bluuebunny/crossref_metadata_2025 huggingface dataset:
MACROINVERTEBRATE COMMUNITY STRUCTURE AS A PREDICTOR OF WATER DURATION IN WISCONSIN WETLANDS1
Authors: Lillie Richard A.
Published: June 2007

ABSTRACT: Fifty‐four Wisconsin wetlands were surveyed in spring 1996 to determine relationships between macroinvertebrate community structure and a suite of 11 environmental attributes. Canonical correspondence analysis (CCA) showed that, after alkalinity, hydroperiod was the next most significant environmental factor influencing macroinvertebrate community structure within the wetlands sampled. CCA and direct gradient biplots were used to identify indicator taxa characteristic of the spring macroinvertebrate communities in persistent and ephemeral wetlands, and taxa characteristic of semi‐terrestrial habitats adjacent to wetlands. Two models were developed to permit the prediction of a wetland's hydroperiod class. One model assigns a range of probabilities that a wetland has a hydroperiod longer or shorter than eight months based on the occurrence or abundance of fairy shrimp, mayflies, scuds, mosquitoes, and phantom midges. A second model predicts that a wetland's hydroperiod is longer or shorter than five months based on the joint occurrences of seven persistent indicator taxa. Data used in both models were derived from a rapid bioassessment of three shoreline D‐frame net sweeps. The use of a coarse level taxonomic identification (primarily order and family) allows the approach to be performed in the field or laboratory. The macroinvertebrate models allow a manager to estimate a wetland's hydroperiod when long term water duration records do not exist. This ability is important to water resource managers because hydroperiod classification (i.e., water permanency) is one criterion used in differentiating wetlands from lakes in Wisconsin and because Wisconsin's legal system affords lakes substantially greater protection than wetlands.
OPTIMIZATION PROCEDURE FOR COST EFFECTIVE BMP PLACEMENT AT A WATERSHED SCALE1
Authors: Veith Tamie L. , Wolfe Mary Leigh , Heatwole Conrad D.
Published: June 2007

ABSTRACT: A combinatorial optimization procedure for best management practice (BMP) placement at the watershed level facilitates selection of cost effective BMP scenarios to control non point source (NFS) pollution. A genetic algorithm (GA) was selected from among several optimization heuristics. The GA combines an optimization component written in the C++ language with spatially variable NFS pollution prediction and economic analysis components written within the Arc View geographic information system. The procedure is modular in design, allowing for component modifications while maintaining the basic conceptual framework. An objective function was developed to lexicographically optimize pollution reduction followed by cost increase. Scenario cost effectiveness is then calculated for scenario comparisons. The NPS pollutant fitness score allows for evaluation of multiple pollutants, based on prioritization of each pollutant. The economic component considers farm level public and private costs, cost distribution, and land area requirements. Development of a sediment transport function, used with the Universal Soil Loss Equation, allows the optimization procedure to run within a reasonable timeframe. The procedure identifies multiple near optimal solutions, providing an indication of which fields have a more critical impact on overall cost effectiveness and flexibility in the final solution selected for implementation. The procedure was demonstrated for a 1,014‐ha watershed in the Ridge and Valley physiographic region of Virginia.
HISTORICAL EVOLUTION OF FLOODING DAMAGE ON A USA/QUEBEC RIVER BASIN1
Authors: Brissette François P. , Leconte Robert , Marche Claude , Rousselle Jean
Published: June 2007

ABSTRACT:There is a general belief in the public eye that extreme events such as floods are becoming more and more common. This paper explores this hypothesis by examining the historical evolution of annual expected flooding damage on the Chateauguay River Basin, located at the border between the United States and the province of Quebec, Canada. A database of basin land use was constructed for the years 1930 and 1995 to assess anthropogenic changes and their impact on the basin's hydrology. The progressive modification of the likelihood of a flooding event over the same period was then investigated using homogeneity and statistical tests on available hydrometric data. The evolution of the annual expected flooding damage was then evaluated using a coupled hydrologic/hydraulic simulator linked to a damage analysis model. The simulator and model were used to estimate flooding damage over a wide range of flooding return periods, for conditions prevailing in 1963 and 1995. Results of the analysis reveal the absence of any increasing or decreasing trend in the historical occurrence of flooding events. However, a general increase in the annual expected flooding damage was observed for all studied river sections. This increase is linked to an historical increase in damages for a given flooding event, and is the result of unbridled construction and development within the flood zone. To assess for future trends, this study also examined the potential impacts linked to the anticipated global warming. Results indicate that a significant increase in seasonal flooding events and annual expected flooding damage is possible over the next century. In fact, what is now considered a 100‐year flooding event for the summer/fall season could become a ten‐year event by the end of this century. This shows that potentialfutureimpacts linked to climate change should be considerednowby engineers, land planners, and decision makers. This is especially critical if a design return period is part of the decision making process.
USE OF ACOUSTIC DOPPLER CURRENT PROFILERS TO DESCRIBE VELOCITY DISTRIBUTIONS AT THE REACH SCALE1
Authors: Shields F. Douglas , Knight Scott S. , III Sam Testa , Cooper Charles M.
Published: June 2007

ABSTRACT: Research has demonstrated the utility of metrics based on spatial velocity gradients to characterize and describe stream habitat, with higher mean spatial gradients indicative of higher levels of physical heterogeneity and thus habitat quality. However, detailed description of the velocity field that is needed to compute these metrics is difficult to obtain. Acoustic Doppler current profilers (ADCPs) may be used to rapidly collect detailed representations of river depth and velocity fields in rivers deeper than 1 m. Such data were collected in March 2000 from cross sections of the Little Tallahatchie River, Mississippi, representing three distinct habitat types (naturally sinuous, channelized, and abandoned channel). These datasets were used to compute component velocities, vorticity, and area weighted mean vorticity (circulation). Velocities and circulation were highest in the meander, lowest in the abandoned channel, and intermediate in the channelized reach. Secondary flow, expressed as the average magnitude of the lateral (transverse) velocity divided by the total velocity, was significantly higher in the meander. The sinuous natural channel and abandoned channel displayed distinctive spatial patterns, with regions of depressed velocity consistently occurring near banks. ADCPs hold great potential as tools for the study of riverine ecosystems, but data reduction is difficult using existing software.
DESIGN AND IMPLEMENTATION OF A COOPERATIVE WATER QUALITY MONITORING PROGRAM IN COLORADO'S BIG THOMPSON WATERSHED1
Authors: Greve Adrienne I. , Loftis Jim C. , Brown Juliane B. , Buirgy Rob R. , Alexander Ben
Published: June 2007

ABSTRACT: In 1996, the Big Thompson Watershed Forum (BTWF) was formed “to assess and protect the quality of water” in the Big Thompson Watershed in northern Colorado. However, until 1999, water quality monitoring in the watershed was performed by many state, local, and federal agencies with no coordination among programs and with few efforts toward efficiency, data comparability, or information exchange. To better meet the needs of its stakeholders, the BTWF since 1999 has been actively pursuing the design and implementation of a cooperative water quality monitoring program. The program design involved consensus building among the funding participants, primarily drinking water providers. The final design included 38 parameters to be sampled 15 times per year at 24 stream and canal locations plus two reservoirs. Although the collaborative consensus based approach has been successful for the BTWF, this approach has its drawbacks; most notable among these are the time and labor this approach requires. Also, the BTWF struggled with achieving equal representation of all interests, since those agencies that provided funding had the greatest voice in the final product. While a collaborative approach may not always be best for monitoring program design, it should be appropriate for many watershed organizations that face the common problem of severe financial constraints.
EFFECTS OF CLIMATE VARIABILITY ON RIVERS: CONSEQUENCES FOR LONG TERM WATER QUALITY ANALYSIS1
Authors: Scarsbrook Mike R. , McBride Chris G. , McBride Graham B. , Bryers Graham G.
Published: June 2007

ABSTRACT: Associations between the El Nino Southern Oscillation (ENSO) climate pattern and temporal variability in flow and 12 water quality variables were assessed at 77 river sites throughout New Zealand over a 13‐year period (1989 through 2001). Trends in water quality were determined for the same period. All 13 variables showed statistically significant linear regression relationships with values of the Southern Oscillation Index (SOI). The strongest relationships were for water temperature (mean R2= 0.20), dissolved reactive phosphorus (0.18), and oxidized nitrogen (0.17). The association with SOI varied by climate region. The observed patterns were generally consistent with known ENSO effects on New Zealand rainfall and air temperature. Trends in water quality variables for the periods 1989 through 1993, 1994 through 1998, and 1989 through 1998 were reasonably consistent with trends in SOI, even when the influence of river flow was removed from the data. This suggests that SOI effects on water quality are not necessarily a direct consequence of changes in flow associated with rainfall variation. In addition, both Baseline (32 upstream) and Impact (45 downstream) sites showed similar trends, indicating that changes in management were not directly responsible. We conclude that interpretation of long term water quality datasets in rivers requires that climate variability be fully acknowledged and dealt with explicitly in trend analyses.
INCORPORATING NATURAL VARIABILITY, UNCERTAINTY, AND RISK INTO WATER QUALITY EVALUATIONS USING DURATION CURVES1
Authors: Bonta James V. , Cleland Bruce
Published: June 2007

ABSTRACT: Quantifying natural variability, uncertainty, and risk with minimal data is one of the greatest challenges facing those engaged in water quality evaluations, such as development of total maximum daily loads (TMDL), because of regulatory, natural, and analytical constraints. Quantification of uncertainty and variability in natural systems is illustrated using duration curves (DCs), plots that illustrate the percent of time that a particular flow rate (FDC), concentration (CDC), or load rate (LDC; “TMDL”) is exceeded, and are constructed using simple derived distributions. Duration curves require different construction methods and interpretations, depending on whether there is a statistically significant correlation between concentration (C) and flow (Q), and on the sign of the C‐Q regression slope (positive or negative). Flow DCs computed from annual runoff data vary compared with an FDC developed using all data. Percent exceedance for DCs can correspond to risk; however, DCs are not composed of independent quantities. Confidence intervals of data about a regression line can be used to develop confidence limits for the CDC and LDC. An alternate expression to a fixed TMDL is suggested as the risk of a load rate being exceeded and lying between confidence limits. Averages over partial ranges of DCs are also suggested as an alternative expression of TMDLs. DCs can be used to quantify watershed response in terms of changes in exceedances, concentrations, and load rates after implementation of best management practices.
EFFECTS OF INCREASED DELTA EXPORTS ON SACRAMENTO VALLEY'S ECONOMY AND WATER MANAGEMENT1
Authors: Tanaka Stacy K. , Lund Jay R.
Published: June 2007

ABSTRACT: Exports from the Sacramento‐San Joaquin Delta are an important source of water for Central Valley and Southern California users. The purpose of this paper is to estimate and analyze the effects increased exports to south of Delta users would have on the Sacramento Valley economy and water management if water were managed and reallocated for purely economic benefits, as if there were an ideal Sacramento Valley water market. Current Delta exports of 6,190 thousand acre‐feet per year were increased incrementally to maximum export pumping plant capacities. Initial increases in Delta exports did not increase regional water scarcity, but decreased surplus Delta flows. Further export increases raised agricultural scarcity. Urban users suffer increased scarcity only for exports exceeding 10,393 taf/yr. Expanding exports raises the economic value of expanding key facilities (such as Engle bright Lake and South Folsom Canal) and the opportunity costs of environmental requirements. The study illustrates the physical and economic capacity of the Sacramento Valley to further increase exports of water to drier parts of the state, even within significant environmental flow restrictions. More generally, the results illustrate the physical capacity for greater economic benefits and flexibility in water management within environmental constraints, given institutional capability to reoperate or reallocate water resources, as implied by water markets.
WATER EXCHANGES: TOOLS TO BEAT EL NIÑO CLIMATE VARIABILITY IN IRRIGATED AGRICULTURE1
Authors: Scott Michael J. , Vail Lance W. , Jaksch John , Stöckle Claudia O. , Kemanian Armen
Published: June 2007

ABSTRACT: Using a case study of the Yakima River Valley in Washington State, this paper shows that relatively simple tools can be used to forecast the impact of the El Niño phenomenon on water supplies to irrigated agriculture, that this information could be used to estimate the significantly shifted probability distribution of water shortages in irrigated agriculture during El Niño episodes, and that these shifted probabilities can be used to estimate the value of exchanges of water between crops to relieve some of the adverse consequences of such shortages under western water law. Further, recently devised water‐trading tools, while not completely free under western water law to respond to forecasted El Niño episodes (ocean circulation patterns), are currently being employed during declared drought to reduce the devastating effects of water shortages in junior water districts on high valued perennial crops. Additional institutional flexibility is needed to take full advantage of climate forecasting, but even current tools clearly could prove useful in controlling the effects of climate variability in irrigated agriculture. Analysis shows the significant benefit of temporarily transferring or renting water rights from low‐value to high‐value crops, based on El Niño forecasts.
DEVELOPMENT OF AN INVERTEBRATE COMMUNITY INDEX FOR AN ALABAMA COASTAL PLAIN WATERSHED1
Authors: Bennett Holly H. , Mullen Michael W. , Stewart Paul M. , Sawyer James A. , Webber E. Cliff
Published: June 2007

ABSTRACT: Activities such as agriculture, silviculture, and mining contribute nonpoint pollution to Alabama's streams through polluted runoff and excessive sedimentation. Highly erodible soils characteristic of the Choctawhatchee‐Pea Rivers watershed, combined with intense rainfall and land use practices, contribute large amounts of sediment to streams. Biological monitoring can reflect the acute impacts of pollutants as well as prolonged effects of habitat alteration, and development of biological criteria is important for the establishment of enforceable laws regarding nonpoint source pollution. Macroinvertebrates were collected from 49 randomly selected sites from first through sixth‐order streams in the Choctawhatchee‐Pea Rivers watershed and were identified to genus level. Thirty‐eight candidate metrics were examined, and an invertebrate community index (ICI) was calibrated by eliminating metrics that failed to separate impaired from unimpaired streams. Each site was scored with those metrics, and narrative scores were assigned based on ICI scores. Least impacted sites scored significantly lower than sites impacted by row crop agriculture, cattle, and urban land uses. Conditions in the watershed suggest that the entire area has experienced degradation through past and current land use practices. An initial validation of the index was performed and is described. Additional evaluations of the index are in progress.
IMPLICATIONS OF ON‐GROUND NITROGEN LOADING AND SOIL TRANSFORMATIONS ON GROUND WATER QUALITY MANAGEMENT1
Authors: Almasri Mohammad N. , Kaluarachchi Jagath J.
Published: June 2007

ABSTRACT: This paper presents a modeling approach based on a geographic information system (GIS) to estimate the variability of on‐ground nitrogen loading and the corresponding nitrate leaching to ground water. The methodology integrates all point and nonpoint sources of nitrogen, the national land cover database, soil nitrogen transformations, and the uncertainty of key soil and land use‐related parameters to predict the nitrate mass leaching to ground water. The analysis considered 21 different land use classes with information derived from nitrogen sources such as fertilizer and dairy manure applications, dairy lagoons, septic systems, and dry and wet depositions. Simulations were performed at a temporal resolution of one month to capture seasonal trends. The model was applied to a large aquifer of 376 square miles in Washington State that serves more than 100,000 residents with drinking water. The results showed that dairy manure is the main source of nitrogen in the area followed by fertilizers. It was also seen that nitrate leaching is controlled by the recharge rate, and there can be a substantial buildup of soil nitrogen over long periods of time. Uncertainty analysis showed that denitrification rate is the most influential parameter on nitrate leaching. The results showed that combining management alternatives is a successful strategy, especially with the use of nitrification inhibitors. Also, change in the land use pattern has a noticeable impact on nitrate leaching.
SEDIMENT RESUSPENSION AND DRAWDOWN IN A WATER SUPPLY RESERVOIR1
Authors: Effler Steven W. , Matthews David A.
Published: June 2007

ABSTRACT: The magnitudes and patterns of sediment resuspension are assessed in Cannonsville Reservoir, New York, to quantify and characterize this internal source of sediment. The assessment is based on analyses of sediment trap collections from 10 sites over the spring to fall interval of two years. Temporal and spatial patterns in sediment deposition are demonstrated to be driven by resuspension/redeposition processes. Sediment that had been resuspended and redeposited represented 80 to 96 percent, on average, of the depositing solids collected along the main axis of the lake. About 90 percent of the redeposited sediment was inorganic. Increased resuspension caused by drawdown of the reservoir surface and fall turnover resulted in 10 to 50‐fold increases in deposition rates compared to levels observed when the reservoir was full and strongly thermally stratified. Elevated levels of redeposition from resuspension in the reservoir have been driven by both higher water column concentrations of suspended solids and settling velocities. Recurring longitudinal and lateral gradients in resuspension are delineated, establishing that resuspended solids are transported from the riverine to the lacustrine zone and from near‐shore to pelagic areas. Resuspension is demonstrated to cause increases in inanimate particle (tripton) concentrations. Higher tripton levels have been observed in years with greater drawdown. Water quality impacts of the resuspension phenomenon are considered.
FIELD SCALE MULTIOBJECTIVE DECISION MAKING: A CASE STUDY FROM WESTERN IOWA1
Authors: Heilman Philip , Hatfield Jerry L. , Adkins Martin , Porter Jeffrey , Kurth Russell
Published: June 2007

ABSTRACT: Water quality issues in agriculture are growing in importance. A common theme is the provision of better information to decision makers. This study reports the trial of a prototype decision support system by the U.S. Department of Agriculture Natural Resources Conservation Service and the Agricultural Research Service in the NRCS Harrison County Field Office in 1998. Observed data collected at the Deep Loess Research Station (DLRS) near Treynor, Iowa, were extrapolated using a modified GLEAMS field scale simulation model that included a nitrogen leaching component and a crop growth component. An accounting tool was used to convert crop yield estimates into crop budgets. A model interface was built to specify the climate, soil, and topography of the field, as well as the management scenarios for the alternative management systems. For the Deep Loess Hills area of Harrison County, a total of six soil and slope groups, with 66 total combinations of management practices forming management systems, were defined and simulated based on previously calibrated data from DLRS. A multi‐objective decision support system, the Water Quality Decision Support System, or WQDSS, was used to examine the tradeoffs in a comprehensive set of variables affected by alternative management systems with farmers in Harrison County. The study concluded that a multiobjective decision support system should be developed to support conservation planning by the NRCS. Currently, a larger scale effort to improve water quality decision making is underway.
QUANTIFICATION OF ACTINIDE MIGRATION PATHWAYS AT ROCKY FLATS, COLORADO1
Authors: Paton Ian B. , Dayton Christine S. , Jubenville David M. , Weiner Eugene R. , Hyder Martha W.
Published: June 2007

ABSTRACT: Migration of plutonium, americium, and uranium (actinides) in the environment at the Rocky Flats Environmental Technology Site (RFETS) is the subject of ongoing studies to develop effective strategies for cleanup and regulatory closure of the Department of Energy facility. The Actinide Migration Evaluation pathway analysis quantified actinide transport processes to validate a qualitative conceptual model of environmental actinide transport. Major actinide transport mechanisms evaluated include surface water, ground water, airborne, and biological pathways. Relative quantities of actinide movement via different pathways were compared in terms of actinide loads delivered off the RFETS, using a combination of monitoring data, predictive transport models and results from historic RFETS studies. Results indicate air and surface water constitute the dominant transport mechanisms for plutonium and americium. In ground water, shallow alluvial flow is a limited pathway for plutonium and americium because of the low aqueous solubility of these actinides and their tendency to sorb to soil. However, localized flow in shallow alluvium is a more significant pathway for uranium movement, because of the relatively higher solubility of uranium (VI) species, though isotopic ratios indicate much of the uranium is from natural sources. Biological transport of actinides by mammals, birds, fish, and arthropods is small compared to the other pathways.
SIMULATING THE EFFECTS OF REDUCED PRECIPITATION ON GROUND WATER AND STREAMFLOW IN THE NEBRASKA SAND HILLS1
Authors: Chen Xunhong , Chen Xi
Published: June 2007

ABSTRACT: The Nebraska Sand Hills have a unique hydrologic system with very little runoff and thick aquifers that constantly supply water to rivers, lakes, and wetlands. A ground water flow model was developed to determine the interactions between ground water and streamflow and to simulate the changes in ground water systems by reduced precipitation. The numerical modeling method includes a water balance model for the vadose zone and MOD‐FLOW for the saturated zone. The modeling results indicated that, between 1979 and 1990, 13 percent of the annual precipitation recharged to the aquifer and annual ground water loss by evapotranspiration (ET) was only about one‐fourth of this recharge. Ground water discharge to rivers accounts for about 96 percent of the streamflow in the Dismal and Middle Loup rivers. When precipitation decreased by half the average amount of the 1979 to 1990 period, the average decline of water table over the study area was 0.89 m, and the streamflow was about 87 percent of the present rate. This decline of the water table results in significant reductions in ET directly from ground water and so a significant portion of the streamflow is maintained by capture of the salvaged ET.
DECISION SUPPORT SYSTEM FOR MANAGING GROUND WATER RESOURCES IN THE CHOUSHUI RIVER ALLUVIAL IN TAIWAN1
Authors: Liu Chen Wuing
Published: June 2007

ABSTRACT: Ground water is a vital water resource in the Choushui River alluvial fan in Taiwan. A significantly increased demand for water, resulting from rapid economic development, has led to large scale ground water extraction. Overdraft of ground water has considerably lowered the ground water level, and caused seawater intrusion, land subsidence, and other environmental damage. Sound ground water management thus is essential. This study presents a decision support system (DSS) for managing ground water resources in the Choushui River alluvial fan. This DSS integrates geographic information, ground water simulation, and expert systems. The geographic information system effectively analyzes and displays the spatially varied data and interfaces with the ground water simulation system to compute the dynamic behavior of ground water flow and solute transport in the aquifer. Meanwhile, a ground water model, MODFLOW‐96, is used to determine the permissible yield in the Choushui River alluvial fan. Additionally, an expert system of DSS employs the determined aquifer permissible yield to assist local government agencies in issuing water rights permits and managing ground water resources in the Choushui River alluvial fan.
NITRATE CONCENTRATIONS IN ILLINOIS RIVERS 1967 TO 1974: COMPARISON AMONG REPORTING AGENCIES1
Authors: Mclsaac Gregory F. , Short Matthew B. , Groschen George , Terrio Paul
Published: June 2007

ABSTRACT: Long term data on surface water quality can sometimes be assembled by combining data collected by different agencies at different times and assuming that between agency differences in data quality are insignificant. The objective of this paper was to assess the quality of riverine nitrate (NO3) concentrations in Illinois measured and reported by four agencies from 1967 to 1974 by comparing median values for similar sampling locations and periods. A total of 17 river reaches were identified for which two agencies reported NO3 concentrations during similar periods. Nonparametric comparison of median values and analysis of covariance with discharge as a covariant produced similar results. Nitrate concentrations reported by the U.S. Geological Survey (USGS) from 1967 to 1971 were not statistically (P > 0.05) different from values reported by the Illinois State Water Survey (ISWS) for two of three river reaches. Additionally, NO3 concentrations reported by USGS from 1972 to 1974 were not statistically different than concentrations reported by the Illinois Environmental Protection Agency (IEPA) for four of five river reaches. From 1969 to 1971, NO3 concentrations reported by the Illinois Department of Public Heath and the Illinois Environmental Protection Agency (IDPH/IEPA) were less than one‐fourth the magnitude of values reported by ISWS. The median NO3 concentrations measured by the Central Illinois Public Service (CIPS) were significantly greater than those measured by USGS and IDPH/IEPA in the three comparable sampling locations. The use of NO3 concentrations measured by CIPS and IDPH/IEPA prior to 1972 is not recommended.
URBANIZATION INFLUENCES ON AQUATIC COMMUNITIES IN NORTHEASTERN ILLINOIS STREAMS1
Authors: Fitzpatrick Faith A. , Harris Mitchell A. , Arnold Terri L. , Richards Kevin D.
Published: June 2007

ABSTRACT: Biotic indices and sediment trace element concentrations for 43 streams in northeastern Illinois (Chicago area) from the 1980s and 1990s were examined along an agricultural to urban land cover gradient to explore the relations among biotic integrity, sediment chemistry, and urbanization. The Illinois fish Alternative Index of Biotic Integrity (AIBI) ranged from poor to excellent in agricultural/rural streams, but streams with more than 10 percent watershed urban land (about 500 people/mi2) had fair or poor index scores. A macroinvertebrate index (MBI) showed similar trends. A qualitative habitat index (PIBI) did not correlate to either urban indicator. The AIBI and MBI correlated with urban associated sediment trace element concentrations. Elevated copper concentrations in sediment occurred in streams with greater than 40 percent watershed urban land. The number of intolerant fish species and modified index of biotic integrity scores increased in some rural, urbanizing, and urban streams from the 1980s to 1990s, with the largest increases occurring in rural streams with loamy/sandy surficial deposits. However, smaller increases also occurred in urban streams with clayey surficial deposits and over 50 percent watershed urban land. These data illustrate the potentially complex spatial and temporal relations among biotic integrity, sediment chemistry, watershed urban land, population density, and regional and local geologic setting.
SUWANNEE RIVER LONG RANGE STREAMFLOW FORECASTS BASED ON SEASONAL CLIMATE PREDICTORS1
Authors: Tootle Glenn A. , Piechota Thomas C.
Published: June 2007

ABSTRACT: A study of the influence of climate variability on streamflow in the southeastern United States is presented. Using a methodology previously applied to watersheds in Australia and the United States, a long range streamflow forecast (0 to 9 months in advance) is developed. Persistence (i.e., the previous season's streamflow) and climate predictors of the previous season are used to forecast the following season's (winter and spring) streamflow of the Suwannee River located in northern Florida. The winter and spring streamflow is historically the most likely to have severe flood events due to large scale cyclonic (frontal) storms. Results of the analysis indicated that a strong El Nino‐Southern Oscillation (ENSO) signal exists at various lead times to the winter and spring streamflow of the Suwannee River. These results are based on the high correlation values of two commonly used measurements of ENSO strength, the Multivariate ENSO Index (MEI) and Sea Surface Temperature Range 1. Using the relationships developed between climate and streamflow, a continuous exceedance probability forecast was developed for two Suwannee River stations. The forecast system provided an improved forecast for ENSO years. The ability to predict above normal (flood) or below normal (drought) years can provide communities the necessary lead time to protect life, property, sensitive wetlands, and endangered and threatened species.
Cell content of phosphatidylinositol (4,5)bisphosphate in Ehrlich mouse ascites tumour cells in response to cell volume perturbations in anisotonic and in isosmotic media
Authors: Nielsen Doris K. , Jensen Annelie Kolbjørn , Harbak Henrik , Christensen Søren C. , Simonsen Lars Ole
Published: June 2007

The labelling pattern of cellular phosphoinositides (PtdInsPn) was studied in Ehrlich ascites cells labelled in vivo for 24 h with myo‐[2‐3H]‐ or l‐myo‐[1‐3H]inositol and exposed to anisotonic or isosmotic volume perturbations. In parallel experiments the cell volume ([14C]3‐OMG space) was monitored. In hypotonic media the cells initially swelled osmotically and subsequently as expected showed a regulatory volume decrease (RVD) response. Concurrently, the cell content of PtdInsP2 showed a marked, transient decrease and the content of PtdInsP a small, transient increase. The changes in PtdInsP2 and PtdInsP content increased progressively with the extent of hypotonicity (in the range 1.00–0.50 relative osmolarity). No evidence was found for either hydrolysis of PtdInsP2 or formation of PtdInsP3. In hypertonic medium (relative osmolarity 1.50), cells initially shrank osmotically and subsequently as expected showed a small regulatory volume increase (RVI) response. Concurrently, the cell content of PtdInsP2 showed a marked increase and the content of PtdInsP a small decrease, i.e. changes in the opposite direction of those seen in hypotonic media. In isosmotic media with high (100 mm) or low (0.8 mm) K+ concentration, cells slowly swelled or shrank due to uptake or loss of isosmotic KCl. Under these conditions, with largely unchanged intracellular ionic strength, the cell content of PtdInsP2 and PtdInsP remained constant. Our results show that PtdInsP2 is not volume sensitive per se, and moreover that the regulatory volume adjustments in Ehrlich ascites cells are not mediated by PtdInsP2 hydrolysis and its subsequent production of second messengers. The simplest interpretation of the observed effects would be that PtdInsP2 is controlled by ionic strength, probably via activation/inhibition of phosphoinositide‐specific phosphatases/kinases. In Ehrlich ascites cells, as shown previously, the opposing ion channels and transporters activated during RVD and RVI, respectively, are controlled with tight negative coordination by a common cell volume ‘set‐point’ that is shifted in anisotonic media, but unchanged during cell swelling in isosmotic high K+ medium. We hypothesize that PtdInsP2 might orchestrate this ‘set‐point’ shift.
Intracortical circuits modulate transcallosal inhibition in humans
Authors: Avanzino L. , Teo J. T. H. , Rothwell J. C.
Published: June 2007

Previous results using paired‐pulse transcranial magnetic stimulation (TMS) have suggested that the excitability of transcallosal (TC) connections between the hand areas of the two motor cortices is modulated by intracortical inhibitory circuits in the same way as corticospinal tract (CTS) projections to spinal motoneurons. Here we describe two further similarities in TC and CTS control using (1) an I‐wave facilitation protocol and (2) preconditioning with rTMS. In experiment 1, excitability of TC pathways was measured using interhemispheric inhibition (IHI) and the ipsilateral silent period (iSP), whilst excitability of CTS pathways was measured by recording the EMG response evoked in the first dorsal interosseous muscle contralateral to the conditioning stimulus (cMEP). The intensity of the conditioning stimulus was first adjusted to threshold for evoking IHI and iSP, then pairs of conditioning stimuli were applied randomly at interstimulus intervals (ISIs) from 1.3 to 4.3 ms. IHI and iSP were facilitated at ISI = 1.5 ms and 3.0 ms, respectively, as was the MEP evoked by the conditioning stimuli in the contralateral hand. We suggest that TC projections receive I‐wave‐like facilitation similar to that seen in CTS projections. In experiment 2, short interval inhibition of the iSP (SICIiSP), and short interval intracortical inhibition of the cMEP (SICIcMEP) were examined before and after 600 pulses of 5 Hz rTMS at 90% resting motor threshold. Both SICIiSP and SICIcMEP were reduced, as was the iSP; the cMEP was unchanged. This shows that the population of inhibitory interneurons that control TC neurons respond in the same way to 5 Hz rTMS as those that control CTS neurons. Taken together, the data from the two experiments suggest that the layer III and layer V pyramidal neurons that give rise to TC and CTS pathways, respectively, are controlled by neuronal circuitry with similar properties.
Elementary properties of spontaneous fusion of peptidergic vesicles: fusion pore gating
Authors: Vardjan Nina , Stenovec Matjaž , Jorgačevski Jernej , Kreft Marko , Zorec Robert
Published: June 2007

The release of hormones and neurotransmitters by regulated exocytosis requires the delivery of secretory vesicles to the plasma membrane, where they dock and become primed for fusion with the plasma membrane. Upon stimulation a fusion pore is formed through which cargo molecules diffuse out of the vesicle lumen into the extracellular space. After the cargo release the fusion pore either closes (kiss‐and‐run, transient exocytosis), fluctuates between an open and a closed state (for short times, fusion pore flickering, or for rather longer periods, ‘pulsing pore’) or expands irreversibly (full fusion exocytosis). In almost all secretory cells spontaneous secretion of vesicle cargo can be detected in the absence of stimulation. Spontaneous and stimulated exocytosis were thought to exhibit similar properties at elementary level, differing only in the probability of occurrence. However, recent studies indicate that spontaneous exocytosis differs from the stimulated one in many respects, therefore opening questions about the physiological role of spontaneous exocytosis. In this report we address the elementary properties of spontaneous and stimulated peptidergic vesicle discharge which appears to be modulated by fusion pore conductance (diameter) and fusion pore gating.
Dentate Gyrus NMDA Receptors Mediate Rapid Pattern Separation in the Hippocampal Network
Authors: McHugh Thomas J. , Jones Matthew W. , Quinn Jennifer J. , Balthasar Nina , Coppari Roberto , Elmquist Joel K. , Lowell Bradford B. , Fanselow Michael S. , Wilson Matthew A. , Tonegawa Susumu
Published: June 2007

Forming distinct representations of multiple contexts, places, and episodes is a crucial function of the hippocampus. The dentate gyrus subregion has been suggested to fulfill this role. We have tested this hypothesis by generating and analyzing a mouse strain that lacks the gene encoding the essential subunit of the
N
-methyl-
d
-aspartate (NMDA) receptor NR1, specifically in dentate gyrus granule cells. The mutant mice performed normally in contextual fear conditioning, but were impaired in the ability to distinguish two similar contexts. A significant reduction in the context-specific modulation of firing rate was observed in the CA3 pyramidal cells when the mutant mice were transferred from one context to another. These results provide evidence that NMDA receptors in the granule cells of the dentate gyrus play a crucial role in the process of pattern separation.
The prognostic significance of determining DNA content in breast cancer by DNA image cytometry: the role of high grade aneuploidy in node negative breast cancer
Authors: Yildirim-Assaf Selma , Coumbos Alexandra , Hopfenmüller Werner , Foss Hans-Dieter , Stein Harald , Kühn Wolfgang
Published: June 2007

Aim:To investigate the role of DNA aneuploidy, particularly in patients with node negative breast cancer, in order to identify the different risk profiles within the pool of heterogeneous breast cancers.

Methods:Imprint smears from 370 breast carcinomas were Feulgen-stained and measured by DNA image analysis. DNA aneuploidy was graded by the amount of aneuploid cells (DNA content >5c) and highly aneuploid cells (DNA content >9c) in a breast tumour population. These results were correlated to the clinical long-term follow-up. A statistical cut-off value of >10 aneuploid cells (>5c) and of >1 highly aneuploid cell (>9c) was evaluated as significant for disease-free survival (DFS) and overall survival (OS).

Results:Subgroups among patients with breast cancer with aneuploid cells below the cut-off value showed a significantly longer DFS and OS than those with aneuploid cells above this value. Patients withnode negative breast cancerwith >10 aneuploid cells (>5c) and >1 highly aneuploid cell (>9c) showed an unfavourable prognosis similar to patients with node positive breast cancer with <10 aneuploid cells (>5c) and <1 highly aneuploid tumour cell (>9c) in DFS and OS.

Conclusion:Nuclear DNA content, as an objective marker of tumour aggressiveness, provides prognostic information in patients with both node negative and node positive breast cancer. Based on DNA aneuploidy, the clinically inhomogeneous group of patients with node negative breast cancer can be stratified into low-risk and high-risk subgroups. Therefore, DNA ploidy analysis may identify high-risk patients with lymph node negative breast cancer who might benefit from additional adjuvant therapy.
Epigenetic dysregulation of the death-associated protein kinase/p14/HDM2/p53/Apaf-1 apoptosis pathway in multiple myeloma
Authors: Chim Chor-Sang , Liang Raymond , Fung Tsz-Kin , Choi Chi-Lung , Kwong Yok-Lam
Published: June 2007

Aim:To study the role of gene promoter hypermethylation of the putative tumour suppressor genes involved in the death-associated protein (DAP) kinase/p14/HDM2/p53/Apaf-1 apoptosis pathway in multiple myeloma (MM).

Method:DNAs from 55 primary MM marrow samples and myeloma cell lines were analysed for aberrant promoter methylation ofDAP kinase,p14andApaf-1genes by methylation-specific polymerase chain reaction (MSP).

Result:In the methylated positive control, the sensitivity of M-MSP forDAP kinasewas 1×10−3.Aberrant hypermethylation ofDAP kinasewas found in 29/55 (52.7%) primary MM samples, whereas hypermethylation ofp14orApaf-1was undetectable in any of the samples tested. 5-Azacytidine treatment of two myeloma cell lines, WL2 and HS-Sultan, led to de-methylation and re-expression ofDAP kinase, thereby confirming gene silencing associated with promoter hypermethylation. Hypermethylation ofDAP kinasedid not correlate with age, sex, paraprotein subtype or Durie–Salmon stage, but negatively affected the overall survival.

Conclusion:Of the putative tumour suppressor genes in the DAP kinase/p14/HDM2/p53/Apaf-1 apoptosis pathway, onlyDAP kinaseis frequently methylated in MM, which is associated with gene silencing and might be of prognostic significance.p14andApaf-1were not methylated in MM.
Involvement of mast cells in gastritis caused byHelicobacter pylori: a potential role in epithelial cell apoptosis
Authors: Hofman Véronique , Lassalle Sandra , Selva Eric , Kalem Kheira , Steff Adrien , Hébuterne Xavier , Sicard Dominique , Auberger Patrick , Hofman Paul
Published: June 2007

Background:The role(s) of mast cells (MC) in gastric mucosal inflammation caused byHelicobacterpyloriis (are) still debated.

Aim:To determine whether there is an association between MC density and epithelial cell apoptosis in antral gastric mucosa infected byH pylori.

Patients and methods:Biopsy specimens from 122H pylori-positive subjects with chronic active gastritis, 84 patients with non-steroidal anti-inflammatory drug-induced gastritis and 48 volunteers were included.H pylorigenotypes were determined by PCR amplification of bacterial cultures. Immunohistochemical analysis was performed on tissue microarrays with anti-CD117, anti-chymase, anti-tryptase, anti-myeloperoxidase, anti-Bcl-2, anti-Bcl-x, anti-Bax and anti-caspase 3 antibodies.

Results:Of the 122 patients infected withH pylori, 76 (62.3%) harbouredcagApositive strains.H pyloriisolates belonged to thevacAs1/m1genotype in 82 (67%) cases, to thevacAs2/m2genotype in 23 (18.8%) cases and to thevacAs1/m2genotype in 17 (13.9%) cases. 61 (50%)H pyloriisolates werebabA2+. In patients infected withH pylori, the density of MC, and in particular the number of MC-associated epithelial cells, was correlated with a high number of apoptotic epithelial cells. Moreover, the density of MC was correlated with the number of neutrophils infiltrating the antral gastric mucosa, and was strongly increased in patients infected withcagA,vacAs1/m1andbabA2positive strains.

Conclusions:Taken together, these data show that the density of MC can be considered as a histopathological criterion of gastritis activity in patients infected withH pylori.
THREE SCHEMES TO SYNCHRONIZE CHAOTIC FRACTIONAL-ORDER RUCKLIDGE SYSTEMS
Authors: ZHANG YANBIN , ZHOU TIANSHOU
Published: June 2007

The synchronization problem of chaotic fractional-order Rucklidge systems is studied both theoretically and numerically. Three different synchronization schemes based on the Pecora–Carroll principle, the linear feedback control and the bidirectional coupling are proposed to realize chaotic synchronization. It is shown that such schemes can achieve the same aim for the same set of system parameter values (including fractional orders). This provides an alternate choice for applications of fractional-order dynamical systems in engineering fields.
CENTRIFUGAL FORCE INDUCED COLLAPSE OF STRANGE STARS INTO BLACK HOLES
Authors: DE PAOLIS F. , INGROSSO G. , NUCITA A. A. , QADIR ASGHAR
Published: June 2007

It has been suggested that there could be objects even more compact than neutron stars, like the so-called strange stars, P-stars, and magnetars. Strange stars are collapsed stars consisting of u, d, and s quarks. P-stars are a new class of compact stars made of u and d quarks in β-equilibrium with electrons in an Abelian chromomagnetic condensate. It has also been shown that a particle in a circular orbit around a stationary black hole is subject to a centrifugal force that turns out to be directed inwards if the particle orbit radius is between the Schwarzschild radius rs and 3rs/2. Here it is proposed that rotation of a sufficiently compact collapsed object may lead to a centrifugal force induced collapse to a black hole that could emit short gamma-ray bursts.
MASSIVE UNCHARGED AND CHARGED PARTICLES' TUNNELING FROM THE HOROWITZ–STROMINGER DILATON BLACK HOLE
Authors: HU YAPENG , ZHANG JINGYI , ZHAO ZHENG
Published: June 2007

Originally, Parikh and Wilczek's work is only suitable for the massless particles' tunneling. But their work has been further extended to the cases of massive uncharged and charged particles' tunneling recently. In this paper, as a particular black hole solution, we apply this extended method to reconsider the tunneling effect of the Horowitz–Strominger Dilaton black hole. We investigate the behavior of both massive uncharged and charged particles, and respectively calculate the emission rate at the event horizon. Our result shows that their emission rates are also consistent with the unitary theory. Moreover, comparing with the case of massless particles' tunneling, we find that this conclusion is independent of the kind of particles. And it is probably caused by the underlying relationship between this method and the laws of black hole thermodynamics.
A note on Cohen's formal model for computer viruses
Authors: Kauranen Kimmo , Makinen Erkki
Published: June 2007

This note discusses the formal model for computer viruses presented by Fred Cohen. We propose some refinements for the model. Especially, we define a computer virus to be a description of a Turing machine capable of writing a description of another Turing machine to the tape of a universal Turing machine.
Minicomputers, main frames, and distributed systems (Keynote Address)
Authors: Wilkes Maurice V.
Published: June 2007

I propose to divide this lecture into three parts. I would first like to look at the situation as it exists at the present day and to consider the question “When do we use mini-computers and when do we use a main frame? ”. Secondly, I would like to canvass a few ideas, some of them admittedly speculative, on the way in which minicomputers may develop. Thirdly, I would like to consider possible computer systems of the future in which mini-computers form the principal building blocks.
Comparative performance of COBOL programs on mini vs. large computer systems
Authors: Jalics Paul J.
Published: June 2007

The comparative performance characteristics of COBOL programs in a small versus large computer systems are investigated. The vehicle consists of a set of synthetic benchmark COBOL programs, each measuring a particular aspects of COBOL programs; and in addition a large actual COBOL program. Measurement of the CPU execution time and the elapsed clock time for various COBOL computations, data manipulation, and input/output is made on both a large scale computer (IBM 370/158) and a minicomputer (Texas Instruments TI980). Results of a number of such experiments are presented and comparisons made between results gotten from the two systems.