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1

Analytical approach for predicting fresh water discharge in an estuary based on tidal water level observations  

NASA Astrophysics Data System (ADS)

As the tidal wave propagates into an estuary, the tidally averaged water level tends to rise in landward direction due to the density difference between saline and fresh water and the asymmetry of the friction. The effect of friction on the residual slope is even more remarkable when accounting for fresh water discharge. In this study, we investigate the influence of river discharge on tidal wave propagation in the Yangtze estuary with specific attention to residual water level slope. This is done by using a one-dimensional analytical model for tidal hydrodynamics accounting for the residual water level. We demonstrate the importance of the residual slope on tidal dynamics and use it to improve the prediction of the tidal propagation in estuaries (i.e. tidal damping, velocity amplitude, wave celerity and phase lag), especially when the influence of river discharge is significant. Finally, we develop a new inverse analytical approach for estimating fresh water discharge on the basis of tidal water level observations along the estuary, which can be used as a tool to obtain information on the river discharge that is otherwise difficult to measure in the tidal region.

Cai, H.; Savenije, H. H. G.; Jiang, C.

2014-10-01

2

Study of two-cell immune feedback control for water level of boiler drum based on gray prediction  

Microsoft Academic Search

Due to the `false water level' phenomenon in power station makes the traditional control strategy can't be a good solution to the problem, a two-cell immune feedback control strategy based on gray prediction for water level of boiler drum in power station is proposed, which using the function of gray prediction with strong self-adaptability and advanced control functions, and learning

Dao-Gang Peng; Hao Zhang; Cong-Hua Huang; Fei Xia; Hui Li

2010-01-01

3

A Statistical Model for Predicting Chloroform Levels in Chlorinated Surface Water Supplies  

Microsoft Academic Search

Multiple regression analysis of a number of routinely measured characteristics—temperature, turbidity, color, pH, free residual chlorine, total residual chlorine, and chloroform—of the raw water, finished plant water, and distribution system water of nineteen Massachusetts communities showed chlorine dosage to be the most reliable predictor of chloroform levels in the water supply.

Gary S. Moore; Robert W. Tuthill; David W. Polakoff

1979-01-01

4

Construction and use of special drawdown scales for use in prediction of water-level changes throughout heavily pumped areas  

USGS Publications Warehouse

Problem and Proposed Method of Solution Frequently the Theis nonequilibrium formula is use din the quantitative analyses that are part of many-ground-water investigations. The computations associated therewith may become quite involved and tedious, especially when dealing with predictions of the decline of water levels throughout large areas in which there are many discharging wells. The process of predicting future water-level declines can be greatly simplified and shortened by preparing a special draw-down scale for given conditions. Through use of such a scale much of the computation can be reduced to scaling the values sought from a map, on which the pumped wells have been spotted. The net drawdown effect, which is the sum of the water-level declines caused by the many individual pumped wells, can be determined readily for any desired point in the area. If the net drawdown effect is desired, a summation of the effects of all the pumped wells can be repeated for each point. By determining the water-level change at a number of points, for a given period of time, a contour map of predicted water-level changes for the multiple-well system can be drawn.

Conover, C.S.; Reeder, H.O.

1957-01-01

5

Predicting wetland plant community responses to proposed water-level-regulation plans for Lake Ontario: GIS-based modeling  

USGS Publications Warehouse

Integrated, GIS-based, wetland predictive models were constructed to assist in predicting the responses of wetland plant communities to proposed new water-level regulation plans for Lake Ontario. The modeling exercise consisted of four major components: 1) building individual site wetland geometric models; 2) constructing generalized wetland geometric models representing specific types of wetlands (rectangle model for drowned river mouth wetlands, half ring model for open embayment wetlands, half ellipse model for protected embayment wetlands, and ellipse model for barrier beach wetlands); 3) assigning wetland plant profiles to the generalized wetland geometric models that identify associations between past flooding / dewatering events and the regulated water-level changes of a proposed water-level-regulation plan; and 4) predicting relevant proportions of wetland plant communities and the time durations during which they would be affected under proposed regulation plans. Based on this conceptual foundation, the predictive models were constructed using bathymetric and topographic wetland models and technical procedures operating on the platform of ArcGIS. An example of the model processes and outputs for the drowned river mouth wetland model using a test regulation plan illustrates the four components and, when compared against other test regulation plans, provided results that met ecological expectations. The model results were also compared to independent data collected by photointerpretation. Although data collections were not directly comparable, the predicted extent of meadow marsh in years in which photographs were taken was significantly correlated with extent of mapped meadow marsh in all but barrier beach wetlands. The predictive model for wetland plant communities provided valuable input into International Joint Commission deliberations on new regulation plans and was also incorporated into faunal predictive models used for that purpose.

Wilcox, D. A.; Xie, Y.

2007-01-01

6

Soil moisture versus depth-to-water-level: Which is better for predicting plant composition in a restored floodplain wetland?  

NASA Astrophysics Data System (ADS)

Depth-to-water-level (DTWL) measurements in shallow groundwater piezometers are commonly used to develop relationships between wetland plant composition and the available water regime. Such relationships can provide useful predictions of plant composition for land managers under potential changing conditions (e.g., climate change, land use change, environmental flow releases, groundwater pumping) when combined with a hydrologic model. These analyses, however, implicitly use DTWL as a surrogate for the water regime within the root zone, which is experienced by plants. Bi-weekly field measurements of both variables (DTWL and SM) were made at a restored floodplain wetland over the 2009 and 2010 growing seasons. Plant species composition and percent cover were also sampled at the same locations (N=62). Nonmetric multidimensional scaling (NMS) and nonparametric multiplicative regression (NPMR) were used to compare how effectively the two hydrologic metrics explain the overall plant community ordination space (NMS) and predict the probability of presence of certain dominant species (NPMR). Both statistical techniques revealed that SM was more successful than DTWL at explaining the overall plant community structure and predicting plant composition for certain dominant species. The predictive modeling results also suggest that hydrologic extremes on a species-specific basis are effective predictors of plant composition. Field evidence based on soil coring and geophysical imaging suggests that the reason for the discrepancy in the efficacy of the two hydrologic variables is the presence of a confining silt-clay layer in some areas of the floodplain that partially decouples soil moisture in the root zone from groundwater in a deeper gravel layer. While DTWL may be adequate as a predictive variable in vegetation modeling at some sites, SM is likely to be more valuable - especially at sites where soil moisture and groundwater are decoupled - at developing robust relationships between the water regime and vegetation.

Booth, E.; Loheide, S. P.

2010-12-01

7

Alternative configurations of quantile regression for estimating predictive uncertainty in water level forecasts for the upper Severn River: a comparison  

NASA Astrophysics Data System (ADS)

The present study comprises an intercomparison of different configurations of a statistical post-processor that is used to estimate predictive hydrological uncertainty. It builds on earlier work by Weerts, Winsemius and Verkade (2011; hereafter referred to as WWV2011), who used the quantile regression technique to estimate predictive hydrological uncertainty using a deterministic water level forecast as a predictor. The various configurations are designed to address two issues with the WWV2011 implementation: (i) quantile crossing, which causes non-strictly rising cumulative predictive distributions, and (ii) the use of linear quantile models to describe joint distributions that may not be strictly linear. Thus, four configurations were built: (i) a ''classical" quantile regression, (ii) a configuration that implements a non-crossing quantile technique, (iii) a configuration where quantile models are built in normal space after application of the normal quantile transformation (NQT) (similar to the implementation used by WWV2011), and (iv) a configuration that builds quantile model separately on separate domains of the predictor. Using each configuration, four reforecasting series of water levels at 14 stations in the upper Severn River were established. The quality of these four series was intercompared using a set of graphical and numerical verification metrics. Intercomparison showed that reliability and sharpness vary across configurations, but in none of the configurations do these two forecast quality aspects improve simultaneously. Further analysis shows that skills in terms of the Brier skill score, mean continuous ranked probability skill score and relative operating characteristic score is very similar across the four configurations.

López López, P.; Verkade, J. S.; Weerts, A. H.; Solomatine, D. P.

2014-09-01

8

Ground-water-level monitoring for earthquake prediction; a progress report based on data collected in Southern California, 1976-79  

USGS Publications Warehouse

The U.S. Geological Survey is conducting a research program to determine if groundwater-level measurements can be used for earthquake prediction. Earlier studies suggest that water levels in wells may be responsive to small strains on the order of 10 to the minus 8th power to 10 to the minus 10th power (dimensionless). Water-level data being collected in the area of the southern California uplift show response to earthquakes and other natural and manmade effects. The data are presently (1979) being made ready for computer analysis. The completed analysis may indicate the presence of precursory earthquake information. (USGS)

Moyle, W. R., Jr.

1980-01-01

9

Improved sea level anomaly prediction through combination of data relationship analysis and genetic programming in Singapore Regional Waters  

NASA Astrophysics Data System (ADS)

With recent advances in measurement and information technology, there is an abundance of data available for analysis and modelling of hydrodynamic systems. Spatial and temporal data coverage, better quality and reliability of data modelling and data driven techniques have resulted in more favourable acceptance by the hydrodynamic community. The data mining tools and techniques are being applied in variety of hydro-informatics applications ranging from data mining for pattern discovery to data driven models and numerical model error correction. The present study explores the feasibility of applying mutual information theory by evaluating the amount of information contained in observed and prediction errors of non-tidal barotropic numerical modelling (i.e. assuming that the hydrodynamic model, available at this point, is best representation of the physics in the domain of interest) by relating them to variables that reflect the state at which the predictions are made such as input data, state variables and model output. In addition, the present study explores the possibility of employing ‘genetic programming' (GP) as an offline data driven modelling tool to capture the sea level anomaly (SLA) dynamics and then using them for updating the numerical model prediction in real time applications. These results suggest that combination of data relationship analysis and GP models helps to improve the forecasting ability by providing information of significant predicative parameters. It is found that GP based SLA prediction error forecast model can provide significant improvement when applied as data assimilation schemes for updating the SLA prediction obtained from primary hydrodynamic models.

Kurniawan, Alamsyah; Ooi, Seng Keat; Babovic, Vladan

2014-11-01

10

Reasons and Predictions of The Caspian Sea Water Level Fluctuations: Impact of Climate Factors and Man's Activities.  

NASA Astrophysics Data System (ADS)

The Caspian Sea - the largest lake in the world - has no connection with the Ocean and is lower than its surface. Fluctuations of the Sea level are very significant: during the period of instrumental observations (since 1830) the level amplitude was 3.78 m with maximum of -25.22 m in 1882 and minimum of -29.00 m in 1978. These fluctuations lead to a great damage for the economy of five countries sharing its coast (Azerbaijan, Iran, Kazakhstan, Russia and Turkmenistan). Deep knowledge of hydrological and hydrodynamic Sea regime and scientifically justified forecasts of possible changes in its level, taking into account variability in climate and future climate change, are re- quired for undertaking urgent measures for protection of coastal territories. The inter- national research project CASSEAS, carried out in 1997-2000 within the framework of the INCO-COPERNICUS programme by the scientists of 5 countries: France, Rus- sia, Germany, Turkmenistan and UK, was devoted to these problems. Research made within the Project made it possible to get new precise data on all water balance com- ponents of the Caspian Sea for 1880-1996; moreover, all water balance components for 1940-1996 were computed independently. It was shown that the Sea level fluctua- tions depended on the water balance almost completely. Assessment of possible future runoff changes in the Caspian Sea basin was made using the mathematical model of runoff formation developed at the SHI. Several scenarios from a range of GCMs and on the basis of paleoclimatic reconstructions were used as the models of the future climate for the nearest 3 decades. Besides changes in climate characteristics, three variants were accepted for the future water use in the basins of rivers discharging to the Caspian Sea. All scenarios gave similar results for changes in annual river inflow to the Caspian Sea: its increase would be from 5% to 10% by 2030. The same scenarios, used to estimate changes in precipitation onto the Sea surface and evaporation from it, made it possible to expect visible evaporation increase by 5-10%. To make a prob- abilistic forecast of the Caspian Sea level before 2030 a dynamic stochastic model of the Caspian Sea long-term level fluctuations developed at the SHI was used. The main conclusions based on the modelling results are as follows: - Water level fall is most probable in the future. Mean Sea level mark may be within -27.2 ...-27.3 m (2005), -27.6 ...-28.0 m (2015), -28.4 ...-28.9 m (2030); - A probable Sea level deviation from its mean position at the confidence probability of 95% may be +/- 0.75 m by 2005, +/- 1 1.3 m by 2015 and +/- 1.6 m by 2030; - During the nearest decade the probability of exceedence of the Sea level above -26.0 m would be less than 1%, above -25.5 m less than 0.1% (once per 1000 years); in the next two decades the probability of this event would be even lower; - These conclusions should be considered for decision-making on a development and implementation of projects to protect the coastal zone of the Caspian Sea. 2

Erlich, M.; Shiklomanov, I.; Yezhov, A.; Georgievsky, V.; Shalygin, A.

11

Predicted water-level and water-quality effects of artificial recharge in the Upper Coachella Valley, California, using a finite-element digital model  

USGS Publications Warehouse

From 1936 to 1974, water levels declined more than 100 feet in the Palm Springs area and 60 feet in the Palm Desert area of the upper Coachella Valley, Calif. Water from the Colorado River Aqueduct is presently being recharged to the basin. The dissolved-solids concentration of native ground water in the recharge area is about 210 mg/liter and that of recharge water ranges from 600 to 750 mg/liter. A finite-element model indicates that without recharge the 1974 water levels in the Palm Springs area will decline 200 feet by the year 2000 because of pumpage. If the aquifer is recharged at a rate from about 7 ,500 acre-feet per year in 1973 increasing to 61,200 acre-feet per year in 1990 and thereafter, the water level in the Palm Springs area will decline about 20 feet below the 1974 level by 1991 and recover to the 1974 level by 2000. The solute-transport finite-element model of the recharge area indicates that the artificial recharge plume (bounded by the 300-mg/liter line) will move about 1.1 miles downgradient of the recharge ponds by 1981 and about 4.5 miles from the ponds by 2000. (Woodard-USGS)

Swain, Lindsay A.

1978-01-01

12

Sentence-Level Attachment Prediction  

NASA Astrophysics Data System (ADS)

Attachment prediction is the task of automatically identifying email messages that should contain an attachment. This can be useful to tackle the problem of sending out emails but forgetting to include the relevant attachment (something that happens all too often). A common Information Retrieval (IR) approach in analyzing documents such as emails is to treat the entire document as a bag of words. Here we propose a finer-grained analysis to address the problem. We aim at identifying individual sentences within an email that refer to an attachment. If we detect any such sentence, we predict that the email should have an attachment. Using part of the Enron corpus for evaluation we find that our finer-grained approach outperforms previously reported document-level attachment prediction in similar evaluation settings.

Albakour, M.-Dyaa; Kruschwitz, Udo; Lucas, Simon

13

Tides and Water Levels  

NSDL National Science Digital Library

This site serves as a gateway to three sections devoted to learning about tides and water levels: an online tutorial, an list of links to tidal resources, and formal lesson plans. The tutorial is an overview of the complex systems that govern the movement of tides and water levels. It is content rich, is presented in easy-to-understand language, and includes many illustrative and interactive graphics to visually enhance the text. The links direct users to specific tidal and current data offered within the National Ocean Service and National Oceanic and Atmospheric Administration's family of products. Lesson plans integrate information presented in the tutorial with online data. These lesson plans have been developed for students in grades 9-12 and focus on the forces that cause and effect tides, analysis of the variations in tidal patterns and what conditions may cause them, and the effect of lunar cycles on living organisms.

14

How predictable are water resources?  

NASA Astrophysics Data System (ADS)

Peter Mason, technical director of international dams and hydropower at MWH, explains how some water resources might be more predictable than generally supposed. Some years ago the writer examined the levels of Lake Victoria in east Africa as part of a major refurbishment project. This revealed a clear cyclic behavior in lake level and hence in discharges from the lake down the Nile system and up into Egypt. A recent study by the writer demonstrated that 20-year mean flows in the Kafue River in Zambia corresponded well to reconstructed rainfall records based on regional tree ring records. The Rio Parana has a catchment area of 3,100,000km 2 and a mean stream flow of 21,300m 3/sec. In the wider context an improved understanding of apparent periodicities in the natural record would seem to offer at least one planning scenario to be considered in terms of investment and even for the long term planning of aid and famine relief.

Mason, P.

2010-10-01

15

Prediction of concentration levels of metformin and other high consumption pharmaceuticals in wastewater and regional surface water based on sales data.  

PubMed

Local consumption data of pharmaceuticals were used to study the emission to wastewater and surface waters in two small Dutch water catchments. For nine high consumption pharmaceuticals: metformin, metoprolol, sotalol, losartan, valsartan, irbesartan, hydrochlorothiazide, diclofenac and carbamazepine, predicted emissions were compared to wastewater concentrations, removal in sewage treatment plants and recovery in regional surface water. The study shows that local consumption data can be very useful to select pharmaceuticals for monitoring and to predict wastewater concentrations. Measured influent concentrations were on average 78% with a range of 31-138% of predicted influent concentrations. Metformin is the pharmaceutical with the highest concentration in wastewater (64-98 ?g/L) but it is removed with >98% in sewage treatment plants (STP). Guanylurea, a biodegradation product of metformin, was detected in STP effluents and surface waters at concentrations of 39-56 ?g/L and 1.8-3.9 ?g/L, respectively. The STP removal of the different pharmaceuticals varied strongly. For carbamazepine, hydrochlorothiazide and sotalol a significant better removal was found at higher temperatures and longer hydraulic retention times while for metoprolol significantly better removal was only observed at higher temperatures. Predicting environmental concentrations from regional consumption data might be an alternative to monitoring of pharmaceuticals in wastewater and surface waters. PMID:23183121

Oosterhuis, Mathijs; Sacher, Frank; Ter Laak, Thomas L

2013-01-01

16

Myeloperoxidase Levels Predict Executive Function  

Microsoft Academic Search

The main purpose of the study was to investigate whether baseline\\u000a myeloperoxidase (MPO) levels are associated with executive cognitive\\u000a function in individuals with high physical activity. Baseline serum MPO\\u000a levels of 56 elderly marathon runners and 58 controls were assessed by\\u000a ELISA. Standardized tests were applied to survey domain-specific\\u000a cognitive functions. Changes in brain morphology were visualized by\\u000a magnetic resonance

H. Haslacher; T. Perkmann; I. Lukas; A. Barth; E. Ponocny-Seliger; M. Michlmayr; V. Scheichenberger; O. Wagner; R. Winker

2012-01-01

17

Computer program to predict aircraft noise levels  

NASA Technical Reports Server (NTRS)

Methods developed at the NASA Lewis Research Center for predicting the noise contributions from various aircraft noise sources were programmed to predict aircraft noise levels either in flight or in ground tests. The noise sources include fan inlet and exhaust, jet, flap (for powered lift), core (combustor), turbine, and airframe. Noise propagation corrections are available for atmospheric attenuation, ground reflections, extra ground attenuation, and shielding. Outputs can include spectra, overall sound pressure level, perceived noise level, tone-weighted perceived noise level, and effective perceived noise level at locations specified by the user. Footprint contour coordinates and approximate footprint areas can also be calculated. Inputs and outputs can be in either System International or U.S. customary units. The subroutines for each noise source and propagation correction are described. A complete listing is given.

Clark, B. J.

1981-01-01

18

2, 11071145, 2005 Water level  

E-print Network

for the journal Hydrology and Earth System Sciences Water level forecasting through fuzzy logic and artificial are based on the Mamdani and the Takagi-Sugeno fuzzy logic approaches, respec- tively.5 All of them with great attention to the reliability and accuracy of each model, with reference to the Reno river

Paris-Sud XI, Université de

19

Blind prediction of interfacial water positions in CAPRI.  

PubMed

We report the first assessment of blind predictions of water positions at protein-protein interfaces, performed as part of the critical assessment of predicted interactions (CAPRI) community-wide experiment. Groups submitting docking predictions for the complex of the DNase domain of colicin E2 and Im2 immunity protein (CAPRI Target 47), were invited to predict the positions of interfacial water molecules using the method of their choice. The predictions-20 groups submitted a total of 195 models-were assessed by measuring the recall fraction of water-mediated protein contacts. Of the 176 high- or medium-quality docking models-a very good docking performance per se-only 44% had a recall fraction above 0.3, and a mere 6% above 0.5. The actual water positions were in general predicted to an accuracy level no better than 1.5 Å, and even in good models about half of the contacts represented false positives. This notwithstanding, three hotspot interface water positions were quite well predicted, and so was one of the water positions that is believed to stabilize the loop that confers specificity in these complexes. Overall the best interface water predictions was achieved by groups that also produced high-quality docking models, indicating that accurate modelling of the protein portion is a determinant factor. The use of established molecular mechanics force fields, coupled to sampling and optimization procedures also seemed to confer an advantage. Insights gained from this analysis should help improve the prediction of protein-water interactions and their role in stabilizing protein complexes. PMID:24155158

Lensink, Marc F; Moal, Iain H; Bates, Paul A; Kastritis, Panagiotis L; Melquiond, Adrien S J; Karaca, Ezgi; Schmitz, Christophe; van Dijk, Marc; Bonvin, Alexandre M J J; Eisenstein, Miriam; Jiménez-García, Brian; Grosdidier, Solène; Solernou, Albert; Pérez-Cano, Laura; Pallara, Chiara; Fernández-Recio, Juan; Xu, Jianqing; Muthu, Pravin; Praneeth Kilambi, Krishna; Gray, Jeffrey J; Grudinin, Sergei; Derevyanko, Georgy; Mitchell, Julie C; Wieting, John; Kanamori, Eiji; Tsuchiya, Yuko; Murakami, Yoichi; Sarmiento, Joy; Standley, Daron M; Shirota, Matsuyuki; Kinoshita, Kengo; Nakamura, Haruki; Chavent, Matthieu; Ritchie, David W; Park, Hahnbeom; Ko, Junsu; Lee, Hasup; Seok, Chaok; Shen, Yang; Kozakov, Dima; Vajda, Sandor; Kundrotas, Petras J; Vakser, Ilya A; Pierce, Brian G; Hwang, Howook; Vreven, Thom; Weng, Zhiping; Buch, Idit; Farkash, Efrat; Wolfson, Haim J; Zacharias, Martin; Qin, Sanbo; Zhou, Huan-Xiang; Huang, Shen-You; Zou, Xiaoqin; Wojdyla, Justyna A; Kleanthous, Colin; Wodak, Shoshana J

2014-04-01

20

Water-Level Monitoring in 2010 During water year 2010, groundwater levels were mea-  

E-print Network

.S. Geological Survey http://nj.usgs.gov October 2011 Summary of the Groundwater-Level Hydrologic ConditionsWater-Level Monitoring in 2010 During water year 2010, groundwater levels were mea- sured in 192 States--Water Year 2010 Annual Water Data Report at http://wdr.water.usgs.gov. Water Levels in Unconfined

21

Predicting Trihalomethanes (THMs) in the New York City Water Supply  

NASA Astrophysics Data System (ADS)

Chlorine, a commonly used disinfectant in most water supply systems, can combine with organic carbon to form disinfectant byproducts including carcinogenic trihalomethanes (THMs). We used water quality data from 24 monitoring sites within the New York City (NYC) water supply distribution system, measured between January 2009 and April 2012, to develop site-specific empirical models for predicting total trihalomethane (TTHM) levels. Terms in the model included various combinations of the following water quality parameters: total organic carbon, pH, specific conductivity, and water temperature. Reasonable estimates of TTHM levels were achieved with overall R2 of about 0.87 and predicted values within 5 ?g/L of measured values. The relative importance of factors affecting TTHM formation was estimated by ranking the model regression coefficients. Site-specific models showed improved model performance statistics compared to a single model for the entire system most likely because the single model did not consider locational differences in the water treatment process. Although never out of compliance in 2011, the TTHM levels in the water supply increased following tropical storms Irene and Lee with 45% of the samples exceeding the 80 ?g/L Maximum Contaminant Level (MCL) in October and November. This increase was explained by changes in water quality parameters, particularly by the increase in total organic carbon concentration and pH during this period.

Mukundan, R.; Van Dreason, R.

2013-12-01

22

Predicting light penetration into river waters  

Microsoft Academic Search

Lighting in rivers often needs to be quantified, particularly for modeling benthic plant growth, but is seldom measured because of difficulties associated with limited depth and strong currents. Therefore, methods for predicting light attenuation from river water quality data would be very useful. We used measurements of the diffuse light attenuation coefficient, K d (m-1), at 17 optically diverse rivers

Robert J. Davies-Colley; John W. Nagels

2008-01-01

23

Predicting light penetration into river waters  

Microsoft Academic Search

Lighting in rivers often needs to be quantified, particularly for modeling benthic plant growth, but is seldom measured because of difficulties associated with limited depth and strong currents. Therefore, methods for predicting light attenuation from river water quality data would be very useful. We used measurements of the diffuse light attenuation coefficient, Kd (m?1), at 17 optically diverse rivers in

Robert J. Davies-Colley; John W. Nagels

2008-01-01

24

Predicting light penetration into river waters  

NASA Astrophysics Data System (ADS)

Lighting in rivers often needs to be quantified, particularly for modeling benthic plant growth, but is seldom measured because of difficulties associated with limited depth and strong currents. Therefore, methods for predicting light attenuation from river water quality data would be very useful. We used measurements of the diffuse light attenuation coefficient, Kd (m-1), at 17 optically diverse rivers in New Zealand to develop simple empirical models of light penetration as functions of the beam attenuation coefficient at 550 nm, c550 (m-1, an index of visual water clarity) and the light absorption coefficient of membrane filtrates at 340 nm, g340 (m-1, an index of colored dissolved organic matter). The beam attenuation coefficient can be measured by beam transmissometer or estimated, as in this study, from black disc visibility observations. Alternatively, nephelometric turbidity, Tn (an index of light scattering), which is more commonly measured in water quality monitoring programs, can be used to predict Kd. The models performed satisfactorily when tested over a wide range of optical water quality (varying with flow) at one river site. We expect that these empirical models will have wide practical application for estimating light availability in rivers and streams.

Davies-Colley, Robert J.; Nagels, John W.

2008-09-01

25

Two-level adaptive training branch prediction  

Microsoft Academic Search

High-performance microarchitectures use, among other structures, deep pipelines to help speed up exe- cution. The importance of a good branch predictor to the effectiveness of a deep pipeline in the presence of condi- tional branches is well-known. In fact, the literature contains proposals for a number of branch prediction schemes. Some are static in that they use opcode information and

Tse-Yu Yeh; Yale N. Patt

1991-01-01

26

Predicting Demonstrations' Violence Level Using Qualitative Reasoning  

NASA Astrophysics Data System (ADS)

In this paper we describe a method for modeling social behavior of large groups, and apply it to the problem of predicting potential violence during demonstrations. We use qualitative reasoning techniques which to our knowledge have never been applied to modeling crowd behaviors, nor in particular to demonstrations. Such modeling may not only contribute to the police decision making process, but can also provide a great opportunity to test existing theories in social science. We incrementally present and compare three qualitative models, based on social science theories. The results show that while two of these models fail to predict the outcomes of real-world events reported and analyzed in the literature, one model is successful. We believe that this demonstrates the efficacy of qualitative reasoning in the development and testing of social sciences theories.

Fridman, Natalie; Zilberstein, Tomer; Kaminka, Gal A.

27

Predicting DNA methylation level across human tissues  

PubMed Central

Differences in methylation across tissues are critical to cell differentiation and are key to understanding the role of epigenetics in complex diseases. In this investigation, we found that locus-specific methylation differences between tissues are highly consistent across individuals. We developed a novel statistical model to predict locus-specific methylation in target tissue based on methylation in surrogate tissue. The method was evaluated in publicly available data and in two studies using the latest IlluminaBeadChips: a childhood asthma study with methylation measured in both peripheral blood leukocytes (PBL) and lymphoblastoid cell lines; and a study of postoperative atrial fibrillation with methylation in PBL, atrium and artery. We found that our method can greatly improve accuracy of cross-tissue prediction at CpG sites that are variable in the target tissue [R2 increases from 0.38 (original R2 between tissues) to 0.89 for PBL-to-artery prediction; from 0.39 to 0.95 for PBL-to-atrium; and from 0.81 to 0.98 for lymphoblastoid cell line-to-PBL based on cross-validation, and confirmed using cross-study prediction]. An extended model with multiple CpGs further improved performance. Our results suggest that large-scale epidemiology studies using easy-to-access surrogate tissues (e.g. blood) could be recalibrated to improve understanding of epigenetics in hard-to-access tissues (e.g. atrium) and might enable non-invasive disease screening using epigenetic profiles. PMID:24445802

Ma, Baoshan; Wilker, Elissa H.; Willis-Owen, Saffron A. G.; Byun, Hyang-Min; Wong, Kenny C. C.; Motta, Valeria; Baccarelli, Andrea A.; Schwartz, Joel; Cookson, William O. C. M.; Khabbaz, Kamal; Mittleman, Murray A.; Moffatt, Miriam F.; Liang, Liming

2014-01-01

28

Source Level Static Branch Prediction Department of Computer Science  

E-print Network

static branch predictions are invaluable information for (static) compiler optimization or performanceSource Level Static Branch Prediction W. F. Wong Department of Computer Science School of Computing-4580 Email: wongwf@comp.nus.edu.sg March 24, 1999 Abstract The ability to predict the directions of branches

Wong, Weng Fai

29

How Rules Determine the Operator Analysis of Water Height Prediction  

E-print Network

How Rules Determine the Operator Analysis of Water Height Prediction Alexander Nezhinsky October 31, 2007 #12;Abstract The project concerns water height prediction by the Rijkswaterstaat employ- ees. The employees predict the water height based on some rules. We want to find out by which rules an employee can

Emmerich, Michael

30

Platelet Serotonin Level Predicts Survival in Amyotrophic Lateral Sclerosis  

E-print Network

Platelet Serotonin Level Predicts Survival in Amyotrophic Lateral Sclerosis Luc Dupuis1,2 *, Odile Abstract Background: Amyotrophic lateral sclerosis (ALS) is a life-threatening neurodegenerative disease) Platelet Serotonin Level Predicts Survival in Amyotrophic Lateral Sclerosis. PLoS ONE 5(10): e13346. doi:10

Paris-Sud XI, Université de

31

Water level dynamics in the Amazon floodplain  

NASA Astrophysics Data System (ADS)

Nonlinear analysis of Amazonian River systems suggests that water level variability is due to Brownian-like motions BH. Dynamical properties of the water level is probably a response of rainfall and runoff smoothing by the stored water in the floodplain; additional inputs of water results in attenuated perturbations of the water level. This implies that noise is a self-affine fractal with scale invariance, and in accordance with surrogate and correlation dimension analysis, which refused the hypothesis of low dimensional chaos for water level dynamics. Opposing to the chaotic approach, we present a fractal model formed by a periodic signal and a BH process that mimics original water level variability. Dynamical exponents are remarkably similar between real and modeled data when BH influence is about 1% the amplitude of the periodic signal. In comparison to natural systems, a hydroelectric reservoir produces different exponents, due to the control of the water level, as demonstrated for the Tucuru?´ dam in the Tocantins River. The Amazon floodplain at Óbidos and Curuai exhibits a fortnight cycle most probably due to bore tide influence in the river mouth.

Lima, Ivan Bergier Tavares; Rosa, Reinaldo Roberto; Ramos, Fernando Manuel; de Moraes Novo, Evlyn Márcia Leão

32

Quantifying and Predicting Outdoor Water Use in Los Angeles  

NASA Astrophysics Data System (ADS)

Residential water consumption is the largest urban water user and represents the largest potential for conservation according to a peer-reviewed study by the Pacific Institute in California (2003). Outdoor water use represents a large percentage of the residential water budget but significant uncertainties are associated with current estimates and predictive models. The objectives of the current study are to analyze the spatial and temporal trends in outdoor use, determine correlations to climate and vegetation patterns, and establish key drivers of outdoor use in Los Angeles. Monthly individual water use records were acquired from the Los Angeles Department of Water and Power (LADWP) for the 2000 to 2010 period. Indoor use was estimated at the census tract level using a range of established models; with outdoor use then calculated as the residual between total and indoor use. The comparison of different estimates at the census tract level reveals significant variability between commonly-used outdoor use methods. Two of the Pacific Institute methods show that outdoor use percentages vary from 7%-10% to 60%-67% of total residential water use at the tract level across the City. A third tested method, based on average household size to model indoor use, presents a broader range of results, with outdoor use ranging from 2% to 93% of total water use. Climate variables, property characteristics as well as remotely-sensed vegetation indices and evapotranspiration estimates were also collected and aggregated at the census tract level for the same period. A linear regression model was developed using these variables to identify the key predictors of outdoor use for the study area. The residual and regression model estimates will serve to validate the development of a biophysical model including tree and grass cover areas, climate variables and high resolution evapotranspiration estimates. Ultimately, models will be used for predictions for a range of future climate and landscape scenarios. Finally, project results will inform water managers to implement efficient landscaping irrigation conservation strategies part of an integrated water resources management plan for sustainable regional water supply system in Southern California.

Mini, C.; Hogue, T. S.; Pincetl, S.

2012-12-01

33

Using meteorologic data to predict daily ragweed pollen levels  

Microsoft Academic Search

Pollen-related allergy is a common disease resulting in symptoms of hay fever and asthma. Control of symptoms depends (generally)\\u000a on avoidance and pharmacological treatment. Both of these approaches could benefit from accurate predictions of pollen levels\\u000a for future days. We have constructed a model that uses meteorological data to predict ragweed pollen levels based on air samples\\u000a collected daily in

Paul C. Stark; Louise M. Ryan; James L. McDonald; Harriet A. Burge

1997-01-01

34

Does acquirer cash level predict post-acquisition returns?  

Microsoft Academic Search

This paper investigates whether an acquirer’s pre-announcement cash level can predict post-acquisition returns. Harford (1999, Journal of Finance, 54, 1969–1997) shows that some cash-rich acquirers have lower announcement period returns than other acquirers, suggesting the\\u000a market partially anticipates poor future performance. This paper shows that the acquirer’s cash level is also strongly and\\u000a negatively predictive of post-acquisition returns, indicating that

Derek K. Oler

2008-01-01

35

Predicting Students' Homework Environment Management at the Secondary School Level  

ERIC Educational Resources Information Center

The present study examined empirical models of variables posited to predict students' homework environment management at the secondary school level. The participants were 866 8th graders from 61 classes and 745 11th graders from 46 classes. Most of the variance in homework environment management occurred at the student level, with classmates'…

Xu, Jianzhong

2012-01-01

36

Predicting students’ homework environment management at the secondary school level  

Microsoft Academic Search

The present study examined empirical models of variables posited to predict students’ homework environment management at the secondary school level. The participants were 866 8th graders from 61 classes and 745 11th graders from 46 classes. Most of the variance in homework environment management occurred at the student level, with classmates’ shared homework interest as the only significant predictor at

Jianzhong Xu

2011-01-01

37

Predicting students’ homework environment management at the secondary school level  

Microsoft Academic Search

The present study examined empirical models of variables posited to predict students’ homework environment management at the secondary school level. The participants were 866 8th graders from 61 classes and 745 11th graders from 46 classes. Most of the variance in homework environment management occurred at the student level, with classmates’ shared homework interest as the only significant predictor at

Jianzhong Xu

2012-01-01

38

Predicting Order and Disorder for ?-Peptide Foldamers in Water.  

PubMed

Following a quantitative validation approach, we tested the AMBER ff03 and GAFF force fields with the TIP3P explicit water model in molecular dynamic simulations of ?-peptide foldamers. The test sequences were selected to represent a wide range of folding behavior in water: compact helix, strand mimetic geometry, and the state of disorder. The combination AMBER ff03-TIP3P successfully predicted the experimentally observed conformational properties and reproduced the NOE distances and backbone (3)J coupling data at a good level. GAFF was unable to produce folded structures correctly due to its biased torsion potentials. We can recommend AMBER ff03-TIP3P for simulations involving ?-peptide sequences in aqueous media including ordered and disordered structures. PMID:25177775

Németh, Lukács J; Hegedüs, Zsófia; Martinek, Tamás A

2014-10-27

39

Fuzzy Neural Networks for water level and discharge forecasting  

NASA Astrophysics Data System (ADS)

A new procedure for water level (or discharge) forecasting under uncertainty using artificial neural networks is proposed: uncertainty is expressed in the form of a fuzzy number. For this purpose, the parameters of the neural network, namely, the weights and biases, are represented by fuzzy numbers rather than crisp numbers. Through the application of the extension principle, the fuzzy number representative of the output variable (water level or discharge) is then calculated at each time step on the basis of a set of crisp inputs and fuzzy parameters of the neural network. The proposed neural network thus allows uncertainty to be taken into account at the forecasting stage not providing only deterministic or crisp predictions, but rather predictions in terms of 'the discharge (or level) will fall between two values, indicated according to the level of credibility considered, whereas it will take on a certain value when the level of credibility is maximum'. The fuzzy parameters of the neural network are estimated using a calibration procedure that imposes a constraint whereby for an assigned h-level the envelope of the corresponding intervals representing the outputs (forecasted levels or discharges, calculated at different points in time) must include a prefixed percentage of observed values. The proposed model is applied to two different case studies. Specifically, the data related to the first case study are used to develop and test a flood event-based water level forecasting model, whereas the data related to the latter are used for continuous discharge forecasting. The results obtained are compared with those provided by other data-driven models - Bayesian neural networks (Neal, R.M. 1992, Bayesian training of backpropagation networks by the hybrid Monte Carlo method. Tech. Rep. CRG-TR-92-1, Dep. of Comput. Sci., Univ. of Toronto, Toronto, Ont., Canada.) and the Local Uncertainty Estimation Model (Shrestha D.L. and Solomatine D.P. 2006, Machine learning approaches for estimation of prediction interval for the model output. Neural Networks, 19(2), 225-235.). The comparison shows the effectiveness of the fuzzy neural network forecasting model in estimating water levels or discharges under uncertainty. In particular, the fuzzy neural network enables us to define bands that describe, for an assigned h-level, the range of variability of the predicted variable. An analysis of the results obtained reveals that these bands generally have a slightly smaller width compared to the bands obtained using other data-driven models, the percentage of observed values contained within the bands being equal.

Alvisi, Stefano; Franchini, Marco

2010-05-01

40

Applying adaptive prediction to sea-water quality measurements  

Microsoft Academic Search

This study explores the possibility of using adaptive filters to predict sea-water quality indicators such as water temperature, pH and dissolved oxygen based on measurements produced by an under-water measurement set-up. Two alternative adaptive approaches are tested, namely a projection algorithm and a least squares algorithm. These algorithms were chosen for comparison because they are widely used prediction algorithms. The

Evaggelos V. Hatzikos; Jari J. Hätönen; Nick Bassiliades; Ioannis P. Vlahavas; Eleni Fournou

2009-01-01

41

Development and evaluation of a water level proportional water sampler  

NASA Astrophysics Data System (ADS)

We developed and adapted a new type of sampler for time-integrated, water level proportional water quality sampling (e.g. nutrients, contaminants and stable isotopes). Our samplers are designed for sampling small to mid-size streams based on the law of Hagen-Poiseuille, where a capillary (or a valve) limits the sampling aliquot by reducing the air flux out of a submersed plastic (HDPE) sampling container. They are good alternatives to battery-operated automated water samplers when working in remote areas, or at streams that are characterized by pronounced daily discharge variations such as glacier streams. We evaluated our samplers against standard automated water samplers (ISCO 2900 and ISCO 6712) during the snowmelt in the Black Forest and the Alps and tested them in remote glacial catchments in Iceland, Switzerland and Kyrgyzstan. The results clearly showed that our samplers are an adequate tool for time-integrated, water level proportional water sampling at remote test sites, as they do not need batteries, are relatively inexpensive, lightweight, and compact. They are well suited for headwater streams - especially when sampling for stable isotopes - as the sampled water is perfectly protected against evaporation. Moreover, our samplers have a reduced risk of icing in cold environments, as they are installed submersed in water, whereas automated samplers (typically installed outside the stream) may get clogged due to icing of hoses. Based on this study, we find these samplers to be an adequate replacement for automated samplers when time-integrated sampling or solute load estimates are the main monitoring tasks.

Schneider, P.; Lange, A.; Doppler, T.

2013-12-01

42

Behavioral/Cognitive Glutamate and Choline Levels Predict Individual Differences  

E-print Network

Behavioral/Cognitive Glutamate and Choline Levels Predict Individual Differences in Reading Ability spectroscopy. Both continuous and group analyses revealed that choline and glutamate concentra- tions were obtained 24 months later reveal stability for the relationship between glutamate and reading performance

43

High temperature, high pressure water level sensor  

SciTech Connect

A sensor was developed to measure water level over a range of 750 mm with an uncertainty of +- 20 mm at a temperature from 20 to 250/sup 0/C and pressure up to 15.2 MPa. The sensor is type 304, flattened stainless steel rod. Its cross section is 1.6 x 3.2 mm, and its measured torsional transit time is a function of water density rho, level L, and temperature T. To minimize the influence of T, the extensional transit time is also measured in the same sensor. To interrogate the sensor with both modes, Joule and Wiedemann transducers are multiplexed in an alternating sequence. Experimental results, problems, and remedies are discussed.

Miller, G.N.; Anderson, R.L.; Lynnworth, L.C.

1980-01-01

44

Plasma metabolite levels predict bird growth rates: A field test of model predictive ability.  

PubMed

Bird growth rates are usually derived from nonlinear relationships between age and some morphological structure, but this procedure may be limited by several factors. To date, nothing is known about the capacity of plasma metabolite profiling to predict chick growth rates. Based on laboratory-trials, we here develop predictive logistic models of body mass, and tarsus and wing length growth rates in Gull-billed Tern Gelochelidon nilotica chicks from measurements of plasma metabolite levels at different developmental stages. The predictive model obtained during the fastest growth period (at the age of 12 days) explained 65-68% of the chicks' growth rates, with fasting triglyceride level explaining most of the variation in growth rate. At the end of pre-fledging period, ?-hydroxybutyrate level was also a good predictor of growth rates. Finally, we carried out a field test to check the predictive capacity of the models in two colonies of wild Gull-billed Tern, comparing field-measured and model-predicted growth rates between groups. Both, measured and predicted growth rates, matched statistically. Plasma metabolite levels can thus be applied in comparative studies of chick growth rates when semi-precocial birds can be captured only once. PMID:21575739

Albano, Noelia; Masero, José A; Villegas, Auxiliadora; Abad-Gómez, José María; Sánchez-Guzmán, Juan M

2011-09-01

45

GNSS-Reflectometry based water level monitoring  

NASA Astrophysics Data System (ADS)

Due to climate changing conditions severe changes in the Mekong delta in Vietnam have been recorded in the last years. The goal of the German Vietnamese WISDOM (Water-related Information system for the Sustainable Development Of the Mekong Delta) project is to build an information system to support and assist the decision makers, planners and authorities for an optimized water and land management. One of WISDOM's tasks is the flood monitoring of the Mekong delta. Earth reflected L-band signals from the Global Navigation Satellite System show a high reflectivity on water and ice surfaces or on wet soil so that GNSS-Reflectometry (GNSS-R) could contribute to monitor the water level in the main streams of the Mekong delta complementary to already existing monitoring networks. In principle, two different GNSS-R methods exist: the code- and the phase-based one. As the latter being more accurate, a new generation of GORS (GNSS Occultation, Reflectometry and Scatterometry) JAVAD DELTA GNSS receiver has been developed with the aim to extract precise phase observations. In a two week lasting measurement campaign, the receiver has been tested and several reflection events at the 150-200 m wide Can Tho river in Vietnam have been recorded. To analyze the geometrical impact on the quantity and quality of the reflection traces two different antennas height were tested. To track separately the direct and the reflected signal, two antennas were used. To derive an average height of the water level, for a 15 min observation interval, a phase model has been developed. Combined with the coherent observations, the minimum slope has been calculated based on the Least- Squares method. As cycle slips and outliers will impair the results, a preprocessing of the data has been performed. A cycle slip detection strategy that allows for automatic detection, identification and correction is proposed. To identify outliers, the data snooping method developed by Baarda 1968 is used. In this context, issues related to the stochastic modeling of GPS observations are addressed and a first model is proposed. First results of water level derivation with precisions below decimeter level are presented. These results could then be used as an approximation for the next computation step: the ambiguities fixing.

Beckheinrich, Jamila; Schön, Steffen; Beyerle, Georg; Apel, Heiko; Semmling, Maximilian; Wickert, Jens

2013-04-01

46

AUTOMATED WATER LEVEL MEASUREMENTS IN SMALL-DIAMETER AQUIFER TUBES  

SciTech Connect

Groundwater contaminated with hexavalent chromium, strontium-90, and uranium discharges into the Columbia River along approximately 16 km (10 mi) of the shoreline. Various treatment systems have and will continue to be implemented to eliminate the impact of Hanford Site contamination to the river. To optimize the various remediation strategies, it is important to understand interactions between groundwater and the surface water of the Columbia River. An automated system to record water levels in aquifer sampling tubes installed in the hyporheic zone was designed and tested to (1) gain a more complete understanding of groundwater/river water interactions based on gaining and losing conditions ofthe Columbia River, (2) record and interpret data for consistent and defensible groundwater/surface water conceptual models that may be used to better predict subsurface contaminant fate and transport, and (3) evaluate the hydrodynamic influence of extraction wells in an expanded pump-and-treat system to optimize the treatment system. A system to measure water levels in small-diameter aquifer tubes was designed and tested in the laboratory and field. The system was configured to allow manual measurements to periodically calibrate the instrument and to permit aquifer tube sampling without removing the transducer tube. Manual measurements were collected with an e-tape designed and fabricated especially for this test. Results indicate that the transducer system accurately records groundwater levels in aquifer tubes. These data are being used to refine the conceptual and numeric models to better understand interactions in the hyporheic zone of the Columbia River and the adjacent river water and groundwater, and changes in hydrochemistry relative to groundwater flux as river water recharges the aquifer and then drains back out in response to changes in the river level.

PETERSEN SW; EDRINGTON RS; MAHOOD RO; VANMIDDLESWORTH PE

2011-01-14

47

Water Management, Rainwater Harvesting and Predictive Variables in Rural Households  

Microsoft Academic Search

Water management in rural domestic households plays an important role in reducing water-related health risks. This study was\\u000a conducted to examine the relationships between the dependent variable (rural domestic rainwater management) and the independent\\u000a predictive variables (personal characteristics, tank size, years of water harvest, rainwater harvesting associations, usage\\u000a instructions including water borne health risk, and tank operation and maintenance) in

David Baguma; Willibald Loiskandl; Helmut Jung

2010-01-01

48

PREDICTING WATER QUALITY IN DISTRIBUTION SYSTEMS  

EPA Science Inventory

The quality of a public water supply although acceptable when it leaves the treatment plant, may deteriorate before it reaches the user. Deterioration may be caused by either chemical or biological transformations or by a loss of system integrity. There have been a growing number...

49

Improved Water Level Forecasting Performance by Using Optimal Steepness Coefficients in an Artificial Neural Network  

Microsoft Academic Search

Developing water level forecasting models is essential in water resources management and flood prediction. Accurate water\\u000a level forecasting helps achieve efficient and optimum use of water resources and minimize flooding damages. The artificial\\u000a neural network (ANN) is a computing model that has been successfully tested in many forecasting studies, including river flow.\\u000a Improving the ANN computational approach could help produce

Muhammad Sulaiman; Ahmed El-Shafie; Othman Karim; Hassan Basri

2011-01-01

50

On-line hydraulic state prediction for water distribution systems  

E-print Network

This paper describes and demonstrates a method for on?line hydraulic state prediction in urban water networks. The proposed method uses a Predictor?Corrector (PC) approach in which a statistical data?driven algorithm is ...

Whittle, Andrew

51

Predicting ICU survival: A meta-level approach  

PubMed Central

Background The performance of separate Intensive Care Unit (ICU) status scoring systems vis-à-vis prediction of outcome is not satisfactory. Computer-based predictive modeling techniques may yield good results but their performance has seldom been extensively compared to that of other mature or emerging predictive models. The objective of the present study was twofold: to propose a prototype meta-level predicting approach concerning Intensive Care Unit (ICU) survival and to evaluate the effectiveness of typical mining models in this context. Methods Data on 158 men and 46 women, were used retrospectively (75% of the patients survived). We used Glasgow Coma Scale (GCS), Acute Physiology And Chronic Health Evaluation II (APACHE II), Sequential Organ Failure Assessment (SOFA) and Injury Severity Score (ISS) values to structure a decision tree (DTM), a neural network (NNM) and a logistic regression (LRM) model and we evaluated the assessment indicators implementing Receiver Operating Characteristics (ROC) plot analysis. Results Our findings indicate that regarding the assessment of indicators' capacity there are specific discrete limits that should be taken into account. The Az score ± SE was 0.8773± 0.0376 for the DTM, 0.8061± 0.0427 for the NNM and 0.8204± 0.0376 for the LRM, suggesting that the proposed DTM achieved a near optimal Az score. Conclusion The predicting processes of ICU survival may go "one step forward", by using classic composite assessment indicators as variables. PMID:18655727

Gortzis, Lefteris G; Sakellaropoulos, Filippos; Ilias, Ioannis; Stamoulis, Konstantinos; Dimopoulou, Ioanna

2008-01-01

52

True prediction of lowest observed adverse effect levels.  

PubMed

A database of structurally heterogeneous chemical structures with their experimental values of Lowest Observed Adverse Effect Levels (LOAELs) was modeled using graph theoretical descriptors. Variable selection for multiple linear regression (MLR) and linear discriminant analysis (LDA) was accomplished by the Internal Test Set (ITS) method in order to achieve true predicted LOAEL values. The results obtained can be considered good if we take in count the structural diversity of the training set. PMID:16721628

García-Domenech, R; de Julián-Ortiz, J V; Besalú, E

2006-05-01

53

Predicting parent–child interactions from children's activity level  

Microsoft Academic Search

Examined the relationship between children's activity level and parent–child (P–C) interactions in 117 preschool children and their parents. Four P–C combinations (mother–daughter, father–daughter, mother–son, and father–son) were studied. Using R. Q. Bell's conceptualization of upper and lower limit parental control behavior, it was predicted that P–C interactions involving active children would be marked by more strife and conflict than P–C

David M. Buss

1981-01-01

54

Looking at soluble CD23 levels to predict lymphoma.  

PubMed

As we noted in our first article on lymphoma, there isn't any quick and simple test to diagnose or predict which PHAs will develop this cancer. Nor are there any symptoms that specifically occur from having lymphoma. To try to remedy the situation, researchers in Italy have been monitoring levels of the a protein called soluble CD23 (sCD23) in the blood and fluid surrounding the brain--cerebrospinal fluid (CSF). They have found higher-than-normal levels of sCD23 in the CSF of PHAs who have brain lymphoma. PMID:11768872

2001-10-01

55

Predictive models for forecasting hourly urban water demand  

NASA Astrophysics Data System (ADS)

SummaryOne of the goals of efficient water supply management is the regular supply of clean water at the pressure required by consumers. In this context, predicting water consumption in urban areas is of key importance for water supply management. This prediction is also relevant in processes for reviewing prices; as well as for operational management of a water network. In this paper, we describe and compare a series of predictive models for forecasting water demand. The models are obtained using time series data from water consumption in an urban area of a city in south-eastern Spain. This includes highly non-linear time series data, which has conditioned the type of models we have included in our study. Namely, we have considered artificial neural networks, projection pursuit regression, multivariate adaptive regression splines, random forests and support vector regression. Apart from these models, we also propose a simple model based on the weighted demand profile resulting from our exploratory analysis of the data. In our comparative study, all predictive models were evaluated using an experimental methodology for hourly time series data that detailed water demand in a hydraulic sector of a water supply network in a city in south-eastern Spain. The accuracy of the obtained results, together with the medium size of the demand area, suggests that this was a suitable environment for making adequate management decisions.

Herrera, Manuel; Torgo, Luís; Izquierdo, Joaquín; Pérez-García, Rafael

2010-06-01

56

Water Habitat Study: Prediction Makes It More Meaningful.  

ERIC Educational Resources Information Center

Suggests a teaching strategy for water habitat studies to help students make a meaningful connection between physiochemical data (dissolved oxygen content, pH, and water temperature) and biological specimens they collect. Involves constructing a poster and using it to make predictions. Provides sample poster. (DC)

Glasgow, Dennis R.

1982-01-01

57

Predictive capabilities of a two-dimensional model in the ground water transport of radionuclides. [Uranium mill tailings  

Microsoft Academic Search

The discharge of low-level radioactive waste into tailings ponds is a potential source of ground water contamination. The estimation of the radiological hazards related to the ground water transport of radionuclides from tailings retention systems depends on reasonably accurate estimates of the movement of both water and solute. A two-dimensional mathematical model having predictive capability for ground water flow and

A. B. Gureghian; N. J. Beskid; G. J. Marmer

1978-01-01

58

Enhancing Water Supply Reliability Through Improved Predictive Capacity and Response  

NASA Astrophysics Data System (ADS)

This project is a multi-pronged approach to enhancing water supply reliability from the Colorado River and encouraging dissemination of new scientific information into the water management process. The science of linking paleoclimatology and climate modeling to stream flow predictions and river system operational models is advancing rapidly. However, there is a time lag between scientific advances and their use by water managers in supply planning and reservoir operations. We have assessed current Bureau of Reclamation use of climate information in river modeling and management and are identifying strategies to better utilize paleoclimatology, climate forecasts and climate change predictions to improve water supply predictive capacity for the lower Colorado River and the Central Arizona Project. Our research questions, which were initially based on an assessment of stakeholder needs, include extending the paleoclimatic record and doing statistical reanalysis of existing tree ring data to expand our understanding of past water supply variability and drought; evaluating the potential to input new types of information, such as precipitation data downscaled from global climate models, into the CRSS model; identifying state and federal management tools to translate improved predictive capacity into enhanced supply reliability for water users; and developing practical supply reliability strategies for use by water users and managers at various scales. Project staffare participating in Bureau of Reclamation shortage sharing activities and distributing a quarterly newsletter on drought status for key stakeholders as part of this project.

Jacobs, K.; Meko, D.; Nijssen, B.; Colby, B.

2005-12-01

59

Predicted effects of a proposed water-resources management plan in the lower San Luis Rey River Valley, California, using digital ground-water flow models  

USGS Publications Warehouse

A proposed plan for water-resource management in the lower San Luis Rey River valley, Calif. has been evaluated using digital models of ground-water flow. Two projections of water-level changes and salt balance in 1977 were made. The first projection used 1972 climatic and pumping conditions. The second projection used these same conditions plus a plan of recharging and pumping various areas of the aquifer. The predicted salt balance in 1977 under the proposed plan improved for the Pala, Bonsall, and Mission basins when compared to the predicted 1977 salt balance using 1972 pumpage alone. The plan did not affect the predicted salt balance for the Pauma basin. Under the plan, water levels decreased in the Pala basin and water levels increased in the Bonsall and Mission basins. In addition, an area of potential water logging exists in the Mission basin. The plan did not affect water levels for the Pauma basin. (Woodard-USGS)

Skrivan, James A.

1976-01-01

60

Hepcidin level predicts hemoglobin concentration in individuals undergoing repeated phlebotomy.  

PubMed

Dietary iron absorption is regulated by hepcidin, an iron regulatory protein produced by the liver. Hepcidin production is regulated by iron stores, erythropoiesis and inflammation, but its physiology when repeated blood loss occurs has not been characterized. Hepcidin was assayed in plasma samples obtained from 114 first-time/reactivated (no blood donations in preceding 2 years) female donors and 34 frequent (?3 red blood cell donations in preceding 12 months) male donors as they were phlebotomized ?4 times over 18-24 months. Hepcidin levels were compared to ferritin and hemoglobin levels using multivariable repeated measures regression models. Hepcidin, ferritin and hemoglobin levels declined with increasing frequency of donation in the first-time/reactivated females. Hepcidin and ferritin levels correlated well with each other (Spearman's correlation of 0.74), but on average hepcidin varied more between donations for a given donor relative to ferritin. In a multivariable repeated measures regression model the predicted inter-donation decline in hemoglobin varied as a function of hepcidin and ferritin; hemoglobin was 0.51 g/dL lower for subjects with low (>45.7 ng/mL) or decreasing hepcidin and low ferritin (>26 ng/mL), and was essentially zero for other subjects including those with high (>45.7 ng/mL) or increasing hepcidin and low ferritin (>26 ng/mL) levels (P<0.001). In conclusion, hepcidin levels change rapidly in response to dietary iron needed for erythropoiesis. The dynamic regulation of hepcidin in the presence of a low levels of ferritin suggests that plasma hepcidin concentration may provide clinically useful information about an individual's iron status (and hence capacity to tolerate repeated blood donations) beyond that of ferritin alone. Clinicaltrials.gov identifier: NCT00097006. PMID:23445875

Mast, Alan E; Schlumpf, Karen S; Wright, David J; Johnson, Bryce; Glynn, Simone A; Busch, Michael P; Olbina, Gordana; Westerman, Mark; Nemeth, Elizabeta; Ganz, Tomas

2013-08-01

61

Cerebrospinal Fluid PKR Level Predicts Cognitive Decline in Alzheimer's Disease  

PubMed Central

The cerebrospinal fluid (CSF) levels of the proapoptotic kinase R (PKR) and its phosphorylated PKR (pPKR) are increased in Alzheimer’s disease (AD), but whether CSF PKR concentrations are associated with cognitive decline in AD patients remain unknown. In this study, 41 consecutive patients with AD and 11 patients with amnestic mild cognitive impairment (aMCI) from our Memory Clinic were included. A lumbar puncture was performed during the following month of the clinical diagnosis and Mini-Mental State Examination (MMSE) evaluations were repeated every 6 months during a mean follow-up of 2 years. In AD patients, linear mixed models adjusted for age and sex were used to assess the cross-sectional and longitudinal associations between MMSE scores and baseline CSF levels of A? peptide (A? 1-42), Tau, phosphorylated Tau (p-Tau 181), PKR and pPKR. The mean (SD) MMSE at baseline was 20.5 (6.1) and MMSE scores declined over the follow-up (-0.12 point/month, standard error [SE]?=?0.03). A lower MMSE at baseline was associated with lower levels of CSF A? 1–42 and p-Tau 181/Tau ratio. pPKR level was associated with longitudinal MMSE changes over the follow-up, higher pPKR levels being related with an exacerbated cognitive deterioration. Other CSF biomarkers were not associated with MMSE changes over time. In aMCI patients, mean CSF biomarker levels were not different in patients who converted to AD from those who did not convert.These results suggest that at the time of AD diagnosis, a higher level of CSF pPKR can predict a faster rate of cognitive decline. PMID:23320095

Lapalus, Pauline; Prevot, Magali; Laplanche, Jean-Louis

2013-01-01

62

A Seamless Framework for Global Water Cycle Monitoring and Prediction  

NASA Astrophysics Data System (ADS)

The Global Earth Observation System of Systems (GEOSS) Water Strategy ('From Observations to Decisions') recognizes that 'water is essential for ensuring food and energy security, for facilitating poverty reduction and health security, and for the maintenance of ecosystems and biodiversity', and that water cycle data and observations are critical for improved water management and water security - especially in less developed regions. The GEOSS Water Strategy has articulated a number of goals for improved water management, including flood and drought preparedness, that include: (i) facilitating the use of Earth Observations for water cycle observations; (ii) facilitating the acquisition, processing, and distribution of data products needed for effective management; (iii) providing expertise, information systems, and datasets to the global, regional, and national water communities. There are several challenges that must be met to advance our capability to provide near real-time water cycle monitoring, early warning of hydrological hazards (floods and droughts) and risk assessment under climate change, regionally and globally. Current approaches to monitoring and predicting hydrological hazards are limited in many parts of the world, and especially in developing countries where national capacity is limited and monitoring networks are inadequate. This presentation describes the development of a seamless monitoring and prediction framework at all time scales that allows for consistent assessment of water variability from historic to current conditions, and from seasonal and decadal predictions to climate change projections. At the center of the framework is an experimental, global water cycle monitoring and seasonal forecast system that has evolved out of regional and continental systems for the US and Africa. The system is based on land surface hydrological modeling that is driven by satellite remote sensing precipitation to predict current hydrological conditions, flood potential and the state of drought. Seasonal climate model forecasts are downscaled and bias-corrected to drive the land surface model to provide hydrological forecasts and drought products out 6-9 months. The system relies on historic reconstructions of water variability over the 20th century, which forms the background climatology to which current conditions can be assessed. Future changes in water availability and drought risk are quantified based on bias-corrected and downscaled climate model projections that are used to drive the land surface models. For regions with lack of on-the-ground data we are field-testing low-cost environmental sensors and along with new satellite products for terrestrial hydrology and vegetation, integrating these into the system for improved monitoring and prediction. We provide an overview of the system and some examples of real-world applications to flood and drought events, with a focus on Africa.

Sheffield, J.; Wood, E. F.; Chaney, N.; Fisher, C. K.; Caylor, K. K.

2013-12-01

63

Predictive modelling of the mine water rebound in an old abandoned Dongwon mine in Korea  

NASA Astrophysics Data System (ADS)

The closure of over three-hundred deep coal mines in Korea since the late-1980s, primarily due to the energy and environmental concerns, has produced significant side effects. One of the major challenges is to assess the risk from mine water rebound to overlying aquifers and surface waters, which can produce significant environmental hazards. Some numerical models such as VSS-NET, GRAM and MODFLOW have been developed to predict the quantity, timing and location of discharges resulting from mine water rebound. In this study, we developed a GRAM-based windows program for mine water rebound modelling in abandoned deep mine systems. The program consists of the simulation engine and the GUI modules, each has several subroutines. Changes in mine water level of the Dongwon coal mine, presumably hydrogeologically connected to nearby old abandoned mines, has been monitored after the mine was finally closed in 2005. The water level in the vertical shaft rised up to 420m during the period of 3 years. The system was modelled as two ponds connected by a pipe. Input data include the areas of each pond, catchment areas, the storage coefficient, etc. The predicted changes in the mine water level was very similar to the observed data in the field. For this modelling, in fact, some of the input variable were roughly assumed to match the field data. Nevertheless, this program can be effectively applied to predict the rising of the mine water after the mine closure.

Baek, Hwanjo; Kim, Daehoon; Park, Seunghwan; Kim, Gyoungman

2014-05-01

64

Water cooling tower and water level control system therefor  

Microsoft Academic Search

This patent describes an improved water cooling tower system including a water cooling tower structure having a top portion, a bottom portion, an intermediate portion therebetween, a water-collecting basin operatively disposed in the bottom portion of the structure, a heat exchange means operatively disposed in the intermediate portion of the structure, means for recirculating the water from the water-collecting basin

Kinkead

1989-01-01

65

Integrating Non-Tidal Sea Level data from altimetry and tide gauges for coastal sea level prediction  

NASA Astrophysics Data System (ADS)

The main objective of this paper is to integrate Non-Tidal Sea Level (NSL) from the joint TOPEX, Jason-1 and Jason-2 satellite altimetry with tide gauge data at the west and north coast of the United Kingdom for coastal sea level prediction. The temporal correlation coefficient between altimetric NSLs and tide gauge data reaches a maximum higher than 90% for each gauge. The results show that the multivariate regression approach can efficiently integrate the two types of data in the coastal waters of the area. The Multivariate Regression Model is established by integrating the along-track NSL from the joint TOPEX/Jason-1/Jason-2 altimeters with that from eleven tide gauges. The model results give a maximum hindcast skill of 0.95, which means maximum 95% of NSL variance can be explained by the model. The minimum Root Mean Square Error (RMSe) between altimetric observations and model predictions is 4.99 cm in the area. The validation of the model using Envisat satellite altimetric data gives a maximum temporal correlation coefficient of 0.96 and a minimum RMSe of 4.39 cm between altimetric observations and model predictions, respectively. The model is furthermore used to predict high frequency NSL variation (i.e., every 15 min) during a storm surge event at an independent tide gauge station at the Northeast of the UK (Aberdeen).

Cheng, Yongcun; Andersen, Ole Baltazar; Knudsen, Per

2012-10-01

66

NOAA Water Level and Meteorological Data Report HURRICANE ISAAC  

E-print Network

NOAA Water Level and Meteorological Data Report HURRICANE ISAAC Silver Spring, Maryland October 14 Environmental Satellite, Data & Information Service GOES Imagery #12;NOAA Water Level and Meteorological Data Hurricane Isaac Water Level & Meteorological Data Report 1 Overview The National Oceanic and Atmospheric

67

NOAA Water Level and Meteorological Data Report HURRICANE SANDY  

E-print Network

NOAA Water Level and Meteorological Data Report HURRICANE SANDY Silver Spring, Maryland January 24 Environmental Satellite, Data & Information Service GOES Imagery #12;NOAA Water Level and Meteorological Data, Richard Edwing #12;NOAA NOS Hurricane Sandy Water Level & Meteorological Data Report 1 Table of Contents

68

Diabetes is predicted by the beta cell level of autoantigen.  

PubMed

Two novel transgenic (Tg) strains were created expressing hen egg-white lysozyme (HEL) in a pancreas-specific fashion. RmHP.111 mice had levels of HEL per cell similar to that of the established ILK-3 strain, while RmHP.117 mice had 10-fold lower levels (50,000 molecules per cell). When bred to 3A9 TCR Tg mice, negative selection occurred equally in all three double-Tg combinations, yet only ILK-3 x 3A9 and RmHP.111 x 3A9 mice became diabetic. Additionally, activated 3A9 cells readily transferred diabetes into ILK-3 or RmHP.111 mice, but only marginally into the RmHP.117 strain. In the peripancreatic lymph node, division of naive 3A9 cells was similar between RmHP.111 and RmHP.117 strains, but pancreatic APCs from RmHP.111 x 3A9 mice stimulated HEL-reactive cells to a much greater degree than those from RmHP.117 x 3A9 mice. In this model, diabetes was dependent upon both initial priming in the peripancreatic lymph node and subsequent presentation in the pancreas, with disease incidence predicted by the beta cell level of autoantigen. PMID:16177075

Byersdorfer, Craig A; Schweitzer, George G; Unanue, Emil R

2005-10-01

69

Prediction of final error level in learning and repetitive control  

NASA Astrophysics Data System (ADS)

Repetitive control (RC) is a field that creates controllers to eliminate the effects of periodic disturbances on a feedback control system. The methods have applications in spacecraft problems, to isolate fine pointing equipment from periodic vibration disturbances such as slight imbalances in momentum wheels or cryogenic pumps. A closely related field of control design is iterative learning control (ILC) which aims to eliminate tracking error in a task that repeats, each time starting from the same initial condition. Experiments done on a robot at NASA Langley Research Center showed that the final error levels produced by different candidate repetitive and learning controllers can be very different, even when each controller is analytically proven to converge to zero error in the deterministic case. Real world plant and measurement noise and quantization noise (from analog to digital and digital to analog converters) in these control methods are acted on as if they were error sources that will repeat and should be cancelled, which implies that the algorithms amplify such errors. Methods are developed that predict the final error levels of general first order ILC, of higher order ILC including current cycle learning, and of general RC, in the presence of noise, using frequency response methods. The method involves much less computation than the corresponding time domain approach that involves large matrices. The time domain approach was previously developed for ILC and handles a certain class of ILC methods. Here methods are created to include zero-phase filtering that is very important in creating practical designs. Also, time domain methods are developed for higher order ILC and for repetitive control. Since RC and ILC must be implemented digitally, all of these methods predict final error levels at the sample times. It is shown here that RC can easily converge to small error levels between sample times, but that ILC in most applications will have large and diverging intersample error if in fact zero error is reached at the sample times. This is independent of the ILC law used, and is purely a property of the physical system. Methods are developed to address this issue.

Levoci, Peter A.

70

Predicting fire activity using terrestrial water storage data  

NASA Astrophysics Data System (ADS)

High fire activity periods in the Amazon region can be predicted months in advance on the basis of water storage data, a new study shows. Chen et al. analyzed satellite observations of terrestrial water storage from the Gravity Recovery and Climate Experiment (GRACE) mission, along with satellite observations of fire activity from the Moderate Resolution Imaging Spectroradiometer (MODIS) mission. GRACE measures the Earth's gravity field by calculating the changes in the distance between two satellites as slight variations in density pull on one satellite more than the other. The gravity measurements provide information about the amount of groundwater or surface water in a given region.

Balcerak, Ernie

2013-05-01

71

Predicting Soil-Water Partition Coefficients for Cadmium  

E-print Network

Predicting Soil-Water Partition Coefficients for Cadmium S U E N - Z O N E L E E Department and chemical composition, particularly organic matter and metal oxides. The adsorption of Cd(II) followed concentration, greater adsorption was observed for soils with higher organic matter content. To better

Sparks, Donald L.

72

Neural networks for predicting chilled water demand in buildings  

SciTech Connect

A neural network was designed, trained, and tested to predict chilled water demands. The input data to the neural network included temperature, wet bulb temperature, 24 hours of past loads, a day-of-the-week indicator, an hour-of-the-day indicator, and a holiday indicator. A two-layer network was used to predict the chilled water demand for the current hour plus 23 hours into the future. Therefore, the output of the neutral network consisted of 24 outputs, each representing a chilled water demand forecast. A hidden layer was used in the neural network consisting of 20 hidden units. A variety of network configurations were tested, as were learning algorithms, learning rates, and network threshold types (unipolar, bipolar or linear). The coefficient of determination, R2, measured how well the network predicted into the future. In general, the network training was smooth and the resulting network predicted the future chilled water demand with a coefficient of determination greater than 0.9, even for 24-hour ahead forecasts. This paper discusses the network design training protocol and results of the performance of the network on test data.

Hittle, D.C.; Flocken, P.A.; Anderson, C.W. [Colorado State Univ., Fort Collins, CO (United States)

1996-12-31

73

Predicting Salmonella Populations from Biological, Chemical, and Physical Indicators in Florida Surface Waters  

PubMed Central

Coliforms, Escherichia coli, and various physicochemical water characteristics have been suggested as indicators of microbial water quality or index organisms for pathogen populations. The relationship between the presence and/or concentration of Salmonella and biological, physical, or chemical indicators in Central Florida surface water samples over 12 consecutive months was explored. Samples were taken monthly for 12 months from 18 locations throughout Central Florida (n = 202). Air and water temperature, pH, oxidation-reduction potential (ORP), turbidity, and conductivity were measured. Weather data were obtained from nearby weather stations. Aerobic plate counts and most probable numbers (MPN) for Salmonella, E. coli, and coliforms were performed. Weak linear relationships existed between biological indicators (E. coli/coliforms) and Salmonella levels (R2 < 0.1) and between physicochemical indicators and Salmonella levels (R2 < 0.1). The average rainfall (previous day, week, and month) before sampling did not correlate well with bacterial levels. Logistic regression analysis showed that E. coli concentration can predict the probability of enumerating selected Salmonella levels. The lack of good correlations between biological indicators and Salmonella levels and between physicochemical indicators and Salmonella levels shows that the relationship between pathogens and indicators is complex. However, Escherichia coli provides a reasonable way to predict Salmonella levels in Central Florida surface water through logistic regression. PMID:23624476

McEgan, Rachel; Mootian, Gabriel; Goodridge, Lawrence D.; Schaffner, Donald W.

2013-01-01

74

Prediction of anhydrite precipitation in field water heating systems  

Microsoft Academic Search

A key step in feed water treatment for the generation of wet steam for thermal oil recovery is the removal of calcium and magnesium hardness by cation exchange series softening. A knowledge of the solubility of any scale- forming salts in brines at elevated temperatures is necessary for fixing the level to which the feed water must be softened. Solubility

C. C. Templeton; J. C. Rodgers

1967-01-01

75

Ecology predicts levels of genetic differentiation in neotropical birds.  

PubMed

Despite the theoretical link between the ecology and the population genetics of species, little empirical evidence is available that corroborates the association. Here, we examined genetic variation in 40 codistributed species of lowland Neotropical rain forest birds that have populations isolated on either side of the Andes, the Amazon River, and the Madeira River. We found widely varying levels of genetic divergence among these taxa across the same biogeographic barriers. Our investigation of the extent to which ecological traits predicted the amount of cross-barrier divergence revealed a strongly significant relationship between the forest stratum at which a species forages and the level of cross-barrier genetic differentiation. Canopy species had statistically lower genetic divergence values across the Andes and the two Amazonian rivers than did understory birds. We hypothesize that the association reflects an effect of dispersal propensity, which is greater in canopy birds, on the movement of alleles among demes (i.e., migration) and, consequently, on the interdemic proportion of the genetic variance. Differences in dispersal propensity may also explain the observation that understory species contain a significantly greater number of subspecies than do canopy species. This result indicates that higher rates of diversification may occur in lineages with lower dispersal propensity. PMID:19627230

Burney, Curtis W; Brumfield, Robb T

2009-09-01

76

Groundwater-level prediction using multiple linear regression and artificial neural network techniques: a comparative assessment  

NASA Astrophysics Data System (ADS)

The potential of multiple linear regression (MLR) and artificial neural network (ANN) techniques in predicting transient water levels over a groundwater basin were compared. MLR and ANN modeling was carried out at 17 sites in Japan, considering all significant inputs: rainfall, ambient temperature, river stage, 11 seasonal dummy variables, and influential lags of rainfall, ambient temperature, river stage and groundwater level. Seventeen site-specific ANN models were developed, using multi-layer feed-forward neural networks trained with Levenberg-Marquardt backpropagation algorithms. The performance of the models was evaluated using statistical and graphical indicators. Comparison of the goodness-of-fit statistics of the MLR models with those of the ANN models indicated that there is better agreement between the ANN-predicted groundwater levels and the observed groundwater levels at all the sites, compared to the MLR. This finding was supported by the graphical indicators and the residual analysis. Thus, it is concluded that the ANN technique is superior to the MLR technique in predicting spatio-temporal distribution of groundwater levels in a basin. However, considering the practical advantages of the MLR technique, it is recommended as an alternative and cost-effective groundwater modeling tool.

Sahoo, Sasmita; Jha, Madan K.

2013-12-01

77

Drought-trigger ground-water levels and analysis of historical water-level trends in Chester County, Pennsylvania  

USGS Publications Warehouse

The Chester County observation-well network was established in 1973 through a cooperative agreement between the Chester County Water Resources Authority (CCWRA) and the U.S. Geological Survey. The network was established to monitor local ground-water levels, to determine drought conditions, and to monitor ground-water-level trends. Drought-warning and drought-emergency water-level triggers were determined for 20 of the 23 wells in the Chester County observation-well network. A statistical test to determine either rising or declining water-level trends was performed on data for all wells in the network. Water-level data from both of these wells showed a rising trend. A decrease in ground-water pumping in the area near these wells was probably the reason for the rise in water levels.

Schreffler, Curtis L.

1996-01-01

78

Entropy principles in the prediction of water quality values at discontinued monitoring stations  

NASA Astrophysics Data System (ADS)

A new methodology for predicting water quality values at discontinued water quality monitoring stations is proposed. The method is based upon the Principle of Maximum Entropy (POME) and provides unbiased predictions of water quality levels at upstream tributaries and on the mainstem of a river given observed changes in the distribution of the same water quality parameter at a downstream location. Changes in the values of water quality parameters which are known a priori to have occurred upstream, but which are not sufficiently large to account for all the observed change in the same water quality parameter at the downstream location are able to be incorporated in the method through the introduction of a new term in the basic entropy expression. Application of the procedure to water quality monitoring on the Mackenzie River in Queensland, Australia indicates the method has considerable potential for prediction of water quality at discontinued stations. The method also has potential for identifying the location of causes of observed changes in water quality at a downstream station.

Kusmulyono, A.; Goulter, I.

1994-12-01

79

Predicting tree water use and drought tolerance from leaf traits in the Los Angeles urban ecosystem  

NASA Astrophysics Data System (ADS)

Urban green space provides a suite of valuable ecosystem services. In semiarid systems, like Los Angeles, trees rely primarily on irrigation water for transpiration. Managers may need to reduce irrigation associated with urban trees given climate change, urban expansion, and the steady decrease in available freshwater. While leaf and whole plant water relations have been extensively studied, we are only now gaining a detailed understanding of diverse leaf anatomical designs, and their use for predicting physiology and water use at landscape scale. For 50 diverse urban species, we quantified leaf anatomical and physiological traits important to tree drought tolerance and water use efficiency including turgor loss point, vein architecture, cellular anatomy, leaf mass per unit area, and petiole and leaf dimensions. We hypothesized detailed relationships to develop models relating leaf functional traits to tree water relations. These models provide key insights regarding the role of anatomical designs in leaf stress tolerance and water use efficiency. Additionally we predicted how traits measured at the leaf level would scale with existing data for individuals at the whole plant level. We tested our predictions by determining correlations between leaf level anatomical traits and drought tolerance. Additionally, we determined correlations between functional traits, physiology and water use, and the climate of origin for the urban species. Leaf level measurements will be valuable for rapid estimation of more difficult to measure whole plant water relations traits important at the landscape scale. The Los Angeles urban ecosystem can serve as a model for other semiarid system and provide more informed system wide water conservation strategies.

John, G. P.; Scoffoni, C.; Sack, L.

2013-12-01

80

Predicting Risk from Radon in Source Waters from Water Quality Parameters  

EPA Science Inventory

Overall, 47 groundwater samples were collected from 45 small community water systems (CWSs) and analyzed for radon and other water quality constituents. In general, groundwater from unconsolidated deposits and sedimentary rocks had lower average radon levels (ranging from 223 to...

81

26. Mechanical float gages used to monitor level of water ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

26. Mechanical float gages used to monitor level of water in the filtration bed reservoir. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

82

Water hammer prediction and control: the Green's function method  

NASA Astrophysics Data System (ADS)

By Green's function method we show that the water hammer (WH) can be analytically predicted for both laminar and turbulent flows (for the latter, with an eddy viscosity depending solely on the space coordinates), and thus its hazardous effect can be rationally controlled and minimized. To this end, we generalize a laminar water hammer equation of Wang et al. (J. Hydrodynamics, B2, 51, 1995) to include arbitrary initial condition and variable viscosity, and obtain its solution by Green's function method. The predicted characteristic WH behaviors by the solutions are in excellent agreement with both direct numerical simulation of the original governing equations and, by adjusting the eddy viscosity coefficient, experimentally measured turbulent flow data. Optimal WH control principle is thereby constructed and demonstrated.

Xuan, Li-Jun; Mao, Feng; Wu, Jie-Zhi

2012-04-01

83

Prediction of the safety level to an installation of the tritium process through predictive maintenance  

SciTech Connect

The safety level for personnel and environment to a nuclear installation is given in generally by the technological process quality of operation and maintenance and in particular by a lot of technical, technological, economic and human factors. The maintenance role is fundamental because it has to quantify all the technical, economic and human elements as an integrated system for it creates an important feedback for activities concerning the life cycle of the nuclear installation. In maintenance activities as in any dynamic area, new elements appear continuously which, sometimes require new approaches. The theory of fuzzy logic and the software LabVIEW supplied to the Nuclear Detritiation Plant (NDP) is part of National Research and Development Inst. for Cryogenics and Isotopic Technologies-ICIT, Rm.Valcea, used for predictive maintenance to assure safety operation. The final aim is to achieve the best practices for maintenance of the Plant that processes tritium. (authors)

Anghel, V. [National Research and Development Inst. for Cryogenics and Isotopic Technologies - ICIT, Rm. Valcea Uzinei Street no.4, 240050 (Romania)

2008-07-15

84

Ground-water levels and quality data for Georgia, 1978  

USGS Publications Warehouse

Mean water levels in wells across Georgia were from 0.25 foot higher to 11.4 feet lower in 1978 than in 1977, and in some areas were the lowest on record. Water levels in the principal artesian aquifer underwent a long-term decline during the period 1969-78. In some areas water levels dropped more than 10 feet. Wells tapping the Clayton Limestone in the Albany area showed a long-term decline during the period 1969-78, and in some wells water levels dropped more than 20 feet. Water levels in the Cretaceous aquifer system showed little fluctuation during 1978; however, in a well located in Chattahoochee County, water levels declined 4.4 feet during 1969-78. In the Piedmont area mean water levels remained the same to 2.2 feet lower in 1978 than in 1977, and showed no long-term trend. Chloride concentrations in the principal artesian aquifer in the Savannah area remained stable and in the Brunswick area continued to rise during 1978. Daily mean water-level fluctuations and trends for 1978 and fluctuations of the monthly mean water level for the previous 10 years are shown in hydrographs of 33 selected observation wells in Georgia. Chloride concentrations in 11 wells in the Savannah and Brunswick areas are shown in graphs of monthly values over the previous 10 years. A short narrative explains fluctuations and trends in each of the hydrographs and chloride concentration graphs shown. (Woodard-USGS)

Clarke, J. S.; Hester, W. G.; O'Byrne, M. P.

1979-01-01

85

Relevant variables to predict macrophyte communities in running waters  

Microsoft Academic Search

In both predictive theoretical and empirical models for aquatic plant communities in running waters, the development and competition are many times explained in terms of nutrients. Minerals necessary for growth are generally not assumed to be limiting, although they influence the important pH-value. At the same time it is known that factors such as oxygen-concentration, solar energy, salinity, dimension of

Aat Barendregt; Ana M. F. Bio

2003-01-01

86

Sea-level change model predictions based on geomorphological data in Cyclades (Greece) and Tunisia  

NASA Astrophysics Data System (ADS)

The palaeo relative sea-level indicators are the most important type of data as far as the Glacial Isostatic Adjustment (GIA) related to the Last Glacial Maximum is concerned. The geomorphological and archaeological indicators have recorded the long-term sea-level variation that accompanied and followed the melting of the Late Pleistocene ice sheets. This bathymetry change stems for the combined effects of the eustatic sea-level change, the gravitational interactions between the geoid and the ice sheets and the deformation of the solid Earth. Since these three factors are fully described by the sea level equation in a self-consistent manner, the comparison of relative sea-level (rsl) data and predicted Holocene curves provides fundamental constraints on the GIA models. While the rsl data from the formerly glaciated area may provide constraints on both the extent and thickness with time of the ice sheets and the local shallow Earth structure and rheology, the palaeo sea-levels from the Mediterranean Sea may constrain the volumes of melt water that has been globally released through time and also the lower mantle rheological parameters. In this work we combine archaeological and geomorphological rsl indicators with GIA-model predictions to investigate the Holocene sea level changes in Tunisia and Cyclades islands (Central Aegean). While the former area has been proven to be vertically stable on the long timescale, the Central Aegean could be affected by local tectonics that would result in vertical deformations. We therefore compare at first the available rsl data from Tunisia with GIA predictions based on a suite of available late Pleistocene ice chronologies and Earth rheological models. We find the best combination of ice and earth models to explain the rsl data from Tunisia and finally apply those to investigate the vertical stability at the Cyclades islands and to quantify the tectonics-related rates of vertical crustal deformation.

Stocchi, Paolo; Evelpidou, Niki; Pirazzoli, Paolo; Vassilopoulos, Andreas; Ruggieri, Gabriella; Vermeersen, Bert; Spada, Giorgio

2010-05-01

87

Hydrological and water management related applications of long term meteorological prediction  

NASA Astrophysics Data System (ADS)

Seasonal forecast activities at the Hungarian Meteorological Service have a long history. Published forecasts used to be the results of different statistical procedures based on clustering of different typical sequences. Long term meteorological forecasts of recent years are based on ECMWF long term projections. Those are interpreted and downscaled for the territory of Hungary and Danube catchments. 1 - 6-month forecasts of 2-m temperatures and precipitation are used for hydrological projections. Seasonal forecasts of Lake Balaton water budget, monthly mean streamflow and low water estimates for central Danube are targeted. The catchments comprising the river system are situated in various climatological and geo-morphological settings across the region. Skill score of the projections are investigated for average and extreme conditions. The five year period in between 2000-2004 resulted dry conditions over the Balaton drainage area. The continuous extreme low values in water budget of the Lake led to significant drop of water levels. Starting with the summer of 2000 water level of the Lake remained most time below the lower regulation level. Typical patterns of water level fluctuation remained in this dry period (rises during cold half year, decreases during warm half year). However the series of annual deficits are expressed in lower and lower annual minimum of water levels. The accumulated deficit of natural water budget relative to multi-annual average reached a maximum for lake surface without any precedent for the period of water budget accounting. Danube monthly flow, minimum flow and water level predictions for the period 1984-2009 are also analysed.

Varga, György; Body, Károly; Hunyady, Adrienn; Balint, Gabor

2010-05-01

88

Statistical and Biophysical Models for Predicting Total and Outdoor Water Use in Los Angeles  

NASA Astrophysics Data System (ADS)

Modeling water demand is a complex exercise in the choice of the functional form, techniques and variables to integrate in the model. The goal of the current research is to identify the determinants that control total and outdoor residential water use in semi-arid cities and to utilize that information in the development of statistical and biophysical models that can forecast spatial and temporal urban water use. The City of Los Angeles is unique in its highly diverse socio-demographic, economic and cultural characteristics across neighborhoods, which introduces significant challenges in modeling water use. Increasing climate variability also contributes to uncertainties in water use predictions in urban areas. Monthly individual water use records were acquired from the Los Angeles Department of Water and Power (LADWP) for the 2000 to 2010 period. Study predictors of residential water use include socio-demographic, economic, climate and landscaping variables at the zip code level collected from US Census database. Climate variables are estimated from ground-based observations and calculated at the centroid of each zip code by inverse-distance weighting method. Remotely-sensed products of vegetation biomass and landscape land cover are also utilized. Two linear regression models were developed based on the panel data and variables described: a pooled-OLS regression model and a linear mixed effects model. Both models show income per capita and the percentage of landscape areas in each zip code as being statistically significant predictors. The pooled-OLS model tends to over-estimate higher water use zip codes and both models provide similar RMSE values.Outdoor water use was estimated at the census tract level as the residual between total water use and indoor use. This residual is being compared with the output from a biophysical model including tree and grass cover areas, climate variables and estimates of evapotranspiration at very high spatial resolution. A genetic algorithm based model (Shuffled Complex Evolution-UA; SCE-UA) is also being developed to provide estimates of the predictions and parameters uncertainties and to compare against the linear regression models. Ultimately, models will be selected to undertake predictions for a range of climate change and landscape scenarios. Finally, project results will contribute to a better understanding of water demand to help predict future water use and implement targeted landscaping conservation programs to maintain sustainable water needs for a growing population under uncertain climate variability.

Mini, C.; Hogue, T. S.; Pincetl, S.

2012-04-01

89

STORM WATER POLLUTION PREVENTION PLAN (RISK LEVEL 1)  

E-print Network

STORM WATER POLLUTION PREVENTION PLAN (RISK LEVEL 1) for BUILDING 90 USER TEST BED FACILITY.G., GEOLOGIST/QSD (530) 222-4339 SWPPP Preparation Date: JUNE 10, 2012 #12;Storm Water Pollution Prevention Plan) 222-4339 Name and Title Telephone Number #12;Storm Water Pollution Prevention Plan Building 90 User

Eisen, Michael

90

Multi-Level Learning Processes in (Water) Resource Governance  

E-print Network

Multi-Level Learning Processes in (Water) Resource Governance Systems Claudia Pahl-Wostl Professor towards more Adaptive Governance in River Basins) GWSP (Global Water System Project) #12;Tradition ,,Messy" Problems ? Government & Technical Experts Governance by many actors #12;Paradigm Shift in Water

Slatton, Clint

91

Statistical summaries of ground-water level data collected in the Suwannee River Water Management District, 1948 to 1994  

USGS Publications Warehouse

Since 1948, ground-water level data have beensystematically collected from selected wells in theSuwannee River Water Management District (SRWMD) by the U.S. Geological Survey (USGS),the SRWMD, and other agencies. Records of waterlevels in the SRWMD (fig. 1), collected by the USGS and SRWMD through 1990, and by the SRWMD from 1990 to 1994, have been published for many years in the USGS annual report series "Water Resources Data for Florida." However, no systematic statistical summaries of water levels in the SRWMD have been previously published. The need for such statistical summary data forevaluations of drought severity, ground-water supplyavailability, and minimum water levels for regulatory purposes increases daily as demands for ground-water usage increase. Also, much of the base flow of the Suwannee River is dependent upon ground water. As the population and demand for ground water for drinking water and irrigation purposes increase, the ability to quickly and easily predict trends in ground-water availability will become paramount. In response to this need, the USGS, in cooperation with the SRWMD, compiled this report. Ground-water sta tistics for 136 sites are presented as well as figures showing water levels that were measured in wells from 1948 through September 1994. In 1994, the SRWMD and the USGS began a long- term program of cooperative studies designed tobetter understand minimum and maximum streamflows and ground-water levels in the SRWMD. Minimum and maximum flows and levels are needed by the district to manage the surface- and ground-water resources of the SRWMD and to maintain or improve the various ecosystems. Data evaluation was a necessary first step in the long- term SRWMD ground-water investigations program, because basic statistics for ground-water levels are not included in the USGS annual data reports such as "Water Resources Data for Florida, Water Year 1994" (Fran klin and others, 1995). Statistics included in this report were generated using the USGS computer pro gram ADAPS (Automatic Data Processing System) to characterize normal ground-water levels and depar tures from normal. The report has been organized so that the statisti cal analyses of water levels in the wells are presentedfollowing this introductory material, a description ofthe hydrogeology in the study area, and a description of the statistics used to present the water-level data. Specifically, the report presents statistical analyses for each well, as appropriate, in the following manner: Description of the well.Hydrographs of ground-water levels for the period of record, for the last 10 years of record, and for the last 5 years of record. Graphs of maximum, minimum, and mean of monthly mean ground-water levels for wells with 5 or more years of record.Frequency hydrographs (25, 50, and 75 percent) of monthly mean ground-water levels for wells with 5 or more years of record. Water-level data and statistical plots are grouped by county and sorted within the county by ascendingsite identification number. Well locations are plottedon county maps preceding the well descriptions andhydrographs.

Collins, J. J.; Freeman, L. D.

1996-01-01

92

On Water-Level Error Propagation in Controlled Irrigation Channels  

Microsoft Academic Search

We consider the propagation of water-level errors in a controlled string of (identical) pools comprising an open-water irrigation channel. It is shown that water-level errors are amplified as they propagate upstream, whenever the feedback control scheme is decentralised and load-disturbance rejection is required in steady-state. Moreover, a design trade-off is identified between local performance, in terms of set-point regulation and

Yuping Li; Michael Cantoni; Erik Weyer

2005-01-01

93

Nestling activity levels during begging behaviour predicts activity level and body mass in adulthood  

PubMed Central

Across a range of species including humans, personality traits, or differences in behaviour between individuals that are consistent over time, have been demonstrated. However, few studies have measured whether these consistent differences are evident in very young animals, and whether they persist over an individual’s entire lifespan. Here we investigated the begging behaviour of very young cross-fostered zebra finch nestlings and the relationship between that and adult activity levels. We found a link between the nestling activity behaviour head movements during begging, measured at just five and seven days after hatching, and adult activity levels, measured when individuals were between three and three and a half years old. Moreover, body mass was found to be negatively correlated with both nestling and adult activity levels, suggesting that individuals which carry less body fat as adults are less active both as adults and during begging as nestlings. Our work suggests that the personality traits identified here in both very young nestlings and adults may be linked to physiological factors such as metabolism or environmental sources of variation. Moreover, our work suggests it may be possible to predict an individual’s future adult personality at a very young age, opening up new avenues for future work to explore the relationship between personality and a number of aspects of individual life history and survival.

Griffith, Simon C.

2014-01-01

94

Predictive control of water distribution in the Dutch National Hydrological Instrument (NHI)  

NASA Astrophysics Data System (ADS)

In the Netherlands, water is extracted from rivers, lakes and canals for drinking water supply as well as industrial, agricultural and environmental water demands. These water extractions must be managed in such a way that constraints such as water quality, safety and minimum water levels for navigation are maintained as long as possible. The National Hydrological Instrument (NHI) has been developed for modeling the water distribution in the Netherlands and supporting the development of water management strategies. It is also integrated into the national Dutch forecasting system for predicting dry periods and their impacts on water supply, agriculture, aquatic ecosystems and navigation. With such setup, the NHI will be a fundamental tool for drought forecast in the Netherlands. The NHI consists of a groundwater model (MODFLOW), an unsaturated zone model (Metaswap) and surface water models which interact with each other in every time step via an OpenMI interface. The surface water models consist of a hydrological model MOZART for representing the regional catchments and computing a desired water demand, a SOBEK open channel flow model for flow routing in the network of the larger rivers, lakes and canals, and a real-time control component (RTC-Tools). The latter links the water demand generated by MOZART to the availably supply in the network for generating optimum water allocation policies within the prediction horizon of 10 days of the operational forecasting system. The approach relies on predictive control consisting of a simplified internal model of the network within a system-wide optimization algorithm. In a period of water shortages, the user can refine the water allocation by defining specific objectives and related priorities. Finally, the optimum water extractions from RTC-Tools are passed back to MOZART and SOBEK as allocated values. The RTC-Tools integration into the NHI is an ongoing activity. We present the new functionality based on a pilot system and demonstrate the ability of the approach dealing with different drought situations and distributed, prioritized water demands. Furthermore, we discuss the added value of the approach compared to previous NHI set-ups focusing in particular on operational drought management features.

Talsma, J.; Patzke, S.; Becker, B. P. J.; Schwanenberg, D.; Jansen, M.

2012-04-01

95

Striatal volume predicts level of video game skill acquisition.  

PubMed

Video game skills transfer to other tasks, but individual differences in performance and in learning and transfer rates make it difficult to identify the source of transfer benefits. We asked whether variability in initial acquisition and of improvement in performance on a demanding video game, the Space Fortress game, could be predicted by variations in the pretraining volume of either of 2 key brain regions implicated in learning and memory: the striatum, implicated in procedural learning and cognitive flexibility, and the hippocampus, implicated in declarative memory. We found that hippocampal volumes did not predict learning improvement but that striatal volumes did. Moreover, for the striatum, the volumes of the dorsal striatum predicted improvement in performance but the volumes of the ventral striatum did not. Both ventral and dorsal striatal volumes predicted early acquisition rates. Furthermore, this early-stage correlation between striatal volumes and learning held regardless of the cognitive flexibility demands of the game versions, whereas the predictive power of the dorsal striatal volumes held selectively for performance improvements in a game version emphasizing cognitive flexibility. These findings suggest a neuroanatomical basis for the superiority of training strategies that promote cognitive flexibility and transfer to untrained tasks. PMID:20089946

Erickson, Kirk I; Boot, Walter R; Basak, Chandramallika; Neider, Mark B; Prakash, Ruchika S; Voss, Michelle W; Graybiel, Ann M; Simons, Daniel J; Fabiani, Monica; Gratton, Gabriele; Kramer, Arthur F

2010-11-01

96

Prediction of water loss and viscoelastic deformation of apple tissue using a multiscale model  

NASA Astrophysics Data System (ADS)

A two-dimensional multiscale water transport and mechanical model was developed to predict the water loss and deformation of apple tissue (Malus?×?domestica Borkh. cv. ‘Jonagold’) during dehydration. At the macroscopic level, a continuum approach was used to construct a coupled water transport and mechanical model. Water transport in the tissue was simulated using a phenomenological approach using Fick’s second law of diffusion. Mechanical deformation due to shrinkage was based on a structural mechanics model consisting of two parts: Yeoh strain energy functions to account for non-linearity and Maxwell’s rheological model of visco-elasticity. Apparent parameters of the macroscale model were computed from a microscale model. The latter accounted for water exchange between different microscopic structures of the tissue (intercellular space, the cell wall network and cytoplasm) using transport laws with the water potential as the driving force for water exchange between different compartments of tissue. The microscale deformation mechanics were computed using a model where the cells were represented as a closed thin walled structure. The predicted apparent water transport properties of apple cortex tissue from the microscale model showed good agreement with the experimentally measured values. Deviations between calculated and measured mechanical properties of apple tissue were observed at strains larger than 3%, and were attributed to differences in water transport behavior between the experimental compression tests and the simulated dehydration-deformation behavior. Tissue dehydration and deformation in the high relative humidity range (?>?97% RH) could, however, be accurately predicted by the multiscale model. The multiscale model helped to understand the dynamics of the dehydration process and the importance of the different microstructural compartments (intercellular space, cell wall, membrane and cytoplasm) for water transport and mechanical deformation.

Aregawi, Wondwosen A.; Abera, Metadel K.; Fanta, Solomon W.; Verboven, Pieter; Nicolai, Bart

2014-11-01

97

Prediction of water loss and viscoelastic deformation of apple tissue using a multiscale model.  

PubMed

A two-dimensional multiscale water transport and mechanical model was developed to predict the water loss and deformation of apple tissue (Malus?×?domestica Borkh. cv. 'Jonagold') during dehydration. At the macroscopic level, a continuum approach was used to construct a coupled water transport and mechanical model. Water transport in the tissue was simulated using a phenomenological approach using Fick's second law of diffusion. Mechanical deformation due to shrinkage was based on a structural mechanics model consisting of two parts: Yeoh strain energy functions to account for non-linearity and Maxwell's rheological model of visco-elasticity. Apparent parameters of the macroscale model were computed from a microscale model. The latter accounted for water exchange between different microscopic structures of the tissue (intercellular space, the cell wall network and cytoplasm) using transport laws with the water potential as the driving force for water exchange between different compartments of tissue. The microscale deformation mechanics were computed using a model where the cells were represented as a closed thin walled structure. The predicted apparent water transport properties of apple cortex tissue from the microscale model showed good agreement with the experimentally measured values. Deviations between calculated and measured mechanical properties of apple tissue were observed at strains larger than 3%, and were attributed to differences in water transport behavior between the experimental compression tests and the simulated dehydration-deformation behavior. Tissue dehydration and deformation in the high relative humidity range (?>?97% RH) could, however, be accurately predicted by the multiscale model. The multiscale model helped to understand the dynamics of the dehydration process and the importance of the different microstructural compartments (intercellular space, cell wall, membrane and cytoplasm) for water transport and mechanical deformation. PMID:25347182

Aregawi, Wondwosen A; Abera, Metadel K; Fanta, Solomon W; Verboven, Pieter; Nicolai, Bart

2014-11-19

98

Prediction of effects of measures to reduce eutrophication in surface water in rural areas - a case study  

Microsoft Academic Search

The effectiveness of measures to reduce nutrient concentrations in surface water was predicted by a combination of a nutrient leaching model for groundwater and a nutrient simulation model for surface water. Scenarios were formulated based on several measures. Different combinations of drainage level and fertilizer use gave slightly different leaching concentrations. Removing duckweed, dredging the total sediment layer, improving the

Kolk van der J. W. H

1995-01-01

99

Developing and implementing the use of predictive models for estimating water quality at Great Lakes beaches  

USGS Publications Warehouse

Predictive models have been used at beaches to improve the timeliness and accuracy of recreational water-quality assessments over the most common current approach to water-quality monitoring, which relies on culturing fecal-indicator bacteria such as Escherichia coli (E. coli.). Beach-specific predictive models use environmental and water-quality variables that are easily and quickly measured as surrogates to estimate concentrations of fecal-indicator bacteria or to provide the probability that a State recreational water-quality standard will be exceeded. When predictive models are used for beach closure or advisory decisions, they are referred to as “nowcasts.” During the recreational seasons of 2010-12, the U.S. Geological Survey (USGS), in cooperation with 23 local and State agencies, worked to improve existing nowcasts at 4 beaches, validate predictive models at another 38 beaches, and collect data for predictive-model development at 7 beaches throughout the Great Lakes. This report summarizes efforts to collect data and develop predictive models by multiple agencies and to compile existing information on the beaches and beach-monitoring programs into one comprehensive report. Local agencies measured E. coli concentrations and variables expected to affect E. coli concentrations such as wave height, turbidity, water temperature, and numbers of birds at the time of sampling. In addition to these field measurements, equipment was installed by the USGS or local agencies at or near several beaches to collect water-quality and metrological measurements in near real time, including nearshore buoys, weather stations, and tributary staff gages and monitors. The USGS worked with local agencies to retrieve data from existing sources either manually or by use of tools designed specifically to compile and process data for predictive-model development. Predictive models were developed by use of linear regression and (or) partial least squares techniques for 42 beaches that had at least 2 years of data (2010-11 and sometimes earlier) and for 1 beach that had 1 year of data. For most models, software designed for model development by the U.S. Environmental Protection Agency (Virtual Beach) was used. The selected model for each beach was based on a combination of explanatory variables including, most commonly, turbidity, day of the year, change in lake level over 24 hours, wave height, wind direction and speed, and antecedent rainfall for various time periods. Forty-two predictive models were validated against data collected during an independent year (2012) and compared to the current method for assessing recreational water quality-using the previous day’s E. coli concentration (persistence model). Goals for good predictive-model performance were responses that were at least 5 percent greater than the persistence model and overall correct responses greater than or equal to 80 percent, sensitivities (percentage of exceedances of the bathing-water standard that were correctly predicted by the model) greater than or equal to 50 percent, and specificities (percentage of nonexceedances correctly predicted by the model) greater than or equal to 85 percent. Out of 42 predictive models, 24 models yielded over-all correct responses that were at least 5 percent greater than the use of the persistence model. Predictive-model responses met the performance goals more often than the persistence-model responses in terms of overall correctness (28 versus 17 models, respectively), sensitivity (17 versus 4 models), and specificity (34 versus 25 models). Gaining knowledge of each beach and the factors that affect E. coli concentrations is important for developing good predictive models. Collection of additional years of data with a wide range of environmental conditions may also help to improve future model performance. The USGS will continue to work with local agencies in 2013 and beyond to develop and validate predictive models at beaches and improve existing nowcasts, restructuring monitoring activities to accommodate future uncertainties in

Francy, Donna S.; Brady, Amie M. G.; Carvin, Rebecca B.; Corsi, Steven R.; Fuller, Lori M.; Harrison, John H.; Hayhurst, Brett A.; Lant, Jeremiah; Nevers, Meredith B.; Terrio, Paul J.; Zimmerman, Tammy M.

2013-01-01

100

Army Study Improves Ability to Predict Drinking Water Needs  

NSDL National Science Digital Library

The study, ÃÂExpanded prediction equations of human sweat loss and water needs,ÃÂ appears in the online edition of the journal. The researchers are Richard R. Gonzalez, Samuel N. Cheuvront, Scott J. Montain, Daniel A. Goodman, Laurie A. Blanchard, Larry G. Berglund and Michael N. Sawka. The researchers are with the U.S. Army Research Institute of Environmental Medicine, except for Dr. Gonzalez, who is an adjunct professor at New Mexico State University. The American Physiological Society published the study. (The full link to the study appears at the bottom of the release.)

APS Communications Office (American Physiological Society Communications Office)

2006-07-08

101

Low level range coverage performance prediction for VHF radar  

NASA Astrophysics Data System (ADS)

A VHF radar frequencies the range coverage is not strictly limited by the quasi-optical horizon like at microwave radar frequencies but is extended due to diffraction propagation. This effect, here called beyond-the-horizon (BTH) detection capability is strongly dependent on the propagation path and thus on the terrain structure. The availability of digital terrain maps gives way to the use of computerized methods for the prediction of radar range coverage in real environment. In combination with wave propagation models suitable for diffraction at terrain structures, digital terrain data can even be used for the prediction of BTH target detectability at VHF radar. Here the digital landmass system (DLSS) terrain database was used in combination with a multiple-knife-edge diffraction model to predict the diffraction attenuation between the radar and the potential target positions, especially beyond the optical horizon. The propagation paths extracted from the database are modeled as a sequence of diffraction screens suited for the application of a Fresnel-Kirchhoff algorithm yielding the knife-edge-diffraction attenuation. This terrain related propagation model was verified by a large number of measurements at different frequencies. Implemented in a fast computer system, this prediction model can be used for mission planning of air operations. Considering hostile VHF radar coverage and terrain condition for flight path optimization or, on the other hand it can assist in siting mobile radars for gap filling according to the actual threat situation. Calculations of the diffraction propagation using the prediction model, yield range coverage patterns in real terrain situations, allowing to quantify the BTH detection advantage of VHF radar compared to microwave radar. An experimental large wavelength radar LARA (VHF) built flying targets beyond the close horizon. Here, especially the detection of hiding helicopters by exploiting diffractive wave propagation was examined. Measurements at different VHF frequencies were carried out, to validate the results obtained by simulation.

Kuschel, H.

1989-09-01

102

Model simulation of water and nitrate movement in a level-basin under fertigation treatments  

Microsoft Academic Search

Simulation models, once validated for local conditions, can play an important role in predicting the distribution patterns of yield factors and thus help the farmer with decisions on management practices. Results from a soil water and N03-N concentration analysis are presented describing their behaviour under irrigation by temporary flooding (level basin). The data was used for validation of Opus model

D. V. Santos; P. L. Sousa; R. E. Smith

1997-01-01

103

Effects of water turbidity and salt concentration levels on penetration of solar radiation under water  

Microsoft Academic Search

Two large, outdoor tanks were constructed in order to investigate the effects of water turbidity and salt concentration levels at various depths of water on penetration of solar radiation. These experiments were followed by a laboratory investigation that measured spectral transmittance and the extinction coefficient of water at different salt concentrations and turbidity levels. Both the outdoor and laboratory results

J. Wang; J. Seyed-Yagoobi

1994-01-01

104

Prediction of functional residues in water channels and related proteins.  

PubMed Central

In this paper, we present an updated classification of the ubiquitous MIP (Major Intrinsic Protein) family proteins, including 153 fully or partially sequenced members available in public databases. Presently, about 30 of these proteins have been functionally characterized, exhibiting essentially two distinct types of channel properties: (1) specific water transport by the aquaporins, and (2) small neutral solutes transport, such as glycerol by the glycerol facilitators. Sequence alignments were used to predict amino acids and motifs discriminant in channel specificity. The protein sequences were also analyzed using statistical tools (comparisons of means and correspondence analysis). Five key positions were clearly identified where the residues are specific for each functional subgroup and exhibit high dissimilar physico-chemical properties. Moreover, we have found that the putative channels for small neutral solutes clearly differ from the aquaporins by the amino acid content and the length of predicted loop regions, suggesting a substrate filter function for these loops. From these results, we propose a signature pattern for water transport. PMID:9655351

Froger, A.; Tallur, B.; Thomas, D.; Delamarche, C.

1998-01-01

105

Predicting FCAT Reading Scores Using the Reading-Level Indicator  

ERIC Educational Resources Information Center

Multiple regression analysis indicates that the Reading-Level Indicator, a paper-and-pencil test, is a moderately strong predictor for the high-stakes standardized test, the Florida Comprehensive Achievement Test in Reading. Classroom teachers can administer the inexpensive Reading-Level Indicator in a short period of time and use the results as a…

Stanley, Nile; Stanley, Laurel

2011-01-01

106

Groundwater Level Dynamic Prediction Based on Chaos Optimization and Support Vector Machine  

Microsoft Academic Search

Groundwater level has random characters because of influences factors of natural and anthropogenic. Study random prediction model of groundwater level on the basis of groundwater physical process analysis is important to groundwater appraisal. The theory of supporting vector machine based on small-sample machine learning theory is introduced into dynamic prediction of groundwater level. A least square support vector machine groundwater

Jin Liu; Jian-xia Chang; Wen-ge Zhang

2009-01-01

107

J. Mol. Biol. (1997) 265, 445464 Predicting Conserved Water-mediated and Polar  

E-print Network

J. Mol. Biol. (1997) 265, 445­464 Predicting Conserved Water-mediated and Polar Ligand Interactions 48824 on 13 non-homologous proteins, Consolv predicted the conservation ofUSA active-site water. Mispredictions typically involved water molecules predicted to be conserved that were displaced by a polar ligand

108

PLIO: a generic tool for real-time operational predictive optimal control of water networks.  

PubMed

This paper presents a generic tool, named PLIO, that allows to implement the real-time operational control of water networks. Control strategies are generated using predictive optimal control techniques. This tool allows the flow management in a large water supply and distribution system including reservoirs, open-flow channels for water transport, water treatment plants, pressurized water pipe networks, tanks, flow/pressure control elements and a telemetry/telecontrol system. Predictive optimal control is used to generate flow control strategies from the sources to the consumer areas to meet future demands with appropriate pressure levels, optimizing operational goals such as network safety volumes and flow control stability. PLIO allows to build the network model graphically and then to automatically generate the model equations used by the predictive optimal controller. Additionally, PLIO can work off-line (in simulation) and on-line (in real-time mode). The case study of Santiago-Chile is presented to exemplify the control results obtained using PLIO off-line (in simulation). PMID:22097020

Cembrano, G; Quevedo, J; Puig, V; Pérez, R; Figueras, J; Verdejo, J M; Escaler, I; Ramón, G; Barnet, G; Rodríguez, P; Casas, M

2011-01-01

109

Validation of Aircraft Noise Prediction Models at Low Levels of Exposure  

NASA Technical Reports Server (NTRS)

Aircraft noise measurements were made at Denver International Airport for a period of four weeks. Detailed operational information was provided by airline operators which enabled noise levels to be predicted using the FAA's Integrated Noise Model. Several thrust prediction techniques were evaluated. Measured sound exposure levels for departure operations were found to be 4 to 10 dB higher than predicted, depending on the thrust prediction technique employed. Differences between measured and predicted levels are shown to be related to atmospheric conditions present at the aircraft altitude.

Page, Juliet A.; Hobbs, Christopher M.; Plotkin, Kenneth J.; Stusnick, Eric; Shepherd, Kevin P. (Technical Monitor)

2000-01-01

110

“Vodolei” jet level gauge for waste-water disposal systems  

Microsoft Academic Search

A method for determination of the level of an electrically conductive liquid flowing through an open channel by measurement\\u000a of the electrical resistance of a water jet striking the surface is examined.

I. D. Vel't

2000-01-01

111

Trace-level mercury removal from surface water  

SciTech Connect

Many sorbents have been developed for the removal of mercury and heavy metals from waters; however, most of the data published thus far do not address the removal of mercury to the target levels represented in this project. The application to which these sorbents are targeted for use is the removal of mercury from microgram-per-liter levels to low nanogram-per-liter levels. Sorbents with thiouronium, thiol, amine, sulfur, and proprietary functional groups were selected for these studies. Mercury was successfully removed from surface water via adsorption onto Ionac SR-4 and Mersorb resins to levels below the target goal of 12 ng/L in batch studies. A thiol-based resin performed the best, indicating that over 200,000 volumes of water could be treated with one volume of resin. The cost of the resin is approximately $0.24 per 1,000 gal of water.

Klasson, K.T.; Bostick, D.T.

1998-06-01

112

3. View of Santa Elena, looking from water level (Note: ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. View of Santa Elena, looking from water level (Note: The lighthouse of Del Morro is just visible in the background) - Murallas del Viejo San Juan, Baluarte de Santa Elena, San Juan, San Juan Municipio, PR

113

Terrestrial Waters and Sea Level Variations on Interannual Time Scale  

NASA Technical Reports Server (NTRS)

On decadal to multi-decadal time scales, thermal expansion of sea waters and land ice loss are the main contributors to sea level variations. However, modification of the terrestrial water cycle due to climate variability and direct anthropogenic forcing may also affect sea level. For the past decades, variations in land water storage and corresponding effects on sea level cannot be directly estimated from observations because these are almost non-existent at global continental scale. However, global hydrological models developed for atmospheric and climatic studies can be used for estimating total water storage. For the recent years (since mid-2002), terrestrial water storage change can be directly estimated from observations of the GRACE space gravimetry mission. In this study, we analyse the interannual variability of total land water storage, and investigate its contribution to mean sea level variability at interannual time scale. We consider three different periods that, each, depend on data availability: (1) GRACE era (2003-2009), (2) 1993-2003 and (3) 1955-1995. For the GRACE era (period 1), change in land water storage is estimated using different GRACE products over the 33 largest river basins worldwide. For periods 2 and 3, we use outputs from the ISBA-TRIP (Interactions between Soil, Biosphere, and Atmosphere-Total Runoff Integrating Pathways) global hydrological model. For each time span, we compare change in land water storage (expressed in sea level equivalent) to observed mean sea level, either from satellite altimetry (periods 1 and 2) or tide gauge records (period 3). For each data set and each time span, a trend has been removed as we focus on the interannual variability. We show that whatever the period considered, interannual variability of the mean sea level is essentially explained by interannual fluctuations in land water storage, with the largest contributions arising from tropical river basins.

Llovel, W.; Becker, M.; Cazenave, A.; Jevrejeva, S.; Alkama, R.; Decharme, B.; Douville, H.; Ablain, M.; Beckley, B.

2011-01-01

114

Prediction of corrosion rates of water distribution pipelines according to aggressive corrosive water in Korea.  

PubMed

The drinking water network serving Korea has been used for almost 100 years. Therefore, pipelines have suffered various degrees of deterioration due to aggressive environments. The pipe breaks were caused by in-external corrosion, water hammer, surface loading, etc. In this paper, we focused on describing corrosion status in water distribution pipes in Korea and reviewing some methods to predict corrosion rates. Results indicate that corrosive water of lakes was more aggressive than river water and the winter was more aggressive compared to other seasons. The roughness growth rates of Dongbok lake showed 0.23 mm/year. The high variation of corrosion rates is controlled by the aging pipes and smaller diameter. Also the phenolphthalein test on a cementitious core of cement mortar lined ductile cast iron pipe indicated the pipes over 15 years old had lost 50-100% of their lime active cross sectional area. PMID:14982159

Chung, W S; Yu, M J; Lee, H D

2004-01-01

115

Ground-water levels in Arkansas, Spring 1984  

SciTech Connect

The report contains 680 ground-water level measurements made in observation wells in Arkansas in the Spring of 1984. In addition, the report contains well hydrographs relating to the alluvial aquifer and the Sparta Sand and Memphis Sand aquifers, the most important aquifers with respect to ground-water availability and use in Arkansas. 18 refs., 14 tabs.

Edds, J.

1984-01-01

116

Prediction of Socioeconomic Levels Using Cell Phone Records  

Microsoft Academic Search

\\u000a The socioeconomic status of a population or an individual provides an understanding of its access to housing, education, health\\u000a or basic services like water and electricity. In itself, it is also an indirect indicator of the purchasing power and as such\\u000a a key element when personalizing the interaction with a customer, especially for marketing campaigns or offers of new products.

Victor Soto; Vanessa Frias-Martinez; Jesus Virseda; Enrique Frias-Martinez

117

Predicting water consumption habits for seven arsenic-safe water options in Bangladesh  

PubMed Central

Background In Bangladesh, 20 million people are at the risk of developing arsenicosis because of excessive arsenic intake. Despite increased awareness, many of the implemented arsenic-safe water options are not being sufficiently used by the population. This study investigated the role of social-cognitive factors in explaining the habitual use of arsenic-safe water options. Methods Eight hundred seventy-two randomly selected households in six arsenic-affected districts of rural Bangladesh, which had access to an arsenic-safe water option, were interviewed using structured face-to-face interviews in November 2009. Habitual use of arsenic-safe water options, severity, vulnerability, affective and instrumental attitudes, injunctive and descriptive norms, self-efficacy, and coping planning were measured. The data were analyzed using multiple linear regressions. Results Linear regression revealed that self-efficacy (B?=?0.42, SE?=?.03, p?water option (B?=?0.24, SE?=?.04, p?water options (R2?=?0.688). This model proved highly generalizable to all seven arsenic-safe water options investigated, even though habitual use of single options were predicted on the basis of parameters estimated without these options. Conclusions This general model for the habitual use of arsenic-safe water options may prove useful to predict other water consumption habits. Behavior-change interventions are derived from the model to promote the habitual use of arsenic-safe water options. PMID:23634950

2013-01-01

118

Predicted Transport Of Pyrethroid Insecticides From An Urban Landscape To Surface Water  

PubMed Central

We developed a simple screening-level model of exposure of aquatic species to pyrethroid insecticides for the lower American River watershed (California, USA). The model incorporated both empirically derived washoff functions based on existing, small-scale precipitation simulations and empirical data on pyrethroid insecticide use and watershed properties for Sacramento County, California. We calibrated the model to in-stream monitoring data and used it to predict daily river pyrethroid concentration from 1995 through 2010. The model predicted a marked increase in pyrethroid toxic units starting in 2000, coincident with an observed watershed-wide increase in pyrethroid use. After 2000, approximately 70% of the predicted total toxic unit exposure in the watershed was associated with the pyrethroids bifenthrin and cyfluthrin. Pyrethroid applications for above-ground structural pest control on the basis of suspension concentrate product formulations accounted for greater than 97% of the predicted total toxic unit exposure. Projected application of mitigation strategies, such as curtailment of structural perimeter band and barrier treatments as recently adopted by the California Department of Pesticide Regulation, reduced predicted total toxic unit exposure by 84%. The model also predicted that similar reductions in surface water concentrations of pyrethroids could be achieved through a switch from suspension concentrate categorized products to emulsifiable concentrate categorized products without restrictions on current use practice. Even with these mitigation actions, the predicted concentration of some pyrethroids would continue to exceed chronic aquatic life criteria. PMID:24115122

Jorgenson, Brant; Brown, Larry; Fleishman, Erica; Macneale, Kate; Schlenk, Daniel; Scholz, Nat; Spromberg, Julann; Werner, Inge; Weston, Don; Young, Thomas M.; Zhang, Minghua; Zhao, Qingfu

2014-01-01

119

Inter-comparison of time series models of lake levels predicted by several modeling strategies  

NASA Astrophysics Data System (ADS)

Five modeling strategies are employed to analyze water level time series of six lakes with different physical characteristics such as shape, size, altitude and range of variations. The models comprise chaos theory, Auto-Regressive Integrated Moving Average (ARIMA) - treated for seasonality and hence SARIMA, Artificial Neural Networks (ANN), Gene Expression Programming (GEP) and Multiple Linear Regression (MLR). Each is formulated on a different premise with different underlying assumptions. Chaos theory is elaborated in a greater detail as it is customary to identify the existence of chaotic signals by a number of techniques (e.g. average mutual information and false nearest neighbors) and future values are predicted using the Nonlinear Local Prediction (NLP) technique. This paper takes a critical view of past inter-comparison studies seeking a superior performance, against which it is reported that (i) the performances of all five modeling strategies vary from good to poor, hampering the recommendation of a clear-cut predictive model; (ii) the performances of the datasets of two cases are consistently better with all five modeling strategies; (iii) in other cases, their performances are poor but the results can still be fit-for-purpose; (iv) the simultaneous good performances of NLP and SARIMA pull their underlying assumptions to different ends, which cannot be reconciled. A number of arguments are presented including the culture of pluralism, according to which the various modeling strategies facilitate an insight into the data from different vantages.

Khatibi, R.; Ghorbani, M. A.; Naghipour, L.; Jothiprakash, V.; Fathima, T. A.; Fazelifard, M. H.

2014-04-01

120

RECIRCULATION PROCESS OF DEMINERALIZATION WATER TREATMENT PLANT TO REDUCE CONDUCTIVITY LEVEL OF WATER  

E-print Network

Demineralization Water Treatment Plant serves to treat water that has been filtered at the Water Treatment Plant to be "good quality water " with the process of reverse osmosis. The initial design of Demineralization Water Treatment Plant in Pemaron – Bali Gas Turbine is to produce water that have conductivity level in 15 microsimens / cm, which is used for gas turbine cooling water system. At the moment we are planning to install Hydrogen Plant, it turns out this equipment takes raw water with a maximum conductivity of 5 microsimens / cm. So the product of Demineralization Water Treatment Plant is unable. Do a little innovation in production process of Demineralization Water Treatment Plant, namely recirculation, so that it can reduce the value conductivity to below 5 microsimens / cm. From result of laboratory test, it can be concluded that conductivity water after recirculation process is 2 microsimens / cm, thus meet requirement and can be used as raw water for Hydrogen Plant

Kukuh Pambudi; Widi Nurcahyo; K. Adi Dharma; W Tantrawan

121

VEHICLE DYNAMICS MODEL FOR PREDICTING MAXIMUM TRUCK ACCELERATION LEVELS  

E-print Network

that were collected along the Smart Road test facility at Virginia Tech utilizing a truck and trailer for 10, the percentage of trucks, and the level of congestion along the roadway section. Although the Highway Capacity collected along the Smart Road test facility. In order to demonstrate the applicability of the model

Rakha, Hesham A.

122

Predicting the Proficiency Level of Language Learners Using Lexical Indices  

ERIC Educational Resources Information Center

This study explores how second language (L2) texts written by learners at various proficiency levels can be classified using computational indices that characterize lexical competence. For this study, 100 writing samples taken from 100 L2 learners were analyzed using lexical indices reported by the computational tool Coh-Metrix. The L2 writing…

Crossley, Scott A.; Salsbury, Tom; McNamara, Danielle S.

2012-01-01

123

Orion Crew Member Injury Predictions during Land and Water Landings  

NASA Technical Reports Server (NTRS)

A review of astronaut whole body impact tolerance is discussed for land or water landings of the next generation manned space capsule named Orion. LS-DYNA simulations of Orion capsule landings are performed to produce a low, moderate, and high probability of injury. The paper evaluates finite element (FE) seat and occupant simulations for assessing injury risk for the Orion crew and compares these simulations to whole body injury models commonly referred to as the Brinkley criteria. The FE seat and crash dummy models allow for varying the occupant restraint systems, cushion materials, side constraints, flailing of limbs, and detailed seat/occupant interactions to minimize landing injuries to the crew. The FE crash test dummies used in conjunction with the Brinkley criteria provides a useful set of tools for predicting potential crew injuries during vehicle landings.

Lawrence, Charles; Littell, Justin D.; Fasanella, Edwin L.; Tabiei, Ala

2008-01-01

124

Climate variability in Malawi, part 2: sensitivity and prediction of lake levels  

NASA Astrophysics Data System (ADS)

Southern Africa has only a few large lakes, one of which is Lake Malawi. It forms part of the lower Zambezi catchment and the Great Rift Valley. The lake provides food, energy, transport and recreation to the local people. Inflow to the lake increases through summer (December to April) when the equatorial convection zone lies overhead. An analysis of lake levels in the period 1937-95 has been conducted and changes are related to variations in rainfall and atmospheric conditions. Interannual cycles in the time series are consistent with those found for Zambezi River streamflows, suggesting a degree of regional coherence. Years with high inflow are contrasted with mean conditions using the National Centres for Environmental Prediction reanalysis data for the period since 1958. Composite anomalies of wind fields for wet years reveal a zonal overturning circulation. Low (upper) level westerlies (easterlies) link with a sub-tropical trough in the Mozambique Channel to enhance regional convection and lake inflows. The results provide input to predictive models for Lake Malawi to plan better the management of water resources in this part of Africa.

Jury, M. R.; Gwazantini, M. E.

2002-09-01

125

ELEVATED LEVELS OF SODIUM IN COMMUNITY DRINKING WATER  

EPA Science Inventory

A comparison study of students from towns with differing levels of sodium in drinking water revealed statistically significantly higher blood pressure distributions among the students from the town with high sodium levels. Differences were found in both systolic and diastolic rea...

126

The Dead Sea: Impacts of the Rapidly Declining Water Level and the Expected "Anthropogenic" Meromixis Upon Water Level Stabilization  

NASA Astrophysics Data System (ADS)

The Dead Sea (DS) is a highly perturbed terminal lake experiencing major changes in its limnology. Exploitation of water resources in its drainage basin as well as salt extraction through brine evaporation by Israeli and Jordanian chemical industries have resulted in a decline of its water level by more than 25 meter over the past few decades. The DS current level, which is the lowest surface on Earth, is 418 meters below mean sea level, and the level continues to drop at a rate of about 1 m/yr. This represents annual water deficient of about 650 MCM/yr, which is equivalent to more than a third and a half of the water consumptions in Israel and Jordan, respectively. The declining water level is having negative environmental impacts on the lake's surroundings such as exposure of large mud flats and development of sinkholes in the vicinity of the lake. Yet, it is unlikely that in this water scarce region, stabilization of the DS level would be achieved through new freshwater allocation. Introduction of seawater, which is being considered today as a mean of stabilizing or raising lake level, will however have other environmental impacts, including changes in the DS chemical composition. We present a study providing forecast for the evolution of the DS under different operational scenarios, including conveyance of seawater from the Red Sea. The impact of increasing inflows (fresh or seawater) on the lake's dynamics is considered. All scenarios assumed continuation of operation of the chemical plants. Modeling was carried out using the modified 1-D POM-based code adopted for the DS chemistry. Long term dilution and the development of meromixis is expected to occur when lake level is raised. However, we show that meromixis would occur also when inflow volumes are smaller but enough to stabilize water level or decrease the current rate of water level decline. This seemingly unlikely behavior of a terminal lake experiencing a negative or a balanced water regime will be due to the continued operation of the chemical industries. Stratification develops because of excess inflow over evaporation, while water level decline occurs due to brine withdrawal from the hypolimnion by the industries. Anthropogenic impact would thus continue to control the DS evolution, even if lake level is stabilized. If the additional inflow is derived from seawater, the anthropogenic impact on the DS evolution would be even more pronounced.

Gavrieli, I.; Dvorkin, Y.; Lensky, N. G.; Lyakhovsky, V.

2006-12-01

127

Effects of water turbidity and salt concentration levels on penetration of solar radiation under water  

SciTech Connect

Two large, outdoor tanks were constructed in order to investigate the effects of water turbidity and salt concentration levels at various depths of water on penetration of solar radiation. These experiments were followed by a laboratory investigation that measured spectral transmittance and the extinction coefficient of water at different salt concentrations and turbidity levels. Both the outdoor and laboratory results indicate that the salt concentration level does not significantly affect solar radiation penetration. However, water clarity, quantified in terms of the turbidity level, plays a critical role on the magnitude of the solar radiation penetration, with the effect of turbidity on penetration increasing with the depth of water. A best-fit model is developed that gives the solar radiation penetration as a function of turbidity level and depth of water.

Wang, J.; Seyed-Yagoobi, J. (Texas A M Univ., College Station, TX (United States))

1994-05-01

128

Predicting airborne particle levels aboard Washington State school buses  

NASA Astrophysics Data System (ADS)

School buses contribute substantially to childhood air pollution exposures yet they are rarely quantified in epidemiology studies. This paper characterizes fine particulate matter (PM 2.5) aboard school buses as part of a larger study examining the respiratory health impacts of emission reducing retrofits. To assess onboard concentrations, continuous PM 2.5 data were collected during 85 trips aboard 43 school buses during normal driving routines, and aboard hybrid lead vehicles traveling in front of the monitored buses during 46 trips. Ordinary and partial least squares regression models for PM 2.5 onboard buses were created with and without control for roadway concentrations, which were also modeled. Predictors examined included ambient PM 2.5 levels, ambient weather, and bus and route characteristics. Average concentrations aboard school buses (21 ?g m -3) were four and two-times higher than ambient and roadway levels, respectively. Differences in PM 2.5 levels between the buses and lead vehicles indicated an average of 7 ?g m -3 originating from the bus's own emission sources. While roadway concentrations were dominated by ambient PM 2.5, bus concentrations were influenced by bus age, diesel oxidative catalysts, and roadway concentrations. Cross-validation confirmed the roadway models but the bus models were less robust. These results confirm that children are exposed to air pollution from the bus and other roadway traffic while riding school buses. In-cabin air pollution is higher than roadway concentrations and is likely influenced by bus characteristics.

Adar, Sara D.; Davey, Mark; Sullivan, James R.; Compher, Michael; Szpiro, Adam; Sally Liu, L.-J.

129

Predicting Airborne Particle Levels Aboard Washington State School Buses  

PubMed Central

School buses contribute substantially to childhood air pollution exposures yet they are rarely quantified in epidemiology studies. This paper characterizes fine particulate matter (PM2.5) aboard school buses as part of a larger study examining the respiratory health impacts of emission-reducing retrofits. To assess onboard concentrations, continuous PM2.5 data were collected during 85 trips aboard 43 school buses during normal driving routines, and aboard hybrid lead vehicles traveling in front of the monitored buses during 46 trips. Ordinary and partial least square regression models for PM2.5 onboard buses were created with and without control for roadway concentrations, which were also modeled. Predictors examined included ambient PM2.5 levels, ambient weather, and bus and route characteristics. Concentrations aboard school buses (21 ?g/m3) were four and two-times higher than ambient and roadway levels, respectively. Differences in PM2.5 levels between the buses and lead vehicles indicated an average of 7 ?g/m3 originating from the bus's own emission sources. While roadway concentrations were dominated by ambient PM2.5, bus concentrations were influenced by bus age, diesel oxidative catalysts, and roadway concentrations. Cross validation confirmed the roadway models but the bus models were less robust. These results confirm that children are exposed to air pollution from the bus and other roadway traffic while riding school buses. In-cabin air pollution is higher than roadway concentrations and is likely influenced by bus characteristics. PMID:18985175

Adar, Sara D.; Davey, Mark; Sullivan, James R.; Compher, Michael; Szpiro, Adam; Liu, L.-J. Sally

2008-01-01

130

Real time prediction of sea level anomaly data with the Prognocean system - comparison of results obtained using different prediction techniques  

NASA Astrophysics Data System (ADS)

Prognocean is a near-real time modeling and prediction system elaborated and based at University of Wroclaw, Poland. It operates on gridded Sea Level Anomaly (SLA) data obtained from the Archiving, Validation and Interpretation of Satellite Oceanographic data (AVISO), France. The data acquisition flow from AVISO to Prognocean is entirely automatic and is implemented in Python. The core of the system - including data pre-processing, modeling, prediction, validation and visualization procedures - is composed of a series of R scripts that are interrelated and work at three levels of generalization. The objective of the work presented here is to show the results of our numerical experiment that have been carried out since early 2012. Four prediction models have been implemented to date: (1) extrapolation of polynomial-harmonic model and the extrapolation of polynomial-harmonic model with (2) autoregressive model, (3) threshold autoregressive model and (4) autocovariance procedure. Although the presentation is limited to four models and their predictive skills, Prognocean consists of modules and hence new techniques may be plugged in at any time. In this paper, the comparison of the results into forecasting sea level anomaly maps is presented. Along with sample predictions, with various lead times up to two weeks, we present and discuss a set of root mean square prediction error maps computed in real time after the observations have been available. We identified areas where linear prediction models reveal considerable errors, which may indicate a non-linear mode of sea level change. In addition, we have identified an agreement between the spatial pattern of large prediction errors and the spatial occurrence of key mesoscale ocean eddies.

Mizinski, Bartlomiej; Niedzielski, Tomasz; Kosek, Wieslaw

2013-04-01

131

Analysis for water level data for Everglades National Park, Florida  

USGS Publications Warehouse

Stage-duration curves were developed for five gaging stations in Everglades National Park, Florida. Four of the five curves show similar characteristics with an increase in the slope when the water level is below land surface. Monthly stage-duration curves, developed for one of the stations, reflect the seasonal trends of the water level. Recession curves were prepared for the same five stations. These curves represent the average water-level decline during periods of little or no rainfall. They show the decline in level at the end of 10, 20, and 60 days for any given initial stage. A family of curves was also prepared to give the recession from various initial stages for any period up to 60 days.

Buchanan, T.J.; Hartwell, J.H.

1972-01-01

132

Predicting gene expression levels from codon biases in ?-proteobacterial genomes  

PubMed Central

Predicted highly expressed (PHX) genes in five currently available high G+C complete ?-proteobacterial genomes are analyzed. These include: the nitrogen-fixing plant symbionts Sinorhizobium meliloti (SINME) and Mesorhizobium loti (MESLO), the nonpathogenic aquatic bacterium Caulobacter crescentus (CAUCR), the plant pathogen Agrobacterium tumefaciens (AGRTU), and the mammalian pathogen Brucella melitensis (BRUME). Three of these genomes, SINME, AGRTU, and BRUME, contain multiple chromosomes or megaplasmids (>1 Mb length). PHX genes in these genomes are concentrated mainly in the major (largest) chromosome with few PHX genes found in the secondary chromosomes and megaplasmids. Tricarboxylic acid cycle and aerobic respiration genes are strongly PHX in all five genomes, whereas anaerobic pathways of glycolysis and fermentation are mostly not PHX. Only in MESLO (but not SINME) and BRUME are most glycolysis genes PHX. Many flagellar genes are PHX in MESLO and CAUCR, but mostly are not PHX in SINME and AGRTU. The nonmotile BRUME also carries many flagellar genes but these are generally not PHX and all but one are located in the second chromosome. CAUCR stands out among available prokaryotic genomes with 25 PHX TonB-dependent receptors. These are putatively involved in uptake of iron ions and other nonsoluble compounds. PMID:12775761

Karlin, Samuel; Barnett, Melanie J.; Campbell, Allan M.; Fisher, Robert F.; Mrázek, Jan

2003-01-01

133

Prediction of Turbulent Jet Mixing Noise Reduction by Water Injection  

NASA Technical Reports Server (NTRS)

A one-dimensional control volume formulation is developed for the determination of jet mixing noise reduction due to water injection. The analysis starts from the conservation of mass, momentum and energy for the confrol volume, and introduces the concept of effective jet parameters (jet temperature, jet velocity and jet Mach number). It is shown that the water to jet mass flow rate ratio is an important parameter characterizing the jet noise reduction on account of gas-to-droplet momentum and heat transfer. Two independent dimensionless invariant groups are postulated, and provide the necessary relations for the droplet size and droplet Reynolds number. Results are presented illustrating the effect of mass flow rate ratio on the jet mixing noise reduction for a range of jet Mach number and jet Reynolds number. Predictions from the model show satisfactory comparison with available test data on perfectly expanded hot supersonic jets. The results suggest that significant noise reductions can be achieved at increased flow rate ratios.

Kandula, Max

2008-01-01

134

Multiple metals predict prolactin and thyrotropin (TSH) levels in men  

SciTech Connect

Exposure to a number of metals can affect neuroendocrine and thyroid signaling, which can result in adverse effects on development, behavior, metabolism, reproduction, and other functions. The present study assessed the relationship between metal concentrations in blood and serum prolactin (PRL) and thyrotropin (TSH) levels, markers of dopaminergic, and thyroid function, respectively, among men participating in a study of environmental influences on male reproductive health. Blood samples from 219 men were analyzed for concentrations of 11 metals and serum levels of PRL and TSH. In multiple linear regression models adjusted for age, BMI and smoking, PRL was inversely associated with arsenic, cadmium, copper, lead, manganese, molybdenum, and zinc, but positively associated with chromium. Several of these associations (Cd, Pb, Mo) are consistent with limited studies in humans or animals, and a number of the relationships (Cr, Cu, Pb, Mo) remained when additionally considering multiple metals in the model. Lead and copper were associated with non-monotonic decrease in TSH, while arsenic was associated with a dose-dependent increase in TSH. For arsenic these findings were consistent with recent experimental studies where arsenic inhibited enzymes involved in thyroid hormone synthesis and signaling. More research is needed for a better understanding of the role of metals in neuroendocrine and thyroid function and related health implications.

Meeker, John D., E-mail: meekerj@umich.edu [Department of Environmental Health Sciences, University of Michigan School of Public Health, 6635 SPH Tower, 109 S. Observatory St., Ann Arbor, MI 48109 (United States); Rossano, Mary G. [Department of Animal and Food Sciences, University of Kentucky, Lexington, KY (United States)] [Department of Animal and Food Sciences, University of Kentucky, Lexington, KY (United States); Protas, Bridget [Department of Epidemiology, Michigan State University, East Lansing, MI (United States)] [Department of Epidemiology, Michigan State University, East Lansing, MI (United States); Diamond, Michael P.; Puscheck, Elizabeth [Department of Obstetrics and Gynecology, Wayne State University, Detroit, MI (United States)] [Department of Obstetrics and Gynecology, Wayne State University, Detroit, MI (United States); Daly, Douglas [Grand Rapids Fertility and IVF, Grand Rapids, MI (United States)] [Grand Rapids Fertility and IVF, Grand Rapids, MI (United States); Paneth, Nigel [Department of Obstetrics and Gynecology, Michigan State University, East Lansing, MI (United States)] [Department of Obstetrics and Gynecology, Michigan State University, East Lansing, MI (United States); Wirth, Julia J. [Department of Epidemiology, Michigan State University, East Lansing, MI (United States) [Department of Epidemiology, Michigan State University, East Lansing, MI (United States); Department of Obstetrics and Gynecology, Michigan State University, East Lansing, MI (United States)

2009-10-15

135

Multiple Metals Predict Prolactin and Thyrotropin (TSH) Levels in Men  

PubMed Central

Exposure to a number of metals can affect neuroendocrine and thyroid signaling, which can result in adverse effects on development, behavior, metabolism, reproduction, and other functions. The present study assessed the relationship between metal concentrations in blood and serum prolactin (PRL) and thyrotropin (TSH) levels, markers of dopaminergic and thyroid function, respectively, among men participating in a study of environmental influences on male reproductive health. Blood samples from 219 men were analyzed for concentrations of 11 metals and serum levels of PRL and TSH. In multiple linear regression models adjusted for age, BMI and smoking, PRL was inversely associated with arsenic, cadmium, copper, lead, manganese, molybdenum, and zinc, but positively associated with chromium. Several of these associations (Cd, Pb, Mo) are consistent with limited studies in humans or animals, and a number of the relationships (Cr, Cu, Pb, Mo) remained when additionally considering multiple metals in the model. Lead and copper were associated with non-monotonic decreases in TSH, while arsenic was associated with a dose-dependent increase in TSH. For arsenic these findings were consistent with recent experimental studies where arsenic inhibited enzymes involved in thyroid hormone synthesis and signaling. More research is needed for a better understanding of the role of metals in neuroendocrine and thyroid function and related health implications. PMID:19595304

Meeker, John D.; Rossano, Mary G.; Protas, Bridget; Diamond, Michael P.; Puscheck, Elizabeth; Daly, Douglas; Paneth, Nigel; Wirth, Julia J.

2009-01-01

136

Level of evidence for reasonable assurance guides to prediction  

SciTech Connect

Over the past years, the DOE Contractors have produced a great deal of work that has been extensively reviewed and criticized by the Nuclear Regulatory Commission (NRC), the Materials Review Board (MRB) of the DOE, the Advisory Committee on Reactor Safeguards (ACRS), and the technical support group at Brookhaven National Laboratory (BNL). Common aspects of the reviews and criticisms have provided information on the level of evidence required by the scientific community to defend performance claims. Important indicators of the type of evidence that the NRC will require for favorable decisions of reasonable assurance also can be obtained from 10 CFR 60 and its rationale, from NRC guides and Technical Position papers, from past reviews of the DOE programs by NRC Contractors, and from the use of reasonable assurance by the NRC in its 1984 Waste Confidence Decision. This report describes general concepts related to the acceptability and unacceptability of the level of evidence needed to defend claims with reasonable assurance. The concepts were formulated on the basis of analyses of the NRC position papers, and of common aspects of the reviews and criticisms dealing with compliance demonstration.

Schweitzer, D.G.; Sastre, C.

1987-04-01

137

Water quality prediction for recreational use of Kranji Reservoir, Singapore  

E-print Network

Singapore has been making efforts in relieving its water shortage problems and has been making great progress through its holistic water management. Via the Active, Beautiful, Clean Waters (ABC Waters) Programme, Singapore's ...

Zhang, Yangyue

2011-01-01

138

Water pair potential of near spectroscopic accuracy. II. Vibrationrotationtunneling levels of the water dimer  

E-print Network

Water pair potential of near spectroscopic accuracy. II. Vibration­rotation­tunneling levels of the rotational quantum numbers J and K 2 show that the SAPT-5s water pair potential presented in the preceding of the water dimer G. C. Groenenboom, P. E. S. Wormer, and A. van der Avoird Institute of Theoretical Chemistry

139

CALCULATION OF NONLINEAR CONFIDENCE AND PREDICTION INTERVALS FOR GROUND-WATER FLOW MODELS.  

USGS Publications Warehouse

A method is derived to efficiently compute nonlinear confidence and prediction intervals on any function of parameters derived as output from a mathematical model of a physical system. The method is applied to the problem of obtaining confidence and prediction intervals for manually-calibrated ground-water flow models. To obtain confidence and prediction intervals resulting from uncertainties in parameters, the calibrated model and information on extreme ranges and ordering of the model parameters within one or more independent groups are required. If random errors in the dependent variable are present in addition to uncertainties in parameters, then calculation of prediction intervals also requires information on the extreme range of error expected. A simple Monte Carlo method is used to compute the quantiles necessary to establish probability levels for the confidence and prediction intervals. Application of the method to a hypothetical example showed that inclusion of random errors in the dependent variable in addition to uncertainties in parameters can considerably widen the prediction intervals.

Cooley, Richard, L.; Vecchia, Aldo, V.

1987-01-01

140

Regional and State Level Water Scarcity Report: Northeast United States  

NASA Astrophysics Data System (ADS)

There are an abundance of large-scale, coarse resolution global water scarcity studies, but the existing literature fails to address regional and state specific scarcity measures. Moreover, while environmental water requirements are an integral factor in the development and implementation of sustainable water management practices, only recently has this notion been introduced to water scarcity research. In this paper, we argue that developing a preliminary measure of water scarcity, at the regional and state levels, will allow for more informed policy development. The goal of this study is to generate a more comprehensive understanding of water scarcity in the Northeast, by gathering fine scale data, applying a consistent methodology to the calculation of a scarcity index, and analyzing the results to see relative trends in spatio-temporal water scarcity. Public supply, irrigation, rural, industrial and thermo-power withdrawals have been compiled from USGS state water use publications from 1950 to 1985. Using the WBMplus water model runoff data, state specific in-stream environmental water requirements were calculated using the accepted hydro-ecological methodology. Water scarcity was then calculated as a ratio of water withdrawals to total available water minus environmental flow requirements for the system. In so doing, this study generates a spatially explicit and temporally varying water scarcity indicator (WSI) for the Northeastern United States between 1950 and 2000 at the regional and state levels at a five-year time interval. Calculation of a spatial and temporal water scarcity indicator enabled us to identify regions and specific states that were: slightly exploited (WSI < 0.3), moderately exploited (0.31.0). The minimum environmental water requirements to maintain in-stream aquatic and riparian ecosystems for the Northeastern states ranged between 27.5 to 36.3 percent of the mean annual runoff within Vermont and Maryland, respectively. The regional WSI values ranged between 0.199 in 1950 and 0.512 in 1995, indicating increasing water scarcity over time as population and employment growth has placed greater demands on water resources. Additionally, our study revealed that in 1980, Massachusetts, Pennsylvania and New Jersey scarcity levels were 0.733, 0.790 and 0.857, respectively. Although the Northeastern United States is commonly perceived as a water rich region, moderate to heavily exploited levels of water stress were observed over the time period when a finer spatial scale is utilized. Water scarcity indicator values were disaggregated by state for each time period and illustrated using a series of maps. Additional descriptive statistics were used to elucidate the differences in water scarcity between states over time.

Nicoletti, C. K.; Lopez-Morales, C. A.; Hoover, J. H.; Voigt, B. G.; Vorosmarty, C. J.; Mohammed, I. N.

2010-12-01

141

Prediction of Solid Polycyclic Aromatic Hydrocarbons Solubility in Water with the NRTL-PR Model  

E-print Network

Prediction of Solid Polycyclic Aromatic Hydrocarbons Solubility in Water with the NRTL-PR Model conditions. The aim of this work is to explore the capability of the NRTL-PR model to predict the solubility consider the prediction of the solid solubility of PAH in water, by fitting group parameters either only

Paris-Sud XI, Université de

142

Modeling water ages and thermal structure of Lake Mead under changing water levels  

Microsoft Academic Search

Water age and thermal structure of Lake Mead were modeled using the 3-dimensional hydrodynamic Environmental Fluid Dynamics Code (EFDC). The model was calibrated using observed data from 2005 and then applied to simulate 2 scenarios: high-stage with an initial water level of 370.0 m and low-stage with a projected initial water level of 320.0 m. The high-stage simulation described predrought

Yiping Li; Kumud Acharya; Dong Chen; Mark Stone

2010-01-01

143

Perchlorate levels in soil and waters from the Atacama Desert.  

PubMed

Perchlorate is an anion that originates as a contaminant in ground and surface waters. The presence of perchlorate in soil and water samples from northern Chile (Atacama Desert) was investigated by ion chromatography-electrospray mass spectrometry. Results indicated that perchlorate was found in five of seven soils (cultivated and uncultivated) ranging from 290 ± 1 to 2,565 ± 2 ?g/kg. The greatest concentration of perchlorate was detected in Humberstone soil (2,565 ± 2 ?g/kg) associated with nitrate deposits. Perchlorate levels in Chilean soils are greater than those reported for uncultivated soils in the United States. Perchlorate was also found in superficial running water ranging from 744 ± 0.01 to 1,480 ± 0.02 ?g/L. Perchlorate water concentration is 30-60 times greater than levels established by the United States Environmental Protection Agency (24.5 ?g/L) for drinking. PMID:24165784

Calderón, R; Palma, P; Parker, D; Molina, M; Godoy, F A; Escudey, M

2014-02-01

144

Jack-up leveling barge for shallow water rigs  

SciTech Connect

Generally, the only alternative to a shell pad is a shallow water jack-up or a submersible rig. And in some instances, it is impractical to tow these mobile rigs to the location because of the necessary dredging. A possible solution to this problem, devised by Chain Jacks, Inc., is a jack-up leveling barge that extends its legs and pads to the bottom in waters ranging to 35 ft deep, then ballasts down to a depth of 10 ft or so below the surface. The barge-mounted rigs move over the leveling barges, ballast down and start rigging up. At this point, the leveling barge de-ballasts to minimize the load on the legs and mats. Chain Jack says the concept will enable barge mounted rigs to drill in waters ranging from 25 to 35 ft, and the cost will be considerably less than that of jack-ups or submersibles.

Not Available

1982-07-01

145

Daily water level by ENVISAT altimetry of the Amazon River  

NASA Astrophysics Data System (ADS)

Radar Altimetry is a remote sensing technique applied in order to obtain the level of water of the hydrological processes, mostly in remote regions such as in the Amazon basin. However, the altimetry satellites have a limitation in their temporal resolution, which in the case of ENVISAT is 35 days, which prevents the study of short-term hydrological events alert of floods and droughts and etc. Thus, a method of obtaining altimetric daily time series water level, based on a linear model of interpolation by optimization with multi-objective criteria was applied, using data from in situ on pluvial stations, along the Amazon River. The altimetry data validation show accurate results with a RMS of 11 cm, while the estimates carried out by the model obtained 63% of altimetric daily time series water level data with RMS less than 40 cm, thus allowing the use of altimetry data daily at various hydrological studies, hydrodynamic modeling and monitoring of extreme events.

Sousa, A. C.; Pereira, P.; Silva, J. S.; Calmant, S.; Seyler, F.

2013-05-01

146

A physically-based model to predict the water retention curve from basic geotechnical properties  

E-print Network

A physically-based model to predict the water retention curve from basic geotechnical properties M author: Michel Aubertin (michel.aubertin@polymtl.ca) #12;1 A physically-based model to predict the water means to estimate the water retention curve from basic geotechnical properties. A discussion follows

Aubertin, Michel

147

Isoform-level microRNA-155 target prediction using RNA-seq  

PubMed Central

Computational prediction of microRNA targets remains a challenging problem. The existing rule-based, data-driven and expression profiling approaches to target prediction are mostly approached from the gene-level. The increasing availability of RNA-seq data provides a new perspective for microRNA target prediction on the isoform-level. We hypothesize that the splicing isoform is the ultimate effector in microRNA targeting and that the proposed isoform-level approach is capable of predicting non-dominant isoform targets as well as their targeting regions that are otherwise invisible to many existing approaches. To test the hypothesis, we used an iterative expectation maximization (EM) algorithm to quantify transcriptomes at the isoform-level. The performance of the EM algorithm in transcriptome quantification was examined in simulation studies using FluxSimulator. We used joint evidence from isoform-level down-regulation and seed enrichment to predict microRNA-155 targets. We validated our computational approach using results from 149 in-house performed in vitro 3?-UTR assays. We also augmented the splicing database using exon–exon junction evidence, and applied the EM algorithm to predict and quantify 1572 cell line specific novel isoforms. Combined with seed enrichment analysis, we predicted 51 novel microRNA-155 isoform targets. Our work is among the first computational studies advocating the isoform-level microRNA target prediction. PMID:21317189

Deng, Nan; Puetter, Adriane; Zhang, Kun; Johnson, Kristen; Zhao, Zhiyu; Taylor, Christopher; Flemington, Erik K.; Zhu, Dongxiao

2011-01-01

148

The effects of water levels on Two Lake Ontario Wetlands  

USGS Publications Warehouse

Lake Ontario's water levels have been regulated since 1959, after the completion of the St. Lawrence River navigation and hydropower development project. The plan used to guide the regulation (1958-D) has been in effect since 1963 (Bryce, 1982). The purpose of the regulation was to prevent extreme high-water levels which increased erosion on the south shore of Lake Ontario, while protecting the interests of commercial navigation and hydropower production in the St. Lawrence River (T. Brown, personal communication, member of the Board of Control). Major user groups have sought further reductions in the range of lake level fluctuations. However, the biological resources, especially the lake influenced wetlands, benefit from the waterlevel fluctuations. Great Lakes wetlands are the most important habitat for wildlife of the region (Tilton and Schwegler, 1978). We provide information here on the responses of wetland plant communities in two wetlands to changes in lake levels over time.

Busch, Wolf-Dieter N.; Osborn, Ronald G.; Auble, Gregor T.

1990-01-01

149

Predicting population dynamics from the properties of individuals: a cross-level test of dynamic energy budget theory.  

PubMed

Individual-based models (IBMs) are increasingly used to link the dynamics of individuals to higher levels of biological organization. Still, many IBMs are data hungry, species specific, and time-consuming to develop and analyze. Many of these issues would be resolved by using general theories of individual dynamics as the basis for IBMs. While such theories have frequently been examined at the individual level, few cross-level tests exist that also try to predict population dynamics. Here we performed a cross-level test of dynamic energy budget (DEB) theory by parameterizing an individual-based model using individual-level data of the water flea, Daphnia magna, and comparing the emerging population dynamics to independent data from population experiments. We found that DEB theory successfully predicted population growth rates and peak densities but failed to capture the decline phase. Further assumptions on food-dependent mortality of juveniles were needed to capture the population dynamics after the initial population peak. The resulting model then predicted, without further calibration, characteristic switches between small- and large-amplitude cycles, which have been observed for Daphnia. We conclude that cross-level tests help detect gaps in current individual-level theories and ultimately will lead to theory development and the establishment of a generic basis for individual-based models and ecology. PMID:23535615

Martin, Benjamin T; Jager, Tjalling; Nisbet, Roger M; Preuss, Thomas G; Grimm, Volker

2013-04-01

150

Response in the trophic state of stratified lakes to changes in hydrology and water level: potential effects of climate change  

USGS Publications Warehouse

To determine how climate-induced changes in hydrology and water level may affect the trophic state (productivity) of stratified lakes, two relatively pristine dimictic temperate lakes in Wisconsin, USA, were examined. Both are closed-basin lakes that experience changes in water level and degradation in water quality during periods of high water. One, a seepage lake with no inlets or outlets, has a small drainage basin and hydrology dominated by precipitation and groundwater exchange causing small changes in water and phosphorus (P) loading, which resulted in small changes in water level, P concentrations, and productivity. The other, a terminal lake with inlets but no outlets, has a large drainage basin and hydrology dominated by runoff causing large changes in water and P loading, which resulted in large changes in water level, P concentrations, and productivity. Eutrophication models accurately predicted the effects of changes in hydrology, P loading, and water level on their trophic state. If climate changes, larger changes in hydrology and water levels than previously observed could occur. If this causes increased water and P loading, stratified (dimictic and monomictic) lakes are expected to experience higher water levels and become more eutrophic, especially those with large developed drainage basins.

Robertson, Dale M.; Rose, William J.

2011-01-01

151

Prediction of projectile ricochet behavior after water impact.  

PubMed

Although not very common, forensic investigation related to projectile ricochet on water can be required when undesirable collateral damage occurs. Predicting the ricochet behavior of a projectile is challenging owing to numerous parameters involved: impact velocity, incident angle, projectile stability, angular velocity, etc. Ricochet characteristics of different projectiles (K50 BMG, 0.5-cal Ball M2, 0.5-cal AP-T C44, 7.62-mm Ball C21, and 5.56-mm Ball C77) were studied in a pool. The results are presented to assess projectile velocity after ricochet, ricochet angle, and projectile azimuth angle based on impact velocity or incident angle for each projectile type. The azimuth ranges show the highest variability at low postricochet velocity. The critical ricochet angles were ranging from 15 to 30°. The average ricochet angles for all projectiles were pretty close for all projectiles at 2.5 and 10° incident angles for the range of velocities studied. PMID:22536929

Baillargeon, Yves; Bergeron, Guy

2012-11-01

152

[Sodium levels in the Dalmatian water resources in 2003].  

PubMed

The objective of this paper was to analyse the sodium levels in the spring water, surface and groundwater in Dalmatia during 2003. The sodium concentrations were computed from the difference between coefficient K1 (the ratio between the chlorides and sulfates sum and the carbonate hardness) and K2 (the ratio between non-carbonate and carbonate hardness) and carbonate hardness. The average sodium concentrations have been expressed by a median and they ranged from 1.8 mg/L Na to 17.6 mg/L Na in the spring water, in the surface water they ranged from 1.0 to 502 mg/L Na and in the groundwater they ranged from 11.1 mg/L Na to 124.3 mg/L Na. In the spring water the sodium concentrations varied from 32% to 217%, in the surface water from 40% to 159% and in the groundwater from 77.3% to 180%. According to the corrosiveness coefficient K1, 83% of the spring waters are classified as non-corrosive and 17% as water with a low degree of corrosiveness; 84% of the surface waters are classified as non-corrosive water and 16% as very corrosive; all groundwater is classified as very corrosive water. Out of the total of 60 analyzed water resources 64% are classified as hypotensive, 20% as normotensive and 17% as hypertensive water. The drinking water has been defined as hypotensive (<10 mg/L Na), normotensive (from 11 to 20 mg/L Na) and hypertensive (>20 mg/L Na) by relating the sodium concentration projectively with the notion of arterial pressure knowing that an increased sodium concentration in blood increases the blood pressure. From the informatics standpoint the data related to health should be classified into data bases which can serve as a methodological starting point for studying the influence of sodium upon human health. Consequently, epidemiological studies should relate various sodium levels in drinking water to other factors which affect human health. PMID:16808101

Stambuk-Giljanovi?, Nives; Stambuk, Drago

2006-01-01

153

Effect of Increased Water Vapor Levels on TBC Lifetime  

SciTech Connect

To investigate the effect of increased water vapor levels on thermal barrier coating (TBC) lifetime, furnace cycle tests were performed at 1150 C in air with 10 vol.% water vapor (similar to natural gas combustion) and 90 vol.%. Either Pt diffusion or Pt-modified aluminide bond coatings were applied to specimens from the same batch of a commercial second-generation single-crystal superalloy and commercial vapor-deposited yttria-stabilized zirconia (YSZ) top coats were applied. Three coatings of each type were furnace cycled to failure to compare the average lifetimes obtained in dry O{sub 2}, using the same superalloy batch and coating types. Average lifetimes with Pt diffusion coatings were unaffected by the addition of water vapor. In contrast, the average lifetime of Pt-modified aluminide coatings was reduced by more than 50% with 10% water vapor but only slightly reduced by 90% water vapor. Based on roughness measurements from similar specimens without a YSZ coating, the addition of 10% water vapor increased the rate of coating roughening more than 90% water vapor. Qualitatively, the amount of {beta}-phase depletion in the coatings exposed in 10% water vapor did not appear to be accelerated.

Pint, Bruce A [ORNL; Garner, George Walter [ORNL; Lowe, Tracie M [ORNL; Haynes, James A [ORNL; Zhang, Ying [Tennessee Technological University

2011-01-01

154

Low-level measurements of tritium in water.  

PubMed

Using a liquid scintillation counter, an experimental procedure for measuring low-level activity concentrations of tritium in environmental water has been developed by our laboratory, using the electrolytic tritium enrichment. Additionally, some quality tests were applied in order to assure the goodness of the method. Well-known water samples collected in the Tagus River (West of Spain) and the Danube River (Bulgaria), both affected by nuclear plant releases, were analysed and results were compared to previous data. The analytical procedure was applied to drinking water samples from the public water supply of Seville and mineral waters from different springs in Spain in order to characterize its origin. Due to the very low levels of tritium in the analysed samples, some results were reported as lower than the minimum detectable activity concentration (MDA). However, the count rate of these measurements was over the background count rate of LS counter in all the cases. For that reason, an exhaustive discussion about the meaning of the MDA, using an experimental essay, was made in order to establish a rigorous criterion that leads to a reliable value in the case of low-level measurements. PMID:15177365

Villa, M; Manjón, G

2004-01-01

155

Analysis of water level variations in Brazilian basins using GRACE  

NASA Astrophysics Data System (ADS)

A comparison between daily in-situ water level time series measured at ground-based hydrometric stations (HS - 1,899 stations located in twelve Brazilian basins) of the Agência Nacional de Águas (ANA) with vertically-integrated water height anomaly deduced from the Gravity Recovery and Climate Experiment (GRACE) geoid is carried out in Brazil. The equivalent water height (EWH) of 10-day intervals of GRACE models were computed by GRGS/CNES. It is a 6-year analysis (July-2002 to May-2008). The coefficient of determination is computed between the ANA water level and GRACE EWH. Values higher than 0.6 were detected in the following basins: Amazon, north of Paraguay, Tocantins-Araguaia, Western North-East Atlantic and north of the Parnaíba. In the Uruguay (Pampas region) and the west of São Francisco basins, the coefficient of determination is around 0.5 and 0.6. These results were adjusted with a linear transfer function and two second degree polynomials (flood and ebb period) between GRACE EWH and ANA water level. The behavior of these two polynomials is related to the phase difference of the two time series and yielded four different types of responses. This paper shows seven ANA stations that represent these responses and relates them with their hydro-geological domain.

Matos, A.; Blitzkow, D.; Almeida, F.; Costa, S.; Campos, I.; Barbosa, A.

2012-01-01

156

Water-Table Levels and Gradients, Nevada, 1947-2004  

USGS Publications Warehouse

In 1999, the U.S. Environmental Protection Agency began a program to protect the quality of ground water in areas other than ground-water protection areas. These other sensitive ground water areas (OSGWA) are areas that are not currently, but could eventually be, used as a source of drinking water. The OSGWA program specifically addresses existing wells that are used for underground injection of motor-vehicle waste. To help determine whether a well is in an OSGWA, the Nevada Division of Environmental Protection needs statewide information on depth to water and the water table, which partly control the susceptibility of ground water to contamination and contaminant transport. This report describes a study that used available maps and data to create statewide maps of water-table and depth-to-water contours and surfaces, assessed temporal changes in water-table levels, and characterized water-table gradients in selected areas of Nevada. A literature search of published water-table and depth-to-water contours produced maps of varying detail and scope in 104 reports published from 1948 to 2004. Where multiple maps covered the same area, criteria were used to select the most recent, detailed maps that covered the largest area and had plotted control points. These selection criteria resulted in water-table and depth-to-water contours that are based on data collected from 1947 to 2004 being selected from 39 reports. If not already available digitally, contours and control points were digitized from selected maps, entered into a geographic information system, and combined to make a statewide map of water-table contours. Water-table surfaces were made by using inverse distance weighting to estimate the water table between contours and then gridding the estimates. Depth-to-water surfaces were made by subtracting the water-table altitude from the land-surface altitude. Water-table and depth-to-water surfaces were made for only 21 percent of Nevada because of a lack of information for 49 of 232 basins and for most consolidated-rock hydrogeologic units. Depth to water is commonly less than 50 feet beneath valley floors, 50 to 500 feet beneath alluvial fans, and more than 500 feet in some areas such as north-central and southern Nevada. In areas without water-table information, greasewood and mapped ground-water discharge areas are good indicators of depth to water less than 100 feet. The average difference between measured depth to water and depth to water estimated from surfaces was 90 feet. More recent and detailed information may be needed than that presented in this report to evaluate a specific site. Temporal changes in water-table levels were evaluated for 1,981 wells with 10 or more years between the first depth-to-water measurement and last measurement made since 1990. The greatest increases in depth to water occurred where the first measurement was less than 200 feet, where the time between first and last measurements was 40 years or less, and for wells between 100 and 600 feet deep. These characteristics describe production wells where ground water is fairly shallow in recently developing areas such as the Las Vegas and Reno metropolitan areas. In basins with little pumping, 90 percent of the changes during the past 100 years are within ?20 feet, which is about the natural variation in the water table due to changes in the climate and recharge. Gradients in unconsolidated sediments of the Great Basin are generally steep near mountain fronts, shallow beneath valley floors, and depend on variables such as the horizontal hydraulic conductivity of adjacent consolidated rocks and recharge. Gradients beneath alluvial fans and valley floors at 58 sites were correlated with selected variables to identify those variables that are statistically related. Water-table measurements at three sites were used to characterize the water table between the valley floor and consolidated rock. Water-table gradients beneath alluvial fan

Lopes, Thomas J.; Buto, Susan G.; Smith, J. LaRue; Welborn, Toby L.

2006-01-01

157

Predicting Homework Time Management at the Secondary School Level: A Multilevel Analysis  

ERIC Educational Resources Information Center

The purpose of this study is to test empirical models of variables posited to predict homework time management at the secondary school level. Student- and class-level predictors of homework time management were analyzed in a survey of 1895 students from 111 classes. Most of the variance in homework time management occurred at the student level,…

Xu, Jianzhong

2010-01-01

158

Predicting homework time management at the secondary school level: A multilevel analysis  

Microsoft Academic Search

The purpose of this study is to test empirical models of variables posited to predict homework time management at the secondary school level. Student- and class-level predictors of homework time management were analyzed in a survey of 1895 students from 111 classes. Most of the variance in homework time management occurred at the student level, with parent education appearing as

Jianzhong Xu

2010-01-01

159

Average County-Level IQ Predicts County-Level Disadvantage and Several County-Level Mortality Risk Rates  

ERIC Educational Resources Information Center

Research utilizing individual-level data has reported a link between intelligence (IQ) scores and health problems, including early mortality risk. A growing body of evidence has found similar associations at higher levels of aggregation such as the state- and national-level. At the same time, individual-level research has suggested the…

Barnes, J. C.; Beaver, Kevin M.; Boutwell, Brian B.

2013-01-01

160

Heavy Metal Levels in Fish from Coastal Waters of Uruguay  

Microsoft Academic Search

Copper, mercury, and zinc levels were determined in muscle and liver (N?=?163) of seven fish species caught in coastal waters off Montevideo and Piriápolis (control site): Odontesthes spp., Mugil platanus, Micropogonias furnieri, Urophycis brasiliensis, Cynoscion guatucupa, Menticirrhus americanus, and Mustelus schmitti. The local population commonly uses these species for consumption. Heavy metal concentrations determined in this study were generally below

F. Viana; R. Huertas; E. Danulat

2005-01-01

161

Multi-level learning: improving the prediction of protein, domain and residue interactions by allowing information flow between levels  

PubMed Central

Background Proteins interact through specific binding interfaces that contain many residues in domains. Protein interactions thus occur on three different levels of a concept hierarchy: whole-proteins, domains, and residues. Each level offers a distinct and complementary set of features for computationally predicting interactions, including functional genomic features of whole proteins, evolutionary features of domain families and physical-chemical features of individual residues. The predictions at each level could benefit from using the features at all three levels. However, it is not trivial as the features are provided at different granularity. Results To link up the predictions at the three levels, we propose a multi-level machine-learning framework that allows for explicit information flow between the levels. We demonstrate, using representative yeast interaction networks, that our algorithm is able to utilize complementary feature sets to make more accurate predictions at the three levels than when the three problems are approached independently. To facilitate application of our multi-level learning framework, we discuss three key aspects of multi-level learning and the corresponding design choices that we have made in the implementation of a concrete learning algorithm. 1) Architecture of information flow: we show the greater flexibility of bidirectional flow over independent levels and unidirectional flow; 2) Coupling mechanism of the different levels: We show how this can be accomplished via augmenting the training sets at each level, and discuss the prevention of error propagation between different levels by means of soft coupling; 3) Sparseness of data: We show that the multi-level framework compounds data sparsity issues, and discuss how this can be dealt with by building local models in information-rich parts of the data. Our proof-of-concept learning algorithm demonstrates the advantage of combining levels, and opens up opportunities for further research. Availability The software and a readme file can be downloaded at . The programs are written in Java, and can be run on any platform with Java 1.4 or higher and Apache Ant 1.7.0 or higher installed. The software can be used without a license. PMID:19656385

Yip, Kevin Y; Kim, Philip M; McDermott, Drew; Gerstein, Mark

2009-01-01

162

Exploring predictions of safe operating spaces for human water use  

NASA Astrophysics Data System (ADS)

In the Nature article 'A safe operating space for humanity', Rockström et al. (2009) introduce the idea of a safe space for human activities that will not push the planet out of the 'Holocene state'. Rockström et al. have identified nine earth-system processes and associated thresholds which, if crossed, are expected to generate unacceptable environmental change. Rockström et al. (2009) focus on the scientific prediction of these thresholds. Concerning the use of these boundaries for public policy, these authors limit their efforts to concluding that the evidence so far suggests that, as long as the thresholds are not crossed, humanity has the freedom to pursue long-term social and economic development. The approach advocated by Rockström et al. (2009) is plagued by two related problems: uncertainty and dynamic complexity (Molden, 2009; Brewer, 2009). The latter problem addresses the reductionist approach of Rockström et al and argues, in opposition, that the limits on each of the nine earth-system processes are co-depended and thus the safe operating space constitutes a single multi-dimensional space that can only be identified holistically. The first problem is that our current scientific knowledge and understanding of the earth system is incomplete and partly contested. A majority of the authors reacting on the global limit concept do however emphasize their relevance as "targets for policy makers". However, the two problems imply that the establishment of predicted global limits as a substantive base for public policy is meaningless. Still, the presence of scientific uncertainty and dynamic complexity and thus the omnipresence of unpredictability need not be used as an excuse to ignore the importance of a substantive grounding of these policies. In this paper, we argue and show how despite dynamic complexity and irreducible uncertainty, policies can be designed, tested, and shown to be effective in reaching broad social goals related to social and economic development. To this end, we utilize ANEMI (Davies and Simonovic, 2011), a dynamic impact assessment model of the planetary fresh water cycle and related systems (e.g. economy, land use, population, and climate). We assess the dynamics of this model over a broad range of different uncertainties; we identify combinations of uncertainties that produce dynamics that threaten the flourishing of humanity, and use these insights to develop public policies that can counteract these undesirable dynamics.

Kwakkel, J. H.; Timmermans, J. S.

2012-04-01

163

Protinfo PPC: A web server for atomic level prediction of protein complexes  

Microsoft Academic Search

Protinfo PPC' (Prediction of Protein Complex) is a web server that predicts atomic level structures of interacting proteins from their amino-acid sequences. It uses the interolog method to search for experimental protein complex structures that are homologous to the input sequences submitted by a user. These structures are then used as starting templates to generate protein complex models, which are

Weerayuth Kittichotirat; Michal Guerquin; Roger Eugene Bumgarner; Ram Samudrala

2009-01-01

164

A Bayesian network to predict coastal vulnerability to sea level rise  

USGS Publications Warehouse

Sea level rise during the 21st century will have a wide range of effects on coastal environments, human development, and infrastructure in coastal areas. The broad range of complex factors influencing coastal systems contributes to large uncertainties in predicting long-term sea level rise impacts. Here we explore and demonstrate the capabilities of a Bayesian network (BN) to predict long-term shoreline change associated with sea level rise and make quantitative assessments of prediction uncertainty. A BN is used to define relationships between driving forces, geologic constraints, and coastal response for the U.S. Atlantic coast that include observations of local rates of relative sea level rise, wave height, tide range, geomorphic classification, coastal slope, and shoreline change rate. The BN is used to make probabilistic predictions of shoreline retreat in response to different future sea level rise rates. Results demonstrate that the probability of shoreline retreat increases with higher rates of sea level rise. Where more specific information is included, the probability of shoreline change increases in a number of cases, indicating more confident predictions. A hindcast evaluation of the BN indicates that the network correctly predicts 71% of the cases. Evaluation of the results using Brier skill and log likelihood ratio scores indicates that the network provides shoreline change predictions that are better than the prior probability. Shoreline change outcomes indicating stability (-1 1 m/yr) was not well predicted. We find that BNs can assimilate important factors contributing to coastal change in response to sea level rise and can make quantitative, probabilistic predictions that can be applied to coastal management decisions. Copyright ?? 2011 by the American Geophysical Union.

Gutierrez, B.T.; Plant, N.G.; Thieler, E.R.

2011-01-01

165

Mountain Pine Beetle Impact on Stand-level Water Balance  

NASA Astrophysics Data System (ADS)

The recent mountain pine beetle (MPB) epidemic has disturbed millions of hectares throughout the Rocky Mountain West. The most persistent effects of MPB infestation on the stand-level water balance are likely concomitant with the grey stage of the disturbance cycle. The grey stage occurs within 3 to 5 years of the initial infestation after the needles of an infected tree have turned red and fallen off due to tree death. Large numbers of grey-stage trees in a stand may remain on the landscape for up to 20 years, until windthrow or another disturbance sends them to the forest floor. The greater temporal persistence of the grey stage over antecedent stages suggested that an examination of the grey stage would best capture long-term effects of MPB disturbance on the forest water balance. In this study we hypothesized that changes to the forest canopy associated with MPB disturbance may affect the stand-level water balance. The needle loss and windthrow that follows MPB disturbance is expected to increase the amount of precipitation reaching the forest floor. Additionally, overstory evapotranspiration (ET) demand is expected to decrease as MPB-induced tree mortality increases within disturbed stands. The expected cumulative effect of MPB disturbance on the stand-level water balance is an increase in soil moisture due to increased precipitation inputs and reduced overstory ET. This study was conducted in Lubrecht Experimental Forest and adjacent Bureau of Land Management areas near Missoula, Montana. Sub-canopy measurements of soil moisture, precipitation (rain and snow water equivalent), overstory transpiration and micro-meteorological data (net radiation, temperature, wind speed, etc.) were collected in three 50 x 50 meter plots. The plots consisted of a uniform stand of grey-stage lodgepole pine, a uniform stand of non-infested lodgepole pine, and a recent clear-cut stand, which served as a control unit. Water balances for each stand were constructed using a mass-balance approach and compared to investigate how MPB disturbance affects the stand-level water balance. Preliminary results from the first of two years of data collection suggests wetter soils in the grey-stage stand compared to the non-infested and clear cut stands. Continued data collection and analysis will provide further insight into the partitioning of the stand-level water balance in the grey stage of MPB disturbance.

Reilly, J. A.; Woods, S.

2012-12-01

166

Calibration of Predicted Hourly Zone-Level Supply Air Flows with Measurements  

E-print Network

data extracted from the Building Energy Management System (EMS). The paper presents the calibration of predicted hourly zone-level supply air flows with measurements. The suggested approach is applied to a new institutional building of Concordia...

Mihai, A.; Zmeureanu, R.

2013-01-01

167

Prediction of light aircraft interior sound pressure level using the room equation  

NASA Astrophysics Data System (ADS)

The room equation is investigated for predicting interior sound level. The method makes use of an acoustic power balance, by equating net power flow into the cabin volume to power dissipated within the cabin using the room equation. The sound power level transmitted through the panels was calculated by multiplying the measured space averaged transmitted intensity for each panel by its surface area. The sound pressure level was obtained by summing the mean square sound pressures radiated from each panel. The data obtained supported the room equation model in predicting the cabin interior sound pressure level.

Atwal, M.; Bernhard, R.

1984-05-01

168

Prediction of light aircraft interior sound pressure level using the room equation  

NASA Technical Reports Server (NTRS)

The room equation is investigated for predicting interior sound level. The method makes use of an acoustic power balance, by equating net power flow into the cabin volume to power dissipated within the cabin using the room equation. The sound power level transmitted through the panels was calculated by multiplying the measured space averaged transmitted intensity for each panel by its surface area. The sound pressure level was obtained by summing the mean square sound pressures radiated from each panel. The data obtained supported the room equation model in predicting the cabin interior sound pressure level.

Atwal, M.; Bernhard, R.

1984-01-01

169

Remotely mapping river water quality using multivariate regression with prediction validation.  

SciTech Connect

Remote spectral sensing offers an attractive means of mapping river water quality over wide spatial regions. While previous research has focused on development of spectral indices and models to predict river water quality based on remote images, little attention has been paid to subsequent validation of these predictions. To address this oversight, we describe a retrospective analysis of remote, multispectral Compact Airborne Spectrographic Imager (CASI) images of the Ohio River and its Licking River and Little Miami River tributaries. In conjunction with the CASI acquisitions, ground truth measurements of chlorophyll-a concentration and turbidity were made for a small set of locations in the Ohio River. Partial least squares regression models relating the remote river images to ground truth measurements of chlorophyll-a concentration and turbidity for the Ohio River were developed. Employing these multivariate models, chlorophyll-a concentrations and turbidity levels were predicted in river pixels lacking ground truth measurements, generating detailed estimated water quality maps. An important but often neglected step in the regression process is to validate prediction results using a spectral residual statistic. For both the chlorophyll-a and turbidity regression models, a spectral residual value was calculated for each river pixel and compared to the associated statistical confidence limit for the model. These spectral residual statistic results revealed that while the chlorophyll-a and turbidity models could validly be applied to a vast majority of Ohio River and Licking River pixels, application of these models to Little Miami River pixels was inappropriate due to an unmodeled source of spectral variation.

Stork, Christopher Lyle; Autry, Bradley C. (U.S. Environmental Protection Agency)

2005-07-01

170

Water Quality Prediction of Changjiang of Jingdezhen through Particle Swarm Optimization Algorithm  

Microsoft Academic Search

In order to obtain the water quality trend of Changjiang of Jingdezhen and prevent water pollution events, a water quality prediction model is built. Water quality index data, which are observed from a section of Changjiang, are taken as training samples. And eight indexes are selected, such as PH, chloride, sulfate, dissolved oxygen (DO), ammonia, permanganate, iron, total phosphorus (TP).

Xing Xu; Na Hu; Bingxiang Liu

2011-01-01

171

THE EFFECT OF LOCATION OF THE PREDICTED PERFORMANCE OF A HEAT PUMP WATER HEATER  

E-print Network

#12;THE EFFECT OF LOCATION OF THE PREDICTED PERFORMANCE OF A HEAT PUMP WATER HEATER Laboratory testing and field testing have shown that a heat pump water heater (HPWH) uses about half the electrical energy input that an electric resistance water heater does. However, since the heat pump water heater

Oak Ridge National Laboratory

172

Relationships between levels of heterotrophic bacteria and water quality parameters in a drinking water distribution system  

Microsoft Academic Search

Conventional plating methods were used to quantify heterotrophic bacteria from a drinking water distribution system. Three media, plate count agar (PCA), R2A agar and sheep blood agar (TSA-SB) were used to determine heterotrophic plate count (HPC) levels. Grab samples were collected weekly during the summer and autumn of 1997 at four locations in a municipal water distribution system. The four

J. T Carter; E. W Rice; S. G Buchberger; Y Lee

2000-01-01

173

Study of the influence of temperature and precipitations on the levels of BTEX in natural waters.  

PubMed

Assessment of seasonal changes in surface water quality is an important aspect for evaluating temporal variation of water due to natural or anthropogenic inputs of point and non-point sources. The objective of this paper was to investigate the influence of seasonal temperature fluctuations and precipitations on the levels of BTEX in natural waters. Principal component analysis (PCA) was used to evaluate the seasonal correlations of BTEX levels in water and to extract the parameters that are most important in assessing seasonal variations of water quality. This study was carried out as a part of VOCs monitoring program in natural water samples from Mediterranean coast. To carry out this project, a multiresidue analytical method was used. The method was based on headspace solid-phase microextraction (HS-SPME) followed by gas chromatography coupled to flame ionization detector (FID). The limits of detection LODs found for the tested analyte tested were in the 0.001-1 ?g/L range. These values were adequate for the analysis of these compounds in water samples according to the regulated values. Water samples from different points of the Mediterranean coast were analyzed during a period of three years, and were taken four times per year. Most of the compounds were below the limit established by the legislation. The results obtained by a chemometric study indicated that temperature and precipitations can be related on the BTEX levels found in water. A regression model between temperature or precipitations and BTEX concentration was obtained, thus these models can be used as predictive model for detection any non-normal concentration level. PMID:23978603

Moliner-Martínez, Y; Herraez-Hernandez, R; Verdú-Andres, J; Campíns-Falcó, P; Garrido-Palanca, C; Molins-Legua, C; Seco, A

2013-12-15

174

A Study on Predicting Shinkansen Noise Levels Using the Sound Intensity Method  

NASA Astrophysics Data System (ADS)

The purpose of this paper is to demonstrate a new method developed to predict track wayside noise levels resulting from the passage of high-speed trains. The method calculates noise levels based on data acquired by the sound intensity method developed by the Central Japan Railway Company. This measurement method allows one to identify each sound source and its characteristics as well as identify how much each source contributes to the overall resulting noise level. Structure borne noise and multiple reflected noise between train car bodies and noise barriers are also studied. As a result of this study, a prediction method was created which can calculate and predict noise levels resulting from such various factors as structure, train type, train speed and noise barrier. Noise levels predicted during this study agreed well with those actually measured under various conditions, thus indicating the prediction method model resulting from the study is a useful tool to verify noise levels occurring at receiver positions. Furthermore, it can also verify in advance how much effect noise barriers or train source noise level reduction devices would have on noise reduction.

Okada, Tadashi

175

Fuzzy system modelling of drinking water consumption prediction  

Microsoft Academic Search

It is important to determine the amount of daily drinking water requirement for a person not only for the health of people but also for the planning and management of the water resources. Physical activity, body weight and temperature play significant role in drinking water consumption rates. Human activity variables are most often given in crisp numerical interval classifications for

Zekâi Sen; Abdüsselam Altunkaynak

2009-01-01

176

Predicting ground water nitrate concentration from land use  

Microsoft Academic Search

Ground water nitrate concentrations on Nantucket Island, Massachusetts, were analyzed to assess the effects of land use on ground water quality. Exploratory data analysis was applied to historic ground water nitrate con- centrations to determine spatial and temporal trends. Maximum likelihood Tobit and logistic regression analyses of explanatory variables that characterize land use within a 1000-foot radius of each well

Kristin K. Gardner; Richard M. Vogel

2005-01-01

177

BIOASSAY PROCEDURE FOR PREDICTING COLIFORM BACTERIAL GROWTH IN DRINKING WATER  

EPA Science Inventory

Water quality degradation due to the growth of microorganisms Is an area of concern for many water utilities. urrently the nutrient status of drinking water is difficult to measure and can only be defined in relative terms. o date, the procedures developed for determining the amo...

178

BIOASSAY PROCEDURES FOR PREDICTING COLIFORM BACTERIAL GROWTH IN DRINKING WATER  

EPA Science Inventory

Water quality degradation due to the growth of microorganisms is an area of concern for many water utilities. o date, the procedures developed or determining the amount of biodegradable material present in potable water have utilized heterotrophic non-coliform bacteria as bioassa...

179

Personality disorders and the five-factor model: a test of facet-level predictions.  

PubMed

We tested predicted relationships (Widiger, 1993; Widiger, Trull, Clarkin, Sanderson, & Costa, 1994) between personality disorder scores and facets of the five-factor model, and evaluated the relative benefits of facet-level analyses over domain-level analyses. Data from 614 undergraduates indicated: (a) 63% of the predicted facet relationships were significant, although many unpredicted relationships also emerged; (b) facet-level analyses did not yield substantially stronger effect sizes than domain-level analyses; but (c) facet-level analyses provided much better discrimination between personality disorders than domain-level analyses. Facets of the openness to experience domain also helped discriminate between personality disorders, which is in contrast to previous domain-level findings that openness is not important. PMID:9573518

Dyce, J A; O'Connor, B P

1998-01-01

180

Predicting the water retention characteristic of Sicilian soils by pedotransfer functions  

Microsoft Academic Search

The accuracy in predicting the water retention characteristics of some widely used pedotransfer functions (PTFs) was tested using a database of 149 soil samples collected in three Sicilian areas. The PTFs performance was assessed in terms of maximum error (ME), average error (AE) and root mean square error (RMSE) between predicted and measured water content data. The influence of pressure

C. Antinoro; V. Bagarello; M. Castellini; A. Giangrosso; G. Giordano; M. Iovino; A. Sgroi

181

Impact of eustatic sea level changes on the salt-water fresh-water interface in coastal ground waters  

NASA Astrophysics Data System (ADS)

During the Holocene sea level rise has been inundating former glacial to inter-glacial deposits at the North German coast some of which are in use for municipal drinking water abstraction. Sea water intrusion into these sediments represents a serious threat to the coastal freshwater resources. To date, mechanisms and timing of salt water intrusion have not been explored. Interstitial waters from two drilling cores recovered about 3 km offshore the coastline of Northern Germany now offer the possibility of investigating the origin and possible age of the sea water intrusion. The chloride inventory shows that the sea-water fresh-water interface in the subsurface is currently not in equilibrium with the position of todaýs coastline. Furthermore, the shape of the chloride depth profile suggests that at least one regression must have intermitted the Holocene transgression. Based on these findings we conducted a transient numerical simulation to elucidate the impact of eustatic sea level changes on the salt-water fresh-water distribution within the subsurface of coastal regions. We applied a modified Henry model with an inclined surface and forced by a dynamic sea level. The results show that salt fronts in the subsurface follow the coastline during transgressions and promote a fast salinization of the model aquifer. A regression immediately leads to the freshening of surface sediments via the replacement of saline and brackish waters with meteoric waters, while flushing of deeper parts of the model aquifer with fresh-water was significantly slower. Although the coastline has moved seaward saline ground waters remained at depth because ground water velocities are slower and density-driven recirculation of sea water constantly resupplies salt water. The results indicate that the shape of the salt-water fresh-water interface in coastal aquifers may strongly be affected by eustatic sea level changes. They also provide evidence that man-made fixation of the coast line by land reclamation and the subsequent construction of dykes in Northern Germany has impacted the salt-water distribution in the subsurface. But although dyking has started around 1000 years ago some areas still do not have completely freshened. This implies that freshening of aquifers once intruded by sea water may be a slow process which takes te?s to hundreds of years.

Riedel, Thomas; Lettmann, Karsten; Brumsack, Hans-Jürgen

2010-05-01

182

Predicting the Conflict Level in Television Political Debates: an Approach Based on Crowdsourcing,  

E-print Network

Predicting the Conflict Level in Television Political Debates: an Approach Based on Crowdsourcing proposes an approach for the automatic detection of conflict level in television political debates interactions are one of the most com- mon subjects in multimedia data (e.g., television programs, Youtube

Vinciarelli, Alessandro

183

Prediction of light aircraft interior sound pressure level using the room equation  

Microsoft Academic Search

The room equation is investigated for predicting interior sound level. The method makes use of an acoustic power balance, by equating net power flow into the cabin volume to power dissipated within the cabin using the room equation. The sound power level transmitted through the panels was calculated by multiplying the measured space averaged transmitted intensity for each panel by

M. Atwal; R. Bernhard

1984-01-01

184

Multiagent Meta-level Control for predicting Meteorological Phenomenon Shanjun Cheng and Anita Raja  

E-print Network

on weather data to recognize significant meteorological phenomenon [Kra07]. Meta-level controlMultiagent Meta-level Control for predicting Meteorological Phenomenon Shanjun Cheng and Anita Raja NetRads [Kra07] is a network of adaptive radars controlled by a collection of Meteorological Command

Raja, Anita

185

Enhanced DO-RE-ME based defect level prediction using defect site aggregation-MPG-D  

Microsoft Academic Search

Predicting the final value of the defective part level after the application of a set of test vectors is not a simple problem. In order for the defective part level to decrease, both the excitation and observation of defects must occur. This research shows that the probability of exciting an as yet undetected defect does indeed decrease exponentially as the

Jennifer Dworak; Michael R. Grimaila; Sooryong Lee; Li-C. Wang; M. Ray Mercer

2000-01-01

186

Social Status Predicts How Sex Steroid Receptors Regulate Complex Behavior across Levels of  

E-print Network

Social Status Predicts How Sex Steroid Receptors Regulate Complex Behavior across Levels, in part mediated by gonadal hormones, although how each sex steroid acts across levels of biological organization is not well understood. We examine the role of sex steroids in modulating social behavior

Hofmann, Hans A.

187

Simulated effects of pumping irrigation wells on ground-water levels in western Saginaw County, Michigan  

USGS Publications Warehouse

Success of agriculture in many areas of Michigan relies on withdrawal of large quantities of ground water for irrigation. In some areas of the State, water-level declines associated with large ground-water withdrawals may adversely affect nearby residential wells. Residential wells in several areas of Saginaw County, in Michigan?s east-central Lower Peninsula, recently went dry shortly after irrigation of crop lands commenced; many of these wells also went dry during last year?s agricultural cycle (summer 2000). In September 2000, residential wells that had been dry returned to function after cessation of pumping from large-capacity irrigation wells. To evaluate possible effects of ground-water withdrawals from irrigation wells on residential wells, the U.S. Geological Survey used hydrogeologic data including aquifer tests, water-level records, geologic logs, and numerical models to determine whether water-level declines and the withdrawal of ground water for agricultural irrigation are related. Numerical simulations based on representative irrigation well pumping volumes and a 3-month irrigation period indicate water-level declines that range from 5.3 to 20 feet, 2.8 to 12 feet and 1.7 to 6.9 feet at distances of about 0.5, 1.5 and 3 miles from irrigation wells, respectively. Residential wells that are equipped with shallow jet pumps and that are within 0.5 miles of irrigation wells would likely experience reduced yield or loss of yield during peak periods of irrigation. The actual extent that irrigation pumping cause reduced function of residential wells, however, cannot be fully predicted on the basis of the data analyzed because many other factors may be adversely affecting the yield of residential wells.

Hoard, Christopher J.; Westjohn, David B.

2001-01-01

188

Prediction of daily ground-level ozone concentration maxima over New Delhi  

Microsoft Academic Search

The pollution levels in New Delhi from industrial, residential, and transportation sources are continuously growing. As one\\u000a of the major pollutants, ground-level ozone is responsible for various adverse effects on both humans and foliage. The present\\u000a study aims to predict daily ground-level ozone concentration maxima over a site situated in New Delhi through neural networks\\u000a (NN) and multiple-regression (MR) analysis.

Amita Mahapatra

2010-01-01

189

Comparison of Artificial Neural Network And M5 Model Tree Technique In Water Level Forecasting of Solo River  

NASA Astrophysics Data System (ADS)

Flood events along the Solo River flow at the end of December 2007 has caused lose of properties and lives. Floods occurred in the city of Ngawi, Madiun, Bojonegoro, Babat and surrounding areas. To reduce future losses, one of the important efforts that will occur during a flood is to get information about the magnitude and time will be floods, so that people can make an effort to reduce its impact. Flood forecasting model can provide information of water level in the river some time before the incident. This paper will compare the flood forecasting model at Bojonegoro City was built using the technique of Artificial Neural Network (ANN) and M5 Model Tree (M5MT). The model will forecast the water level of 1, 3 and 6 hours ahead at the point of water level recorders in the City of Bojonegoro using input from the water level at some point water level recorders in the upstream such as Karangnongko, Sekayu, Jurug and Wonogiri. The same data set of hourly water level records are used to build the model of ANN and M5MT technique. The selection of parameters and setup of ANN and M5MT technique is done to obtain the best result. The results of the model are evaluated by calculating the Root Mean Square Error (RMSE) between the predictions and observations. RMSE produced by the water level forecasting model 1, 3 and 6 hours ahead with M5MT technique are 0.2723, 0.6279 and 0.7176 meters. While the ANN technique are 0.1829, 0.3192 and 0517 meters. ANN technique has a better ability in predicting low flow, whereas M5 Model Tree technique has a better ability in predicting high flow. Keywords : Water level forecasting, Solo River, M5 Model Tree, Artificial Neural Network

Lasminto, Umboro; Hery Mularta, Listya

2010-05-01

190

The effects of using ground water to maintain water levels of Cedar Lake, Wisconsin  

USGS Publications Warehouse

Cedar Lake, a kettle lake with no surface inlet or outlet, was studied to evaluate the feasibility of maintaining water levels of lakes in the glaciated kettle moraine area of eastern Wisconsin by pumping ground water into them. A volume of water equivalent to that needed to raise the lake level 47 inches was pumped from the shallow aquifer system into Cedar Lake between February 1 and September 30, 1977. The water budget for the lake during this period indicated that approximately 90 percent of pumped water was either recycled from the lake to the well or otherwise lost as seepage from the lake. There were no identifiable changes in measured physical and chemical characteristics of lake water during the pumping period, nor were there identifiable changes in the number or makeup of the phytoplankton community. Differences in physical and chemical characteristics of lake water and ground water added to the lake probably were not great enough to cause changes within the lake. (USGS)

McLeod, R.S.

1980-01-01

191

Seismic refraction methodology for groundwater level determination: “Water seismic index”  

NASA Astrophysics Data System (ADS)

Recently, there has been increased interest in the use of refraction seismic data for the exploration and development of hydrological reservoirs. The aim of this study is to provide a procedure in order to identify groundwater levels by means of seismic refraction profiles. Assuming that the velocity of shear waves increases much less than the velocity of compressional waves in a saturated soil, seismic refraction surveys were performed for the determination of the water table. In order to have a perfect overlay of the tomography 2D grids, P and S wave seismic profiles were obtained with the same geometrical configuration. Based on the propagation of the P and S waves in the unsaturated and saturated media, a "Water Seismic Index" (WSI) was defined. WSI is related to the local variations of the P and S wave velocities and, in theoretical terms, it is correlated to groundwater level. Preliminary results indicate that there is a good agreement between the depth of the ground water and the WSI parameter.

Grelle, Gerardo; Guadagno, Francesco Maria

2009-07-01

192

Numerical prediction of droplet dynamics in turbulent flow, using the level set method  

Microsoft Academic Search

In the present article, the droplet dynamics in turbulent flow is numerically predicted. The modelling is based on an interfacial marker-level set (IMLS) method, coupled with the Reynolds-averaged Navier–Stokes (RANS) equations to predict the dynamics of turbulent two-phase flow. The governing equations for time-dependent, two-dimensional and incompressible two-phase flow are described in both phases and solved separately using a control

Ashraf Balabel

2011-01-01

193

Concentrating low-level tritiated water through isotope exchange  

SciTech Connect

Trapping of tritium on polymers with specific functional groups was investigated as a means of treating waste streams containing low levels of tritium. Chemical exchange of tritium with hydrogen on the functional group was used as the mechanism for trapping. The polymers tested include Aurorez polybenzimidazole resin beads, Chelex 100 resin beads, Duolite GT-73, microcrystalline cellulose, and polyethylenimine. The tests were performed under simulated operating conditions on water obtained from the Radioactive Liquid Waste Treatment Facility at Los Alamos National Laboratory, Tritiated water from the Tritium Systems Test Assembly is discharged to this plant. Polyethylenimine is a water-soluble polymer that was tested using a stirred membrane cell with an ultrafiltration membrane. All of the polymers except polyethylenimine took up tritium from the water. Polybenzimidazole demonstrated the highest tritium uptake. The results are explained on the basis of the type of functional group, hydrogen bonding, and rigidity of the molecular structure of the polymer. The theoretical calculations indicate that significant isotope discrimination requires high-frequency modes with hydrogen bonding contribution and support the experimental findings. Modeling suggested trends that may lead to structures that are more efficient in trapping tritium.

Jorgensen, B.S.; Dye, R.C.; Pratt, L.R.; Gomez, M.A.; Meadows, J.E.

2000-03-01

194

Predicting the Frequency of Water Quality Standard Violations Using Bayesian Calibration of Eutrophication Models  

E-print Network

and confidence of compliance of different water quality criteria. The proposed methodological framework canPredicting the Frequency of Water Quality Standard Violations Using Bayesian Calibration Toronto, Ontario M1C 1A4 ABSTRACT. The water quality standard setting process usually relies

Arhonditsis, George B.

195

Water Research 38 (2004) 33313339 Testing a surface tension-based model to predict the salting  

E-print Network

Water Research 38 (2004) 3331­3339 Testing a surface tension-based model to predict the salting out associated with transferring solutes from water to a salt solution to the difference in surface tensions]. With respect to inorganic salts, numerous researchers have reported that the presence of ionic species in water

Herbert, Bruce

196

Prediction of water quality in lakes and reservoirs. Part I — Model description  

Microsoft Academic Search

A one-dimensional water quality model (DYRESM Water Quality) is described which combines a process based hydrodynamic model (DYRESM) with numerical descriptions of phytoplankton production, nutrient cycling, the oxygen budget and particle dynamics. The hydrodynamic component is free from calibration, which ensures that it is readily transferable to other lakes and reservoirs. This improves water quality predictions derived for different hydrodynamic

David P. Hamilton; S. Geoffrey Schladow

1997-01-01

197

A new model for predicting relative nonwetting phase permeability from soil water retention curves  

E-print Network

A new model for predicting relative nonwetting phase permeability from soil water retention curves by combining soil water retention curves with relative nonwetting phase permeability models. Experimental permeability from soil water retention curves is proposed in this paper. A closed form expression can

Jiao, Jiu Jimmy

198

Simulated effects of water-level changes in the Mississippi River and Pokegama Reservoir on ground-water levels, Grand Rapids area, Minnesota  

USGS Publications Warehouse

The U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, used an existing, three-dimensional, numerical ground-water flow model (referred to as the calibrated model) to assess the effects of water-level changes in the Mississippi River and Pokegama Reservoir on ground-water levels in adjacent glaciofluvial aquifers in the Grand Rapids area of north-central Minnesota. Pokegama Reservoir consists of Pokegama Lake, Little Jay Gould Lake, Jay Gould Lake, Cut-off Lake, and Blackwater Lake. Water levels in the Pokegama Reservoir are regulated at Pokegama Dam on the Mississippi River west of Grand Rapids. A steady-state model was used, and simulations represent 'worse-case' scenarios for the effects of lowering or raising the river and lake water levels. The simulated ground-water levels represent levels that would result if the river and lake stages permanently declined or rose by the specified amounts. Eight hypothetical scenarios were simulated by varying water levels in the Mississippi River and Pokegama Reservoir from values used in the calibrated model. In the simulations, water levels for the Mississippi River, riverine wetlands of the Mississippi River, and lakes of the Pokegama Reservoir were raised and lowered uniformly by 0.50, 1.00, 2.00, and 3.00 feet from calibrated water levels. The extent of aquifer water-level changes resulting from these river, wetland, and lake water-level changes varied because of the complex hydrogeology of the study area. A 1.00-foot decline in reservoir/river water levels caused a maximum simulated ground-water-level decline in the middle aquifer near Jay Gould and Little Jay Gould Lakes of 1.09 feet and a maximum simulated ground-water-level decline of 1.00 foot in the lower aquifer near Cut-off and Blackwater Lakes. The amount and extent of ground-water-level changes in the middle and lower aquifers can be explained by the thickness, extent, and connectivity of the aquifers. Surface-water/ground-water interactions near wetlands and lakes with water levels unchanged from the calibrated model resulted in small water-table altitude differences among the simulations. Results of the ground-water modeling indicate that lowering of the reservoir and river water levels by 1.00 foot likely will not substantially affect water levels in the middle and lower aquifers.

Jones, Perry M.

2005-01-01

199

Variation of Great Lakes Water Levels Derived from Geosat Altimetry  

NASA Technical Reports Server (NTRS)

A technique for using satellite radar altimetry data to estimate the temporal variation of the water level in moderate to large lakes and enclosed seas is described. Great Lakes data from the first 2 years of the U.S. Navy's Geosat Exact Repeat Mission (November 1986 to November 1988), for which there is an improved orbit, are used to demonstrate the technique. The Geosat results are compared to the lake level data collected by the Great Lakes Section, National Ocean Service, National Oceanic and Atmospheric Administration, and are found to reproduce the temporal variations of the five major lakes with Root-Mean-Square error (RMS) ranging from 9.4 to 13.8 cm and a combined average of 11.1 cm. Geosat data are also analyzed for Lake St. Clair, representing a moderate-sized lake, with a resulting rms of 17.0 cm. During this study period, the water level in the Great Lakes varied in a typical annual cycle of about 0.2 m (0.5 in for Lake Ontario) superimposed on a general decline of approximately 0.5 m. The altimeter data reproduced the general decline reasonably well for all the lakes, but the annual cycle was obscured in some lakes due to systematic errors in the altimeter data. Current and future altimetry missions will have markedly improved accuracy which will permit many moderate (25 km diameter) or larger lakes or enclosed seas to be routinely monitored.

Morris, Charles S.; Gill, Stephen K.

1994-01-01

200

Predicting water quality criteria for protecting aquatic life from physicochemical properties of metals or metalloids.  

PubMed

Metals are widely distributed pollutants in water and can have detrimental effects on some aquatic life and humans. Over the past few decades, the United States Environmental Protection Agency (U.S. EPA) has published a series of criteria guidelines, which contain specific criteria maximum concentrations (CMCs) for 10 metals. However, CMCs for other metals are still lacking because of financial, practical, or ethical restrictions on toxicity testing. Herein, a quantitative structure activity relationship (QSAR) method was used to develop a set of predictive relationships, based on physical and chemical characteristics of metals, and predict acute toxicities of each species for five phyla and eight families of organisms for 25 metals or metalloids. In addition, species sensitivity distributions (SSDs) were developed as independent methods for determining predictive CMCs. The quantitative ion character-activity relationships (QICAR) analysis showed that the softness index (?p), maximum complex stability constants (log -?(n)), electrochemical potential (?E(0)), and covalent index (X(m)(2)r) were the minimum set of structure parameters required to predict toxicity of metals to eight families of representative organisms. Predicted CMCs for 10 metals are in reasonable agreement with those recommended previously by U.S. EPA within a difference of 1.5 orders of magnitude. CMCs were significantly related to ?p (r(2) = 0.76, P = 7.02 × 10(-9)) and log -?(n) (r(2) = 0.73, P = 3.88 × 10(-8)). The novel QICAR-SSD model reported here is a rapid, cost-effective, and reasonably accurate method, which can provide a beneficial supplement to existing methodologies for developing preliminarily screen level toxicities or criteria for metals, for which little or no relevant information on the toxicity to particular classes of aquatic organisms exists. PMID:23199259

Wu, Fengchang; Mu, Yunsong; Chang, Hong; Zhao, Xiaoli; Giesy, John P; Wu, K Benjamin

2013-01-01

201

An empirical method for predicting the mixing noise levels of subsonic circular and coaxial jets  

NASA Technical Reports Server (NTRS)

An empirical method for predicting the static free field source noise levels of subsonic circular and coaxial jet flow streams is presented. The method was developed from an extensive data base of 817 jet tests obtained from five different government and industry sources in three nations. The prediction method defines the jet noise in terms of four components which are overall power level, power spectrum level, directivity index, and relative spectrum level. The values of these noise level components are defined on a grid consisting of seven frequency parameter values (Strouhal numbers) and seven directivity angles. The value of the noise level at each of these grid points is called a noise level coordinate and was defined as a function of five jet exhaust flow state parameters which are equivalent jet velocity, equivalent jet total temperature, the velocity ratio (outer stream to inner stream), temperature ratio, and area ratio. The functions were obtained by curve fitting in a least squares sense the noise level coordinates from the data base in a five dimensional flow state space using a third order Taylor series. The noise level coordinates define the component noise levels for all frequencies and directivities through a bicubic spline function.

Russell, J. W.

1984-01-01

202

Space-time model to predict tropospheric ozone concentration levels in an industrial region  

NASA Astrophysics Data System (ADS)

The main goal of this work was to develop a space-time model to predict tropospheric ozone (O3) concentration levels in the surroundings of an industrial Portuguese region, Sines. Regional air quality monitoring network is composed by three conventional monitoring stations, which register hourly O3 concentrations levels on a high temporal resolution but with very low spatial resolution. To overcome the lack of spatial data to characterize ozone dispersion, O3 spatial patterns were obtained through several field campaigns of passive samplers (Radiello diffusive tubes) performed over time. This passive sampler allows collecting data on a high spatial density sampling design but for periods of time between 1 to 2 weeks for each campaign, obtaining O3 mean concentrations over this period. The proposed space-time model is based in a two steps methodology: 1. Time prediction of O3 concentration levels on monitoring stations location using Multilayer perceptron (MLP) networks. 2. Spatial prediction of O3 concentration levels for the Sines region using block simulation. The main advantages of applying MLP networks to predict pollutant concentrations are that MLP models do not need exhaustive information about measured pollutant concentrations, reaction mechanisms, meteorological parameters or emission pollutant concentrations, identifying and reproducing nonlinear relationships between the different predictor variables. The developed MLP models presented good performances with values reaching up to 78% of prediction success of O3 hourly concentrations levels. In the second step Block Sequential Simulation (BSSIM) algorithm is applied to predict spatial pattern of O3 concentration levels. This simulation method is based on direct sequential simulation (DSS) (Soares, 2001), which does not require a non-linear transformation of the main variable; hence, data with different supports can be jointly used in the same model. In this study we considered O3 concentrations measured/predicted in point locations but in different time supports. Hence, BSSIM algorithm allowed the integration of hourly O3 concentration predictions at monitoring station locations and block data such as O3 mean ozone concentrations over the passive samplers exposure period of time on their locations. Block data error was set for different weather conditions, based on the field campaigns exposed data periods. Preliminary results are quite satisfactory since Block simulation seems able to reproduce the relation between real and predicted values, guaranteeing that the implementation conditions of the stochastic simulation algorithm (variograms, histograms and correlation coefficient of each pair of variables) are reproduced in the final results.

Melo Durao, Rita; João Pereira, Maria; Soares, Amílcar

2014-05-01

203

The application of powdered activated carbon for MIB and geosmin removal: predicting PAC doses in four raw waters.  

PubMed

Blooms of blue-green algae in reservoirs often produce the musty-earthy taste and odour algal metabolites 2-methylisoborneol (MIB) and geosmin. MIB and geosmin are not removed by conventional water treatment and their presence in the distribution system, even at low ng L-1 levels, can result in consumer complaints. Powdered activated carbon (PAC) can effectively remove MIB and geosmin when the correct dose is applied. The homogeneous surface diffusion model (HSDM) was used to predict PAC doses required to reduce MIB and geosmin concentrations to below 10 ng L-1 at four water treatment plants in Adelaide, South Australia. In jar tests, undertaken under treatment plant conditions, the predicted doses were found to produce water of the desired quality in three of the four waters. The poor predictions found in the fourth water, which had a considerably higher turbidity, were attributed to the incorporation of PAC in a larger, denser floc, leading to a reduced effective contact time of the adsorbent. It was found that higher doses of PAC were required for both compounds to produce acceptable quality water when turbidities rose above 26 NTU. PMID:11268853

Cook, D; Newcombe, G; Sztajnbok, P

2001-04-01

204

Earthquake dates and water level changes in wells in the Eskisehir region,Turkey Hydrology and Earth System Sciences, 7(5), 777781 (2003) EGU  

E-print Network

Earthquake dates and water level changes in wells in the Eskisehir region,Turkey 777 Hydrology and Earth System Sciences, 7(5), 777781 (2003) © EGU Technical Note: Earthquake dates and water level@ogu.edu.tr Abstract Although satisfactory results have yet to be obtained in earthquake prediction, one of the most

Paris-Sud XI, Université de

205

Statistical procedures for determination and verification of minimum reporting levels for drinking water methods.  

PubMed

The United States Environmental Protection Agency's Office of Ground Water and Drinking Water has developed a single-laboratory quantitation procedure: the lowest concentration minimum reporting level (LCMRL). The LCMRL is the lowest true concentration for which future recovery is predicted to fall, with high confidence (99%), between 50% and 150%. The procedure takes into account precision and accuracy. Multiple concentration replicates are processed through the entire analytical method and the data are plotted as measured sample concentration (y-axis) versus true concentration (x-axis). If the data support an assumption of constant variance over the concentration range, an ordinary least-squares regression line is drawn; otherwise, a variance-weighted least-squares regression is used. Prediction interval lines of 99% confidence are drawn about the regression. At the points where the prediction interval lines intersect with data quality objective lines of 50% and 150% recovery, lines are dropped to the x-axis. The higher of the two values is the LCMRL. The LCMRL procedure is flexible because the data quality objectives (50-150%) and the prediction interval confidence (99%) can be varied to suit program needs. The LCMRL determination is performed during method development only. A simpler procedure for verification of data quality objectives at a given minimum reporting level (MRL) is also presented. The verification procedure requires a single set of seven samples taken through the entire method procedure. If the calculated prediction interval is contained within data quality recovery limits (50-150%), the laboratory performance at the MRL is verified. PMID:16433362

Winslow, Stephen D; Pepich, Barry V; Martin, John J; Hallberg, George R; Munch, David J; Frebis, Christopher P; Hedrick, Elizabeth J; Krop, Richard A

2006-01-01

206

Coastal retreat and improved water quality mitigate losses of seagrass from sea level rise.  

PubMed

The distribution and abundance of seagrass ecosystems could change significantly over the coming century due to sea level rise (SLR). Coastal managers require mechanistic understanding of the processes affecting seagrass response to SLR to maximize their conservation and associated provision of ecosystem services. In Moreton Bay, Queensland, Australia, vast seagrass meadows supporting populations of sea turtles and dugongs are juxtaposed with the multiple stressors associated with a large and rapidly expanding human population. Here, the interactive effects of predicted SLR, changes in water clarity, and land use on future distributions of seagrass in Moreton Bay were quantified. A habitat distribution model of present day seagrass in relation to benthic irradiance and wave height was developed which correctly classified habitats in 83% of cases. Spatial predictions of seagrass and presence derived from the model and bathymetric data were used to initiate a SLR inundation model. Bathymetry was iteratively modified based on SLR and sedimentary accretion in seagrass to simulate potential seagrass habitat at 10 year time steps until 2100. The area of seagrass habitat was predicted to decline by 17% by 2100 under a scenario of SLR of 1.1 m. A scenario including the removal of impervious surfaces, such as roads and houses, from newly inundated regions, demonstrated that managed retreat of the shoreline could potentially reduce the overall decline in seagrass habitat to just 5%. The predicted reduction in area of seagrass habitat could be offset by an improvement in water clarity of 30%. Greater improvements in water clarity would be necessary for larger magnitudes of SLR. Management to improve water quality will provide present and future benefits to seagrasses under climate change and should be a priority for managers seeking to compensate for the effects of global change on these valuable habitats. PMID:23564697

Saunders, Megan I; Leon, Javier; Phinn, Stuart R; Callaghan, David P; O'Brien, Katherine R; Roelfsema, Chris M; Lovelock, Catherine E; Lyons, Mitchell B; Mumby, Peter J

2013-08-01

207

Reverse water-level fluctuations associated with fracture connectivity.  

PubMed

Reverse water-level fluctuations (RWFs), a phenomenon in which water levels rise briefly in response to pumping, were detected in monitoring wells in a fractured siliciclastic aquifer system near a deep public supply well. The magnitude and timing of RWFs provide important information that can help interpret aquifer hydraulics near pumping wells. A RWF in a well is normally attributed to poroelastic coupling between the solid and fluid components in an aquifer system. In addition to revealing classical pumping-induced poroelastic RWFs, data from pressure transducers located at varying depths and distances from the public supply well suggest that the RWFs propagate rapidly through fractures to influence wells hundreds of meters from the pumping well. The rate and cycling frequency of pumping is an important factor in the magnitude of RWFs. The pattern of RWF propagation can be used to better define fracture connectivity in an aquifer system. Rapid, cyclic head changes due to RWFs may also serve as a mechanism for contaminant transport. PMID:23473020

Gellasch, Christopher A; Wang, Herbert F; Bradbury, Kenneth R; Bahr, Jean M; Lande, Lauren L

2014-01-01

208

Comparison of predicted and measured oxygen levels in a semi-closed underwater breathing apparatus  

Microsoft Academic Search

An analytical model has recently been developed for predicting the circuit oxygen levels in semi-closed underwater breathing apparatus at various mission depths and diver activity levels (Nuckols, Clarke, Marr, 1999). Unmanned testing in June 2000 with a commercially available US Divers Aqualung OxyMix rebreather (NEDU Test Plan Number 00-06 dated May 2000) showed good agreement with this analytical model over

Marshall L. Nuckols; W. Scott Finlayson; Brian Newville

2001-01-01

209

Predicting Impacts of Increased CO2 and Climate Change on the Water Cycle and Water Quality in the Semiarid James River Basin of the Midwestern USA  

USGS Publications Warehouse

Emissions of greenhouse gases and aerosols from human activities continue to alter the climate and likely will have significant impacts on the terrestrial hydrological cycle and water quality, especially in arid and semiarid regions. We applied an improved Soil and Water Assessment Tool (SWAT) to evaluate impacts of increased atmospheric CO2 concentration and potential climate change on the water cycle and nitrogen loads in the semiarid James River Basin (JRB) in the Midwestern United States. We assessed responses of water yield, soil water content, groundwater recharge, and nitrate nitrogen (NO3–N) load under hypothetical climate-sensitivity scenarios in terms of CO2, precipitation, and air temperature. We extended our predictions of the dynamics of these hydrological variables into the mid-21st century with downscaled climate projections integrated across output from six General Circulation Models. Our simulation results compared against the baseline period 1980 to 2009 suggest the JRB hydrological system is highly responsive to rising levels of CO2 concentration and potential climate change. Under our scenarios, substantial decrease in precipitation and increase in air temperature by the mid-21st century could result in significant reduction in water yield, soil water content, and groundwater recharge. Our model also estimated decreased NO3–N load to streams, which could be beneficial, but a concomitant increase in NO3–N concentration due to a decrease in streamflow likely would degrade stream water and threaten aquatic ecosystems. These results highlight possible risks of drought, water supply shortage, and water quality degradation in this basin.

Wu, Yiping; Liu, Shuguang; Gallant, Alisa L.

2012-01-01

210

POST-BETZE PIT LAKE WATER QUALITY PREDICTION, NEVADA1  

Microsoft Academic Search

The Barrick Goldstrike Mine is located in the Carlin Trend, about 20 miles northwest of Carlin, Nevada. The majority of the ore mined at Goldstrike is from the Post-Betze open pit, the largest open pit operation in Nevada. Nevada law requires that the water quality of temporary or permanent reservoirs that may develop in open pits be periodically tested. Pit

William M. Schafer; Mark Logsdon; Guosheng Zhan; Ron Espell

211

7 Predictive Risk Mapping of Water Table Depths in  

E-print Network

of the country with extensions into Para- guay and Bolivia. Before recent human disturbances, Cerrados probably the hydrological system (Klink and Moreira, 2002). With irrigation increasing, lowering of the water table occurs land use pur- poses (Von Asmuth and Knotters, 2004). In hydrology, wat

Camara, Gilberto

212

Baseline serum TARC levels predict therapy outcome in patients with Hodgkin lymphoma.  

PubMed

Hodgkin lymphoma (HL) has become one of the best curable cancers. However, better biomarkers are needed for outcome prediction that would allow protecting patients from over- or under-dosing of treatment. Thymus and activation-regulated chemokine/CCL17 (TARC) is highly and specifically elevated in this disease and has been proposed as possible biomarker in HL patients. In this study, we show that pretreatment TARC levels were associated with established clinical risk factors and predictive for response to treatment in a large cohort of HL patients treated in clinical trials by the German Hodgkin Study Group. Moreover, TARC levels also significantly contributed to a novel multivariate model predicting treatment response. These data clearly suggest an important role for this chemokine as biomarker in HL. PMID:23225085

Sauer, Maike; Plütschow, Annette; Jachimowicz, Ron D; Kleefisch, Dominik; Reiners, Katrin S; Ponader, Sabine; Engert, Andreas; von Strandmann, Elke Pogge

2013-02-01

213

Available online at www.sciencedirect.com Late pregnancy glucocorticoid levels predict responsiveness in  

E-print Network

Available online at www.sciencedirect.com Late pregnancy glucocorticoid levels predict in glucocorticoid (GC) hormones in new mothers. Despite these intriguing reports, questions remain about of this pattern across species and in wild populations. Glucocorticoids modulate animals' responses to ongoing

Nguyen, Nga

214

Exploring content validity, item level analysis and predictive validity for two algebra progress monitoring measures  

Microsoft Academic Search

This study examines the content validity, item level analysis and predictive validity of two algebra progress monitoring measures. The content in two algebra progress monitoring measures was examined to determine alignment with the Common Core State Standards (CCSS) for algebra. The content for one algebra measure, namely, Algebra Content Analysis (ACA), aligned well with the Common Core State Standards, with

Subhalakshmi Singamaneni

2011-01-01

215

The Level of Quality of Work Life to Predict Work Alienation  

ERIC Educational Resources Information Center

The current research aims to determine the level of elementary school teachers' quality of work life (QWL) to predict work alienation. The study was designed using the relational survey model. The research population consisted of 1096 teachers employed at 25 elementary schools within the city of Van in the academic year 2010- 2011, and 346…

Erdem, Mustafa

2014-01-01

216

Predicting county-level cancer incidence rates and counts in the USA.  

PubMed

Many countries, including the USA, publish predicted numbers of cancer incidence and death in current and future years for the whole country. These predictions provide important information on the cancer burden for cancer control planners, policymakers and the general public. Based on evidence from several empirical studies, the joinpoint (segmented-line linear regression) model (JPM) has been adopted by the American Cancer Society to estimate the number of new cancer cases in the USA and in individual states since 2007. Recently, cancer incidence in smaller geographic regions such as counties, and local policy makers are increasingly interested with Federal Information Processing Standard code regions. The natural extension is to directly apply the JPM to county-level cancer incidence data. The direct application has several drawbacks and its performance has not been evaluated. To address the concerns, we developed a spatial random-effects JPM for county-level cancer incidence data. The proposed model was used to predict both cancer incidence rates and counts at the county level. The standard JPM and the proposed method were compared through a validation study. The proposed method outperformed the standard JPM for almost all cancer sites, especially for moderate or rare cancer sites and for counties with small population sizes. As an application, we predicted county-level prostate cancer incidence rates and counts for the year 2011 in Connecticut. PMID:23670947

Yu, Binbing

2013-09-30

217

Towards a predictive systems-level model of the human microbiome: progress, challenges, and opportunities  

E-print Network

orthology groups to determine the taxo- nomic or functional composition of the community. Using, determining the core taxa and genes present in the microbiome and the range of variation [9 ,10,11 ]. AdditionTowards a predictive systems-level model of the human microbiome: progress, challenges

Borenstein, Elhanan

218

Strength and Comprehensiveness of District School Wellness Policies Predict Policy Implementation at the School Level  

ERIC Educational Resources Information Center

Background: In 2006, all local education agencies in the United States participating in federal school meal programs were required to establish school wellness policies. This study documented the strength and comprehensiveness of 1 state's written district policies using a coding tool, and tested whether these traits predicted school-level

Schwartz, Marlene B.; Henderson, Kathryn E.; Falbe, Jennifer; Novak, Sarah A.; Wharton, Christopher M.; Long, Michael W.; O'Connell, Meghan L.; Fiore, Susan S.

2012-01-01

219

Amygdala norepinephrine levels after training predict inhibitory avoidance retention performance in rats  

E-print Network

and enhancing effects of drugs affecting GABA, opiate and glucocorticoid receptors (McGaugh et al., 1995., 1998). Additionally, systemic injections of epinephrine or drugs that enhance memory consolida- tionAmygdala norepinephrine levels after training predict inhibitory avoidance retention performance

O'Toole, Alice J.

220

Prediction of altimetric sea level anomalies using time series models based on spatial correlation  

NASA Astrophysics Data System (ADS)

Sea level anomaly (SLA) times series, which are time-varying gridded data, can be modelled and predicted using time series methods. This approach has been shown to provide accurate forecasts within the Prognocean system, the novel infrastructure for anticipating sea level change designed and built at the University of Wroc?aw (Poland) which utilizes the real-time SLA data from Archiving, Validation and Interpretation of Satellite Oceanographic data (AVISO). The system runs a few models concurrently, and our ocean prediction experiment includes both uni- and multivariate time series methods. The univariate ones are: extrapolation of polynomial-harmonic model (PH), extrapolation of polynomial-harmonic model and autoregressive prediction (PH+AR), extrapolation of polynomial-harmonic model and self-exciting threshold autoregressive prediction (PH+SETAR). The following multivariate methods are used: extrapolation of polynomial-harmonic model and vector autoregressive prediction (PH+VAR), extrapolation of polynomial-harmonic model and generalized space-time autoregressive prediction (PH+GSTAR). As the aforementioned models and the corresponding forecasts are computed in real time, hence independently and in the same computational setting, we are allowed to compare the accuracies offered by the models. The objective of this work is to verify the hypothesis that the multivariate prediction techniques, which make use of cross-correlation and spatial correlation, perform better than the univariate ones. The analysis is based on the daily-fitted and updated time series models predicting the SLA data (lead time of two weeks) over several months when El Niño/Southern Oscillation (ENSO) was in its neutral state.

Mizi?ski, Bart?omiej; Niedzielski, Tomasz

2014-05-01

221

Application of short-term water demand prediction model to Seoul.  

PubMed

To predict daily water demand for Seoul, Korea, the artificial neural network (ANN) was used. For the cross correlation, the factors affecting water demand such as maximum temperature, humidity, and wind speed as natural factors, holidays as a social factor and daily demand 1 day before were used. From the results of learning using various hidden layers and units in order to establish the structure of optimal ANN, the case of 3 hidden layers and numbers of unit with the same number of input factors showed the best result and, therefore, it was applied to seasonal water demand prediction. The performance of ANN was compared with a multiple regression method. We discuss the representation ability of the model building process and the applicability of the ANN approach for the daily water demand prediction. ANN provided reasonable results for time series prediction. PMID:12380999

Joo, C N; Koo, J Y; Yu, M J

2002-01-01

222

METHOD FOR QUANTIFYING THE PREDICTION UNCERTAINTIES ASSOCIATED WITH WATER QUALITY MODELS  

EPA Science Inventory

Many environmental regulatory agencies depend on models to organize, understand, and utilize the information for regulatory decision-making. eneral analytical protocol was developed to quantify prediction rror associated with commonly used surface, water quality models. ts applic...

223

Construal Levels and Psychological Distance: Effects on Representation, Prediction, Evaluation, and Behavior  

PubMed Central

Construal level theory (CLT) is an account of how psychological distance influences individuals’ thoughts and behavior. CLT assumes that people mentally construe objects that are psychologically near in terms of low-level, detailed, and contextualized features, whereas at a distance they construe the same objects or events in terms of high-level, abstract, and stable characteristics. Research has shown that different dimensions of psychological distance (time, space, social distance, and hypotheticality) affect mental construal and that these construals, in turn, guide prediction, evaluation, and behavior. The present paper reviews this research and its implications for consumer psychology. PMID:21822366

Trope, Yaacov; Liberman, Nira; Wakslak, Cheryl

2011-01-01

224

Mapping soil water holding capacity over large areas to predict the potential production of forest stands  

E-print Network

at the soil pit scale (SWHC') and both the stone content at the soil pit scale and rock outcrop at the plot predictions being recorded for soils developed on marl, clay, and hollow silicate rocks, and in flat areas1 Mapping soil water holding capacity over large areas to predict the potential production

Paris-Sud XI, Université de

225

Effects of soil data resolution on SWAT model stream flow and water quality predictions  

Microsoft Academic Search

The prediction accuracy of agricultural nonpoint source pollution models such as Soil and Water Assessment Tool (SWAT) depends on how well model input spatial parameters describe the characteristics of the watershed. The objective of this study was to assess the effects of different soil data resolutions on stream flow, sediment and nutrient predictions when used as input for SWAT. SWAT

Mengistu Geza; John E. McCray

2008-01-01

226

Effect of vertical resolution on predictions of transpiration in water-limited ecosystems  

E-print Network

Effect of vertical resolution on predictions of transpiration in water-limited ecosystems Andrew J the vegetation root zone. Average transpiration in such environments is controlled by precipitation, and accurate of vertical resolution on predictions of transpiration, we conduct a series of numerical experiments

Guswa, Andrew J.

227

SEASONAL SOIL MOISTURE PREDICTION USING A CLIMATE-PLANT-SOIL COUPLED AGROECOSYSTEM WATER MANAGEMENT MODEL  

E-print Network

distribution of the forecast. We use observed soil moisture data from four SCAN sites: Ames, IA (42°00' N 933.13 SEASONAL SOIL MOISTURE PREDICTION USING A CLIMATE-PLANT-SOIL COUPLED AGROECOSYSTEM WATER moisture prediction is a critical factor for economic decision-making in agriculture. The national outlook

Takle, Eugene S.

228

Prediction of the environmental concentration of pesticide in paddy field and surrounding surface water bodies  

Microsoft Academic Search

Pesticides are very important in European rice production. For appropriate environmental protection, it is useful to predict the potential impact of pesticides after application, in paddy fields, in paddy runoff, and in the surrounding water, by calculating predicted environmental concentrations (PECs). In this paper, a joint simulation is described, coupling a field-scale pesticide fate model (RICEWQ) and a transportation model

Zewei Miao; Laura Padovani; Carlo Riparbelli; Amy M. Ritter; Marco Trevisan; Ettore Capri

2003-01-01

229

Fish in Long Beach waters have risky contamination levels From staff reports Long Beach Press Telegram  

E-print Network

Fish in Long Beach waters have risky contamination levels From staff reports Long Beach Press coast showed high levels of methylmercury and moderate levels of PCBs in fish in Long Beach bay waters the coast. In the bay waters of Long Beach, the levels found in fish were of "high concern," according

230

Ground-water levels near the top of the water-table mound, western Cape Cod, Massachusetts, 2002-04  

USGS Publications Warehouse

In January 2002 the U.S. Geological Survey began continuous water-level monitoring in three wells in the vicinity of the Southeast Ranges of Camp Edwards, near the Impact Area of the Massachusetts Military Reservation on Cape Cod. The purpose of this effort was to examine how water levels at sites with different unsaturated-zone thicknesses near the top of the water-table mound beneath western Cape Cod are affected by temporally variable recharge from precipitation, which is the sole source of water to the sand and gravel aquifer. The depths to water at the well sites are about 18, 30, and 101 feet below land surface. This report presents the first 3 years of water-level records and an estimate of aquifer recharge calculated from climatological measurements by the Jensen and Haise method and the Thornthwaite method. The water levels in the three wells varied temporally by about 4.5 feet during the study period. A comparison of the water levels with those measured in a nearby monitoring well with about 42 years of monthly measurements indicates that the 3-year monitoring period included the lowest water levels on western Cape Cod since the drought of the 1960's. The response of water levels to recharge was related to the depth to water. Water levels in the two wells with shallow depths to water responded quickly (within hours or days) to recharge, whereas the water-level response in the well with the greatest depth to water often lagged the recharge event by a month or more. The variations in the water levels among the wells changed as the location of the top of the water-table mound moved with the changing water-table altitude.

Massey, Andrew J.; Carlson, Carl S.; LeBlanc, Denis R.

2006-01-01

231

Project Water Science. General Science High School Level.  

ERIC Educational Resources Information Center

This teacher's guide presents 12 hands-on laboratory activities for high school science classes that cover the environmental issue of water resources in California. The activities are separated into three sections. Five activities in the section on water quality address the topics of groundwater, water hardness, bottled water, water purity, and…

Water Education Foundation, Sacramento, CA.

232

Predictive Modeling of Large-Scale Commercial Water Desalination Plants: Data-Based Neural Network and Model-Based Process  

E-print Network

predictive models of large-scale commercial water desalination plants by (1) a data- based approach usingPredictive Modeling of Large-Scale Commercial Water Desalination Plants: Data-Based Neural Network for developing predictive models for large-scale commercial water desalination plants by (1) a data

Liu, Y. A.

233

Differences in influence patterns between groups predicting the adoption of a solar disinfection technology for drinking water in Bolivia.  

PubMed

The lack of safe drinking water is one of the major problems faced by developing countries. The consequences of contaminated water are diseases such as diarrhea, one of the main causes of infant mortality. Because of its simplicity, solar water-disinfection technology provides a good way of treating water at the household level. Despite its obvious advantages and considerable promotional activities, this innovation has had rather a slow uptake. We conducted a field survey in which 644 households in Bolivia were interviewed in order to gain insights on motivations that resulted in adopting the technology. The aim was to examine possible differences in the predictors for adopting this technology during the diffusion process using the theory of innovation diffusion. Our findings indicate that early adoption was predicted by increased involvement in the topic of drinking water and that adoption in the middle of the diffusion process was predicted by increased involvement by opinion leaders and by recognition of a majority who supported the technology. Finally, late adoption was predicted by recognition that a majority had already adopted. Suggestions for future promotional strategies are outlined. PMID:18508169

Moser, Stephanie; Mosler, Hans-Joachim

2008-08-01

234

Implementing algorithms for modelling and prediction of sea level change using threshold models  

NASA Astrophysics Data System (ADS)

The aim of this work is to present how threshold time series models can be used to model sea level change recorded in gridded time series data and to predict such time-varying maps. This task is carried out mostly in R, the Language and Environment, using satellite altimetric gridded time series from the Archiving, Validation and Interpretation of Satellite Oceanographic data (AVISO). During El Niño/Southern Oscillation (ENSO) warm and cold episodes sea level anomalies exceed certain thresholds, principally in the equatorial Pacific and in the tropical Indian Ocean. This encourages to use threshold autoregressive models to predict sea level change, particularly in the aforementioned locations. It is likely, however, that during the ENSO mode one should use the models which differ from those suitable for normal environmental conditions. Associated with this is a notion of threshold that allows one to determine various models if a certain limit value is attained or exceeded. Firstly, having the global mean sea level anomaly data spanning the time interval from 1992 onwards, available courtesy of AVISO, the autoregressive threshold model is fitted in R. Subsequently, the global mean sea level change univariate time series is forecasted, and various lead times are adopted. Secondly, based on the gridded delayed-time data as well as their near-real time equivalents provided by AVISO, predictions of sea level change determined as a function of latitude and longitude, and with various lead times, are produced. Due to the fact, that the near-real time data are being automatically updated at the local server in Wroclaw, Poland, it is possible to generate new predictions every day automatically. Such a forecasting process, which intrinsically involves the automated verification and quality control modules, is based on the above-mentioned threshold models as well as polynomial-harmonic deterministic empirical functions.

Hewelt, M.; Mizi?ski, B.; Niedzielski, T.

2012-04-01

235

A Noise Level Prediction Method Based on Electro-Mechanical Frequency Response Function for Capacitors  

PubMed Central

The capacitors in high-voltage direct-current (HVDC) converter stations radiate a lot of audible noise which can reach higher than 100 dB. The existing noise level prediction methods are not satisfying enough. In this paper, a new noise level prediction method is proposed based on a frequency response function considering both electrical and mechanical characteristics of capacitors. The electro-mechanical frequency response function (EMFRF) is defined as the frequency domain quotient of the vibration response and the squared capacitor voltage, and it is obtained from impulse current experiment. Under given excitations, the vibration response of the capacitor tank is the product of EMFRF and the square of the given capacitor voltage in frequency domain, and the radiated audible noise is calculated by structure acoustic coupling formulas. The noise level under the same excitations is also measured in laboratory, and the results are compared with the prediction. The comparison proves that the noise prediction method is effective. PMID:24349105

Zhu, Lingyu; Ji, Shengchang; Shen, Qi; Liu, Yuan; Li, Jinyu; Liu, Hao

2013-01-01

236

Hair loss in females after sleeve gastrectomy: predictive value of serum zinc and iron levels.  

PubMed

A common complication after bariatric surgery is hair loss, which is related to rapid weight reduction, but zinc, iron, and other micronutrient deficiencies can also be involved. Little is studied after laparoscopic sleeve gastrectomy (LSG). A prospective observational study was performed of 42 morbidly obese females undergoing LSG. Incidence of hair loss was monitored. Micronutrients were investigated preoperatively and three, six, and 12 months after surgery. Sixteen patients (41%) reported hair loss in the postoperative course. A significant association was observed between hair loss and zinc levels (P = 0.021) but mean zinc levels were within the normal range in patients reporting hair loss. Only three patients (7.7%) presented low zinc levels, all of them reporting hair loss. There was also a significant association between iron levels and alopecia (P = 0.017), but mean values of the patients with hair loss were within normal range. Only four patients (10.2%) presented low iron levels, all of them presenting hair loss. A variable consisting of the addition of zinc + iron showed a significant association with hair loss (P = 0.013). A cutoff point was established in 115 (odds ratio, 4; P = 0.006). All the patients but two reporting hair loss presented addition levels under 115. This variable showed sensibility 88 per cent, specificity 84 per cent, positive predictive value 79 per cent, and negative predictive value 91 per cent to predict hair loss. Hair loss is a frequent condition after sleeve gastrectomy. In most cases, iron and zinc levels are within the normal range. The variable addition (zinc + iron) is a good predictor of hair loss. Patients with addition levels below 115 are fourfold more susceptible to present hair loss. In these cases, zinc supplements achieve the stop of hair loss in most cases. PMID:24887725

Ruiz-Tovar, Jaime; Oller, Inmaculada; Llavero, Carolina; Zubiaga, Lorea; Diez, María; Arroyo, Antonio; Calero, Alicia; Calpena, Rafael

2014-05-01

237

Water-level Fluctuations in the Eberswalde crater (Mars)  

NASA Astrophysics Data System (ADS)

The Eberswalde crater represents a spectacularly exposed example of water-related activity on Mars past geological history [1,2,3,4,5,6,7]. Eberswalde Crater at about 24.9° S., 33.7° W., lies just NE of Holden Crater and Uzboi Valles in Margaritifer Terra, Mars. We investigated the geology of this crater using MOC NA and HRSC imagery in combination with MOLA and HRSC derived DTM in order to recognize water-related processes and to infer depositional environments and depositional architecture. The fan delta located in the easternmost part of the crater presents well developed morphologies [1,2,3,4,5,6,7]. It consists of five lobes, suggesting prevalence of input related processes [4], even if wave- related processes seem to have been present as well [7]. Some of these lobes are coeval with the emplacement of synsedimentary tectonics and their morphology appears at least partly structural-controlled. The delta is made of bright and dark interlayered deposits. Some of the bright layers consist of very poorly sorted material, with boulders up to 10 meters of diameter floating in a finer matrix suggesting an emplacement as mass flows. Other layers consist of finer and better-sorted material. Most of the lobes display a low-dipping proximal area (1°-2°), a distal high-dipping area (6°-10°) and a more distal low-dipping area (1°-2°). We interpret the low dipping proximal part as delta plain consisting of distributary areas, mostly built by coalescing point bars [4,5], and interdistributary areas, in which crevasse splays flooded into the plain [7]. At places the topset-foreset-bottomset architecture typical of fan delta is present. In other cases, friction-related processes appear to be dominant. We interpret the high-dipping part of the fan delta as delta front deposits [7]. The oldest lobe display a transgressive-regressive cycle with a retrogradational stacking pattern at the base on top of which progradation develops. We interpret the retrogradational stacking pattern as formed during a Transgressive System Tract and the progradational stacking pattern related to a HighStand System Tract. The transition among these systems is marked by a Maximum Flooding Surface. A change in the morphology of the distributary channels from meandering to braided associated with a distal shift of the system appear to be related to a drop of the water level depicting a forced regression scenario. We interpret this lobe as formed during a Falling Stage System Tract. Friction-related processes appear to be dominant in this shallow-water type fan delta. The following lobe was deposited during another phase of rising water table which displays an overall aggradational stacking pattern [6,7] suggesting a certain equilibrium between sedimentary input, tectonic subsidence and level of the water table. The youngest two lobes do not display such a well developed depositional architecture, suggesting more episodic sedimentary activity. References 1. Malin, and Edgett, Science, 302, 1931-1934, 2003.2. Moore et al., Geophys. Res. Lett., 30, 24, 2292, doi: 10.1029/2003GL019002, 2003.3. Jerolmack et al., Geophys. Res. Lett., 31, L21701, doi: 10.1029/2004GL021326, 2004.4. Bhattacharya et al., Geophys. Res. Lett., 32, L10201, doi: 10.1029/2005GL022747, 2005.5. Wood, GSA Bulletin, 118, 5-6, 557-566; doi: 10.1130/B25822.1, 2006.6. Lewis and Aharanson, J. Geophys. Res., 111, E06001, doi: 10.1029/2005JE002558, 2006.7. Pondrelli et al., LPSC XXXVII, abstract 1555, 2006.

Pondrelli, M.; Rossi, A. P.; Marinangeli, L.; Hauber, E.; Baliva, A.; Gwinner, K.

2006-12-01

238

Molecular-level engineering of protein physical hydrogels for predictive sol-gel phase behavior  

PubMed Central

Predictable tuning of bulk mechanics from the molecular level remains elusive in many physical hydrogel systems due to the reliance on non-specific and non-stoichiometric chain interactions for network formation. We describe a Mixing-Induced Two-Component Hydrogel (MITCH) system, in which network assembly is driven by specific and stoichiometric peptide-peptide binding interactions. By integrating protein science methodologies with simple polymer physics model, we manipulate the polypeptide binding interactions and demonstrate the direct ability to predict the resulting effects on network crosslinking density, sol-gel phase behavior, and gel mechanics. PMID:21861461

Mulyasasmita, Widya; Lee, Ji Seok; Heilshorn, Sarah C.

2011-01-01

239

Derivation of a drinking water equivalent level (DWEL) related to the maximum contaminant level goal for perfluorooctanoic acid (PFOA), a persistent water soluble compound  

Microsoft Academic Search

Water soluble compounds persistent in humans and the environment pose a challenge for estimating safe levels in tap water. A viable approach to estimate a drinking water equivalent level (DWEL) for perfluorooctanoic acid (PFOA) was applied to its extensive relevant information from human and laboratory animal studies. PFOA has been identified at 3.5?g\\/L (mean) in tap water in proximity to

Robert G. Tardiff; M. Leigh Carson; Lisa M. Sweeney; Christopher R. Kirman; Yu-Mei Tan; Melvin Andersen; Christopher Bevan; Michael L. Gargas

2009-01-01

240

Sensitivity of tributaries to water-level fluctuations along the St-Lawrence corridor, Québec, Canada  

NASA Astrophysics Data System (ADS)

During the course of the last century, variations in the St-Lawrence water levels, caused by different uses of the river and the Great Lakes, have already had major impacts on riparian habitats and on a number of tributaries. Anticipated changes caused by climate change will only accentuate these impacts. At present, climate change scenarios forecast a decrease of the St-Lawrence water discharge by 20% over the next fifty years, which would correspond to a drop in water level between 0.5 and 1 metre at Montréal. Because the St- Lawrence corridor is in a region of lowlands, such fluctuations in water levels are expected to cause major adjustments in the morphology and longitudinal profiles of the tributaries through the erosion and incision of the river bed. These changes are important because ultimately, the sediment loads delivered to the St-Lawrence river are linked to the erosion processes occurring along its tributaries. However, given the important physical diversity of the tributaries, their sensitivity will differ, making it difficult to predict their individual response to environmental changes, especially given the paucity of data on the present state of the tributaries. Thus, our goal was to obtain data on the variability in morphosedimentology and dynamics of the tributaries in order to infer their sensitivity to fluctuations in baselevels. Bathymetric, hydraulic, and sedimentological surveys were conducted in 2004 and 2005 on five tributaries of the St-Lawrence: the Yamachiche, the St-Maurice, and the Batiscan rivers on the north shore, and the Richelieu and St-François rivers on the south shore. These tributaries cover a wide range of sizes and sedimentological characteristics, from cohesive clays to silts and gravel. Their hydrological regimes are also varied and are in some cases regulated, limiting the sediment capacity of certain tributaries. For example, the Yamachiche and St-François rivers have been under intense agricultural pressure, have fine sediments and have migrated significantly over the last fifty years, highlighting their instability and suggesting that changes in water levels may accentuate these erosion processes. On the other hand, the St-Maurice is highly regulated, has greater bank stability, due to its coarser sediment and intact riparian vegetation, and has remained fairly unmoved. This suggests that this river will respond more slowly to fluctuations in water levels. Investigating the current physical conditions of the tributaries will allow a better understanding of the long-term impacts of sustained periods of low water levels due to environmental change, and will help us develop a sensitivity index of the response of these rivers.

Charron, I.; Roy, A.; Boyer, C.; Verhaar, P.; Biron, P.; Morin, J.

2006-05-01

241

Method for Measuring Enriched Levels of Deuterium in Soil Water.  

National Technical Information Service (NTIS)

This report describes procedures for analyzing hydrogen isotope ratios. Hydrogen is separated from liquid water or soil water by reacting the water with heated uranium. An isotope-ratio mass spectrometer determines the atom % deuterium in the hydrogen to ...

J. L. Oliphant, T. F. Jenkins, A. R. Tice

1982-01-01

242

A Catastrophe Model for Water Bloom Prediction: A Case Study of China's Lake Chaohu  

Microsoft Academic Search

Using a case study of Lake Chaohu, the fifth largest lake in China, we constructed a cusp model for water bloom prediction that used TP (total phosphorus), T (temperature), Chla (chlorophyll-a), and DO (dissolved oxygen). These four parameters were assumed to be the most important factors in eutrophication and water bloom of the lake. The model was found to be

Chen Yun-Feng; Yin Fu-Cai; Lu Gen-Fa

2007-01-01

243

SWAT—A Semiempirical Model to Predict Concentrations of Pesticides Entering Surface Waters from Agricultural Land  

Microsoft Academic Search

A semi-empirical model called SWAT has been developed to predict concentrations of agriculturall y applied pesticides moving to surface waters, an aspect which is not well described by current models for pesticide fate. The model is based upon a direct hydrological link established between soil type and the amount of water moving rapidly to streams in response to rainfall. Attenuation

Colin D. Brown; John M. Hollis

1996-01-01

244

A semi-analytical model for predicting water quality from an aquifer storage and recovery system  

Microsoft Academic Search

Aquifer storage and recovery (ASR) involves the injection of freshwater in an aquifer through wells for the purpose of creating a subsurface water supply that is recovered at a later time, often using the same wells, to meet seasonal, long-term, emergency, or other demands. In this paper a numerically efficient semi-analytical model is developed for predicting the quality of water

Ali Sedighi; Harald Klammler; Chris Brown; Kirk Hatfield

2006-01-01

245

Predicting the effect of livestock inputs of E. coli on microbiological compliance of bathing waters  

Microsoft Academic Search

Three alternative approaches to predicting delivery of faecal indicators from livestock sources to surface water in the catchment of the River Irvine, Ayrshire, Scotland, are described. These are a soil transport model which assumes all E. coli are transported through the soil, a regression model using observed E. coli concentrations in surface waters, and a distributed catchment model (PAMIMO). Each

Andrew J. A Vinten; D. R Lewis; M McGechan; A Duncan; M Aitken; C Hill; C Crawford

2004-01-01

246

Predicting water table depths in space and time using a regionalised time series model  

Microsoft Academic Search

A regionalised autoregressive exogenous variable (RARX) model is presented for the relationship between precipitation surplus and water table depth. The parameters of the RARX model are ‘guessed’ at unvisited locations using auxiliary information such as soil profile descriptions, topographic maps and digital elevation models (DEM). In the direct method, the guessed parameters are used to predict time series of water

Martin Knotters; Marc F. P. Bierkens

2001-01-01

247

Predicting hemoglobin levels in whole blood donors using transition models and mixed effects models  

PubMed Central

Background To optimize the planning of blood donations but also to continue motivating the volunteers it is important to streamline the practical organization of the timing of donations. While donors are asked to return for donation after a suitable period, still a relevant proportion of blood donors is deferred from donation each year due to a too low hemoglobin level. Rejection of donation may demotivate the candidate donor and implies an inefficient planning of the donation process. Hence, it is important to predict the future hemoglobin level to improve the planning of donors’ visits to the blood bank. Methods The development of the hemoglobin prediction rule is based on longitudinal (panel) data from blood donations collected by Sanquin (the only blood product collecting and supplying organization in the Netherlands). We explored and contrasted two popular statistical models, i.e. the transition (autoregressive) model and the mixed effects model as plausible models to account for the dependence among subsequent hemoglobin levels within a donor. Results The predictors of the future hemoglobin level are age, season, hemoglobin levels at the previous visits, and a binary variable indicating whether a donation was made at the previous visit. Based on cross-validation, the areas under the receiver operating characteristic curve (AUCs) for male donors are 0.83 and 0.81 for the transition model and the mixed effects model, respectively; for female donors we obtained AUC values of 0.73 and 0.72 for the transition model and the mixed effects model, respectively. Conclusion We showed that the transition models and the mixed effects models provide a much better prediction compared to a multiple linear regression model. In general, the transition model provides a somewhat better prediction than the mixed effects model, especially at high visit numbers. In addition, the transition model offers a better trade-off between sensitivity and specificity when varying the cut-off values for eligibility in predicted values. Hence transition models make the prediction of hemoglobin level more precise and may lead to less deferral from donation in the future. PMID:23635008

2013-01-01

248

Plasma copeptin level predicts acute traumatic coagulopathy and progressive hemorrhagic injury after traumatic brain injury.  

PubMed

Higher plasma copeptin levels correlate with poor clinical outcomes after traumatic brain injury. Nevertheless, their links with acute traumatic coagulopathy and progressive hemorrhagic injury are unknown. Therefore, we aimed to investigate the relationship between plasma copeptin levels, acute traumatic coagulopathy and progressive hemorrhagic injury in patients with severe traumatic brain injury. We prospectively studied 100 consecutive patients presenting within 6h from head trauma. Progressive hemorrhagic injury was present when the follow-up computerized tomography scan reported any increase in size or number of the hemorrhagic lesion, including newly developed ones. Acute traumatic coagulopathy was defined as an activated partial thromboplastic time greater than 40s and/or international normalized ratio greater than 1.2 and/or a platelet count less than 120×10(9)/L. We measured plasma copeptin levels on admission using an enzyme-linked immunosorbent assay in a blinded fashion. In multivariate logistic regression analysis, plasma copeptin level emerged as an independent predictor of progressive hemorrhagic injury and acute traumatic coagulopathy. Using receiver operating characteristic curves, we calculated areas under the curve for progressive hemorrhagic injury and acute traumatic coagulopathy. The predictive performance of copeptin was similar to that of Glasgow Coma Scale score. However, copeptin did not obviously improve the predictive value of Glasgow Coma Scale score. Thus, copeptin may help in the prediction of progressive hemorrhagic injury and acute traumatic coagulopathy after traumatic brain injury. PMID:24905622

Yang, Ding-Bo; Yu, Wen-Hua; Dong, Xiao-Qiao; Du, Quan; Shen, Yong-Feng; Zhang, Zu-Yong; Zhu, Qiang; Che, Zhi-Hao; Liu, Qun-Jie; Wang, Hao; Jiang, Li; Du, Yuan-Feng

2014-08-01

249

GPS water level measurements for Indonesia's Tsunami Early Warning System  

NASA Astrophysics Data System (ADS)

On Boxing Day 2004, a severe tsunami was generated by a strong earthquake in Northern Sumatra causing a large number of casualties. At this time, neither an offshore buoy network was in place to measure tsunami waves, nor a system to disseminate tsunami warnings to local governmental entities. Since then, buoys have been developed by Indonesia and Germany, complemented by NOAA's Deep-ocean Assessment and Reporting of Tsunamis (DART) buoys, and have been moored offshore Sumatra and Java. The suite of sensors for offshore tsunami detection in Indonesia has been advanced by adding GPS technology for water level measurements. The usage of GPS buoys in tsunami warning systems is a relatively new approach. The concept of the German Indonesian Tsunami Early Warning System (GITEWS) (Rudloff et al., 2009) combines GPS technology and ocean bottom pressure (OBP) measurements. Especially for near-field installations where the seismic noise may deteriorate the OBP data, GPS-derived sea level heights provide additional information. The GPS buoy technology is precise enough to detect medium to large tsunamis of amplitudes larger than 10 cm. The analysis presented here suggests that for about 68% of the time, tsunamis larger than 5 cm may be detectable.

Schöne, T.; Pandoe, W.; Mudita, I.; Roemer, S.; Illigner, J.; Zech, C.; Galas, R.

2011-03-01

250

A global observing system for monitoring and prediction of sea level change  

NASA Astrophysics Data System (ADS)

The rise of global sea level is a direct consequence of climate change. A one-meter rise by the end of the century is estimated to have global economic impacts by trillions of US dollars and displacement of 10% of the world’s population if no adaptation is applied. Before the advent of satellite observations of sea surface height with radar altimetry, it was not possible to make direct determination of the global mean sea level. The sparsely located tide gauges were not able to sample the uneven spatial distribution of sea level change, leading to biased measurement. The 20-year record from satellite altimetry is the first directly measured time series of the global mean sea level. The satellite’s uniform global sampling also reveals the complex geographic pattern of sea level change over the past 20 years, underscoring the uncertainty from sparse tide gauge measurement. The contributions to recent sea level rise have roughly equal partitions among the steric effect from ocean warming, the melting of mountain glaciers, and the melting of polar ice sheets. The measurement of the change of Earth’s gravity field from the GRACE Mission has for the first time provided direct observation of the mass added to the ocean from ice melting. The difference between altimetry and gravity measurements is attributed to the steric sea level change, which has been observed by an in-situ network of float measurement (Argo). The intercomparison of satellite and in-situ observations has provided cross-calibration and mutual validation of the measurement system, demonstrating a calibrated measurement system for global sea level. The ability to diagnose sea level change in terms of its various components represents a key step towards understanding the physical processes. In order to assess the societal impact of sea level rise, one must be able to predict its regional pattern, which involves a host of other factors. The prediction of sea level change thus requires an Earth system science approach. The system consists of the following elements: (1) the measurement of sea level relative to the land, (2) the measurement of the main components of the ice mass contribution to sea level (i.e. surface mass balance and ice dynamics), (3) the steric contribution to sea level, (4) the mechanisms determining the geographic distribution of sea level change; and (5) the integration of these observations in advanced numerical models for hindcast and projection of sea level change. This global observing system will be discussed in the presentation.

Fu, Lee-Lueng

251

Can sediment data be used to predict alkalinity and base cation chemistry of surface waters?  

PubMed

We hypothesise that stream sediment elemental composition can predict mean and minimum concentrations of alkalinity, Ca and Mg in the river water throughout a river network. We tested this hypothesis for the River Derwent catchment in North Yorkshire, England, by using 6 years of water chemistry data from the Environment Agency and a digital elevation model to flow path-weight British Geological Survey (BGS) sediment element concentration data. The predictive models for mean concentrations were excellent for Ca and alkalinity, but less good for Mg, and did not require land use data inputs as stream water sediment composition seems to reflect all aspects of the riparian zone soil system. Predictive model forms were linear. Attempts to predict minimum values for Ca and alkalinity also were less satisfactory. This probably is due to variations in hydrological response times to individual precipitation events across the catchment. PMID:21051075

Begum, S; McClean, C J; Cresser, M S; Breward, N

2010-12-15

252

[Analysis of pollution levels of 16 antibiotics in the river water of Daliao River water system].  

PubMed

The detection of the pollution level of antibiotics in Daliao River system is a meaningful work. Sixteen antibiotics (6 sulfonamides, 5 fluoroquinolones, 3 tetracyclines and 2 chloramphenicols) were simultaneously quantified with solid-phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). In the SPE procedure, methanol and 2% (v/v) ammonia/methanol were used as the elution solvents in sequence to reduce the elution volume and improve the recovery. The results showed that this method have good sensitivity and enrichment effect for the target antibiotics in aqueous water, the recoveries ranged from 69.5% to 122.6%, the detection limits ranged from 0.05 ng/L to 0.32 ng/L. Thirteen antibiotics were found in the river water of Daliao River water system. Sulfa antibiotics were widely distributed, in which sulfamethoxazole was detected in all the sampling sites. The concentration of fluoroquinolones was relatively high in some sampling sites. The highest detection concentration of enoxacin was 41.3 ng/L. The frequencies and concentrations of tetracyclines and chloramphenicols were lower. In the upper reaches of the river, the concentrations of the 4 types of antibiotics appeared lower, but around the large cities such as Shenyang City, Benxi City, Liaoyang City, the concentrations showed higher levels. The study indicated that the Daliao River water system suffered from the pollution of antibiotics to a certain extent. PMID:23256376

Yang, Changqing; Wang, Longxing; Hou, Xiaohong; Chen, Jiping

2012-08-01

253

A water marker monitored by satellites to predict seasonal endemic cholera  

PubMed Central

The ability to predict an occurrence of cholera, a water-related disease, offers a significant public health advantage. Satellite based estimates of chlorophyll, a surrogate for plankton abundance, have been linked to cholera incidence. However, cholera bacteria can survive under a variety of coastal ecological conditions, thus constraining the predictive ability of the chlorophyll, since it provides only an estimate of greenness of seawater. Here, a new remote sensing based index is proposed: Satellite Water Marker (SWM), which estimates condition of coastal water, based on observed variability in the difference between blue (412 nm) and green (555 nm) wavelengths that can be related to seasonal cholera incidence. The index is bounded between physically separable wavelengths for relatively clear (blue) and turbid (green) water. Using SWM, prediction of cholera with reasonable accuracy, with at least two month in advance, can potentially be achieved in the endemic coastal regions. PMID:23878762

JUTLA, ANTARPREET; AKANDA, ALI SHAFQAT; HUQ, ANWAR; FARUQUE, ABU SYED GOLAM; COLWELL, RITA; ISLAM, SHAFIQUL

2013-01-01

254

Predicting population-level risk effects of predation from the responses of individuals.  

PubMed

Fear of predation produces large effects on prey population dynamics through indirect risk effects that can cause even greater impacts than direct predation mortality. As yet, there is no general theoretical framework for predicting when and how these population risk effects will arise in specific prey populations, meaning that there is often little consideration given to the key role predator risk effects can play in understanding conservation and wildlife management challenges. Here, we propose that population predator risk effects can be predicted through an extension of individual risk trade-off theory and show for the first time that this is the case in a wild vertebrate system. Specifically, we demonstrate that the timing (in specific months of the year), occurrence (at low food availability), cause (reduction in individual energy reserves), and type (starvation mortality) of a population-level predator risk effect can be successfully predicted from individual responses using a widely applicable theoretical framework (individual-based risk trade-off theory). Our results suggest that individual-based risk trade-off frameworks could allow a wide range of population-level predator risk effects to be predicted from existing ecological theory, which would enable risk effects to be more routinely integrated into consideration of population processes and in applied situations such as conservation. PMID:25163131

MacLeod, Colin D; MacLeod, Ross; Learmonth, Jennifer A; Cresswell, Will; Pierce, Graham J

2014-07-01

255

Seasonal prediction of global sea level anomalies using an ocean-atmosphere dynamical model  

NASA Astrophysics Data System (ADS)

Advanced warning of extreme sea level events is an invaluable tool for coastal communities, allowing the implementation of management policies and strategies to minimise loss of life and infrastructure damage. This study is an initial attempt to apply a dynamical coupled ocean-atmosphere model to the prediction of seasonal sea level anomalies (SLA) globally for up to 7 months in advance. We assess the ability of the Australian Bureau of Meteorology's operational seasonal dynamical forecast system, the Predictive Ocean Atmosphere Model for Australia (POAMA), to predict seasonal SLA, using gridded satellite altimeter observation-based analyses over the period 1993-2010 and model reanalysis over 1981-2010. Hindcasts from POAMA are based on a 33-member ensemble of seasonal forecasts that are initialised once per month for the period 1981-2010. Our results show POAMA demonstrates high skill in the equatorial Pacific basin and consistently exhibits more skill globally than a forecast based on persistence. Model predictability estimates indicate there is scope for improvement in the higher latitudes and in the Atlantic and Southern Oceans. Most characteristics of the asymmetric SLA fields generated by El-Nino/La Nina events are well represented by POAMA, although the forecast amplitude weakens with increasing lead-time.

Miles, Elaine R.; Spillman, Claire M.; Church, John A.; McIntosh, Peter C.

2014-10-01

256

Quantitative structure-ion intensity relationship strategy to the prediction of absolute levels without authentic standards.  

PubMed

The lack of authentic standards represents a major bottleneck in the quantitative analysis of complex samples. Here we propose a quantitative structure and ionization intensity relationship (QSIIR) approach to predict the absolute levels of compounds in complex matrixes. An absolute quantitative method for simultaneous quantification of 25 organic acids was firstly developed and validated. Napierian logarithm (LN) of the relative slope rate derived from the calibration curves was applied as an indicator of the relative ionization intensity factor (RIIF) and serves as the dependent variable for building a QSIIR model via a multiple linear regression (MLR) approach. Five independent variables representing for hydrogen bond acidity, HOMO energy, the number of hydrogen bond donating group, the ratio of organic phase, and the polar solvent accessible surface area were found as the dominant contributors to the RIIF of organic acids. This QSIIR model was validated to be accurate and robust, with the correlation coefficients (R(2)), R(2) adjusted, and R(2) prediction at 0.945, 0.925, and 0.89, respectively. The deviation of accuracy between the predicted and experimental value in analyzing a real complex sample was less than 20% in most cases (15/18). Furthermore, the high adaptability of this model was validated one year later in another LC/MS system. The QSIIR approach is expected to provide better understanding of quantitative structure and ionization efficiency relationship of analogous compounds, and also to be useful in predicting the absolute levels of analogous analytes in complex mixtures. PMID:23972977

Wu, Liang; Wu, Yuzheng; Shen, Hanyuan; Gong, Ping; Cao, Lijuan; Wang, Guangji; Hao, Haiping

2013-09-10

257

Can the amount of corn acreage predict fall armyworm (Lepidoptera: Noctuidae) infestation levels in nearby cotton?  

PubMed

Fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is a major pest of corn, Zea mays L., and a significant, but more sporadic, pest of cotton, Gossypium hirsutum L., in the Western Hemisphere. Previous studies showed that the cotton infestations primarily involve a fall armyworm subpopulation known as the "corn-strain" for which corn is the preferred host plant. It was suggested that the fall armyworm infesting cotton originated in corn and spread into secondary hosts as their numbers increased. In this study, high positive correlations were found between corn acreage and fall armyworm infestation levels in cotton. These occurred between areas that are either geographically close or along plausible migration pathways. Formulae were derived from scatter plot and linear regression analysis that can predict infestation levels in cotton based on corn acreage. The implications of these results for describing and predicting fall armyworm population movements are discussed. PMID:19253639

Nagoshi, Rodney N

2009-02-01

258

Spatial and temporal statistical analysis of a ground-water level network, Broward County, Florida  

USGS Publications Warehouse

The U.S. Geological Survey has developed a method to evaluate the spatial and temporal statistics of a continuous ground-water level recorder network in Broward County, Florida. Because the Broward County network is sparse for most spatial statistics, a technique has been developed to define polygons for each well that represent the area monitored by the well within specified criteria. The boundaries of these "confidence polygons" are defined by the endpoints of radial lines oriented toward the other wells. The lengths of these lines are determined as the statistically estimated distances to the points at which ground-water levels can be predicted within specirfied criteria. The confidence polygons indicate: (1) the areal coverage of the network, (2) locations where data are unavailable, and (3) areas of redundant data collection. Comparison with data from a noncontinuous recorder well indicates that the confidence polygons are a good represen- tation of areal coverages. The temporal analysis utilizes statistical techniques similar to those used in the spatial method, defining variations in time rather than in space. Consequently, instead of defining radial distances to points, time intervals are defined over which water-level values can be predicted within a specified confidence. These "temporal confidence intervals" correspond to maximum allowable periods between field measure- ments. To combine all results from the analyses, a single coefficient reflecting the spatial and temporal results has been developed. The coefficient is referred to as the Spatial and Temporal Adequacy and Redundancy Evaluation (STARE) and is determined by three factors: the size of the confidence polygon, the number of times the well is part of a redundant pair, and the temporal confidence interval. This coefficient and the individual results of each analysis are used in evaluating the present network and determining future management decisions.

Swain, E. D.; Sonenshein, R. S.

1994-01-01

259

Regional water table (2000) and ground-water-level changes in the Mojave River and the Morongo ground-water basins, southwestern Mojave Desert, California  

USGS Publications Warehouse

The Mojave River and Morongo ground-water basins are in the southwestern part of the Mojave Desert in southern California. Ground water from these basins supplies a major part of the water requirements for the region. The continuous population growth in this area has resulted in ever-increasing demands on local ground-water resources. The collection and interpretation of ground-water data helps local water districts, military bases, and private citizens gain a better understanding of the ground-water systems, and consequently, water availability. During 2000, the U. S. Geological Survey and other agencies made approximately 2,500 water-level measurements in the Mojave River and the Morongo ground-water basins. These data document recent conditions and, when compared with previous data, changes in ground-water levels. A water-level contour map was drawn using data from about 500 wells, providing coverage for most of the basins. Twenty-nine hydrographs show long-term (up to 70 years) water-level conditions throughout the basins, and 13 short-term (1996 to 2000) hydrographs show the effects of recharge and discharge along the Mojave River. In addition, a water-level-change map was compiled to compare 1998 and 2000 water-levels throughout the basins. In the Mojave River ground-water basins, water-level data showed little change from 1998 to 2000, with the exception of areas along the Mojave River. Water levels along the Mojave River were typically in decline or unchanged, with exceptions near the Hodge and the Lenwood outlet, where water levels rose in response to artificial recharge. The Morongo ground-water basin had virtually no change in water levels from 1998 to 2000, with the exception of Yucca Valley, where artificial recharge and ground-water withdrawal continues.

Smith, Gregory A.

2003-01-01

260

CD4 memory T cell levels predict life span in genetically heterogeneous mice  

Microsoft Academic Search

Aging leads to changes in the relative proportions of several functionally distinct T cell sub- sets, including increases in the proportions of mem- ory cells in the CD4 and CD8 subsets and in the proportion of T cells expressing the multiple-drug resistance pump P-glycoprotein. To see whether in- dividual differences in T cell subset levels predict life span, we measured

RICHARD A. MILLER; CLARENCE CHRISP; ANDRZEJ GALECKV

261

NAFLD: Predictive value of ALT levels for NASH and advanced fibrosis.  

PubMed

With expanding waistlines, the prevalence of NAFLD has burgeoned to become the leading cause of chronic liver disease in the USA. A subset of patients with NAFLD meet criteria for NASH with its inherent risk of progression to cirrhosis. Verma et al. addressed the utility of alanine aminotransferase levels for predicting NASH or advanced fibrosis to decide who would benefit from the definitive test of liver biopsy. PMID:23897284

Torres, Dawn M; Harrison, Stephen A

2013-09-01

262

An electromigration and thermal model of power wires for a priori high-level reliability prediction  

Microsoft Academic Search

In this paper, a simple power-distribution electrothermal model including the interconnect self-heating is used together with a statistical model of average and rms currents of functional blocks and a high-level model of fanout distribution and interconnect wirelength. Following the 2001 SIA roadmap projections, we are able to predict a priori that the minimum width that satisfies the electromigration constraints does

Mario R. Casu; Mariagrazia Graziano; Guido Masera; Gianluca Piccinini; Maurizio Zamboni

2004-01-01

263

Low Pro-Brain Natriuretic Peptide Levels Predict Benign Clinical Outcome in Acute Pulmonary Embolism  

Microsoft Academic Search

Background—The role of pro-brain natriuretic peptide (proBNP) for the prediction of clinical outcome has not been examined in patients with acute pulmonary embolism (PE). Methods and Results—ProBNP levels were measured in 73 patients with acute PE within 4 hours of admission. Adverse clinical outcome was defined as in-hospital death or the need for at least 1 of the following: cardiopulmonary

Nils Kucher; Gert Printzen; Tanja Doernhoefer; Stephan Windecker; Bernhard Meier; Otto Martin Hess

2011-01-01

264

Analysis of water levels in the Frenchman Flat area, Nevada Test Site  

Microsoft Academic Search

Analysis of water levels in 21 wells in the Frenchman Flat area, Nevada Test Site, provides information on the accuracy of hydraulic-head calculations, temporal water-level trends, and potential causes of water-level fluctuations. Accurate hydraulic heads are particularly important in Frenchman Flat where the hydraulic gradients are relatively flat (less than 1 foot per mile) in the alluvial aquifer. Temporal water-level

D. J. Bright; S. A. Watkins; B. A. Lisle

2001-01-01

265

Computer predictions of photochemical oxidant levels for initial precursor concentrations characteristic of southeastern Virginia  

NASA Technical Reports Server (NTRS)

A computer study was performed with a photochemical box model, using a contemporary chemical mechanism and procedure, and a range of initial input pollutant concentrations thought to encompass those characteristic of the Southeastern Virginia region before a photochemical oxidant episode. The model predictions are consistent with the expectation of high summer afternoon ozone levels when initial nonmethane hydrocarbon (NMHC) levels are in the range 0.30-0.40 ppmC and NOx levels are in the range 0.02-0.05 ppm. Calculations made with a Lagrangian model, for one of the previously calculated cases, which had produced intermediate afternoon ozone levels, suggest that urban source additions of NMHC and NOx exacerbate the photochemical oxidant condition.

Wakelyn, N. T.; Mclain, A. G.

1979-01-01

266

Prediction of daily ground-level ozone concentration maxima over New Delhi.  

PubMed

The pollution levels in New Delhi from industrial, residential, and transportation sources are continuously growing. As one of the major pollutants, ground-level ozone is responsible for various adverse effects on both humans and foliage. The present study aims to predict daily ground-level ozone concentration maxima over a site situated in New Delhi through neural networks (NN) and multiple-regression (MR) analysis. Although these methodologies are case and site specific, they are being developed and used widely. Therefore, to test these methodologies for New Delhi where no such study is available for ground-level ozone, six models have been developed based on NNs and MR using the same input data set. The changes in the performance capability of the two methods are sensitive to the selection of input parameters. The results are encouraging, and remarkable improvements in the performance of the models have been observed. PMID:19859819

Mahapatra, Amita

2010-11-01

267

A Model for Predicting Daily Peak Visitation and Implications for Recreation Management and Water Quality: Evidence  

E-print Network

Visitor use surveys and water quality data indicates that high visitor use levels of two rivers in Puerto Rico does not appear to adversely affect several water quality parameters. Optimum visitor use to maximize vis- itor defined satisfaction is a more constraining limit on visitor use than water quality. Our

268

Stathmin Protein Level, a Potential Predictive Marker for Taxane Treatment Response in Endometrial Cancer  

PubMed Central

Stathmin is a prognostic marker in many cancers, including endometrial cancer. Preclinical studies, predominantly in breast cancer, have suggested that stathmin may additionally be a predictive marker for response to paclitaxel. We first evaluated the response to paclitaxel in endometrial cancer cell lines before and after stathmin knock-down. Subsequently we investigated the clinical response to paclitaxel containing chemotherapy in metastatic endometrial cancer in relation to stathmin protein level in tumors. Stathmin level was also determined in metastatic lesions, analyzing changes in biomarker status on disease progression. Knock-down of stathmin improved sensitivity to paclitaxel in endometrial carcinoma cell lines with both naturally higher and lower sensitivity to paclitaxel. In clinical samples, high stathmin level was demonstrated to be associated with poor response to paclitaxel containing chemotherapy and to reduced disease specific survival only in patients treated with such combination. Stathmin level increased significantly from primary to metastatic lesions. This study suggests, supported by both preclinical and clinical data, that stathmin could be a predictive biomarker for response to paclitaxel treatment in endometrial cancer. Re-assessment of stathmin level in metastatic lesions prior to treatment start may be relevant. Also, validation in a randomized clinical trial will be important. PMID:24587245

Werner, Henrica M. J.; Trovik, Jone; Halle, Mari K.; Wik, Elisabeth; Akslen, Lars A.; Birkeland, Even; Bredholt, Therese; Tangen, Ingvild L.; Krakstad, Camilla; Salvesen, Helga B.

2014-01-01

269

Predicting Gene Expression Level from Relative Codon Usage Bias: An Application to Escherichia coli Genome  

PubMed Central

We present an expression measure of a gene, devised to predict the level of gene expression from relative codon bias (RCB). There are a number of measures currently in use that quantify codon usage in genes. Based on the hypothesis that gene expressivity and codon composition is strongly correlated, RCB has been defined to provide an intuitively meaningful measure of an extent of the codon preference in a gene. We outline a simple approach to assess the strength of RCB (RCBS) in genes as a guide to their likely expression levels and illustrate this with an analysis of Escherichia coli (E. coli) genome. Our efforts to quantitatively predict gene expression levels in E. coli met with a high level of success. Surprisingly, we observe a strong correlation between RCBS and protein length indicating natural selection in favour of the shorter genes to be expressed at higher level. The agreement of our result with high protein abundances, microarray data and radioactive data demonstrates that the genomic expression profile available in our method can be applied in a meaningful way to the study of cell physiology and also for more detailed studies of particular genes of interest. PMID:19131380

Roymondal, Uttam; Das, Shibsankar; Sahoo, Satyabrata

2009-01-01

270

Prospects for useful sea-level predictions from Earth-system models (Invited)  

NASA Astrophysics Data System (ADS)

Earth-system models (ESMs) to date have been unable to provide useful predictions of 21st century sea-level rise, largely because of uncertainties in the dynamic response of the Greenland and Antarctic ice sheets. As a result, planners and policymakers have had to rely on semi-empirical methods and extrapolations of current trends. In order to obtain comprehensive, physically-based sea-level predictions from ESMs, two major innovations are required: (1) Ice sheet models must represent the physical processes responsible for fast ice flow, and (2) these models must be integrated with models of the ocean, land, and atmosphere. There has been much recent progress in developing ice sheet models that include (among other improvements) higher-order stresses, adaptive and unstructured grids, and more realistic treatments of basal sliding and iceberg calving. Progress has been slower, however, in coupling ice sheet models to ESMs. In particular, work is needed to simulate small-scale ice-ocean interactions that could trigger the abrupt retreat of marine ice sheets. The barriers to coupling are cultural and technical as well as scientific. As new ice sheet models are added to ESMs, scientific understanding will grow quickly, but large uncertainties in sea-level predictions will likely remain. New assessment mechanisms are needed to communicate complex results to end users in a useful, timely fashion.

Lipscomb, W. H.

2010-12-01

271

Ground-water levels in water year 1987 and estimated ground-water pumpage in water years 1986-87, Carson Valley, Douglas County, Nevada  

USGS Publications Warehouse

Groundwater levels were measured at 58 wells during water year 1987 and a summary of estimated pumpage is given for water years 1986 and 1987 in Carson Valley, Douglas County, Nevada. The data were collected to provide a record of groundwater changes over the long-term and pumpage estimates that can be incorporated into an existing groundwater model. The estimated total pumpage in water year 1986 was 10,200 acre-ft and in water year 1987 was 13,400 acre-ft. Groundwater levels exhibited seasonal fluctuations but remained relatively stable over the reporting period throughout most of the valley. (USGS)

Berger, D.L.

1990-01-01

272

Involving regional expertise in nationwide modeling for adequate prediction of climate change effects on different demands for fresh water  

NASA Astrophysics Data System (ADS)

Nationwide modeling aims to produce a balanced distribution of climate change effects (e.g. harm on crops) and possible compensation (e.g. volume fresh water) based on consistent calculation. The present work is based on the Netherlands Hydrological Instrument (NHI, www.nhi.nu), which is a national, integrated, hydrological model that simulates distribution, flow and storage of all water in the surface water and groundwater systems. The instrument is developed to assess the impact on water use on land-surface (sprinkling crops, drinking water) and in surface water (navigation, cooling). The regional expertise involved in the development of NHI come from all parties involved in the use, production and management of water, such as waterboards, drinking water supply companies, provinces, ngo's, and so on. Adequate prediction implies that the model computes changes in the order of magnitude that is relevant to the effects. In scenarios related to drought, adequate prediction applies to the water demand and the hydrological effects during average, dry, very dry and extremely dry periods. The NHI acts as a part of the so-called Deltamodel (www.deltamodel.nl), which aims to predict effects and compensating measures of climate change both on safety against flooding and on water shortage during drought. To assess the effects, a limited number of well-defined scenarios is used within the Deltamodel. The effects on demand of fresh water consist of an increase of the demand e.g. for surface water level control to prevent dike burst, for flushing salt in ditches, for sprinkling of crops, for preserving wet nature and so on. Many of the effects are dealt with? by regional and local parties. Therefore, these parties have large interest in the outcome of the scenario analyses. They are participating in the assessment of the NHI previous to the start of the analyses. Regional expertise is welcomed in the calibration phase of NHI. It aims to reduce uncertainties by improving the rules for manmade re-direction of surface water, schematizations & parameters included in the model. This is carried out in workshops and in one-to-one expert meetings on regional models & the NHI. All results of NHI are presented on the internet and any expert may suggest improvements to the model. The final goal of the involvement of regional parties is the acceptation by decision impact receiving authorities

de Lange, Wim; Prinsen, Geert.; Hoogewoud, Jacco; Veldhuizen, Ab; Ruijgh, Erik; Kroon, Timo

2013-04-01

273

Effects of soil data resolution on SWAT model stream flow and water quality predictions.  

PubMed

The prediction accuracy of agricultural nonpoint source pollution models such as Soil and Water Assessment Tool (SWAT) depends on how well model input spatial parameters describe the characteristics of the watershed. The objective of this study was to assess the effects of different soil data resolutions on stream flow, sediment and nutrient predictions when used as input for SWAT. SWAT model predictions were compared for the two US Department of Agriculture soil databases with different resolution, namely the State Soil Geographic database (STATSGO) and the Soil Survey Geographic database (SSURGO). Same number of sub-basins was used in the watershed delineation. However, the number of HRUs generated when STATSGO and SSURGO soil data were used is 261 and 1301, respectively. SSURGO, with the highest spatial resolution, has 51 unique soil types in the watershed distributed in 1301 HRUs, while STATSGO has only three distributed in 261 HRUS. As a result of low resolution STATSGO assigns a single classification to areas that may have different soil types if SSURGO were used. SSURGO included Hydrologic Response Units (HRUs) with soil types that were generalized to one soil group in STATSGO. The difference in the number and size of HRUs also has an effect on sediment yield parameters (slope and slope length). Thus, as a result of the discrepancies in soil type and size of HRUs stream flow predicted was higher when SSURGO was used compared to STATSGO. SSURGO predicted less stream loading than STATSGO in terms of sediment and sediment-attached nutrients components, and vice versa for dissolved nutrients. When compared to mean daily measured flow, STATSGO performed better relative to SSURGO before calibration. SSURGO provided better results after calibration as evaluated by R(2) value (0.74 compared to 0.61 for STATSGO) and the Nash-Sutcliffe coefficient of Efficiency (NSE) values (0.70 and 0.61 for SSURGO and STATSGO, respectively) although both are in the same satisfactory range. Modelers need to weigh the benefits before selecting the type of data resolution they are going to use depending on the watershed size and level of accuracy required because more effort is required to prepare and calibrate the model when a fine resolution soil data is used. PMID:17475392

Geza, Mengistu; McCray, John E

2008-08-01

274

The effects of sea-level rise on water quality in coastal floodplain sediments  

NASA Astrophysics Data System (ADS)

Sea level has risen approximately 1.2 mm/year over the last 100 years (Hennessy et al. 2004) and is predicted to rise up to 80 cm by 2100 relative to 1990 sea levels (IPCC 2007). The number of extreme events related to sea level such as higher sea levels and increased inter-annual variability have also increased in frequency in the same time period (Hennessy et al. 2004). Globally, large areas of coastal and estuarine floodplains are underlain by sulfidic sediments and acid sulfate soils (ASS). These sediments frequently contain high concentrations of acidity and trace metals. A significant portion of the stored acidity occurs in the form of exchangeable and hydrolysable acidic metal cations such as Al and Fe. Watertables in these environments are often close to the surface and intercepted by relatively shallow drains. Due to their low elevation and locations, these floodplains are highly susceptible to pulses of saline water caused by saltwater intrusion, storm surge and rising sea levels. Construction of extensive drainage systems has further increased the susceptibility of the floodplain to seawater inundation by increasing connectivity to the estuarine channel. This risk is likely to increase in the future with predicted increases in sea level and extreme events due to climate change. This study uses both batch experiments to determine the effects of increasing ionic strength on exchange processes and trace metal desorption in oxidised floodplain sediments and sulfidic drain sediments, and intact soil cores to determine the surface water-porewater interactions over the short term following seawater inundation in coastal floodplain sediments. We found that that saline inundation of oxidised ASS floodplain sediments, even by relatively brackish water may cause rapid, shorter-term water quality changes and a pulse release of acidity due to desorption of acidic metal cations (Wong et al. 2010). We also found that trace metals can be mobilised from sulfidic estuarine drain sediments at near-neutral pH values without oxidation as a result of increased ionic strength and competitive desorption of metal cations (Wong et al. in press). Rapid seawater incursion in CASS drainage networks is likely to adversely impact drain water quality by increasing trace metal mobilization. Drainage networks on ASS floodplains are highly susceptible to rapid seawater inundation through storm surge, seasonal salt wedge migration, floodgate failure or floodgate opening. The experimental results show that the initial addition of marine derived salts will result in a decrease in pH and increase in trace metals, even at low salt concentrations such as that found in brackish waters in estuarine environments. References Hennessy K, Page C, McInnes K, Jones R, Bathols J, Collins D, Jones D (2004) Climate Change in New South Wales. In. CSIRO, Canberra. IPCC (2007) Climate Change 2007: Synthesis Report. In: An Assessment of the Intergovernmental Panel on Climate Change. Intergovernmental Panel on Climate Change. Wong VNL, Johnston SG, Burton ED, Bush RT, Sullivan LA, Slavich PG (2010) Seawater causes rapid trace metal mobilisation in coastal lowland acid sulfate soils: Implications of sea level rise for water quality. Geoderma 160(2): 252-263 Wong VNL, Johnston SG, Burton ED, Bush RT, Sullivan LA, Slavich PG (in press) Seawater-induced mobilization of trace metals from mackinawite-rich estuarine sediments. Water Research

Wong, Vanessa; Johnston, Scott; Burton, Edward; Bush, Richard; Sullivan, Leigh; Slavich, Peter

2013-04-01

275

Setting background nutrient levels for coastal waters with oceanic influences  

NASA Astrophysics Data System (ADS)

Nutrient enrichment of coastal water bodies as a result of human activities can lead to ecological changes. As part of a strategy to monitor such changes and detect potential eutrophication, samples were collected during research cruises conducted around the Scottish coast each January over the period 2007-2013. Data were obtained for total oxidised nitrogen (TOxN; nitrite and nitrate), phosphate and silicate, and incorporated into data-driven spatial models. Spatial averages in defined sea areas were calculated for each year in order to study inter-annual variability and systematic trends over time. Variation between some years was found to be significant (p < 0.05) but no evidence was found for any trends over the time period studied. This may have been due to the relatively short time series considered here. Modelled distributions were developed using data from groups of years (2007-2009, 2010-2011 and 2012-2013) and compared to the OSPAR Ecological Quality Objectives (EcoQOs) for dissolved inorganic nitrogen (DIN; the concentration of TOxN and ammonia), the ratio of DIN to dissolved inorganic phosphorous (N/P) and the ratio of DIN to dissolved silicate (N/S). In these three models, TOxN was below the offshore background concentration of 10 ?M (12 ?M at coastal locations) over more than 50% of the modelled area while N/S exceeded the upper assessment criterion of 2 over more than 50% of the modelled area. In the 2007-2009 model, N/P was below the background ratio (16) over the entire modelled area. In the 2010-2011 model the N/P ratio exceeded the background in 91% of the modelled area but remained below the upper assessment criterion (24). Scottish shelf sea waters were found to be depleted in TOxN relative to oceanic waters. This was not accounted for in the development of background values for the OSPAR EcoQOs so new estimates of these background values were derived. The implications of these results for setting reasonable background nutrient levels when the relationship between oceanic and coastal nutrient compositions is complex are discussed.

Smith, Alastair F.; Fryer, Rob J.; Webster, Lynda; Berx, Bee; Taylor, Alison; Walsham, Pamela; Turrell, William R.

2014-05-01

276

Water-Level Responses to Barometric-Pressure Fluctuations in Wells in Semi-Confined Aquifers  

Microsoft Academic Search

Hydrologists have long recognized that changes in barometric pressure can produce changes in water levels in wells. The relationship between barometric pressure and water level has traditionally been characterized using the barometric efficiency (BE), the ratio of the change in water level to the change in barometric pressure head. Although BE has proven to be an effective means of characterizing

W. Jin; J. J. Butler

2009-01-01

277

Estimating Impaired Waters on a County Level for Public Health Analysis  

EPA Science Inventory

Assessing the population-level impact of water quality on health can be difficult. Water quality data are measured at a watershed level and health data are organized at different levels of aggregation. To address this discrepancy and enable the consideration of water quality for ...

278

Disaggregating Hot Water Use and Predicting Hot Water Waste in Five Test Homes.  

National Technical Information Service (NTIS)

While it is important to make the equipment (or 'plant') in a residential hot water system more efficient, the hot water distribution system also affects overall system performance and energy use. Energy wasted in heating water that is not used is estimat...

H. Henderson, J. Wade, M. Gestwick

2014-01-01

279

Regional water table (1996) and water-level changes in the Mojave River, and Morongo, and the Fort Irwin ground-water basins, San Bernardino County, California  

USGS Publications Warehouse

The Mojave River, the Morongo, and the Fort Irwin ground-water basins lie in the southwestern part of the Mojave Desert Region of southern California. These basins supply ground water to local water districts, military bases, and private wells. The rapid growth in population in these basins, which is due, in part, to their proximity toLos Angeles, has increased the demand for water and, therefore, the need to understand the Mojave ground-water systems. Ground-water conditions for the Mojave River, the Morongo, and the Fort Irwin ground-water basins for 1996 and areas with significant changes in water levels are identified in this report. Water-level data were compiled for 632 wells in the study area during January-September 1996 to define the water- table surface and direction of ground-watermovement. These data were used to construct the water-table map included in this report. Also shown on the map are 31 hydrographs that show long-term water-level changes in the study area. Short-term water-level changes were determined and a water- level change map was made by comparing 1996 ground-water conditions to 1990-94 conditions in the Mojave ground-water basin and to 1994 conditions in the Morongo and the Fort Irwin ground-water basins. In general, ground-water levels and the direction of ground-water movement in the regional aquifer have not changed significantly since previously published maps (1995). However, the short-term water level did change at specific locations in all three ground-water basins. Water levels in the Mojave River ground-water basin had a maximum rise during the period 1992-96 of 52 feet and a maximum decline of 28. Water levels in the Morongo ground-water basin had a maximum rise of 66 feet and a maximum decline of 57 feet. The Fort Irwin ground-water basins, however, had relatively little change in water level with a maximum rise of 6 feet and a maximum decline of 8 feet. Hydrographs in the regional aquifer systemindicate a decline or, in some areas, no change in the water table during the period of record. Water levels in the shallow alluvial aquifer, generally within 1 mile of the Mojave River, fluctuate in response to streamflow. Ground-water levels rise during wet periods, when floodflows in the Mojave River recharge the shallow alluvial aquifer.

Mendez, Gregory O.; Christensen, Allen H.

1997-01-01

280

Adapting to Climate ChangeAdapting to Climate Change ExtremeExtreme Water Levels, Invasive Species andWater Levels, Invasive Species and  

E-print Network

Adapting to Climate ChangeAdapting to Climate Change ­­ ExtremeExtreme Water Levels, Invasive." IPCC Risk management is the framework to discuss adaptation to climate change impacts. Risk The Water Resources Working Group will assess and synthesize climate change impacts to Wisconsin's water

Sheridan, Jennifer

281

Lake-level Variability and Water Availability in the Great Lakes  

Microsoft Academic Search

Key components of water availability in a hydrologic system4 are the amount of water in storage and the variability of that amount. In the Great Lakes Basin, a vast amount of water is stored in the lakes themselves. Because of the lakes’ size, small changes in water levels cause huge changes in the amount of water in storage. Approximately 5,439

Douglas A. Wilcox; Todd A. Thompson; Robert K. Booth; J. R. Nicholas

2007-01-01

282

Water level effects on breaking wave setup for Pacific Island fringing reefs  

NASA Astrophysics Data System (ADS)

effects of water level variations on breaking wave setup over fringing reefs are assessed using field measurements obtained at three study sites in the Republic of the Marshall Islands and the Mariana Islands in the western tropical Pacific Ocean. At each site, reef flat setup varies over the tidal range with weaker setup at high tide and stronger setup at low tide for a given incident wave height. The observed water level dependence is interpreted in the context of radiation stress gradients specified by an idealized point break model generalized for nonnormally incident waves. The tidally varying setup is due in part to depth-limited wave heights on the reef flat, as anticipated from previous reef studies, but also to tidally dependent breaking on the reef face. The tidal dependence of the breaking is interpreted in the context of the point break model in terms of a tidally varying wave height to water depth ratio at breaking. Implications for predictions of wave-driven setup at reef-fringed island shorelines are discussed.

Becker, J. M.; Merrifield, M. A.; Ford, M.

2014-02-01

283

Investigations on boron levels in drinking water sources in China  

Microsoft Academic Search

To evaluate boron contamination of public drinking water in China, both dissolved and total boron contents in 98 public drinking\\u000a water sources from 49 cities, 42 brands of bottled water samples from supermarkets in several cities, and 58 water samples\\u000a from boron industrial area were measured by inductively coupled plasma-mass spectrometry (ICP-MS). Our experimental results\\u000a showed that boron existed in

Ren-ji Xu; Xiao-ru Xing; Qun-fang Zhou; Gui-bin Jiang; Fu-sheng Wei

2010-01-01

284

Determinations of coal water mixture properties for predictions of products of combustion characteristics  

SciTech Connect

The United States Department of Energy (DOE) has initiated a program to investigate the potential for coal water mixtures (CWM's) to serve as direct substitutes in combustion processes for liquid petroleum and natural gas. As a part of this overall DOE effort, Morgantown Energy Technology Center (METC) is investigating the feasibility for the combustion of ultra-clean coal water mixtures (UCCWM's) in gas turbines. A necessary goal of this program is to develop an understanding of the chemistry of the products of combustion (POC) of UCCWM's. Both experimental and modeling efforts are in progress to investigate POC chemistry. Based on these results, specifications for a UCCWM turbine fuel can be developed. In support of the modeling and experimental efforts, detailed characterization studies of coal, CWM's, and UCCWM's have been conducted to quantify levels and the distribution of minerals and trace elements. An analytical scheme has been developed for the detailed analysis of these feed fuels for input to the modeling programs for prediction of UCCWM products of combustion. The extensive chemical and physical analysis of CWM's includes determinations of percent water, ultimate and proximate analysis of the coal, elemental and compositional analysis of low-temperature ash of coal, heating values of CWM, viscosity, and coal particle size distributions. Similar analysis of samples of ash from the POC have allowed comparisons of composition and evaluations of the change in ash composition during combustion. The results of this study indicate that the detailed characterization of the CWM/UCCWM will supply the data necessary to analyze the products of combustion. 7 references, 1 figure, 7 tables.

Romanosky, R.R. Jr.; Kovach, J.J.; Anderson, R.J.

1983-04-01

285

Research SummaryFluoride levels in bottled water  

Microsoft Academic Search

Objective The aims of this study were to measure the fluoride content of still bottled waters on sale in the UK and to estimate and compare the fluoride intake from tap and bottled water for British children.Methods Three bottles of 25 commercial brands of bottled water were purchased from supermarkets, grocery stores and health shops in the North-East of England.

Andrew Rugg-Gunn

2003-01-01

286

Predicting hourly-based flow discharge hydrographs from level data using genetic algorithms  

NASA Astrophysics Data System (ADS)

SummaryThis study developed a genetic algorithm model to predict flow rates at sites receiving significant lateral inflow. It predicts flow rate at a downstream station from flow stage measured at upstream and downstream stations. For this purpose, it constructed two different models: First is analogous to the rating curve model (RCM) of Moramarco et al. [Moramarco, M., Barbetta, S., Melone, F., Singh, V.P., 2005. Relating local stage and remote discharge with significant lateral inflow. J. Hydrologic Eng., ASCE, 10(1)] and the second is based on summation of contributions from upstream station and lateral inflows using kinematic wave approximation. The model was applied to predict flow rates at three different gauging stations located on Tiber River, Upper Tiber River Basin, Italy. The model used average wave travel time for each river reach and obtained average set of parameter values for all the events observed in the same river reach. The GA model was calibrated, for each river reach and for each formulation, by three events and tested against three other events. The results showed that the GA model produced satisfactory results and it was superior over the most recently developed rating curve method. This study further analyzed the case where only water surface elevation data were used in the input vector to predict flow rates. The results showed that using elevation data produces satisfactory results. This has an implication for predicting flow rates at ungauged river sites since the surface elevation data can be obtained without needing the detailed geometry of river section which could change significantly during a flood.

Tayfur, Gokmen; Moramarco, Tommaso

2008-04-01

287

A Bayesian network to predict vulnerability to sea-level rise: data report  

USGS Publications Warehouse

During the 21st century, sea-level rise is projected to have a wide range of effects on coastal environments, development, and infrastructure. Consequently, there has been an increased focus on developing modeling or other analytical approaches to evaluate potential impacts to inform coastal management. This report provides the data that were used to develop and evaluate the performance of a Bayesian network designed to predict long-term shoreline change due to sea-level rise. The data include local rates of relative sea-level rise, wave height, tide range, geomorphic classification, coastal slope, and shoreline-change rate compiled as part of the U.S. Geological Survey Coastal Vulnerability Index for the U.S. Atlantic coast. In this project, the Bayesian network is used to define relationships among driving forces, geologic constraints, and coastal responses. Using this information, the Bayesian network is used to make probabilistic predictions of shoreline change in response to different future sea-level-rise scenarios.

Gutierrez, Benjamin T.; Plant, Nathaniel G.; Thieler, E. Robert

2011-01-01

288

Prediction of full-scale dewatering results of sewage sludges by the physical water distribution.  

PubMed

The dewaterability of sewage sludge can be described by the total solids concentration of the sludge cake and the polymer-demand for conditioning. The total solids concentration of the sludge cake depends on the physical water distribution. The various types of water in sewage sludge are mainly distinguished by the type and the intensity of their physical bonding to the solids. In a sewage sludge suspension four different types of water can be distinguished. These are the free water, which is not bound to the particles, the interstitial water, which is bound by capillary forces between the sludge flocs, the surface water, which is bound by adhesive forces and intracellular water. Only the share of free water can be separated during mechanical dewatering. It can be shown, that by thermo-gravimeteric measurement of the free water content, an exact prediction of full-scale dewatering results is possible. By separation of all free water during centrifugation the maximum dewatering result is reached. Polymer conditioning increases the velocity of the sludge water release, but the free water content is not influenced by this process. Furthermore it is not possible, to replace the measuring of the water distribution by other individual parameters such as ignition loss. PMID:11443955

Kopp, J; Dichtl, N

2001-01-01

289

River flow controls on tides and tide-mean water level profiles in a tidal freshwater river  

NASA Astrophysics Data System (ADS)

Tidal rivers feature oscillatory and steady gradients in the water surface, controlled by interactions between river flow and tides. The river discharge attenuates the tidal motion, and tidal motion increases tidal-mean friction in the river, which may act as a barrier to the river discharge. Time series of tidal water level amplitudes at five gauge stations along the River Mahakam in Indonesia, and tidal flow velocity amplitudes at a discharge monitoring station were obtained applying wavelet analysis. Temporal variations in tidal damping coefficients for quaterdiurnal, semidiurnal, and diurnal tidal species were quantified from the observed amplitude profiles. The analysis shows that tidal damping during the rising limb of a discharge wave differs from damping during the falling limb. Wavelet cross-correlations between surface levels yielded empirical estimates of wave numbers. An empirical relation between tidal damping and river flow is derived to describe subtidal bottom friction along an idealized tidal river resembling the Mahakam. The subtidal friction is decomposed into contributions from the river flow only, from river-tide interaction, and from tidal asymmetry. Even for high river flow and low tidal velocity, river flow enhances friction attributed to river-tide interaction, causing subtidal water level setup. A simple multilinear regression model using subtidal bottom friction is employed to predict subtidal water levels at locations upstream, with a relatively good agreement between predictions and observations. The explicit expression shows the nonlinear dependence of subtidal friction on river flow velocity, explaining the complex behavior of tidal-mean surface level profiles.

Sassi, M. G.; Hoitink, A. J. F.

2013-09-01

290

Predicting spatial kelp abundance in shallow coastal waters using the acoustic ground discrimination system RoxAnn  

NASA Astrophysics Data System (ADS)

Kelp forests represent a major habitat type in coastal waters worldwide and their structure and distribution is predicted to change due to global warming. Despite their ecological and economical importance, there is still a lack of reliable spatial information on their abundance and distribution. In recent years, various hydroacoustic mapping techniques for sublittoral environments evolved. However, in turbid coastal waters, such as off the island of Helgoland (Germany, North Sea), the kelp vegetation is present in shallow water depths normally excluded from hydroacoustic surveys. In this study, single beam survey data consisting of the two seafloor parameters roughness and hardness were obtained with RoxAnn from water depth between 2 and 18 m. Our primary aim was to reliably detect the kelp forest habitat with different densities and distinguish it from other vegetated zones. Five habitat classes were identified using underwater-video and were applied for classification of acoustic signatures. Subsequently, spatial prediction maps were produced via two classification approaches: Linear discriminant analysis (LDA) and manual classification routine (MC). LDA was able to distinguish dense kelp forest from other habitats (i.e. mixed seaweed vegetation, sand, and barren bedrock), but no variances in kelp density. In contrast, MC also provided information on medium dense kelp distribution which is characterized by intermediate roughness and hardness values evoked by reduced kelp abundances. The prediction maps reach accordance levels of 62% (LDA) and 68% (MC). The presence of vegetation (kelp and mixed seaweed vegetation) was determined with higher prediction abilities of 75% (LDA) and 76% (MC). Since the different habitat classes reveal acoustic signatures that strongly overlap, the manual classification method was more appropriate for separating different kelp forest densities and low-lying vegetation. It became evident that the occurrence of kelp in this area is not simply linked to water depth. Moreover, this study shows that the two seafloor parameters collected with RoxAnn are suitable indicators for the discrimination of different densely vegetated seafloor habitats in shallow environments.

Mielck, F.; Bartsch, I.; Hass, H. C.; Wölfl, A.-C.; Bürk, D.; Betzler, C.

2014-04-01

291

Prediction of water vapor transport rates across polyvinylchloride packaging systems using a novel radiotracer method  

SciTech Connect

A radiotracer method is used to study the transport properties of water vapor in polyvinylchloride (PVC), a plastic commonly used in the packaging of parenteral solutions. Water vapor transport across a PVC film appears to be Fickian in nature. Using the steady-state solution of Fick's second law and the permeability coefficient of water vapor across the PVC film obtained using the described method, the predicted water vapor transport rate (WVTR) for a parenteral solution packaged in PVC is in reasonable agreement with actual WVTR as determined by weight loss under precisely controlled conditions.

Wood, R.W.; Mulski, M.J.; Kuu, W.Y. (Baxter Healthcare Corporation, Round Lake, IL (USA))

1990-09-01

292

Regional water table (2004) and water-level changes in the Mojave River and Morongo ground-water basins, Southwestern Mojave Desert, California  

USGS Publications Warehouse

The Mojave River and Morongo ground-water basins are in the southwestern part of the Mojave Desert in southern California. Ground water from these basins supplies a major part of the water requirements for the region. The continuous population growth in this area has resulted in ever-increasing demands on local ground-water resources. The collection and interpretation of ground-water data helps local water districts, military bases, and private citizens gain a better understanding of the ground-water flow systems, and consequently, water availability. During March and April 2004, the U.S. Geological Survey and other agencies made almost 900 water-level measurements in about 740 wells in the Mojave River and Morongo ground-water basins. These data document recent conditions and, when compared with historical data, changes in ground-water levels. A water-level contour map was drawn using data from 500 wells, providing coverage for most of the basins. In addition, 26 long-term (as much as 74 years) hydrographs were constructed which show water-level conditions throughout the basins, 9 short-term (1992 to 2004) hydrographs were constructed which show the effects of recharge and discharge along the Mojave River, and a water-level-change map was compiled to compare 2002 and 2004 water levels throughout the basins. The water-level change data show that in the Mojave River ground-water basin, more than one half (102) of the wells had water-level declines of 0.5 ft or more and almost one fifth (32) of the wells had declines greater than 5 ft. between 2002 and 2004. The water-level change data also show that about one tenth (17) of the wells compared in the Mojave River ground-water basin had water level increases of 0.5 ft or more. Most of the water-level increases were the result of stormflow in the Mojave River during March 2004, which resulted in recharge to wells in the floodplain aquifer mainly along the river in the Alto subarea and the Transition zone, and along the river east of Barstow. In the Morongo ground-water basin, nearly one half (55) of the wells had water-level declines of 0.5 ft or more, and about one tenth (13) of the wells had declines greater than 5 ft. The Warren subbasin, where artificial-recharge operations in Yucca Valley (pl. 1) have caused water levels to rise, had water-level increases of as much as about 97 ft since 2002.

Stamos, Christina L.; Huff, Julia A.; Predmore, Steven K.; Clark, Dennis A.

2004-01-01

293

Muscle Architecture Predicts Maximum Strength and Is Related to Activity Levels in Cerebral Palsy  

PubMed Central

Background Muscle architecture is known to be predictive of muscle function. However, it is unknown whether this relationship is similar in children and adolescents with and without cerebral palsy (CP). Objective The objective of this study was to determine whether the architecture of the rectus femoris (RF) and vastus lateralis (VL) muscles was predictive of maximum voluntary knee extensor torque in children and adolescents with and without CP and whether these measures were related to activity and participation levels. Design A case-control design was used. Methods Eighteen participants with CP (mean age=12.0 years, SD=3.2) at Gross Motor Function Classification System (GMFCS) levels I through IV and 12 age-matched peers with typical development (mean age=12.3 years, SD=3.9) were evaluated. Muscle thickness, fascicle length, and fascicle angle of the RF and VL muscles were measured with 2-dimensional, B-mode ultrasound imaging. The activity and participation measures used for participants with CP were the Pediatric Outcomes Data Collection Instrument (PODCI) and the Activities Scale for Kids, Performance Version (ASKp). Results When age and GMFCS level were controlled for, VL muscle thickness was the best predictor of knee extensor isometric torque in the group with CP (R2=.85). This prediction was similar to the prediction from VL muscle thickness and age in participants with typical development (R2=.91). Rectus femoris muscle fascicle length was significantly correlated with the Sports and Physical Functioning Scale of the PODCI (?=.49), and VL muscle fascicle angle was correlated with the Transfers and Basic Mobility Scale of the PODCI (r=.47) and with ASKp Locomotion subdomain (r=.50). Limitations A limitation of this study was the small sample size. Conclusions Ultrasound measures of VL muscle thickness, adjusted for age and GMFCS level, were highly predictive of maximum torque and have the potential to serve as surrogate measures of voluntary strength (force-generating capacity) in children and adolescents with and without CP. PMID:20847035

Simpson, Kit N.; Teefey, Sharlene A.; Damiano, Diane L.

2010-01-01

294

Fasting Serum C-Peptide Levels Predict Cardiovascular and Overall Death in Nondiabetic Adults  

PubMed Central

Background Insulin resistance, characterized by hyperinsulinemia and normal or elevated serum glucose, is an established precursor to diabetes and cardiovascular disease. Despite fasting serum C?peptide levels being an accurate and stable marker of endogenous insulin production used in patients with diabetes, it is unknown whether C?peptide could serve as a marker of insulin resistance and predict outcomes in patients without diabetes. Method and Results This is a retrospective cohort study using data from the NHANES?3 (1988–1994) survey with mortality follow?up through December 31, 2006. Participants included 5153 subjects, 40 to 74 years of age with fasting glucose ?70 mg/dL, without diabetes by history or laboratory testing. Receiver?operating?curve analysis compared fasting C?peptide against known insulin resistance measures such as fasting plasma glucose, serum insulin, HOMA?IR, quantitative?insulin?sensitivity?check?index, and metabolic syndrome for the prediction of cardiovascular and overall death. Subjects were then stratified by quartiles of C?peptide levels. Cox proportional?hazards modeling compared hazards of cardiovascular and overall death amongst C?peptide quartiles and adjusted for potential confounders of cardiovascular and diabetes risk. Fasting serum C?peptide levels predicted cardiovascular and overall death better than other studied measures (AUC=0.62 and 0.60 respectively vs the rest, with AUC?0.58 and ?0.57 respectively, P<0.001). When compared with the lowest C?peptide quartile, subjects in the highest quartile had significantly higher adjusted hazard ratios (HR) of cardiovascular death (HR=1.60, 95%CI 1.07 to 2.39) and overall mortality (HR=1.72, 95%CI 1.34 to 2.21) after controlling for confounders. Conclusions C?peptide levels significantly related to hazards of cardiovascular and overall death in nondiabetic adults and was a better predictor of these outcomes than serum insulin and/or glucose derived measures. PMID:23316320

Patel, Nileshkumar; Taveira, Tracey H.; Choudhary, Gaurav; Whitlatch, Hilary; Wu, Wen-Chih

2012-01-01

295

Model analysis of effects on water levels at Indiana Dunes National Lakeshore caused by construction dewatering  

USGS Publications Warehouse

The computer models were developed to investigate possible hydrologic effects within the Indiana Dunes National Lakeshore caused by planned dewatering at the adjacent Bailly Nuclear Generator construction site. The model analysis indicated that the planned dewatering would cause a drawdown of about 4 ft under the westernmost pond of the Lakeshore and that this drawdown would cause the pond to go almost dry--less than 0.5 ft of water remaining in about 1 percent of the pond--under average conditions during the 18-month dewatering period. When water levels are below average, as during late July and early August 1974, the pond would go dry in about 5.5 months. However, the pond may not have to go completely dry to damage the ecosystem. If the National Park Service 's independent study determines the minimum pond level at which ecosystem damage would be minimized, the models developed in this study could be used to predict the hydrologic conditions necessary to maintain that level. (Woodard-USGS)

Marie, James R.

1976-01-01

296

Nitrates in drinking water and methemoglobin levels in pregnancy: a longitudinal study  

Microsoft Academic Search

BACKGROUND: Private water systems are more likely to have nitrate levels above the maximum contaminant level (MCL). Pregnant women are considered vulnerable to the effects of exposure to high levels of nitrates in drinking water due to their altered physiological states. The level of methemoglobin in the blood is the biomarker often used in research for assessing exposure to nitrates.

Deana M Manassaram; Lorraine C Backer; Rita Messing; Lora E Fleming; Barbara Luke; Carolyn P Monteilh

2010-01-01

297

Analysis on the characteristics of parameters in groundwater table fluctuation model for predicting groundwater levels in Hancheon watershed, South Korea  

NASA Astrophysics Data System (ADS)

A novel application of groundwater table fluctuation method is suggested to predict groundwater level by means of groundwater table variation due to recharge and discharge under unsteady condition. This model analyzes transient groundwater characteristics by using reaction factor related with groundwater flow and specific yield related with recharge. The groundwater level varies according to the characteristics and composite materials of aquifer. In this study, specific yield and reaction factor which are the major two hydrogeological parameters in the WTF(Water Table Fluctuation) method were estimated and analyzed their spatial characteristics. 8 groundwater level stations which have enough measuring period and high correlation with rainfall in the Hancheon watershed were used. The results showed that specific yield was randomly distributed and reaction factor showed inverse trend with altitude. If the enough data were collected, reaction factor according to altitude in ungauged points could be estimated by using these parameter characteristics. keywords: Key words : Groundwater level, parameters, reaction factor, specific yield Acknowledgements This research was supported by the Regional Innovative Technology Project 2B from KICTTEP.

Kim, Nam Won; Kim, Youn Jung; Chung, Il-Moon; Lee, Jeongwoo

2014-05-01

298

U.S. Geological Survey Water science strategy--observing, understanding, predicting, and delivering water science to the nation  

USGS Publications Warehouse

This report expands the Water Science Strategy that began with the USGS Science Strategy, “Facing Tomorrow’s Challenges—U.S. Geological Survey Science in the Decade 2007–2017” (U.S. Geological Survey, 2007). This report looks at the relevant issues facing society and develops a strategy built around observing, understanding, predicting, and delivering water science for the next 5 to 10 years by building new capabilities, tools, and delivery systems to meet the Nation’s water-resource needs. This report begins by presenting the vision of water science for the USGS and the societal issues that are influenced by, and in turn influence, the water resources of our Nation. The essence of the Water Science Strategy is built on the concept of “water availability,” defined as spatial and temporal distribution of water quantity and quality, as related to human and ecosystem needs, as affected by human and natural influences. The report also describes the core capabilities of the USGS in water science—the strengths, partnerships, and science integrity that the USGS has built over its 134-year history. Nine priority actions are presented in the report, which combine and elevate the numerous specific strategic actions listed throughout the report. Priority actions were developed as a means of providing the audience of this report with a list for focused attention, even if resources and time limit the ability of managers to address all of the strategic actions in the report.

Evenson, Eric J.; Orndorff, Randall C.; Blome, Charles D.; Böhlke, John Karl; Hershberger, Paul K.; Langenheim, Victoria E.; McCabe, Gregory J.; Morlock, Scott E.; Reeves, Howard W.; Verdin, James P.; Weyers, Holly S.; Wood, Tamara M.

2013-01-01

299

Serum creatinine level, a surrogate of muscle mass, predicts mortality in peritoneal dialysis patients  

PubMed Central

Background In hemodialysis patients, higher serum creatinine (Cr) concentration represents larger muscle mass and predicts greater survival. However, this association remains uncertain in peritoneal dialysis (PD) patients. Methods In a cohort of 10 896 PD patients enrolled from 1 July 2001 to 30 June 2006, the association of baseline serum Cr level and change during the first 3 months after enrollment with all-cause mortality was examined. Results The cohort mean ± SD age was 55 ± 15 years old and included 52% women, 24% African-Americans and 48% diabetics. Compared with patients with serum Cr levels of 8.0–9.9 mg/dL, patients with serum Cr levels of <4.0 mg/dL and 4.0–5.9 mg/dL had higher risks of death {HR 1.36 [95% confidence interval (95% CI) 1.19–1.55] and 1.19 (1.08–1.31), respectively} whereas patients with serum Cr levels of 10.0–11.9 mg/dL, 12.0–13.9 mg/dL and ?14.0 mg/dL had lower risks of death (HR 0.88 [95% CI 0.79–0.97], 0.71 [0.62–0.81] and 0.64 [0.55–0.75], respectively) in the fully adjusted model. Decrease in serum Cr level over 1.0 mg/dL during the 3 months predicted an increased risk of death additionally. The serum Cr–mortality association was robust in patients with PD treatment duration of ?12 months, but was not observed in those with PD duration of <3 months. Conclusions Muscle mass reflected in serum Cr level may be associated with survival even in PD patients. However, the serum Cr–mortality association is attenuated in the early period of PD treatment, suggesting competing effect of muscle mass versus residual renal function on mortality. PMID:23743018

Park, Jongha; Mehrotra, Rajnish; Rhee, Connie M.; Molnar, Miklos Z.; Lukowsky, Lilia R.; Patel, Sapna S.; Nissenson, Allen R.; Kopple, Joel D.; Kovesdy, Csaba P.; Kalantar-Zadeh, Kamyar

2013-01-01

300

Study on short term prediction using observed water quality from 8-day intervals in Nakdong river  

NASA Astrophysics Data System (ADS)

There are lots of accidents on water quality, like green algal blooms, occurring in Nakdong river which is one of the largest river in Korea. This is because of climate change around the world. It is essential to develop scientific and quantitative assessment methods. In this study, artificial neural network based on back propagation algorithm, which is simple and flexible method, was used for forecasting the water quality on the purpose of water resources management. Especially, as used observed water quality data from 8-day intervals in Nakdong river, it makes to increase the accuracy of water quality forecast over short term. This was established for predicting the water quality factors 1, 3, and 7 days ahead. The best model, as evaluated by its performance functions with RMSE and R2, was selected and applied to established models of BOD, DO, COD, and Chl-a using artificial neural network. The results showed that the models were suitable for 1 and 3 days forecasts in particular. This method is strong and convenient to predict water quality factors over the short term easily based on observed data. It is possible to overcome and manage problems related to the water resources. In the future, this will be a powerful method because it is basically based on observed water quality data.

Kim, M.; Shon, T.; Joo, J.; Kim, J.; Shin, H.

2012-12-01

301

Effect of censoring trace-level water-quality data on trend-detection capability  

USGS Publications Warehouse

Monte Carlo experiments were used to evaluate whether trace-level water-quality data that are routinely censored (not reported) contain valuable information for trend detection. Measurements are commonly censored if they fall below a level associated with some minimum acceptable level of reliability (detection limit). Trace-level organic data were simulated with best- and worst-case estimates of measurement uncertainty, various concentrations and degrees of linear trend, and different censoring rules. The resulting classes of data were subjected to a nonparametric statistical test for trend. For all classes of data evaluated, trends were most effectively detected in uncensored data as compared to censored data even when the data censored were highly unreliable. Thus, censoring data at any concentration level may eliminate valuable information. Whether or not valuable information for trend analysis is, in fact, eliminated by censoring of actual rather than simulated data depends on whether the analytical process is in statistical control and bias is predictable for a particular type of chemical analyses.

Gilliom, R.J.; Hirsch, R.M.; Gilroy, E.J.

1984-01-01

302

Water levels in continuously monitored wells in the Yucca Mountain area, Nevada, 1985--88  

SciTech Connect

Water levels have been monitored hourly in 15 wells completed in 23 depth intervals in the Yucca Mountain area, Nevada. Water levels were monitored using pressure transducers and were recorded by data loggers. The pressure transducers were periodically calibrated by raising and lowering them in the wells. The water levels were normally measured at approximately the same time that the transducers were calibrated. Where the transducer output appeared reasonable, it was converted to water levels using the calibrations and manual water- level measurements. The amount of transducer output that was converted to water levels ranged from zero for several intervals to about 98 percent for one interval. Fourteen of the wells were completed in Tertiary volcanic rocks and one well was completed in Paleozoic carbonate rocks. Each well monitored from one to four depth intervals. Water-level fluctuation caused by barometric pressure changes and earth tides were observed.

Luckey, R.R.; Lobmeyer, D.H.; Burkhardt, D.J.

1993-07-01

303

Simplified combustion noise theory yielding a prediction of fluctuating pressure level  

NASA Technical Reports Server (NTRS)

The first order equations for the conservation of mass and momentum in differential form are combined for an ideal gas to yield a single second order partial differential equation in one dimension and time. Small perturbation analysis is applied. A Fourier transformation is performed that results in a second order, constant coefficient, nonhomogeneous equation. The driving function is taken to be the source of combustion noise. A simplified model describing the energy addition via the combustion process gives the required source information for substitution in the driving function. This enables the particular integral solution of the nonhomogeneous equation to be found. This solution multiplied by the acoustic pressure efficiency predicts the acoustic pressure spectrum measured in turbine engine combustors. The prediction was compared with the overall sound pressure levels measured in a CF6-50 turbofan engine combustor and found to be in excellent agreement.

Huff, R. G.

1984-01-01

304

A method for predicting the noise levels of coannular jets with inverted velocity profiles  

NASA Technical Reports Server (NTRS)

A coannular jet was equated with a single stream equivalent jet with the same mass flow, energy, and thrust. The acoustic characteristics of the coannular jet were then related to the acoustic characteristics of the single jet. Forward flight effects were included by incorporating a forward exponent, a Doppler amplification factor, and a Strouhal frequency shift. Model test data, including 48 static cases and 22 wind tunnel cases, were used to evaluate the prediction method. For the static cases and the low forward velocity wind tunnel cases, the spectral mean square pressure correlation coefficients were generally greater than 90 percent, and the spectral sound pressure level standard deviation were generally less than 3 decibels. The correlation coefficient and the standard deviation were not affected by changes in equivalent jet velocity. Limitations of the prediction method are also presented.

Russell, J. W.

1979-01-01

305

Influence of Summer Water-Level Variability on St. Lawrence River-Wetland Fish Assemblages  

Microsoft Academic Search

Water-level and associated variability are substantial influences on wetland and shallow aquatic communities. The Akwesasne Wetland Complex is an extensive St. Lawrence River system affected by water regulation. The responses offish assemblages to short-term summer water-level variation were examined throughout this section of the St. Lawrence River and its tributaries. An influence of water-level variability was detected on abundance of

James E. McKenna Jr; Joyce L. Barkley; James H. Johnson

2008-01-01

306

Predicting Different Levels of Academic Success in College Using High School GPA and ACT Composite Score. ACT Research Report Series.  

ERIC Educational Resources Information Center

This study compared the effectiveness of American College Testing (ACT) Composite score and high school grade point average (GPA) for predicting different levels of first-year college GPA. Logistic regression models were estimated for predicting first-year GPA levels ranging from 2.00 to 3.75 for a sample of postsecondary institutions. The…

Noble, Julie; Sawyer, Richard

307

Droplet size distribution and liquid volume concentration in a water spray: Predictions and measurements  

NASA Astrophysics Data System (ADS)

A water spray, from a twin fluid atomizer, was studied at different air temperatures and at atmospheric pressure. The Sauter Mean Diameter, D sub 32, and the droplet volume distribution were measured at four different distances from the injector. An optical method was used to measure droplet sizes. Predictions of the Sauter Mean Diameter, liquid volume concentration and droplet size distribution were also evaluated. The influence of the air velocity, air temperature and of the water flow rate in the spray S.M.D. and in the liquid volume concentration at different distances from the injector have been measured. The predictions showed good agreement with experimental results.

Pita, G. P.

1984-01-01

308

Effect of water level drawdown on decomposition in boreal peatlands  

NASA Astrophysics Data System (ADS)

Plant litter production and decomposition are key processes in element cycling in most ecosystems. In peatlands, there has been a long-term imbalance between litter production and decay caused by high water levels (WL) and consequent anoxia. This has resulted in peatlands being a significant sink of carbon (C) from the atmosphere. However, peatlands are experiencing both "natural" (global climate change) and anthropogenic (ditching) changes that threaten their ability to retain this ecosystem identity and function. Many of these alterations can be traced back to WL drawdown, which can cause increased aeration, higher acidity, falling temperatures, and a greater probability of drought. Such changes are also associated with an increasing decomposition rate, and therefore a greater amount of C released back to the atmosphere. Yet studies about how the overall C balance of peatlands will be affected have come up with conflicting conclusions, demonstrating that the C store could increase, decrease, or remain static. A factor that has been largely overlooked is the change in litter type composition following persistent WL drawdown. It is the aim of our study, then, to help to resolve this issue. We studied the effects of short-term (ca. 4 years) and long-term (ca. 40 years) persistent WL drawdown on the decomposition of numerous types of above-ground and below-ground plant litters at three boreal peatland sites: bog, oligotrophic fen and mesotrophic fen. We thus believe that enough permutations have been created to obtain a good assessment of how each factor, site nutrient level, WL regime, and litter type composition, influences decomposition. We used the litter bag method to measure the decomposition rates: placed measured amounts of plant litter, or cellulose strips as a control, into closed mesh bags, and installed the bags in the natural environment for decomposition for each litter type for varying amounts of time. Following litter bag recovery, the litter was cleaned of excess debris and analyzed for changes in mass, enzyme activity, mesofauna presence, and microbial community composition, among other things. The experiment has a run-time of ten years, the results from the first two years are presented in the poster.

Straková, Petra; Penttilä, Timo; Laiho, Raija

2010-05-01

309

Hepcidin levels predict nonresponsiveness to oral iron therapy in patients with iron deficiency anemia.  

PubMed

Levels of hepcidin, a major regulator of iron homeostasis, may identify patients with iron deficiency anemia (IDA) who will not respond to oral iron therapy. In this study, IDA patients underwent a 14-day trial (run-in) course of ferrous sulfate therapy. Nonresponders (Hgb increase <1 g/dL with 67% compliance rate) were randomized to IV ferric carboxymaltose (FCM; two injections of 750 mg) or further oral iron for 14 days. Screening hepcidin levels were 38.4 versus 11.3 ng/mL, P = 0.0002 in nonresponders versus responders to a trial of oral iron. Hepcidin of > 20 ng/mL, showed sensitivity of 41.3%, specificity of 84.4%, and positive predictive value of 81.6% for predicting nonresponsiveness to oral iron. PPVs for ferritin> 30 ng/mL or transferrin saturation (TSAT)>15% were 59.2 and 55%, respectively. Negative predictive values for hepcidin, ferritin, and TSAT were 46.3, 22.7, and 19.7, respectively. FCM versus oral iron showed Hgb increases of ? 1 gm/dL in 65.3% versus 20.8% (P < 0.0001) and Hgb increases of 1.7 ± 1.3 versus 0.6 ± 0.9 g/dL (P = 0.0025), respectively. We conclude that hepcidin predicts nonresponsiveness to oral iron in patients with IDA and is superior to TSAT or ferritin for this purpose. Nonresponse to oral iron therapy does not rule out IDA, since two-thirds of patients subsequently responded to intravenous iron. PMID:23335357

Bregman, David B; Morris, David; Koch, Todd A; He, Andy; Goodnough, Lawrence T

2013-02-01

310

Using land surface model and satellite observations to simulate lake water level and thermal variations  

NASA Astrophysics Data System (ADS)

In this study, lakes are included in a coupled routing model and catchment-based land surface model (CHARMS), which is modified from the land-surface component (CLM4) of an Earth system model (CESM1). In the routing scheme, lakes are connected with rivers using upstream/downstream relationships in a lake basin. Evaporation, precipitation, and river runoff are modeled in order to close the lake water budget. However, the original lake model in CLM4 poorly predicts the lake temperature, which highly affects the evaporation and surface energy fluxes. Using an improved lake model (CLM4-LISSS) the lake water temperature and surface energy flux are better predicted. This new version of CHARMS is tested on several large lakes around the world (e.g., the Great Lakes, and Lake Victoria) to evaluate its performance in different climate zones. Modeled lake level time series are compared with satellite altimetry. In order to test the ability of CHARMS to simulating the variations of lake temperature, we compare the amount of thermal expansion calculated from modeled lake temperature with the amount of thermal expansion determined from Gravity Recovery and Climate Experiment (GRACE) and satellite altimetry data.

Liu, H.; Famiglietti, J. S.; Subin, Z. M.

2011-12-01

311

Prediction of high level vibration test results by use of available inelastic analysis techniques  

SciTech Connect

As part of a cooperative study between the United States and Japan, the US Nuclear Regulatory Commission and the Ministry of International Trade and Industry of Japan agreed to perform a test program that would subject a large scale piping model to significant plastic strains under excitation conditions much greater than the design condition for nuclear power plants. The objective was to compare the results of the tests with state-of-the-art analyses. Comparisons were done at different excitation levels from elastic to elastic-plastic to levels where cracking was induced in the test model. The program was called the high Level Vibration Test (HLVT). The HLVT was performed on the seismic table at the Tadotsu Engineering Laboratory of Nuclear Power Engineering Test Center in Japan. The test model was constructed by modifying the 1/2.5 scale model of one loop of a PWR primary coolant system which was previously tested by NUPEC as part of their seismic proving test program. A comparison of various analysis techniques with test results shows a higher prediction error in the detailed strain values than in the overall response values. This prediction error is magnified as the plasticity in the test model increases. There is no significant difference in the peak responses between the simplified and the detailed analyses. A comparison between various detailed finite element model runs indicates that the material properties and plasticity modeling have a significant impact on the plastic strain responses under dynamic loading reversals. 5 refs., 12 figs.

Hofmayer, C.H.; Park, Y.J. (Brookhaven National Lab., Upton, NY (USA)); Costello, J.F. (Nuclear Regulatory Commission, Washington, DC (USA))

1991-01-01

312

Investigating Storm-Induced Total Water Levels on Complex Barred Beaches  

NASA Astrophysics Data System (ADS)

Water levels in coastal environments are not static, but rather vary from a range of factors including mean sea level, tides, storm surge, and wave runup. Cumulatively these superimposed factors determine the total water level (TWL), the extent of which has major implications for coastal erosion and inundation during periods of high energy. Storm-induced, super-elevated water levels pose a threat to low lying coastal regions, as clearly demonstrated by recent events such as Hurricanes Sandy and Katrina. For this reason, the ability to accurately predict the TWL is crucial for both emergency managers and coastal planners. While some components of TWL are well understood (e.g., tides) there is still significant uncertainty in predicting runup, a process that can be a major contributor to instantaneous TWLs. Traditionally, empirical relationships derived from observational field data have been used to estimate runup, including wave setup and both incident and infragravity swash (Stockdon et al., 2006). While these formulations have shown skill in predicting the runup extent on natural beaches, these equations consider only the most basic contributing factors - namely the mean foreshore beach slope, the offshore wave height, and offshore wave period. Not included in these empirical estimates is the role of nearshore morphology on TWLs. However, it has long been recognized that nearshore sandbars act as natural barriers to coastal erosion during storm events by dissipating wave energy far from the beach face. Nonetheless, the influence of nearshore morphology on inner surf zone processes, including wave runup, is poorly understood. Recent pioneering studies (eg., Soldini et al., 2013 and Stephens et al., 2011) have explored the role of simple nearshore features (single Gaussian bars) on swash processes. Many locations in the world, however, are characterized by more complex morphologies such as multiple barred systems. Further, in many such places, including Columbia River Littoral Cell (USA), Duck, NC (USA), Hasaki (Japan), and the Netherlands, a net offshore bar migration (NOM) cycle has been observed whereby bars migrate seaward across the surf zone and decay offshore on interannual cycles. Depending on the stage of the cycle, the number and configuration of the bars may differ widely. For example in the Columbia River Littoral Cell there are typically 2 to 4 nearshore bars. In 1999, the outermost bar crest was located in a water depth of 6.5 m (relative to MLLW) while in 2009 it was located only in 3 m of water. Such large differences in nearshore morphology clearly influence wave breaking patterns and have the potential for influencing the corresponding wave runup as well. Here we apply a numerical, short-wave averaged yet long-wave resolving, non-linear hydrodynamic model (XBeach) to investigate the role that real world (non-synthetic), complex morphologies exert on TWLs. Model simulations under moderate to extreme wave forcing conditions are being used to develop relationships between offshore wave conditions, bar configuration, and runup extent. Additionally, we are exploring how, under the same wave conditions, a particular location may be more vulnerable to flooding simply based on the stage of the NOM cycle. Comparisons with the Stockdon et al. (2006) runup equation will be made to assess traditional empirical approaches relative to model predictions.

Cohn, N.; Ruggiero, P.; Walstra, D.

2013-12-01

313

Predicting impacts of increased CO? and climate change on the water cycle and water quality in the semiarid James River Basin of the Midwestern USA.  

PubMed

Emissions of greenhouse gases and aerosols from human activities continue to alter the climate and likely will have significant impacts on the terrestrial hydrological cycle and water quality, especially in arid and semiarid regions. We applied an improved Soil and Water Assessment Tool (SWAT) to evaluate impacts of increased atmospheric CO(2) concentration and potential climate change on the water cycle and nitrogen loads in the semiarid James River Basin (JRB) in the Midwestern United States. We assessed responses of water yield, soil water content, groundwater recharge, and nitrate nitrogen (NO(3)-N) load under hypothetical climate-sensitivity scenarios in terms of CO(2), precipitation, and air temperature. We extended our predictions of the dynamics of these hydrological variables into the mid-21st century with downscaled climate projections integrated across output from six General Circulation Models. Our simulation results compared against the baseline period 1980 to 2009 suggest the JRB hydrological system is highly responsive to rising levels of CO(2) concentration and potential climate change. Under our scenarios, substantial decrease in precipitation and increase in air temperature by the mid-21st century could result in significant reduction in water yield, soil water content, and groundwater recharge. Our model also estimated decreased NO(3)-N load to streams, which could be beneficial, but a concomitant increase in NO(3)-N concentration due to a decrease in streamflow likely would degrade stream water and threaten aquatic ecosystems. These results highlight possible risks of drought, water supply shortage, and water quality degradation in this basin. PMID:22641243

Wu, Yiping; Liu, Shuguang; Gallant, Alisa L

2012-07-15

314

Effect of time step size and turbulence model on the open water hydrodynamic performance prediction of contra-rotating propellers  

NASA Astrophysics Data System (ADS)

A growing interest has been devoted to the contra-rotating propellers (CRPs) due to their high propulsive efficiency, torque balance, low fuel consumption, low cavitations, low noise performance and low hull vibration. Compared with the single-screw system, it is more difficult for the open water performance prediction because forward and aft propellers interact with each other and generate a more complicated flow field around the CRPs system. The current work focuses on the open water performance prediction of contra-rotating propellers by RANS and sliding mesh method considering the effect of computational time step size and turbulence model. The validation study has been performed on two sets of contra-rotating propellers developed by David W Taylor Naval Ship R & D center. Compared with the experimental data, it shows that RANS with sliding mesh method and SST k-? turbulence model has a good precision in the open water performance prediction of contra-rotating propellers, and small time step size can improve the level of accuracy for CRPs with the same blade number of forward and aft propellers, while a relatively large time step size is a better choice for CRPs with different blade numbers.

Wang, Zhan-zhi; Xiong, Ying

2013-04-01

315

A morphometrically based method for predicting water layer boundaries in meromictic lakes  

Microsoft Academic Search

Many general mass-balance models that simulate processes in one or two water layers have been successfully constructed, tested\\u000a and used to predict effects from remediating lake pollution and other environmental disturbances. However, these models are\\u000a poorly suited for meromictic lakes which consist of yet another water layer. In order to determine a cross-systems based algorithm\\u000a for the depth of the

Andreas C. Bryhn

2009-01-01

316

Regional Water Table (2002) and Water-Level Changes in the Mojave River and Morongo Ground-Water Basins, Southwestern Mojave Desert, California  

USGS Publications Warehouse

The Mojave River and Morongo ground-water basins are in the southwestern part of the Mojave Desert in southern California. Ground water from these basins supplies a major part of the water requirements for the region. The continuous population growth in this area has resulted in ever-increasing demands on local ground-water resources. The collection and interpretation of ground-water data helps local water districts, military bases, and private citizens gain a better understanding of the ground-water flow systems, and consequently, water availability. During 2002, the U.S. Geological Survey and other agencies made approximately 2,500 water-level measurements in the Mojave River and Morongo ground-water basins. These data document recent conditions and, when compared with previous data, changes in ground-water levels. A water-level contour map was drawn using data from about 600 wells, providing coverage for most of the basins. Twenty-eight hydrographs show long-term (up to 70 years) water-level conditions throughout the basins, and 9 short-term (1997 to 2002) hydrographs show the effects of recharge and discharge along the Mojave River. In addition, a water-level-change map was compiled to compare 2000 and 2002 water levels throughout the basins. In the Mojave River ground-water basin, about 66 percent of the wells had water-level declines of 0.5 ft or more since 2000 and about 27 percent of the wells had water-level declines greater than 5 ft. The only area that had water-level increases greater than 5 ft that were not attributed to fluctuations in nearby pumpage was in the Harper Lake (dry) area where there has been a significant reduction in pumpage during the last decade. In the Morongo ground-water basin, about 36 percent of the wells had water-level declines of 0.5 ft or more and about 10 percent of the wells had water-level declines greater than 5 ft. Water-level increases greater than 5 ft were measured only in the Warren subbasin, where artificial-recharge operations have caused water levels to rise almost 60 ft since 2000.

Smith, Gregory A.; Stamos, Christina L.; Predmore, Steven K.

2004-01-01

317

Corrosion models for predictions of performance of high-level radioactive-waste containers  

SciTech Connect

The present plan for disposal of high-level radioactive waste in the US is to seal it in containers before emplacement in a geologic repository. A proposed site at Yucca Mountain, Nevada, is being evaluated for its suitability as a geologic repository. The containers will probably be made of either an austenitic or a copper-based alloy. Models of alloy degradation are being used to predict the long-term performance of the containers under repository conditions. The models are of uniform oxidation and corrosion, localized corrosion, and stress corrosion cracking, and are applicable to worst-case scenarios of container degradation. This paper reviews several of the models.

Farmer, J.C.; McCright, R.D. [Lawrence Livermore National Lab., CA (United States); Gdowski, G.E. [KMI Energy Services, Livermore, CA (United States)

1991-11-01

318

Increased total serum random cortisol levels predict mortality in critically ill trauma patients.  

PubMed

Dysfunction in the hypothalamopituitary adrenal axis is thought to exist; however, there continues to be controversy about what level of serum cortisol corresponds to adrenal insufficiency. Few studies have focused on the significance of serum random cortisol in the critically ill trauma patient. Trauma patients with total serum random cortisol levels drawn in the intensive care unit within the first seven days of hospitalization were retrospectively reviewed. The primary outcome measured was in-hospital mortality. Two hundred forty-two patients were analyzed. Nonsurvivors had significantly higher mean cortisol levels than survivors (28.7 ± 15.80 ?g/dL vs 22.9 ± 12.35 ?g/dL, P = 0.01). Patients with cortisol 30 ?g/dL or greater were more likely to die with odds ratio of 2.7 (95% confidence interval [CI], 1.5 to 5). The odds ratio increased to 4.0 and 3.8 (95% CI, 1.4 to 11.4 and 1.3 to 10.9) when cortisol was drawn on hospital Day 2 and Days 3 through 7, respectively. Among nonsurvivors, patients with an injury severity score less than 25 had significantly higher cortisol levels than patients with an Injury Severity Score 25 or higher (35.3 ± 19.21 ?g/dL vs 25.7 ± 13.21 ?g/dL, P = 0.009). Patients with massive transfusion, traumatic brain injury, spinal cord injury, or solid organ injury did not have significantly different cortisol levels. The covariate-adjusted area under the receiver operating characteristic curve indicated that cortisol level has a 77 per cent accuracy in differentiating survivors from nonsurvivors. Higher cortisol levels were predictive of mortality in critically ill trauma patients. Whether serum cortisol level is a marker that can be modified remains an area of interest for future study. PMID:25347501

Pandya, Urmil; Polite, Nathan; Wood, Teresa; Lieber, Michael

2014-11-01

319

Predicting Trigger Level for Ice Jam Flooding of the lower Mohawk River using LiDAR and GIS  

NASA Astrophysics Data System (ADS)

Ice jams are an annual occurrence along the Mohawk River in upstate New York. The jams commonly result in significant flooding especially when the progress of the ice is impeded by obstructions to the channel and flood plain. To minimize flooding hazards it is critical to know the trigger level of flooding so that we can better understand chronic jam points and simulate flooding events as jams occur as the lower Mohawk. A better understanding of jamming and trigger points may facilitate measures to reduce flooding and avoid the costly damage associated with these hazards. To determine the flood trigger level for one segment of the lower Mohawk we used Air-LiDAR elevation data to construct a digital elevation model to simulate a flooding event. The water flood simulation using a LiDAR elevation model allows accurate water level measurements for determining trigger levels of ice dam flooding. The study area comprises three sections of the lower Mohawk River from the (Before location) to the (After location), which are constrained by lock stations centered at the New York State Canal System Lock 9 (E9 Lock) and the B&M Rail Bridge at the Schenectady International (SI) Plant. This area is notorious for ice jams including one that resulted in a major flooding event on January 25th, 2010 which resulted in flood levels at 74.4 m in the upper portion of the second section of the study area (Lock 9) and at 73.4 m in the lower portion (SI plant). Minimum and maximum elevation levels were found to determine the values at which up stream water builds up and when flooding occurs. From these values, we are able to predict the flooding as the ice jam builds up and breaks as it progresses downstream. Similar methodology is applied to find the trigger points for flooding along other sections of the Mohawk River constrained by lock stations, and it may provide critical knowledge as to how to better manage the hazard of flooding due to ice jams.

Foster, J.; Marsellos, A.; Garver, J.

2011-12-01

320

A new method of analysis of water-level response to a moving boundary of a longwall mine  

NASA Astrophysics Data System (ADS)

Longwall coal mining is an economical method for coal extraction that allows most of the coal to be extracted from a wide rectangular panel. The roof of the working face area is temporarily held up by supports which advance as the mine face advances. A basin-like subsidence trough develops at the ground surface over the panel as the panel roof behind the supports collapses. A dynamic subsidence front causes a water-level drop at wells ahead of the panel. We examine the effects of subsidence on water-level by introducing a sink that moves with the mining face, using the one-dimensional flow equation. To test the validity of this method, we estimated aquifer parameters of Trivoli Sandstone aquifer over a longwall coal mine in the Illinois Basin by analyzing water-level versus time data measured from three observation wells. The presented method predicts a value of transmissivity and storage coefficient that is reasonably close to the average of pumping test results. With this method we provide solutions to two significant problems: (1) Presubs(2) water-level drops can be predicted for a planned longwall mine if the aquifer parameters are known.

Karaman, Abdullah; Akhiev, Seyidali S.; Carpenter, Philip J.

1999-04-01

321

Regional Water Table (1998) and Ground-Water-Level Changes in the Mojave River, and the Morongo Ground-Water Basins, San Bernardino County, California  

USGS Publications Warehouse

The Mojave River and the Morongo ground-water basins are in the southwestern part of the Mojave Desert in southern California. Ground water from these basins supplies a major part of the water requirements for the region. The rapid and continuous population growth in this area has resulted in ever-increasing demands on local ground-water resources. The continuing collection and interpretation of ground-water data helps local water districts, military bases, and private citizens gain a better understanding of the ground-water systems and, consequently, water availability. During 1998 the U.S. Geological Survey and other agencies made approximately 2,370 water-level measurements in the Mojave River and the Morongo ground-water basins. These data document recent conditions and changes in ground-water levels. A water-level contour map was drawn using data from 450 wells, providing coverage for most of both basins. Twenty-three hydrographs show long-term (as much as 70 years) water-level trends throughout the basins. To help show effects of late seasonal recharge along the Mojave River, 14 short-term (13 years) hydrographs were created. A water-level change map was compiled to enable comparison of 1996 and 1998 water levels. The Mojave River and the Morongo ground-water basins had little change in water levels between 1996 and 1998 - with the exception of the areas of the Yucca Valley affected by artificial recharge. Other water-level changes were localized and reflected pumping or measurements made before seasonal recharge. Three areas of perched ground water were identified: El Mirage Lake (dry), Adelanto, and Lucerne Valley.

Smith, Gregory A.; Pimentel, M. Isabel

2000-01-01

322

Techniques for monitoring and predicting water vulnerability with an application in Ethiopia  

NASA Astrophysics Data System (ADS)

A lack of water will be one of the great challenges facing humanity in the 21st century. UN projections for 2050 suggest that between 2 and 7 billion people will face chronic water insecurity. Improved information tools for assessing, monitoring and predicting water insecurity will become increasingly important. This study combines rainfall estimates with surface runoff estimates and population density information to create a Water Vulnerability Index. The WVI is a standardized index that expresses the relative availability of surface water. A WVI of 100 denotes sufficient water to support typical agro-pastoral livelihoods. We apply the WVI in Ethiopia, which has a large, growing, and increasingly food and water insecure population. Recent research performed for the USAID Famine Early Warning System Network has identified large water insecure populations threatened by a recent decrease in rainfall, probably associated with warming in the southwest Indian Ocean. We use a 40-year time-series of WVI values to explore trends, seasonal and intra-seasonal predictability, with particular attention paid to climate forcing in the Indian Ocean. An early warning tool combining satellite rainfall observations and climate-based projections will be described and evaluated.

Funk, C. C.; Verdin, J.; Senay, G.

2005-12-01

323

A regional neural network ensemble for predicting mean daily river water temperature  

NASA Astrophysics Data System (ADS)

Water temperature is a fundamental property of river habitat and often a key aspect of river resource management, but measurements to characterize thermal regimes are not available for most streams and rivers. As such, we developed an artificial neural network (ANN) ensemble model to predict mean daily water temperature in 197,402 individual stream reaches during the warm season (May-October) throughout the native range of brook trout Salvelinus fontinalis in the eastern U.S. We compared four models with different groups of predictors to determine how well water temperature could be predicted by climatic, landform, and land cover attributes, and used the median prediction from an ensemble of 100 ANNs as our final prediction for each model. The final model included air temperature, landform attributes and forested land cover and predicted mean daily water temperatures with moderate accuracy as determined by root mean squared error (RMSE) at 886 training sites with data from 1980 to 2009 (RMSE = 1.91 °C). Based on validation at 96 sites (RMSE = 1.82) and separately for data from 2010 (RMSE = 1.93), a year with relatively warmer conditions, the model was able to generalize to new stream reaches and years. The most important predictors were mean daily air temperature, prior 7 day mean air temperature, and network catchment area according to sensitivity analyses. Forest land cover at both riparian and catchment extents had relatively weak but clear negative effects. Predicted daily water temperature averaged for the month of July matched expected spatial trends with cooler temperatures in headwaters and at higher elevations and latitudes. Our ANN ensemble is unique in predicting daily temperatures throughout a large region, while other regional efforts have predicted at relatively coarse time steps. The model may prove a useful tool for predicting water temperatures in sampled and unsampled rivers under current conditions and future projections of climate and land use changes, thereby providing information that is valuable to management of river ecosystems and biota such as brook trout.

DeWeber, Jefferson Tyrell; Wagner, Tyler

2014-09-01

324

6 ManagingWaterResourcesin DynamicSettings:AMulti-level,  

E-print Network

Ngana1 , Benedikt Notter2 , Peter Messerli3 , Urs Wiesmann4 , Gimbage Mbeyale5 , Tuli Msuya6. Growing popula- tions and increasing economic activity are resulting in greater demand for water of the world. The great dynamics of the changes that affect water supply, cou- pled with the fact that negative

Richner, Heinz

325

Prediction of infarct severity from triiodothyronine levels in patients with ST-elevation myocardial infarction  

PubMed Central

Background/Aims The aim of the present study was to evaluate the relationship between thyroid hormone levels and infarct severity in patients with ST-elevation myocardial infarction (STEMI). Methods We retrospectively reviewed thyroid hormone levels, infarct severity, and the extent of transmurality in 40 STEMI patients evaluated via contrast-enhanced cardiac magnetic resonance imaging. Results The high triiodothyronine (T3) group (? 68.3 ng/dL) exhibited a significantly higher extent of transmural involvement (late transmural enhancement > 75% after administration of gadolinium contrast agent) than did the low T3 group (60% vs. 15%; p = 0.003). However, no significant difference was evident between the high- and low-thyroid-stimulating hormone/free thyroxine (FT4) groups. When the T3 cutoff level was set to 68.3 ng/dL using a receiver operating characteristic curve, the sensitivity was 80% and the specificity 68% in terms of differentiating between those with and without transmural involvement. Upon logistic regression analysis, high T3 level was an independent predictor of transmural involvement after adjustment for the presence of diabetes mellitus (DM) and the use of glycoprotein IIb/IIIa inhibitors (odds ratio, 40.62; 95% confidence interval, 3.29 to 502; p = 0.004). Conclusions The T3 level predicted transmural involvement that was independent of glycoprotein IIb/IIIa inhibitor use and DM positivity. PMID:25045293

Kim, Dong Hun; Kim, Hyun-Wook; Choi, Seo-Won; Kim, Bo-Bae; Chung, Joong-Wha; Koh, Young-Youp; Chang, Kyong-Sig; Hong, Soon-Pyo

2014-01-01

326

Information-based system identification for predicting the groundwater-level fluctuations of hillslopes  

NASA Astrophysics Data System (ADS)

The analysis of pre-existing landslides and landslide-prone hillslopes requires an estimation of maximum groundwater levels. Rapid increase in groundwater levels may be a dominant factor for evaluating the occurrence of landslides. System identification—use of mathematical tools and algorithms for building dynamic models from measured data—is adopted in this study. The fluid mass-balance equation is used to model groundwater-level fluctuations, and the model is analytically solved using the finite-difference method. Entropy-based classification (EBC) is used as a data-mining technique to identify the appropriate ranges of influencing variables. The landslide area at Wushe Reservoir, Nantou County, Taiwan, is chosen as a field test site for verification. The study generated 65,535 sets of numbers for the groundwater-level variables of the governing equation, which is judged by root mean square errors. By applying cross-validation methods and EBC, limited numbers of validation samples are used to find the range of each parameter. For these ranges, a heuristic method is employed to find the best results of each parameter for the prediction model of groundwater level. The ranges for governing factors are evaluated and the resulting performance is examined.

Hong, Yao-Ming; Wan, Shiuan

2011-09-01

327

Predicting wear and blood metal ion levels in metal-on-metal hip resurfacing.  

PubMed

Suboptimal component position and design are thought to lead to edge wear and raised blood metal ion levels in metal-on-metal hip resurfacing (MOM-HR). These factors are thought to influence the "contact patch to rim distance" (CPRD), and calculation of this distance may improve prediction of wear and blood metal ion levels. We measured blood cobalt and chromium ion levels and the wear rates of the bearing surfaces in 165 MOM-HR retrieval cases. We then determined the contribution and effect sizes of cup inclination and version angles, component size and design, and CPRD (calculated from case-specific data) on blood metal ion levels and component wear rates. Acetabular orientation explained between 16.3% and 28.5% of the variation in wear rates and metal ion levels, whereas component size and design explained between 7.3% and 21.8% of the variability. In comparison, CPRD explained up to 67.7% of the variability, significantly greater than any other variable (all p < 0.0001). CPRD is a good predictor of wear and improves our understanding of wear performance and the mechanisms leading to edge loading. PMID:24115200

Matthies, Ashley K; Henckel, Johann; Cro, Suzie; Suarez, Alexander; Noble, Philip C; Skinner, John; Hart, Alister J

2014-01-01

328

Sources of Elevated Sodium Levels in Drinking Water...and Recommendations for Reduction.  

ERIC Educational Resources Information Center

Sodium enters drinking water by a variety of human activities and by natural means. Evidence suggests elevated levels of sodium in drinking water may adversely affect health. Action should be taken to reduce the level of human exposure to sodium in drinking water. (RE)

Calabrese, Edward J.; Tuthill, Robert W.

1978-01-01

329

Comparison of recreation use values among alternative reservoir water level management scenarios  

Microsoft Academic Search

Throughout the United States, reservoirs are managed for multiple uses, including hydropower, stream flow regulation, flood control, and recreation. Water level drawdowns for hydropower, stream flow regulation, and flood control often reduce the suitability of reservoirs for water-based recreation. The gain in aggregate economic use value of outdoor recreation under three alternative water level management scenarios was measured for four

H. Ken Cordell; John C. Bergstrom

1993-01-01

330

Visualizing relationships between hydrology, climate, and water level fluctuations on Earth's largest system of lakes  

E-print Network

: Data visualization Water levels Great Lakes Climate change Hydroclimate Net basin supply Understanding surface of fresh water on Earth (Gronewold et al., 2013b). Understanding drivers behind the recent recordNotes Visualizing relationships between hydrology, climate, and water level fluctuations on Earth

331

Terrestrial waters and sea level variations on interannual time scale W. Llovel a,  

E-print Network

Terrestrial waters and sea level variations on interannual time scale W. Llovel a, , M. Becker model. For each time span, we compare change in land water storage (expressed in sea level equivalent to multidecadal time scales, thermal expansion of sea waters and land ice loss are the main contributors to sea

Ribes, Aurélien

332

Time response of the water table and saltwater transition zone to a base level drop  

E-print Network

Time response of the water table and saltwater transition zone to a base level drop Y. Kiro,1,2 Y by defining two characteristic times that describe the response of the water table and the transition zone and saline water has not been monitored over a period of time during a lake level drop. Furthermore

Lyakhovsky, Vladimir

333

Short term comparison of climate model predictions and satellite altimeter measurements of sea levels  

Microsoft Academic Search

Climate models (http:\\/\\/climatecommission.govspace.gov.au\\/files\\/2011\\/05\\/4108-CC-Science-Update-PRINT-CHANGES.pdf, 2011; http:\\/\\/www.ipcc.ch\\/publications_and_data\\/publications_ipcc_fourth_assessment_report_synthesis_report.htm, 2011; Rahmstorf, 2007, 2010) calculate that temperatures are increasing globally and sea level rises are increasing due to anthropogenic carbon dioxide emissions. More recent predictions (http:\\/\\/climatecommission.govspace.gov.au\\/files\\/2011\\/05\\/4108-CC-Science-Update-PRINT-CHANGES.pdf, 2011; Rahmstorf, 2007, 2010) have forecasted that sea level rises by 2100 will be higher than the 2007 projections by the Intergovernmental Panel on Climate Change (http:\\/\\/www.ipcc.ch\\/publications_and_data\\/publications_ipcc_fourth_assessment_report_synthesis_report.htm, 2011), with

Alberto A. Boretti

334

Prediction of the hemoglobin level in hemodialysis patients using machine learning techniques.  

PubMed

Patients who suffer from chronic renal failure (CRF) tend to suffer from an associated anemia as well. Therefore, it is essential to know the hemoglobin (Hb) levels in these patients. The aim of this paper is to predict the hemoglobin (Hb) value using a database of European hemodialysis patients provided by Fresenius Medical Care (FMC) for improving the treatment of this kind of patients. For the prediction of Hb, both analytical measurements and medication dosage of patients suffering from chronic renal failure (CRF) are used. Two kinds of models were trained, global and local models. In the case of local models, clustering techniques based on hierarchical approaches and the adaptive resonance theory (ART) were used as a first step, and then, a different predictor was used for each obtained cluster. Different global models have been applied to the dataset such as Linear Models, Artificial Neural Networks (ANNs), Support Vector Machines (SVM) and Regression Trees among others. Also a relevance analysis has been carried out for each predictor model, thus finding those features that are most relevant for the given prediction. PMID:25070755

Martínez-Martínez, José M; Escandell-Montero, Pablo; Barbieri, Carlo; Soria-Olivas, Emilio; Mari, Flavio; Martínez-Sober, Marcelino; Amato, Claudia; Serrano López, Antonio J; Bassi, Marcello; Magdalena-Benedito, Rafael; Stopper, Andrea; Martín-Guerrero, José D; Gatti, Emanuele

2014-11-01

335

Circulating Level of miR-378 Predicts Left Ventricular Hypertrophy in Patients with Aortic Stenosis  

PubMed Central

Aims Excessively high left ventricle mass is an independent predictor of adverse prognosis. MicroRNAs (miRs) play crucial roles in the regulation of left ventricle hypertrophy (LVH). However, few circulating miRs have been established as predictors of LVH in aortic stenosis (AS) patients. In this study, we aimed to investigate whether circulating levels of miR-1, miR-133, and miR-378 predict LVH in patients with AS. Methods and Results One-hundred twelve patients with moderate to severe AS and 40 healthy controls were included in the study. Levels of miR-1, miR-133, and miR-378 in the plasma were measured by qPCR. Compared with healthy controls, AS patients had significantly lower circulating levels of miR-1, miR-133, and miR-378. AS patients with LVH had significantly lower miR-378 but not miR-1 and miR-133 compared with those without LVH. Linear regression analysis showed circulating miR-378 had strong correlation with left ventricular mass index (r?=?0.283, p?=?0.002) and logistic regression showed that lower miR-378 was an independent predictor for LVH in patients with AS (p?=?0.037, OR 4.110, 95% CI 1.086 to 15.558). Conclusion Circulating levels of miR-1, miR-133 and miR-378 were decreased in AS patients, and miR-378 predicts LVH independent of the pressure gradient. Further prospective investigations are needed to elucidate whether these circulating miRs affect clinical outcome. PMID:25157568

Xu, Yuanning; Li, Yajiao; Yang, Hao; Rao, Li

2014-01-01

336

Predicting the Impact of Climate Change on Threatened Species in UK Waters  

E-print Network

species. Furthermore, the adverse consequences of climate change on the habitat suitability of protectedPredicting the Impact of Climate Change on Threatened Species in UK Waters Miranda C. Jones1 Kingdom, 3 Tyndall Centre for Climate Change Research, Norwich, Norfolk, United Kingdom, 4 Atmospheric

Rodgers, Keith

337

Critical heat flux prediction for saturated flow boiling of water in vertical tubes  

Microsoft Academic Search

This study presents a new analytical model for the prediction of the critical heat flux (CHF) in water saturated flow boiling in round vertical and uniformly heated pipes. The CHF is assumed to occur in annular flow when the liquid film vanishes at the exit section of the heated channel. Channel pressure drop is calculated using the Friedel correlation. Liquid

Gian Piero Celata; Kaichiro Mishima; Giuseppe Zummo

2001-01-01

338

COMPARISON OF MODEL PREDICTIONS AND CONSUMPTIVE WATER USE OF CLOSED CYCLE COOLING SYSTEMS  

EPA Science Inventory

The report gives results of a comparison of field-data-derived water evaporation rates with predictive model values for cooling towers and cooling ponds at steam-electric generating plants. The Leung Moore cooling tower model and five cooling pond models (Harbeck and Marciano; Ha...

339

Flood Control with Model Predictive Control for River Systems with Water Reservoirs  

E-print Network

- ature for controlling channels, such as proportional-integral, heu- ristic, predictive, and optimal on these equations, to- gether with the dynamics of hydraulic structures and junctions, a mathematical model can the nonlinearities of gates and hydraulic structures into account (Thai 2005), and none of them have water reservoirs

340

Thermosiphon solar domestic water heating systems: long-term performance prediction using artificial neural networks  

Microsoft Academic Search

The objective of this work is to use artificial neural networks (ANN) for the long-term performance prediction of thermosiphonic type solar domestic water heating (SDWH) systems. Thirty SDWH systems have been tested and modelled according to the procedures outlined in the standard ISO 9459-2 at three locations in Greece. From these, data from 27 of the systems were used for

Soteris A Kalogirou; Sofia Panteliou

2000-01-01

341

Developing methods to assess and predict the population level effects of environmental contaminants.  

USGS Publications Warehouse

The field of ecological toxicity seems largely to have drifted away from what its title implies--assessing and predicting the ecological consequences of environmental contaminants--moving instead toward an emphasis on individual effects and physiologic case studies. This paper elucidates how a relatively new ecological methodology, interaction assessment (INTASS), could be useful in addressing the field's initial goals. Specifically, INTASS is a model platform and methodology, applicable across a broad array of taxa and habitat types, that can be used to construct population dynamics models from field data. Information on environmental contaminants and multiple stressors can be incorporated into these models in a form that bypasses the problems inherent in assessing uptake, chemical interactions in the environment, and synergistic effects in the organism. INTASS can, therefore, be used to evaluate the effects of contaminants and other stressors at the population level and to predict how changes in stressor levels or composition of contaminant mixtures, as well as various mitigation measures, might affect population dynamics.

Emlen, J.M.; Springman, K.R.

2007-01-01

342

A demonstration of level-anchored ratio scaling for prediction of grip strength.  

PubMed

Level-anchored ratio scaling, such as the Borg CR10 scale(®) and the Borg CR100 scale(®), uses verbal anchors in congruence with numbers to give ratio data together with natural levels of intensity. This presupposes that the anchors possess natural positions in the subjective dynamic range and also "numerical" inter-relations. In an experiment, subjects had to produce a force of handgrip corresponding to their conception of "Strong", followed by a "Maximal" performance. By using the previously found relationship between "Strong" and "Maximal" of 1:2 together with knowledge of the exponent in the power S-R-function (R = c × S(n)) for grip strength, n = 1.8, predictions of individual maximal performances were obtained. The predicted values correlated 0.76 with, and deviated only 3% (ns) from, actual maximal performances of grip strength. This result -as previously also found for aerobic capacity-gives a strong support for the use of verbal anchors, so common in category scaling, also in "ratio scaling" and that the Borg CR-scales fulfill the requirements for ratio scales. For estimation of muscular strength, such as grip strength, this present study points to the value of using submaximal determinations as a compliment to maximal performances (e.g., to obtain measures of functional capacity). The results also support the increasingly common use of the CR-methodology in other ergonomic settings concerning suitable design of tools and equipment. PMID:23490301

Borg, Elisabet; Borg, Gunnar

2013-09-01

343

Serum hepatitis B surface antigen levels predict treatment response to nucleos(t)ide analogues  

PubMed Central

Quantification of hepatitis B surface antigen (HBsAg) has been suggested to be helpful in the management of chronic hepatitis B (CHB) patients. Nucleos(t)ide analogs (NAs) are the therapy of choice for CHB and are used in the majority of CHB patients. NAs are able to induce hepatitis B virus (HBV) viral suppression, normalization of alanine aminotransferase (ALT) levels, and improvement in liver histology. Automated quantitative assays for serum HBsAg have recently become available, facilitating standardized quantification of serum HBsAg. This has led to increased interest in the clinical application of quantitative serum HBsAg for predicting therapeutic response to NAs. Recent studies have shown that a decline in serum HBsAg levels in patients receiving peginterferon may signal successful induction of immune control over HBV, and can therefore be used to predict therapeutic response. NA treatment typically induces a less rapid decline in HBsAg than interferon treatment; it has been estimated that full HBsAg clearance can require decades of NA treatment. However, a rapid HBsAg decline during NA therapy may identify patients who will show clearance of HBsAg. Currently, there is no consensus on the clinical utility of serum HBsAg monitoring for evaluating patient responses to NA therapy. This review focuses on recent findings regarding the potential application of HBsAg quantification in the management of CHB patients receiving NA therapy. PMID:24976706

Chen, Chien-Hung; Chiu, Yi-Chun; Lu, Sheng-Nan; Lee, Chuan-Mo; Wang, Jing-Houng; Hu, Tsung-Hui; Hung, Chao-Hung

2014-01-01

344

Prediction of Clarified Water Turbidity of Moyog Water Treatment Plant Using Artificial Neural Network  

Microsoft Academic Search

This study outlines the artificial neural networks application to improve the prediction capability by investigating the effect of data sampling, network type and configuration as well as the inclusion of past data at the neural network input. Multi layered perception and Elman network were used. Validation results using input data based on 5 min and 1 h sampling was compared.

Duduku Krishnaiah; Siva Kumar Kumaresan; Matthew Isidore; Rosalam Sarbatly

2007-01-01

345

Health Belief Model and Reasoned Action Theory in Predicting Water Saving Behaviors in Yazd, Iran  

PubMed Central

Background: People's behaviors and intentions about healthy behaviors depend on their beliefs, values, and knowledge about the issue. Various models of health education are used in deter¬mining predictors of different healthy behaviors but their efficacy in cultural behaviors, such as water saving behaviors, are not studied. The study was conducted to explain water saving beha¬viors in Yazd, Iran on the basis of Health Belief Model and Reasoned Action Theory. Methods: The cross-sectional study used random cluster sampling to recruit 200 heads of households to collect the data. The survey questionnaire was tested for its content validity and reliability. Analysis of data included descriptive statistics, simple correlation, hierarchical multiple regression. Results: Simple correlations between water saving behaviors and Reasoned Action Theory and Health Belief Model constructs were statistically significant. Health Belief Model and Reasoned Action Theory constructs explained 20.80% and 8.40% of the variances in water saving beha-viors, respectively. Perceived barriers were the strongest Predictor. Additionally, there was a sta¬tistically positive correlation between water saving behaviors and intention. Conclusion: In designing interventions aimed at water waste prevention, barriers of water saving behaviors should be addressed first, followed by people's attitude towards water saving. Health Belief Model constructs, with the exception of perceived severity and benefits, is more powerful than is Reasoned Action Theory in predicting water saving behavior and may be used as a framework for educational interventions aimed at improving water saving behaviors. PMID:24688927

Morowatisharifabad, Mohammad Ali; Momayyezi, Mahdieh; Ghaneian, Mohammad Taghi

2012-01-01

346

PREDICTS  

NASA Technical Reports Server (NTRS)

PREDICTS is a computer program that predicts the frequencies, as functions of time, of signals to be received by a radio science receiver in this case, a special-purpose digital receiver dedicated to analysis of signals received by an antenna in NASA s Deep Space Network (DSN). Unlike other software used in the DSN, PREDICTS does not use interpolation early in the calculations; as a consequence, PREDICTS is more precise and more stable. The precision afforded by the other DSN software is sufficient for telemetry; the greater precision afforded by PREDICTS is needed for radio-science experiments. In addition to frequencies as a function of time, PREDICTS yields the rates of change and interpolation coefficients for the frequencies and the beginning and ending times of reception, transmission, and occultation. PREDICTS is applicable to S-, X-, and Ka-band signals and can accommodate the following link configurations: (1) one-way (spacecraft to ground), (2) two-way (from a ground station to a spacecraft to the same ground station), and (3) three-way (from a ground transmitting station to a spacecraft to a different ground receiving station).

Zhou, Hanying

2007-01-01

347

Application of empirical predictive modeling using conventional and alternative fecal indicator bacteria in eastern North Carolina waters.  

PubMed

Coastal and estuarine waters are the site of intense anthropogenic influence with concomitant use for recreation and seafood harvesting. Therefore, coastal and estuarine water quality has a direct impact on human health. In eastern North Carolina (NC) there are over 240 recreational and 1025 shellfish harvesting water quality monitoring sites that are regularly assessed. Because of the large number of sites, sampling frequency is often only on a weekly basis. This frequency, along with an 18-24 h incubation time for fecal indicator bacteria (FIB) enumeration via culture-based methods, reduces the efficiency of the public notification process. In states like NC where beach monitoring resources are limited but historical data are plentiful, predictive models may offer an improvement for monitoring and notification by providing real-time FIB estimates. In this study, water samples were collected during 12 dry (n = 88) and 13 wet (n = 66) weather events at up to 10 sites. Statistical predictive models for Escherichiacoli (EC), enterococci (ENT), and members of the Bacteroidales group were created and subsequently validated. Our results showed that models for EC and ENT (adjusted R(2) were 0.61 and 0.64, respectively) incorporated a range of antecedent rainfall, climate, and environmental variables. The most important variables for EC and ENT models were 5-day antecedent rainfall, dissolved oxygen, and salinity. These models successfully predicted FIB levels over a wide range of conditions with a 3% (EC model) and 9% (ENT model) overall error rate for recreational threshold values and a 0% (EC model) overall error rate for shellfish threshold values. Though modeling of members of the Bacteroidales group had less predictive ability (adjusted R(2) were 0.56 and 0.53 for fecal Bacteroides spp. and human Bacteroides spp., respectively), the modeling approach and testing provided information on Bacteroidales ecology. This is the first example of a set of successful statistical predictive models appropriate for assessment of both recreational and shellfish harvesting water quality in estuarine waters. PMID:22981488

Gonzalez, Raul A; Conn, Kathleen E; Crosswell, Joseph R; Noble, Rachel T

2012-11-15

348

Analysis of water levels in the Frenchman Flat area, Nevada Test Site  

USGS Publications Warehouse

Analysis of water levels in 21 wells in the Frenchman Flat area, Nevada Test Site, provides information on the accuracy of hydraulic-head calculations, temporal water-level trends, and potential causes of water-level fluctuations. Accurate hydraulic heads are particularly important in Frenchman Flat where the hydraulic gradients are relatively flat (less than 1 foot per mile) in the alluvial aquifer. Temporal water-level trends with magnitudes near or exceeding the regional hydraulic gradient may have a substantial effect on ground-water flow directions. Water-level measurements can be adjusted for the effects of barometric pressure, formation water density (from water-temperature measurements), borehole deviation, and land-surface altitude in selected wells in the Frenchman Flat area. Water levels in one well were adjusted for the effect of density; this adjustment was significantly greater (about 17 feet) than the adjustment of water levels for barometric pressure, borehole deviation, or land-surface altitude (less than about 4 feet). Water-level measurements from five wells exhibited trends that were statistically and hydrologically significant. Statistically significant water-level trends were observed for three wells completed in the alluvial aquifer (WW-5a, UE-5n, and PW-3), for one well completed in the carbonate aquifer (SM-23), and for one well completed in the quartzite confining unit (Army-6a). Potential causes of water-level fluctuations in wells in the Frenchman Flat area include changes in atmospheric conditions (precipitation and barometric pressure), Earth tides, seismic activity, past underground nuclear testing, and nearby pumping. Periodic water-level measurements in some wells completed in the carbonate aquifer indicate cyclic-type water-level fluctuations that generally correlate with longer term changes (more than 5 years) in precipitation. Ground-water pumping fromthe alluvial aquifer at well WW-5c and pumping and discharge from well RNM-2s appear to cause water-level fluctuations in nearby observation wells. The remaining known sources of water-level fluctuations do not appear to substantially affect water-level changes (seismic activity and underground nuclear testing) or do not affect changes over a period of more than 1 year (barometric pressure and Earth tides) in wells in the Frenchman Flat area.

Bright, D. J.; Watkins, S. A.; Lisle, B. A.

2001-01-01

349

Analysis of water levels in the Frenchman Flat area, Nevada Test Site  

SciTech Connect

Analysis of water levels in 21 wells in the Frenchman Flat area, Nevada Test Site, provides information on the accuracy of hydraulic-head calculations, temporal water-level trends, and potential causes of water-level fluctuations. Accurate hydraulic heads are particularly important in Frenchman Flat where the hydraulic gradients are relatively flat (less than 1 foot per mile) in the alluvial aquifer. Temporal water-level trends with magnitudes near or exceeding the regional hydraulic gradient may have a substantial effect on ground-water flow directions. Water-level measurements can be adjusted for the effects of barometric pressure, formation water density (from water-temperature measurements), borehole deviation, and land-surface altitude in selected wells in the Frenchman Flat area. Water levels in one well were adjusted for the effect of density; this adjustment was significantly greater (about 17 feet) than the adjustment of water levels for barometric pressure, borehole deviation, or land-surface altitude (less than about 4 feet). Water-level measurements from five wells exhibited trends that were statistically and hydrologically significant. Statistically significant water-level trends were observed for three wells completed in the alluvial aquifer (WW-5a, UE-5n, and PW-3), for one well completed in the carbonate aquifer (SM-23), and for one well completed in the quartzite confining unit (Army-6a). Potential causes of water-level fluctuations in wells in the Frenchman Flat area include changes in atmospheric conditions (precipitation and barometric pressure), Earth tides, seismic activity, past underground nuclear testing, and nearby pumping. Periodic water-level measurements in some wells completed in the carbonate aquifer indicate cyclic-type water-level fluctuations that generally correlate with longer term changes (more than 5 years) in precipitation. Ground-water pumping from the alluvial aquifer at well WW-5c and pumping and discharge from well RNM- 2s appear to cause water-level fluctuations in nearby observation wells. The remaining known sources of water-level fluctuations do not appear to substantially affect water-level changes (seismic activity and underground nuclear testing) or do not affect changes over a period of more than 1 year (barometric pressure and Earth tides) in wells in the Frenchman Flat area.

Bright, D.J.; Watkins, S.A.; Lisle, B.A.

2001-04-18

350

The Impact of Climate Change on Great Lakes Water Levels Region: Great Lakes  

E-print Network

students research water pollution laws in cities around the Great Lakes. Have students compare the lawsThe Impact of Climate Change on Great Lakes Water Levels Region: Great Lakes Grade Level(s): 9 on the Great Lakes? Learning Objectives: · The students will construct and explain theories for the decline

351

Model-Free Based Water Level Control for Hydroelectric Power Plants  

E-print Network

Model-Free Based Water Level Control for Hydroelectric Power Plants Cédric JOIN Gérard ROBERT polytechnique, 91128 Palaiseau, France (e-mail: Michel.Fliess@polytechnique.edu) Abstract: Automatic water level for hydroelectric run-of-the river power plants. To modulate power generation, a level trajectory is planned

Paris-Sud XI, Université de

352

Simultaneous prediction of Cryptosporidium parvum oocyst inactivation and bromate formation during ozonation of synthetic waters.  

PubMed

A model was developed to simultaneously assess Cryptosporidium parvum oocyst inactivation and bromate formation during ozonation of synthetic solutions in batch and flow-through reactors. The model incorporated 65 elementary chemical reactions involved in the decomposition of ozone and the oxidation of bromine species and their corresponding rate or equilibrium constants reported in the literature. Ozonation experiments were performed with a laboratory-scale batch reactor to evaluate the model with respect to the rate of ozone decomposition and bromate formation. The model was found to provide a good representation of experimental results when the ozone decomposition initiation reaction with hydroxide ion was assumed to produce superoxide radical instead of the alternatively proposed product hydrogen peroxide. The model was further developed to simulate the performance of a flow-through bubble-diffuser reactor with an external recirculation line. Each compartment of the reactor (bubble column and recirculation line) was assumed to behave as a plug flow reactor as supported by tracer test results, and an empirical correlation was used to represent the rate of ozone gas transfer in the bubble column. Model predictions of the performance of the flow-through ozone bubble-diffuser contactor were in good agreement with experimental results obtained for bromate formation and C. parvum oocyst inactivation under all conditions investigated. Additional model simulations revealed that hydrodynamic conditions had a more pronounced effect on C. parvum oocyst inactivation than on bromate formation. In contrast, pH had a strong effect on bromate formation without affecting the inactivation efficiency of C. parvum oocysts for a given level of exposure to ozone. These findings suggested that bromate formation could be minimized while achieving target inactivation levels for C. parvum oocysts by designing ozone reactors with hydrodynamic conditions approaching that of an ideal plug flow reactor and by lowering the pH of the target water. PMID:15112829

Kim, Jae-Hong; Von Gunten, Urs; Mariñas, Benito J

2004-04-01

353

Nitrates in drinking water and methemoglobin levels in pregnancy: a longitudinal study  

PubMed Central

Background Private water systems are more likely to have nitrate levels above the maximum contaminant level (MCL). Pregnant women are considered vulnerable to the effects of exposure to high levels of nitrates in drinking water due to their altered physiological states. The level of methemoglobin in the blood is the biomarker often used in research for assessing exposure to nitrates. The objective of this study was to assess methemoglobin levels and examine how various factors affected methemoglobin levels during pregnancy. We also examined whether differences in water use practices existed among pregnant women based on household drinking water source of private vs. public supply. Methods A longitudinal study of 357 pregnant women was conducted. Longitudinal regression models were used to examine changes and predictors of the change in methemoglobin levels over the period of gestation. Results Pregnant women showed a decrease in methemoglobin levels with increasing gestation although <1% had levels above the physiologic normal of 2% methemoglobin, regardless of the source of their drinking water. The multivariable analyses did not show a statistically significant association between methemoglobin levels and the estimated nitrate intake from tap water among pregnant women around 36 weeks gestation (? = 0.046, p = 0.986). Four women had tap water nitrate levels above the MCL of 10 mg/L. At enrollment, a greater proportion of women who reported using water treatment devices were private wells users (66%) compared to public system users (46%) (p < 0.0001). Also, a greater proportion of private well users (27%) compared to public system users (13%) were using devices capable of removing nitrate from water (p < 0.0001). Conclusion Pregnant women potentially exposed to nitrate levels primarily below the MCL for drinking water were unlikely to show methemoglobin levels above the physiologic normal. Water use practices such as the use of treatment devices to remove nitrates varied according to water source and should be considered in the assessment of exposure to nitrates in future studies. PMID:20946657

2010-01-01

354

Modelling irrigation scheduling to analyse water management at farm level, during water shortages  

Microsoft Academic Search

The area under irrigated corn has significantly increased in the Charente river basin during the last 10 years. Corn water requirements are maximum in the summer, the period with low water flows and highest environmental vulnerability. Periods of water shortage during which irrigation is temporarily forbidden occur frequently. To reduce water demand, specific water saving policies are required. This paper

F. Labbé; P. Ruelle; P. Garin; P. Leroy

2000-01-01

355

Water Wizards: School Program on Water Conservation for Third and Fourth Grade Levels.  

ERIC Educational Resources Information Center

Water is precious. It is also easy to take for granted. Many people recognize that water is scarce in desert areas. but it is harder to realize that places like Massachusetts could face a shortage of pure drinking water. This manual provides teachers with curriculum resources to introduce concepts of water supply and water conservation to third…

Massachusetts State Water Resources Authority, Boston.

356

Ground Water Level Measurements in Selected Boreholes Near the Site of the Proposed Repository  

SciTech Connect

The Harry Reid Center for Environmental Studies (HRC) at the University of Nevada, Las Vegas (UNLV) acquired quarterly and continuous data on water levels from approximately 26 boreholes that comprise a periodic monitoring network (Table 1) between October 2003 and September 2007. During this period we continued to observe and analyze short and long-term ground water level trends in periodically monitored boreholes. In this report we summarize and discuss four key findings derived from analysis of water level data acquired during this period: 1. Rapid ground water level rise after storm events in Forty Mile Canyon; 2. Seismically-induced ground water level fluctuations; 3. A sample of synoptic observations and barometric influences on short term fluctuations; and 4. Long term ground water level trends observed from mid-2001 through late-2005.

Page, H. Scott

2007-11-29

357

A model on water level dynamics in natural circulation drum-type boilers  

Microsoft Academic Search

A model for water level dynamics in the drum-riser-downcomer loop of a natural circulation drum-type boiler is presented. The model is based on basic conservation rules of mass, momentum, and energy, together with well-known constitutional equations. Steam–water mixture in a drum is divided into three sub-volumes; water, steam above and below water level, and a mass balance relation is applied

H. Kim; S. Choi

2005-01-01

358

Environmental Factors Predicting Blood Lead Levels in Pregnant Women in the UK: The ALSPAC Study  

PubMed Central

Background Lead is a widespread environmental toxin. The behaviour and academic performance of children can be adversely affected even at low blood lead levels (BLL) of 5–10 µg/dl. An important contribution to the infant's lead load is provided by maternal transfer during pregnancy. Objectives Our aim was to determine BLL in a large cohort of pregnant women in the UK and to identify the factors that contribute to BLL in pregnant women. Methods Pregnant women resident in the Avon area of the UK were enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC) in 1991–1992. Whole blood samples were collected at median gestational age of 11 weeks and analysed by inductively coupled plasma dynamic reaction cell mass spectrometry (n?=?4285). Self-completion postal questionnaires were used to collect data during pregnancy on lifestyle, diet and other environmental exposures. Statistical analysis was carried out with SPSS v19. Results The mean±SD BLL was 3.67±1.47 (median 3.41, range 0.41–19.14) µg/dl. Higher educational qualification was found to be one of the strongest independent predictor of BLL in an adjusted backwards stepwise logistic regression to predict maternal BLL <5 or ?5 µg/dl (odds ratio 1.26, 95% confidence interval 1.12–1.42; p<0.001). Other predictive factors included cigarette smoking, alcohol and coffee drinking, and heating the home with a coal fire, with some evidence for iron and calcium intake having protective effects. Conclusion The mean BLL in this group of pregnant women is higher than has been found in similar populations in developed countries. The finding that high education attainment was independently associated with higher BLL was unexpected and currently unexplained. Reduction in maternal lead levels can best be undertaken by reducing intake of the social drugs cigarettes, alcohol and caffeine, although further investigation of the effect of calcium on lead levels is needed. PMID:24039753

Taylor, Caroline M.; Golding, Jean; Hibbeln, Joseph; Emond, Alan M.

2013-01-01

359

Prediction of ozone levels using a Hidden Markov Model (HMM) with Gamma distribution  

NASA Astrophysics Data System (ADS)

Ground level ozone, generated by the photochemical reaction between nitrogen oxides and volatile hydrocarbons, is harmful to humans and the environment. Prediction and forecasting play an important role in the regulatory policies aimed at the control and reduction of surface ozone. Belonging to the family of model-driven statistical models, Hidden Markov Models (HMMs) provide a rich mathematical structure and perform well in many applications. While conventional HMM applications assume Gaussian distribution for the observation statistics, several key meteorological factors and most ozone precursors exhibit a non-Gaussian distribution, which would weaken the performance of a conventional HMM in modeling ozone exceedances. We propose a method based on a HMM with a Gamma distribution (HMM-Gamma) where each monitoring day is pre-labeled according to its maximum 8-h average ozone concentration and monitoring days are further grouped into zones with different ozone levels. Then, HMMs associated with each zone are trained using air quality monitoring data where the model parameters are estimated by a modified Expectation-Maximization (EM) algorithm. We derive a new re-estimation formula for the model parameters for observation sequences that exhibit a Gamma distribution. The trained HMM-Gamma models are used to predict ozone exceedances in two geographic areas, Livermore Valley near San Francisco, CA and Houston Metropolitan Area, TX. Compared to the conventional HMM (HMM-Gaussian), HMM-Gamma for the ground level ozone in Livermore Valley can reduce false alarms by 77% and HMM-Gamma for that in Houston Metropolitan Area can reduce false alarms by 32%.

Zhang, Hao; Zhang, Weidong; Palazoglu, Ahmet; Sun, Wei

2012-12-01

360

Accelerometry predicts daily energy expenditure in a bird with high activity levels  

PubMed Central

Animal ecology is shaped by energy costs, yet it is difficult to measure fine-scale energy expenditure in the wild. Because metabolism is often closely correlated with mechanical work, accelerometers have the potential to provide detailed information on energy expenditure of wild animals over fine temporal scales. Nonetheless, accelerometry needs to be validated on wild animals, especially across different locomotory modes. We merged data collected on 20 thick-billed murres (Uria lomvia) from miniature accelerometers with measurements of daily energy expenditure over 24 h using doubly labelled water. Across three different locomotory modes (swimming, flying and movement on land), dynamic body acceleration was a good predictor of daily energy expenditure as measured independently by doubly labelled water (R2 = 0.73). The most parsimonious model suggested that different equations were needed to predict energy expenditure from accelerometry for flying than for surface swimming or activity on land (R2 = 0.81). Our results demonstrate that accelerometers can provide an accurate integrated measure of energy expenditure in wild animals using many different locomotory modes. PMID:23256182

Elliott, Kyle H.; Le Vaillant, Maryline; Kato, Akiko; Speakman, John R.; Ropert-Coudert, Yan

2013-01-01

361

Tide gauge records, water level rise, and subsidence in the Northern Gulf of Mexico  

Microsoft Academic Search

Long-term water level changes in the northern Gulf of Mexico were examined using tide gauge records for this century. Strong\\u000a coherence exists between the annual mean water changes at Galveston, Texas, and (1) the relatively geologically-stable west\\u000a coast of Florida, (2) global mean sea level, and 93) the subsiding Louisiana coast. Water levels at the Galveston gauge, one\\u000a of the

R. Eugene Turner

1991-01-01

362

Influence of summer water-level variability on St. Lawrence River-wetland fish assemblages  

USGS Publications Warehouse

Water-level and associated variability are substantial influences on wetland and shallow aquatic communities. The Akwesasne Wetland Complex is an extensive St. Lawrence River system affected by water regulation. The responses of fish assemblages to short-term summer water-level variation were examined throughout this section of the St. Lawrence River and its tributaries. An influence of water-level variability was detected on abundance of three common species [bluntnose minnow (Pimephales notatus), rock bass (Amboplites rupestris), and white sucker (Catastomus commersonii)] and explained 30-44% of variation. This influence has implications for water regulation and natural resource management, and a larger scope evaluation may reveal more extensive effects.

McKenna, J.E., Jr.; Barkley, J.L.; Johnson, J.H.

2008-01-01

363

Ground-water levels in water years 1984-86 and estimated ground-water pumpage in water years 1984-85, Carson Valley, Douglas County, Nevada  

USGS Publications Warehouse

Tabulations of groundwater level measurements made during the water years 1984-86 and summaries of estimated pumpage for water years 1984 and 1985 in Carson valley, Douglas County, Nevada, are included in this report. The data are being collected to provide a record of long-term groundwater changes and pumpage estimates that can be incorporated in a groundwater model change at a later date. (USGS)

Berger, D.L.

1987-01-01

364

Coral reef growth in an era of rapidly rising sea level: predictions and suggestions for long-term research  

Microsoft Academic Search

Coral reef growth is intimately linked to sea level. It has been postulated that over the next century, sea level will rise at a probable average rate of 15 mm\\/year, in response to fossil fuel emissions, heating, and melting of the Antarctic ice cap. This predicted rate of sea level rise is five times the present modal rate of vertical

R. W. Buddemeier; S. V. Smith

1988-01-01

365

Aircraft Structural Mass Property Prediction Using Conceptual-Level Structural Analysis  

NASA Technical Reports Server (NTRS)

This paper describes a methodology that extends the use of the Equivalent LAminated Plate Solution (ELAPS) structural analysis code from conceptual-level aircraft structural analysis to conceptual-level aircraft mass property analysis. Mass property analysis in aircraft structures has historically depended upon parametric weight equations at the conceptual design level and Finite Element Analysis (FEA) at the detailed design level. ELAPS allows for the modeling of detailed geometry, metallic and composite materials, and non-structural mass coupled with analytical structural sizing to produce high-fidelity mass property analyses representing fully configured vehicles early in the design process. This capability is especially valuable for unusual configuration and advanced concept development where existing parametric weight equations are inapplicable and FEA is too time consuming for conceptual design. This paper contrasts the use of ELAPS relative to empirical weight equations and FEA. ELAPS modeling techniques are described and the ELAPS-based mass property analysis process is detailed. Examples of mass property stochastic calculations produced during a recent systems study are provided. This study involved the analysis of three remotely piloted aircraft required to carry scientific payloads to very high altitudes at subsonic speeds. Due to the extreme nature of this high-altitude flight regime, few existing vehicle designs are available for use in performance and weight prediction. ELAPS was employed within a concurrent engineering analysis process that simultaneously produces aerodynamic, structural, and static aeroelastic results for input to aircraft performance analyses. The ELAPS models produced for each concept were also used to provide stochastic analyses of wing structural mass properties. The results of this effort indicate that ELAPS is an efficient means to conduct multidisciplinary trade studies at the conceptual design level.

Sexstone, Matthew G.

1998-01-01

366

Aircraft Structural Mass Property Prediction Using Conceptual-Level Structural Analysis  

NASA Technical Reports Server (NTRS)

This paper describes a methodology that extends the use of the Equivalent LAminated Plate Solution (ELAPS) structural analysis code from conceptual-level aircraft structural analysis to conceptual-level aircraft mass property analysis. Mass property analysis in aircraft structures has historically depended upon parametric weight equations at the conceptual design level and Finite Element Analysis (FEA) at the detailed design level ELAPS allows for the modeling of detailed geometry, metallic and composite materials, and non-structural mass coupled with analytical structural sizing to produce high-fidelity mass property analyses representing fully configured vehicles early in the design process. This capability is especially valuable for unusual configuration and advanced concept development where existing parametric weight equations are inapplicable and FEA is too time consuming for conceptual design. This paper contrasts the use of ELAPS relative to empirical weight equations and FEA. ELAPS modeling techniques are described and the ELAPS-based mass property analysis process is detailed Examples of mass property stochastic calculations produced during a recent systems study are provided This study involved the analysis of three remotely piloted aircraft required to carry scientific payloads to very high altitudes at subsonic speeds. Due to the extreme nature of this high-altitude flight regime,few existing vehicle designs are available for use in performance and weight prediction. ELAPS was employed within a concurrent engineering analysis process that simultaneously produces aerodynamic, structural, and static aeroelastic results for input to aircraft performance analyses. The ELAPS models produced for each concept were also used to provide stochastic analyses of wing structural mass properties. The results of this effort indicate that ELAPS is an efficient means to conduct multidisciplinary trade studies at the conceptual design level.

Sexstone, Matthew G.

1998-01-01

367

Blood Levels of Sulfamethazine Achieved in Beef Calves on Medicated Drinking Water  

PubMed Central

Studies on the use of sodium sulfamethazine in drinking water at three levels (572, 1028 and 1848 mg/L) were conducted in healthy weaned beef calves under similar dietary and environmental conditions. Blood sulfonamide levels greater than 5 mg/dl were attained with each treatment level but at different time intervals. The maximum levels in blood were achieved with the highest concentration in the water. However, a reduction in water intake caused a lower than anticipated dose of sulfamethazine. Under the conditions of the experiment the administration of sulfonamide in drinking water may be an effective means of mass medication of cattle. PMID:436105

Church, T. L.; Janzen, E. D.; Sisodia, C. S.; Radostits, O. M.

1979-01-01

368

Predicting the Effect of Changing Precipitation Extremes and Land Cover Change on Urban Water Quality  

NASA Astrophysics Data System (ADS)

Recent research shows that precipitation extremes in many of the largest U.S. urban areas have increased over the last 60 years. These changes have important implications for stormwater runoff and water quality, which in urban areas are dominated by the most extreme precipitation events. We assess the potential implications of changes in extreme precipitation and changing land cover in urban and urbanizing watersheds at the regional scale using a combination of hydrology and water quality models. Specifically, we describe the integration of a spatially distributed hydrological model - the Distributed Hydrology Soil Vegetation Model (DHSVM), the urban water quality model in EPA's Storm Water Management Model (SWMM), the semi-Lagrangian stream temperature model RBM10, and dynamical and statistical downscaling methods applied to global climate predictions. Key output water quality parameters include total suspended solids (TSS), toal nitrogen, total phosphorous, fecal coliform bacteria and stream temperature. We have evaluated the performance of the modeling system in the highly urbanized Mercer Creek watershed in the rapidly growing Bellevue urban area in WA, USA. The results suggest that the model is able to (1) produce reasonable streamflow predictions at fine temporal and spatial scales; (2) provide spatially distributed water temperature predictions that mostly agree with observations throughout a complex stream network, and characterize impacts of climate, landscape, near-stream vegetation change on stream temperature at local and regional scales; and (3) capture plausibly the response of water quality constituents to varying magnitude of precipitation events in urban environments. Next we will extend the scope of the study from the Mercer Creek watershed to include the entire Puget Sound Basin, WA, USA.

SUN, N.; Yearsley, J. R.; Lettenmaier, D. P.

2013-12-01

369

Bio-predictive tablet disintegration: effect of water diffusivity, fluid flow, food composition and test conditions.  

PubMed

Food intake may delay tablet disintegration. Current in vitro methods have little predictive potential to account for such effects. The effect of a variety of factors on the disintegration of immediate release tablets in the gastrointestinal tract has been identified. They include viscosity of the media, precipitation of food constituents on the surface of the tablet and reduction of water diffusivity in the media as well as changes in the hydrodynamics in the surrounding media of the solid dosage form. In order to improve the predictability of food affecting the disintegration of a dosage form, tablet disintegration in various types of a liquefied meal has been studied under static vs. dynamic (agitative) conditions. Viscosity, water diffusivity, osmolality and Reynolds numbers for the different media were characterized. A quantitative model is introduced which predicts the influence of the Reynolds number in the tablet disintegration apparatus on the disintegration time. Viscosity, water diffusivity and media flow velocity are shown to be important factors affecting dosage form disintegration. The results suggest the necessity of considering these parameters when designing a predictive model for simulating the in vivo conditions. Based on these experiments and knowledge on in vivo hydrodynamics in the GI tract, it is concluded that the disintegration tester under current pharmacopoeial conditions is operated in an unphysiological mode and no bioprediction may be derived. Recommendations regarding alternative mode of operation are made. PMID:24036239

Radwan, Asma; Wagner, Manfred; Amidon, Gordon L; Langguth, Peter

2014-06-16

370

Water pollution risk simulation and prediction in the main canal of the South-to-North Water Transfer Project  

NASA Astrophysics Data System (ADS)

The middle route of the South-to-North Water Transfer Project (MRP) will divert water to Beijing Tuancheng Lake from Taocha in the Danjiangkou reservoir located in the Hubei province of China. The MRP is composed of a long canal and complex hydraulic structures and will transfer water in open channel areas to provide drinking water for Beijing, Shijiazhuang and other cities under extremely strict water quality requirements. A large number of vehicular accidents, occurred on the many highway bridges across the main canal would cause significant water pollution in the main canal. To ensure that water quality is maintained during the diversion process, the effects of pollutants on water quality due to sudden pollution accidents were simulated and analyzed in this paper. The MIKE11 HD module was used to calculate the hydraulic characteristics of the 42-km Xishi-to-Beijuma River channel of the MRP. Six types of hydraulic structures, including inverted siphons, gates, highway bridges, culverts and tunnels, were included in this model. Based on the hydrodynamic model, the MIKE11 AD module, which is one-dimensional advection dispersion model, was built for TP, NH3-N, CODMn and F. The validated results showed that the computed values agreed well with the measured values. In accordance with transportation data across the Dianbei Highway Bridge, the effects of traffic accidents on the bridge on water quality were analyzed. Based on simulated scenarios with three discharge rates (ranged from 12 m3/s to 17 m3/s, 40 m3/s, and 60 m3/s) and three pollution loading concentration levels (5 t, 10 t and 20 t) when trucks spill their contents (i.e., phosphate fertilizer, cyanide, oil and chromium solution) into the channel, emergency measures were proposed. Reasonable solutions to ensure the water quality with regard to the various types of pollutants were proposed, including treating polluted water, maintaining materials, and personnel reserves.

Tang, Caihong; Yi, Yujun; Yang, Zhifeng; Cheng, Xi

2014-11-01

371

LEVEL III: RECEIVING WATER QUALITY MODELING FOR URBAN STORMWATER MANAGEMENT  

EPA Science Inventory

A simplified continuous receiving water quality model has been developed as a planning guide to permit preliminary screening of areawide wastewater treatment strategies. The model simulates the hypothetical response of the stream or tidal river system to the separate and combined...

372

Applied Budyko curve analysis for county level water resources management  

NASA Astrophysics Data System (ADS)

Human population growth and urbanization exert significant controls on the water and energy balance of many watersheds. The framework of Budyko curve analysis provides a systematic approach to distinguish the local human influences such as surface water regulation, groundwater pumping and land cover change from global climate variation in such watersheds. Two indices, Budyko curve distance (?BC, the distance between a-ratios to the origin on the Budyko diagram) and Budyko curve deviation (?BC, the distance between a-ratios to the original Budyko curve on the Budyko diagram), are computed from the Budyko curve for McHenry County, Illinois (USA), and we test the hypothesis that these indices represent the impact of climate variation and human influences, respectively. Spatial and temporal analysis of the Budyko curve demonstrates that the dominant land cover within a watershed affects the shape and position of the Budyko curve and, therefore, the slope and intercept of the logarithmic regression function defining the curve (i.e., the water and energy characteristics of the watershed). Correlations between per capita water use and ?BC and between farm proprietors’ income and ?BC may explain how climate and human control factors affect these socioeconomic phenomena. Further studies are required to reduce the uncertainties of these correlations.

Yang, Y. E.; Lin, Y. F.

2010-12-01

373

DETERMINATION OF LOW-LEVEL RADIOACTIVITY IN WATER. PART 2  

Microsoft Academic Search

The use of a membrane filter to retain activity, with retention of up to ; 3% with relatively high concentrations of uranyl acetate is described. Alpha ; plus beta activity retained was found to be lower in water samples containing ; 1805 ppm added solids, probably due to larger selfadsorption factor. Experiments ; were also made with flocculating agents, with

W. N. Grune; R. B. Hughes; G. W. Wilson

1963-01-01

374

Evaluation of multivariate linear regression and artificial neural networks in prediction of water quality parameters.  

PubMed

This paper examined the efficiency of multivariate linear regression (MLR) and artificial neural network (ANN) models in prediction of two major water quality parameters in a wastewater treatment plant. Biochemical oxygen demand (BOD) and chemical oxygen demand (COD) as well as indirect indicators of organic matters are representative parameters for sewer water quality. Performance of the ANN models was evaluated using coefficient of correlation (r), root mean square error (RMSE) and bias values. The computed values of BOD and COD by model, ANN method and regression analysis were in close agreement with their respective measured values. Results showed that the ANN performance model was better than the MLR model. Comparative indices of the optimized ANN with input values of temperature (T), pH, total suspended solid (TSS) and total suspended (TS) for prediction of BOD was RMSE?=?25.1 mg/L, r?=?0.83 and for prediction of COD was RMSE?=?49.4 mg/L, r?=?0.81. It was found that the ANN model could be employed successfully in estimating the BOD and COD in the inlet of wastewater biochemical treatment plants. Moreover, sensitive examination results showed that pH parameter have more effect on BOD and COD predicting to another parameters. Also, both implemented models have predicted BOD better than COD. PMID:24456676

Zare Abyaneh, Hamid

2014-01-01

375

RCWIM - an improved global water isotope pattern prediction model using fuzzy climatic clustering regionalization  

NASA Astrophysics Data System (ADS)

Prediction of geospatial H and O isotopic patterns in precipitation has become increasingly important to diverse disciplines beyond hydrology, such as climatology, ecology, food authenticity, and criminal forensics, because these two isotopes of rainwater often control the terrestrial isotopic spatial patterns that facilitate the linkage of products (food, wildlife, water) to origin or movement (food, criminalistics). Currently, spatial water isotopic pattern prediction relies on combined regression and interpolation techniques to create gridded datasets by using data obtained from the Global Network of Isotopes In Precipitation (GNIP). However, current models suffer from two shortcomings: (a) models may have limited covariates and/or parameterization fitted to a global domain, which results in poor predictive outcomes at regional scales, or (b) the spatial domain is intentionally restricted to regional settings, and thereby of little use in providing information at global geospatial scales. Here we present a new global climatically regionalized isotope prediction model which overcomes these limitations through the use of fuzzy clustering of climatic data subsets, allowing us to better identify and customize appropriate covariates and their multiple regression coefficients instead of aiming for a one-size-fits-all global fit (RCWIM - Regionalized Climate Cluster Water Isotope Model). The new model significantly reduces the point-based regression residuals and results in much lower overall isotopic prediction uncertainty, since residuals are interpolated onto the regression surface. The new precipitation ?2H and ?18O isoscape model is available on a global scale at 10 arc-minutes spatial and at monthly, seasonal and annual temporal resolution, and will provide improved predicted stable isotope values used for a growing number of applications. The model further provides a flexible framework for future improvements using regional climatic clustering.

Terzer, Stefan; Araguás-Araguás, Luis; Wassenaar, Leonard I.; Aggarwal, Pradeep K.

2013-04-01

376

Hormone levels predict individual differences in reproductive success in a passerine bird  

PubMed Central

Hormones mediate major physiological and behavioural components of the reproductive phenotype of individuals. To understand basic evolutionary processes in the hormonal regulation of reproductive traits, we need to know whether, and during which reproductive phases, individual variation in hormone concentrations relates to fitness in natural populations. We related circulating concentrations of prolactin and corticosterone to parental behaviour and reproductive success during both the pre-breeding and the chick-rearing stages in both individuals of pairs of free-living house sparrows, Passer domesticus. Prolactin and baseline corticosterone concentrations in pre-breeding females, and prolactin concentrations in pre-breeding males, predicted total number of fledglings. When the strong effect of lay date on total fledgling number was corrected for, only pre-breeding baseline corticosterone, but not prolactin, was negatively correlated with the reproductive success of females. During the breeding season, nestling provisioning rates of both sexes were negatively correlated with stress-induced corticosterone levels. Lastly, individuals of both sexes with low baseline corticosterone before and high baseline corticosterone during breeding raised the most offspring, suggesting that either the plasticity of this trait contributes to reproductive success or that high parental effort leads to increased hormone concentrations. Thus hormone concentrations both before and during breeding, as well as their seasonal dynamics, predict reproductive success, suggesting that individual variation in absolute concentrations and in plasticity is functionally significant, and, if heritable, may be a target of selection. PMID:21247953

Ouyang, Jenny Q.; Sharp, Peter J.; Dawson, Alistair; Quetting, Michael; Hau, Michaela

2011-01-01

377

Hormone levels predict individual differences in reproductive success in a passerine bird.  

PubMed

Hormones mediate major physiological and behavioural components of the reproductive phenotype of individuals. To understand basic evolutionary processes in the hormonal regulation of reproductive traits, we need to know whether, and during which reproductive phases, individual variation in hormone concentrations relates to fitness in natural populations. We related circulating concentrations of prolactin and corticosterone to parental behaviour and reproductive success during both the pre-breeding and the chick-rearing stages in both individuals of pairs of free-living house sparrows, Passer domesticus. Prolactin and baseline corticosterone concentrations in pre-breeding females, and prolactin concentrations in pre-breeding males, predicted total number of fledglings. When the strong effect of lay date on total fledgling number was corrected for, only pre-breeding baseline corticosterone, but not prolactin, was negatively correlated with the reproductive success of females. During the breeding season, nestling provisioning rates of both sexes were negatively correlated with stress-induced corticosterone levels. Lastly, individuals of both sexes with low baseline corticosterone before and high baseline corticosterone during breeding raised the most offspring, suggesting that either the plasticity of this trait contributes to reproductive success or that high parental effort leads to increased hormone concentrations. Thus hormone concentrations both before and during breeding, as well as their seasonal dynamics, predict reproductive success, suggesting that individual variation in absolute concentrations and in plasticity is functionally significant, and, if heritable, may be a target of selection. PMID:21247953

Ouyang, Jenny Q; Sharp, Peter J; Dawson, Alistair; Quetting, Michael; Hau, Michaela

2011-08-22

378

Prediction of vibrational frequencies of UO2(2+) at the CCSD(T) level.  

PubMed

Electronic structure calculations at the coupled cluster (CCSD(T)) and density functional theory levels with relativistic effective core potentials and large basis sets were used to predict the isolated uranyl ion frequencies. The effects of anharmonicity and spin-orbit corrections on the harmonic frequencies were calculated. The anharmonic effects are larger than the spin-orbit corrections, but both are small. The anharmonic effects decreased all the frequencies, whereas the spin-orbit corrections increased the stretches and decreased the bend. Overall, these two corrections decreased the harmonic asymmetric stretch frequency by 6 cm-1, the symmetric stretch by 3 cm-1, and the bend by 3 cm-1. The best calculated values for UO22+ for the asymmetric stretch, symmetric stretch, and bend were 1113, 1032, and 174 cm-1, respectively. The separation between the asymmetric and the symmetric stretch band origins was predicted to be 81 cm-1, which is consistent with experimental trends for substituted uranyls in solution and in the solid state. The anharmonic vibrational frequencies of the isoelectronic ThO2 molecule also were calculated and compared to experiment to calibrate the UO22+ results. PMID:18348547

Jackson, Virgil E; Craciun, Raluca; Dixon, David A; Peterson, Kirk A; de Jong, Wibe A

2008-05-01

379

An investigation of the origin of large water level oscillations during storms at Banneg Island, France  

NASA Astrophysics Data System (ADS)

We investigate the generation mechanism for unusually high water levels observed at Banneg Island, France, where loose boulders have been reportedly transported during storms over distances exceeding 100m (Fichaut and Suanez, 2011). The site is characterized by steep cliffs with slopes from 0.3 to 3 and composed of fractured rock and boulders. The lowest points along Banneg Island cliff crest are at 5m above the highest predicted tide, which is 10m above mean sea level. Wave and tide levels were observed using pressure gauges over a period of approximately 7 months. Two gauges (P3 and P4) were deployed offshore near the 4m isobath, and were submerged for the entire duration of the experiment. A third gauge (P2), located on the island just above the maximum predicted tide, and approximately cross-shore with respect to P3, was intermittently submerged during storms, for periods of the order of 2-3 min. On milder slopes (Sheremet et al. 2011), nonlinear shoaling of wind waves is typically associated with the generation of infragavity (IG) waves. We investigate the relationship between the water level oscillations observed at Banneg Island, and wave set-up and infragravity waves generated during swell shoaling. To circumvent the difficulty posed by the intermittent P2 signal, wavelet cross-correlation and cross-bispectral analysis is used to study the phase correlation between the swell envelope and IG waves at P3 and P4. A uni-directional deterministic wave model (Agnon and Sheremet, 1997) is used to investigate the generation mechanism, and assess the magnitude of the infragravity waves. REFERENCES Agnon, Y and A. Sheremet. Stochastic nonlinear shoaling of directional spectra. Journal of Fluid Mechanics. 345, p. 79-99, 1997. Fichaut, B and S. Suanez. Quarrying, transport and deposition of cliff-top storm deposits during extreme events: Banneg island. Marine Geology, pages 36-55, 2011. Sheremet, A, J. Kaihatu, S. Su, E. Smith, and J. Smith. Modeling of nonlinear wave propagation over fringing reefs. Coastal Engineering. 58(12). 1125-1137, 2011.

Staples, T.; TIAN, M.; Ardhuin, F.; Sheremet, A.; Suanez, S.; Fichaut, B.

2012-12-01

380

Glutamate level in anterior cingulate predicts anxiety in healthy humans: a magnetic resonance spectroscopy study.  

PubMed

Anxiety, a personality dimension in healthy humans, has been found to be associated with many functional consequences such as increased distractibility and attentional bias in favour of threat-related information, along with morphological and microstructural changes in the brain. The associated metabolic/neurochemical alterations are sparsely studied. In the present magnetic resonance spectroscopy (MRS) study, we investigated the possible relationship between regional brain chemistry within anterior cingulate cortex (4-cm(3) voxel) and hippocampus (2.5-cm(3) voxel) and anxiety (measured by State-Trait Anxiety Inventory) in our subject group. In the anterior cingulate cortex, multivariate analysis of covariance showed an increase in myo-inositol and combined glutamate and glutamine levels in the high anxiety subject group as compared with the low anxiety group. In the partial correlation analysis between neurochemicals and anxiety, glutamate and combined glutamate and glutamine also showed a predictive value for anxiety. On analysing the trait anxiety sub-score separately, we found glutamate, inositol and combined glutamate and glutamine levels to be increased in the high trait anxiety group as compared with the low trait anxiety group. All three resonances also had a predictive value for trait anxiety. In the hippocampus, none of the neurochemicals showed significant difference between high and low anxiety groups. The study provides a first account of alterations in anterior cingulate cortex neurochemistry in relation to anxiety in healthy subjects. The study thus contributes to the limited literature available on altered metabolism and neural mechanisms underlying sub-clinical anxiety. PMID:25156662

Modi, Shilpi; Rana, Poonam; Kaur, Prabhjot; Rani, Nisha; Khushu, Subash

2014-10-30

381

Prediction of residential pet and cockroach allergen levels using questionnaire information.  

PubMed Central

We assessed the accuracy of questionnaire reports of cat and dog ownership and presence of cockroaches in predicting measured allergen concentrations in house dust. We collected dust samples in the homes of 932 newborns living in New England. Dust samples were taken from the main living area and the infant's bedding. Allergen content of house dust was measured by enzyme-linked immunosorbent assays (ELISA) and related to questionnaire information on past and current cat and dog ownership and presence of cockroaches. Allergen levels were dichotomized using the limit of detection and the following cut points: 1.0 microg/g and 8.0 microg/g for cat, 2.0 microg/g and 10.0 microg/g for dog, and 2 U/g and 8 U/g for cockroach allergen. For the upper cut point, both specificity and sensitivity of questionnaire-reported cat and dog ownership and presence of cockroaches were high. For the limit of detection and lower cut point, specificity was high (> 80%), whereas sensitivity was low, particularly for current cat and dog ownership (21-60%). Taking pet ownership during the preceding 2 years into account increased the sensitivity by 10%, but it remained relatively poor. In conclusion, questionnaire-reported pet ownership and presence of cockroaches predicts allergen levels above the upper cut point but is a relatively poor measure of allergen exposure above the limit of detection and the lower cut point. Knowledge of past pet ownership can improve pet allergen exposure assessment by means of questionnaire. However, for epidemiologic purposes, measured concentrations of allergens are necessary. PMID:15175169

Gehring, Ulrike; Triche, Elizabeth; van Strien, Robert T; Belanger, Kathleen; Holford, Theodore; Gold, Diane R; Jankun, Thomas; Ren, Ping; McSharry, Jean-ellen; Beckett, William S; Platts-Mills, Thomas A E; Chapman, Martin D; Bracken, Michael B; Leaderer, Brian P

2004-01-01

382

Non-invasive prediction of hemoglobin levels by principal component and back propagation artificial neural network  

PubMed Central

To facilitate non-invasive diagnosis of anemia, specific equipment was developed, and non-invasive hemoglobin (HB) detection method based on back propagation artificial neural network (BP-ANN) was studied. In this paper, we combined a broadband light source composed of 9 LEDs with grating spectrograph and Si photodiode array, and then developed a high-performance spectrophotometric system. By using this equipment, fingertip spectra of 109 volunteers were measured. In order to deduct the interference of redundant data, principal component analysis (PCA) was applied to reduce the dimensionality of collected spectra. Then the principal components of the spectra were taken as input of BP-ANN model. On this basis we obtained the optimal network structure, in which node numbers of input layer, hidden layer, and output layer was 9, 11, and 1. Calibration and correction sample sets were used for analyzing the accuracy of non-invasive hemoglobin measurement, and prediction sample set was used for testing the adaptability of the model. The correlation coefficient of network model established by this method is 0.94, standard error of calibration, correction, and prediction are 11.29g/L, 11.47g/L, and 11.01g/L respectively. The result proves that there exist good correlations between spectra of three sample sets and actual hemoglobin level, and the model has a good robustness. It is indicated that the developed spectrophotometric system has potential for the non-invasive detection of HB levels with the method of BP-ANN combined with PCA. PMID:24761296

Ding, Haiquan; Lu, Qipeng; Gao, Hongzhi; Peng, Zhongqi

2014-01-01

383

Prediction of prostate cancer volume using prostate-specific antigen levels, transrectal ultrasound, and systematic sextant biopsies  

Microsoft Academic Search

Objectives.Prostate-specific antigen (PSA) levels, transrectal ultrasound, and systematic sextant biopsies have each shown limited ability to predict prostate cancer volume. In combination, these studies may allow more accurate estimation of volume and prognosis.

Martha K. Terris; Douglas J. Haney; Iain M. Johnstone; John E. McNeal; Thomas A. Stamey

1995-01-01

384

Comparison of measured and predicted pure tone propagation levels from JAPE-1: An evaluation of the performance of ASOPRAT  

NASA Technical Reports Server (NTRS)

Joint Acoustic Propagation Experiment Phase One (JAPE-1 ) short range propagation data has been used to evaluate the performance of the Advanced Sound Propagation in the Atmosphere (ASOPRAT) prediction code. The pure tone short range data was Fourier analyzed giving the propagated pressure levels as a function of frequency. Meteorological profiles measured at the experimental site were used as input for the acoustic prediction routine ASOPRAT. Predicted and measured propagation levels are compared in decibels (dB) relative to one of the measurement positions for receivers on the line passing between the two thirty meter towers. Agreement between predicted and measured levels is very good. Source strength data was not available, hence the comparisons show good agreement as to the shape of the propagation loss curve not necessarily the propagation levels.

Frederickson, Carl K.; Bass, Henry E.; Raspet, Richard; Messer, John

1993-01-01

385

Natural radioactivity levels in bottled water in Spain  

Microsoft Academic Search

Spain is a country rich in mineral springs. A nationwide study on the natural radioactivity has been made to determine the gross-? and gross-? activities in bottled water. These measurements are important for extracting radiological information of the activity present in a sample. Of all samples collected, only 26.2% have an ?-activity higher than 100 mBq\\/l, and none of them

M. C. Fernández; E. Liger; J. Carretero

1997-01-01

386

Prediction  

Microsoft Academic Search

This chapter first presents a rather personal view of some different aspects of predictability, going in crescendo from simple linear systems to high-dimensional nonlinear systems with stochastic forcing, which exhibit emergent properties such as phase transitions and regime shifts. Then, a detailed correspondence between the phenomenology of earthquakes, financial crashes and epileptic seizures is offered. The presented statistical evidence provides

Didier Sornette; Ivan Osorio

2010-01-01

387

Variants in Iron Metabolism Genes Predict Higher Blood Lead Levels in Young Children  

PubMed Central

Background Given the association between iron deficiency and lead absorption, we hypothesized that variants in iron metabolism genes would predict higher blood lead levels in young children. Objective We examined the association between common missense variants in the hemochromatosis (HFE) and transferrin (TF) genes and blood lead levels in 422 Mexican children. Methods Archived umbilical cord blood samples were genotyped for HFE (H63D and C282Y) and TF (P570S) variants. Blood lead was measured at 24, 30, 36, 42, and 48 months of age. A total of 341 subjects had at least one follow-up blood lead level available and data available on covariates of interest for inclusion in the longitudinal analyses. We used random-effects models to examine the associations between genotype (HFE, TF, and combined HFE + TF) and repeated measures of blood lead, adjusting for maternal blood lead at delivery and child’s concurrent anemia status. Results Of 422 children genotyped, 17.7, 3.3, and 18.9% carried the HFE H63D, HFE C282Y, and TF P570S variants, respectively. One percent of children carried both the HFE C282Y and TF P570S variants, and 3% of children carried both the HFE H63D and TF P570S variants. On average, carriers of either the HFE (? = 0.11, p = 0.04) or TF (? = 0.10, p = 0.08) variant had blood lead levels that were 11% and 10% higher, respectively, than wild-type subjects. In models examining the dose effect, subjects carrying both variants (? = 0.41, p = 0.006) had blood lead 50% higher than wild-type subjects and a significantly higher odds of having a blood lead level > 10 ?g/dL (odds ratio = 18.3; 95% confidence interval, 1.9–177.1). Conclusions Iron metabolism gene variants modify lead metabolism such that HFE variants are associated with increased blood lead levels in young children. The joint presence of variant alleles in the HFE and TF genes showed the greatest effect, suggesting a gene-by-gene-by-environment interaction. PMID:18795173

Hopkins, Marianne R.; Ettinger, Adrienne S.; Hernandez-Avila, Mauricio; Schwartz, Joel; Tellez-Rojo, Martha Maria; Lamadrid-Figueroa, Hector; Bellinger, David; Hu, Howard; Wright, Robert O.

2008-01-01

388

Preoperative high level of D-dimers predicts unresectability of pancreatic head cancer  

PubMed Central

AIM: To assess the value of D-dimer level in determining resectability of pancreatic cancer. METHODS: Preoperative prediction of pancreatic head cancer resectability remains inaccurate. The use of hemostatic factors may be of potential help, since D-dimers correlate with tumor stage. Single center clinical trial study comprised patients with potentially resectable pancreatic head tumor and without detectable venous thrombosis (n = 64). Resectability was defined as no evidence of nodal involvement, distant spread and no invasion of mesenteric vessels. Final decision of resectability was confirmed intraoperatively. Experienced pancreatic surgeon performed all surgeries. Following the dissection of hepatoduodenal ligament, samples of portal blood and bile were taken. Peripheral blood via central line and urine via Foley catheter were sampled. D-dimer levels were further measured. RESULTS: At laparotomy only 29 (45.3%) tumors were found to be resectable. Our analysis showed higher by 57.5% (P < 0.001) mean D-dimer values in peripheral and 43.7% (P = 0.035) in portal blood of patients with unresectable pancreatic cancer. Significant differences were not observed when analyzing D-dimer levels in bile and urine. Peripheral D-dimer level correlated with pancreatic cancer resectability. When cut-off D-dimer value of 570.6 ?g/L was used, the sensitivity for assessment of tumor unresectability was 82.8%. Furthermore, D-dimer level in peripheral blood of metastatic disease (n = 15) was significantly higher when compared to locally advanced (n = 20) pancreatic cancer (2470 vs 1168, P = 0.029). The area under ROC curve for this subgroup of patients was 0.87; for determination of unresectable disease when threshold of 769.8 ?g/L was used, sensitivity and specificity was 86.6% and 80%, respectively. CONCLUSION: Patients with resectable pancreatic head cancer based on preoperative imaging studies and high D-dimer level may be considered unresectable due to occult hepatic metastases. These patients may benefit from diagnostic laparoscopy to avoid exploratory laparotomy.

Durczynski, Adam; Kumor, Anna; Hogendorf, Piotr; Szymanski, Dariusz; Grzelak, Piotr; Strzelczyk, Janusz

2014-01-01

389

Serum lipid levels in neighboring communities with chlorinated and nonchlorinated drinking water  

SciTech Connect

The Wisconsin Heart Health Research Program was designed to ascertain levels of serum lipids and other clinical parameters among residents of a total of forty-six neighboring small communities in central Wisconsin. The purpose of the study was to determine whether distribution of serum lipids, blood pressure or thyroid hormones differed according to the chlorination of the water supply, or to the calcium and magnesium content (hardness) of the drinking water supply. This report examines the relationship of chlorination and water calcium to estimated community mean serum lipid levels. The estimated community means are adjusted for potential confounders, including age, education level, alcohol intake, smoking, dietary fat and dietary calcium. Serum cholesterol levels proved to be significantly higher in chlorinated communities for females. Levels of serum cholesterol were also higher in chlorinated communities for males, but differences were considerably smaller and not statistically significant. Low-density lipoprotein cholesterol levels were also higher in chlorinated communities for females (p = .06). Levels of high-density lipoprotein (HDL) cholesterol were higher in hard water communities than in soft water communities, although the p-value for the hardness term did not quite reach significance at p < .05 in either model. The regression of community mean HDL levels on both drinking water calcium and magnesium levels was positive, indicating increasing mean HDL levels with increasing calcium and/or magnesium content in the drinking water.

Zeighami, E.A.; Watson, A.P.; Craun, G.F.

1987-01-01

390

Levels of water-soluble vitamins in methanogenic and non-methanogenic bacteria  

Microsoft Academic Search

The levels of seven water-soluble vitamins in Methanobacterium thermoautotropicum, Methanococcus voltae, Escherichia coli, Bacillus subtillis, Pseudomonas fluorescens, and Bacteroides thetaiotaomicron were compared by using a vitamin-requiring Leuconostoc strain. Both methanogens contained levels