Science.gov

Sample records for 100-year peak flow

  1. Estimated 100-year peak flows and flow volumes in the Big Lost River and Birch Creek at the Idaho National Engineering Laboratory, Idaho

    SciTech Connect

    Kjelstrom, L.C.; Berenbrock, C.

    1996-12-31

    The purpose of this report is to provide estimates of the 100-year peak flows and flow volumes that could enter the INEL area from the Big Lost River and Brich Creek are needed as input data for models that will be used to delineate the extent of the 100-year flood plain at the INEL. The methods, procedures and assumptions used to estimate the 100-year peak flows and flow volumes are described in this report.

  2. Simulation of water-surface elevations for a hypothetical 100-year peak flow in Birch Creek at the Idaho National Engineering and Environmental Laboratory, Idaho

    SciTech Connect

    Berenbrock, C.; Kjelstrom, L.C.

    1997-10-01

    Delineation of areas at the Idaho National Engineering and Environmental Laboratory that would be inundated by a 100-year peak flow in Birch Creek is needed by the US Department of Energy to fulfill flood-plain regulatory requirements. Birch Creek flows southward about 40 miles through an alluvium-filled valley onto the northern part of the Idaho National Engineering and Environmental laboratory site on the eastern Snake River Plain. The lower 10-mile reach of Birch Creek that ends in Birch Creek Playa near several Idaho National Engineering and Environmental Laboratory facilities is of particular concern. Twenty-six channel cross sections were surveyed to develop and apply a hydraulic model to simulate water-surface elevations for a hypothetical 100-year peak flow in Birch Creek. Model simulation of the 100-year peak flow (700 cubic feet per second) in reaches upstream from State Highway 22 indicated that flow was confined within channels even when all flow was routed to one channel. Where the highway crosses Birch Creek, about 315 cubic feet per second of water was estimated to move downstream--115 cubic feet per second through a culvert and 200 cubic feet per second over the highway. Simulated water-surface elevation at this crossing was 0.8 foot higher than the elevation of the highway. The remaining 385 cubic feet per second flowed southwestward in a trench along the north side of the highway. Flow also was simulated with the culvert removed. The exact location of flood boundaries on Birch Creek could not be determined because of the highly braided channel and the many anthropogenic features (such as the trench, highway, and diversion channels) in the study area that affect flood hydraulics and flow. Because flood boundaries could not be located exactly, only a generalized flood-prone map was developed.

  3. Peak flow meter (image)

    MedlinePlus

    A peak flow meter is commonly used by a person with asthma to measure the amount of air that can be ... become narrow or blocked due to asthma, peak flow values will drop because the person cannot blow ...

  4. Make peak flow a habit!

    MedlinePlus

    Asthma - make peak flow a habit; Reactive airway disease - peak flow; Bronchial asthma - peak flow ... your airways are narrowed and blocked due to asthma, your peak flow values drop. You can check ...

  5. Peak flow meter use - slideshow

    MedlinePlus

    ... medlineplus.gov/ency/presentations/100202.htm Peak flow meter use - Series—Peak flow meter use - part one To use the sharing features ... 7 out of 7 Overview A peak flow meter helps you check how well your asthma is ...

  6. How to use your peak flow meter

    MedlinePlus

    Peak flow meter - how to use; Asthma - peak flow meter; Reactive airway disease - peak flow meter; Bronchial asthma - peak flow meter ... your airways are narrowed and blocked due to asthma, your peak flow values drop. You can check ...

  7. Measuring Your Peak Flow Rate

    MedlinePlus

    ... collected in the meter may make your peak flow measurements inaccurate. If you have a cold or other respiratory infection, germs or mucus may also collect in the meter. Proper cleaning with mild detergent in hot water will keep your peak flow meter working accurately and may keep you healthier. ...

  8. Quantification of uncertainties in the 100-year flow at an ungaged site near a gaged station and its application in Georgia

    NASA Astrophysics Data System (ADS)

    Cho, Huidae; Bones, Emma

    2016-08-01

    The Federal Emergency Management Agency has introduced the concept of the "1-percent plus" flow to incorporate various uncertainties in estimation of the 100-year or 1-percent flow. However, to the best of the authors' knowledge, no clear directions for calculating the 1-percent plus flow have been defined in the literature. Although information about standard errors of estimation and prediction is provided along with the regression equations that are often used to estimate the 1-percent flow at ungaged sites, uncertainty estimation becomes more complicated when there is a nearby gaged station because regression flows and the peak flow estimate from a gage analysis should be weighted to compute the weighted estimate of the 1-percent flow. In this study, an equation for calculating the 1-percent plus flow at an ungaged site near a gaged station is analytically derived. Also, a detailed process is introduced for calculating the 1-percent plus flow for an ungaged site near a gaged station in Georgia as an example and a case study is performed. This study provides engineers and practitioners with a method that helps them better assess flood risks and develop mitigation plans accordingly.

  9. Peak-flow frequency relations and evaluation of the peak-flow gaging network in Nebraska

    USGS Publications Warehouse

    Soenksen, Philip J.; Miller, Lisa D.; Sharpe, Jennifer B.; Watton, Jason R.

    1999-01-01

    Estimates of peak-flow magnitude and frequency are required for the efficient design of structures that convey flood flows or occupy floodways, such as bridges, culverts, and roads. The U.S. Geological Survey, in cooperation with the Nebraska Department of Roads, conducted a study to update peak-flow frequency analyses for selected streamflow-gaging stations, develop a new set of peak-flow frequency relations for ungaged streams, and evaluate the peak-flow gaging-station network for Nebraska. Data from stations located in or within about 50 miles of Nebraska were analyzed using guidelines of the Interagency Advisory Committee on Water Data in Bulletin 17B. New generalized skew relations were developed for use in frequency analyses of unregulated streams. Thirty-three drainage-basin characteristics related to morphology, soils, and precipitation were quantified using a geographic information system, related computer programs, and digital spatial data.For unregulated streams, eight sets of regional regression equations relating drainage-basin to peak-flow characteristics were developed for seven regions of the state using a generalized least squares procedure. Two sets of regional peak-flow frequency equations were developed for basins with average soil permeability greater than 4 inches per hour, and six sets of equations were developed for specific geographic areas, usually based on drainage-basin boundaries. Standard errors of estimate for the 100-year frequency equations (1percent probability) ranged from 12.1 to 63.8 percent. For regulated reaches of nine streams, graphs of peak flow for standard frequencies and distance upstream of the mouth were estimated.The regional networks of streamflow-gaging stations on unregulated streams were analyzed to evaluate how additional data might affect the average sampling errors of the newly developed peak-flow equations for the 100-year frequency occurrence. Results indicated that data from new stations, rather than more

  10. Peak expiratory flow at altitude.

    PubMed

    Thomas, P S; Harding, R M; Milledge, J S

    1990-08-01

    The mini Wright peak flow meter is a useful, portable instrument for field studies but being sensitive to air density will under-read at altitude. True peak expiratory flow will increase at altitude, however, because of the decreased air density, given that dynamic resistance is unchanged. The effect of simulated altitude on peak expiratory flow (PEF) was determined in six subjects with both the mini Wright meter and a volumetric spirometer (which is unaffected by air density). With increasing altitude PEF as measured by the spirometer increased linearly with decreasing pressure, so that at a barometric pressure of 380 mm Hg* (half an atmosphere, corresponding to an altitude of 5455 m) there was a 20% increase over sea level values. The mini Wright flow meter gave readings 6% below sea level values for this altitude--that is, under-reading by 26%. Measurements of PEF made at altitude with the mini Wright meter should be corrected by adding 6.6% per 100 mm Hg drop in barometric pressure.

  11. Seasonal solar wind speeds for the last 100 years: Unique coronal hole structures during the peak and demise of the Grand Modern Maximum

    NASA Astrophysics Data System (ADS)

    Mursula, K.; Holappa, L.; Lukianova, R.

    2017-01-01

    Solar coronal holes are sources of high-speed solar wind streams, which cause persistent geomagnetic activity especially at high latitudes. Here we estimate seasonal solar wind speeds at 1 AU for the last 100 years using high-latitude geomagnetic measurements and show that they give information on the long-term evolution of important structures of the solar large-scale magnetic field, such as persistent coronal holes. We find that the centennial evolution of solar wind speed at 1 AU is different for equinoxes and solstices, reflecting differences in the evolution of polar coronal hole extensions and isolated low-latitude coronal holes. Equinoctial solar wind speeds had their centennial maximum in 1952, during the declining phase of solar cycle 18, verifying that polar coronal holes had exceptionally persistent extensions just before the peak of the Grand Modern Maximum of solar activity. On the other hand, solstice speeds had their centennial maximum during the declining phase of solar cycle 23 due to large low-latitude coronal holes. A similar configuration of seasonal speeds as in cycle 23 was not found earlier, not even during the less active cycles of early 20th century. Therefore, the exceptional occurrence of persistent, isolated low-latitude coronal holes in cycle 23 is not related to the absolute level of sunspot activity but, most likely, to the demise of the Grand Modern Maximum.

  12. Peak-flow characteristics of Virginia streams

    USGS Publications Warehouse

    Austin, Samuel H.; Krstolic, Jennifer L.; Wiegand, Ute

    2011-01-01

    Peak-flow annual exceedance probabilities, also called probability-percent chance flow estimates, and regional regression equations are provided describing the peak-flow characteristics of Virginia streams. Statistical methods are used to evaluate peak-flow data. Analysis of Virginia peak-flow data collected from 1895 through 2007 is summarized. Methods are provided for estimating unregulated peak flow of gaged and ungaged streams. Station peak-flow characteristics identified by fitting the logarithms of annual peak flows to a Log Pearson Type III frequency distribution yield annual exceedance probabilities of 0.5, 0.4292, 0.2, 0.1, 0.04, 0.02, 0.01, 0.005, and 0.002 for 476 streamgaging stations. Stream basin characteristics computed using spatial data and a geographic information system are used as explanatory variables in regional regression model equations for six physiographic regions to estimate regional annual exceedance probabilities at gaged and ungaged sites. Weighted peak-flow values that combine annual exceedance probabilities computed from gaging station data and from regional regression equations provide improved peak-flow estimates. Text, figures, and lists are provided summarizing selected peak-flow sites, delineated physiographic regions, peak-flow estimates, basin characteristics, regional regression model equations, error estimates, definitions, data sources, and candidate regression model equations. This study supersedes previous studies of peak flows in Virginia.

  13. Flow and sediment processes in a cutoff meander of the Danube Delta during 100-year recurrent flood

    NASA Astrophysics Data System (ADS)

    Jugaru Tiron, L.; Le Coz, J.; Provansal, M.; Dutu, F.

    2009-04-01

    River training operations, such as meander cutoff, initiated for navigational purposes often lead to dramatic changes in the streamwise profiles (Hooke, 1986, Kesel, 2003; Kiss et al., 2007). Meander correction affects both the hydraulic and morphodynamical behavior of the modified branches that sedimentation occurs in time, while newly built canals usually experience degradation (Jugaru et. al, 2006). This study reports and analyzes new data on the hydrological and sedimentary processes at work during a morphogenic flood in a large modified meander (the Mahmudia meander) of the St. George branch, the southern branch of the Danube Delta. The 100-year recurrent flood that occurred in 2006 offered an exceptional opportunity for scanning different cross sections of the Mahmudia meander system by means of the emerging Doppler profiler (aDcp) technology in order to analyze the impact on sedimentation and dynamic processes in the study area. The Mahmudia study site corresponds to a vast natural meander which was cut off in 1984-1988 by an artificial canal opened to shipping. The meander correction accelerated fluxes through the artificial canal and dramatically enhanced deposition in the former meander. After his formation, the cutoff meander acted as sediment storage locations, essentially removing channel and point bar sediments from the active sediment budget of the main channel (Popa, 1997). During the one-hundred-year recurrent flood in April 2006, bathymetry, flow velocity and discharge data were acquired across several sections of both natural and artificial channels with an acoustic Doppler current profiler (aDcp Workhorse Sentinel 600 kHz, Teledyne RDI) in order to investigate the distribution of the flow and sediment and his impact on sedimentation in a channelized reach and its adjacent cutoff. The contrasting hydro-sedimentary processes at work in both channels and bifurcation/confluence nodal points are analyzed from the measured flux distribution

  14. Characterization of peak flow events with local singularity method

    NASA Astrophysics Data System (ADS)

    Cheng, Q.; Li, L.; Wang, L.

    2009-07-01

    Three methods, return period, power-law frequency plot (concentration-area) and local singularity index, are introduced in the paper for characterizing peak flow events from river flow data for the past 100 years from 1900 to 2000 recorded at 25 selected gauging stations on rivers in the Oak Ridges Moraine (ORM) area, Canada. First a traditional method, return period, was applied to the maximum annual river flow data. Whereas the Pearson III distribution generally fits the values, a power-law frequency plot (C-A) on the basis of self-similarity principle provides an effective mean for distinguishing "extremely" large flow events from the regular flow events. While the latter show a power-law distribution, about 10 large flow events manifest departure from the power-law distribution and these flow events can be classified into a separate group most of which are related to flood events. It is shown that the relation between the average water releases over a time period after flow peak and the time duration may follow a power-law distribution. The exponent of the power-law or singularity index estimated from this power-law relation may be used to characterize non-linearity of peak flow recessions. Viewing large peak flow events or floods as singular processes can anticipate the application of power-law models not only for characterizing the frequency distribution of peak flow events, for example, power-law relation between the number and size of floods, but also for describing local singularity of processes such as power-law relation between the amount of water released versus releasing time. With the introduction and validation of singularity of peak flow events, alternative power-law models can be used to depict the recession property as well as other types of non-linear properties.

  15. Tuskegee: 100 Years Later.

    ERIC Educational Resources Information Center

    Higgins, Renelda

    1981-01-01

    Reviews the history and accomplishments of Tuskegee Institute over the past 100 years. Highlights the role played by Booker T. Washington, and W. E. B. DuBois; discusses the career of the school's retiring president, Luther Foster. Provides information on the new president, Dr. Benjamin Payton, and discusses future directions for the college. (APM)

  16. Amplification of postwildfire peak flow by debris

    NASA Astrophysics Data System (ADS)

    Kean, J. W.; McGuire, L. A.; Rengers, F. K.; Smith, J. B.; Staley, D. M.

    2016-08-01

    In burned steeplands, the peak depth and discharge of postwildfire runoff can substantially increase from the addition of debris. Yet methods to estimate the increase over water flow are lacking. We quantified the potential amplification of peak stage and discharge using video observations of postwildfire runoff, compiled data on postwildfire peak flow (Qp), and a physically based model. Comparison of flood and debris flow data with similar distributions in drainage area (A) and rainfall intensity (I) showed that the median runoff coefficient (C = Qp/AI) of debris flows is 50 times greater than that of floods. The striking increase in Qp can be explained using a fully predictive model that describes the additional flow resistance caused by the emergence of coarse-grained surge fronts. The model provides estimates of the amplification of peak depth, discharge, and shear stress needed for assessing postwildfire hazards and constraining models of bedrock incision.

  17. Amplification of postwildfire peak flow by debris

    USGS Publications Warehouse

    Kean, Jason W.; Mcguire, Luke; Rengers, Francis; Smith, Joel B.; Staley, Dennis M.

    2016-01-01

    In burned steeplands, the peak depth and discharge of postwildfire runoff can substantially increase from the addition of debris. Yet methods to estimate the increase over water flow are lacking. We quantified the potential amplification of peak stage and discharge using video observations of postwildfire runoff, compiled data on postwildfire peak flow (Qp), and a physically based model. Comparison of flood and debris flow data with similar distributions in drainage area (A) and rainfall intensity (I) showed that the median runoff coefficient (C = Qp/AI) of debris flows is 50 times greater than that of floods. The striking increase in Qp can be explained using a fully predictive model that describes the additional flow resistance caused by the emergence of coarse-grained surge fronts. The model provides estimates of the amplification of peak depth, discharge, and shear stress needed for assessing postwildfire hazards and constraining models of bedrock incision.

  18. Predicting Peak Flows following Forest Fires

    NASA Astrophysics Data System (ADS)

    Elliot, William J.; Miller, Mary Ellen; Dobre, Mariana

    2016-04-01

    Following forest fires, peak flows in perennial and ephemeral streams often increase by a factor of 10 or more. This increase in peak flow rate may overwhelm existing downstream structures, such as road culverts, causing serious damage to road fills at stream crossings. In order to predict peak flow rates following wildfires, we have applied two different tools. One is based on the U.S.D.A Natural Resource Conservation Service Curve Number Method (CN), and the other is by applying the Water Erosion Prediction Project (WEPP) to the watershed. In our presentation, we will describe the science behind the two methods, and present the main variables for each model. We will then provide an example of a comparison of the two methods to a fire-prone watershed upstream of the City of Flagstaff, Arizona, USA, where a fire spread model was applied for current fuel loads, and for likely fuel loads following a fuel reduction treatment. When applying the curve number method, determining the time to peak flow can be problematic for low severity fires because the runoff flow paths are both surface and through shallow lateral flow. The WEPP watershed version incorporates shallow lateral flow into stream channels. However, the version of the WEPP model that was used for this study did not have channel routing capabilities, but rather relied on regression relationships to estimate peak flows from individual hillslope polygon peak runoff rates. We found that the two methods gave similar results if applied correctly, with the WEPP predictions somewhat greater than the CN predictions. Later releases of the WEPP model have incorporated alternative methods for routing peak flows that need to be evaluated.

  19. Historical changes in annual peak flows in Maine and implications for flood-frequency analyses

    USGS Publications Warehouse

    Hodgkins, Glenn A.

    2010-01-01

    To safely and economically design bridges, culverts, and other structures that are in or near streams (fig. 1 for example), it is necessary to determine the magnitude of peak streamflows such as the 100-year flow. Flood-frequency analyses use statistical methods to compute peak flows for selected recurrence intervals (100 years, for example). The recurrence interval is the average number of years between peak flows that are equal to or greater than a specified peak flow. Floodfrequency analyses are based on annual peak flows at a stream. It has long been assumed that annual peak streamflows are stationary over very long periods of time, except in river basins subject to urbanization, regulation, and other direct human activities. Stationarity is the concept that natural systems fluctuate within an envelope of variability that does not change over time (Milly and others, 2008). Because of the potential effects of global warming on peak flows, the assumption of peak-flow stationarity has recently been questioned (Milly and others, 2008). Maine has many streamgaging stations with 50 to 105 years of recorded annual peak streamflows. This long-term record has been tested for historical flood-frequency stationarity, to provide some insight into future flood frequency (Hodgkins, 2010). This fact sheet, prepared by the U.S. Geological Survey (USGS) in cooperation with the Maine Department of Transportation (MaineDOT), provides a partial summary of the results of the study by Hodgkins (2010).

  20. Estimates of Flow Duration, Mean Flow, and Peak-Discharge Frequency Values for Kansas Stream Locations

    USGS Publications Warehouse

    Perry, Charles A.; Wolock, David M.; Artman, Joshua C.

    2004-01-01

    Streamflow statistics of flow duration and peak-discharge frequency were estimated for 4,771 individual locations on streams listed on the 1999 Kansas Surface Water Register. These statistics included the flow-duration values of 90, 75, 50, 25, and 10 percent, as well as the mean flow value. Peak-discharge frequency values were estimated for the 2-, 5-, 10-, 25-, 50-, and 100-year floods. Least-squares multiple regression techniques were used, along with Tobit analyses, to develop equations for estimating flow-duration values of 90, 75, 50, 25, and 10 percent and the mean flow for uncontrolled flow stream locations. The contributing-drainage areas of 149 U.S. Geological Survey streamflow-gaging stations in Kansas and parts of surrounding States that had flow uncontrolled by Federal reservoirs and used in the regression analyses ranged from 2.06 to 12,004 square miles. Logarithmic transformations of climatic and basin data were performed to yield the best linear relation for developing equations to compute flow durations and mean flow. In the regression analyses, the significant climatic and basin characteristics, in order of importance, were contributing-drainage area, mean annual precipitation, mean basin permeability, and mean basin slope. The analyses yielded a model standard error of prediction range of 0.43 logarithmic units for the 90-percent duration analysis to 0.15 logarithmic units for the 10-percent duration analysis. The model standard error of prediction was 0.14 logarithmic units for the mean flow. Regression equations used to estimate peak-discharge frequency values were obtained from a previous report, and estimates for the 2-, 5-, 10-, 25-, 50-, and 100-year floods were determined for this report. The regression equations and an interpolation procedure were used to compute flow durations, mean flow, and estimates of peak-discharge frequency for locations along uncontrolled flow streams on the 1999 Kansas Surface Water Register. Flow durations, mean

  1. 100 Years of Mathematics Teacher

    ERIC Educational Resources Information Center

    National Council of Teachers of Mathematics, 2007

    2007-01-01

    "Mathematics Teacher" (MT) is celebrating 100 years of publication. Help commemorate this centennial with this special issue of MT, filled with information on the journal's history, with notable articles and fresh perspectives on mathematics education from the past 100 years.

  2. Trends in peak flows of selected streams in Kansas

    USGS Publications Warehouse

    Rasmussen, T.J.; Perry, C.A.

    2001-01-01

    The possibility of a systematic change in flood potential led to an investigation of trends in the magnitude of annual peak flows in Kansas. Efficient design of highway bridges and other flood-plain structures depends on accurate understanding of flood characteristics. The Kendall's tau test was used to identify trends at 40 stream-gaging stations during the 40-year period 1958-97. Records from 13 (32 percent) of the stations showed significant trends at the 95-percent confidence level. Only three of the records (8 percent) analyzed had increasing trends, whereas 10 records (25 percent) had decreasing trends, all of which were for stations located in the western one-half of the State. An analysis of flow volume using mean annual discharge at 29 stations in Kansas resulted in 6 stations (21 percent) with significant trends in flow volumes. All six trends were decreasing and occurred in the western one-half of the State. The Kendall's tau test also was used to identify peak-flow trends over the entire period of record for 54 stream-gaging stations in Kansas. Of the 23 records (43 percent) showing significant trends, 16 (30 percent) were decreasing, and 7 (13 percent) were increasing. The trend test then was applied to 30-year periods moving in 5-year increments to identify time periods within each station record when trends were occurring. Systematic changes in precipitation patterns and long-term declines in ground-water levels in some stream basins may be contributing to peak-flow trends. To help explain the cause of the streamflow trends, the Kendall's tau test was applied to total annual precipitation and ground-water levels in Kansas. In western Kansas, the lack of precipitation and presence of decreasing trends in ground-water levels indicated that declining water tables are contributing to decreasing trends in peak streamflow. Declining water tables are caused by ground-water withdrawals and other factors such as construction of ponds and terraces. Peak-flow

  3. Effect of reservoir storage on peak flow

    USGS Publications Warehouse

    Mitchell, William D.

    1962-01-01

    For observation of small-basin flood peaks, numerous crest-stage gages now are operated at culverts in roadway embankments. To the extent that they obstruct the natural flood plains of the streams, these embankments serve to create detention reservoirs, and thus to reduce the magnitude of observed peak flows. Hence, it is desirable to obtain a factor, I/O, by which the observed outflow peaks may be adjusted to corresponding inflow peaks. The problem is made more difficult by the fact that, at most of these observation sites, only peak stages and discharges are observed, and complete hydrographs are not available. It is postulated that the inflow hydrographs may be described in terms of Q, the instantaneous discharge; A, the size of drainage area; Pe, the amount of rainfall excess; H, the time from beginning of rainfall excess; D, the duration of rainfall excess; and T and k, characteristic times for the drainage area, and indicative of the time lag between rainfall and runoff. These factors are combined into the dimensionless ratios (QT/APe), (H/T), (k/T), and (D/T), leading to families of inflow hydrographs in which the first ratio is the ordinate, the second is the abscissa, and the third and fourth are distinguishing parameters. Sixteen dimensionless inflow hydrographs have been routed through reservoir storage to obtain 139 corresponding outflow hydrographs. In most of the routings it has been assumed that the storage-outflow relation is linear; that is, that storage is some constant, K, times the outflow. The existence of nonlinear storage is recognized, and exploratory nonlinear routings are described, but analyses and conclusions are confined to the problems of linear storage. Comparisons between inflow hydrographs and outflow hydrographs indicate that, at least for linear storage, I/O=f(k/T, D/T, K/T) in which I and O are, respectively, the magnitudes of the inflow and the outflow peaks, and T, k, D, and K are as defined above. Diagrams are presented to

  4. Historical changes in annual peak flows in Maine and implications for flood-frequency analyses

    USGS Publications Warehouse

    Hodgkins, Glenn A.

    2010-01-01

    and multiple sub-periods of that record using the guidelines (Bulletin 17B) of the Interagency Advisory Committee on Water Data. Magnitudes of 100- and 5-year peak flows computed from sub-periods then were compared to those computed from the full period. Sub-periods of 30 years with starting years staggered by 10 years were evaluated (1907–36, 1917–46, 1927–56, 1937–66, 1947–76, 1957–86, 1967–96, and 1977–2006). Two other sub-periods were evaluated using older data (start-of-record to 1970) and newer data (1971 to 2006). The 5-year peak flow is used to represent small and relatively frequent flood flows in Maine, whereas the 100-year peak flow is used to represent large flood flows. The 1967–96 sub-period generated the highest 100- and 5-year peak flows overall when compared to peak flows based on the full period of record; the median difference for all 28 streamgages is 8 percent for 100- and 5-year peak flows. The 1977–2006 and 1971–2006 sub-periods also generated 100- and 5-year peak flows higher than peak flows based on the full period of record, but not as high as the peak flows based on the 1967–96 sub-period. The 1937–66 sub-period generated the lowest 100- and 5-year peak flows overall. The median difference from full-period peak flows is -11 percent for 100-year peak flows and -8 percent for 5-year peak flows. Overall, differences between peak flows based on the sub-periods and those based on the full periods, generated using the 20 unregulated streamgages, are similar to differences using all 28 streamgages. Increases in the 5- and 100-year peak flows based on recent years of record are, in general, modest when compared to peak flows based on complete periods of record. The highest peak flows are based on the 1967–96 sub-period rather than the most recent sub-period (1977-2006). Peak flows for selected recurrence intervals are sensitive to very high peak flows that may occur once in a century or even less frequently. It is

  5. Estimating the Magnitude of Peak Flows for Streams in Maine for Selected Recurrence Intervals

    USGS Publications Warehouse

    Hodgkins, Glenn A.

    1999-01-01

    This report gives estimates of, and presents techniques for estimating, the magnitude of peak flows for streams in Maine for recurrence intervals of 2, 5, 10, 25, 50, 100, and 500 years. A flowchart in this report guides the user to the appropriate estimates and (or) estimating techniques for a site on a specific stream. Section 1, 'Estimates of peak flows and maximum recorded flows at USGS streamflow-gaging stations,' contains peak-flow estimates and the maximum recorded flows at 98 U.S. Geological Survey (USGS) streamflow-gaging stations. In the development of the peak-flow estimates at gaging stations, a new generalized skew coefficient was calculated for Maine. This single statewide value of 0.029 (with a standard error of prediction of 0.297) is more accurate for Maine than the national skew isoline map in Bulletin 17B of the Interagency Advisory Committee on Water Data. Two techniques are presented to estimate the peak flows for ungaged, unregulated streams in rural drainage basins. These two techniques were developed using generalized least squares regression procedures at 70 USGS gaging stations in Maine and eastern New Hampshire. Section 2, 'Estimating peak flows for ungaged, unregulated streams in rural drainage basins,' uses the final explanatory variables of drainage area and basin wetlands. The average standard error of prediction for the 100-year peak flow regression equation in section 2 was 48.6 percent to -32.7 percent. Drainage area was the only explanatory variable used in section 3, 'Estimating peak flows for ungaged, unregulated streams in rural drainage basins - Simplified technique.' The average standard error of prediction for the 100-year peak flow regression equation in section 3 was 80.3 percent to -44.5 percent. Section 4 of the report describes techniques for estimating peak flows for ungaged sites on gaged, unregulated streams in rural drainage basins. Section 5, 'Estimating peak flows for ungaged, unregulated streams in urbanized

  6. NETL: The First 100 Years

    ScienceCinema

    None

    2016-07-12

    The National Energy Technology Laboratory celebrates 100 years of innovative energy technology development. NETL has been a leader in energy technology development. This video takes a look back at the many accomplishments over the past 100 years. These advances benefit the American people, enhance our nation's energy security and protect our natural resources.

  7. NETL: The First 100 Years

    SciTech Connect

    2015-07-21

    The National Energy Technology Laboratory celebrates 100 years of innovative energy technology development. NETL has been a leader in energy technology development. This video takes a look back at the many accomplishments over the past 100 years. These advances benefit the American people, enhance our nation's energy security and protect our natural resources.

  8. Estimating instantaneous peak flow from mean daily flow

    NASA Astrophysics Data System (ADS)

    Chen, B.; Krajewski, W. F.

    2015-12-01

    While instantaneous peak flow (IPF) records have historically been necessary for practical applications in flood risk management and hydraulic structure design, mean daily flow (MDF) values are often all that are available. To address this problem, we propose a simple method, which requires only MDF records as its input and uses the rising and falling slopes of daily hydrographs, to estimate IPFs. We applied this method to 144 catchments in Iowa, USA, with drainage areas ranging from about 7 to 220,000 km2. This application involves about 3800 peak flow events originating from different flood generation mechanisms over the period from 1997 to 2014. About 55% of the catchments have prediction errors within ±10%, and 85% of the catchments have predictions errors within ±20%. The method works well for catchments larger than 500 km2, poorly for catchments smaller than 100 km2, and fairly well for catchments in between these sizes. The reduction in the method's effectiveness with decreasing catchment size is due to the fact that the smaller the catchment, the more information is lost when using MDF to characterize the instantaneous flow processes. Our proposed method is simple and promising in terms of estimating IPFs from MDFs for areas where IPF records are unavailable or are insufficient.

  9. Historical changes in annual peak flows in Maine and implications for flood-frequency analyses

    USGS Publications Warehouse

    Hodgkins, Glenn A.

    2010-01-01

    multiple sub-periods of that record using the guidelines (Bulletin 17B) of the Interagency Advisory Committee on Water Data. Magnitudes of 100- and 5-year peak flows computed from sub-periods then were compared to those computed from the full period. Sub-periods of 30 years with starting years staggered by 10 years were evaluated (1907-36, 1917-46, 1927-56, 1937-66, 1947-76, 1957-86, 1967-96, and 1977-2006). Two other sub-periods were evaluated using older data (start-of-record to 1970) and newer data (1971 to 2006). The 5-year peak flow is used to represent small and relatively frequent flood flows in Maine, whereas the 100-year peak flow is used to represent large flood flows. The 1967-96 sub-period generated the highest 100- and 5-year peak flows overall when compared to peak flows based on the full period of record; the median difference for all 28 streamgages is 8 percent for 100- and 5-year peak flows. The 1977-2006 and 1971-2006 sub-periods also generated 100- and 5-year peak flows higher than peak flows based on the full period of record, but not as high as the peak flows based on the 1967-96 sub-period. The 1937-66 sub-period generated the lowest 100- and 5-year peak flows overall. The median difference from full-period peak flows is -11 percent for 100-year peak flows and -8 percent for 5-year peak flows. Overall, differences between peak flows based on the sub-periods and those based on the full periods, generated using the 20 unregulated streamgages, are similar to differences using all 28 streamgages. Increases in the 5- and 100-year peak flows based on recent years of record are, in general, modest when compared to peak flows based on complete periods of record. The highest peak flows are based on the 1967-96 sub-period rather than the most recent sub-period (1977-2006). Peak flows for selected recurrence intervals are sensitive to very high peak flows that may occur once in a century or even less frequently. It is difficult, therefore, to determ

  10. Comparison of Peak-Flow Estimation Methods for Small Drainage Basins in Maine

    USGS Publications Warehouse

    Hodgkins, Glenn A.; Hebson, Charles; Lombard, Pamela J.; Mann, Alexander

    2007-01-01

    Understanding the accuracy of commonly used methods for estimating peak streamflows is important because the designs of bridges, culverts, and other river structures are based on these flows. Different methods for estimating peak streamflows were analyzed for small drainage basins in Maine. For the smallest basins, with drainage areas of 0.2 to 1.0 square mile, nine peak streamflows from actual rainfall events at four crest-stage gaging stations were modeled by the Rational Method and the Natural Resource Conservation Service TR-20 method and compared to observed peak flows. The Rational Method had a root mean square error (RMSE) of -69.7 to 230 percent (which means that approximately two thirds of the modeled flows were within -69.7 to 230 percent of the observed flows). The TR-20 method had an RMSE of -98.0 to 5,010 percent. Both the Rational Method and TR-20 underestimated the observed flows in most cases. For small basins, with drainage areas of 1.0 to 10 square miles, modeled peak flows were compared to observed statistical peak flows with return periods of 2, 50, and 100 years for 17 streams in Maine and adjoining parts of New Hampshire. Peak flows were modeled by the Rational Method, the Natural Resources Conservation Service TR-20 method, U.S. Geological Survey regression equations, and the Probabilistic Rational Method. The regression equations were the most accurate method of computing peak flows in Maine for streams with drainage areas of 1.0 to 10 square miles with an RMSE of -34.3 to 52.2 percent for 50-year peak flows. The Probabilistic Rational Method was the next most accurate method (-38.5 to 62.6 percent). The Rational Method (-56.1 to 128 percent) and particularly the TR-20 method (-76.4 to 323 percent) had much larger errors. Both the TR-20 and regression methods had similar numbers of underpredictions and overpredictions. The Rational Method overpredicted most peak flows and the Probabilistic Rational Method tended to overpredict peak flows

  11. Peak-flow characteristics of small urban drainages along the Wasatch Front, Utah

    USGS Publications Warehouse

    Lindskov, K.L.; Thompson, K.R.

    1989-01-01

    Designers and planners for local, State, and Federal agencies need up-to- date methods for determining peak-flow characteristics for urban drainages along the Wasatch Front, Utah. This report summarizes methods used to develop equations that estimate peak-flows for small urban drainages along the Wasatch Front. Mathematical equations were developed that estimate peak flows for recurrence intervals of 2, 5, 10, 25, 50 and 100 years, for small urban drainages. Data entry to the equations requires measurements of basin slope, size and percent impervious area. Rainfall and runoff data collected from eight urban drainages along the Wasatch Front from 1984-86, were used to calibrate a rainfall-runoff model called DR3M-II. Rainfall data collected from 1948-83 at the National Weather Service Salt Lake City Airport station provided additional long-term data to the calibrated models. Log Pearson fits made to the peak flow data were used to estimate the recurrence interval peaks for each basin. Paired stations on Little Cottonwood Creek near Salt Lake City were used to help determine the effects of intervening urban drainage on peaks of larger streams. In general, peaks on larger streams caused by snowmelt and peaks caused by rainfall (where urban areas may have a significant effect) did not occur simultaneously. (USGS)

  12. The clinical value of peak nasal inspiratory flow, peak oral inspiratory flow, and the nasal patency index.

    PubMed

    Tsounis, Michael; Swart, Karin M A; Georgalas, Christos; Markou, Konstantinos; Menger, Dirk J

    2014-12-01

    The aim of this study was to ascertain the most reliable objective measurement for the assessment of nasal patency by investigating the relationship between peak nasal inspiratory flow, peak oral inspiratory flow, and the nasal patency index in relation to the patient's subjective perception regarding nasal obstruction. Prospective cohort study. This study included 131 volunteers of both genders, aged 18 years or older, with or without nasal symptoms, who were able to give informed consent, completed the study protocol, and could speak and write Dutch fluently. Peak nasal inspiratory flow and peak oral inspiratory flow were performed and nasal patency index was computed. The results were evaluated and compared with the subjective perception of nasal passage, using the validated Nasal Obstruction Symptom Evaluation scale and visual analog scale for nasal passage. Our study showed that peak nasal inspiratory flow, nasal patency index and nasal patency visual analog scale correlate with the Nasal Obstruction Symptom Evaluation scale in contrast to peak oral inspiratory flow. Peak nasal inspiratory flow and nasal patency index also showed significant association with the Nasal Obstruction Symptom Evaluation scale after adjustment for confounders. Peak nasal inspiratory flow is the most reliable method for the assessment of nasal patency. It is quick, inexpensive, and easy to perform, and correlates significantly with the subjective feeling of nasal obstruction. There is no clinical need to measure peak oral inspiratory flow or to calculate the nasal patency index in the evaluation of nasal patency. 4 © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

  13. Flood Hydrograph and Peak Flow Frequency Analysis.

    DTIC Science & Technology

    1979-03-01

    such as length and elevation change of main channel, soil characteristics, and land cover. The x -mlnute rainfall intensity for the desired frequency is...have developed their own rainfall frequency analysis techniques (22) and link these techniques directly with their watershed models. These techniques as...study tools ranging front water quality simulation to unsteady flow dam break flood routings. The technical analysis tools all link together with a

  14. Providing peak river flow statistics and forecasting in the Niger River basin

    NASA Astrophysics Data System (ADS)

    Andersson, Jafet C. M.; Ali, Abdou; Arheimer, Berit; Gustafsson, David; Minoungou, Bernard

    2017-08-01

    Flooding is a growing concern in West Africa. Improved quantification of discharge extremes and associated uncertainties is needed to improve infrastructure design, and operational forecasting is needed to provide timely warnings. In this study, we use discharge observations, a hydrological model (Niger-HYPE) and extreme value analysis to estimate peak river flow statistics (e.g. the discharge magnitude with a 100-year return period) across the Niger River basin. To test the model's capacity of predicting peak flows, we compared 30-year maximum discharge and peak flow statistics derived from the model vs. derived from nine observation stations. The results indicate that the model simulates peak discharge reasonably well (on average + 20%). However, the peak flow statistics have a large uncertainty range, which ought to be considered in infrastructure design. We then applied the methodology to derive basin-wide maps of peak flow statistics and their associated uncertainty. The results indicate that the method is applicable across the hydrologically active part of the river basin, and that the uncertainty varies substantially depending on location. Subsequently, we used the most recent bias-corrected climate projections to analyze potential changes in peak flow statistics in a changed climate. The results are generally ambiguous, with consistent changes only in very few areas. To test the forecasting capacity, we ran Niger-HYPE with a combination of meteorological data sets for the 2008 high-flow season and compared with observations. The results indicate reasonable forecasting capacity (on average 17% deviation), but additional years should also be evaluated. We finish by presenting a strategy and pilot project which will develop an operational flood monitoring and forecasting system based in-situ data, earth observations, modelling, and extreme statistics. In this way we aim to build capacity to ultimately improve resilience toward floods, protecting lives and

  15. flowPeaks: a fast unsupervised clustering for flow cytometry data via K-means and density peak finding.

    PubMed

    Ge, Yongchao; Sealfon, Stuart C

    2012-08-01

    For flow cytometry data, there are two common approaches to the unsupervised clustering problem: one is based on the finite mixture model and the other on spatial exploration of the histograms. The former is computationally slow and has difficulty to identify clusters of irregular shapes. The latter approach cannot be applied directly to high-dimensional data as the computational time and memory become unmanageable and the estimated histogram is unreliable. An algorithm without these two problems would be very useful. In this article, we combine ideas from the finite mixture model and histogram spatial exploration. This new algorithm, which we call flowPeaks, can be applied directly to high-dimensional data and identify irregular shape clusters. The algorithm first uses K-means algorithm with a large K to partition the cell population into many small clusters. These partitioned data allow the generation of a smoothed density function using the finite mixture model. All local peaks are exhaustively searched by exploring the density function and the cells are clustered by the associated local peak. The algorithm flowPeaks is automatic, fast and reliable and robust to cluster shape and outliers. This algorithm has been applied to flow cytometry data and it has been compared with state of the art algorithms, including Misty Mountain, FLOCK, flowMeans, flowMerge and FLAME. The R package flowPeaks is available at https://github.com/yongchao/flowPeaks. yongchao.ge@mssm.edu Supplementary data are available at Bioinformatics online.

  16. Technique for simulating peak-flow hydrographs in Maryland

    USGS Publications Warehouse

    Dillow, Jonathan J.A.

    1998-01-01

    The efficient design and management of many bridges, culverts, embankments, and flood-protection structures may require the estimation of time-of-inundation and (or) storage of floodwater relating to such structures. These estimates can be made on the basis of information derived from the peak-flow hydrograph. Average peak-flow hydrographs corresponding to a peak discharge of specific recurrence interval can be simulated for drainage basins having drainage areas less than 500 square miles in Maryland, using a direct technique of known accuracy. The technique uses dimensionless hydrographs in conjunction with estimates of basin lagtime and instantaneous peak flow. Ordinary least-squares regression analysis was used to develop an equation for estimating basin lagtime in Maryland. Drainage area, main channel slope, forest cover, and impervious area were determined to be the significant explanatory variables necessary to estimate average basin lagtime at the 95-percent confidence interval. Qualitative variables included in the equation adequately correct for geographic bias across the State. The average standard error of prediction associated with the equation is approximated as plus or minus (+/-) 37.6 percent. Volume correction factors may be applied to the basin lagtime on the basis of a comparison between actual and estimated hydrograph volumes prior to hydrograph simulation. Three dimensionless hydrographs were developed and tested using data collected during 278 significant rainfall-runoff events at 81 stream-gaging stations distributed throughout Maryland and Delaware. The data represent a range of drainage area sizes and basin conditions. The technique was verified by applying it to the simulation of 20 peak-flow events and comparing actual and simulated hydrograph widths at 50 and 75 percent of the observed peak-flow levels. The events chosen are considered extreme in that the average recurrence interval of the selected peak flows is 130 years. The average

  17. Measuring peak expiratory flow in general practice: comparison of mini Wright peak flow meter and turbine spirometer.

    PubMed Central

    Jones, K P; Mullee, M A

    1990-01-01

    OBJECTIVE--To compare measurements of the peak expiratory flow rate taken by the mini Wright peak flow meter and the turbine spirometer. DESIGN--Pragmatic study with randomised order of use of recording instruments. Phase 1 compared a peak expiratory flow type expiration recorded by the mini Wright peak flow meter with an expiration to forced vital capacity recorded by the turbine spirometer. Phase 2 compared peak expiratory flow type expirations recorded by both meters. Reproducibility was assessed separately. SETTING--Routine surgeries at Aldermoor Health Centre, Southampton. SUBJECTS--212 Patients aged 4 to 78 presenting with asthma or obstructive airways disease. Each patient contributed only once to each phase (105 in phase 1, 107 in phase 2), but some entered both phases on separate occasions. Reproducibility was tested on a further 31 patients. MAIN OUTCOME MEASURE--95% Limits of agreement between measurements on the two meters. RESULTS--208 (98%) Of the readings taken by the mini Wright meter were higher than the corresponding readings taken by the turbine spirometer, but the 95% limits of agreement (mean difference (2 SD] were wide (1 to 173 l/min). Differences due to errors in reproducibility were not sufficient to predict this level of disagreement. Analysis by age, sex, order of use, and the type of expiration did not detect any significant differences. CONCLUSIONS--The two methods of measuring peak expiratory flow rate were not comparable. The mini Wright meter is likely to remain the preferred instrument in general practice. PMID:2142611

  18. Mean annual runoff and peak flow estimates based on channel geometry of streams in southeastern Montana

    USGS Publications Warehouse

    Omang, R.J.; Parrett, Charles; Hull, J.A.

    1983-01-01

    Equations using channel-geometry measurements were developed for estimating mean runoff and peak flows of ungaged streams in southeastern Montana. Two separate sets of esitmating equations were developed for determining mean annual runoff: one for perennial streams and one for ephemeral and intermittent streams. Data from 29 gaged sites on perennial streams and 21 gaged sites on ephemeral and intermittent streams were used in these analyses. Data from 78 gaged sites were used in the peak-flow analyses. Southeastern Montana was divided into three regions and separate multiple-regression equations for each region were developed that relate channel dimensions to peak discharge having recurrence intervals of 2, 5, 10, 25, 50, and 100 years. Channel-geometery relations were developed using measurements of the active-channel width and bankfull width. Active-channel width and bankfull width were the most significant channel features for estimating mean annual runoff for al types of streams. Use of this method requires that onsite measurements be made of channel width. The standard error of estimate for predicting mean annual runoff ranged from about 38 to 79 percent. The standard error of estimate relating active-channel width or bankfull width to peak flow ranged from about 37 to 115 percent. (USGS)

  19. flowPeaks: a fast unsupervised clustering for flow cytometry data via K-means and density peak finding

    PubMed Central

    Ge, Yongchao; Sealfon, Stuart C.

    2012-01-01

    Motivation: For flow cytometry data, there are two common approaches to the unsupervised clustering problem: one is based on the finite mixture model and the other on spatial exploration of the histograms. The former is computationally slow and has difficulty to identify clusters of irregular shapes. The latter approach cannot be applied directly to high-dimensional data as the computational time and memory become unmanageable and the estimated histogram is unreliable. An algorithm without these two problems would be very useful. Results: In this article, we combine ideas from the finite mixture model and histogram spatial exploration. This new algorithm, which we call flowPeaks, can be applied directly to high-dimensional data and identify irregular shape clusters. The algorithm first uses K-means algorithm with a large K to partition the cell population into many small clusters. These partitioned data allow the generation of a smoothed density function using the finite mixture model. All local peaks are exhaustively searched by exploring the density function and the cells are clustered by the associated local peak. The algorithm flowPeaks is automatic, fast and reliable and robust to cluster shape and outliers. This algorithm has been applied to flow cytometry data and it has been compared with state of the art algorithms, including Misty Mountain, FLOCK, flowMeans, flowMerge and FLAME. Availability: The R package flowPeaks is available at https://github.com/yongchao/flowPeaks. Contact: yongchao.ge@mssm.edu Supplementary information: Supplementary data are available at Bioinformatics online PMID:22595209

  20. Robust detection of peak signals for lateral flow immunoassays

    NASA Astrophysics Data System (ADS)

    Kim, Jongwon; Kim, Jong Dae; Nahm, Kie Bong; Choi, Eui Yul; Lee, Geumyoung

    2011-02-01

    Template matching method is presented to identify the peaks from the scanned signals of lateral flow immunoassay strips. The template is composed of two pulses separated by the distance of the control and the target ligand line in the assay, and is convolved with the scanned signal to deliver the maximum at the center of the two peaks. The peak regions were identified with the predefined distances from the center. Glycosylated haemoglobin immunoassay strips and fluorescent strip readers from Boditechmed Inc. were tested to estimate the lot and reader variations of the concentration measurands. The results showed the robustness of the propose method.

  1. Emergency assessment of potential debris-flow peak discharges, Coal Seam fire, Colorado

    USGS Publications Warehouse

    Cannon, Susan H.; Michael, John A.; Gartner, Joseph E.; Rea, Alan H.; Garcia, Steven P.

    2002-01-01

    These maps present the results of assessments of peak discharges that can potentially be generated by debris flows issuing from the basins burned by the Coal Seam fire of June and July 2002, near Glenwood Springs, Colorado. The maps are based on a regression model for debris-flow peak discharge normalized by average storm intensity as a function of basin gradient and burned extent, and limited field checking. A range of potential peak discharges that could potentially be produced from each of the burned basins between 1 ft3/s (0.03 m3/s) and greater than 5,000 ft3/s (>141 m3/s) is calculated for the 5-year, 1-hour storm of 0.80 inches (20 mm). The 25-year, 1-hour storm of 1.3 inches (33 mm). The 100- year, 1-hour storm of 1.8 inches (46 mm) produced peak discharges between 1 and greater than 8,000 ft3/s (>227 m3/s). These maps are intended for use by emergency personnel to aid in the preliminary design of mitigation measures, and the planning of evacuation timing and routes.

  2. Assessment of a peak flow whistle in nonasthmatic children.

    PubMed

    Terblanche, E; Fourie, P R; Wessels, J A

    1999-06-01

    We tested the agreement of peak expiratory flow (PEF) measurements between an electronic spirometer and a peak flow whistle (Whistle Watch, HarMed, Capetown, South Africa). One hundred and three healthy children between ages 6-13 years and with no previous experience in lung function tests participated in the study. Sequential PEF-readings were obtained from the spirometer and the peak flow whistle; all children had an equal number of attempts using both devices. In the case of the spirometer, the highest PEF reading of three acceptable and reproducible efforts was noted as the best PEF (PEF(SPIRO)). Whistle Watch readings were taken as the highest value when the child could activate the whistle. Despite a strong correlation (r = 0.91; R2 = 83%) between the readings of the spirometer and Whistle Watch, there was a lack of agreement between the two devices. For any individual subject, the 95% probability interval ranged between +30.4 to -47 L.min(-1); 64% of the children obtained higher PEF-values on Whistle Watch, compared to the spirometer. These findings suggest that the whistle sound of the peak flow whistle was a significant incentive, which resulted in greater maximal expiratory efforts.

  3. Changes in storm peak flows after clearcut logging

    Treesearch

    Jack Lewis

    1997-01-01

    Streamflow in a rain-dominated, 473-ha watershed bearing second-growth redwood forest was monitored at 13 locations before and after 50% of the watershed was logged, primarily by clearcutting. Three gauged subwatersheds were maintained as unlogged controls through-out the 11-year study period. The analysis included 526 observations of peak flow from 59 storm events....

  4. Peak expiratory flow in rural residents of Tamil Nadu, India.

    PubMed Central

    Ray, D; Rajaratnam, A; Richard, J

    1993-01-01

    BACKGROUND: In a country such as India that covers several latitudes, climatic zones, ethnic groups, and dietary habits lung function within the normal population would be expected to vary. Several studies have looked at normal values of peak expiratory flow (PEF) in different regions of urban India but none has looked at rural South India. A study of PEF has now been carried out in a rural population of Tamil Nadu. METHODS: All subjects were of Dravidian stock and lived at sea level with rice as their staple food. Ten five year age groups from 10 to 59 years with 100 males and 100 females in each were studied. Peak flow was measured by mini-Wright peak flow meter, and height was also measured. Regression equations for predicting normal PEF were calculated. RESULTS: Peak flow ranged from 150 to 680 l/min in males and from 150 to 500 l/min in females. Maximum values of PEF were attained at the age of 32.5 years in men and 35.6 years in women. There was a significant linear correlation between height and PEF and a curvilinear relation between age and PEF in both sexes. CONCLUSION: Regression equations are now available for PEF values in normal subjects from rural South India. PEF was related to age and height and values were greatest in the fourth decade. PMID:8493632

  5. Potential effects of translatory waves on estimation of peak flows

    USGS Publications Warehouse

    Hjalmarson, H.W.; Phillips, J.V.

    1997-01-01

    During the afternoon of August 19, 1971, an intense thunderstorm a few miles southwest of Wikieup, Arizona, produced one of the largest known flood peaks for a 49.2-square-km drainage basin. Initial computations of the peak discharge assumed stable flow conditions and a four-section slope area measurement indicated that discharge was 2,082 m3/s. Recent findings based on free-surface instability characteristics at the site suggest that gravitational forces exceeded boundary retarding forces, and flow in the wide sand channel was unstable. Computations for roll or translatory waves indicate that waves crashed into the highway bridge at velocities of as much as 12.5 m/s. The close agreement of free surface instability results, translatory wave computations, estimates of the steady flow on which the translatory waves traveled, and an eyewitness account of the translatory waves suggest the total peak discharge could have been 2,742 m3/s or 32% greater than the published discharge. The occurrence of translatory waves in natural channels may be more common than previously thought, and instability criteria should be considered for hydraulic analysis of flow in steep smooth channels.

  6. Estimation of instantaneous peak flow from simulated maximum daily flow using the HBV model

    NASA Astrophysics Data System (ADS)

    Ding, Jie; Haberlandt, Uwe

    2014-05-01

    Instantaneous peak flow (IPF) data are the foundation of the design of hydraulic structures and flood frequency analysis. However, the long discharge records published by hydrological agencies contain usually only average daily flows which are of little value for design in small catchments. In former research, statistical analysis using observed peak and daily flow data was carried out to explore the link between instantaneous peak flow (IPF) and maximum daily flow (MDF) where the multiple regression model is proved to have the best performance. The objective of this study is to further investigate the acceptability of the multiple regression model for post-processing simulated daily flows from hydrological modeling. The model based flood frequency analysis allows to consider change in the condition of the catchments and in climate for design. Here, the HBV model is calibrated on peak flow distributions and flow duration curves using two approaches. In a two -step approach the simulated MDF are corrected with a priory established regressions. In a one-step procedure the regression coefficients are calibrated together with the parameters of the model. For the analysis data from 18 mesoscale catchments in the Aller-Leine river basin in Northern Germany are used. The results show that: (1) the multiple regression model is capable to predict the peak flows with the simulated MDF data; (2) the calibrated hydrological model reproduces well the magnitude and frequency distribution of peak flows; (3) the one-step procedure outperforms the two-step procedure regarding the estimation of peak flows.

  7. Peak Sediment Flow Scaling in a Small Hortonian Watershed

    NASA Astrophysics Data System (ADS)

    Abebe, N. A.; Ogden, F. L.

    2008-12-01

    . Estimation of fine-sediment delivery rates at the watershed-scale is a long-standing problem. We investigated this problem using data from the Goodwin Creek Experimental Watershed (GCEW) located in the Northern-central Mississippi. The GCEW is a Hortonian catchment with 13 nested sub-catchments and a total area of 21.3 km2. Previous studies in this catchment showed that flood quantiles in nearly all sub- catchments are self-similar as described by simple scaling theory. We analyzed sixteen years of peak suspended sediment data from 12 gauging stations. Results showed that simple scaling holds better for peak sediment flow quantiles for the larger sub-catchments with slopes similar to the average slope of the catchment. In the same manner, predictions using derived power-law relations showed better performance for the larger sub-catchments. The log-transform of peak sediment flow and the computed event-total sediment volume showed a strong relation, which could be exploited in estimating the total sediment volume from single measured sediment concentrations. We hypothesize that the relatively uniform distribution of precipitation and land use and the similarity in slope of many of the subcatchments contributes to simple scaling behavior in the GCEW. Moreover, the balance between deposition and re-suspension of sediment along the river reach, which enables channels to have a relatively uniform sediment concentration, helps the peak suspended sediment flux to be proportional to the flow peak and area for larger sub-catchments with similar slopes.

  8. Peak expiratory flow rate in Nigerian school children.

    PubMed

    Jaja, S I; Fagbenro, A O

    1995-12-01

    Peak expiratory flow rate (PEFR) was measured using the Wright's peak flow meter in 263 school boys and 275 school girls living in Lagos, Nigeria. Their ages ranged from 6.0 years to 19.0 years (mean 11.9 +/- 3.8 yrs. for boys and 11.8 +/- 3.9 yrs. for girls). Mean PEFR was 359.2 +/- 102.0 L/min (range 160.0-610.0 L/min) in boys and 327.7 +/- 81.3 L/min (range 160.0-500.0 L/min) in girls. Apart from ages 17, 18 and 19, peak expiratory flow rates were similar in both boys and girls. In both sexes, PEFR correlated positively and significantly with age, height, weight and body surface area. Also in both sexes and in all age groups studied, PEFR was significantly higher than predicted values obtained from previous Nigerian and caucasian prediction equations. When compared with values obtained from a second caucasian prediction equation, observed values were significantly higher in the 6-10 years and 16-19 years age groups in boys and 11-15 years and 16-19 years age groups in girls. New prediction equations for calculating PEFR in Nigerian boys and girls are presented. Observed PEFR may be due to enhanced stature in Nigerian children resulting from improved environment and genetic factors.

  9. Effect of air pollution on peak expiratory flow rate variability.

    PubMed

    Singh, Virendra; Khandelwal, Rakesh; Gupta, A B

    2003-02-01

    Exposure to air pollution affects pulmonary functions adversely. Effect of exposure to pollution on diurnal variation of peak flow was assessed in healthy students. Three hundred healthy age-matched nonsmoker students were studied. They were categorized into two groups on the basis of their residence: commuters and living on campus. Peak expiratory flow (PEF) recordings were made twice daily for 2 days with the Pink City Flow Meter. The measurement was then used to calculate for each subject the amplitude percentage mean, which is an index for expressing PEF variability for epidemiological purposes (Higgins BG, Britton JR, Chinns Jones TD, Jenkinson D, Burnery PG, Tattersfield AE. Distribution of peak expiratory flow variability in a population sample. Am Rev Respir Dis 1989; 140:1368-1372). Air pollution parameters were quantified by measurement of sulfur dioxide (SO2), oxides of nitrogen (NO2), carbon monoxide (CO), and respirable suspended particulate matter (RSPM) in the ambient air at the campus and on the roadside. The mean values of PEF variability (amplitude percent mean) in the students living on campus and in the commuters were 5.7 +/- 3.2 and 11 +/- 3.6, respectively (P < .05). Among the commuters, maximum number of subjects showed amplitude percentage mean PEFR at the higher end of variability distribution, as compared to the students living on campus, among whom the majority of subjects fell in the lower ranges of variability distribution. The ambient air quality parameters, namely SO2, NO2, CO, and RSPM were significantly lower on the campus. It can be concluded that long-term periodic exposure to air pollution can lead to increased PEF variability even in healthy subjects. Measurement of PEF variability may prove to be a simple test to measure effect of air pollution in healthy subjects.

  10. Estimating peak flow characteristics at ungaged sites by ridge regression

    USGS Publications Warehouse

    Tasker, Gary D.

    1982-01-01

    A regression simulation model, is combined with a multisite streamflow generator to simulate a regional regression of 50-year peak discharge against a set of basin characteristics. Monte Carlo experiments are used to compare the unbiased ordinary lease squares parameter estimator with Hoerl and Kennard's (1970a) ridge estimator in which the biasing parameter is that proposed by Hoerl, Kennard, and Baldwin (1975). The simulation results indicate a substantial improvement in parameter estimation using ridge regression when the correlation between basin characteristics is more than about 0.90. In addition, results indicate a strong potential for improving the mean square error of prediction of a peak-flow characteristic versus basin characteristics regression model when the basin characteristics are approximately colinear. The simulation covers a range of regression parameters, streamflow statistics, and basin characteristics commonly found in regional regression studies.

  11. Changes in Peak Flow value during immunotherapy administration.

    PubMed

    Saporta, Diego

    2012-01-01

    Nasal allergies are prevalent affecting a large percentage of the population. Not only the upper respiratory tract but the whole body is involved. Allergies produce morbidity (and even occasional mortality) as they can lead to asthma development, and increased number of accidents. Immunotherapy results can be evaluated by following symptom scores, medication use, and objective measurements. Using a Peak Flow Meter (PFM) to evaluate immunotherapy results, it became evident that patients with and without asthma exhibited an improvement in the Peak Flow (PF) value, suggesting that lower airway involvement in allergic patients could be more prevalent than assumed. A consecutive chart review was performed including patients of any age with nasal allergies (with or without asthma) treated with immunotherapy for at least 6 months that had at least 2 complete evaluations. When immunotherapy was successful, most patients exhibited an increase in the PF value regardless of asthma status. A very significant finding was that most allergy sufferers may have lower airway inflammation. The use of the PF value to assess immunotherapy results and the potential failure to diagnose asthma in allergy sufferers are discussed. A better diagnosis of lower airway inflammation could be substantial in the management of these patients.

  12. 100 Years of the Physics of Diodes

    NASA Astrophysics Data System (ADS)

    Luginsland, John

    2013-10-01

    The Child-Langmuir Law (CL), discovered 100 years ago, gives the maximum current that can be transported across a planar diode in the steady state. As a quintessential example of the impact of space-charge shielding near a charged surface, it is central to the studies of high current diodes, such as high power microwave sources, vacuum microelectronics, electron and ion sources, and high current drivers used in high-energy density physics experiments. CL remains a touchstone of fundamental sheath physics, including contemporary studies of nano-scale quantum diodes and plasmonic devices. Its solid state analog is the Mott-Gurney law, governing the maximum charge injection in solids, such as organic materials and other dielectrics, which is important to energy devices, such as solar cells and light-emitting diodes. This paper reviews the important advances in the physics of diodes since the discovery of CL, including virtual cathode formation and extension of CL to multiple dimensions, to the quantum regime, and to ultrafast processes. We will review the influence of magnetic fields, multiple species in bipolar flow, electromagnetic and time dependent effects in both short pulse and high frequency THz limits, and single electron regimes. Transitions from various emission mechanisms (thermionic, field, and photo-emission) to the space charge limited state (CL) will be addressed, especially highlighting important simulation and experimental developments in selected contemporary areas of study. This talk will stress the fundamental physical links between the physics of beams to limiting currents in other areas, such as low temperature plasmas, laser plasmas, and space propulsion. Also emphasized is the role of non-equilibrium phenomena associated with materials and plasmas in close contact. Work supported by the Air Force Office of Scientific Research.

  13. Peak power prediction of a vanadium redox flow battery

    NASA Astrophysics Data System (ADS)

    Yu, V. K.; Chen, D.

    2014-12-01

    The vanadium redox flow battery (VRFB) is a promising grid-scale energy storage technology, but future widespread commercialization requires a considerable reduction in capital costs. Determining the appropriate battery size for the intended power range can help minimize the amount of materials needed, thereby reducing capital costs. A physics-based model is an essential tool for predicting the power range of large scale VRFB systems to aid in the design optimization process. This paper presents a modeling framework that accounts for the effects of flow rate on the pumping losses, local mass transfer rate, and nonuniform vanadium concentration in the cell. The resulting low-order model captures battery performance accurately even at high power densities and remains computationally practical for stack-level optimization and control purposes. We first use the model to devise an optimal control strategy that maximizes battery life during discharge. Assuming optimal control is implemented, we then determine the upper efficiency limits of a given VRFB system and compare the net power and associated overpotential and pumping losses at different operating points. We also investigate the effects of varying the electrode porosity, stack temperature, and total vanadium concentration on the peak power.

  14. Determining the minimum instream flow for hydro peaking projects

    SciTech Connect

    Milhous, R.T. )

    1992-10-01

    A new analytical technique is available for quantifying and predicting the effect that a proposed hydro peaking operation, or a change in an existing project's operation, will have on physical habitat for aquatic populations downstream of the project. The technique, known as the dual flow analysis, is based on elements of the US Fish and Wildlife Service's Physical Habitat Simulation System (PHABSIM). PHABSIM is used to calculate the physical habitat for aquatic organisms in a stream. The assumption behind the development of this technique is that if the effects of a proposed project on physical habitat are known, one can better understand the effects on aquatic organisms. Thus, a defensible selection of an instream flow requirement can be made. The technique was developed as a result of a joint study by the US Fish and Wildlife Service and Niagara Mohawk Power Corp. at the 26.4-MW Bennetts Bridge and the 7.8-MW Lighthouse Hill developments on the Salmon river in upstate New York.

  15. Determining the minimum instream flow for hydro peaking projects

    USGS Publications Warehouse

    Milhous, Robert T.

    1992-01-01

    A new analytical technique is available for quantifying and predicting the effect that a proposed hydro peaking operation, or a change in an existing project's operation, will have on physical habitat for aquatic populations downstream of the project. The technique, known as the dual flow analysis, is based on elements of the US Fish and Wildlife Service's Physical Habitat Simulation System (PHABSIM). PHABSIM is used to calculate the physical habitat for aquatic organisms in a stream. The assumption behind the development of this technique is that if the effects of a proposed project on physical habitat are known, one can better understand the effects on aquatic organisms. Thus, a defensible selection of an instream flow requirement can be made. The technique was developed as a result of a joint study by the US Fish and Wildlife Service and Niagara Mohawk Power Corp. at the 26.4-MW Bennetts Bridge and the 7.8-MW Lighthouse Hill developments on the Salmon river in upstate New York.

  16. The journal Priroda — 100 years old

    NASA Astrophysics Data System (ADS)

    Andreev, Aleksandr F.

    2012-01-01

    This paper reviews the key highlights in the 100-year history of Priroda (Nature), the popular science journal which has been highly instrumental in promoting the natural sciences virtually continuously in Russia and the USSR since its first issue in January 1912.

  17. Convergence: Human Intelligence The Next 100 Years

    ERIC Educational Resources Information Center

    Fluellen, Jerry E., Jr.

    2005-01-01

    How might human intelligence evolve over the next 100 years? This issue paper explores that idea. First, the paper summarizes five emerging perspectives about human intelligence: Howard Gardner's multiple intelligences theory, Robert Sternberg's triarchic theory of intelligence, Ellen Langer's mindfulness theory, David Perkins' learnable…

  18. 21 CFR 868.1860 - Peak-flow meter for spirometry.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Peak-flow meter for spirometry. 868.1860 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1860 Peak-flow meter for spirometry. (a) Identification. A peak-flow meter for spirometry is a device used to measure a...

  19. 21 CFR 868.1860 - Peak-flow meter for spirometry.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Peak-flow meter for spirometry. 868.1860 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1860 Peak-flow meter for spirometry. (a) Identification. A peak-flow meter for spirometry is a device used to measure a...

  20. 21 CFR 868.1860 - Peak-flow meter for spirometry.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Peak-flow meter for spirometry. 868.1860 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1860 Peak-flow meter for spirometry. (a) Identification. A peak-flow meter for spirometry is a device used to measure a...

  1. 21 CFR 868.1860 - Peak-flow meter for spirometry.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Peak-flow meter for spirometry. 868.1860 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1860 Peak-flow meter for spirometry. (a) Identification. A peak-flow meter for spirometry is a device used to measure a...

  2. 21 CFR 868.1860 - Peak-flow meter for spirometry.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Peak-flow meter for spirometry. 868.1860 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1860 Peak-flow meter for spirometry. (a) Identification. A peak-flow meter for spirometry is a device used to measure a...

  3. The AAS: Its Next 100 Years

    NASA Astrophysics Data System (ADS)

    Wolff, S.

    1999-05-01

    The AAS: Its Next Hundred Years "We are probably nearing the limit of all we can know about astronomy."-- Simon Newcomb, 1888. The best way to celebrate the centennial of the AAS is to look forward, not backward, and to begin planning for the next 100 years. However, predicting the future is even more difficult than it was in Newcomb's time. We live in an era characterized by an unprecedented rate of change in the kinds of scientific questions we ask, the tools we use to answer them, and the way we communicate our results. This talk will highlight some of the issues that we will face as a community during the next 10--but not the next 100!--years and suggests that the AAS has a fundamental role to play in shaping the community response to these issues.

  4. Impact of Wet-Weather Peak Flow Blending on Disinfection Performance

    EPA Science Inventory

    A U.S. EPA study evaluated the impact on disinfection during peak flows (wet-weather flow events) when a portion of the flow to the wastewater treatment plant (WWTP) bypasses secondary treatment prior to disinfection. The practice of bypassing secondary treatment during peak flow...

  5. Impact of Wet-Weather Peak Flow Blending on Disinfection Performance

    EPA Science Inventory

    A U.S. EPA study evaluated the impact on disinfection during peak flows (wet-weather flow events) when a portion of the flow to the wastewater treatment plant (WWTP) bypasses secondary treatment prior to disinfection. The practice of bypassing secondary treatment during peak flow...

  6. Remembering Robert Goddard's vision 100 years later

    NASA Astrophysics Data System (ADS)

    Stern, David P.

    “Life, liberty, and the pursuit of happiness” —such are the goals of most of us.Yet a few always exist who feel called by a higher purpose. Society often owes them a great deal.Robert Hutchins Goddard, whose work made spaceflight possible, found his vision 100 years ago this October as a youth of 17. His family was staying on the farm of a relative, when he was asked to trim the branches of a cherry tree behind the barn.

  7. Gas turbines fire up after 100 years

    SciTech Connect

    Zink, J.C.

    1996-06-01

    It`s a familiar story. The ancient Greeks, Romans or Egyptians discovered a major physical principle and demonstrated it in a device that can be regarded as the forerunner of some modern technology. Then, as the industrial age dawned, various tinkerers constructed machines using these basic principles but found serious problems that couldn`t be solved with the technology then available. Finally, a ``cost is no object`` program fostered by military needs brings the device to life and, ultimately, gives it a form that is commercially suitable. This article describes how gas turbines have progressed from the theoretical to the commonplace in 100 years.

  8. [100 years of conflict about schizophrenias].

    PubMed

    Hell, D

    1995-01-01

    A systematic concept of a homogeneous group of psychoses, which Eugen Bleuler subsequently termed "Schizophrenia", goes back to Emil Kraepelin initially, in fact it has not existed for more than 100 years. The dynamics inherent in its history show that it is advisable to make allowance for contemporary influences when arriving at conclusions on schizophrenia in our times. The article in question presents a brief review of the origins and the historic development of the concept of schizophrenia, and attempts to set the present-day "neo-kraepelian" re-assessment of schizophrenic disorders in a modifying historic context.

  9. Assessment of potential debris-flow peak discharges from basins burned by the 2002 Missionary Ridge fire, Colorado

    USGS Publications Warehouse

    Cannon, Susan H.; Michael, John A.; Gartner, Joseph E.; Gleason, J. Andrew

    2003-01-01

    These maps present the results of assessments of peak discharges that can potentially be generated by debris flows issuing from the basins burned by the Missionary Ridge fire of June 9 through July 14, 2002, near Durango, Colorado. The maps are based on a regression model for debris-flow peak discharge normalized by average storm intensity as a function of basin gradient and burned extent, and limited field checking. A range of potential peak discharges that could be produced from each of the burned basins between 1 ft3/s (0.03 m3/s) and 6,446 ft3/s (183 m3/s) is calculated for the 5-year, 1-hour storm of 0.80 inches (20 mm). Potential peak discharges between 1 ft3/s (0.03 m3/s) and >8,000 ft3/s (227 m3/s) are calculated for the 25-year, 1-hour storm of 1.3 inches (33 mm) and for the 100-year, 1-hour storm of 1.8 inches (46 mm). These maps are intended for use by emergency personnel to aid in the preliminary design of mitigation measures, and for the planning of evacuation timing and routes.

  10. Assessment of potential debris-flow peak discharges from basins burned by the 2002 Coal Seam fire, Colorado

    USGS Publications Warehouse

    Cannon, Susan H.; Michael, John A.; Gartner, Joseph E.

    2003-01-01

    These maps present the results of assessments of peak discharges that can potentially be generated by debris flows issuing from the basins burned by the Coal Seam fire of June and July 2002, near Glenwood Springs, Colorado. The maps are based on a regression model for debris-flow peak discharge normalized by average storm intensity as a function of basin gradient and burned extent, and limited field checking. A range of potential peak discharges that could potentially be produced from each of the burned basins between 1 ft3/s (0.03 m3/s) and greater than 5,000 ft3/s (>141 m3/s) is calculated for the 5-year, 1-hour storm of 0.80 inches (20 mm). The 25-year, 1-hour storm of 1.3 inches (33 mm). The 100- year, 1-hour storm of 1.8 inches (46 mm) produced peak discharges between 1 and greater than 8,000 ft3/s (>227 m3/s). These maps are intended for use by emergency personnel to aid in the preliminary design of mitigation measures, and the planning of evacuation timing and routes.

  11. Combined effects of projected sea level rise, storm surge, and peak river flows on water levels in the Skagit Floodplain

    USGS Publications Warehouse

    Hamman, Josheph J; Hamlet, Alan F.; Fuller, Roger; Grossman, Eric

    2016-01-01

    Current understanding of the combined effects of sea level rise (SLR), storm surge, and changes in river flooding on near-coastal environments is very limited. This project uses a suite of numerical models to examine the combined effects of projected future climate change on flooding in the Skagit floodplain and estuary. Statistically and dynamically downscaled global climate model scenarios from the ECHAM-5 GCM were used as the climate forcings. Unregulated daily river flows were simulated using the VIC hydrology model, and regulated river flows were simulated using the SkagitSim reservoir operations model. Daily tidal anomalies (TA) were calculated using a regression approach based on ENSO and atmospheric pressure forcing simulated by the WRF regional climate model. A 2-D hydrodynamic model was used to estimate water surface elevations in the Skagit floodplain using resampled hourly hydrographs keyed to regulated daily flood flows produced by the reservoir simulation model, and tide predictions adjusted for SLR and TA. Combining peak annual TA with projected sea level rise, the historical (1970–1999) 100-yr peak high water level is exceeded essentially every year by the 2050s. The combination of projected sea level rise and larger floods by the 2080s yields both increased flood inundation area (+ 74%), and increased average water depth (+ 25 cm) in the Skagit floodplain during a 100-year flood. Adding sea level rise to the historical FEMA 100-year flood resulted in a 35% increase in inundation area by the 2040's, compared to a 57% increase when both SLR and projected changes in river flow were combined.

  12. 100 years of photometry and radiometry

    NASA Astrophysics Data System (ADS)

    Hardis, Jonathan E.

    2001-06-01

    Measurement of light is an old subject, though the past 100 years have seen significant advances. 100 years ago, photometry - the art and science of measuring light as it is perceived by people - had the greater technological importance. Even today SI (the metric system) retains a base unit for photometry, the candela. However, early work at NBS included pivotal projects in the field of radiometry - the measurement of the physical characteristics of light. These included the validation of Planck's newly-minted theory of blackbody radiation, determining the radiation constants with good accuracy, and the definitive analysis of the spectral responsivity of human vision, so as to relate photometry to radiometry. This latter work has only increased in importance over the past 75 years as the definition of the candela has changed and improved. Today, NIST makes radiometric, and hence photometric measurements, with unprecedented precision. Cryogenic radiometers based on the principle of electrical substitution measure optical flux with uncertainties of 0.02%. Additional facilities enable measurement of spectral responsivity, spectral radiance, and spectral irradiance. Novel detectors, such as light-traps, allow the best accuracy to be transferred from the primary standards to routinely-used instruments and to calibration customers. Filtered detectors are used to realize photometric scales, radiation temperature scales, and other specialized measurements. Indeed, the story of the metrology of light is the story of continuous improvement, both driven by and enabled by advances in technology. We touch upon some of these as a prelude to the other talks in this Conference.

  13. Ultrasonic 3-D Vector Flow Method for Quantitative In Vivo Peak Velocity and Flow Rate Estimation.

    PubMed

    Holbek, Simon; Ewertsen, Caroline; Bouzari, Hamed; Pihl, Michael Johannes; Hansen, Kristoffer Lindskov; Stuart, Matthias Bo; Thomsen, Carsten; Nielsen, Michael Bachmann; Jensen, Jorgen Arendt

    2017-03-01

    Current clinical ultrasound (US) systems are limited to show blood flow movement in either 1-D or 2-D. In this paper, a method for estimating 3-D vector velocities in a plane using the transverse oscillation method, a 32×32 element matrix array, and the experimental US scanner SARUS is presented. The aim of this paper is to estimate precise flow rates and peak velocities derived from 3-D vector flow estimates. The emission sequence provides 3-D vector flow estimates at up to 1.145 frames/s in a plane, and was used to estimate 3-D vector flow in a cross-sectional image plane. The method is validated in two phantom studies, where flow rates are measured in a flow-rig, providing a constant parabolic flow, and in a straight-vessel phantom ( ∅=8 mm) connected to a flow pump capable of generating time varying waveforms. Flow rates are estimated to be 82.1 ± 2.8 L/min in the flow-rig compared with the expected 79.8 L/min, and to 2.68 ± 0.04 mL/stroke in the pulsating environment compared with the expected 2.57 ± 0.08 mL/stroke. Flow rates estimated in the common carotid artery of a healthy volunteer are compared with magnetic resonance imaging (MRI) measured flow rates using a 1-D through-plane velocity sequence. Mean flow rates were 333 ± 31 mL/min for the presented method and 346 ± 2 mL/min for the MRI measurements.

  14. The generation of spring peak flows by short-term meteorological events

    Treesearch

    Harold F. Haupt

    1968-01-01

    Spring peak flows recorded over a 25-year period in Benton Creek, a small forested watershed in northern Idaho, were studied in their relation to meteorological events. More peak flows were generated by rain-on-snow than by clear-weather snowmelt; the two types of peaks differ in magnitude and in other characteristics. Two rather simple techniques were used to...

  15. Vitamins: preparing for the next 100 years.

    PubMed

    Blumberg, Jeffrey B

    2012-10-01

    The insights gained from the last 100 years of vitamin research and applications have contributed substantially to our fundamental understanding of biology and importantly to the promotion of human health. There is no reason to think that the next 100 years will be any less fruitful if we are committed to preparing for them, particularly by changing four critical nutrition paradigms. First, we must move beyond the concept of preventing vitamin deficiencies and inadequacies to establishing health and, further, to creating optimal physiological functions. Each essential vitamin possesses different concentration thresholds for its variety of effects and the required balance necessary to achieving each has yet to be fully defined. Second, we must apply the research approaches and methods of “-omics,” systems biology, and imaging technologies to define the dynamic role of vitamins and their broad array of genomic, molecular, biochemical, and functional interactions. Such work is necessary to understand the multiplicity of vitamin actions and ultimately apply them directly at the level of the individual. Third, we must revise the concept of evidence-based nutrition away from its current hierarchical system to recognize in a comprehensive and integrated way the attributes of each type of approach to research. To adhere to a single gold standard of the randomized clinical trial ignores both how we have moved forward so productively during the last 100 years and the vital information to be gained from basic research and other human studies; further, it acts to stifle innovation in both scientific and regulatory affairs. Fourth, we must understand that changes in the supply and distribution of food during the next century are likely to be at least as dramatic as those which have occurred over this last one. For example, inevitable environmental constraints will require more food protein be derived from plant than animal sources, a shift that will directly impact the

  16. Geiger-Marsden experiments: 100 years on

    NASA Astrophysics Data System (ADS)

    Rowley, Neil

    2012-09-01

    The perceptive analysis of Rutherford, celebrated at this conference, turned the experiments of Geiger and Marsden into a measurement of the radius of the object that became known as the atomic "nucleus". We now know that the nucleus can have a range of radii that depend on its static and dynamical deformations. These deformations give rise to the distributions of reaction barriers that have been extensively studied over recent years. While fusion reactions are most often used for such studies, there are cases where, for physical or practical reasons, the scattering channels must be exploited. Despite the major advantages gained from modern experimental techniques, the resulting experiments are in spirit essentially the same as those performed over 100 years ago by Rutherford and his colleagues.

  17. Adolescent medicine with a 100 year perspective.

    PubMed

    Hardoff, Daniel; Eisenstein, Evelyn

    2004-01-01

    Adolescent medicine was born out of scientific advances from a wide variety of disciplines, changes in societal mores and the explosion of technology that occurred during the 20th century. The past 100 years of clinical practice and research have provided a wealth of information that has improved our understanding of the biologic and physical development of adolescents as well as the epidemiology of high-risk adolescent behaviors. The present challenge for all providers of health care to adolescents is to continue to examine the effect of these high-risk behaviors and develop mechanisms to address and limit the impact of these behaviors, just as the scientists and practitioners of the 20th century made great strides in treatment and cure of medical illnesses. With a broad base of scientific knowledge, formalization into an academic field and strong government and organizational support adolescent medicine are energized by these factors and can only envision continued growth in this important field of medicine.

  18. Remediation scenarios for attenuating peak flows and reducing sediment transport in Fountain Creek, Colorado, 2013

    USGS Publications Warehouse

    Kohn, Michael S.; Fulton, John W.; Williams, Cory A.; Stogner, Sr., Robert W.

    2014-01-01

    -RAS version 4.2 was used to simulate streamflow and sediment transport for the Fountain Creek watershed generated by a design-storm event. The Laursen-Copeland sediment-transport function was used in conjunction with the Exner 5 sorting method and the Ruby fall-velocity method to predict sediment transport. Six USGS streamgages equipped with suspended-sediment samplers were used to develop sediment-flow rating curves for the sediment-transport-model calibration. The critical Shields number in the Laursen-Copeland sediment-transport function and the volume of sediment available at a given cross section were adjusted during the HEC-RAS sediment-model calibration process. HEC-RAS model simulations used to evaluate the 14 remediation scenarios were based on unsteady-state streamflows associated with a 24-hour, 1-percent annual exceedance probability (100-year) National Oceanic and Atmospheric Administration Type II precipitation event. Scenario 0 represents the baseline or current conditions in the watershed and was used to compare the remaining 13 scenarios. Scenarios 1–8 and 12 rely on side-detention facilities to reduce peak flows and sediment transport. Scenario 9 has a diversion channel, and scenario 10 has a reservoir. Scenarios 11 and 13 incorporate channel armoring and channel widening, respectively. Scenarios 8 and 10, the scenario with the most side-detention facilities, and the scenario with the reservoir, respectively, were the most effective at reducing sediment transport and peak flow at the Pueblo, Colorado, streamgage. Scenarios 8 and 10 altered the peak flow by –58.9 and –56.4 percent, respectively. In turn, scenarios 8 and 10 altered the sediment transport by –17.7 and –62.1 percent, respectively.

  19. IMPACT ON DISINFECTION AT PEAK FLOWS DURING BLENDING/PARTIAL BYPASSING OF SECONDARY TREATMENT

    EPA Science Inventory

    A U.S EPA study evaluated the impact on disinfection during peak flows when a portion of the flow to the wastewater treatment plant (WWTP) bypasses secondary treatment prior to disinfection. The practice of bypassing secondary treatment during peak flows, referred to as “blending...

  20. IMPACT ON DISINFECTION AT PEAK FLOWS DURING BLENDING/PARTIAL BYPASSING OF SECONDARY TREATMENT

    EPA Science Inventory

    A U.S EPA study evaluated the impact on disinfection during peak flows when a portion of the flow to the wastewater treatment plant (WWTP) bypasses secondary treatment prior to disinfection. The practice of bypassing secondary treatment during peak flows, referred to as “blending...

  1. Scaling of Peak Flows with Constant Flow Velocity in Random Self-Similar Networks

    NASA Astrophysics Data System (ADS)

    Mantilla, Ricardo; Gupta, Vijay K.; Troutman, Brent M.

    2010-05-01

    We present a methodology to understand the role of the statistical self-similar topology of real river networks on flow hydrographs for rainfall-runoff events. Monte Carlo generated ensembles of 1000 Random Self-similar Networks (RSNs) with geometrically distributed interior and exterior generators are created. These networks emulate the topology of real networks. Hydrographs for every link in each of these networks are obtained by numerically solving the link-based mass and momentum conservation equation under the assumption of constant flow velocity. From these simulated RSNs and hydrographs, the scaling parameters for the peak of the width function β and the hydrograph peak flow ? are estimated. It was found that ? > β, which supports a similar finding first reported for the Walnut Gulch basin, Arizona, and that is in qualitatively different from previous results on idealized river networks (e.g. Peano Network, Mandelbrot- Viscek Network). The use of numerical simulations is necessary as theoretical estimation of β and ? in RSNs is a complex mathematical open problem. However, other scaling features of the average width function can the average hydrograph are calculated analytically and compared with the estimation from the RSN-ensemble. Scaling of peak flows during individual rainfall runoff events is a new area of research that offers a path to understand regional scaling of flood quantiles, an important open problem in river network hydrology. For example, our results show an interesting connection between unit-hydrograph theory and flow dynamics. In addition, our methodology provides a reference framework to study scaling exponents under more complex scenarios of flow dynamics and runoff generation processes using ensembles of RSNs.

  2. Flow among Musicians: Measuring Peak Experiences of Student Performers

    ERIC Educational Resources Information Center

    Sinnamon, Sarah; Moran, Aidan; O'Connell, Michael

    2012-01-01

    "Flow" is a highly coveted yet elusive state of mind that is characterized by complete absorption in the task at hand as well as by enhanced skilled performance. Unfortunately, because most measures of this construct have been developed in physical activity and sport settings, little is known about the applicability of flow scales to the…

  3. Flow among Musicians: Measuring Peak Experiences of Student Performers

    ERIC Educational Resources Information Center

    Sinnamon, Sarah; Moran, Aidan; O'Connell, Michael

    2012-01-01

    "Flow" is a highly coveted yet elusive state of mind that is characterized by complete absorption in the task at hand as well as by enhanced skilled performance. Unfortunately, because most measures of this construct have been developed in physical activity and sport settings, little is known about the applicability of flow scales to the…

  4. Scaling of Peak Flows with Constant Flow Velocity in Random Self-Similar Networks

    NASA Astrophysics Data System (ADS)

    Mantilla, R.; Gupta, V. K.; Troutman, B. M.

    2010-12-01

    We present a methodology to understand the role of the statistical self-similar topology of real river networks on flow hydrographs for rainfall-runoff events. Monte Carlo generated ensembles of 1000 Random Self-similar Networks (RSNs) with geometrically distributed interior and exterior generators are created. We show how these networks emulate the statistical self-similarity present in real networks by presenting results for 30 river networks in the continental USA. Hydrographs for every link in each of these networks are obtained by numerically solving the link-based mass and momentum conservation equation under the assumption of constant flow velocity. From these simulated hydrographs for an ensemble of RSNs, the scaling parameters for the peak of the width function (β) and the hydrograph peak flow (φ) are estimated. It was found that φ > β, which supports a similar finding first reported for the Walnut Gulch basin, Arizona, and that is qualitatively different from previous results on idealized river networks (e.g. Peano Network, Mandelbrot- Viscek Network). Scaling of peak flows for individual rainfall runoff events is a new area of research that offers a path to physically understand regional scaling of flood quantiles. It addresses an important open problem in river network hydrology through studying the statistics of ensembles of multiple events in RSNs. In addition, our methodology provides a reference framework to study scaling exponents and intercepts under more complex scenarios of flow dynamics and runoff generation processes using ensembles of RSNs. Preliminary examples of such scenarios will also be given.

  5. The Psychoanalytic Review: 100 years of history.

    PubMed

    Barnett, Alan J

    2013-02-01

    This paper is written in celebration of the centenary of The Psychoanalytic Review and aims to bring to life its entire history-100 years of publication. Almost as old as psychoanalysis itself, established by Jelliffe and White as a nonorthodox journal, and guided by all its subsequent editors, the Review has maintained its original mission: to serve as an open venue for all psychoanalytic perspectives, "a free forum for all." But the history of the Review is not without controversy. Freud made no original contributions to the Review. The paper unveils the Review's, rich history by looking briefly into the lives of some of its editors, the circumstances surrounding the creation of the Review (including pertinent correspondence between Freud and Brill and between Freud and Jelliffe), the years (with their engrossing politics) that followed the establishment of the Review until its merger with the journal Psychoanalysis (the official journal of NPAP), and the years that followed the merger to the present, including some of the important events that reshaped psychoanalysis. The role of the Review in promoting and reflecting almost the entire evolution of psychoanalysis is illustrated throughout.

  6. Simulation of Peak Flows Using Remote Sensing Systems

    NASA Astrophysics Data System (ADS)

    Magaña Hernández, F.; Ba, K. M.; Guerra-Cobián, V.

    2013-05-01

    In this study we utilized remotely sensed data (radar and satellite precipitation products) to simulate the peak discharges of some storm events of the Escondido River. This is a poorly gauged watershed located in Northern Mexico, in the State of Coahuila and is a sub-basin of Rio Bravo, known also as Río Grande. The radar data are from NOAA (Radar KDFX located in Laughlin Air Force Base, Texas). We used two satellite product estimates PERSIANN and CMORPH. These three estimated precipitation products have been compared using the hydrologic model HEC-HMS to simulate the peak discharge. The results of the simulations show the importance of the use of this type of data in hydrologic modeling.

  7. [Radical prostatectomy--100 years of evolution].

    PubMed

    Gofrit, Ofer N; Shalhav, Arieh L

    2008-07-01

    Prostate cancer is the most common malignant disease in men. The incidence of prostate cancer has been rising since the early 1990s. Not all men inflicted by prostate cancer will develop clinical disease. Therefore, sorting these cases is a great clinical challenge. Radical prostatectomy has undergone evolution in the last 100 years. Better understanding of the pelvic anatomy has led to a decrease in the blood loss during surgery and in the rate of urinary incontinence and erectile dysfunction following surgery. The introduction of laparoscopy in the late 1990s to this surgery provided the surgeon with a magnified multi-angle field of view and facilitated accurate dissection and suturing. Decreased damage to neighboring tissue made recovery hastier. Nevertheless, laparoscopic radical prostatectomy is a technically challenging surgery and did not become popular. The last step in the evolution of radical prostatectomy is the introduction of robotic systems for assistance in laparoscopic radical prostatectomy. A master-slave robotic system is composed of console and mechanical arms. The surgeon is provided with a magnified three dimensional view of the operative field and with two mechanical arms that accurately replicate its fingers movements. The initial results of robotic-assisted laparoscopic prostatectomy seem promising, however, long-term follow-up and comparison to open surgeries are lacking. Robotic systems were rapidly implemented in the American market and in the year 2006, 40% of all radical prostatectomies were robotic assisted. Future systems may reveal deep structures to the visualized surface by superimposing MRI images on the surgical field.

  8. Peak-flow frequency and extreme flood potential for streams in the vicinity of the Highland Lakes, central Texas

    USGS Publications Warehouse

    Asquith, William H.; Slade, R.M.; Lanning-Rush, Jennifer

    1996-01-01

    The Highland Lakes on the Colorado River are in an area periodically threatened by large storms and floods. Many storms exceeding 10 inches (in.) in depth have been documented in the area, including some with depths approaching 40 in. These storms typically produce large peak discharges that often threaten lives and property. The storms sometimes occur with little warning. Steep stream slopes and thin soils characteristic of the area often cause large peak discharges and rapid movement of floods through watersheds. A procedure to predict the discharge associated with large floods is needed for the area so that appropriate peak discharges can be used in the design of flood plains, bridges, and other structures.The U.S. Geological Survey (USGS), in cooperation with the Lower Colorado River Authority (LCRA), studied flood peaks for streams in the vicinity of the Highland Lakes of central Texas. The Highland Lakes are a series of reservoirs constructed on the Colorado River. The chain of lakes (and year each was completed) comprises Lake Buchanan (1937), Inks Lake (1938), Lake Lyndon B. Johnson (1950), Lake Marble Falls (1951), Lake Travis (1942), and lake Austin (1890). The study area (fig. 1), which includes all or parts of 21 counties in the vicinity of the Highland Lakes, was selected because most streams in the area have flood characteristics similar to streams entering the Highland Lakes. The entire study area is in a region subject to large storms.The purpose of this report is to present (1) peak-flow frequency data for stations and equations to estimate peak-flow frequency for large streams with natural drainage basins in the vicinity of the Highland Lakes, and (2) a technique to estimate the extreme flood peak discharges for the large streams in the vicinity of the Highland Lakes. Peak-flow frequency in this report refers to the peak discharges for recurrence intervals of 2,5, 10,25,50, and 100 years. A large stream is defined as having a contributing drainage

  9. Flood boundaries and water-surface profile for the computed 100-year flood, Swift Creek at Afton, Wyoming, 1986

    USGS Publications Warehouse

    Rankl, James G.; Wallace, Joe C.

    1989-01-01

    Flood flows on Swift Creek near Afton, Wyoming, were analyzed. Peak discharge with an average recurrence interval of 100 years was computed and used to determine the flood boundaries and water surface profile in the study reach. The study was done in cooperation with Lincoln County and the Town of Afton to determine the extent of flooding in the Town of Afton from a 100-year flood on Swift Creek. The reach of Swift Creek considered in the analysis extends upstream from the culvert at Allred County Road No. 12-135 to the US Geological Survey streamflow-gaging station located in the Bridger National Forest , a distance of 3.2 miles. Boundaries of the 100-year flood are delineated on a map using the computed elevation of the flood at each cross section, survey data, and a 1983 aerial photograph. The computed water surface elevation for the 100-year flood was plotted at each cross section, then the lateral extent of the flood was transferred to the flood map. Boundaries between cross sections were sketched using information taken from the aerial photograph. Areas that are inundated, but not part of the active flow, are designated on the cross sections. (Lantz-PTT)

  10. Lower crustal xenoliths, Chinese Peak lava flow, central Sierra Nevada.

    USGS Publications Warehouse

    Dodge, F.C.W.; Calk, L.C.; Kistler, R.W.

    1986-01-01

    This assemblage of pyroxenite, peridotite and mafic granulite xenoliths in the toe of a 10 m.y. trachybasalt flow remnant overlying late Cretaceous granitic rocks, indicates the presence of a mafic-ultramafic complex beneath this part of central California; orthopyroxenites, websterites and clinopyroxenites are dominant. A few of the xenoliths contain ovoid opaque patches that are apparently pseudomorphs after garnet and have pyralspite garnet compositions; using a garnet-orthopyroxene geobarometer, they indicate a lower crustal depth of approx 40 km. Abundant mafic granulites can be subdivided into those with Al2O3 = or 15% and showing considerable scatter on oxide variation diagrams. The high-alumina granulite xenoliths have relatively low 87Rb/86Sr but high 87Sr/86Sr, whereas the low-alumina and ultramafic xenoliths have a wide range of 87Rb/86Sr, but lower 87Sr/86Sr; the isotopic data indicate roughly the same age as that of overlying granitic plutons (approx 100 m.y.). However, the granitic rocks have initial 87Sr/86Sr ratios intermediate between those of the high-alumina and ultramafic xenoliths, suggesting that they result from the mixing of basaltic magma (represented by the ultramafic rocks) and crustal materials, with subsequent crystal fractionation.-R.A.H.

  11. Impacts of Mountain Pine Beetle on Peak Flow in the Fraser Basin in British Columbia

    NASA Astrophysics Data System (ADS)

    Scheffler, C.; Rosin, K.; Weiler, M.

    2008-12-01

    Increasing winter temperature in combination with forest management practices are the main drivers for the Mountain Pine Beetle (MPB) epidemic in British Columbia (BC). The infestation of MPB has now turned into a major threat to the natural habitat of the province. The Fraser basin, the largest watershed in BC, is the most affected watershed with an infested forest area of 7.7 million hectares (88% of the watershed) [Redding and Pike 2007]. Forest cover is a key modifier of the watershed's peak flow regime. The peak flow generally increases when forest cover is reduced. Major parts of the Fraser basin have only a limited number of gauging stations (or are even ungauged). The goal of the project was to develop a hydrological model that can predict peak flow increases but does not rely on complex data inputs for its validation and calibration procedures. The model consists of two major components: climate input and runoff. The climate input component determines the mean annual snowmelt as well as the maximum rainfall based on long term climatic averages. This information is then used to determine the time and the capacity of the peak flow for every 3rd order watershed. The runoff component delineates hydrologic processes such as Hortonain Overland Flow, Saturation Overland Flow and Shallow Surface Flow. The model combines the two components and computes a map of peak flow contribution. A peak flow analysis has been carried out to validate the model results using available gauging stations in subcatchments. The validated model has been then applied to the entire watershed to analyze the impacts of MPB on peak flow in the Fraser basin. The presentation will show the conceptual presentation of the hydrological model. It will highlight the results of the peak flow analysis and show initial results of the application of the model. Cited Literature: Redding, T. and Pike, R (2007). Mountain Pine Beetle and Watershed Hydrology Workshop Summary, Streamline Watershed

  12. Peak-flow frequency estimates through 1994 for gaged streams in South Dakota

    USGS Publications Warehouse

    Burr, M.J.; Korkow, K.L.

    1996-01-01

    Annual peak-flow data are listed for 250 continuous-record and crest-stage gaging stations in South Dakota. Peak-flow frequency estimates for selected recurrence intervals ranging from 2 to 500 years are given for 234 of these 250 stations. The log-Pearson Type III procedure was used to compute the frequency relations for the 234 stations, which in 1994 included 105 active and 129 inactive stations. The log-Pearson Type III procedure is recommended by the Hydrology Subcommittee of the Interagency Advisory Committee on Water Data, 1982, "Guidelines for Determining Flood Flow Frequency."No peak-flow frequency estimates are given for 16 of the 250 stations because: (1) of extreme variability in data set; (2) more than 20 percent of years had no flow; (3) annual peak flows represent large outflow from a spring; (4) of insufficient peak-flow record subsequent to reservoir regulation; and (5) peak-flow records were combined with records from nearby stations.

  13. Scaling of peak flows with constant flow velocity in random self-similar networks

    USGS Publications Warehouse

    Troutman, Brent M.; Mantilla, Ricardo; Gupta, Vijay K.

    2011-01-01

    A methodology is presented to understand the role of the statistical self-similar topology of real river networks on scaling, or power law, in peak flows for rainfall-runoff events. We created Monte Carlo generated sets of ensembles of 1000 random self-similar networks (RSNs) with geometrically distributed interior and exterior generators having parameters pi and pe, respectively. The parameter values were chosen to replicate the observed topology of real river networks. We calculated flow hydrographs in each of these networks by numerically solving the link-based mass and momentum conservation equation under the assumption of constant flow velocity. From these simulated RSNs and hydrographs, the scaling exponents β and φ characterizing power laws with respect to drainage area, and corresponding to the width functions and flow hydrographs respectively, were estimated. We found that, in general, φ > β, which supports a similar finding first reported for simulations in the river network of the Walnut Gulch basin, Arizona. Theoretical estimation of β and φ in RSNs is a complex open problem. Therefore, using results for a simpler problem associated with the expected width function and expected hydrograph for an ensemble of RSNs, we give heuristic arguments for theoretical derivations of the scaling exponents β(E) and φ(E) that depend on the Horton ratios for stream lengths and areas. These ratios in turn have a known dependence on the parameters of the geometric distributions of RSN generators. Good agreement was found between the analytically conjectured values of β(E) and φ(E) and the values estimated by the simulated ensembles of RSNs and hydrographs. The independence of the scaling exponents φ(E) and φ with respect to the value of flow velocity and runoff intensity implies an interesting connection between unit hydrograph theory and flow dynamics. Our results provide a reference framework to study scaling exponents under more complex scenarios

  14. 100 years of the physics of diodes

    NASA Astrophysics Data System (ADS)

    Zhang, Peng; Valfells, Ágúst; Ang, L. K.; Luginsland, J. W.; Lau, Y. Y.

    2017-03-01

    The Child-Langmuir Law (CL), discovered a century ago, gives the maximum current that can be transported across a planar diode in the steady state. As a quintessential example of the impact of space charge shielding near a charged surface, it is central to the studies of high current diodes, such as high power microwave sources, vacuum microelectronics, electron and ion sources, and high current drivers used in high energy density physics experiments. CL remains a touchstone of fundamental sheath physics, including contemporary studies of nanoscale quantum diodes and nano gap based plasmonic devices. Its solid state analog is the Mott-Gurney law, governing the maximum charge injection in solids, such as organic materials and other dielectrics, which is important to energy devices, such as solar cells and light emitting diodes. This paper reviews the important advances in the physics of diodes since the discovery of CL, including virtual cathode formation and extension of CL to multiple dimensions, to the quantum regime, and to ultrafast processes. We review the influence of magnetic fields, multiple species in bipolar flow, electromagnetic and time dependent effects in both short pulse and high frequency THz limits, and single electron regimes. Transitions from various emission mechanisms (thermionic-, field-, and photoemission) to the space charge limited state (CL) will be addressed, especially highlighting the important simulation and experimental developments in selected contemporary areas of study. We stress the fundamental physical links between the physics of beams to limiting currents in other areas, such as low temperature plasmas, laser plasmas, and space propulsion.

  15. Accuracy of mini peak flow meters in indicating changes in lung function in children with asthma.

    PubMed Central

    Sly, P. D.; Cahill, P.; Willet, K.; Burton, P.

    1994-01-01

    OBJECTIVE--To assess whether mini flow meters used to measure peak expiratory flow can track changes in lung function and indicate clinically important changes. DESIGN--Comparison of measurements with a spirometer and different brands of mini flow meter; the meters were allocated to subjects haphazardly. SUBJECTS--12 boys with asthma aged 11 to 17 attending boarding school. MAIN OUTCOME MEASURES--Peak expiratory flow measured twice daily for three months with a spirometer and at least one of four brands of mini flow meter. RESULTS--The relation between changes in lung function measured with the spirometer and those measured with the mini flow meters was generally poor. In all, 26 episodes (range 1-3 in an individual child) of clinically important deterioration in lung function were detected from the records obtained with the spirometer. One mini flow meter detected six of 19 episodes, one detected six of 15, one detected six of 18, and one detected three of 21. CONCLUSIONS--Not only are the absolute values of peak expiratory flow obtained with mini flow meters inaccurate but the clinical message may also be incorrect. These findings do not imply that home monitoring of peak expiratory flow has no place in the management of childhood asthma but that the values obtained should be interpreted cautiously. PMID:8148680

  16. Pig standard bivariate flow karyotype and peak assignment for chromosomes X, Y, 3, and 7.

    PubMed

    Schmitz, A; Chardon, P; Gainche, I; Chaput, B; Guilly, M N; Frelat, G; Vaiman, M

    1992-10-01

    A standard pig flow karyotype (2N = 38 chromosomes) was defined by standardization of several flow karyotypes obtained from stimulated peripheral blood lymphocytes of normal male and female pigs. Depending on the animals under study, the flow analysis of their chromosome suspensions gave rise to bivariate flow karyotypes comprising from 15 to 17 peaks, of which 11 to 15 represented single chromosomes. The results were used to propose a peak nomenclature. In addition, a male miniature pig lymphoblastoid cell line was characterized by flow cytogenetics. A very high-resolution flow karyotype, in which all peaks but one superimposed on those of the standard karyotype, was obtained. Peaks were assigned for chromosomes X and Y. Analysis of flow karyotypes obtained from translocated t(3,7)(p1.3;q2.1) pigs combined with polymerase chain reaction (PCR) studies of major histocompatibility complex (MHC)-linked sequences on flow-sorted chromosomes allowed identification of peaks 3 and 7 of normal pig chromosomes and of the derivative chromosomes associated with the t(3,7)(p1.3;q2.1) translocation.

  17. Aspen clearcutting increases snowmelt and storm flow peaks in north central Minnesota

    Treesearch

    Elon S. Verry; Jeffrey R. Lewis; Kenneth N. Brooks

    1983-01-01

    Clearcutting aspen from the upland portion of an upland peatland watershed in north central Minnesota caused snowmelt peak discharge to increase 11 to 143 percent. Rainfall peak discharge size increased as much as 250 percent during the first two years after clearcutting, then decreased toward precutting levels in subsequent years. Storm flow volumes from rain during...

  18. Estimating the magnitude of peak flows for streams in Kentucky for selected recurrence intervals

    USGS Publications Warehouse

    Hodgkins, Glenn A.; Martin, Gary R.

    2003-01-01

    This report gives estimates of, and presents techniques for estimating, the magnitude of peak flows for streams in Kentucky for recurrence intervals of 2, 5, 10, 25, 50, 100, 200, and 500 years. A flowchart in this report guides the user to the appropriate estimates and (or) estimating techniques for a site on a specific stream. Estimates of peak flows are given for 222 U.S. Geological Survey streamflow-gaging stations in Kentucky. In the development of the peak-flow estimates at gaging stations, a new generalized skew coefficient was calculated for the State. This single statewide value of 0.011 (with a standard error of prediction of 0.520) is more appropriate for Kentucky than the national skew isoline map in Bulletin 17B of the Interagency Advisory Committee on Water Data. Regression equations are presented for estimating the peak flows on ungaged, unregulated streams in rural drainage basins. The equations were developed by use of generalized-least-squares regression procedures at 187 U.S. Geological Survey gaging stations in Kentucky and 51 stations in surrounding States. Kentucky was divided into seven flood regions. Total drainage area is used in the final regression equations as the sole explanatory variable, except in Regions 1 and 4 where main-channel slope also was used. The smallest average standard errors of prediction were in Region 3 (from -13.1 to +15.0 percent) and the largest average standard errors of prediction were in Region 5 (from -37.6 to +60.3 percent). One section of this report describes techniques for estimating peak flows for ungaged sites on gaged, unregulated streams in rural drainage basins. Another section references two previous U.S. Geological Survey reports for peak-flow estimates on ungaged, unregulated, urban streams. Estimating peak flows at ungaged sites on regulated streams is beyond the scope of this report, because peak flows on regulated streams are dependent upon variable human activities.

  19. Predicting Extubation Outcome by Cough Peak Flow Measured Using a Built-in Ventilator Flow Meter.

    PubMed

    Gobert, Florent; Yonis, Hodane; Tapponnier, Romain; Fernandez, Raul; Labaune, Marie-Aude; Burle, Jean-François; Barbier, Jack; Vincent, Bernard; Cleyet, Maria; Richard, Jean-Christophe; Guérin, Claude

    2017-09-12

    Successful weaning from mechanical ventilation depends on the patient's ability to cough efficiently. Cough peak flow (CPF) could predict extubation success using a dedicated flow meter but required patient disconnection. We aimed to predict extubation outcome using an overall model, including cough performance assessed by a ventilator flow meter. This was a prospective observational study conducted from November 2014 to October 2015. Before and after a spontaneous breathing trial, subjects were encouraged to cough as strongly as possible before freezing the ventilator screen to assess CPF and tidal volume (VT) in the preceding inspiration. Early extubation success rate was defined as the proportion of subjects not re-intubated 48h after extubation. Diagnostic performance of CPF and VT was assessed by using the area under the curve of the receiver operating characteristic curve. Cut-off values for CPF and VT were defined according to median values and used to describe the performance of a predictive test combining them with risk factors of early extubation failure. Among 673 subjects admitted, 92 had a cough assessment before extubation. For the 81 subjects with early extubation success, the median CPF was -67.7L/min, and median VT was 0.646L. For the 11 subjects with early extubation failure, the median CPF was -57.3L/min, and median VT was 0.448L. Area under the curve was 0.61 (95% CI 0.37-0.83) for CPF and 0.64 (95% CI 0.42-0.84) for CPF/VT combined. After dichotomization (CPF < -60L/min or VT> 0.55L), there was a synergistic effect to predict early extubation success (P < .001). The predictive value of success reached 94.2% for CPF/VT combined. The overall model including pH before extubation < 7.45 reached a 66.7% predictive value of failure. CPF measured using the flow meter of an ICU ventilator was able to predict extubation success and to build a composite score to predict extubation failure. The results were close to that found in previous studies that

  20. Simulated peak flows and water-surface profiles for Scott Creek near Sylva, North Carolina

    USGS Publications Warehouse

    Pope, B.F.

    1996-01-01

    Peak flows were simulated for Scott Creek, just upstream from Sylva, in Jackson County, North Carolina, in order to provide Jackson County officials with information that can be used to improve preparation for and response to flash floods along the reach of Scott Creek that flows through Sylva. A U.S. Geological Survey rainfall-runoff model was calibrated using observed rainfall and streamflow data collected from March 1994 through September 1995. Standard errors for calibration were 34 percent for runoff volumes and 21 percent for peak flows. The calibrated model was used to simulate peak flows resulting from syn- thetic rainfall amounts of 1.0, 2.5, 5.0, and 7.5 inches in 24-hour periods. For each rainfall amount, peak flows were simulated under low-, moderate-, and high-antecedent soil-moisture conditions, represented by selected 3-month periods of daily rainfall and evaporation record from nearby climatic-data measuring stations. Simulated peak flows ranged from 89 to 10,100 cubic feet per second. Profiles of water-surface elevations for selected observed and simu- lated peak flows were computed for the reach of Scott Creek that flows through Sylva, North Carolina. The profiles were computed using the U.S. Army Corps of Engineers HEC-2 Water Surface Profiles computer program and channel cross-section data collected by the Tennessee Valley Authority. The stage-discharge relation for Scott Creek at the simulation site has changed since the collection of the cross-section data. These changes, however, are such that the water-surface profiles presented in this report likely overestimate the true water-surface elevations at the simulation site for a given peak flow

  1. Influence of peak flow changes on the macroinvertebrate drift downstream of a Brazilian hydroelectric dam.

    PubMed

    Castro, D M P; Hughes, R M; Callisto, M

    2013-11-01

    Successive daily peak flows from hydropower plants can disrupt aquatic ecosystems and alter the composition and structure of macroinvertebrates downstream. We evaluated the influence of peak flow changes on macroinvertebrate drift downstream of a hydroelectric plant as a basis for determining ecological flows that might reduce the disturbance of aquatic biota. The aim of this study was to assess the influence of flow fluctuations on the seasonal and daily drift patterns of macroinvertebrates. We collected macroinvertebrates during fixed flow rates (323 m3.s-1 in the wet season and 111 m3.s-1 in the dry season) and when peak flows fluctuated (378 to 481 m3.s-1 in the wet season, and 109 to 173 m3.s-1 in the dry season) in 2010. We collected 31,924 organisms belonging to 46 taxa in the four sampling periods. Taxonomic composition and densities of drifting invertebrates differed between fixed and fluctuating flows, in both wet and dry seasons, but family richness varied insignificantly. We conclude that macroinvertebrate assemblages downstream of dams are influenced by daily peak flow fluctuations. When making environmental flow decisions for dams, it would be wise to consider drifting macroinvertebrates because they reflect ecological changes in downstream biological assemblages.

  2. 100 years of sedimentation study by the USGS

    USGS Publications Warehouse

    Glysson, G. Douglas

    1989-01-01

    On January 15, 1889, the U.S. Geological Survey began collecting sediment data on the Rio Grande at Embudo, New Mexico. During the past 100 years the U.S. Geological Survey's Water Resources Division (WRD) has collected daily sediment data at more than 1,200 sites. Projects have addressed the problems associated with reservoir construction, agricultural irrigation projects, energy production, and transport and deposition of pollutants sorbed to sediments. The Survey has been active as a charter member of the Federal Interagency Sediment Project and currently has three full-time hydrologists working on the project. The WRD's sediment-research projects have covered a wide variety of subjects from the fundamental theories of resistance to flow and sediment transport in alluvial channels to lunar erosion mechanisms.

  3. Flood moderation: Declining peak flows along some Rocky Mountain rivers and the underlying mechanism

    NASA Astrophysics Data System (ADS)

    Rood, Stewart B.; Foster, Stephen G.; Hillman, Evan J.; Luek, Andreas; Zanewich, Karen P.

    2016-05-01

    It has been proposed that global warming will amplify the water cycle and intensify river floods. We tested this hypothesis by investigating historic trends in magnitudes, durations and timing of the annual peak flows of rivers that drain the Rocky Mountains around the North American hydrographic apex, the source for rivers flowing to the Pacific, Arctic (including Hudson Bay) and Atlantic Oceans. We sought century-long records and to reduce influences from land-use we assessed drainages from parks and protected areas. Of 30 rivers and reaches that were free-flowing or slightly regulated, seven displayed declining peak flows (7 p < 0.1, 4 p < 0.05), and one showed increase (p < 0.05); three of five moderately regulated rivers displayed decline (p < 0.05). Substantial floods, exceeding the 1-in-5 year recurrence (Q5), were more common in the early versus latter halves of the records for some Arctic drainages and were more common during the Pacific Decadal Oscillation negative phase for all regions. The timing of peak flows was relatively unchanged and Q5 flood durations declined for a few rivers. These results indicate flood moderation rather than flood intensification, particularly for Arctic Ocean drainages. This could reflect regional hydrological consequences from climate change including: (1) declining overall annual river flows; (2) winter warming that would increase the rain versus snow proportion, thus reducing snow accumulation and melt; and (3) spring warming that advances snow melt, lengthening the melt interval before peak flows. These changes would shift the seasonality of river flows and reduce annual peaks. We might expect continuing moderation of peak flows but there will probably still be occasional major floods from exceptional rain events such as occurred in northern Montana in 1964 and in southern Alberta in 2013.

  4. Annual Peak-Flow and Peak Dam-Pool-Elevation Frequency Characteristics of Selected Dry Dams in the Great Miami River Basin, Ohio

    USGS Publications Warehouse

    Koltun, G.F.

    2009-01-01

    This report describes the results of a study to determine frequency characteristics of post-regulation annual peak flows at streamflow-gaging stations near the Taylorsville, Huffman, and Germantown dry dams in the Miami Conservancy District flood-protection system (southwestern Ohio), and of annual peak elevations of the corresponding dam pools. Log-Pearson Type III distributions were fit to annual peak flow values for the period 1921 or 1922 through 2007 (the most recent year of published peak flow values at the time of this analysis) and annual peak dam-pool storage values for the period 1922- 2008 to determine peaks with recurrence intervals of 2, 5, 10, 25, 50, 100, 200, and 500 years. Once storages had been estimated for the various recurrence intervals, corresponding dam-pool elevations were determined from elevation-storage ratings provided by the Miami Conservancy District.

  5. Suspended sediment dynamics in a tidal channel network under peak river flow

    NASA Astrophysics Data System (ADS)

    Achete, Fernanda Minikowski; van der Wegen, Mick; Roelvink, Dano; Jaffe, Bruce

    2016-05-01

    Peak river flows transport fine sediment, nutrients, and contaminants that may deposit in the estuary. This study explores the importance of peak river flows on sediment dynamics with special emphasis on channel network configurations. The Sacramento-San Joaquin Delta, which is connected to San Francisco Bay (California, USA), motivates this study and is used as a validation case. Besides data analysis of observations, we applied a calibrated process-based model (D-Flow FM) to explore and analyze high-resolution (˜100 m, ˜1 h) dynamics. Peak river flows supply the vast majority of sediment into the system. Data analysis of six peak flows (between 2012 and 2014) shows that on average, 40 % of the input sediment in the system is trapped and that trapping efficiency depends on timing and magnitude of river flows. The model has 90 % accuracy reproducing these trapping efficiencies. Modeled deposition patterns develop as the result of peak river flows after which, during low river flow conditions, tidal currents are not able to significantly redistribute deposited sediment. Deposition is quite local and mainly takes place at a deep junction. Tidal movement is important for sediment resuspension, but river induced, tide residual currents are responsible for redistributing the sediment towards the river banks and to the bay. We applied the same forcing for four different channel configurations ranging from a full delta network to a schematization of the main river. A higher degree of network schematization leads to higher peak-sediment export downstream to the bay. However, the area of sedimentation is similar for all the configurations because it is mostly driven by geometry and bathymetry.

  6. Finding the peak velocity in a flow from its Doppler spectrum.

    PubMed

    Vilkomerson, David; Ricci, Stefano; Tortoli, Piero

    2013-10-01

    The signal backscattered by blood cells crossing a sample volume produces a Doppler power spectrum determined by the scatterers¿ velocity distribution. Because of intrinsic spectral broadening, the peak Doppler frequency observed does not correspond to the peak velocity in the flow. Several methods have been proposed for estimating the maximum velocity component--an important clinical parameter--but these methods are approximate, based on heuristic thresholds that can be inaccurate and strongly affected by noise. Reported here is a method of modeling the Doppler power spectrum of a flow, and from that model, determining what Doppler frequency on the descending slope of the power spectrum corresponds to the peak velocity in the insonated flow. It is shown that, for a fully insonated flow with a parabolic velocity distribution, the peak velocity corresponds to the Doppler frequency at the half-power point on that slope. The method is demonstrated to be robust with regard to the effects of noise and valid for a wide range of acquisition parameters. Experimental maximum velocity measurements on steady flows with rates between 100 and 300 mL/min (peak velocity range 6.6 cm/s to 19.9 cm/s) show a mean bias error that is smaller than 1%.

  7. Peak expiratory flow rates in healthy Saudi Arabian children living in Riyadh.

    PubMed

    Graff-Lonnevig, V; Harfi, H; Tipirneni, P

    1993-11-01

    The peak expiratory flow rate (PEFR) was measured in 457 healthy Saudi schoolchildren (235 boys and 222 girls) aged 6 to 16 years, living in Riyadh, using two simple and commercially available airflow meters, Wright peak flow meter and the mini-Wright peak flow meter. All measurements were obtained in the standing position and the best of three trials was recorded. Standing height and age were used as independent variables. The regression equations for PEFR were determined for boys and girls separately. The boys had higher values than the girls at all heights. The difference was not significant. Both boys and girls had lower PEFRs as compared with European children and American children of different racial origin (P < .0001). When age was added to height as the second independent variable the Saudi boys and girls had significantly lower PEFRs than Swedish and British children (P < .0001). One explanation for these differences may be that the Saudi children on the average are shorter and have lower body weights than, eg, American children. The PEFR did not differ when using the Wright peak flow meter or the mini-Wright peak flow meter. These findings will serve as an important basis for preparing charts for normal PEFR values for Saudi children.

  8. Physical Origins of Statistical Scale Invariance or Scaling in Peak Flows in Real River Networks

    NASA Astrophysics Data System (ADS)

    Mantilla, R.; Gupta, V. K.; Furey, P.

    2005-12-01

    For nearly forty years, regional flood frequency analyses in unnested and in nested basins have shown that annual peak-flow quantiles can be related to drainage areas as power laws that arise from the property of scale invariance. This empirical feature has instigated a basic hydrologic question: Can power laws be obtained from physical processes governing rainfall-runoff transformations on real channel networks? There has been steady progress in answering this question since 1990. A physical understanding of peak flow scaling requires the time scales of individual rainfall-runoff events as a first step before going to longer time scales. We have used data from two Agriculture Research Service (ARS) experimental basins in the United States to test the physical basis of scaling in peak flows. The first basin is Goodwin Creek in Mississippi (21 km2), and the second one is Walnut Gulch in Arizona (150 km2). We have tested the hypothesis that scaling parameters of individual flood events on Goodwin Creek vary from one event to the next due to the effect of temporal rainfall variability. On the Walnut Gulch, we have tested the hypothesis that scaling in peak flows for short duration rainfall events is controlled by the river network topological and geometric configuration and the downstream hydraulic-geometric properties. Based on these results we present a gauging strategy to investigate peak flow scaling in the 1100 km2 Whitewater basin in Kansas.

  9. Understanding atmospheric and landscape level drivers of peak flow variability in the Pacific Northwest, USA

    NASA Astrophysics Data System (ADS)

    Safeeq, M.; Grant, G.; Lewis, S.; Staab, B. P.

    2013-12-01

    Changes in timing and magnitude of streamflows under climate change pose significant risks to ecosystems, infrastructure, and overall availability of water for human use. Previously, we have successfully developed a spatial analysis that predicts how low flows are likely to change in the future over the Pacific Northwest. Potential changes in peak flows pose a very different set of risks and concerns to land managers, but this subject has received little attention despite potentially greater economic and environmental loss. The Pacific Northwest (PNW) is potentially quite vulnerable to changes in peak flow regimes due to a warming climate. In the PNW snowpacks are considered 'warm' by climatological standards, meaning that snow typically falls and snowpacks ripen near the 0 degree C freezing point, so that a change of a few degrees can mean the difference between snow and rain, or between snow accumulation and rapid melt. Nearly 40% of the region is classified as in the transitional snow zone (TSZ), where the precipitation regime shifts between snow and rain depending on temperature. As a consequence of warming, hence changes in snowpack accumulation and melt, winter streamflows are likely to change in the future. The direction and magnitude of these changes are much less certain, however, and can be expected to vary dramatically across the landscape depending on sensitivity of precipitation regime to temperature. For example, in higher elevation watersheds, there may be increased risk for heavy winter rains or rain-on-snow events, both of which are major factors contributing to floods. In other areas, decreased winter snowpacks due to a greater proportion of winter rain may actually decrease the probability of rain-on-snow flooding. In this study we develop a set of spatial tools by combining the estimates of peak flows for a range of recurrence intervals, including 2, 5, 10, and 25 years with climate, hydro-morphologic, and land cover variables. Selected

  10. Estimating peak-flow frequency statistics for selected gaged and ungaged sites in naturally flowing streams and rivers in Idaho

    USGS Publications Warehouse

    Wood, Molly S.; Fosness, Ryan L.; Skinner, Kenneth D.; Veilleux, Andrea G.

    2016-06-27

    The U.S. Geological Survey, in cooperation with the Idaho Transportation Department, updated regional regression equations to estimate peak-flow statistics at ungaged sites on Idaho streams using recent streamflow (flow) data and new statistical techniques. Peak-flow statistics with 80-, 67-, 50-, 43-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance probabilities (1.25-, 1.50-, 2.00-, 2.33-, 5.00-, 10.0-, 25.0-, 50.0-, 100-, 200-, and 500-year recurrence intervals, respectively) were estimated for 192 streamgages in Idaho and bordering States with at least 10 years of annual peak-flow record through water year 2013. The streamgages were selected from drainage basins with little or no flow diversion or regulation. The peak-flow statistics were estimated by fitting a log-Pearson type III distribution to records of annual peak flows and applying two additional statistical methods: (1) the Expected Moments Algorithm to help describe uncertainty in annual peak flows and to better represent missing and historical record; and (2) the generalized Multiple Grubbs Beck Test to screen out potentially influential low outliers and to better fit the upper end of the peak-flow distribution. Additionally, a new regional skew was estimated for the Pacific Northwest and used to weight at-station skew at most streamgages. The streamgages were grouped into six regions (numbered 1_2, 3, 4, 5, 6_8, and 7, to maintain consistency in region numbering with a previous study), and the estimated peak-flow statistics were related to basin and climatic characteristics to develop regional regression equations using a generalized least squares procedure. Four out of 24 evaluated basin and climatic characteristics were selected for use in the final regional peak-flow regression equations.Overall, the standard error of prediction for the regional peak-flow regression equations ranged from 22 to 132 percent. Among all regions, regression model fit was best for region 4 in west

  11. Pedernales oilfield, eastern Venezuela: The first 100 years

    SciTech Connect

    Gluyas, J.; Oliver, J.; Wilson, W.

    1996-08-01

    Petroleum seeps and surface tar mats attracted oil explorers to Pedernales in eastern Venezuela 100 years ago. Commercial production from the Pedernales Field was established by Creole in 1933. In three production periods, broken by WWII and the end of the Creole-Texaco refining contract, Creole and Lagoven produced about 60 MMSTB from about 60 wells in about 60 years. Peak production was in the late 1950s, when the field delivered 12,000 BOPD. Production was stopped in 1986. In March 1993, BP Venezuela acquired the license to reactivate Pedernales on behalf of Lagoven, and BP`s first well in the field was drilled in August 1994. A second was completed in early 1995. The production from each well was sufficiently encouraging for commerciality to be declared in March 1995. Phase 1 of the field reactivation demanded a production rate of 11,500 BOPD. As of now (September, 1995) six wells, including one gas disposal well, have been completed. Wells have been placed using a combination of old well data and mapping based on a close spaced 2D seismic survey shot in early 1994. Results from these first few wells indicate that the required production rate will be achieved despite severely depleted reservoir pressures. This paper tells the story of reactivation and re-evaluation of one of eastern Venezuela`s oldest oilfields.

  12. Decadal oscillations and extreme value distribution of river peak flows in the Meuse catchment

    NASA Astrophysics Data System (ADS)

    De Niel, Jan; Willems, Patrick

    2017-04-01

    In flood risk management, flood probabilities are often quantified through Generalized Pareto distributions of river peak flows. One of the main underlying assumptions is that all data points need to originate from one single underlying distribution (i.i.d. assumption). However, this hypothesis, although generally assumed to be correct for variables such as river peak flows, remains somehow questionable: flooding might indeed be caused by different hydrological and/or meteorological conditions. This study confirms these findings from previous research by showing a clear indication of the link between atmospheric conditions and flooding for the Meuse river in The Netherlands: decadal oscillations of river peak flows can (at least partially) be attributed to the occurrence of westerly weather types. The study further proposes a method to take this correlation between atmospheric conditions and river peak flows into account when calibrating an extreme value distribution for river peak flows. Rather than calibrating one single distribution to the data and potentially violating the i.i.d. assumption, weather type depending extreme value distributions are derived and composed. The study shows that, for the Meuse river in The Netherlands, such approach results in a more accurate extreme value distribution, especially with regards to extrapolations. Comparison of the proposed method with a traditional extreme value analysis approach and an alternative model-based approach for the same case study shows strong differences in the peak flow extrapolation. The design-flood for a 1,250 year return period is estimated at 4,800 m3s-1 for the proposed method, compared with 3,450 m3s-1 and 3,900 m3s-1 for the traditional method and a previous study. The methods were validated based on instrumental and documentary flood information of the past 500 years.

  13. Dispersion-convolution model for simulating peaks in a flow injection system.

    PubMed

    Pai, Su-Cheng; Lai, Yee-Hwong; Chiao, Ling-Yun; Yu, Tiing

    2007-01-12

    A dispersion-convolution model is proposed for simulating peak shapes in a single-line flow injection system. It is based on the assumption that an injected sample plug is expanded due to a "bulk" dispersion mechanism along the length coordinate, and that after traveling over a distance or a period of time, the sample zone will develop into a Gaussian-like distribution. This spatial pattern is further transformed to a temporal coordinate by a convolution process, and finally a temporal peak image is generated. The feasibility of the proposed model has been examined by experiments with various coil lengths, sample sizes and pumping rates. An empirical dispersion coefficient (D*) can be estimated by using the observed peak position, height and area (tp*, h* and At*) from a recorder. An empirical temporal shift (Phi*) can be further approximated by Phi*=D*/u2, which becomes an important parameter in the restoration of experimental peaks. Also, the dispersion coefficient can be expressed as a second-order polynomial function of the pumping rate Q, for which D*(Q)=delta0+delta1Q+delta2Q2. The optimal dispersion occurs at a pumping rate of Qopt=sqrt[delta0/delta2]. This explains the interesting "Nike-swoosh" relationship between the peak height and pumping rate. The excellent coherence of theoretical and experimental peak shapes confirms that the temporal distortion effect is the dominating reason to explain the peak asymmetry in flow injection analysis.

  14. Plantation Forestry and Peak Flow Responses in Experimental Catchments and Large River Basins in Chile

    NASA Astrophysics Data System (ADS)

    Iroume, A.; Huber, A.

    2007-05-01

    Land use changes are inextricably linked to water resources and the consequences of such changes are a problem faced by water managers and governments across the world. This particular study considers the impact of changes in plantation forest cover on the hydrological response, with a specific focus on the issue of peak flow conditions and variation. The research still in progress is focused in small catchments and large river basins of Chile. The analysis of the data and the preparation of this document were carried out within the framework of the INCO- CT2004-510739 EPIC FORCE Project. EPIC FORCE aims to improve the integrated management of forest and water resources at the river basin scale through the development of policies based on sound science, focusing on extreme rainfall/snowmelt events. The focus areas are four Latin American countries (Costa Rica, Ecuador, Chile and Argentina.), which represent a range of humid forest and rainfall/snowmelt regimes with major flood and erosion problems and which suffer from a lack of integrated water and forest policies. Much of the controversy surrounding changes in peak flows following forest treatment arises from uncertainty over the response from different sizes of storms; whilst most studies agree that mean peak flow generally increases (even for only a short period) in the post harvesting period, there have been a number of different conclusions regarding influence of forest cover on peak flows from small storms compared with the flows from large events. In Chile, this research is been carried out in experimental catchments (less than 1 km2) and in large river basins (greater than 94 and up to 1,545 km2). Results from La Reina (34.4 ha), where peak flows from the pre-harvesting period (years 1997 to 1999, plantation of Pinus radiata established in 1977 covering the 79.5% of the area) were compared with those from the post- harvesting period (plantation clearcut between end of 1999 and first months of 2000 and

  15. Peak expiratory flow rate in Sri Lankan schoolchildren of Sinhalese ethnic origin.

    PubMed

    Udupihille, M

    1994-03-01

    Normal values for lung function indices are not available for Sri Lankan children. Reference standards for peak expiratory flow rate (PEFR) in non-smoking Sri Lankan schoolchildren belonging to the Sinhalese ethnic group have been derived. A total of 1206 schoolchildren of age range 5-19 years was studied. The mini-Wright peak flow meter was used to measure peak expiratory flow rates. The highest of three readings was taken as the correct value. The results were correlated with age, standing height, weight and surface area. The flow rate was only marginally higher in pre-pubertal boys than in girls. Girls reached a maximum at 15 years of age. The boys continued to show an increase in the PEFR until, at the age of 19 years, they had values about 150 l min-1 higher than females of the same age. Up to a height of 150 cm, a weight of 35 kg and l.1 m2 surface area, the two sexes showed similar gradients of increase of PEFR. Beyond these limits, the relationships changed abruptly, the boys showing an increase and the girls, a decrease in the gradient. There was a high correlation between PEFR and the anthropometric measurements studied. The peak flow rates compared favourably with those of other ethnic groups. Prediction formulae were developed with age and height as the independent variables. A nomogram based on these equations was constructed. These results would be useful in obtaining predicted normal values in Sinhalese school children with respiratory dysfunction.

  16. Assessing the ecological base and peak flow of the alpine streams in Central Taiwan

    NASA Astrophysics Data System (ADS)

    Wei, C.; Yang, P. S.; Tian, P. L.

    2009-04-01

    The ecological base and peak flow are crucial for the assessment and design for habitat rehabilitation and recovery. The amount of discharge affects the aquatic creatures and may severely damage the existence and balance of the community under extreme conditions. Aquatic insects are selected as the target species in this study to evaluate the influence of the discharge and to estimate the ecological base and peak flow. The distribution of the number of species and abundance (density) versus discharge is assessed to define the critical discharge. Two streams located at the alpine area in central Taiwan are selected as the study area to evaluate the base and peak flow. From the preliminary data (Aug 2008 to Dec 2008) collected from one stream Creek C originating from Sitou Area in Central Taiwan shows that the abundance of several species varies with the discharge. The dominate family and genus of aquatic insects is Baetidae (Order Ephemeroptera) and Baetis spp. that accounts for 32.47% and 31.11%, respectively. The Hilsenhoff family biotic index (FBI) shows that the water quality is classified to "Good" and "Very Good" level while the river pollution index (RPI) indicates that the stream is non-polluted. The discharge of base flow interpreted from the 95% curve of duration for the daily discharge is 0.0234 cms. Consistent observations are yet to be collected to yield more accurate result and ecological peak flow in rainy and typhoon seasons.

  17. Tests of peak flow scaling in simulated self-similar river networks

    USGS Publications Warehouse

    Menabde, M.; Veitzer, S.; Gupta, V.; Sivapalan, M.

    2001-01-01

    The effect of linear flow routing incorporating attenuation and network topology on peak flow scaling exponent is investigated for an instantaneously applied uniform runoff on simulated deterministic and random self-similar channel networks. The flow routing is modelled by a linear mass conservation equation for a discrete set of channel links connected in parallel and series, and having the same topology as the channel network. A quasi-analytical solution for the unit hydrograph is obtained in terms of recursion relations. The analysis of this solution shows that the peak flow has an asymptotically scaling dependence on the drainage area for deterministic Mandelbrot-Vicsek (MV) and Peano networks, as well as for a subclass of random self-similar channel networks. However, the scaling exponent is shown to be different from that predicted by the scaling properties of the maxima of the width functions. ?? 2001 Elsevier Science Ltd. All rights reserved.

  18. Center-to-center analysis of flow lineation and flow direction in Eocene welded ignimbrites, Twin Peaks, Idaho

    SciTech Connect

    Olsen, H.J. . Geology Dept.)

    1993-04-01

    Ignimbrites of the Eocene Twin Peaks caldera (Hardyman, 1982) in central Idaho's Challis Volcanic Field comprise both caldera-fill and outflow facies. The vents and mode of emplacement of these ignimbrites are problematic, because the Twin Peaks caldera has been strongly structurally disrupted, and lineations are sparse in the ignimbrites. Six oriented samples from three separate cooling units were studied using the Fry center-to-center method (Seaman and Williams, 1992) in order to determine flow lineation and flow direction of the ignimbrites inside the caldera. Flow lineation is defined in the plane parallel to flattened pumice and assumes that phenocryst are at maximum spacing in this plane. The flow lineation then coincides with the long axis of a center-to-center ellipse. Flow direction is defined in the plane perpendicular to flattening, which is inclined with respect to the flow plane and dips towards the source of flow. Four of five samples from the upper two cooling units near the thickest part of the caldera fill have well developed center-to-center strain ellipsoids producing flow lineations oriented N35W ([+-]7[degree]). The samples from the bottom cooling unit also has a well developed strain ellipsoid, but with a lineation oriented N80E. The difference in flow lineation suggests that the lowest cooling unit had a separate vent. Strain analysis of perpendicular sections are underway to establish the flow direction of the ignimbrites.

  19. Flow in a mechanical bileaflet heart valve at laminar and near-peak systole flow rates: CFD simulations and experiments.

    PubMed

    Ge, Liang; Leo, Hwa-Liang; Sotiropoulos, Fotis; Yoganathan, Ajit P

    2005-10-01

    Time-accurate, fully 3D numerical simulations and particle image velocity laboratory experiments are carried out for flow through a fully open bileaflet mechanical heart valve under steady (nonpulsatile) inflow conditions. Flows at two different Reynolds numbers, one in the laminar regime and the other turbulent (near-peak systole flow rate), are investigated. A direct numerical simulation is carried out for the laminar flow case while the turbulent flow is investigated with two different unsteady statistical turbulence modeling approaches, unsteady Reynolds-averaged Navier-Stokes (URANS) and detached-eddy simulation (DES) approach. For both the laminar and turbulent cases the computed mean velocity profiles are in good overall agreement with the measurements. For the turbulent simulations, however, the comparisons with the measurements demonstrate clearly the superiority of the DES approach and underscore its potential as a powerful modeling tool of cardiovascular flows at physiological conditions. The study reveals numerous previously unknown features of the flow.

  20. Reconstructing the ca. 100-year flood in Northern Thailand

    NASA Astrophysics Data System (ADS)

    Kidson, R.; Richards, K. S.; Carling, P. A.

    2005-09-01

    The key utilities of palaeohydrological studies are the potential to extend the flood record of a catchment and improve estimates of flood frequency and magnitude. In this study, we use a hydraulic model to produce estimates of discharge based on PSI (Palaeo-Stage Indicator) evidence from large floods for a study reach of the Mae Chaem River, Thailand. Careful calibration of this model, especially Manning's n, was possible because of the availability of PSIs from several modern gauged flows. Organic PSI evidence, contained in a cave, permitted dating of the largest flood for which evidence was available, which is close to the 100-year flood. The magnitude of this flood is twice that predicted from an extrapolation of the 49-year gauging record employing the Gumbel EV1 flood frequency model, officially endorsed by water management agencies in Thailand. This magnitude of flood is, however, very similar to that predicted from a Power Law model and suggests that extreme flood magnitude and frequency in this catchment conform to Power Law behaviour. These results significantly increase the perception of flood risk for the area, and this palaeohydrological case study represents the first for the region.

  1. Classical and generalized Horton laws for peak flows in rainfall-runoff events.

    PubMed

    Gupta, Vijay K; Ayalew, Tibebu B; Mantilla, Ricardo; Krajewski, Witold F

    2015-07-01

    The discovery of the Horton laws for hydrologic variables has greatly lagged behind geomorphology, which began with Robert Horton in 1945. We define the classical and the generalized Horton laws for peak flows in rainfall-runoff events, which link self-similarity in network geomorphology with river basin hydrology. Both the Horton laws are tested in the Iowa River basin in eastern Iowa that drains an area of approximately 32 400 km(2) before it joins the Mississippi River. The US Geological Survey continuously monitors the basin through 34 stream gauging stations. We select 51 rainfall-runoff events for carrying out the tests. Our findings support the existence of the classical and the generalized Horton laws for peak flows, which may be considered as a new hydrologic discovery. Three different methods are illustrated for estimating the Horton peak-flow ratio due to small sample size issues in peak flow data. We illustrate an application of the Horton laws for diagnosing parameterizations in a physical rainfall-runoff model. The ideas and developments presented here offer exciting new directions for hydrologic research and education.

  2. Classical and generalized Horton laws for peak flows in rainfall-runoff events

    NASA Astrophysics Data System (ADS)

    Gupta, Vijay K.; Ayalew, Tibebu B.; Mantilla, Ricardo; Krajewski, Witold F.

    2015-07-01

    The discovery of the Horton laws for hydrologic variables has greatly lagged behind geomorphology, which began with Robert Horton in 1945. We define the classical and the generalized Horton laws for peak flows in rainfall-runoff events, which link self-similarity in network geomorphology with river basin hydrology. Both the Horton laws are tested in the Iowa River basin in eastern Iowa that drains an area of approximately 32 400 km2 before it joins the Mississippi River. The US Geological Survey continuously monitors the basin through 34 stream gauging stations. We select 51 rainfall-runoff events for carrying out the tests. Our findings support the existence of the classical and the generalized Horton laws for peak flows, which may be considered as a new hydrologic discovery. Three different methods are illustrated for estimating the Horton peak-flow ratio due to small sample size issues in peak flow data. We illustrate an application of the Horton laws for diagnosing parameterizations in a physical rainfall-runoff model. The ideas and developments presented here offer exciting new directions for hydrologic research and education.

  3. Mouth breathing evaluation: use of Glatzel mirror and peak nasal inspiratory flow.

    PubMed

    Melo, Danielle de Lima e; Santos, Roberta Viviane Moreira; Perilo, Tatiana Vargas de Castro; Becker, Helena Maria Gonçalves; Motta, Andréa Rodrigues

    2013-01-01

    To compare the use of the Glatzel mirror and peak nasal inspiratory flow in the evaluation of mouth-breathing participants and to analyze the correlation between these instruments. Sixty-four children were evaluated--32 mouth breathers and 32 nasal breathers; the children were aged 4 to 12 years. The mouth breathers were subdivided according to the cause of obstruction by a multidisciplinary team. The Glatzel mirror and peak nasal inspiratory flow were used in both groups to evaluate patency and nasal airflow. Data were then subjected for statistical analysis. The Glatzel mirror allowed us to differentiate the breathing mode considering gender, age, weight, height, and body mass index, but it did not help in identifying the cause of mouth breathing. The peak nasal inspiratory flow did not allow differentiation of the breathing mode and identification of the cause of mouth breathing. In our sample, there was no correlation between the instruments used. The Glatzel mirror was reliable in identifying participants with and without nasal obstruction, although it was not possible to differentiate subgroups of mouth breathers using this instrument. The peak nasal inspiratory flow showed differences only between nasal breathers and surgical mouth breathers. Low correlation was found between these two instruments.

  4. Effect of right ventricular bypass peak flow-rate on intrapulmonary shunt ratio.

    PubMed

    Hashimoto, S; Moriya, H

    1988-02-01

    The effect of total right ventricular bypass peak flow-rate on the intrapulmonary shunt ratio was quantitatively investigated in animal tests. To give variations in the peak flow-rate (from pulsatile to intermediate to non-pulsatile), three types of blood pump (piston-bellows, screw, and centrifugal) were applied to dogs. The intrapulmonary shunt ratio was calculated from blood oxygen content drawn every 30 min from the outlet of the right ventricular bypass pump and from the femoral artery, while the canine lung was ventilated with 100% oxygen gas by an artificial respirator. The results show that when the intrapulmonary shunt ratio ranged between 0.095 and 0.392 there is no clear relation to the peak-flow-rate index (which varied from 1.1-17.0 l min-1 m-2) over the preceding 30 min. This study demonstrates that the intrapulmonary shunt ratio is able to be kept within the range of control values for 6 h even with a peak-flow-rate index of less than 4.0 l min-1 m-2.

  5. Impacts of logging on storm peak flows, flow volumes and suspended sediment loads in Caspar Creek, California

    Treesearch

    Jack Lewis; Sylvia R. Mori; Elizabeth T. Keppeler; Robert R. Ziemer

    2001-01-01

    Abstract - Models are fit to 11 years of storm peak flows, flow volumes, and suspended sediment loads on a network of 14 stream gaging stations in the North Fork Caspar Creek, a 473-ha coastal watershed bearing a second-growth forest of redwood and Douglas-fir. For the first 4 years of monitoring, the watershed was in a relatively undisturbed state, having last been...

  6. Effect of altitude on spirometric parameters and the performance of peak flow meters.

    PubMed Central

    Pollard, A. J.; Mason, N. P.; Barry, P. W.; Pollard, R. C.; Collier, D. J.; Fraser, R. S.; Miller, M. R.; Milledge, J. S.

    1996-01-01

    BACKGROUND: Portable peak flow meters are used in clinical practice for measurement of peak expiratory flow (PEF) at many different altitudes throughout the world. Some PEF meters are affected by gas density. This study was undertaken to establish which type of meter is best for use above sea level and to determine changes in spirometric measurements at altitude. METHODS: The variable orifice mini-Wright peak flow meter was compared with the fixed orifice Micro Medical Microplus turbine microspirometer at sea level and at Everest Base Camp (5300 m). Fifty one members of the 1994 British Mount Everest Medical Expedition were studied (age range, 19-55). RESULTS: Mean forced vital capacity (FVC) fell by 5% and PEF rose by 25.5%. However, PEF recorded with the mini-Wright peak flow meter underestimated PEF by 31%, giving readings 6.6% below sea level values. FVC was lowest in the mornings and did not improve significantly with acclimatisation. Lower PEF values were observed on morning readings and were associated with higher acute mountain sickness scores, although the latter may reflect decreased effort in those with acute mountain sickness. There was no change in forced expiratory volume in one second (FEV1) at altitude when measured with the turbine microspirometer. CONCLUSIONS: The cause of the fall in FVC at 5300 m is unknown but may be attributed to changes in lung blood volume, interstitial lung oedema, or early airways closure. Variable orifice peak flow meters grossly underestimate PEF at altitude and fixed orifice devices are therefore preferable where accurate PEF measurements are required above sea level. PMID:8711651

  7. Peak Flow Responses and Recession Flow Characteristics After Thinning of Japanese Cypress Forest in a Headwater Catchment

    EPA Science Inventory

    We evaluated the effects of forest thinning on peak flow and recession characteristics of storm runoff in headwater catchments at Mie Prefecture, Japan. In catchment M5, 58.3% of stems were removed, whereas catchment M4 remained untreated as a control catchment. Storm precipitati...

  8. Peak Flow Responses and Recession Flow Characteristics After Thinning of Japanese Cypress Forest in a Headwater Catchment

    EPA Science Inventory

    We evaluated the effects of forest thinning on peak flow and recession characteristics of storm runoff in headwater catchments at Mie Prefecture, Japan. In catchment M5, 58.3% of stems were removed, whereas catchment M4 remained untreated as a control catchment. Storm precipitati...

  9. 100-Year Flood-It's All About Chance

    USGS Publications Warehouse

    Holmes, Jr., Robert R.; Dinicola, Karen

    2010-01-01

    In the 1960's, the United States government decided to use the 1-percent annual exceedance probability (AEP) flood as the basis for the National Flood Insurance Program. The 1-percent AEP flood was thought to be a fair balance between protecting the public and overly stringent regulation. Because the 1-percent AEP flood has a 1 in 100 chance of being equaled or exceeded in any 1 year, and it has an average recurrence interval of 100 years, it often is referred to as the '100-year flood'. The term '100-year flood' is part of the national lexicon, but is often a source of confusion by those not familiar with flood science and statistics. This poster is an attempt to explain the concept, probabilistic nature, and inherent uncertainties of the '100-year flood' to the layman.

  10. 100-Year flood–it's all about chance

    USGS Publications Warehouse

    Holmes, Jr., Robert R.; Dinicola, Karen

    2010-01-01

    In the 1960's, the United States government decided to use the 1-percent annual exceedance probability (AEP) flood as the basis for the National Flood Insurance Program. The 1-percent AEP flood was thought to be a fair balance between protecting the public and overly stringent regulation. Because the 1-percent AEP flood has a 1 in 100 chance of being equaled or exceeded in any 1 year, and it has an average recurrence interval of 100 years, it often is referred to as the '100-year flood'. The term '100-year flood' is part of the national lexicon, but is often a source of confusion by those not familiar with flood science and statistics. This poster is an attempt to explain the concept, probabilistic nature, and inherent uncertainties of the '100-year flood' to the layman.

  11. Evaluation of the Effects of Development on Peak-Flow Hydrographs for Collyer Brook, Maine

    USGS Publications Warehouse

    Dudley, Robert W.; Hodgkins, Glenn A.; Mann, Alexander; Chisolm, John

    2001-01-01

    The development of former agricultural or forested lands creates more impervious areas and drainage improvements that can increase the volume of runoff and decrease infiltration and ground-water recharge in a watershed. Drainage improvements also can improve the conveyance of runoff, decreasing the time of rise to peak flow between the start of a rainfall event and the peak surface-water runoff, and likewise decreasing the duration of the peak-flow event. The watershed of Collyer Brook in southern Maine was studied to evaluate the effect of land-use changes on peakflow hydrographs because of the known development in the area during the past 35 years and the availability of aerial photos and streamflow data for this time period. Although aerial photography indicates that suburban development has increased in the watershed between 1964 and 1999, the overall effect of suburbanization on rainfall-runoff processes in the watershed did not produce a statistically detectable change in the peak-flow hydrographs for Collyer Brook.

  12. Impact of Wet-Weather Peak Flow Blending on Disinfection and Treatment: A Case Study at Three Wastewater Treatment Plants

    EPA Science Inventory

    A U.S. EPA study evaluated the impact on disinfection during peak flows (wet-weather flow events) when a portion of the flow to the wastewater treatment plant (WWTP) bypasses secondary treatment prior to disinfection. The practice of bypassing secondary treatment during peak flo...

  13. Impact of Wet Weather Peak Flow Blending on Disinfection and Treatment: A Case Study at Three Wastewater Treatment Plants

    EPA Science Inventory

    A U.S. EPA study evaluated the impact on disinfection during peak flows (wet-weather flow events) when a portion of the flow to the wastewater treatment plant (WWTP) bypasses secondary treatment prior to disinfection. The practice of bypassing secondary treatment during peak flo...

  14. Impact of Wet-Weather Peak Flow Blending on Disinfection and Treatment: A Case Study at Three Wastewater Treatment Plants

    EPA Science Inventory

    A U.S. EPA study evaluated the impact on disinfection during peak flows (wet-weather flow events) when a portion of the flow to the wastewater treatment plant (WWTP) bypasses secondary treatment prior to disinfection. The practice of bypassing secondary treatment during peak flo...

  15. Impact of Wet Weather Peak Flow Blending on Disinfection and Treatment: A Case Study at Three Wastewater Treatment Plants

    EPA Science Inventory

    A U.S. EPA study evaluated the impact on disinfection during peak flows (wet-weather flow events) when a portion of the flow to the wastewater treatment plant (WWTP) bypasses secondary treatment prior to disinfection. The practice of bypassing secondary treatment during peak flo...

  16. Comparing MiniWright and spirometer measurements of peak expiratory flow.

    PubMed

    Hankinson, J L; Filios, M S; Kinsley, K B; Petsonk, E L

    1995-08-01

    The accuracy and instrument variability of the MiniWright (Clement Clarke) peak expiratory flow (PEF) meter was determined with 6 of the 24 American Thoracic Society's (ATS) standard waveforms using a mechanical pump. Both room air and air heated to 37 degrees C and saturated with water vapor were used. In addition, MiniWright-determined PEF measurements were compared with those obtained using a dry rolling-seal spirometer (Ohio No. 822; Ohio Medical Products; Madison, Wis) from 75 subjects on 2 different days. The MiniWright average coefficient of variation within a waveform was found to be 2.8%. Results using heated and humidified air (body temperature, ambient pressure, and saturated with water: body conditions) were 2.5% lower than those obtained using room air. Comparisons with mechanically simulated PEF and with spirometry-determined peak flow in 75 human subjects showed that MiniWright meters over-estimated flows at lower flow rates and slightly under-estimated flows at higher flow rates. These results suggest that the new "mechanical PEF" MiniWright scale should be used instead of the "traditional" MiniWright scale.

  17. Regionalisation of climate change factors of peak flow quantiles in Lower Saxony

    NASA Astrophysics Data System (ADS)

    Plötner, Stefan; Haberlandt, Uwe; Petry, Uwe

    2017-04-01

    In order to project changes in flood flows climate change factors can be used. These are estimated by hydrological modelling for future and historical conditions, deriving flood peak distributions each and calculating ratios of the obtained peak flow quantiles. The changes factors can then be applied to observed or modelled flood quantiles to estimate possible future design flows. To predict in ungauged basins a regionalisation of the change factors is necessary. This utilisation of change factors is assumed to be more robust regarding the bias in climate models, regarding scale problems when using daily time steps for modelling and allows the application to any reference data set. For 178 meso-scale catchments in Lower Saxony the conceptual rainfall-runoff-model HBV-IWW is set up on a lumped and daily basis. The models are calibrated using a multi-criteria optimisation approach for the time period 1951-2013. 8 RCP 8.5 and 6 SRES A1B scenario datasets are used to derive the climate change factors of peak flow quantiles for the far future 2071-2100 against the reference time period 1971-2000. Three different methods: Multiple Linear Regression, Ordinary Kriging and Kriging with External Drift are investigated to regionalise the climate change factors. Due to the uncertainty of future climate an ensemble of simulations is used. This contribution answers questions regarding the best interpolation method, the optimal combination of climate scenarios and the assessment of uncertainty in the prediction.

  18. Geomorphic and hydrologic study of peak-flow management on the Cedar River, Washington

    USGS Publications Warehouse

    Magirl, Christopher S.; Gendaszek, Andrew S.; Czuba, Christiana R.; Konrad, Christopher P.; Marineau, Mathieu D.

    2012-01-01

    Assessing the linkages between high-flow events, geomorphic response, and effects on stream ecology is critical to river management. High flows on the gravel-bedded Cedar River in Washington are important to the geomorphic function of the river; however, high flows can deleteriously affect salmon embryos incubating in streambed gravels. A geomorphic analysis of the Cedar River showed evidence of historical changes in river form over time and quantified the effects of anthropogenic alterations to the river corridor. Field measurements with accelerometer scour monitors buried in the streambed provided insight into the depth and timing of streambed scour during high-flow events. Combined with a two-dimensional hydrodynamic model, the recorded accelerometer disturbances allowed the prediction of streambed disturbance at the burial depth of Chinook and sockeye salmon egg pockets for different peak discharges. Insight gained from these analyses led to the development of suggested monitoring metrics for an ongoing geomorphic monitoring program on the Cedar River.

  19. Information flow in a kinetic Ising model peaks in the disordered phase.

    PubMed

    Barnett, Lionel; Lizier, Joseph T; Harré, Michael; Seth, Anil K; Bossomaier, Terry

    2013-10-25

    There is growing evidence that for a range of dynamical systems featuring complex interactions between large ensembles of interacting elements, mutual information peaks at order-disorder phase transitions. We conjecture that, by contrast, information flow in such systems will generally peak strictly on the disordered side of a phase transition. This conjecture is verified for a ferromagnetic 2D lattice Ising model with Glauber dynamics and a transfer entropy-based measure of systemwide information flow. Implications of the conjecture are considered, in particular, that for a complex dynamical system in the process of transitioning from disordered to ordered dynamics (a mechanism implicated, for example, in financial market crashes and the onset of some types of epileptic seizures); information dynamics may be able to predict an imminent transition.

  20. Estimating the magnitude of peak flows at selected recurrence intervals for streams in Idaho

    USGS Publications Warehouse

    Berenbrock, Charles

    2002-01-01

    The region-of-influence method is not recommended for use in determining flood-frequency estimates for ungaged sites in Idaho because the results, overall, are less accurate and the calculations are more complex than those of regional regression equations. The regional regression equations were considered to be the primary method of estimating the magnitude and frequency of peak flows for ungaged sites in Idaho.

  1. Peak expiratory flow as a predictor for the effectiveness of sport for patients with COPD.

    PubMed

    Jungblut, S; Frickmann, H; Klingler, J; Zimmermann, B; Bargon, Joachim

    2006-01-31

    This study intended to find simple parameters that were able to determine the increase in physical performance as a result of sport in a group of patients with COPD (lung sport). We regularly investigated pulse, oxygenation and peak expiratory flow in participants with COPD of a "lung sport group", who participated in a structured weekly training program under professional supervision. Ten volunteers (7 females, 3 males, median of age = 69) with COPD (grade II-III) took part in the study. - The relative changes after 3 and 6 months were compared with the values of the first month of exercise. Measurements were carried out before exercise, after stamina training and at the end of the program. - Pulse and oxygenation did not show any changes. However, there was a significant improvement of peak flow after 6 months. - These peak flow changes represent further evidence of positive effects of sport in COPD and provide a parameter which allows the patients themselves to measure and evaluate the success of their physical activity.

  2. Suspended particle and pathogen peak discharge buffering by a surface-flow constructed wetland.

    PubMed

    Mulling, Bram T M; van den Boomen, Rob M; van der Geest, Harm G; Kappelhof, Joost W N M; Admiraal, Wim

    2013-03-01

    Constructed wetlands (CWs) have been shown to improve the water quality of treated wastewater. The capacity of CWs to reduce nutrients, pathogens and organic matter and restore oxygen regime under normal operating conditions cannot be extrapolated to periods of incidental peak discharges. The buffering capacity of CWs during peak discharges is potentially a key factor for water quality in the receiving waters. Therefore, the aim of the present study was to investigate the behaviour of peak discharges of suspended particles, (associated) physiochemical parameters and pathogenic organisms from a wastewater treatment plant (WWTP) in a full scale constructed wetland (CW). By mixing clarified water and sludge rich water from the settlement tank of the WWTP, the suspended particle concentration was increased for 8 h from ± 3.5 to ± 230 mg L(-1), and discharged into a full scale horizontal surface flow constructed wetland. An increase of suspended particle concentration following the peak discharge concurred with increases in turbidity and oxygen demand, total nutrient load (nitrogen, phosphorus and carbon) and pathogens (Escherichia coli and Enterococci). Temperature, pH, conductivity and dissolved nutrient concentrations (nitrogen, phosphorus and carbon) were however unaffected by the initial peak discharge. After retention in the unvegetated ponds (the first CW compartment) the applied suspended particle peak with a total load of 86.2 kg was reduced by >99%. Similar peak buffering was observed for the turbidity, oxygen demand and settable volume. Simultaneously dissolved nutrient concentrations increased, indicating partial mineralization of the suspended particles during retention in the unvegetated ponds. The peak buffering of pathogens was lower (40-84%), indicating differences in removal processes between other suspended particles and pathogens. The results indicated that the suspended particles were probably mostly removed by sedimentation and mineralization

  3. Post-fire hydrologic model assessment for peak flow estimates across diverse watersheds and climate conditions

    NASA Astrophysics Data System (ADS)

    Hale, B.; Kinoshita, A. M.; Hogue, T. S.; Napper, C.

    2011-12-01

    Wildfires alter land surfaces and land-atmosphere interactions, enhancing hydrologic responses such as flooding and debris flows. Accurate prediction of post-fire events is important for efficient mitigation. The US Forest Service (USFS) Burn Area Emergency Response (BAER) teams are required to estimate post-fire runoff and sediment fluxes in areas that have values at risk or threaten human life and natural resources. The purpose of this study is to provide specialists and policy makers with guidance on tools to assist in post-fire hydrologic monitoring and management. A survey of post-fire hydrologic model usage by the USFS reveals inconsistency in model parameter attainment, model usage, and awareness of alternative modeling practices. To address the USFS needs for quick and accurate model predictions, an assessment of current modeling systems (USGS Regression, TR-55, HEC-HMS, Wildcat5, etc.), parameters (inputs and outputs), and regional application under pre- and post-fire scenarios is undertaken. This suite of models is then applied to a diverse set of sites affected by wildfire in the western United States to estimate peak flow events (pre- and post-fire). Results show inconsistency between model predictions for peak flow events at each site, with less confidence in the larger return periods (25- and 50-year peak flow events). Pre-fire, models developed and fine-tuned specifically for a region produce similar results to observed flows, however models are not readily transferable to different regions. More complex models are time and parameter intensive but often do not produce more confident results. Peak flow in all models is highly sensitive to model parameters and currently, a strict protocol for gathering parameters and running models does not exist. To validate study models, several post-fire sites (southern and northern California, Colorado, and Montana) have been instrumented and are being used to monitor in situ hydrologic variables such as discharge

  4. The value of cough peak flow measurements in the assessment of extubation or decannulation readiness.

    PubMed

    Winck, J C; LeBlanc, C; Soto, J L; Plano, F

    2015-01-01

    Insufficient cough strength has a major role in extubation and decannulation outcomes. Cough capacity can be easily evaluated by measuring flows during coughing. Values vary depending on whether cough flows are measured through the mouth or through a tracheostomy or endotracheal tube. It is important to standardize these measurements and start using them routinely in the extubation and decannulation processes. Values of cough peak flow >160 L/min measured at the mouth or a value of cough PEF >60 L/min measured at the endotracheal tube suggest successful decannulation or extubation. Copyright © 2014 Sociedade Portuguesa de Pneumologia. Published by Elsevier España, S.L.U. All rights reserved.

  5. Uncertainty of the peak flow reconstruction of the 1907 flood in the Ebro River in Xerta (NE Iberian Peninsula)

    NASA Astrophysics Data System (ADS)

    Ruiz-Bellet, Josep Lluís; Castelltort, Xavier; Balasch, J. Carles; Tuset, Jordi

    2017-02-01

    There is no clear, unified and accepted method to estimate the uncertainty of hydraulic modelling results. In historical floods reconstruction, due to the lower precision of input data, the magnitude of this uncertainty could reach a high value. With the objectives of giving an estimate of the peak flow error of a typical historical flood reconstruction with the model HEC-RAS and of providing a quick, simple uncertainty assessment that an end user could easily apply, the uncertainty of the reconstructed peak flow of a major flood in the Ebro River (NE Iberian Peninsula) was calculated with a set of local sensitivity analyses on six input variables. The peak flow total error was estimated at ±31% and water height was found to be the most influential variable on peak flow, followed by Manning's n. However, the latter, due to its large uncertainty, was the greatest contributor to peak flow total error. Besides, the HEC-RAS resulting peak flow was compared to the ones obtained with the 2D model Iber and with Manning's equation; all three methods gave similar peak flows. Manning's equation gave almost the same result than HEC-RAS. The main conclusion is that, to ensure the lowest peak flow error, the reliability and precision of the flood mark should be thoroughly assessed.

  6. Generalized Skew Coefficients of Annual Peak Flows for Rural, Unregulated Streams in West Virginia

    USGS Publications Warehouse

    Atkins, John T.; Wiley, Jeffrey B.; Paybins, Katherine S.

    2009-01-01

    Generalized skew was determined from analysis of records from 147 streamflow-gaging stations in or near West Virginia. The analysis followed guidelines established by the Interagency Advisory Committee on Water Data described in Bulletin 17B, except that stations having 50 or more years of record were used instead of stations with the less restrictive recommendation of 25 or more years of record. The generalized-skew analysis included contouring, averaging, and regression of station skews. The best method was considered the one with the smallest mean square error (MSE). MSE is defined as the following quantity summed and divided by the number of peaks: the square of the difference of an individual logarithm (base 10) of peak flow less the mean of all individual logarithms of peak flow. Contouring of station skews was the best method for determining generalized skew for West Virginia, with a MSE of about 0.2174. This MSE is an improvement over the MSE of about 0.3025 for the national map presented in Bulletin 17B.

  7. A model of rapid preferential hillslope runoff contributions to peak flow generation in a temperate rain forest watershed

    NASA Astrophysics Data System (ADS)

    Beckers, Jos; Alila, Younes

    2004-03-01

    A model for the 10 km2 Carnation Creek watershed on Vancouver Island, British Columbia, is used to assess preferential hillslope runoff contributions to peak flow generation. The model combines the matrix flow algorithm of the distributed hydrology soil vegetation model with a Green-Ampt formulation for calculating matrix and by-pass infiltration, preferential hillslope runoff initiation controlled by rainfall depth, and downslope subsurface flow rates prescribed based on at-site tracer tests. Model evaluation using 1972-1990 hydrometeorological data reveals that this formulation is successful in simulating subannual and larger peak flows. Model results suggest that preferential flow contributions to streamflow generation become greater than matrix flow contributions for unit area discharge values in excess of 2.8 mm/hr, corresponding to a peak flow return period of 2-3 months. This transition from matrix flow dominated runoff to preferential flow dominated runoff is consistent with an observed upper limit of groundwater response to precipitation for return periods in excess of 2 months. A break in slope in peak flow frequency curves at a return period of about 20 months appears to correspond to a change in storm characteristics. Thus at least three physically distinct populations of peak flows may exist at Carnation Creek. The ability of the model to simulate peak flows and groundwater responses for small and large storms suggests that it may be useful for addressing runoff process considerations in the debate whether forest management effects for annual and larger peak flows are similar to those inferred from analyses dominated by subannual peak flows.

  8. Women in July Fourth Cartoons: A 100-Year Look.

    ERIC Educational Resources Information Center

    Meyer, Katherine; And Others

    1980-01-01

    Analyzes the dominance, appearance, and role of women as depicted in newspaper Independence Day political cartoons over a 100-year period. Concludes that woman's place has gradually broadened to include activities beyond wife and mother. Indicates a resistance to changing norms and difficulty in coping with emerging ones. (JMF)

  9. A 100-year review: Carbohydrates - characterization, digestion, and utilization

    USDA-ARS?s Scientific Manuscript database

    Our knowledge of the role of carbohydrates in dairy cattle nutrition has advanced substantially during the 100 years in which the Journal of Dairy Science has been published. In this review, we traced the history of scientific investigation and discovery from crude fiber, nitrogen-free extract, and ...

  10. 100 Years of Commitment to Children: Change and Continuity.

    ERIC Educational Resources Information Center

    Shore, Rima

    The Foundation for Child Development (FCD) is the oldest philanthropy in the nation focused on improving the life prospects of children. This booklet, produced for FCD's centennial, describes the organization's origins and changes during the past 100 years. The booklet's sections, which include photographs, quotes, and a timeline, are: (1)…

  11. Spring wheat gliadins: Have they changed in 100 years?

    USDA-ARS?s Scientific Manuscript database

    There have been many hard red spring (HRS) wheat cultivars released in North Dakota during the last 100 years. These cultivars have been improved for various characteristics such as, adaptation to weather conditions, high yield, and good milling and baking quality. The objectives of this study wer...

  12. Centennial Calendar- 100 Years of the American Phytopathological Society

    USDA-ARS?s Scientific Manuscript database

    I edited a 40-page publication (calendar) that covered 18 chapters written by members of our society. This covered pioneering researchers, departments, and epidemics of the last 100 years of plant pathology in the U. S. This was given to all members of the American Phytopathological Society who att...

  13. Women in July Fourth Cartoons: A 100-Year Look.

    ERIC Educational Resources Information Center

    Meyer, Katherine; And Others

    1980-01-01

    Analyzes the dominance, appearance, and role of women as depicted in newspaper Independence Day political cartoons over a 100-year period. Concludes that woman's place has gradually broadened to include activities beyond wife and mother. Indicates a resistance to changing norms and difficulty in coping with emerging ones. (JMF)

  14. A short history of corneal transplantation: commemorating 100 years.

    PubMed

    Kirkwood, Bradley J

    2006-01-01

    Corneal transplantation is the most commonly performed transplant surgery in the world today. This procedure replaces all or some of the recipient cornea with a cadaveric donor cornea. It has been 100 years since the first successful human allograft corneal transplantation was performed. This article provides the reader with a brief history of corneal transplantation.

  15. [Peak expiratory flow in 6-12 year-old children from Merida, Yucatan, Mexico].

    PubMed

    Baeza Bacab, Manuel Antonio; Dávila Velázquez, Jorge Rubén; Palma Chan, Adolfo Gonzalo; Albertos Alpuche, Nelly E

    2004-01-01

    Assessment of pulmonary function may be done by several procedures, such as spirometric and flow metric ones. To obtain a peak expiratory flow rate (PEFR) percentilar curve in healthy schoolchildren of both sexes of Merida, Yucatan, Mexico. We carried out a transversal and observational study in schoolchildren between 6 and 12 years old of both sexes. They were evaluated by a demographic questionnaire that included age, weight, height and health status, and then the PEFR was assessed using a mini-Wright Peak Flow Meter recording the highest of the three numbers achieved. We included 621 healthy schoolchildren between 6 and 12 years old of both sexes, 321 girls and 300 boys, of two schools that were selected by random sampling. The media age was 9 +/- 2 years old, height 128 +/- 10 cm, weight 30.34 +/- 9.75 kg, corporal surface 1.049 +/- 0.22 m2, and PEFR 293.72 +/- 66 L/min. When we compared the PEFR with age, height and weight, we saw that height was a more reliable predictor than age or weight, since higher values of R were obtained. There was not a significant difference of PEFR between boys and girls. Our results show that the pulmonary function values increase proportionally to height, which showed the higher correlation to FEM.

  16. Variations in peak nasal inspiratory flow among healthy students after using saline solutions.

    PubMed

    Olbrich Neto, Jaime; Olbrich, Sandra Regina Leite Rosa; Mori, Natália Leite Rosa; Oliveira, Ana Elisa de; Corrente, José Eduardo

    2016-01-01

    Nasal hygiene with saline solutions has been shown to relieve congestion, reduce the thickening of the mucus and keep nasal cavity clean and moist. Evaluating whether saline solutions improve nasal inspiratory flow among healthy children. Students between 8 and 11 years of age underwent 6 procedures with saline solutions at different concentrations. The peak nasal inspiratory flow was measured before and 30 min after each procedure. Statistical analysis was performed by means of t test, analysis of variance, and Tukey's test, considering p<0.05. We evaluated 124 children at all stages. There were differences on the way a same concentration was used. There was no difference between 0.9% saline solution and 3% saline solution by using a syringe. The 3% saline solution had higher averages of peak nasal inspiratory flow, but it was not significantly higher than the 0.9% saline solution. It is important to offer various options to patients. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  17. An Automated Measurement of Ciliary Beating Frequency using a Combined Optical Flow and Peak Detection

    PubMed Central

    Kim, Woojae; Han, Tae Hwa; Kim, Hyun Jun; Park, Man Young; Kim, Ku Sang

    2011-01-01

    Objectives The mucociliary transport system is a major defense mechanism of the respiratory tract. The performance of mucous transportation in the nasal cavity can be represented by a ciliary beating frequency (CBF). This study proposes a novel method to measure CBF by using optical flow. Methods To obtain objective estimates of CBF from video images, an automated computer-based image processing technique is developed. This study proposes a new method based on optical flow for image processing and peak detection for signal processing. We compare the measuring accuracy of the method in various combinations of image processing (optical flow versus difference image) and signal processing (fast Fourier transform [FFT] vs. peak detection [PD]). The digital high-speed video method with a manual count of CBF in slow motion video play, is the gold-standard in CBF measurement. We obtained a total of fifty recorded ciliated sinonasal epithelium images to measure CBF from the Department of Otolaryngology. The ciliated sinonasal epithelium images were recorded at 50-100 frames per second using a charge coupled device camera with an inverted microscope at a magnification of ×1,000. Results The mean square errors and variance for each method were 1.24, 0.84 Hz; 11.8, 2.63 Hz; 3.22, 1.46 Hz; and 3.82, 1.53 Hz for optical flow (OF) + PD, OF + FFT, difference image [DI] + PD, and DI + FFT, respectively. Of the four methods, PD using optical flow showed the best performance for measuring the CBF of nasal mucosa. Conclusions The proposed method was able to measure CBF more objectively and efficiently than what is currently possible. PMID:21886872

  18. Secondary peak in the Nusselt number distribution of impinging jet flows: A phenomenological analysis

    NASA Astrophysics Data System (ADS)

    Aillaud, P.; Duchaine, F.; Gicquel, L. Y. M.; Didorally, S.

    2016-09-01

    This paper focuses on a wall-resolved Large Eddy Simulation (LES) of an isothermal round submerged air jet impinging on a heated flat plate, at a Reynolds number of 23 000 (based on the nozzle diameter and the bulk velocity at the nozzle outlet) and for a nozzle to plate distance of two jet diameters. This specific configuration is known to lead to a non-monotonic variation of the temporal-mean Nusselt number as a function of the jet center distance, with the presence of two distinct peaks located on the jet axis and close to two nozzle diameters from the jet axis. The objectives are here twofold: first, validate the LES results against experimental data available in the literature and second to explore this validated numerical database by the use of high order statistics such as skewness and probability density functions of the temporal distribution of temperature and pressure to identify flow features at the origin of the second Nusselt peak. Skewness (Sk) of the pressure temporal distribution reveals the rebound of the primary vortices located near the location of the secondary peak and allows to identify the initiation of the unsteady separation linked to the local minimum in the mean heat transfer distribution. In the region of mean heat transfer enhancement, joint velocity-temperature analyses highlight that the most probable event is a cold fluid flux towards the plate produced by the passage of the vortical structures. In parallel, heat transfer distributions, analyzed using similar statistical tools, allow to connect the above mentioned events to the heat transfer on the plate. Thanks to such advanced analyses, the origin of the double peak is confirmed and connected to the flow dynamics.

  19. Flood-hazard study: 100-year flood stage for Lucerne Lake, San Bernadino County, California

    USGS Publications Warehouse

    Busby, Mark William

    1977-01-01

    A study of the flood hydrology of Lucerne Valley, Calif., was made to develop the 100-year stage for Lucerne Lake. Synthetic-hydrologic techniques were used; and the 100-year flood stage was estimated to be at an elevation of 2,849.3 feet above mean sea level. Channel dimensions were measured at 59 sites in Lucerne Valley. Dranage area-discharge relations developed from channel-geometry data for sites nearby were used to estimate the discharge at 12 additional sites where channel geometry could not be measured. In order to compute the total volume discharge into the playa, the peak discharges were converted to volumes. From the Apple Valley report (Busby, 1975) the equation formulated from the relation between peak discharge and flood volume for the deserts of California was used to compute the flood volumes for routing into Lucerne Lake. (Woodard-USGS)

  20. Access to spacers and peak flow meters among medicaid patients with asthma.

    PubMed

    Magee, James S; Jones, Stacie M; Ayers, Mark E; Golden, William; Vargas, Perla A

    2002-12-01

    Asthma morbidity and mortality have increased at alarming rates. Morbidity is significantly higher among minorities and low-income populations. The purpose of this study was to survey pharmacies licensed to provide both asthma medications and durable medical equipment (DME) to evaluate their acceptance of Medicaid as payment for spacers and peak flow meters in patients with Medicaid. Twenty-four pharmacies were identified and completed a telephone survey. Only 64% of the pharmacies licensed to accept Medicaid for DME provide this service. We postulate that improving DME licensing and claims reimbursement will impact medication compliance, as well as asthma morbidity and mortality.

  1. Base (100-year) flood elevations for selected sites in Livingston County, Missouri

    USGS Publications Warehouse

    Southard, Rodney E.; Richards, Joseph M.

    2002-01-01

    The primary criteria for community participation in the National Flood Insurance Program is the adoption and enforcement of floodplain management requirements that minimize the potential for flood damages to existing and proposed development in flood-hazard areas. This report provides base flood elevations (BFE) for a 100-year recurrence-interval flood for use in the management and regulation of 18 flood-hazard areas designated by the Federal Emergency Management Agency as approximate Zone A areas in Livingston County, Missouri. The one-dimensional surface-water flow models HEC-RAS and Water-Surface PROfile (WSPRO) were used to compute base (100-year) flood elevations for 18 Zone A sites. The HEC-RAS model was used at BFE sites 1 to 6, 9, 10, and 15 to 18. The WSPRO model was used at BFE sites 7, 8, and 11 to 14. The 18 sites are all located in Livingston County, Missouri, at U.S., State, or County road crossings, and the base flood elevation was determined at the upstream side of each crossing. The base (100-year) flood elevations for BFE 1, 2, and 3 on Shoal Creek at Dawn and Shoal Creek Drainage Ditch near Dawn are 701.0, 701.0, and 696.5 feet, respectively. The base (100-year) flood elevations for BFE 4 and 5 on Indian Branch near Sampsel and a tributary to Indian Branch near Sampsel are 711.7 and 755.4 feet, respectively. Site BFE 6 is located on Honey Creek near Farmersville and the base (100-year) flood elevation for this site is 730.8 feet. One site (BFE 7) is located on No Creek near Farmersville. The base (100-year) flood elevation for this site is 731.3 feet. Site BFE 8 is located on Crooked Creek near Chillicothe and the base (100-year) elevation is 716.4 feet. One site (BFE 9) is located on a tributary to Coon Creek at Chillicothe. The base (100-year) flood elevation for this site is 734.9 feet. Two sites (BFE 10 and 11) are located on Blackwell Branch at Chillicothe. The base (100-year) flood elevation for BFE 10 is 738.9 feet and for BFE 11 is 701

  2. Peak flow rate and recession-curve characteristics of a karst spring in the Inner Bluegrass, central Kentucky

    USGS Publications Warehouse

    Felton, G.K.; Currens, J.C.

    1994-01-01

    The flow rate at the terminal spring of a 1929 ha karst ground-water catchment has been continuously monitored for 2 years, and 108 identifiable events were analyzed. The peak flow rates followed a beta frequency distribution with parameters ?? = 0.365 and ?? = 1.135. Events were separated into high-flow and low-flow. High-flow events had characteristics attributable to pipe flow. Correlation and stepwise regression were used to develop peak flow rate prediction equations for the combined 108 events and for the 81 low-flow events. The portion of the recession curve identified as pipe flow was a watershed constant and time invariant. The base flow was seasonal, increasing in the winter to approximately 0.071 m3s-1 and decreasing in the summer to approximately 0.014 m3s-1. ?? 1994.

  3. Lung function in North American Indian children: reference standards for spirometry, maximal expiratory flow volume curves, and peak expiratory flow.

    PubMed

    Wall, M A; Olson, D; Bonn, B A; Creelman, T; Buist, A S

    1982-02-01

    Reference standards of lung function was determined in 176 healthy North American Indian children (94 girls, 82 boys) 7 to 18 yr of age. Spirometry, maximal expiratory flow volume curves, and peak expiratory flow rate were measured using techniques and equipment recommended by the American Thoracic Society. Standing height was found to be an accurate predictor of lung function, and prediction equations for each lung function variable are presented using standing height as the independent variable. Lung volumes and expiratory flow rates in North American Indian children were similar to those previously reported for white and Mexican-American children but were greater than those in black children. In both boys and girls, lung function increased in a curvilinear fashion. Volume-adjusted maximal expiratory flow rates after expiring 50 or 75% of FVC tended to decrease in both sexes as age and height increased. Our maximal expiratory flow volume curve data suggest that as North American Indian children grow, lung volume increases at a slightly faster rate than airway size does.

  4. Relationship between the transition frequency of local fluid flow and the peak frequency of attenuation

    NASA Astrophysics Data System (ADS)

    Cao, Cheng-Hao; Zhang, Hong-Bing; Pan, Yi-Xin; Teng, Xin-Bao

    2016-03-01

    Local fluid flow (LFF) at the mesoscopic scale is the main dissipation mechanism of seismic waves in heterogeneous porous media within the seismic frequency band. LFF is easily influenced by the structure and boundary conditions of the porous media, which leads to different behaviors of the peak frequency of attenuation. The associated transition frequency can provide detailed information about the trend of LFF; therefore, research on the transition frequency of LFF and its relationship with the peak frequency of the corresponding attenuation (i.e., inverse of quality factor) facilitates the detailed understanding of the effect of inner structures and boundary conditions in porous media. In this study, we firstly obtain the transition frequency of fluid flux based on Biot's theory of poroelasticity and the fast Fourier transform algorithm in a sample containing one repeating unit cell (RUC). We then analyze changes of these two frequencies in porous media with different porous properties. Finally, we extend our analysis to the influence of the undrained boundary condition on the transition frequency and peak frequency in porous media with multiple RUCs. This setup can facilitate the understanding of the effect from the undrained boundary condition. Results demonstrate that these two frequencies have the same trend at low water saturation, but amplitude variations differ between the frequencies as the amount of saturation increases. However, for cases of high water saturation, both the trend and the amplitude variation of these two frequencies fit well with each other.

  5. Peak flow rate records in the diagnosis of occupational asthma due to isocyanates.

    PubMed Central

    Burge, P S; O'Brien, I M; Harries, M G

    1979-01-01

    Peak expiratory flow rate (PEFR) has been recorded hourly or two-hourly from waking to sleeping in workers with respiratory symptoms who were exposed to isocyanate fumes at work. Twenty-three recordings averaging 33 days duration were recorded in 20 workers. Each worker was also admitted for bronchial provocation testing to toluene di-isocyanate (TDI) or diphenylmethane di-isocyanate (MDI) fumes or both. A final assessment of work-related asthma made from subsequent work exposure was compared with the results of bronchial provocation testing and a subjective assessment of the peak flow records. Both techniques were specific and sensitive. Physiological patterns of occupational asthma were defined from the records of PEFR. The most striking finding was the slow recovery from work-induced asthma. This commonly took several days to start and in one worker took 70 days to complete after leaving work. Several workers developed a pattern resembling fixed airways obstruction after repeated exposure at work. The consequences of these findings for the recording of symptoms of occupational asthma are discussed and recommendations are made for the recording of PEFR in workers in general. PMID:225841

  6. Change in peak expiratory flow over time among workers exposed to polyvinyl chloride dust.

    PubMed

    Lawin, H; Ayelo, P; Hinson, V; Kagima, J; Fayomi, B

    2015-04-01

    To evaluate the variation of peak expiratory flow (PEF) over a working week among non-smoking workers without previous asthma who have been exposed to polyvinyl chloride (PVC) dust. We conducted a cross-sectional study among 42 operators with exposure to PVC dust (filling hoppers to feed extrusion machines) and 23 employees without exposure to PVC dust in a plant producing PVC pipes in West Africa. A pre-tested questionnaire was administered and PEF was measured using a portable peak flow meter after a day off (day 1), on day 3 and at the end of the week (day 6). The two groups did not differ by age or body mass index. Dyspnoea was more prevalent in exposed workers than controls (52% vs. 13%, P = 0.002). PEF decreased more significantly in exposed workers than controls (-8% vs. -3% on day 3 and -10% vs. -5% on day 6, both P = 0.004). The duration of exposure did not affect PEF variability in the exposed groups. The decrease of PEF over the working week in workers exposed to PVC dust is consistent with occupational asthma, although standard measures to diagnose occupational asthma were not used. This result reinforces the need to prevent excessive exposure to PVC dust.

  7. Entropy-based snow network design for spring peak flow forecasting

    NASA Astrophysics Data System (ADS)

    Keum, J.; Coulibaly, P. D.; Tapsoba, D.

    2015-12-01

    In northern regions the dominant phase of precipitation is snow, this precipitation persists and accumulates throughout the winter season until freshet. Quantitative information on snow, such as snow water equivalent and snow cover extent, is essential for water resources management in northern regions. Due to the inaccessibility and remoteness of snow course locations, snow surveys are usually expensive. Therefore an efficient network design strategy is required to provide a maximum amount of information while also minimizing the network cost. In this study, an entropy-based multiobjective optimization method is applied to design a snow network by adding new stations to the existing network in the La Grande River Basin of Quebec, Canada. Three hydrologic models, Sacramento, HBV, and HSAMI, are calibrated to 12 subwatersheds in the La Grande River Basin. Pareto optimal networks are given by the multiobjective optimization by maximizing joint entropy and minimizing total correlation. Each of the potential optimal networks is then evaluated using the calibrated hydrologic models to determine the most appropriate network for spring peak flow forecasting. The proposed methodology provides useful information for designing snow network appropriate for spring peak flow forecasting, which is essential for reservoir operation.

  8. Respiratory symptoms and peak expiratory flow rates in workers of a Nigerian soap and detergent industry.

    PubMed

    Bamidele, J O

    2002-01-01

    This comparative cross-sectional study was carried out to assess the respiratory symptoms and peak expiratory flow rates of the factory(study group) and office(control group) workers in a soap and detergent industry in Ilorin in relation to the occupational hazards of chemical fumes and detergent dust in the industry. Upper respiratory tract infections were found in 67.5% and 10.6% of the study group and control group respectively. The study shows that the factory workers experienced hazards (e.g. chemical fumes and detergent dust) at work more than the office workers. Personal protective devices such as boots, face masks, gloves, earmuffs and goggles were not consistently used since they were inadequate in supply, worn out and of substandard qualities. The general reduction in the mean values of peak expiratory flow rate in the factory workers than in the office workers as observed in this study may possibly, be a pointer to the effect of industrial exposure to chemical fumes and detergent dust over the years. There is the need to follow up these workers in order to detect early any possible disease and complications that may arise.

  9. Relation between respiratory symptoms, pulmonary function and peak flow variability in adults.

    PubMed Central

    Boezen, H. M.; Schouten, J. P.; Postma, D. S.; Rijcken, B.

    1995-01-01

    BACKGROUND--A study was carried out to determine whether subjects with respiratory symptoms are more likely to have impaired lung function or increased airway lability, and to quantify these relationships in a population of adults. METHODS--Data were collected from 511 participants (aged 20-70 years) from the Dutch part of the European Community Respiratory Health Survey (ECRHS). The symptoms analysed were: wheeze, dyspnoea > or = grade 3, nocturnal dyspnoea, cough and phlegm, and history of allergy. Lung function was measured by peak expiratory flow (PEF) and forced expiratory volume in one second (FEV1). PEF variability was used as an index for bronchial lability. RESULTS--Both FEV1 and PEF were decreased with increasing numbers of symptoms. Subjects with one symptom had an increased risk of having an FEV1 value of < 70% (OR = 4.2) and this risk increased with an increasing number of symptoms. Subjects with three or more symptoms had an increased risk of having a PEF value of < 70%, a diurnal variation in PEF of > 10% (both OR = 4.4), and an increased risk of high between day variation (OR = 6.6). CONCLUSIONS--Subject-reported symptoms are related to impaired lung function and to increased variability of peak flow. PMID:7701448

  10. Peak expiratory flow rates in healthy Turkish children living in Istanbul, Turkey.

    PubMed

    Oneş, Ulker; Somer, Ayper; Sapan, Nihat; Dişçi, Rian; Güler, Nermin

    2004-01-01

    In the evaluation and management of bronchial asthma, simple instruments for measurements of the peak expiratory flow (PEF) rate are needed. The aim of this study was to determine normal PEF values of Turkish children living in Istanbul. This is the largest study conducted in Turkey. In a cross-sectional study, we measured PEF in 2791 healthy schoolchildren (1468 boys and 1323 girls) aged 7-14 years, with a Mini Wright peak flow meter. We entered height, age, and sex into the regression equation. The equation for prediction of PEF in boys was calculated as (3.5 x height [cm]) + (9.2 x age [years]) - 256.5, (p < 0.0001; r = 0.83) and for girls as (3.3 x height [cm]) + (10.2 x age [years]) - 263.7 (p < 0.0001; r = 0.81). We found that PEF values of Turkish children were similar to British and Danish children, but significant differences were noted with Greek Irish, Mexican American, African-American, and white American children. Our results were significantly lower compared with another study conducted in Adana, a small southern city (< 1 million inhabitants) in Turkey. Istanbul being a cosmopolitan big city (> 7 millions inhabitants) can reflect more reliably real PEF values of Turkish children. We concluded that our findings would serve as an important basis for preparing centile curves for normal PEF values for Turkish children.

  11. Methods and results of peak-flow frequency analyses for streamgages in and bordering Minnesota, through water year 2011

    USGS Publications Warehouse

    Kessler, Erich W.; Lorenz, David L.; Sanocki, Christopher A.

    2013-01-01

    Peak-flow frequency analyses were completed for 409 streamgages in and bordering Minnesota having at least 10 systematic peak flows through water year 2011. Selected annual exceedance probabilities were determined by fitting a log-Pearson type III probability distribution to the recorded annual peak flows. A detailed explanation of the methods that were used to determine the annual exceedance probabilities, the historical period, acceptable low outliers, and analysis method for each streamgage are presented. The final results of the analyses are presented.

  12. A regression approach to the analysis of serial peak flow among fuel oil ash exposed workers.

    PubMed

    Hauser, R; Daskalakis, C; Christiani, D C

    1996-10-01

    We investigated the association between exposure to fuel oil ash and acute airway obstruction in 31 boilermakers and 31 utility workers during the overhaul of a large oil-fired boiler. Air flow was assessed with self-recorded serial peak expiratory flow rate measurements (PEFR) using a mini-Wright meter. Exposure to thoracic particulates with an aerodynamic diameter of 10 gm or smaller (PM10) was assessed using personal sampling devices and detailed work diaries. All subjects were male, with an average age of 43 yr, and an average of 18 yr at their current trade. Average PM10 exposure on work days was 2.75 mg/m3 for boilermakers and 0.57 mg/m3 for utility workers. Three daily PEFR measurements (start-of-shift, end-of-shift, and bed-time) were analyzed simultaneously, using Huber linear regression. After adjustment for job title, welder status, age, height, smoking, and weld-years, for each mg/m3 increase in PM10, the estimated decline in PEFR was 13.2 L/min (p = 0.008) for end-of-shift, 9.9 L/min (p = 0.045) for bed-time, and 6.6 L/min (p = 0.26) for start-of-shift of the following day. This decline of the exposure effect over the 24-h period that follows was statistically significant (p = 0.004). No other factors were found to significantly modify the effect of exposure. Our results suggest that occupational exposure to fuel oil ash is associated with significant acute decrements in peak flow.

  13. The effect of drain blocking on dissolved organic carbon under the peak flow conditions

    NASA Astrophysics Data System (ADS)

    zhang, zhuoli

    2014-05-01

    There are numerous studies that have shown increasing dissolved organic carbon (DOC) concentration down stream of upland peat catchments (eg. Worrall et al., 2007; Clark et al., 2007; Gibson et al., 200). In the UK, upland peat soils are both an important water source and an important carbon store, therefore, the transportation of DOC from soil to the aquatic system remains a critical part of the impact that upland peat environments have on wider society. The majority of the DOC is delivered from the peat soil during the peak flow events (Clark et al., 2008), however, most of the storm events analysis has been developed for organo-mineral soil rather than for peat soil catchments. Worrall et al., (2007) suggested that drain blocking as a potential method for controlling DOC release from peat soil. An events analysis was conducted on the drain blocking data collected from 2008 to 2010 from Cronkley Fell (UK National grid reference NY 83800 26996). A total of 756 peak flow events were chosen to access the impact of drain blocking on DOC concentration and flux during the events. The data was analysed by the combination of principal components analysis (PCA) and end member mixing analysis (EMMA). The results showed that during the peak flow events, the effects of drain blocking was minimised by the rapid flushing of the event water: the DOC concentration on storm events increased after blocking rather than decreased; DOC flux did decrease after blocking but rather as a result of the increased volume of the event water. Worrall, F., Armstrong, A., Holden, J., 2007. Short term impact of peat drain blocking on water color, dissolved organic carbon concentration and water table depth. Journal of Hydrology 337,315-325 Clark, J.M., Lane, S.N., Chapman, P.J., Adamson, J.K., 2007. Export of dissolved organic carbon from an upland peat during storm events: Implication for flux estimates. Journal of Hydrology 347, 438-447. Aitkenhead, J.A., McDowell, W. H., 2000. Soil C: N ratio

  14. A Reanalysis of Geomagnetic Activity during the Last 100 Years

    NASA Astrophysics Data System (ADS)

    Martini, D.; Mursula, K.; Karinen, A.

    2004-12-01

    Long-term geomagnetic activity presented by the aa index has recently been used to show that the heliospheric magnetic field has more than doubled during the last 100 years. However, serious concern has recently been raised on the long-term consistency of the aa index and, thereby, on the centennial rise of solar magnetic activity. Here we reanalyze geomagnetic activity during the last 100 years by calculating the recently suggested IHV index for seven stations. We find that local geomagnetic activity in all stations follows the same qualitative long-term pattern as depicted by the aa index, and has a higher average level during the last two decennia of the 20th century than in the first two decennia. This verifies the result based on the aa index that global geomagnetic activity, and thereby, the open solar magnetic field has indeed increased during the last 100 years. However, quantitatively, the estimated centennial increase varies greatly from one station to another. We find that the relative increase is higher at the high-latitude stations and lower at the low and mid-latitude stations. Moreover, we find a considerably smaller (about 24-35%) centennial increase for global geomagnetic activity than given by the aa index (about 65%). We also show that the IHV index needs to be corrected for the long-term change of the daily curve, and calculate the corrected IHV values. We find that in four out of seven stations this correction further reduces the estimated centennial increase of local geomagnetic activity.

  15. Palama Settlement: 100 years of serving a neighborhood's needs.

    PubMed

    Rath, P

    1995-11-01

    The founding of Palama Settlement brought to those who might not be able to afford it public health nurses for maternal care and nutrition, well-baby clinics, tuberculosis clinics, medical and dental clinics, and eventually major support of medical needs during and after the attack on Pearl Harbor. Palama Settlement celebrates its centennial year with many of its early functions assumed by state and private organizations, but it is prepared to enter the next 100 years of service to the community. Palama was founded by James Arthur Rath with the purpose of serving the community; many people today remember their childhood and Palama Settlement.

  16. NASA Administrator Dan Goldin greets 100-year-old VIP.

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Among the VIPs attending the launch of STS-99 is Captain Ralph Charles (left), standing next to NASA Administrator Dan Goldin. Charles hopes to have his wish fulfilled of watching a Shuttle launch in person. The 100-year-old aviator has experienced nearly a century of flight history, from the Wright Brothers to the Space Program. He took flying lessons from one of the first fliers trained by Orville Wright, first repaired then built airplanes, went barnstorming, operated a charter service in the Caribbean, and worked as a test pilot for the Curtiss Wright Airplane Co. Charles is the oldest licensed pilot in the United States, and is still flying.

  17. Base (100-year) flood elevations for selected sites in Marion County, Missouri

    USGS Publications Warehouse

    Southard, Rodney E.; Wilson, Gary L.

    1998-01-01

    The primary requirement for community participation in the National Flood Insurance Program is the adoption and enforcement of floodplain management requirements that minimize the potential for flood damages to new construction and avoid aggravating existing flooding conditions. This report provides base flood elevations (BFE) for a 100-year recurrence flood for use in the management and regulation of 14 flood-hazard areas designated by the Federal Emergency Management Agency as approximate Zone A areas in Marion County, Missouri. The one-dimensional surface-water flow model, HEC-RAS, was used to compute the base (100-year) flood elevations for the 14 Zone A sites. The 14 sites were located at U.S., State, or County road crossings and the base flood elevation was determined at the upstream side of each crossing. The base (100-year) flood elevations for BFE 1, 2, and 3 on the South Fork North River near Monroe City, Missouri, are 627.7, 579.2, and 545.9 feet above sea level. The base (100-year) flood elevations for BFE 4, 5, 6, and 7 on the main stem of the North River near or at Philadelphia and Palmyra, Missouri, are 560.5, 539.7, 504.2, and 494.4 feet above sea level. BFE 8 is located on Big Branch near Philadelphia, a tributary to the North River, and the base (100-year) flood elevation at this site is 530.5 feet above sea level. One site (BFE 9) is located on the South River near Monroe City, Missouri. The base (100-year) flood elevation at this site is 619.1 feet above sea level. Site BFE 10 is located on Bear Creek near Hannibal, Missouri, and the base (100-year) elevation is 565.5 feet above sea level. The four remaining sites (BFE 11, 12, 13, and 14) are located on the South Fabius River near Philadelphia and Palmyra, Missouri. The base (100-year) flood elevations for BFE 11, 12, 13, and 14 are 591.2, 578.4, 538.7, and 506.9 feet above sea level.

  18. Temporal and Spatial Power Laws of River Peak Flows and Flood Frequency Estimation

    NASA Astrophysics Data System (ADS)

    Krajewski, W. F.; Mantilla, R.; Perez, G.

    2016-12-01

    It is well known that the quantiles of annual peak flows (floods) are related as power law functions of basin drainage areas. These relationships constitute the basis for the current methods of regional flood frequency estimation. It is less well known that flood events obey similar laws but with different and varied (from event to event) parameters. It has also been demonstrated that power law probability distributions offer very good fit to flood data and lead to more conservative estimates of extreme events compared to the standard methods. The authors review some of the previous findings and show additional analyses of temporal flood data from Iowa. They supplement the data-based analyses with simulations from a space-time model. The overall goal of the research is to connect the spatial and temporal aspects of flood genesis and improve our understanding of the physical aspects that control flood frequency.

  19. Curvilinear formulae for predicting peak expiratory flow rate in adult Nigerians.

    PubMed

    Njoku, C H; Anah, C O

    2001-01-01

    Predicted values of Peak expiratory flow rate (PEF) using linear formulae do not closely agree with observed trends. Predicted values tend to be higher than observed values among youths and the elderly while they are usually lower than observed values among people within the prime of life. All prediction formulae in Nigeria are linear. In this study, more fitting curvilinear formulae were derived for male and female subjects from PEF values obtained from a study of 1009 subjects made up of 668 males and 341 females between the ages of 15 and 82 years living and/or working in Port Harcourt, Nigeria and its environs. We hope that these formulae may be put to greater use since they agree more closely with the observed trends.

  20. Heart rate variability biofeedback increases baroreflex gain and peak expiratory flow.

    PubMed

    Lehrer, Paul M; Vaschillo, Evgeny; Vaschillo, Bronya; Lu, Shou-En; Eckberg, Dwain L; Edelberg, Robert; Shih, Weichung Joe; Lin, Yong; Kuusela, Tom A; Tahvanainen, Kari U O; Hamer, Robert M

    2003-01-01

    We evaluated heart rate variability biofeedback as a method for increasing vagal baroreflex gain and improving pulmonary function among 54 healthy adults. We compared 10 sessions of biofeedback training with an uninstructed control. Cognitive and physiological effects were measured in four of the sessions. We found acute increases in low-frequency and total spectrum heart rate variability, and in vagal baroreflex gain, correlated with slow breathing during biofeedback periods. Increased baseline baroreflex gain also occurred across sessions in the biofeedback group, independent of respiratory changes, and peak expiratory flow increased in this group, independently of cardiovascular changes. Biofeedback was accompanied by fewer adverse relaxation side effects than the control condition. Heart rate variability biofeedback had strong long-term influences on resting baroreflex gain and pulmonary function. It should be examined as a method for treating cardiovascular and pulmonary diseases. Also, this study demonstrates neuroplasticity of the baroreflex.

  1. [Variability in peak expiratory flow does not classify asthma according to severity].

    PubMed

    Pérez-Yarza, Eduardo G; Cobos, Nicolás; de la Cruz, Juan José

    2007-10-01

    The aim of this study was to determine whether variability in peak expiratory flow (PEF) could be used to classify the level of severity of asthma in children. We studied 387 boys and girls diagnosed with asthma and classified severity according to clinical criteria (Spanish Society of Pediatric Pneumology). PEF variability was determined using a portable mini-Wright peak flow meter (Clement Clarke International, London, UK; range, 50 L/min-800 L/min) over a 14-day period, with no changes in normal treatment. The following indices were used to calculate PEF variability: 1) difference between morning PEF and nighttime PEF, expressed as a percentage of the mean value of the PEF measurements taken on that day; 2) minimum PEF rate during a week, expressed as a percentage of the highest value recorded during that week; 3) difference between the highest and the lowest PEF values, expressed as a percentage of the highest value; and 4) the 10th percentile of PEF values recorded during a week, expressed as a percentage of the highest value recorded during that week. We assessed agreement between clinical classification and PEF variability using the weighted kappa coefficient. We also analyzed the sensitivity and specificity of PEF variability indices for episodic and persistent asthma. The analysis of levels of agreement between clinical classification of asthma and formulas 1, 2, 3, and 4 gave quadratic weighted kappa coefficients of 0.494, 0, 0.488, and 0.346, respectively. The results were similar when patients were grouped and analyzed by type of asthma (episodic or persistent asthma). The monitoring of PEF variability, a recommendation common in national and international guidelines on the management of asthma in children, is not valid for classifying severity of asthma in children.

  2. Traffic-related air pollution affects peak expiratory flow, exhaled nitric oxide, and inflammatory nasal markers.

    PubMed

    Steerenberg, P A; Nierkens, S; Fischer, P H; van Loveren, H; Opperhuizen, A; Vos, J G; van Amsterdam, J G

    2001-01-01

    The authors used a longitudinal observational design, with repeated measures, to study the association between traffic-related air pollutants (i.e., nitric oxide, nitrogen dioxide, carbon monoxide, and Black Smoke) and respiratory symptoms. Subjects (N = 82) attended an elementary school in either Utrecht (i.e., urban children) or Bilthoven (i.e., suburban children). These two geographic areas differed with respect to levels of Black Smoke (means = 53 microg/m3 and 18 microg/m3, respectively). Levels of nitric oxide, nitrogen dioxide, carbon monoxide, and Black Smoke were consistently higher in Utrecht than in Bilthoven (mean daily ratios were 8, 1.5, 1.8, and 2.7, respectively). The authors compared mean levels of short-term effects of the aforementioned air pollutants on suburban and urban children. Urban children had higher mean levels (p = .05) of interleukin-8 (32%), urea (39%), uric acid (26%), albumin (15%), and nitric oxide metabolites (21%) in nasal lavage than did suburban children. Peak expiratory flow, exhaled nitric oxide levels, and nasal markers were associated with levels of particulate matter with diameters less than or equal to 10 microm, Black Smoke, nitrogen dioxide, and nitric oxide. With respect to per-unit increases in air pollution, urban children had more increased peak expiratory flow, higher levels of exhaled nitric oxide, and more increased release of uric acid, urea, and nitric oxide metabolites than suburban children. In summary, urban children had increased levels of inflammatory nasal markers, and their responses were more pronounced than were the suburban children's responses to the same increments of air pollution.

  3. Association of the Asthma Control Test with peak flow measures in a population in Puerto Rico.

    PubMed

    Malinow, Iona; Rivera-Santiago, Roberto; López-Malpica, Fernando; Zaragoza, Rafael; Velázquez, Vylma; Acantilado, Carmen; Rodríguez, Ray; Rivera, Angel; López-Almodóvar, Carlos; Nazario, Sylvette

    2014-09-01

    The Asthma Control Test (ACT) questionnaire has been widely used and validated in various ethnic groups, showing an adequate correlation with physician assessment of asthma control. We sought to evaluate the relationship between ACT-defined asthma control and peak flow measures in subjects living in Puerto Rico. A retrospective evaluation of data collected by a mobile asthma clinic in 2 cities in Puerto Rico was conducted. The participants completed an asthma and rhinitis survey. Self-reported asthmatics answered the age-appropriate Spanish version of the ACT. Peak flows (PEF) were measured. Subjects were skin-tested against the common local aeroallergens. The study was approved by the University of Puerto Rico's IRB. We evaluated data from 70 subjects aged 4 to 68. Of them, 82.85% were 12 years old or older, 64.3% reported having a history of asthma, 57.14% reported that they still suffered from asthma, 81.4% reported that they suffered from rhinitis, and 78.57% were sensitized to at least 1 antigen. The mean ACT score of current asthmatics was 18.97, while that of past asthmatics was 23.83 (p = 6.6e-6). The variability of PEF increased as the ACT score increased. Age had no impact on asthma control (p > 0.25), while the effect of PEF on the control of asthma was tied to gender. Rhinitis was also associated with poor asthma control as defined by the ACT score. No other covariate was found to be statistically significant (p < 0.05). Our study supports the use of the ACT to evaluate asthma control in asthmatics living in Puerto Rico. Research into factors associated with poor asthma control, and the importance of rhinitis with regard to such control, is needed.

  4. Changes in peak flow with decreased forestry practices: analysis using watershed runoff data.

    PubMed

    Komatsu, Hikaru; Shinohara, Yoshinori; Kume, Tomonori; Otsuki, Kyoichi

    2011-06-01

    The prevalence of forestry practices such as thinning and pruning have gradually decreased since the 1980s. Researchers have noted an increased flood risk with decreased forestry practices for coniferous plantations in Japan on the basis of infiltration and overland flow measurements at a plot scale (typically several square meters). However, no studies have examined changes in peak flow with decreased forestry practices at a watershed scale (typically several tens or hundreds of square kilometers) even though flood disasters generally occur at this scale in Japan. We examined changes in frequency distributions of daily precipitation (P) and runoff (Q) during the period 1979-2007 at the Terauchi watershed, where forestry practices are known to have decreased. For this purpose, we divided P and Q data into 14 and 15 classes according to the magnitude, respectively, and examined changes in the frequency for each class during the period. We observed no significant increasing trend for any P or Q class. Even when taking into account the effect of interannual variations in precipitation on the frequency for each Q class, there was no significant increasing trend in the frequencies except for two Q classes with moderate Q values. These results suggest that the increase in flood risk due to decreased forestry practices might be less than expected. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Influences of gender and anthropometric features on inspiratory inhaler acoustics and peak inspiratory flow rate.

    PubMed

    Taylor, Terence E; Holmes, Martin S; Sulaiman, Imran; Costello, Richard W; Reilly, Richard B

    2015-01-01

    Inhalers are hand-held devices used to treat chronic respiratory diseases such as asthma and chronic obstructive pulmonary disease (COPD). Medication is delivered from an inhaler to the user through an inhalation maneuver. It is unclear whether gender and anthropometric features such as age, height, weight and body mass index (BMI) influence the acoustic properties of inspiratory inhaler sounds and peak inspiratory flow rate (PIFR) in inhalers. In this study, healthy male (n=9) and female (n=7) participants were asked to inhale at an inspiratory flow rate (IFR) of 60 L/min in four commonly used inhalers (Turbuhaler(™), Diskus(™), Ellipta(™) and Evohaler(™)). Ambient inspiratory sounds were recorded from the mouthpiece of each inhaler and over the trachea of each participant. Each participant's PIFR was also recorded for each of the four inhalers. Results showed that gender and anthropometric features have the potential to influence the spectral properties of ambient and tracheal inspiratory inhaler sounds. It was also observed that males achieved statistically significantly higher PIFRs in each inhaler in comparison to females (p<;0.05). Acoustic features were found to be significantly different across inhalers suggesting that acoustic features are modulated by the inhaler design and its internal resistance to airflow.

  6. Extending dry storage of spent LWR fuel for 100 years.

    SciTech Connect

    Einziger, R. E.

    1998-12-16

    Because of delays in closing the back end of the fuel cycle in the U.S., there is a need to extend dry inert storage of spent fuel beyond its originally anticipated 20-year duration. Many of the methodologies developed to support initial licensing for 20-year storage should be able to support the longer storage periods envisioned. This paper evaluates the applicability of existing information and methodologies to support dry storage up to 100 years. The thrust of the analysis is the potential behavior of the spent fuel. In the USA, the criteria for dry storage of LWR spent fuel are delineated in 10 CFR 72 [1]. The criteria fall into four general categories: maintain subcriticality, prevent the release of radioactive material above acceptable limits, ensure that radiation rates and doses do not exceed acceptable levels, and maintain retrievability of the stored radioactive material. These criteria need to be considered for normal, off-normal, and postulated accident conditions. The initial safety analysis report submitted for licensing evaluated the fuel's ability to meet the requirements for 20 years. It is not the intent to repeat these calculations, but to look at expected behavior over the additional 80 years, during which the temperatures and radiation fields are lower. During the first 20 years, the properties of the components may change because of elevated temperatures, presence of moisture, effects of radiation, etc. During normal storage in an inert atmosphere, there is potential for the cladding mechanical properties to change due to annealing or interaction with cask materials. The emissivity of the cladding could also change due to storage conditions. If there is air leakage into the cask, additional degradation could occur through oxidation in breached rods, which could lead to additional fission gas release and enlargement of cladding breaches. Air in-leakage could also affect cover gas conductivity, cladding oxidation, emissivity changes, and

  7. Estimating an Impedance-to-Flow Parameter for Flood Peak Prediction in Semi-Arid Watersheds 1997

    USDA-ARS?s Scientific Manuscript database

    The time of concentration equation used in Pima County, Arizona, includes a hydrologic parameter representing the impedance to flow for peak discharge estimation on small (<10 mi2) semiarid watersheds. The impedance-to-flow parameter is similar in function to the hydraulic Manning’s n roughness coef...

  8. Opening the 100-Year Window for Time-Domain Astronomy

    NASA Astrophysics Data System (ADS)

    Grindlay, Jonathan; Tang, Sumin; Los, Edward; Servillat, Mathieu

    2012-04-01

    The large-scale surveys such as PTF, CRTS and Pan-STARRS-1 that have emerged within the past 5 years or so employ digital databases and modern analysis tools to accentuate research into Time Domain Astronomy (TDA). Preparations are underway for LSST which, in another 6 years, will usher in the second decade of modern TDA. By that time the Digital Access to a Sky Century @ Harvard (DASCH) project will have made available to the community the full sky Historical TDA database and digitized images for a century (1890-1990) of coverage. We describe the current DASCH development and some initial results, and outline plans for the ``production scanning'' phase and data distribution which is to begin in 2012. That will open a 100-year window into temporal astrophysics, revealing rare transients and (especially) astrophysical phenomena that vary on time-scales of a decade. It will also provide context and archival comparisons for the deeper modern surveys.

  9. NASA Administrator Dan Goldin greets 100-year-old VIP.

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Astronaut Andy Thomas (left) greets 100-year-old Captain Ralph Charles, one of the VIPs attending the launch of STS-99. Charles also met NASA Administrator Dan Goldin. An aviator who has the distinction of being the oldest licensed pilot in the United States, Charles is still flying. He has experienced nearly a century of flight history, from the Wright Brothers to the Space Program. He took flying lessons from one of the first fliers trained by Orville Wright, first repaired then built airplanes, went barnstorming, operated a charter service in the Caribbean, and worked as a test pilot for the Curtiss Wright Airplane Co. Charles watches all the Shuttle launches from his home in Ohio and his greatest wish is to be able to watch one in person from KSC.

  10. 100 years after Smoluchowski: stochastic processes in cell biology

    NASA Astrophysics Data System (ADS)

    Holcman, D.; Schuss, Z.

    2017-03-01

    100 years after Smoluchowski introduced his approach to stochastic processes, they are now at the basis of mathematical and physical modeling in cellular biology: they are used for example to analyse and to extract features from a large number (tens of thousands) of single molecular trajectories or to study the diffusive motion of molecules, proteins or receptors. Stochastic modeling is a new step in large data analysis that serves extracting cell biology concepts. We review here Smoluchowski’s approach to stochastic processes and provide several applications for coarse-graining diffusion, studying polymer models for understanding nuclear organization and finally, we discuss the stochastic jump dynamics of telomeres across cell division and stochastic gene regulation.

  11. Global change and water resources in the next 100 years

    USGS Publications Warehouse

    Larsen, Matthew C.; Hirsch, R.M.

    2010-01-01

    We are in the midst of a continental-scale, multi-year experiment in the United States, in which we have not defined our testable hypotheses or set the duration and scope of the experiment, which poses major water-resources challenges for the 21st century. What are we doing? We are expanding population at three times the national growth rate in our most water-scarce region, the southwestern United States, where water stress is already great and modeling predicts decreased streamflow by the middle of this century. We are expanding irrigated agriculture from the west into the east, particularly to the southeastern states, where increased competition for ground and surface water has urban, agricultural, and environmental interests at odds, and increasingly, in court. We are expanding our consumption of pharmaceutical and personal care products to historic high levels and disposing them in surface and groundwater, through sewage treatment plants and individual septic systems. These substances are now detectable at very low concentrations and we have documented significant effects on aquatic species, particularly on fish reproduction function. We don’t yet know what effects on human health may emerge, nor do we know if we need to make large investments in water treatment systems, which were not designed to remove these substances. These are a few examples of our national-scale experiment. In addition to these water resources challenges, over which we have some control, climate change models indicate that precipitation and streamflow patterns will change in coming decades, with western mid-latitude North America generally drier. We have already documented trends in more rain and less snow in western mountains. This has large implications for water supply and storage, and groundwater recharge. We have documented earlier snowmelt peak spring runoff in northeastern and northwestern States, and western montane regions. Peak runoff is now about two weeks earlier than it was

  12. Mineral resources of the Little Black Peak and Carrizozo Lava Flow wilderness study areas, Lincoln County, New Mexico

    SciTech Connect

    Stoeser, D.B.; Senterfit, M.K.; Zelten, J.E.

    1989-01-01

    This book discusses the Little Black Peak and Carrizozo Lava Flow Wilderness Study Areas in east-central New Mexico (24,249 acres) which are underlain by Quaternary basaltic lava flows and upper Paleozoic to Mesozoic sedimentary rocks. The only identified resource is lava from the basalt flows, which is used for road metal, construction materials, and decorative stone. The basalt is classed as an inferred subeconomic resource. Both areas have low resource potential for sediment-hosted uranium and copper oil, gas, coal, and geothermal energy and moderate potential for gypsum and salt. The Little Black Peak area also has low potential for uranium associated with Tertiary alkaline intrusive rocks. Two aeromagnetic anomalies occur beneath the northern part of the Carrizozo lava flow area and the southern part of the Little Black Peak area; the resource potential for these rocks is unknown.

  13. Precipitation-Snowmelt Timing and Snowmelt Augmentation of Large Peak Flow Events, Western Cascades, Oregon

    NASA Astrophysics Data System (ADS)

    Jennings, K. S.; Jones, J. A.

    2014-12-01

    Extreme rain-on-snow floods are known to result from snowmelt coincident with precipitation, but comparatively little is known about the relative timing of these factors within storm events. Cumulative net snowmelt (hourly, from a snowmelt lysimeter) was plotted against precipitation for 26 large storms (> 1-yr return period) over the period 1991-2012 in the transient snow zone of the H.J. Andrews Experimental Forest in the western Cascades of Oregon. The relative timing of precipitation and net snowmelt at the hourly time scale was assessed with wavelet coherence. Five precipitation-net snowmelt response categories were identified: flat; persistent melt; persistent snow accumulation; late melt; and late snow accumulation. Persistent melt events were characterized by increasing cumulative net snowmelt and precipitation and had the highest mean peak flow and water available for runoff. Both the persistent melt and persistent snow accumulation categories had large, contiguous regions of significant wavelet coherence at multiple temporal scales, but pulses of precipitation preceded pulses of snowmelt in the persistent melt events, whereas precipitation was absorbed by the snowpack in the persistent accumulation category. A dewpoint temperature consistently above 0.5°C, elevated wind speeds, and a high fraction of precipitation falling as rain in the persistent melt category facilitated rapid snowmelt rates. During the two extreme rain-on-snow events in the sample, snowmelt was significantly synchronized with precipitation at 1-h to 64-h time scales throughout the 10-day event duration. Event categorization and analysis of wavelet coherence between precipitation and snowmelt can help predict peak discharge magnitude.

  14. Respiratory symptoms and peak expiratory flow rates among furniture-decoration students.

    PubMed

    Arbak, Peri; Bilgin, Cahit; Balbay, Oner; Yeşildal, Nuray; Annakkaya, Ali Nihat; Ulger, Füsun

    2004-01-01

    This study was designed to evaluate the effects of furniture production, mainly including fir tree (aberia mulleriana), on respiratory health of young workers and to compare the results with those obtained from previous studies. Sixty-four furniture-decoration students (57 males and 7 females) and 62 controls (54 male, 8 female) from different departments in the same school were included into the study. All participants were assessed with a questionnaire (concerning history of occupational exposure, work-related respiratory and other symptoms, smoking history, previous asthma history), full physical examination, spirometric evaluation and chest radiograph. Participants then performed serial monitoring of peak expiratory flow rates (PEFR) at work and away from work within a month. Mean age of students was 20.9 +/- 3.7 years, 20.5 +/- 2.6 years in controls. There was no difference between study and control groups with regard to age, gender, smoking status and previous asthma history. Reported cough (23.4 % vs. 8.1 %) and shortness of breath (18.8 % vs. 6.5 %) were significantly higher in furniture-decoration students than in controls (p = 0.016 and p = 0.034, respectively). Furniture-decoration students had higher conjunctivitis (34.4 % vs. 9.7 %, p = 0.001) and rhinitis (34.4 % vs. 19.4 %, p = 0.044) history when compared with controls. Both students and controls were normal in terms of respiratory examination. PEF recordings were performed for approximately one month. Diurnal variability greater than 20 % was seen in 12/64 (18.7 %) of students at work, whereas it was detected in 4/62 (6.4 %) of controls (p = 0.034). When comparing for the presence of diurnal variability greater than 20 % in weekends, no difference was found between groups (p = 0.457). In conclusion, early detection of work-related respiratory changes by serial monitoring of peak expiratory flows should save the workers from hazardous respiratory effects of the furniture production, especially in

  15. Mean annual runoff and peak flow estimates based on channel geometry of streams in northeastern and western Montana

    USGS Publications Warehouse

    Parrett, Charles; Omang, R.J.; Hull, J.A.

    1983-01-01

    Equations for estimating mean annual runoff and peak discharge from measurements of channel geometry were developed for western and northeastern Montana. The study area was divided into two regions for the mean annual runoff analysis, and separate multiple-regression equations were developed for each region. The active-channel width was determined to be the most important independent variable in each region. The standard error of estimate for the estimating equation using active-channel width was 61 percent in the Northeast Region and 38 percent in the West region. The study area was divided into six regions for the peak discharge analysis, and multiple regression equations relating channel geometry and basin characteristics to peak discharges having recurrence intervals of 2, 5, 10, 25, 50 and 100 years were developed for each region. The standard errors of estimate for the regression equations using only channel width as an independent variable ranged from 35 to 105 percent. The standard errors improved in four regions as basin characteristics were added to the estimating equations. (USGS)

  16. RNICO: a new simple geometric index for assessing the impact of urban development pattern on peak flows in urban catchments

    NASA Astrophysics Data System (ADS)

    Kasaee Roodsari, B.; Chandler, D. G.

    2016-12-01

    Urban sprawl is widespread across the world and the associated hydrologic impacts are increasing in peri-urban catchments due to increased area of impervious. There is a strong agreement on the positive correlation between the fractional impervious area and peak flows in urban catchments. Nevertheless, the effect of land development pattern on peak flows is not well investigated. In this study, a new simple geometric index, Relative Nearness of Imperviousness to the Catchment Outlet (RNICO), is defined to correlate imperviousness distribution of peri-urban catchments to runoff peak flows. Results of applying RNICO to 20 sub-catchments in New York State showed a strong positive correlation (R2>0.97) between RNICO and runoff peak flows for small peri-urban catchments (A< 42 km2) indicating higher flood risk of downstream urbanization. For large catchments (A> 42 km2), no correlation was indicated between RNICO and peak flows. We highlight the necessity of a greater discharge monitoring network at small peri-urban catchments to support local urban flood forecast.

  17. Effect of swimming on peak expiratory flow rate of atopic children.

    PubMed

    Bemanian, Mohammad Hassan; Shirkhoda, Shima; Nakhjavani, Mina; Mozafari, Habibeh

    2009-06-01

    This study was conducted to evaluate the role of swimming on mechanic of lung in healthy individual and patients with asthma. A total 76 girls who took part in the course of regular swimming session three day per week for eight weeks enrolled in this study. All of them completed ISAAC written questionnaire and individual who was suspected of asthma or other atopic diseases was referred to allergist for more evaluation. Peak expiratory flow rate was recorded for participants at beginning, one hour after swimming and two months later. According to ISAAC questionnaire 35.4% had asthma or other atopic diseases. Increase in PEFR more than 20% of personal best was seen in 21.9% after one hour swimming and in 27.6% after two months. Increase in PEFR was significant in healthy individual and asthmatic patients and obese but was not significant in patients with allergic rhinitis or eczema. This study suggests swimming in indoor pool is useful for patients with asthma in spite of potential toxic role of chlorine in exacerbation of asthma symptoms and lung mechanics.

  18. Diurnal variation in peak expiratory flow rate among polyvinylchloride compounding workers.

    PubMed Central

    Lee, H S; Ng, T P; Ng, Y L; Phoon, W H

    1991-01-01

    The diurnal variation in peak expiratory flow rate (PEFR) was studied in 24 mixers and 24 non-mixers in three polyvinylchloride (PVC) compounding plants and 24 non-PVC controls from a marine police workshop. The three groups (all men) were matched for age, race, and smoking. The mean respirable dust concentration (essentially PVC dust) was 1.6 mg/m3 for mixers and 0.4 mg/m3 for nonmixers. The mean diurnal variation in PEFR of the mixers was 6.5%. This was significantly higher than the 4.8% for non-mixers and 4.3% for the non-PVC controls. Six mixers had a diurnal variation of more than 15% on at least one day compared with none among the other two groups. Twenty nine per cent of mixers complained of wheezing compared with 4% of non-mixers and none among non-PVC workers. These differences were significant. Forced expiratory volume in one second (FEV1) for the mixers was 10% below the predicted values whereas that of non-PVC workers was 2% below predicted values. The study indicates a significant acute airway constriction from occupational exposure to PVC dust. PMID:2025595

  19. The longitudinal relationship of work stress with peak expiratory flow: a cohort study.

    PubMed

    Loerbroks, Adrian; Karrasch, Stefan; Lunau, Thorsten

    2017-05-29

    Research has suggested that psychological stress is associated with reduced lung function and with the development of respiratory disease. Among the major potential sources of stress in adulthood are working conditions. We aimed to examine the relationship of work stress with lung function. We drew on 4-year prospective data from the Survey of Health, Ageing and Retirement in Europe. The analyzed sample comprised 2627 workers aged 50 years or older who were anamnestically free of respiratory disease. Work stress at baseline was operationalized by abbreviated instruments measuring the well-established effort-reward imbalance model (seven items) and the control component of the job-demand control (two items). Peak expiratory flow (PEF) was determined at baseline and at follow-up. Continuous and categorized (i.e., by the tertile) work stress variables were employed in multivariable linear regression models to predict PEF change. Work stress did not show statistically significant associations with PEF change. For instance, the unstandardized regression coefficient for PEF decline according to high versus low effort-reward imbalance was -1.41 (95% confidence interval = -3.75, 0.94). Our study is the first to examine prospective relationships between work stress and PEF. Overall, we did not observe meaningful associations. Future studies should consider a broader spectrum of spirometric parameters and should expand research to younger and possibly less-selected working populations (i.e., aged <50 years).

  20. Respiratory symptoms and peak expiratory flow in survivors of the Nyos disaster.

    PubMed

    Afane Ze, E; Roche, N; Atchou, G; Carteret, P; Huchon, G J

    1996-11-01

    In August 1986, gases from the Nyos volcanic lake killed 1,746 persons in northwestern Cameroun, but 1,500 others living in the affected area survived. Gas emanations contained carbon dioxide, sulfur dioxide, and hydrogen sulfide. The objective of this study was to evaluate the delayed respiratory consequences of the inhalation of such volcanic gases. Two groups of subjects living in the same area, exposed (Nyos group; n = 381) or not exposed (control group; n = 128) to Nyos gases, were evaluated with a short questionnaire and by measurement of peak expiratory flow (PEF, percent predicted) in March 1991. Eleven percent of the subjects smoked, more often men than women (23% vs 4%; p < 0.001). In the whole population (exposed and unexposed), smoking was associated with a 3.6-fold increase in the frequency of cough (p < 0.001) and with a 6-fold increase in the frequency of sputum production (p < 0.005), but not with a decrease in PEF. There was no difference in the frequency of dyspnea, cough, sputum production, and PEF between Nyos and control groups. We conclude that 55 months after the emanation of gases from Nyos volcanic lake, there was no difference in respiratory symptoms, and PEF between survivors who inhaled volcanic gases and control subjects, whereas smoking was associated with cough and sputum production.

  1. Evaluation of home-monitoring of asthmatic children with the mini-Wright peak flow meter.

    PubMed

    Battu, K; Collins-Williams, C; Zaleskey, C

    1982-01-01

    The amount of medication required to control asthmatic wheezing varies from patient to patient. While the amount required can be assessed clinically from history and physical examination, an objective measurement to assess the patient's requirements is highly desirable. For this purpose the mini-Wright peak flow meter was used. The patient was shown in the office how to use the meter and then sent home to use the meter three times daily for 2 weeks and record each reading on the chart provided. After 2 weeks the chart and meter were mailed to the office where the patient's readings were compared with normal values. Then the patient's medications could be adjusted if necessary. A study of 55 patients showed that this is a very valuable method to assist the practicing physician in prescribing sufficient medication for adequate control, particularly in those patients who minimize their symptoms, either intentionally or unintentionally, so that the physician cannot make an adequate judgment. It was also very useful for convincing the parents or patients that continuous medication is necessary in many cases where they felt PRN medication to be sufficient. The use of this instrument should become a routine part of the management of all difficult asthmatic patients.

  2. Relationship of non-specific airway hyperresponsiveness (AHR) to measures of peak expiratory flow (PEF) variability.

    PubMed

    Kolbe, J; Richards, G; Mercer-Fenwick, J; Rea, H

    1996-02-01

    The relationship between airway hyper-responsiveness (AHR) and clinical asthma remains controversial and unclear. To test the hypothesis that serial measures of variability of peak expiratory flow rate (PEF) correlate with serial measures of AHR, and to determine which mathematical expression of variability provides the best correlation. A longitudinal study over 180 days of 20 atopic, moderately severe asthmatics was undertaken. A diary of medication use and morning and evening PEFR before and after beta agonist was kept and AHR (PD20 histamine) was measured at three-weekly intervals. Using group data (128 sets) in PD20 was correlated with various measures of PEF variability over 9 days. [Table: see text] Within the group there was a weak but highly statistically significant correlation between AHR and measures of PEF variability--the strongest correlation being with mean morning PEF. Within individual subjects, however, the correlation was not a consistent finding and only four patients had a statistically significant relationship (p < 0.05) between AHR and mean morning PEF. These results suggest that while PEF variability may reflect AHR for the purposes of epidemiologic studies, it is unlikely to be useful as a simple 'non-invasive' means of assessing AHR in individual patients. More complex measures of PEF variability do not have an advantage over simpler measures such as mean morning PEF.

  3. Silica Exposure and Effect on Peak Expiratory Flow: Slate Pencil Workers' Study.

    PubMed

    Tiwari, Rajnarayan Ramshankar

    2016-12-01

    Peak expiratory flow (PEF) is a spirometric test that detects obstructive changes in the respiratory tract; has good correlation with the FEV1; and is much less expensive, simpler, and easier to perform under field conditions than FEV1. Chronic silicosis is also known to have obstructive features in advanced stages. Thus, this study was performed to assess the effect of silica exposure on PEF and the factors related to it. The present study was carried out among 193 slate pencil cutting workers of Multanpura village of Madhya Pradesh, India. An interview technique was used to record demographic characteristics and occupational history on a predesigned form, which included a questionnaire regarding occupational history and silica-related respiratory morbidities. This was followed by a complete medical examination and measurement of PEF using a spirometer. The mean age was 43.35 ± 11.31 y, and the mean duration of exposure was 18.72 ± 9.33 y. In the present study, PEF was found to be significantly reduced in those age ≥40 y, those who were female, those having duration of exposure >10 y, and those having respiratory morbidity, whereas the reduction in PEF was statistically nonsignificant for smokers. Higher age, female sex, higher duration of exposure, and respiratory morbidity were found to be important correlates of PEF. Copyright © 2016 by Daedalus Enterprises.

  4. Can a normal peak expiratory flow exclude severe chronic obstructive pulmonary disease?

    PubMed Central

    Perez-Padilla, R.; Vollmer, W. M.; Vázquez-García, J. C.; Enright, P. L.; Menezes, A. M. B.; Buist, A. S.

    2011-01-01

    SUMMARY BACKGROUND Chronic obstructive pulmonary disease (COPD) is underdiagnosed. One barrier to diagnosis is the limited availability of spirometry testing, but in adults at risk for COPD, a normal pre-bronchodilator (pre-BD) peak expiratory flow (PEF) may rule out clinically significant COPD. OBJECTIVE To identify post-BD airway obstruction using data from 13 708 individuals aged ≥40 years from the PLATINO and BOLD studies. METHODS We evaluated different cut-off points of pre-BD. The PEF was obtained from a diagnostic-quality spirometer (not a mechanical PEF meter). At least one of the following COPD risk factors was present in 77% of the subjects: chronic respiratory symptoms; exposure to tobacco smoke, biomass smoke or dust in the workplace; or a previous diagnosis of asthma, COPD, emphysema or chronic bronchitis. RESULTS Although the positive predictive value was low as expected, a pre-BD PEF of ≥70% predicted effectively ruled out Stages III and IV COPD of the Global Initiative for Chronic Obstructive Lung Disease. Among those with at least one risk factor, only 12% would require confirmatory spirometry using this criterion. CONCLUSIONS Adding PEF measurement to a screening questionnaire may rule out severe to very severe COPD without the need for pre- and post-BD spirometry testing. Confirmation is needed from a study using inexpensive PEF meters or pocket spirometers with a staged screening protocol. PMID:19275802

  5. Effect of Cigarette and Cigar Smoking on Peak Expiratory Flow Rate

    PubMed Central

    Medabala, Tambi; B.N., Rao; Mohesh M.I., Glad; Kumar M., Praveen

    2013-01-01

    Background: Tobacco smoking in India has been increasing alarmingly. Smoking is a known risk factor for chronic obstructive pulmonary disease (COPD), cardiovascular diseases and certain cancers, especially, the lung cancer. The percentage prevalence of cigarette smoking (18.5%) and cigar smoking (4%) in males is high in Andhra Pradesh compared to other southern states. There is not enough scientific literature to correlate about intensity of cigarette and cigar smoking and their impact on lung function though high prevalence is reported in Andhra Pradesh, India. Objectives: The purpose of this study was to examine whether PEFR differs between cigarette and cigar smokers compared to non-smokers and also to estimate the intensity of cigarette and cigar smoking on PEFR. Methods: PEFR was recorded in cigarette smokers (n=49) and cigar smokers (n=10) as well as in non-smokers (n=64) using Wright’s mini Peak Flow Meter. Results: PEFR is decreased in both cigarette as well in cigar smokers compared to non-smokers and the magnitude of decline was higher in cigar smoking elderly individuals. Conclusion: The intensity of cigarette and cigar smoking (pack-years) emerged as the main variable to influence airway obstruction in smokers that caused greater reduction in PEFR. PMID:24179889

  6. [Comparison of Different Mechanical Insufflator-Exsufflator Systems by Measurement of the Peak Exspiratory Flow (PEF)].

    PubMed

    Schütz, Ansgar; Wagner, Janine; Conrad, Anne; Funke, Andreas

    2017-03-01

    Background The management of pulmonary secretion in patients with respiratory muscle weakness using mechanical insufflator-exsufflator systems (MIE) is an established treatment option. There are significant differences in the efficiency of different devices in practical use. The intention of this study was to evaluate the peak exspiratory flow (PEF) values of different devices with and without use of equipment. Methods PEFs of ten MIE were investigated in vitro using different equipment. Results The efficiency of the devices showed significant differences. The use of two bacterial filters showed a significant reduction of 13 % compared to one filter, the use of a catheter mount revealed a significant reduction of 10 %, with an elbow connector additionally 15 %. With a commonly used equipment (1800 mm tube, one filter, catheter tube with elbow) there was a difference of 58 % between the devices Nippy (2,86 l/s) and Pulsar (1,2 l/s). Conclusion There are significant differences in PEF of different MIE and use of different equipment. That could be of therapeutic relevance. Further studies are needed to investigate the clinical relevance of these findings. Recommendations for the use of devices and equipment are necessary to ensure the efficacy of the elimination of pulmonary mucus.

  7. Development of flood regressions and climate change scenarios to explore estimates of future peak flows

    USGS Publications Warehouse

    Burns, Douglas A.; Smith, Martyn J.; Freehafer, Douglas A.

    2015-12-31

    The application uses predictions of future annual precipitation from five climate models and two future greenhouse gas emissions scenarios and provides results that are averaged over three future periods—2025 to 2049, 2050 to 2074, and 2075 to 2099. Results are presented in ensemble form as the mean, median, maximum, and minimum values among the five climate models for each greenhouse gas emissions scenario and period. These predictions of future annual precipitation are substituted into either the precipitation variable or a water balance equation for runoff to calculate potential future peak flows. This application is intended to be used only as an exploratory tool because (1) the regression equations on which the application is based have not been adequately tested outside the range of the current climate and (2) forecasting future precipitation with climate models and downscaling these results to a fine spatial resolution have a high degree of uncertainty. This report includes a discussion of the assumptions, uncertainties, and appropriate use of this exploratory application.

  8. Colloquium: 100 years of mass spectrometry: Perspectives and future trends

    NASA Astrophysics Data System (ADS)

    Maher, Simon; Jjunju, Fred P. M.; Taylor, Stephen

    2015-01-01

    Mass spectrometry (MS) is widely regarded as the most sensitive and specific general purpose analytical technique. More than a century has passed for MS since the ground-breaking work of Nobel laureate Sir Joseph John Thomson in 1913. This Colloquium aims to (1) give an historical overview of the major instrumentation achievements that have driven mass spectrometry forward in the past century, including those leading up to the initial work of Thomson, (2) provide the nonspecialist with an introduction to MS, and (3) highlight some key applications of MS and explore the current and future trends. Because of the vastness of the subject area and quality of the manifold research efforts that have been undertaken over the last 100 years, which have contributed to the foundations and subsequent advances in mass spectrometry, it should be understood that not all of the key contributions may have been included in this Colloquium. Mass spectrometry has embraced a multitude of scientific disciplines and to recognize all of the achievements is an impossible task, such has been the diverse impact of this invaluable technique. Scientific progress is usually made via the cumulative effort of a large number of researchers; the achievements reported herein are only a representation of that effort.

  9. Slope restoration for a 100-year old canal

    SciTech Connect

    Skaggs, R.L.; Lewis, S.W.; Liebersbach, D.C.

    1995-12-31

    Turlock Irrigation District (TID) is located in the northern portion of the fertile San Joaquin Valley of California. TID`s primary water supply is conveyed from the 100-year-old LaGrange Diversion Dam via their historic Upper Main Canal. The original canal was constructed by excavating into slate bedrock for the uphill (cut) bank, and constructing unmortared rock walls and rock fill for the downhill (fill) embankment; the excavation was then lined with concrete. Soil fill raises of the downhill embankment over the last 30 years have reduced the slope stability to unacceptable levels in the steepest embankment areas. In March of 1994, two surficial slides prompted investigation of the long term embankment stability in the Warehouse Slide Area. Based on results of analysis for various stabilization scenarios, TID chose a stabilization method which included: (1) excavation of an access bench below the existing canal, (2) installation of steel pipe piles through the existing rock fill and into the bedrock, (3) construction of a mechanically stabilized earth (MSE) retaining wall and (4) construction of a soil-cement canal roadway pavement. The design was chosen by the owner because of cost competitiveness compared to other design alternatives and because the construction sequence allowed uninterrupted use of the canal. By using local river cobble for the MSE wall facing material, TID met the desired 50-year design life of the repair while maintaining the area`s historic visual features.

  10. [Rudolf Virchow's influence on medicine after 100 years].

    PubMed

    Dhom, G

    2003-02-01

    100 years after Rudolf Virchow's death, we find it necessary to demonstrate the mark his work has left on present day medicine. Curt Froboese wrote 50 years ago: "To come to know Rudolf Virchow well, it is sufficient to read him". Therefore the present collection of literal quotations from Virchow tries to show how valid many statements of Virchow still are. His definition of "health" precedes the well-known formulation of the World Health Organization. Virchow had a presentiment of molecular pathology, without defining this word, when he ascribed molecular forces to the cell and particularly to the cellular nucleus. As a terminologist he played a guiding role. His linguistic sense enabled him to prematurely find out "barbarisms" in medical terminology. At the same time, he also supported an international understanding. In particular the surgeons came to know through Virchow that malignant tumors are also primarily local events to be surgically treated preferably in the early stage. Therefore he requested a population-based statistical survey as developed by the cancer registries today. The legend that Virchow fought against bacteriology is not true. He did not stop in his efforts to differentiate between etiology, germs and the course of infection which presupposes knowledge of the respective cellular phenomena. Summing up it can be said that Virchow still plays an important role in our medical world.

  11. Overuse syndrome in musicians--100 years ago. An historical review.

    PubMed

    Fry, H J

    Overuse syndrome in musicians was extensively reported 100 years ago. The clinical features and results of treatment, which were recorded in considerable detail, match well the condition that is described today. The medical literature that is reviewed here extends from 1830 to 1911 and includes 21 books and 54 articles from the English language literature, apart from two exceptions; however, the writers of the day themselves reviewed French, German and Italian literature on the subject. The disorder was said to result from the overuse of the affected parts. Two theories of aetiology, not necessarily mutually exclusive, were argued. The central theory regarded the lesion as being in the central nervous system, the peripheral theory implied a primary muscle disorder. No serious case was put forward for a psychogenic origin, though emotional factors were believed to aggravate the condition. Advances in musical instrument manufacture--particularly the development of the concert piano and the clarinet--may have played a part in the prevalence of overuse syndrome in musicians. Total rest from the mechanical use of the hand was the only effective treatment recorded.

  12. The history of atrial fibrillation: the last 100 years.

    PubMed

    Prystowsky, Eric N

    2008-06-01

    Atrial fibrillation (AF) has had a rich history that has touched the careers of many of the great clinicians and investigators of the 20th century. More recently, there has been an explosion of research into various aspects of the mechanisms and therapy for AF, as evidenced by over 8,000 publications on AF from 2000 to 2007. A century of research and clinical observations, coupled with modern investigative technologies, has enabled modern investigators to have their own "fantastic voyage" as they travel beyond the cell borders into the ionic mechanisms responsible for AF and its many atrial perturbations. One can only imagine the satisfaction of Wenckebach, MacKenzie, and Lewis if they could see how their seeds of wisdom have grown into such sturdy ideas, or how delighted Scherf would be to learn that his ectopic focus theory for AF has been given new life. This paper on 100 years of AF was initially prepared for presentation as the Plenary Lecture at the AFib Summit for Heart Rhythm 2007 in Denver, Colorado. I have tried to provide the reader with some of the most important observations on AF, realizing that it would be impossible to include all or even most of the major research done during this time frame. I apologize to my many colleagues whose research has helped us to understand better the clinical and basic aspects of AF, yet who could not be cited for lack of space.

  13. [Sheehan's syndrome--a forgotten disease with 100 years' history].

    PubMed

    Krysiak, Robert; Okopień, Bogusław

    2015-01-01

    Although named after Harold Sheehan, postpartum ischemic pituitary necrosis was reported for the first time 100 years ago in Przeglad Lekarski by Leon Konrad Gliński. In the majority of cases, the syndrome is a consequence of severe postpartum bleeding episode resulting in severe hypotension or hemorrhagic shock. The frequency of Sheehan's syndrome has decreased in developed countries as a result of improved obstetrical care, but this clinical entity remains a common cause of hypopituitarism in developing countries. The syndrome is characterized by varying degrees of anterior pituitary dysfunction resulting from the deficiency of multiple pituitary hormones. The order of frequency of hormone loss has generally been found to be growth hormone and prolactin, gonadotropins, ACTH and thyrotropin. Women with Sheehan's syndrome exhibit a variety of signs and symptoms including failure to lactate or resume menses, loss of genital and axillary hair, and often occurring long after delivery clinical manifestations of central hypothyroidism and secondary adrenal insufficiency. Diagnosis is based on laboratory studies, including hormone levels and hormone stimulation tests. Treatment of Sheehan's syndrome involves hormone replacement therapy. The aim of this study is to review current knowledge on clinically relevant aspects of this clinical entity and to provide the reader with recommendations concerning its diagnosis and treatment.

  14. Peak flow responses to landscape disturbances caused by the cataclysmic 1980 eruption of Mount St. Helens, Washington

    USGS Publications Warehouse

    Major, Jon J.; Mark, Linda E.

    2006-01-01

    Years of discharge measurements that precede and follow the cataclysmic 1980 eruption of Mount St. Helens, Washington, provide an exceptional opportunity to examine the responses of peak flows to abrupt, widespread, devastating landscape disturbance. Multiple basins surrounding Mount St. Helens (300–1300 km2 drainage areas) were variously disturbed by: (1) a debris avalanche that buried 60 km2 of valley; (2) a lateral volcanic blast and associated pyroclastic flow that destroyed 550 km2 of mature forest and blanketed the landscape with silt-capped lithic tephra; (3) debris flows that reamed riparian corridors and deposited tens to hundreds of centimeters of gravelly sand on valley floors; and (4) a Plinian tephra fall that blanketed areas proximal to the volcano with up to tens of centimeters of pumiceous silt, sand, and gravel. The spatially complex disturbances produced a variety of potentially compensating effects that interacted with and influenced hydrological responses. Changes to water transfer on hillslopes and to flow storage and routing along channels both enhanced and retarded runoff. Rapid post-eruption modifications of hillslope surface textures, adjustments of channel networks, and vegetation recovery, in conjunction with the complex nature of the eruptive impacts and strong seasonal variability in regional climate hindered a consistent or persistent shift in peak discharges. Overall, we detected a short-lived (5–10 yr) increase in the magnitudes of autumn and winter peak flows. In general, peak flows were larger, and moderate to large flows (>Q2 yr) were more substantively affected than predicted by early modeling efforts. Proportional increases in the magnitudes of both small and large flows in basins subject to severe channel disturbances, but not in basins subject solely to hillslope disturbances, suggest that eruption-induced modifications to flow efficiency along alluvial channels that have very mobile beds differentially affected flows of

  15. Global change and water resources in the next 100 years

    NASA Astrophysics Data System (ADS)

    Larsen, M. C.; Hirsch, R. M.

    2010-03-01

    We are in the midst of a continental-scale, multi-year experiment in the United States, in which we have not defined our testable hypotheses or set the duration and scope of the experiment, which poses major water-resources challenges for the 21st century. What are we doing? We are expanding population at three times the national growth rate in our most water-scarce region, the southwestern United States, where water stress is already great and modeling predicts decreased streamflow by the middle of this century. We are expanding irrigated agriculture from the west into the east, particularly to the southeastern states, where increased competition for ground and surface water has urban, agricultural, and environmental interests at odds, and increasingly, in court. We are expanding our consumption of pharmaceutical and personal care products to historic high levels and disposing them in surface and groundwater, through sewage treatment plants and individual septic systems. These substances are now detectable at very low concentrations and we have documented significant effects on aquatic species, particularly on fish reproduction function. We don’t yet know what effects on human health may emerge, nor do we know if we need to make large investments in water treatment systems, which were not designed to remove these substances. These are a few examples of our national-scale experiment. In addition to these water resources challenges, over which we have some control, climate change models indicate that precipitation and streamflow patterns will change in coming decades, with western mid-latitude North America generally drier. We have already documented trends in more rain and less snow in western mountains. This has large implications for water supply and storage, and groundwater recharge. We have documented earlier snowmelt peak spring runoff in northeastern and northwestern States, and western montane regions. Peak runoff is now about two weeks earlier than it was

  16. Peak flow regression equations For small, ungaged streams in Maine: Comparing map-based to field-based variables

    USGS Publications Warehouse

    Lombard, Pamela J.; Hodgkins, Glenn A.

    2015-01-01

    Regression equations to estimate peak streamflows with 1- to 500-year recurrence intervals (annual exceedance probabilities from 99 to 0.2 percent, respectively) were developed for small, ungaged streams in Maine. Equations presented here are the best available equations for estimating peak flows at ungaged basins in Maine with drainage areas from 0.3 to 12 square miles (mi2). Previously developed equations continue to be the best available equations for estimating peak flows for basin areas greater than 12 mi2. New equations presented here are based on streamflow records at 40 U.S. Geological Survey streamgages with a minimum of 10 years of recorded peak flows between 1963 and 2012. Ordinary least-squares regression techniques were used to determine the best explanatory variables for the regression equations. Traditional map-based explanatory variables were compared to variables requiring field measurements. Two field-based variables—culvert rust lines and bankfull channel widths—either were not commonly found or did not explain enough of the variability in the peak flows to warrant inclusion in the equations. The best explanatory variables were drainage area and percent basin wetlands; values for these variables were determined with a geographic information system. Generalized least-squares regression was used with these two variables to determine the equation coefficients and estimates of accuracy for the final equations.

  17. Methods for estimating peak-flow frequencies at ungaged sites in Montana based on data through water year 2011: Chapter F in Montana StreamStats

    USGS Publications Warehouse

    Sando, Roy; Sando, Steven K.; McCarthy, Peter M.; Dutton, DeAnn M.

    2016-04-05

    This report chapter also presents other methods for estimating peak-flow frequencies at ungaged sites. Two methods for estimating peak-flow frequencies at ungaged sites located on the same streams as streamflow-gaging stations are described. Additionally, envelope curves relating maximum recorded annual peak flows to contributing drainage area for each of the eight hydrologic regions in Montana are presented and compared to a national envelope curve. In addition to providing general information on characteristics of large peak flows, the regional envelope curves can be used to assess the reasonableness of peak-flow frequency estimates determined using the regression equations.

  18. Framing 100-year overflowing and overtopping marine submersion hazard resulting from the propagation of 100-year joint hydrodynamic conditions

    NASA Astrophysics Data System (ADS)

    Nicolae Lerma, A.; Bulteau, T.; Elineau, S.; Paris, F.; Pedreros, R.

    2016-12-01

    Marine submersion is an increasing concern for coastal cities as urban development reinforces their vulnerabilities while climate change is likely to foster the frequency and magnitude of submersions. Characterising the coastal flooding hazard is therefore of paramount importance to ensure the security of people living in such places and for coastal planning. A hazard is commonly defined as an adverse phenomenon, often represented by a magnitude of a variable of interest (e.g. flooded area), hereafter called response variable, associated with a probability of exceedance or, alternatively, a return period. Characterising the coastal flooding hazard consists in finding the correspondence between the magnitude and the return period. The difficulty lies in the fact that the assessment is usually performed using physical numerical models taking as inputs scenarios composed by multiple forcing conditions that are most of the time interdependent. Indeed, a time series of the response variable is usually not available so we have to deal instead with time series of forcing variables (e.g. water level, waves). Thus, the problem is twofold: on the one hand, the definition of scenarios is a multivariate matter; on the other hand, it is tricky and approximate to associate the resulting response, being the output of the physical numerical model, to the return period defined for the scenarios. In this study, we illustrate the problem on the district of Leucate, located in the French Mediterranean coast. A multivariate extreme value analysis of waves and water levels is performed offshore using a conditional extreme model, then two different methods are used to define and select 100-year scenarios of forcing variables: one based on joint exceedance probability contours, a method classically used in coastal risks studies, the other based on environmental contours, which are commonly used in the field of structure design engineering. We show that these two methods enable one to

  19. [100 years of Hashimoto thyroiditis, still an intriguing disease].

    PubMed

    Baretić, Maja

    2011-12-01

    In 1912 Japanese physician Hashimoto Hakaru described 4 patients with chronic thyroid disease. The histopathology findings exactly 100 years ago described lymphocyte infiltration, fibrosis, parenchymal atrophy and eosinophilic changes of some acinar cells. Those findings are typical for the autoimmune thyroid disease named by the author Hashimoto thyroiditis or lymphocytic thyroiditis. Hashimoto thyroiditis: The pathophysiology of thyroid autoimmunity during the past decades was described in details. Many thyroid antigens were identified (thyroid - stimulating hormone or TSH, thyroglobulin, thyreoperoxidase) and antibodies are directed towards them. Thyreocyte is also able to function as antigen presenting cell. It presents antigen on its surface and expresses MHC class II and class I molecules. Etiology of autoimmune thyroiditis combines genetic and environmental factors. Genetic factors dominate, and influence with about 80% on the occurrence of immunity. Some HLA genes (HLA-DR3, HLA-DR4, HLA-DR5 and HLA-DQA) and some non-HLA genes (cytotoxic T-lymphocyte antigen 4 -CTLA-4, CD40 gene, gene for protein tyrosine phosphatase 22 -PTPN22, thyroglobulin and TSH gene) are involved. 20% of etiology is attributed to environmental factors (smoking, iodine intake, selenium deficiency, pollution, infectious conditions, physical and emotional stress) and physiological states (puberty, rapid growth, pregnancy, menopause, aging, female gender). Although Hashimoto thyroiditis is known for many years, it is still sometimes presented with surprisingly diverse clinical entities and frequently astonishes many physicians. A case of a female patient with long-standing hypothesis (fine needle aspiration showed lymphocytic infiltration, thyreoperoxidase antibodies were positive) is presented. During the postpartum period, complicated with septic endometritis a new onset of hyperthyreosis appeared. The etiology of hyperthyroidism was unclear, with three possible explanations. The first

  20. Geomorphic response of rivers to glacial retreat and increasing peak flows downstream from Mount Rainier, Washington

    NASA Astrophysics Data System (ADS)

    Czuba, J. A.; Barnas, C. R.; Magirl, C. S.; Voss, F. D.

    2010-12-01

    On Mount Rainier, Washington, the National Park Service has documented widespread aggradation of as much as 10 m since the early 20th century, of rivers draining the glaciated stratovolcano. This rapid sedimentation appears to be related to glacial retreat and also may be a function of the increased magnitude and timing of peak flows that mobilize and transport sediment. We are conducting an assessment of the Puget Lowland rivers that drain Mount Rainier, 25-100 km downstream from the park boundary, to document the geomorphic response of the downstream reaches given the widespread aggradation upstream. These downstream reaches provide critical aquatic habitat for spawning and rearing of several species of salmonids, including endangered Chinook salmon and steelhead. Fluvial sedimentation can have both deleterious and beneficial effects on aquatic habitat depending on sediment particle size, river slope and width, and river management. To date, our work shows sedimentation of as much as 2 m between 1984 and 2009 in these lowland rivers. Aggradation rates that were calculated by comparing channel change at 156 cross sections, ranged between 4.8 and 9.1 cm/yr in reaches where rivers exit the mountain front and enter the lowland. Analysis of streamflow-gaging station data from throughout the watersheds draining Mount Rainier show rapid incision and aggradation, suggesting pulses of coarse-grained bedload may be moving down the mountainous rivers as kinetic waves. Preliminary results, however, seem to indicate that the rivers in the Puget Lowland have not yet experienced significant widespread sedimentation directly related to glacial retreat. Estimating the time of arrival of mobilized alluvium is a critical need for resource managers given the potential effects of sedimentation on river flood-conveyance capacity, fish habitat, and estuarine wetlands.

  1. Factors affecting peak expiratory flow variability and bronchial reactivity in a random population sample.

    PubMed Central

    Higgins, B. G.; Britton, J. R.; Chinn, S.; Lai, K. K.; Burney, P. G.; Tattersfield, A. E.

    1993-01-01

    BACKGROUND--Bronchial reactivity measurements are widely used in epidemiological studies to provide an objective marker of asthma. There are, however, several potential advantages of measuring peak expiratory flow (PEF) variability instead, particularly in large studies. PEF variability and bronchial reactivity were compared in a population sample to assess the relationships of the two measurements to factors known to be associated with airways disease, and to compare their response rates. METHODS--Subjects aged 18-65 were randomly selected from the electoral register of an administrative area in eastern England and randomised to attend either for a bronchial challenge test measuring the provocative dose of methacholine producing a 20% fall in FEV1 (PD20), or to measure PEF at two hourly intervals during waking hours for one week. Skin tests with common allergens were performed and a smoking history obtained. PEF variability was expressed as the amplitude % mean (highest - lowest x 100/mean). RESULTS--A total of 273 subjects (69%) collected a PEF meter but a completed record sheet was returned by only 247 (62%); this was still significantly more than the 202 subjects (54%) who attended for and successfully completed a challenge test. Amplitude % mean was higher in women than in men (9.7% v 8.5%). In multiple regression analysis amplitude % mean increased significantly with age, mean skin weal diameter, and with current smoking. The odds of having a PD20 below 24.5 mumol increased with mean skin weal diameter and were greater in current smokers. Neither age nor sex had a significant effect on bronchial reactivity but there were significant interactions between age and the effects of both smoking and atopy. CONCLUSIONS--The higher response rate associated with the use of PEF variability measurement, and the association with factors implicated in the pathogenesis of airways disease, suggest that PEF variability would be a useful measurement to employ in

  2. Fluctuation Analysis of Peak Expiratory Flow and Its Association with Treatment Failure in Asthma.

    PubMed

    Kaminsky, David A; Wang, Lucy L; Bates, Jason H T; Thamrin, Cindy; Shade, David M; Dixon, Anne E; Wise, Robert A; Peters, Stephen; Irvin, Charles G

    2017-04-15

    Temporal fluctuations have been demonstrated in lung function and asthma control, but the effect of controller therapy on these fluctuations is unknown. To determine if fluctuations in peak expiratory flow (PEF) are predictive of subsequent treatment failure and may be modified by controller therapy. We applied detrended fluctuation analysis to once-daily PEF data from 493 participants in the LOCCS (Leukotriene Modifier Corticosteroid or Corticosteroid-Salmeterol) trial of the American Lung Association Airways Clinical Research Centers. We evaluated the coefficient of variation of PEF (CVpef) and the scaling exponent α, reflecting self-similarity of PEF, in relation to treatment failure from the run-in period of open-label inhaled fluticasone, and the treatment periods for subjects randomized to (1) continued twice daily fluticasone (F), (2) once daily fluticasone plus salmeterol (F + S), or (3) once daily oral montelukast (M). The CVpef was higher in those with treatment failure in the F and F + S groups in the run-in phase, and all three groups in the treatment phase. α was similar between those with and without treatment failure in all three groups during the run-in phase but was higher among those with treatment failure in the F and F + S groups during the treatment phase. Participants in all three groups showed variable patterns of change in α leading up to treatment failure. We conclude that increased temporal self-similarity (α) of more variable lung function (CVpef) is associated with treatment failure, but the pattern of change in self-similarity leading up to treatment failure is variable across individuals.

  3. Daily changes of peak expiratory flow and respiratory symptom occurrence around a soy processing factory.

    PubMed

    Heederik, Dick; Doekes, Gert; van Strien, Rob; Brunekreef, Bert

    2014-01-01

    To evaluate sensitization and acute respiratory health effects in inhabitants living in the vicinity of a factory producing soy oil. Two panels of potential responders were created on the basis of a response to a short screening questionnaire sent to random samples of 1,000 exposed and 1,000 non-exposed individuals living around the factory and a control area. Individuals responding to the questionnaire were invited for a medical evaluation, including a respiratory symptom questionnaire and skin prick testing, for a panel of common allergens and a soy allergen extract. This resulted in 53 atopic and/or asthmatic inhabitants from the area surrounding the factory and 30 comparable control subjects. In these subjects, morning and evening Peak Expiratory Flow (PEF), respiratory symptoms and medication use were recorded daily during a 10-week period in the autumn. At the same time, soy allergen and endotoxin concentrations were determined in airborne dust in the exposed and the control area. The wind direction relative to the location of a subjects' house and the factory was used to determine whether an individual was exposed on a particular day. Only few of the atopic subjects were sensitized to soy. PEF showed a decrease, respiratory symptoms and bronchodilator use, an increase among soy sensitized subjects after having been downwind from the factory. Airborne soy allergen was found more frequently in the area surrounding the factory and levels were higher than in the control area. Highest levels were found on the factory premises. Only a weak association was found with wind direction. Airborne endotoxin concentrations did not show a consistent pattern with distance, but levels were clearly higher on the factory premises. Sensitization to soy allergen was not increased among the population sample living in the vicinity of the factory. Soy sensitized individuals living in the surroundings of the factory reported more respiratory symptoms, used bronchodilators more

  4. Peak expiratory flow rates among women exposed to different cooking fuels in rural India.

    PubMed

    Neelam, Sukhsohale D; Uday, Narlawar W; Sushama, Thakre S; Suresh, Ughade N

    2013-09-01

    Plant or animal based material burned for cooking or heating (biofuels) can cause indoor air pollution. We studied the effect of exposure to biofuel and other types of fuel smoke on peak expiratory flow rates (PEFR) among rural Indian women. We conducted a community based cross-sectional study of 760 non-smoking women who cooked using one of four types of fuel: biofuel, kerosene, liquefied petroleum gas (LPG) or a combination of two or more fuels. A PEFR <80% of predicted was considered abnormal. An abnormal PEFR was seen in 43.3% of women using biofuels, 20.5% of those using kerosene, 23.4% of those using LPG and 21.4% of those using mixed fuel. Multivariate logistic regression analysis showed among those using mixed fuel, age [OR: - 2.08, 95% confidence interval (CI): 1.32 - 3.28, p = 0.00], height (OR: -1.06, 95% CI: 1.00 - 1.12, p = 0.02) and exposure index (estimated hours spent cooking daily multiplied by the years cooked) (OR: -2.74, 95% CI: 1.68 - 4.47, p = 0.00) were significant predictors of abnormal PEFR. Among women using biofuels and LPG, only exposure index was found to be a significant predictor of abnormal PEFR (p<0.05). No significant association was found between abnormal PEFR and exposure index among women who used only kerosene for fuel (p>0.05). Using mixed fuel was found to be more likely to cause an abnormal PEFR.

  5. The relationship between movement-evoked versus spontaneous pain and peak expiratory flow after abdominal hysterectomy.

    PubMed

    Gilron, Ian; Tod, Debbie; Goldstein, David H; Parlow, Joel L; Orr, Elizabeth

    2002-12-01

    The pathogenesis of postoperative lung dysfunction implies a role for movement-evoked pain (e.g., splinting/hypoventilation because of pain avoidance). However, interactions between evoked pain and respiratory physiology are poorly understood. Thus, we examined the relationship between evoked versus spontaneous pain and one index of pulmonary function. In 25 patients having undergone a hysterectomy, visual analog scale ratings (100 mm) for spontaneous pain (REST) and pain during sitting (SIT), forced expiration (BLOW), and coughing (COUGH) were measured together with peak expiratory flow (PEF) at eight time points during postoperative Days 1 and 2. Secondary outcome measures included oxygen saturation and oxygen requirements. Pain was significantly correlated with PEF for COUGH, SIT, BLOW, and REST at eight, seven, four, and two of the eight studied time points, respectively. Mean visual analog scale scores [SE] for COUGH (26.1 mm [1.7]) and SIT (21.5 mm [1.5]) were greater (P < 0.05) than REST (10.5 mm [0.8]), and COUGH was greater (P < 0.05) than BLOW (16.8 mm [1.3]). All pain measures diminished (P < 0.05), and PEF reductions improved (P < 0.05) across the study period. We hypothesize that the consistent negative correlation of COUGH-evoked pain with PEF is, in part, caused by avoidance of coughing, which ultimately limits deep inspiration, lung reexpansion, and clearance of secretions. Movement-evoked pain may be an important contributor to postoperative complications, but its mechanisms are poorly understood. This study provides the first evidence that postoperative evoked pain correlates with lung function and highlights the need for future research on mechanisms and implications of this phenomenon.

  6. Fascia Research Congress evidence from the 100 year perspective of Andrew Taylor Still.

    PubMed

    Findley, Thomas W; Shalwala, Mona

    2013-07-01

    More than 100 years ago A.T. Still MD founded osteopathic medicine, and specifically described fascia as a covering, with common origins of layers of the fascial system despite diverse names for individual parts. Fascia assists gliding and fluid flow and is highly innervated. Fascia is intimately involved with respiration and with nourishment of all cells of the body, including those of disease and cancer. This paper reviews information presented at the first three International Fascia Research Congresses in 2007, 2009 and 2012 from the perspective of Dr Still, that fascia is vital for organism's growth and support, and it is where disease is sown.

  7. Does harvest in west slope Douglas-fir increase peak flow in small forest streams?

    Treesearch

    Jack. Rothatcher

    1973-01-01

    Logging in Douglas-fir has only minor effect on major peak streamflows that occur when soils are thoroughly wet. Exceptions are the early fall storms following the dry summers characteristic of the west coast climate. At this time, peak streamflow from unlogged areas may be less than from the harvested area because the soil in the unlogged area is drier and has greater...

  8. Regional regression equations to estimate peak-flow frequency at sites in North Dakota using data through 2009

    USGS Publications Warehouse

    Williams-Sether, Tara

    2015-08-06

    Annual peak-flow frequency data from 231 U.S. Geological Survey streamflow-gaging stations in North Dakota and parts of Montana, South Dakota, and Minnesota, with 10 or more years of unregulated peak-flow record, were used to develop regional regression equations for exceedance probabilities of 0.5, 0.20, 0.10, 0.04, 0.02, 0.01, and 0.002 using generalized least-squares techniques. Updated peak-flow frequency estimates for 262 streamflow-gaging stations were developed using data through 2009 and log-Pearson Type III procedures outlined by the Hydrology Subcommittee of the Interagency Advisory Committee on Water Data. An average generalized skew coefficient was determined for three hydrologic zones in North Dakota. A StreamStats web application was developed to estimate basin characteristics for the regional regression equation analysis. Methods for estimating a weighted peak-flow frequency for gaged sites and ungaged sites are presented.

  9. Impact of Wet-Weather Peak Flow Blending on Disinfection and Treatment: A Case Study at Three Wastewater Treatment Plants

    EPA Science Inventory

    This research project was administered by the EPA Office of Research and Development and funded by Office of Water; Office of Policy, Economics and Innovation; and Office of R4search and Development. Blending is the practice of diverting apart of peak wet-weather flows at was...

  10. Impact of Wet-Weather Peak Flow Blending on Disinfection and Treatment: A Case Study at Three Wastewater Treatment Plants

    EPA Science Inventory

    This research project was administered by the EPA Office of Research and Development and funded by Office of Water; Office of Policy, Economics and Innovation; and Office of R4search and Development. Blending is the practice of diverting apart of peak wet-weather flows at was...

  11. Progress of Cometary Science in the Past 100 Years

    NASA Technical Reports Server (NTRS)

    Sekanina, Zdenek

    1999-01-01

    Enormous strides made by cometary science during the 20th century defy any meaningful comparison of its state 100 years ago and now. The great majority of the subfields enjoying much attention nowadays did not exist in the year 1900. Dramatic developments, especially in the past 30-50 years, have equally affected observational and theoretical studies of comets. The profound diversification of observing techniques has been documented by the ever widening limits on the electromagnetic spectrum covered. While the time around 1900 marked an early period of slow and painful experimentation with photographic methods in cometary studies, observations of comets from the x-ray region to the radio waves have by now become routine. Many of the new techniques, and all those involved with the wavelengths shorter than about 300 nm, were made possible by another major breakthrough of this century - observing from space. Experiments on dedicated Earth-orbiting satellites as well as several deep-space probes have provided fascinating new information on the nature and makeup of comets. In broader terms, much of the progress has been achieved thanks to fundamental discoveries and major advances in electronics, whose applications resulted in qualitatively new instruments (e.g. radiotelescopes) and sensors or detectors (e.g. CCD arrays). The most universal effect on the entire cometary science, from observing to data handling to quantitative interpretations, has been, as in any other branch of science, due to the introduction of electronic computers, with their processing capabilities not only unheard of, but literally unimaginable, in the age of classical desk calculators. As if all this should not be enough, the today's generations of comet scientists have, in addition, been blessed with nature's highly appreciated cooperation. Indeed, in the span of a dozen years, between 1985 and 1997, we were privileged to witness four remarkable cometary events: (i) a return of Halley

  12. Progress of Cometary Science in the Past 100 Years

    NASA Technical Reports Server (NTRS)

    Sekanina, Zdenek

    1999-01-01

    Enormous strides made by cometary science during the 20th century defy any meaningful comparison of its state 100 years ago and now. The great majority of the subfields enjoying much attention nowadays did not exist in the year 1900. Dramatic developments, especially in the past 30-50 years, have equally affected observational and theoretical studies of comets. The profound diversification of observing techniques has been documented by the ever widening limits on the electromagnetic spectrum covered. While the time around 1900 marked an early period of slow and painful experimentation with photographic methods in cometary studies, observations of comets from the x-ray region to the radio waves have by now become routine. Many of the new techniques, and all those involved with the wavelengths shorter than about 300 nm, were made possible by another major breakthrough of this century - observing from space. Experiments on dedicated Earth-orbiting satellites as well as several deep-space probes have provided fascinating new information on the nature and makeup of comets. In broader terms, much of the progress has been achieved thanks to fundamental discoveries and major advances in electronics, whose applications resulted in qualitatively new instruments (e.g. radiotelescopes) and sensors or detectors (e.g. CCD arrays). The most universal effect on the entire cometary science, from observing to data handling to quantitative interpretations, has been, as in any other branch of science, due to the introduction of electronic computers, with their processing capabilities not only unheard of, but literally unimaginable, in the age of classical desk calculators. As if all this should not be enough, the today's generations of comet scientists have, in addition, been blessed with nature's highly appreciated cooperation. Indeed, in the span of a dozen years, between 1985 and 1997, we were privileged to witness four remarkable cometary events: (i) a return of Halley

  13. Investigation of the watershed area- peak flow relationship using artificial neural networks

    NASA Astrophysics Data System (ADS)

    Lekkas, D.; Modarres, R.

    2009-04-01

    The relationship between catchment size and streamflow magnitude is a well known hydrological theory and is usually used for prediction at ungauged basins (PUB). However, the nonlinear behavior of this relationship generates a number of problems when used for flood peak prediction for design purposes due to increased uncertainty. In this study, artificial neural networks are used to develop the area-peak flood relation in the north of Iran. A number of different network architectures have been tested in order to define the best performing network. Preliminary results show that the ANNs can marginally increase the accuracy of the area-peak flood relationship when compared to the nonlinear regression method. Keywords: Flood peak, prediction at ungauged basin, artificial neural network, catchment size, hydrologic modeling, scaling

  14. Ernst Mach on the vestibular organ 100 years ago

    NASA Technical Reports Server (NTRS)

    Henn, V.; Young, L. R.

    1975-01-01

    The paper reviews the contributions of Ernst Mach to vestibular research. His experiments, mainly psychophysical in nature, included measurements of threshold and investigation of the vestibular-visual interaction. Among his conclusions are that the adequate stimulus for the semicircular canals must be pressure, and that the sustained endolymph flow theory of Breuer (1874) and Crum Brown (1874) is erroneous. Excerpts are given of Mach's publications on vestibular functions.-

  15. Investigations of different chemiluminescent peaks in H2O2-SCN(-)-Cu(2+)-OH(-)-luminol flow system.

    PubMed

    Zhao, Changchun; Zheng, Juhua; Xie, Jingxuan; Liu, Haimiao; Gao, Qingyu

    2011-01-01

    In the H2O2-SCN(-) -Cu(2+)-OH(-)-luminol oscillatory system of chemiluminescence, the effects of the ingredient concentrations, temperature, flow rate and complexing agent on the oscillatory dynamics were investigated in a continuous-flow stirred tank reactor (CSTR). The dynamical structure of two peaks during a period was discussed in detail. By addition of EDTA to the oscillating system, the peak I height decreased sharply while the peak II height was little affected, and the period kept constant. This may be due to the fast reaction between Cu(II) and EDTA and the highly stable complex Cu(II)-EDTA. From the experimental study and mechanism analysis, the chemiluminescent peak I corresponds to Cu(II) → Cu(I) transformation and the peak II corresponds to the Cu(I) → Cu(II) transformation process. The key species involving in the two-transformation process are inferred to be superoxide radical and hydroxyl radical. Copyright © 2010 John Wiley & Sons, Ltd.

  16. Prediction of peak response values of structures with and without TMD subjected to random pedestrian flows

    NASA Astrophysics Data System (ADS)

    Lievens, Klaus; Van Nimmen, Katrien; Lombaert, Geert; De Roeck, Guido; Van den Broeck, Peter

    2016-09-01

    In civil engineering and architecture, the availability of high strength materials and advanced calculation techniques enables the construction of slender footbridges, generally highly sensitive to human-induced excitation. Due to the inherent random character of the human-induced walking load, variability on the pedestrian characteristics must be considered in the response simulation. To assess the vibration serviceability of the footbridge, the statistics of the stochastic dynamic response are evaluated by considering the instantaneous peak responses in a time range. Therefore, a large number of time windows are needed to calculate the mean value and standard deviation of the instantaneous peak values. An alternative method to evaluate the statistics is based on the standard deviation of the response and a characteristic frequency as proposed in wind engineering applications. In this paper, the accuracy of this method is evaluated for human-induced vibrations. The methods are first compared for a group of pedestrians crossing a lightly damped footbridge. Small differences of the instantaneous peak value were found by the method using second order statistics. Afterwards, a TMD tuned to reduce the peak acceleration to a comfort value, was added to the structure. The comparison between both methods in made and the accuracy is verified. It is found that the TMD parameters are tuned sufficiently and good agreements between the two methods are found for the estimation of the instantaneous peak response for a strongly damped structure.

  17. [Normal values of peak expiratory flow in 6-15 year-old healthy children of Puebla's city].

    PubMed

    Gómez Tello, Héctor; Gutiérrez Brito, Maricruz; Gutiérrez Sánchez, Segalix

    2006-01-01

    The peak expiratory flow (PEF) is a clinical tool for the evaluation of flow pulmonary, integrated in many studies and guides for the management of asthma, so it is important to have references about its normal values in healthy children Puebla's city. We did an observation, descriptive, transversal and prospective study, where we evaluated to 1154 children from Puebla's city and peak expiratory flow measurements were obtained. The mean values by stature and sex for PEF were dispersed in both sex, the average for males were of 286 L/min, females 251 L/min, finding the major average value in males, with Z = 0.6946 level to confidence of 80%, so the PEF was major in males. We compared variations; and the value of the proof of Fisher was 1.12 with a level of confidence of 90%. The lineal regression straight was: males B1 = 5.3 and B0 = -481, females B1 = 4.82, B0 = -436. The correlation between height and peak expiratory flow was: males R2 = 0.8283, females R2 = 0.7652, for the standard mistake it was calculated with the sum of square of mistakes and the number of observations corresponding for males 22.6% and females 20.3%. The values of healthy children's PEF in Puebla's city are different to other experiences. By first time we have reference values of PEF in healthy children of Puebla's city by sex and height.

  18. From Snow to Flow: Predicting the Timing of Peak Streamflow Using SNOTEL Ablation Curves

    NASA Astrophysics Data System (ADS)

    Ferguson, K. J.; McNamara, J. P.; Abramovich, R.

    2014-12-01

    It is well understood that there exists a relationship between mountainous snowpack and seasonal streamflow. For snow-dominated river basins within the western United States, ~ 80% of streamflow is a result of seasonal snowmelt. In Idaho, where a significant amount of winter precipitation is stored as snowpack, predictions for the timing and magnitude of peak streamflow are essential for many water users, including water resource and irrigation managers. Of particular interest is the relationship between the timing of snowmelt and the timing of peak streamflow. While agencies such as the Natural Resources Conservation Service (NRCS) are tasked with the responsibility of providing water supply forecasts, few methods have used a data-driven, empirical modeling approach to investigate relationships between ablation timing monitored by the NRCS SNOTEL program and streamflow monitored by the United States Geological Survey (USGS). Such analyses could provide predictive tools that allow water users and managers to easily access and interpret information about peak streamflow. Idaho hosts over 80 SNOTEL sites that report hydrometeorological data, and 213 streamflow gauging stations. The goal of this study is to establish relationships between the timing of ablation at SNOTEL stations and peak streamflow within select basins in Idaho, and to synthesize results into user-friendly visualization tools that will provide estimates of the probability that peak streamflow will occur within a certain number of days as ablation progresses from 0 to 100%. In our initial test basin, the Boise River basin, we evaluated melt-out levels in increments of 10% from three SNOTEL sites located in the basin and produced cumulative density function (CDF) curves to illustrate the probability of peak streamflow occurring within a given number of days from the date at which the SNOTEL site reached each melt-out level.

  19. Temporal trends and stationarity in annual peak flow and peak-flow timing for selected long-term streamflow-gaging stations in or near Montana through water year 2011: Chapter B in Montana StreamStats

    USGS Publications Warehouse

    Sando, Steven K.; McCarthy, Peter M.; Sando, Roy; Dutton, DeAnn M.

    2016-04-05

    The two low-elevation gaging stations in eastern Montana (Poplar River at international boundary [gaging station 06178000] and Powder River at Moorhead, Montana [gaging station 06324500]) had considerable changes in annual-peakflow characteristics after the mid-1970s, which might provide evidence of potential nonstationarity in the peak-flow records. The two low-elevation gaging stations that have potential nonstationarity are located in drainage basins that are strongly affected by agricultural activities that potentially affect the hydrologic regimes. Primary agricultural activities that might alter natural hydrologic conditions include construction of small impoundments (primarily for stock-watering purposes) and irrigation diversions. Temporal variability in these activities might contribute to the potential nonstationarity issues. Changes in climatic characteristics after the mid-1970s also possibly contribute to the potential nonstationarity issues. Lack of considerable indication of potential nonstationarity in annual peak flow for the other long-term gaging stations in this study might indicate that climatic changes have been more pronounced with respect to effects on peak flows in low elevation areas in eastern Montana than in areas represented by the other long-term gaging stations. Another possibility is that climatic changes after the mid-1970s are exacerbated in low-elevation areas where small-impoundment development and potential effects of irrigation diversions might be more extensive.

  20. Evaluation of Potential Wetlands to Reduce Peak Flows in Future Climate Scenarios in the Eagle Creek Watershed, IN

    NASA Astrophysics Data System (ADS)

    Walters, K. M.; Babbar-Sebens, M.

    2014-12-01

    Global climate change is expected to increase the severity of floods and droughts and the frequency of extreme streamflow events in the Midwestern United States. Managing these projected impacts poses a major challenge for water resources, conservation, and land use management. Wetlands have been considered as a conservation strategy and work to increase the capacity of watersheds by storing runoff upstream. The implementation of wetlands, especially in tile-drained agricultural watersheds, can reduce peak flows and help mitigate the anticipated impacts of climate change. The goal of this study was to evaluate the long-term performance of wetlands to reduce peak flows in future climate scenarios in the Eagle Creek Watershed in Indiana. A secondary goal of this research was to establish a methodology for incorporating climate change into hydrological models to conduct long-term land management studies and decisions. The Soil and Water Assessment Tool (SWAT) model was forced with an ensemble of bias corrected climate projections from the North American Regional Climate Change Assessment Program (NARCCAP) to evaluate the impacts of climate change on watershed hydrology and the ability of wetlands to reduce peak flows. Long-term monthly streamflow results predicted a slight increase in streamflow in the winter and a slight decrease in the summer from the past (1971-2000) to future (2041-2070) time periods. About half of the climate realizations produced an increase in the 5% exceedance flow and half a decrease, but all predictions agreed that high flow events will increase in frequency in the winter and decrease in the spring and summer. Results from the wetland analysis showed that if all potential wetlands identified in a previous study are installed in the watershed, maximum peak flow reductions of around 20-50 cubic meters per second for the past and future, as well as decreased frequency of extreme events, can be seen. Wetlands proved to be a robust solution for

  1. An adaptive model for vanadium redox flow battery and its application for online peak power estimation

    NASA Astrophysics Data System (ADS)

    Wei, Zhongbao; Meng, Shujuan; Tseng, King Jet; Lim, Tuti Mariana; Soong, Boon Hee; Skyllas-Kazacos, Maria

    2017-03-01

    An accurate battery model is the prerequisite for reliable state estimate of vanadium redox battery (VRB). As the battery model parameters are time varying with operating condition variation and battery aging, the common methods where model parameters are empirical or prescribed offline lacks accuracy and robustness. To address this issue, this paper proposes to use an online adaptive battery model to reproduce the VRB dynamics accurately. The model parameters are online identified with both the recursive least squares (RLS) and the extended Kalman filter (EKF). Performance comparison shows that the RLS is superior with respect to the modeling accuracy, convergence property, and computational complexity. Based on the online identified battery model, an adaptive peak power estimator which incorporates the constraints of voltage limit, SOC limit and design limit of current is proposed to fully exploit the potential of the VRB. Experiments are conducted on a lab-scale VRB system and the proposed peak power estimator is verified with a specifically designed "two-step verification" method. It is shown that different constraints dominate the allowable peak power at different stages of cycling. The influence of prediction time horizon selection on the peak power is also analyzed.

  2. Assessment of impact of high particulate concentration on peak expiratory flow rate of lungs of sand stone quarry workers.

    PubMed

    Singh, Suresh Kumar; Chowdhary, G R; Purohit, Gopal

    2006-12-01

    This study was designed to assess the impact of high particulate concentration on peak expiratory flow rate of lungs of sand stone quarry workers. The workers were engaged in different types of activities such as drilling, loading and dressing. These different working conditions had different concentrations of RSPM, leading to different exposure levels in workers. It was found that exposure duration and exposure concentrations were the main factors responsible for damage to the respiratory tracts of the workers. The particles were deposited at various areas of the respiratory system and reduced the peak flow rate. It was also revealed from the study that most of the workers suffered from silicosis if the exposure duration was more than 20 years.

  3. Effects of 24-week resistance exercise training on carotid peak systolic and end diastolic flow velocity in healthy older adults

    PubMed Central

    Park, Jinkee

    2016-01-01

    [Purpose] The aim of this study was to examine the effect of resistance exercise on carotid intima-media thickness, luminal diameter, peak systolic flow velocity, end diastolic flow velocity, and wall shear rate in healthy elderly men. [Subjects and Methods] Thirty healthy elderly men (age ≥65 years) were randomly divided into a control (n=15) and resistance exercise (n=15) groups. The 24-week exercise intervention consisted of 3 days of resistance exercise per week using an elastic band per week. Body composition, physical function, blood pressure, and carotid variables were measured at baseline and after 24 weeks. [Results] Body fat percent, skeletal muscle mass, systolic blood pressure, grip strength, arm curl, chair stand up, sit and reach, maximum walking speed, time up and go, and two-minute step test showed significant interaction. Peak systolic flow velocity, end diastolic flow velocity, and wall shear rate also showed significant interaction. [Conclusion] A 24-week resistance exercise program, using elastic bands, effectively improves carotid flow velocity and wall shear rate in healthy elderly men. PMID:27821937

  4. The bovine bivariate flow karyotype and peak identification by chromosome painting with PCR-generated probes.

    PubMed

    Schmitz, A; Oustry, A; Chaput, B; Bahri-Darwich, I; Yerle, M; Millan, D; Frelat, G; Cribiu, E P

    1995-06-01

    A bovine bivariate flow karyotype has been established from a primary fibroblast cell culture carrying a 4;10 Robertsonian translocation. From 27 to 36 populations could be resolved by flow cytometry although the anticipated number was 31. Separation of chromosomal pairs into two populations explains this high resolution and confirms the high level of heteromorphism previously observed. We used a PARM-PCR (Priming Authorizing Random Mismatches) procedure for the production of paint probes from flow-sorted chromosome fractions. These probes were used for chromosome identification by fluorescence in situ hybridization (FISH) on R-banded metaphase spreads. We present the localization of all the bovine chromosome types on the flow karyotype. Twenty-two chromosome types including the translocated chromosome were sorted as pure fractions.

  5. Wetland Restoration as a Tool for Peak Flow Mitigation: Combining Watershed Scale Modeling with a Genetic Algorithm Approach.

    NASA Astrophysics Data System (ADS)

    Dalzell, B. J.; Gassman, P. W.; Kling, C.

    2015-12-01

    In the Minnesota River Basin, sediments originating from failing stream banks and bluffs account for the majority of the riverine load and contribute to water quality impairments in the Minnesota River as well as portions of the Mississippi River upstream of Lake Pepin. One approach for mitigating this problem may be targeted wetland restoration in Minnesota River Basin tributaries in order to reduce the magnitude and duration of peak flow events which contribute to bluff and stream bank failures. In order to determine effective arrangements and properties of wetlands to achieve peak flow reduction, we are employing a genetic algorithm approach coupled with a SWAT model of the Cottonwood River, a tributary of the Minnesota River. The genetic algorithm approach will evaluate combinations of basic wetland features as represented by SWAT: surface area, volume, contributing area, and hydraulic conductivity of the wetland bottom. These wetland parameters will be weighed against economic considerations associated with land use trade-offs in this agriculturally productive landscape. Preliminary results show that the SWAT model is capable of simulating daily hydrology very well and genetic algorithm evaluation of wetland scenarios is ongoing. Anticipated results will include (1) combinations of wetland parameters that are most effective for reducing peak flows, and (2) evaluation of economic trade-offs between wetland restoration, water quality, and agricultural productivity in the Cottonwood River watershed.

  6. Solving the Supreme Problem: 100 years of selection and recruitment at the Journal of Applied Psychology.

    PubMed

    Ployhart, Robert E; Schmitt, Neal; Tippins, Nancy T

    2017-03-01

    This article reviews 100 years of research on recruitment and selection published in the Journal of Applied Psychology. Recruitment and selection research has been present in the Journal from the very first issue, where Hall (1917) suggested that the challenge of recruitment and selection was the Supreme Problem facing the field of applied psychology. As this article shows, the various topics related to recruitment and selection have ebbed and flowed over the years in response to business, legal, and societal changes, but this Supreme Problem has captivated the attention of scientist-practitioners for a century. Our review starts by identifying the practical challenges and macro forces that shaped the sciences of recruitment and selection and helped to define the research questions the field has addressed. We then describe the evolution of recruitment and selection research and the ways the resulting scientific advancements have contributed to staffing practices. We conclude with speculations on how recruitment and selection research may proceed in the future. Supplemental material posted online provides additional depth by including a summary of practice challenges and scientific advancements that affected the direction of selection and recruitment research and an outline of seminal articles published in the Journal and corresponding time line. The 100-year anniversary of the Journal of Applied Psychology is very much the celebration of recruitment and selection research, although predictions about the future suggest there is still much exciting work to be done. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  7. Is There an Advection-dominated Accretion Flow in Radio Galaxies with Double-peaked Balmer Lines?

    NASA Astrophysics Data System (ADS)

    Nagao, Tohru; Murayama, Takashi; Shioya, Yasuhiro; Taniguchi, Yoshiaki

    2002-03-01

    In order to examine the prediction that the broad-line radio galaxies (BLRGs) with double-peaked Balmer lines harbor an accretion disk characterized by an advection-dominated accretion flow (ADAF) in their nuclei, we investigate narrow emission line flux ratios of the narrow-line regions (NLRs) which are photoionized by nuclear continuum radiation. We compile data from the literature and confirm the pioneering work of Eracleous & Halpern that the BLRGs with the double-peaked Balmer emission exhibit larger flux ratios of both [O I] λ6300/[O III] λ5007 and [O II] λ3727/[O III] λ5007 than the BLRGs without the double-peaked Balmer emission. To examine whether or not these properties are attributed to the difference in the spectral energy distribution (SED) of the ionizing radiation between the BLRGs with and without the double-peaked Balmer emission, we perform photoionization model calculations using two types of input continuum radiation; one has the strong big blue bump which is expected for standard optically thick accretion disks and the other does not exhibit a strong big blue bump as expected for optically thin ADAFs. We find that the data of the BLRGs with the double-peaked Balmer lines are consistent with the models adopting the SED without a strong big blue bump, while the data of the BLRGs without the double-peaked emission lines are well described by the models adopting the SED with a strong big blue bump. On the other hand, the observed differences in the NLR emission are hard to explain by the difference in the contribution of shocks. These results support the idea that the double-peaked Balmer lines arise at an outer region of an accretion disk which is illuminated by an inner, geometrically thick ADAF.

  8. Evaluating Titan2D mass-flow model using the 1963 Little Tahoma Peak avalanches, Mount Rainier, Washington

    NASA Astrophysics Data System (ADS)

    Sheridan, M. F.; Stinton, A. J.; Patra, A.; Pitman, E. B.; Bauer, A.; Nichita, C. C.

    2005-01-01

    The Titan2D geophysical mass-flow model is evaluated by comparing its simulation results and those obtained from another flow model, FLOW3D, with published data on the 1963 Little Tahoma Peak avalanches on Mount Rainier, Washington. The avalanches, totaling approximately 10×10 6 m 3 of broken lava blocks and other debris, traveled 6.8 km horizontally and fell 1.8 km vertically ( H/ L=0.246). Velocities calculated from runup range from 24 to 42 m/s and may have been as high as 130 m/s while the avalanches passed over Emmons Glacier. Titan2D is a code for an incompressible Coulomb continuum; it is a depth-averaged, 'shallow-water', granular-flow model. The conservation equations for mass and momentum are solved with a Coulomb-type friction term at the basal interface. The governing equations are solved on multiple processors using a parallel, adaptive mesh, Godunov scheme. Adaptive gridding dynamically concentrates computing power in regions of special interest; mesh refinement and coarsening key on the perimeter of the moving avalanche. The model flow initiates as a pile defined as an ellipsoid by a height ( z) and an elliptical base defined by radii in the x and y planes. Flow parameters are the internal friction angle and bed friction angle. Results from the model are similar in terms of velocity history, lateral spreading, location of runup areas, and final distribution of the Little Tahoma Peak deposit. The avalanches passed over the Emmons Glacier along their upper flow paths, but lower in the valley they traversed stream gravels and glacial outwash deposits. This presents difficulty in assigning an appropriate bed friction angle for the entire deposit. Incorporation of variable bed friction angles into the model using GIS will help to resolve this issue.

  9. Techniques for Estimating the Magnitude and Frequency of Peak Flows on Small Streams in Minnesota Based on Data through Water Year 2005

    USGS Publications Warehouse

    Lorenz, David L.; Sanocki, Chris A.; Kocian, Matthew J.

    2010-01-01

    Knowledge of the peak flow of floods of a given recurrence interval is essential for regulation and planning of water resources and for design of bridges, culverts, and dams along Minnesota's rivers and streams. Statistical techniques are needed to estimate peak flow at ungaged sites because long-term streamflow records are available at relatively few places. Because of the need to have up-to-date peak-flow frequency information in order to estimate peak flows at ungaged sites, the U.S. Geological Survey (USGS) conducted a peak-flow frequency study in cooperation with the Minnesota Department of Transportation and the Minnesota Pollution Control Agency. Estimates of peak-flow magnitudes for 1.5-, 2-, 5-, 10-, 25-, 50-, 100-, and 500-year recurrence intervals are presented for 330 streamflow-gaging stations in Minnesota and adjacent areas in Iowa and South Dakota based on data through water year 2005. The peak-flow frequency information was subsequently used in regression analyses to develop equations relating peak flows for selected recurrence intervals to various basin and climatic characteristics. Two statistically derived techniques-regional regression equation and region of influence regression-can be used to estimate peak flow on ungaged streams smaller than 3,000 square miles in Minnesota. Regional regression equations were developed for selected recurrence intervals in each of six regions in Minnesota: A (northwestern), B (north central and east central), C (northeastern), D (west central and south central), E (southwestern), and F (southeastern). The regression equations can be used to estimate peak flows at ungaged sites. The region of influence regression technique dynamically selects streamflow-gaging stations with characteristics similar to a site of interest. Thus, the region of influence regression technique allows use of a potentially unique set of gaging stations for estimating peak flow at each site of interest. Two methods of selecting streamflow

  10. Analysis of Daily Peaking and Run-of-River Operations with Flow Variability Metrics, Considering Subdaily to Seasonal Time Scales

    SciTech Connect

    Haas, Nicholas A.; O'Connor, Ben L.; Hayse, John W.; Bevelhimer, Mark S.; Endreny, Theodore A.

    2014-07-22

      Environmental flows are an important consideration in licensing hydropower projects  because operational flow releases can result in adverse conditions to downstream ecological  communities. Flow variability assessments have typically focused on pre- and post-dam conditions using    metrics based on daily-averaged flow values.  This study used subdaily and daily flow data to assess    environmental flow response to changes in hydropower operations from daily-peaking to run-of-river.  An analysis tool was developed to quantify subdaily to seasonal flow variability metrics and was applied    to four hydropower projects that underwent operational changes based on regulatory requirements.  Results indicate that the distribution of flows is significantly different between daily-peaking and run-of- river operations and that daily-peaking operations are flashier than run-of-river operations; these  differences are seen using hourly-averaged flow datasets and are less pronounced or not noticeable  using daily-averaged flow datasets.  Of all variability metrics analyzed, hydrograph rise and fall rates  were the most sensitive to using daily versus subdaily flow data. This outcome has implications for the    development of flow-ecology relationships that quantify effects of rate of change on processes such as  fish stranding and displacement, along with habitat stability. The quantification of flow variability    statistics should be done using subdaily datasets and metric to accurately represent the nature of  hydropower operations , especially for facilities that utilize daily-peaking operations. 

  11. Grizzly Peak cauldron, Colorado: structure and petrology of a deeply dissected resurgent ash-flow caldera

    SciTech Connect

    Fridrich, C.J.

    1987-01-01

    The 34-Ma-old Grizzly Peak cauldron is a deeply eroded 17- by 23-k caldera structure on the crest of the Sawatch Range in west-central Colorado. Subsidence of the cauldron along bounding ring faults resulted from eruption of the Grizzly Peak Tuff, which ponded in the caldera as it formed. An inner ring fracture zone divides the cauldron into two segments and is a growth fault in the intracaldera tuff. Following subsidence, the cauldron was uplifted to form a complexely faulted resurgent dome. Intracaldera Grizzly Peak Tuff, as thick as 2.7 km, is a single cooling unit zoned from high-silica rhyolite at the base to low-silica rhyolite at the eroded top and, further, contains dacite to mafic latite welded pumice clasts (fiamme) in two heterogeneous tuff horizons in the upper half of the unit. Tuff zoning defined by fiamme is unusually strong for a single volcanic unit: 77 to 57% SiO2. Major-element trends can be modeled by crystal fractionation using observed phenocrysts. Inflections in the trends of Zr, Hf, Th, REE, Y, Mn, and Sc correlated with changes in phenocryst mineralogy and composition, indicating control by crystal-liquid equilibria. Trends for some trace-element cannot be fit with the crystal-fractionation model; over different portions of the zonation, Zr, Hf, LREE, and Rb enrich at too high a rate, and Ta, Nb, and Ba enrich at too low a rate. Progressive batch melting of a single source can also be eliminated because Co, Cr, Eu, and Sr, and Ba are too strongly depleted over different silica intervals. The zonation must therefore be the result of a combination of processes. Compositional trends defined by a series of intracaldera intrusions can be explained by hybridization, during resurgence, of the unerupted portion of the zoned magma column sampled in the tuff eruption.

  12. Annual Peak-Flow Frequency Characteristics and (or) Peak Dam-Pool-Elevation Frequency Characteristics of Dry Dams and Selected Streamflow-Gaging Stations in the Great Miami River Basin, Ohio

    USGS Publications Warehouse

    Koltun, G.F.

    2009-01-01

    This report describes the results of a study to determine frequency characteristics of postregulation annual peak flows at streamflow-gaging stations at or near the Lockington, Taylorsville, Englewood, Huffman, and Germantown dry dams in the Miami Conservancy District flood-protection system (southwestern Ohio) and five other streamflow-gaging stations in the Great Miami River Basin further downstream from one or more of the dams. In addition, this report describes frequency characteristics of annual peak elevations of the dry-dam pools. In most cases, log-Pearson Type III distributions were fit to postregulation annual peak-flow values through 2007 (the most recent year of published peak-flow values at the time of this analysis) and annual peak dam-pool storage values for the period 1922-2008 to determine peaks with recurrence intervals of 2, 5, 10, 25, 50, 100, 200, and 500 years. For one streamflow-gaging station (03272100) with a short period of record, frequency characteristics were estimated by means of a process involving interpolation of peak-flow yields determined for an upstream and downstream gage. Once storages had been estimated for the various recurrence intervals, corresponding dam-pool elevations were determined from elevation-storage ratings provided by the Miami Conservancy District.

  13. How do flow peaks and durations change in suburbanizing semi-arid watersheds? A southern California case study

    NASA Astrophysics Data System (ADS)

    Hawley, Robert J.; Bledsoe, Brian P.

    2011-07-01

    SummaryForty-three US Geological Survey gauges with records greater than ˜15 yrs located in watersheds less than ˜250 km 2 were used to model the effects of suburbanization on streams in semi-arid southern California. The watersheds spanned a gradient of urban development, ranging 0-23% total impervious area in 2001. With little flow control at the subdivision scale, most impervious area in the region is relatively well-connected to surface-drainage networks and hydrologically effective. Consequently, total impervious area was an effective hydrologic surrogate for urbanization, emerging from an expansive array of geospatially-derived hydrologic variables as a statistically-significant ( p < 0.05) predictor of instantaneous peak-flow rates at the 1.5- and 2-yr recurrence intervals and the durations of all geomorphically-important flows. To represent the effects of urbanization on flow durations, we developed duration density functions by using power functions (typical R2 > 0.95) to predict occurrence of logarithmically-binned mean daily discharges greater than some nominal value. This approach expands on previous scaling procedures to produce histogram-style cumulative flow durations for ungauged sites using urbanization extent and other watershed descriptors. For a particular watershed size and climatic setting, urbanization resulted in proportionally-longer durations of all geomorphically-effective flows, with a more pronounced effect on the durations of moderate flows. For example, a representative watershed with ˜20% imperviousness could experience five times as many days of mean daily flows on the order of 100 cfs (3 m 3/s) and approximately three times as many days on the order of 1000 cfs (30 m 3/s) relative to the undeveloped setting. Increased duration of sediment-transporting flows is a primary driver of accelerated changes in channel form that are often concurrent with urbanization throughout southern California, particularly in unconfined, fine

  14. Rib Fracture Fixation Restores Inspiratory Volume and Peak Flow in a Full Thorax Human Cadaveric Breathing Model

    PubMed Central

    Slobogean, Gerard P.; Kim, Hyunchul; Russell, Joseph P.; Stockton, David J.; Hsieh, Adam H.; O’Toole, Robert V.

    2015-01-01

    Background: Multiple rib fractures cause significant pain and potential for chest wall instability. Despite an emerging trend of surgical management of flail chest injuries, there are no studies examining the effect of rib fracture fixation on respiratory function. Objectives: Using a novel full thorax human cadaveric breathing model, we sought to explore the effect of flail chest injury and subsequent rib fracture fixation on respiratory outcomes. Patients and Methods: We used five fresh human cadavers to generate negative breathing models in the left thorax to mimic physiologic respiration. Inspiratory volumes and peak flows were measured using a flow meter for all three chest wall states: intact chest, left-sided flail chest (segmental fractures of ribs 3 - 7), and post-fracture open reduction and internal fixation (ORIF) of the chest wall with a pre-contoured rib specific plate fixation system. Results: A wide variation in the mean inspiratory volumes and peak flows were measured between specimens; however, the effect of a flail chest wall and the subsequent internal fixation of the unstable rib fractures was consistent across all samples. Compared to the intact chest wall, the inspiratory volume decreased by 40 ± 19% in the flail chest model (P = 0.04). Open reduction and internal fixation of the flail chest returned the inspiratory volume to 130 ± 71% of the intact chest volumes (P = 0.68). A similar 35 ± 19% decrease in peak flows was seen in the flail chest (P = 0.007) and this returned to 125 ± 71% of the intact chest following ORIF (P = 0.62). Conclusions: Negative pressure inspiration is significantly impaired by an unstable chest wall. Restoring mechanical stability of the fractured ribs improves respiratory outcomes similar to baseline values. PMID:26848471

  15. Air Stacking: A Detailed Look Into Physiological Acute Effects on Cough Peak Flow and Chest Wall Volumes of Healthy Subjects.

    PubMed

    Sarmento, Antonio; de Andrade, Armèle F Dornelas; Lima, Íllia Nadinne Df; Aliverti, Andrea; de Freitas Fregonezi, Guilherme Augusto; Resqueti, Vanessa R

    2017-04-01

    Air stacking (AS) is a lung insufflation method that requires the use of a manual insufflator to provide air volumes higher than inspiratory capacity. Neuromuscular patients benefit the most from the maneuver; however, the acute effects of AS in healthy subjects are still unclear. Twenty healthy subjects (8 males) were studied by optoelectronic plethysmography to investigate the immediate effects of AS on cough peak flow, operational volume variations, distribution of these volumes in the chest wall compartments (pulmonary rib cage, abdominal rib cage, and abdominal), breathing pattern, and shortening velocity of the respiratory muscles during a protocol that included vital capacity maneuvers and spontaneous coughs before and after AS. Statistically significant increases in cough peak flow (P < .03) and inspiratory capacity (P < .001) were found immediately after AS. During its application, the pulmonary rib cage compartment was the largest contributor (P = .002) to chest wall volume displacement. A significant increase in chest wall tidal volume (P < .001), mainly in the pulmonary rib cage (P < .001), was observed. Significant increases (P < .001) in end-inspiratory chest wall volume were observed with main distribution in pulmonary (P < .001) and abdominal rib cage (P = .01). Significant increases in shortening velocity index of inspiratory muscles (P < .001), expiratory muscles (P < .001), and diaphragm (P < .001) were also observed. In addition, significant decreases in expiratory time (P < .001) and increases in duty cycle (P = .02), breathing frequency (P = .02), minute ventilation (P < .001), maximum inspiratory (P < .001), and expiratory flow (P < .001) were observed. In healthy subjects, cough peak flow and chest wall volumes can be increased immediately after the application of the AS maneuver. Copyright © 2017 by Daedalus Enterprises.

  16. Effects of forest practices on peak flows and consequent channel response: a state-of-science report for western Oregon and Washington.

    Treesearch

    Gordon E. Grant; Sarah L. Lewis; Frederick J. Swanson; John H. Cissel; Jeffrey J. McDonnell

    2008-01-01

    This is a state-of-the-science synthesis of the effects of forest harvest activities on peak flows and channel morphology in the Pacific Northwest, with a specific focus on western Oregon and Washington. We develop a database of relevant studies reporting peak flow data across rain-, transient-, and snow-dominated hydrologic zones, and provide a quantitative comparison...

  17. Peak discharges and flow volumes for streams in the Northern Plains, 1996-97

    USGS Publications Warehouse

    Macek-Rowland, K. M.; Burr, M.J.; Mitton, G.B.

    2001-01-01

    Winter snowfall of 1996-97, combined with the spring floods of 1997, caused one of the worst natural disasters in recent history on the Northern Plains. The flow volumes for water year 1997 at selected streamflow-gaging stations on the Red River of the North, the Minnesota River, and the James River were 186 to 788 percent of the mean annual volumes for the periods of record for those stations. Recurrence intervals ranged from 10 to 500 years.

  18. Impact of urban WWTP and CSO fluxes on river peak flow extremes under current and future climate conditions.

    PubMed

    Keupers, Ingrid; Willems, Patrick

    2013-01-01

    The impact of urban water fluxes on the river system outflow of the Grote Nete catchment (Belgium) was studied. First the impact of the Waste Water Treatment Plant (WWTP) and the Combined Sewer Overflow (CSO) outflows on the river system for the current climatic conditions was determined by simulating the urban fluxes as point sources in a detailed, hydrodynamic river model. Comparison was made of the simulation results on peak flow extremes with and without the urban point sources. In a second step, the impact of climate change scenarios on the urban fluxes and the consequent impacts on the river flow extremes were studied. It is shown that the change in the 10-year return period hourly peak flow discharge due to climate change (-14% to +45%) was in the same order of magnitude as the change due to the urban fluxes (+5%) in current climate conditions. Different climate change scenarios do not change the impact of the urban fluxes much except for the climate scenario that involves a strong increase in rainfall extremes in summer. This scenario leads to a strong increase of the impact of the urban fluxes on the river system.

  19. Comparison of hydrochemical tracers to estimate source contributions to peak flow in a small, forested, headwater catchment

    USGS Publications Warehouse

    Rice, Karen C.; Hornberger, George M.

    1998-01-01

    Three-component (throughfall, soil water, groundwater) hydrograph separations at peak flow were performed on 10 storms over a 2-year period in a small forested catchment in north-central Maryland using an iterative and an exact solution. Seven pairs of tracers (deuterium and oxygen 18, deuterium and chloride, deuterium and sodium, deuterium and silica, chloride and silica, chloride and sodium, and sodium and silica) were used for three-component hydrograph separation for each storm at peak flow to determine whether or not the assumptions of hydrograph separation routinely can be met, to assess the adequacy of some commonly used tracers, to identify patterns in hydrograph-separation results, and to develop conceptual models for the patterns observed. Results of the three-component separations were not always physically meaningful, suggesting that assumptions of hydrograph separation had been violated. Uncertainties in solutions to equations for hydrograph separations were large, partly as a result of violations of assumptions used in deriving the separation equations and partly as a result of improper identification of chemical compositions of end-members. Results of three-component separations using commonly used tracers were widely variable. Consistent patterns in the amount of subsurface water contributing to peak flow (45-100%) were observed, no matter which separation method or combination of tracers was used. A general conceptual model for the sequence of contributions from the three end-members could be developed for 9 of the 10 storms. Overall results indicated that hydrochemical and hydrometric measurements need to be coupled in order to perform meaningful hydrograph separations.

  20. Evaluating TITAN2D mass-flow model using the 1963 Little Tahoma Peak avalanches, Mount Rainier, Washington.

    NASA Astrophysics Data System (ADS)

    Sheridan, M. F.; Stinton, A. J.; Patra, A.; Pitman, B.; Bauer, A.; Nichita, C.

    2003-04-01

    The TITAN2D geophysical mass-flow model that is currently under development is evaluated by comparing simulation results with those obtained from another flow model, FLOW3D, and the published data on the 1963 Little Tahoma Peak avalanches on Mount Rainier, Washington. The avalanches, totaling approximately 10 x 106 m3 of brecciated lava flows and other debris, traveled 6.8 km horizontally and fell 1.8 km vertically (H/L = 0.246). Velocities calculated from run up range from 24-42 m/sec and may have been as high as 130 m/sec as the avalanches moved over Emmons Glacier. The avalanches formed a deposit up to 30 m thick. The FLOW3D model uses a sliding block principle to simulate flow movement over a TIN. Results from this model show similarities in terms of velocity history, location of run up areas, run out length and aerial distribution of deposit, although post-avalanche topography in the TIN affects the latter. The TITAN2D model is appropriate for fluid flow in open channels. It is a 2-D, depth-averaged model that uses a raster grid instead of a TIN for the topography. The model flow initiates as a pile defined as an ellipsoid by a height (z) and a radius in the x and y planes. Flow parameters are the internal friction and bed friction angles. Results from this model are promising. Good comparisons can be drawn early during the simulations when the model results fit closely with the mapped extent of the avalanches. However, as the simulated flows move downstream they deviate more from the mapped extent. An area that needs to be addressed is the incorporation of variable bed friction in the model. Simulations done using a low bed friction angle appropriate for movement on the glacier traveled far beyond the limits of the actual deposits, while a high angle suitable for flow over a gravely surface caused the avalanches to stop well short of the mapped limits, never leaving Emmons Glacier. Incorporation of variable bed friction angles into the model using GIS will

  1. Model Related Estimates of time dependent quantiles of peak flows - case study for selected catchments in Poland

    NASA Astrophysics Data System (ADS)

    Strupczewski, Witold G.; Bogdanowich, Ewa; Debele, Sisay

    2016-04-01

    Under Polish climate conditions the series of Annual Maxima (AM) flows are usually a mixture of peak flows of thaw- and rainfall- originated floods. The northern, lowland regions are dominated by snowmelt floods whilst in mountainous regions the proportion of rainfall floods is predominant. In many stations the majority of AM can be of snowmelt origin, but the greatest peak flows come from rainfall floods or vice versa. In a warming climate, precipitation is less likely to occur as snowfall. A shift from a snow- towards a rain-dominated regime results in a decreasing trend in mean and standard deviations of winter peak flows whilst rainfall floods do not exhibit any trace of non-stationarity. That is why a simple form of trends (i.e. linear trends) are more difficult to identify in AM time-series than in Seasonal Maxima (SM), usually winter season time-series. Hence it is recommended to analyse trends in SM, where a trend in standard deviation strongly influences the time -dependent upper quantiles. The uncertainty associated with the extrapolation of the trend makes it necessary to apply a relationship for trend which has time derivative tending to zero, e.g. we can assume a new climate equilibrium epoch approaching, or a time horizon is limited by the validity of the trend model. For both winter and summer SM time series, at least three distributions functions with trend model in the location, scale and shape parameters are estimated by means of the GAMLSS package using the ML-techniques. The resulting trend estimates in mean and standard deviation are mutually compared to the observed trends. Then, using AIC measures as weights, a multi-model distribution is constructed for each of two seasons separately. Further, assuming a mutual independence of the seasonal maxima, an AM model with time-dependent parameters can be obtained. The use of a multi-model approach can alleviate the effects of different and often contradictory trends obtained by using and identifying

  2. Estimation of the supplementary axial wall stress generated at peak flow by an arterial stenosis

    NASA Astrophysics Data System (ADS)

    Doriot, Pierre-André

    2003-01-01

    Mechanical stresses in arterial walls are known to be implicated in the development of atherosclerosis. While shear stress and circumferential stress have received a lot of attention, axial stress has not. Yet, stenoses can be intuitively expected to produce a supplementary axial stress during flow systole in the region immediately proximal to the constriction cone. In this paper, a model for the estimation of this effect is presented, and ten numerical examples are computed. These examples show that the cyclic increase in axial stress can be quite considerable in severe stenoses (typically 120% or more of the normal stress value). This result is in best agreement with the known mechanical or morphological risk factors of stenosis progression and restenosis (hypertension, elevated pulse pressure, degree of stenosis, stenosis geometry, residual stenosis, etc). The supplementary axial stress generated by a stenosis might create the damages in the endothelium and in the elastic membranes which potentiate the action of the other risk factors (hyperlipidaemia, diabetes, etc). It could thus be an important cause of stenosis progression and of restenosis.

  3. Investigating flow properties of partially cemented fractures in Travis Peak Formation using image-based pore-scale modeling

    NASA Astrophysics Data System (ADS)

    Tokan-Lawal, Adenike; Prodanović, Maša.; Eichhubl, Peter

    2015-08-01

    Natural fractures can provide preferred flow pathways in otherwise low-permeability reservoirs. In deep subsurface reservoirs including tight oil and gas reservoirs, as well as in hydrothermal systems, fractures are frequently lined or completely filled with mineral cement that reduces or occludes fracture porosity and permeability. Fracture cement linings potentially reduce flow connectivity between the fracture and host rock and increase fracture wall roughness, which constricts flow. We combined image-based fracture space characterization, mercury injection capillary pressure and permeability experiments, and numerical simulations to evaluate the influence of fracture-lining cement on single-phase and multiphase flows along a natural fracture from the Travis Peak Formation, a tight gas reservoir sandstone in East Texas. Using X-ray computed microtomographic image analysis, we characterized fracture geometry and the connectivity and geometric tortuosity of the fracture pore space. Combining level set method-based progressive quasistatic and lattice Boltzmann simulations, we assessed the capillary-dominated displacement properties and the (relative) permeability of a cement-lined fracture. Published empirical correlations between aperture and permeability for barren fractures provide permeability estimates that vary among each other, and differ from our results, vary by several orders of magnitude. Compared to barren fractures, cement increases the geometric tortuosity, aperture variation of the pore space, and capillary pressure while reducing the single-phase permeability by up to 2 orders of magnitude. For multiphase displacement, relative permeability and fluid entrapment geometry resemble those of porous media and differ from those characteristic of barren fractures.

  4. Changes in stream peak flow and regulation in Naoli River watershed as a result of wetland loss.

    PubMed

    Yao, Yunlong; Wang, Lei; Lv, Xianguo; Yu, Hongxian; Li, Guofu

    2014-01-01

    Hydrology helps determine the character of wetlands; wetlands, in turn, regulate water flow, which influences regional hydrology. To understand these dynamics, we studied the Naoli basin where, from 1954 to 2005, intensive marshland cultivation took place, and the watershed's wetland area declined from 94.4 × 10(4)ha to 17.8 × 10(4)ha. More than 80% of the wetland area loss was due to conversion to farmland, especially from 1976 to 1986. The processes of transforming wetlands to cultivated land in the whole Naoli basin and subbasins can be described using a first order exponential decay model. To quantify the effects of wetlands cultivation, we analyzed daily rainfall and streamflow data measured from 1955 to 2005 at two stations (Baoqing Station and Caizuizi Station). We defined a streamflow regulation index (SRI) and applied a Mann-Kendall-Sneyers test to further analyze the data. As the wetland area decreased, the peak streamflow at the Caizuizi station increased, and less precipitation generated heavier peak flows, as the runoff was faster than before. The SRI from 1959 to 2005 showed an increasing trend; the SRI rate of increase was 0.05/10a, demonstrating that the watershed's regulation of streamflow regulation was declined as the wetlands disappeared.

  5. Changes in Stream Peak Flow and Regulation in Naoli River Watershed as a Result of Wetland Loss

    PubMed Central

    Yao, Yunlong; Wang, Lei; Lv, Xianguo; Yu, Hongxian; Li, Guofu

    2014-01-01

    Hydrology helps determine the character of wetlands; wetlands, in turn, regulate water flow, which influences regional hydrology. To understand these dynamics, we studied the Naoli basin where, from 1954 to 2005, intensive marshland cultivation took place, and the watershed's wetland area declined from 94.4 × 104 ha to 17.8 × 104 ha. More than 80% of the wetland area loss was due to conversion to farmland, especially from 1976 to 1986. The processes of transforming wetlands to cultivated land in the whole Naoli basin and subbasins can be described using a first order exponential decay model. To quantify the effects of wetlands cultivation, we analyzed daily rainfall and streamflow data measured from 1955 to 2005 at two stations (Baoqing Station and Caizuizi Station). We defined a streamflow regulation index (SRI) and applied a Mann-Kendall-Sneyers test to further analyze the data. As the wetland area decreased, the peak streamflow at the Caizuizi station increased, and less precipitation generated heavier peak flows, as the runoff was faster than before. The SRI from 1959 to 2005 showed an increasing trend; the SRI rate of increase was 0.05/10a, demonstrating that the watershed's regulation of streamflow regulation was declined as the wetlands disappeared. PMID:25114956

  6. Error of the modelled peak flow of the hydraulically reconstructed 1907 flood of the Ebro River in Xerta (NE Iberian Peninsula)

    NASA Astrophysics Data System (ADS)

    Lluís Ruiz-Bellet, Josep; Castelltort, Xavier; Carles Balasch, J.; Tuset, Jordi

    2016-04-01

    The estimation of the uncertainty of the results of the hydraulic modelling has been deeply analysed, but no clear methodological procedures as to its determination have been formulated when applied to historical hydrology. The main objective of this study was to calculate the uncertainty of the resulting peak flow of a typical historical flood reconstruction. The secondary objective was to identify the input variables that influenced the result the most and their contribution to peak flow total error. The uncertainty of 21-23 October 1907 flood of the Ebro River (NE Iberian Peninsula) in the town of Xerta (83,000 km2) was calculated with a series of local sensitivity analyses of the main variables affecting the resulting peak flow. Besides, in order to see to what degree the result depended on the chosen model, the HEC-RAS resulting peak flow was compared to the ones obtained with the 2D model Iber and with Manning's equation. The peak flow of 1907 flood in the Ebro River in Xerta, reconstructed with HEC-RAS, was 11500 m3·s-1 and its total error was ±31%. The most influential input variable over HEC-RAS peak flow results was water height; however, the one that contributed the most to peak flow error was Manning's n, because its uncertainty was far greater than water height's. The main conclusion is that, to ensure the lowest peak flow error, the reliability and precision of the flood mark should be thoroughly assessed. The peak flow was 12000 m3·s-1 when calculated with the 2D model Iber and 11500 m3·s-1 when calculated with the Manning equation.

  7. Achieving Peak Flow and Sediment Loading Reductions through Increased Water Storage in the Le Sueur Watershed, Minnesota: A Modeling Approach

    NASA Astrophysics Data System (ADS)

    Mitchell, N. A.; Gran, K. B.; Cho, S. J.; Dalzell, B. J.; Kumarasamy, K.

    2015-12-01

    A combination of factors including climate change, land clearing, and artificial drainage have increased many agricultural regions' stream flows and rates at which channel banks and bluffs are eroded. Increasing erosion rates within the Minnesota River Basin have contributed to higher sediment-loading rates, excess turbidity levels, and increases in sedimentation rates in Lake Pepin further downstream. Water storage sites (e.g., wetlands) have been discussed as a means to address these issues. This study uses the Soil and Water Assessment Tool (SWAT) to assess a range of water retention site (WRS) implementation scenarios in the Le Sueur watershed in south-central Minnesota, a subwatershed of the Minnesota River Basin. Sediment loading from bluffs was assessed through an empirical relationship developed from gauging data. Sites were delineated as topographic depressions with specific land uses, minimum areas (3000 m2), and high compound topographic index values. Contributing areas for the WRS were manually measured and used with different site characteristics to create 210 initial WRS scenarios. A generalized relationship between WRS area and contributing area was identified from measurements, and this relationship was used with different site characteristics (e.g., depth, hydraulic conductivity (K), and placement) to create 225 generalized WRS scenarios. Reductions in peak flow volumes and sediment-loading rates are generally maximized by placing site with high K values in the upper half of the watershed. High K values allow sites to lose more water through seepage, emptying their storages between precipitation events and preventing frequent overflowing. Reductions in peak flow volumes and sediment-loading rates also level off at high WRS extents due to the decreasing frequencies of high-magnitude events. The generalized WRS scenarios were also used to create a simplified empirical model capable of generating peak flows and sediment-loading rates from near

  8. StreamStats in Oklahoma - Drainage-Basin Characteristics and Peak-Flow Frequency Statistics for Ungaged Streams

    USGS Publications Warehouse

    Smith, S. Jerrod; Esralew, Rachel A.

    2010-01-01

    drainage-basin outlet for the period 1961-1990, 10-85 channel slope (slope between points located at 10 percent and 85 percent of the longest flow-path length upstream from the outlet), and percent impervious area. The Oklahoma StreamStats application interacts with the National Streamflow Statistics database, which contains the peak-flow regression equations in a previously published report. Fourteen peak-flow (flood) frequency statistics are available for computation in the Oklahoma StreamStats application. These statistics include the peak flow at 2-, 5-, 10-, 25-, 50-, 100-, and 500-year recurrence intervals for rural, unregulated streams; and the peak flow at 2-, 5-, 10-, 25-, 50-, 100-, and 500-year recurrence intervals for rural streams that are regulated by Natural Resources Conservation Service floodwater retarding structures. Basin characteristics and streamflow statistics cannot be computed for locations in playa basins (mostly in the Oklahoma Panhandle) and along main stems of the largest river systems in the state, namely the Arkansas, Canadian, Cimarron, Neosho, Red, and Verdigris Rivers, because parts of the drainage areas extend outside of the processed hydrologic units.

  9. From Anzac to Afghanistan: have 100 years taught us nothing about the devastation of war?

    PubMed

    Carragee, Eugene J

    2015-12-01

    Commentary On: Atkinson Brigadier (Ret'd) RN, Fraser RD. 100 years-Anzac, Vietnam to now. Spine J 2015:15:2454-6 (in this issue). Robertson PA. Gallipoli 100 years on: a New Zealand perspective. Spine J 2015:15:2457-8 (in this issue).

  10. Model for predicting peak expiratory flow rate of Nigerian workers in a cement factory in Itori, Ogun State, Nigeria.

    PubMed

    Ismaila, Salami Olasunkanmi; Akanbi, Olusegun Gabriel; Olaoniye, Wasiu

    2015-01-01

    The main aim of the study was to propose a model for predicting the peak expiratory flow rate (PEFR) of Nigerian workers in a cement factory. Sixty randomly selected non-smoker and healthy workers (30 in production sections, 30 in the administrative section of the factory) participated in the study. Their physical characteristics and PEFR were measured. Multiple correlations using SPSS version 16.0 were performed on the data. The values of PEFR, using the obtained model, were compared with the measured values using a two-tailed t test. There were positive correlations among age, height and PEFR. A prediction equation for PEFR based on age, height, weight and years of exposure (experience) was obtained with R² = .843 (p < 0.001). The developed model will be useful for the management in determining PEFR of workers in the cement industry for possible medical attention.

  11. Applying Physically Representative Watershed Modelling to Assess Peak and Low Flow Response to Timber Harvest: Application for Watershed Assessments

    NASA Astrophysics Data System (ADS)

    MacDonald, R. J.; Anderson, A.; Silins, U.; Craig, J. R.

    2014-12-01

    Forest harvesting, insects, disease, wildfire, and other disturbances can combine with climate change to cause unknown changes to the amount and timing of streamflow from critical forested watersheds. Southern Alberta forest and alpine areas provide downstream water supply for agriculture and water utilities that supply approximately two thirds of the Alberta population. This project uses datasets from intensely monitored study watersheds and hydrological model platforms to extend our understanding of how disturbances and climate change may impact various aspects of the streamflow regime that are of importance to downstream users. The objectives are 1) to use the model output of watershed response to disturbances to inform assessments of forested watersheds in the region, and 2) to investigate the use of a new flexible modelling platform as a tool for detailed watershed assessments and hypothesis testing. Here we applied the RAVEN hydrological modelling framework to quantify changes in key hydrological processes driving peak and low flows in a headwater catchment along the eastern slopes of the Canadian Rocky Mountains. The model was applied to simulate the period from 2006 to 2011 using data from the Star Creek watershed in southwestern Alberta. The representation of relevant hydrological processes was verified using snow survey, meteorological, and vegetation data collected through the Southern Rockies Watershed Project. Timber harvest scenarios were developed to estimate the effects of cut levels ranging from 20 to 100% over a range of elevations, slopes, and aspects. We quantified changes in the timing and magnitude of low flow and high flow events during the 2006 to 2011 period. Future work will assess changes in the probability of low and high flow events using a long-term meteorological record. This modelling framework enables relevant processes at the watershed scale to be accounted in a physically robust and computational efficient manner. Hydrologic

  12. Understand the impacts of wetland restoration on peak flow and baseflow by coupling hydrologic and hydrodynamic models

    NASA Astrophysics Data System (ADS)

    Gao, H.; Sabo, J. L.

    2016-12-01

    Wetlands as the earth's kidneys provides various ecosystem services, such as absorbing pollutants, purifying freshwater, providing habitats for diverse ecosystems, sustaining species richness and biodiversity. From hydrologic perspective, wetlands can store storm-flood water in flooding seasons and release it afterwards, which will reduce flood peaks and reshape hydrograph. Therefore, as a green infrastructure and natural capital, wetlands provides a competent alternative to manage water resources in a green way, with potential to replace the widely criticized traditional gray infrastructure (i.e. dams and dikes) in certain cases. However, there are few systematic scientific tools to support our decision-making on site selection and allow us to quantitatively investigate the impacts of restored wetlands on hydrological process, not only in local scale but also in the view of entire catchment. In this study, we employed a topographic index, HAND (the Height Above the Nearest Drainage), to support our decision on potential site selection. Subsequently, a hydrological model (VIC, Variable Infiltration Capacity) was coupled with a macro-scale hydrodynamic model (CaMa-Flood, Catchment-Based Macro-scale Floodplain) to simulate the impact of wetland restoration on flood peaks and baseflow. The results demonstrated that topographic information is an essential factor to select wetland restoration location. Different reaches, wetlands area and the change of roughness coefficient should be taken into account while evaluating the impacts of wetland restoration. The simulated results also clearly illustrated that wetland restoration will increase the local storage and decrease the downstream peak flow which is beneficial for flood prevention. However, its impact on baseflow is ambiguous. Theoretically, restored wetlands will increase the baseflow due to the slower release of the stored flood water, but the increase of wetlands area may also increase the actual evaporation

  13. Evaluation of polyvinylidene fluoride nasal sensor to assess deviated nasal septum in comparision with peak nasal inspiratory flow measurements.

    PubMed

    Manjunatha, Roopa G; Rajanna, K; Mahapatra, D Roy; Prakash, Surya

    2014-01-01

    Deviated nasal septum (DNS) is one of the major causes of nasal obstruction. Polyvinylidene fluoride (PVDF) nasal sensor is the new technique developed to assess the nasal obstruction caused by DNS. This study evaluates the PVDF nasal sensor measurements in comparison with PEAK nasal inspiratory flow (PNIF) measurements and visual analog scale (VAS) of nasal obstruction. Because of piezoelectric property, two PVDF nasal sensors provide output voltage signals corresponding to the right and left nostril when they are subjected to nasal airflow. The peak-to-peak amplitude of the voltage signal corresponding to nasal airflow was analyzed to assess the nasal obstruction. PVDF nasal sensor and PNIF were performed on 30 healthy subjects and 30 DNS patients. Receiver operating characteristic was used to analyze the DNS of these two methods. Measurements of PVDF nasal sensor strongly correlated with findings of PNIF (r = 0.67; p < 0.01) in DNS patients. A significant difference (p < 0.001) was observed between PVDF nasal sensor measurements and PNIF measurements of the DNS and the control group. A cutoff between normal and pathological of 0.51 Vp-p for PVDF nasal sensor and 120 L/min for PNIF was calculated. No significant difference in terms of sensitivity of PVDF nasal sensor and PNIF (89.7% versus 82.6%) and specificity (80.5% versus 78.8%) was calculated. The result shows that PVDF measurements closely agree with PNIF findings. Developed PVDF nasal sensor is an objective method that is simple, inexpensive, fast, and portable for determining DNS in clinical practice.

  14. Acute effects of bushfires on peak expiratory flow rates in children with wheeze: a time series analysis.

    PubMed

    Jalaludin, B; Smith, M; O'Toole, B; Leeder, S

    2000-04-01

    To determine the effects of the January 1994 Sydney bushfire on evening peak expiratory flow rates (PEFR) in children with wheeze. Children with a history of wheeze were enrolled in the longitudinal study and completed a daily asthma diary. We obtained daily air pollution, meteorological, pollen and alternaria data. We then used generalised estimating equation techniques to determine associations between the bushfire period and particulate matter less than 10 microns (PM10) and PEFR. The maximum daily PM10 level peaked at 210 ug/m3, which was nearly seven times the usual PM10 level for the rest of January and February 1994. There was no significant association between mean PM10 and PEFR (beta-coefficient = -0.009, p = 0.86). Children without bronchial hyper-reactivity had a significant negative association between PEFR and PM10 (beta-coefficient = -0.1029, p = 0.03). The bushfire period was not significant in any of the models. We did not find an association between the bushfire period or PM10 and evening PEFR, although in a subgroup of children without bronchial hyper-reactivity, a significant negative association was present between PM10 and evening PEFR. We conclude that the high levels of particulate pollution caused by the Sydney bushfires did not lead to any clinically significant reductions in PEFR in symptomatic children. Our results have implications for community risk communication during future bushfires.

  15. Cross-shift peak expiratory flow changes are unassociated with respirable coal dust exposure among South African coal miners

    SciTech Connect

    Naidoo, R.N.; Robins, T.G.; Becklake, M.; Seixas, N.; Thompson, M.L.

    2007-12-15

    he objectives of this study were to determine whether cross-shift changes in peak expiratory flow rate (PEFR) were related to respirable dust exposure in South African coalminers. Fifty workers were randomly selected from a cohort of 684 miners from 3 bituminous coal mines in Mpumalanga, South Africa. Peak expiratory efforts were measured prior to the commencement of the shift, and at the end of the shift on at least two occasions separated by at least 2 weeks, with full shift personal dust sampling being conducted on each occasion for each participant. Interviews were conducted, work histories were obtained and cumulative exposure estimates were constructed. Regression models examined the associations of cross-shift changes in PEFR with current and cumulative exposure, controlling for shift, smoking and past history of tuberculosis. There were marginal differences in cross-shift PEFR (ranging from 0.1 to 2 L/min). Linear regression analyses showed no association between cross-shift change in PEFR and current or cumulative exposure. The specific shift worked by participants in the study showed no effect. Our study showed no association between current respirable dust exposure and cross-shift changes in PEFR. There was a non-significant protective effect of cumulative dust exposure on the outcome, suggesting the presence of a 'healthy worker survivor effect' in this data.

  16. Quantifying volume reduction and peak flow mitigation for three bioretention cells in clay soils in northeast Ohio.

    PubMed

    Winston, Ryan J; Dorsey, Jay D; Hunt, William F

    2016-05-15

    Green infrastructure aims to restore watershed hydrologic function by more closely mimicking pre-development groundwater recharge and evapotranspiration (ET). Bioretention has become a popular stormwater control due to its ability to reduce runoff volume through these pathways. Three bioretention cells constructed in low permeability soils in northeast Ohio were monitored for non-winter quantification of inflow, drainage, ET, and exfiltration. The inclusion of an internal water storage (IWS) zone allowed the three cells to reduce runoff by 59%, 42%, and 36% over the monitoring period, in spite of the tight underlying soils. The exfiltration rate and the IWS zone thickness were the primary determinants of volume reduction performance. Post-construction measured drawdown rates were higher than pre-construction soil vertical hydraulic conductivity tests in all cases, due to lateral exfiltration from the IWS zones and ET, which are not typically accounted for in pre-construction soil testing. The minimum rainfall depths required to produce outflow for the three cells were 5.5, 7.4, and 13.8mm. During events with 1-year design rainfall intensities, peak flow reduction varied from 24 to 96%, with the best mitigation during events where peak rainfall rate occurred before the centroid of the rainfall volume, when adequate bowl storage was available to limit overflow.

  17. [Assessment of 2 portable peak expiratory flow meters and reference values for students 6 to 16 years of age].

    PubMed

    Cobos Barroso, N; Reverté Bover, C; Liñán Cortés, S

    1996-12-01

    This study examines the technical characteristics of two different peak expiratory flow meters, of high range, and the reference values of peak expiratory flow (PEF) for schoolchildren. The gauge accuracy and precision were previously determined in 20 units of each model (PF-Control and Mini-Wright), with a syringe servocontrolled by simulating 4 predetermined PEF fluxes (125, 262, 424 and 587 L/min). Relatives were asked about passive smoking and the childhood background concerning asthma, recurrent bronchitis or recent respiratory infection. The PEF of 1,142 schoolchildren, 669 boys and 473 girls between 6 and 16 years of age and coming from 6 different locations of different demographic and social characteristic of Catalonia, Spain, were measured. Readings of both gauges differed in accuracy, although they presented a good intradevice precision. The PF-control is within the reliance intervals for fluxes of 425 and 587 L/min, with a suprareading of 15.3% for the 262 L/min and infrareading of 19.2% for the 125 L/min controls. Flux with the Mini-Wright shows systematic over-reading of between 17.9% and 30.2%, with an accurate reading only in the 587 L/min control flux. No significant correlation was found between the PEF and family passive smoking (56.3%), pupils with asthma background (7.1%), recurrent bronchitis (11%) or recent respiratory infection (7.7%). The accuracy difference forces the use of diverse percentile tables for each of the PEF gauge patterns; hence, we present the reference tables for each gauge, in means of 10, 50 and 90 percentiles, which can be used as reference values for our school population according to their age, size and sex.

  18. Serial Peak Expiratory Flow Rates in Patients Undergoing Upper Abdominal Surgeries Under General Anaesthesia and Thoracic Epidural Analgesia.

    PubMed

    Misquith, Julie C R; Rao, Rammoorthi; Ribeiro, Karl Sa

    2016-02-01

    Anaesthesia and upper abdominal surgeries alter lung compliance and functional residual capacity resulting from atelectasis. Upper abdominal surgeries also cause a decrease in peak expiratory flow rates, cough reflex due to pain limited inspiration. This study aimed to study the effect of thoracic epidural analgesia (TEA) on the peak expiratory flow rates in patients undergoing upper abdominal surgeries. A total of 44 patients posted for elective surgery were enrolled. Group 1 patients received GA + 0.125% bupivacaine infusion TEA and Group 2 received GA + Inj. Diclofenac sodium 50 mg slow i.v. TID for Postoperative analgesia. Haemodynamics, VAS pain score, PEFR measurements were done at 60 minutes, 24 hours, 48 hours and 4 days after surgery in both groups. ABG analysis was taken pre operatively and 24 hours after surgery. The SBP and DBP values obtained at 60 minutes (p<0.016) 24 and 48 hours (p<0.001) and day 4 (p<0.02) postoperative showed highly significant difference between the two groups which indicate better haemodynamic parameters in patients receiving epidural analgesia. Postoperatively the difference in PEFR values at 60 minutes, 24 hour, 48 hour and day 4 were very highly significant. (p<0.001). Group1 had a 10.739% deficit on day 4 from its pre operative baseline value while group 2 showed a 34.825 % deficit which was very highly significant (p<0.001). The difference in VAS scores recorded at 60 minutes, 24 hours, 48 hours and day 4 post op were very highly statistically significant (p < 0.001). The ABG taken at 24 hours shows statistically significant difference with patients in group 2 showing decreased values in pCO2 and pO2 reflecting poorer ventilation and oxygenation. Thoracic epidural analgesia provides superior analgesia, better cough reflex as seen by better PEFR values, were haemodynamically more stable and their ABG values were better than the NSAID group.

  19. Effects of inactivated influenza virus vaccination on bronchial reactivity symptom scores and peak expiratory flow variability in patients with asthma.

    PubMed

    Sener, M; Gürsel, G; Türktaş, H

    1999-01-01

    Even though annual influenza vaccinations are recommended by many authorities, some doctors may be reluctant to vaccinate asthmatic patients because of the risk of inducing bronchial reactivity and exacerbating the asthma. In this study we investigated the effect of inactivated trivalent influenza vaccine on airway reactivity symptom scores and peak expiratory flow (PEF) variability in 24 patients with mild stable asthma. Baseline spirometry and methacholine challenge tests were performed on all patients. Patients were then asked to record their peak expiratory flow every morning and evening, complete daily symptom score charts (morning tightness, daytime asthma, cough, and night asthma), and note bronchodilator usage for 1 week. After baseline measurements, the patients were allocated to inactivated vaccine and placebo in a random and single-blind manner. The lung function measurements and methacholine challenge tests were repeated 1 week after vaccination and placebo administration at the same time of day. PD20 (mg/mL) methacholine doses were 3.06+/-3.0 mg/mL before vaccination, 2.96+/-3.2 mg/mL after vaccination, and 2.76+/-2.91 mg/mL after placebo administration. There were no significant changes in PD20 methacholine after influenza vaccination (p>0.05). There were also no significant changes in symptom scores, bronchodilator usage, and PEFR after vaccination (p>0.05). None of the patients experienced significant local or systemic side effects after vaccination. Immunization with inactivated influenza vaccine does not induce clinical exacerbations of asthma or airway hyperreactivity in patients with mild asthma.

  20. Estimated Magnitudes and Recurrence Intervals of Peak Flows on the Mousam and Little Ossipee Rivers for the Flood of April 2007 in Southern Maine

    USGS Publications Warehouse

    Hodgkins, Glenn A.; Stewart, Gregory J.; Cohn, Timothy A.; Dudley, Robert W.

    2007-01-01

    Large amounts of rain fell on southern Maine from the afternoon of April 15, 2007, to the afternoon of April 16, 2007, causing substantial damage to houses, roads, and culverts. This report provides an estimate of the peak flows on two rivers in southern Maine--the Mousam River and the Little Ossipee River--because of their severe flooding. The April 2007 estimated peak flow of 9,230 ft3/s at the Mousam River near West Kennebunk had a recurrence interval between 100 and 500 years; 95-percent confidence limits for this flow ranged from 25 years to greater than 500 years. The April 2007 estimated peak flow of 8,220 ft3/s at the Little Ossipee River near South Limington had a recurrence interval between 100 and 500 years; 95-percent confidence limits for this flow ranged from 50 years to greater than 500 years.

  1. Real-time three-dimensional color Doppler echocardiography for characterizing the spatial velocity distribution and quantifying the peak flow rate in the left ventricular outflow tract

    NASA Technical Reports Server (NTRS)

    Tsujino, H.; Jones, M.; Shiota, T.; Qin, J. X.; Greenberg, N. L.; Cardon, L. A.; Morehead, A. J.; Zetts, A. D.; Travaglini, A.; Bauer, F.; Panza, J. A.; Thomas, J. D.

    2001-01-01

    Quantification of flow with pulsed-wave Doppler assumes a "flat" velocity profile in the left ventricular outflow tract (LVOT), which observation refutes. Recent development of real-time, three-dimensional (3-D) color Doppler allows one to obtain an entire cross-sectional velocity distribution of the LVOT, which is not possible using conventional 2-D echo. In an animal experiment, the cross-sectional color Doppler images of the LVOT at peak systole were derived and digitally transferred to a computer to visualize and quantify spatial velocity distributions and peak flow rates. Markedly skewed profiles, with higher velocities toward the septum, were consistently observed. Reference peak flow rates by electromagnetic flow meter correlated well with 3-D peak flow rates (r = 0.94), but with an anticipated underestimation. Real-time 3-D color Doppler echocardiography was capable of determining cross-sectional velocity distributions and peak flow rates, demonstrating the utility of this new method for better understanding and quantifying blood flow phenomena.

  2. Real-time three-dimensional color Doppler echocardiography for characterizing the spatial velocity distribution and quantifying the peak flow rate in the left ventricular outflow tract

    NASA Technical Reports Server (NTRS)

    Tsujino, H.; Jones, M.; Shiota, T.; Qin, J. X.; Greenberg, N. L.; Cardon, L. A.; Morehead, A. J.; Zetts, A. D.; Travaglini, A.; Bauer, F.; hide

    2001-01-01

    Quantification of flow with pulsed-wave Doppler assumes a "flat" velocity profile in the left ventricular outflow tract (LVOT), which observation refutes. Recent development of real-time, three-dimensional (3-D) color Doppler allows one to obtain an entire cross-sectional velocity distribution of the LVOT, which is not possible using conventional 2-D echo. In an animal experiment, the cross-sectional color Doppler images of the LVOT at peak systole were derived and digitally transferred to a computer to visualize and quantify spatial velocity distributions and peak flow rates. Markedly skewed profiles, with higher velocities toward the septum, were consistently observed. Reference peak flow rates by electromagnetic flow meter correlated well with 3-D peak flow rates (r = 0.94), but with an anticipated underestimation. Real-time 3-D color Doppler echocardiography was capable of determining cross-sectional velocity distributions and peak flow rates, demonstrating the utility of this new method for better understanding and quantifying blood flow phenomena.

  3. Fractures, stress and fluid flow prior to stimulation of well 27-15, Desert Peak, Nevada, EGS project

    USGS Publications Warehouse

    Davatzes, Nicholas C.; Hickman, Stephen H.

    2009-01-01

    A suite of geophysical logs has been acquired for structural, fluid flow and stress analysis of well 27-15 in the Desert Peak Geothermal Field, Nevada, in preparation for stimulation and development of an Enhanced Geothermal System (EGS). Advanced Logic Technologies Borehole Televiewer (BHTV) and Schlumberger Formation MicroScanner (FMS) image logs reveal extensive drilling-induced tensile fractures, showing that the current minimum compressive horizontal stress, Shmin, in the vicinity of well 27-15 is oriented along an azimuth of 114±17°. This orientation is consistent with the dip direction of recently active normal faults mapped at the surface and with extensive sets of fractures and some formation boundaries seen in the BHTV and FMS logs. Temperature and spinner flowmeter surveys reveal several minor flowing fractures that are well oriented for normal slip, although over-all permeability in the well is quite low. These results indicate that well 27-15 is a viable candidate for EGS stimulation and complements research by other investigators including cuttings analysis, a reflection seismic survey, pressure transient and tracer testing, and micro-seismic monitoring.

  4. Two-station comparison of peak flows to improve flood-frequency estimates for seven streamflow-gaging stations in the Salmon and Clearwater River Basins, Central Idaho

    USGS Publications Warehouse

    Berenbrock, Charles

    2003-01-01

    Improved flood-frequency estimates for short-term (10 or fewer years of record) streamflow-gaging stations were needed to support instream flow studies by the U.S. Forest Service, which are focused on quantifying water rights necessary to maintain or restore productive fish habitat. Because peak-flow data for short-term gaging stations can be biased by having been collected during an unusually wet, dry, or otherwise unrepresentative period of record, the data may not represent the full range of potential floods at a site. To test whether peak-flow estimates for short-term gaging stations could be improved, the two-station comparison method was used to adjust the logarithmic mean and logarithmic standard deviation of peak flows for seven short-term gaging stations in the Salmon and Clearwater River Basins, central Idaho. Correlation coefficients determined from regression of peak flows for paired short-term and long-term (more than 10 years of record) gaging stations over a concurrent period of record indicated that the mean and standard deviation of peak flows for all short-term gaging stations would be improved. Flood-frequency estimates for seven short-term gaging stations were determined using the adjusted mean and standard deviation. The original (unadjusted) flood-frequency estimates for three of the seven short-term gaging stations differed from the adjusted estimates by less than 10 percent, probably because the data were collected during periods representing the full range of peak flows. Unadjusted flood-frequency estimates for four short-term gaging stations differed from the adjusted estimates by more than 10 percent; unadjusted estimates for Little Slate Creek and Salmon River near Obsidian differed from adjusted estimates by nearly 30 percent. These large differences probably are attributable to unrepresentative periods of peak-flow data collection.

  5. Peak-Flow Frequency Estimates Based on Data through Water Year 2001 for Selected Streamflow-Gaging Stations in South Dakota

    USGS Publications Warehouse

    Sando, Steven K.; Driscoll, Daniel G.; Parrett, Charles

    2008-01-01

    Numerous users, including the South Dakota Department of Transportation, have continuing needs for peak-flow information for the design of highway infrastructure and many other purposes. This report documents results from a cooperative study between the South Dakota Department of Transportation and the U.S. Geological Survey to provide an update of peak-flow frequency estimates for South Dakota. Estimates of peak-flow magnitudes for 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year recurrence intervals are reported for 272 streamflow-gaging stations, which include most gaging stations in South Dakota with 10 or more years of systematic peak-flow records through water year 2001. Recommended procedures described in Bulletin 17B were used as primary guidelines for developing peak-flow frequency estimates. The computer program PEAKFQ developed by the U.S. Geological Survey was used to run the frequency analyses. Flood frequencies for all stations were initially analyzed by using standard Bulletin 17B default procedures for fitting the log-Pearson III distribution. The resulting preliminary frequency curves were then plotted on a log-probability scale, and fits of the curves with systematic data were evaluated. In many cases, results of the default Bulletin 17B analyses were determined to be satisfactory. In other cases, however, the results could be improved by using various alternative procedures for frequency analysis. Alternative procedures for some stations included adjustments to skew coefficients or use of user-defined low-outlier criteria. Peak-flow records for many gaging stations are strongly influenced by low- or zero-flow values. This situation often results in a frequency curve that plots substantially above the systematic record data points at the upper end of the frequency curve. Adjustments to low-outlier criteria reduced the influence of very small peak flows and generally focused the analyses on the upper parts of the frequency curves (10- to 500-year

  6. Determination of the 100-year flood plain on Upper Three Runs and selected tributaries, and the Savannah River at the Savannah River site, South Carolina, 1995

    USGS Publications Warehouse

    Lanier, T.H.

    1996-01-01

    The 100-year flood plain was determined for Upper Three Runs, its tributaries, and the part of the Savannah River that borders the Savannah River Site. The results are provided in tabular and graphical formats. The 100-year flood-plain maps and flood profiles provide water-resource managers of the Savannah River Site with a technical basis for making flood-plain management decisions that could minimize future flood problems and provide a basis for designing and constructing drainage structures along roadways. A hydrologic analysis was made to estimate the 100-year recurrence- interval flow for Upper Three Runs and its tributaries. The analysis showed that the well-drained, sandy soils in the head waters of Upper Three Runs reduce the high flows in the stream; therefore, the South Carolina upper Coastal Plain regional-rural-regression equation does not apply for Upper Three Runs. Conse- quently, a relation was established for 100-year recurrence-interval flow and drainage area using streamflow data from U.S. Geological Survey gaging stations on Upper Three Runs. This relation was used to compute 100-year recurrence-interval flows at selected points along the stream. The regional regression equations were applicable for the tributaries to Upper Three Runs, because the soil types in the drainage basins of the tributaries resemble those normally occurring in upper Coastal Plain basins. This was verified by analysis of the flood-frequency data collected from U.S. Geological Survey gaging station 02197342 on Fourmile Branch. Cross sections were surveyed throughout each reach, and other pertinent data such as flow resistance and land-use were col- lected. The surveyed cross sections and computed 100-year recurrence-interval flows were used in a step-backwater model to compute the 100-year flood profile for Upper Three Runs and its tributaries. The profiles were used to delineate the 100-year flood plain on topographic maps. The Savannah River forms the southwestern border

  7. Diurnal variation in peak expiratory flow rate among workers exposed to toluene diisocyanate in the polyurethane foam manufacturing industry.

    PubMed

    Lee, H S; Phoon, W H

    1992-06-01

    The diurnal variation in peak expiratory flow rate (PEFR) was studied in 26 mixers from eight factories making polyurethane foam, who were exposed to toluene diisocyanate (TDI), and 26 unexposed controls matched for age, race, and smoking. They were all men. The mean diurnal variation in PEFR of the mixers was 6.2%, which was significantly higher than the 4.3% for controls. Six mixers had a diurnal variation of greater than 15% on at least one day compared with none among the controls. There was, however, no overt cause of occupational asthma. All but one of the 24 environmental samples taken exceeded the short term exposure limit of 0.02 ppm for TDI. This accounted for the high prevalence (50%) of irritative symptoms such as cough and eye irritation. Forced expiratory volume in one second (FEV1) and FEV1/forced vital capacity (FVC) (%) was negatively correlated with duration of exposure to TDI. Foam workers may still have high exposure to TDI, high prevalence of irritative symptoms, increased diurnal variation in PEFR and evidence of chronic airway obstruction, particularly in those with greater than or equal to 10 years of exposure.

  8. Decreased Peak Expiratory Flow Associated with Muscle Fiber-Type Switching in Spinal and Bulbar Muscular Atrophy.

    PubMed

    Yamada, Shinichiro; Hashizume, Atsushi; Hijikata, Yasuhiro; Inagaki, Tomonori; Suzuki, Keisuke; Kondo, Naohide; Kawai, Kaori; Noda, Seiya; Nakanishi, Hirotaka; Banno, Haruhiko; Hirakawa, Akihiro; Koike, Haruki; Halievski, Katherine; Jordan, Cynthia L; Katsuno, Masahisa; Sobue, Gen

    2016-01-01

    The aim of this study was to characterize the respiratory function profile of subjects with spinal and bulbar muscular atrophy (SBMA), and to explore the underlying pathological mechanism by comparing the clinical and biochemical indices of this disease with those of amyotrophic lateral sclerosis (ALS). We enrolled male subjects with SBMA (n = 40) and ALS (n = 25) along with 15 healthy control subjects, and assessed their respiratory function, motor function, and muscle strength. Predicted values of peak expiratory flow (%PEF) and forced vital capacity were decreased in subjects with SBMA compared with controls. In SBMA, both values were strongly correlated with the trunk subscores of the motor function tests and showed deterioration relative to disease duration. Compared with activities of daily living (ADL)-matched ALS subjects, %PEF, tongue pressure, and grip power were substantially decreased in subjects with SBMA. Both immunofluorescence and RT-PCR demonstrated a selective decrease in the expression levels of the genes encoding the myosin heavy chains specific to fast-twitch fibers in SBMA subjects. The mRNA levels of peroxisome proliferator-activated receptor gamma coactivator 1-alpha and peroxisome proliferator-activated receptor delta were up-regulated in SBMA compared with ALS and controls. In conclusion, %PEF is a disease-specific respiratory marker for the severity and progression of SBMA. Explosive muscle strength, including %PEF, was selectively affected in subjects with SBMA and was associated with activation of the mitochondrial biogenesis-related molecular pathway in skeletal muscles.

  9. Decreased Peak Expiratory Flow Associated with Muscle Fiber-Type Switching in Spinal and Bulbar Muscular Atrophy

    PubMed Central

    Yamada, Shinichiro; Hashizume, Atsushi; Hijikata, Yasuhiro; Inagaki, Tomonori; Suzuki, Keisuke; Kondo, Naohide; Kawai, Kaori; Noda, Seiya; Nakanishi, Hirotaka; Banno, Haruhiko; Hirakawa, Akihiro; Koike, Haruki; Halievski, Katherine; Jordan, Cynthia L.; Katsuno, Masahisa; Sobue, Gen

    2016-01-01

    The aim of this study was to characterize the respiratory function profile of subjects with spinal and bulbar muscular atrophy (SBMA), and to explore the underlying pathological mechanism by comparing the clinical and biochemical indices of this disease with those of amyotrophic lateral sclerosis (ALS). We enrolled male subjects with SBMA (n = 40) and ALS (n = 25) along with 15 healthy control subjects, and assessed their respiratory function, motor function, and muscle strength. Predicted values of peak expiratory flow (%PEF) and forced vital capacity were decreased in subjects with SBMA compared with controls. In SBMA, both values were strongly correlated with the trunk subscores of the motor function tests and showed deterioration relative to disease duration. Compared with activities of daily living (ADL)-matched ALS subjects, %PEF, tongue pressure, and grip power were substantially decreased in subjects with SBMA. Both immunofluorescence and RT-PCR demonstrated a selective decrease in the expression levels of the genes encoding the myosin heavy chains specific to fast-twitch fibers in SBMA subjects. The mRNA levels of peroxisome proliferator-activated receptor gamma coactivator 1-alpha and peroxisome proliferator-activated receptor delta were up-regulated in SBMA compared with ALS and controls. In conclusion, %PEF is a disease-specific respiratory marker for the severity and progression of SBMA. Explosive muscle strength, including %PEF, was selectively affected in subjects with SBMA and was associated with activation of the mitochondrial biogenesis-related molecular pathway in skeletal muscles. PMID:28005993

  10. Ovine luteinizing hormone. V. Significance of flow-through peaks observed during chromatofocusing as revealed by various methods of sample preparation and application.

    PubMed

    Grotjan, H E; Schanbacher, B D; Keel, B A

    1991-07-19

    In a previous study [Keel et al., Biol, Reprod., 36 (1987) 1102] the ovine luteinizing hormone (oLH) in pituitary extracts was chromatofocused on pH 10.5-7 gradients after equilibration in 25 mM triethylamine-HCl, pH 11.0, by gel permeation. Under these conditions, some immunoreactive oLH flowed through the columns unrestricted and this was interpreted to represent extremely basic isoforms. However, when selected flow-through peaks were re-chromatofocused, each was contaminated with other isoforms of oLH. In order to clarify this dilemma, various methods of sample preparation and application were systematically compared. Consistent with previous observations, variable amounts of the immunoreactive oLH in pituitary extracts equilibrated in triethylamine by gel permeation, dialysis, flow dialysis or ion-retardation chromatography eluted as flow-through peaks when chromatofocused. In contrast, when the ionic components in the pituitary homogenization buffer were removed by these methods as well as ultrafiltration and the proteins were applied to the resin in the elution buffer (1:45 Pharmalyte 8-10.5-HCl, pH 7.0), none of the immunoreactive oLH in pituitary extracts eluted as a flow-through peak. Thus, it appears that oLH eluting as a flow-through peak results from incomplete binding of the hormone to the chromatofocusing resin when applied in triethylamine.

  11. Effect of bedding control on amount of house dust mite allergens, asthma symptoms, and peak expiratory flow rate.

    PubMed

    Lee, Inn-Sook

    2003-04-30

    This quasi-experimental study was designed to investigate the effect of bedding control on the amount of house dust mite (HDM) allergens, asthma symptoms, and peak expiratory flow rate (PEFR) in asthmatics sensitive to HDMs. The subjects in the study were drawn from patients receiving treatment at the allergy clinics of three university-affiliated hospitals in Seoul. Forty-two patients without prior practice of the bedding control used in this study were selected. They commonly showed bronchial asthma caused by HDMs, and exhibited strong positive points (more than 3 points) in skin prick test (D. farinae, D. pteronyssinus), and positive response in both fluoro-allergosorbent test (FAST), and PC20 methacholine test. Of the subjects, alternatively, 22 were assigned to the experimental group and 20 to control group. Bedding control consisted of the use of outer cotton covers, boiling them for 10 minutes fortnightly, and disinfecting bedding by sunlight fortnightly. The experimental group was under bedding control for 4 weeks. The data were collected from October 2000 to January 2001. The results were as follows: 1. After bedding control, the total amount of HDM allergens decreased significantly in the experimental group. However there was no significant difference in the decrease of the amount of HDM allergens between the two groups. 2. Of the asthma symptoms, there was significant difference only in the decrease of the frequency of dyspnea, and in the increase of sleeping disturbance between the two groups after bedding control. 3. After bedding control, PEFR increased in the experimental group whereas it decreased in the control group. However, neither change was significant. The above findings indicate that bedding control improved several asthma symptoms in asthmatics sensitive to HDMs. Accordingly, we suggest that bedding control is adopted as a useful nursing intervention in the field.

  12. Prolonged slow expiration technique in infants: effects on tidal volume, peak expiratory flow, and expiratory reserve volume.

    PubMed

    Lanza, Fernanda C; Wandalsen, Gustavo; Dela Bianca, Ana Caroline; Cruz, Carolina L; Postiaux, Guy; Solé, Dirceu

    2011-12-01

    Prolonged slow expiration (PSE) is a physiotherapy technique often applied in infants to reduce pulmonary obstruction and clear secretions, but there have been few studies of PSE's effects on the respiratory system. To describe PSE's effects on respiratory mechanics in infants. We conducted a cross-sectional study with 18 infants who had histories of recurrent wheezing. The infants were sedated for lung-function testing, which was followed by PSE. The PSE consisted of 3 sequences of prolonged manual thoraco-abdominal compressions during the expiratory phase. We measured peak expiratory flow (PEF), tidal volume (V(T)), and the frequency of sighs during and immediately after PSE. We described the exhaled volume during PSE as a fraction of expiratory reserve volume (%ERV). We quantified ERV with the raised-volume rapid-thoracic-compression technique. The cohort's mean age was 32.2 weeks, and they had an average of 4.8 previous wheezing episodes. During PSE there was significant V(T) reduction (80 ± 17 mL vs 49 ± 11 mL, P < .001), no significant change in PEF (149 ± 32 mL/s vs 150 ± 32 mL/s, P = .54), and more frequent sighs (40% vs 5%, P = .03), compared to immediately after PSE. The exhaled volume increased in each PSE sequence (32 ± 18% of ERV, 41 ± 24% of ERV, and 53 ± 20% of ERV, P = .03). It was possible to confirm and quantify that PSE deflates the lung to ERV. PSE caused no changes in PEF, induced sigh breaths, and decreased V(T), which is probably the main mechanical feature for mucus clearance.

  13. Discharge, gage height, and elevation of 100-year floods in the Hudson River basin, New York

    USGS Publications Warehouse

    Archer, Roger J.

    1978-01-01

    The flood discharge that may be expected to be equaled or exceeded on the average of once in 100 years (100-year flood) was computed by the log-Pearson Type-III frequency relation for 72 stations in the Hudson River basin. These discharges and, where available, their corresponding gage height and elevation above mean sea level are presented in tabular form. A short explanation of computation methods is included. The data are to be used as part of a federally funded study of the water resources and related land resources of the Hudson River basin. (Woodard-USGS)

  14. Peak Flow Responses to Forest Harvesting and Roads in the Maritime Regions of the Pacific Northwest: A Preferential Hillslope Runoff Perspective

    NASA Astrophysics Data System (ADS)

    Alila, Y.; Schnorbus, M.

    2005-12-01

    The debate regarding peak flow responses to forest clearcutting and road building in the maritime regions of the Pacific Northwest has attracted much attention over the past several decades and its outcome is an important scientific and operational concern. Although there appears to be general consensus that small peak discharge events are increased following forest management activities, little conclusive evidence exists regarding the impact of forest management activities on large events. Statistical tests in traditional paired watershed studies have been used to accept or reject hypotheses regarding peak flow responses to clearcutting and roads but provided no insight into watershed processes and other factors leading to their outcome. Furthermore, statistical analyses of peak flow responses to forestry activities in traditional paired watershed studies are confounded by the many factors that may contribute to management effects on watershed hydrology as well as by issues such as shortness of streamflow records and climate variability. To this end, a new perspective is offered in the debate regarding peak flow responses to clearcutting and road building in the maritime regions of the Pacific Northwest by combining numerical modeling with high-quality hydro-meteorological data collected at the 10-km2 Carnation Creek on the west coast of Vancouver Island, British Columbia (BC). In this approach we explicitly account for changes in evapotranspiration loss, forest road construction and, in particular, introduce the concept of the competing influences of matrix versus preferential hillslope runoff. For scenarios involving road construction, forest clearcutting (52% cut rate) and roads and clearcutting combined, peak discharge increases decrease with decreasing event frequency and statistically significant ( = 0.05) increases in peak flow are confined to events with a 1 year or lower return period. For a range of return periods from 0.17 to 20 years, the effect (i

  15. Assessment Gaze, Refraction, and Blur: The Course of Achievement Testing in the Past 100 Years

    ERIC Educational Resources Information Center

    Baker, Eva L.; Chung, Gregory K. W. K.; Cai, Li

    2016-01-01

    This chapter addresses assessment (testing) with an emphasis on the 100-year period since the American Education Research Association was formed. The authors start with definitions and explanations of contemporary tests. They then look backward into the 19th century to significant work by Horace Mann and Herbert Spencer, who engendered two…

  16. A Tale of 3 P's--Penmanship, Product, and Process: 100 Years of Elementary Writing Instruction

    ERIC Educational Resources Information Center

    Hawkins, Lisa K.; Razali, Abu Bakar

    2012-01-01

    From penmanship, to product, to process...this article recounts 100 years of instructional practice in the US elementary writing classroom through the voices of past teaching manuals and curriculum guides. This particular tale begins at the turn of the 20th century--a time when the elementary school was firmly established in the country, and…

  17. Assessment Gaze, Refraction, and Blur: The Course of Achievement Testing in the Past 100 Years

    ERIC Educational Resources Information Center

    Baker, Eva L.; Chung, Gregory K. W. K.; Cai, Li

    2016-01-01

    This chapter addresses assessment (testing) with an emphasis on the 100-year period since the American Education Research Association was formed. The authors start with definitions and explanations of contemporary tests. They then look backward into the 19th century to significant work by Horace Mann and Herbert Spencer, who engendered two…

  18. The life and times of the LED - a 100-year history

    NASA Astrophysics Data System (ADS)

    Zheludev, Nikolay

    2007-04-01

    Many people believe that the LED was discovered by US researchers working in the 1960s. In fact, Henry Round at Marconi Labs noted the emission of light from a semiconductor diode 100 years ago and, independently, a forgotten Russian genius - Oleg Losev - discovered the LED.

  19. Blister rust in North America: What we have not learned in the past 100 years

    Treesearch

    Eugene P. Van Arsdel; Brian W. Geils

    2011-01-01

    Introduction of Cronartium ribicola (white pine blister rust) greatly motivated development of tree disease control and research in America. Although foresters and pathologists have learned much in the past 100 years, more remains to learn. The most important lesson is that fear of blister rust has reduced pine regeneration more than the disease itself. Based on six...

  20. 100 Years of Cotton Production, Harvesting and Ginning Systems Engineering: 1907 - 2007

    USDA-ARS?s Scientific Manuscript database

    The American Society of Agricultural and Biological Engineers (ASABE) celebrated its centennial year during 2007. As part of the ASABE centennial, the authors were asked to describe agricultural engineering accomplishments in U.S. cotton production, harvesting and ginning over the past 100 years. ...

  1. What Would You Look Like If You Were 100 Years Old?

    ERIC Educational Resources Information Center

    Petersen, Hugh

    1998-01-01

    Describes a project inspired by the 100th day of school in which first-grade students created a self-portrait of themselves at 100 years old and wrote an accompanying essay. States that the students drew wrinkles on the faces, age-appropriate clothing, gray or white hair, and even glasses as a finishing touch. (CMK)

  2. ASTM Committee D-7 : Wood : promoting safety and standardization for 100 years

    Treesearch

    David W. Green; Robert L. Ethington

    2004-01-01

    In October 2004, Committee D-7 on Wood of the American Society for Testing and Materials (ASTM) is celebrating 100 years of contributions to the safe and efficient use of wood as a building material. Born during a period of rapid social, economic, and technological change, the Committee faced controversial issues and the challenge of a changing forest resource. This...

  3. Molecules at surfaces: 100 years of physical chemistry in Berlin-Dahlem.

    PubMed

    Ertl, Gerhard

    2013-01-02

    Scratching the surface: for over 100 years the interactions of molecules at surfaces have been studied at the Fritz Haber Institute of the Max Planck Society, Berlin. Nobel Laureate Gerhard Ertl looks back at some of the key developments in this time, and the people who made them. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Evaluation of runoff, peak flow and sediment yield for events simulated by the AnnAGNPS model in a Belgian agricultural watershed

    USDA-ARS?s Scientific Manuscript database

    The AnnAGNPS model, widely utilised as a practical tool in approaching erosion problems and land use planning, was implemented in a small agricultural watershed located in central Belgium, to assess its prediction capacity of runoff, peak flow and sediment yield in humid temperate conditions. Model ...

  5. The Effect on the Flow Conditions of Chinese Sturgeons’ Spawning Sites in the Process of Peak Regulation between the Three Gorges Dam and Gezhou Dam

    NASA Astrophysics Data System (ADS)

    Hui, Guo; Minghai, Huang; Feng, Jin

    Chinese sturgeon (Acipenser sinensis Gray) is a kind of key protected fish in ChangJiang river. Recently the Three Gorges dam has run, the peak regulation process between the two dams has serious effect on the formed spawning sites. Based on the previous research results of suitable flow conditions about the spawning sites, this article builds a 2-D shallow water numerical model, calculates the flow conditions of the spawning sites in the process of peak regulation. The results show that the water depth and velocity are various and affect the spawning sites in one 24-hours process of peak regulation, as a whole, when the discharge is below 9000 m3/s and 7500 m3/s respectively, the two spawning sites will be affected seriously.

  6. Phosphorus and dissolved organic carbon export during peak flow periods in three small homogenous catchments in eastern Germany

    NASA Astrophysics Data System (ADS)

    Benning, R.; Schwärzel, K.; Feger, K. H.

    2012-04-01

    Regional climate change scenarios for Central Europe predict both an overall increase in temperature and alterations in annual precipitation regimes. For large parts of Central Europe, climate change is expected to result in an increase in winter precipitation and a decrease in summer precipitation. In addition, an increase in extreme conditions, such as heat waves, prolonged drought periods, and heavy rainfall events are predicted. This research examines the potential impacts of increased heavy rainfall events on matter export from small catchment areas, and how different vegetation cover and land management options effects these exports. In order to evaluate the export of matter from different land-use types in the Eastern Ore Mountains (Saxony, NE Germany, 50° 48'18.06" North, 13° 36'24.54" East), study sites were established in three small catchments with homogeneous land-use. These study areas are each sub-catchments of the Ammelsdorf catchment, which provides inflow to the Lehnmühle reservoir (a major water supply for the city of Dresden). Each sub catchment represents one of the three main land-use types in the catchment area of the reservoir: crops (winter oilseed rape, winter wheat), grasslands, and forests (primarily spruce). Since November 2009 the discharge from these sub catchments has been continuously measured and water quality was analyzed on a weekly basis. During peak flow events, discharge was collected using automatic water samplers, which allowed for high temporal resolution analysis of matter export during these periods to be made. During the 2010 and 2011 hydrological years, several heavy rainfall events occurred which have been evaluated. During a 110-hour long precipitation event (P = 170 mm) between 37 and 81 water samples per sub catchment were collected and analyzed. The resulting export of dissolved phosphorus (ortho-PO4-) and dissolved organic carbon (DOC) from the sub catchments during this event is provided in the results. In

  7. Effects of Air Stacking Maneuver on Cough Peak Flow and Chest Wall Compartmental Volumes of Subjects With Amyotrophic Lateral Sclerosis.

    PubMed

    Sarmento, Antonio; Resqueti, Vanessa; Dourado-Júnior, Mario; Saturnino, Lailane; Aliverti, Andrea; Fregonezi, Guilherme; de Andrade, Armele Dornelas

    2017-05-17

    To assess the acute effects of air stacking on cough peak flow (CPF) and chest wall compartmental volumes of persons with amyotrophic lateral sclerosis (ALS) versus healthy subjects positioned at 45° body inclination. Cross-sectional study with a matched-pair design. University hospital. Persons (N=24) with ALS (n=12) and age-matched healthy subjects (n=12). CPF, chest wall compartmental inspiratory capacity, chest wall vital capacity, chest wall tidal volume and operational volumes, breathing pattern, and percentage of contribution of the compartments to the inspired volume were measured by optoelectronic plethysmography. Compared with healthy subjects, significantly lower CPF (P=.007), chest wall compartmental inspiratory capacity (P<.001), chest wall vital capacity (P<.001), and chest wall tidal volume (P<.001) were found in subjects with ALS. Immediately after air stacking, CPF (P<.001) and chest wall compartmental inspiratory capacity (P<.001) significantly increased in both groups, with values returning to basal only in healthy subjects. After air stacking, the abdominal compartment (P=.004) was determined to be responsible for the inspired volume in subjects with ALS. Significantly higher chest wall vital capacity (P=.05) was observed in subjects with ALS 5 minutes after air stacking, with the rib cage compartment (P=.049) being responsible for volume change. No differences were found in chest wall vital capacity and compartmental volumes of healthy subjects. Chest wall tidal volume (P<.001) significantly increased during the protocol in the healthy subjects, mainly because of end-inspiratory (P<.001) and abdominal volumes (P=.008). No significant differences were observed in percentage of contribution of the compartments to the inspired volume and end-expiratory volume of both groups. No significant differences were found in chest wall tidal volume, operational volume, and breathing pattern in persons with ALS. Air stacking is effective in increasing CPF

  8. Peak Expiratory Flow, Breath Rate and Blood Pressure in Adults with Changes in Particulate Matter Air Pollution during the Beijing Olympics: A Panel Study

    PubMed Central

    Mu, Lina; Deng, Furong; Tian, Lili; Li, Yanli; Swanson, Mya; Ying, Jingjing; Browne, Richard W; Rittenhouse-Olson, Kate; Zhang, Junfeng (Jim); Zhang, Zuo-Feng; Bonner, Matthew R.

    2014-01-01

    Objectives This study aims to examine whether changes in short-term exposures to particulate matter are associated with changes in lung function, breath rate, and blood pressure among healthy adults and whether smoking status modifies the association. Methods We took advantage of the artificially controlled changes in air pollution levels that occurred during the 2008 Olympic Games in Beijing, China and conducted a panel study of 201 Beijing residents. Data were collected before, during, and after the Olympics, respectively. Linear mixed-effects models and generalized estimating equation models were used to compare measurements of peak expiratory flow, breath rate, blood pressure across the three time points. Results The mean values of peak expiratory flow were 346.0 L/min, 399.3 L/min, and 364.1 L/min over the three study periods. Peak expiratory flow levels increased in 78% of the participants when comparing the during- and pre- Olympics time points, while peak expiratory flow levels decreased in 80% of participants for the post- and during-Olympic periods comparison. In subgroup analyses comparing the during -Olympic to pre-Olympic time points, we found a larger percentage change in peak expiratory flow (+17%) among female, younger and non-smoking participants than among male, elderly and smoking participants (+12%). The percentage of participants with a fast breath rate (>20/min) changed from 9.7%, to 4.9%, to 30.1% among females, and from 7.9%, to 2.6%, to 27.3% among males over the three time points respectively. The changes on blood pressure over the three study periods were not very clear, although there is an increase in diastolic pressure and a decrease in pulse pressure among males during the games. Conclusions The results suggest that exposure to different air pollution levels has significant effects on respiratory function. Smoking, age and gender appear to modify participants’ biological response to changes in air quality. PMID:24906062

  9. Improving Peak Capacity in Fast On-Line Comprehensive Two-Dimensional Liquid Chromatography with Post First Dimension Flow-Splitting

    PubMed Central

    Filgueira, Marcelo R.; Huang, Yuan; Witt, Klaus; Castells, Cecilia; Carr, Peter W.

    2011-01-01

    The use of flow splitters between the two dimensions in on-line comprehensive two dimensional liquid chromatography (LC×LC) has not received very much attention in comparison to their use in GC×GC where they are quite common. In principle, splitting the flow after the first dimension column and performing on-line LC×LC on this constant fraction of the first dimension effluent should allow the two dimensions to be optimized almost independently. When there is no flow splitting any change in the first dimension flow rate has an immediate impact on the second dimension. With a flow splitter one could for example double the flow rate into the first dimension column and do a 1:1 flow split without changing the sample loop size or the sampler’s collection time. Of course, the sensitivity would be diminished but this can be partially compensated by use of a larger injection; this will likely only amount to a small price to pay for this increased resolving power and system flexibility. Among other benefits, we found a 2-fold increase in the corrected 2D peak capacity and the number of observed peaks for a 15 min analysis time by using a post first dimension flow splitter. At a fixed analysis time this improvement results primarily from an increase in the gradient time resulting from the reduced system re-equilibration time and to a smaller extent it is due to the increased peak capacity achieved by full optimization of the first dimension. PMID:22017622

  10. Reduced Fluorescence versus Forward Scatter Time-of-Flight and Increased Peak versus Integral Fluorescence Ratios Indicate Receptor Clustering in Flow Cytometry.

    PubMed

    Fürnrohr, Barbara G; Stein, Merle; Rhodes, Benjamin; Chana, Prabhjoat S; Schett, Georg; Vyse, Timothy J; Herrmann, Martin; Mielenz, Dirk

    2015-07-01

    Clustering of surface receptors is often required to initiate signal transduction, receptor internalization, and cellular activation. To study the kinetics of clustering, we developed an economic high-throughput method using flow cytometry. The quantification of receptor clustering by flow cytometry is based on the following two observations: first, the fluorescence signal length (FL time-of-flight [ToF]) decreases relative to the forward scatter signal length (FSc-ToF), and second, the peak FL (FL-peak) increases relative to the integral FL (FL-integral) upon clustering of FL-labeled surface receptors. Receptor macroclustering can therefore be quantified using the ratios FL-ToF/FSc-ToF (method ToF) or FL-peak/FL-integral (method Peak). We have used these methods to analyze clustering of two immune receptors known to undergo different conformational and oligomeric states: the BCR and the complement receptor 3 (CR3), on murine splenocytes, purified B cells, and human neutrophils. Engagement of both the BCR and CR3, on immortalized as well as primary murine B cells and human neutrophil, respectively, resulted in decreased FL-ToF/FSc-ToF and increased FL-peak/FL-integral ratios. Manipulation of the actin-myosin cytoskeleton altered BCR clustering which could be measured using the established parameters. To confirm clustering of CR3 on neutrophils, we applied imaging flow cytometry. Because receptor engagement is as a biological process dependent on cell viability, energy metabolism, and temperature, receptor clustering can only be quantified by gating on viable cells under physiological conditions. In summary, with this novel method, receptor clustering on nonadherent cells can easily be monitored by high-throughput conventional flow cytometry.

  11. Areas subject to inundation by the 100-year flood in Avra Valley, Pima County, Arizona

    USGS Publications Warehouse

    Roeske, R.H.

    1978-01-01

    Avra Valley in Pima County, Arizona, is sparsely populated and is used mainly for agriculture and cattle grazing; however, its proximity to Tucson makes it desirable for urban development. Administrators and planners concerned with future land development may use the map report to determine the approximate areas that are subject to inundation by the 100-year flood. Avra Valley is drained mainly by Brawley Wash; Blanco Wash drains the west side of the valley. Most of the natural drainage system consists of small braided channels bordered by narrow bands of dense vegetation, which cause floodwater to spread over wide areas of shallow depths. During the 100-year flood, the areas inundated by Brawley and Blanco Washes may join in several places. (Woodard-USGS)

  12. Ice core evidence for significant 100-year regional warming on the Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Thomas, E. R.; Dennis, P. F.; Bracegirdle, T. J.; Franzke, C.

    2009-10-01

    We present a new 150-year, high-resolution, stable isotope record (δ 18O) from the Gomez ice core, drilled on the data sparse south western Antarctic Peninsula, revealing a ˜2.7°C rise in surface temperatures since the 1950s. The record is highly correlated with satellite-derived temperature reconstructions and instrumental records from Faraday station on the north west coast, thus making it a robust proxy for local and regional temperatures since the 1850s. We conclude that the exceptional 50-year warming, previously only observed in the northern Peninsula, is not just a local phenomena but part of a statistically significant 100-year regional warming trend that began around 1900. A suite of coupled climate models are employed to demonstrate that the 50 and 100 year temperature trends are outside of the expected range of variability from pre-industrial control runs, indicating that the warming is likely the result of external climate forcing.

  13. N mineralization, nitrification, and N uptake across a 100-year chronosequence upland hardwood forests

    Treesearch

    Travis W. Idol; Phillip E. Pope; Felix, Jr. Ponder

    2003-01-01

    Net N mineralization, nitrification, and N uptake were monitored in the A (0-8 cm) and B (8-30 cm) soil horizons from 1997 to 1999 across a chronosequence of upland hardwood forest stands in southern Indiana, USA. Stand ages were 1, 6, 12, 31, and 80-100 years at the beginning of the study. Contrary to previous studies, there was no apparent stimulation of N...

  14. Creating Long Term Income Streams for the 100 Year Starship Study Initiative

    NASA Astrophysics Data System (ADS)

    Sylvester, A. J.

    Development and execution of long term research projects are very dependent on a consistent application of funding to maximize the potential for success. The business structure for the 100 Year Starship Study project should allow for multiple income streams to cover the expenses of the research objectives. The following examples illustrate the range of potential avenues: 1) affiliation with a charitable foundation for creating a donation program to fund a long term endowment for research, 2) application for grants to fund initial research projects and establish the core expertise of the research entity, 3) development of intellectual property which can then be licensed for additional revenue, 4) creation of spinout companies with equity positions retained by the lab for funding the endowment, and 5) funded research which is dual use for the technology goals of the interstellar flight research objectives. With the establishment of a diversified stream of funding options, then the endowment can be funded at a level to permit dedicated research on the interstellar flight topics. This paper will focus on the strategy of creating spinout companies to create income streams which would fund the endowment of the 100 Year Starship Study effort. This technique is widely used by universities seeking to commercially develop and market technologies developed by university researchers. An approach will be outlined for applying this technique to potentially marketable technologies generated as a part of the 100 Year Starship Study effort.

  15. Peak flow meter with a questionnaire and mini-spirometer to help detect asthma and COPD in real-life clinical practice: a cross-sectional study.

    PubMed

    Thorat, Yogesh T; Salvi, Sundeep S; Kodgule, Rahul R

    2017-05-09

    Peak flow meter with questionnaire and mini-spirometer are considered as alternative tools to spirometry for screening of asthma and chronic obstructive pulmonary disease. However, the accuracy of these tools together, in clinical settings for disease diagnosis, has not been studied. Two hundred consecutive patients with respiratory complaints answered a short symptom questionnaire and performed peak expiratory flow measurements, standard spirometry with Koko spirometer and mini-spirometry (COPD-6). Spirometry was repeated after bronchodilation. Physician made a final diagnosis of asthma, chronic obstructive pulmonary disease and others. One eighty nine patients (78 females) with age 51 ± 17 years with asthma (115), chronic obstructive pulmonary disease (33) and others (41) completed the study. "Breathlessness > 6months" and "cough > 6months" were important symptoms to detect obstructive airways disease. "Asymptomatic period > 2 weeks" had the best sensitivity (Sn) and specificity (Sp) to differentiate asthma and chronic obstructive pulmonary disease. A peak expiratory flow of < 80% predicted was the best cut-off to detect airflow limitation (Sn 90%, Sp 50%). Respiratory symptoms with PEF < 80% predicted, had Sn 84 and Sp 93% to detect OAD. COPD-6 device under-estimated FEV1 by 13 mL (95% CI: -212, 185). At a cut-off of 0.75, the FEV1/FEV6 had the best accuracy (Sn 80%, Sp 86%) to detect airflow limitation. Peak flow meter with few symptom questions can be effectively used in clinical practice for objective detection of asthma and chronic obstructive pulmonary disease, in the absence of good quality spirometry. Mini-spirometers are useful in detection of obstructive airways diseases but FEV1 measured is inaccurate. DIFFERENTIATING CONDITIONS IN POORLY-EQUIPPED SETTINGS: A simple questionnaire and peak flow meter measurements can help doctors differentiate between asthma and chronic lung disease. In clinical settings where access to

  16. Effects of urbanization on peak streamflows in four Connecticut communities, 1980-84

    USGS Publications Warehouse

    Weiss, L.A.

    1990-01-01

    Ratios of peak flows in urban basins to peak flows in rural basins in Connecticut are about 1.5 to 6.1 for the 2-year flood and 1.1 to 4.3 for the 100-year flood. The lower ratios, in each case, apply where 30% of the area is served by storm sewers, and the higher ratios apply where 90% of the area is served by storm sewers. Peak flows for six small urban streams were determined from rainfall and runoff data collected from 1981 to 1984 and from a distributed-routing rainfall-runoff model that simulated storm runoff for the period 1951-80. Recurrence intervals of the peak flows for these streams and three other urban streams were estimated using the log-Pearson Type III method and compared with peak flows for rural streams that were computed from regression equations. A comparison of the ratios of urban to rural peak flows shows that basins where more than 50% of the area is served by storm sewers have urban to rural ratios that are outside the 95% confidence limits of the rural regression equations. Peak flows for such areas can be adjusted graphically for the effects of urbanization if the streams drain less than 10 sq mi and manmade storage is less than 4.5 million cu ft/sq mi. (USGS)

  17. On the use of late-time peaks of residence time distributions for the characterization of hierarchically nested groundwater flow systems

    NASA Astrophysics Data System (ADS)

    Wang, Jun-Zhi; Wörman, Anders; Bresciani, Etienne; Wan, Li; Wang, Xu-Sheng; Jiang, Xiao-Wei

    2016-12-01

    Previous studies on the characterization of hierarchically nested groundwater flow systems have mainly been based on the spatial distribution analyses of groundwater pathways. In this paper, by considering the discrete nature of the temporal behavior induced by different hierarchical flow systems, a new approach is proposed. The core of this approach is to use the critical residence times defined by the late-time peaks of residence time distributions (RTDs) to divide the groundwater flow field into local, intermediate and regional systems as described by Tóth (1963). We first introduce Tóthian basins of a 2D cross section and a 3D domain as synthetic test cases. The feasibility of the approach is demonstrated by comparing the partitioning results given by the dividing streamlines associated with internal stagnation points in the 2D Tóthian basin and by the hydraulic connections between recharge and discharge zones in the 3D Tóthian basin. Then, the Dosit River Watershed in Northwestern China is introduced as a field case study. Using the calibrated 3D groundwater flow model, one distinct late-time peak is identified from the RTD and indicates that the Dosit River Watershed can generally be regarded as a two-order nested flow structure with local and regional flow systems. This approach can be used to identify the volumes occupied by different orders of flow systems in 3D, and therefore opens up a new perspective in the study of the 3D nature of basin-scale groundwater flow.

  18. Lung function measurement in general practice: a comparison of the Escort spirometer with the Micromed turbine spirometer and the mini-Wright peak flow meter.

    PubMed

    Jones, K P; Mullee, M A

    1995-11-01

    It is important that new types of spirometer for widespread clinical use are pragmatically evaluated in primary care. This study compared measurements taken by a new portable Fleisch pneumotachograph spirometer (known as the Escort) with those of the commonly used mini-Wright peak flow meter and the Micromed Pocket turbine spirometer. A pragmatic study was conducted in two phases during routine surgeries at Aldermoor Health Centre, Southampton. Phase I compared the new spirometer with the mini-Wright peak flow meter and Phase 2 compared the new spirometer and the turbine spirometer. One hundred patients aged 5-88 years (56 patients with a history of chronic respiratory complaints and 44 patients without) entered Phase 1, and 100 patients aged 6-82 years (62 patients with a history of chronic respiratory complaints and 38 patients without) entered Phase 2. Each patient contributed only once to each phase, but some entered both phases on separate occasions. Ninety-five percent limits of agreement (mean +/- SD) were wide for all comparisons. Graphical plots revealed trends towards higher Escort values as mean values rose compared with both mini-Wright and turbine readings for peak expiratory flow rate and forced expiratory volume in one second. Possible over-reading of peak expiratory flow rate with the mini-Wright meter at low mean values was also seen. Readings taken with these different types of meter cannot be interchanged with confidence in clinical practice. The clinical significance of the theoretically more accurate measures of lung function produced with the new meter, and indeed of spirometry itself, needs further investigation.

  19. Voluminous lava-like precursor to a major ash-flow tuff: low-column pyroclastic eruption of the Pagosa Peak Dacite, San Juan volcanic field, Colorado

    NASA Astrophysics Data System (ADS)

    Bachmann, O.; Dungan, M. A.; Lipman, P. W.

    2000-05-01

    The Pagosa Peak Dacite is an unusual pyroclastic deposit that immediately predated eruption of the enormous Fish Canyon Tuff (˜5000 km 3) from the La Garita caldera at 28 Ma. The Pagosa Peak Dacite is thick (to 1 km), voluminous (>200 km 3), and has a high aspect ratio (1:50) similar to those of silicic lava flows. It contains a high proportion (40-60%) of juvenile clasts (to 3-4 m) emplaced as viscous magma that was less vesiculated than typical pumice. Accidental lithic fragments are absent above the basal 5-10% of the unit. Thick densely welded proximal deposits flowed rheomorphically due to gravitational spreading, despite the very high viscosity of the crystal-rich magma, resulting in a macroscopic appearance similar to flow-layered silicic lava. Although it is a separate depositional unit, the Pagosa Peak Dacite is indistinguishable from the overlying Fish Canyon Tuff in bulk-rock chemistry, phenocryst compositions, and 40Ar/ 39Ar age. The unusual characteristics of this deposit are interpreted as consequences of eruption by low-column pyroclastic fountaining and lateral transport as dense, poorly inflated pyroclastic flows. The inferred eruptive style may be in part related to synchronous disruption of the southern margin of the Fish Canyon magma chamber by block faulting. The Pagosa Peak eruptive sources are apparently buried in the southern La Garita caldera, where northerly extensions of observed syneruptive faults served as fissure vents. Cumulative vent cross-sections were large, leading to relatively low emission velocities for a given discharge rate. Many successive pyroclastic flows accumulated sufficiently rapidly to weld densely as a cooling unit up to 1000 m thick and to retain heat adequately to permit rheomorphic flow. Explosive potential of the magma may have been reduced by degassing during ascent through fissure conduits, leading to fracture-dominated magma fragmentation at low vesicularity. Subsequent collapse of the 75×35 km2 La Garita

  20. Voluminous lava-like precursor to a major ash-flow tuff: Low-column pyroclastic eruption of the Pagosa Peak Dacite, San Juan volcanic field, Colorado

    USGS Publications Warehouse

    Bachmann, Olivier; Dungan, M.A.; Lipman, P.W.

    2000-01-01

    The Pagosa Peak Dacite is an unusual pyroclastic deposit that immediately predated eruption of the enormous Fish Canyon Tuff (~5000 km3) from the La Garita caldera at 28 Ma. The Pagosa Peak Dacite is thick (to 1 km), voluminous (>200 km3), and has a high aspect ratio (1:50) similar to those of silicic lava flows. It contains a high proportion (40-60%) of juvenile clasts (to 3-4 m) emplaced as viscous magma that was less vesiculated than typical pumice. Accidental lithic fragments are absent above the basal 5-10% of the unit. Thick densely welded proximal deposits flowed rheomorphically due to gravitational spreading, despite the very high viscosity of the crystal-rich magma, resulting in a macroscopic appearance similar to flow-layered silicic lava. Although it is a separate depositional unit, the Pagosa Peak Dacite is indistinguishable from the overlying Fish Canyon Tuff in bulk-rock chemistry, phenocryst compositions, and 40Ar/39Ar age. The unusual characteristics of this deposit are interpreted as consequences of eruption by low-column pyroclastic fountaining and lateral transport as dense, poorly inflated pyroclastic flows. The inferred eruptive style may be in part related to synchronous disruption of the southern margin of the Fish Canyon magma chamber by block faulting. The Pagosa Peak eruptive sources are apparently buried in the southern La Garita caldera, where northerly extensions of observed syneruptive faults served as fissure vents. Cumulative vent cross-sections were large, leading to relatively low emission velocities for a given discharge rate. Many successive pyroclastic flows accumulated sufficiently rapidly to weld densely as a cooling unit up to 1000 m thick and to retain heat adequately to permit rheomorphic flow. Explosive potential of the magma may have been reduced by degassing during ascent through fissure conduits, leading to fracture-dominated magma fragmentation at low vesicularity. Subsequent collapse of the 75 x 35 km2 La Garita

  1. Does Peak Urine Flow Rate Predict the Development of Incident Lower Urinary Tract Symptoms in Men with Mild to No Current Symptoms? Results from REDUCE.

    PubMed

    Simon, Ross M; Howard, Lauren E; Moreira, Daniel M; Roehrborn, Claus; Vidal, Adriana; Castro-Santamaria, Ramiro; Freedland, Stephen J

    2017-09-01

    We determined whether decreased peak urine flow is associated with future incident lower urinary tract symptoms in men with mild to no lower urinary tract symptoms. Our population consisted of 3,140 men from the REDUCE (Reduction by Dutasteride of Prostate Cancer Events) trial with mild to no lower urinary tract symptoms, defined as I-PSS (International Prostate Symptom Score) less than 8. REDUCE was a randomized trial of dutasteride vs placebo for prostate cancer prevention in men with elevated prostate specific antigen and negative biopsy. I-PSS measures were obtained every 6 months throughout the 4-year study. The association between peak urine flow rate and progression to incident lower urinary tract symptoms, defined as the first of medical treatment, surgery or sustained and clinically significant lower urinary tract symptoms, was tested by multivariable Cox models, adjusting for various baseline characteristics and treatment arm. On multivariable analysis as a continuous variable, decreased peak urine flow rate was significantly associated with an increased risk of incident lower urinary tract symptoms (p = 0.002). Results were similar in the dutasteride and placebo arms. On univariable analysis when peak flow was categorized as 15 or greater, 10 to 14.9 and less than 10 ml per second, flow rates of 10 to 14.9 and less than 10 ml per second were associated with a significantly increased risk of incident lower urinary tract symptoms (HR 1.39, p = 0.011 and 1.67, p <0.001, respectively). Results were similar on multivariable analysis, although in the 10 to 14.9 ml per second group findings were no longer statistically significant (HR 1.26, p = 0.071). In men with mild to no lower urinary tract symptoms a decreased peak urine flow rate is independently associated with incident lower urinary tract symptoms. If confirmed, these men should be followed closer for incident lower urinary tract symptoms. Copyright © 2017 American Urological Association Education and

  2. Use of stable isotope tracers as a diagnostic tool for determining connectedness of road runoff to stream peak flows in disturbed forest environments.

    NASA Astrophysics Data System (ADS)

    Skaugset, A.; McDonnell, J. J.

    2003-12-01

    Forest disturbance, and in particular forest road construction can cause changes in hydrological processes emergent at the catchment scale. The magnitude of the impacts of forest roads on stream peak flows and chronic sedimentation is perceived to be directly proportional to the degree that roads are connected to the stream system. Scientific studies to date that have examined the degree to which the roadside ditch acts as an extension of the stream system have been highly equivocal. The engineering prescription to "fix" the perceived impacts of roads is to isolate the road system from the stream system. This is generally carried out by upgrading the drainage system for the forest road by either installing more drainage structures, cross drain culverts, or simply isolating live stream crossing culverts using water bars or rolling dips. At this time there is no simple, universally applicable method to determine the degree of connectivity of a road system to the stream. This paper presents some preliminary research using stable isotope tracer approaches as a diagnostic tool for quantifying connectedness of road runoff to stream peak flows. We argue that time source hydrograph separation may be a tool for determining whether or not engineering improvements have "worked" and how much current road systems in any given watershed influence stream peak flow. We present data for a rainstorm in the Winter of 2003 from nested sub-catchments and road ditches at the Oak Creek Watershed in the McDonald/Dunn Research Forest, Western Oregon.

  3. Comparative evaluation of ventilatory function through pre and postoperative peak expiratory flow in patients submitted to elective upper abdominal surgery.

    PubMed

    Scheeren, Caio Fernando Cavanus; Gonçalves, José Júlio Saraiva

    2016-01-01

    to evaluate the ventilatory function by Peak Expiratory Flow (PEF) in the immediate pre and postoperative periods of patients undergoing elective surgical procedures in the upper abdomen. we conducted a prospective cohort study including 47 patients admitted to the Hospital Regional de Mato Grosso do Sul from July to December 2014, who underwent elective surgeries of the upper abdomen, and submiited to spirometric evaluation and measurement of PEF immediately before and after surgery. of the 47 patients, 22 (46.8%) were male and 25 (53.20%) female. The mean preoperative PEF was 412.1±91.7, and postoperative, 331.0±87.8, indicating significant differences between the two variables. Men had higher PEF values than women, both in the pre and postoperative periods. There was a reasonable inverse correlation between age and decreased PEF. Both situations showed statistical significance (p<0.001). The group of smokers had lower PEF values both before and after surgery. The group of patients with comorbidities (hypertension and/or diabetes) showed lower PEF values both pre and postoperatively (p=0.005). In both groups, surgery resulted in a significant decrease in PEF (p<0.001). The type of surgery performed and the type of anesthesia did not show significant differences. the variables most involved in decreased lung function were: advanced age, smoking and presence of comorbidities. However, there is no consistent evidence to suggest conducting routine spirometry in such patients. avaliação comparativa da função ventilatória através do Pico de Fluxo Expiratório (PFE) no pré e pós-operatório imediatos de pacientes submetidos a procedimentos cirúrgicos eletivos do andar superior do abdome. estudo prospectivo de coorte incluindo 47 pacientes internados no Hospital Regional de Mato Grosso do Sul de Julho à Dezembro de 2014, e que realizaram cirurgias eletivas do andar superior do abdome, e submetidos à avaliação espirométrica e aferição do PFE no pré e p

  4. Two-dimensional hydrodynamic modeling to quantify effects of peak-flow management on channel morphology and salmon-spawning habitat in the Cedar River, Washington

    USGS Publications Warehouse

    Czuba, Christiana; Czuba, Jonathan A.; Gendaszek, Andrew S.; Magirl, Christopher S.

    2010-01-01

    The Cedar River in Washington State originates on the western slope of the Cascade Range and provides the City of Seattle with most of its drinking water, while also supporting a productive salmon habitat. Water-resource managers require detailed information on how best to manage high-flow releases from Chester Morse Lake, a large reservoir on the Cedar River, during periods of heavy precipitation to minimize flooding, while mitigating negative effects on fish populations. Instream flow-management practices include provisions for adaptive management to promote and maintain healthy aquatic habitat in the river system. The current study is designed to understand the linkages between peak flow characteristics, geomorphic processes, riverine habitat, and biological responses. Specifically, two-dimensional hydrodynamic modeling is used to simulate and quantify the effects of the peak-flow magnitude, duration, and frequency on the channel morphology and salmon-spawning habitat. Two study reaches, representative of the typical geomorphic and ecologic characteristics of the Cedar River, were selected for the modeling. Detailed bathymetric data, collected with a real-time kinematic global positioning system and an acoustic Doppler current profiler, were combined with a LiDAR-derived digital elevation model in the overbank area to develop a computational mesh. The model is used to simulate water velocity, benthic shear stress, flood inundation, and morphologic changes in the gravel-bedded river under the current and alternative flood-release strategies. Simulations of morphologic change and salmon-redd scour by floods of differing magnitude and duration enable water-resource managers to incorporate model simulation results into adaptive management of peak flows in the Cedar River. PDF version of a presentation on hydrodynamic modelling in the Cedar River in Washington state. Presented at the American Geophysical Union Fall Meeting 2010.

  5. Did Open Solar Magnetic Field Increase during the last 100 Years: A Reanalysis of Geomagnetic Activity

    NASA Astrophysics Data System (ADS)

    Mursula, K.; Martini, D.; Karinen, A.

    One of the most interesting and important questions in solar-terrestrial physics is whether the magnetic activity of the Sun has greatly increased during the last 100 years. A significant increase in solar magnetic activity is indicated by the well known fact that the average amplitude of sunspot cycles during the latter part of the 20th century is higher than in the beginning. The increasing sunspot activity leads, in a model presented by Solanki et al. (2000), to a corresponding centennial increase of the total and open (heliospheric) solar magnetic fields. The heliospheric magnetic field is a major driver of cosmic ray modulation and geomagnetic activity. Lockwood et al. (1999) used the geo-magnetic aa index to show that the interplanetary magnetic field has more than doubled during the last 100 years. Also, Usoskin et al. (2003) used long-term measurements of cosmogenic isotopes produced by cosmic rays to show that the average sunspot activity since 1940s is higher than during the last 1000 years. Despite the versatility and reason-able uniformity of these results, serious concern has recently been raised on the long-term consistency of the aa index and, thereby, on the centennial rise of solar magnetic activity. As an alternative to the aa index, Svalgaard et al. (2003) introduced introduced a new IHV index as a more reliable and more homogeneous measure of long-term geomag-netic activity, finding no significant increase during the last 100 years. Here we reanalyse the longest series of geomagnetic observations from a number of stations in order to find out whether or not there is reliable evidence for a centennial increase of geomagnetic activity and, therby, of solar magnetic field.

  6. Did Open Solar Magnetic Field Increase During The Last 100 Years? A Reanalysis of Geomagnetic Activity

    NASA Astrophysics Data System (ADS)

    Mursula, K.; Martini, D.; Karinen, A.

    2004-10-01

    Long-term geomagnetic activity presented by the aa index has been used to show that the heliospheric magnetic field has more than doubled during the last 100 years. However, serious concern has been raised on the long-term consistency of the aa index and on the centennial rise of the solar magnetic field. Here we reanalyze geomagnetic activity during the last 100 years by calculating the recently suggested IHV (Inter-Hour Variability) index as a measure of local geomagnetic activity for seven stations. We find that local geomagnetic activity at all stations follows the same qualitative long-term pattern: an increase from early 1900 to 1960, a dramatic dropout in 1960s and a (mostly weaker) increase thereafter. Moreover, at all stations, the activity at the end of the 20th century has a higher average level than at the beginning of the century. This agrees with the result based on the aa index that global geomagnetic activity, and thereby, the open solar magnetic field has indeed increased during the last 100 years. However, quantitatively, the estimated centennial increase varies greatly from one station to another. We find that the relative increase is higher at the high-latitude stations and lower at the low- and mid-latitude stations. These differences may indicate that the fraction of solar wind disturbances leading to only moderate geomagnetic activity has increased during the studied time interval. We also show that the IHV index needs to be corrected for the long-term change of the daily curve, and calculate the corrected IHV values. Most dramatically, we find the centennial increase in global geomagnetic activity was considerably smaller, only about one half of that depicted by the aa index.

  7. Observed climate variations during the last 100 years in Lapland, northern Finland

    NASA Astrophysics Data System (ADS)

    Lee, Susan E.; Press, M. C.; Lee, J. A.

    2000-03-01

    Many general circulation models (GCMs) predict that high latitude environments will experience substantial warming over the next 100 years, which will be particularly pronounced during the winter months. Precipitation is also expected to increase but there is uncertainty as to the amount and spatial variation.The flora and fauna of the arctic and subarctic regions, together with indigenous people, such as the Saami, are particularly vunerable to rising temperatures and changing precipitation. Mean monthly temperature and precipitation data were examined for the last 100 years for northern Finland. These data were further analysed for the first and second half of the 20th century.There was no discernible warming trend between 1876 and 1993, but a significant annual warming (r=0.344, <0.05) occurred in the period 1901-1945, together with a significant summer warming (r=0.381, ρ<0.05). Warming has occurred consistently in May and June over the last 100 years and there appears to be a current (i.e. post 1990) annual trend, mostly due to winter warming. The greatest temperature anomaly increase for the period 1901-1945 was in the winter months (+0.72°C). The degree of temperature variation in the winter is greater than in the summer and has risen from 3.98°C for December in the period 1901-1945 to 4.37°C in the period 1946-1990. This is attributed to the recent high variability in the North Atlantic Oscillation (NAO) Index. Annual precipitation has increased significantly during the period 1880-1993. The period 1946-1990 was wetter than 1901-1945, with greater variability particularly in the summer months, which contribute most to the annual precipitation in Lapland.

  8. [A case of Bleuler's disease? 100 years of dementia praecox or group of schizophrenias].

    PubMed

    Mirić, J; Bodatsch, M; Gouzoulis-Mayfrank, E; Häussermann, P

    2013-03-01

    Approximately 100 years ago Eugen Bleuler published the most significant contribution to psychiatry by conceptualizing the term schizophrenia as a diagnostic entity. In modern diagnostic manuals Bleuler's concept is only reflected in subordinated criteria, i.e. the negative symptoms. On the occasion of the anniversary of Bleuler's essential publication, the present work aims to exemplify the differences in diagnostic concepts and it will be illustrated that Bleuler's intention to establish his so-called basic symptom as a guideline for diagnostics has to be considered as failed from a present day viewpoint.

  9. 100 years of Epilepsia: landmark papers and their influence in neuropsychology and neuropsychiatry.

    PubMed

    Hermann, Bruce

    2010-07-01

    As part of the 2009 International League Against Epilepsy (ILAE) Centenary Celebration, a special symposium was dedicated to Epilepsia (100 Years of Epilepsia: Landmark Papers and Their Influence). The Associate Editors were asked to identify a particularly salient and meaningful paper in their areas of expertise. From the content areas of neuropsychology and neuropsychiatry two very interesting papers were identified using quite different ascertainment techniques. One paper addressed the problem of psychosis in temporal lobe epilepsy, whereas the other represents the first paper to appear in Epilepsia presenting quantitative assessment of cognitive status in epilepsy. These two papers are reviewed in detail and placed in historical context.

  10. 100 years since the discovery of cosmic rays. A brief history

    NASA Astrophysics Data System (ADS)

    Chiavassa, Andrea

    2012-11-01

    With the words "Cosmic Rays" we mean particles impinging on the earth atmosphere. The existence of these particles was discovered in 1912, i.e. exactly 100 years ago, by the Austrian physicist Victor Hesss. In this contribution I will describe the steps that lead to such a discovery: from the electroscope measurements, showing their spontaneous discharge, to the correct explanation of this results with the existence of charged particles arriving from outside of the atmosphere. Then I will discuss the first steps of experimental particle physics, obtained with experiments performed detecting cosmic rays, that allowed important discoveries as the detection of antimatter and of new subatominc particles as muons and pions.

  11. Peak expiratory flow, breath rate and blood pressure in adults with changes in particulate matter air pollution during the Beijing Olympics: a panel study.

    PubMed

    Mu, Lina; Deng, Furong; Tian, Lili; Li, Yanli; Swanson, Mya; Ying, Jingjing; Browne, Richard W; Rittenhouse-Olson, Kate; Zhang, Junfeng Jim; Zhang, Zuo-Feng; Bonner, Matthew R

    2014-08-01

    This study aims to examine whether changes in short-term exposures to particulate matter are associated with changes in lung function, breath rate, and blood pressure among healthy adults and whether smoking status modifies the association. We took advantage of the artificially controlled changes in air pollution levels that occurred during the 2008 Olympic Games in Beijing, China and conducted a panel study of 201 Beijing residents. Data were collected before, during, and after the Olympics, respectively. Linear mixed-effect models and generalized estimating equation models were used to compare measurements of peak expiratory flow, breath rate and blood pressure across three time points. The mean values of peak expiratory flow were 346.0 L/min, 399.3 L/min, and 364.1L/min over the three study periods. Peak expiratory flow levels increased in 78% of the participants when comparing the during- with pre- Olympics time points, while peak expiratory flow levels decreased in 80% of participants for the post- and during-Olympic periods comparison. In subgroup analyses comparing the during-Olympic to pre-Olympic time points, we found a larger percentage change in peak expiratory flow (+17%) among female, younger and non-smoking participants than among male, elderly and smoking participants (+12%). The percentage of participants with a fast breath rate (>20/min) changed from 9.7% to 4.9% to 30.1% among females, and from 7.9% to 2.6% to 27.3% among males over the three time points. The changes in blood pressure over the three study periods were not very clear, although there is an increase in diastolic pressure and a decrease in pulse pressure among males during the games. The results suggest that exposure to different air pollution levels has significant effects on respiratory function. Smoking, age and gender appear to modify participants' biological response to changes in air quality. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Modeled future peak streamflows in four coastal Maine rivers

    USGS Publications Warehouse

    Hodgkins, Glenn A.; Dudley, Robert W.

    2013-01-01

    the magnitude of air temperatures increase in the four basins, peak flows decrease by larger amounts. If precipitation is held constant (no change from historical values), 17 to 26 percent decreases in peak flow occur at the four basins when temperature is increased by 7.2°F. If temperature is held constant, 26 to 38 percent increases in peak flow result from a 15-percent increase in precipitation. The largest decreases in peak flows at the four basins result from 15-percent decreases in precipitation combined with temperature increases of 10.8°F. The largest increases in peak flows generally result from 30-percent increases in precipitation combined with 3.6 °F decreases in temperatures. In many cases when temperature and precipitation both increase, small increases or decreases in annual daily maximum peak flows result. For likely changes projected for the northeastern United States for the middle of the 21st century (temperature increase of 3.6 °F and precipitation increases of 0 to 15 percent), peak-flow changes at the four coastal Maine basins in this study are modeled to be evenly distributed between increases and decreases of less than 25 percent. Peak flows with 50-percent and 1-percent AEPs (equivalent to 2-year and 100-year recurrence interval peak flows, respectively) were calculated for the four basins in the study using the PRMS-modeled annual daily maximum peak flows. Modeled peak flows with 50-percent and 1-percent AEPs with adjusted temperatures and precipitation were compared to unadjusted (historical) modeled values. Changes in peak flows with 50-percent AEPs are similar to changes in annual daily maximum peak flow; changes in peak flows with 1-percent AEPs are similar in pattern to changes in annual daily maximum peak flow, but some of the changes associated with increasing precipitation are much larger than changes in annual daily maximum peak flow. Substantial decreases in maximum annual winter snowpack water equivalent are modeled to occur

  13. Morphological response of songbirds to 100 years of landscape change in North America.

    PubMed

    Desrochers, A

    2010-06-01

    Major landscape changes caused by humans may create strong selection pressures and induce rapid evolution in natural populations. In the last 100 years, eastern North America has experienced extensive clear-cutting in boreal areas, while afforestation has occurred in most temperate areas. Based on museum specimens, I show that wings of several boreal forest songbirds and temperate songbirds of non-forest habitats have become more pointed over the last 100 years. In contrast, wings of most temperate forest and early-successional boreal forests species have become less pointed over the same period. In contrast to wing shape, the bill length of most species did not change significantly through time. These results are consistent with the "habitat isolation hypothesis", i.e., songbirds evolved in response to recent changes in the amount of available habitat and associated implications for mobility. Rapid morphological evolution may mitigate, without necessarily preventing, negative consequences of habitat loss caused by humans through direct exploitation or climate change.

  14. 100 years Jura décollement hypothesis: how it affects Steinmann's (1892) ``Schwarzwaldlinie''

    NASA Astrophysics Data System (ADS)

    Laubscher, Hans

    2008-11-01

    Steinmann, then professor of geology at Freiburg (Germany), more than a 100 years ago wondered about the southern end of the extensional Rhinegraben and proposed that elements of the graben penetrated the contractional Jura. In particular, he recognized the "Schwarzwaldlinie” in the southern prolongation of the eastern border of the southern Rhinegraben, a line-up of topographic as well as structural irregularities. He conjectured that it was caused by normal faults of the Rhinegraben system. Subsequently—100 years ago—Buxtorf (1907) proposed the hypothesis, that the Jura was a thin-skinned nappe sheared off on Triassic evaporites. In the autochthonous basement underneath the wrinkled skin, the ``Schwarzwald line” is difficult to define. It probably consists of a gentle flexure punctuated by faults that approximately coincides with Steinmann’s original projection, although he sought to identify its constituent faults in the badly deformed allochthonous skin. Current data place the thin-skin elements of the Schwarzwald line in a more westerly, allochthonous position where most of them were reactivated into sinistrally transpressional structures.

  15. Solar wind variations in the 60-100 year period range: A review

    NASA Technical Reports Server (NTRS)

    Feynman, J.

    1983-01-01

    The evidence for and against the reality of a solar wind variation in the period range of 60-100 years is reexamined. Six data sets are reviewed; sunspot numbers, geomagnetic variations, two auroral data sets and two (14)C data sets. These data are proxies for several different aspects of the solar wind and the presence or absence of 60-100 year cyclic behavior in a particular data set does not necessarily imply the presence or absence of this variation in other sets. It was concluded that two different analyses of proxy data for a particular characteristic of the heliospheric solar wind yielded conflicting results. This conflict can be resolved only by future research. It is also definitely confirmed that proxy data for the solar wind in the ecliptic at 1 A.U. undergo a periodic variation with a period of approximately 87 years. The average amplitude and phase of this variation as seen in eleven cycles of proxy data are presented.

  16. Hydrothermal Heat Transport within an Abruptly Formed Permeable Slot: An Application to Heat Flow Peaks Observed at the Japan Trench Offshore of Sanriku

    NASA Astrophysics Data System (ADS)

    Kawada, Y.; Yamano, M.

    2015-12-01

    Anomalous heat flow has been observed within 150 km seaward of the trench axis at the Japan Trench offshore of Sanriku, northeast Japan [Yamano et al., 2008, 2014]. The average heat flow is ~70 mW/m2 (50 mW/m2 is expected for the plate age), and small-scale (2 to 3 km) variations, whose peak value is >100 mW/m2, are embedded. In the area of high heat flow, a high Vp/Vs layer in the oceanic crust has been detected [Fujie et al., 2013]. The layer thickness is increased toward the trench axis. Fujie et al.[2013] interpreted this layer as a result of fracturing due to bending of the subducting plate. This layer may work as an aquifer in which heat is transported by fluid circulation. In a previous study [Kawada et al., 2014], we constructed a model for aquifer thickening in order to explain the observed anomalous heat flow: a 500-m-thick aquifer 150 km seaward of the trench axis is gradually thickened to 3000 m toward the trench axis. We found that hydrothermal circulation within the thickening aquifer mines heat beneath its underlying part, and heat flow is elevated accordingly. Although the model can explain the observed high heat flow in an average sense, the origin of the small-scale heat flow variations remains to be solved. This study expands the previous model by incorporating abrupt thickening of the aquifer to account for the small-scale heat flow. Typically, we consider a situation in which a permeable slot of 2000 m wide and 3000 m deep suddenly appears. This model results in a high heat flow peak of 100 mW/m2 above the permeable slot, which persists over hundreds of thousand years. Heat outside the slot is transported horizontally toward the slot by thermal conduction and then is transported vertically due to hydrothermal circulation within the slot. Because the volume of the permeable slot is smaller than its surrounding region, high heat flow above the slot lasts for a long time.

  17. Fiber-optic delivery of high-peak-power Q-switched laser pulses for in-cylinder flow measurement.

    PubMed

    Stephens, Timothy J; Haste, Martin J; Towers, David P; Thomson, Martin J; Taghizadeh, Mohammed R; Jones, Julian D C; Hand, Duncan P

    2003-07-20

    A bundle of optical fibers was constructed to deliver Q-switched frequency-doubled Nd:YAG laser pulses for the purpose of particle image velocimetry. Data loss that is due to fiber speckle was reduced by ensuring that each fiber was different in length by more than the coherence length of the laser being delivered. Hence, their speckle patterns will overlap but not interfere, producing more even illumination that is shown to reduce data loss. A custom-made diffractive optical element and careful endface preparation help to reduce damage to the fibers by the required high peak powers. With this method, pulse energies in excess of 25 mJ were delivered for a series of experimental trials within the cylinder head of an optically accessed internal combustion engine. Results from these trials are presented along with a comparison of measurements generated by conventionally delivered beams.

  18. Fiber-optic delivery of high-peak-power Q-switched laser pulses for in-cylinder flow measurement

    NASA Astrophysics Data System (ADS)

    Stephens, Timothy J.; Haste, Martin J.; Towers, David P.; Thomson, Martin J.; Taghizadeh, Mohammed R.; Jones, Julian D. C.; Hand, Duncan P.

    2003-07-01

    A bundle of optical fibers was constructed to deliver Q-switched frequency-doubled Nd:YAG laser pulses for the purpose of particle image velocimetry. Data loss that is due to fiber speckle was reduced by ensuring that each fiber was different in length by more than the coherence length of the laser being delivered. Hence, their speckle patterns will overlap but not interfere, producing more even illumination that is shown to reduce data loss. A custom-made diffractive optical element and careful endface preparation help to reduce damage to the fibers by the required high peak powers. With this method, pulse energies in excess of 25 mJ were delivered for a series of experimental trials within the cylinder head of an optically accessed internal combustion engine. Results from these trials are presented along with a comparison of measurements generated by conventionally delivered beams.

  19. Sedimentary records of eutrophication and hypoxia in the Changjiang Estuary over the last 100 years

    NASA Astrophysics Data System (ADS)

    Xuwen, F.; Hongliang, L.; Zhao, M.; Xuefa, S.

    2012-12-01

    We selected two cores in the Changjiang Estuary, one located in the Changjiang Estuary mud area (CEMA) within the region of seasonal hypoxia, the other located in the Cheju Island mud area (SCIMA) and outside the hypoxia region. The grain size, total organic carbon (TOC), stable carbon isotopic ratios (δ13 Corg), biomarkers (the sum of brassicasterol, dinosterol and alkenone) and some redox sensitive elements (RSEs) were determined on the 210Pb-dated sediment cores to study potential hundrend-years eutrophication and hypoxia. The sediment record in CEMA showed that an increase in TOC (21%), biomarkers (141%) and δ13 Corg (1.6‰PDB ) occurred since 1950s and a marked increase since 1970s. These distributions indicated the enhanced productivity and establshed the history of eutrophication in the Changjiang Estuary during the past 100 years. Some RSEs have been enriched significantly since the late 1960s to 1970s, the rates of Mo/Al, Cd/Al and As/Al increased about 83%, 73% and 50% respectively. These data may indicate the onset of hypoxia in the Changjiang Estuary during the last 100 years. The increasing of marine organic matter and RSEs accumulation was corresponding with the fertilizer consumption and high nutrient inputs from the Changjiang River. The riverine runoff of fertilizers and nutrients stimulated the algae (e g. brassicasterol, dinosterol) blooming. Enhanced primary production resulted in an enrichment of organic matter and hypoxia invoked organic matter preserved in the sediment. For the core sediment in SCIMA, the geochemical indicators (TOC, biomarkers and δ13Corg ) increased in difference degrees before 1950s~1970s and then were almost the constant. Productivity in the SCIMA have been mainly influenced by climate ocean circulation changes over the last 100 years. The RSEs were controlled by "grain size effects" which indicated no hypoxia occurred. This study concluded that δ13 Corg, RSEs and biomarkers in sediment could be used to trace or

  20. Short-Term Outcomes Following Hip Fractures in Patients at Least 100 Years Old.

    PubMed

    Manoli, Arthur; Driesman, Adam; Marwin, Rebecca A; Konda, Sanjit; Leucht, Philipp; Egol, Kenneth A

    2017-07-05

    The number of hip fractures is rising as life expectancy increases. As such, the number of centenarians sustaining these fractures is also increasing. The purpose of this study was to determine whether patients who are ≥100 years old and sustain a hip fracture fare worse in the hospital than those who are younger. Using a large database, the New York Statewide Planning and Research Cooperative System (SPARCS), we identified patients who were ≥65 years old and had been treated for a hip fracture over a 12-year period. Data on demographics, comorbidities, and treatment were collected. Three cohorts were established: patients who were 65 to 80 years old, 81 to 99 years old, and ≥100 years old (centenarians). Outcome measures included hospital length of stay, estimated total costs, and in-hospital mortality rates. A total of 168,087 patients with a hip fracture were identified, and 1,150 (0.7%) of them had sustained the fracture when they were ≥100 years old. Centenarians incurred costs and had lengths of stay that were similar to those of younger patients. Despite the similarities, centenarians were found to have a significantly higher in-hospital mortality rate than the younger populations (7.4% compared with 4.4% for those 81 to 99 years old and 2.6% for those 65 to 80 years old; p < 0.01). Male sex and an increasing number of medical comorbidities were found to predict in-hospital mortality for centenarians sustaining extracapsular hip fractures. No significant predictors of in-hospital mortality were identified for centenarians who sustained femoral neck fractures. An increased time to surgery did not influence the odds of in-hospital mortality. Centenarians had increased in-hospital mortality, but the remaining short-term outcomes were comparable with those for the younger cohorts with similar fracture patterns. For this extremely elderly population, time to surgery does not appear to affect short-term mortality rates, suggesting a potential benefit to

  1. Annual peak discharges from small drainage areas in Montana through September 1976

    USGS Publications Warehouse

    Johnson, M.V.; Omang, R.J.; Hull, J.A.

    1977-01-01

    Annual peak discharge from small drainage areas is tabulated for 336 sites in Montana. The 1976 additions included data collected at 206 sites. The program which investigates the magnitude and frequency of floods from small drainage areas in Montana, was begun July 1, 1955. Originally 45 crest-stage gaging stations were established. The purpose of the program is to collect sufficient peak-flow data, which through analysis could provide methods for estimating the magnitude and frequency of floods at any point in Montana. The ultimate objective is to provide methods for estimating the 100-year flood with the reliability needed for road design. (Woodard-USGS)

  2. 100 years of applied psychology research on individual careers: From career management to retirement.

    PubMed

    Wang, Mo; Wanberg, Connie R

    2017-03-01

    This article surveys 100 years of research on career management and retirement, with a primary focus on work published in the Journal of Applied Psychology. Research on career management took off in the 1920s, with most attention devoted to the development and validation of career interest inventories. Over time, research expanded to attend to broader issues such as the predictors and outcomes of career interests and choice; the nature of career success and who achieves it; career transitions and adaptability to change; retirement decision making and adjustment; and bridge employment. In this article, we provide a timeline for the evolution of the career management and retirement literature, review major theoretical perspectives and findings on career management and retirement, and discuss important future research directions. (PsycINFO Database Record

  3. 100 years of Pb deposition and transport in soils in Champaign, Illinois, U.S.A

    USGS Publications Warehouse

    Zhang, Y.

    2003-01-01

    In Illinois, atmospheric deposition is one major source of heavy metal inputs to agricultural land. The atmospheric Pb deposition and transport record in agricultural soils in Champaign, Illinois, was established by studying surface and subsurface soil samples collected during the past 100 years from the Morrow Plots on the campus of the University of Illinois at Urbana-Champaign. The Pb content in the soil samples was measured and the Ph deposition fluxes were calculated. The Pb content in surface soils increased sharply in the first half of the 20th century, and stayed invariant since. The maximum Pb flux from the atmosphere was estimated to be 27 (??14) ??g cm-2 yr-1 around 1940. The major pollution source for this increase probably was residential coal burning. It was estimated that in 50 yr, more than 50% of the Pb input had been lost from the surface soils.

  4. The Reissner Canard: The first all-metal airplane 100 years ago

    NASA Astrophysics Data System (ADS)

    Krause, Egon

    2012-10-01

    In 1912 Professor Hans Reissner of the Technical University Aachen built a canard-type aeroplane, the world-wide first completely out of metal: although the Reissner Canard initiated a new technology with the Junkers J1 the first to follow in 1915 and 1000 more until now, little is known about the very first steps way back in Aachen. This paper tries to recapture some details of the developments 100 years ago with the aid of early publications and photographs and shed some light on the first wing fabricated out of a corrugated aluminum sheet mounted at the tail of the braced-steel-pipe fuselage to earn its airworthiness in Berlin Johannisthal in 1912.

  5. ASCI: reflections on the first 100 years and a proposal for the next.

    PubMed

    Kelley, William N

    2008-04-01

    Congratulations to the ASCI and its membership on the first 100 years. From their first organizational meeting on the Boardwalk in Atlantic City in June 1907, our predecessors recognized the need for an organization for the clinician who had a strong interest in true experimental medicine. These nine Young Turks formed the Society, had their first meeting at the Willard Hotel in Washington, DC, in 1909, and went on to become some of the leaders of American medicine in the first half of the 20th century. The establishment of the JCI in 1924 further enhanced the high standards of the ASCI and its membership. Surely thousands of us have benefited from the foundation of the ASCI and the JCI, as have, I would submit, millions of patients as well.

  6. 100-year DASCH Light Curves of Kepler Planet-Candidate Host Stars

    NASA Astrophysics Data System (ADS)

    Tang, Sumin; Sasselov, Dimitar; Grindlay, Jonathan; Los, Edward; Servillat, Mathieu

    2013-07-01

    We present 100 year light curves of Kepler planet-candidate host stars from the Digital Access to a Sky Century at Harvard (DASCH) project. 261 out of 997 host stars have at least 10 good measurements on DASCH scans of the Harvard plates. 109 of them have at least 100 good measurements, including 70% (73 out of 104) of all host stars with g ≤ 13 mag, and 44% (100 out of 228) of all host stars with g ≤ 14 mag. Our typical photometric uncertainty is ∼0.1–0.15 mag. No variation is found at 3σ level for these host stars, including 21 confirmed or candidate hot Jupiter systems which might be expected to show enhanced flares from magnetic interactions between dwarf primaries and their close and relatively massive planet companions.

  7. PREFACE: Spanish Relativity Meeting (ERE 2014): almost 100 years after Einstein's revolution

    NASA Astrophysics Data System (ADS)

    Cerdá-Durán, P.; Font, J. A.; Ibáñez, J. M.; Lledó, M. A.; Navarro-Salas, J.; Olmo, G. J.

    2015-04-01

    This volume presents the proceedings of the international scientific conference ''Spanish Relativity Meeting (ERE 2014): almost 100 years after Einstein's revolution''. The conference was devoted to discussing the current state-of-the-art of a wide variety of topics of research in the fields of Gravitation and General Relativity in the ''pre-centennial'' year of General Relativity. The name of the conference was chosen to highlight the importance of the upcoming one hundredth anniversary of Einstein's theory of General Relativity, officially established by the Internal Society on General Relativity and Gravitation in November 25th, 2015. In particular, the conference was organized along three main lines of present-day research and applications of the theory, namely, Relativistic Astrophysics, Mathematical Relativity, and the interface between Gravitation and Quantum Field Theory.

  8. Élie Metchnikoff (1845-1916): celebrating 100 years of cellular immunology and beyond.

    PubMed

    Underhill, David M; Gordon, Siamon; Imhof, Beat A; Núñez, Gabriel; Bousso, Philippe

    2016-10-01

    The year 2016 marks 100 years since the death of Élie Metchnikoff (1845-1916), the Russian zoologist who pioneered the study of cellular immunology and who is widely credited with the discovery of phagocytosis, for which he was jointly awarded the Nobel Prize in Physiology or Medicine in 1908. However, his long scientific career spanned many disciplines and has had far-reaching effects on modern immunology beyond the study of phagocytosis. In this Viewpoint article, five leading immunologists from the fields of phagocytosis, macrophage biology, leukocyte migration, the microbiota and intravital imaging tell Nature Reviews Immunology how Metchnikoff's work has influenced past, present and future research in their respective fields.

  9. Sustainable Foods and Medicines Support Vitality, Sex and Longevity for a 100-Year Starship Expedition

    NASA Astrophysics Data System (ADS)

    Edwards, M. R.

    Extended space flight requires foods and medicines that sustain crew health and vitality. The health and therapeutic needs for the entire crew and their children for a 100-year space flight must be sustainable. The starship cannot depend on resupply or carry a large cargo of pharmaceuticals. Everything in the starship must be completely recyclable and reconstructable, including food, feed, textiles, building materials, pharmaceuticals, vaccines, and medicines. Smart microfarms will produce functional foods with superior nutrition and sensory attributes. These foods provide high-quality protein and nutralence (nutrient density), that avoids obesity, diabetes, and other Western diseases. The combination of functional foods, lifestyle actions, and medicines will support crew immunity, energy, vitality, sustained strong health, and longevity. Smart microfarms enable the production of fresh medicines in hours or days, eliminating the need for a large dispensary, which eliminates concern over drug shelf life. Smart microfarms are adaptable to the extreme growing area, resource, and environmental constraints associated with an extended starship expedition.

  10. 100+ years of instrumental seismology: the example of the ISC-GEM Global Earthquake Instrumental Catalogue

    NASA Astrophysics Data System (ADS)

    Storchak, Dmitry; Di Giacomo, Domenico

    2015-04-01

    Systematic seismological observations of earthquakes using seismic instruments on a global scale began more than 100 years ago. Since then seismologists made many discoveries about the Earth interior and the physics of the earthquakes, also thanks to major developments in the seismic instrumentation deployed around the world. Besides, since the establishment of the first global networks (Milne and Jesuit networks), seismologists around the world stored and exchanged the results of routine observations (e.g., picking of arrival times, amplitude-period measurements, etc.) or more sophisticated analyses (e.g., moment tensor inversion) in seismological bulletins/catalogues. With a project funded by the GEM Foundation (www.globalquakemodel.org), the ISC and the Team of International Experts released a new global earthquake catalogue, the ISC-GEM Global Instrumental Earthquake Catalogue (1900 2009) (www.isc.ac.uk/iscgem/index.php), which, differently from previous global seismic catalogues, has the unique feature of covering the entire period of instrumental seismology with locations and magnitude re-assessed using modern approaches for the global earthquakes selected for processing (in the current version approximately 21,000). During the 110 years covered by the ISC-GEM catalogue many seismological developments occurred in terms of instrumentation, seismological practice and knowledge of the physics of the earthquakes. In this contribution we give a brief overview of the major milestones characterizing the last 100+ years of instrumental seismology that were relevant for the production of the ISC-GEM catalogue and the major challenges we faced to obtain a catalogue as homogenous as possible.

  11. Secular changes in growth among Japanese children over 100 years (1900-2000).

    PubMed

    Kagawa, Masaharu; Tahara, Yasuaki; Moji, Kazuhiko; Nakao, Rieko; Aoyagi, Kiyoshi; Hills, Andrew P

    2011-01-01

    Human growth is associated with complex interactions between genetic and environmental factors. While research has reported increased body size and body mass index (BMI) of Japanese children, few studies have compared the magnitude of increments in growth before and after World War II (WW II) and also considered other social and economical events that may have influenced the growth of children. The current study assessed the secular change in growth in Japanese children and adolescents aged between 6 and 17 years using data from the School Health Statistics Survey conducted between 1900 and 2000 with consideration of key social changes during the 20th Century. Over the 100-year period, Japanese boys had height and weight increments of 1.0-2.0 cm per decade and 0.4-1.7 kg per decade whereas girls had rates of 1.1-1.9 cm and 0.4-1.5 kg per decade, respectively. The rates of height increment were significantly (p<0.05) different between pre-, during and post-WW II periods. While Japanese children were considerably larger in 2000 compared to 1900, increments between 1950 and 1960 reflected catch-up growth to restore physical size seen in children prior to WW II. The increments in body size continued after 1960 with greatest changes seen across the pubertal years. While increments in BMI were evident in most age groups, the BMI of 17-year-old girls was consistent over the 100 years. Results clarified secular changes in growth in Japanese school children across the 20th Century and possible factors contributing to these changes.

  12. Application of a GIS-based distributed hydrology model for prediction of forest harvest effects on peak stream flow in the Pacific Northwest

    NASA Astrophysics Data System (ADS)

    Storck, Pascal; Bowling, Laura; Wetherbee, Paul; Lettenmaier, Dennis

    1998-05-01

    Spatially distributed rainfall-runoff models, made feasible by the widespread availability of land surface characteristics data (especially digital topography), and the evolution of high power desktop workstations, are particularly useful for assessment of the hydrological effects of land surface change. Three examples are provided of the use of the Distributed Hydrology-Soil-Vegetation Model (DHSVM) to assess the hydrological effects of logging in the Pacific Northwest. DHSVM provides a dynamic representation of the spatial distribution of soil moisture, snow cover, evapotranspiration and runoff production, at the scale of digital topographic data (typically 30-100 m). Among the hydrological concerns that have been raised related to forest harvest in the Pacific Northwest are increases in flood peaks owing to enhanced rain-on-snow and spring radiation melt response, and the effects of forest roads. The first example is for two rain-on-snow floods in the North Fork Snoqualmie River during November 1990 and December 1989. Predicted maximum vegetation sensitivities (the difference between predicted peaks for all mature vegetation compared with all clear-cut) showed a 31% increase in the peak runoff for the 1989 event and a 10% increase for the larger 1990 event. The main reason for the difference in response can be traced to less antecedent low elevation snow during the 1990 event. The second example is spring snowmelt runoff for the Little Naches River, Washington, which drains the east slopes of the Washington Cascades. Analysis of spring snowmelt peak runoff during May 1993 and April 1994 showed that, for current vegetation relative to all mature vegetation, increases in peak spring stream flow of only about 3% should have occurred over the entire basin. However, much larger increases (up to 30%) would occur for a maximum possible harvest scenario, and in a small headwaters catchment, whose higher elevation leads to greater snow coverage (and, hence, sensitivity

  13. 77 FR 66823 - Freedom of Information Act Request for Papers Submitted to DARPA for the 2011 100 Year Starship...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-07

    ... of the Secretary Freedom of Information Act Request for Papers Submitted to DARPA for the 2011 100 Year Starship Symposium AGENCY: Defense Advanced Research Projects Agency (DARPA), DoD. ACTION: Notice... panels at the 2011 100 Year Starship Symposium must provide DARPA a written response explaining how...

  14. Investigations on the calculation of the third moments of elution peaks: II-linear flow speed dependence of external mass transfer coefficient.

    PubMed

    Gao, Hong; Gritti, Fabrice; Guiochon, Georges

    2013-06-14

    This work is a systematic investigation of the linear velocity dependence of the external mass transfer coefficient provided by fitting experimental results to the solution of the GR (General Rate) model that was previously derived. The second and third statistical moments of eluted peaks were measured at different flow rates, under different experimental conditions and analyzed. The results of this analysis confirm the validity of this dependence under our current experimental conditions. The other mass transfer parameters provided by the GR model were determined. The variations of these parameters with the experimental conditions were measured. The results are discussed and interpreted. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Methods for estimating peak discharge and flood boundaries of streams in Utah

    USGS Publications Warehouse

    Thomas, B.E.; Lindskov, K.L.

    1983-01-01

    Equations for estimating 2-, 5-, 10-, 25-, 50-, and 100-year peak discharges and flood depths at ungaged sites in Utah were developed using multiple-regression techniques. Ratios of 500- to 100-year values also were determined. The peak discharge equations are applicable to unregulated streams and the flood depth equations are applicable to the unregulated flow in natural stream channels. The flood depth data can be used to approximate flood prone areas. Drainage area and mean basin elevation are the two basin characteristics needed to use these equations. The standard error of estimate ranges from 38% to 74% for the 100-year peak discharge and from 23% to 33% for the 100-year flood depth. Five different flood mapping methods are described. Streams are classified into four categories as a basis for selecting a flood mapping method. Procedures for transferring flood depths obtained from the regression equations to a flood boundary map are outlined. Also, previous detailed flood mapping by government agencies and consultants is summarized to assist the user in quality control and to minimize duplication of effort. Methods are described for transferring flood frequency data from gaged to ungaged sites on the same stream. Peak discharge and flood depth frequency relations and selected basin characteristics data, updated through the 1980 water year, are tabulated for more than 300 gaging stations in Utah and adjoining states. In addition, weighted estimates of peak discharge relations based on the station data and the regression estimates are provided for each gaging station used in the regression analysis. (Author 's abstract)

  16. Measurements of nasal airflow and patency: a critical review with emphasis on the use of peak nasal inspiratory flow in daily practice.

    PubMed

    Ottaviano, G; Fokkens, W J

    2016-02-01

    Objective measures can be used to assist the clinician to diagnose and treat nasal obstruction and also to quantify nasal obstruction in research. Objective measurements of nasal obstruction are as important as objective measurements of lung function. peak nasal inspiratory flow (PNIF), acoustic rhinometry (AR) and rhinomanometry (RM), with their specific peculiarity, assess different aspects of nasal obstruction. From the studies available in the literature, it seems that these methods roughly correlate with each other and that all of them can be alternatively utilized very well in research as well as in clinical practice. This review describes the various methods that can be used to measure nasal patency, airflow and resistance, mainly peak nasal inspiratory flow, rhinomanometry and acoustic rhinometry. PNIF has been demonstrated to be reproducible and as good an indication of objective nasal patency as formal rhinomanometry and has the advantage to be cheap, simple and suitable for serial measurements and for home use even in the paediatric population. PNIF normative data are available for children, adults and elderly subjects, and the availability of unilateral PNIF normal values allows evaluation of nasal sides separately. Just as in the lower airways, objective and subjective evaluation gives different information that together optimizes the diagnosis and the treatment of our patients. We argue that PNIF should be used regularly in every outpatient clinic that treats patients with nasal obstruction. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Twin Peaks

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The two hills in the distance, approximately one to two kilometers away, have been dubbed the 'Twin Peaks' and are of great interest to Pathfinder scientists as objects of future study. The white areas on the left hill, called the 'Ski Run' by scientists, may have been formed by hydrologic processes.

    The image was taken by the Imager for Mars Pathfinder (IMP) after its deployment on Sol 3. Mars Pathfinder was developed and managed by the Jet Propulsion Laboratory (JPL) for the National Aeronautics and Space Administration. The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  18. Migration and health in Southern Africa: 100 years and still circulating

    PubMed Central

    Lurie, Mark N.; Williams, Brian G.

    2014-01-01

    Migration has deep historical roots in South and Southern Africa and to this day continues to be highly prevalent and a major factor shaping South African society and health. In this paper we examine the role of migration in the spread of two diseases nearly 100 years apart: tuberculosis following the discovery of gold in 1886 and HIV in the early 1990s. Both cases demonstrate the critical role played by human migration in the transmission and subsequent dissemination of these diseases to rural areas. In both cases, migration acts to assemble in one high-risk environment thousands of young men highly susceptible to new diseases. With poor living and working conditions, these migration destinations act as hot-spots for disease transmission. Migration of workers back to rural areas then serves as a highly efficient means of disseminating these diseases to rural populations. We conclude by raising some more recent questions examining the current role of migration in Southern Africa. PMID:24653964

  19. From Smallpox to Big Data: The Next 100 Years of Epidemiologic Methods.

    PubMed

    Gange, Stephen J; Golub, Elizabeth T

    2016-03-01

    For more than a century, epidemiology has seen major shifts in both focus and methodology. Taking into consideration the explosion of "big data," the advent of more sophisticated data collection and analytical tools, and the increased interest in evidence-based solutions, we present a framework that summarizes 3 fundamental domains of epidemiologic methods that are relevant for the understanding of both historical contributions and future directions in public health. First, the manner in which populations and their follow-up are defined is expanding, with greater interest in online populations whose definition does not fit the usual classification by person, place, and time. Second, traditional data collection methods, such as population-based surveillance and individual interviews, have been supplemented with advances in measurement. From biomarkers to mobile health, innovations in the measurement of exposures and diseases enable refined accuracy of data collection. Lastly, the comparison of populations is at the heart of epidemiologic methodology. Risk factor epidemiology, prediction methods, and causal inference strategies are areas in which the field is continuing to make significant contributions to public health. The framework presented herein articulates the multifaceted ways in which epidemiologic methods make such contributions and can continue to do so as we embark upon the next 100 years. © The Author 2015. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Under Connecticut Skies: Exploring 100 Years of Astronomy at Van Vleck Observatory in Middletown, Connecticut

    NASA Astrophysics Data System (ADS)

    Kilgard, Roy E.; Williams, Amrys; Erickson, Paul; Herbst, William; Redfield, Seth

    2017-01-01

    Under Connecticut Skies examines the history of astronomy at Van Vleck Observatory, located on the campus of Wesleyan University in Middletown, Connecticut. Since its dedication in June of 1916, Van Vleck has been an important site of astronomical research, teaching, and public outreach. Over a thousand visitors pass through the observatory each year, and regular public observing nights happen year-round in cooperation with the Astronomical Society of Greater Hartford. Our project explores the place-based nature of astronomical research, the scientific instruments, labor, and individuals that have connected places around the world in networks of observation, and the broader history of how observational astronomy has linked local people, amateur observers, professional astronomers, and the tools and objects that have facilitated their work under Connecticut’s skies over the past 100 years. Our research team has produced a historical exhibition to help commemorate the observatory’s centennial that opened to the public in May of 2016. Our work included collecting, documenting, and interpretting this history through objects, archival documents, oral histories, photographs, and more. The result is both a museum and a working history "laboratory" for use by student and professional researchers. In addition to the exhibit itself, we have engaged in new interpretive programs to help bring the history of astronomy to life. Future work will include digitization of documents and teaching slides, further collection of oral histories, and expanding the collection to the web for use by off-site researches.

  1. AJRCCM: 100-Year Anniversary. The Shifting Landscape for Lung Cancer: Past, Present, and Future.

    PubMed

    Vachani, Anil; Sequist, Lecia V; Spira, Avrum

    2017-05-01

    The past century has witnessed a transformative shift in lung cancer from a rare reportable disease to the leading cause of cancer death among men and women worldwide. This historic shift reflects the increase in tobacco consumption worldwide, spurring public health efforts over the past several decades directed at tobacco cessation and control. Although most lung cancers are still diagnosed at a late stage, there have been significant advances in screening high-risk smokers, diagnostic modalities, and chemopreventive approaches. Improvements in surgery and radiation are advancing our ability to manage early-stage disease, particularly among patients considered unfit for traditional open resection. Arguably, the most dramatic progress has occurred on the therapeutic side, with the development of targeted and immune-based therapy over the past decade. This article reviews the major shifts in the lung cancer landscape over the past 100 years. Although many ongoing clinical challenges remain, this review will also highlight emerging molecular and imaging-based approaches that represent opportunities to transform the prevention, early detection, and treatment of lung cancer in the years ahead.

  2. Revisiting extreme storms of the past 100 years for future safety of large water management infrastructures

    NASA Astrophysics Data System (ADS)

    Chen, Xiaodong; Hossain, Faisal

    2016-07-01

    Historical extreme storm events are widely used to make Probable Maximum Precipitation (PMP) estimates, which form the cornerstone of large water management infrastructure safety. Past studies suggest that extreme precipitation processes can be sensitive to land surface feedback and the planetary warming trend, which makes the future safety of large infrastructures questionable given the projected changes in land cover and temperature in the coming decades. In this study, a numerical modeling framework was employed to reconstruct 10 extreme storms over CONUS that occurred during the past 100 years, which are used by the engineering profession for PMP estimation for large infrastructures such as dams. Results show that the correlation in daily rainfall for such reconstruction can range between 0.4 and 0.7, while the correlation for maximum 3-day accumulation (a standard period used in infrastructure design) is always above 0.5 for post-1948 storms. This suggests that current numerical modeling and reanalysis data allow us to reconstruct big storms after 1948 with acceptable accuracy. For storms prior to 1948, however, reconstruction of storms shows inconsistency with observations. Our study indicates that numerical modeling and data may not have advanced to a sufficient level to understand how such old storms (pre-1948) may behave in future warming and land cover conditions. However, the infrastructure community can certainly rely on the use of model reconstructed extreme storms of the 1948-present period to reassess safety of our large water infrastructures under assumed changes in temperature and land cover.

  3. The Current Status of Ticks in Turkey: A 100-Year Period Review from 1916 to 2016.

    PubMed

    İnci, Abdullah; Yıldırım, Alparslan; Düzlü, Önder

    2016-09-01

    Environmental and bio-ecological changes, some administrative and political mistakes, and global warming seriously affect the behaviors of ticks in Turkey and globally. The global public sensitivity toward tick infestations has increased along with increases in tick-borne diseases (TBDs). Recently, the World Health Organization (WHO) developed a new political concept, "One Health," for specific struggle strategies against tick infestations and TBDs. To highlight the importance of the issue, the WHO had declared the year 2015 for vector-borne diseases and adopted the slogan "small bites big threat". In global struggle strategies, the epidemiological aspects and dynamics of increasing tick populations and their effects on the incidence of the TBDs mainly with zoonotic characteristics have been specifically targeted. In Turkey, during the last century, approximately 47 tick species, including eight soft and 39 hard tick species in three and six genera belonging to Argasidae and Ixodidae, respectively, had already been reported. In this article, the recorded tick species, regional infestations, and medical and veterinary importance in Turkey were chronologically reviewed based on a 100-year period between 1916 and 2016.

  4. [Nutrient dynamics over the past 100 years and its restoration baseline in Dianshan Lake].

    PubMed

    Li, Xiao-Ping; Chen, Xiao-Hua; Dong, Xu-Hui; Dong, Zhi; Sun, Dun-Ping

    2012-10-01

    The restoration of eutrophic lakes requires a good knowledge on the history and baseline of nutrients in the lakes. This work conducted an analysis on 210Pb/137Cs, water content, loss-on-ignition, sedimentary total phosphorus (TP), total nitrogen (TN), total organic carbon (TOC) and diatoms in the four sediment cores from Dianshan Lake (near Shanghai City). Good coherence in palaeoproxies between the cores indicates a relatively stable sedimentary environment. With increasing human impact, diatom communities shifted from oligo-trophic species Cyclotella bodanica, C. ocelata, Achnanthes minutissima, Cocconeis placentula var lineate, Cymbella sp. , Fragilaria pintata, F. brevistrata, F. construens var venter to recent eutrophic species including Cyclostephanos dubias, C. atomus, Stephanodiscus minitulus, S. hantzschi, Aulacoseria alpigena. The epilimnetic TP over the past 100 years reconstructed using an established diatom-TP transfer function matches well with the monitoring TP where exists. Based on the sedimentary nutrient characteristics and diatom-reconstructed nutrient dynamics, we proposed that the nutrient baseline for Dianshan Lake is 50-60 microg x L(-1), 500 mg x kg(-1) and 550 mg x kg(-1) for water TP concentration, sedimentary TP and TN, respectively.

  5. Rainfall and drought in equatorial east Africa during the past 1,100 years

    NASA Astrophysics Data System (ADS)

    Verschuren, Dirk; Laird, Kathleen R.; Cumming, Brian F.

    2000-01-01

    Knowledge of natural long-term rainfall variability is essential for water-resource and land-use management in sub-humid regions of the world. In tropical Africa, data relevant to determining this variability are scarce because of the lack of long instrumental climate records and the limited potential of standard high-resolution proxy records such as tree rings and ice cores. Here we present a decade-scale reconstruction of rainfall and drought in equatorial east Africa over the past 1,100 years, based on lake-level and salinity fluctuations of Lake Naivasha (Kenya) inferred from three different palaeolimnological proxies: sediment stratigraphy and the species compositions of fossil diatom and midge assemblages. Our data indicate that, over the past millennium, equatorial east Africa has alternated between contrasting climate conditions, with significantly drier climate than today during the `Medieval Warm Period' (~ AD 1000-1270) and a relatively wet climate during the `Little Ice Age' (~ AD 1270-1850) which was interrupted by three prolonged dry episodes. We also find strong chronological links between the reconstructed history of natural long-term rainfall variation and the pre-colonial cultural history of east Africa, highlighting the importance of a detailed knowledge of natural long-term rainfall fluctuations for sustainable socio-economic development.

  6. Rainfall and drought in equatorial east Africa during the past 1,100 years.

    PubMed

    Verschuren, D; Laird, K R; Cumming, B F

    2000-01-27

    Knowledge of natural long-term rainfall variability is essential for water-resource and land-use management in sub-humid regions of the world. In tropical Africa, data relevant to determining this variability are scarce because of the lack of long instrumental climate records and the limited potential of standard high-resolution proxy records such as tree rings and ice cores. Here we present a decade-scale reconstruction of rainfall and drought in equatorial east Africa over the past 1,100 years, based on lake-level and salinity fluctuations of Lake Naivasha (Kenya) inferred from three different palaeolimnological proxies: sediment stratigraphy and the species compositions of fossil diatom and midge assemblages. Our data indicate that, over the past millennium, equatorial east Africa has alternated between contrasting climate conditions, with significantly drier climate than today during the 'Medieval Warm Period' (approximately AD 1000-1270) and a relatively wet climate during the 'Little Ice Age' (approximately AD 1270-1850) which was interrupted by three prolonged dry episodes. We also find strong chronological links between the reconstructed history of natural long-term rainfall variation and the pre-colonial cultural history of east Africa, highlighting the importance of a detailed knowledge of natural long-term rainfall fluctuations for sustainable socio-economic development.

  7. Stages of the pathologic process in Alzheimer disease: age categories from 1 to 100 years.

    PubMed

    Braak, Heiko; Thal, Dietmar R; Ghebremedhin, Estifanos; Del Tredici, Kelly

    2011-11-01

    Two thousand three hundred and thirty two nonselected brains from 1- to 100-year-old individuals were examined using immunocytochemistry (AT8) and Gallyas silver staining for abnormal tau; immunocytochemistry (4G8) and Campbell-Switzer staining were used for the detection ofβ-amyloid. A total of 342 cases was negative in the Gallyas stain but when restaged for AT8 only 10 were immunonegative. Fifty-eight cases had subcortical tau predominantly in the locus coeruleus, but there was no abnormal cortical tau (subcortical Stages a-c). Cortical involvement (abnormal tau in neurites) was identified first in the transentorhinal region (Stage 1a, 38 cases). Transentorhinal pyramidal cells displayed pretangle material (Stage 1b, 236 cases). Pretangles gradually became argyrophilic neurofibrillary tangles (NFTs) that progressed in parallel with NFT Stages I to VI. Pretangles restricted to subcortical sites were seen chiefly at younger ages. Of the total cases, 1,031 (44.2%) had β-amyloid plaques. The first plaques occurred in the neocortex after the onset of tauopathy in the brainstem. Plaques generally developed in the 40s in 4% of all cases, culminating in their tenth decade (75%). β-amyloid plaques and NFTs were significantly correlated (p < 0.0001). These data suggest that tauopathy associated with sporadic Alzheimer disease may begin earlier than previously thought and possibly in the lower brainstem rather than in the transentorhinal region.

  8. Cryptic loss of montane avian richness and high community turnover over 100 years.

    PubMed

    Tingley, Morgan W; Beissinger, Steven R

    2013-03-01

    Although there are numerous examples of individual species moving up in elevation and poleward in latitude in response to 20th century climate change, how communities have responded is less well understood and requires fully accounting for changes in species-specific detectability over time, which has been neglected in past studies. We use a hierarchical Bayesian occupancy model to examine bird species richness change and turnover along three elevation gradients surveyed 80-100 years apart in the Sierra Nevada of California, USA. Richness declined over the 20th century across all elevations. Turnover was greatest at the highest and the lowest elevations. These findings were only apparent, however, after species' detectability was incorporated into measures of species richness. Further partitioning of species richness changes by elevational life zone showed that numbers of low- and high-elevation species declined, without a concurrent expansion by mid-elevation species. Our results provide empirical evidence for biodiversity loss in protected montane areas during the 20th century and highlight the importance of accounting for detectability in comparisons of species richness over time.

  9. Individual differences and their measurement: A review of 100 years of research.

    PubMed

    Sackett, Paul R; Lievens, Filip; Van Iddekinge, Chad H; Kuncel, Nathan R

    2017-03-01

    This article reviews 100 years of research on individual differences and their measurement, with a focus on research published in the Journal of Applied Psychology. We focus on 3 major individual differences domains: (a) knowledge, skill, and ability, including both the cognitive and physical domains; (b) personality, including integrity, emotional intelligence, stable motivational attributes (e.g., achievement motivation, core self-evaluations), and creativity; and (c) vocational interests. For each domain, we describe the evolution of the domain across the years and highlight major theoretical, empirical, and methodological developments, including relationships between individual differences and variables such as job performance, job satisfaction, and career development. We conclude by discussing future directions for individual differences research. Trends in the literature include a growing focus on substantive issues rather than on the measurement of individual differences, a differentiation between constructs and measurement methods, and the use of innovative ways of assessing individual differences, such as simulations, other-reports, and implicit measures. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  10. Comparison of the 2-, 25-, and 100-year recurrence interval floods computed from observed data with the 1995 urban flood-frequency estimating equations for Georgia

    USGS Publications Warehouse

    Inman, Ernest J.

    1997-01-01

    Flood-frequency relations were computed for 28 urban stations, for 2-, 25-, and 100-year recurrence interval floods and the computations were compared to corresponding recurrence interval floods computed from the estimating equations from a 1995 investigation. Two stations were excluded from further comparisons or analyses because neither station had a significant flood during the period of observed record. The comparisons, based on the student's t-test statistics at the 0.05 level of significance, indicate that the mean residuals of the 25- and 100-year floods were negatively biased by 26.2 percent and 31.6 percent, respectively, at the 26 stations. However, the mean residuals of the 2-year floods were 2.5 percent lower than the mean of the 2-year floods computed from the equations, and were not significantly biased. The reason for this negative bias is that the period of observed record at the 26 stations was a relatively dry period. At 25 of the 26 stations, the two highest simulated peaks used to develop the estimating equations occurred many years before the observed record began. However, no attempt was made to adjust the estimating equations because higher peaks could occur after the period of observed record and an adjustment to the equations would cause an underestimation of design floods.

  11. 100 years of California’s water rights system: patterns, trends and uncertainty

    NASA Astrophysics Data System (ADS)

    Grantham, Theodore E.; Viers, Joshua H.

    2014-08-01

    For 100 years, California’s State Water Resources Control Board and its predecessors have been responsible for allocating available water supplies to beneficial uses, but inaccurate and incomplete accounting of water rights has made the state ill-equipped to satisfy growing societal demands for water supply reliability and healthy ecosystems. Here, we present the first comprehensive evaluation of appropriative water rights to identify where, and to what extent, water has been dedicated to human uses relative to natural supplies. The results show that water right allocations total 400 billion cubic meters, approximately five times the state’s mean annual runoff. In the state’s major river basins, water rights account for up to 1000% of natural surface water supplies, with the greatest degree of appropriation observed in tributaries to the Sacramento and San Joaquin Rivers and in coastal streams in southern California. Comparisons with water supplies and estimates of actual use indicate substantial uncertainty in how water rights are exercised. In arid regions such as California, over-allocation of surface water coupled with trends of decreasing supply suggest that new water demands will be met by re-allocation from existing uses. Without improvements to the water rights system, growing human and environmental demands portend an intensification of regional water scarcity and social conflict. California’s legal framework for managing its water resources is largely compatible with needed reforms, but additional public investment is required to enhance the capacity of the state’s water management institutions to effectively track and regulate water rights.

  12. The Archives of the Department of Terrestrial Magnetism: Documenting 100 Years of Carnegie Science

    NASA Astrophysics Data System (ADS)

    Hardy, S. J.

    2005-12-01

    The archives of the Department of Terrestrial Magnetism (DTM) of the Carnegie Institution of Washington document more than a century of geophysical and astronomical investigations. Primary source materials available for historical research include field and laboratory notebooks, equipment designs, plans for observatories and research vessels, scientists' correspondence, and thousands of expedition and instrument photographs. Yet despite its history, DTM long lacked a systematic approach to managing its documentary heritage. A preliminary records survey conducted in 2001 identified more than 1,000 linear feet of historically-valuable records languishing in dusty, poorly-accessible storerooms. Intellectual control at that time was minimal. With support from the National Historical Publications and Records Commission, the "Carnegie Legacy Project" was initiated in 2003 to preserve, organize, and facilitate access to DTM's archival records, as well as those of the Carnegie Institution's administrative headquarters and Geophysical Laboratory. Professional archivists were hired to process the 100-year backlog of records. Policies and procedures were established to ensure that all work conformed to national archival standards. Records were appraised, organized, and rehoused in acid-free containers, and finding aids were created for the project web site. Standardized descriptions of each collection were contributed to the WorldCat bibliographic database and the AIP International Catalog of Sources for History of Physics. Historic photographs and documents were digitized for online exhibitions to raise awareness of the archives among researchers and the general public. The success of the Legacy Project depended on collaboration between archivists, librarians, historians, data specialists, and scientists. This presentation will discuss key aspects (funding, staffing, preservation, access, outreach) of the Legacy Project and is aimed at personnel in observatories, research

  13. The tissue, cellular, and molecular regulation of orthodontic tooth movement: 100 years after Carl Sandstedt.

    PubMed

    Meikle, Murray C

    2006-06-01

    The first experimental investigation of orthodontic tooth movement was published by Sandstedt in 1904-1905. After 100 years, there is a good understanding of the sequence of events at both tissue and cellular levels and now the current focus of research is at the molecular level. The techniques of reverse transcription-polymerase chain reaction and in situ hybridization to detect mRNAs of interest have revolutionized tooth movement studies and an expanding list of antibodies and enzyme-linked immunosorbent assays directed against human and animal proteins will facilitate their identification in tissue sections and/or culture supernatants. Nevertheless, although this technology has greatly simplified research for the clinical and laboratory investigator, message is not always translated into protein, and the presence of a protein does not necessarily mean it is biologically active. In vivo and in vitro methods have been widely used in tooth movement studies. However, data from in vitro models, in which the mechanical stimulus can be carefully controlled (tension versus compression; intermittent versus continuous), should be correlated with in vivo data from animal models. The current evidence suggests that downstream from the initial mechanotransduction event at focal adhesions which link the extracellular matrix to the cytoskeleton, mechanically induced remodelling is mediated by a complex feedback mechanism involving the synthesis of cytokines such as interleukin-1 (IL-1), IL-6, and receptor activator of nuclear factor k B ligand by cells of the osteoblast and/or fibroblast lineages. These in turn act in an autocrine/paracrine fashion to regulate the expression of transcription factors, cytokines, growth factors, enzymes, and structural molecules involved in the differentiation, proliferation, and function of mesenchymal and other cell types. Contrary to the impression gained from the literature, tooth movement is not confined to events within the periodontal

  14. An epidemiological review of changes in meningococcal biology during the last 100 years

    PubMed Central

    Abio, Anne; Neal, Keith R; Beck, Charles R

    2013-01-01

    Aim The aim of this study was to assess changes in trends of meningococcal disease and strain diversity of Neisseria meningitidis in Europe, South America, and Africa over the last 100 years. Methods Healthcare databases and sources of grey literature were searched in 2012 and records were screened against the protocol eligibility criteria using a three-stage sifting process. Studies included in the review were subject to data extraction. Results were summarised using a narrative approach. Results Serogroup A was the dominant cause of invasive meningococcal disease in Europe before and during World Wars I and II. Whilst serogroup B has been dominant from the 1970s in Europe and the 1980s in South America, outbreaks have emerged associated with serogroups W135 and Y in the twenty-first century. There has been a shift in the age groups affected by invasive meningococcal disease with an increase in incidence among the elderly associated with serogroup Y and a decline in serogroup C among adolescent populations. Recent outbreaks of serogroup W135 have occurred in some countries in South America. The epidemiological trend of invasive meningococcal disease has remained largely static across Africa and dominated by serogroup A although recently serogroups X and W135 have accounted for a large proportion of morbidity and mortality. Conclusion The epidemiology of N. meningitidis has been dynamic in Europe and South America especially over the last 30 years. Routine vaccination with serogroup C vaccines has led to reduced carriage and incidence of invasive meningococcal disease and herd immunity. PMID:24392681

  15. Caspian tern reproduction in the Saginaw Bay ecosystem following a 100-year flood event

    USGS Publications Warehouse

    Ludwig, James P.; Auman, Heidi J.; Kurita, Hiroko; Ludwig, Matthew E.; Campbell, Loraine M.; Giesy, John P.; Tillitt, Donald E.; Jones, Paul; Yamashita, Nobu; Tanabe, Shinsuke; Tatsukawa, Ryo

    1993-01-01

    In the 2 years that followed the 100-year flood incident of September 1986 in the Saginaw River/Bay ecosystem, the reproduction of Caspian terns collapsed and then slowly recovered. Egg viability and fledging rates of hatched chicks were drastically depressed in 1987 and 1988. Eggs from clutches laid later in the year were less viable and chicks hatched from these eggs displayed wasting syndromes and deformities. The post-flood rate of deformities in hatched chicks in 1987–1989 was 163-fold greater than background rates for this population in 1962–1967. Embryonic abnormalities and deformities were found in many embryos recovered from dead eggs. Recently published data on planar toxic chemicals from samples of forage fish, tern eggs, and chicks from water birds nesting in the bay implicate planar dioxin-like PCBs 77 and 126 as the sources of these severe bioeffects. The planar PCB congeners accounted for >98% of TCDD-EQ toxicity in the tern eggs, and several were present at levels near or at the LD95 levels each for chicken eggs. Actual TCDD was about 1% of the TCDD-EQ toxicity. Very rapid buildup rates of PCBs were measured in tern eggs. The calculated toxic potency of PCB recovered from tern eggs was about 15-fold greater than parent aroclor 1242 PCB. Smaller tern species were projected to be much more at risk than the larger Caspian tern due to greater standard metabolic rates. The study supports the view that sediment disturbance and sediment banks of toxic chemicals are major threats to upper trophic level fish-eating species.

  16. To Humbly Go: Guarding Against Perpetuating Models of Colonization in the 100-Year Starship Study

    NASA Astrophysics Data System (ADS)

    Kramer, W. R.

    Past patterns of exploration, colonization and exploitation on Earth continue to provide the predominant paradigms that guide many space programs. Any project of crewed space exploration, especially of the magnitude envisioned by the 100-Year Starship Study, must guard against the hubris that may emerge among planners, crew, and others associated with the project, including those industries and bureaucracies that will emerge from the effort. Maintaining a non-exploitative approach may be difficult in consideration of the century of preparatory research and development and the likely multigenerational nature of the voyage itself. Starting now with mission dreamers and planners, the purpose of the voyage must be cast as one of respectful learning and humble discovery, not of conquest (either actual or metaphorical) or other inappropriate models, including military. At a minimum, the Study must actively build non-violence into the voyaging culture it is beginning to create today. References to exploitive colonization, conquest, destiny and other terms from especially American frontier mythology, while tempting in their propagandizing power, should be avoided as they limit creative thinking about alternative possible futures. Future voyagers must strive to adapt to new environments wherever possible and be assimilated by new worlds both biologically and behaviorally rather than to rely on attempts to recreate the Earth they have left. Adaptation should be strongly considered over terraforming. This paper provides an overview of previous work linking the language of colonization to space programs and challenges the extension of the myth of the American frontier to the Starship Study. It argues that such metaphors would be counter-productive at best and have the potential to doom long-term success and survival by planting seeds of social decay and self-destruction. Cautions and recommendations are suggested.

  17. Multimodel hydrologic ensemble predictions of peak flows: lessons learned from the real-time experiment in the upper Nysa Klodzka basin (SW Poland)

    NASA Astrophysics Data System (ADS)

    Niedzielski, Tomasz; Mizinski, Bartlomiej

    2015-04-01

    The novel system for issuing the real-time warnings against hydrologic hazards, known as HydroProg (research project no. 2011/01/D/ST10/04171 of the National Science Centre of Poland), has been implemented in the upper Nysa Klodzka basin (SW Poland). The system itself works like a bridge between automatic hydrometeorological observational networks and numerous hydrologic models. Its main objective is to automatically produce and publish flood warnings on a basis of prognoses of river stages calculated from dissimilar models and - most importantly - their multimodel ensembles which are computed in real time within HydroProg. The implementation in question for the upper Nysa Klodzka basin is abbreviated as HydroProg-Klodzko, and is feasible due to the partnership with Klodzko County which maintains the Local System for Flood Monitoring (Lokalny System Oslony Przeciwpowodziowej - LSOP). The HydroProg-Klodzko prototype is continuously, i.e. with 15-minute update, calculating multimodel hydrologic ensemble predictions and publishing them along with prognoses corresponding to individual ensemble members (www.klodzko.hydroprog.uni.wroc.pl). The real-time HydroProg-Klodzko experiment provided us with a valuable database of predictions as well as their errors and performance characteristics. At present, six hydrologic models participate in the experiment, however two of them (multi- and univariate autoregressive time series models) work uninterruptedly since the launch of the system in August 2013. The present study focuses on the detailed characterization of the real-time performance of the two models in predicting a few significant peak flows that occurred over the entire year of the experiment. In particular, we show how the two models can be weighted to produce skilful multimodel ensemble prognoses of river stages during peak flows. We identify phases of a peak flow in which, in order to improve the predictive skills, one should switch between individual models and

  18. Improving calibration of two key parameters in Hydrologic Engineering Center hydrologic modelling system, and analysing the influence of initial loss on flood peak flows.

    PubMed

    Lin, Musheng; Chen, Xingwei; Chen, Ying; Yao, Huaxia

    2013-01-01

    Parameter calibration is a key and difficult issue for a hydrological model. Taking the Jinjiang Xixi watershed of south-east China as the study area, we proposed methods to improve the calibration of two very sensitive parameters, Muskingum K and initial loss, in the Hydrologic Engineering Center hydrologic modelling system (HEC-HMS) model. Twenty-three rainstorm flood events occurring from 1972 to 1977 were used to calibrate the model using a trial-and-error approach, and a relationship between initial loss and initial discharge for these flood events was established; seven rainstorm events occurring from 1978 to 1979 were used to validate the two parameters. The influence of initial loss change on different return-period floods was evaluated. A fixed Muskingum K value, which was calibrated by assuming a flow wave velocity at 3 m/s, could be used to simulate a flood hydrograph, and the empirical power-function relationship between initial loss and initial discharge made the model more applicable for flood forecasting. The influence of initial loss on peak floods was significant but not identical for different flood levels, and the change rate of peak floods caused by the same initial loss change was more remarkable when the return period increased.

  19. Pulmonary testing using peak flow meters of very low birth weight children born in the perisurfactant era and school controls at age 10 years.

    PubMed

    Palta, Mari; Sadek-Badawi, Mona; Madden, Kathleen; Green, Christopher

    2007-09-01

    We determined lung function at age 10 years in very low birthweight (VLBW, peak expiratory flow (PEF), forced expiratory volume in one second (FEV(1)), forced vital capacity (FVC) and their diurnal variation. VLBW children were recruited across the perisurfactant era at admission to six NICUs in Wisconsin and Iowa, and controls from area classrooms. Two hundred sixty five VLBW children and 360 controls were tested by the Jaeger AM1 peak flow meter at age 10 years. Two hundred six VLBW and 79 controls had additional home monitoring. Abnormality was defined as observed/predicted ratio <0.8 for PEF, FEV(1), and FVC, and by criteria of Pelkonen for diurnal PEF variation. VLBW children were compared to controls, VLBW children with bronchopulmonary dysplasia (BPD) to those without, and those with respiratory conditions to those without. PEF and FEV(1) showed high reproducibility (intraclass correlations, ICC 0.75-0.83). Controls and VLBW children with and without BPD differed significantly on all measures. Baseline test results did not differ across birth years, but PEF variation was less after surfactant availability (P = 0.04). Observed over predicted FEV(1) was the most sensitive in detecting differences between groups (P < 0.001), with mean (s.d.) 0.97 (0.12) for controls, 0.88 (0.14) for VLBW children without BPD, and 0.78 (0.13) for those with BPD. Odds ratios for abnormality were especially high with respiratory medication use during the first 5 years of life, 4.4 (95% CI: 2.0-9.8) for FEV(1) and 5.1 (95% CI: 2.0-13.2) for diurnal PEF variation. Our results show that respiratory abnormalities persist to at least age 10 years for VLBW children born in the surfactant era.

  20. Climatic and Hydrological Changes of Past 100 Years in Asian Arid Zone

    NASA Astrophysics Data System (ADS)

    Feng, Zhaodong; Salnikov, Vitaliy; Xu, Changchun

    2014-05-01

    The Asian Arid Zone (AAZ) is here defined to include the following regions: northwestern China, Mongolia, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. Generally speaking, the AAZ has experienced a temperature rising during the past 100 years that was significantly faster than the global average (0.14 ºC per decade). Specifically, the rate was 0.39 ºC per decade in northwestern China (1950-2010), 0.26 ºC per decade in Kazakhstan (1936-2005), 0.22 ºC per decade in Mongolia (1940-2010), 0.29 ºC per decade in Uzbekistan (1950-2005), 0.18 ºC per decade in Turkmenistan (1961-1995). It should be noted that the mountainous parts of AAZ seems to have experienced a slower rate of temperature rising. For example, the rate was 0.10 ºC per decade in Tajikistan (1940-2005) and was 0.08 ºC per decade in Kyrgyzstan (1890-2005). Precipitation has a slight increasing trend in northwestern China, but it has fluctuated along a near-constant line in the rest of the AAZ. Hydrological data from high-elevation basin show that the runoff has been increasing primarily as a result of rising temperature that caused increases in ice melting. A natural decreasing trend of surface runoff in low-elevation basins is undeniable and the decreasing trend is attributable to intensified evaporation under warming conditions. It is true that the total amount of runoff in the Tianshan Mountains and the associated basins has been increased primarily as a result of temperature rising-resulted increases in ice melting. But, approaching to the turning point of glacier-melting supplies to runoff will pose a great threat to socio-economic sustainability and to ecological security. The turning point refers to the transition from increasing runoff to decreasing runoff within ice melting supplied watersheds under a warming climate.

  1. Infrared survey of 50 buildings constructed during 100 years: thermal performances and damage conditions

    NASA Astrophysics Data System (ADS)

    Ljungberg, Sven-Ake

    1995-03-01

    Different building constructions and craftsmanship give rise to different thermal performance and damage conditions. The building stock of most industrial countries consists of buildings of various age, and constructions, from old historic buildings with heavy stone or wooden construction, to new buildings with heavy or light concrete construction, or modern steel or wooden construction. In this paper the result from a detailed infrared survey of 50 buildings from six Swedish military camps is presented. The presentation is limited to a comparison of thermal performance and damage conditions of buildings of various ages, functions, and constructions, of a building period of more than 100 years. The result is expected to be relevant even to civilian buildings. Infrared surveys were performed during 1992-1993, with airborne, and mobile short- and longwave infrared systems, out- and indoor thermography. Interpretation and analysis of infrared data was performed with interactive image and analyzing systems. Field inspections were carried out with fiber optics system, and by ocular inspections. Air-exchange rate was measured in order to quantify air leakages through the building envelope, indicated in thermograms. The objects studied were single-family houses, barracks, office-, service-, school- and exercise buildings, military hotels and restaurants, aircraft hangars, and ship factory buildings. The main conclusions from this study are that most buildings from 1880 - 1940 have a solid construction with a high quality of craftsmanship, relatively good thermal performance, due to extremely thick walls, and adding insulation at the attic floor. From about 1940 - 1960 the quality of construction, thermal performance and craftsmanship seem to vary a lot. Buildings constructed during the period of 1960 - 1990 have in general the best thermal performance due to a better insulation capacity, however, also one finds here the greatest variety of problems. The result from this

  2. Combining Neural Networks with Existing Methods to Estimate 1 in 100-Year Flood Event Magnitudes

    NASA Astrophysics Data System (ADS)

    Newson, A.; See, L.

    2005-12-01

    Over the last fifteen years artificial neural networks (ANN) have been shown to be advantageous for the solution of many hydrological modelling problems. The use of ANNs for flood magnitude estimation in ungauged catchments, however, is a relatively new and under researched area. In this paper ANNs are used to make estimates of the magnitude of the 100-year flood event (Q100) for a number of ungauged catchments. The data used in this study were provided by the Centre for Ecology and Hydrology's Flood Estimation Handbook (FEH), which contains information on catchments across the UK. Sixteen catchment descriptors for 719 catchments were used to train an ANN, which was split into a training, validation and test data set. The goodness-of-fit statistics on the test data set indicated good model performance, with an r-squared value of 0.8 and a coefficient of efficiency of 79 percent. Data for twelve ungauged catchments were then put through the trained ANN to produce estimates of Q100. Two other accepted methodologies were also employed: the FEH statistical method and the FSR (Flood Studies Report) design storm technique, both of which are used to produce flood frequency estimates. The advantage of developing an ANN model is that it provides a third figure to aid a hydrologist in making an accurate estimate. For six of the twelve catchments, there was a relatively low spread between estimates. In these instances, an estimate of Q100 could be made with a fair degree of certainty. Of the remaining six catchments, three had areas greater than 1000km2, which means the FSR design storm estimate cannot be used. Armed with the ANN model and the FEH statistical method the hydrologist still has two possible estimates to consider. For these three catchments, the estimates were also fairly similar, providing additional confidence to the estimation. In summary, the findings of this study have shown that an accurate estimation of Q100 can be made using the catchment descriptors of

  3. The Hunterian Neurosurgical Laboratory: the first 100 years of neurosurgical research.

    PubMed

    Sampath, P; Long, D M; Brem, H

    2000-01-01

    Modern neurosurgery has long had a strong laboratory foundation, and much of this tradition can be traced to the Hunterian Neurosurgical Laboratory of the Johns Hopkins Hospital. Founded with the basic goals of investigating the causes and symptoms of disease and establishing the crucial role that surgeons may play in the treatment of disease, the Hunterian laboratory has adhered to these tenets, despite the dramatic changes in neurosurgery that have occurred in the last 100 years. Named for the famous English surgeon John Hunter (1728-1793), the Hunterian laboratory was conceived by William Welch and William Halsted as a special laboratory for experimental work in surgery and pathology. In 1904, Harvey Cushing was appointed by Halsted to direct the laboratory. With the three primary goals of student education, veterinary surgery that stressed surgical techniques, and meticulous surgical and laboratory record-keeping, the laboratory was quite productive, introducing the use of physiological saline solutions, describing the anatomic features and function of the pituitary gland, and establishing the field of endocrinology. In addition, the original development of hanging drop tissue culture, fundamental investigations into cerebrospinal fluid, and countless contributions to otolaryngology by Samuel Crowe all occurred during this "crucible" period. In 1912, Cushing was succeeded by Walter Dandy, whose work on experimental hydrocephalus and cerebrospinal fluid circulation led to the development of pneumoencephalography. The early days of neurosurgery evolved with close ties to general surgery, and so did the Hunterian laboratory. After Dandy began devoting his time to clinical work, general surgeons (first Jay McLean and then, in 1922, Ferdinand Lee) became the directors of the laboratory. Between 1928 and 1942, more than 150 original articles were issued from the Hunterian laboratory; these articles described significant advances in surgery, including pioneering

  4. Peak-flow frequency analyses and results based on data through water year 2011 for selected streamflow-gaging stations in or near Montana: Chapter C in Montana StreamStats

    USGS Publications Warehouse

    Sando, Steven K.; McCarthy, Peter M.; Dutton, DeAnn M.

    2016-04-05

    Chapter C of this Scientific Investigations Report documents results from a study by the U.S. Geological Survey, in cooperation with the Montana Department of Transportation and the Montana Department of Natural Resources, to provide an update of statewide peak-flow frequency analyses and results for Montana. The purpose of this report chapter is to present peak-flow frequency analyses and results for 725 streamflow-gaging stations in or near Montana based on data through water year 2011. The 725 streamflow-gaging stations included in this study represent nearly all streamflowgaging stations in Montana (plus some from adjacent states or Canadian Provinces) that have at least 10 years of peak-flow records through water year 2011. For 29 of the 725 streamflow-gaging stations, peak-flow frequency analyses and results are reported for both unregulated and regulated conditions. Thus, peak-flow frequency analyses and results are reported for a total of 754 analyses. Estimates of peak-flow magnitudes for 66.7-, 50-, 42.9-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance probabilities are reported. These annual exceedance probabilities correspond to 1.5-, 2-, 2.33-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year recurrence intervals.

  5. Peak flow velocities in the ascending aorta—real-time phase-contrast magnetic resonance imaging vs. cine magnetic resonance imaging and echocardiography

    PubMed Central

    Sohns, Jan M.; Kowallick, Johannes T.; Joseph, Arun A.; Merboldt, K. Dietmar; Voit, Dirk; Fasshauer, Martin; Staab, Wieland; Lotz, Joachim; Unterberg-Buchwald, Christina

    2015-01-01

    This prospective study of eight healthy volunteers evaluates peak flow velocities (PFV) in the ascending aorta using real-time phase-contrast magnetic resonance imaging (MRI) in comparison to cine phase-contrast MRI and echocardiography. Flow measurements by echocardiography and cine phase-contrast MRI with breath-holding were performed according to clinical standards. Real-time phase-contrast MRI at 40 ms temporal resolution and 1.3 mm in-plane resolution was based on highly undersampled radial fast low-angle shot (FLASH) sequences with image reconstruction by regularized nonlinear inversion (NLINV). Evaluations focused on the determination of PFV. Linear regressions and Bland-Altman plots were used for comparisons of methods. When averaged across subjects, real-time phase-contrast MRI resulted in PFV of 120±20 cm s−1 (mean ± SD) in comparison to 122±16 cm s−1 for cine MRI and 124±20 cm s−1 for echocardiography. The maximum deviations between real-time phase-contrast MRI and echocardiography ranged from –20 to +14 cm s−1 (cine MRI: –10 to +12 cm s−1). Thus, in general, real-time phase-contrast MRI of cardiac outflow revealed quantitative agreement with cine MRI and echocardiography. The advantages of real-time MRI are measurements during free breathing and access to individual cardiac cycles. PMID:26682138

  6. Peak flow velocities in the ascending aorta-real-time phase-contrast magnetic resonance imaging vs. cine magnetic resonance imaging and echocardiography.

    PubMed

    Sohns, Jan M; Kowallick, Johannes T; Joseph, Arun A; Merboldt, K Dietmar; Voit, Dirk; Fasshauer, Martin; Staab, Wieland; Frahm, Jens; Lotz, Joachim; Unterberg-Buchwald, Christina

    2015-10-01

    This prospective study of eight healthy volunteers evaluates peak flow velocities (PFV) in the ascending aorta using real-time phase-contrast magnetic resonance imaging (MRI) in comparison to cine phase-contrast MRI and echocardiography. Flow measurements by echocardiography and cine phase-contrast MRI with breath-holding were performed according to clinical standards. Real-time phase-contrast MRI at 40 ms temporal resolution and 1.3 mm in-plane resolution was based on highly undersampled radial fast low-angle shot (FLASH) sequences with image reconstruction by regularized nonlinear inversion (NLINV). Evaluations focused on the determination of PFV. Linear regressions and Bland-Altman plots were used for comparisons of methods. When averaged across subjects, real-time phase-contrast MRI resulted in PFV of 120±20 cm s(-1) (mean ± SD) in comparison to 122±16 cm s(-1) for cine MRI and 124±20 cm s(-1) for echocardiography. The maximum deviations between real-time phase-contrast MRI and echocardiography ranged from -20 to +14 cm s(-1) (cine MRI: -10 to +12 cm s(-1)). Thus, in general, real-time phase-contrast MRI of cardiac outflow revealed quantitative agreement with cine MRI and echocardiography. The advantages of real-time MRI are measurements during free breathing and access to individual cardiac cycles.

  7. 100 years of mapping the Holocene Rhine-Meuse delta plain: combining research and teaching

    NASA Astrophysics Data System (ADS)

    Cohen, K. M.; Stouthamer, E.; Hoek, W. Z.; Middelkoop, H.

    2012-04-01

    The history of modern soil, geomorphological and shallow geological mapping in the Holocene Rhine-Meuse delta plain goes back about 100 years. The delta plain is of very heterogeneous build up, with clayey and peaty flood basins, dissected by sandy fluvial distributary channel belts with fine textured levees grading into tidal-influenced rivers and estuaries. Several generations of precursor rivers occur as alluvial ridges and buried ribbon sands. They form an intricate network originating from repeated avulsions, back to 8000 years ago. Present rivers have been embanked since ca. 1250 AD and the delta plain (~ 3000 km2) has been reclaimed for agriculture. Soils are young and subject to oxidation and compaction. The first detailed field map of channel belts and floodbasins was made in 1926 by Vink, a geography teacher from Amsterdam. Soil mapping and Holocene geology gained interest after WW-II, with Wageningen soil scientists Edelman, Hoeksema and Pons taking lead. Utrecht University started teaching and research on the subject in 1959, launching an undergraduate mapping field course based on hand augering and field observation. An archive of borehole logs and local maps started to build up. Initially focused on soil mapping, from 1973 the course shifted to a geomorphological-geological focus. Berendsen took over supervision, introduced standard description protocols and legends and increased coring depth. This resulted in 1982 in his influential PhD thesis on the Rhine delta's genesis. New coring and sampling methods came and extensive 14C dating campaigns began. With steadily increasing numbers of students, accumulation of data speeded up, and increasingly larger parts of the delta were mapped. The academic mapping ran in parallel with soil survey and geological survey mapping campaigns. The computer was introduced in the field course and digital data archiving began in 1989. A series of PhD studies on thematic aspects of delta evolution and an increasing number

  8. Hamiltonian Systems and Optimal Control in Computational Anatomy: 100 Years Since D'Arcy Thompson.

    PubMed

    Miller, Michael I; Trouvé, Alain; Younes, Laurent

    2015-01-01

    The Computational Anatomy project is the morphome-scale study of shape and form, which we model as an orbit under diffeomorphic group action. Metric comparison calculates the geodesic length of the diffeomorphic flow connecting one form to another. Geodesic connection provides a positioning system for coordinatizing the forms and positioning their associated functional information. This article reviews progress since the Euler-Lagrange characterization of the geodesics a decade ago. Geodesic positioning is posed as a series of problems in Hamiltonian control, which emphasize the key reduction from the Eulerian momentum with dimension of the flow of the group, to the parametric coordinates appropriate to the dimension of the submanifolds being positioned. The Hamiltonian viewpoint provides important extensions of the core setting to new, object-informed positioning systems. Several submanifold mapping problems are discussed as they apply to metamorphosis, multiple shape spaces, and longitudinal time series studies of growth and atrophy via shape splines.

  9. Erosion and Deposition Patterns of the Mississippi River as a Result of the "100-Year" Flood Event of April 2011

    NASA Astrophysics Data System (ADS)

    Meyer, D.; Magnani, M.; McIntosh, K. D.

    2011-12-01

    Due to damming in the upper Mississippi River system, rates of sedimentation on the Mississippi River have decreased by more than half since the 1930s, which has resulted in the subsidence of the historic deltaic systems. In order to counteract this trend, the US Army Corps of Engineers (USACE) have diverted most of the Mississippi River sediment flow towards the current deltaic system, although there is concern that current sediment deposition rates may not be enough. Modern land loss along the Mississippi River deltaic plain is a function of many parameters, including the sediment storage and the sediment budget of the river. These parameters are poorly constrained for most rivers. This study explores the possibility of estimating the amount of sediment mobilization during the "100-Year" flood that took place in April 2011 in the portion of the Mississippi River flowing by Memphis, Tennessee. The opportunity to acquire high resolution seismic CHIRP data along the Mississippi River immediately after the flood allows us to compare the new data with similar data acquired in September 2009 in the same part of the river, to evaluate changes sedimentary structures and in the sediment removal/deposition due to the exceptional flooding event. The data were acquired in both cases using an Edgetech SB-512i CHIRP, a 0.7 - 1.2 kHz source pulse, and were recorded to a depth of 5 - 50 m sub-bottom. The compared segments were taken along the same 20 km track of river and comparisons were drawn between them at 9 intersection points. Two main observations can be made from the preliminary analysis of the two datasets: 1) the 2011 data show evidence of widespread erosion and limited deposition. Up to 6 m of alluvium appear to have been eroded from the river bottom. Where sediments have been newly deposited, they are characterized by massive appearance and lack of internal structure; 2) the wavelengths of the sandbars imaged in the post-flood data are 1.5 - 3 times longer than those

  10. Peak inspiratory flow rate measurement by using In-Check DIAL for the different inhaler devices in elderly with obstructive airway diseases

    PubMed Central

    Kawamatawong, Theerasuk; Khiawwan, Supattra; Pornsuriyasak, Prapaporn

    2017-01-01

    Background Inhaler device technique is a common cause of treatment failure in patients with asthma and chronic obstructive pulmonary disease. Dry powder inhaler (DPI) requires optimal peak inspiratory flow rate (PIFR) for drug delivery. Low PIFR generation is common in the elderly. Patient lung function and intrinsic inhaler resistance are factors for determining generated PIFR and drug delivery from DPI. Objectives We aimed to identify the PIFR of the older (aged >60 years) and the younger (aged ≤60 years) patients with obstructive airway diseases for the different inhaler devices (Turbuhaler® and Accuhaler). Patients and methods A cross-sectional study was conducted from January to December 2014. Patients with obstructive airway diseases were recruited. Spirometry was performed. PIFR was measured by using an In-Check DIAL device. Individual PIFR values for each inhaler device were obtained for three consecutive measurements and then averaged. Results A total of 139 patients diagnosed with obstructive lung diseases (asthma, n = 109; chronic obstructive pulmonary disease, n = 30) were recruited. Of these, 71 patients (51%) were >60 years. The PIFR generated by the patients who were ≤60 years for nonresistance mode was not different from that generated by those aged >60 years (115.0 ± 15.2 L/min vs 115.4 ± 13.3 L/min, p = 0.86). Regarding the DPI, PIFR generated from the older group was significantly lower than that generated from the younger group for Turbuhaler (72.5 ± 18.8 L/min vs 82.4 ± 21.1 L/min, p = 0.01), but the PIFR generated was not significantly different between the older and the younger groups for the Accuhaler (93.8 ± 22.9 L/min vs 99.4 ± 24.2 L/min, p = 0.86). The low peak expiratory flow rate and PIFR from spirometry were associated with the suboptimal PIFR measured by using In-Check DIAL. Discussion Optimal PIFR is critical for DPI use in the elderly; appropriate DPI selection is essential for management. In-Check DIAL may be useful for

  11. Peak expiratory flow mediates the relationship between handgrip strength and timed up and go performance in elderly women, but not men

    PubMed Central

    Ritti-Dias, Raphael Mendes; Cucato, Gabriel Grizzo; de Mello Franco, Fábio Gazelato; Cendoroglo, Maysa Seabra; Nasri, Fábio; Monteiro-Costa, Maria Luiza; de Carvalho, José Antonio Maluf; de Matos, Luciana Diniz Nagem Janot

    2016-01-01

    OBJECTIVE: The aim of the present study was to verify if there is sex difference in the associations among handgrip strength, peak expiratory flow (PEF) and timed up and go (TUG) test results. METHODS: The sample included 288 consecutive elderly men (n=93) and women (n=195). Functional capacity was measured using the TUG test, and muscle strength was measured based on handgrip. Moreover, as a measure of current health status, PEF was evaluated. Linear regression procedures were performed to analyze the relationships between handgrip and both PEF and TUG test results, with adjustment for confounders, and to identify the possible mediating role of PEF in the association between handgrip strength and TUG test results. RESULTS: In men, handgrip strength was associated with both PEF and TUG performance (p<0.01). After adjustment for PEF, the relationship between handgrip strength and TUG performance remained significant. In women, handgrip strength was also associated with both PEF and TUG performance (p<0.01). However, after adjustment for PEF, the relationship between handgrip strength and TUG performance was no longer significant. CONCLUSION: Mobility in the elderly is sex dependent. In particular, PEF mediates the relationship between handgrip strength and TUG performance in women, but not in men. PMID:27652833

  12. Responses of Six-Weeks Aquatic Exercise on the Autonomic Nervous System, Peak Nasal Inspiratory Flow and Lung Functions in Young Adults with Allergic Rhinitis.

    PubMed

    Janyacharoen, Taweesak; Kunbootsri, Narupon; Arayawichanon, Preeda; Chainansamit, Seksun; Sawanyawisuth, Kittisak

    2015-06-01

    Allergic rhinitis is a chronic respiratory disease. Sympathetic hypofunction is identified in all of the allergic rhinitis patients. Moreover, allergic rhinitis is associated with decreased peak nasal inspiratory flow (PNIF) and impaired lung functions. The aim of this study was to investigate effects of six-week of aquatic exercise on the autonomic nervous system function, PNIF and lung functions in allergic rhinitis patients. Twenty-six allergic rhinitis patients, 12 males and 14 females were recruited in this study. Subjects were diagnosed by a physician based on history, physical examination, and positive reaction to a skin prick test. Subjects were randomly assigned to two groups. The control allergic rhinitis group received education and maintained normal life. The aquatic group performed aquatic exercise for 30 minutes a day, three days a week for six weeks. Heart rate variability, PNIF and lung functions were measured at the beginning, after three weeks and six weeks. There were statistically significant increased low frequency normal units (LF n.u.), PNIF and showed decreased high frequency normal units (HF n.u.) at six weeks after aquatic exercise compared with the control group. Six weeks of aquatic exercise could increase sympathetic activity and PNIF in allergic rhinitis patients.

  13. Peak expiratory flow mediates the relationship between handgrip strength and timed up and go performance in elderly women, but not men.

    PubMed

    Ritti-Dias, Raphael Mendes; Cucato, Gabriel Grizzo; de Mello Franco, Fábio Gazelato; Cendoroglo, Maysa Seabra; Nasri, Fábio; Monteiro-Costa, Maria Luiza; de Carvalho, José Antonio Maluf; de Matos, Luciana Diniz Nagem Janot

    2016-09-01

    The aim of the present study was to verify if there is sex difference in the associations among handgrip strength, peak expiratory flow (PEF) and timed up and go (TUG) test results. The sample included 288 consecutive elderly men (n=93) and women (n=195). Functional capacity was measured using the TUG test, and muscle strength was measured based on handgrip. Moreover, as a measure of current health status, PEF was evaluated. Linear regression procedures were performed to analyze the relationships between handgrip and both PEF and TUG test results, with adjustment for confounders, and to identify the possible mediating role of PEF in the association between handgrip strength and TUG test results. In men, handgrip strength was associated with both PEF and TUG performance (p<0.01). After adjustment for PEF, the relationship between handgrip strength and TUG performance remained significant. In women, handgrip strength was also associated with both PEF and TUG performance (p<0.01). However, after adjustment for PEF, the relationship between handgrip strength and TUG performance was no longer significant. Mobility in the elderly is sex dependent. In particular, PEF mediates the relationship between handgrip strength and TUG performance in women, but not in men.

  14. Effect of indoor air pollution during cooking on peak expiratory flow rate and its association with exposure index in rural women.

    PubMed

    Sukhsohale, Neelam D; Narlawar, Uday W; Phatak, Mrunal S; Agrawal, Sanjay B; Ughade, Suresh N

    2013-01-01

    Routine exposure to domestic cooking fuels is an important source of indoor air pollution causing deterioration of lung function. We conducted a community based cross-sectional study in 760 non-smoking rural women involved in household cooking with four types of cooking fuels i.e. Biomass, Kerosene stove, Liquid Petroleum Gas (LPG) and Mixed (combination of two and more cooking fuels). Peak Expiratory Flow Rate (PEFR) less than 80% of the predicted was considered as abnormal PEFR. The overall prevalence of abnormal PEFR was found to be 29.1% with greater predominance among biomass fuel users (43.3%) with high risk ratio (1.86) as compared to kerosene (0.63), LPG (0.75) and mixed (0.66) fuel users. However the pair wise comparison of different groups of cooking fuels by Marascuilo procedure reported significant differences within different groups except kerosene--mixed group. The study also demonstrated a negative correlation between observed PEFR and exposure indices in different cooking fuels (r = -0.51). Our results indicate that prolonged exposure to cooking fuels particularly biomass fuels as a source of cooking adversely affects PEFR in nonsmoking rural women.

  15. Studies of cardioselectivity and partial agonist activity in beta-adrenoceptor blockade comparing effects on heart rate and peak expiratory flow rate during exercise.

    PubMed Central

    Oh, V M; Kaye, C M; Warrington, S J; Taylor, E A; Wadsworth, J

    1978-01-01

    1 The effects of beta-adrenoceptor antagonists given in single doses by oral or intravenous routes were examined in two double-blind controlled studies performed in healthy volunteers. Heart rate and peak expiratory flow rate (PEFR) were measured at rest and during standardized exercise. 2 Propranolol 80 mg and metoprolol 100 mg orally tended to reduce, and propranolol and metoprolol 0.2 mg/kg intravenously did reduce the physiological increase in PEFR during exercise; oxprenolol 80 mg orally and 0.2 mg/kg intravenously did not. Practolol 200 mg orally reduced this increase, but practolol 1 mg/kg intravenously did not. 3 In a third study of similar design, pindolol 0.05 mg/kg intravenously did not affect exercise-induced increase in PEFR. 4 Heart rate during exercise was reduced to a comparable extent at different times by all the active treatments. 5 Oxprenolol and pindolol share with practolol the property of partial agonist activity, which might contribute to their apparent lack of effect on airways resistance. A further possibility is that alpha-adrenoceptor blockade helps to maintain exercise-induced increase in PEFR. PMID:23136

  16. Comparison of acoustic rhinometry and nasal inspiratory peak flow as objective tools for nasal obstruction assessment in patients with chronic rhinosinusitis.

    PubMed

    Proimos, Efklidis K; Kiagiadaki, Devora E; Chimona, Theognosia S; Seferlis, Fokion G; Maroudias, Nicolas J; Papadakis, Chariton E

    2015-03-01

    Chronic rhinosinusitis (CRS) is a disease with increasing incidence, characterized by persistent symptoms and negative impact on patient`s quality of life. Nasal inspiratory peak flow (NIPF) and acoustic rhinometry (AR) were studied and compared as assessment tools for CRS with or without nasal polyps (NP), as well as, in follow up monitoring of conservative medical treatment. Seventy-eight patients were prospectively studied. Objective assessment included NIPF and AR at baseline and at 4 and 8 weeks after onset medical treatment. Measurements were studied in correlation with Sinonasal Outcome Test-22 (SNOT-22) questionnaire, Visual Analogue Scale (VAS) and endoscopic appearance score (EAS). Both NIPF and AR improved significantly, after medical treatment. NIPF score reflected CRS symptoms` improvement according to SNOT-22 total score at the end of treatment protocol, showing moderate to strong correlation with nasal obstruction VAS grading during the treatment period. AR measures were associated with EAS in all sets of examinations and correlated moderately with VAS scoring at 8 weeks. NIPF and AR were proven to be promising methods for objective evaluation and monitoring of nasal obstruction based on different aspects of nasal physiology in patients with CRS.

  17. Looking toward the Future: New Research Helps Black Sororities and Fraternities Consider New Governing Structures for the Next 100 Years

    ERIC Educational Resources Information Center

    Ruffins, Paul

    2004-01-01

    From a historical perspective, it's interesting to note that at their 100-year mark Black fraternities and sororities are facing some of the very same political criticisms encountered half a century ago. The Black Greeks' ability to be a greater force for social change is also constrained by the basic internal structures of the organizations…

  18. Looking toward the Future: New Research Helps Black Sororities and Fraternities Consider New Governing Structures for the Next 100 Years

    ERIC Educational Resources Information Center

    Ruffins, Paul

    2004-01-01

    From a historical perspective, it's interesting to note that at their 100-year mark Black fraternities and sororities are facing some of the very same political criticisms encountered half a century ago. The Black Greeks' ability to be a greater force for social change is also constrained by the basic internal structures of the organizations…

  19. The Bee Disease Diagnostic Service - 100 Years and Growing at the USDA Bee Research laboratory, Beltsville, MD

    USDA-ARS?s Scientific Manuscript database

    This article discusses the history of honey bee research in the Washington, D.C. area including the 100 year old bee disease diagnostic service available for beekeepers and apiary inspectors. This service provides the Bee Research Laboratory with first-hand knowledge of the problems facing the beek...

  20. Site Index Evaluations in a 100-Year-Old Eastern White Pine Plantation at the Biltmore Estate, NC

    Treesearch

    W. Henry McNab; Brian A. Ritter

    1999-01-01

    The precision of these equations for estimating site index and the effects of four topographic variables on total height were evaluated in a 1.6-acre planted stand of 100-year-old eastern white pines (Pinus strobus L.) on the Biltmore Estate near Asheville, NC. A polymorphic site index equation developed for the Southern Appalachian Mountains was...

  1. Rapid elimination of CO through the lungs: coming full circle 100 years on.

    PubMed

    Fisher, Joseph A; Iscoe, Steve; Fedorko, Ludwik; Duffin, James

    2011-12-01

    At the start of the 20th century, CO poisoning was treated by administering a combination of CO(2) and O(2) (carbogen) to stimulate ventilation. This treatment was reported to be highly effective, even reversing the deep coma of severe CO poisoning before patients arrived at the hospital. The efficacy of carbogen in treating CO poisoning was initially attributed to the absorption of CO(2); however, it was eventually realized that the increase in pulmonary ventilation was the predominant factor accelerating clearance of CO from the blood. The inhaled CO(2) in the carbogen stimulated ventilation but prevented hypocapnia and the resulting reductions in cerebral blood flow. By then, however, carbogen treatment for CO poisoning had been abandoned in favour of hyperbaric O(2). Now, a half-century later, there is accumulating evidence that hyperbaric O(2) is not efficacious, most probably because of delays in initiating treatment. We now also know that increases in pulmonary ventilation with O(2)-enriched gas can clear CO from the blood as fast, or very nearly as fast, as hyperbaric O(2). Compared with hyperbaric O(2), the technology for accelerating pulmonary clearance of CO with hyperoxic gas is not only portable and inexpensive, but also may be far more effective because treatment can be initiated sooner. In addition, the technology can be distributed more widely, especially in developing countries where the prevalence of CO poisoning is highest. Finally, early pulmonary CO clearance does not delay or preclude any other treatment, including subsequent treatment with hyperbaric O(2).

  2. Rapid elimination of CO through the lungs: coming full circle 100 years on

    PubMed Central

    Fisher, Joseph A; Iscoe, Steve; Fedorko, Ludwik; Duffin, James

    2011-01-01

    At the start of the 20th century, CO poisoning was treated by administering a combination of CO2 and O2 (carbogen) to stimulate ventilation. This treatment was reported to be highly effective, even reversing the deep coma of severe CO poisoning before patients arrived at the hospital. The efficacy of carbogen in treating CO poisoning was initially attributed to the absorption of CO2; however, it was eventually realized that the increase in pulmonary ventilation was the predominant factor accelerating clearance of CO from the blood. The inhaled CO2 in the carbogen stimulated ventilation but prevented hypocapnia and the resulting reductions in cerebral blood flow. By then, however, carbogen treatment for CO poisoning had been abandoned in favour of hyperbaric O2. Now, a half-century later, there is accumulating evidence that hyperbaric O2 is not efficacious, most probably because of delays in initiating treatment. We now also know that increases in pulmonary ventilation with O2-enriched gas can clear CO from the blood as fast, or very nearly as fast, as hyperbaric O2. Compared with hyperbaric O2, the technology for accelerating pulmonary clearance of CO with hyperoxic gas is not only portable and inexpensive, but also may be far more effective because treatment can be initiated sooner. In addition, the technology can be distributed more widely, especially in developing countries where the prevalence of CO poisoning is highest. Finally, early pulmonary CO clearance does not delay or preclude any other treatment, including subsequent treatment with hyperbaric O2. PMID:21967899

  3. Why do we live for much less than 100 years? A fluid mechanics view and approach

    NASA Astrophysics Data System (ADS)

    Messaris, Gerasimos A. T.; Hadjinicolaou, Maria; Karahalios, George T.

    2017-08-01

    Blood flow in arteries induces shear stresses on the arterial walls. The present work is motivated by the implications of low shear stress on the human arterial system and its effect on the duration of the life of a subject. The low and/or bidirectional wall shear stress stiffens the arterial wall and in synergy with the fluctuating tissue stress due to the fluctuating blood pressure activates the mechanism of aging. If the shear stress were not low and/or bidirectional and if it did not contribute to local endothelium dysfunctions, the tissue stress alone would take more than 100 yr to cause a failure on the human arterial system. Applying the s-n diagram (tissue stress against the number of cycles to failure) to determine the fatigue life of the aorta, for example, we find that in the absence of other pathogenic factors, for a tissue stress 1.2 times bigger than the tissue stress of a non-stiff aorta, the potential 100 yr of life are reduced to nearly 80 yr. Calculation of the rate of variation of the tissue stress of a subject with time may lead to a possible prognosis about the evolution of wall stiffness and its impact on the arterial aging of this subject. Further patient-specific in vivo mechanistic studies complemented by molecular imaging are needed to contribute to the formation of a data base, from which improved models describing the evolution of the arterial stiffness can be developed. Accordingly, the degree of stiffness of the aorta compared with existing data from a corresponding data base may provide with information about the degree of the fatigue of the aortic wall and its possible future behavior and lead to a patient-adapted medical treatment as a means of a would-be preventive medication.

  4. Ecological studies of polyploidy in the 100 years following its discovery

    PubMed Central

    Ramsey, Justin; Ramsey, Tara S.

    2014-01-01

    Polyploidy is a mutation with profound phenotypic consequences and thus hypothesized to have transformative effects in plant ecology. This is most often considered in the context of geographical and environmental distributions—as achieved from divergence of physiological and life-history traits—but may also include species interactions and biological invasion. This paper presents a historical overview of hypotheses and empirical data regarding the ecology of polyploids. Early researchers of polyploidy (1910s–1930s) were geneticists by training but nonetheless savvy to its phenotypic effects, and speculated on the importance of genome duplication to adaptation and crop improvement. Cytogenetic studies in the 1930s–1950s indicated that polyploids are larger (sturdier foliage, thicker stems and taller stature) than diploids while cytogeographic surveys suggested that polyploids and diploids have allopatric or parapatric distributions. Although autopolyploidy was initially regarded as common, influential writings by North American botanists in the 1940s and 1950s argued for the principle role of allopolyploidy; according to this view, genome duplication was significant for providing a broader canvas for hybridization rather than for its phenotypic effects per se. The emphasis on allopolyploidy had a chilling effect on nascent ecological work, in part due to taxonomic challenges posed by interspecific hybridization. Nonetheless, biosystematic efforts over the next few decades (1950s–1970s) laid the foundation for ecological research by documenting cytotype distributions and identifying phenotypic correlates of polyploidy. Rigorous investigation of polyploid ecology was achieved in the 1980s and 1990s by population biologists who leveraged flow cytometry for comparative work in autopolyploid complexes. These efforts revealed multi-faceted ecological and phenotypic differences, some of which may be direct consequences of genome duplication. Several classical

  5. Towards a robust calving and melt-history for Helheim Glacier, SE Greenland, for the last 100 years

    NASA Astrophysics Data System (ADS)

    Andersen, T. J.; Ellegaard, M.; Markussen, T. N.

    2013-12-01

    Observations of increased ice-discharge from tidewater glaciers in Greenland in the early and mid 2000s has led to concern about a possible rapid loss of ice from the ice sheet in a scenario with increasing air and ocean water temperatures. In order to evaluate the strength and uniqueness of the observed increase a robust data-set on the temporal variation of calving and melt is strongly needed. The only reliable data prior to the period of aerial photographs and instrumental observations is the archive preserved at the seabed in the fjords and coastal waters off the ice sheet. Establishment of core-chronology is central in studies of these archives and is based on Pb-210 dating which will reach approx. 100 years back in time. Establishment of a detailed and accurate core-chronology by means of Pb-210 dating and Cs-137 peaks is by no means a trivial task in environments influenced by episodic deposition of ice-rafted debris (IRD). The deposition will have a relatively large component of random variability which could be mistaken for actual changes in sedimentation rate, especially so if only one or a few cores are analyzed. To increase the reliability of the calving reconstruction, a total of 13 cores have been sampled in this study in Sermilik Fjord in August 2012 at depths between approximately 700 to 900 m. Eleven of the cores are from within the central basin north of 66 degrees North and two are from the outer part of the fjord south of that line. CTD-profiles and measurements of floc size in situ indicate that the sedimentation is significantly influenced by deposition of IRD and temporal changes in sediment accumulation rates will therefore be examined for all the cores. The cores are also being analyzed for their content of dinoflagellate cysts and diatoms in order to examine possible temporal changes in ocean water temperature in the fjord. So far (August 2013) six cores have been studied and the total average accumulation rate for each year since 1925 has

  6. Optimization of green infrastructure network at semi-urbanized watersheds to manage stormwater volume, peak flow and life cycle cost: Case study of Dead Run watershed in Maryland

    NASA Astrophysics Data System (ADS)

    Heidari Haratmeh, B.; Rai, A.; Minsker, B. S.

    2016-12-01

    Green Infrastructure (GI) has become widely known as a sustainable solution for stormwater management in urban environments. Despite more recognition and acknowledgment, researchers and practitioners lack clear and explicit guidelines on how GI practices should be implemented in urban settings. This study is developing a noisy-based multi-objective, multi-scaled genetic algorithm that determines optimal GI networks for environmental, economic and social objectives. The methodology accounts for uncertainty in modeling results and is designed to perform at sub-watershed as well as patch scale using two different simulation models, SWMM and RHESSys, in a Cloud-based implementation using a Web interface. As an initial case study, a semi-urbanized watershed— DeadRun 5— in Baltimore County, Maryland, is selected. The objective of the study is to minimize life cycle cost, maximize human preference for human well-being and the difference between pre-development hydrographs generated from current rainfall events and design storms, as well as those that result from proposed GI scenarios. Initial results for DeadRun5 watershed suggest that placing GI in the proximity of the watershed outlet optimizes life cycle cost, stormwater volume, and peak flow capture. The framework can easily present outcomes of GI design scenarios to both designers and local stakeholders, and future plans include receiving feedback from users on candidate designs, and interactively updating optimal GI network designs in a crowd-sourced design process. This approach can also be helpful in deriving design guidelines that better meet stakeholder needs.

  7. A new diagnostic score for occupational asthma: the area between the curves (ABC score) of peak expiratory flow on days at and away from work.

    PubMed

    Moore, Vicky C; Jaakkola, Maritta S; Burge, Cedd B S G; Robertson, Alastair S; Pantin, Charles F A; Dev Vellore, Arun; Burge, P Sherwood

    2009-02-01

    Evidence-based guidelines recommend serial measurements of peak expiratory flow (PEF) on days at and away from work as the first step in the objective confirmation of occupational asthma. The aim of this study was to improve the diagnostic value of computer-based PEF analysis by using the program Oasys-2 to calculate a score from the area between the curves (ABC) of PEF on days at and away from work. Mean 2-hourly PEFs were plotted separately for workdays and rest days for 109 workers with occupational asthma and 117 control asthmatics. A score based on the ABC was computed from records containing >or= 4 day shifts, >or= 4 rest days, and >or= 6 readings per day. Patients were randomly classified into two data sets (analysis and test sets). Receiver operator characteristic (ROC) curve analysis determined a cutoff point from set 1 that best identified those with occupational asthma, which was then tested in set 2. Logistic regression analysis showed that all ABC PEF scores were significant predictors of occupational asthma, with the best being ABC per hour from waking (odds ratio, 11.9 per 10 L/h/min; 95% confidence interval, 10.8 to 13.1). ROC curve analysis showed that a difference of 15 L/min/h provided a high specificity without compromising sensitivity in diagnosing occupational asthma. Analysis of data set 2 confirmed a specificity of 100% and sensitivity of 72%. The ABC PEF score is sensitive and specific for the diagnosis of occupational asthma and can be calculated from a shorter PEF surveillance than is needed for the current Oasys-2 work effect index.

  8. Prediction of peak flow values followed by feedback improves perception of lung function and adherence to inhaled corticosteroids in children with asthma.

    PubMed

    Feldman, Jonathan M; Kutner, Haley; Matte, Lynne; Lupkin, Michelle; Steinberg, Dara; Sidora-Arcoleo, Kimberly; Serebrisky, Denise; Warman, Karen

    2012-12-01

    Failure to detect respiratory compromise can lead to emergency healthcare use and fatal asthma attacks. The purpose of this study was to examine the effect of predicting peak expiratory flow (PEF) and receiving feedback on perception of pulmonary function and adherence to inhaled corticosteroids (ICS). The sample consisted of 192 ethnic minority, inner-city children (100 Puerto Rican, 54 African-American, 38 Afro-Caribbean) with asthma and their primary caregivers recruited from outpatient clinics in Bronx, New York. Children's PEF predictions were entered into an electronic spirometer and compared with actual PEF across 6 weeks. Children in one study were blinded to PEF (n=88; no feedback) and children in a separate study were able to see PEF (n=104; feedback) after predictions were locked in. Dosers were attached to asthma medications to monitor use. Children in the feedback condition displayed greater accuracy (p<0.001), less under-perception (p<0.001) and greater over-perception (p<0.001) of respiratory compromise than children in the no feedback condition. This between-group difference was evident soon after baseline training and maintained across 6 weeks. The feedback condition displayed greater adherence to ICS (p<0.01) and greater quick-relief medication use (p<0.01) than the no feedback condition. Feedback on PEF predictions for ethnic minority, inner-city children may decrease under-perception of respiratory compromise and increase adherence to controller medications. Children and their families may shift their attention to asthma perception and management as a result of this intervention.

  9. Reliability and acceptability of measuring sniff nasal inspiratory pressure (SNIP) and peak inspiratory flow (PIF) to assess respiratory muscle strength in older adults: a preliminary study.

    PubMed

    Barnes, Nicola; Agyapong-Badu, Sandra; Walsh, Bronagh; Stokes, Maria; Samuel, Dinesh

    2014-04-01

    Sniff nasal inspiratory pressure (SNIP) and peak oral inspiratory flow (PIF) are portable, relatively new methods for indirect measurement of respiratory muscle strength. The reliability and acceptability of these measures were investigated in older adults. The study included 21 self-reported healthy adults, aged 65-84 years (mean 73.5; SD 6.4 years). Participants were tested in a sitting position on two occasions, 1 week apart. The best of three attempts for PIF measured through the mouth, and five for each nostril for SNIP were recorded. Reliability was tested using intra-class correlation coefficient (ICC), standard error of measurement, minimal detectable change (MDC) and Bland and Altman analysis. Feedback on the measures in relation to ease of completion and preference was obtained using a semi-structured interview. Between-day reliability of SNIP and PIF were ICC3,1 0.76 (95 % CI 0.49-0.9) and 0.92 (0.81-0.97), respectively. Standard error of measurement for SNIP (11.94 cmH2O) and MDC (33.10 cmH2O) were at the least 61 % higher than for PIF. The participants reported difficulties in performing SNIP, rating it as being less easy and uncomfortable to perform than PIF, with a higher rate of missing data for SNIP due to participants' dislike of the test. The wide range of SNIP readings, lower ICC value and negative user feedback are suggestive of a less robust and unacceptable clinical measure. PIF showed excellent reliability and acceptability and is therefore recommended for assessing inspiratory muscle strength in older people without known obstructive lung disease.

  10. Peak Stress Testing Protocol Framework

    EPA Science Inventory

    Treatment of peak flows during wet weather is a common challenge across the country for municipal wastewater utilities with separate and/or combined sewer systems. Increases in wastewater flow resulting from infiltration and inflow (I/I) during wet weather events can result in op...

  11. Peak Stress Testing Protocol Framework

    EPA Science Inventory

    Treatment of peak flows during wet weather is a common challenge across the country for municipal wastewater utilities with separate and/or combined sewer systems. Increases in wastewater flow resulting from infiltration and inflow (I/I) during wet weather events can result in op...

  12. 100 Years of Science

    SciTech Connect

    Carrigan, Dick

    2004-07-07

    The last half-century has seen enormous strides in many scientific and technical areas. In fundamental physics previously unrelated fields like weak interactions and electromagnetism have been linked. Cosmology has been probed back to the Big Bang. Computing and communications have moved from minor topics to subjects that dominate the economy. The structure of DNA has been untangled. We may be on the threshold of understanding the origin of life and even discovering life elsewhere in the universe. Several of these diverse topics such as cosmology and fundamental physics are already profoundly coupled. Remarkably, ties exist between all of these subjects. These ties will be reviewed in light of opportunities ahead in the next decades.

  13. 100 Years of Mathematics.

    ERIC Educational Resources Information Center

    Atiyah, Michael

    2000-01-01

    The 20th century was a period of extraordinary expansion and progress in mathematics. Concentrates on a few key themes that can be discerned such as local to global, increase in dimension, commutative to non-commutative, linear to non-linear, and homology theory, although it is impossible to list all the main achievements. (ASK)

  14. Acute Effects of Particulate Matter and Black Carbon from Seasonal Fires on Peak Expiratory Flow of Schoolchildren in the Brazilian Amazon

    PubMed Central

    Jacobson, Ludmilla da Silva Viana; Hacon, Sandra de Souza; de Castro, Hermano Albuquerque; Ignotti, Eliane; Artaxo, Paulo; Saldiva, Paulo Hilário Nascimento; de Leon, Antonio Carlos Monteiro Ponce

    2014-01-01

    Background Panel studies have shown adverse effects of air pollution from biomass burning on children's health. This study estimated the effect of current levels of outdoor air pollution in the Amazonian dry season on peak expiratory flow (PEF). Methods A panel study with 234 schoolchildren from 6 to 15 years old living in the municipality of Tangará da Serra, Brazil was conducted. PEF was measured daily in the dry season in 2008. Mixed-effects models and unified modelling repeated for every child were applied. Time trends, temperature, humidity, and subject characteristics were regarded. Inhalable particulate matter (PM10), fine particulate matter (PM2.5), and black carbon (BC) effects were evaluated based on 24-hour exposure lagged by 1 to 5 days and the averages of 2 or 3 days. Polynomial distributed lag models (PDLM) were also applied. Results The analyses revealed reductions in PEF for PM10 and PM2.5 increases of 10 µg/m3 and 1 µg/m3 for BC. For PM10, the reductions varied from 0.15 (confidence interval (CI)95%: −0.29; −0.01) to 0.25 l/min (CI95%: −0.40; −0.10). For PM2.5, they ranged from 0.46 (CI95%: −0.86 to −0.06) to 0.54 l/min (CI95%:−0.95; −0.14). As for BC, the reduction was approximately 1.40 l/min. In relation to PDLM, adverse effects were noticed in models based on the exposure on the current day through the previous 3 days (PDLM 0–3) and on the current day through the previous 5 days (PDLM 0–5), specially for PM10. For all children, for PDLM 0–5 the global effect was important for PM10, with PEF reduction of 0.31 l/min (CI95%: −0.56; −0.05). Also, reductions in lags 3 and 4 were observed. These associations were stronger for children between 6 and 8 years old. Conclusion Reductions in PEF were associated with air pollution, mainly for lagged exposures of 3 to 5 days and for younger children. PMID:25118606

  15. Acute effects of particulate matter and black carbon from seasonal fires on peak expiratory flow of schoolchildren in the Brazilian Amazon.

    PubMed

    Jacobson, Ludmilla da Silva Viana; Hacon, Sandra de Souza; de Castro, Hermano Albuquerque; Ignotti, Eliane; Artaxo, Paulo; Saldiva, Paulo Hilário Nascimento; de Leon, Antonio Carlos Monteiro Ponce

    2014-01-01

    Panel studies have shown adverse effects of air pollution from biomass burning on children's health. This study estimated the effect of current levels of outdoor air pollution in the Amazonian dry season on peak expiratory flow (PEF). A panel study with 234 schoolchildren from 6 to 15 years old living in the municipality of Tangará da Serra, Brazil was conducted. PEF was measured daily in the dry season in 2008. Mixed-effects models and unified modelling repeated for every child were applied. Time trends, temperature, humidity, and subject characteristics were regarded. Inhalable particulate matter (PM10), fine particulate matter (PM2.5), and black carbon (BC) effects were evaluated based on 24-hour exposure lagged by 1 to 5 days and the averages of 2 or 3 days. Polynomial distributed lag models (PDLM) were also applied. The analyses revealed reductions in PEF for PM10 and PM2.5 increases of 10 µg/m(3) and 1 µg/m(3) for BC. For PM10, the reductions varied from 0.15 (confidence interval (CI)95%: -0.29; -0.01) to 0.25 l/min (CI95%: -0.40; -0.10). For PM2.5, they ranged from 0.46 (CI95%: -0.86 to -0.06) to 0.54 l/min (CI95%:-0.95; -0.14). As for BC, the reduction was approximately 1.40 l/min. In relation to PDLM, adverse effects were noticed in models based on the exposure on the current day through the previous 3 days (PDLM 0-3) and on the current day through the previous 5 days (PDLM 0-5), specially for PM10. For all children, for PDLM 0-5 the global effect was important for PM10, with PEF reduction of 0.31 l/min (CI95%: -0.56; -0.05). Also, reductions in lags 3 and 4 were observed. These associations were stronger for children between 6 and 8 years old. Reductions in PEF were associated with air pollution, mainly for lagged exposures of 3 to 5 days and for younger children.

  16. Respiratory variation in aortic blood flow peak velocity to predict fluid responsiveness in mechanically ventilated children: a systematic review and meta-analysis.

    PubMed

    Desgranges, François-Pierrick; Desebbe, Olivier; Pereira de Souza Neto, Edmundo; Raphael, Darren; Chassard, Dominique

    2016-01-01

    Dynamic indices of preload have been shown to better predict fluid responsiveness than static variables in mechanically ventilated adults. In children, dynamic predictors of fluid responsiveness have not yet been extensively studied. To evaluate the diagnostic accuracy of respiratory variation in aortic blood flow peak velocity (ΔVPeak) for the prediction of fluid responsiveness in mechanically ventilated children. PubMed, Embase, and the Cochrane Database of Systematic Reviews were screened for studies relevant to the use of ΔVPeak to predict fluid responsiveness in children receiving mechanical ventilation. Clinical trials published as full-text articles in indexed journals without language restriction were included. We calculated the pooled values of sensitivity, specificity, diagnostic odds ratio (DOR), and positive and negative likelihood ratio using a random-effects model. In total, six studies (163 participants) met the inclusion criteria. Data are reported as point estimate with 95% confidence interval. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and DOR of ΔVPeak to predict fluid responsiveness for the overall population were 92.0% (84.1-96.7), 85.5% (75.6-92.5), 4.89 (2.92-8.18), 0.13 (0.07-0.25), and 50.44 (17.70-143.74), respectively. The area under the summary receiver operating characteristic curve was 0.94. Cutoff values for ΔVPeak to predict fluid responsiveness varied across studies, ranging from 7% to 20%. Our results confirm that the ΔVPeak is an accurate predictor of fluid responsiveness in children under mechanical ventilation. However, the question of the optimal cutoff value of ΔVPeak to predict fluid responsiveness remains uncertain, as there are important variations between original publications, and needs to be resolved in further studies. The potential impact of intraoperative cardiac output optimization using goal-directed fluid therapy based on ΔVPeak on the perioperative outcome in

  17. Respiratory symptoms and peak expiratory flow in children with asthma in relation to volatile organic compounds in exhaled breath and ambient air.

    PubMed

    Delfino, Ralph J; Gong, Henry; Linn, William S; Hu, Ye; Pellizzari, Edo D

    2003-09-01

    Indoor volatile organic compounds (VOCs) have been associated with asthma, but there is little epidemiologic work on ambient exposures, and no data on relationships between respiratory health and exhaled breath VOCs, which is a biomarker of VOC exposure. We recruited 26 Hispanic children with mild asthma in a Los Angeles community with high VOC levels near major freeways and trucking routes. Two dropped out, three had invalid peak expiratory flow (PEF) or breath VOC data, leaving 21. Children filled out symptom diaries and performed PEF maneuvers daily, November 1999-January 2000. We aimed to collect breath VOC samples on asthma episode and baseline symptom-free days, but six subjects only gave samples on symptom-free days. We analyzed 106 breath samples by GC-MS. Eight VOCs were quantifiable in >75% of breath samples (benzene, methylene chloride, styrene, tetrachloroethylene, toluene, m,p-xylene, o-xylene, and p-dichlorobenzene). Generalized estimating equation and mixed linear regression models for VOC exposure-response relationships controlled for temperature and respiratory infections. We found marginally positive associations between bothersome or more severe asthma symptoms and same day breath concentrations of benzene [odds ratio (OR) 2.03, 95% confidence interval (CI) 0.80, 5.11] but not other breath VOCs. Ambient petroleum-related VOCs measured on the same person-days as breath VOCs showed notably stronger associations with symptoms, including toluene, m,p-xylene, o-xylene, and benzene (OR 5.93, 95% CI 1.64, 21.4). On breath sample days, symptoms were also associated with 1-h ambient NO(2), OR 8.13 (1.52, 43.4), and SO(2), OR 2.36 (1.16, 4.81). Consistent inverse relationships were found between evening PEF and the same ambient VOCs, NO(2), and SO(2). There were no associations with O(3). Given the high traffic density of the region, stronger associations for ambient than for breath VOCs suggest that ambient VOC measurements were better markers for daily

  18. A model to evaluate 100-year energy mix scenarios to facilitate deep decarbonization in the southeastern United States

    SciTech Connect

    Adkisson, Mary A.; Qualls, A. L.

    2016-08-01

    The Southeast United States consumes approximately one billion megawatt-hours of electricity annually; roughly two-thirds from carbon dioxide (CO2) emitting sources. The balance is produced by non-CO2 emitting sources: nuclear power, hydroelectric power, and other renewables. Approximately 40% of the total CO2 emissions come from the electric grid. The CO2 emitting sources, coal, natural gas, and petroleum, produce approximately 372 million metric tons of CO2 annually. The rest is divided between the transportation sector (36%), the industrial sector (20%), the residential sector (3%), and the commercial sector (2%). An Energy Mix Modeling Analysis (EMMA) tool was developed to evaluate 100-year energy mix strategies to reduce CO2 emissions in the southeast. Current energy sector data was gathered and used to establish a 2016 reference baseline. The spreadsheet-based calculation runs 100-year scenarios based on current nuclear plant expiration dates, assumed electrical demand changes from the grid, assumed renewable power increases and efficiency gains, and assumed rates of reducing coal generation and deployment of new nuclear reactors. Within the model, natural gas electrical generation is calculated to meet any demand not met by other sources. Thus, natural gas is viewed as a transitional energy source that produces less CO2 than coal until non-CO2 emitting sources can be brought online. The annual production of CO2 and spent nuclear fuel and the natural gas consumed are calculated and summed. A progression of eight preliminary scenarios show that nuclear power can substantially reduce or eliminate demand for natural gas within 100 years if it is added at a rate of only 1000 MWe per year. Any increases in renewable energy or efficiency gains can offset the need for nuclear power. However, using nuclear power to reduce CO2 will result in significantly more

  19. 100 years of Drosophila research and its impact on vertebrate neuroscience: a history lesson for the future.

    PubMed

    Bellen, Hugo J; Tong, Chao; Tsuda, Hiroshi

    2010-07-01

    Discoveries in fruit flies have greatly contributed to our understanding of neuroscience. The use of an unparalleled wealth of tools, many of which originated between 1910–1960, has enabled milestone discoveries in nervous system development and function. Such findings have triggered and guided many research efforts in vertebrate neuroscience. After 100 years, fruit flies continue to be the choice model system for many neuroscientists. The combinational use of powerful research tools will ensure that this model organism will continue to lead to key discoveries that will impact vertebrate neuroscience.

  20. Central control of information transmission through the intraspinal arborizations of sensory fibers examined 100 years after Ramón y Cajal.

    PubMed

    Rudomin, Pablo

    2002-01-01

    About 100 years ago, Santiago Ramón y Cajal reported that sensory fibers entering the spinal cord have ascending and descending branches, and that each of them sends collaterals to the gray matter where they have profuse ramifications. To him this was a fundamental discovery and proposed that the intraspinal branches of the sensory fibers were "centripetal conductors by which sensory excitation is propagated to the various neurons in the gray matter". In addition, he assumed that "conduction of excitation within the intraspinal arborizations of the afferent fibers would be proportional to the diameters of the conductors", and that excitation would preferentially flow through the coarsest branches. The invariability of some elementary reflexes such as the knee jerk would be the result of a long history of plastic adaptations and natural selection of the safest neuronal organizations. There is now evidence suggesting that in the adult cat, the intraspinal branches of sensory fibers are not hard wired routes that diverge excitation to spinal neurons in an invariable manner, but rather dynamic pathways where excitation flow can be centrally addressed to reach specific neuronal targets. This central control of information flow is achieved by means of specific sets of GABAergic interneurons that produce primary afferent depolarization (PAD) via axo-axonic synapses and reduce transmitter release (presynaptic inhibition). The PAD produced by single, or by small groups of GABAergic interneurons in group I muscle afferents, can remain confined to some sets of intraspinal arborizations of the afferent fibers and not spread to nearby collaterals. In muscle spindle afferents this local character of PAD allows cutaneous and descending inputs to differentially inhibit the PAD in segmental and ascending collaterals of individual fibers, which may be an effective way to decouple the information flow arising from common sensory inputs. This feature appears to play an important role

  1. Spatio-temporal analysis of rainfall trends over a maritime state (Kerala) of India during the last 100 years

    NASA Astrophysics Data System (ADS)

    Nair, Archana; Ajith Joseph, K.; Nair, K. S.

    2014-05-01

    Kerala, a maritime state of India is bestowed with abundant rainfall which is about three times the national average. This study is conducted to have a better understanding of rainfall variability and trend at regional level for this state during the last 100 years. It is found that the rainfall variation in northern and southern regions of Kerala is large and the deviation is on different timescales. There is a shifting of rainfall mean and variability during the seasons. The trend analysis on rainfall data over the last 100 years reveals that there is a significant (99%) decreasing trend in most of the regions of Kerala especially in the month of January, July and November. The annual and seasonal trends of rainfall in most regions of Kerala are also found to be decreasing significantly. This decreasing trend may be related to global anomalies as a result of anthropogenic green house gas (GHG) emissions due to increased fossil fuel use, land-use change due to urbanisation and deforestation, proliferation in transportation associated atmospheric pollutants. We have also conducted a study of the seasonality index (SI) and found that only one district in the northern region (Kasaragod) has seasonality index of more than 1 and that the distribution of monthly rainfall in this district is mostly attributed to 1 or 2 months. In rest of the districts, the rainfall is markedly seasonal. The trend in SI reveals that the rainfall distribution in these districts has become asymmetric with changes in rainfall distribution.

  2. How phenobarbital revolutionized epilepsy therapy: the story of phenobarbital therapy in epilepsy in the last 100 years.

    PubMed

    Yasiry, Zeid; Shorvon, Simon D

    2012-12-01

    Phenobarbital (phenobarbitone) was first used as an antiepileptic drug 100 years ago, in 1912. This article tells the story of the discovery of its antiepileptic action, its early development, and the subsequent course of its clinical use over the 100-year period. The side effects, pharmacokinetics, and misuse of barbiturates are considered, along with the more recent clinical trials and the drug's current clinical utilization. The introduction of controlled drug regulations, the comparative cost of phenobarbital, and its inclusion on the World Health Organization (WHO) essential drug list are discussed. It is one of the few drugs on the formulary in 1912 that is still listed today, and remarkably its efficacy in epilepsy has not been significantly bettered. The current recommendation by the WHO is that phenobarbital should be offered as the first option for therapy for convulsive epilepsy in adults and children if availability can be ensured. This is rated as a strong recommendation because of the proven efficacy and low cost of phenobarbital, and despite its perceived side-effect profile and the practical problems of access. Whether this recommendation puts "a hierarchy on the brain," as has been suggested, is arguable. Much still needs to be learned about the drug's effects, and the issues raised by phenobarbital have lessons for all antiepileptic drug therapy. Wiley Periodicals, Inc. © 2012 International League Against Epilepsy.

  3. A 100 year sedimentary record of heavy metal pollution in a shallow eutrophic lake, Lake Chaohu, China.

    PubMed

    Zan, Fengyu; Huo, Shouliang; Xi, Beidou; Su, Jing; Li, Xiang; Zhang, Jingtian; Yeager, Kevin M

    2011-10-01

    This study has worked on the evaluation of the temporal and spatial evolution of heavy metal contamination in sediment taken from a shallow eutrophic lake, Lake Chaohu, China, over the last 100 years, and thereby used (137)Cs and (210)Pb dating, a PIRLA procedure, statistical analysis, geochemical normalization and a enrichment factor calculation (EF). Concentrations of 5174, 29 325, 10.7, 36.4, 20.4, 386.0, 21.1 and 38.4 mg kg(-1) for Ti, Fe, Co, Cr, Cu, Mn, Pb and Zn, respectively, are proposed as natural background values for the Lake Chaohu based on a PIRLA procedure. The contamination history from the last 100 years can be divided into two periods. Before the 1960s, heavy metal contamination did not occur and there was no spatial difference for heavy metal distribution. Since the 1960s, heavy metal enrichment and contamination has occurred, and the west half of the lake region showed a higher degree of contamination than the east half to various intensified anthropogenic activities. In the east half of the lake region, the anthropogenic source of heavy metals mainly originated from agricultural intensification, whereas in the west half of the lake it originated from city runoff and industry as well as agriculture. In all anthropogenic heavy metals, Co is only from industry.

  4. Development of OASYS-2: a system for the analysis of serial measurement of peak expiratory flow in workers with suspected occupational asthma.

    PubMed Central

    Gannon, P. F.; Newton, D. T.; Belcher, J.; Pantin, C. F.; Burge, P. S.

    1996-01-01

    BACKGROUND: Serial peak expiratory flow (PEF) measurement is usually the most appropriate first step in the confirmation of occupational asthma. Visual assessment of the plotted record is more sensitive and specific than statistical methods so far reported. The use of visual analysis is limited by lack of widespread expertise in the methods. A computer assisted diagnostic aid (OASYS-2) has been developed which is based on a scoring system developed from visual analysis. This removes the requirement for an experienced interpreter and should lead to the more widespread use of the technique. METHODS: PEF records were collected from workers attending an occupational lung disease clinic for investigation of suspected occupational asthma and from workers participating in a study of respiratory symptoms in a postal sorting office. PEF records were divided into two development sets and two gold standard sets. The latter consisted of records from workers in which a final diagnosis had been reached by a method other than PEF recording. An experienced observer scored individual work and rest periods for the two development set PEF records; linear discriminant analysis was used to compare measurements taken from development set 1 records with visual scores. Two equations were produced which allowed prediction of scores for individual work or rest periods. The development set 2 was used to determine how these scores should be used to produce a whole record score. The first gold standard set was used to determine the whole record score which best separated those with and without occupational asthma. The second set determined the sensitivity and specificity of the chosen score. RESULTS: Two hundred and sixty eight PEF records were collected from 169 workers and divided into two development sets (81 and 60 records) and two gold standard sets (60 and 67 records). Linear discriminant analysis produced equations predicting the score for work periods incorporating five indices of PEF

  5. The Journal of the National Medical Association 100 years ago: a new voice of and for African American physicians.

    PubMed

    Savitt, Todd L

    2010-08-01

    Volume 1 of the Journal of the National Medical Association (JNMA), published quarterly during 1909, included a good deal of space devoted to 2 key concerns: (1) building and unifying black health professionals in medicine, surgery, dentistry, and pharmacy; and (2) providing a voice for these African American health professionals to the often-hostile and racist larger world of medicine. The Journal's editor, Charles Victor Roman, and associate editor, John A. Kenney, were well suited to the task. They promoted membership in the National Medical Association (NMA), attendance at NMA annual meetings, and cooperation among the health professions. They also used the pages of the JNMA to firmly respond to the negative articles and biased, even hateful, attitudes expressed by white medical and lay people. The JNMA has continued to speak for the black medical profession over the subsequent 100 years.

  6. Evaluating the 100 year floodplain as an indicator of flood risk in low-lying coastal watersheds

    NASA Astrophysics Data System (ADS)

    Sebastian, A.; Brody, S.; Bedient, P. B.

    2013-12-01

    The Gulf of Mexico is the fastest growing region in the United States. Since 1960, the number of housing units built in the low-lying coastal counties has increased by 246%. The region experiences some of the most intense rainfall events in the country and coastal watersheds are prone to severe flooding characterized by wide floodplains and ponding. This flooding is further exacerbated as urban development encroaches on existing streams and waterways. While the 100 year floodplain should play an important role in our ability to develop disaster resilient communities, recent research has indicated that existing floodplain delineations are a poor indicator of actual flood losses in low-lying coastal regions. Between 2001 and 2005, more than 30% of insurance claims made to FEMA in the Gulf Coast region were outside of the 100 year floodplain and residential losses amounted to more than $19.3 billion. As population density and investments in this region continue to increase, addressing flood risk in coastal communities should become a priority for engineers, urban planners, and decision makers. This study compares the effectiveness of 1-D and a 2-D modeling approaches to spatially capture flood claims from historical events. Initial results indicate that 2-D models perform much better in coastal environments and may serve better for floodplain modeling helping to prevent unintended losses. The results of this study encourage a shift towards better engineering practices using existing 2-D models in order to protect resources and provide guidance for urban development in low-lying coastal regions.

  7. The summer drought related hemlock (Tsuga canadensis) decline in eastern North America 5,700 to 5,100 years ago

    Treesearch

    Jean Nicolas Haas; John H. McAndrews

    2000-01-01

    High resolution paleoecological analyses from Shepherd Lake, Ontario, Canada, show that 10 to 100 year lake level fluctuations due to climatic change were responsible for alterations in the aquatic biodiversity 5,700 to 5,100 years ago. Thermophilic aquatics such as the Bushy pondweed Najas flexilis, charophyte algae and aquatic invertebrates...

  8. The History of Parenting Practices: An Overview! Events, Policies and Theories That Have Influenced Parenting Practices over the Last 100 Years. [Videotape and Worksheets].

    ERIC Educational Resources Information Center

    1999

    Noting that parenting is a learned experience and that the source of information on parenting has changed considerably over the last 100 years, this videotape examines the history of parent education over the past 100 years, highlighting events influencing family life, policies and legislation to assist families, and parenting theories for each…

  9. The History of Parenting Practices: An Overview! Events, Policies and Theories That Have Influenced Parenting Practices over the Last 100 Years. [Videotape and Worksheets].

    ERIC Educational Resources Information Center

    1999

    Noting that parenting is a learned experience and that the source of information on parenting has changed considerably over the last 100 years, this videotape examines the history of parent education over the past 100 years, highlighting events influencing family life, policies and legislation to assist families, and parenting theories for each…

  10. Adjusted peak-flow frequency estimates for selected streamflow-gaging stations in or near Montana based on data through water year 2011: Chapter D in Montana StreamStats

    USGS Publications Warehouse

    Sando, Steven K.; Sando, Roy; McCarthy, Peter M.; Dutton, DeAnn M.

    2016-04-05

    Notice:Table 1–2 in this report is being revised. The regression equations for the Northwest Region are being recalculated; the revised report will be posted at this page as soon as it is complete.AbstractThe climatic conditions of the specific time period during which peak-flow data were collected at a given streamflow-gaging station (hereinafter referred to as gaging station) can substantially affect how well the peak-flow frequency (hereinafter referred to as frequency) results represent long-term hydrologic conditions. Differences in the timing of the periods of record can result in substantial inconsistencies in frequency estimates for hydrologically similar gaging stations. Potential for inconsistency increases with decreasing peak-flow record length. The representativeness of the frequency estimates for a short-term gaging station can be adjusted by various methods including weighting the at-site results in association with frequency estimates from regional regression equations (RREs) by using the Weighted Independent Estimates (WIE) program. Also, for gaging stations that cannot be adjusted by using the WIE program because of regulation or drainage areas too large for application of RREs, frequency estimates might be improved by using record extension procedures, including a mixed-station analysis using the maintenance of variance type I (MOVE.1) procedure. The U.S. Geological Survey, in cooperation with the Montana Department of Transportation and the Montana Department of Natural Resources and Conservation, completed a study to provide adjusted frequency estimates for selected gaging stations through water year 2011.The purpose of Chapter D of this Scientific Investigations Report is to present adjusted frequency estimates for 504 selected streamflow-gaging stations in or near Montana based on data through water year 2011. Estimates of peak-flow magnitudes for the 66.7-, 50-, 42.9-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance

  11. Adjusted peak-flow frequency estimates for selected streamflow-gaging stations in or near Montana based on data through water year 2011: Chapter D in Montana StreamStats

    USGS Publications Warehouse

    Sando, Steven K.; Sando, Roy; McCarthy, Peter M.; Dutton, DeAnn M.

    2016-04-05

    The climatic conditions of the specific time period during which peak-flow data were collected at a given streamflow-gaging station (hereinafter referred to as gaging station) can substantially affect how well the peak-flow frequency (hereinafter referred to as frequency) results represent long-term hydrologic conditions. Differences in the timing of the periods of record can result in substantial inconsistencies in frequency estimates for hydrologically similar gaging stations. Potential for inconsistency increases with decreasing peak-flow record length. The representativeness of the frequency estimates for a short-term gaging station can be adjusted by various methods including weighting the at-site results in association with frequency estimates from regional regression equations (RREs) by using the Weighted Independent Estimates (WIE) program. Also, for gaging stations that cannot be adjusted by using the WIE program because of regulation or drainage areas too large for application of RREs, frequency estimates might be improved by using record extension procedures, including a mixed-station analysis using the maintenance of variance type I (MOVE.1) procedure. The U.S. Geological Survey, in cooperation with the Montana Department of Transportation and the Montana Department of Natural Resources and Conservation, completed a study to provide adjusted frequency estimates for selected gaging stations through water year 2011.The purpose of Chapter D of this Scientific Investigations Report is to present adjusted frequency estimates for 504 selected streamflow-gaging stations in or near Montana based on data through water year 2011. Estimates of peak-flow magnitudes for the 66.7-, 50-, 42.9-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance probabilities are reported. These annual exceedance probabilities correspond to the 1.5-, 2-, 2.33-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year recurrence intervals, respectively.The at-site frequency estimates were

  12. Aboveground and belowground legacies of native Sami land use on boreal forest in northern Sweden 100 years after abandonment.

    PubMed

    Freschet, Grégoire T; Ostlund, Lars; Kichenin, Emilie; Wardle, David A

    2014-04-01

    Human activities that involve land-use change often cause major transformations to community and ecosystem properties both aboveground and belowground, and when land use is abandoned, these modifications can persist for extended periods. However, the mechanisms responsible for rapid recovery vs. long-term maintenance of ecosystem changes following abandonment remain poorly understood. Here, we examined the long-term ecological effects of two remote former settlements, regularly visited for -300 years by reindeer-herding Sami and abandoned -100 years ago, within an old-growth boreal forest that is considered one of the most pristine regions in northern Scandinavia. These human legacies were assessed through measurements of abiotic and biotic soil properties and vegetation characteristics at the settlement sites and at varying distances from them. Low-intensity land use by Sami is characterized by the transfer of organic matter towards the settlements by humans and reindeer herds, compaction of soil through trampling, disappearance of understory vegetation, and selective cutting of pine trees for fuel and construction. As a consequence, we found a shift towards early successional plant species and a threefold increase in soil microbial activity and nutrient availability close to the settlements relative to away from them. These changes in soil fertility and vegetation contributed to 83% greater total vegetation productivity, 35% greater plant biomass, and 23% and 16% greater concentrations of foliar N and P nearer the settlements, leading to a greater quantity and quality of litter inputs. Because decomposer activity was also 40% greater towards the settlements, soil organic matter cycling and nutrient availability were further increased, leading to likely positive feedbacks between the aboveground and belowground components resulting from historic land use. Although not all of the activities typical of Sami have left visible residual traces on the ecosystem after

  13. Regime Shifts in Shallow Lakes: Responses of Cyanobacterial Blooms to Watershed Agricultural Phosphorus Loading Over the Last ~100 Years.

    NASA Astrophysics Data System (ADS)

    Vermaire, J. C.; Taranu, Z. E.; MacDonald, G. K.; Velghe, K.; Bennett, E.; Gregory-Eaves, I.

    2015-12-01

    Rapid changes in ecosystem states have occurred naturally throughout Earth's history. However, environmental changes that have taken place since the start of the Anthropocene may be destabilizing ecosystems and increasing the frequency of regime shifts in response to abrupt changes in external drivers or local intrinsic dynamics. To evaluate the relative influence of these forcers and improve our understanding of the impact of future change, we examined the effects of historical catchment phosphorus loading associated with agricultural land use on lake ecosystems, and whether this caused a shift from a stable, clear-water, regime to a turbid, cyanobacteria-dominated, state. The sedimentary pigments, diatom, and zooplankton (Cladocera) records from a currently clear-water shallow lake (Roxton Pond) and a turbid-water shallow lake (Petit lac Saint-François; PSF) were examined to determine if a cyanobacteria associated pigment (i.e. echinenone) showed an abrupt non-linear response to continued historical phosphorus load index (determined by phosphorus budget) over the last ~100 years. While PSF lake is presently in the turbid-water state, pigment and diatom analyses indicated that both lakes were once in the clear-water state, and that non-linear increases in catchment phosphorus balance resulted in an abrupt transition to cyanobacteria dominated states in each record. These results show that phosphorus loading has resulted in state shifts in shallow lake ecosystems that has been recorded across multiple paleolimnological indicators preserved in the sedimentary record.

  14. DNA from a 100-year-old holotype confirms the validity of a potentially extinct hummingbird species

    PubMed Central

    Kirchman, Jeremy J.; Witt, Christopher C.; McGuire, Jimmy A.; Graves, Gary R.

    2010-01-01

    We used mtDNA sequence data to confirm that the controversial 100-year-old holotype of the Bogotá sunangel (Heliangelus zusii) represents a valid species. We demonstrate that H. zusii is genetically well differentiated from taxa previously hypothesized to have given rise to the specimen via hybridization. Phylogenetic analyses place H. zusii as sister to a clade of mid- to high-elevation Andean species currently placed in the genera Taphrolesbia and Aglaiocercus. Heliangelus zusii, presumed extinct, has never been observed in nature by biologists. We infer that the species occupied a restricted distribution between the upper tropical and temperate zones of the northern Andes and that it was most probably driven to extinction by deforestation that accompanied human population growth during the nineteenth and early twentieth centuries. We demonstrate the feasibility of obtaining DNA from nearly microscopic tissue samples from old hummingbird specimens and suggest that these methods could be used to resolve the taxonomy of dozens of avian taxa known only from type specimens. PMID:19776061

  15. CoSMoS Southern California v3.0 Phase 1 (100-year storm) storm hazard projections

    USGS Publications Warehouse

    Barnard, Patrick; Erikson, Li; Foxgrover, Amy; O'Neill, Andrea; Herdman, Liv

    2016-01-01

    The Coastal Storm Modeling System (CoSMoS) makes detailed predictions (meter-scale) over large geographic scales (100s of kilometers) of storm-induced coastal flooding and erosion for both current and future sea-level rise (SLR) scenarios. CoSMoS v3.0 for Southern California shows projections for future climate scenarios (sea-level rise and storms) to provide emergency responders and coastal planners with critical storm-hazards information that can be used to increase public safety, mitigate physical damages, and more effectively manage and allocate resources within complex coastal settings. Phase I data for Southern California include flood-hazard information for the coast from the Mexican Border to Pt. Conception for a 100-year storm scenario and sea-level rise 0 - 2 m. Changes from previous data releases may be reflected in some areas. Data are complete for the information presented but are considered preliminary; changes may be reflected in the full data release (Phase II) in summer 2016.

  16. Induced metamorphosis in crustacean y-larvae: Towards a solution to a 100-year-old riddle

    PubMed Central

    Glenner, Henrik; Høeg, Jens T; Grygier, Mark J; Fujita, Yoshihisa

    2008-01-01

    Background The y-larva, a crustacean larval type first identified more than 100 years ago, has been found in marine plankton samples collected in the arctic, temperate and tropical regions of all oceans. The great species diversity found among y-larvae (we have identified more than 40 species at our study site alone) indicates that the adult organism may play a significant ecological role. However, despite intense efforts, the adult y-organism has never been identified, and nothing is therefore known about its biology. Results We have successfully and repeatedly induced metamorphosis of y-larvae into a novel, highly reduced juvenile stage by applying the crustacean molting hormone 20-HE. The new stage is slug-like, unsegmented and lacks both limbs and almost all other traits normally characterizing arthropods, but it is capable of vigorous peristaltic motions. Conclusion From our observations on live and preserved material we conclude that adult Facetotecta are endoparasitic in still to be identified marine hosts and with a juvenile stage that represents a remarkable convergence to that seen in parasitic barnacles (Crustacea Cirripedia Rhizocephala). From the distribution and abundance of facetotectan y-larvae in the world's oceans we furthermore suggest that these parasites are widespread and could play an important role in the marine environment. PMID:18492233

  17. DNA from a 100-year-old holotype confirms the validity of a potentially extinct hummingbird species.

    PubMed

    Kirchman, Jeremy J; Witt, Christopher C; McGuire, Jimmy A; Graves, Gary R

    2010-02-23

    We used mtDNA sequence data to confirm that the controversial 100-year-old holotype of the Bogotá sunangel (Heliangelus zusii) represents a valid species. We demonstrate that H. zusii is genetically well differentiated from taxa previously hypothesized to have given rise to the specimen via hybridization. Phylogenetic analyses place H. zusii as sister to a clade of mid- to high-elevation Andean species currently placed in the genera Taphrolesbia and Aglaiocercus. Heliangelus zusii, presumed extinct, has never been observed in nature by biologists. We infer that the species occupied a restricted distribution between the upper tropical and temperate zones of the northern Andes and that it was most probably driven to extinction by deforestation that accompanied human population growth during the nineteenth and early twentieth centuries. We demonstrate the feasibility of obtaining DNA from nearly microscopic tissue samples from old hummingbird specimens and suggest that these methods could be used to resolve the taxonomy of dozens of avian taxa known only from type specimens.

  18. A 100-year sedimentary record of natural and anthropogenic impacts on a shallow eutrophic lake, Lake Chaohu, China.

    PubMed

    Zan, Fengyu; Huo, Shouliang; Xi, Beidou; Zhu, Chaowei; Liao, Haiqing; Zhang, Jingtian; Yeager, Kevin M

    2012-03-01

    In this study, the sediment profiles of total organic carbon, total nitrogen, C/N ratios, total phosphorus, N/P ratios, C/P ratios, particle sizes, and stable carbon and nitrogen isotopes (δ(13)C and δ(15)N) were used to investigate natural and anthropogenic impacts on Lake Chaohu over the past 100 years. Before 1960, Lake Chaohu experienced low productivity and a relatively steady and low nutrient input. The increasing concentration and fluxes of total organic carbon, total nitrogen, total phosphorus, together with changes in the δ(13)C and δ(15)N of organic material in the sediment cores, suggested that the anthropogenic effects on trophic status first started because of an increase in nutrient input caused by a population increase in the drainage area. With the construction of the Chaohu Dam, an increase in the utilization of fertilizer and the population growth which occurred since 1960, stable depositional conditions and increasing nutrient input resulted in a dominantly algae-derived organic matter source and high productivity. Nutrient input increased most significantly around 1980 following the rapidly growing population, with concomitant urbanization, industrial and agricultural development. This study also revealed that the concentration and distribution of nutrients varied between different areas of sediment within Lake Chaohu because of the influence of different drainage basins and pollution sources.

  19. On the Influence of the NAO on Outlet Glacier Stability in SE Greenland during the Past 100 Years

    NASA Astrophysics Data System (ADS)

    Andresen, C. S.

    2014-12-01

    The Greenland Ice sheet has gained massive attention in recent years due to a sudden increase in mass loss at the onset of this century. A significant part of this mass loss has been attributed to increased ice discharge at the margin through iceberg calving from marine-terminating outlet glaciers. However, due to the lack of instrumental data beyond the past 20-30 years it is difficult to evaluate if this was an outstanding event or if it was part of a recurring phenomenon acting on inter-annual, inter-decadal or centennial timescales. In order to improve understanding of the timescales involved in glacier changes and on the influence of ocean and atmosphere variability we investigate sediment archives from fjords with marine terminating glaciers. Near the glacier margin the sedimentation rates are relatively high due to glacial flour input and rafting of iceberg debris. Our studies of several sediment cores obtained from Sermilik Fjord by Helheim Glacier in Southeast Greenland has allowed us to reconstruct glacier calving, shelf temperature and fjord water renewal rate for the past 100 years. These studies show that dominant modes of climate variability, i.e. the North Atlantic Oscillation and the Atlantic Multidecadal Oscillation, affect ocean properties near the glacier and that the recorded variability concurs with reconstructed outlet glacier changes. This presentation provides an overview these studies.

  20. A 100-Year Retrospective Landscape-Level Carbon Budget for the Sooke Lake Watershed, British Columbia: Constraining Estimates of Terrestrial to Aquatic DOC Transfers.

    NASA Astrophysics Data System (ADS)

    Trofymow, J. A.; Smiley, B. P. K.

    2014-12-01

    To address how natural disturbance, forest harvest, and deforestation from reservoir creation affect landscape-level carbon (C) budgets, a retrospective C budget for the 8500 ha Sooke watershed from 1911 - 2012 was developed using historic spatial inventory and disturbance data. Data was input to a spatially-explicit version of the Carbon Budget Model-Canadian Forest Sector (CBM-CFS3), an inventory-based C budget model used to simulate forest C dynamics at multiple scales. In 1911 the watershed was dominated by mature/old Douglas-fir forests with aboveground biomass C (ABC) of 262 Mg C/ha and net ecosystem production (NEP) of 0.63 Mg C/ha/yr. Land was cleared around Sooke Lake, a dam built and lake expanded from 370 to 450 ha in 1915, 610 ha in 1970, 670 ha in 1980 and 810 ha in 2002. Along with deforestation, fires and localized harvest occurred from 1920 - 1940, reducing ABC to 189 Mg C/ha, with NEP varying from -1.63 to 0.13 Mg C/ha/yr. Distributed harvest occurred 1954 - 1998, with a minimum ABC of 148 Mg C/ha in 1991. By 2012 ABC (177 Mg C/ha) and NEP (2.29 Mg C/ha/yr) had increased. Over 100 years, 2430 ha forest was cut and replanted and 640 ha deforested. CBM-CFS3 includes transfers of dissolved organic C (DOC) to aquatic systems, however data has not been available to parameterize DOC flux. DOC fluxes are modelled as a fraction of decay loss from humified soil C with a default of 100% of losses to CO2 and 0% to DOC. Stream flow and [DOC] data from 1996 - 2012 for 3 watershed catchments, Rithet, Judge and Council were used to estimate annual DOC fluxes. Rithet, Judge and Council differed both in area % disturbed (logging or fire) over 100 years (39%, 93%, 91%) and in area % mature/old forest (>80yrs in 2012) (67%, 56%, 21%). DOC flux for Rithet and Judge ranged from 0.037 - 0.057 Mg C/ha/yr, Council averaged 0.017 Mg C/ha/yr. Low DOC fluxes were likely due to influences of a small lake in the catchment. Constraining CBM-CFS3 to observed DOC fluxes, required

  1. PeakWorks

    SciTech Connect

    2016-11-30

    The PeakWorks software is designed to assist in the quantitative analysis of atom probe tomography (APT) generated mass spectra. Specifically, through an interactive user interface, mass peaks can be identified automatically (defined by a threshold) and/or identified manually. The software then provides a means to assign specific elemental isotopes (including more than one) to each peak. The software also provides a means for the user to choose background subtraction of each peak based on background fitting functions, the choice of which is left to the users discretion. Peak ranging (the mass range over which peaks are integrated) is also automated allowing the user to chose a quantitative range (e.g. full-widthhalf- maximum). The software then integrates all identified peaks, providing a background-subtracted composition, which also includes the deconvolution of peaks (i.e. those peaks that happen to have overlapping isotopic masses). The software is also able to output a 'range file' that can be used in other software packages, such as within IVAS. A range file lists the peak identities, the mass range of each identified peak, and a color code for the peak. The software is also able to generate 'dummy' peak ranges within an outputted range file that can be used within IVAS to provide a means for background subtracted proximity histogram analysis.

  2. Dominant simple-shear deformation during peak metamorphism for the lower portion of the Greater Himalayan Sequence in West Nepal: New implications for hybrid channel flow-type mechanisms in the Dolpo region

    NASA Astrophysics Data System (ADS)

    Frassi, Chiara

    2015-12-01

    I conducted new vorticity and deformation temperatures studies to test competing models of the exhumation of the mid-crustal rocks exposed in the Dolpo region (West Nepal). My results indicate that the Main Central Thrust is located ∼5 km structurally below the previous mapped locations. Deformation temperature increasing up structural section from ∼450 °C to ∼650 °C and overlap with peak metamorphic temperature indicating that penetrative shearing was responsible for the exhumation of the GHS occurred at "close" to peak metamorphic conditions. I interpreted the telescoping and the inversion of the paleo-isotherms at the base of the GHS as produced mainly by a sub-simple shearing (Wm = 0.88-1) pervasively distributed through the lower portion of the GHS. My results are consistent with hybrid channel flow-type models where the boundary between lower and upper portions of the GHS, broadly corresponding to the tectonometamorphic discontinuity recently documented in west Nepal, represents the limit between buried material, affected by dominant simple shearing, and exhumed material affected by a general flow dominates by pure shearing. This interpretation is consistent with the recent models suggesting the simultaneous operation of channel flow- and critical wedge-type processes at different structural depth.

  3. Changing patterns of infant death over the last 100 years: autopsy experience from a specialist children's hospital

    PubMed Central

    Pryce, JW; Weber, MA; Ashworth, MT; Roberts, SEA; Malone, M; Sebire, NJ

    2012-01-01

    Objectives Infant mortality has undergone a dramatic reduction in the UK over the past century because of improvements in public health policy and medical advances. Postmortem examinations have been performed at Great Ormond Street Hospital for over 100 years, and analysis of cases across this period has been performed to assess changing patterns of infant deaths undergoing autopsy. Design Autopsy reports from 1909 and 2009 were examined. Age, major pathology and cause of death was reviewed from these cases and entered into an anonymized database. A subsequent comparative analysis was performed. Setting All postmortems performed and reported at Great Ormond Street Hospital in 1909 and 2009. Participants Infant deaths, aged 0–365 days, were identified and subsequently analysed for the two years. Main outcome measures Comparative proportional analysis of postmortem findings from the two time periods. Results Three-hundred and fifty-seven and 347 autopsy reports were identified from 1909 and 2009 including 178 and 128 infant deaths, respectively. The commonest cause of death in 1909 was infection (74%) compared to 20% of deaths in 2009. The most frequent final ‘diagnosis’ in 2009 was ‘unexplained sudden unexpected infant death (SUDI)’, despite a full postmortem including ancillary investigations. In contrast, there were no such cases recorded in 1909, but there were frequent deaths due to gastroenteritis and malnutrition together accounting for 16% of cases, compared to one case of gastroenteritis in 2009. Fifteen percent of 1909 cases had infections which are almost never fatal with appropriate treatment in 2009, including tuberculosis, diphtheria and syphilis. Congenital anomalies were detected with similar frequencies at both time points, (21% and 19% in 1909 and 2009, respectively). Conclusion In the UK, significant changes in patterns of pathology have occurred in paediatric autopsy cases performed at a single specialist centre. Fatal infections and

  4. Extreme climatic events drive mammal irruptions: regression analysis of 100-year trends in desert rainfall and temperature

    PubMed Central

    Greenville, Aaron C; Wardle, Glenda M; Dickman, Chris R

    2012-01-01

    Extreme climatic events, such as flooding rains, extended decadal droughts and heat waves have been identified increasingly as important regulators of natural populations. Climate models predict that global warming will drive changes in rainfall and increase the frequency and severity of extreme events. Consequently, to anticipate how organisms will respond we need to document how changes in extremes of temperature and rainfall compare to trends in the mean values of these variables and over what spatial scales the patterns are consistent. Using the longest historical weather records available for central Australia – 100 years – and quantile regression methods, we investigate if extreme climate events have changed at similar rates to median events, if annual rainfall has increased in variability, and if the frequency of large rainfall events has increased over this period. Specifically, we compared local (individual weather stations) and regional (Simpson Desert) spatial scales, and quantified trends in median (50th quantile) and extreme weather values (5th, 10th, 90th, and 95th quantiles). We found that median and extreme annual minimum and maximum temperatures have increased at both spatial scales over the past century. Rainfall changes have been inconsistent across the Simpson Desert; individual weather stations showed increases in annual rainfall, increased frequency of large rainfall events or more prolonged droughts, depending on the location. In contrast to our prediction, we found no evidence that intra-annual rainfall had become more variable over time. Using long-term live-trapping records (22 years) of desert small mammals as a case study, we demonstrate that irruptive events are driven by extreme rainfalls (>95th quantile) and that increases in the magnitude and frequency of extreme rainfall events are likely to drive changes in the populations of these species through direct and indirect changes in predation pressure and wildfires. PMID:23170202

  5. Russian pioneers of therapeutic hemapheresis and extracorporeal hemocorrection: 100-year anniversary of the world's first successful plasmapheresis.

    PubMed

    Sokolov, Alexey A; Solovyev, Andrey G

    2014-04-01

    On 15 February 2013 (2 February on the Julian Calendar) we celebrated the 100-year anniversary of the world's first successful experimental plasmapheresis. Scientific research projects in this field were carried out by the Department of Infectious Disease, Russian Imperial Medical Surgical Academy located in Saint-Petersburg. Doctor of Medical Sciences and Professor Vadim A. Yurevich was a Principal Investigator for this research, which in 1913 resulted in the discovery of a new way of treatment. The results were published in Russki Vratch (Russian Physician) Journal no. 18 (1914) - V.A. Yurevich and N.K. Rosenberg "For the Question Regarding Washing of Blood Outside of the Body and the Vitality of Red Blood Cells". There was no terminology offered for this medical innovation at that time. Plasma removal was performed not solely, but in combination with washing of blood cells returned to the patient. Nowadays this combination is still considered to be more effective than separate plasmapheresis. According to the published experimental protocols this new treatment was done on 15 February (2 February on the Julian Calendar or "old style"). One year later in 1914 a famous researcher, John Abel and coauthors, repeated a separate plasma removal treatment with retransfusion of the blood cells and suggested the term "plasmapheresis", which is now official. The article entitled "Plasma Removal With Return of Corpuscles (Plasmapheresis)", written by Abel was published 3 months later than the article by Professor Yurevich. In 1924, Dr Ivan P. Mikhailovskiy repeated experiments by Yurevich and Rosenberg in vivo on a dog model, confirmed the clinical efficiency and developed the methodology in his article "Washing of Blood In Vivo, the Methodology, Problems, and Importance for the Treatment of Toxic Conditions."

  6. Acidophilic denitrifiers dominate the N2O production in a 100-year-old tea orchard soil.

    PubMed

    Huang, Ying; Long, Xi-En; Chapman, Stephen J; Yao, Huaiying

    2015-03-01

    Aerobic denitrification is the main process for high N2O production in acid tea field soil. However, the biological mechanisms for the high emission are not fully understood. In this study, we examined N2O emission and denitrifier communities in 100-year-old tea soils with four pH levels (3.71, 5.11, 6.19, and 7.41) and four nitrate concentration (0, 50, 200, and 1000 mg kg(-1) of NO3 (-)-N) addition. Results showed the highest N2O emission (10.1 mg kg(-1) over 21 days) from the soil at pH 3.71 with 1000 mg kg(-1) NO3 (-) addition. The N2O reduction and denitrification enzyme activity in the acid soils (pH <7.0) were significantly higher than that of soils at pH 7.41. Moreover, TRF 78 of nirS and TRF 187 of nosZ dominated in soils of pH 3.71, suggesting an important role of acidophilic denitrifiers in N2O production and reduction. CCA analysis also showed a negative correlation between the dominant denitrifier ecotypes (nirS TRF 78, nosZ TRF 187) and soil pH. The representative sequences were identical to those of cultivated denitrifiers from acidic soils via phylogenetic tree analysis. Our results showed that the acidophilic denitrifier adaptation to the acid environment results in high N2O emission in this highly acidic tea soil.

  7. Future changes in peak river flows across northern Eurasia as inferred from an ensemble of regional climate projections under the IPCC RCP8.5 scenario

    NASA Astrophysics Data System (ADS)

    Shkolnik, Igor; Pavlova, Tatiana; Efimov, Sergey; Zhuravlev, Sergey

    2017-03-01

    Climate change simulation based on 30-member ensemble of Voeikov Main Geophysical Observatory RCM (resolution 25 km) for northern Eurasia is used to drive hydrological model CaMa-Flood. Using this modeling framework, we evaluate the uncertainties in the future projection of the peak river discharge and flood hazard by 2050-2059 relative to 1990-1999 under IPCC RCP8.5 scenario. Large ensemble size, along with reasonably high modeling resolution, allows one to efficiently sample natural climate variability and increase our ability to predict future changes in the hydrological extremes. It has been shown that the annual maximum river discharge can almost double by the mid-XXI century in the outlets of major Siberian rivers. In the western regions, there is a weak signal in the river discharge and flood hazard, hardly discernible above climate variability. Annual maximum flood area is projected to increase across Siberia mostly by 2-5% relative to the baseline period. A contribution of natural climate variability at different temporal scales to the uncertainty of ensemble prediction is discussed. The analysis shows that there expected considerable changes in the extreme river discharge probability at locations of the key hydropower facilities. This suggests that the extensive impact studies are required to develop recommendations for maintaining regional energy security.

  8. The story of the Hawaiian Volcano Observatory -- A remarkable first 100 years of tracking eruptions and earthquakes

    USGS Publications Warehouse

    Babb, Janet L.; Kauahikaua, James P.; Tilling, Robert I.

    2011-01-01

    The year 2012 marks the centennial of the Hawaiian Volcano Observatory (HVO). With the support and cooperation of visionaries, financiers, scientists, and other individuals and organizations, HVO has successfully achieved 100 years of continuous monitoring of Hawaiian volcanoes. As we celebrate this milestone anniversary, we express our sincere mahalo—thanks—to the people who have contributed to and participated in HVO’s mission during this past century. First and foremost, we owe a debt of gratitude to the late Thomas A. Jaggar, Jr., the geologist whose vision and efforts led to the founding of HVO. We also acknowledge the pioneering contributions of the late Frank A. Perret, who began the continuous monitoring of Kīlauea in 1911, setting the stage for Jaggar, who took over the work in 1912. Initial support for HVO was provided by the Massachusetts Institute of Technology (MIT) and the Carnegie Geophysical Laboratory, which financed the initial cache of volcano monitoring instruments and Perret’s work in 1911. The Hawaiian Volcano Research Association, a group of Honolulu businessmen organized by Lorrin A. Thurston, also provided essential funding for HVO’s daily operations starting in mid-1912 and continuing for several decades. Since HVO’s beginning, the University of Hawaiʻi (UH), called the College of Hawaii until 1920, has been an advocate of HVO’s scientific studies. We have benefited from collaborations with UH scientists at both the Hilo and Mänoa campuses and look forward to future cooperative efforts to better understand how Hawaiian volcanoes work. The U.S. Geological Survey (USGS) has operated HVO continuously since 1947. Before then, HVO was under the administration of various Federal agencies—the U.S. Weather Bureau, at the time part of the Department of Agriculture, from 1919 to 1924; the USGS, which first managed HVO from 1924 to 1935; and the National Park Service from 1935 to 1947. For 76 of its first 100 years, HVO has been

  9. Accumulation of Pharmaceuticals, Enterococcus, and Resistance Genes in Soils Irrigated with Wastewater for Zero to 100 Years in Central Mexico

    PubMed Central

    Siebe, Christina; Willaschek, Elisha; Sakinc, Tuerkan; Huebner, Johannes; Amelung, Wulf; Grohmann, Elisabeth; Siemens, Jan

    2012-01-01

    Irrigation with wastewater releases pharmaceuticals, pathogenic bacteria, and resistance genes, but little is known about the accumulation of these contaminants in the environment when wastewater is applied for decades. We sampled a chronosequence of soils that were variously irrigated with wastewater from zero up to 100 years in the Mezquital Valley, Mexico, and investigated the accumulation of ciprofloxacin, enrofloxacin, sulfamethoxazole, trimethoprim, clarithromycin, carbamazepine, bezafibrate, naproxen, diclofenac, as well as the occurrence of Enterococcus spp., and sul and qnr resistance genes. Total concentrations of ciprofloxacin, sulfamethoxazole, and carbamazepine increased with irrigation duration reaching 95% of their upper limit of 1.4 µg/kg (ciprofloxacin), 4.3 µg/kg (sulfamethoxazole), and 5.4 µg/kg (carbamazepine) in soils irrigated for 19–28 years. Accumulation was soil-type-specific, with largest accumulation rates in Leptosols and no time-trend in Vertisols. Acidic pharmaceuticals (diclofenac, naproxen, bezafibrate) were not retained and thus did not accumulate in soils. We did not detect qnrA genes, but qnrS and qnrB genes were found in two of the irrigated soils. Relative concentrations of sul1 genes in irrigated soils were two orders of magnitude larger (3.15×10−3±0.22×10−3 copies/16S rDNA) than in non-irrigated soils (4.35×10−5±1.00×10−5 copies/16S rDNA), while those of sul2 exceeded the ones in non-irrigated soils still by a factor of 22 (6.61×10–4±0.59×10−4 versus 2.99×10−5±0.26×10−5 copies/16S rDNA). Absolute numbers of sul genes continued to increase with prolonging irrigation together with Enterococcus spp. 23S rDNA and total 16S rDNA contents. Increasing total concentrations of antibiotics in soil are not accompanied by increasing relative abundances of resistance genes. Nevertheless, wastewater irrigation enlarges the absolute concentration of resistance genes in soils due to a long-term increase in

  10. Accumulation of pharmaceuticals, Enterococcus, and resistance genes in soils irrigated with wastewater for zero to 100 years in central Mexico.

    PubMed

    Dalkmann, Philipp; Broszat, Melanie; Siebe, Christina; Willaschek, Elisha; Sakinc, Tuerkan; Huebner, Johannes; Amelung, Wulf; Grohmann, Elisabeth; Siemens, Jan

    2012-01-01

    Irrigation with wastewater releases pharmaceuticals, pathogenic bacteria, and resistance genes, but little is known about the accumulation of these contaminants in the environment when wastewater is applied for decades. We sampled a chronosequence of soils that were variously irrigated with wastewater from zero up to 100 years in the Mezquital Valley, Mexico, and investigated the accumulation of ciprofloxacin, enrofloxacin, sulfamethoxazole, trimethoprim, clarithromycin, carbamazepine, bezafibrate, naproxen, diclofenac, as well as the occurrence of Enterococcus spp., and sul and qnr resistance genes. Total concentrations of ciprofloxacin, sulfamethoxazole, and carbamazepine increased with irrigation duration reaching 95% of their upper limit of 1.4 µg/kg (ciprofloxacin), 4.3 µg/kg (sulfamethoxazole), and 5.4 µg/kg (carbamazepine) in soils irrigated for 19-28 years. Accumulation was soil-type-specific, with largest accumulation rates in Leptosols and no time-trend in Vertisols. Acidic pharmaceuticals (diclofenac, naproxen, bezafibrate) were not retained and thus did not accumulate in soils. We did not detect qnrA genes, but qnrS and qnrB genes were found in two of the irrigated soils. Relative concentrations of sul1 genes in irrigated soils were two orders of magnitude larger (3.15 × 10(-3) ± 0.22 × 10(-3) copies/16S rDNA) than in non-irrigated soils (4.35 × 10(-5)± 1.00 × 10(-5) copies/16S rDNA), while those of sul2 exceeded the ones in non-irrigated soils still by a factor of 22 (6.61 × 10(-4) ± 0.59 × 10(-4) versus 2.99 × 10(-5) ± 0.26 × 10(-5) copies/16S rDNA). Absolute numbers of sul genes continued to increase with prolonging irrigation together with Enterococcus spp. 23S rDNA and total 16S rDNA contents. Increasing total concentrations of antibiotics in soil are not accompanied by increasing relative abundances of resistance genes. Nevertheless, wastewater irrigation enlarges the absolute concentration of resistance genes in soils due to a long

  11. The geomorphic structure of the runoff peak

    NASA Astrophysics Data System (ADS)

    Rigon, R.; D'Odorico, P.; Bertoldi, G.

    2011-06-01

    This paper develops a theoretical framework to investigate the core dependence of peak flows on the geomorphic properties of river basins. Based on the theory of transport by travel times, and simple hydrodynamic characterization of floods, this new framework invokes the linearity and invariance of the hydrologic response to provide analytical and semi-analytical expressions for peak flow, time to peak, and area contributing to the peak runoff. These results are obtained for the case of constant-intensity hyetograph using the Intensity-Duration-Frequency (IDF) curves to estimate extreme flow values as a function of the rainfall return period. Results show that, with constant-intensity hyetographs, the time-to-peak is greater than rainfall duration and usually shorter than the basin concentration time. Moreover, the critical storm duration is shown to be independent of rainfall return period as well as the area contributing to the flow peak. The same results are found when the effects of hydrodynamic dispersion are accounted for. Further, it is shown that, when the effects of hydrodynamic dispersion are negligible, the basin area contributing to the peak discharge does not depend on the channel velocity, but is a geomorphic propriety of the basin. As an example this framework is applied to three watersheds. In particular, the runoff peak, the critical rainfall durations and the time to peak are calculated for all links within a network to assess how they increase with basin area.

  12. Are Bragg Peaks Gaussian?

    PubMed Central

    Hammouda, Boualem

    2014-01-01

    It is common practice to assume that Bragg scattering peaks have Gaussian shape. The Gaussian shape function is used to perform most instrumental smearing corrections. Using Monte Carlo ray tracing simulation, the resolution of a realistic small-angle neutron scattering (SANS) instrument is generated reliably. Including a single-crystal sample with large d-spacing, Bragg peaks are produced. Bragg peaks contain contributions from the resolution function and from spread in the sample structure. Results show that Bragg peaks are Gaussian in the resolution-limited condition (with negligible sample spread) while this is not the case when spread in the sample structure is non-negligible. When sample spread contributes, the exponentially modified Gaussian function is a better account of the Bragg peak shape. This function is characterized by a non-zero third moment (skewness) which makes Bragg peaks asymmetric for broad neutron wavelength spreads. PMID:26601025

  13. Simulations of the Greenland ice sheet 100 years into the future with the full Stokes model Elmer/Ice

    NASA Astrophysics Data System (ADS)

    Seddik, H.; Greve, R.; Zwinger, T.; Gillet-Chaulet, F.; Gagliardini, O.

    2011-12-01

    the surface precipitation and temperature and the set S (three experiments) applies an amplification factor to change the basal sliding velocity. The experiments are compared to a constant climate control run beginning at present (epoch 2004-1-1 0:0:0) and running up to 100 years holding the climate constant to its present state. The experiments with the amplification factor (Set S) show high sensitivities. Relative to the control run, the scenario with an amplification factor of 3x applied to the sliding velocity produces a Greenland contribution to sea level rise of ~25 cm. An amplification factor of 2.5x produces a contribution of ~16 cm and an amplification factor 2x produces a contribution of ~9 cm. The experiments with the changes to the surface precipitation and temperature (set C) show a contribution to sea level rise of ~4 cm when a factor 1x is applied to the temperature and precipitation anomalies. A factor 1.5x produces a sea level rise of ~8 cm and a factor 2x produces a sea level rise of ~12 cm.

  14. Peak Experience Project

    ERIC Educational Resources Information Center

    Scott, Daniel G.; Evans, Jessica

    2010-01-01

    This paper emerges from the continued analysis of data collected in a series of international studies concerning Childhood Peak Experiences (CPEs) based on developments in understanding peak experiences in Maslow's hierarchy of needs initiated by Dr Edward Hoffman. Bridging from the series of studies, Canadian researchers explore collected…

  15. Peak Experience Project

    ERIC Educational Resources Information Center

    Scott, Daniel G.; Evans, Jessica

    2010-01-01

    This paper emerges from the continued analysis of data collected in a series of international studies concerning Childhood Peak Experiences (CPEs) based on developments in understanding peak experiences in Maslow's hierarchy of needs initiated by Dr Edward Hoffman. Bridging from the series of studies, Canadian researchers explore collected…

  16. On the trail of double peak hydrographs

    NASA Astrophysics Data System (ADS)

    Martínez-Carreras, Núria; Hissler, Christophe; Gourdol, Laurent; Klaus, Julian; Juilleret, Jérôme; François Iffly, Jean; McDonnell, Jeffrey J.; Pfister, Laurent

    2016-04-01

    A double peak hydrograph features two peaks as a response to a unique rainfall pulse. The first peak occurs at the same time or shortly after the precipitation has started and it corresponds to a fast catchment response to precipitation. The delayed peak normally starts during the recession of the first peak, when the precipitation has already ceased. Double peak hydrographs may occur for various reasons. They can occur (i) in large catchments when lag times in tributary responses are large, (ii) in urban catchments where the first peak is often caused by direct surface runoff on impervious land cover, and the delayed peak to slower subsurface flow, and (iii) in non-urban catchments, where the first and the delayed discharge peaks are explained by different runoff mechanisms (e.g. overland flow, subsurface flow and/or deep groundwater flow) that have different response times. Here we focus on the third case, as a formal description of the different hydrological mechanisms explaining these complex hydrological dynamics across catchments with diverse physiographic characteristics is still needed. Based on a review of studies documenting double peak events we have established a formal classification of catchments presenting double peak events based on their regolith structure (geological substratum and/or its weathered products). We describe the different hydrological mechanisms that trigger these complex hydrological dynamics across each catchment type. We then use hydrometric time series of precipitation, runoff, soil moisture and groundwater levels collected in the Weierbach (0.46 km2) headwater catchment (Luxembourg) to better understand double peak hydrograph generation. Specifically, we aim to find out (1) if the generation of a double peak hydrograph is a threshold process, (2) if the hysteretic relationships between storage and discharge are consistent during single and double peak hydrographs, and (3) if different functional landscape units (the hillslopes

  17. Water-surface profile and flood boundaries for the computed 100-year flood, Lame Deer Creek, Northern Cheyenne Indian Reservation, Montana

    USGS Publications Warehouse

    Omang, R.J.

    1994-01-01

    Hydrologic and hydraulic evaluations of Lame Deer Creek were made to determine the magnitude of the 100-year flood and the extent of flooding that would occur as the result of this flood. SixtY-six cross sections were Surveyed and 25 cross sections were synthesized along a 9.5-mile reach of Lame Deer Creek. Data from the surveys were used to calculate the water-surface elevation at each cross section using a computer program (WSPRO) developed by the U.S. Geological Survey. The water-surface profile of the computed 100-year flood elevations was then drawn. The profile shows the streambed elevation and the location of the bridge, culverts, and cross sections. The computed 100-year flood elevation at each cross section was used to delineate the width of the flood plain at that section. Flood boundaries between cross sections were interpolated using contour lines on topographic maps.

  18. More than 100 Years of Background-Level Sedimentary Metals, Nisqually River Delta, South Puget Sound, Washington

    USGS Publications Warehouse

    Takesue, Renee K.; Swarzenski, Peter W.

    2011-01-01

    The Nisqually River Delta is located about 25 km south of the Tacoma Narrows in the southern reach of Puget Sound. Delta evolution is controlled by sedimentation from the Nisqually River and erosion by strong tidal currents that may reach 0.95 m/s in the Nisqually Reach. The Nisqually River flows 116 km from the Cascade Range, including the slopes of Mount Rainier, through glacially carved valleys to Puget Sound. Extensive tidal flats on the delta consist of late-Holocene silty and sandy strata from normal river streamflow and seasonal floods and possibly from distal sediment-rich debris flows associated with volcanic and seismic events. In the early 1900s, dikes and levees were constructed around Nisqually Delta salt marshes, and the reclaimed land was used for agriculture and pasture. In 1974, U.S. Fish and Wildlife Service established the Nisqually National Wildlife Refuge on the reclaimed land to protect migratory birds; its creation has prevented further human alteration of the Delta and estuary. In October 2009, original dikes and levees were removed to restore tidal exchange to almost 3 km2 of man-made freshwater marsh on the Nisqually Delta.

  19. Flood frequency analysis for nonstationary annual peak records in an urban drainage basin

    USGS Publications Warehouse

    Villarini, G.; Smith, J.A.; Serinaldi, F.; Bales, J.; Bates, P.D.; Krajewski, W.F.

    2009-01-01

    Flood frequency analysis in urban watersheds is complicated by nonstationarities of annual peak records associated with land use change and evolving urban stormwater infrastructure. In this study, a framework for flood frequency analysis is developed based on the Generalized Additive Models for Location, Scale and Shape parameters (GAMLSS), a tool for modeling time series under nonstationary conditions. GAMLSS is applied to annual maximum peak discharge records for Little Sugar Creek, a highly urbanized watershed which drains the urban core of Charlotte, North Carolina. It is shown that GAMLSS is able to describe the variability in the mean and variance of the annual maximum peak discharge by modeling the parameters of the selected parametric distribution as a smooth function of time via cubic splines. Flood frequency analyses for Little Sugar Creek (at a drainage area of 110 km2) show that the maximum flow with a 0.01-annual probability (corresponding to 100-year flood peak under stationary conditions) over the 83-year record has ranged from a minimum unit discharge of 2.1 m3 s- 1 km- 2 to a maximum of 5.1 m3 s- 1 km- 2. An alternative characterization can be made by examining the estimated return interval of the peak discharge that would have an annual exceedance probability of 0.01 under the assumption of stationarity (3.2 m3 s- 1 km- 2). Under nonstationary conditions, alternative definitions of return period should be adapted. Under the GAMLSS model, the return interval of an annual peak discharge of 3.2 m3 s- 1 km- 2 ranges from a maximum value of more than 5000 years in 1957 to a minimum value of almost 8 years for the present time (2007). The GAMLSS framework is also used to examine the links between population trends and flood frequency, as well as trends in annual maximum rainfall. These analyses are used to examine evolving flood frequency over future decades. ?? 2009 Elsevier Ltd.

  20. Flood frequency analysis for nonstationary annual peak records in an urban drainage basin

    NASA Astrophysics Data System (ADS)

    Villarini, Gabriele; Smith, James A.; Serinaldi, Francesco; Bales, Jerad; Bates, Paul D.; Krajewski, Witold F.

    2009-08-01

    Flood frequency analysis in urban watersheds is complicated by nonstationarities of annual peak records associated with land use change and evolving urban stormwater infrastructure. In this study, a framework for flood frequency analysis is developed based on the Generalized Additive Models for Location, Scale and Shape parameters (GAMLSS), a tool for modeling time series under nonstationary conditions. GAMLSS is applied to annual maximum peak discharge records for Little Sugar Creek, a highly urbanized watershed which drains the urban core of Charlotte, North Carolina. It is shown that GAMLSS is able to describe the variability in the mean and variance of the annual maximum peak discharge by modeling the parameters of the selected parametric distribution as a smooth function of time via cubic splines. Flood frequency analyses for Little Sugar Creek (at a drainage area of 110km) show that the maximum flow with a 0.01-annual probability (corresponding to 100-year flood peak under stationary conditions) over the 83-year record has ranged from a minimum unit discharge of 2.1mskm to a maximum of 5.1mskm. An alternative characterization can be made by examining the estimated return interval of the peak discharge that would have an annual exceedance probability of 0.01 under the assumption of stationarity (3.2mskm). Under nonstationary conditions, alternative definitions of return period should be adapted. Under the GAMLSS model, the return interval of an annual peak discharge of 3.2mskm ranges from a maximum value of more than 5000 years in 1957 to a minimum value of almost 8 years for the present time (2007). The GAMLSS framework is also used to examine the links between population trends and flood frequency, as well as trends in annual maximum rainfall. These analyses are used to examine evolving flood frequency over future decades.

  1. Peak power ratio generator

    DOEpatents

    Moyer, Robert D.

    1985-01-01

    A peak power ratio generator is described for measuring, in combination with a conventional power meter, the peak power level of extremely narrow pulses in the gigahertz radio frequency bands. The present invention in a preferred embodiment utilizes a tunnel diode and a back diode combination in a detector circuit as the only high speed elements. The high speed tunnel diode provides a bistable signal and serves as a memory device of the input pulses for the remaining, slower components. A hybrid digital and analog loop maintains the peak power level of a reference channel at a known amount. Thus, by measuring the average power levels of the reference signal and the source signal, the peak power level of the source signal can be determined.

  2. Significance of periodogram peaks

    NASA Astrophysics Data System (ADS)

    Süveges, Maria; Guy, Leanne; Zucker, Shay

    2016-10-01

    Three versions of significance measures or False Alarm Probabilities (FAPs) for periodogram peaks are presented and compared for sinusoidal and box-like signals, with specific application on large-scale surveys in mind.

  3. Peak power ratio generator

    DOEpatents

    Moyer, R.D.

    A peak power ratio generator is described for measuring, in combination with a conventional power meter, the peak power level of extremely narrow pulses in the gigahertz radio frequency bands. The present invention in a preferred embodiment utilizes a tunnel diode and a back diode combination in a detector circuit as the only high speed elements. The high speed tunnel diode provides a bistable signal and serves as a memory device of the input pulses for the remaining, slower components. A hybrid digital and analog loop maintains the peak power level of a reference channel at a known amount. Thus, by measuring the average power levels of the reference signal and the source signal, the peak power level of the source signal can be determined.

  4. Pikes Peak, Colorado

    USGS Publications Warehouse

    Brunstein, Craig; Quesenberry, Carol; Davis, John; Jackson, Gene; Scott, Glenn R.; D'Erchia, Terry D.; Swibas, Ed; Carter, Lorna; McKinney, Kevin; Cole, Jim

    2006-01-01

    For 200 years, Pikes Peak has been a symbol of America's Western Frontier--a beacon that drew prospectors during the great 1859-60 Gold Rush to the 'Pikes Peak country,' the scenic destination for hundreds of thousands of visitors each year, and an enduring source of pride for cities in the region, the State of Colorado, and the Nation. November 2006 marks the 200th anniversary of the Zebulon M. Pike expedition's first sighting of what has become one of the world's most famous mountains--Pikes Peak. In the decades following that sighting, Pikes Peak became symbolic of America's Western Frontier, embodying the spirit of Native Americans, early explorers, trappers, and traders who traversed the vast uncharted wilderness of the Western Great Plains and the Southern Rocky Mountains. High-quality printed paper copies of this poster are available at no cost from Information Services, U.S. Geological Survey (1-888-ASK-USGS).

  5. Central Peak Crater

    NASA Image and Video Library

    2010-10-07

    As crater size increases, craters become more complex. This moderate size crater contains a central peak, created by rebound of molten material just following the impact. This image was captured by NASA Mars Odyssey on Sept. 8, 2010.

  6. METHOD OF PEAK CURRENT MEASUREMENT

    DOEpatents

    Baker, G.E.

    1959-01-20

    The measurement and recording of peak electrical currents are described, and a method for utilizing the magnetic field of the current to erase a portion of an alternating constant frequency and amplitude signal from a magnetic mediums such as a magnetic tapes is presented. A portion of the flux from the current carrying conductor is concentrated into a magnetic path of defined area on the tape. After the current has been recorded, the tape is played back. The amplitude of the signal from the portion of the tape immediately adjacent the defined flux area and the amplitude of the signal from the portion of the tape within the area are compared with the amplitude of the signal from an unerased portion of the tape to determine the percentage of signal erasure, and thereby obtain the peak value of currents flowing in the conductor.

  7. Peak Oil, Peak Coal and Climate Change

    NASA Astrophysics Data System (ADS)

    Murray, J. W.

    2009-05-01

    Research on future climate change is driven by the family of scenarios developed for the IPCC assessment reports. These scenarios create projections of future energy demand using different story lines consisting of government policies, population projections, and economic models. None of these scenarios consider resources to be limiting. In many of these scenarios oil production is still increasing to 2100. Resource limitation (in a geological sense) is a real possibility that needs more serious consideration. The concept of 'Peak Oil' has been discussed since M. King Hubbert proposed in 1956 that US oil production would peak in 1970. His prediction was accurate. This concept is about production rate not reserves. For many oil producing countries (and all OPEC countries) reserves are closely guarded state secrets and appear to be overstated. Claims that the reserves are 'proven' cannot be independently verified. Hubbert's Linearization Model can be used to predict when half the ultimate oil will be produced and what the ultimate total cumulative production (Qt) will be. US oil production can be used as an example. This conceptual model shows that 90% of the ultimate US oil production (Qt = 225 billion barrels) will have occurred by 2011. This approach can then be used to suggest that total global production will be about 2200 billion barrels and that the half way point will be reached by about 2010. This amount is about 5 to 7 times less than assumed by the IPCC scenarios. The decline of Non-OPEC oil production appears to have started in 2004. Of the OPEC countries, only Saudi Arabia may have spare capacity, but even that is uncertain, because of lack of data transparency. The concept of 'Peak Coal' is more controversial, but even the US National Academy Report in 2007 concluded only a small fraction of previously estimated reserves in the US are actually minable reserves and that US reserves should be reassessed using modern methods. British coal production can be

  8. The geomorphic structure of the runoff peak

    NASA Astrophysics Data System (ADS)

    Rigon, R.; D'Odorico, P.; Bertoldi, G.

    2011-01-01

    This paper develops a theoretical framework to investigate the core dependence of peak flows on the geomorphic properties of river basins. Based on the theory of transport by travel times, and simple hydrodynamic characterization of floods, this new framework invokes the linearity and invariance of the hydrologic response to provide analytical and semi-analitical expressions for peak flow, time to peak, and area contributing to the peak runoff. These results are obtained for the case of constant-intensity hyetograph using the Intensity-Duration-Frequency (IDF) curves to estimate extreme flow values as a function of the rainfall return period. Results show that, with constant-intensity hyetographs, the time-to-peak is greater than rainfall duration and usually shorter than the basin concentration time. Moreover, the critical storm duration is shown to be independent of rainfall return period. Further, it is shown that the basin area contributing to the peak discharge does not depend on the channel velocity, but is a geomorphic propriety of the basin. The same results are found when the effects of hydrodynamic dispersion are accounted for. As an example this framework is applied to three watersheds. In particular, the runoff peak, the critical rainfall durations and the time to peak are calculated for all links within a network to assess how they increase with basin area.

  9. Log and lumber grades as indicators of wood quality in 20- to 100-year-old Douglas-fir trees from thinned and unthinned stands.

    Treesearch

    R. James Barbour; Dean L. Parry

    2001-01-01

    This report examines the differences in wood characteristics found in coastal Pacific Northwest Douglas-fir (Pseudotsuga mensziesii (Mirb.) Franco) trees harvested at the age of 70 to 100 years old to wood characteristics of trees harvested at the age of 40 to 60 years. Comparisons of differences in domestic log grades suggest that the proportion...

  10. Santa Rita Experimental Range: 100 years (1903 to 2003) of accomplishments and contributions; conference proceedings; 2003 October 30-November 1; Tucson, AZ

    Treesearch

    Mitchel P. McClaran; Peter F. Ffolliott; Carleton B. Edminster

    2003-01-01

    The purpose of this conference was to celebrate the 100 years of accomplishments and contributions of the Santa Rita Experimental Range, the longest continuously operating research area dedicated to the sustainable management of North American rangelands. The conference consisted of one-and-a-half days of invited synthesis papers and contributed poster presentations...

  11. The Changing Role of the Hawaiian Volcano Observatory within the Volcanological Community through its 100 year history

    NASA Astrophysics Data System (ADS)

    Kauahikaua, J. P.; Poland, M. P.

    2011-12-01

    When Thomas Jaggar, Jr., founded the Hawaiian Volcano Observatory in 1912, he wanted to "keep and publish careful records, invite the whole world of science to co-operate, and interest the business man." After studying the disastrous volcanic eruption at Martinique and Naples and the destructive earthquakes at Messina and the Caribbean Ocean, he saw observatories with these goals as a way to understand and mitigate these hazards. Owing to frequent eruptions, ease of access, and continuous record of activity (since January 17, 1912), Kilauea Volcano has been the focus for volcanological study by government, academic, and international investigators. New volcano monitoring techniques have been developed and tested on Hawaiian volcanoes and exported worldwide. HVO has served as a training ground for several generations of volcanologists; many have contributed to volcano research and hazards mitigation around the world. In the coming years, HVO and the scientific community will benefit from recent upgrades in our monitoring network. HVO had the first regional seismic network in the US and it will be fully digital; continuous GPS, tilt, gravity, and strain data already complement the seismic data; an array of infrared and visual cameras simultaneously track geologic surface changes. Scientifically, HVO scientists and their colleagues are making great advances in understanding explosive basaltic eruptions, volcanic gas emission and dispersion and its hazards, and lava flow mechanics with these advanced instruments. Activity at Hawaiian volcanoes continues to provide unparalleled opportunities for research and education, made all the more valuable by HVO's scientific legacy.

  12. Correlation-Peak Imaging

    NASA Astrophysics Data System (ADS)

    Ziegler, A.; Metzler, A.; Köckenberger, W.; Izquierdo, M.; Komor, E.; Haase, A.; Décorps, M.; von Kienlin, M.

    1996-08-01

    Identification and quantitation in conventional1H spectroscopic imagingin vivois often hampered by the small chemical-shift range. To improve the spectral resolution of spectroscopic imaging, homonuclear two-dimensional correlation spectroscopy has been combined with phase encoding of the spatial dimensions. From the theoretical description of the coherence-transfer signal in the Fourier-transform domain, a comprehensive acquisition and processing strategy is presented that includes optimization of the width and the position of the acquisition windows, matched filtering of the signal envelope, and graphical presentation of the cross peak of interest. The procedure has been applied to image the spatial distribution of the correlation peaks from specific spin systems in the hypocotyl of castor bean (Ricinus communis) seedlings. Despite the overlap of many resonances, correlation-peak imaging made it possible to observe a number of proton resonances, such as those of sucrose, β-glucose, glutamine/glutamate, lysine, and arginine.

  13. Hale Central Peak

    NASA Technical Reports Serv