS channel. Values of g(H) in diphytanoyl bilayers were also significantly larger than in membranes made of the more common biological phospholipids 1-palmitoyl 2-oleoyl phosphocholine (POPC) or 1-palmitoyl 2-oleoyl phosphoethanolamine (POPE). These differences, however, cannot be accounted for by different surface charge effects or by different internal dipole potentials. On the other hand, maximum g(H) measured in the SS channel

  2. The association between fluoride in drinking water and dental caries in Danish children. Linking data from health registers, environmental registers and administrative registers

    DEFF Research Database (Denmark)

    Kirkeskov, Lilli; Kristiansen, Eva; Bøggild, Henrik

    2010-01-01

    Kirkeskov L, Kristiansen E, Bøggild H, von Platen-Hallermund F, Sckerl H, Carlsen A, Larsen MJ, Poulsen S. The association between fluoride in drinking water and dental caries in Danish children. Linking data from health registers, environmental registers and administrative registers. Community...... Dent Oral Epidemiol 2010. (c) 2010 John Wiley & Sons A/S Abstract - Objectives: To study the association between fluoride concentration in drinking water and dental caries in Danish children. Methods: The study linked registry data on fluoride concentration in drinking water over a 10-year period...... with data on dental caries from the Danish National Board of Health database on child dental health for 5-year-old children born in 1989 and 1999, and for 15-year-old children born in 1979 and 1989. The number of children included in the cohorts varied between 41.000 and 48.000. Logistic regression was used...

  3. Ultraviolet-B radiation induced cross-linking improves physical properties of cold- and warm-water fish gelatin gels and films.

    Science.gov (United States)

    Otoni, Caio G; Avena-Bustillos, Roberto J; Chiou, Bor-Sen; Bilbao-Sainz, Cristina; Bechtel, Peter J; McHugh, Tara H

    2012-09-01

    Cold- and warm-water fish gelatin granules were exposed to ultraviolet-B radiation for doses up to 29.7 J/cm(2). Solutions and films were prepared from the granules. Gel electrophoresis and refractive index were used to examine changes in molecular weight of the samples. Also, the gel strength and rheological properties of the solutions as well as the tensile and water vapor barrier properties of the films were characterized. SDS-PAGE and refractive index results indicated cross-linking of gelatin chains after exposure to radiation. Interestingly, UV-B treated samples displayed higher gel strengths, with cold- and warm-water fish gelatin having gel strength increases from 1.39 to 2.11 N and from 7.15 to 8.34 N, respectively. In addition, both gelatin samples exhibited an increase in viscosity for higher UV doses. For gelatin films, the cold-water fish gelatin samples made from irradiated granules showed greater tensile strength. In comparison, the warm-water gelatin films made from irradiated granules had lower tensile strength, but better water vapor barrier properties. This might be due to the UV induced cross-linking in warm-water gelatin that disrupted helical structures.

  4. Spatial and temporal allocation of ship exhaust emissions in Australian coastal waters using AIS data: Analysis and treatment of data gaps

    Science.gov (United States)

    Goldsworthy, Brett

    2017-08-01

    Ship exhaust emissions need to be allocated accurately in both space and time in order to examine many of the associated impacts, including on air quality and health. Data on ship activity from the Automatic Identification System (AIS) allow ship exhaust emissions to be calculated with fine spatial and temporal resolution. However, there are spatial gaps in the coverage afforded by the coastal network of ground stations that are used to collect the AIS data. This paper focuses on the problem of allocating emissions to the coastal gap regions. Allocating emissions to these regions involves generating interpolated ship tracks that both span the gaps and avoid coming too close to land. In most cases, a simple shortest path or straight line interpolation produces tracks that do not overlap or come too close to land. Where the simple method does not produce acceptable results, vessel tracks are steered around land on shortest available paths using a combination of visibility graphs and Dijkstra's algorithm. A geographical cluster analysis is first used to identify the boundary regions of the data gaps. The properties of the data gaps are summarised in terms of the length, duration and speed of the spanning tracks. The interpolation methods are used to improve the spatial distribution of emissions. It is also shown that emissions in the gap regions can contribute substantially to the total ship exhaust emissions in close proximity to highly populated areas.

  5. Going against the flow: A critical analysis of virtual water trade in the context of India's National River Linking Programme

    NARCIS (Netherlands)

    Verma, Shilp; Kampman, Doeke A.; Zaag, van der Pieter; Hoekstra, Arjen Y.

    2007-01-01

    Virtual water trade has been promoted as a tool to address national and regional water scarcity. In the context of international (food) trade, this concept has been applied with a view to optimize the flow of commodities considering the water endowments of nations. The concept states that water-rich

  6. Targeting and valuing conservation investments in support of a water fund: linking upstream land management with downstream services in the Upper Tana catchment, Kenya

    Science.gov (United States)

    Bryant, B. P.; Droogers, P.; Hunink, J.; Vogl, A.; Wolny, S.

    2014-12-01

    We apply an integrated modeling framework to both target and value watershed management interventions in the Upper Tana watershed, which provides municipal water, irrigation water, and hydropower services to Nairobi and surrounding areas. The analysis begins by applying an index model approach that incorporates existing land use and land surface characteristics to prioritize the type and location of conservation investments in different subbasins, subject to budget constraints and stakeholder concerns (Resource Investment Optimization System -- RIOS). We then run the Soil and Water Assessment Tool (SWAT) using the RIOS-identified investment scenarios to produce spatially explicit scenarios that simulate changes in water yield and suspended sediment. Finally, we link those biophysical outputs to monetary and non-monetary human well-being metrics for multiple benefit streams, including: Reduced water treatment costs, increased hydropower production, and crop yield benefits for upstream farmers in the conservation area. The viability of a payment for watershed services scheme is discussed, with attention to the various components of value assessed and to dependencies on water management approaches. While other studies have examined links between land use and the provision of hydrologic services, this study is novel in that it presents an integrated analysis that targets interventions in a decision context and then relies on calibrated, process-based, biophysical models to demonstrate the return on those investments considering multiple (and sometimes competing) hydrological services, doing so at a sub-annual time-scale.

  7. Gap between active and passive solar heating

    Energy Technology Data Exchange (ETDEWEB)

    Balcomb, J.D.

    1985-01-01

    The gap between active and passive solar could hardly be wider. The reasons for this are discussed and advantages to narrowing the gap are analyzed. Ten years of experience in both active and passive systems are reviewed, including costs, frequent problems, performance prediction, performance modeling, monitoring, and cooling concerns. Trends are analyzed, both for solar space heating and for service water heating. A tendency for the active and passive technologies to be converging is observed. Several recommendations for narrowing the gap are presented.

  8. Gap-filling of dry weather flow rate and water quality measurements in urban catchments by a time series modelling approach

    DEFF Research Database (Denmark)

    Sandoval, Santiago; Vezzaro, Luca; Bertrand-Krajewski, Jean-Luc

    2016-01-01

    seeks to evaluate the potential of the Singular Spectrum Analysis (SSA), a time-series modelling/gap-filling method, to complete dry weather time series. The SSA method is tested by reconstructing 1000 artificial discontinuous time series, randomly generated from real flow rate and total suspended...... solids (TSS) online measurements (year 2007, 2 minutes time-step, combined system, Ecully, Lyon, France). Results show up the potential of the method to fill gaps longer than 0.5 days, especially between 0.5 days and 1 day (mean NSE > 0.6) in the flow rate time series. TSS results still perform very...

  9. Divergent NEE balances from manual-chamber CO2 fluxes linked to different measurement and gap-filling strategies: A source for uncertainty of estimated terrestrial C sources and sinks?

    DEFF Research Database (Denmark)

    Huth, Vytas; Vaidya, Shrijana; Hoffmann, Mathias

    2017-01-01

    Manual closed-chamber measurements are commonly used to quantify annual net CO2 ecosystem exchange (NEE) in a wide range of terrestrial ecosystems. However, differences in both the acquisition and gap filling of manual closed-chamber data are large in the existing literature, complicating inter......-study comparisons and meta analyses. The aim of this study was to compare common approaches for quantifying CO2 exchange at three methodological levels. (1) The first level included two different CO2 flux measurement methods: one via measurements during mid-day applying net coverages (mid-day approach) and one via...... of the agricultural field diverged strongly (–200 to 425 g CO2-C m−2). NEE balances were most similar to previous studies when derived from sunrise measurements and indirect GPP modeling. Overall, the large variation in NEE balances resulting from different data-acquisition or gap-filling strategies indicates...

  10. Towards more spatially explicit assessments of virtual water flows: linking local water use and scarcity to global demand of Brazilian farming commodities

    Science.gov (United States)

    Flach, Rafaela; Ran, Ylva; Godar, Javier; Karlberg, Louise; Suavet, Clement

    2016-07-01

    Global consumption of farming commodities is an important driver of water demand in regions of production. This is the case in Brazil, which has emerged as one of the main producers of globally traded farming commodities. Traditional methods to assess environmental implications of this demand rely on international trade material flows at country resolution; we argue for the need of finer scales that capture spatial heterogeneity in environmental variables in the regions of production, and that account for differential sourcing within the borders of a country of production. To illustrate this, we obtain virtual water flows from Brazilian municipalities to countries of consumption, by allocating high-resolution water footprints of sugarcane and soy production to spatially-explicit material trade flows. We found that this approach results in differences of virtual water use estimations of over 20% when compared to approaches that disregard spatial heterogeneity in sourcing patterns, for three of the main consumers of the analysed crops. This discrepancy against methods using national resolution in trade flows is determined by national heterogeneity in water resources, and differential sourcing. To illustrate the practical implications of this approach, we relate virtual water flows to water stress, identifying where global demand for water coincides with high levels of water stress. For instance, the virtual water flows for Brazilian sugarcane sourced by China were disproportionally less associated to areas with higher water stress when compared to those of the EU, due to EU’s much higher reliance on sugarcane from water scarce areas in Northeast Brazil. Our findings indicate that the policy relevance of current assessments of virtual water flows that rely on trade data aggregated at the national level may be hampered, as they do not capture the spatial heterogeneity in water resources, water use and water management options.

  11. Propensity to Click on Suspicious Links

    DEFF Research Database (Denmark)

    Sudzina, Frantisek; Pavlicek, Antonin

    2017-01-01

    There already exists a certain, not huge, body of knowledge about impact of personality traits on susceptibility to phishing. But there is a gap when it comes specifically to phishing with links pretending to lead to deal sites. The paper analyzes if gender, age and personality traits influence.......1. Openness to experience was linked positively linked to responsible behavior, narcissism was negatively linked....

  12. School Segregation and Racial Academic Achievement Gaps

    Directory of Open Access Journals (Sweden)

    Sean F. Reardon

    2016-09-01

    Full Text Available Although it is clear that racial segregation is linked to academic achievement gaps, the mechanisms underlying this link have been debated since James Coleman published his eponymous 1966 report. In this paper, I examine sixteen distinct measures of segregation to determine which is most strongly associated with academic achievement gaps. I find clear evidence that one aspect of segregation in particular—the disparity in average school poverty rates between white and black students’ schools—is consistently the single most powerful correlate of achievement gaps, a pattern that holds in both bivariate and multivariate analyses. This implies that high-poverty schools are, on average, much less effective than lower-poverty schools and suggests that strategies that reduce the differential exposure of black, Hispanic, and white students to poor schoolmates may lead to meaningful reductions in academic achievement gaps.

  13. River basins as social-ecological systems: linking levels of societal and ecosystem water metabolism in a semiarid watershed

    Directory of Open Access Journals (Sweden)

    Violeta Cabello

    2015-09-01

    Full Text Available River basin modeling under complexity requires analytical frameworks capable of dealing with the multiple scales and dimensions of environmental problems as well as uncertainty in the evolution of social systems. Conceptual and methodological developments can now be framed using the wide socio-eco-hydrological approach. We add hierarchy theory into the mix to discuss the conceptualization of river basins as complex, holarchic social-ecological systems. We operationalize the social-ecological systems water metabolism framework in a semiarid watershed in Spain, and add the governance dimension that shapes human-environment reciprocity. To this purpose, we integrate an eco-hydrological model with the societal metabolism accounting scheme for land use, human activity, and water use. We explore four types of interactions: between societal organization and water uses/demands, between ecosystem organization and their water requirements/supplies, between societal metabolism and aquatic ecosystem health, and between water demand and availability. Our results reveal a metabolic pattern of a high mountain rural system striving to face exodus and agricultural land abandonment with a multifunctional economy. Centuries of social-ecological evolution shaping waterscapes through traditional water management practices have influenced the eco-hydrological functioning of the basin, enabling adaptation to aridity. We found a marked spatial gradient on water supply, use pattern, and impact on water bodies from the head to the mouth of the basin. Management challenges posed by the European water regulatory framework as a new driver of social-ecological change are highlighted.

  14. Links between purchase location and stable isotope ratios of bottled water, soda, and beer in the United States.

    Science.gov (United States)

    Chesson, Lesley A; Valenzuela, Luciano O; O'Grady, Shannon P; Cerling, Thure E; Ehleringer, James R

    2010-06-23

    This study investigated the impact of purchase location on the stable isotope ratios of beverages by measuring the delta(2)H and delta(18)O values of bottled water, soda, beer, and tap water collected across the contiguous United States. Measured beverage delta(2)H and delta(18)O values generally fit the Global Meteoric Water Line (GMWL), suggesting region-of-origin information is recorded in beverage water. Tap water delta(2)H and delta(18)O values were strongly correlated with the stable isotope ratios of bottled water and soda purchased in the same location. Beer water delta(2)H and delta(18)O values were also correlated with tap water, although not as strongly. Variability in delta(2)H and delta(18)O values among beverages purchased at a single location ranged from 2 to 41 per thousand and from 0.3 to 5.2 per thousand, respectively, but was generally moderate in most locations. It was concluded that the isotopic composition of local tap water is a reasonable proxy for consumers' fluid intake in most U.S. cities.

  15. Columbia River Component Data Gap Analysis

    Energy Technology Data Exchange (ETDEWEB)

    L. C. Hulstrom

    2007-10-23

    This Data Gap Analysis report documents the results of a study conducted by Washington Closure Hanford (WCH) to compile and reivew the currently available surface water and sediment data for the Columbia River near and downstream of the Hanford Site. This Data Gap Analysis study was conducted to review the adequacy of the existing surface water and sediment data set from the Columbia River, with specific reference to the use of the data in future site characterization and screening level risk assessments.

  16. Gains from trans-boundary water quality management in linked catchment and coastal socio-ecological systems: a case study for the Minho region

    Science.gov (United States)

    Roebeling, P. C.; Brito, A. G.; Rocha, J.; Alves, H.; Mamede, J.

    2012-04-01

    Worldwide, aquatic and coastal ecosystems are affected by point and diffuse source water pollution originating from rural, urban and industrial land uses in catchments, even though these ecosystems are of vital importance from an environmental and economic perspective. Integrated Catchment and Coastal Zone Management (ICCZM) specifically takes into account this inherent relationship between terrestrial land use, surface and ground water pollution, aquatic and coastal ecosystem state, and associated environmental values. To warrant sustainable regional economic development, we need to balance the marginal costs from terrestrial water pollution abatement and the associated marginal benefits from aquatic and coastal resource appreciation. In doing so, however, we need to differentiate between intra- and trans-boundary catchments because benefactors and beneficiaries from water quality improvement are not one and the same. In trans-boundary catchments, private (national) welfare maximizing rates of water quality improvement differ across nations as benefits from water quality improvement generally accrue to one nation while the costs are paid by multiple nations. While approaches for water quality management in linked catchment and coastal socio-ecological systems are fairly recent though existent, water quality management in trans-boundary catchments poses additional challenges. The objective of this paper is to develop and apply a deterministic optimal control approach that allows us to explore private and social welfare maximizing rates of water pollution abatement in linked catchment and coastal socio-ecological systems. For a case study of the Minho region in the Iberian Peninsula, we estimate nation-specific water pollution abatement cost (based on management practice adoption) and benefit (based on aquatic and coastal environmental values) functions, to determine as well as compare private (national) and social (trans-national) welfare maximizing rates of water

  17. Gap junction intercellular communication and benzene toxicity.

    Science.gov (United States)

    Rivedal, Edgar; Witz, Gisela; Leithe, Edward

    2010-03-19

    Aberrant regulation of gap junction intercellular communication (GJIC) has been linked to several human diseases, including cancer and abnormal hematopoietic development. Benzene exposure has been shown to cause hematotoxicity and leukemia, but the underlying mechanisms involved remain unclear. We have observed that several metabolites of benzene have the ability to block gap junction intercellular communication. The ring-opened trans,trans-muconaldehyde (MUC) was found to be the most potent inhibitor of gap junction channels. MUC was found to induce cross-linking of the gap junction protein connexin43, which seemed to be responsible for the induced inhibition of GJIC. Glutaraldehyde, which has a similar molecular structure as MUC, was found to possess similar effects on gap junctions as MUC, while the mono-aldehyde formaldehyde shows lower potency, both as a connexin cross-linker, and as an inhibitor of GJIC. Both glutaraldehyde and formaldehyde have previously been associated with induction of leukemia and disturbance of hematopoiesis. Taken together, the data support a possible link between the effect of MUC on gap junctions, and the toxic effects of benzene. Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.

  18. Chloride absorption in salt-sensitive Carrizo citrange and salt-tolerant Cleopatra mandarin citrus rootstocks is linked to water use.

    Science.gov (United States)

    Moya, José Luís; Gómez-Cadenas, Aurelio; Primo-Millo, Eduardo; Talon, Manuel

    2003-02-01

    In this work, seedlings of two citrus rootstocks, the salt-tolerant Cleopatra mandarin (Citrus reshni Hort. ex Tan.) and the salt-sensitive Carrizo citrange (Citrus sinensis [L.] Osb. x Poncirus trifoliata [L.] Raf.) were used to study the relationship between chloride and water uptake. The results indicated that net chloride uptake rates in both genotypes were alike and decreased linearly with the time of salinity exposure, although they were more rapidly reduced in the tolerant genotype. In each rootstock, chloride uptake rates paralleled the decreases in transpiration rates. When transpiration was modified, concomitant changes in leaf Cl(-) concentrations were observed. There was a high positive correlation between total chloride content per plant and total water absorbed. In addition, the data indicate that the tolerant genotype "excluded" more chloride, i.e. it absorbed lower amounts of chloride per volume of water. Cleopatra also possessed a less efficient root system for water uptake and a higher shoot-to-root ratio. The results show that, overall, chloride absorption is linked to water use and that further tolerance in Cleopatra is mostly conferred by superior root resistance to Cl(-) uptake. Therefore, it is proposed that chloride absorption and, hence, salt tolerance in citrus depends to a great extent upon water use.

  19. Predictive Time Series Analysis Linking Bengal Cholera with Terrestrial Water Storage Measured from Gravity Recovery and Climate Experiment Sensors

    Science.gov (United States)

    Jutla, Antarpreet; Akanda, Ali; Unnikrishnan, Avinash; Huq, Anwar; Colwell, Rita

    2015-01-01

    Outbreaks of diarrheal diseases, including cholera, are related to floods and droughts in regions where water and sanitation infrastructure are inadequate or insufficient. However, availability of data on water scarcity and abundance in transnational basins, are a prerequisite for developing cholera forecasting systems. With more than a decade of terrestrial water storage (TWS) data from the Gravity Recovery and Climate Experiment, conditions favorable for predicting cholera occurrence may now be determined. We explored lead–lag relationships between TWS in the Ganges–Brahmaputra–Meghna basin and endemic cholera in Bangladesh. Since bimodal seasonal peaks in cholera in Bangladesh occur during spring and autumn seasons, two separate logistical models between TWS and disease time series (2002–2010) were developed. TWS representing water availability showed an asymmetrical, strong association with cholera prevalence in the spring (τ = −0.53; P < 0.001) and autumn (τ = 0.45; P < 0.001) up to 6 months in advance. One unit (centimeter of water) decrease in water availability in the basin increased odds of above normal cholera by 24% (confidence interval [CI] = 20–31%; P < 0.05) in the spring, while an increase in regional water by 1 unit, through floods, increased odds of above average cholera in the autumn by 29% (CI = 22–33%; P < 0.05). PMID:26526921

  20. An approach to link water resource management with landscape art to enhance its aesthetic appeal, ecological utility and social benefits

    Science.gov (United States)

    Mukherjee, Anita; Sen, Somnath; Paul, Saikat Kumar

    2017-04-01

    Landscape art or land art is the discourse of scientific application of artistic skill to integrate man-made structures with the natural landscape for planning, design, management, preservation and rehabilitation of natural and built environment. It does beautification of the landscape enhancing its utility for habitats. Availability of water with acceptable quality is crucial for economic growth, social peace and equality and of course for environmental sustainability. Development of new and growth of existing urban and suburban units are obvious. It postulates the increase of population density and percent of the impervious area in an urban unit. The demand for water is increasing with progressive concentration of population, the volume and velocity of surface runoff increase and the travel time decreases. At the same time, an increase in the volume of gray water not only contaminate water bodies, it also reduces the quantity of available freshwater transforming a portion of blue and green water to gray one and would intensify the pressure on water resources of the area. Therefore, to meet the incremental pressure of demand for and pollution of water collection, treatment and reuse of wastewater, both sewage and storm water, are on the requirement to improve urban water security. People must be concerned not to stifle urban lives with concrete; rather must provide all basic amenities for achieving a higher standard of life than the previous one with the essence of natural green spaces. The objective of the study is to propose a conceptual design and planning guidelines for developing urban and suburban drainage network and reuse of surface runoff and sewage water utilizing less used natural water bodies, such as paleo-channels or lakes or moribund channels as retention or detention basin. In addition to wastewater management, the proposal serves to promote the aesthetics of environmental engagement, ecological utility and restoration of moribund channels

  1. Scandinavian links

    DEFF Research Database (Denmark)

    Matthiessen, Christian Wichmann; Knowles, Richard D.

    2014-01-01

    centres, one joins more thinly populated regions, and the last one links peripheral areas. Two of them (The Great Belt Link and the Oresund Link) have been constructed and are in full operation. The third (the Fehmarnbelt Link) has been decided 2008 on bilateral government level. The three links...

  2. Water use by black wattle (Acacia mearnsii): implications for the link between removal of invading trees and catchment streamflow response

    CSIR Research Space (South Africa)

    Dye, P

    2004-01-01

    Full Text Available This paper reviews relevant available information on rates of total evaporation from black waffle and from grasslands and fynbos shrublands. These data provide an indication of the likely change in catchment water yield following invasion...

  3. Evaluation of CDOM sources and their links with water quality in the lakes of Northeast China using fluorescence spectroscopy

    Science.gov (United States)

    Zhao, Ying; Song, Kaishan; Wen, Zhidan; Fang, Chong; Shang, Yingxin; Lv, Lili

    2017-07-01

    The spatial distributions of the fluorescence intensities Fmax for chromophoric dissolved organic matter (CDOM) components, the fluorescence indices (FI370 and FI310) and their correlations with water quality of 19 lakes in the Songhua River Basin (SHRB) across semiarid regions of Northeast China were examined with the data collected in September 2012 and 2015. The 19 lakes were divided into two groups according to EC (threshold value = 800 μS cm-1): fresh water (N = 13) and brackish water lakes (N = 6). The fluorescent characteristics of CDOM in the 19 lakes were investigated using excitation-emission matrix fluorescence spectroscopy (EEM) coupled with parallel factor (PARAFAC) and multivariate analysis. Two humic-like components (C1 and C3), one tryptophan-like component (C2), and one tyrosine-like component (C4) were identified by PARAFAC. The component C4 was not included in subsequent analyses due to the strong scatter in some colloidal water samples from brackish water lakes. The correlations between Fmax for the three EEM-PARAFAC extracted CDOM components C1-C3, the fluorescence indices (FI370 and FI310) and the water quality parameters (i.e., TN, TP, Chl-a, pH, EC, turbidity (Turb) and dissolved organic carbon (DOC)) were determined by redundancy analysis (RDA). The results of RDA analysis showed that spatial variation in land cover, pollution sources, and salinity/EC gradients in water quality affected Fmax for the fluorescent components C1-C3 and the fluorescence indices (FI370 and FI310). Further examination indicated that the CDOM fluorescent components and the fluorescence indices (FI370 and FI310) did not significantly differ (t-test, p > 0.05) in fresh water (N = 13) and brackish water lakes (N = 6). There was a difference in the distribution of the average Fmax for the CDOM fluorescent components between C1 to C3 from agricultural sources and urban wastewater sources in hypereutrophic brackish water lakes. The Fmax for humic-like components C1 and

  4. Cholera outbreak linked with lack of safe water supply following a tropical cyclone in Pondicherry, India, 2012.

    Science.gov (United States)

    Fredrick, Tony; Ponnaiah, Manickam; Murhekar, Manoj V; Jayaraman, Yuvaraj; David, Joseph K; Vadivoo, Selvaraj; Joshua, Vasna

    2015-03-01

    In the aftermath of a severe cyclonic storm on 7 January 2012, a cluster of acute diarrhoea cases was reported from two localities in Pondicherry, Southern India. We investigated the outbreak to identify causes and recommend control measures. We defined a case as occurrence of diarrhoea of more than three loose stools per day with or without vomiting in a resident of affected areas during 6-18 January 2012. We used active (door-to-door survey) and stimulated passive (healthy facility-based) surveillance to identify cases. We described the outbreak by time, place, and person. We compared the case-patients with up to three controls without any apparent signs and symptoms of diarrhoea and matched for age, gender, and neighbourhood. We calculated matched odds ratio (MOR), 95% confidence intervals (CI), and population attributable fractions (PAF). We collected rectal swabs and water samples for laboratory diagnosis and tested water samples for microbiological quality. We identified 921 cases and one death among 8,367 residents (attack rate: 11%, case-fatality: 0.1%). The attack rate was the highest among persons of 50 years and above (14%) and females (12%). The outbreak started on 6 January and peaked on the 9th and lasted till 14 January. Cases were clustered around two major leakages in water supply system. Nine of the 16 stool samples yielded V. cholerae O1 Ogawa. We identified that consumption of water from the public distribution system (MOR=37, 95% CI 4.9-285, PAF: 97%), drinking unboiled water (MOR=35, 95% CI 4.5-269, PAF: 97%), and a common latrine used by two or more households (MOR=2.7, 95% CI 1.3-5.6) were independently associated with cholera. Epidemiological evidence suggested that this outbreak was due to ingestion of water contaminated by drainage following rains during cyclone. We recommended repair of the water supply lines, cleaning-up of the drains, handwashing, and drinking of boiled water.

  5. Assessing Links Between Water and Carbon Storage in Indonesian Peatlands Using Data from the Gravity Recovery and Climate Experiment

    Science.gov (United States)

    Swails, E.; Reager, J. T., II; Randerson, J. T.; Famiglietti, J. S.; Lawrence, D.; Yu, K.

    2014-12-01

    Deforestation and drainage of tropical peat swamp forests for conversion to other uses results in a loss of carbon storage through the clearing and burning of forest vegetation as well as decomposition of peat soils and increased frequency of fires following drainage. We used Gravity Recovery and Climate Experiment (GRACE) terrestrial water storage observations and a global forest cover change product to investigate trends in terrestrial water storage associated with land use conversion in Indonesian peatlands between 2002 and 2012. Our initial analysis indicated that secular trends in GRACE terrestrial water storage were consistent with the spatial distribution of peatlands drained for the establishment of oil palm plantations. A decreasing trend in GRACE terrestrial water storage measurements over the observation period indicated a substantial decrease in water table heights. Combining this information with measurements of bulk density and carbon content of surface peat layers, we estimated potential emissions from carbon stocks now vulnerable to oxidation. Independent measurements of fire carbon emissions were used to estimate the fraction of committed emission that was combusted. Our research represents the first known application of GRACE data to assess loss of soil carbon storage associated with depletion of soil water.

  6. The association between fluoride in drinking water and dental caries in Danish children. Linking data from health registers, environmental registers and administrative registers.

    Science.gov (United States)

    Kirkeskov, Lilli; Kristiansen, Eva; Bøggild, Henrik; von Platen-Hallermund, Frants; Sckerl, Halfdan; Carlsen, Anders; Larsen, M Joost; Poulsen, Sven

    2010-06-01

    To study the association between fluoride concentration in drinking water and dental caries in Danish children. The study linked registry data on fluoride concentration in drinking water over a 10-year period with data on dental caries from the Danish National Board of Health database on child dental health for 5-year-old children born in 1989 and 1999, and for 15-year-old children born in 1979 and 1989. The number of children included in the cohorts varied between 41.000 and 48.000. Logistic regression was used to assess the correlations, adjusting for gender and taxable family income as a proxy variable for socioeconomic status.   Fluoride concentration in drinking water varied considerably within the country from very low (Dental caries in both 5-year-olds and 15-year-olds decreased over the study period. An inverse relation between the risk of dental caries and fluoride concentration in drinking water was found in both primary and permanent teeth. The risk was reduced by approximately 20% already at the lowest level of fluoride exposure (0.125-0.25mg/l). At the highest level of fluoride exposure (>1 mg/l), a reduction of approximately 50% was found. Similar findings were found if analysis was limited to children residing in the same place during the entire study period. The study confirmed previous findings of an inverse relation between fluoride concentration in the drinking water and dental caries in children. This correlation was found in spite of the extensive use of fluoridated toothpaste and caries-preventive programs implemented by the municipal dental services in Denmark. Linking Danish health registers with environmental and administrative registers offers an opportunity for obtaining sample sizes large enough to identify health effect, which otherwise could not be identified. © 2010 John Wiley & Sons A/S.

  7. The link in Linking

    Science.gov (United States)

    Caldwell, Jane C; Chiale, Pablo A; Gonzalez, Mario D; Baranchuk, Adrian

    2013-01-01

    We present 2 cases of the slow-fast form of AVNRT with initially narrow QRS complexes followed by sudden unexpected transition to persistently wide QRS complexes due to aberrant intraventricular conduction. Introduction of a properly timed extrastimulus in one case and critical oscillations in cycle length due to short-long coupling in the second case set the stage for the initial bundle branch block. However, persistence of the aberrancy pattern once the initial event abated was maintained by the "linking" phenomenon. Delayed, retrograde concealed activation from the contralateral bundle branch perpetuated the initial bundle branch block. PMID:23840106

  8. Linking Plant Water-Use Efficiency and Depth of Water Uptake to Field­-Level Productivity Under Surplus and Deficit Irrigation in Almond Orchards

    Science.gov (United States)

    Seely, T.; Shackel, K.; Silva, L. C. R.

    2016-12-01

    The impact of water stress on depth of water uptake, as well as water­-use efficiency (WUE) at the tree-level and field-level was examined in almond orchards under varying degrees of deficit and surplus irrigation treatments. Three different orchards, spanning a latitudinal gradient (35° to 39° N) were sampled during two growing seasons in the central valley of CA. The orchards encompass a range of climatic and edaphic conditions, providing an opportunity for comparisons of WUE and orchard yield under contrasting environmental conditions. In each orchard, the control treatment received 100% replacement of water lost to evapotranspiration (ET), while the surplus treatment received 110% and the deficit treatment received 70% replenishment of ET, the latter simulating conditions of water stress. Preliminary results based on the analysis of carbon isotope ratios (δ13C) in leaves throughout the 2015 and 2016 growing seasons, reveal a significant change in WUE in all three orchard sites, increasing up to 20% on average in the deficit irrigation treatment relative to controls. In contrast, trees growing under surplus irrigation had the lowest WUE across all orchard sites. The difference in WUE between surplus irrigated trees and control irrigated trees within each orchard was not always statistically significant. These physiological responses to levels of water availability were not reflected in field-level orchard productivity, which was highly variable across orchard sites and treatments. Additionally, analysis of oxygen (δ18O) and hydrogen (δ2H) isotope ratios of stem, leaf, and soil water has been undertaken to determine the effect of water stress on the depth of root water uptake. The hypothesis that almond trees can effectively acclimate to water stress through higher WUE and deeper root water uptake compared to well-watered trees will be tested. This multi-scale, ecohydrological study will elucidate the impacts of drought on almond orchards, one of the most

  9. Linking the physical and the socio-economic compartments of an integrated water and land use management model on a river basin scale using an object-oriented water supply model

    Science.gov (United States)

    Barthel, Roland; Nickel, Darla; Meleg, Alejandro; Trifkovic, Aleksandar; Braun, Juergen

    Within the framework of the research project ‘GLOWA-Danube’, a model of the water supply sector has been developed. GLOWA-Danube investigates long-term changes in the water cycle of the Upper Danube river basin in light of global change. For this purpose, the decision support system DANUBIA, comprising 15 fully coupled models, has been developed. Within DANUBIA the water supply model (‘WaterSupply’) forms the link between various physical models determining water quality and availability and several socio-economic models determining water consumption and demand. Having a central focus on public drinking water supply, its purpose is to correctly simulate the present day system of water extraction and distribution and the related costs, but also to allow meaningful response to possible future changes of boundary conditions, first and foremost changes in water demand or water availability and quality. Response mechanisms are also envisioned for changes in political and economic boundary conditions, and advances in technology. The model will be used locate critical regions which could experience water stress in the future, but does not aim to find the appropriate solutions or to predict the optimal organisation of water supply in the Danube Basin under such changing conditions. In the object-oriented model structure, both water supply companies (WSC) and communities are represented by main classes. Both classes have a limited view and knowledge of their environment. A community knows where and how much water is consumed and from which WSC it is served. A WSC possesses information regarding extraction sites and water rights, raw water quality and potential collaborating WSC. The WSC can perform actions that are different from ‘business as usual’. These deviations from their usual behaviour can be interpreted by decision makers but should not be regarded as a replacement for the decision-making process itself. The model is conceptualised using object

  10. Towards smaller gap microbulks

    CERN Document Server

    Attié, D.; Dafni, T; Ferrer-Ribas, E.; Ferrer-Ribas, E; Ferry, S; Giomataris, Y; Herrera, D C; Iguaz, F J; Irastorza, I G; Kebbiri, M; Papaevangelou, T; de Oliveira, R; Seguí, L; Tomás, A

    2014-01-01

    Small gap Micromegas detectors ( < 50 μm) are expected to be optimal for high pressure applications. Combining the microbulk manufacturing technique with a small gap can result in attractive detectors for rare event detection, in particular double beta decay or dark matter searches. We present novel results obtained with small gap microbulks (25 and 12.5 μm) that have been manufactured recently. For the first time for this type of detectors, we show experimentally that for each amplification gap there is an optimal pressure and that smaller gaps are more suitable for higher pressures.

  11. Variations of DOM quality in inflows of a drinking water reservoir: linking of van Krevelen diagrams with EEMF spectra by rank correlation.

    Science.gov (United States)

    Herzsprung, Peter; von Tümpling, Wolf; Hertkorn, Norbert; Harir, Mourad; Büttner, Olaf; Bravidor, Jenny; Friese, Kurt; Schmitt-Kopplin, Philippe

    2012-05-15

    Elevated concentrations of dissolved organic matter (DOM) such as humic substances in raw water pose significant challenges during the processing of the commercial drinking water supplies. This is a relevant issue in Saxony, Central East Germany, and many other regions worldwide, where drinking water is produced from raw waters with noticeable presence of chromophoric DOM (CDOM), which is assumed to originate from forested watersheds in spring regions of the catchment area. For improved comprehension of DOM molecular composition, the seasonal and spatial variations of humic-like fluorescence and elemental formulas in the catchment area of the Muldenberg reservoir were recorded by excitation emission matrix fluorescence (EEMF) and ultrahigh-resolution mass spectrometry (FT-ICR-MS). The Spearman rank correlation was applied to link the EEMF intensities with exact molecular formulas and their corresponding relative mass peak abundances. Thereby, humic-like fluorescence could be allocated to the pool of oxygen-rich and relatively unsaturated components with stoichiometries similar to those of tannic acids, which are suspected to have a comparatively high disinfection byproduct formation potential associated with the chlorination of raw water. Analogous relationships were established for UV absorption at 254 nm (UV(254)) and dissolved organic carbon (DOC) and compared to the EEMF correlation.

  12. A reconsideration of the link between the energetics of water and of ATP hydrolysis energy in the power strokes of molecular motors in protein structures.

    Science.gov (United States)

    Widdas, Wilfred F

    2008-09-01

    Mechanical energy from oxygen metabolism by mammalian tissues has been studied since 1837. The production of heat by mechanical work was studied by Fick in about 1860. Prior to Fick's work, energetics were revised by Joule's experiments which founded the First Law of Thermodynamics. Fenn in 1923/24 found that frog muscle contractions generated extra heat proportional to the amount of work done in shortening the muscle. This was fully consistent with the Joule, Helmholtz concept used for the First Law of Thermodynamics. The link between the energetics of water and ATP hydrolysis in molecular motors is recommended for reconsideration.

  13. Linking climate projections to performance: A yield-based decision scaling assessment of a large urban water resources system

    Science.gov (United States)

    Turner, Sean W. D.; Marlow, David; Ekström, Marie; Rhodes, Bruce G.; Kularathna, Udaya; Jeffrey, Paul J.

    2014-04-01

    Despite a decade of research into climate change impacts on water resources, the scientific community has delivered relatively few practical methodological developments for integrating uncertainty into water resources system design. This paper presents an application of the "decision scaling" methodology for assessing climate change impacts on water resources system performance and asks how such an approach might inform planning decisions. The decision scaling method reverses the conventional ethos of climate impact assessment by first establishing the climate conditions that would compel planners to intervene. Climate model projections are introduced at the end of the process to characterize climate risk in such a way that avoids the process of propagating those projections through hydrological models. Here we simulated 1000 multisite synthetic monthly streamflow traces in a model of the Melbourne bulk supply system to test the sensitivity of system performance to variations in streamflow statistics. An empirical relation was derived to convert decision-critical flow statistics to climatic units, against which 138 alternative climate projections were plotted and compared. We defined the decision threshold in terms of a system yield metric constrained by multiple performance criteria. Our approach allows for fast and simple incorporation of demand forecast uncertainty and demonstrates the reach of the decision scaling method through successful execution in a large and complex water resources system. Scope for wider application in urban water resources planning is discussed.

  14. Ecological links between water storage behaviors and Aedes aegypti production: implications for dengue vector control in variable climates.

    Science.gov (United States)

    Padmanabha, H; Soto, E; Mosquera, M; Lord, C C; Lounibos, L P

    2010-08-01

    Understanding linkages between household behavior and Aedes aegypti (L.) larval ecology is essential for community-based dengue mitigation. Here we associate water storage behaviors with the rate of A. aegypti pupal production in three dengue-endemic Colombian cities with different mean temperatures. Qualitative, semi-structured interviews and pupal counts were conducted over a 7-15-day period in 235 households containing a water storage vessel infested with larvae. Emptying vessels more often than every 7 days strongly reduced pupal production in all three cities. Emptying every 7-15 days reduced production by a similar magnitude as emptying Barranquilla (29.0 degrees C). Lidding vessels reduced mosquito production and was most feasible in Barranquilla because of container structure. Vessel emptying strongly correlated with usage in Barranquilla, where many households stored water in case of interruptions in piped service rather than for regular use. In the cooler cities, >90% of households regularly used stored water for washing clothes, generating a weaker correlation between emptying and usage. Emptying was less frequent in the households surveyed in the dry season in all three cities. These results show that A. aegypti production and human behaviors are coupled in a temperature-dependent manner. In addition to biological effects on aquatic stages, climate change may impact A. aegypti production through human behavioral adaptations. Vector control programs should account for geographic variation in temperature and water usage behaviors in designing targeted interventions.

  15. Linking benthic hydrodynamics and cold-water coral occurrences: A high-resolution model study at three cold-water coral provinces in the NE Atlantic

    OpenAIRE

    2014-01-01

    Observations from numerous cold-water coral locations in the NE Atlantic show energetic near-bottom flow dynamics along the European continental margin at individual coral mounds and mound clusters. Dynamics are largely controlled by tide-topography interaction generating and enhancing periodic motions such as trapped waves, freely propagating internal tides and internal hydraulic jumps. In this study, linkages between key abiotic parameters and cold water coral occurrences are explored acros...

  16. Linking ground-water age and chemistry data along flow paths: Implications for trends and transformations of nitrate and pesticides

    Science.gov (United States)

    Tesoriero, Anthony J.; Saad, David A.; Burow, Karen R.; Frick, Elizabeth A.; Puckett, Larry J.; Barbash, Jack E.

    2007-10-01

    Tracer-based ground-water ages, along with the concentrations of pesticides, nitrogen species, and other redox-active constituents, were used to evaluate the trends and transformations of agricultural chemicals along flow paths in diverse hydrogeologic settings. A range of conditions affecting the transformation of nitrate and pesticides (e.g., thickness of unsaturated zone, redox conditions) was examined at study sites in Georgia, North Carolina, Wisconsin, and California. Deethylatrazine (DEA), a transformation product of atrazine, was typically present at concentrations higher than those of atrazine at study sites with thick unsaturated zones but not at sites with thin unsaturated zones. Furthermore, the fraction of atrazine plus DEA that was present as DEA did not increase as a function of ground-water age. These findings suggest that atrazine degradation occurs primarily in the unsaturated zone with little or no degradation in the saturated zone. Similar observations were also made for metolachlor and alachlor. The fraction of the initial nitrate concentration found as excess N 2 (N 2 derived from denitrification) increased with ground-water age only at the North Carolina site, where oxic conditions were generally limited to the top 5 m of saturated thickness. Historical trends in fluxes to ground water were evaluated by relating the times of recharge of ground-water samples, estimated using chlorofluorocarbon concentrations, with concentrations of the parent compound at the time of recharge, estimated by summing the molar concentrations of the parent compound and its transformation products in the age-dated sample. Using this approach, nitrate concentrations were estimated to have increased markedly from 1960 to the present at all study sites. Trends in concentrations of atrazine, metolachlor, alachlor, and their degradates were related to the timing of introduction and use of these compounds. Degradates, and to a lesser extent parent compounds, were detected

  17. Linking ecological sensitivity to hydrological information in perspective of flow-ecology compliance status and water management

    Science.gov (United States)

    Lathouri, Maria; Klaar, Megan; Hannah, David; Dunbar, Mike; Futter, Alison; England, Judy; Warren, Mark

    2016-04-01

    Increasing pressures and climate change effects on water resources suggest that we may need to re-consider flow regulations in the context of river ecological sensitivity to abstraction, and how this can be better integrated into flow standards. An increasing number of ecosystems have been identified as vulnerable to hydrological change. Different flow pressures, especially very low flows, can be can be very destructive to aquatic biodiversity. However, although this vulnerability is recognized, knowledge is lacking regarding the most ecologically sensitive regimes to hydrology and associated water stress and habitat disturbance. In addition, any interaction between hydromorphology and river ecology is still generally poorly understood - particularly in quantitative terms. To further understand the relationships between hydrology and ecology and to help us protect the long term future of the water environment for water resources management, the present study is focused on underpinning different aspects of flow pressures on ecology and establishing quantitative relationships between physicochemical factors, hydrological pressures and biological indicators. This includes carrying-out a review of existing typology approaches to grouping water bodies on the basis of similar ecological sensitivity to flow and therefore to evaluate the ecological impacts of the flow regime alterations. Explicitly generalised additive models are applied to demonstrate a relationship between ecology (macroinvertebrate) scores and flow pressure data, including geographical, geological and physical habitat conditions. This evidence base will to be used to further recommend ecologically appropriate flow regimes in rivers to help provide efficient flow management practices and support the classification of the ecological status under the Water Framework Directive.

  18. Effectiveness of Geoelectrical Resistivity Surveys for the Detection of a Debris Flow Causative Water Conducting Zone at KM 9, Gap-Fraser’s Hill Road (FT 148, Fraser’s Hill, Pahang, Malaysia

    Directory of Open Access Journals (Sweden)

    Mohamad Anuri Ghazali

    2013-01-01

    Full Text Available This study reports the findings of resistivity surveys which were conducted at the initiation area of debris flow at KM 9, Fraser’s Hill Gap road (FT148. The study involves three slope parallel survey lines and two lines perpendicular to the slope face. The parallel lines are FH01, FH02, and FH03, while the lines FH04 and FH05 are perpendicular. A granite body was detected at the central part of the east line and is nearest to the ground surface along FH02. The existence of low resistivity zones within the granite body is interpreted as highly fractured, water conducting zones. These zones are continuous as they have been detected in both the east-west as well as the north-south lines. The residual soil layer is relatively thin at zones where weathered granite dominates the slope face of the failure mass. The weak layer is relatively thick with an estimated thickness of 80 m and water flow occurs at the base of it. The high water flow recorded from the horizontal drains further supports the possible existence of these highly fractured, water conducting zones located within the granite. The shallow fractured granite is virtually “floating” above the water saturated zone and therefore is considered unstable.

  19. The links between global carbon, water and nutrient cycles in an urbanizing world — the case of coastal eutrophication

    NARCIS (Netherlands)

    Kroeze, C.; Hofstra, N.; Ivens, W.; Löhr, A.; Strokal, M.; Wijnen, van J.

    2013-01-01

    The natural cycles of carbon (C), nitrogen (N), phosphorus (P) and water have been disturbed substantially by human activities. Urbanizing coastal drainage basins and large river deltas are located at the interface of freshwater and coastal components of the larger earth system and the process of ur

  20. Exploring industry specific social welfare maximizing rates of water pollution abatement in linked terrestrial and marine ecosystems

    NARCIS (Netherlands)

    Roebeling, P.C.; Hendrix, E.M.T.; Grieken, van M.E.

    2009-01-01

    Marine ecosystems are severely affected by water pollution originating from coastal catchments, while these ecosystems are of vital importance from an environmental as well as an economic perspective. To warrant sustainable economic development of coastal regions, we need to balance the marginal

  1. Predictive Time Series Analysis Linking Bengal Cholera with Terrestrial Water Storage Measured from Gravity Recovery and Climate Experiment Sensors.

    Science.gov (United States)

    Jutla, Antarpreet; Akanda, Ali; Unnikrishnan, Avinash; Huq, Anwar; Colwell, Rita

    2015-12-01

    Outbreaks of diarrheal diseases, including cholera, are related to floods and droughts in regions where water and sanitation infrastructure are inadequate or insufficient. However, availability of data on water scarcity and abundance in transnational basins, are a prerequisite for developing cholera forecasting systems. With more than a decade of terrestrial water storage (TWS) data from the Gravity Recovery and Climate Experiment, conditions favorable for predicting cholera occurrence may now be determined. We explored lead-lag relationships between TWS in the Ganges-Brahmaputra-Meghna basin and endemic cholera in Bangladesh. Since bimodal seasonal peaks in cholera in Bangladesh occur during spring and autumn seasons, two separate logistical models between TWS and disease time series (2002-2010) were developed. TWS representing water availability showed an asymmetrical, strong association with cholera prevalence in the spring (τ = -0.53; P cholera by 24% (confidence interval [CI] = 20-31%; P cholera in the autumn by 29% (CI = 22-33%; P < 0.05). © The American Society of Tropical Medicine and Hygiene.

  2. Exploring industry specific social welfare maximizing rates of water pollution abatement in linked terrestrial and marine ecosystems

    NARCIS (Netherlands)

    Roebeling, P.C.; Hendrix, E.M.T.; Grieken, van M.E.

    2009-01-01

    Marine ecosystems are severely affected by water pollution originating from coastal catchments, while these ecosystems are of vital importance from an environmental as well as an economic perspective. To warrant sustainable economic development of coastal regions, we need to balance the marginal cos

  3. Poverty-environmental links: The impact of soil and water conservation and tenure security on household welfare in Kenya.

    NARCIS (Netherlands)

    Kabubo-Mariara, J.; Linderhof, V.G.M.; Kruseman, G.; Atieno, R.; Mwabu, G.

    2010-01-01

    This paper investigated the impact of investment in soil and water conservation strategies and tenure security on household welfare in Kenya. The paper used survey data collected from a sample of about 450 households in 2004. The paper estimated reduced form models to test the hypothesis that

  4. Beyond the Dams: Linking Rural Smallholder Soil and Water Management Practices in Tropical Deltas to Sea Level Rise Vulnerability

    Science.gov (United States)

    Rogers, K. G.; Syvitski, J. P.; Brondizio, E. S.

    2014-12-01

    The increased vulnerability of deltaic communities to coastal flooding as a result of upstream engineering has been acknowledged for decades. What has received less attention is the sensitivity of deltas to the interactions of river basin modifications and cultivation and irrigation in their coastal regions, particularly in tropical deltas. Embanking, tilling, and crop or stock choice all affect the movement of sediment and water on deltas. Combined with reduced river and sediment discharge, soil and water management practices in coastal areas may in fact exacerbate the risk of tidal flooding, erosion of arable land, and salinization of soils and groundwater associated with sea level rise. Thus exists a cruel irony to smallholder subsistence farmers whose priorities are food, water and economic security, rather than sustainability of the regional environment. Such issues challenge disciplinary approaches and require integrated social-biophysical models able to understand and diagnose these complex relationships. The complementary Institutional Analysis and Development and SocioEcological Systems frameworks are applied to the southwestern Bengal Delta (Bangladesh). The method helps to define the relevant social and physical units operating on the common pool of environmental resources, those of climate, water and sediment. The conceptual frameworks are designed to inform development of a nested geospatial analysis and a dynamic coupled model to identify the social-biophysical feedbacks associated with smallholder soil and water management practices, coastal dynamics, and climate vulnerability in rural Bangladesh. Our presentation will discuss components of the conceptual frameworks and will introduce a bi-directional pilot study designed for obtaining and disseminating information about environmental change to farmers in southwest Bangladesh with potential application to rural farming communities in other tropical deltas.

  5. Linking River Basin Modifications and Rural Soil and Water Management Practices in Tropical Deltas to Sea Level Rise Vulnerability

    Science.gov (United States)

    Rogers, K. G.; Brondizio, E.; Roy, K.; Syvitski, J. P.

    2015-12-01

    The increased vulnerability of deltaic communities to coastal flooding as a result of upstream engineering has been acknowledged for decades. What has received less attention is the sensitivity of deltas to the interactions between river basin modifications and local scale cultivation and irrigation. Combined with reduced river and sediment discharge, soil and water management practices in coastal areas may exacerbate the risk of tidal flooding, erosion of arable land, and salinization of soils and groundwater associated with sea level rise. This represents a cruel irony to smallholder subsistence farmers whose priorities are food, water and economic security, rather than sustainability of the environment. Such issues challenge disciplinary approaches and require integrated social-biophysical models able to understand and diagnose these complex relationships. This study applies a new conceptual framework to define the relevant social and physical units operating on the common pool resources of climate, water and sediment in the Bengal Delta (Bangladesh). The new framework will inform development of a nested geospatial analysis and a coupled model to identify multi-scale social-biophysical feedbacks associated with smallholder soil and water management practices, coastal dynamics, basin modification, and climate vulnerability in tropical deltas. The framework was used to create household surveys for collecting data on climate perceptions, land and water management, and governance. Test surveys were administered to rural farmers in 14 villages during a reconnaissance visit to coastal Bangladesh. Initial results demonstrate complexity and heterogeneity at the local scale in both biophysical conditions and decision-making. More importantly, the results illuminate how national and geopolitical-level policies scale down to impact local-level environmental and social stability in communities already vulnerable to coastal flooding. Here, we will discuss components of the

  6. Paradigm Shift in Transboundary Water Management Policy: Linking Water Environment Energy and Food (weef) to Catchment Hydropolitics - Needs, Scope and Benefits

    Science.gov (United States)

    RAI, S.; Wolf, A.; Sharma, N.; Tiwari, H.

    2015-12-01

    The incessant use of water due to rapid growth of population, enhanced agricultural and industrial activities, degraded environment and ecology will in the coming decades constrain the socioeconomic development of humans. To add on to the precarious situation, political boundaries rarely embrace hydrological boundaries of lakes, rivers, aquifers etc. Hydropolitics relate to the ability of geopolitical institutions to manage shared water resources in a politically sustainable manner, i.e., without tensions or conflict between political entities. Riparian hydropolitics caters to differing objectives, needs and requirements of states making it difficult to administer the catchment. The diverse riparian objectives can be merged to form a holistic catchment objective of sustainable water resources development and management. It can be proposed to make a paradigm shift in the present-day transboundary water policy from riparian hydropolitics (in which the focal point of water resources use is hinged on state's need) to catchment hydropolitics (in which the interest of the basin inhabitants are accorded primacy holistically over state interests) and specifically wherein the water, environment, energy and food (WEEF) demands of the catchment are a priority and not of the states in particular. The demands of the basin pertaining to water, food and energy have to be fulfilled, keeping the environment and ecology healthy in a cooperative political framework; the need for which is overwhelming. In the present scenario, the policy for water resources development of a basin is segmented into independent uncoordinated parts controlled by various riparians; whereas in catchment hydropolitics the whole basin should be considered as a unit. The riparians should compromise a part of national interest and work in collaboration on a joint objective which works on the principle of the whole as against the part. Catchment hydropolitics may find greater interest in the more than 250

  7. Thermodynamic Analysis of the Use a Chemical Heat Pump to Link a Supercritical Water-Cooled Nuclear Reactor and a Thermochemical Water-Splitting Cycle for Hydrogen Production

    Science.gov (United States)

    Granovskii, Mikhail; Dincer, Ibrahim; Rosen, Marc A.; Pioro, Igor

    Increases in the power generation efficiency of nuclear power plants (NPPs) are mainly limited by the permissible temperatures in nuclear reactors and the corresponding temperatures and pressures of the coolants in reactors. Coolant parameters are limited by the corrosion rates of materials and nuclear-reactor safety constraints. The advanced construction materials for the next generation of CANDU reactors, which employ supercritical water (SCW) as a coolant and heat carrier, permit improved “steam” parameters (outlet temperatures up to 625°C and pressures of about 25 MPa). An increase in the temperature of steam allows it to be utilized in thermochemical water splitting cycles to produce hydrogen. These methods are considered by many to be among the most efficient ways to produce hydrogen from water and to have advantages over traditional low-temperature water electrolysis. However, even lower temperature water splitting cycles (Cu-Cl, UT-3, etc.) require an intensive heat supply at temperatures higher than 550-600°C. A sufficient increase in the heat transfer from the nuclear reactor to a thermochemical water splitting cycle, without jeopardizing nuclear reactor safety, might be effectively achieved by application of a heat pump, which increases the temperature of the heat supplied by virtue of a cyclic process driven by mechanical or electrical work. Here, a high-temperature chemical heat pump, which employs the reversible catalytic methane conversion reaction, is proposed. The reaction shift from exothermic to endothermic and back is achieved by a change of the steam concentration in the reaction mixture. This heat pump, coupled with the second steam cycle of a SCW nuclear power generation plant on one side and a thermochemical water splitting cycle on the other, increases the temperature of the “nuclear” heat and, consequently, the intensity of heat transfer into the water splitting cycle. A comparative preliminary thermodynamic analysis is conducted

  8. Linking local riverbed flow patterns and pore-water chemistry to hydrogeologic and geomorphic features across scales

    Science.gov (United States)

    Ibrahim, T. G.; Thornton, S.; Surridge, B.; Wainwright, J.

    2009-12-01

    The groundwater-surface water interface (GSI) is a critical environmental hotspot, a key area influencing the fate of carbon, nutrients and contaminants of surface and subsurface origin, and a zone of ecological importance. Policy seeking to mitigate issues relating to dissolved contaminants and to improve stream health, increasingly recognizes its significance, particularly in the context of integrated management of streams and aquifers. Techniques assessing riverbed flow and solute patterns are often limited to the local scale. When related to the multi-scale pattern of hydrogeologic and geomorphic features controlling stream, hyporheic and groundwater fluxes, they can improve larger scale predictions of flow and solute behaviour at the GSI. This study develops a conceptual model of riverbed flow and solute patterns, and tests it in a 4th order stream in the UK. It assesses the interaction between large scale subsurface flowpaths, driven by the distribution of bedrock outcrops, and the expansion and closure of alluvial deposits, and small-scale hyporheic flowpaths, driven by riffle-pool sequences. It uses two networks of riverbed mini-piezometers and multi-level samplers: network 1, across fifteen sites in a 7.2 km length of river in unconstrained (open alluvial valley), asymmetric (bedrock outcropping on one bank) and constrained (bedrock on both banks) contexts; and network 2, across six riffle-pool sequences in a 350-m reach, at the transition between asymmetric/unconstrained and constrained contexts. Subsurface flowpaths and stream-water infiltration were deduced by relating vertical exchange fluxes to stream and pore-water patterns of conservative natural tracers. Biogeochemical processes were highlighted using reactive natural tracers. At network 2, measurements of surface water profiles and riverbed coring were also undertaken, and dissolved metal concentrations in the first 15 cm of sediments assessed using gel probes. Network 1 was sampled twice. Monthly

  9. Linking water and carbon fluxes in a Mediterranean oak woodland using a combined flux and ?18O partitioning approach

    Science.gov (United States)

    Dubbert, M.; Piayda, A.; Costa e Silva, F.; Correia, A.; Pereira, J. S.; Cuntz, M.; Werner, C.

    2013-12-01

    Water is one of the key factors driving ecosystem productivity, especially in water-limited ecosystems, where global climate change is expected to intensify drought and alter precipitation patterns. One such ecosystem is the ';Montado', where two vegetation layers respond differently to drought: oak trees avoid drought due to their access to deeper soil layers and ground water while herbaceous plants, surviving the summer in the form of seeds. We aimed at 1) quantifying the impact of the understory herbaceous vegetation on ecosystem carbon and water fluxes throughout the year, 2) determining the driving environmental factors for evapotranspiration (ET) and net ecosystem exchange (NEE) and 3) disentangling how ET components of the ecosystem relate to carbon dioxide exchange. We present one year data set comparing modeled and measured stable oxygen isotope signatures (δ18O) of soil evaporation, confirming that the Craig and Gordon equation leads to good agreement with measured δ18O of evaporation (Dubbert et al. 2013). Partitioning ecosystem ET and NEE into its three sources revealed a strong contribution of soil evaporation (E) and herbaceous transpiration (T) to ecosystem ET during spring and fall. In contrast, soil respiration (R) and herbaceous net carbon gain contributed to a lesser amount to ecosystem NEE during spring and fall, leading to consistently smaller water use efficiencies (WUE) of the herbaceous understory compared to the cork-oaks. Here, we demonstrate that the ability to assess ET, NEE and WUE independent of soil evaporation dynamics enables the understanding of the mechanisms of the coupling between water and carbon fluxes and their responses to drought. Dubbert, M., Cuntz, M., Piayda, A., Maguas, C., Werner, C., 2013: Partitioning evapotranspiration - Testing the Craig and Gordon model with field measurements of oxygen isotope ratios of evaporative fluxes. J Hydrol. a) Oxygen isotope signatures of soil evaporation on bare soil plots calculated

  10. Long-term study of migration of volatile organic compounds from cross-linked polyethylene (PEX) pipes and effects on drinking water quality.

    Science.gov (United States)

    Lund, Vidar; Anderson-Glenna, Mary; Skjevrak, Ingun; Steffensen, Inger-Lise

    2011-09-01

    The objectives of this study were to investigate migration of volatile organic compounds (VOCs) from cross-linked polyethylene (PEX) pipes used for drinking water produced by different production methods, and to evaluate their potential risk for human health and/or influence on aesthetic drinking water quality. The migration tests were carried out in accordance with EN-1420-1, and VOCs were analysed by gas chromatography-mass spectrometry. The levels of VOC migrating from new PEX pipes were generally low, and decreasing with time of pipe use. No association was found between production method of PEX pipes and concentration of migration products. 2,4-di-tert-butyl phenol and methyl tert-butyl ether (MTBE) were two of the major individual components detected. In three new PEX pipes, MTBE was detected in concentrations above the recommended US EPA taste and odour value for drinking water, but decreased below this value after 5 months in service. However, the threshold odour number (TON) values for two pipes were similar to new pipes even after 1 year in use. For seven chemicals for which conclusions on potential health risk could be drawn, this was considered of no or very low concern. However, odour from some of these pipes could negatively affect drinking water for up to 1 year.

  11. Determination of alachlor and its sulfonic acid metabolite in water by solid-phase extraction and enzyme-linked immunosorbent assay

    Science.gov (United States)

    Aga, D.S.; Thurman, E.M.; Pomes, M.L.

    1994-01-01

    Solid-phase extraction (SPE) and enzyme-linked immunosorbent assay (ELISA) were combined for the trace analysis of the herbicide alachlor and its major soil metabolite, ethanesulfonic acid (ESA). The anti-alachlor antibody cross-reacted with ESA, which produced false-positive detections of alachlor in water samples by immunoassay screens. Alachlor and ESA were isolated from water by SPE on a C18 resin and eluted sequentially with ethyl acetate and methanol. Alachlor is soluble in ethyl acetate while the anionic ESA is not. Thus ESA remained adsorbed on the C18 resin and was eluted later with methanol. The combination of SPE with ELISA effectivety separated and quantified both alachlor and ESA using the same antibody for two ELISA methods. The general method may have applicability for the separation of other herbicides and their ionic metabolites. The SPE-ELISA method has a, detection limit of 0.01 ??g/L for alachlor and 0.05 ??g/L for ESA, with a precision of ?? 10%. Analyses of surface and ground water samples were confirmed by gas chromatography/mass spectrometry and high-performance liquid chromatography with photodiode-array detection. Results showed widespread occurrence of ESA in surface and ground water of the midwestern United States, with concentrations ranging from 10 ??g/L.

  12. Ecosystem engineering creates a direct nutritional link between 600-m deep cold-water coral mounds and surface productivity

    Science.gov (United States)

    Soetaert, Karline; Mohn, Christian; Rengstorf, Anna; Grehan, Anthony; van Oevelen, Dick

    2016-10-01

    Cold-water corals (CWCs) form large mounds on the seafloor that are hotspots of biodiversity in the deep sea, but it remains enigmatic how CWCs can thrive in this food-limited environment. Here, we infer from model simulations that the interaction between tidal currents and CWC-formed mounds induces downwelling events of surface water that brings organic matter to 600-m deep CWCs. This positive feedback between CWC growth on carbonate mounds and enhanced food supply is essential for their sustenance in the deep sea and represents an example of ecosystem engineering of unparalleled magnitude. This ’topographically-enhanced carbon pump’ leaks organic matter that settles at greater depths. The ubiquitous presence of biogenic and geological topographies along ocean margins suggests that carbon sequestration through this pump is of global importance. These results indicate that enhanced stratification and lower surface productivity, both expected consequences of climate change, may negatively impact the energy balance of CWCs.

  13. Cross-linked cyclodextrin-based material for treatment of metals and organic substances present in industrial discharge waters

    Directory of Open Access Journals (Sweden)

    Élise Euvrard

    2016-08-01

    Full Text Available In this study, a polymer, prepared by crosslinking cyclodextrin (CD by means of a polycarboxylic acid, was used for the removal of pollutants from spiked solutions and discharge waters from the surface treatment industry. In spiked solutions containing five metals, sixteen polycyclic aromatic hydrocarbons (PAH and three alkylphenols (AP, the material exhibited high adsorption capacities: >99% of Co2+, Ni2+ and Zn2+ were removed, between 65 and 82% of the PAHs, as well as 69 to 90% of the APs. Due to the structure of the polymer and its specific characteristics, such as the presence of carboxylic groups and CD cavities, the adsorption mechanism involves four main interactions: ion exchange, electrostatic interactions and precipitation for metal removal, and inclusion complexes for organics removal. In industrial discharge waters, competition effects appeared, especially because of the presence of calcium at high concentrations, which competed with other pollutants for the adsorption sites of the adsorbent.

  14. Release of drinking water contaminants and odor impacts caused by green building cross-linked polyethylene (PEX) plumbing systems.

    Science.gov (United States)

    Kelley, Keven M; Stenson, Alexandra C; Dey, Rajarashi; Whelton, Andrew J

    2014-12-15

    Green buildings are increasingly being plumbed with crosslinked polyethylene (PEX) potable water pipe. Tap water quality was investigated at a six month old plumbing system and chemical and odor quality impacts of six PEX pipe brands were examined. Eleven PEX related contaminants were found in the plumbing system; one regulated (toluene) and several unregulated: Antioxidant degradation products, resin solvents, initiator degradation products, or manufacturing aides. Water chemical and odor quality was monitored for new PEX-a, -b and -c pipes with (2 mg/L free chlorine) and without disinfectant over 30 days. Odor and total organic carbon (TOC) levels decreased for all pipes, but odor remained greater than the USA's Environmental Protection Agency's (USEPA) secondary maximum contaminant level. Odors were not attributed to known odorants ethyl-tert-butyl ether (ETBE) or methyl-tert-butyl ether (MTBE). Free chlorine caused odor levels for PEX-a1 pipe to increase from 26 to 75 threshold odor number (TON) on day 3 and affected the rate at which TOC changed for each brand over 30 days. As TOC decreased, the ultraviolet absorbance at 254 nm increased. Pipes consumed as much as 0.5 mg/L as Cl2 during each 3 day stagnation period. Sixteen organic chemicals were identified, including toluene, pyridine, methylene trichloroacetate and 2,4-di-tert-butylphenol. Some were also detected during the plumbing system field investigation. Six brands of PEX pipes sold in the USA and a PEX-a green building plumbing system impacted chemical and drinking water odor quality.

  15. Occurrence of human enteric viruses at freshwater beaches during swimming season and its link to water inflow.

    Science.gov (United States)

    Lee, Chang Soo; Lee, Cheonghoon; Marion, Jason; Wang, Qiuhong; Saif, Linda; Lee, Jiyoung

    2014-02-15

    Human enteric viruses are significant etiological agents for many recreational waterborne illnesses. The occurrence and density of human enteric viruses such as human adenovirus (HAdV), human enterovirus (HEnV), and human norovirus genogroups I/II (HNoV GI/GII) were investigated using quantitative real-time PCR (qPCR) at freshwater beaches along with monitoring fecal indicators and environmental parameters. During the 2009 swimming season, water samples were collected from three inland freshwater beaches in Ohio, USA. Of the total samples, 40% (26/65) and 17% (11/65) were positive for HAdV and HEnV respectively, but HNoV GI/GII were not detected. There was no significant association among the detected human enteric viruses (HAdV and HEnV) and fecal bacteria indicators (Escherichia coli and Bacteroides) by Spearman correlation and principal component analyses. Logistic regression analysis also revealed that the odds of finding HAdV or HEnV was not influenced by levels of fecal bacteria indicators. However, there was a 14-fold increase in the odds of HEnV detection for each 1-log increase in daily water inflow (m(3)/s) into freshwater beach reservoirs (adjusted odds ratio=14.2; 95% confidence interval=1.19-171). In summary, the viral occurrence at the freshwater beaches was not readily explained by the levels of fecal bacteria indicators, but appeared to be more related to water reservoir inflows. These results suggest that hydrological data must be considered in future epidemiology efforts aimed at characterizing beach water safety.

  16. Legionnaires' disease on a cruise ship linked to the water supply system: clinical and public health implications.

    Science.gov (United States)

    Castellani Pastoris, M; Lo Monaco, R; Goldoni, P; Mentore, B; Balestra, G; Ciceroni, L; Visca, P

    1999-01-01

    The occurrence of legionnaires' disease has been described previously in passengers of cruise ships, but determination of the source has been rare. A 67-year-old, male cigarette smoker with heart disease contracted legionnaires' disease during a cruise in September 1995 and died 9 days after disembarking. Legionella pneumophila serogroup 1 was isolated from the patient's sputum and the ship's water supply. Samples from the air-conditioning system were negative. L. pneumophila serogroup 1 isolates from the water supply matched the patient's isolate, by both monoclonal antibody subtyping and genomic fingerprinting. None of 116 crew members had significant antibody titers to L. pneumophila serogroup 1. One clinically suspected case of legionnaires' disease and one confirmed case were subsequently diagnosed among passengers cruising on the same ship in November 1995 and October 1996, respectively. This is the first documented evidence of the involvement of a water supply system in the transmission of legionella infection on ships. These cases were identified because of the presence of a unique international system of surveillance and collaboration between public health authorities.

  17. A Water Mass Tracer Detected in Aerosols Demonstrates Ocean-Atmosphere Mass Transfer and Links Sea Spray Aerosol to Source Waters

    Science.gov (United States)

    Pendergraft, M.; Grimes, D. J.; Giddings, S. N.; Feddersen, F.; Prather, K. A.; Santander, M.; Lee, C.; Beall, C.

    2016-12-01

    During September and October of 2015 the Cross Surfzone/Inner-shelf Dye Exchange (CSIDE) project released rhodamine WT dye to study nearshore water movement and exchange offshore along a Southern California sandy beach. We utilized this opportunity to investigate ocean-atmosphere mass transfer via sea spray aerosol and linkage to source waters. Aerosol-concentrating sampling equipment was deployed at beachside and inland locations during three dye releases. Concentrated aerosol samples were analyzed for dye content using fluorescence spectroscopy. Here we present the ocean and atmosphere conditions associated with the presence and absence of dye in aerosol samples. Dye was identified in aerosol samples collected 0.1-0.3 km from the shoreline for 6 hs during the first and third dye releases of the CSIDE project. During these releases the dye persisted in the waters upwind of the sampling equipment. Dye was not detected in aerosol samples collected during the second release during which dye was moved away from waters upwind of the sampling equipment. Recovery of a chemical tracer in sea spray aerosol allows direct linkage to a known source area in the ocean that is independent of, but supported by, wind data. Our observations demonstrate: a tight ocean-atmosphere spatial coupling; a short residence time of coastal marine constituents before transfer to the atmosphere; that the ocean is both a sink for and a source of atmospheric and terrestrial material; and that human inputs to the ocean can return to us in sea spray aerosol.

  18. Linking benthic hydrodynamics and cold-water coral occurrences: A high-resolution model study at three cold-water coral provinces in the NE Atlantic

    NARCIS (Netherlands)

    Mohn, C.; Rengstorf, A.; White, M.; Mienis, F.; Soetaert, K.; Grehan, A.; Duineveld, G.

    2014-01-01

    Observations from numerous cold-water coral locations in the NE Atlantic show energetic near-bottom flow dynamics along the European continental margin at individual coral mounds and mound clusters. Dynamics are largely controlled by tide-topography interaction generating and enhancing periodic moti

  19. Linking benthic hydrodynamics and cold-water coral occurrences: A high-resolution model study at three cold-water coral provinces in the NE Atlantic

    NARCIS (Netherlands)

    Mohn, C.; Rengstorf, A.; White, M.; Mienis, F.; Soetaert, K.; Grehan, A.; Duineveld, G.

    2014-01-01

    Observations from numerous cold-water coral locations in the NE Atlantic show energetic near-bottom flow dynamics along the European continental margin at individual coral mounds and mound clusters. Dynamics are largely controlled by tide-topography interaction generating and enhancing periodic

  20. Bridging the Gap

    OpenAIRE

    Kramer Overgaard, Majken; Broeng, Jes; Jensen, Monika Luniewska; Murdock, Karen; Schmidt, Iben Julie

    2015-01-01

    Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ventures. Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ve...

  1. Bridging the Gap

    DEFF Research Database (Denmark)

    Kramer Overgaard, Majken; Broeng, Jes; Jensen, Monika Luniewska;

    Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ventures.......Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ventures....

  2. Gap and density theorems

    CERN Document Server

    Levinson, N

    1940-01-01

    A typical gap theorem of the type discussed in the book deals with a set of exponential functions { \\{e^{{{i\\lambda}_n} x}\\} } on an interval of the real line and explores the conditions under which this set generates the entire L_2 space on this interval. A typical gap theorem deals with functions f on the real line such that many Fourier coefficients of f vanish. The main goal of this book is to investigate relations between density and gap theorems and to study various cases where these theorems hold. The author also shows that density- and gap-type theorems are related to various propertie

  3. Using Atmospheric δ13C of CO2 observations to link the water and carbon cycles with climate

    Science.gov (United States)

    Alden, C. B.; Miller, J. B.; White, J. W.; Yadav, V.; Michalak, A. M.; Andrews, A. E.; Huang, L.

    2013-12-01

    The ratio of stable carbon isotopes, 13C:12C in atmospheric CO2 (expressed as δ13C) offers unique insights into atmosphere-land CO2 fluxes and the modulating effects of stomatal conductance on this exchange. Photosynthesis discriminates against 13CO2 during uptake. The magnitude of this fractionation is strongly dependent upon ambient CO2 concentrations and water availability, as well as on the mix of C3 and C4 vegetation types. C3 and C4 plants have very different discrimination because of carboxylation pathways, and C3 stomatal conductance varies with water availability because stomata close to reduce transpiration when plants are water stressed. Further, plant stomata respond to ambient CO2 concentrations in order to optimize leaf internal [CO2] while reducing transpirative water loss. Atmospheric δ13C therefore carries information about local and upwind drought conditions and the consequent likelihood of ground-to-atmosphere water transfer via transpiration, and the balance of latent and sensible heat fluxes, as well as about local and upwind distributions of C3 and C4 vegetation and variability therein. δ13C offers a unique lens through which to identify key thresholds and relationships between climate anomalies/change and the modulating climate impacts of plant biosphere response. By unraveling this relationship at local to continental scales, we stand to gain crucial understanding of the drivers of land CO2 uptake variability as well as knowledge of how to predict future climate impacts on the carbon cycle and vice versa. We use a two-step Bayesian inversion model to optimize 1x1 degree and 3-hourly (interpreted at regional and weekly to monthly scales) fields of δ13C of assimilated biomass over North America for the year 2010, using influence functions generated with FLEXPART, driven by National Centers for Environmental Prediction Global Forecast System meteorology. Prior fluxes and fossil fuel, ocean and fire fluxes are from CarbonTracker 2011, and

  4. Linking air and water transport in intact soils to macropore characteristics inferred from X-ray computed tomography

    DEFF Research Database (Denmark)

    Katuwal, S.; Nørgaard, Trine; Møldrup, Per

    2015-01-01

    Soil macropores often control fluid flow and solute transport, and quantification of macropore characteristics including their variability in space and time are essential to predict soil hydraulic and hydrogeochemical functions. In this study, measurements of air and solute transport properties...... and direct macropore visualization by X-ray CT scanning were carried out on 17 large (19-cm diam.; 20-cm length) undisturbed soil columns sampled across a field site (Silstrup, Denmark) with natural gradients in texture and density. Air permeability (ka) at in-situ water content and -20 hPa of matric...

  5. Modeling Water and Nutrient Transport through the Soil-Root-Canopy Continuum: Explicitly Linking the Below- and Above-Ground Processes

    Science.gov (United States)

    Kumar, P.; Quijano, J. C.; Drewry, D.

    2010-12-01

    Vegetation roots provide a fundamental link between the below ground water and nutrient dynamics and above ground canopy processes such as photosynthesis, evapotranspiration and energy balance. The “hydraulic architecture” of roots, consisting of the structural organization of the root system and the flow properties of the conduits (xylem) as well as interfaces with the soil and the above ground canopy, affect stomatal conductance thereby directly linking them to the transpiration. Roots serve as preferential pathways for the movement of moisture from wet to dry soil layers during the night, both from upper soil layer to deeper layers during the wet season (‘hydraulic descent’) and vice-versa (‘hydraulic lift’) as determined by the moisture gradients. The conductivities of transport through the root system are significantly, often orders of magnitude, larger than that of the surrounding soil resulting in movement of soil-moisture at rates that are substantially larger than that through the soil. This phenomenon is called hydraulic redistribution (HR). The ability of the deep-rooted vegetation to “bank” the water through hydraulic descent during wet periods for utilization during dry periods provides them with a competitive advantage. However, during periods of hydraulic lift these deep-rooted trees may facilitate the growth of understory vegetation where the understory scavenges the hydraulically lifted soil water. In other words, understory vegetation with relatively shallow root systems have access to the banked deep-water reservoir. These inter-dependent root systems have a significant influence on water cycle and ecosystem productivity. HR induced available moisture may support rhizosphere microbial and mycorrhizal fungi activities and enable utilization of heterogeneously distributed water and nutrient resources To capture this complex inter-dependent nutrient and water transport through the soil-root-canopy continuum we present modeling

  6. Water-carbon Links in a Tropical Forest: How Interbasin Groundwater Flow Affects Carbon Fluxes and Ecosystem Carbon Budgets

    Energy Technology Data Exchange (ETDEWEB)

    Genereux, David [NC State University; Osburn, Christopher [NC State University; Oberbauer, Steven [Florida International University; Oviedo Vargas, Diana [NC State University; Dierick, Diego [Florida International University

    2017-03-27

    This report covers the outcomes from a quantitative, interdisciplinary field investigation of how carbon fluxes and budgets in a lowland tropical rainforest are affected by the discharge of old regional groundwater into streams, springs, and wetlands in the forest. The work was carried out in a lowland rainforest of Costa Rica, at La Selva Biological Station. The research shows that discharge of regional groundwater high in dissolved carbon dioxide represents a significant input of carbon to the rainforest "from below", an input that is on average larger than the carbon input "from above" from the atmosphere. A stream receiving discharge of regional groundwater had greatly elevated emissions of carbon dioxide (but not methane) to the overlying air, and elevated downstream export of carbon from its watershed with stream flow. The emission of deep geological carbon dioxide from stream water elevates the carbon dioxide concentrations in air above the streams. Carbon-14 tracing revealed the presence of geological carbon in the leaves and stems of some riparian plants near streams that receive inputs of regional groundwater. Also, discharge of regional groundwater is responsible for input of dissolved organic matter with distinctive chemistry to rainforest streams and wetlands. The discharge of regional groundwater in lowland surface waters has a major impact on the carbon cycle in this and likely other tropical and non-tropical forests.

  7. Linking benthic hydrodynamics and cold-water coral occurrences: A high-resolution model study at three cold-water coral provinces in the NE Atlantic

    Science.gov (United States)

    Mohn, Christian; Rengstorf, Anna; White, Martin; Duineveld, Gerard; Mienis, Furu; Soetaert, Karline; Grehan, Anthony

    2014-03-01

    Observations from numerous cold-water coral locations in the NE Atlantic show energetic near-bottom flow dynamics along the European continental margin at individual coral mounds and mound clusters. Dynamics are largely controlled by tide-topography interaction generating and enhancing periodic motions such as trapped waves, freely propagating internal tides and internal hydraulic jumps. In this study, linkages between key abiotic parameters and cold water coral occurrences are explored across entire cold-water coral mound provinces using an integrated modelling and observational approach. The 3-D ocean circulation model ROMS-AGRIF was applied to simulate near-bottom hydrodynamic conditions at three provinces in the NE Atlantic (Logachev mounds, Arc mounds and Belgica mounds) adopting a nested model setup with a central grid resolution of 250 m. Simulations were carried out with a focus on accurate high-resolution topography and tidal forcing. The central model bathymetry was taken from high-resolution INSS (Irish National Seabed Survey) seafloor mapping data. The model was integrated over a full one-year reference period starting from the 1st January 2010. Interannual variability was not considered. Tidal forcing was obtained from a global solution of the Oregon State University (OSU) inverse tidal model. Modelled fields of benthic currents were validated against available independent in situ observations. Coral assemblage patterns (presence and absence locations) were obtained from benthic surveys of the EU FP7 CoralFISH programme and supplemented by data from additional field surveys. Modelled near-bottom currents, temperature and salinity were analysed for a 1-month subset (15th April to 15th May 2010) corresponding to the main CoralFISH survey period. The model results show intensified near-bottom currents in areas where living corals are observed by contrast with coral absence and random background locations. Instantaneous and time-mean current speeds at

  8. Bridging a Cultural Gap

    Science.gov (United States)

    Leviatan, Talma

    2008-01-01

    There has been a broad wave of change in tertiary calculus courses in the past decade. However, the much-needed change in tertiary pre-calculus programmes--aimed at bridging the gap between high-school mathematics and tertiary mathematics--is happening at a far slower pace. Following a discussion on the nature of the gap and the objectives of a…

  9. Senseless Extravagance, Shocking Gaps

    Science.gov (United States)

    Weissbourd, Richard; Dodge, Trevor

    2012-01-01

    Although most people in the United States believe, at least theoretically, in educational equality, fewer and fewer appear to care about the resource gaps between affluent and poor schools, says Weissbourd. He illustrates these gaps with vivid descriptions of what he calls an "opulence arms race" among affluent independent schools, but…

  10. Bridge the Gap

    DEFF Research Database (Denmark)

    Marselis, Randi Lorenz

    2017-01-01

    This article focuses on photo projects organised for teenage refugees by the Society for Humanistic Photography (Berlin, Germany). These projects, named Bridge the Gap I (2015), and Bridge the Gap II (2016), were carried out in Berlin and brought together teenagers with refugee and German...

  11. A review of quantitative structure-property relationships for the fate of ionizable organic chemicals in water matrices and identification of knowledge gaps.

    Science.gov (United States)

    Nolte, Tom M; Ragas, Ad M J

    2017-03-22

    Many organic chemicals are ionizable by nature. After use and release into the environment, various fate processes determine their concentrations, and hence exposure to aquatic organisms. In the absence of suitable data, such fate processes can be estimated using Quantitative Structure-Property Relationships (QSPRs). In this review we compiled available QSPRs from the open literature and assessed their applicability towards ionizable organic chemicals. Using quantitative and qualitative criteria we selected the 'best' QSPRs for sorption, (a)biotic degradation, and bioconcentration. The results indicate that many suitable QSPRs exist, but some critical knowledge gaps remain. Specifically, future focus should be directed towards the development of QSPR models for biodegradation in wastewater and sediment systems, direct photolysis and reaction with singlet oxygen, as well as additional reactive intermediates. Adequate QSPRs for bioconcentration in fish exist, but more accurate assessments can be achieved using pharmacologically based toxicokinetic (PBTK) models. No adequate QSPRs exist for bioconcentration in non-fish species. Due to the high variability of chemical and biological species as well as environmental conditions in QSPR datasets, accurate predictions for specific systems and inter-dataset conversions are problematic, for which standardization is needed. For all QSPR endpoints, additional data requirements involve supplementing the current chemical space covered and accurately characterizing the test systems used.

  12. Water

    Science.gov (United States)

    ... www.girlshealth.gov/ Home Nutrition Nutrition basics Water Water Did you know that water makes up more ... to drink more water Other drinks How much water do you need? top Water is very important, ...

  13. Removal of some organic pollutants in water employing ceramic membranes impregnated with cross-linked silylated dendritic and cyclodextrin polymers.

    Science.gov (United States)

    Allabashi, Roza; Arkas, Michael; Hörmann, Gerold; Tsiourvas, Dimitris

    2007-01-01

    Triethoxysilylated derivatives of poly(propylene imine) dendrimer, polyethylene imine and polyglycerol hyperbranched polymers and beta-cyclodextrin have been synthesized and characterized. These compounds impregnated ceramic membranes made from Al(2)O(3), SiC and TiO(2) and subsequently sol-gel reaction led to their polymerization and chemical bond formation with the ceramic substrates. The resulting organic-inorganic filters were tested for the removal of a variety of organic pollutants from water. They were found to remove of polycyclic aromatic hydrocarbons (up to 99%), of monocyclic aromatic hydrocarbons (up to 93%), trihalogen methanes (up to 81%), pesticides (up to 43%) and methyl-tert-butyl ether (up to 46%).

  14. Linking nitrifying biofilm characteristics and nitrification performance in moving-bed biofilm reactors for polluted raw water pretreatment.

    Science.gov (United States)

    Zhang, Shuangfu; Wang, Yayi; He, Weitao; Xing, Meiyan; Wu, Min; Yang, Jian; Gao, Naiyun; Sheng, Guangyao; Yin, Daqiang; Liu, Shanhu

    2013-10-01

    Biofilm physiology was characterized by four biofilm constituents, i.e., polysaccharides, proteins (PN), humic-like substances and phospholipids (PL), for the first time to explore the relationships between biofilm characteristics and nitrification performance in moving-bed biofilm reactors (MBBRs) designed for pretreatment of polluted raw surface water for potable supply. The biofilm compositions depended highly on the balance of microbial decay and nitrification processes. The increased ammonia loading greatly regulated the community structure, promoting the dominance of nitrifiers and their proportions in the nitrifying biofilm. Nitrification rate and activity correlated linearly with the fractions of volatile solids (VS), PN and PL, which were related to nitrification processes in the biofilm. The specific biofilm activity demonstrated an exponential-asymptotic relationship with ratios of PN/VS and PL/VS. Thus, analyzing biofilm characteristics can be valid for estimating nitrification performance in MBBRs, and may offer engineers with basis to optimize MBBR design and operation.

  15. Optimized measurement of gaps

    Science.gov (United States)

    Harding, Kevin; Ramamurthy, Rajesh

    2017-05-01

    Gaps are important in a wide range of measurements in manufacturing, from the fitting of critical assemblies too cosmetic features on cars. There are a variety of potential sensors that can measure a gap opening, each with aspects of gap measurements that they do well and other aspects where the technology may lack capability. This paper provides a review of a wide range of optical gages from structured light to passive systems and from line to area measurement. Each technology is considered relative to the ability to accurately measure a gap, including issues of edge effects, edge shape, surface finish, and transparency. Finally, an approach will be presented for creating an optimize measurement off gap openings for critical assembly applications.

  16. Measurement of bubble velocity in an air/water flow through a narrow gap by using high-speed cinematography; Ermittlung der Blasengeschwindigkeit einer Luft/Wasser-Spaltstroemung mit Hilfe der Hochgeschwindigkeitskinematographie

    Energy Technology Data Exchange (ETDEWEB)

    Koerner, S.; Friedel, L. [Technische Univ. Hamburg-Harburg, Hamburg (Germany)

    1997-12-01

    To predict the mass flow of a two phase mixture at a given pressure difference through narrow gaps, apart from the change in state of the gas phase during pressure reduction, the knowledge of the fluid dynamics on balance which occurs in the form of a relative velocity between the phases is important. These two influences were examined with the aid of high speed cinematography for a water/air bubble flow. Apart from the quick reduction in pressure due to the sudden reduction in crossection at the entry to the gap, there are no significant differences between the experimentally determined volume change in bubbles of different sizes and that calculated assuming an isothermal change in state. The mean velocity of the bubbles does not differ appreciably from that calculated assuming an homogeneous flow. [Deutsch] Zur Vorhersage des sich bei gegebener Druckdifferenz einstellenden Massenstroms eines Zweiphasengemischs durch enge Spalte ist neben der Zustandsaenderung der Gasphase waehrend der Druckabsenkung u.a. auch die Kenntnis des sich dabei einstellenden fluiddynamischen Ungleichgewichts in Form einer Relativgeschwindigkeit zwischen den Phasen von Bedeutung. Diese beiden Einfluesse wurden mit Hilfe der Hochgeschwindigkeitskinematographie fuer eine Wasser/Luft-Blasenstroemung untersucht. Abgesehen von der raschen Druckabsenkung aufgrund der ploetzlichen Querschnittsverengung im Spalteintritt treten keine nennenswerten Unterschiede zwischen den experimentell ermittelten und den unter der Annahme einer isothermen Zustandsaenderungen berechneten Volumenaenderung verschiedengrosser Blasen auf. Die mittlere Geschwindigkeit der Blasen unterscheidet sich dabei nicht wesentlich von der unter der Annahme einer homogenen Stroemung berechneten. (orig.)

  17. Molar ratios of therapeutic water-soluble phenothiazine⋅water-insoluble phospholipid adducts reveal a Fibonacci correlation and a putative link for structure–activity relationships

    DEFF Research Database (Denmark)

    Keyzer, Hendrik; Fey, S. J.; Thornton, Barry

    2015-01-01

    1,2diacyl-sn-glycero-3-phospholipids (PL) with even-numbered symmetric saturated diacyl chains with the headgroups choline (PC), glycerol (PG), serine (PS), ethanolamine (PE), phosphatidic acid (PA). We observed water soluble products with replicable molar ratios (MR) that could be divided into two...... larger than that of the self-associated pure PTH. In summary, the reproducibility and similarity of the measurements using different PTH derivatives and PL suggests that similar adducts are formed in all the cases. We propose that the PTH$PL adduct has a “helical shape” showing Fibonacci properties...

  18. Tropical Ocean Evaporation/SST Sensitivity and It's Link to Water and Energy Budget Variations During ENSO

    Science.gov (United States)

    Robertson, Franklin R.; Marshall, Susan; Oglesby, Robert; Roads, John; Sohn, Byung-Ju; Arnold, James E. (Technical Monitor)

    2001-01-01

    The continuing debate over feedback mechanisms governing tropical sea surface temperatures (SSTs) and tropical climate in general has highlighted the diversity of potential checks and balances within the climate system. Competing feedbacks due to changes in surface evaporation, water vapor, and cloud long- and shortwave radiative properties each may serve critical roles in stabilizing or destabilizing the climate system. It is also intriguing that even those climate variations having origins internal to the climate system - changes in ocean heat transport for example, apparently require complementary equilibrating effects by changes in atmospheric energy fluxes. Perhaps the best observational evidence of this is the relatively invariant nature of tropically averaged net radiation exiting the top-of-atmosphere (TOA) as measured by broadband satellite sensors over the past two decades. Thus, analyzing how these feedback mechanisms are operating within the context of current interannual variability may offer considerable insight for anticipating future climate change. In this paper we focus primarily on interannual variations of ocean evaporative fluxes and their significance for coupled water and energy cycles within the tropical climate system. In particular, we use both the da Silva estimates of surface fluxes (based on the Comprehensive Ocean Atmosphere Data Set, COADS) and numerical simulations from several global climate models to examine evaporation sensitivity to perturbations in SST associated with warm and cold ENSO events. The specific questions we address are as follows: (1) What recurring patterns of surface wind and humidity anomalies are present during ENSO and how do they combine to yield systematic evaporation anomalies?, (2) What is the resulting tropical ocean mean evaporation-SST sensitivity associated with this climate perturbation?, and (3) What role does this evaporation play in tropical heat and water balance over tropical oceanic regions? We

  19. A Reconsideration of the Link between the Energetics of Water and of ATP Hydrolysis Energy in the Power Strokes of Molecular Motors in Protein Structures

    Directory of Open Access Journals (Sweden)

    Wilfred F. Widdas

    2008-09-01

    Full Text Available Mechanical energy from oxygen metabolism by mammalian tissues has been studied since 1837. The production of heat by mechanical work was studied by Fick in about 1860. Prior to Fick’s work, energetics were revised by Joule’s experiments which founded the First Law of Thermodynamics. Fenn in 1923/24 found that frog muscle contractions generated extra heat proportional to the amount of work done in shortening the muscle. This was fully consistent with the Joule, Helmholtz concept used for the First Law of Thermodynamics. The link between the energetics of water and ATP hydrolysis in molecular motors is recommended for reconsideration.

  20. One-Step Synthesis of Cross-Linked Ionic Polymer Thin Films in Vapor Phase and Its Application to an Oil/Water Separation Membrane.

    Science.gov (United States)

    Joo, Munkyu; Shin, Jihye; Kim, Jiyeon; You, Jae Bem; Yoo, Youngmin; Kwak, Moo Jin; Oh, Myung Seok; Im, Sung Gap

    2017-02-15

    In spite of the huge research interest, ionic polymers could not have been synthesized in the vapor phase because the monomers of ionic polymers contain nonvolatile ionic salts, preventing the monomers from vaporization. Here, we suggest a new, one-step synthetic pathway to form a series of cross-linked ionic polymers (CIPs) in the vapor phase via initiated chemical vapor deposition (iCVD). 2-(Dimethylamino)ethyl methacrylate (DMAEMA) and 4-vinylbenzyl chloride (VBC) monomers are introduced into the iCVD reactor in the vapor phase to form a copolymer film. Simultaneously in the course of the deposition process, the tertiary amine in DMAEMA and benzylic chloride in VBC undergo a Menshutkin nucleophilic substitution reaction to form an ionic ammonium-chloride complex, forming a highly cross-linked ionic copolymer film of p(DMAEMA-co-VBC). To the best of our knowledge, this is the first report on the synthesis of CIP films in the vapor phase. The newly developed CIP thin film is further applied to the surface modification of the membrane for oil/water separation. With the hydrophilic and underwater oleophobic membrane whose surface is modified with the CIP film, excellent separation efficiency (>99%) and unprecedentedly high permeation flux (average 2.32 × 10(5) L m(-2) h(-1)) are achieved.

  1. Formation and cleaning function of physically cross-linked dual strengthened water-soluble chitosan-based core-shell particles.

    Science.gov (United States)

    Dong, Yanrui; Xiao, Congming

    2017-09-01

    Facile and mild ionic cross-linking and freezing/thawing technologies were applied to prepare double strengthened core-shell particles by using water-soluble chitosan (WSC), sodium alginate (SA) and poly(vinyl alcohol) (PVA) as starting materials. The aqueous solution contained WSC and PVA was dropped in ethanol to form beads. The beads were converted into WSC/PVA hydrogel particles by being subjected to three freeze/thaw cycles. Subsequently, ionic cross-linked hydrogel layer was formed around each WSC/PVA particle to generate core-shell particulates. Fourier transform infrared spectra confirmed the combination among various components. Dynamic mechanical thermal analysis indicated that the storage modulus of the core-shell hydrogel was improved obviously. Thermogravimetric analysis exhibited the thermal stability of the particles was also enhanced by incorporation of PVA. It was found that the particles were able to adsorb carbon dioxide, lead ion and copper ion. The adsorption capacities of dry particles toward carbon dioxide, Pb(II) and Cu(II) could reach 199.62, 39.28 and 26.03mg/g, respectively. The rates of the particles for binding Pb(II) and Cu(II) at initial stage were 26.57 and 4.30%/min, respectively. These experimental results suggested that the particles were an efficient sorbent for removing hazardous substances such as carbon dioxide and heavy-metal ions. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Linking Environmental Research and Practice: Lessons From The Integration of Climate Science and Water Management in the Western United States

    Science.gov (United States)

    Ferguson, D. B.; Rice, J.; Woodhouse, C. A.

    2015-12-01

    Efforts to better connect scientific research with people and organizations involved in environmental decision making are receiving increased interest and attention. Some of the challenges we currently face, however—including complex questions associated with climate change—present unique challenges because of their scale and scope. Focused research on the intersections between environment and society has provided substantial insight into dynamics of large-scale environmental change and the related impacts on people, natural resources, and ecosystems, yet our ability to connect this research to real-world decision making remains limited. Addressing these complex environmental problems requires broad cooperation between scientists and those who may apply research results in decision making, but there are few templates for guiding the growing number of scientists and practitioners now engaging in this kind of cooperative work. This presentation will offer a set of heuristics for carrying out collaborative work between scientists and practitioners. These heuristics were derived from research that examined the direct experiences of water resources professionals and climate researchers who have been working to integrate science and practice.

  3. Consequences of seasonal variation in reservoir water level for predatory fishes: linking visual foraging and prey densities

    Science.gov (United States)

    Klobucar, Stephen L.; Budy, Phaedra

    2016-01-01

    In reservoirs, seasonal drawdown can alter the physical environment and may influence predatory fish performance. We investigated the performance of lake trout (Salvelinus namaycush) in a western reservoir by coupling field measurements with visual foraging and bioenergetic models at four distinct states (early summer, mid-summer, late summer, and fall). The models suggested that lake trout prey, juvenile kokanee (Oncorhynchus nerka), are limited seasonally by suitable temperature and dissolved oxygen. Accordingly, prey densities were greatest in late summer when reservoir volume was lowest and fish were concentrated by stratification. Prey encounter rates (up to 68 fish·day−1) and predator consumption are also predicted to be greatest during late summer. However, our models suggested that turbidity negatively correlates with prey detection and consumption across reservoir states. Under the most turbid conditions, lake trout did not meet physiological demands; however, during less turbid periods, predator consumption reached maximum bioenergetic efficiency. Overall, our findings demonstrate that rapid reservoir fluctuations and associated abiotic conditions can influence predator–prey interactions, and our models describe the potential impacts of water level fluctuation on valuable sport fishes.

  4. Why Seedlings Die: Linking Carbon and Water Limitations to Mechanisms of Mortality During Establishment in Conifer Seedlings

    Science.gov (United States)

    Reinhardt, K.; Germino, M. J.; Kueppers, L. M.; Mitton, J.; Castanha, C.

    2012-12-01

    /or reduced hydraulic conductance), associated with roots unable to escape the seasonal drying front in the soil, would limit seedling survival at least as much as C-balance dysfunction; and 3) seedling mortality would not be due to exhaustion of whole-plant NSC, as suggested by appreciable NSC in dead conifer seedlings reported in alpine treeline studies. RESULTS AND INTERPRETATIONS Preliminary results suggest that photosynthesis, fluorescence, and whole-tree NSC remained high until mortality, when plant water potentials decreased below -5 MPa. As seedlings approached mortality, NSC concentrations (both soluble sugars and starch) in roots decreased from ~9% to phloem-translocation in stems. Thus, seedling death could not be directly attributed to dysfunction of C-balance physiology, or exhaustion of NSC at the whole-plant level. We propose that hydraulic failure was likely the proximate cause of mortality under the conditions we evaluated, and drought-induced inhibition of NSC transport to roots may ultimately undermine the ability of seedlings to tap progressively deeper water sources during summer drying.

  5. Modelling Gender Pay Gaps

    OpenAIRE

    2004-01-01

    EXECUTIVE SUMMARYIntroductionThere has been little change in the full-time gender pay gap since the mid 1990s andin the female part-time/male full-time pay gap since the mid 1970s. The gender gapin hourly earnings for those employed full-time in Britain in 2003 was 18 per cent,while that between women working part-time and men working full-time was 40 percent.This research uses statistical methods to identify how much of the gender pay gap isassociated with different factors. The data set ana...

  6. Filling the Income Gap

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ Income distribution has become one of the people's main concerns in China where more than 30years of reform and opening up have also resulted in an ever-expanding wealth gap.But narrowing down the rich-poor disparity will prove to be no easy task.Wei Zhong,a researcher with the Institute of Economics under the Chinese Academy of Social Sciences,elaborated on the origins and trends of China's widening income gap,and discussed solutions to curb the gap,in a recent article.Edited excerpts follow:

  7. Bridging The Inferential Gap

    Science.gov (United States)

    Stewart, Walter F.; Shah, Nirav R.; Selna, Mark J.; Paulus, Ronald A.; Walker, James M.

    2009-01-01

    Most clinical decisions involve bridging the inferential gap: Clinicians are required to “fill in” where they lack knowledge or where no knowledge yet exists. In this context we consider how the inferential gap is a product, in part, of how knowledge is created, the limits to gaining access to such knowledge, and the variable ways in which knowledge is translated into decisions. We consider how electronic health records (EHRs) will help narrow this gap by accelerating the creation of evidence relevant to everyday practice needs and facilitating real-time use of knowledge in practice. PMID:17259202

  8. Cutting the Link Between Drugs and Terrorists: Countering Major Terrorist-Financing Means

    Science.gov (United States)

    2013-06-01

    try to fill these gaps of the terrorist narcotic interactions by providing a model which could offer a reasonable solution for cutting the links...consumption. In addition to undermining economic and social development, the use of these drugs has brought misery to thousands of people and contributed...consists of nine stages: extracting the morphine from raw opium, separating the morphine solution from the water-insoluble opium components, treatment

  9. Filling the Income Gap

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Income distribution has become one of the people’s main concerns in China where more than 30 years of reform and opening up have also resulted in an ever-expanding wealth gap. But narrowing down the

  10. An ecohydrological sketch of climate change impacts on water and natural ecosystems for The Netherlands: bridging the gap between science and society

    Directory of Open Access Journals (Sweden)

    J. P. M. Witte

    2012-05-01

    Full Text Available For policy making and spatial planning, information is needed about the impacts of climate change on natural ecosystems. To provide this information, commonly hydrological and ecological models are used. We give arguments for our assessment that modelling only is insufficient for determining the impacts of climate changes on natural ecosystems at regional scales. Instead, we proposed a combination of hydrological simulations, a literature review and process-knowledge on climate-hydrology-vegetation interactions, to compile a sketch-map that indicates climate change effects on a number of ecosystems in The Netherlands. Soon after its introduction, copies of our sketch-map appeared in policy documents and in a commercial and popular atlas of The Netherlands. Moreover, the map led to a question in the Dutch parliament about the survivability of bog reserves in the future climate. Apparently, there was an urgent need for the information provided by the map.

    The map shows that climate change will presumably have the largest influence on ecosystems in The Netherlands that depend on precipitation as the major water source, like heathlands, dry grasslands, rain-fed moorland pools and raised bogs. Also highly susceptible are fens in reserves surrounded by deeply drained polders, because such fens depend on the inlet of surface water, of which quality is likely to deteriorate upon climate change. While the map is indicative for directions of change, in view of the uncertainties of our study no conclusions should be drawn that may have far-reaching consequences, such as giving up certain nature targets that might no longer be feasible in the future climate. Instead, we advise to anticipate on the potential threats from climate change by taking a number of adaptation measures that enhance the robustness of nature reserves.

    To improve climate change projections on hydrology and ecosystems, future research should especially focus on

  11. Linking carbon-water- and nitrogen fluxes at forest ecosystems throughout Europe with a coupled soil-vegetation process model "LandscapeDNDC"

    Science.gov (United States)

    Molina Herrera, Saul; Grote, Rüdiger; Haas, Edwin; Kiese, Ralf; Butterbach-Bahl, Klaus

    2013-04-01

    Forest ecosystems in Europe play a key role in the emission reduction commitment agreed in the Kyoto Protocol for mitigating climatic change. Forest ecological functioning and potential services (such as carbon sequestration) are a matter of debate for policy decision makers resulting from the need of identifying affordable strategies for forest management and exploitation against climate change. Forest ecosystem functioning and the linkages governing carbon-, water- and nitrogen fluxes at site scale was evaluated for three dominant tree species (Pinus sylvestris, Picea abies and Fagus sylvatica) grown on 10 different sites across Europe. We did answer in particular the following questions: a) is LandscapeDNDC able to represent NEE, GPP, TER and ET fluxes for dominant forest types in Europe at different sites with only a species specific parameterization? b) What is the relation between carbon input into the ecosystem and on the emission of carbon and nitrogen from the forest soil? Furthermore we analyzed the interaction between carbon-, nitrogen-, and water cycle, in particular the dependence of gaseous fluxes on water and litter availability. LandscapeDNDC is a process based model that integrates modules for carbon, nitrogen and water cycling within terrestrial ecosystems (i.e. forest) on the site and regional scale. Biosphere, atmosphere and hydrosphere processes in forest ecosystems are linked by daily time step integration of the microclimate, water cycle, soil biogeochemistry and tree physiology and dimensional growth modules which balances all three aforementioned cycles. All processes and state variables are considered in a vertically structured one dimensional vertical column that reaches from rooting depth (more than 1 m depth) to the uppermost canopy layer. LandscapeDNDC was tested against long term (about 10 years) field data. The capability of the applied model for reproducing daily derived GPP and TER was accompanied by a high statistical precision (r

  12. Modeling groundwater-surface water interactions in an operational setting by linking object- oriented river basin management model (RiverWare) with 3-D finite-difference groundwater model (MODFLOW).

    Science.gov (United States)

    Valerio, A.; Rajaram, H.; Zagona, E.

    2007-12-01

    Accurate representation of groundwater-surface water interactions is critical to modeling low river flow periods in riparian environments in the semi-arid southwestern United States. As an example, over-appropriation of human water use in the Middle Rio Grande region adversely impacts the habitat of the endangered Rio Grande silvery minnow. Improved management practices during low flow conditions could prevent channel desiccation and habitat destruction. We present a modeling tool with significant potential for improved decision-making in stream reaches influenced by significant surface-groundwater interactions. While river basin management models typically represent operational complexities such as human elements of water demand and consumption with a high degree of sophistication, they often represent groundwater-surface water interactions semi-empirically or at coarse resolution. In contrast, distributed groundwater models, with an adequately fine grid represent groundwater-surface water interactions accurately, but seldom incorporate complex details of water rights and user demands. To best exploit the strengths of both classes of models, we have developed a link between the object-oriented river management software package RiverWare and the USGS groundwater modeling program MODFLOW. An interactive time stepping approach is used in the linked model. RiverWare and MODFLOW run in parallel exchanging data after each time-step. This linked framework incorporates several features critical to modeling groundwater-surface interactions in riparian zones, including riparian ET, localized variations in seepage rates and rule-based water allocations to users and/or environmental flows, and is expected to be an improved tool for modeling groundwater-surface water interaction in regions where groundwater storage repose to changing river conditions is rapid. The performance of the linked model is illustrated through applications on the Rio Grande in the vicinity of

  13. Gap junction communication in myelinating glia.

    Science.gov (United States)

    Nualart-Marti, Anna; Solsona, Carles; Fields, R Douglas

    2013-01-01

    Gap junction communication is crucial for myelination and axonal survival in both the peripheral nervous system (PNS) and central nervous system (CNS). This review examines the different types of gap junctions in myelinating glia of the PNS and CNS (Schwann cells and oligodendrocytes respectively), including their functions and involvement in neurological disorders. Gap junctions mediate intercellular communication among Schwann cells in the PNS, and among oligodendrocytes and between oligodendrocytes and astrocytes in the CNS. Reflexive gap junctions mediating transfer between different regions of the same cell promote communication between cellular compartments of myelinating glia that are separated by layers of compact myelin. Gap junctions in myelinating glia regulate physiological processes such as cell growth, proliferation, calcium signaling, and participate in extracellular signaling via release of neurotransmitters from hemijunctions. In the CNS, gap junctions form a glial network between oligodendrocytes and astrocytes. This transcellular communication is hypothesized to maintain homeostasis by facilitating restoration of membrane potential after axonal activity via electrical coupling and the re-distribution of potassium ions released from axons. The generation of transgenic mice for different subsets of connexins has revealed the contribution of different connexins in gap junction formation and illuminated new subcellular mechanisms underlying demyelination and cognitive defects. Alterations in metabolic coupling have been reported in animal models of X-linked Charcot-Marie-Tooth disease (CMTX) and Pelizaeus-Merzbarcher-like disease (PMLD), which are caused by mutations in the genes encoding for connexin 32 and connexin 47 respectively. Future research identifying the expression and regulation of gap junctions in myelinating glia is likely to provide a better understanding of myelinating glia in nervous system function, plasticity, and disease. This

  14. Holographic Quenches with a Gap

    CERN Document Server

    da Silva, Emilia; Mas, Javier; Serantes, Alexandre

    2016-01-01

    In order to holographically model quenches with a gapped final hamiltonian, we consider a gravity-scalar theory in anti-de Sitter space with an infrared hard wall. We allow a time dependent profile for the scalar field at the wall. This induces an energy exchange between bulk and wall and generates an oscillating scalar pulse. We argue that such backgrounds are the counterpart of quantum revivals in the dual field theory. We perform a qualitative comparison with the quench dynamics of the massive Schwinger model, which has been recently analyzed using tensor network techniques. Agreement is found provided the width of the oscillating scalar pulse is inversely linked to the energy density communicated by the quench. We propose this to be a general feature of holographic quenches.

  15. Holographic quenches with a gap

    Science.gov (United States)

    da Silva, Emilia; Lopez, Esperanza; Mas, Javier; Serantes, Alexandre

    2016-06-01

    In order to holographically model quenches with a gapped final hamiltonian, we consider a gravity-scalar theory in anti-de Sitter space with an infrared hard wall. We allow a time dependent profile for the scalar field at the wall. This induces an energy exchange between bulk and wall and generates an oscillating scalar pulse. We argue that such backgrounds are the counterpart of quantum revivals in the dual field theory. We perform a qualitative comparison with the quench dynamics of the massive Schwinger model, which has been recently analyzed using tensor network techniques. Agreement is found provided the width of the oscillating scalar pulse is inversely linked to the energy density communicated by the quench. We propose this to be a general feature of holographic quenches.

  16. Design of Constant Pressure Water Supply System Based on ARM and CC-Link%基于ARM和CC-Link的恒压供水加压站设计

    Institute of Scientific and Technical Information of China (English)

    黄江平; 吴昊

    2012-01-01

    To meet the current requirements of constant pressure watei supply station system in China,a design method based on ARM9 and CC-Link was proposed. The hardware was designed,drivers and application software ware were developed. ARM9 microprocessor and CC-Link remote long-distance station's core chip MFP3 was used for embedded hardware ware platform,the operating system was Linux,application software ware was developed with Qt/Embedded. The results show that all parts of the system can slablely operate,it can flexibility to build different needs constant pressure water supply systems,storage and display operation of remote device station work. The instrument can meet the functional requirements of system design.%文中提出了一种基于ARM和CC-Link的恒压供水加压站设计方法,进行了硬件的设计、驱动程序以及应用程序的开发.使用ARM9微处理器和CC-Link远程设备站芯片MFP3作为系统的硬件平台,Linux作为操作系统,应用程序使用Qt/Embedded编写.通过实际运行表明,系统远行稳定,可以灵活地组建不同需求的恒压供水系统,存储和显示远程设备站工作运行情况,实现了系统设计的功能要求.

  17. 茅台水源功能区次生林分林窗边缘效应及林窗大小研究%Edge Effect and Size of Secondary Forest Gap in Maotai Water Functional Areas

    Institute of Scientific and Technical Information of China (English)

    李飒; 张玉武; 刘藜; 王华斌; 喻理飞

    2012-01-01

    采用林窗边缘效应测定的方法,对茅台水源功能区次生林分林窗,开展边缘效应及林窗大小关系研究。共调查23个林窗,面积分布在75~300m2。通过对不同大小林窗中树种多样性、边缘效应强度研究,揭示了随着面积的增大,林窗树种的多样性和均匀度增加,优势度降低,其边缘效应在小范围内波动的规律。根据边缘效应起伏的波谷值,将林窗划分成4个大小等级:〈100m2、100~150m2、150~240m2、〉240m2。各等级的树种多样性、边缘效应强度不同,其中150~240m2处,边缘效应强度最强,其次为〉240m2。%Using the edge effect determination, the relationship between edge effect and size of 23 secondary for- est gap was studied in Maotai water functional areas and the size ranges from 75 m2 to 300 m2. Through species di- versity and edge effect on different gap sizes, the study revealed that with the increase of size, the diversity and evenness go up, but dominance goes down, and their edge effect fluctuates in a small scope. Based on troughs of rolling edge effect, gap size is divided into four levels: 〈 100 m2, 100-150 m2, 150-240 m2 and 〉240 m2. Each level has different diversity and edge effect. When in 150-240 m2, the edge effect reaches the strongest, followed by 〉 240 m2.

  18. Integrating Linked Data into Discovery

    Directory of Open Access Journals (Sweden)

    Götz Hatop

    2013-07-01

    Full Text Available Although the Linked Data paradigm has evolved from a research idea to a practical approach for publishing structured data on the web, the performance gap between currently available RDF data stores and the somewhat older search technologies could not be closed. The combination of Linked Data with a search engine can help to improve ad-hoc retrieval. This article presents and documents the process of building a search index for the Solr search engine from bibliographic records published as linked open data.

  19. Communication Links

    OpenAIRE

    2003-01-01

    This interactive tutorial helps learners to: Identify key upward, lateral, downward, and informal communication links in their organizations. , Reflect on the benefits, control, satisfaction, information filters, and feedback mechanism of various communication links in the organizations. OCL1000 Communicating Change in Complex Organizations

  20. Operative links

    DEFF Research Database (Denmark)

    Wistoft, Karen

    2010-01-01

    as networks: second, a semantic perspective on discourses and concepts of health, and, third, a health pedagogical perspective on participation, intervention, and roles. This paper argues for the importance of 'operative links' between different levels in health strategies. It is proposed that such links...

  1. The protein kinase C phosphorylation site on GAP-43 differentially regulates information storage.

    Science.gov (United States)

    Holahan, Matthew; Routtenberg, Aryeh

    2008-01-01

    Protein kinase C (PKC) is known to regulate phosphorylation of substrates such as MARCKS, GAP-43, and the NMDA receptor, all of which have been linked to synaptic plasticity underlying information storage processes. Here we report on three transgenic mice isoforms differentiated both by mutation of the PKC site on GAP-43 as well as by their performance in three learning situations: (1) a radial arm maze task, which evaluates spatial memory and its retention, (2) fear conditioning which assesses contextual memory, and (3) the water maze which also evaluates spatial memory and its retention. The present results show, for the first time to our knowledge, that the phosphorylation state of a single site on an identified brain growth- and plasticity-associated protein differentially regulates performance of three different memory-associated tasks.

  2. Semantic Gaps Are Dangerous

    DEFF Research Database (Denmark)

    Ejstrup, Michael; le Fevre Jakobsen, Bjarne

    Semantic gaps are dangerous Language adapts to the environment where it serves as a tool to communication. Language is a social agreement, and we all have to stick to both grammaticalized and non-grammaticalized rules in order to pass information about the world around us. As such language develops...... unpolite language and tend to create dangerous relations where specialy language creates problems and trouble that could be avoided if we had better language tools at hand. But we have not these tools of communication, and we are in a situation today where media and specially digital and social media......, supported by new possibilities of migration, create dangerous situations. How can we avoid these accidental gaps in language and specially the gaps in semantic and metaphoric tools. Do we have to keep silent and stop discusing certain isues, or do we have other ways to get acces to sufficient language tools...

  3. Gap Cycling for SWIFT

    CERN Document Server

    Corum, Curtis A; Snyder, Carl J; Garwood, Michael

    2013-01-01

    Purpose: SWIFT (SWeep Imaging with Fourier Transformation) is a non- Cartesian MRI method with unique features and capabilities. In SWIFT, radiofrequency (RF) excitation and reception are performed nearly simultaneously, by rapidly switching between transmit and receive during a frequency-swept RF pulse. Because both the transmitted pulse and data acquisition are simultaneously amplitude-modulated in SWIFT (in contrast to continuous RF excitation and uninterrupted data acquisition in more familiar MRI sequences), crosstalk between different frequency bands occurs in the data. This crosstalk leads to a "bulls-eye" artifact in SWIFT images. We present a method to cancel this inter-band crosstalk by cycling the pulse and receive gap positions relative to the un-gapped pulse shape. We call this strategy "gap cycling." Methods: We carry out theoretical analysis, simulation and experiments to characterize the signal chain, resulting artifacts, and their elimination for SWIFT. Results: Theoretical analysis reveals t...

  4. Missing the gap

    DEFF Research Database (Denmark)

    Tanggaard, Lene; Glaveanu, Vlad Petre

    creative learning at the borders need not minimize differences, but handle and learn from them? If not, schools and educational institutions risk becoming bad copies of the labour marked instead of enabling students to enter the market with something new, something radically dissimilar from what......Missing the gap This paper is focused on an exploration of creative learning involved in boundary crossing (Tanggaard, 2007). Our aim is to explore the trajectories and pathways realised by students as they move from education to work and vice versa (Tanggaard & Beghetto, 2015), guided...... by the premise that difference and gaps are places where creative learning is intensified (Glaveanu & Gillespie, 2015). The public discourse around education is often concerned with minding or avoiding the gap by making education more relevant for or similar to the labour market, but what if facilitating...

  5. Use of Heavy Water (D2O in Developing Thermostable Recombinant p26 Protein Based Enzyme-Linked Immunosorbent Assay for Serodiagnosis of Equine Infectious Anemia Virus Infection

    Directory of Open Access Journals (Sweden)

    Harisankar Singha

    2014-01-01

    Full Text Available Thermostabilizing effect of heavy water (D2O or deuterium oxide has been demonstrated previously on several enzymes and vaccines like oral poliovirus vaccine and influenza virus vaccine. In view of the above observations, effect of heavy water on in situ thermostabilization of recombinant p26 protein on enzyme-linked immunosorbent assay (ELISA for serodiagnosis of equine infectious anemia virus (EIAV infection was investigated in the present study. The carbonate-bicarbonate coating buffer was prepared in 60% and 80% D2O for coating the p26 protein in 96-well ELISA plate and thermal stability was examined at 4°C, 37°C, 42°C, and 45°C over a storage time from 2 weeks to 10 months. A set of positive serum (n=12 consisting of strong, medium, and weak titer strength (4 samples in each category and negative serum (n=30 were assessed in ELISA during the study period. At each time point, ELISA results were compared with fresh plate to assess thermal protective effect of D2O. Gradual increase in the stabilizing effect of 80% D2O at elevated temperature (37°C < 42°C < 45°C was observed. The 80% D2O provides the thermal protection to rp26 protein in ELISA plate up to 2 months of incubation at 45°C. The findings of the present study have the future implication of adopting cost effective strategies for generating more heat tolerable ELISA reagents with extended shelf life.

  6. Use of heavy water (D2O) in developing thermostable recombinant p26 protein based enzyme-linked immunosorbent assay for serodiagnosis of equine infectious anemia virus infection.

    Science.gov (United States)

    Singha, Harisankar; Goyal, Sachin K; Malik, Praveen; Singh, Raj K

    2014-01-01

    Thermostabilizing effect of heavy water (D2O) or deuterium oxide has been demonstrated previously on several enzymes and vaccines like oral poliovirus vaccine and influenza virus vaccine. In view of the above observations, effect of heavy water on in situ thermostabilization of recombinant p26 protein on enzyme-linked immunosorbent assay (ELISA) for serodiagnosis of equine infectious anemia virus (EIAV) infection was investigated in the present study. The carbonate-bicarbonate coating buffer was prepared in 60% and 80% D2O for coating the p26 protein in 96-well ELISA plate and thermal stability was examined at 4 °C, 37 °C, 42 °C, and 45 °C over a storage time from 2 weeks to 10 months. A set of positive serum (n = 12) consisting of strong, medium, and weak titer strength (4 samples in each category) and negative serum (n = 30) were assessed in ELISA during the study period. At each time point, ELISA results were compared with fresh plate to assess thermal protective effect of D2O. Gradual increase in the stabilizing effect of 80% D2O at elevated temperature (37 °C < 42 °C < 45 °C) was observed. The 80% D2O provides the thermal protection to rp26 protein in ELISA plate up to 2 months of incubation at 45 °C. The findings of the present study have the future implication of adopting cost effective strategies for generating more heat tolerable ELISA reagents with extended shelf life.

  7. Comparison of enzyme-linked immunosorbent assay and gas chromatography procedures for the detection of cyanazine and metolachlor in surface water samples

    Science.gov (United States)

    Schraer, S.M.; Shaw, D.R.; Boyette, M.; Coupe, R.H.; Thurman, E.M.

    2000-01-01

    Enzyme-linked immunosorbent assay (ELISA) data from surface water reconnaissance were compared to data from samples analyzed by gas chromatography for the pesticide residues cyanazine (2-[[4-chloro-6-(ethylamino)-l,3,5-triazin-2-yl]amino]-2-methylpropanenitrile ) and metolachlor (2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide). When ELISA analyses were duplicated, cyanazine and metolachlor detection was found to have highly reproducible results; adjusted R2s were 0.97 and 0.94, respectively. When ELISA results for cyanazine were regressed against gas chromatography results, the models effectively predicted cyanazine concentrations from ELISA analyses (adjusted R2s ranging from 0.76 to 0.81). The intercepts and slopes for these models were not different from 0 and 1, respectively. This indicates that cyanazine analysis by ELISA is expected to give the same results as analysis by gas chromatography. However, regressing ELISA analyses for metolachlor against gas chromatography data provided more variable results (adjusted R2s ranged from 0.67 to 0.94). Regression models for metolachlor analyses had two of three intercepts that were not different from 0. Slopes for all metolachlor regression models were significantly different from 1. This indicates that as metolachlor concentrations increase, ELISA will over- or under-estimate metolachlor concentration, depending on the method of comparison. ELISA can be effectively used to detect cyanazine and metolachlor in surface water samples. However, when detections of metolachlor have significant consequences or implications it may be necessary to use other analytical methods.

  8. Milk progesterone enzyme-linked immunosorbent assay as a tool to investigate ovarian cyclicity of water buffaloes in relation to body condition score and milk production

    Directory of Open Access Journals (Sweden)

    Banu Turgish A

    2012-05-01

    Full Text Available Abstract Background Application of assisted reproductive technologies in buffaloes is limited to some extent by farmers’ inability to detect oestrus because of its poor expression. The present study aimed at investigating reliability of a milk progesterone enzyme-linked immunosorbent assay (ELISA to assess the ovarian cyclicity during post partum, oestrus and post-breeding periods in water buffaloes. Methods Progesterone concentrations were measured by an ELISA in milk of 23 postpartum buffaloes in relation to oestrus, pregnancy, body condition score (BCS and milk production. Two milk samples were taken at 10 days intervals, every month starting from day 30 and continued to day 150 post partum. BCS and milk production were recorded during sample collection. Milk samples from bred buffaloes were collected at Day 0 (day of breeding, Days 10–12 and Days 22–24. Defatted milk was preserved at −80°C until analysis. Pregnancy was confirmed by palpation per rectum on Days 70–90. Results Seventeen buffaloes had 47 ovulatory cycles, one to four in each, 13 were detected in oestrus once (28 % oestrus detection rate. Progesterone concentration ≥1 ng/ml in one of the two 10-day-interval milk samples reflected ovulation and corpus luteum formation. The intervals between calving to first luteal activity and to first detected oestrus varied from 41 to 123 days (n = 17 and 83 to 135 (n = 13 days, respectively. Eight buffaloes were bred in the course of the study and seven were found pregnant. These buffaloes had a progesterone profile of low (P P  Conclusions Milk progesterone ELISA is a reliable tool for monitoring ovarian cyclicity and good BCS may be an indicator of resuming cyclicity in water buffalo.

  9. Gap junction diseases of the skin.

    NARCIS (Netherlands)

    Steensel, M.A.M. van

    2004-01-01

    Gap junctions are intercellular channels that allow the passage of water, ions, and small molecules. They are involved in quick, short-range messaging between cells and are found in skin, nervous tissue, heart, and muscle. An increasing number of hereditary skin disorders appear to be caused by muta

  10. Gap junction diseases of the skin.

    NARCIS (Netherlands)

    Steensel, M.A.M. van

    2004-01-01

    Gap junctions are intercellular channels that allow the passage of water, ions, and small molecules. They are involved in quick, short-range messaging between cells and are found in skin, nervous tissue, heart, and muscle. An increasing number of hereditary skin disorders appear to be caused by muta

  11. Terminology gap in hydrological cycle

    Science.gov (United States)

    Zhuo, Lu; Han, Dawei

    2016-04-01

    Water is central to life on Earth. People have been trying to understand how water moves in the hydrosphere throughout the human history. In the 9th century BC, the famous Greek poet Homer described the hydrological cycle in Iliad as "okeanos whose stream bends back in a circle" with a belief that rivers are ocean-fed from subterranean seas. Later, Aristotle (4th century BC) claimed that most of the water came from underground caverns in which air was transformed into water. It was only until 1674, French scientist Perrault developed the correct concept of the water cycle. In modern times, scientists are interested in understanding the individual processes of the hydrological cycle with a keen focus on runoff which supplies water to rivers, lakes, and oceans. Currently, the prevailing concepts on runoff processes include 'infiltration excess runoff' and 'saturation excess runoff'. However, there is no term to describe another major runoff due to the excess beyond the soil water holding capacity (i.e., the field capacity). We argue that a new term should be introduced to fill this gap, and it could be called 'holding excess runoff' which is compatible with the convention. This new term is significant in correcting a half-century misnomer where 'holding excess runoff' has been incorrectly named as 'saturation excess runoff', which was introduced by the Xinanjiang model in China in 1960s. Similar concept has been adopted in many well-known hydrological models such as PDM and HBV in which the saturation refers to the field capacity. The term 'holding excess runoff' resolves such a common confusion in the hydrological community.

  12. The longevity gender gap

    DEFF Research Database (Denmark)

    Aviv, Abraham; Shay, Jerry; Christensen, Kaare

    2005-01-01

    In this Perspective, we focus on the greater longevity of women as compared with men. We propose that, like aging itself, the longevity gender gap is exceedingly complex and argue that it may arise from sex-related hormonal differences and from somatic cell selection that favors cells more...... resistant to the ravages of time. We discuss the interplay of these factors with telomere biology and oxidative stress and suggest that an explanation for the longevity gender gap may arise from a better understanding of the differences in telomere dynamics between men and women....

  13. Peroxidase-like catalytic activity of water-insoluble complex linked Fe(III)-thiacalix[4]arenetetrasulfonate with tetrakis(1-methylpyridinium-4-yl)porphine via ionic interaction.

    Science.gov (United States)

    Odo, Junichi; Sumihiro, Manabu; Okadome, Takuma; Inoguchi, Masahiko; Akashi, Haruo; Nakagoe, Kazunori

    2009-12-01

    A new water-insoluble Fe(3+)-TCAS[4]/TMPyP complex linked tetraanionic Fe(III)-thiacalix[4]arenetetrasulfonate (Fe(3+)-TCAS[4]) with tetracationic tetrakis(1-methylpyridinium-4-yl)porphine (TMPyP) via ionic interaction was prepared. The peroxidase-like catalytic activity of the Fe(3+)-TCAS[4]/TMPyP complex was investigated based on the dye formation reaction by oxidation of 4-aminoantipyrine and phenol with H(2)O(2) catalyzed by peroxidase. This Fe(3+)-TCAS[4]/TMPyP complex showed the highest activity in pH 5.5 acetate buffer solutions, and it was applied to the photometric determination of trace amounts of H(2)O(2). The calibration curve was linear over the range from 1.0 to 35 microg of H(2)O(2) in a 1.0 ml sample solution. Moreover, the method using glucoseoxidase and the Fe(3+)-TCAS[4]/TMPyP complex was applied to the determination of glucose, and the results were satisfactory even in control sera. The Fe(3+)-TCAS[4]/TMPyP complex can be applied to a practical sample, such as blood or urine, as an analytical reagent for the photometric determination of H(2)O(2) in place of peroxidase.

  14. Efficient removal of aniline by a water-compatible microporous and mesoporous hyper-cross-linked resin and XAD-4 resin: A comparative study

    Science.gov (United States)

    Xiao, Guqing; Long, Liping

    2012-06-01

    A novel water-compatible microporous and mesoporous hyper-cross-linked resin modified with phenolic hydroxyl group (named as GQ-03) was synthesized to remove aniline in aqueous solution as compared with XAD-4. The maximum adsorption capacity of GQ-03 emerged at the molecular state for both aniline and p-cresol while the pH dependency trend of aniline adsorbed onto XAD-4 was accordant with the dissociation curve of aniline. The ionic strength influenced the adsorption obviously. The pseudo-first-order rate equation could describe the adsorption process of aniline onto GQ-03 in two stages while this equation could characterize the entire adsorption process of XAD-4. The adsorption isotherms could be correlated to the Freundlich model, higher KF and n values for GQ-03 than XAD-4. The breakthrough capacity and the total adsorption capacity of GQ-03 and XAD-4 was up to 47.2 mg mL-1 and 28.3 mg mL-1, 271.7 mg mL-1 and 115.6 mg mL-1, respectively. The size matching between the pore diameter of GQ-03 and the molecular size of aniline, and hydrogen bonding between GQ-03 and aniline resulted in the larger adsorption capacity.

  15. Water-quality modeling of Klamath Straits Drain recirculation, a Klamath River wetland, and 2011 conditions for the Link River to Keno Dam reach of the Klamath River, Oregon

    Science.gov (United States)

    Sullivan, Annett B.; Sogutlugil, I. Ertugrul; Deas, Michael L.; Rounds, Stewart A.

    2014-01-01

    The upper Klamath River and adjacent Lost River are interconnected basins in south-central Oregon and northern California. Both basins have impaired water quality with Total Maximum Daily Loads (TMDLs) in progress or approved. In cooperation with the Bureau of Reclamation, the U.S. Geological Survey (USGS) and Watercourse Engineering, Inc., have conducted modeling and research to inform management of these basins for multiple purposes, including agriculture, endangered species protection, wildlife refuges, and adjacent and downstream water users. A water-quality and hydrodynamic model (CE-QUAL-W2) of the Link River to Keno Dam reach of the Klamath River for 2006–09 is one of the tools used in this work. The model can simulate stage, flow, water velocity, ice cover, water temperature, specific conductance, suspended sediment, nutrients, organic matter in bed sediment and the water column, three algal groups, three macrophyte groups, dissolved oxygen, and pH. This report documents two model scenarios and a test of the existing model applied to year 2011, which had exceptional water quality. The first scenario examined the water-quality effects of recirculating Klamath Straits Drain flows into the Ady Canal, to conserve water and to decrease flows from the Klamath Straits Drain to the Klamath River. The second scenario explicitly incorporated a 2.73×106 m2 (675 acre) off-channel connected wetland into the CE-QUAL-W2 framework, with the wetland operating from May 1 through October 31. The wetland represented a managed treatment feature to decrease organic matter loads and process nutrients. Finally, the summer of 2011 showed substantially higher dissolved-oxygen concentrations in the Link-Keno reach than in other recent years, so the Link-Keno model (originally developed for 2006–09) was run with 2011 data as a test of model parameters and rates and to develop insights regarding the reasons for the improved water-quality conditions.

  16. Gap junctions: structure and function (Review).

    Science.gov (United States)

    Evans, W Howard; Martin, Patricia E M

    2002-01-01

    Gap junctions are plasma membrane spatial microdomains constructed of assemblies of channel proteins called connexins in vertebrates and innexins in invertebrates. The channels provide direct intercellular communication pathways allowing rapid exchange of ions and metabolites up to approximately 1 kD in size. Approximately 20 connexins are identified in the human or mouse genome, and orthologues are increasingly characterized in other vertebrates. Most cell types express multiple connexin isoforms, making likely the construction of a spectrum of heteromeric hemichannels and heterotypic gap junctions that could provide a structural basis for the charge and size selectivity of these intercellular channels. The precise nature of the potential signalling information traversing junctions in physiologically defined situations remains elusive, but extensive progress has been made in elucidating how connexins are assembled into gap junctions. Also, participation of gap junction hemichannels in the propagation of calcium waves via an extracellular purinergic pathway is emerging. Connexin mutations have been identified in a number of genetically inherited channel communication-opathies. These are detected in connexin 32 in Charcot Marie Tooth-X linked disease, in connexins 26 and 30 in deafness and skin diseases, and in connexins 46 and 50 in hereditary cataracts. Biochemical approaches indicate that many of the mutated connexins are mistargeted to gap junctions and/or fail to oligomerize correctly into hemichannels. Genetic ablation approaches are helping to map out a connexin code and point to specific connexins being required for cell growth and differentiation as well as underwriting basic intercellular communication.

  17. Link Analysis

    Science.gov (United States)

    Donoho, Steve

    Link analysis is a collection of techniques that operate on data that can be represented as nodes and links. This chapter surveys a variety of techniques including subgraph matching, finding cliques and K-plexes, maximizing spread of influence, visualization, finding hubs and authorities, and combining with traditional techniques (classification, clustering, etc). It also surveys applications including social network analysis, viral marketing, Internet search, fraud detection, and crime prevention.

  18. Estimating Gender Wage Gaps

    Science.gov (United States)

    McDonald, Judith A.; Thornton, Robert J.

    2011-01-01

    Course research projects that use easy-to-access real-world data and that generate findings with which undergraduate students can readily identify are hard to find. The authors describe a project that requires students to estimate the current female-male earnings gap for new college graduates. The project also enables students to see to what…

  19. Closing the Gap

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    China's recent economic success has brought positive changes to its urban population,but left those in the countryside way behind.The gap in income and living standrs that always existed between urban and rural dwellers has widened alarmingly in the past two decades,causing serious problems.

  20. Structuring the Information Gap.

    Science.gov (United States)

    Edge, Julian

    1984-01-01

    Describes an information gap procedure to teach a new structure which requires students to look for and exchange information in order to complete a task in an English as a second language class. Illustrates the method with a set of materials and suggests ways for teachers to produce similar materials. (SED)

  1. 'Mind the Gap!'

    DEFF Research Database (Denmark)

    Persson, Karl Gunnar

    This paper challenges the widely held view that sharply falling real transport costs closed the transatlantic gap in grain prices in the second half of the 19th century. Several new results emerge from an analysis of a new data set of weekly wheat prices and freight costs from New York to UK mark...

  2. Bridging the Technological Gap.

    Science.gov (United States)

    Lazow, Robert; And Others

    The aim of "Bridging the Technological Gap" (BTG), a federally funded demonstration project, is to use microcomputer technology in the rehabilitation of the psychiatrically disabled. Through the use of a custom designed microcomputer software package, clients receive remediation in areas of specific cognitive and behavioral deficits. The project…

  3. Co-localisation of K(ir)4.1 and AQP4 in rat and human cochleae reveals a gap in water channel expression at the transduction sites of endocochlear K(+) recycling routes.

    Science.gov (United States)

    Eckhard, Andreas; Gleiser, Corinna; Rask-Andersen, Helge; Arnold, Heinz; Liu, Wei; Mack, Andreas; Müller, Marcus; Löwenheim, Hubert; Hirt, Bernhard

    2012-10-01

    Sensory transduction in the cochlea depends on perilymphatic-endolymphatic potassium (K(+)) recycling. It has been suggested that the epithelial supporting cells (SCs) of the cochlear duct may form the intracellular K(+) recycling pathway. Thus, they must be endowed with molecular mechanisms that facilitate K(+) uptake and release, along with concomitant osmotically driven water movements. As yet, no molecules have been described that would allow for volume-equilibrated transepithelial K(+) fluxes across the SCs. This study describes the subcellular co-localisation of the K(ir)4.1 K(+) channel (K(ir)4.1) and the aquaporin-4 water channel (AQP4) in SCs, on the basis of immunohistochemical double-labelling experiments in rat and human cochleae. The results of this study reveal the expression of K(ir)4.1 in the basal or basolateral membranes of the SCs in the sensory domain of the organ of Corti that are adjacent to hair cells and in the non-sensory domains of the inner and outer sulci that abut large extracellular fluid spaces. The SCs of the inner sulcus (interdental cells, inner sulcus cells) and the outer sulcus (Hensen's cells, outer sulcus cells) display the co-localisation of K(ir)4.1 and AQP4 expression. However, the SCs in the sensory domain of the organ of Corti reveal a gap in the expression of AQP4. The outer pillar cell is devoid of both K(ir)4.1 and AQP4. The subcellular co-localisation of K(ir)4.1 and AQP4 in the SCs of the cochlea described in this study resembles that of the astroglia of the central nervous system and the glial Mueller cells in the retina.

  4. Synthesis of Submicron Hexagonal Plate-Type SnS2 and Band Gap-Tuned Sn1−xTixS2 Materials and Their Hydrogen Production Abilities on Methanol/Water Photosplitting

    Directory of Open Access Journals (Sweden)

    Kang Min Kim

    2014-01-01

    Full Text Available SnS2 and Sn1−xTixS2 (x = 0, 0.1, 0.3, 0.5, and 0.7 mol materials were designed using solvothermal method with the aim to enhance hydrogen production from water/methanol water photosplitting. Scanning electron microscopy revealed hexagonal plates with one side, 3.0 μm in length, in the SnS2 materials. Pure SnS2 showed absorption band edges of above 660 nm, and the absorption was shifted to low wavelengths with the insertion of Ti ions. The evolution of H2 from MeOH/H2O (1 : 1 photosplitting over SnS2 hexagonal plates in the photocatalytic liquid system was 0.016 mL h−1 g−1, and the evolutions were enhanced in Sn1−xTixS2. In particular, 0.049 mL h−1 g−1 of H2 gas was produced in Sn0.7Ti0.3S2 without electrolytes and it increased significantly to more than 90.6% (0.47 mL h−1 g−1 evolutions at higher pH using 0.1 M of KOH. Based on the UV-visible absorption spectra, the high photocatalytic activity of Sn1−xTixS2 was attributed to the existence of an appropriate band-gap state that retarded recombination between the electrons and holes.

  5. What is the Mass of a Gap-opening Planet?

    Science.gov (United States)

    Dong, Ruobing; Fung, Jeffrey

    2017-02-01

    High-contrast imaging instruments such as GPI and SPHERE are discovering gap structures in protoplanetary disks at an ever faster pace. Some of these gaps may be opened by planets forming in the disks. In order to constrain planet formation models using disk observations, it is crucial to find a robust way to quantitatively back out the properties of the gap-opening planets, in particular their masses, from the observed gap properties, such as their depths and widths. Combining 2D and 3D hydrodynamics simulations with 3D radiative transfer simulations, we investigate the morphology of planet-opened gaps in near-infrared scattered-light images. Quantitatively, we obtain correlations that directly link intrinsic gap depths and widths in the gas surface density to observed depths and widths in images of disks at modest inclinations under finite angular resolution. Subsequently, the properties of the surface density gaps enable us to derive the disk scale height at the location of the gap h, and to constrain the quantity Mp2/α, where Mp is the mass of the gap-opening planet and α characterizes the viscosity in the gap. As examples, we examine the gaps recently imaged by VLT/SPHERE, Gemini/GPI, and Subaru/HiCIAO in HD 97048, TW Hya, HD 169142, LkCa 15, and RX J1615.3-3255. Scale heights of the disks and possible masses of the gap-opening planets are derived assuming each gap is opened by a single planet. Assuming α = 10‑3, the derived planet masses in all cases are roughly between 0.1 and 1 MJ.

  6. Recent Advances in Quantifying Hydrological Processes Linking Water, Carbon, and Energy Exports into Coastal Margins Along the Arctic Land-Sea Boundary

    Science.gov (United States)

    Rawlins, M. A.

    2014-12-01

    The high northern latitudes have experienced rapid warming in recent decades with projections of larger increases likely by the end of this century. Warming permafrost and an acceleration of the arctic freshwater cycle are among the myriad interconnected changes taking place that have the potential to impact ecosystems throughout the pan-Arctic. The Arctic Ocean receives a disproportionately large amount of global freshwater runoff and as such near-shore coastal margins along the arctic land-sea boundary are strongly influenced by riverine freshwater discharge. Alterations in hydrological flows driven by a changing climate and other perturbations, therefore, are likely to impact the biology and biogeochemistry of arctic coastal margins. Advances have been made in the quantification of water, carbon, and materials transports with recent studies documenting significant changes in exports of quantities such as dissolved organic carbon from large rivers, linked in turn to changes in landscape characteristics and hydrological flow rates. Here key measured data sets, derived empirical relationships, and the resulting pan-Arctic estimates for several constituents are described for the major arctic rivers and full pan-Arctic basin. Complementary estimates from a process-based model are presented, illustrating the potential for leveraging measured data to derive more accurate flows at basin and continental scales. A series of retrospective model simulations point to an increasing influence of river-borne heat transport on ice melt in coastal margins. Case studies of large freshwater anomalies provide a framework for understanding connections between river discharge and the biology and biogeochemistry of arctic coastal margins.

  7. Small Generation Gap

    Institute of Scientific and Technical Information of China (English)

    JANE SHAW

    1994-01-01

    IT was while I was making milk for my son that I discovered the generation gap between us. A little thing of two years and three months, my son stood on a big chair I brought him and joined me to make milk. Holding a small spoon in his plump little hand, he scooped flour out of a jar and poured it into the feeding bottle and then scooped milk powder and

  8. Gap junction diseases of the skin.

    Science.gov (United States)

    van Steensel, M A M

    2004-11-15

    Gap junctions are intercellular channels that allow the passage of water, ions, and small molecules. They are involved in quick, short-range messaging between cells and are found in skin, nervous tissue, heart, and muscle. An increasing number of hereditary skin disorders appear to be caused by mutations in one of the genes coding for the constituent proteins of gap junctions, known as connexins. In this review, the currently known connexin disorders that feature skin abnormalities are described: keratitis-ichthyosis deafness syndrome, erythrokeratoderma variabilis, Vohwinkel's syndrome, and a novel disorder called hypotrichosis-deafness syndrome. What is known about the pathogenesis of these disorders is discussed and related to gap junction physiology. (c) 2004 Wiley-Liss, Inc.

  9. European water policy and research on water-related topics - An overview

    Science.gov (United States)

    Quevauviller, Philippe

    2014-10-01

    European water policy developments are essentially linked to the implementation of the EU Water Framework Directive and parent legislation, which is built upon the principle of river basin management planning with the objective of achieving good status for all European water bodies. Recent policy developments in the climate change area call for ‘climate proofing' of EU actions through mainstreaming of adaptation measures into policies and programmes. These policy trends are very closely related to the capacity to get access to supporting scientific information and to bridge the knowledge gap. This paper is about these features, serving as an introduction to the special issue of Journal of Hydrology on climatic change impact on water: overcoming data and science gaps.

  10. EVA Systems Technology Gaps and Priorities 2017

    Science.gov (United States)

    Johnson, Brian J.; Buffington, Jesse A.

    2017-01-01

    Performance of Extra-Vehicular Activities (EVA) has been and will continue to be a critical capability for human space flight. Human exploration missions beyond LEO will require EVA capability for either contingency or nominal activities to support mission objectives and reduce mission risk. EVA systems encompass a wide array of products across pressure suits, life support systems, EVA tools and unique spacecraft interface hardware (i.e. EVA Translation Paths and EVA Worksites). In a fiscally limited environment with evolving transportation and habitation options, it is paramount that the EVA community's strategic planning and architecture integration products be reviewed and vetted for traceability between the mission needs far into the future to the known technology and knowledge gaps to the current investments across EVA systems. To ascertain EVA technology and knowledge gaps many things need to be brought together, assessed and analyzed. This includes an understanding of the destination environments, various mission concept of operations, current state of the art of EVA systems, EVA operational lessons learned, and reference advanced capabilities. A combined assessment of these inputs should result in well-defined list of gaps. This list can then be prioritized depending on the mission need dates and time scale of the technology or knowledge gap closure plan. This paper will summarize the current state of EVA related technology and knowledge gaps derived from NASA's Exploration EVA Reference Architecture and Operations Concept products. By linking these products and articulating NASA's approach to strategic development for EVA across all credible destinations an EVA could be done in, the identification of these gaps is then used to illustrate the tactical and strategic planning for the EVA technology development portfolio. Finally, this paper illustrates the various "touch points" with other human exploration risk identification areas including human health and

  11. GapBlaster-A Graphical Gap Filler for Prokaryote Genomes.

    Science.gov (United States)

    de Sá, Pablo H C G; Miranda, Fábio; Veras, Adonney; de Melo, Diego Magalhães; Soares, Siomar; Pinheiro, Kenny; Guimarães, Luis; Azevedo, Vasco; Silva, Artur; Ramos, Rommel T J

    2016-01-01

    The advent of NGS (Next Generation Sequencing) technologies has resulted in an exponential increase in the number of complete genomes available in biological databases. This advance has allowed the development of several computational tools enabling analyses of large amounts of data in each of the various steps, from processing and quality filtering to gap filling and manual curation. The tools developed for gap closure are very useful as they result in more complete genomes, which will influence downstream analyses of genomic plasticity and comparative genomics. However, the gap filling step remains a challenge for genome assembly, often requiring manual intervention. Here, we present GapBlaster, a graphical application to evaluate and close gaps. GapBlaster was developed via Java programming language. The software uses contigs obtained in the assembly of the genome to perform an alignment against a draft of the genome/scaffold, using BLAST or Mummer to close gaps. Then, all identified alignments of contigs that extend through the gaps in the draft sequence are presented to the user for further evaluation via the GapBlaster graphical interface. GapBlaster presents significant results compared to other similar software and has the advantage of offering a graphical interface for manual curation of the gaps. GapBlaster program, the user guide and the test datasets are freely available at https://sourceforge.net/projects/gapblaster2015/. It requires Sun JDK 8 and Blast or Mummer.

  12. GapBlaster-A Graphical Gap Filler for Prokaryote Genomes.

    Directory of Open Access Journals (Sweden)

    Pablo H C G de Sá

    Full Text Available The advent of NGS (Next Generation Sequencing technologies has resulted in an exponential increase in the number of complete genomes available in biological databases. This advance has allowed the development of several computational tools enabling analyses of large amounts of data in each of the various steps, from processing and quality filtering to gap filling and manual curation. The tools developed for gap closure are very useful as they result in more complete genomes, which will influence downstream analyses of genomic plasticity and comparative genomics. However, the gap filling step remains a challenge for genome assembly, often requiring manual intervention. Here, we present GapBlaster, a graphical application to evaluate and close gaps. GapBlaster was developed via Java programming language. The software uses contigs obtained in the assembly of the genome to perform an alignment against a draft of the genome/scaffold, using BLAST or Mummer to close gaps. Then, all identified alignments of contigs that extend through the gaps in the draft sequence are presented to the user for further evaluation via the GapBlaster graphical interface. GapBlaster presents significant results compared to other similar software and has the advantage of offering a graphical interface for manual curation of the gaps. GapBlaster program, the user guide and the test datasets are freely available at https://sourceforge.net/projects/gapblaster2015/. It requires Sun JDK 8 and Blast or Mummer.

  13. Going against the flow: a critical analysis of inter-state virtual water trade in the context of India’s National River Linking Program

    NARCIS (Netherlands)

    Verma, Shilp; Kampman, Doeke A.; Zaag, van der Pieter; Hoekstra, Arjen Y.

    2009-01-01

    Virtual water trade has been promoted as a tool to address national and regional water scarcity. In the context of international (food) trade, this concept has been applied with a view to optimize the flow of commodities considering the water endowments of nations. The concept states that water rich

  14. Water

    Science.gov (United States)

    Leopold, Luna Bergere; Baldwin, Helene L.

    1962-01-01

    What do you use water for?If someone asked you this question you would probably think right away of water for drinking. Then you would think of water for bathing, brushing teeth, flushing the toilet. Your list would get longer as you thought of water for cooking, washing the dishes, running the garbage grinder. Water for lawn watering, for play pools, for swimming pools, for washing the car and the dog. Water for washing machines and for air conditioning. You can hardly do without water for fun and pleasure—water for swimming, boating, fishing, water-skiing, and skin diving. In school or the public library, you need water to wash your hands, or to have a drink. If your home or school bursts into flames, quantities of water are needed to put it out.In fact, life to Americans is unthinkable without large supplies of fresh, clean water. If you give the matter a little thought, you will realize that people in many countries, even in our own, may suffer from disease and dirt simply because their homes are not equipped with running water. Imagine your own town if for some reason - an explosion, perhaps - water service were cut off for a week or several weeks. You would have to drive or walk to a neighboring town and bring water back in pails. Certainly if people had to carry water themselves they might not be inclined to bathe very often; washing clothes would be a real chore.Nothing can live without water. The earth is covered by water over three-fourths of its surface - water as a liquid in rivers, lakes and oceans, and water as ice and snow on the tops of high mountains and in the polar regions. Only one-quarter of our bodies is bone and muscle; the other three-fourths is made of water. We need water to live, and so do plants and animals. People and animals can live a long time without food, but without water they die in a few days. Without water, everything would die, and the world would turn into a huge desert.

  15. Microwave resonant activation in hybrid single-gap/two-gap Josephson tunnel junctions

    Science.gov (United States)

    Carabello, Steven; Lambert, Joseph G.; Mlack, Jerome; Dai, Wenqing; Li, Qi; Chen, Ke; Cunnane, Daniel; Xi, X. X.; Ramos, Roberto C.

    2016-09-01

    Microwave resonant activation is a powerful, straightforward technique to study classical and quantum systems, experimentally realized in Josephson junction devices cooled to very low temperatures. These devices typically consist of two single-gap superconductors separated by a weak link. We report the results of the first resonant activation experiments on hybrid thin film Josephson junctions consisting of a multi-gap superconductor (MgB2) and a single-gap superconductor (Pb or Sn). We can interpret the plasma frequency in terms of theories both for conventional and hybrid junctions. Using these models, we determine the junction parameters including critical current, resistance, and capacitance and find moderately high quality factors of Q0˜ 100 for these junctions.

  16. Research on Power Frequency Discharge Characteristics and Mechanism of the Protection Gap of the Combined Fluid of Air And Water Used on Transformer Neutral Points%变压器中性点气水两相组合流体保护间隙的工频放电特性与机制研究

    Institute of Scientific and Technical Information of China (English)

    李博江; 文习山; 严玉婷; 李博洋; 王贺; 于建立

    2014-01-01

    为克服变压器中性点传统空气保护间隙存在的缺陷,提出了“气水间隙”概念,并在武汉大学电气工程学院高电压与绝缘技术试验室进行了气水间隙工频放电特性试验。试验结果表明:当水流从低压电极喷射到高压电极时,间隙很难击穿;当间隙总长度固定,工频放电电压随喷射水流长度减小呈先减小后增大的变化趋势;当喷射水流长度略小于间隙总长度时,工频放电电压与间隙总长度呈线性递增关系;同等长度的气水间隙比空气间隙和全水间隙易击穿,等等。基于气泡击穿理论和空气与水不同的电特性,对试验观察到的放电现象、规律和机制进行分析,指出水流的击穿起因是其中的“气泡桥”的存在和发展,以及水中电离子作用的结果;在气水间隙中,空气段率先击穿形成的电弧高温加热水流促使水中气泡的产生和发展,最终导致水流段的击穿;气水间隙放电特性曲线具有先减小后增大的变化趋势特征是空气和水流不同的电特性相互作用的结果;将气水间隙应用于变压器中性点保护,具有较可观的研究价值和应用前景。%To overcome the disadvantages of traditional protection air gaps of transformer neutral points, the concept of the gap of water and air was presented. The power frequency discharge test between the gap of air and water was conducted in high voltage test room of School of Electrical Engineering in Wuhan University. Test results show that breakdown of the gap is very hard to occur when flow is jetted to the high voltage electrode from low voltage electrode; power frequency discharge voltage will decrease first and increase then with flow length decreasing when the total length of the gap is constant; there is a linear increasing relation between power frequency discharge voltage and total length of the gap when the flow length is somewhat less than the

  17. Gap Opening in 3D: Single Planet Gaps

    CERN Document Server

    Fung, Jeffrey

    2016-01-01

    Giant planets can clear deep gaps when embedded in 2D (razor-thin) viscous circumstellar disks. We show by direct simulation that giant planets are just as capable of carving out gaps in 3D. Surface density maps are similar between 2D and 3D, even in detail. In particular, the scaling $\\Sigma_{\\rm gap} \\propto q^{-2}$ of gap surface density with planet mass, derived from a global "zero-dimensional" balance of Lindblad and viscous torques, applies equally well to results obtained at higher dimensions. Our 3D simulations reveal extensive, near-sonic, meridional flows both inside and outside the gaps; these large-scale circulations might bear on disk compositional gradients, in dust or other chemical species. At high planet mass, gap edges are mildly Rayleigh unstable and intermittently shed streams of material into the gap - less so in 3D than in 2D.

  18. Water

    Science.gov (United States)

    ... Lead Poisoning Prevention Training Center (HHLPPTC) Training Tracks Water Language: English Español (Spanish) Recommend on Facebook Tweet Share Compartir For information about lead in water in Flint, MI, please visit http://www.phe. ...

  19. Unveiling the Gap

    DEFF Research Database (Denmark)

    Jensson, Pall; Rokkjær, Ole; Nørgaard, Bente

    discussing their NQF and Sweden has decided not to adjust to the EQF for the moment. Analysis of the subject focus for the individual programmes showed a high degree of variation. In the context of CDIO this means that what seems to be a well-known and commonly accepted definition of a discipline like IE...... needs, how universities decide what to teach, and how to bridge the gap. Do the university programs simply reflect the expertise of the faculty members? Is there need for increasing emphasis on continuing education? Is life-long education the answer, and has this been addressed by the CDIO community?...

  20. Mind the gap

    Energy Technology Data Exchange (ETDEWEB)

    Bhagwat, M.S.; Roberts, C.D. [Argonne National Laboratory, Physics Division, Argonne, IL (United States); Krassnigg, A. [Universitaet Graz, Fachbereich Theoretische Physik, Graz (Austria); Maris, P. [University of Pittsburgh, Department of Physics and Astronomy, PA (United States)

    2007-03-15

    In this summary of the application of Dyson-Schwinger equations to the theory and phenomenology of hadrons, some deductions following from a nonperturbative, symmetry-preserving truncation are highlighted, notable amongst which are results for pseudoscalar mesons. We also describe inferences from the gap equation relating to the radius of convergence of a chiral expansion, applications to heavy-light and heavy-heavy mesons, and quantitative estimates of the contribution of quark orbital angular momentum in pseudoscalar mesons; and recapitulate upon studies of nucleon electromagnetic form factors. (orig.)

  1. Mind the gap.

    Energy Technology Data Exchange (ETDEWEB)

    Bhagwat, M. S.; Krassnigg, A.; Maris, P.; Roberts, C. D.; Physics; Univ. Graz; Univ. of Pittsburgh

    2007-03-01

    In this summary of the application of Dyson-Schwinger equations to the theory and phenomenology of hadrons, some deductions following from a nonperturbative, symmetry-preserving truncation are highlighted, notable amongst which are results for pseudoscalar mesons. We also describe inferences from the gap equation relating to the radius of convergence of a chiral expansion, applications to heavy-light and heavy-heavy mesons, and quantitative estimates of the contribution of quark orbital angular momentum in pseudoscalar mesons; and recapitulate upon studies of nucleon electromagnetic form factors.

  2. Photonic band gap materials

    Science.gov (United States)

    Cassagne, D.

    Photonic band gap materials Photonic band gap materials are periodic dielectric structures that control the propagation of electromagnetic waves. We describe the plane wave method, which allows to calculate the band structures of photonic crystals. By symmetry analysis and a perturbative approach, we predict the appearance of the low energy photonic band gaps of hexagonal structures. We propose new two-dimensional structures called graphite and boron nitride. Using a transfer matrix method, we calculate the transmission of the graphite structure and we show the crucial role of the coupling with external modes. We study the appearance of allowed modes in the photonic band gap by the introduction of localized defects in the periodicity. Finally, we discuss the properties of opals formed by self-organized silica microspheres, which are very promising for the fabrication of three-dimensional photonic crystals. Les matériaux à bandes interdites photoniques sont des structures diélectriques périodiques qui contrôlent la propagation des ondes électromagnétiques. Nous décrivons la méthode des ondes planes qui permet de calculer les structures de bandes des cristaux photoniques. Par une analyse de la symétrie et une approche perturbative, nous précisons les conditions d'existence des bandes interdites de basse énergie. Nous proposons de nouvelles structures bidimensionnelles appelées graphite et nitrure de bore. Grâce à une méthode de matrices de transfert, nous calculons la transmission de la structure graphite et nous mettons en évidence le rôle fondamental du couplage avec les modes extérieurs. Nous étudions l'apparition de modes permis dans la bande interdite grâce à l'introduction de défauts dans la périodicité. Enfin, nous discutons les propriétés des opales constituées de micro-billes de silice auto-organisées, qui sont très prometteuses pour la fabrication de cristaux photoniques tridimensionnels.

  3. Closing the stop gap

    Energy Technology Data Exchange (ETDEWEB)

    Czakon, Michal [RWTH Aachen Univ. (Germany). Inst. fuer Theoretische Teilchnphysik und Kosmologie; Mitov, Alexander [Univ. of Cambridge (United Kingdom). Cavendish Lab.; Papucci, Michele [Lawrence Berkeley National Laboratory, CA (United States). Theoretical Physics Group; California Univ., Berkeley, CA (United States). Dept. of Physics; Ruderman, Joshua T. [Lawrence Berkeley National Laboratory, CA (United States). Theoretical Physics Group; California Univ., Berkeley, CA (United States). Dept. of Physics; New York Univ., NY (United States). Center for Cosmology and Particle Physics; Weiler, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); CERN - European Organization for Nuclear Research, Geneva (Switzerland). Theory Div.

    2014-07-15

    Light stops are a hallmark of the most natural realizations of weak-scale supersymmetry. While stops have been extensively searched for, there remain open gaps around and below the top mass, due to similarities of stop and top signals with current statistics. We propose a new fast-track avenue to improve light stop searches for R-parity conserving supersymmetry, by comparing top cross section measurements to the theoretical prediction. Stop masses below ∝180 GeV can now be ruled out for a light neutralino. The possibility of a stop signal contaminating the top mass measurement is also briefly addressed.

  4. Mind the Gap

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    While a growing number of Chinese people are enjoying the benefits brought by economic reform and social development, some are being left behind. The divide between the rich and the poor is widening in China, resulting in an increasingly dissatisfied populace. Some argue that a wealth gap is not a big deal in a market economy and that the problem in China has been exaggerated. But in an article published by China Economic Times, Wu Zhongmin, a sociology professor at the Central Party School of the Commun...

  5. The fiscal gap: An estimate for Russia

    Directory of Open Access Journals (Sweden)

    Evgeny Goryunov

    2015-09-01

    Full Text Available The fiscal gap is an indicator of the long-term balance of public finance and is calculated based on the intertemporal government budget constraint, which links government tax revenues and expenditures over long intervals. The estimate of the fiscal gap for the Russian general government has been determined according to three scenarios with varying assumptions regarding demographic trends, productivity growth rates, oil and gas prices and the quantity of extractable reserves. The calculations show that the current fiscal policy cannot provide for the stability of public finance in the long run. The main factors of budget imbalances are the growth of pension and health care expenditures caused by demographic trends and the gradual decline in tax receipts from the oil and gas sector.

  6. Board affiliation and pay gap

    Institute of Scientific and Technical Information of China (English)

    Shenglan; Chen; Hui; Ma; Danlu; Bu

    2014-01-01

    This paper examines the effects of board affiliation on the corporate pay gap.Using a sample of Chinese listed firms from 2005 to 2011, we find that boards with a greater presence of directors appointed by block shareholders have lower pay gaps. Furthermore, the governance effects of board affiliation with and without pay are distinguished. The empirical results show that board affiliation without pay is negatively related to the pay gap, while board affiliation with pay is positively related to the pay gap. Overall, the results shed light on how block shareholders affect their companies’ pay gaps through board affiliation.

  7. Household decisions and child health : Estimating the links between water treatment and the incidence of diarrhea using non-recursive two-equation causal models

    OpenAIRE

    Tan, Carlos Antonio R.; Capuno, Joseph J.

    2012-01-01

    The treatment of drinking water is advocated to reduce the incidence of child diarrhea. However, evaluating the impact of water treatment with only observational data leads to biased estimates since it could be the occurrence of child diarrhea that induced the household to treat their drinking water. To deal with the possible simultaneity between the treatment of drinking water and the incidence of child diarrhea, we specify non-recursive two-equation causal models and apply it on a sub-sampl...

  8. Gap Task Force

    CERN Multimedia

    Lissuaer, D

    One of the more congested areas in the ATLAS detector is the GAP region (the area between the Barrel Calorimeter and the End Cap calorimeter) where Inner Detector services, LAr Services and some Tile services all must co-habitat in a very limited area. It has been clear for some time that the space in the GAP region is not sufficient to accommodate all that is needed. In the last few month additional problems of routing all the services to Z=0 have been encountered due to the very limited space between the Tile Calorimeter and the first layer of Muon chambers. The Technical Management Board (TMB) and the Executive Board (EB) decided in the middle of March to establish a Task Force to look at this problem and come up with a solution within well-specified guidelines. The task force consisted of experts from the ID, Muon, Liquid Argon and Tile systems in addition to experts from the Technical Coordination team and the Physics coordinator. The task force held many meetings and in general there were some very l...

  9. Geology and health:closing the gap

    Institute of Scientific and Technical Information of China (English)

    A.B.Kampunzu

    2004-01-01

    It was discovered several decades ago that the natural geo-environment could substantially impact on the health of animals and humans. However, despite the growth of evidence supporting this discovery, there has not been a close interaction between geoscientists and health scientists in assessing the need to study the various facets of the relationships between human and animal health and air, water, soils and rocks. This book is timely in closing that gap as stated in its title.

  10. Assessing changes in availability of land and water for food (1960-2050) : An analysis linking food demand and available resources

    NARCIS (Netherlands)

    Ibarrola Rivas, M. J.; Nonhebel, S.

    2016-01-01

    Future global food demand will require more land and water. We group the global population into six Gross Domestic Product groups and study changes in the availability of land and water for food in relation to demographic and nutrition transition theories. We show large differences in land and water

  11. Assessing changes in availability of land and water for food (1960-2050) : An analysis linking food demand and available resources

    NARCIS (Netherlands)

    Ibarrola Rivas, M. J.; Nonhebel, S.

    Future global food demand will require more land and water. We group the global population into six Gross Domestic Product groups and study changes in the availability of land and water for food in relation to demographic and nutrition transition theories. We show large differences in land and water

  12. The Politics of Achievement Gaps

    DEFF Research Database (Denmark)

    Valant, J.; Newark, D. A.

    2016-01-01

    on achievement gaps have received little attention from researchers, despite playing an important role in shaping policymakers’ behaviors. Drawing on randomized experiments with a nationally representative sample of adults, we explore the public’s beliefs about test score gaps and its support for gap......-closing initiatives. We find that Americans are more concerned about—and more supportive of proposals to close—wealth-based achievement gaps than Black-White or Hispanic-White gaps. Americans also explain the causes of wealth-based gaps more readily. © 2016 AERA.......For decades, researchers have documented large differences in average test scores between minority and White students and between poor and wealthy students. These gaps are a focal point of reformers’ and policymakers’ efforts to address educational inequities. However, the U.S. public’s views...

  13. The inverse F-BAR domain protein srGAP2 acts through srGAP3 to modulate neuronal differentiation and neurite outgrowth of mouse neuroblastoma cells.

    Directory of Open Access Journals (Sweden)

    Yue Ma

    Full Text Available The inverse F-BAR (IF-BAR domain proteins srGAP1, srGAP2 and srGAP3 are implicated in neuronal development and may be linked to mental retardation, schizophrenia and seizure. A partially overlapping expression pattern and highly similar protein structures indicate a functional redundancy of srGAPs in neuronal development. Our previous study suggests that srGAP3 negatively regulates neuronal differentiation in a Rac1-dependent manner in mouse Neuro2a cells. Here we show that exogenously expressed srGAP1 and srGAP2 are sufficient to inhibit valporic acid (VPA-induced neurite initiation and growth in the mouse Neuro2a cells. While ectopic- or over-expression of RhoGAP-defective mutants, srGAP1(R542A and srGAP2(R527A exert a visible inhibitory effect on neuronal differentiation. Unexpectedly, knockdown of endogenous srGAP2 fails to facilitate the neuronal differentiation induced by VPA, but promotes neurite outgrowth of differentiated cells. All three IF-BAR domains from srGAP1-3 can induce filopodia formation in Neuro2a, but the isolated IF-BAR domain from srGAP2, not from srGAP1 and srGAP3, can promote VPA-induced neurite initiation and neuronal differentiation. We identify biochemical and functional interactions of the three srGAPs family members. We propose that srGAP3-Rac1 signaling may be required for the effect of srGAP1 and srGAP2 on attenuating neuronal differentiation. Furthermore, inhibition of Slit-Robo interaction can phenocopy a loss-of-function of srGAP3, indicating that srGAP3 may be dedicated to the Slit-Robo pathway. Our results demonstrate the interplay between srGAP1, srGAP2 and srGAP3 regulates neuronal differentiation and neurite outgrowth. These findings may provide us new insights into the possible roles of srGAPs in neuronal development and a potential mechanism for neurodevelopmental diseases.

  14. Environmental control of natural gap size distribution in tropical forests

    Science.gov (United States)

    Goulamoussène, Youven; Bedeau, Caroline; Descroix, Laurent; Linguet, Laurent; Hérault, Bruno

    2017-01-01

    Natural disturbances are the dominant form of forest regeneration and dynamics in unmanaged tropical forests. Monitoring the size distribution of treefall gaps is important to better understand and predict the carbon budget in response to land use and other global changes. In this study, we model the size frequency distribution of natural canopy gaps with a discrete power law distribution. We use a Bayesian framework to introduce and test, using Monte Carlo Markov chain and Kuo-Mallick algorithms, the effect of local physical environment on gap size distribution. We apply our methodological framework to an original light detecting and ranging dataset in which natural forest gaps were delineated over 30 000 ha of unmanaged forest. We highlight strong links between gap size distribution and environment, primarily hydrological conditions and topography, with large gaps being more frequent on floodplains and in wind-exposed areas. In the future, we plan to apply our methodological framework on a larger scale using satellite data. Additionally, although gap size distribution variation is clearly under environmental control, variation in gap size distribution in time should be tested against climate variability.

  15. Small Multiples with Gaps.

    Science.gov (United States)

    Meulemans, Wouter; Dykes, Jason; Slingsby, Aidan; Turkay, Cagatay; Wood, Jo

    2017-01-01

    Small multiples enable comparison by providing different views of a single data set in a dense and aligned manner. A common frame defines each view, which varies based upon values of a conditioning variable. An increasingly popular use of this technique is to project two-dimensional locations into a gridded space (e.g. grid maps), using the underlying distribution both as the conditioning variable and to determine the grid layout. Using whitespace in this layout has the potential to carry information, especially in a geographic context. Yet, the effects of doing so on the spatial properties of the original units are not understood. We explore the design space offered by such small multiples with gaps. We do so by constructing a comprehensive suite of metrics that capture properties of the layout used to arrange the small multiples for comparison (e.g. compactness and alignment) and the preservation of the original data (e.g. distance, topology and shape). We study these metrics in geographic data sets with varying properties and numbers of gaps. We use simulated annealing to optimize for each metric and measure the effects on the others. To explore these effects systematically, we take a new approach, developing a system to visualize this design space using a set of interactive matrices. We find that adding small amounts of whitespace to small multiple arrays improves some of the characteristics of 2D layouts, such as shape, distance and direction. This comes at the cost of other metrics, such as the retention of topology. Effects vary according to the input maps, with degree of variation in size of input regions found to be a factor. Optima exist for particular metrics in many cases, but at different amounts of whitespace for different maps. We suggest multiple metrics be used in optimized layouts, finding topology to be a primary factor in existing manually-crafted solutions, followed by a trade-off between shape and displacement. But the rich range of possible

  16. Impacts of climate and land use change on ecosystem hydrology and net primary productivity: Linking water availability to food security in Asia

    Science.gov (United States)

    Dangal, S. R. S.; Tian, H.; Pan, S.; Zhang, B.; Yang, J.

    2015-12-01

    The nexus approach to food, water and energy security in Asia is extremely important and relevant as the region has to feed two-third of the world's population and accounts for 59% of the global water consumption. The distribution pattern of food, water and energy resources have been shaped by the legacy effect of both natural and anthropogenic disturbances and therefore are vulnerable to climate change and human activities including land use/cover change (LUCC) and land management (irrigation and nitrogen fertilization). In this study, we used the Dynamic Land Ecosystem Model (DLEM) to examine the effects of climate change, land use/cover change, and land management practices (irrigation and nitrogen fertilization) on the spatiotemporal trends and variability in water availability and its role in limiting net primary productivity (NPP) and food security in the 20th and early 21st centuries. Our specific objectives are to quantify how climate change, LUCC and other environmental changes have interactively affected carbon and water dynamics across the Asian region. In particular, we separated the Asian region into several sub-region based on the primary limiting factor - water, food and energy. We then quantified how changes in environmental factors have altered the water and food resources during the past century. We particularly focused on Net Primary Productivity (NPP) and water cycle (Evapotranspiration, discharge, and runoff) as a measure of available food and water resources, respectively while understanding the linkage between food and water resources in Asia.

  17. Critical heat removal rate through a hemispherical narrow gap

    Energy Technology Data Exchange (ETDEWEB)

    Park, R.J.; Ha, K.S.; Kang, K.H.; Kim, S.B.; Kim, H.D. [Severe Accident Research Project, Korea Atomic Energy Research Institute Yusong, P.O. Box 105, Daejeon (Korea); Jeong, J.H. [Chonan College of Foreign Studies, An-seo-Wong 150, Chun-an (Korea)

    2003-02-01

    An experimental study has been performed to investigate boiling mechanism and to estimate critical heat removal rate from a critical power through a hemispherical narrow gap using distilled water and Freon R-113. The distilled water data on the critical heat removal rate were compared with the R-113 data. The experimental results on the critical heat removal rate were also compared with the existing correlations, developed in flat plate, annuli, and spherical gaps. The test results have shown that a CCFL (Counter Current Flow Limitation) brings about local dryout and finally global dryout in the hemispherical gap thickness of 0.5, 1.0, and 2.0 mm. The boiling mechanism in a hemispherical gap thickness of 5.0 mm is the combination of the CCFL and the pool boiling condition. An increase in gap thickness of 10.0 mm leads to the pool boiling condition rather than the CCFL. Increases in the gap thickness and pressure lead to increase in critical heat removal rate, but the pressure effect on the critical heat removal rate was found to be much milder than the predictions by flat plate and annuli gaps. The measured critical heat removal rate using the R-113 in hemispherical narrow gap thickness of 1.0 and 2.0 mm are 51.5%, 44.5% lower than that using the distilled water due to the lower boiling point and the bubble size, which is different from the pool boiling condition of approximately 14.8%. The measured critical heat removal rate using the R-113 in a gap thickness of 5 mm is 21.6% lower than that using distilled water, which approaches to the pool boiling condition. (orig.)

  18. Gaps in Political Interest

    DEFF Research Database (Denmark)

    Robison, Joshua

    2015-01-01

    sought to measure respondents’ general interest in politics by asking them how often they follow public affairs. In this article, we uncover novel sources of measurement error concerning this question. We first show that other nationally representative surveys that frequently use this item deliver......Political interest fundamentally influences political behavior, knowledge, and persuasion (Brady, Verba, & Schlozman, 1995; Delli Carpini & Keeter, 1996; Luskin, 1990; Zukin, Andolina, Keeter, Jenkins, & Delli Carpini, 2006). Since the early 1960s, the American National Election Studies (ANES) has...... drastically higher estimates of mass interest. We then use a survey experiment included on a wave of the ANES’ Evaluating Government and Society Surveys (EGSS) to explore the influence of question order in explaining this systemic gap in survey results. We show that placing batteries of political...

  19. Closing the Gap

    DEFF Research Database (Denmark)

    Tamke, Martin; Kobiella, Olaf

    2007-01-01

    The e4d design series is looking for an innovative use of digital technology in architectural education to overcome the gap between design development and the acquisition of digital skills. Digital design approaches include multimedia technology, the crossover of analogue and digital techniques......, rapid-prototyping, visualization, and the presentation in artistic movies. Over the past two years a problem- based design approach was developed, which enabled students to learn digital and architectural skills simultaneously and efficiently. The educational concept consisted generally of four steps......, which, though independent of each other, are determined by questions of the ongoing design process. The first step consists of an abstract or subjective research phase; in the second step the findings are transferred into dynamic spatial structures. Later, the detected qualities are used to develop...

  20. Closing the Gap

    DEFF Research Database (Denmark)

    Tamke, Martin; Kobiella, Olaf

    2007-01-01

    The e4d design series is looking for an innovative use of digital technology in architectural education to overcome the gap between design development and the acquisition of digital skills. Digital design approaches include multimedia technology, the crossover of analogue and digital techniques......, rapid-prototyping, visualization, and the presentation in artistic movies. Over the past two years a problem- based design approach was developed, which enabled students to learn digital and architectural skills simultaneously and efficiently. The educational concept consisted generally of four steps...... architectural projects can be discussed; in addition, a competent monitoring of the process and outcome of innovative and efficient design strategies in architectural and pedagogical aspect is included....

  1. The Gap-Tpc

    Science.gov (United States)

    Rossi, B.; Anastasio, A.; Boiano, A.; Catalanotti, S.; Cocco, A. G.; Covone, G.; Di Meo, P.; Longo, G.; Vanzanella, A.; Walker, S.; Wang, H.; Wang, Y.; Fiorillo, G.

    2016-02-01

    Several experiments have been conducted worldwide, with the goal of observing low-energy nuclear recoils induced by WIMPs scattering off target nuclei in ultra-sensitive, low-background detectors. In the last few decades noble liquid detectors designed to search for dark matter in the form of WIMPs have been extremely successful in improving their sensitivities and setting the best limits. One of the crucial problems to be faced for the development of large size (multi ton-scale) liquid argon experiments is the lack of reliable and low background cryogenic PMTs: their intrinsic radioactivity, cost, and borderline performance at 87 K rule them out as a possible candidate for photosensors. We propose a brand new concept of liquid argon-based detector for direct dark matter search: the Geiger-mode Avalanche Photodiode Time Projection Chamber (GAP-TPC) optimized in terms of residual radioactivity of the photosensors, energy and spatial resolution, light and charge collection efficiency.

  2. The GAP-TPC

    CERN Document Server

    Rossi, B; Boiano, A; Catalanotti, S; Cocco, A G; Covone, G; Di Meo, P; Longo, G; Vanzanella, A; Walker, S; Wang, H; Wang, Y; Fiorillo, G

    2016-01-01

    Several experiments have been conducted worldwide, with the goal of observing low-energy nuclear recoils induced by WIMPs scattering off target nuclei in ultra-sensitive, low-background detectors. In the last few decades noble liquid detectors designed to search for dark matter in the form of WIMPs have been extremely successful in improving their sensitivities and setting the best limits. One of the crucial problems to be faced for the development of large size (multi ton-scale) liquid argon experiments is the lack of reliable and low background cryogenic PMTs: their intrinsic radioactivity, cost, and borderline performance at 87 K rule them out as a possible candidate for photosensors. We propose a brand new concept of liquid argon-based detector for direct dark matter search: the Geiger-mode Avalanche Photodiode Time Projection Chamber (GAP-TPC) optimized in terms of residual radioactivity of the photosensors, energy and spatial resolution, light and charge collection efficiency

  3. Closing the Gap

    DEFF Research Database (Denmark)

    Tamke, Martin; Kobiella, Olaf

    2007-01-01

    The e4d design series is looking for an innovative use of digital technology in architectural education to overcome the gap between design development and the acquisition of digital skills. Digital design approaches include multimedia technology, the crossover of analogue and digital techniques...... architectural projects can be discussed; in addition, a competent monitoring of the process and outcome of innovative and efficient design strategies in architectural and pedagogical aspect is included......., rapid-prototyping, visualization, and the presentation in artistic movies. Over the past two years a problem- based design approach was developed, which enabled students to learn digital and architectural skills simultaneously and efficiently. The educational concept consisted generally of four steps...

  4. Seropositivity rates of water channel protein 4 antibodies compared between a cell-based immunofluorescence assay and an enzyme-linked immunosorbent assay in neuromyelitis optica patients

    Institute of Scientific and Technical Information of China (English)

    Xiaoli Wu; Zhangyuan Liao; Jing Ye; Huiqing Dong; Chaodong Wang; Piu Chan

    2011-01-01

    A total of 66 samples (from 27 cases with neuromyelitis optica, 26 cases with multiple sclerosis, and 13 cases with optic neuritis) were tested for aquaporin-4 antibody by a cell-based immunofluorescence assay and an enzyme-linked immunosorbent assay.The sensitivities and specificities of the two assays were similar.We further analyzed an additional 68 patients and 93 healthy controls using the enzyme-linked immunosorbent assay.A Kappa test showed good consistency between the two methods in terms of detection of anti-aquaporin-4 antibody in the sera of neuromyelitis optica patients.No significant correlations were identified with onset age or disease duration, suggesting that aquaporin-4 antibody is a good marker for neuromyelitis optica.The enzyme-linked immunosorbent assay can be used for quantifying aquaporin-4 antibody concentrations and may be useful to dynamically monitor changes in the levels of aquaporin-4 antibody during disease duration.

  5. Health disparities and gaps in school readiness.

    Science.gov (United States)

    Currie, Janet

    2005-01-01

    The author documents pervasive racial disparities in the health of American children and analyzes how and how much those disparities contribute to racial gaps in school readiness. She explores a broad sample of health problems common to U.S. children, such as attention deficit hyperactivity disorder, asthma, and lead poisoning, as well as maternal health problems and health-related behaviors that affect children's behavioral and cognitive readiness for school. If a health problem is to affect the readiness gap, it must affect many children, it must be linked to academic performance or behavior problems, and it must show a racial disparity either in its prevalence or in its effects. The author focuses not only on the black-white gap in health status but also on the poor-nonpoor gap because black children tend to be poorer than white children. The health conditions Currie considers seriously impair cognitive skills and behavior in individual children. But most explain little of the overall racial gap in school readiness. Still, the cumulative effect of health differentials summed over all conditions is significant. Currie's rough calculation is that racial differences in health conditions and in maternal health and behaviors together may account for as much as a quarter of the racial gap in school readiness. Currie scrutinizes several policy steps to lessen racial and socioeconomic disparities in children's health and to begin to close the readiness gap. Increasing poor children's eligibility for Medicaid and state child health insurance is unlikely to be effective because most poor children are already eligible for public insurance. The problem is that many are not enrolled. Even increasing enrollment may not work: socioeconomic disparities in health persist in Canada and the United Kingdom despite universal public health insurance. The author finds more promise in strengthening early childhood programs with a built-in health component, like Head Start; family

  6. Gains from trans-boundary water quality management in linked catchment and coastal socioecological systems: a case study for the Minho region

    OpenAIRE

    2013-01-01

    Sustainable economic development requires balancing of marginal costs from catchment water pollution abatement and associated marginal benefits from freshwater/coastal ecosystem appreciation. Hence we need to differentiate between intra- and trans-boundary catchments because benefactors and beneficiaries from water quality improvement are not one and the same. In trans-boundary catchments, private (national) welfare maximizing rates of water quality improvement differ across natio...

  7. Water

    CSIR Research Space (South Africa)

    Van Wyk, Llewellyn V

    2010-08-01

    Full Text Available Water scarcity is without a doubt on of the greatest threats to the human species and has all the potential to destabilise world peace. Falling water tables are a new phenomenon. Up until the development of steam and electric motors, deep groudwater...

  8. Transatlantic link

    Science.gov (United States)

    (left) European Geophysical Society (EGS) President Rolf Meissner at AGU Headquarters with (center) Executive Director Fred Spilhaus and (right) Foreign Secretary Juan Roederer. Meissner attended the meeting of AGU's Committee on International Participation (CIP) on February 26, 1988. At that meeting, specific ways of fostering close links between AGU and EGS were discussed.A few weeks later, Roederer and AGU staff, working with EGS Secretary-General Arne Richter at the EGS meeting in Bologna, Italy, March 21-25, planned details of the establishment of an AGU office in Europe. The Copernicus Gesellschaft, a new entity located on the premises of the Max Planck Institute for Aeronomy in Lindau, Federal Republic of Germany, will provide the administrative staff and handle logistics.

  9. The Adaptation Finance Gap Report

    DEFF Research Database (Denmark)

    UNEP’s Adaptation Gap Report series focuses on Finance, Technology and Knowledge gaps in climate change adaptation. It compliments the Emissions Gap Report series, and explores the implications of failing to close the emissions gap. The report builds on a 2014 assessment by the United Nations...... Environment Programme (UNEP), which laid out the concept of ‘adaptation gaps’ and outlined three such gaps: technology, finance and knowledge. The 2016 Adaptation Gap Report assesses the difference between the financial costs of adapting to climate change in developing countries and the amount of money...... actually available to meet these costs – a difference known as the “adaptation finance gap”. Like the 2014 report, the 2016 report focuses on developing countries, where adaptation capacity is often the lowest and needs the highest, and concentrates on the period up to 2050. The report identifies trends...

  10. Gap solitons in periodic Schrodinger lattice system with nonlinear hopping

    Directory of Open Access Journals (Sweden)

    Ming Cheng

    2016-10-01

    Full Text Available This article concerns the periodic discrete Schrodinger equation with nonlinear hopping on the infinite integer lattice. We obtain the existence of gap solitons by the linking theorem and concentration compactness method together with a periodic approximation technique. In addition, the behavior of such solutions is studied as $\\alpha\\to 0$. Notice that the nonlinear hopping can be sign changing.

  11. Reflexive Land and Water Management in Iran: Linking Technology, Governance and Culture, Part 2: Stakeholders'Attitudes and the Key Elements of Reflexive Framework

    NARCIS (Netherlands)

    Balali, M.R.; Keulartz, F.W.J.; Korthals, M.J.J.A.A.

    2011-01-01

    In order to get a better grasp of the opportunities and constraints of transition to sustainable land and water management in Iran, four large-scale qualitative–quantitative surveys were designed to find out the attitudes, interests, and values of land and water stakeholders including farmers,

  12. Understanding the Tax Gap1

    OpenAIRE

    Mazur, Mark J.; Plumley, Alan H.

    2007-01-01

    The Tax Gap is defined as the difference between the amount of tax imposed by the Tax Code and the amount that is reported and paid with timely filed returns. For the federal government, the gross tax gap is estimated at $345 billion for Tax Year 2001 (after the collection of late and enforced payments, the net tax gap is estimated at $290 billion for Tax Year 2001). This paper explains the concept of the tax gap, discusses how it is estimated, and points out some limitations with the estimates.

  13. Negative Link Prediction in Social Media

    OpenAIRE

    Tang, Jiliang; Chang, Shiyu; Aggarwal, Charu; Liu, Huan

    2014-01-01

    Signed network analysis has attracted increasing attention in recent years. This is in part because research on signed network analysis suggests that negative links have added value in the analytical process. A major impediment in their effective use is that most social media sites do not enable users to specify them explicitly. In other words, a gap exists between the importance of negative links and their availability in real data sets. Therefore, it is natural to explore whether one can pr...

  14. Water

    Directory of Open Access Journals (Sweden)

    E. Sanmuga Priya

    2017-05-01

    Full Text Available Phytoremediation through aquatic macrophytes treatment system (AMATS for the removal of pollutants and contaminants from various natural sources is a well established environmental protection technique. Water hyacinth (Eichhornia crassipes, a worst invasive aquatic weed has been utilised for various research activities over the last few decades. The biosorption capacity of the water hyacinth in minimising various contaminants present in the industrial wastewater is well studied. The present review quotes the literatures related to the biosorption capacity of the water hyacinth in reducing the concentration of dyestuffs, heavy metals and minimising certain other physiochemical parameters like TSS (total suspended solids, TDS (total dissolved solids, COD (chemical oxygen demand and BOD (biological oxygen demand in textile wastewater. Sorption kinetics through various models, factors influencing the biosorption capacity, and role of physical and chemical modifications in the water hyacinth are also discussed.

  15. Measuring the Gap

    Directory of Open Access Journals (Sweden)

    Xinshu She MD, MPH

    2016-02-01

    Full Text Available China is a large country where rapid development is accompanied by growing inequalities. How economic inequalities translate to health inequalities is unknown. Baseline health assessment is lacking among rural Chinese children. We aimed at assessing baseline student health of rural Chinese children and comparing them with those of urban children of similar ages. A cross-sectional study was conducted using the 2003 Global School-Based Student Health Survey among 100 students Grade 4 to 6 from rural Guizhou, China. Results were summarized and compared with public data from urban Beijing using multivariate logistic regression models. Rural children are more likely to not wash their hands before a meal (odds ratio [OR] = 5.71, P .05. Rural parents are more likely to not know their children’s whereabouts (OR = 1.81, P < .05. Rural children are more than 4 times likely to have serious injuries (OR = 4.64, P < .01 and to be bullied (OR = 4.01, P < .01. In conclusion, school-age rural Chinese children exhibit more health risk behaviors and fewer protective factors at baseline compared to their urban counterparts. Any intervention aimed at improving child health should take this distributive gap into consideration.

  16. Measuring the Gap

    Science.gov (United States)

    She, Xinshu; Zhao, Deqing; Scholnick, Jenna

    2016-01-01

    China is a large country where rapid development is accompanied by growing inequalities. How economic inequalities translate to health inequalities is unknown. Baseline health assessment is lacking among rural Chinese children. We aimed at assessing baseline student health of rural Chinese children and comparing them with those of urban children of similar ages. A cross-sectional study was conducted using the 2003 Global School-Based Student Health Survey among 100 students Grade 4 to 6 from rural Guizhou, China. Results were summarized and compared with public data from urban Beijing using multivariate logistic regression models. Rural children are more likely to not wash their hands before a meal (odds ratio [OR] = 5.71, P suicidal ideation in the past year (OR = 0.68, P > .05). Rural parents are more likely to not know their children’s whereabouts (OR = 1.81, P bullied (OR = 4.01, P < .01). In conclusion, school-age rural Chinese children exhibit more health risk behaviors and fewer protective factors at baseline compared to their urban counterparts. Any intervention aimed at improving child health should take this distributive gap into consideration. PMID:27335999

  17. Causes of Domestic Water Consumption Trends in the City of Alicante: Exploring the Links between the Housing Bubble, the Types of Housing and the Socio-Economic Factors

    Directory of Open Access Journals (Sweden)

    Álvaro-Francisco Morote

    2016-08-01

    Full Text Available The European Mediterranean coastline has experienced major tourism-related urbanization since 1960. This is a dynamic that has led to increased spending on water consumption for urban and tourism-related uses. The objective of this paper is to define and to analyze how domestic water consumption in the city of Alicante evolved between 2000 and 2013. Real billing figures for individual households were analyzed according to the type of housing and the income level of the occupants. The conclusions drawn show that consumption fell over the period studied, and that there are different patterns in water expenditure depending on the type of housing and the inhabitants.

  18. Detection of Poly- and Perfluoroalkyl Substances (PFASs) in U.S. Drinking Water Linked to Industrial Sites, Military Fire Training Areas, and Wastewater Treatment Plants

    DEFF Research Database (Denmark)

    Hu, Xindi C; Andrews, David Q; Lindstrom, Andrew B

    2016-01-01

    Drinking water contamination with poly- and perfluoroalkyl substances (PFASs) poses risks to the developmental, immune, metabolic, and endocrine health of consumers. We present a spatial analysis of 2013-2015 national drinking water PFAS concentrations from the U.S. Environmental Protection Agency...... and concentrations in public water supplies. Among samples with detectable PFAS levels, each additional military site within a watershed's eight-digit hydrologic unit is associated with a 20% increase in PFHxS, a 10% increase in both PFHpA and PFOA, and a 35% increase in PFOS. The number of civilian airports...

  19. Dancing links

    CERN Document Server

    Knuth, Donald E

    2009-01-01

    The author presents two tricks to accelerate depth-first search algorithms for a class of combinatorial puzzle problems, such as tiling a tray by a fixed set of polyominoes. The first trick is to implement each assumption of the search with reversible local operations on doubly linked lists. By this trick, every step of the search affects the data incrementally. The second trick is to add a ghost square that represents the identity of each polyomino. Thus puts the rule that each polyomino be used once on the same footing as the rule that each square be covered once. The coding simplifies to a more abstract form which is equivalent to 0-1 integer programming. More significantly for the total computation time, the search can naturally switch between placing a fixed polyomino or covering a fixed square at different stages, according to a combined heuristic. Finally the author reports excellent performance for his algorithm for some familiar puzzles. These include tiling a hexagon by 19 hexiamonds and the N queen...

  20. GAP Analysis. Bulletin Number 11

    Science.gov (United States)

    2002-01-01

    in 2002 ( ESSB • Creation of a stewardship map is central to GAP’s analysis 6400) that authorizes a comprehensive review to identify the state’s method...governments and their consultants. "Washington State Law ESSB 6400 can be accessed at www.leg.wa.gov/pubfbillinfo/2001-02/Senate, January 10, 2003. Gap

  1. PhoneGap for enterprise

    CERN Document Server

    Shotts, Kerri

    2014-01-01

    This book is intended for developers who wish to use PhoneGap to develop useful, rich, secure mobile applications for their enterprise environment. The book assumes you have working knowledge of PhoneGap, HTML5, CSS3, and JavaScript, and a reasonable understanding of networking and n-tier architectures.

  2. Components of the Belief Gap

    Directory of Open Access Journals (Sweden)

    Cecilie Gaziano

    2014-01-01

    Full Text Available Knowledge gap research focuses on education as an indicator of socioeconomic status (SES. Belief gap research centers on ideology as potentially more powerful than education in comparing sociopolitical groups with scientifically established knowledge and groups with opposing beliefs accepted on faith. This study examined the relationship between education and ideology to understand belief gaps better. The study used 2008 American National Election Study (ANES data to compare conservatives, moderates, and liberals by education on religiosity, child rearing values, opinionation, need for cognition, orientation toward politics, and mass media access and use. Although liberals tended to be more educated than conservatives overall, better-educated conservatives had the highest household incomes and were a much larger group. No known knowledge gap studies have reported results on one group characterized by high education and an opposing group distinguished by a different indicator of SES. Reformulations of the belief gap hypothesis are offered.

  3. GAP Analysis Bulletin Number 15

    Science.gov (United States)

    Maxwell, Jill; Gergely, Kevin; Aycrigg, Jocelyn; Canonico, Gabrielle; Davidson, Anne; Coffey, Nicole

    2008-01-01

    The Mission of the Gap Analysis Program (GAP) is to promote conservation by providing broad geographic information on biological diversity to resource managers, planners, and policy makers who can use the information to make informed decisions. As part of the National Biological Information Infrastructure (NBII) ?a collaborative program to provide increased access to data and information on the nation?s biological resources--GAP data and analytical tools have been used in hundreds of applications: from basic research to comprehensive state wildlife plans; from educational projects in schools to ecoregional assessments of biodiversity. The challenge: keeping common species common means protecting them BEFORE they become threatened. To do this on a state or regional basis requires key information such as land cover descriptions, predicted distribution maps for native animals, and an assessment of the level of protection currently given to those plants and animals. GAP works cooperatively with Federal, state, and local natural resource professionals and academics to provide this kind of information. GAP activities focus on the creation of state and regional databases and maps that depict patterns of land management, land cover, and biodiversity. These data can be used to identify ?gaps? in conservation--instances where an animal or plant community is not adequately represented on the existing network of conservation lands. GAP is administered through the U.S. Geological Survey. Through building partnerships among disparate groups, GAP hopes to foster the kind of collaboration that is needed to address conservation issues on a broad scale. For more information, contact: John Mosesso National GAP Director 703-648-4079 Kevin Gergely National GAP Operations Manager 208-885-3565

  4. Binding water to a PEG-linked flexible bichromophore: IR spectra of diphenoxyethane-(H2O)n clusters, n = 2-4

    Science.gov (United States)

    Walsh, Patrick S.; Buchanan, Evan G.; Gord, Joseph R.; Zwier, Timothy S.

    2015-04-01

    The single-conformation infrared (IR) and ultraviolet (UV) spectroscopies of neutral 1,2-diphenoxyethane-(H2O)n clusters with n = 2-4 (labeled henceforth as 1:n) have been studied in a molecular beam using a combination of resonant two-photon ionization, IR-UV holeburning, and resonant ion-dip infrared (RIDIR) spectroscopies. Ground state RIDIR spectra in the OH and CH stretch regions were used to provide firm assignments for the structures of the clusters by comparing the experimental spectra with the predictions of calculations carried out at the density functional M05-2X/6-31+G(d) level of theory. At all sizes in this range, the water molecules form water clusters in which all water molecules engage in a single H-bonded network. Selective binding to the tgt monomer conformer of 1,2-diphenoxyethane (C6H5-O-CH2-CH2-O-C6H5, DPOE) occurs, since this conformer provides a binding pocket in which the two ether oxygens and two phenyl ring π clouds can be involved in stabilizing the water cluster. The 1:2 cluster incorporates a water dimer "chain" bound to DPOE much as it is in the 1:1 complex [E. G. Buchanan et al., J. Phys. Chem. Lett. 4, 1644 (2013)], with primary attachment via a double-donor water that bridges the ether oxygen of one phenoxy group and the π cloud of the other. Two conformers of the 1:3 cluster are observed and characterized, one that extends the water chain to a third molecule (1:3 chain) and the other incorporating a water trimer cycle (1:3 cycle). A cyclic water structure is also observed for the 1:4 cluster. These structural characterizations provide a necessary foundation for studies of the perturbations imposed on the two close-lying S1/S2 excited states of DPOE considered in the adjoining paper [P. S. Walsh et al., J. Chem. Phys. 142, 154304 (2015)].

  5. Binding water to a PEG-linked flexible bichromophore: IR spectra of diphenoxyethane-(H{sub 2}O){sub n} clusters, n = 2-4

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Patrick S.; Buchanan, Evan G.; Gord, Joseph R.; Zwier, Timothy S., E-mail: zwier@purdue.edu [Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084 (United States)

    2015-04-21

    The single-conformation infrared (IR) and ultraviolet (UV) spectroscopies of neutral 1,2-diphenoxyethane-(H{sub 2}O){sub n} clusters with n = 2-4 (labeled henceforth as 1:n) have been studied in a molecular beam using a combination of resonant two-photon ionization, IR-UV holeburning, and resonant ion-dip infrared (RIDIR) spectroscopies. Ground state RIDIR spectra in the OH and CH stretch regions were used to provide firm assignments for the structures of the clusters by comparing the experimental spectra with the predictions of calculations carried out at the density functional M05-2X/6-31+G(d) level of theory. At all sizes in this range, the water molecules form water clusters in which all water molecules engage in a single H-bonded network. Selective binding to the tgt monomer conformer of 1,2-diphenoxyethane (C{sub 6}H{sub 5}-O-CH{sub 2}-CH{sub 2}-O-C{sub 6}H{sub 5}, DPOE) occurs, since this conformer provides a binding pocket in which the two ether oxygens and two phenyl ring π clouds can be involved in stabilizing the water cluster. The 1:2 cluster incorporates a water dimer “chain” bound to DPOE much as it is in the 1:1 complex [E. G. Buchanan et al., J. Phys. Chem. Lett. 4, 1644 (2013)], with primary attachment via a double-donor water that bridges the ether oxygen of one phenoxy group and the π cloud of the other. Two conformers of the 1:3 cluster are observed and characterized, one that extends the water chain to a third molecule (1:3 chain) and the other incorporating a water trimer cycle (1:3 cycle). A cyclic water structure is also observed for the 1:4 cluster. These structural characterizations provide a necessary foundation for studies of the perturbations imposed on the two close-lying S{sub 1}/S{sub 2} excited states of DPOE considered in the adjoining paper [P. S. Walsh et al., J. Chem. Phys. 142, 154304 (2015)].

  6. A systematic approach for the assessment of bacterial growth-controlling factors linked to biological stability of drinking water in distribution systems

    KAUST Repository

    Prest, E. I.

    2016-01-06

    A systematic approach is presented for the assessment of (i) bacterial growth-controlling factors in drinking water and (ii) the impact of distribution conditions on the extent of bacterial growth in full-scale distribution systems. The approach combines (i) quantification of changes in autochthonous bacterial cell concentrations in full-scale distribution systems with (ii) laboratoryscale batch bacterial growth potential tests of drinking water samples under defined conditions. The growth potential tests were done by direct incubation of water samples, without modification of the original bacterial flora, and with flow cytometric quantification of bacterial growth. This method was shown to be reproducible (ca. 4% relative standard deviation) and sensitive (detection of bacterial growth down to 5 μg L-1 of added assimilable organic carbon). The principle of step-wise assessment of bacterial growth-controlling factors was demonstrated on bottled water, shown to be primarily carbon limited at 133 (±18) × 103 cells mL-1 and secondarily limited by inorganic nutrients at 5,500 (±1,700) × 103 cells mL-1. Analysis of the effluent of a Dutch full-scale drinking water treatment plant showed (1) bacterial growth inhibition as a result of end-point chlorination, (2) organic carbon limitation at 192 (±72) × 103 cells mL-1 and (3) inorganic nutrient limitation at 375 (±31) × 103 cells mL-1. Significantly lower net bacterial growth was measured in the corresponding full-scale distribution system (176 (±25) × 103 cells mL-1) than in the laboratory-scale growth potential test of the same water (294 (±35) × 103 cells mL-1), highlighting the influence of distribution on bacterial growth. The systematic approach described herein provides quantitative information on the effect of drinking water properties and distribution system conditions on biological stability, which can assist water utilities in decision-making on treatment or distribution system improvements to

  7. Forming Gaps in Debris Disks with Fewer Planets via Planet Migration

    Science.gov (United States)

    Morrison, Sarah J.; Kratter, Kaitlin M.

    2016-10-01

    Debris disks across a wide range of ages can possess wide gaps of several AU or more; these gaps have been attributed to the presence of multiple planets. While at least two planets are likely needed for maintaining the edges of such gaps, large gaps may require more than two in more dynamically packed configurations to be able to have cleared material within the gap in the present day. As an alternative to currently packed planets occupying gaps in debris disks, we assess whether planetesimal and dynamical instability-driven planet migration could produce wide gaps with lower mass, fewer planets on relevant timescales to be consistent with the observed properties of debris disk systems. We also discuss implications for the disk properties in which these mechanisms could operate within the broader evolutionary context linking planets, debris disks, and the protoplanetary disks from which they originated.

  8. The fluctuating gap model

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Xiaobin

    2011-01-15

    The quasi-one-dimensional systems exhibit some unusual phenomenon, such as the Peierls instability, the pseudogap phenomena and the absence of a Fermi-Dirac distribution function line shape in the photoemission spectroscopy. Ever since the discovery of materials with highly anisotropic properties, it has been recognized that fluctuations play an important role above the three-dimensional phase transition. This regime where the precursor fluctuations are presented can be described by the so called fluctuating gap model (FGM) which was derived from the Froehlich Hamiltonian to study the low energy physics of the one-dimensional electron-phonon system. Not only is the FGM of great interest in the context of quasi-one-dimensional materials, liquid metal and spin waves above T{sub c} in ferromagnets, but also in the semiclassical approximation of superconductivity, it is possible to replace the original three-dimensional problem by a directional average over effectively one-dimensional problem which in the weak coupling limit is described by the FGM. In this work, we investigate the FGM in a wide temperature range with different statistics of the order parameter fluctuations. We derive a formally exact solution to this problem and calculate the density of states, the spectral function and the optical conductivity. In our calculation, we show that a Dyson singularity appears in the low energy density of states for Gaussian fluctuations in the commensurate case. In the incommensurate case, there is no such kind of singularity, and the zero frequency density of states varies differently as a function of the correlation lengths for different statistics of the order parameter fluctuations. Using the density of states we calculated with non-Gaussian order parameter fluctuations, we are able to calculate the static spin susceptibility which agrees with the experimental data very well. In the calculation of the spectral functions, we show that as the correlation increases, the

  9. More on gapped Goldstones at finite density: More gapped Goldstones

    CERN Document Server

    Nicolis, Alberto; Piazza, Federico; Rosen, Rachel A

    2013-01-01

    It was recently argued that certain relativistic theories at finite density can exhibit an unconventional spectrum of Goldstone excitations, with gapped Goldstones whose gap is exactly calculable in terms of the symmetry algebra. We confirm this result as well as previous ones concerning gapless Goldstones for non-relativistic systems via a coset construction of the low-energy effective field theory. Moreover, our analysis unveils additional gapped Goldstones, naturally as light as the others, but this time with a model-dependent gap. Their exact number cannot be inferred solely from the symmetry breaking pattern either, but rather depends on the details of the symmetry breaking mechanism--a statement that we explicitly verify with a number of examples. Along the way we provide what we believe to be a particularly transparent interpretation of the so-called inverse-Higgs constraints for spontaneously broken spacetime symmetries.

  10. Sex-linked dominant

    Science.gov (United States)

    Inheritance - sex-linked dominant; Genetics - sex-linked dominant; X-linked dominant; Y-linked dominant ... can be either an autosomal chromosome or a sex chromosome. It also depends on whether the trait ...

  11. The Income Gap GROWS Large

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The income gap between regions, urban and rural areas, industries and various social groups is widening in China. The gap, as indicated by the Gini Coefficient, extended beyond an alarming level. A World Bank report said the Gini Coefficient for China surged to 0.47 in 2009, exceeding the "red line" of 0.4. The problems caused by the rising income disparity have been the focus of public attention. Some experts believe that it is high time for China to shrink this income gap. A Xinhua News Agency research team recently analyzed this trend, and published an article in the Economic Information Daily. Edited excerpts follow:

  12. The Income Gap Grows Large

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ The income gap between regions,urban and rural areas,industries and various social groups is widening in China.The gap,as indicated by the Gini Coefficient,extended beyond an alarming level.A World Bank report said the Gini Coefficient for China surged to 0A7 in 2009,exceeding the "red line"of 0.4.The problems caused by the rising income disparity have been the focus of public attention.Some experts believe that it is high time for China to shrink this income gap.

  13. Linking benthic dynamics and cold-water coral occurrences: A high-resolution model study at three carbonate mound provinces in the NE Atlantic

    DEFF Research Database (Denmark)

    Mohn, Christian; Rengstorf, Anna; Grehan, Anthony;

    We used the 3-D ocean circulation model with grid refinement ROMS-AGRIF to describe the hydrodynamic conditions at three cold-water coral provinces in the NE Atlantic (Logachev Mounds, Arc Mounds and Belgica Mounds). Modelled fields of currents, temperature and salinity were analysed for observed...

  14. Linking Environmental Exposure with Public Health: Dichlorodiphenyltrichloroethane Extracted from Soils and Water of Recently Exposed Communities of Selected Locations in Zambia

    Directory of Open Access Journals (Sweden)

    Nosiku Sipilanyambe Munyinda

    2015-01-01

    Full Text Available Background. In 2000, a Zambian private mining company reintroduced the use of dichlorodiphenyltrichloroethane (DDT to control malaria in two districts. From 2000 to 2010, DDT had been applied in homes without any studies conducted to ascertain its fate in the environment. We aimed to quantify the presence of DDT and its metabolites in the soil and water around communities where it was recently used. Methods. We collected superficial soil and water samples from drinking sources of three study areas. DDT was extracted by QuEChERS method and solid phase extraction for soils and water, respectively. Analysis was by gas chromatography-mass spectrometry. A revalidated method with limits of detection ranging from 0.034 to 0.04 ppb was used. Results. Median levels of total DDT were found at 100.4 (IQR 90.9–110 and 725.4 ng/L (IQR 540–774.5 for soils and water, respectively. No DDT above detection limits was detected in the reference area. These results are clinically significant given the persistent characteristics of DDT. Conclusion. DDT presence in these media suggests possible limitations in the environmental safeguards during IRS. Such occurrence could have potential effects on humans, especially children; hence, there is a need to further examine possible associations between this exposure and humans.

  15. New sedimentary constraints for changes in Iceland-Scotland Overflow Water linked to North Atlantic climate variability during the last interglacial period

    Science.gov (United States)

    Irvali, N.; Kleiven, H. F.; Ninnemann, U. S.

    2012-12-01

    Model studies suggest that variations in Nordic Seas deep water formation, and associated meridional heat transports, exert a strong influence on North Atlantic climate and played a formative role in the evolution and demise of the previous interglacial period. Yet, paleoceanographic reconstructions, which rely on geochemical proxies, have yet to definitively resolved the precise relationship between past changes in meridional overturning and North Atlantic climate. One possible reason for this is that geochemical proxies are unable to differentiate between changes in the preformed chemistry and variations in the ventilation rate of deep waters. Here we present high-resolution records of a new sediment proxy for deep-ocean flow and a record of North Atlantic climate from a sediment core, ODP Site 983 (60°24'N, 23°38'W) at 1983 m water depth south of Iceland. Site 983 is located near the head of the Gardar Drift, which extends to the south-south-west, following the path of deep overflows (Iceland-Scotland Overflow Water, ISOW) from the Iceland-Scotland Ridge. In this study we use sortable silt (SS) grain-size data to reconstruct past changes in the speed of deep-water overflow from the Nordic Seas, stable oxygen and carbon isotope measurements together with planktonic foraminiferal assemblage and ice-rafted debris counts in order to reconstruct North Atlantic climate and deep-water circulation across the last interglacial period; Marine Isotope Stage (MIS) 5e. We further compare our records with recently published high-resolution stable isotope records from the IODP Site U1304 (53° 3.401'N, 33° 31.781'W, 3082 m), located on the southern edge of the Gardar Drift, elucidating changes in the vertical and southward extent of ISOW. Our results suggest that at least three different modes of deep water ventilation existed between MIS 6 to 5d. ISOW vigor was decreased, and mid-depth (1983-m) to deep (3082-m) δ13C gradients developed in the North Atlantic during MIS 6

  16. Cycle flux algebra for ion and water flux through the KcsA channel single-file pore links microscopic trajectories and macroscopic observables.

    Science.gov (United States)

    Oiki, Shigetoshi; Iwamoto, Masayuki; Sumikama, Takashi

    2011-01-31

    In narrow pore ion channels, ions and water molecules diffuse in a single-file manner and cannot pass each other. Under such constraints, ion and water fluxes are coupled, leading to experimentally observable phenomena such as the streaming potential. Analysis of this coupled flux would provide unprecedented insights into the mechanism of permeation. In this study, ion and water permeation through the KcsA potassium channel was the focus, for which an eight-state discrete-state Markov model has been proposed based on the crystal structure, exhibiting four ion-binding sites. Random transitions on the model lead to the generation of the net flux. Here we introduced the concept of cycle flux to derive exact solutions of experimental observables from the permeation model. There are multiple cyclic paths on the model, and random transitions complete the cycles. The rate of cycle completion is called the cycle flux. The net flux is generated by a combination of cyclic paths with their own cycle flux. T.L. Hill developed a graphical method of exact solutions for the cycle flux. This method was extended to calculate one-way cycle fluxes of the KcsA channel. By assigning the stoichiometric numbers for ion and water transfer to each cycle, we established a method to calculate the water-ion coupling ratio (CR(w-i)) through cycle flux algebra. These calculations predicted that CR(w-i) would increase at low potassium concentrations. One envisions an intuitive picture of permeation as random transitions among cyclic paths, and the relative contributions of the cycle fluxes afford experimental observables.

  17. Investigation of Swedish cases reveals an outbreak of cryptosporidiosis at a Norwegian hotel with possible links to in-house water systems.

    Science.gov (United States)

    Hajdu, Agnes; Vold, Line; Østmo, Torild A; Helleve, Anna; Helgebostad, Sigrid R; Krogh, Truls; Robertson, Lucy; de Jong, Birgitta; Nygård, Karin

    2008-11-01

    In March 2007, the Norwegian Institute of Public Health was notified of Swedish individuals diagnosed with cryptosporidiosis after staying at a Norwegian hotel. In Norway, cryptosporidiosis is not reportable, and human infections are rarely diagnosed. A questionnaire on illness and exposure history was e-mailed to seven organised groups who had visited the hotel in March. Cases were defined as persons with diarrhoea for more than two days or laboratory-confirmed cryptosporidiosis during or within two weeks of the hotel visit. The risk factor analysis was restricted to two groups with the highest attack rates (AR) and same hotel stay period. Local food safety authorities conducted environmental investigations. In total, 25 diarrhoeal cases (10 laboratory-confirmed) were identified among 89 respondents. Although environmental samples were negative, epidemiological data suggest an association with in-house water consumption. In one group, the AR was higher amongst consumers of water from hotel dispenser (relative risk [RR] = 3.0; 95% confidence interval [CI]: 0.9-9.8), tap water (RR = 2.3; CI: 0.9-5.8), and lower amongst commercial bottled water drinkers (RR = 0.6; CI: 0.4-1.0). Consumption of ice cubes was a risk-factor (RR = 7.1; CI: 1.1-45.7) in the two groups combined. This outbreak would probably have remained undetected without the alert from Swedish health authorities, illustrating the difficulties in outbreak detection due to low health care seeking behaviour for diarrhoea and limited parasite diagnostics in Norway. Awareness of cryptosporidiosis should be raised amongst Norwegian medical personnel to improve case and outbreak detection, and possible risks related to in-house water systems should be assessed.

  18. Interhemispheric teleconnections: Late Pliocene change in Mediterranean outflow water linked to changes in Indonesian Through-Flow and Atlantic Meridional Overturning Circulation, a review and update

    Science.gov (United States)

    Sarnthein, Michael; Grunert, Patrick; Khélifi, Nabil; Frank, Martin; Nürnberg, Dirk

    2017-07-01

    The ultimate, possibly geodynamic control and potential impact of changes in circulation activity and salt discharge of Mediterranean outflow waters (MOW) on Atlantic meridional overturning circulation have formed long-standing objectives in paleoceanography. Late Pliocene changes in the distal advection of MOW were reconstructed on orbital timescales for northeast Atlantic DSDP/ODP sites 548 and 982 off Brittany and on Rockall Plateau, supplemented by a proximal record from Site U1389 west off Gibraltar, and compared to Western Mediterranean surface and deep-water records of Alboran Sea Site 978. From 3.43 to 3.3 Ma, MOW temperatures and salinities form a prominent rise by 2-4 °C and 3 psu, induced by a preceding and coeval rise in sea surface and deep-water salinity and increased summer aridity in the Mediterranean Sea. We speculate that these changes triggered an increased MOW flow and were ultimately induced by a persistent 2.5 °C cooling of Indonesian Through-Flow waters. The temperature drop resulted from the northward drift of Australia that crossed a threshold value near 3.6-3.3 Ma and led to a large-scale cooling of the eastern subtropical Indian Ocean and in turn, to a reduction of African monsoon rains. Vice versa, we show that the distinct rise in Mediterranean salt export after 3.4 Ma induced a unique long-term rise in the formation of Upper North Atlantic Deep Water, that followed with a phase lag of 100 ky. In summary, we present evidence for an interhemispheric teleconnection of processes in the Indonesian Gateways, the Mediterranean and Labrador Seas, jointly affecting Pliocene climate.

  19. Gap Junctions and Cancer: Communicating for 50 Years’

    Science.gov (United States)

    Aasen, Trond; Mesnil, Marc; Naus, Christian C.; Lampe, Paul D.; Laird, Dale W.

    2017-01-01

    Fifty years ago, tumour cells were found to lack electrical coupling, leading to the hypothesis that loss of direct intercellular communication is commonly associated with cancer onset and progression. Subsequent studies linked this phenomenon to gap junctions composed of connexin proteins. While many studies support the notion that connexins are tumour suppressors, recent evidence suggests that, in some tumour types, they may facilitate specific stages of tumour progression through both junctional and non-junctional signalling pathways. This Timeline article highlights the milestones connecting gap junctions to cancer, and underscores important unanswered questions, controversies and therapeutic opportunities in the field. PMID:27782134

  20. Gap Surface Plasmon Waveguide Analysis

    DEFF Research Database (Denmark)

    Nielsen, Michael Grøndahl; Bozhevolnyi, Sergey I.

    2014-01-01

    Plasmonic waveguides supporting gap surface plasmons (GSPs) localized in a dielectric spacer between metal films are investigated numerically and the waveguiding properties at telecommunication wavelengths are presented. Especially, we emphasize that the mode confinement can advantageously...

  1. Talent Management: Bridging the Gap

    Science.gov (United States)

    2015-06-12

    Cooper and Colton, you are the greatest gift I could have ever imagined. Daddy’s done with his homework and now we can go to the park–I promise...45 Gap 4: Up-Or-Out Promotions ..................................................................................... 49

  2. Closing the Cybersecurity Skills Gap

    Directory of Open Access Journals (Sweden)

    Rebecca Vogel

    2016-05-01

    Full Text Available The current consensus is that there is a worldwide gap in skills needed for a competent cybersecurity workforce. This skills gap has implications for the national security sector, both public and private. Although the view is that this will take a concerted effort to rectify, it presents an opportunity for IT professionals, university students, and aspirants to take-up jobs in national security national intelligence as well military and law enforcement intelligence. This paper examines context of the issue, the nature of the cybersecurity skills gap, and some key responses by governments to address the problem. The paper also examines the emerging employment trends, some of the employment challenges, and what these might mean for practice. The paper argues that the imperative is to close the cyber skills gap by taking advantage of the window of opportunity, allowing individuals interested in moving into the cybersecurity field to do so via education and training.

  3. Linking catchment-scale subglacial discharge to subsurface glacially modified waters near the front of a marine terminating outlet glacier using an autonomous underwater vehicle

    Science.gov (United States)

    Stevens, L. A.; Straneo, F.; Das, S. B.; Plueddemann, A. J.; Kukulya, A. L.; Morlighem, M.

    2015-09-01

    Measurements of near-ice (Autonomous Underwater Vehicle as close as 150 m from the ice/ocean interface of the Sarqardliup sermia/Sarqardleq Fjord system, West Greenland, with modeled and observed subglacial discharge locations and magnitudes. We find evidence of two main types of subsurface glacially modified water localized in space and with distinct properties that are consistent with runoff discharged at two locations along the grounded margin. These locations, in turn, correspond with two prominent subglacial subcatchments beneath Sarqardliup sermia. Thus, near-ice observations and subglacial discharge routing indicate that subglacial discharge from this glacier occurs at only two primary locations and gives rise to two distinct glacially modified waters. Furthermore, we show that the location with the largest discharge flux is associated with the lighter, fresher glacially modified watermass. This is qualitatively consistent with results from an idealized plume model.

  4. Linking benthic dynamics and cold-water coral occurrences: A high-resolution model study at three carbonate mound provinces in the NE Atlantic

    OpenAIRE

    2012-01-01

    We used the 3-D ocean circulation model with grid refinement ROMS-AGRIF to describe the hydrodynamic conditions at three cold-water coral provinces in the NE Atlantic (Logachev Mounds, Arc Mounds and Belgica Mounds). Modelled fields of currents, temperature and salinity were analysed for observed occurrences and presence/absence of living coral frameworks, living coral colonies within each province. The central model grid has a horizontal resolution of approximately 250 m, except for the Arc ...

  5. Linking the diffusion of water in compacted clays at two different time scales: tracer through-diffusion and quasielastic neutron scattering.

    Science.gov (United States)

    González Sánchez, Fátima; Gimmi, Thomas; Jurányi, Fanni; Van Loon, Luc; Diamond, Larryn W

    2009-05-15

    Diffusion of water and solutes through compacted clays or claystones is important when assessing the barrier function of engineered or geological barriers in waste disposal. The shape and the connectivity of the pore network as well as electrostatic interactions between the diffusant and the charged clay surfaces or cations compensating negative surface charges affect the resistance of the porous medium to diffusion. Comparing diffusion measurements performed at different spatial or time scales allows identification and extraction of the different factors. We quantified the electrostatic constraint q for five different highly compacted clays (rhob = 1.85 +/- 0.05 g/cm3) using quasielastic neutron scattering (QENS) data. We then compared the QENS data with macroscopic diffusion data for the same clays and could derive the true geometric tortuosities G of the samples. Knowing the geometric and electrostatic factors for the different clays is essential when trying to predict diffusion coefficients for other conditions. We furthermore compared the activation energies Ea for diffusion at the two measurement scales. Because Ea is mostly influenced by the local, pore scale surroundings of the water, we expected the results to be similar at both scales. This was indeed the case for the nonswelling clays kaolinite and illite, which had Ea values lower than that of bulk water, but not for montmorillonite, which had values lower than that in bulk water at the microscopic scale, but larger at the macroscopic scale. The differences could be connected to the strongly temperature dependent mobility of the cations in the clays, which may act as local barriers in the narrow pores at low temperatures.

  6. Linking nursery nutritional status and water availability post-planting under intense summer drought: the case of a South American Mediterranean tree species

    Directory of Open Access Journals (Sweden)

    Ovalle JF

    2016-10-01

    Full Text Available Drought-avoidance traits of South American Mediterranean tree species are crucial attributes to be considered in nursery practices aimed at improving the performance of seedlings exposed to intense summer drought in dryland reforestation projects. In this study, we determined the relation between nursery fertilization doses and the development of drought-avoidance traits of the soapbark tree Quillaja saponaria (Mol. under contrasting watering regimes following post-planting. Seedlings were grown for 6 months using four increasing doses of controlled-release fertilizer (0, 3, 6, and 12 g L-1 of Basacote® Plus 15:8:12. After outplanting, half of the seedlings were watered weekly and the other half were left unwatered for one growing season from September 2011 to May 2012. Seedlings were periodically measured for morphological and ecophysiological parameters, and carefully harvested for root measurements at the end of the study. Our results showed that high fertilization doses produced significantly larger seedlings in the nursery with high nitrogen and phosphorous foliar concentrations, which resulted in a significantly higher shoot dry mass after outplanting. Unfertilized seedlings grown with water application had a significantly higher stem diameter, root dry mass and lower shoot/root compared with seedlings with high fertilizer dose. These results highlight the ability of this species to maintain drought-avoidance traits, such as high xylem water potential and chlorophyll fluorescence, during the first 3 months of the 7-month drought period. High nutrient loading, although resulting in improved shoot productivity after outplanting, did not make a significant contribution to the early development of drought-avoidance traits in Q. saponaria.

  7. Linking sedimentary sulfur and iron biogeochemistry to growth patterns of a cold-water coral mound in the Porcupine Basin, S.W. Ireland (IODP Expedition 307).

    Science.gov (United States)

    Wehrmann, L M; Titschack, J; Böttcher, M E; Ferdelman, T G

    2015-09-01

    Challenger Mound, a 150-m-high cold-water coral mound on the eastern flank of the Porcupine Seabight off SW Ireland, was drilled during Expedition 307 of the Integrated Ocean Drilling Program (IODP). Retrieved cores offer unique insight into an archive of Quaternary paleo-environmental change, long-term coral mound development, and the diagenetic alteration of these carbonate fabrics over time. To characterize biogeochemical carbon-iron-sulfur transformations in the mound sediments, the contents of dithionite- and HCl-extractable iron phases, iron monosulfide and pyrite, and acid-extractable calcium, magnesium, manganese, and strontium were determined. Additionally, the stable isotopic compositions of pore-water sulfate and solid-phase reduced sulfur compounds were analyzed. Sulfate penetrated through the mound sequence and into the underlying Miocene sediments, where a sulfate-methane transition zone was identified. Small sulfate concentration decreases (<7 mM) within the top 40 m of the mound suggested slow net rates of present-day organoclastic sulfate reduction. Increasing δ(34)S-sulfate values due to microbial sulfate reduction mirrored the decrease in sulfate concentrations. This process was accompanied by oxygen isotope exchange with water that was indicated by increasing δ(18)O-sulfate values, reaching equilibrium with pore-water at depth. Below 50 mbsf, sediment intervals with strong (34)S-enriched imprints on chromium-reducible sulfur (pyrite S), high degree-of-pyritization values, and semi-lithified diagenetic carbonate-rich layers characterized by poor coral preservation, were observed. These layers provided evidence for the occurrence of enhanced microbial sulfate-reducing activity in the mound in the past during periods of rapid mound aggradation and subsequent intervals of non-deposition or erosion when geochemical fronts remained stationary. During these periods, especially during the Early Pleistocene, elevated sulfate reduction rates facilitated

  8. Cooperative protein structural dynamics of homodimeric hemoglobin linked to water cluster at subunit interface revealed by time-resolved X-ray solution scattering.

    Science.gov (United States)

    Kim, Jong Goo; Muniyappan, Srinivasan; Oang, Key Young; Kim, Tae Wu; Yang, Cheolhee; Kim, Kyung Hwan; Kim, Jeongho; Ihee, Hyotcherl

    2016-03-01

    Homodimeric hemoglobin (HbI) consisting of two subunits is a good model system for investigating the allosteric structural transition as it exhibits cooperativity in ligand binding. In this work, as an effort to extend our previous study on wild-type and F97Y mutant HbI, we investigate structural dynamics of a mutant HbI in solution to examine the role of well-organized interfacial water cluster, which has been known to mediate intersubunit communication in HbI. In the T72V mutant of HbI, the interfacial water cluster in the T state is perturbed due to the lack of Thr72, resulting in two less interfacial water molecules than in wild-type HbI. By performing picosecond time-resolved X-ray solution scattering experiment and kinetic analysis on the T72V mutant, we identify three structurally distinct intermediates (I1, I2, and I3) and show that the kinetics of the T72V mutant are well described by the same kinetic model used for wild-type and F97Y HbI, which involves biphasic kinetics, geminate recombination, and bimolecular CO recombination. The optimized kinetic model shows that the R-T transition and bimolecular CO recombination are faster in the T72V mutant than in the wild type. From structural analysis using species-associated difference scattering curves for the intermediates, we find that the T-like deoxy I3 intermediate in solution has a different structure from deoxy HbI in crystal. In addition, we extract detailed structural parameters of the intermediates such as E-F distance, intersubunit rotation angle, and heme-heme distance. By comparing the structures of protein intermediates in wild-type HbI and the T72V mutant, we reveal how the perturbation in the interfacial water cluster affects the kinetics and structures of reaction intermediates of HbI.

  9. Homogenization conditions affect the oxidative stability of fish oil enriched milk emulsions: oxidation linked to changes in protein composition at the oil-water interface

    DEFF Research Database (Denmark)

    Sørensen, Ann-Dorit M.; Baron, Caroline P.; Let, Mette B.

    2007-01-01

    Fish oil was incorporated into milk under different homogenization temperatures (50 and 72 °C) and pressures (5, 15, and 22.5 MPa). Subsequently, the oxidative stability of the milk and changes in the protein composition of the milk fat globule membrane (MFGM) were examined. Results showed that h...... casein seemed to be present at the oil−water interface with increasing pressure. Overall, the results indicated that a combination of more β-lactoglobulin and less casein at the oil−water interface gave the most stable emulsions with respect to lipid oxidation....... was increased by high temperature (72 °C) and with increasing pressure. Furthermore, SDS-PAGE and confocal laser scanning microscopy (CLSM) indicated that high temperature resulted in an increase in β-lactoglobulin adsorbed at the oil−water interface. This was even more pronounced with higher pressure. Less......Fish oil was incorporated into milk under different homogenization temperatures (50 and 72 °C) and pressures (5, 15, and 22.5 MPa). Subsequently, the oxidative stability of the milk and changes in the protein composition of the milk fat globule membrane (MFGM) were examined. Results showed...

  10. Homogenization conditions affect the oxidative stability of fish oil enriched milk emulsions: oxidation linked to changes in protein composition at the oil-water interface.

    Science.gov (United States)

    Sørensen, Ann-Dorit M; Baron, Caroline P; Let, Mette B; Brüggemann, Dagmar A; Pedersen, Lise R L; Jacobsen, Charlotte

    2007-03-07

    Fish oil was incorporated into milk under different homogenization temperatures (50 and 72 degrees C) and pressures (5, 15, and 22.5 MPa). Subsequently, the oxidative stability of the milk and changes in the protein composition of the milk fat globule membrane (MFGM) were examined. Results showed that high pressure and high temperature (72 degrees C and 22.5 MPa) resulted in less lipid oxidation, whereas low pressure and low temperature (50 degrees C and 5 MPa) resulted in faster lipid oxidation. Analysis of protein oxidation indicated that especially casein was prone to oxidation. The level of free thiol groups was increased by high temperature (72 degrees C) and with increasing pressure. Furthermore, SDS-PAGE and confocal laser scanning microscopy (CLSM) indicated that high temperature resulted in an increase in beta-lactoglobulin adsorbed at the oil-water interface. This was even more pronounced with higher pressure. Less casein seemed to be present at the oil-water interface with increasing pressure. Overall, the results indicated that a combination of more beta-lactoglobulin and less casein at the oil-water interface gave the most stable emulsions with respect to lipid oxidation.

  11. Impact of Ca-amendments and soil management in physical properties linked to soil-water relationship in degraded Ultisols from South-Europe

    Science.gov (United States)

    Mariscal-Sancho, I.; Gonzalez-Fernandez, P.; León, P.; Gómez-Paccard, C.; Benito, M.; Espejo, R.

    2012-04-01

    Cañamerós raña formation in western Spain was cleared for cropping in 1940´s. Its highly weathered acidic soils (Ultisols) were deeply affected by tillage. The soil organic matter (SOM) content and specially the particulate organic matter (POM), a labile fraction, were drastically reduced, and most of their chemical and physical soil properties related to its quality were negatively affected. The extraction of Ca through the harvest and the release of Al retained in organic-Al complexes resulted in a lower Ca/Al ratio which increased the Al toxicity. These effects led to a drastic yield reduction and the abandon of many degraded fields after 20-70 years of unsustainable managements. On these degraded soils we studied the effect of different soil management strategies (no-till with wild pasture (WP) and no-till with an improved pasture (IP)), and amendment applications (sugar foam waste (SF), and SF + Phosphogypsum (PH) versus control (C)). One of the objectives of this work was to evaluate the efficiency of these practices to recover soil quality parameters, especially those related to soil-water relationship. A Split-plot experiment was established in a degraded field. We evaluated the changes in superficial infiltration, bulk density, and content of water-stable aggregates per 100 g of soil before the Ca-amendment applications and pasture establishments, and after 4.5 years. We also measured the changes in SOM and POM contents which are closely related with the previous parameters. The Ca applications reduced Al toxicity, improved the pasture yield and increased organic matter inputs to soil. The results showed a significant increase of POM in all treatment compared with the POM content at the beginning of this experiment. However the "SOM minus POM" which could be classified as recalcitrant organic matter did not show significant increments. The increase of POM had a positive effect on the content of water-stable aggregates per 100 g of soil and the water

  12. Physical properties and processes in the Perth Canyon, Western Australia: Links to water column production and seasonal pygmy blue whale abundance

    Science.gov (United States)

    Rennie, S.; Hanson, C. E.; McCauley, R. D.; Pattiaratchi, C.; Burton, C.; Bannister, J.; Jenner, C.; Jenner, M.-N.

    2009-04-01

    The oceanography of the Perth Canyon, off southwestern Australia, was examined through two major field excursions in austral spring/summer 2003/2004 combined with previous results from field analysis and numerical simulations. Water properties were used to identify water masses and vertical displacement. The field cruises and numerical simulation indicated unique circulation features of the Leeuwin Current and Undercurrent within the canyon associated with the topographic features. The input of nutrients to the euphotic zone occurred sporadically as the Leeuwin Current generally suppressed upwelling, although the Perth Canyon had increased nutrient concentrations within its rims. The distribution of chlorophyll in the surface layers indicated high spatial variability, with a prevalent deep chlorophyll (and phytoplankton biomass) maximum at ~ 80 m. Depth-integrated primary production within the study region ranged from 360 to 760 mg C m - 2 d - 1 , which was on average 2.5 times higher than rates measured in continental shelf and offshore waters north of the canyon. Aggregations of krill and other acoustic backscatter targets were concentrated near the head of the canyon at a range of depths, which may have been promoted by the circulation. The findings here are consistent with seasonal variations in wind and insolation, along with variations in the Leeuwin Current, influencing the seasonal changes and mesoscale features within the region, while the canyon promotes localised upwelling, and enhances both pelagic production and physical aggregation of plankton to attract the whales. Canyon processes must be combined with outside factors to allow upwelled nutrients to reach the photic zone. It is concluded that a combination of factors, rather than one factor alone, contributes favourably to the appearance of feeding blue whales in the Perth Canyon during the summer.

  13. Cooperative protein structural dynamics of homodimeric hemoglobin linked to water cluster at subunit interface revealed by time-resolved X-ray solution scattering

    Directory of Open Access Journals (Sweden)

    Jong Goo Kim

    2016-03-01

    Full Text Available Homodimeric hemoglobin (HbI consisting of two subunits is a good model system for investigating the allosteric structural transition as it exhibits cooperativity in ligand binding. In this work, as an effort to extend our previous study on wild-type and F97Y mutant HbI, we investigate structural dynamics of a mutant HbI in solution to examine the role of well-organized interfacial water cluster, which has been known to mediate intersubunit communication in HbI. In the T72V mutant of HbI, the interfacial water cluster in the T state is perturbed due to the lack of Thr72, resulting in two less interfacial water molecules than in wild-type HbI. By performing picosecond time-resolved X-ray solution scattering experiment and kinetic analysis on the T72V mutant, we identify three structurally distinct intermediates (I1, I2, and I3 and show that the kinetics of the T72V mutant are well described by the same kinetic model used for wild-type and F97Y HbI, which involves biphasic kinetics, geminate recombination, and bimolecular CO recombination. The optimized kinetic model shows that the R-T transition and bimolecular CO recombination are faster in the T72V mutant than in the wild type. From structural analysis using species-associated difference scattering curves for the intermediates, we find that the T-like deoxy I3 intermediate in solution has a different structure from deoxy HbI in crystal. In addition, we extract detailed structural parameters of the intermediates such as E-F distance, intersubunit rotation angle, and heme-heme distance. By comparing the structures of protein intermediates in wild-type HbI and the T72V mutant, we reveal how the perturbation in the interfacial water cluster affects the kinetics and structures of reaction intermediates of HbI.

  14. GAP junctional communication in brain secondary organizers.

    Science.gov (United States)

    Bosone, Camilla; Andreu, Abraham; Echevarria, Diego

    2016-06-01

    Gap junctions (GJs) are integral membrane proteins that enable the direct cytoplasmic exchange of ions and low molecular weight metabolites between adjacent cells. They are formed by the apposition of two connexons belonging to adjacent cells. Each connexon is formed by six proteins, named connexins (Cxs). Current evidence suggests that gap junctions play an important part in ensuring normal embryo development. Mutations in connexin genes have been linked to a variety of human diseases, although the precise role and the cell biological mechanisms of their action remain almost unknown. Among the big family of Cxs, several are expressed in nervous tissue but just a few are expressed in the anterior neural tube of vertebrates. Many efforts have been made to elucidate the molecular bases of Cxs cell biology and how they influence the morphogenetic signal activity produced by brain signaling centers. These centers, orchestrated by transcription factors and morphogenes determine the axial patterning of the mammalian brain during its specification and regionalization. The present review revisits the findings of GJ composed by Cx43 and Cx36 in neural tube patterning and discuss Cx43 putative enrollment in the control of Fgf8 signal activity coming from the well known secondary organizer, the isthmic organizer. © 2016 The Authors. Development, Growth & Differentiation published by John Wiley & Sons Australia, Ltd on behalf of Japanese Society of Developmental Biologists.

  15. Environmental contributors to the achievement gap.

    Science.gov (United States)

    Miranda, Marie Lynn; Kim, Dohyeong; Reiter, Jerome; Overstreet Galeano, M Alicia; Maxson, Pamela

    2009-11-01

    Extensive research shows that blacks, those of low socioeconomic status, and other disadvantaged groups continue to exhibit poorer school performance compared with middle and upper-class whites in the United States' educational system. Environmental exposures may contribute to the observed achievement gap. In particular, childhood lead exposure has been linked to a number of adverse cognitive outcomes. In previous work, we demonstrated a relationship between early childhood lead exposure and end-of-grade (EOG) test scores on a limited dataset. In this analysis, data from the North Carolina Childhood Lead Poisoning Prevention Program surveillance registry were linked to educational outcomes available through the North Carolina Education Research Data Center for all 100 counties in NC. Our objectives were to confirm the earlier study results in a larger population-level database, determine whether there are differences in the impact of lead across the EOG distribution, and elucidate the impact of cumulative childhood social and environmental stress on educational outcomes. Multivariate and quantile regression techniques were employed. We find that early childhood lead exposure is associated with lower performance on reading EOG test scores in a clear dose-response pattern, with the effects increasingly more pronounced in moving from the high end to the low end of the test score distribution. Parental educational attainment and family poverty status also affect EOG test scores, in a similar dose-response fashion, with the effects again most pronounced at the low end of the EOG test score distribution. The effects of environmental and social stressors (especially as they stretch out the lower tail of the EOG distribution) demonstrate the particular vulnerabilities of socioeconomically and environmentally disadvantaged children. Given the higher average lead exposure experienced by African American children in the United States, lead does in fact explain part of the

  16. Use of {gamma}-irradiation cross-linking to improve the water vapor permeability and the chemical stability of milk protein films

    Energy Technology Data Exchange (ETDEWEB)

    Ouattara, B.; Canh, L.T.; Vachon, C.; Mateescu, M.A.; Lacroix, M. E-mail: monique.lacroix@inrs-iaf.uquebec.ca

    2002-03-01

    {gamma}-irradiation was used to produce free-standing cross-linked milk proteins. Film forming solutions were prepared according to a method previously developed in our laboratory using calcium caseinate (cas) with various proportions of whey protein isolate (wpi) or whey protein concentrate (wpc). The following caseinate-whey protein (cas:wp) ratio were prepared: 100:0, 75:25, 50:50, 25:75, and 0:100. The WVP of the films was determined gravimetrically at 23 deg. C using a modified ASTM procedure. Molecular properties characterization was performed by size exclusion chromatography (SEC). Results showed significant (p{<=}0.05) reduction of the WVP of protein films for the following formulations: cas:wpi or cas:wpc (100:0); cas:wpi (25:75); cas:wpc (25:75); and cas:wpc (0:100). Mixture of cas and wpi produced a synergistic effect. The strongest combined effect was obtained for cas:wpi (25:75) formulation with permeability values of 2.07 and 1.38 g mm/m{sup 2} d mm Hg for unirradiated and irradiated samples, respectively. {gamma}-irradiation also induced a substantial increase of high molecular weight protein components in film forming solutions. The predominant fraction was {>=}10x10{sup 6} Da for irradiated film forming solutions, compared to less than 0.2x10{sup 6} Da for native unirradiated solutions.

  17. Use of /γ-irradiation cross-linking to improve the water vapor permeability and the chemical stability of milk protein films

    Science.gov (United States)

    Ouattara, B.; Canh, L. T.; Vachon, C.; Mateescu, M. A.; Lacroix, M.

    2002-03-01

    γ-irradiation was used to produce free-standing cross-linked milk proteins. Film forming solutions were prepared according to a method previously developed in our laboratory using calcium caseinate (cas) with various proportions of whey protein isolate (wpi) or whey protein concentrate (wpc). The following caseinate-whey protein (cas:wp) ratio were prepared: 100:0, 75:25, 50