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Sample records for long-term flow testing

  1. Long-term durability test of axial-flow ventricular assist device under pulsatile flow.

    PubMed

    Nishida, Masahiro; Kosaka, Ryo; Maruyama, Osamu; Yamane, Takashi; Shirasu, Akio; Tatsumi, Eisuke; Taenaka, Yoshiyuki

    2017-03-01

    A long-term durability test was conducted on a newly developed axial-flow ventricular assist device (VAD) with hydrodynamic bearings. The mock circulatory loop consisted of a diaphragm pump with a mechanical heart valve, a reservoir, a compliance tank, a resistance valve, and flow paths made of polymer or titanium. The VAD was installed behind the diaphragm pump. The blood analog fluid was a saline solution with added glycerin at a temperature of 37 °C. A pulsatile flow was introduced into the VAD over a range of flow rates to realize a positive flow rate and a positive pressure head at a given impeller rotational speed, yielding a flow rate of 5 L/min and a pressure of 100 mmHg. Pulsatile flow conditions were achieved with the diastolic and systolic flow rates of ~0 and 9.5 L/min, respectively, and an average flow rate of ~5 L/min at a pulse rate of 72 bpm. The VAD operation was judged by not only the rotational speed of the impeller, but also the diastolic, systolic, and average flow rates and the average pressure head of the VAD. The conditions of the mock circulatory loop, including the pulse rate of the diaphragm pump, the fluid temperature, and the fluid viscosity were maintained. Eight VADs were tested with testing periods of 2 years, during which they were continuously in operation. The VAD performance factors, including the power consumption and the vibration characteristics, were kept almost constant. The long-term durability of the developed VAD was successfully demonstrated.

  2. Long-term testing

    SciTech Connect

    Ferber, M.; Graves, G.A. Jr.

    1994-12-31

    Land-based gas turbines are significantly different from automotive gas turbines in that they are designed to operate for 50,000 h or greater (compared to 5,000--10,000 h). The primary goal of this research is to determine the long-term survivability of ceramic materials for industrial gas turbine applications. Research activities in this program focus on the evaluation of the static tensile creep and stress rupture (SR) behavior of three commercially available structural ceramics which have been identified by the gas turbine manufacturers as leading candidates for use in industrial gas turbines. For each material investigated, a minimum of three temperatures and four stresses will be used to establish the stress and temperature sensitivities of the creep and SR behavior. Because existing data for many candidate structural ceramics are limited to testing times less than 2,000 h, this program will focus on extending these data to times on the order of 10,000 h, which represents the lower limit of operating time anticipated for ceramic blades and vanes in gas turbine engines. A secondary goal of the program will be to investigate the possibility of enhancing life prediction estimates by combining interrupted tensile SR tests and tensile dynamic fatigue tests in which tensile strength is measured as a function of stressing rate. The third goal of this program will be to investigate the effects of water vapor upon the SR behavior of the three structural ceramics chosen for the static tensile studies by measuring the flexural strength as a function of stressing rate at three temperatures.

  3. Tracer experiment results during the Long-Term Flow Test of the Fenton Hill reservoir

    SciTech Connect

    Rodrigues, N.E.V.; Robinson, B.A.; Counce, D.A.

    1993-02-01

    Three chemical tracer experiments and one extended injection of fluid low in concentration of dissolved species have been carried out during the Long Term Flow Test (LTFT) of the Fenton Hill Hot Dry Rock (HDR) reservoir. The tracer tests,results illustrate the dynamic nature of the flow system, with more fluid traveling through longer residence time paths as heat is extracted. The total fracture volumes calculated from these tests allow us to determine the fate of unrecovered injection fluid, examine the pressure-dependence of fracture volume, and, through a comparison to the hydraulic performance, postulate a model for the nature of the pressure drops through the system. The Fresh Water Flush (FWF) test showed that while no dissolved specie behavior is truly conservative (no sources or sinks), several breakthrough curves are well explained with a pore fluid displacement model. Other dissolved components are clearly influenced by dissolution or precipitation reactions. Finally, the transient response of the chemistry during the FWF to an increase in production well pressure showed that some fractures connected to the production well preferentially open when pressure is raised.

  4. Long-term durability testing of ceramic cross-flow filter. Final report, September 29, 1987--December 31, 1992

    SciTech Connect

    Lippert, T.E.; Smeltzer, E.E.; Alvin, M.A.; Bachovchin, D.M.

    1993-08-01

    Long term durability testing of the cross flow filter is described. Two high temperature, high pressure test facilities were built and operated. The facilities were designed to simulate dirty gas environments typical of Pressurized Fluidized Bed Combustion (PFBC) and coal gasification. Details of the design and operation of the test facilities and filter testing results are described.

  5. HDR Opportunities and Challenges Beyond the Long-Term Flow Test

    SciTech Connect

    Duchane, David

    1992-03-24

    The long term flow test (LTFT) of the worlds largest, deepest, and hottest hot dry rock (HDR) reservoir currently underway at Fenton Hill, NM, is expected to demonstrate that thermal energy can be mined from hot rock within the earth on a sustainable basis with minimal water consumption. This test will simulate the operations of a commercial facility in some ways, but it will not show that energy from HDR can be produced at a variety of locations with different geological settings. Since the Fenton Hill system was designed as a research facility rather than strictly for production purposes, it will also not demonstrate economic viability, although it may well give indications of system modifications needed for economic HDR operations. A second production site must be constructed, ideally under the direction of the private geothermal community, to begin the process of proving that the vast HDR resources can be accessed on a worldwide scale. This facility should be designed and engineered to produce and market energy at competitive prices. At the same time, a wide variety of techniques to advance the state-of-the-art of HDR technology must be pursued to develop this infant technology rapidly to its maximum potential. A number of design and operational techniques have been conceived which may lead to improved economics in HDR systems. After careful technical and economic scrutiny, those showing merit should be vigorously pursued. Finally, research and development work in areas such as reservoir interrogation, and system modeling must be accelerated to increase the competitiveness and geographical applications of HDR and the geothermal industry in general. This paper addresses the above issues in detail and outlines possible paths to future prosperity for the commercial geothermal industry.

  6. Pre-test estimates of temperature decline for the LANL Fenton Hill Long-Term Flow Test

    SciTech Connect

    Robinson, B.A.; Kruger, P.

    1992-06-01

    Pre-test predications for the Long-Term Flow Test (LTFT) of the experimental Hot Dry Rock (HDR) reservoir at Fenton Hill were made using two models. Both models are dependent on estimates of the ``effective`` reservoir volume accessed by the fluid and the mean fracture spacing (MFS) of major joints for fluid flow. The effective reservoir volume was estimated using a variety of techniques, and the range of values for the MFS was set through experience in modeling the thermal cooldown of other experimental HDR reservoirs. The two pre-test predictions for cooldown to 210{degrees}C (a value taken to compare the models) from initial temperature of 240{degrees}C are 6.1 and 10.7 years. Assuming that a minimum of 10{degrees}C is required to provide an unequivocal indication of thermal cooldown, both models predict that the reservoir will not exhibit observable cooldown for at least two years.

  7. A groundwater flow and transport model of long-term radionuclide migration in central Frenchman flat, Nevada test site

    SciTech Connect

    Kwicklis, Edward Michael; Becker, Naomi M; Ruskauff, Gregory; De Novio, Nicole; Wilborn, Bill

    2010-11-10

    A set of groundwater flow and transport models were created for the Central Testing Area of Frenchman Flat at the former Nevada Test Site to investigate the long-term consequences of a radionuclide migration experiment that was done between 1975 and 1990. In this experiment, radionuclide migration was induced from a small nuclear test conducted below the water table by pumping a well 91 m away. After radionuclides arrived at the pumping well, the contaminated effluent was discharged to an unlined ditch leading to a playa where it was expected to evaporate. However, recent data from a well near the ditch and results from detailed models of the experiment by LLNL personnel have convincingly demonstrated that radionuclides from the ditch eventually reached the water table some 220 m below land surface. The models presented in this paper combine aspects of these detailed models with concepts of basin-scale flow to estimate the likely extent of contamination resulting from this experiment over the next 1,000 years. The models demonstrate that because regulatory limits for radionuclide concentrations are exceeded only by tritium and the half-life of tritium is relatively short (12.3 years), the maximum extent of contaminated groundwater has or will soon be reached, after which time the contaminated plume will begin to shrink because of radioactive decay. The models also show that past and future groundwater pumping from water supply wells within Frenchman Flat basin will have negligible effects on the extent of the plume.

  8. A study of pumps for the Hot Dry Rock Geothermal Energy extraction experiment (LTFT (Long Term Flow Test))

    SciTech Connect

    Tatro, C.A.

    1986-10-01

    A set of specifications for the hot dry rock (HDR) Phase II circulation pumping system is developed from a review of basic fluid pumping mechanics, a technical history of the HDR Phase I and Phase II pumping systems, a presentation of the results from experiment 2067 (the Initial Closed-Loop Flow Test or ICFT), and consideration of available on-site electrical power limitations at the experiment site. For the Phase II energy extraction experiment (the Long Term Flow Test or LTFT) it is necessary to provide a continuous, low maintenance, and highly efficient pumping capability for a period of twelve months at variable flowrates up to 420 gpm and at surface injection pressures up to 5000 psi. The pumping system must successfully withstand attacks by corrosive and embrittling gases, erosive chemicals and suspended solids, and fluid pressure and temperature fluctuations. In light of presently available pumping hardware and electric power supply limitations, it is recommended that positive displacement multiplex plunger pumps, driven by variable speed control electric motors, be used to provide the necessary continuous surface injection pressures and flowrates for LTFT. The decision of whether to purchase the required circulation pumping hardware or to obtain contractor provided pumping services has not been made.

  9. Contaminant transfer and hydrodispersive parameters in basaltic lava flows: artificial tracer test and implications for long-term management

    NASA Astrophysics Data System (ADS)

    Bertrand, G.; Celle-Jeanton, H.; Huneau, F.; Baillieux, A.; Mauri, G.; Lavastre, V.; Undereiner, G.; Girolami, L.; Moquet, J. S.

    2015-10-01

    The aim of this paper is to evaluate the vulnerability after point source contamination and characterize water circulations in volcanic flows located in the Argnat basin volcanic system (Chaîne des Puys, French Massif Central) using a tracer test performed by injecting a iodide solution. The analysis of breakthrough curves allowed the hydrodispersive characteristics of the massive lava flows to be determined. Large Peclet numbers indicated a dominant advective transport. The multimodal feature of breakthrough curves combined with high values of mean velocity and low longitudinal dispersion coefficients indicated thatwater flows in an environment analogous to a fissure system, and only slightly interacts with a low porosity matrix (ne < 1%). Combining this information with lava flow stratigraphy provided by several drillings allowed a conceptual scheme of potential contaminant behaviour to be designed. Although lava flows are vulnerable to point source pollution due to the rapid transfer of water within fractures, the saturated scoriaceous layers located between massive rocks should suffice to strongly buffer the transit of pollution through dilution and longer transit times. This was consistent with the low recovery rate of the presented tracer test.

  10. Neurotoxicity testing during long-term studies.

    PubMed

    Ivens, I

    1990-01-01

    Several tests and methods for the investigation of neurotoxicity were performed with female Wistar rats for up to 187 days. The methods were validated by testing 10 rats treated with beta,beta'-iminodipropionitrile (IDPN) and 10 control rats. Cage side observation of the animals revealed signs of altered behavior and motor dysfunction of the IDPN-treated rats. Results of a neuromuscular screen indicated changes in gait, righting reflex, grip strength and performance of the negative geotropism test. Investigation of the animals in activity monitors and on the accelerating rotarod showed changes of several parameters. The motor nerve conduction velocity, measured 6 months after the first treatment, was reduced by 6.7 meters per second in the IDPN group compared to controls. From the results of the tests it can be concluded that the methods chosen can be used during long-term studies but may be most useful for animals not older than 12 months.

  11. Long-term corrosion testing pan.

    SciTech Connect

    Wall, Frederick Douglas; Brown, Neil R.

    2008-08-01

    This document describes the testing and facility requirements to support the Yucca Mountain Project long-term corrosion testing needs. The purpose of this document is to describe a corrosion testing program that will (a) reduce model uncertainty and variability, (b) reduce the reliance upon overly conservative assumptions, and (c) improve model defensibility. Test matrices were developed for 17 topical areas (tasks): each matrix corresponds to a specific test activity that is a subset of the total work performed in a task. A future document will identify which of these activities are considered to be performance confirmation activities. Detailed matrices are provided for FY08, FY09 and FY10 and rough order estimates are provided for FY11-17. Criteria for the selection of appropriate test facilities were developed through a meeting of Lead Lab and DOE personnel on October 16-17, 2007. These criteria were applied to the testing activities and recommendations were made for the facility types appropriate to carry out each activity. The facility requirements for each activity were assessed and activities were identified that can not be performed with currently available facilities. Based on this assessment, a total of approximately 10,000 square feet of facility space is recommended to meet all future testing needs, given that all testing is consolidated to a single location. This report is a revision to SAND2007-7027 to address DOE comments and add a series of tests to address NWTRB recommendations.

  12. Long-term corrosion testing plan.

    SciTech Connect

    Wall, Frederick Douglas; Brown, Neil R.

    2009-02-01

    This document describes the testing and facility requirements to support the Yucca Mountain Project long-term corrosion testing program. The purpose of this document is to describe a corrosion testing program that will (a) reduce model uncertainty and variability, (b) reduce the reliance upon overly conservative assumptions, and (c) improve model defensibility. Test matrices were developed for 17 topical areas (tasks): each matrix corresponds to a specific test activity that is a subset of the total work performed in a task. A future document will identify which of these activities are considered to be performance confirmation activities. Detailed matrices are provided for FY08, FY09 and FY10 and rough order estimates are provided for FY11-17. Criteria for the selection of appropriate test facilities were developed through a meeting of Lead Lab and DOE personnel on October 16-17, 2007. These criteria were applied to the testing activities and recommendations were made for the facility types appropriate to carry out each activity. The facility requirements for each activity were assessed and activities were identified that can not be performed with currently available facilities. Based on this assessment, a total of approximately 10,000 square feet of facility space is recommended to accommodate all future testing, given that all testing is consolidated to a single location. This report is a revision to SAND2008-4922 to address DOE comments.

  13. Online Continuous Flow Differential Electrochemical Mass Spectrometry with a Realistic Battery Setup for High-Precision, Long-Term Cycling Tests.

    PubMed

    Berkes, Balázs B; Jozwiuk, Anna; Vračar, Miloš; Sommer, Heino; Brezesinski, Torsten; Janek, Jürgen

    2015-06-16

    We describe the benefits of an online continuous flow differential electrochemical mass spectrometry (DEMS) method that allows for realistic battery cycling conditions. We provide a detailed description on the buildup and the role of the different components in the system. Special emphasis is given on the cell design. The retention time and response characteristics of the system are tested with the electrolysis of Li2O2. Finally, we show a practical application in which a Li-ion battery is examined. The value of long-term DEMS measurements for the proper evaluation of electrolyte decomposition is demonstrated by an experiment where a Li(1+x)Ni(0.5)Mn(0.3)Co(0.2)O2 (NMC 532)/graphite cell is cycled over 20 charge/discharge cycles.

  14. An electric propulsion long term test facility

    NASA Technical Reports Server (NTRS)

    Trump, G.; James, E.; Vetrone, R.; Bechtel, R.

    1979-01-01

    An existing test facility was modified to provide for extended testing of multiple electric propulsion thruster subsystems. A program to document thruster subsystem characteristics as a function of time is currently in progress. The facility is capable of simultaneously operating three 2.7-kW, 30-cm mercury ion thrusters and their power processing units. Each thruster is installed via a separate air lock so that it can be extended into the 7m x 10m main chamber without violating vacuum integrity. The thrusters exhaust into a 3m x 5m frozen mercury target. An array of cryopanels collect sputtered target material. Power processor units are tested in an adjacent 1.5m x 2m vacuum chamber or accompanying forced convection enclosure. The thruster subsystems and the test facility are designed for automatic unattended operation with thruster operation computer controlled. Test data are recorded by a central data collection system scanning 200 channels of data a second every two minutes. Results of the Systems Demonstration Test, a short shakedown test of 500 hours, and facility performance during the first year of testing are presented.

  15. An electric propulsion long term test facility

    NASA Technical Reports Server (NTRS)

    Trump, G.; James, E.; Vetrone, R.; Bechtel, R.

    1979-01-01

    An existing test facility was modified to provide for extended testing of multiple electric propulsion thruster subsystems. A program to document thruster subsystem characteristics as a function of time is currently in progress. The facility is capable of simultaneously operating three 2.7-kW, 30-cm mercury ion thrusters and their power processing units. Each thruster is installed via a separate air lock so that it can be extended into the 7m x 10m main chamber without violating vacuum integrity. The thrusters exhaust into a 3m x 5m frozen mercury target. An array of cryopanels collect sputtered target material. Power processor units are tested in an adjacent 1.5m x 2m vacuum chamber or accompanying forced convection enclosure. The thruster subsystems and the test facility are designed for automatic unattended operation with thruster operation computer controlled. Test data are recorded by a central data collection system scanning 200 channels of data a second every two minutes. Results of the Systems Demonstration Test, a short shakedown test of 500 hours, and facility performance during the first year of testing are presented.

  16. Long-Term Materials Test Program: materials exposure test plan

    SciTech Connect

    1981-12-01

    The Long Term Materials Test Program is designed to identify promising corrosion resistant materials for coal-fired gas turbine applications. Resistance of materials to long term accelerated corrosion will be determined through realistic PFB environmental exposure of candidate turbine materials for up to 14,000 hours. Selected materials also will be evaluated for their ability to withstand the combined erosive and corrosive aspects of the PFB effluent. A pressurized fluidized bed combustor facility has been constructed at the General Electric Coal Utilization Research Laboratory at Malta, New York. The 12-inch diameter combustor will burn high sulfur coal with moderate-to-high chlorine and alkali levels and utilize dolomite as the sulfur sorbent. Hot gas cleanup is achieved using three stages of cyclone separators. Downstream of the cylone separators, a low velocity test section (approx. 30 ft/s) capable of housing 180 pin specimens 1/4'' diameter has been installed to assess the corrosion resistance of the various materials at three different temperatures ranging from 1300 to 1600/sup 0/F. Following the low velocity test section is a high velocity test section consisting of four cascades of airfoil shaped specimens, six specimens per cascade. This high velocity test section is being used to evaluate the combined effects of erosion and corrosion on the degradation of gas turbine materials at gas velocities of 800 to 1400 ft/s. This report summarizes the materials selection and materials exposure test plan for the Long Term Materials Test.

  17. Long Term Stability of Coriolis Flow Meters: DESY experience

    NASA Astrophysics Data System (ADS)

    Boeckmann, T.; Bozhko, Y.; Escherich, K.; Petersen, B.; Putselyk, S.; Schnautz, T.; Sellmann, D.; Zhirnov, A.

    2017-02-01

    The measurement of coolant flow is important operational parameter for reliable operation of cryogenic system with superconducting magnets or cavities as well as for the system diagnostics in case of non-steady-state operation, e.g. during cool-down/warm-up or other transients. Proper flowmeter is chosen according to the different parameters, e.g. turn-down, operating temperature range, leak-tightness, pressure losses, long-term stability, etc. For helium cryogenics, the Venturi tube or Orifice, as well as Coriolis flow meters are often applied. For the present time, the orifices are usually used due to their simplicity and low costs, however, low turn-down range, large pressure drop, restriction of flow area, susceptibility to thermoacoustic oscillations limit their useful operation range. Operational characteristics of Venturi tubes is substantially improved in comparison to orifices, however, relative high costs and susceptibility to thermoacoustic oscillations still limit their application to special cases. The Coriolis flow meters do not have typical drawbacks of Venturi tube and orifices, however long-term stability over many years was not demonstrated yet. This paper describes the long-term behaviour of Coriolis flow meters after many years of operation at AMTF and XMTS facilities.

  18. Long-term flow monitoring of submarine gas emanations

    NASA Astrophysics Data System (ADS)

    Spickenbom, K.; Faber, E.; Poggenburg, J.; Seeger, C.

    2009-04-01

    One of the Carbon Capture and Storage (CCS) strategies currently under study is the sequestration of CO2 in sub-seabed geological formations. Even after a thorough review of the geological setting, there is the possibility of leaks from the reservoirs. As part of the EU-financed project CO2ReMoVe (Research, Monitoring, Verification), which aims to develop innovative research and technologies for monitoring and verification of carbon dioxide geological storage, we are working on the development of submarine long-term gas flow monitoring systems. Technically, however, these systems are not limited to CO2 but can be used for monitoring of any free gas emission (bubbles) on the seafloor. The basic design of the gas flow sensor system was derived from former prototypes developed for monitoring CO2 and CH4 on mud volcanoes in Azerbaijan. This design was composed of a raft floating on the surface above the gas vent to collect the bubbles. Sensors for CO2 flux and concentration and electronics for data storage and transmission were mounted on the raft, together with battery-buffered solar panels for power supply. The system was modified for installation in open sea by using a buoy instead of a raft and a funnel on the seafloor to collect the gas, which is then guided above water level through a flexible tube. Besides some technical problems (condensed water in the tube, movement of the buoys due to waves leading to biased measurement of flow rates), this setup provides a cost-effective solution for shallow waters. However, a buoy interferes with ship traffic, and it is also difficult to adapt this design to greater water depths. These requirements can best be complied by a completely submersed system. To allow unattended long-term monitoring in a submarine environment, such a system has to be extremely durable. Therefore, we focussed on developing a mechanically and electrically as simple setup as possible, which has the additional advantage of low cost. The system

  19. Evaluation of the Long-Term Performance of Titanate Ceramics for Immobilization of Excess Weapons Plutonium: Results from Pressurized Unsaturated Flow and Single Pass Flow-Through Testing

    SciTech Connect

    BP McGrail; HT Schaef; JP Icenhower; PF Martin; RD Orr; VL Legore

    1999-09-13

    This report summarizes our findings from pressurized unsaturated flow (PUF) and single-pass flow-through (SPFT) experiments to date. Results from the PUF test of a Pu-bearing ceramic with enclosing surrogate high-level waste glass show that the glass reacts rapidly to alteration products. Glass reaction causes variations in the solution pH in contact with the ceramic materials. We also document variable concentrations of Pu in solution, primarily in colloidal form, which appear to be related to secular variations in solution composition. The apparent dissolution rate of the ceramic waste form, based on Ba concentrations in the effluent, is estimated at {le} 10{sup {minus}5} g/(m{sup 2} {center_dot} d). Pu-bearing colloids were recovered in the size range of 0.2 to 2 {micro}m, but it is not clear that such entities would be transported in a system that is not advective-flow dominated. Results from SPFT experiments give information on the corrosion resistance of two surrogate Pu-ceramics (Ce-pyrochlore and Ce-zirconolite) at 90 C over a pH range of 2 to 12. The two ceramics were doped with minor quantities ({approximately}0.1 mass%) of MoO{sub 3}, so that concentrations of Mo in the effluent solution could be used to monitor the reaction behavior of the materials. The data obtained thus far from experiments with durations up to 150 d do not conclusively prove that the solid-aqueous solution systems have reached steady-state conditions. Therefore, the dissolution mechanism cannot be determined. Apparent dissolution rates of the two ceramic materials based on Ce, Gd, and Mo concentrations in the effluent solutions from the SPFT are nearly identical and vary between 1.1 to 8.5 x 10{sup {minus}4} g/(m{sup 2} {center_dot} d). In addition, the data reveal a slightly amphoteric dissolution behavior, with a minimum apparent rate at pH = 7 to 8, over the pH range examined. Results from two related ceramic samples suggest that radiation damage can have a measurable effect on

  20. Long-term stability test of a triple GEM detector

    NASA Astrophysics Data System (ADS)

    Adak, R. P.; Biswas, S.; Das, S.; Ghosal, D.; Ghosh, S. K.; Mondal, A.; Nag, D.; Nayak, T. K.; Patra, R. N.; Prasad, S. K.; Raha, S.; Sahu, P. K.; Sahu, S.; Swain, S.

    2016-10-01

    The main aim of the study is to perform the long-term stability test of gain of the single mask triple GEM detector. A simple method is used for this long-term stability test using a radioactive X-ray source with high activity. The test is continued till accumulation of charge per unit area > 12.0 mC/mm2. The details of the chamber fabrication, the test set-up, the method of measurement and the test results are presented in this paper.

  1. Long-term module testing at Wyle Laboratories

    NASA Technical Reports Server (NTRS)

    Otth, D. H.

    1986-01-01

    Results are presented for a current set of accelerated long-term endurance tests on crystalline silicon module of various constructions. Cell materials include single crystal, semicrystal, EFG ribbon, and dendritic web ribbon. The latest data set is for the equivalent of 20-year life and showed satisfactory performance.

  2. Long-term operational testing of quantum cascade lasers

    NASA Astrophysics Data System (ADS)

    Myers, Tanya L.; Cannon, Bret D.; Brauer, Carolyn S.; Phillips, Mark C.; Taubman, Matthew S.; Bernacki, Bruce E.

    2016-05-01

    In this paper, we present the results of long-term operational testing of several quantum cascade laser (QCL) variants to illustrate their robustness and long lifetimes. Performance factors are investigated including power and spectral stability over different timescales ranging from days to years. The effects of burn-in, packaging, mounting, and facet coatings are considered with respect to their influence on long-term laser performance. In addition, the results from the several years' operation of a custom external cavity quantum cascade laser-based trace gas sensor are presented to highlight the reliable performance of QCL-based sensor systems. This sensor monitored the laboratory air for multiple chemicals and operated continuously for two years without any evidence of degradation in performance. The data from all of these experiments will be discussed to demonstrate the reliability and robust performance of QCLs.

  3. Group sequential tests for long-term survival comparisons.

    PubMed

    Logan, Brent R; Mo, Shuyuan

    2015-04-01

    Sometimes in clinical trials, the hazard rates are anticipated to be nonproportional, resulting in potentially crossing survival curves. In these cases, researchers are usually interested in which treatment has better long-term survival. The log-rank test and the weighted log-rank test may not be appropriate or efficient to use here, because they are sensitive to differences in survival at any time and don't just focus on long-term outcomes. Also in a prospective clinical trial, patients are entered sequentially over calendar time, so that group sequential designs may be considered for ethical, administrative and economic concerns. Here we develop group sequential methods for testing the null hypothesis that the survival curves are identical after a prespecified time point. Several classes of tests are considered, including an integrated difference in survival probabilities after this time point, and linear or quadratic combinations of two component test statistics (pointwise comparisons of survival at the time point and comparisons of hazard rates after the time point). We examine the type I errors, stopping probabilities, and powers of these tests through simulation studies under the null and different alternatives, and we apply them to a real bone marrow transplant clinical trial.

  4. Multiphase pumping: The lessons of long-term field testing

    SciTech Connect

    Elf-Aquitaine, E.L.; Taiani, S.

    1995-12-31

    The field testing of a POSEIDON rotodynamic helicoaxial pump (P302) manufactured by SULZER is being conducted since June 1994 on the Elf Aquitaine`s onshore site of the PECORADE oil field located in the south-west of France. This one-year testing program is aimed at qualifying this design of multiphase pump for future field applications. The multiphase pump has been previously tested at the IFP`s test loop of SOLAIZE for factory acceptance and performance test. This paper describes the PECORADE multiphase loop, the multiphase pump testing procedures and the results obtained in the field of performance, sensitivity, and endurance. The operational and maintenance lessons to be learned from this long-term field testing are presented from the point of view of the operator.

  5. The Long-Term Inflow and Structural Test Program

    SciTech Connect

    SUTHERLAND,HERBERT J; JONES,PERRY L.; NEAL,BYRON A.

    2000-10-17

    The Long-term Inflow and Structural Test (LIST) program is collecting long-term, continuous inflow and structural response data to characterize the extreme loads on wind turbines. A heavily instrumented Micon 65/13M turbine with SERI 8-m blades is being used as the first test turbine for this test program. This turbine and its two sister turbines are located in Bushland, TX a test site that exposes the turbines to a wind regime that is representative of a Great Plains commercial site. The turbines and their inflow are being characterized with 60 measurements: 34 to characterize the inflow, 19 to characterize structural response, and 7 to characterize the time-varying state of the turbine. The primary characterization of the inflow into the LIST turbine relies upon an array of five sonic anemometers. These three-axis anemometers are placed approximately 2-diameters upstream of the turbine in a pattern designed to describe the inflow. Primary characterization of the structural response of the turbine uses several sets of strain gauges to measure bending loads on the blades and the tower and two accelerometers to measure the motion of the nacelle. Data from the various instruments are sampled at a rate of 30 Hz using a newly developed data acquisition system that features a time-synchronized continuous data stream that is telemetered from the turbine rotor. The data, taken continuously, are automatically divided into 10-minute segments and archived for analysis. Preliminary data are presented to illustrate the operation of the turbine and the data acquisition and analysis system.

  6. Disk oxygen generator with closed flow loop for long-term COIL operation

    NASA Astrophysics Data System (ADS)

    Schreiber, Christian J. M.; Gruenewald, Karin; Handke, Juergen; Duschek, Frank; Schall, Wolfgang O.

    2003-11-01

    A test facility was designed to operate a disk type singlet delta oxygen generator in a closed loop for the flow of basic hydrogen peroxide (BHP). The facility allows the investigations of the influence of operating conditions like BHP flow, gas flow, disk rotation speed, and system components like disk package parameters and type of liquid separator on the generator performance and the ascertainment of the facilities capability for long term COIL operation. The dimension of the generator in the closed flow loop is chosen in accordance with the 10 kW-DLR-COIL.

  7. Genetic testing for Alzheimer's and long-term care insurance.

    PubMed

    Taylor, Donald H; Cook-Deegan, Robert M; Hiraki, Susan; Roberts, J Scott; Blazer, Dan G; Green, Robert C

    2010-01-01

    A genetic marker known as apolipoprotein E provides a clear signal of a person's risk of developing Alzheimer's disease and thus that person's future need for long-term care. People who find that they have the variant of the trait that increases Alzheimer's disease risk are more likely to purchase long-term care insurance after receiving this information. If the information is widely introduced into the insurance market, coverage rates could be affected in different ways, depending on who possesses that information. Policymakers will eventually need to confront the issue of the use of this and other markers in the pricing of long-term care insurance.

  8. Long Term Corrosion/Degradation Test Six Year Results

    SciTech Connect

    M. K. Adler Flitton; C. W. Bishop; M. E. Delwiche; T. S. Yoder

    2004-09-01

    The Subsurface Disposal Area (SDA) of the Radioactive Waste Management Complex (RWMC) located at the Idaho National Engineering and Environmental Laboratory (INEEL) contains neutron-activated metals from non-fuel, nuclear reactor core components. The Long-Term Corrosion/Degradation (LTCD) Test is designed to obtain site-specific corrosion rates to support efforts to more accurately estimate the transfer of activated elements to the environment. The test is using two proven, industry-standard methods—direct corrosion testing using metal coupons, and monitored corrosion testing using electrical/resistance probes—to determine corrosion rates for various metal alloys generally representing the metals of interest buried at the SDA, including Type 304L stainless steel, Type 316L stainless steel, Inconel 718, Beryllium S200F, Aluminum 6061, Zircaloy-4, low-carbon steel, and Ferralium 255. In the direct testing, metal coupons are retrieved for corrosion evaluation after having been buried in SDA backfill soil and exposed to natural SDA environmental conditions for times ranging from one year to as many as 32 years, depending on research needs and funding availability. In the monitored testing, electrical/resistance probes buried in SDA backfill soil will provide corrosion data for the duration of the test or until the probes fail. This report provides an update describing the current status of the test and documents results to date. Data from the one-year and three-year results are also included, for comparison and evaluation of trends. In the six-year results, most metals being tested showed extremely low measurable rates of general corrosion. For Type 304L stainless steel, Type 316L stainless steel, Inconel 718, and Ferralium 255, corrosion rates fell in the range of “no reportable” to 0.0002 mils per year (MPY). Corrosion rates for Zircaloy-4 ranged from no measurable corrosion to 0.0001 MPY. These rates are two orders of magnitude lower than those specified in

  9. Long-Term Recency Is Not Found on a Recognition Test.

    ERIC Educational Resources Information Center

    Glenberg, Arthur M.; Kraus, Thomas A.

    1981-01-01

    The results of this study disconfirm the predictions of the decay hypothesis because long-term recency effects appear to result from the use of contextually based retrieval cues. Long-term recency effects were attenuated on immediate recognition tests, while long-term recency effects were found on free recall tests. (DWH)

  10. Test methods for determining short and long term VOC emissions from latex paint

    SciTech Connect

    Krebs, K.; Lao, H.C.; Fortmann, R.; Tichenor, B.

    1998-09-01

    The paper discusses an evaluation of latex paint (interior, water based) as a source of indoor pollution. A major objective of the research is the development of methods for predicting emissions of volatile organic compounds (VOCs) over time. Test specimens of painted gypsumboard are placed in dynamic flow-through test chambers. Samples of the outlet air are collected on Tenax sorbents and thermally desorbed for analysis by gas chromatography/flame ionization detection. These tests produce short- and long-term data for latex paint emissions of Texanol, 2-2(-butoxyethoxy)-ethanol, and glycols. Evaluation of the data shows that most of the Texanol emissions occur within the first few days, and emissions of the glycols occur over several months. This behavior may be described by an evaporative mass transfer process that dominates the short-term emissions, while long-term emissions are limited by diffusion processes within the dry paint-gypsumboard.

  11. PROTEC TM TEAR-OFFS: RESULTS OF LONG TERM TESTING

    SciTech Connect

    Peeler, D

    2008-07-24

    damage that would result from acid etching, base damage (as a result of a sludge spill or splatter), gamma radiation damage, and/or accidental scratching (due to manipulator/tool contact). Although identified as a potential solution, the Phase 1 testing was relatively short-term with exposure times up to 1-2 months for the acid and gamma radiation tests. Phase 2 testing included longer exposure times for the acid resistance (up to 456 days) and gamma radiation exposure (700 days with a cumulative gamma dose of {approx}3.1 x 10{sup 5} rad) assessments. The tear-off system continued to perform well in these longer-term acid resistance testing and gamma exposure conditions. Complete removal of the tear-offs after these long-term exposure times indicate that not only could visual clarity be restored but the mechanical integrity could be retained. The results also provided insight into the ability of the ProTec tear-off system to withstand the chemical and physical abuses expected in off-normal shielded cells operations. The conceptual erasing of scratches or marks by excessive manipulator abuse was demonstrated in the SRNL Shielded Cells mock-up facility through the removal of the outer layer tear-off with manipulators. In addition, the Phase 2 testing included an in-situ assessment of a prototype tear-off system in the DWPF Sampling Cells where the system was exposed to actual field conditions including radioactive sources, acidic and basic environments, dusting, and chemical cleaning solutions over a 5-6 month period. DWPF personnel were extremely satisfied with the performance (including the successful removal of 3 layers with manipulators) of the ProTec tear-off system under actual field conditions. The successful removal of the outer layer tear-offs with the manipulator, using tabs not specifically designed for remote operations, demonstrates that the system is 'manipulator-friendly' and could be implemented in a remote environment. The ability to remove the outer layer

  12. The inbuilt long-term unfeasibility of environmental flows when disregarding riparian vegetation requirements

    NASA Astrophysics Data System (ADS)

    Rivaes, R.; Boavida, I.; Santos, J. M.; Pinheiro, A. N.; Ferreira, M. T.

    2015-10-01

    Environmental flows remain biased towards the traditional fish biological group and ignore the inter-annual flow variability that rules longer species life cycles, thus disregarding the long-term perspective of the riverine ecosystem. Incorporating riparian vegetation requirements into environmental flows could bring an important contribute to fill in this gap. The long-term after-effects of this shortcoming on the biological communities downstream of dams were never estimated before. We address this concern by evaluating the effects of environmental flow regimes disregarding riparian vegetation in the long-term perspective of the fluvial ecosystem. To achieve that purpose, the riparian vegetation evolution was modeled considering its structural response to a decade of different environmental flows, and the fish habitat availability was assessed for each of the resulting riparian habitat scenarios. We demonstrate that fish habitat availability changes accordingly to the long-term structural adjustments that riparian habitat endure following river regulation. Environmental flow regimes considering only aquatic biota become obsolete in few years due to the change of the habitat premises in which they were based on and, therefore, are unsustainable in the long run. Therefore, considering riparian vegetation requirements on environmental flows is mandatory to assure the effectiveness of those in the long-term perspective of the fluvial ecosystem.

  13. Long-term Monitoring Plan for the Central Nevada Test Area

    SciTech Connect

    A. Hassan

    2003-09-02

    The groundwater flow and transport model of the Faultless underground nuclear test conducted at the Central Nevada Test Area (CNTA) was accepted by the state regulator and the environmental remediation efforts at the site have progressed to the stages of model validation and long-term monitoring design. This report discusses the long-term monitoring strategy developed for CNTA. Subsurface monitoring is an expensive and time-consuming process, and the design approach should be based on a solid foundation. As such, a thorough literature review of monitoring network design is first presented. Monitoring well networks can be designed for a number of objectives including aquifer characterization, parameter estimation, compliance monitoring, detection monitoring, ambient monitoring, and research monitoring, to name a few. Design methodologies also range from simple hydrogeologic intuition-based tools to sophisticated statistical- and optimization-based tools. When designing the long-term monitoring well network for CNTA, a number of issues are carefully considered. These are the uncertainty associated with the subsurface environment and its implication for monitoring design, the cost associated with monitoring well installation and operation, the design criteria that should be used to select well locations, and the potential conflict between different objectives such as early detection versus impracticality of placing wells in the vicinity of the test cavity. Given these considerations and the literature review of monitoring design studies, a multi-staged approach for development of the long-term monitoring well network for CNTA is proposed. This multi-staged approach will proceed in parallel with the validation efforts for the groundwater flow and transport model of CNTA. Two main stages are identified as necessary for the development of the final long-term monitoring well network for the site. The first stage is to use hydrogeologic expertise combined with model

  14. Long-Term Reliability of the Wonderlic Personnel Test.

    ERIC Educational Resources Information Center

    Dodrill, Carl B.

    1983-01-01

    Compared the Wonderlic Personal Test and the Wechsler Adult Intelligence Scale for a sample of 30 adults first tested in 1976. The two tests were similar in reliability of clinical classification, but the Wonderlic demonstrated fewer practice effects. Despite its ease of administration, Wonderlic intelligence estimates appear stable. (Author/JAC)

  15. Long-Term Durability of Pressure-Treated Wood in a Severe Test Site

    Treesearch

    Stan Lebow; Bessie Woodward; Grant Kirker; Patricia Lebow

    2013-01-01

    Improved estimates of the long-term durability of treated wood products are needed to guide choices about construction materials and allow estimates of design life. This report summarizes the long-term decay and insect resistance of treated wood post and lumber specimens placed in ground contact at a test site of the U.S. Department of Agriculture, Forest Service,...

  16. Operational summary of an electric propulsion long term test facility

    NASA Technical Reports Server (NTRS)

    Trump, G. E.; James, E. L.; Bechtel, R. T.

    1982-01-01

    An automated test facility capable of simultaneously operating three 2.5 kW, 30-cm mercury ion thrusters and their power processors is described, along with a test program conducted for the documentation of thruster characteristics as a function of time. Facility controls are analog, with full redundancy, so that in the event of malfunction the facility automaticcally activates a backup mode and notifies an operator. Test data are recorded by a central data collection system and processed as daily averages. The facility has operated continuously for a period of 37 months, over which nine mercury ion thrusters and four power processor units accumulated a total of over 14,500 hours of thruster operating time.

  17. Operational summary of an electric propulsion long term test facility

    NASA Technical Reports Server (NTRS)

    Trump, G. E.; James, E. L.; Bechtel, R. T.

    1982-01-01

    An automated test facility capable of simultaneously operating three 2.5 kW, 30-cm mercury ion thrusters and their power processors is described, along with a test program conducted for the documentation of thruster characteristics as a function of time. Facility controls are analog, with full redundancy, so that in the event of malfunction the facility automaticcally activates a backup mode and notifies an operator. Test data are recorded by a central data collection system and processed as daily averages. The facility has operated continuously for a period of 37 months, over which nine mercury ion thrusters and four power processor units accumulated a total of over 14,500 hours of thruster operating time.

  18. Water flows of MSW landfills and implications for long-term emissions.

    PubMed

    Huber, Renate; Fellner, Johann; Doeberl, Gernot; Brunner, Paul H

    2004-01-01

    A test landfill served for experiments to describe the water and material household of municipal solid waste (MSW) landfills. Special emphasis was given to the determination of the influence of the water flow on the substance balance. Therefore, a water balance was measured and the discharge was modeled by means of a mathematical model. A model, which separates the landfill into an area of preferential flow and an area of matrix flow fits best water flow data measured from 1987 to 1989 in the Breitenau landfill of 95,000 t MSW. This test landfill consists of three compartments C1, C2 and C3 with different covering systems. Leachate amount was highest in C1 with a permeable cover of silt and gravel. The lowest amount of leachate was found in C3 with a less permeable cover of gravel, humus, and plants. The values for C2 lie in between. An input-output balance for the substances C, N, S, P, Cl, Na, Ca, Fe, Zn, Pb, Cd and Cu was prepared. Contrary to the expectations the output of some substances was higher for C2 than for C1 with more leachate. Possibly a higher flow rate leads to preferential water flows that contact only small parts of the landfill body while most part of the landfill stays more or less dry. The substance balance reveals that most of the substances still remain in the landfill after 15 years of leaching. Hence, focusing on leachate concentrations only results in underestimating the after-care period of MSW landfills. Leachate concentrations reflect just a small part of a landfill. Understanding water flows and measuring substance balances improve considerably the assessment of the long-term emission potentials of landfills.

  19. Long term testing of peanut oil in engines

    SciTech Connect

    Goodrum, J.W.

    1985-01-01

    Durability tests of engines using crude peanut oil blended with no. 2 diesel were conducted, using the E.M.A. screening procedure. Direct and indirect injection designs were operated on 20:80 and 80:28 fuel blends. Time-dependent exhaust temperature changes, mechanical wear, and crank-case oil viscosity changes were evaluated.

  20. Long Term Outdoor Testing of Low Concentration Solar Modules

    NASA Astrophysics Data System (ADS)

    Fraas, Lewis; Avery, James; Minkin, Leonid; Huang, H. X.; Hebrink, Tim; Hurt, Rik; Boehm, Robert

    2011-12-01

    A 1-axis carousel tracker equipped with four 3-sun low-concentration mirror modules has now been under test outdoors at the University of Nevada in Las Vegas (UNLV) for three years. There are three unique features associated with this unit. First, simple linear mirrors are used to reduce the amount of expensive single crystal silicon in order to potentially lower the module cost while potentially maintaining cell efficiencies over 20% and high module efficiency. Simple linear mirrors also allow the use of a single axis tracker. Second, the azimuth carousel tracker is also unique allowing trackers to be used on commercial building rooftops. Third, an experiment is underway comparing aluminum based mirrors with novel 3M Company multilayer polymeric mirrors which are potentially very low cost. Comparing the data from March of 2008 through March of 2011 shows that the aluminum mirror degradation to date is negligible and that the carousel tracker has been operating continuously and reliable. Also, no degradation has been observed for the 3M brand cool mirrors after one year in use.

  1. Testing the long term stability of vancomycin ophthalmic solution.

    PubMed

    McLellan, Christine; Ngo, Van; Pasedis, Sophia; Dohlman, Claes H

    2008-01-01

    Some patients with a keratoprosthesis (artificial cornea) are required to use prophylactic vancomycin ophthalmic solution daily for life to prevent infection, a regimen which has proven to be highly successful. The objective of this study was to determine whether such vancomycin solutions would remain stable at room temperature for an extended period of time, beyond that suggested by available published stability data and used in current practice. By relaxing the storage requirement and extending the expiration date of this solution, it was hoped that patient adherence and satisfaction would increase. The studied vancomycin ophthalmic solutions were compounded at the Massachusetts Eye and Ear Infirmary, Department of Pharmacy Services, Boston, Massachusetts, and were sent to an outside laboratory for high-performance liquid chromatography potency testing at predefined time points. Vancomycin 14-mg/mL ophthalmic solution compounded with 0.005% benzalkonium retains potency for at least 60 days at room temperature and 6 months frozen. Extending the beyond-use dating of vancomycin may lead to improved patient adherence by lowering costs and increasing convenience of storage and shipment of the medication.

  2. Environmental Flows: Evaluating Long-Term Baselines for Hydrological Regime Change in the Southern United States

    NASA Astrophysics Data System (ADS)

    Deines, A. M.; Morrison, A. M.; Menzie, C.

    2016-12-01

    The wide variety of ecosystem services associated with running fresh waters are dependent on an assortment of flow conditions including timing and duration of seasonal floods as well as intermittent flows, such as storm peaks. Modern methods of assessing environmental flows consider hydrological regime change by comparing actual or simulated baseline flow conditions against putatively altered regime flows. These calculated flow changes are used as inputs to models of ecosystem responses such as for fish populations, inundated habitat area, or nutrient supplies. However, common and recommended tools and software used to make flow comparisons between putative regimes lack robust mechanisms for evaluating the significance of hydrological regime change in the context of long-term (multiple decades, centuries, or greater) trends, such as climatic conditions, or the facility to determine the existence and causes of regime changes when no obvious discontinuity exists, such as the construction of a dam. As such, environmental flow decisions based on short (recent) baseline records or baseline records assumed to represent stable hydrological conditions may lead to inefficient water use and ecosystem services distribution. Here we examine long-term patterns in discharge, the frequency and severity of regional droughts, and the Atlantic Multidecadal Oscillation to better understand the occurrence and causes of hydrological regime change in rivers in the Southern United States. For each river we ask: 1) Has hydrological regime change occurred? 2) To what degree is observed regime change associated with regional climatic drivers? 3) How might environmental flows suggested by current methods (e.g. the USGS Hydroecological Integrity Assessment or the Indicators of Hydrologic Alteration software) compare with flows derived by additional consideration of long-term drivers of hydrological change? We discuss the different temporal scales through which climate can influence a

  3. The value of long-term monitoring in the development of ground-water-flow models

    USGS Publications Warehouse

    Feinstein, Daniel T.; Hart, David J.; Krohelski, James T.

    2004-01-01

    As environmental issues have come to the forefront of public concern, so has the awareness of the importance of ground water in the overall water cycle and as a source of the Nation’s drinking water. Heightened interest has spawned a host of scientific enterprises (Taylor and Alley, 2001). Some activities are directed toward collection of water-level data and related information to monitor the physical and chemical state of the resource. Other activities are directed at interpretive studies undertaken, for example, to optimize the location of new water-supply wells or to protect rivers and lakes fed by ground water. An important type of interpretive study is the computer ground-water-flow model that inte- grates field data in a mathematical framework. Long-term, systematic collection of hydro- logic data is crucial to the construction and testing of ground-water models so that they can reproduce the evolution of flow systems and forecast future conditions. 

  4. Interlaminar shear test method development for long term durability testing of composites

    NASA Technical Reports Server (NTRS)

    Ifju, Peter G.

    1994-01-01

    The high speed civil transport is a commercial aircraft that is expected to carry 300 passengers at Mach 2.4 over a range of more than 6000 nautical miles. With the existing commercial structural material technology (i.e., aluminum) the performance characteristics of the high speed civil transport would not be realized. Therefore there has been a concerted effort in the development of light weight materials capable of withstanding elevated temperatures for long duration. Thermoplastic composite materials are such candidate materials and the understanding of how these materials perform over the long term under harsh environments is essential to safe and effective design. The matrix dominated properties of thermoplastic composites are most affected by both time and temperature. There is currently an effort to perform short term testing to predict long term behavior of in-plane mechanical properties E22 (transverse modulus of elasticity) and G12 (shear modulus). Out-of-plane properties such as E33, G13, and G23 are inherently more difficult to characterize. This is especially true for the out-of-plane shear modulus G23 and hence there is no existing acceptable standard test method. Since G23 is the most matrix dominated property, it is essential that a test method be developed. A shear test methodology is developed to do just that. The test method, called the double notched specimen, along with the previously developed shear gage was tested at room temperature. Mechanical testing confirmed the attributes of the methodology. A finite element parametric study was conducted for specimen optimization. Moire interferometry, a high sensitivity laser optical method, was used for full-field analysis of the specimen. From this work, material parameters will be determined and thus enable the prediction of long term material behavior of laminates subjected to general loading states.

  5. Cerebral blood flow velocity positively correlates with brain volumes in long-term remitted depression.

    PubMed

    Desmidt, Thomas; Andersson, Frédéric; Brizard, Bruno; Cottier, Jean-Philippe; Patat, Frédéric; Gissot, Valérie; Belzung, Catherine; El-Hage, Wissam; Camus, Vincent

    2017-09-20

    Mechanisms involved in brain changes observed in major depression have been poorly investigated in clinical populations. Changes in cerebral blood flow (CBF) have been found in depressed patients and constitute a potential mechanism by which brain volume varies in depression. We have tested the association of cerebral blood flow velocity (CBFV) as assessed with Transcranial Doppler (TCD) and cerebral blood flow (CBF) as assessed with Arterial Spin Labeling Magnetic Resonance Imaging (ASL-MRI) with Total Brain Volume (TBV) and the volume of seven subcortical regions, in currently depressed and long-term remitted patients. In addition, we have evaluated other potential confounders for the association depression/brain volume, including dimensional symptoms of depression, cardiovascular risk factors (CVRF) and antidepressants. Seventy-five individuals were recruited, divided in 3 equal groups (currently depressed, remitted individuals and healthy controls) and were submitted to clinical assessment, MRI and Transcranial Doppler. CBFV was positively correlated with TBV, Hippocampus and Thalamus volume, but only in remitted patients, who tend to have larger brains compared to both currently depressed and controls. CVRF were negatively associated with brain volumes in the 3 groups and antidepressant use was associated with larger Thalamus. We found no association between brain volumes and CBF as assessed with ASL-MRI, anhedonia, anxiety or psychomotor retardation. Greater CBFV may be a physiological mechanism by which brain is enlarged in remitted patients. Future studies should consider CBFV, CVRF and antidepressants as possible confounders for the association depression/brain volumes, especially in remitted patients. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Long-term performance of landfill covers - results of lysimeter test fields in Bavaria (Germany).

    PubMed

    Henken-Mellies, Wolf-Ulrich; Schweizer, Andreas

    2011-01-01

    A comprehensive study was conducted to examine the performance and possible changes in the effectiveness of landfill surface covers. Three different profiles of mineral landfill caps were examined. The results of precipitation and flow measurements show distinct seasonal differences which are typical for middle-European climatic conditions. In the case of the simple landfill cap design consisting of a thick layer of loamy sand, approximately 100-200 L m(-2) of annual seepage into the landfill body occurs during winter season. The three-layer systems of the two other test fields performed much better. Most of the water which percolated through the top soil profile drained sideways in the drainage layer. Only 1-3% of precipitation percolated through the sealing layer. The long-term effectiveness of the mineral sealing layer depended on the ability of the top soil layer to protect it from critical loss of soil water/critical increase of suction. In dry summers there was even a loss in soil water content at the base of the 2.0 m thick soil cover. The results of this study demonstrate the importance of the long-term aspect when assessing the effectiveness of landfill covers: The hydraulic conductivity at the time of construction gives only an initial (minimum) value. The hydraulic conductivity of the compacted clay layer or of the geosynthetic clay liner may increase substantially, if there is no long-lasting protection against desiccation (by a thick soil cover or by a geomembrane). This has to be taken into account in landfill cover design.

  7. Long-term Monitoring Plan for the Central Nevada Test Area

    SciTech Connect

    Hassan, Ahmed E.

    2003-09-01

    This report discusses the long-term monitoring strategy developed for the Central Nevada Test Area (CNTA), where the Faultless underground nuclear test was conducted. It includes a thorough literature review of monitoring well network design. A multi-staged approach for development of the long-term monitoring well network for CNTA is proposed, incorporating a number of issues, including uncertainty of the subsurface environment, cost, selection of well locations, etc. The first stage is to use hydrogeologic expertise combined with model simulations and probability based approaches to select the first set of monitoring wells. The second stage will be based on an optimum design methodology that uses a suitable statistical approach, combined with an optimization approach, to augment the initial set of wells and develop the final long-term monitoring network.

  8. A zero-flow microfluidics for long-term cell culture and detection

    NASA Astrophysics Data System (ADS)

    Sang, Shengbo; Tang, Xiaoliang; Feng, Qiliang; Jian, Aoqun; Zhang, Wendong

    2015-04-01

    A zero-flow microfluidic design is proposed in this paper, which can be used for long-term cell culture and detection, especially for a lab-on-chip integrated with a biosensor. It consists of two parts: a main microchannel; and a circle microchamber. The Finite Element Method (FEM) was employed to predict the fluid transport properties for a minimum fluid flow disturbance. Some commonly used microfluidic structures were also analysed systematically to prove the designed structure. Then the designed microfluidics was fabricated. Based on the simulations and experiments, this design provides a continuous flow environment, with a relatively stable and low shear stress atmosphere, similar to a zero-flow environment. Furthermore, the nutrients maintaining cells' normal growth can be taken into the chamber through the diffusion effect. It also proves that the microfluidics can realize long-term cell culture and detection. The application of the structure in the field of biological microelectromechenical systems (BioMEMS) will provide a research foundation for microfluidic technology.

  9. Role of debris flows in long-term landscape denudation in the central Appalachians of Virginia

    USGS Publications Warehouse

    Eaton, L.S.; Morgan, B.A.; Kochel, R.C.; Howard, A.D.

    2003-01-01

    Four major storms that triggered debris flows in the Virginia-West Virginia Appalachians provide new insights into the role of high-magnitude, low-frequency floods in long-term denudation and landscape evolution in mountainous terrain. Storm denudation in the Blue Ridge Mountain drainage basins in approximately an order of magnitude greater compared to basins located in the mountains of the Valley and Ridge province. This difference is probably the result of higher storm rainfall from the Blue Ridge storms. Radiocarbon dating of debris-flow deposits in the Blue Ridge indicates a debris-flow return interval of not more than 2-4 k.y, in mountainous river basins. This finding, combined with measurements of basin denudation, suggests that approximately half of the long-term denudation from mechanical load occurs episodically by debris-flow processes. Although floods of moderate magnitude are largely responsible for mobilizing sediment in low-gradient streams, our data suggest that high-magnitude, low-frequency events are the most significant component in delivering coarse-grained regolith from mountainous hollows and channels to the lowland floodplains.

  10. Ethical aspects of a predictive test for Huntington's Disease: A long term perspective.

    PubMed

    Andersson, Petra Lilja; Petersén, Åsa; Graff, Caroline; Edberg, Anna-Karin

    2016-08-01

    A predictive genetic test for Huntington's disease can be used before any symptoms are apparent, but there is only sparse knowledge about the long-term consequences of a positive test result. Such knowledge is important in order to gain a deeper understanding of families' experiences. The aim of the study was to describe a young couple's long-term experiences and the consequences of a predictive test for Huntington's disease. A descriptive case study design was used with a longitudinal narrative life history approach. The study was based on 18 interviews with a young couple, covering a period of 2.5 years; starting 6 months after the disclosure of the test results showing the woman to be a carrier of the gene causing Huntington's disease. Even though the study was extremely sensitive, where potential harm constantly had to be balanced against the benefits, the couple had a strong wish to contribute to increased knowledge about people in their situation. The study was approved by the ethics committee. The results show that the long-term consequences were devastating for the family. This 3-year period was characterized by anxiety, repeated suicide attempts, financial difficulties and eventually divorce. By offering a predictive test, the healthcare system has an ethical and moral responsibility. Once the test result is disclosed, the individual and the family cannot live without the knowledge it brings. Support is needed in a long-term perspective and should involve counselling concerning the families' everyday life involving important decision-making, reorientation towards a new outlook of the future and the meaning of life. As health professionals, our ethical and moral responsibility thus embraces not only the phase in direct connection to the actual genetic test but also a commitment to provide support to help the family deal with the long-term consequences of the test. © The Author(s) 2015.

  11. Donor Selection in Flow Replacement Bypass Surgery for Cerebral Aneurysms: Quantitative Analysis of Long-term Native Donor Flow Sufficiency.

    PubMed

    Rustemi, Oriela; Amin-Hanjani, Sepideh; Shakur, Sophia F; Du, Xinjian; Charbel, Fady T

    2016-03-01

    Graft selection in extracranial-intracranial bypass surgery for cerebral aneurysms has traditionally been based on clinical impression and operator preference. However, decision making can be optimized with a donor selection algorithm based on intraoperative flow data. To present long-term follow-up and quantitative assessment of flow sufficiency for native donors selected in this manner. Patients with bypass for anterior circulation intracranial aneurysms using only a native donor (superficial temporal artery) selected on the basis of an intraoperative flow algorithm over a 10-year period were retrospectively studied. Intracranial hemispheric and bypass flows were assessed preoperatively and postoperatively when available with quantitative magnetic resonance angiography. Twenty-two patients with flow data were included (median aneurysm size, 22 mm). The intraoperative flow offer (cut flow) of the superficial temporal artery was sufficient in these cases relative to the flow demand in the sacrificed vessel (59 vs 28 mL/min) to warrant its use. Bypass flow averaged 81 mL/min postoperatively (n = 19). Bypass flows were highest in the immediate postoperative period but remained stable between the intermediate and final follow-up (40 vs 52 mL/min; P = .39; n = 8). Mean ipsilateral hemisphere flows were maintained after bypass (299 vs 335 mL/min; P = .42; n = 7), and remained stable over intermediate and long-term follow-up. Ipsilateral hemispheric flows remained similar to contralateral flows at all time points. Despite a relative reduction in bypass flow over time, hemispheric flows were maintained, indicating that simple native donors can carry sufficient flow for territory demand long term when an intraoperative flow-based algorithm is used for donor selection.

  12. The Effect of Repeated Testing on Long Term Retention and Generalization in a General Psychology Course.

    ERIC Educational Resources Information Center

    Gosser, Jon; And Others

    A study involving four sections of a general psychology course at Delta College (Michigan) was conducted to determine: (1) the effectiveness of repeated, cumulative testing on long-term retention of information; (2) its effect on students' ability to generalize information learned as measured by the College Level Examination Program (CLEP) general…

  13. Microvascular Angina - Long-Term Exercise Stress Test Follow-up.

    PubMed

    Lanza, Gaetano A; Filice, Monica; De Vita, Antonio; Villano, Angelo; Manfredonia, Laura; Lamendola, Priscilla; Crea, Filippo

    2017-09-09

    A sizeable proportion of patients with primary stable microvascular angina (MVA; exercise-induced angina, positive exercise stress test [EST], normal coronary arteries) have recurrent symptoms during follow-up. There have been no previous studies, however, on the long-term results of EST and their correlation with symptom outcome.Methods and Results:Follow-up EST was performed in 71 MVA patients at an average of 16.2 years (range, 5-25 years) from the first EST. Angina status was assessed on weekly frequency of angina episodes and nitroglycerin consumption and by whether symptoms had worsened, improved, or remained unchanged over time. At follow-up EST, 41 patients (group 1) had exercise-induced ischemia, whereas 30 patients (group 2) had negative EST. Compared to group 2, group 1 patients more frequently had exercise-induced dyspnea, and had a greater maximum ST-segment depression and a lower coronary blood flow response to adenosine and cold pressor test, but group 2 patients had a more frequent history of rest angina. No differences between the 2 groups were found at follow-up in angina status or change in symptom status during follow-up. Electrocardiogram results improve significantly in a sizeable proportion of patients with MVA. Changes in EST results, however, were not associated with clinical outcome.

  14. Providing Extrinsic Reward for Test Performance Undermines Long-Term Memory Acquisition.

    PubMed

    Kuhbandner, Christof; Aslan, Alp; Emmerdinger, Kathrin; Murayama, Kou

    2016-01-01

    Based on numerous studies showing that testing studied material can improve long-term retention more than restudying the same material, it is often suggested that the number of tests in education should be increased to enhance knowledge acquisition. However, testing in real-life educational settings often entails a high degree of extrinsic motivation of learners due to the common practice of placing important consequences on the outcome of a test. Such an effect on the motivation of learners may undermine the beneficial effects of testing on long-term memory because it has been shown that extrinsic motivation can reduce the quality of learning. To examine this issue, participants learned foreign language vocabulary words, followed by an immediate test in which one-third of the words were tested and one-third restudied. To manipulate extrinsic motivation during immediate testing, participants received either monetary reward contingent on test performance or no reward. After 1 week, memory for all words was tested. In the immediate test, reward reduced correct recall and increased commission errors, indicating that reward reduced the number of items that can benefit from successful retrieval. The results in the delayed test revealed that reward additionally reduced the gain received from successful retrieval because memory for initially successfully retrieved words was lower in the reward condition. However, testing was still more effective than restudying under reward conditions because reward undermined long-term memory for concurrently restudied material as well. These findings indicate that providing performance-contingent reward in a test can undermine long-term knowledge acquisition.

  15. Providing Extrinsic Reward for Test Performance Undermines Long-Term Memory Acquisition

    PubMed Central

    Kuhbandner, Christof; Aslan, Alp; Emmerdinger, Kathrin; Murayama, Kou

    2016-01-01

    Based on numerous studies showing that testing studied material can improve long-term retention more than restudying the same material, it is often suggested that the number of tests in education should be increased to enhance knowledge acquisition. However, testing in real-life educational settings often entails a high degree of extrinsic motivation of learners due to the common practice of placing important consequences on the outcome of a test. Such an effect on the motivation of learners may undermine the beneficial effects of testing on long-term memory because it has been shown that extrinsic motivation can reduce the quality of learning. To examine this issue, participants learned foreign language vocabulary words, followed by an immediate test in which one-third of the words were tested and one-third restudied. To manipulate extrinsic motivation during immediate testing, participants received either monetary reward contingent on test performance or no reward. After 1 week, memory for all words was tested. In the immediate test, reward reduced correct recall and increased commission errors, indicating that reward reduced the number of items that can benefit from successful retrieval. The results in the delayed test revealed that reward additionally reduced the gain received from successful retrieval because memory for initially successfully retrieved words was lower in the reward condition. However, testing was still more effective than restudying under reward conditions because reward undermined long-term memory for concurrently restudied material as well. These findings indicate that providing performance–contingent reward in a test can undermine long-term knowledge acquisition. PMID:26869978

  16. Effect of the Long-Term Warming Since the Last Glacial Maximum on Terrestrial Heat Flow

    NASA Astrophysics Data System (ADS)

    Huang, S.; Duan, W.; Wang, H.

    2013-12-01

    Terrestrial heat flow is a geophysical parameter enumerating the outward energy flux from the interior of Earth. It is conventionally measured in boreholes as the product of thermal conductivity of rocks and geothermal gradient, which is subject to the influence from the variations in ground surface temperature condition. As such, on the one hand variation of heat flow density with depth is a direct temperature record of paleoclimate change; on the other hand ground surface temperature history imposes transient perturbation on a heat flow measurement. The assessment of the paleoclimate effect on a heat flow measurement requires a good understanding of the paleoclimate history. In this study, we evaluate the transient effect of the long-term warming since the last glacial maximum on the continental heat flow with both forward and inversion approaches. With the forward approach, we calculate the subsurface temperature response to climate change based on the latest reconstruction of the last 30,000 year paleoclimate history. We then translate the thermal response to the perturbation to a heat flow measurement. With the inversion approach, we use a set of 6,144 qualified data selected from more than 13,000 reported continental heat flow measurements to synthesize a global profile of heat flow versus depth. We then invert this synthesized profile for a paleoclimate history and a steady-state heat flow profile. Our result shows that continental heat flow measurements within the depths down to around 2000 m are systematically lower than the steady state heat flow because of the effect of the last deglacial warming. If this transient perturbation is leaved uncorrected, the mean continental heat flow could be underestimated by as much as twenty percents. This study is supported by the NSF Grant 1202673 and Grant SKLLQG1201 of the Institute of Earth Environment, Chinese Academy of Sciences.

  17. Groundwater flow patterns adjacent to a long-term stratified (meromictic) lake

    NASA Astrophysics Data System (ADS)

    Oz, I.; Shalev, E.; Gvirtzman, H.; Yechieli, Y.; Gavrieli, I.

    2011-08-01

    This paper examines, for the first time, the unique situation of a groundwater system adjacent to a long-term stratified (meromictic) lake. Using conceptual and numerical models, the configuration of groundwater interfaces between the three different water bodies (regional groundwater and upper and lower lake waters) and the flow patterns were quantitatively evaluated assuming a homogenous aquifer. A complex flow system, controlled by density difference, is created near the lake, where three circulation cells are developed. These results are different from the classic circulation cell that is found adjacent to nonstratified water bodies (lakes or oceans). Sensitivity analyses reveal that the results are sensitive to changes in thickness and density of the upper water mass of the lake. The Dead Sea, under its possible future meromictic conditions, serves as an ideal example of such a system. Thus, the model's results can be used as a preliminary assessment for groundwater behavior adjacent to the lake, if and when stratification will develop.

  18. Long-Term Degradation Testing of High-Temperature Electrolytic Cells

    SciTech Connect

    C.M. Stoots; J.E. O'Brien; J.S. Herring; G.K. Housley; D.G. Milobar; M.S. Sohal

    2009-08-01

    The Idaho National Laboratory (INL) has been researching the application of solid-oxide electrolysis cell for large-scale hydrogen production from steam over a temperature range of 800 to 900ºC. The INL has been testing various solid oxide cell designs to characterize their electrolytic performance operating in the electrolysis mode for hydrogen production. Some results presented in this report were obtained from cells, with an active area of 16 cm2 per cell. The electrolysis cells are electrode-supported, with ~10 µm thick yttria-stabilized zirconia (YSZ) electrolytes, ~1400 µm thick nickel-YSZ steam-hydrogen electrodes, and manganite (LSM) air-oxygen electrodes. The experiments were performed over a range of steam inlet mole fractions (0.1 to 0.6), gas flow rates, and current densities (0 to 0.6 A/cm2). Steam consumption rates associated with electrolysis were measured directly using inlet and outlet dewpoint instrumentation. On a molar basis, the steam consumption rate is equal to the hydrogen production rate. Cell performance was evaluated by performing DC potential sweeps at 800, 850, and 900°C. The voltage-current characteristics are presented, along with values of area-specific resistance as a function of current density. Long-term cell performance is also assessed to evaluate cell degradation. Details of the custom single-cell test apparatus developed for these experiments are also presented. NASA, in conjunction with the University of Toledo, has developed a new cell concept with the goals of reduced weight and high power density. This report presents results of the INL's testing of this new solid oxide cell design as an electrolyzer. Gas composition, operating voltage, and other parameters were varied during testing. Results to date show the NASA cell to be a promising design for both high power-to-weight fuel cell and electrolyzer applications.

  19. Data acquisition for low-temperature geothermal well tests and long-term monitoring. Final report

    SciTech Connect

    Lienau, P.J.

    1992-09-01

    Groundwater monitoring is an essential part of the development of a low-temperature geothermal field for production and injection wells. State water resource and environmental departments are requiring both geothermal well testing and long-term monitoring as a part of the permitting process for geothermal developments. This report covers water-level measurement methods, instruments used for well testing, geochemical sampling, examples of data acquisition and regulatory mandates on groundwater monitoring.

  20. Comparability of results of postnatal and long-term tests for carcinogenicity.

    PubMed

    Sýkora, I; Vortel, V

    1993-01-01

    A method of testing postnatal carcinogenicity in rats was elaborated. The substances to be tested were administered from the 1st day after birth to the 5th, 10th and 20th days of age. The subsequent supply of a substance in diet from weaning (28th day of age) up to the end of the first year of survival was an optimal combination. A total of 12 substances were tested by this method. For all substances it was possible to provide a comparison with the results of long-term studies. For nine substances carcinogenicity was demonstrated in both tests, out of them in eight cases in identical organ systems. In three cases no carcinogenicity was ascertained in the postnatal study, in two compounds identical negative results were obtained by the two approaches. In one case (the cytostatic TS-160) development of sarcomas was found at the site of subcutaneous administration in the long-term study, and this effect was not observed in the postnatal study. Results identical for the two methods (carcinogenic or noncarcinogenic) were achieved in 11 substances, i.e. 91.7%. In addition, in 10 compounds, for which carcinogenicity was demonstrated either in the postnatal study or in the long-term study, the occurrence of tumors was found in identical organ systems after 8 compounds which is an 80% agreement. In mice, this identity of organs was demonstrated only in 62.5% of the compounds tested. The present results demonstrated that the use of postnatal carcinogenicity test in rats offers the determination of possible carcinogenic effect of the compound tested with a high probability, under economically more advantageous conditions, and with almost the same qualitative results as with the use of the long-term tests for carcinogenicity.

  1. Data acquisition for low-temperature geothermal well tests and long-term monitoring

    SciTech Connect

    Lienau, P.J.

    1992-09-01

    Groundwater monitoring is an essential part of the development of a low-temperature geothermal field for production and injection wells. State water resource and environmental departments are requiring both geothermal well testing and long-term monitoring as a part of the permitting process for geothermal developments. This report covers water-level measurement methods, instruments used for well testing, geochemical sampling, examples of data acquisition and regulatory mandates on groundwater monitoring.

  2. Evaluation of Long-Term Migration Testing from Can Coatings into Food Simulants: Polyester Coatings.

    PubMed

    Paseiro-Cerrato, Rafael; Noonan, Gregory O; Begley, Timothy H

    2016-03-23

    FDA guidance for food contact substances recommends that for food packaging intended for use at sterilized, high temperature processed, or retorted conditions, a migration test with a retort step at 121 °C for 2 h followed by a 10 day migration test at 40 °C should be performed. These conditions are in intended to simulate processing and long-term storage. However, can coatings may be in contact with food for years, and there are very few data evaluating if this short-term testing accurately simulates migration over extended time periods. A long-term migration test at 40 °C with retorted and non-retorted polyester cans using several food simulants (water, 3% acetic acid, 10% ethanol, 50% ethanol, and isooctane) was conducted to verify whether traditional migration testing protocols accurately predict migration from food contact materials used for extended time periods. Time points were from 1 day to 515 days. HPLC-MS/MS was used to analyze polyester monomers, and oligomer migration was monitored using HPLC-DAD/CAD and HPLC-MS. Concentrations of monomers and oligomers increased during the migration experiments, especially in ethanol food simulants. The data suggest that current FDA migration protocols may need to be modified to address changes in migrants as a result of long-term storage conditions.

  3. A long-term national-scale hydrological simulation of river flows across Great Britain

    NASA Astrophysics Data System (ADS)

    Rudd, Alison; Bell, Victoria; Kay, Alison; Davies, Helen

    2016-04-01

    The Centre for Ecology and Hydrology's national-scale hydrological model, Grid-to-Grid, can be used to estimate river flows and soil moisture across Great Britain. It is used operationally at the flood forecasting centre and there have been a number of studies on floods and climate change using this model, however to date, low flows and droughts have been comparatively neglected. The launch of a five-year NERC-funded interdisciplinary research programme "UK Droughts and Water Scarcity" is allowing us to address this. Our work on one of these projects, MaRIUS (Managing the Risks, Impacts and Uncertainties of droughts and water Scarcity), uses the model to identify drought periods. The model is driven by a new long-term (1890 - 2012) precipitation dataset (CEH-GEAR) and estimates of potential evaporation. Model performance is assessed against observed river flows for both high and low flows. Gridded time series of monthly mean river flow and soil moisture from the model have been analysed to identify historic hydrological droughts across Great Britain using concepts such as severity and duration. We also investigate how drought occurrence and severity have changed over the last 100 years and identify regions that have been particularly susceptible to drought.

  4. Method of long-term corrosion-mechanical tests of metal of gas industry pipes

    SciTech Connect

    Gutman, E.M.; Zainullin, R.S.

    1987-10-01

    The resistance of the metal of gas industry pipes to hydrogen-sulfide (sulfide) cracking is usually evaluated on the basis of the results of long-term corrosion-mechanical tests on cylindrical specimens (diameter 6 mm) in the conditions of uniaxial tensile loading generated by the force constant with time. Because of the comparatively large dimensions of devices for producing the stress state in these specimens, it is difficult to carry out large-scale corrosion-mechanical tests. The authors assume that it is more advantageous to evaluate the hydrogen-sulfide cracking resistance of gas industry pipes on the basis of the results of corrosion-mechanical tests on semicircular specimens compressed or tensile-loaded at the ends. The method proposed was used in long-term corrosion-mechanical tests on the metal of seamless pipes made of low-alloy (08G2SFT) and low-carbon (St20) steels. The steel with the lower ratio of the yield stress to ultimate strength k/sub TB/ is characterized by a higher limit of the long-term corrosion strength expressed in the fractions of the yield stress of the metal. This indicates that it is useful to take into account the k/sub TB/ ratio in determining the safety factor of the strength of the gas industry pipes.

  5. Accelerated testing of module-level power electronics for long-term reliability

    DOE PAGES

    Flicker, Jack David; Tamizhmani, Govindasamy; Moorthy, Mathan Kumar; ...

    2016-11-10

    This work has applied a suite of long-term-reliability accelerated tests to a variety of module-level power electronics (MLPE) devices (such as microinverters and optimizers) from five different manufacturers. This dataset is one of the first (only the paper by Parker et al. entitled “Dominant factors affecting reliability of alternating current photovoltaic modules,” in Proc. 42nd IEEE Photovoltaic Spec. Conf., 2015, is reported for reliability testing in the literature), as well as the largest, experimental sets in public literature, both in the sample size (five manufacturers including both dc/dc and dc/ac units and 20 units for each test) and the numbermore » of experiments (six different experimental test conditions) for MLPE devices. The accelerated stress tests (thermal cycling test per IEC 61215 profile, damp heat test per IEC 61215 profile, and static temperature tests at 100 and 125 °C) were performed under powered and unpowered conditions. The first independent long-term experimental data regarding damp heat and grid transient testing, as well as the longest term (>9 month) testing of MLPE units reported in the literature for thermal cycling and high-temperature operating life, are included in these experiments. Additionally, this work is the first to show in situ power measurements, as well as periodic efficiency measurements over a series of experimental tests, demonstrating whether certain tests result in long-term degradation or immediate catastrophic failures. Lastly, the result of this testing highlights the performance of MLPE units under the application of several accelerated environmental stressors.« less

  6. Accelerated testing of module-level power electronics for long-term reliability

    SciTech Connect

    Flicker, Jack David; Tamizhmani, Govindasamy; Moorthy, Mathan Kumar; Thiagarajan, Ramanathan; Ayyanar, Raja

    2016-11-10

    This work has applied a suite of long-term-reliability accelerated tests to a variety of module-level power electronics (MLPE) devices (such as microinverters and optimizers) from five different manufacturers. This dataset is one of the first (only the paper by Parker et al. entitled “Dominant factors affecting reliability of alternating current photovoltaic modules,” in Proc. 42nd IEEE Photovoltaic Spec. Conf., 2015, is reported for reliability testing in the literature), as well as the largest, experimental sets in public literature, both in the sample size (five manufacturers including both dc/dc and dc/ac units and 20 units for each test) and the number of experiments (six different experimental test conditions) for MLPE devices. The accelerated stress tests (thermal cycling test per IEC 61215 profile, damp heat test per IEC 61215 profile, and static temperature tests at 100 and 125 °C) were performed under powered and unpowered conditions. The first independent long-term experimental data regarding damp heat and grid transient testing, as well as the longest term (>9 month) testing of MLPE units reported in the literature for thermal cycling and high-temperature operating life, are included in these experiments. Additionally, this work is the first to show in situ power measurements, as well as periodic efficiency measurements over a series of experimental tests, demonstrating whether certain tests result in long-term degradation or immediate catastrophic failures. Lastly, the result of this testing highlights the performance of MLPE units under the application of several accelerated environmental stressors.

  7. Receiving, handling, and storage of specimens for long-term corrosion testing

    SciTech Connect

    Gdowski, G

    1995-09-11

    The purpose of this TIP is to describe the procedures that will be followed in order to ensure that the test specimens for Activity E-20-50, "Long-Term Corrosion Studies" are received, handled, and stored in a manner in which they are not damaged, degraded, or lost. This TIP was written to comply with LLNL YMP procedure 033-YMP-QP 13.0, "Handling, Storage, and Shipping."

  8. Standardizing flow cytometric assays in long-term population-based studies

    NASA Astrophysics Data System (ADS)

    Melzer, Susanne; Bocsi, Jozsef; Tárnok, Attila

    2015-03-01

    Quantification of leukocyte subpopulations and characterization of antigen-expression pattern on the cellular surface can play an important role in diagnostics. The state of cellular immunology on the single-cell level was analyzed by polychromatic flow cytometry in a recent comparative study within the average Leipzig population (LIFE - Leipzig Research Centre for Civilization Diseases). Data of 1699 subjects were recorded over a long-time period of three years (in a total of 1126 days). To ensure compatibility of such huge data sets, quality-controls on many levels (stability of instrumentation, low intra-laboratory variance and reader independent data analysis) are essential. The LIFE study aims to analyze various cytometric pattern to reveal the relationship between the life-style, the environmental effects and the individual health. We therefore present here a multi-step quality control procedure for long-term comparative studies.

  9. Long-term continuous-flow left ventricular assist devices (LVAD) as bridge to heart transplantation.

    PubMed

    Pozzi, Matteo; Giraud, Raphaël; Tozzi, Piergiorgio; Bendjelid, Karim; Robin, Jacques; Meyer, Philippe; Obadia, Jean François; Banfi, Carlo

    2015-03-01

    Heart transplantation (HTx) is the treatment of choice for end-stage heart failure but the limited availability of heart's donors still represents a major issue. So long-term mechanical circulatory support (MCS) has been proposed as an alternative treatment option to assist patients scheduled on HTx waiting list bridging them for a variable time period to cardiac transplantation-the so-called bridge-to-transplantation (BTT) strategy. Nowadays approximately 90% of patients being considered for MCS receive a left ventricular assist device (LVAD). In fact, LVAD experienced several improvements in the last decade and the predominance of continuous-flow over pulsatile-flow technology has been evident since 2008. The aim of the present report is to give an overview of continuous-flow LVAD utilization in the specific setting of the BTT strategy taking into consideration the most representative articles of the scientific literature and focusing the attention on the evolution, clinical outcomes, relevant implications on the HTx strategy and future perspectives of the continuous-flow LVAD technology.

  10. Patient empowerment in long-term conditions: development and preliminary testing of a new measure

    PubMed Central

    2013-01-01

    Background Patient empowerment is viewed by policy makers and health care practitioners as a mechanism to help patients with long-term conditions better manage their health and achieve better outcomes. However, assessing the role of empowerment is dependent on effective measures of empowerment. Although many measures of empowerment exist, no measure has been developed specifically for patients with long-term conditions in the primary care setting. This study presents preliminary data on the development and validation of such a measure. Methods We conducted two empirical studies. Study one was an interview study to understand empowerment from the perspective of patients living with long-term conditions. Qualitative analysis identified dimensions of empowerment, and the qualitative data were used to generate items relating to these dimensions. Study two was a cross-sectional postal study involving patients with different types of long-term conditions recruited from general practices. The survey was conducted to test and validate our new measure of empowerment. Factor analysis and regression were performed to test scale structure, internal consistency and construct validity. Results Sixteen predominately elderly patients with different types of long-term conditions described empowerment in terms of 5 dimensions (identity, knowledge and understanding, personal control, personal decision-making, and enabling other patients). One hundred and ninety seven survey responses were received from mainly older white females, with relatively low levels of formal education, with the majority retired from paid work. Almost half of the sample reported cardiovascular, joint or diabetes long-term conditions. Factor analysis identified a three factor solution (positive attitude and sense of control, knowledge and confidence in decision making and enabling others), although the structure lacked clarity. A total empowerment score across all items showed acceptable levels of internal

  11. Evaluation of long-term gas hydrate production testing locations on the Alaska north slope

    USGS Publications Warehouse

    Collett, T.S.; Boswell, R.; Lee, M.W.; Anderson, B.J.; Rose, K.; Lewis, K.A.

    2011-01-01

    The results of short duration formation tests in northern Alaska and Canada have further documented the energy resource potential of gas hydrates and justified the need for long-term gas hydrate production testing. Additional data acquisition and long-term production testing could improve the understanding of the response of naturally-occurring gas hydrate to depressurization-induced or thermal-, chemical-, and/or mechanical-stimulated dissociation of gas hydrate into producible gas. The Eileen gas hydrate accumulation located in the Greater Prudhoe Bay area in northern Alaska has become a focal point for gas hydrate geologic and production studies. BP Exploration (Alaska) Incorporated and ConocoPhillips have each established research partnerships with U.S. Department of Energy to assess the production potential of gas hydrates in northern Alaska. A critical goal of these efforts is to identify the most suitable site for production testing. A total of seven potential locations in the Prudhoe Bay, Kuparuk, and Milne Point production units were identified and assessed relative to their suitability as a long-term gas hydrate production test site. The test site assessment criteria included the analysis of the geologic risk associated with encountering reservoirs for gas hydrate testing. The site selection process also dealt with the assessment of the operational/logistical risk associated with each of the potential test sites. From this review, a site in the Prudhoe Bay production unit was determined to be the best location for extended gas hydrate production testing. The work presented in this report identifies the key features of the potential test site in the Greater Prudhoe Bay area, and provides new information on the nature of gas hydrate occurrence and potential impact of production testing on existing infrastructure at the most favorable sites. These data were obtained from well log analysis, geological correlation and mapping, and numerical simulation

  12. Evaluation of long-term gas hydrate production testing locations on the Alaska North Slope

    USGS Publications Warehouse

    Collett, Timothy S.; Boswell, Ray; Lee, Myung W.; Anderson, Brian J.; Rose, Kelly K.; Lewis, Kristen A.

    2012-01-01

    The results of short-duration formation tests in northern Alaska and Canada have further documented the energy-resource potential of gas hydrates and have justified the need for long-term gas-hydrate-production testing. Additional data acquisition and long-term production testing could improve the understanding of the response of naturally occurring gas hydrate to depressurization-induced or thermal-, chemical-, or mechanical-stimulated dissociation of gas hydrate into producible gas. The Eileen gashydrate accumulation located in the Greater Prudhoe Bay area in northern Alaska has become a focal point for gas-hydrate geologic and production studies. BP Exploration (Alaska) Incorporated and ConocoPhillips have each established research partnerships with the US Department of Energy to assess the production potential of gas hydrates in northern Alaska. A critical goal of these efforts is to identify the most suitable site for production testing. A total of seven potential locations in the Prudhoe Bay, Kuparuk River, and Milne Point production units were identified and assessed relative to their suitability as a long-term gas-hydrate-production test sites. The test-site-assessment criteria included the analysis of the geologic risk associated with encountering reservoirs for gas-hydrate testing. The site-selection process also dealt with the assessment of the operational/logistical risk associated with each of the potential test sites. From this review, a site in the Prudhoe Bay production unit was determined to be the best location for extended gas-hydrate-production testing. The work presented in this report identifies the key features of the potential test site in the Greater Prudhoe Bay area and provides new information on the nature of gas-hydrate occurrence and the potential impact of production testing on existing infrastructure at the most favorable sites. These data were obtained from well-log analysis, geological correlation and mapping, and numerical

  13. Evaluation of long-term gas hydrate production testing locations on the Alaska North Slope

    USGS Publications Warehouse

    Collett, Timothy; Boswell, Ray; Lee, Myung W.; Anderson, Brian J.; Rose, Kelly K.; Lewis, Kristen A.

    2011-01-01

    The results of short duration formation tests in northern Alaska and Canada have further documented the energy resource potential of gas hydrates and justified the need for long-term gas hydrate production testing. Additional data acquisition and long-term production testing could improve the understanding of the response of naturally-occurring gas hydrate to depressurization-induced or thermal-, chemical-, and/or mechanical-stimulated dissociation of gas hydrate into producible gas. The Eileen gas hydrate accumulation located in the Greater Prudhoe Bay area in northern Alaska has become a focal point for gas hydrate geologic and production studies. BP Exploration (Alaska) Incorporated and ConocoPhillips have each established research partnerships with U.S. Department of Energy to assess the production potential of gas hydrates in northern Alaska. A critical goal of these efforts is to identify the most suitable site for production testing. A total of seven potential locations in the Prudhoe Bay, Kuparuk, and Milne Point production units were identified and assessed relative to their suitability as a long-term gas hydrate production test site. The test site assessment criteria included the analysis of the geologic risk associated with encountering reservoirs for gas hydrate testing. The site selection process also dealt with the assessment of the operational/logistical risk associated with each of the potential test sites. From this review, a site in the Prudhoe Bay production unit was determined to be the best location for extended gas hydrate production testing. The work presented in this report identifies the key features of the potential test site in the Greater Prudhoe Bay area, and provides new information on the nature of gas hydrate occurrence and potential impact of production testing on existing infrastructure at the most favorable sites. These data were obtained from well log analysis, geological correlation and mapping, and numerical simulation.

  14. How Do Tests and Summary Writing Tasks Enhance Long-Term Retention of Students with Different Levels of Test Anxiety?

    ERIC Educational Resources Information Center

    Mok, Wilson Shun; Chan, Winnie Wai

    2016-01-01

    Testing has been found to facilitate students' long-term retention of information. However, the learning performance of highly test-anxious students can be impaired by tests. Thus, these students may learn ineffectively in a testing context. By contrast, summary writing may not trigger test anxiety and is therefore another learning strategy to…

  15. How Do Tests and Summary Writing Tasks Enhance Long-Term Retention of Students with Different Levels of Test Anxiety?

    ERIC Educational Resources Information Center

    Mok, Wilson Shun; Chan, Winnie Wai

    2016-01-01

    Testing has been found to facilitate students' long-term retention of information. However, the learning performance of highly test-anxious students can be impaired by tests. Thus, these students may learn ineffectively in a testing context. By contrast, summary writing may not trigger test anxiety and is therefore another learning strategy to…

  16. Test Plan for Long-Term Operation of a Ten-Cell High Temperature Electrolysis Stack

    SciTech Connect

    James E. O'Brien; Carl M. Stoots; J. Stephen Herring

    2008-07-01

    This document defines a test plan for a long-term (2500 Hour) test of a ten-cell high-temperature electrolysis stack to be performed at INL during FY09 under the Nuclear Hydrogen Initiative. This test was originally planned for FY08, but was removed from our work scope as a result of the severe budget cuts in the FY08 NHI Program. The purpose of this test is to evaluate stack performance degradation over a relatively long time period and to attempt to identify some of the degradation mechanisms via post-test examination. This test will be performed using a planar ten-cell Ceramatec stack, with each cell having dimensions of 10 cm × 10 cm. The specific makeup of the stack will be based on the results of a series of shorter duration ten-cell stack tests being performed during FY08, funded by NGNP. This series of tests was aimed at evaluating stack performance with different interconnect materials and coatings and with or without brazed edge rails. The best performing stack from the FY08 series, in which five different interconnect/coating/edge rail combinations were tested, will be selected for the FY09 long-term test described herein.

  17. Materials in embolotherapy of high-flow priapism: results and long-term follow-up.

    PubMed

    Oztürk, Mehmet Halil; Gümüş, Mehmet; Dönmez, Halil; Peynircioğlu, Bora; Onal, Baran; Dinç, Hasan

    2009-09-01

    To review our experience with embolic materials used in the selective arterial embolization of high-flow priapism and present the results of long-term follow-up. Eight patients with traumatic high-flow priapism were reviewed. The patients were evaluated with clinical findings, laboratory examinations, and imaging findings including color Doppler ultrasonography and angiography. Diagnostic angiography demonstrated a connection between the cavernosal artery and the corpus cavernosum. Fistulas were embolized using autologous blood clot, polyvinyl alcohol particles, detachable coils, or acrylic glue. One or more procedures per patient were needed to achieve success. Eleven embolization procedures were performed in eight patients. Immediate resolution of priapism was obtained after the procedures. Three patients (37.5%) had recurrence of priapism in the subsequent 1-3 weeks and required a repeat procedure. After the final procedures, all patients had complete resolution of priapism. Normal recurrence of erectile function was obtained in six of the patients (75%) after the final embolization. Selective arterial embolization is a useful therapeutic option in the management of patients with high-flow priapism. Various materials can be used successfully as embolizing agents in the procedures according to the patient's status.

  18. Effect of long-term successive storm flows on water reclamation plant resilience.

    PubMed

    Zhu, Jun-Jie; Anderson, Paul R

    2017-03-15

    A water reclamation plant (WRP) needs to be resilient to successfully operate through different kinds of perturbations. Perturbations such as storm events, especially long-term successive storm flows, can adversely affect operations. A better understanding of these effects can provide benefits for plant operation, in terms of effluent quality and energy efficiency. However, the concept of resilience for a WRP has not been widely studied, and we are not aware of any studies specifically related to storm flows. In this work we applied measures of resistance and recovery time to quantify resilience, and used a WRP simulation model to investigate how different storm flow characteristics (flowrate and duration) and the amount of aeration influence resilience. Not surprisingly, increasing storm flowrate leads to decreasing resilience. Although the aeration rate plays an important role in determining resilience, there is an aeration threshold (6 m(3)/s for our WRP model); higher aeration rates do not increase resilience. Results suggest that aeration costs could be reduced by as much as 50% while still maintaining the resilience needed to meet effluent quality permit requirements through the perturbations examined in this study.

  19. Very-long-term chromatic adaptation: test of gain theory and a new method.

    PubMed

    Belmore, Suzanne C; Shevell, Steven K

    2008-01-01

    This research had two goals. First, a new method of very-long-term chromatic adaptation was compared to an older method of long-wavelength ambient illumination. In the new method, the observer viewed for 1 h per day for 12 or 14 days a CRT screen composed of oriented lines that appeared red. One observer also replicated a previous procedure (Neitz et al., 2002) in which she was exposed to long-wavelength room illumination for 4 h per day for 14 days. For both methods, equilibrium yellow was measured each day about 20 h after the end of the adaptation period. Both methods of very-long-term chromatic adaptation gave similar results. Second, shifts in equilibrium yellow were measured over a 30:1 range of light levels to determine if changes in color percepts were explained solely by a gain change in cone sensitivities (von Kries coefficient law). The magnitude of shift of equilibrium yellow depended on the level of the test light, which was not consistent with a gain theory of very-long-term chromatic adaptation.

  20. Methodological study investigating long term laser Doppler measured cerebral blood flow changes in a permanently occluded rat stroke model.

    PubMed

    Eve, David J; Musso, James; Park, Dong-Hyuk; Oliveira, Cathy; Pollock, Kenny; Hope, Andrew; Baradez, Marc-Olivier; Sinden, John D; Sanberg, Paul R

    2009-05-30

    Cerebral blood flow is impaired during middle cerebral artery occlusion in the rat model of stroke. However, the long term effects on cerebral blood flow following occlusion have received little attention. We examined cerebral blood flow in both sides at multiple time points following middle cerebral artery occlusion of the rat. The bilateral cerebral blood flow in young male Sprague Dawley rats was measured at the time of occlusion, as well as 4, 10 and 16 weeks after occlusion. Under the present experimental conditions, the difference between the left and right side's cerebral blood flow was observed to appear to switch in direction in a visual oscillatory fashion over time in the sham-treated group, whereas the occluded animals consistently showed left side dominance. One group of rats was intraparenchymally transplanted with a human neural stem cell line (CTX0E03 cells) known to have benefit in stroke models. Cerebral blood flow in the lesioned side of the cell-treated group was observed to be improved compared to the untreated rats and to demonstrate a similar oscillatory nature as that observed in sham-treated animals. These findings suggest that multiple bilateral monitoring of cerebral blood flow over time can show effects of stem cell transplantation efficiently as well as functional tests in an animal stroke model.

  1. Long term pre-qualification testing program on a 230kV XLPE cable system

    SciTech Connect

    Champion, T.C.; Agostinelli, F.M.; Rosevear, R.D.

    1994-12-31

    this paper describes the installation, testing, and results of a long term, full scale laboratory evaluation of a 230kV XLPE insulated cable system. System components included two innovative, pre-molded splices a 128 meter (420 foot) cable run, and two silicone oil filled, porcelain cable terminations. Load cycle aging was performed on the cable system over a four year period. After successfully completing the outdoor aging program, the system was exposed to a final impulses breakdown test. Results demonstrated the importance of considering thermomechanical bending in aluminum conductor, XLPE insulated designs. The influence on cable ampacity of solar heating at riser transitions was also demonstrated.

  2. Long term pre-qualification testing program on a 230kV XLPE cable system

    SciTech Connect

    Champion, T.C.; Agostinelli, F.M.; Rosevear, R.D.

    1995-01-01

    This paper describes the installation, testing, and results of a long term, full scale laboratory evaluation of a 230kV XLPE insulated cable system. System components included two innovative, pre-molded splices, a 128 meter (420 foot) cable run, and two silicone oil filled, porcelain cable terminations. Load cycle aging was performed on the cable system over a four year period. After successfully completing the outdoor aging program, the system was exposed to a final impulse breakdown test. Results demonstrated the importance or considering thermomechanical bending in aluminum conductor, XLPE insulated designs. The influence on cable ampacity of solar beating at riser transitions was also demonstrated.

  3. Multiple pollutant removal using the condensing heat exchanger. Task 3, Long term testing at the ECTC

    SciTech Connect

    Schulze, K.H.

    1996-01-01

    The objective of this task is to demonstrate long term operation of a condensing heat exchanger for coal-fired conditions. A small condensing heat exchanger will be installed at the Environmental Control Technology Center in Barker, New York. It will be installed downstream of the flue gas particulate removal system. The test will determine the amount of wear, if any, on the Teflon{trademark} covered internals of the heat exchanger. Visual inspection and measurements will be obtained for the Teflon{trademark} covered tubes during the test. The material wear study will conducted over a one year calendar period, and the CHX equipment will be operated to the fullest extent allowable.

  4. An improved design of optical sensor for long-term measurement of arterial blood flow waveform.

    PubMed

    Djurić, Biljana; Suzić, Slavica; Stojadinović, Bojana; Nestorović, Zorica; Ivanović, Marija; Suzić-Lazić, Jelena; Nešić, Dejan; Mazić, Sanja; Tenne, Tamar; Zikich, Dragoslav; Žikić, Dejan

    2017-09-01

    We present here the improved design and development of optical sensor for non-invasive measurements of arterial blood flow waveform. The sensor is based on a physical principle of reflective photoplethysmography (PPG). As the light source we used serially connected infrared diodes whereas NPN silicon phototransistors were used as light detectors. The electronic components were molded into square package and poured with silicone. Such preparation produced an elastic superficies that allowed excellent attachment of the sensor on the skin's surface. Moreover, a serial connection of infrared diodes and phototransistors completely eliminated signal artifacts caused by minor muscle contractions. The sensor recording performances were examined at the photoplethysmographic sites on three different arteries; the commune carotid, femoral and radial and, on each site the sensor demonstrated remarkable capability to make a consistent, reproducible measurements. Because of the advantageous physical and electrical properties, the new sensor is suitable for various cardiovascular diagnostics procedures, especially when long-term measurements of arterial blood flow waveform are required, for monitoring of different parameters in cardiovascular units and for research.

  5. Accuracy and reproducibility of long-term implanted transit-time ultrasound flow probes in dogs.

    PubMed

    Picker, O; Schindler, A; Scheeren, T W

    2000-05-01

    To assess the accuracy and reproducibility of long-term implanted ultrasound transit-time flow probes for measuring cardiac output. Prospective animal study. Animal research laboratory in a university department. Eleven anaesthetised dogs, 24-34 kg. Flow probes (16-24 mm S-series, Transonic) were implanted around the pulmonary artery for a mean duration of 22 months (range 6-47 months). Comparisons (n = 147) were made between cardiac output thus obtained and that measured by the direct Fick principle using oxygen uptake (Deltatrac II Metabolic Monitor) and the arterial to mixed venous oxygen content difference measured by a galvanic cell (Lex-O2-Con-TL). Measurements were made either during baseline conditions or during pharmacologically altered cardiac output (range 22-180 ml x kg(-1) x min(-1)). Regardless of the intervention, the two methods yielded the same results in half of the dogs. In the others, however, cardiac output was underestimated by the flow probes by up to 38% (probably because of non-perpendicular position of the probe towards the vessel). This difference was constant for the whole range of cardiac output studied and remained constant over the entire observation period for each individual dog, so that a correction factor was used. Thereafter, the mean difference between the two methods was -1.1 ml x kg(-1) x min(-1) with a precision (SD) of 14.2 ml x kg(-1) x min(-1) for all experiments. After in vivo calibration, ultrasound transit-time flow probes measure cardiac output precisely for several years, regardless of the intervention.

  6. Lesser Neural Pattern Similarity across Repeated Tests Is Associated with Better Long-Term Memory Retention.

    PubMed

    Karlsson Wirebring, Linnea; Wiklund-Hörnqvist, Carola; Eriksson, Johan; Andersson, Micael; Jonsson, Bert; Nyberg, Lars

    2015-07-01

    Encoding and retrieval processes enhance long-term memory performance. The efficiency of encoding processes has recently been linked to representational consistency: the reactivation of a representation that gets more specific each time an item is further studied. Here we examined the complementary hypothesis of whether the efficiency of retrieval processes also is linked to representational consistency. Alternatively, recurrent retrieval might foster representational variability--the altering or adding of underlying memory representations. Human participants studied 60 Swahili-Swedish word pairs before being scanned with fMRI the same day and 1 week later. On Day 1, participants were tested three times on each word pair, and on Day 7 each pair was tested once. A BOLD signal change in right superior parietal cortex was associated with subsequent memory on Day 1 and with successful long-term retention on Day 7. A representational similarity analysis in this parietal region revealed that beneficial recurrent retrieval was associated with representational variability, such that the pattern similarity on Day 1 was lower for retrieved words subsequently remembered compared with those subsequently forgotten. This was mirrored by a monotonically decreased BOLD signal change in dorsolateral prefrontal cortex on Day 1 as a function of repeated successful retrieval for words subsequently remembered, but not for words subsequently forgotten. This reduction in prefrontal response could reflect reduced demands on cognitive control. Collectively, the results offer novel insights into why memory retention benefits from repeated retrieval, and they suggest fundamental differences between repeated study and repeated testing. Repeated testing is known to produce superior long-term retention of the to-be-learned material compared with repeated encoding and other learning techniques, much because it fosters repeated memory retrieval. This study demonstrates that repeated memory

  7. LONG-TERM GRADIENT TEMPERATURE STRESS RELAXATION TESTING AND MODELING OF CERAMIC INSULATION MATERIALS

    SciTech Connect

    Hemrick, James Gordon; Lara-Curzio, Edgar; King, James

    2010-01-01

    Testing was carried out to characterize and predict the long-term thermomechanical properties of Thermal Ceramics Min-K 1400TE thermal insulation material, hereafter referred to as Min-K. In particular, the high temperature compressive strength and stress relaxation behavior of Min-K up to 900 C was evaluated under various thermal gradients and a helium atmosphere for test times of up to over two years. Additionally, finite element and mathematical models were formulated to predict the mechanical behavior exhibited by Min-K out to 35,000 hours (4 years) based on this testing. This presentation will discuss the design and construction of unique test equipment to carry out this testing, along with the results of the testing and the subsequent modeling.

  8. Long-term prediction test procedure for most ICs, based on linear response theory

    NASA Technical Reports Server (NTRS)

    Litovchenko, V.; Ivakhnenko, I.

    1991-01-01

    Experimentally, thermal annealing is known to be a factor which enables a number of different integrated circuits (IC's) to recover their operating characteristics after suffering radiation damage in the space radiation environment; thus, decreasing and limiting long term cumulative total-dose effects. This annealing is also known to be accelerated at elevated temperatures both during and after irradiation. Linear response theory (LRT) was applied, and a linear response function (LRF) to predict the radiation/annealing response of sensitive parameters of IC's for long term (several months or years) exposure to the space radiation environment were constructed. Compressing the annealing process from several years in orbit to just a few hours or days in the laboratory is achieved by subjecting the IC to elevated temperatures or by increasing the typical spaceflight dose rate by several orders of magnitude for simultaneous radiation/annealing only. The accomplishments are as follows: (1) the test procedure to make predictions of the radiation response was developed; (2) the calculation of the shift in the threshold potential due to the charge distribution in the oxide was written; (3) electron tunneling processes from the bulk Si to the oxide region in an MOS IC were estimated; (4) in order to connect the experimental annealing data to the theoretical model, constants of the model of the basic annealing process were established; (5) experimental data obtained at elevated temperatures were analyzed; (6) time compression and reliability of predictions for the long term region were shown; (7) a method to compress test time and to make predictions of response for the nonlinear region was proposed; and (8) nonlinearity of the LRF with respect to log(t) was calculated theoretically from a model.

  9. Long-term prognostic value of coronary flow velocity reserve in renal transplant recipients.

    PubMed

    Akagun, T; Caliskan, Y; Alpay, N; Ozkok, A; Yazici, H; Polat, N; Guz, G; Oflaz, H; Turkmen, A; Sukru Sever, M

    2011-09-01

    In this prospective study, we sought to investigate the long-term prognostic value of coronary flow reserve (CFR) and carotid intima media thickness (IMT) estimates in renal transplant recipients without known coronary artery disease. The 20 renal transplant recipients included in this study underwent CFR recordings performed by trans-thoracic Doppler echocardiography (TTDE) and carotid IMT measured by carotid Doppler ultrasonography. During a 3-year follow-up only one patient experienced a cardiac event. The baseline CFR and carotid IMT values of the patients were 1.77 ± 0.47 and 0.67 ± 0.15 mm, respectively. After 3 years of follow-up, there were no significant differences compared with baseline measurements with regard to CFR and IMT values. CFR values at the third year of follow-up showed significant correlation with age as well as IMT at baseline and at the third year. Upon multivariate analysis, baseline carotid IMT (β = -0.562; P = .05) was a significant independent predictor of CFR at the third year. Carotid IMT showed a greater predictive value for impaired CFR in renal transplant recipients. CFR was not an independent predictor for cardiovascular events among renal transplant recipients within the first 3 years of follow-up measurements. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. Design and Field Test of a WSN Platform Prototype for Long-Term Environmental Monitoring

    PubMed Central

    Lazarescu, Mihai T.

    2015-01-01

    Long-term wildfire monitoring using distributed in situ temperature sensors is an accurate, yet demanding environmental monitoring application, which requires long-life, low-maintenance, low-cost sensors and a simple, fast, error-proof deployment procedure. We present in this paper the most important design considerations and optimizations of all elements of a low-cost WSN platform prototype for long-term, low-maintenance pervasive wildfire monitoring, its preparation for a nearly three-month field test, the analysis of the causes of failure during the test and the lessons learned for platform improvement. The main components of the total cost of the platform (nodes, deployment and maintenance) are carefully analyzed and optimized for this application. The gateways are designed to operate with resources that are generally used for sensor nodes, while the requirements and cost of the sensor nodes are significantly lower. We define and test in simulation and in the field experiment a simple, but effective communication protocol for this application. It helps to lower the cost of the nodes and field deployment procedure, while extending the theoretical lifetime of the sensor nodes to over 16 years on a single 1 Ah lithium battery. PMID:25912349

  11. The Role of Long-Term Memory in a Test of Visual Working Memory: Proactive Facilitation but No Proactive Interference

    ERIC Educational Resources Information Center

    Oberauer, Klaus; Awh, Edward; Sutterer, David W.

    2017-01-01

    We report 4 experiments examining whether associations in visual working memory are subject to proactive interference from long-term memory (LTM). Following a long-term learning phase in which participants learned the colors of 120 unique objects, a working memory (WM) test was administered in which participants recalled the precise colors of 3…

  12. The Role of Long-Term Memory in a Test of Visual Working Memory: Proactive Facilitation but No Proactive Interference

    ERIC Educational Resources Information Center

    Oberauer, Klaus; Awh, Edward; Sutterer, David W.

    2017-01-01

    We report 4 experiments examining whether associations in visual working memory are subject to proactive interference from long-term memory (LTM). Following a long-term learning phase in which participants learned the colors of 120 unique objects, a working memory (WM) test was administered in which participants recalled the precise colors of 3…

  13. Experimental implantation and long-term testing of an intraocular vision aid in rabbits.

    PubMed

    Szurman, Peter; Warga, Max; Roters, Sigrid; Grisanti, Salvatore; Heimann, Uta; Aisenbrey, Sabine; Rohrbach, Jens M; Sellhaus, Bernd; Ziemssen, Focke; Bartz-Schmidt, Karl U

    2005-07-01

    To develop an intraocular vision aid to provide artificial vision in severely traumatized eyes, where neuroretinal function could be preserved but irreversible anterior segment opacification resulted in blindness. The basis of an intraocular vision aid is in principle a telemetric circuit to bridge the opaque cornea and to allow for artificial light stimulation of the retina. The visual prosthesis comprises an external high-dynamic range complementary metal oxide semiconductor camera and digital signal processing unit and an intraocular miniaturized light-emitting diode array to project the image onto the retina. For in vivo testing of long-term function and biocompatibility, silicone-encapsulated active photodiodes were implanted in 13 pigmented rabbits and were followed up for up to 21 months. Lens extraction and stable fixation of the device in the ciliary sulcus were successful in all cases. For up to 21 months inductive energy transmission and wireless stimulation of the implants could be maintained. Electrophysiologic data and histology demonstrated a good tissue biocompatibility in the long-term follow-up. The results demonstrate the general feasibility and biocompatibility to implant and fixate an intraocular light-emitting diode prosthesis. Inductive energy transmission to the intraocular device and wireless light stimulation are assured in the long term but depend on meticulous water-impermeable encapsulation of the delicate microelectronic components. Clinical Relevance An intraocular vision aid compound system with a high-resolution light-emitting diode matrix might be a future treatment option to restore vision in blind eyes with severe anterior segment disorders.

  14. Long-term contraction of pyroclastic flow deposits at Augustine Volcano using InSAR

    NASA Astrophysics Data System (ADS)

    McAlpin, D. B.; Meyer, F. J.; Lu, Z.; Beget, J. E.

    2013-12-01

    Augustine Island is a small, 8x11 km island in South Central Alaska's lower Cook Inlet. It is approximately 280 km southwest of Anchorage, and occupied entirely by its namesake Augustine Volcano. The volcano's nearly symmetrical central cone reaches an altitude of 1260 m, and the surrounding island is composed almost entirely of volcanic deposits. It is the youngest and most frequently active volcano in the lower Cook Inlet, with at least seven known eruptions since the beginning of written records in 1812. Its two most recent eruptions occurred during March-August 1986, and January-March 2006 The 1986 and 2006 Augustine eruptions produced significant pyroclastic flow deposits (PFDs) on the island, both which have been well mapped by previous studies. Subsidence of material deposited by these pyroclastic flows has been measured by InSAR data, and can be attributed to at least four processes: (1) initial, granular settling; (2) thermal contraction; (3) loading of 1986 PFDs from overlying 2006 deposits; and (4) continuing subsidence of 1986 PFDs buried beneath 2006 flows. For this paper, SAR data for PFDs from Augustine Volcano were obtained from 1992 through 2005, from 2006-2007, and from 2007-2011. These time frames provided InSAR data for long-term periods after both 1986 and 2006 eruptions. From time-series analysis of these datasets, deformation rates of 1986 PFDs and 2006 PFDs were determined, and corrections applied where newer deposits were emplaced over old deposits. The combination of data sets analyzed in this study enabled, for the first time, an analysis of long and short term subsidence rates of volcanic deposits emplaced by the two eruptive episodes. The generated deformation time series provides insight into the significance and duration of the initial settling period and allows us to study the thermal regime and heat loss of the PFDs. To extract quantitative information about thermal properties and composition of the PFDs, we measured the thickness

  15. The Long-Term Corrosion Test Facility at the Lawrence Livermore National Laboratory

    SciTech Connect

    Fix, D V; Rebak, R B

    2007-03-21

    The long-term corrosion test facility (LTCTF) at the Lawrence Livermore National Laboratory (LLNL) consisted of 22 vessels that housed more than 7,000 corrosion test specimens from carbon steels to highly corrosion resistant materials such Alloy 22 and Ti Grade 7. The specimens from LTCTF range from standard weight-loss coupons to U-bend specimens for testing susceptibility to environmentally assisted cracking. Each vessel contained approximately 1000 liters of concentrated brines at 60 C or 90 C. The LTCTF started its operations in late 1996. The thousands of specimens from the LTCTF were removed in August-September 2006. The specimens are being catalogued and stored for future characterization. Previously removed specimens (e.g. 1 and 5 years) are also archived for further studies.

  16. Long-Term Correlations and Multifractality of Traffic Flow Measured by GIS for Congested and Free-Flow Roads

    NASA Astrophysics Data System (ADS)

    di, Baofeng; Shi, Kai; Zhang, Kaishan; Svirchev, Laurence; Hu, Xiaoxi

    2016-02-01

    In this paper, a GIS-based method was developed to extract the real-time traffic information (RTTI) from the Google Maps system for city roads. The method can be used to quantify both congested and free-flow traffic conditions. The roadway length was defined as congested length (CL) and free-flow length (FFL). Chengdu, the capital of Sichuan Province in the southwest of China, was chosen as a case study site. The RTTI data were extracted from the Google real-time maps in May 12-17, 2013 and were used to derive the CL and FFL for the study areas. The Multifractal Detrended Fluctuation Analysis (MFDFA) was used to characterize the long-term correlations of CL and FFL time series and their corresponding multifractal properties. Analysis showed that CL and FFL had demonstrated time nonlinearity and long-term correlations and both characteristics differed significantly. A shuffling procedure and a phase randomization procedure were further integrated with multifractal detrending moving average (MFDMA) to identify the major sources of multifractality of these two time series. The results showed that a multifractal process analysis could be used to characterize complex traffic data. Traffic data collected and methods developed in this paper will help better understand the complex traffic systems.

  17. Long term impacts of flow abstraction upon basin scale sedimentation processes in an Alpine valley system

    NASA Astrophysics Data System (ADS)

    Lane, Stuart; Regamey, Benoit

    2014-05-01

    Flow abstraction and diversion to large water storage systems is a common element of Alpine hydro-electric power schemes. However, such systems are commonly associated with exceptionally high sediment production rates, necessitating very particular approaches to sediment management. Commonly, whilst water is abstracted, sediment (both coarse and fine fractions) is left behind. In order to avoid infrastructure failure, the latter is commonly designed to allow sediment to pass in short duration high magnitude sedimentary floods. The importance of such schemes aside, there has been relatively little investigation of the geomorphic impacts of such sediment management systems. In this paper, we present results from two spatio-temporal scales of analysis in order to establish these impacts. The first applies image processing to archival aerial photography to document the long-term impacts of flow abstraction and sedimentary floods in the Val d'Héréns, Switzerland. Results show that flow abstraction significantly reduces the time when the river was competent to transport sediment, and hence the total sediment transport capacity. The result has been a temporary disconnection of sediment flux through the system, and reflected in significantly reduced rates of sediment delivery to Lac Léman downstream. However, the image analysis also shows that whilst sedimentation was initially restricted to close to the abstraction sites, this sediment has been progressively reworked through a succession of sedimentary floods, causing deposition sites to move progressively further downstream. These deposition sites are themselves constrained by geomorphic forcing, centred on reaches of lower river bed slope and with sufficient lateral accommodation space. The implication of these observations is that the sediment flux will eventually reconnect with the main valley stems further downstream. The second scale sought to quantify this response in more detail by laser scanning on a 400 m

  18. Mapping Long-Term Functional Changes in Cerebral Blood Flow by Arterial Spin Labeling

    PubMed Central

    Ssali, Tracy; Anazodo, Udunna C.; Bureau, Yves; MacIntosh, Bradley J.; Günther, Matthias; St. Lawrence, Keith

    2016-01-01

    Although arterial spin labeling (ASL) is appealing for mapping long-term changes in functional activity, inter-sessional variations in basal blood flow, arterial transit times (ATTs), and alignment errors, can result in significant false activation when comparing images from separate sessions. By taking steps to reduce these sources of noise, this study assessed the ability of ASL to detect functional CBF changes between sessions. ASL data were collected in three sessions to image ATT, resting CBF and CBF changes associated with motor activation (7 participants). Activation maps were generated using rest and task images acquired in the same session and from sessions separated by up to a month. Good agreement was found when comparing between-session activation maps to within-session activation maps with only a 16% decrease in precision (within-session: 90 ± 7%) and a 13% decrease in the Dice similarity (within-session: 0.75 ± 0.07) coefficient after a month. In addition, voxel-wise reproducibility (within-session: 4.7 ± 4.5%) and reliability (within-session: 0.89 ± 0.20) of resting grey-matter CBF decreased by less than 18% for the between-session analysis relative to within-session values. ATT variability between sessions (5.0 ± 2.7%) was roughly half the between-subject variability, indicating that its effects on longitudinal CBF were minimal. These results demonstrate that conducting voxel-wise analysis on CBF images acquired on different days is feasible with only modest loss in precision, highlighting the potential of ASL for longitudinal studies. PMID:27706218

  19. Long-term flow rates and biomat zone hydrology in soil columns receiving septic tank effluent.

    PubMed

    Beal, C D; Gardner, E A; Kirchhof, G; Menzies, N W

    2006-07-01

    Soil absorption systems (SAS) are used commonly to treat and disperse septic tank effluent (STE). SAS can hydraulically fail as a result of the low permeable biomat zone that develops on the infiltrative surface. The objectives of this experiment were to compare the hydraulic properties of biomats grown in soils of different textures, to investigate the long-term acceptance rates (LTAR) from prolonged application of STE, and to assess if soils were of major importance in determining LTAR. The STE was applied to repacked sand, Oxisol and Vertisol soil columns over a period of 16 months, at equivalent hydraulic loading rates of 50, 35 and 8L/m(2)/d, respectively. Infiltration rates, soil matric potentials, and biomat hydraulic properties were measured either directly from the soil columns or calculated using established soil physics theory. Biomats 1 to 2 cm thick developed in all soils columns with hydraulic resistances of 27 to 39 d. These biomats reduced a 4 order of magnitude variation in saturated hydraulic conductivity (K(s)) between the soils to a one order of magnitude variation in LTAR. A relationship between biomat resistance and organic loading rate was observed in all soils. Saturated hydraulic conductivity influenced the rate and extent of biomat development. However, once the biomat was established, the LTAR was governed by the resistance of the biomat and the sub-biomat soil unsaturated flow regime induced by the biomat. Results show that whilst initial soil K(s) is likely to be important in the establishment of the biomat zone in a trench, LTAR is determined by the biomat resistance and the unsaturated soil hydraulic conductivity, not the K(s) of a soil. The results call into question the commonly used approach of basing the LTAR, and ultimately trench length in SAS, on the initial K(s) of soils.

  20. Histopathology Image Analysis in Two Long-Term Animal Experiments with Helical Flow Total Artificial Heart.

    PubMed

    Wotke, Jiri; Homolka, Pavel; Vasku, Jaromír; Dobsak, Petr; Palanova, Petra; Mrkvicova, Veronika; Konecny, Petr; Soska, Vladimir; Pohanka, Michal; Novakova, Marie; Yurimoto, Terumi; Saito, Itsuro; Inoue, Yusuke; Isoyama, Takashi; Abe, Yusuke

    2016-12-01

    Histopathological analysis can provide important information in long-term experiments with total artificial heart (TAH). Recently, a new type of blood pump, the helical flow total artificial heart (HF-TAH) was developed. This study aimed to investigate the changes in selected vital organs in animal experiments with implanted HF-TAH. Samples from lung, liver, and kidneys from two female goats (No. 1301 and No. 1304) with implanted HF-TAH were analyzed. Tissue samples were fixed in 10% formaldehyde and 4 µm thick transverse sections were stained with hematoxylin-eosin (HE). Additional staining was done for detection of connective tissue (Masson-Goldner stain) and for detection of iron (hemosiderin) deposits (Perls stain). Sections were scanned at 100× and 500× magnification with a light microscope. Experiment no. 1301 survived 100 days (cause of termination was heavy damage of the right pump); experimental goat no.1304 survived 68 days and was sacrificed due to severe right hydrodynamic bearing malfunction. Histopathological analysis of liver samples proved signs of chronic venostasis with limited focal necrotic zones. Dilated tubules, proteinaceous material in tubular lumen, and hemosiderin deposits were detected in kidney samples. Contamination of the organs by embolized micro-particles was suspected at the autopsy after discovery of visible damage (scratches) of the pump impeller surface (made from titanium alloy) in both experiments. Sporadic deposits of foreign micro-particles (presumably titanium) were observed in most of the analyzed parenchymal organs. However, the described deposits were not in direct connection with inflammatory reactions in the analyzed tissues. Histopathological analysis showed the presence of minimal contamination of the lung, kidney, and liver tissue samples by foreign material (titanium very likely). The analysis showed only limited pathological changes, especially in liver and kidneys, which might be attributed to the influence of

  1. Lessons Learned During the Refurbishment and Testing of an Observatory After Long-Term Storage

    NASA Technical Reports Server (NTRS)

    Hawk, John; Peabody, Sharon; Stavely, Richard

    2015-01-01

    Thermal Fluids Analysis Workshop (TFAWS) 2015, Silver Spring, MD NCTS 21070-15. This paper addresses the lessons learned during the refurbishment and testing of the thermal control system for a spacecraft which was placed into long-term storage. The DSCOVR (Deep Space Climate Observatory) Observatory (formerly known as Triana) was originally scheduled to launch on the Space Shuttle in 2002. With the Triana spacecraft nearly complete, the mission was canceled and the satellite was abruptly put into storage in 2001. In 2008 the observatory was removed from storage to begin refurbishment and testing. Problems arose associated with hardware that was not currently manufactured, coatings degradation, and a significant lack of documentation. Also addressed is the conversion of the thermal and geometric math models for use with updated thermal analysis software tools.

  2. Long-term macroinvertebrate response to flow abstraction at Alpine water intakes

    NASA Astrophysics Data System (ADS)

    Gabbud, Chrystelle; Savioz, Amélie; Lane, Stuart

    2016-04-01

    The natural flow hydrological characteristics of Alpine streams, dominated by snowmelt and glacier melt, have been established for many years. More recently, the ecosystems that they sustain have been described and explained, following the hydrological, biochemical, morphodynamic, and biotic elements specific to Alpine streams. However, natural Alpine flow regimes may be strongly modified by hydroelectric power production, which impacts upon both river discharge and sediment transfer, and hence on downstream flora and fauna. These kinds of impacts are well studied where river are regulated by dams, with sediments retained behind walls, but they are much less focus on water intakes, whose storage capacity is very smaller and thus have to flush flow and sediment regularly. Here we focus on the impacts of flow abstraction on macroinvertebrates, the most widely ecological group used in freshwater biomonitoring as they act typically as indicators of environmental health. Some key generalizations can be made. For instance, in European glacially fed river systems, Plecoptera, Chironomidae, Ephemeroptera, Simuliidae, and Diptera are the main taxa found in spring as they are better adapted to cold conditions. Petts and Bickerton (1994) published macroinvertebrate samples from the upper part of the glacial stream system the Borgne d'Arolla (Valais, Switzerland), highlighting that: (1) taxa variability and productivity decline in the river because of flow abstraction, (2) 60 % of the communities were provided by tributaries, (3) there is migration upstream of the species in response to the passage from a dominant ice-melt to a snow-melt regime, (4) the colonisation is difficult because of a significant modification of the habitat in the river by sediment transport, until it becomes warmer, clearer and more stable further downstream. In order to establish the long-term impacts of flow abstraction upon instream ecology where sediment delivery is maintained but transport

  3. Interlaboratory evaluation of Hyalella azteca and Chironomus tentans short-term and long-term sediment toxicity tests

    USGS Publications Warehouse

    Norberg-King, T. J.; Sibley, P.K.; Burton, G.A.; Ingersoll, C.G.; Kemble, N.E.; Ireland, S.; Mount, D.R.; Rowland, C.D.

    2006-01-01

    Methods for assessing the long-term toxicity of sediments to Hyalella azteca and Chironomus tentans can significantly enhance the capacity to assess sublethal effects of contaminated sediments through multiple endpoints. Sublethal tests allow us to begin to understand the relationship between short-term and long-term effects for toxic sediments. We present an interlaboratory evaluation with long-term and 10-d tests using control and contaminated sediments in which we assess whether proposed and existing performance criteria (test acceptability criteria [TAC]) could be achieved. Laboratories became familiar with newly developed, long-term protocols by testing two control sediments in phase 1. In phase 2, the 10-d and long-term tests were examined with several sediments. Laboratories met the TACs, but results varied depending on the test organism, test duration, and endpoints. For the long-term tests in phase 1, 66 to 100% of the laboratories consistently met the TACs for survival, growth, or reproduction using H. azteca, and 70 to 100% of the laboratories met the TACs for survival and growth, emergence, reproduction, and hatchability using C. tentans. In phase 2, fewer laboratories participated in long-term tests: 71 to 88% of the laboratories met the TAC for H. azteca, whereas 50 to 67% met the TAC for C. tentans. In the 10-d tests with H. azteca and C. tentans, 82 and 88% of the laboratories met the TAC for survival, respectively, and 80% met the TAC for C. tentans growth. For the 10-d and long-term tests, laboratories predicted similar toxicity. Overall, the interlaboratory evaluation showed good precision of the methods, appropriate endpoints were incorporated into the test protocols, and tests effectively predicted the toxicity of sediments. ?? 2006 SETAC.

  4. Accelerated Testing for Long-Term Durability of Various FRP Laminates for Marine Use

    NASA Astrophysics Data System (ADS)

    Miyano, Yasushi; Nakada, Masayuki

    The prediction of long-term fatigue life of various FRP laminates combined with resins, fibers and fabrics for marine use under temperature and water environments were performed by our developed accelerated testing methodology based on the time-temperature superposition principle (TTSP). The base material of five kinds of FRP laminates employed in this study was plain fabric CFRP laminates T300 carbon fibers/vinylester (T300/VE). The first selection of FRP laminate to T300/VE was the combinations of different fabrics, that is flat yarn plain fabric T700 carbon fibers/vinylester (T700/VE-F) and multi-axial knitted T700 carbon fibers/vinylester (T700/VE-K) for marine use and the second selection of FRP laminates to T300/VE was the combinations with different fibers and matrix resin, that is plain fabric T300 carbon fibers/epoxy (T300/EP) and plain fabric E-glass fibers/vinylester (E-glass/VE). These five kinds of FRP laminates were prepared under three water absorption conditions of Dry, Wet and Wet C Dry after molding. The three-point bending constant strain rate (CSR) tests for these FRP laminates at three conditions of water absorption were carried out at various temperatures and strain rates. Furthermore, the three-point bending fatigue tests for these specimens were carried out at various temperatures and frequencies. The flexural CSR and fatigue strengths of these five kinds of FRP laminates strongly depend on water absorption as well as time and temperature. The mater curves of fatigue strength as well as CSR strength for these FRP laminates at three water absorption conditions are constructed by using the test data based on TTSP. It is possible to predict the long term fatigue life for these FRP laminates under an arbitrary temperature and water absorption conditions by using the master curves.

  5. Simulation of a long-term aquifer test conducted near the Rio Grande, Albuquerque, New Mexico

    USGS Publications Warehouse

    McAda, Douglas P.

    2001-01-01

    A long-term aquifer test was conducted near the Rio Grande in Albuquerque during January and February 1995 using 22 wells and piezometers at nine sites, with the City of Albuquerque Griegos 1 production well as the pumped well. Griegos 1 discharge averaged about 2,330 gallons per minute for 54.4 days. A three-dimensional finite-difference ground-water-flow model was used to estimate aquifer properties in the vicinity of the Griegos well field and the amount of infiltration induced into the aquifer system from the Rio Grande and riverside drains as a result of pumping during the test. The model was initially calibrated by trial-and-error adjustments of the aquifer properties. The model was recalibrated using a nonlinear least-squares regression technique. The aquifer system in the area includes the middle Tertiary to Quaternary Santa Fe Group and post-Santa Fe Group valley- and basin-fill deposits of the Albuquerque Basin. The Rio Grande and adjacent riverside drains are in hydraulic connection with the aquifer system. The hydraulic-conductivity values of the upper part of the Santa Fe Group resulting from the model calibrated by trial and error varied by zone in the model and ranged from 12 to 33 feet per day. The hydraulic conductivity of the inner-valley alluvium was 45 feet per day. The vertical to horizontal anisotropy ratio was 1:140. Specific storage was 4 x 10-6 per foot of aquifer thickness, and specific yield was 0.15 (dimensionless). The sum of squared errors between the observed and simulated drawdowns was 130 feet squared. Not all aquifer properties could be estimated using nonlinear regression because of model insensitivity to some aquifer properties at observation locations. Hydraulic conductivity of the inner-valley alluvium, middle part of the Santa Fe Group, and riverbed and riverside-drain bed and specific yield had low sensitivity values and therefore could not be estimated. Of the properties estimated, hydraulic conductivity of the upper part of

  6. Long-term flow-through column experiments and their relevance to natural granitoid weathering rates

    USGS Publications Warehouse

    White, Arthur F.; Schulz, Marjorie S.; Lawrence, Corey R.; Vivit, Davison V.; Stonestrom, David A.

    2017-01-01

    reaction (fresh granitoids) or increased slowly with time (weathered granitoids). Analysis of cumulative Na release indicated that plagioclase dissolution achieved steady state in 3 of the 4 fresh granitoids during the last decade of reaction. Surface-area normalized plagioclase dissolution rates exhibited a narrow range (0.95 to 1.26 10-13 moles m-2 s-1), in spite of significant stoichiometric differences (An0.21 to An0.50). Rates were an order of magnitude slower than previously reported in shorter duration experiments but generally 2 to 3 orders of magnitude faster than corresponding natural analogs. CrunchFlow simulations indicated that more than a hundredfold decrease in column flow rates would be required to produce near-saturation reaction affinities that would start to slow plagioclase weathering to real-world levels. Extending simulations to approximate long term weathering in naturally weathered profiles required additional decreases in the intrinsic plagioclase dissolution and kaolinite precipitation rates and relatively large decreases in the fluid flow rate, implying that exposure to reactive mineral surfaces is significantly limited in the natural environment compared to column experiments.

  7. Long-term flow-through column experiments and their relevance to natural granitoid weathering rates

    NASA Astrophysics Data System (ADS)

    White, Art F.; Schulz, Marjorie S.; Lawrence, Corey R.; Vivit, Davison V.; Stonestrom, David A.

    2017-04-01

    (fresh granitoids) or increased slowly with time (weathered granitoids). Analysis of cumulative Na release indicated that plagioclase dissolution achieved steady state in 3 of the 4 fresh granitoids during the last decade of reaction. Surface-area normalized plagioclase dissolution rates exhibited a narrow range (0.95-1.26 10-13 moles m-2 s-1), in spite of significant stoichiometric differences (An0.21 to An0.50). Rates were an order of magnitude slower than previously reported in shorter duration experiments but generally 2-3 orders of magnitude faster than corresponding natural analogs. CrunchFlow simulations indicated that more than a hundredfold decrease in column flow rates would be required to produce near-saturation reaction affinities that would start to slow plagioclase weathering to real-world levels. Extending simulations to approximate long term weathering in naturally weathered profiles required additional decreases in the intrinsic plagioclase dissolution and kaolinite precipitation rates and relatively large decreases in the fluid flow rate, implying that exposure to reactive mineral surfaces is significantly limited in the natural environment compared to column experiments.

  8. Long-term Monitoring Plan for the Shoal Underground Nuclear Test

    SciTech Connect

    Ahmed Hassan

    2005-02-01

    The flow and transport model of Shoal is used to design a three-well monitoring network to be part of the long-term monitoring network for the site and achieve two objectives: (1) detect the presence of radionuclides in case they migrate to the monitoring well locations, and (2) provide field data to compare with model predictions as part of the model validation process. Using three different quantitative approaches and the numerical groundwater flow and transport model developed for Shoal, three new monitoring well locations were identified from 176 different networks. In addition to the quantitative analyses using the numerical model, the development of the monitoring network for Shoal will also be subject to qualitative hydrogeologic interpretation during implementation. information will only be available during the fieldwork, it will be incorporated in the monitoring well design at the time of well installation. Finally, it should be noted that the CADD-CAP for Shoal, including the compliance boundary, is not yet approved. Should the compliance boundary change from the 1,000-year MCL contaminant boundary, well locations may also need to change. However, the analysis reported here provides a number of alternatives with reasonable detection efficiency.

  9. Long-term product consistency test of simulated 90-19/Nd HLW glass

    NASA Astrophysics Data System (ADS)

    Gan, X. Y.; Zhang, Z. T.; Yuan, W. Y.; Wang, L.; Bai, Y.; Ma, H.

    2011-01-01

    Chemical durability of 90-19/Nd glass, a simulated high-level waste (HLW) glass in contact with the groundwater was investigated with a long-term product consistency test (PCT). Generally, it is difficult to observe the long term property of HLW glass due to the slow corrosion rate in a mild condition. In order to overcome this problem, increased contacting surface ( S/ V = 6000 m -1) and elevated temperature (150 °C) were employed to accelerate the glass corrosion evolution. The micro-morphological characteristics of the glass surface and the secondary minerals formed after the glass alteration were analyzed by SEM-EDS and XRD, and concentrations of elements in the leaching solution were determined by ICP-AES. In our experiments, two types of minerals, which have great impact on glass dissolution, were found to form on 90-19/Nd HLW glass surface when it was subjected to a long-term leaching in the groundwater. One is Mg-Fe-rich phyllosilicates with honeycomb structure; the other is aluminosilicates (zeolites). Mg and Fe in the leaching solution participated in the formation of phyllosilicates. The main components of phyllosilicates in alteration products of 90-19/Nd HLW glass are nontronite (Na 0.3Fe 2Si 4O 10(OH) 2·4H 2O) and montmorillonite (Ca 0.2(Al,Mg) 2Si 4O 10(OH) 2·4H 2O), and those of aluminosilicates are mordenite ((Na 2,K 2,Ca)Al 2Si 10O 24·7H 2O)) and clinoptilolite ((Na,K,Ca) 5Al 6Si 30O 72·18H 2O). Minerals like Ca(Mg)SO 4 and CaCO 3 with low solubility limits are prone to form precipitant on the glass surface. Appearance of the phyllosilicates and aluminosilicates result in the dissolution rate of 90-19/Nd HLW glass resumed, which is increased by several times over the stable rate. As further dissolution of the glass, both B and Na in the glass were found to leach out in borax form.

  10. Test plan for long-term, low-temperature oxidation of BWR spent fuel

    SciTech Connect

    Einziger, R.E.

    1988-12-01

    Preliminary studies indicated the need for more spent fuel oxidation data in order to determine the probable behavior of spent fuel in a tuff repository. Long-term, low-temperature testing was recommended in a comprehensive technical approach to (1) confirm the findings of the short-term thermogravimetric analysis tests; (2) evaluate the effects of variables such as burnup, atmospheric moisture,and fuel type on the oxidation rate; and (3) extend the oxidation data base to representative repository temperatures and better define the temperature dependence of the operative oxidation mechanisms. This document presents the test plan to study the effects of atmospheric moisture and temperature on oxidation rate and phase formation using a large number of boiling-water reactor fuel samples. Tests will run for up to two years, use characterized fragmented and pulverized fuel samples, cover a temperature range of 110{degree}C to 175{degree}C, and be conducted with an atmospheric moisture content ranging from <{minus}55{degree}C to {approximately}80{degree}C dew point. After testing, the samples will be examined and made available for leaching testing. 15 refs., 2 figs., 2 tabs.

  11. Long-term soil organic carbon changes in cereal and ley rotations: model testing

    NASA Astrophysics Data System (ADS)

    Kynding Borgen, Signe; Dörsch, Peter; Krogstad, Tore; Azzaroli Bleken, Marina

    2015-04-01

    Reliable modeling of soil organic carbon (SOC) dynamics in agroecosystems is crucial to define mitigation strategies related to crop management on the farm scale as well as the regional scale. International climate agreements and national political decisions rely to a large extent on the National Greenhouse gas Inventory Reports that are submitted annually to the UNFCCC. However, lower tier methods are used to estimate SOC changes on cropland in most country reports. The application of mechanistic models in national greenhouse gas inventory estimation requires proper model testing against measurements in order to verify the estimated emissions. Few long-term field experiments measuring SOC stock changes have been conducted in Norway. We evaluate the performance of the Introductory Carbon Balance Model (ICBM) in simulating SOC changes over 60 years in a field experiment conducted in Ås from 1953-2013. The site is located in south-eastern Norway, on the boarder of the boreal and temperate climate zone, where the majority of the country's grain production occurs. The field trial consisted of four rotations: I) continuous cereal, II) cereal + row crops, III) 2 years of ley + 4 years of cereal, IV) 4 years of ley + 2 years of cereal, and four treatments per rotation: a) low NPK, b) high NPK, c) low NPK + FYM, and d) straw (on rotations I and II) or high NPK + FYM (on rotations III and IV). The annual external modifying factor of the decomposition rate was calculated based on daily minimum and maximum temperature, precipitation, relative humidity, wind speed, and net radiation, and adjusted for soil type and crop management according to default ICBM calibration. We present results of simulated C changes for the long term plots and explore options to improve parameter calibration. Finally, we provide suggestions for how problems regarding model verification can be handled with when applying the model on a national scale for inventory reporting.

  12. Quantifying long-term microelectrode array functionality using chronic in vivo impedance testing

    NASA Astrophysics Data System (ADS)

    Prasad, Abhishek; Sanchez, Justin C.

    2012-04-01

    Long-term acquisition of high-quality neural recordings is a cornerstone of neuroprosthetic system design. Mitigating the experimental variability of chronically implanted arrays has been a formidable task because the sensor recording sites can be influenced by biotic and abiotic responses. Several studies have implicated changes in electrical interface impedance as a preliminary marker to infer electrode viability. Microelectrode impedance plays an important role in the monitoring of low amplitude and high-resolution extracellular neural signals. In this work, we seek to quantify long-term microelectrode array functionality and derive an impedance-based predictor for electrode functionality that correlates the recording site electrical properties with the functional neuronal recordings in vivo. High temporal resolution metrics of this type would allow one to assess, predict, and improve electrode performance in the future. In a large cohort of animals, we performed daily impedance measurements and neural signal recordings over long periods (up to 21 weeks) of time in rats using tungsten microwire arrays implanted into the somatosensory cortex. This study revealed that there was a time-varying trend in the modulation of impedance that was related to electrode performance. Single units were best detected from electrodes at time points when the electrode entered into the 40-150 KΩ impedance range. This impedance trend was modeled across the full cohort of animals to predict future electrode performance. The model was tested on data from all animals and was able to provide predictions of electrode performance chronically. Insight from this study can be combined with knowledge of electrode materials and histological analysis to provide a more comprehensive predictive model of electrode failure in the future.

  13. The effect of physicians' long-term use of CPOE on their test management work practices.

    PubMed

    Callen, Joanne L; Westbrook, Johanna I; Braithwaite, Jeffrey

    2006-01-01

    To explore physicians' work practices in relation to their long-term use of a computerized physician order entry system (CPOE). A cross-sectional qualitative study was conducted in four clinical units in two large Australian teaching hospitals. One hospital had used CPOE for over 10 years to order all clinical laboratory and radiology tests and view test results and the other had used the computerized viewing facility of the system for over seven years with tests ordered manually. Data were collected by non-participatory observations of physicians (55 sessions) and 28 interviews. Content analysis of the observation field notes, reflections on observations and interview transcripts were conducted by two researchers independently. A thematic grounded theory approach was used to derive key themes that would explain physicians work practices associated with CPOE use. Three themes relating to physicians' established use of CPOE were identified: (1) the effect of the hospital and clinical environment; (2) changes to work practices; and (3) physicians' management of information. Physicians' test management work practices using CPOE were related to diversity between: the hospitals; the clinical units' environment, and the users of the system. Hospitals need to understand and analyze physicians' test management work practices prior to and during the implementation of CPOE to accommodate their diverse ways of working with computerized information systems. In the current mixed media environment, physicians' use of manual and computerized information systems for sourcing and recording information impacts on efficiency and patient safety.

  14. Children's and adults' spontaneous false memories: long-term persistence and mere-testing effects.

    PubMed

    Brainerd, C J; Mojardin, A H

    1998-10-01

    In studies of children's false memories of word lists, it has been found that false alarms are stable over long-term retention intervals (persistence effect), that the stability of false alarms can equal or exceed that of hits, that earlier memory tests increase the frequency of hits on later tests (true-memory inoculation effect), that earlier memory tests increase the frequency of false alarms on later tests (false-memory creation effect), and that test-induced increases in false alarms can equal or exceed increases for hits. We studied these phenomena in 6-, 8-, and 11-year-olds and in adults using short narratives about everyday objects and events. All of the phenomena were detected at all ages, but levels of spontaneous memory falsification were much higher than for word lists and patterns of developmental change were somewhat different. Important new findings were that the persistence effect and the false-memory creation effect were greatest for statements that would be regarded as factually incorrect reports of events in sworn testimony and that, like suggestive questioning, interviews that involve nonsuggestive recognition questions may nevertheless taint children's memories.

  15. The Effect of Physicians’ Long-term Use of CPOE on Their Test Management Work Practices

    PubMed Central

    Callen, Joanne L.; Westbrook, Johanna I.; Braithwaite, Jeffrey

    2006-01-01

    Objective To explore physicians’ work practices in relation to their long-term use of a computerized physician order entry system (CPOE). Design A cross-sectional qualitative study was conducted in four clinical units in two large Australian teaching hospitals. One hospital had used CPOE for over 10 years to order all clinical laboratory and radiology tests and view test results and the other had used the computerized viewing facility of the system for over seven years with tests ordered manually. Data were collected by non-participatory observations of physicians (55 sessions) and 28 interviews. Measurements Content analysis of the observation field notes, reflections on observations and interview transcripts were conducted by two researchers independently. A thematic grounded theory approach was used to derive key themes that would explain physicians work practices associated with CPOE use. Results Three themes relating to physicians’ established use of CPOE were identified: (1) the effect of the hospital and clinical environment; (2) changes to work practices; and (3) physicians’ management of information. Physicians’ test management work practices using CPOE were related to diversity between: the hospitals; the clinical units’ environment, and the users of the system. Conclusion Hospitals need to understand and analyze physicians’ test management work practices prior to and during the implementation of CPOE to accommodate their diverse ways of working with computerized information systems. In the current mixed media environment, physicians’ use of manual and computerized information systems for sourcing and recording information impacts on efficiency and patient safety. PMID:16929035

  16. Test plan for long-term, low-temperature oxidation of spent fuel, Series 1

    SciTech Connect

    Einziger, R.E.

    1986-06-01

    Preliminary studies indicated the need for more spent fuel oxidation data in order to determine the probable behavior of spent fuel in a tuff repository. Long-term, low-temperature testing was recommended in a comprehensive technical approach to: (1) confirm the findings of the short-term thermogravimetric analyses scoping experiments; (2) evaluate the effects of variables such as burnup, atmospheric moisture and fuel type on the oxidation rate; and (3) extend the oxidation data base ot representative repository temperatures and better define the temperature dependence of the operative oxidation mechanisms. This document presents the Series 1 test plan to study, on a large number of samples, the effects of atmospheric moisture and temperature on oxidation rate and phase formation. Tests will run for up to two years, use characterized fragmented, and pulverized fuel samples, cover a temperature range of 110{sup 0}C to 175{sup 0}C and be conducted with an atmospheric moisture content rangeing from <-55{sup 0}C to {similar_to}80{sup 0}C dew point. After testing, the samples will be examined and made available for leaching testing.

  17. Results from long-term dissolution tests using oxidized spent fuel

    SciTech Connect

    Wilson, C.N.

    1990-11-01

    Two semi-static dissolution tests using oxidized PWR spent fuel specimens are being conducted under ambient hot cell conditions in Nevada Test Site J-13 well water and unsealed fused silica vessels. The test specimens were oxidized at 250{degree}C in air to bulk oxygen-to-metal (O/M) values of 2.21 and 2.33. Following an initial 191-day test cycle, the specimens were restarted in fresh J-13 water for a second long-term test cycle. Results through the first 40 months of Cycle 2 are compared with results from similar tests at 25{degree}C and 85{degree}C using unoxidized spent fuel specimens. Increased concentrations of U, Am, Cm and NP were measured in 0.4-{mu}m filtered samples from the oxidized fuel tests compared to the unoxidized fuel tested at 25{degree}C; Pu concentrations were not affected by the fuel oxidation state. Most of the Am and Cm, and a portion of the Pu, measured in 0.4-{mu}m filtered samples was removed by 2-nm filtration. Fission product release results were normalized to specimen inventories and reported as fractional release. No attempt was made to normalize the data to surface area. Initial {sup 99}Tc release was greatly increased, and prolonged increases in the fractional release rates of {sup 99}Tc and {sup 129}I occurred as a result of fuel oxidation. Fractional release rates for {sup 137}Cs and {sup 90}Sr from oxidized fuel eventually decreased to levels similar to those observed with unoxidized fuel after equivalent testing times, suggesting that matrix dissolution rates normalized to fuel mass were not increased as a result of oxidation. 6 refs., 3 figs., 2 tabs.

  18. Some Trends in Radioactive Waste Form Behavior Revealed in Long-Term Field Tests

    SciTech Connect

    Ojovan, M. I.; Ojovan, N. V.; Startceva, I. V.; Barinov, A. S.

    2002-02-25

    Results from long-term field tests with borosilicate glass, cement and bitumen waste forms containing actual intermediate-level radioactive waste are summarized and discussed in the paper. Leaching behavior of the waste forms was evaluated by monitoring the contamination of contacting water. Measured leach rates of the three waste-form materials were in a narrow range in shallow subsurface repositories, but varied in a wide range at an open testing site owing to weathering of bitumen and cement materials. The repositories were opened after 12-year testing for visual examination, sampling and analysis. All retrieved waste forms were in good physical condition. The study has not revealed any negative changes in the waste glass. Some ageing processes were detected in cement and bitumen waste forms, which can positively (bitumen) or negatively (cement) affect physical and containment properties of these waste materials. It has been established that a significant proportion of the radioactive inventory in the bitumen waste form became associated with the bitumen phase. Phase separation of this radioactive bitumen has shown, than the asphaltene fraction is responsible for the major part of the radioactivity retained by the bitumen.

  19. Long-term stability testing of optical fibre Fabry-Perot temperature sensors

    NASA Astrophysics Data System (ADS)

    Polyzos, Dimitrios; Jinesh, Mathew; MacPherson, William N.; Maier, Robert R. J.

    2016-05-01

    Applications of fibre optic sensors at high temperatures have gained a huge interest recently, as they appeared to be suitable for temperature recording in harsh environments. In this paper, we are demonstrating two intrinsic Fabry-Perot (F-P) fibre optic sensors for high temperature monitoring. The sensors are consisting of a 125μm diameter single mode fibre (SMF28) and a 125μm diameter PCF ESM-12B pure fused silica fibre spliced to a SMF28, respectively. The result was a low finesse optical SMF-Cr-SMF, and SMF-Cr-PCF, sensor with cavity lengths varying from 50μm to 100μm. Both types of Fabry-Perot sensors were tested in a tube furnace over a temperature range from room temperature up to 1100°C. Following a number of annealing cycles, between the above mentioned temperatures range, very good repeatability of the phase response was achieved. During the cycling process, thermal stress relief takes place which makes the sensors suitable for temperature testing at temperatures just in excess of 1000°C. After initial cycling the sensors are subjected to long term stability tests. The phase response is stable, less than 4°C, over a period of 5 days at a temperature of 1050°C for both sensors. The temperature resolution is around 3°C.

  20. The long-term reliability of static and dynamic Quantitative Sensory Testing in healthy individuals.

    PubMed

    Marcuzzi, Anna; Wrigley, Paul J; Dean, Catherine M; Adams, Roger; Hush, Julia M

    2017-03-21

    Quantitative sensory tests (QST) have been increasingly used to investigate alterations in somatosensory function in a wide range of painful conditions. The interpretation of these findings is based on the assumption that the measures are stable and reproducible. To date, reliability of QST has been investigated for short test-retest intervals. The aim of this study was to investigate the long-term reliability of a multimodal QST assessment in healthy people, with testing conducted on three occasions over 4-months. Forty-two healthy people were enrolled in the study. Static and dynamic tests were performed, including cold and heat pain threshold (CPT, HPT), mechanical wind up (WUR), pressure pain threshold (PPT), two-point discrimination (TPD) and conditioned pain modulation (CPM). Systematic bias, relative reliability and agreement were analysed using repeated measure ANOVA, intraclass correlation coefficients (ICCs3,1) and standard error of the measurement (SEM), respectively. Static QST (CPT, HPT, PPT and TPD) showed good to excellent reliability (ICCs: 0.68 to 0.90). Dynamic QST (WUR and CPM) showed poor to good reliability (ICCs: 0.35 to 0.61). A significant linear decrease over time was observed for mechanical QST at the back (PPT and TPD) and for CPM (p<0.01). Static QST were stable over a period of 4 months; however, a small systematic decrease over time has been observed for mechanical QST. Dynamic QST showed considerable variability over time; in particular, CPM using PPT as the test stimulus did not show adequate reliability, suggesting that this test paradigm may be less useful for monitoring individuals over time.

  1. Long term testing of Microbial Fuel Cells: Comparison of different anode materials.

    PubMed

    Hidalgo, D; Tommasi, T; Velayutham, K; Ruggeri, B

    2016-11-01

    This paper focuses on the long term operation and testing of three Microbial Fuel Cells (MFC) having three different anode materials: commercial carbon felt (C-FELT), polyaniline-deposited carbon felt (C-PANI) and carbon-coated Berl saddles (C-SADDLES). A mixed consortium from seawater was used as inoculum and acetate was used as substrate. Tests were conducted for four months under 1000Ω external load. The maximum power generation was obtained by C-SADDLES (102mWm(-2)) followed by C-FELT and C-PANI, respectively. A similar trend was obtained with the evaluation of electrical energy produced: C-SADDLES (2222J), C-PANI (2183J) and C-FELT (2114J). However, the performance of C-PANI decreased over time, most evidently due to degradation or deactivation of deposited polyaniline by the microorganisms' activity. These results provide evidence that the three-dimensional structure, C-SADDLES, offers excellent biocompatibility, high specific surface area, high conductivity and most importantly these properties are maintained for a long period of time. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Long-term monitoring and field testing of an innovative multistory timber building

    NASA Astrophysics Data System (ADS)

    Omenzetter, Piotr; Morris, Hugh; Worth, Margaret; Kohli, Varun; Uma, S. R.

    2011-04-01

    An innovative three-story timber building, using self-centering, post-tensioned timber shear walls as the main horizontal load resisting system and lightweight composite timber-concrete floors, has recently been completed in Nelson, New Zealand. It is expected to be the trailblazer for similar but taller structures to be more widely adopted. Performance based standards require an advanced understanding of building responses and in order to meet the need for in-situ performance data the building has been subjected to forced vibration testing and instrumented for continuous monitoring using a total of about 90 data channels to capture its dynamic and long-term responses. The first part of the paper presents a brief discussion of the existing research on the seismic performance of timber frame buildings and footfall induced floor vibrations. An outline of the building structural system, focusing on the novel design solutions, is then discussed. This is followed by the description of the monitoring system. The paper emphasizes the need for optimal placement of a limited number of sensors and demonstrates how this was achieved for monitoring floor vibrations with the help of the effective independence-driving point residue (EfI-DPR) technique. A novel approach to the EfI-DPR method proposed here uses a combinatorial search algorithm that increases the chances of obtaining the globally optimal solution. Finally, the results from the forced vibration tests conducted on the whole building at different construction stages are reviewed.

  3. Long term materials test program. Quarterly report, October-December 1983

    SciTech Connect

    Not Available

    1984-01-01

    The long-term exposure of gas turbine vane and blade base alloys and a variety of protective coating systems to the effluent from a pressurized fluidized bed coal combustor has reached 4398 hours. After 4053 hours, FeCrAlY overlay coatings and platinum/rhodium-aluminide pack diffusion coatings show excellent resistance to corrosion attack at 1500/sup 0/F. Cobalt-base coatings are somewhat more susceptible to hot corrosion, and the unprotected nickel and cobalt-base alloys are most susceptible to corrosion, although corrosion rates have decreased to less than 1 mil/1000 hours for all materials at 1500/sup 0/F; i.e., corrosion penetration data is evolving parabolically. The three-stage cyclone cleanup system became severely distorted after approximately 5600 hours total service life. Distortion of the cyclones contributed to an increased dust loading to the material test sections, 110 to 250 ppM versus normal loadings of 30 to 90 ppM, for a period of about 75 hours. This increase in dust loading caused severe erosion of the airfoils in the high-velocity test section. Metal recession ranged 4 to 18 mils of leading edge loss on the impulse airfoils, and 11 to 27 mils of leading edge loss on the reaction airfoils. A new three-stage cyclone system was installed and dust loadings now range from 15 to 45 ppM.

  4. Long-term materials test program. Quarterly report, January-March 1983

    SciTech Connect

    1984-03-01

    Exposure of gas turbine materials to a PFBC effluent under the Long-Term Materials Test Program has reached 1507 hours. Unprotected nickel and cobalt base blade and vane alloys show susceptibility to hot corrosion at 1500/sup 0/F (gas temperature), 1300/sup 0/F, and 1100/sup 0/F (air-cooled pins). Precious metal aluminide and M (Co,Fe) CrAlY overlay coatings continue to show good resistance to corrosion above 1450/sup 0/F, but are susceptible to varying degrees of pitting attack between 1050 and 1300/sup 0/F. Significant erosion/corrosion degradation of both base alloys and protective coatings/claddings has been observed on airfoil specimens exposed at 1350/sup 0/F, 800 to 900 fps and dust loadings less than 100 ppM for 1085 hours. Corrosion predominately occurred in areas of direct particle impaction; i.e., leading edge and pressure surface, indicating an erosion/corrosion synergism. At gas velocities of 1200 to 1400 fps, a platinum-aluminide coated IN-738 pin experienced a metal recession rate of 8 mils/1000-hours. The PFBC facility continues to show excellent operational reliability, accumulating over 1100 test hours this quarter. The only concern from an operations standpoint is the gradual thinning of the in-bed heat exchanger tubing at a rate of about 5 mils/100 hours off the diameter.

  5. Long Term Materials Test Program. Quarterly report, July-September 1983

    SciTech Connect

    Not Available

    1984-04-01

    Corrosion and erosion/corrosion testing of gas turbine vane and blade base alloys and a variety of protective coating systems under the Long Term Materials Test program has surpassed 3400 hours. The PFBC facility at Malta, New York continues to show an exceptionally high degree of reliability and consistency in performance. Operating conditions include a 1650/sup 0/F bed temperature at 10 atmospheres pressures utilizing Pittsburgh No. 8 coal and a low alkali dolomite sulfur sorbent. After 2687 hours, unprotected nickel and cobalt base vane and blade alloys generally experienced corrosion rates of 1 to 2 mils/1000 hours at metal temperatures of 1100, 1300, and 1500/sup 0/F. Precious metal aluminide and MCrAlY coatings continue to show excellent corrosion resistance (<0.5 mils/1000 hrs) at 1500/sup 0/F, but are susceptible to varying degrees of pitting attack at 1100/sup 0/ and 1300/sup 0/F. Erosion/corrosion degradation rates at 800 to 900 fps., 1350/sup 0/F and less than 100 ppM dust loading ranged from 1 to 4 mils/1000 hours with corrosion predominately concentrated in areas of particle impaction indicating an erosion/corrosion synergism.

  6. Long-term performance of a 20-L continuous flow microbial fuel cell for treatment of brewery wastewater

    NASA Astrophysics Data System (ADS)

    Lu, Mengqian; Chen, Shing; Babanova, Sofia; Phadke, Sujal; Salvacion, Michael; Mirhosseini, Auvid; Chan, Shirley; Carpenter, Kayla; Cortese, Rachel; Bretschger, Orianna

    2017-07-01

    Microbial fuel cells (MFCs) have been shown as a promising technology for wastewater treatment. Integration of MFCs into current wastewater treatment plant have potential to reduce the operational cost and improve the treatment performance, and scaling up MFCs will be essential. However, only a few studies have reported successful scale up attempts. Fabrication cost, treatment performance and operational lifetime are critical factors to optimize before commercialization of MFCs. To test these factors, we constructed a 20 L MFC system containing two 10 L MFC reactors and operated the system with brewery wastewater for nearly one year. Several operational conditions were tested, including different flowrates, applied external resistors, and poised anodic potentials. The condition resulting in the highest chemical oxygen demand (COD) removal efficiency (94.6 ± 1.0%) was a flow rate of 1 mL min-1 (HRT = 313 h) and an applied resistor of 10 Ω across each MFC circuit. Results from each of the eight stages of operation (325 days total) indicate that MFCs can sustain treatment rates over a long-term period and are robust enough to sustain performance even after system perturbations. possible ways to improve MFC performance were discussed for future studies.

  7. Relationship between cerebral blood flow and blood pressure in long-term heart transplant recipients.

    PubMed

    Smirl, Jonathan D; Haykowsky, Mark J; Nelson, Michael D; Tzeng, Yu-Chieh; Marsden, Katelyn R; Jones, Helen; Ainslie, Philip N

    2014-12-01

    Heart transplant recipients are at an increased risk for cerebral hemorrhage and ischemic stroke; yet, the exact mechanism for this derangement remains unclear. We hypothesized that alterations in cerebrovascular regulation is principally involved. To test this hypothesis, we studied cerebral pressure-flow dynamics in 8 clinically stable male heart transplant recipients (62±8 years of age and 9±7 years post transplant, mean±SD), 9 male age-matched controls (63±8 years), and 10 male donor controls (27±5 years). To increase blood pressure variability and improve assessment of the pressure-flow dynamics, subjects performed squat-stand maneuvers at 0.05 and 0.10 Hz. Beat-to-beat blood pressure, middle cerebral artery velocity, and end-tidal carbon dioxide were continuously measured during 5 minutes of seated rest and throughout the squat-stand maneuvers. Cardiac baroreceptor sensitivity gain and cerebral pressure-flow responses were assessed with linear transfer function analysis. Heart transplant recipients had reductions in R-R interval power and baroreceptor sensitivity low frequency gain (P<0.01) compared with both control groups; however, these changes were unrelated to transfer function metrics. Thus, in contrast to our hypothesis, the increased risk of cerebrovascular complication after heart transplantation does not seem to be related to alterations in cerebral pressure-flow dynamics. Future research is, therefore, warranted. © 2014 American Heart Association, Inc.

  8. Long-term tracking of neutrally buoyant tracer particles in two-dimensional fluid flows

    NASA Astrophysics Data System (ADS)

    Pervez, M. S.; Solomon, T. H.

    1994-07-01

    An experimental technique has been developed to produce and to track neutrally buoyant particles in a two-dimensional fluid flow. The key aspect of the technique is the ability to track particles for extended intervals (over an hour), which is essential for quantitative studies of transport and mixing. The approach is composed of two stages. In the first stage, digital image processing hardware partially processes the images, reducing the data rate to 50 kbyte/s (typically) and allowing several hours of data to be stored on a conventional computer disk. In the second stage, programs extract particle trajectories from the reduced data. The approach is tested in an experiment on planetary-type flows in a rotating annulus. In an appendix, a technique is discussed for fabricating wax or crayon particles with arbitrary density.

  9. Optimizing laboratory test utilization in long-term acute care hospitals

    PubMed Central

    Krug, Brian S.; Grigonis, Antony M.; Dawson, Amanda; Jing, Yuqing; Hammerman, Samuel I.

    2017-01-01

    Laboratory tests can be considered inappropriate if overused or when repeated, unnecessary “routine” testing occurs. For chronically critically ill patients treated in long-term acute care hospitals (LTACHs), inappropriate testing may result in unnecessary blood draws that could potentially harm patients or increase infections. A quality improvement initiative was designed to increase physician awareness of their patterns of lab utilization in the LTACH environment. Within a large network of LTACHs, 9 hospitals were identified as having higher patterns of lab utilization than other LTACHs. Meetings were held with administrative staff and physicians, who designed and implemented hospital-specific strategies to address lab utilization. Lab utilization was measured in units of lab tests ordered per inpatient day (lab UPPD) for 8 months prior to the initial meeting and 7 months after the meeting. A repeated measures mixed model determined that postintervention lab utilization improved, on average and adjusted by case mix index, by 0.37 lab UPPD (t = −3.61, 95% CI 0.17 to 0.58) compared to the preintervention period. Overall, the case mix index 8 months prior to the intervention was no different than it was 7 months after the initial meeting (t[8] = −0.96, P = 0.37). Patient safety and outcome measures, including percentage of patients weaned from a ventilator, readmission rates, central catheter utilization rates, and the incidence of methicillin-resistant Staphylococcus aureus and other multidrug resistant organisms, showed no significant change. Hospital staff meetings focused on lab utilization and the development and deployment of tailored lab utilization strategies were associated with LTACHs achieving significantly lower lab utilization without negatively impacting quality outcomes. PMID:28127124

  10. Quality testing of autoclaved rodent drinking water during short-term and long-term storage.

    PubMed

    Peveler, Jessica L; Crisler, Robin; Hickman, Deb

    2015-06-01

    All animals need clean water to drink. At the authors' animal facility, drinking water for immunocompromised rodents is filtered by reverse osmosis, acidified during bottling and sterilized in an autoclave. Autoclaved water bottles can be stored in unopened autoclave bags for 7 d or in opened bags for 2 d; if not used during that time, they are emptied, cleaned, refilled and sterilized again. The authors wished to determine whether the storage period of 2-7 d was adequate and necessary to ensure the quality of drinking water. They tested water bottles for pH levels and for the presence of adenosine triphosphate as a measure of organic contamination during short-term and long-term storage. The pH of autoclaved drinking water generally remained stable during storage. Furthermore, no instances of organic contamination were detected in autoclaved water bottles stored for up to 22 d in unopened bags and only one instance was detected in bottles stored for up to 119 d in opened bags in a room with individually ventilated cages. On the basis of these findings, the acceptable storage period for autoclaved water bottles in opened bags at the authors' facility was extended to 21 d.

  11. Long-term laser irradiation tests of optical elements for ESA mission ADM-Aeolus

    NASA Astrophysics Data System (ADS)

    Leinhos, Uwe; Mann, Klaus; Bayer, Armin; Endemann, Martin; Wernham, Denny; Pettazzi, Federico; Thibault, Dominique

    2010-08-01

    The European Space Agency ESA is running a series of earth observation missions. In order to perform global windprofile observation based on Doppler-LIDAR, the satellite ADM-Aelolus will be launched in April 2011 and injected into an orbit 400 km above Earth's surface. ADM-Aeolus will be the first satellite ever that is equipped with a UV-laser (emitting at 355 nm) and a reflector telescope. At LLG, a setup was developed that allows monitoring transmission, reflection and fluorescence of laser-irradiated optical components, in order to assess their possible optical degradation due to radiation-induced contaminant deposition in orbit. For both a high-reflecting mirror and an anti-reflective coated window long-term irradiation tests (up to 500 million laser pulses) were performed at a base pressure < 10-9 mbar, using a XeF excimer laser (wavelength 351 nm, repetition rate 1kHz). At this, samples of polymers used inside the satellite (insulators for cabling, adhesives, etc.) were installed into the chamber, and the interaction of their degassing with the sample surfaces under laser irradiation was investigated. Various paramters were varied including pulse repetition rate, view factor and coatings. Optical degradation associated with contaminant adsorption was detected on the irradiated sample sites.

  12. Connectivity structures local population dynamics: a long-term empirical test in a large metapopulation system.

    PubMed

    Castorani, Max C N; Reed, Daniel C; Alberto, Filipe; Bell, Tom W; Simons, Rachel D; Cavanaugh, Kyle C; Siegel, David A; Raimondi, Peter T

    2015-12-01

    Ecological theory predicts that demographic connectivity structures the dynamics of local populations within metapopulation systems, but empirical support has been constrained by major limitations in data and methodology. We tested this prediction for giant kelp Macrocystis pyrifera, a key habitat-forming species in temperate coastal ecosystems worldwide, in southern California, USA. We combined a long-term (22 years), large-scale (~500 km coastline), high-resolution census of abundance with novel patch delineation methods and an innovative connectivity measure incorporating oceanographic transport and source fecundity. Connectivity strongly predicted local dynamics (well-connected patches had lower probabilities of extinction and higher probabilities of colonization, leading to greater likelihoods of occupancy) but this relationship was mediated by patch size. Moreover, the relationship between connectivity and local population dynamics varied over time, possibly due to temporal variation in oceanographic transport processes. Surprisingly, connectivity had a smaller influence on colonization relative to extinction, possibly because local ecological factors differ greatly between extinct and extant patches. Our results provide the first comprehensive evidence that southern California giant kelp populations function as a metapopulation system, challenging the view that populations of this important foundation species are governed exclusively by self-replenishment.

  13. Long term culture of epithelia in a continuous fluid gradient for biomaterial testing and tissue engineering.

    PubMed

    Minuth, W W; Strehl, R; Schumacher, K; de Vries, U

    2001-01-01

    Epithelia perform barrier functions being exposed to different fluids on the luminal and basal side. For long-term testing of new biomaterials as artificial basement membrane substitutes, it is important to simulate this fluid gradient. Individually-selected biomaterials can be placed in tissue carriers and in gradient containers, where different media are superfused. Epithelia growing on the tissue carriers form a physiological barrier during the whole culture period. Frequently however, pressure differences between the luminal and basal compartments occur. This is caused by a unilateral accumulation of gas bubbles in the container compartments resulting in tissue damage. Consequently, the occurence of gas bubbles has to be minimized. Air bubbles in the perfusion culture medium preferentially accumulate at sites where different materials come into contact. The first development is new screw caps for media bottles, specifically designed to allow fluid contact with only the tube and not the cap material. The second development is the separation of remaining gas bubbles from the liquid phase in the medium using newly-developed gas expander modules. By the application of these new tools, the yield of embryonic renal collecting duct epithelia with intact barrier function on a fragile natural support material can be significantly increased compared to earlier experiments.

  14. Long-term aging and loss-of-coolant accident (LOCA) testing of electrical cables

    SciTech Connect

    Nelson, C.F.; Gauthier, G.; Carlin, F.

    1996-10-01

    Experiments were performed to assess the aging degradation and loss-of-coolant accident (LOCA) behavior of electrical cables subjected to long-term aging exposures. Four different cable types were tested in both the U.S. and France: (1) U.S. 2 conductor with ethylene propylene rubber (EPR) insulation and a Hypalon jacket. (2) U.S. 3 conductor with cross-linked polyethylene (XLPE) insulation and a Hypalon jacket. (3) French 3 conductor with EPR insulation and a Hypalon jacket. (4) French coaxial with polyethylene (PE) insulation and a PE jacket. The data represent up to 5 years of simultaneous aging where the cables were exposed to identical aging radiation doses at either 40{degrees}C or 70{degrees}C; however, the dose rate used for the aging irradiation was varied over a wide range (2-100 Gy/hr). Aging was followed by exposure to simulated French LOCA conditions. Several mechanical, electrical, and physical-chemical condition monitoring techniques were used to investigate the degradation behavior of the cables. All the cables, except for the French PE cable, performed acceptably during the aging and LOCA simulations. In general, cable degradation at a given dose was highest for the lowest dose rate, and the amount of degradation decreased as the dose rate was increased.

  15. Flow barrier system for long-term high-level-waste isolation: Experimental results

    SciTech Connect

    Conca, J.L.; Apted, M.J.; Zhou, W.; Arthur, R.C.; Kessler, J.H.

    1998-10-01

    A flow barrier system (FBS) that includes a Richards barrier acts in an unsaturated hydrogeologic system to prevent the advective flow of water down through the barrier. Thus, an FBS placed above any solid waste material buried in the unsaturated zone could greatly aid in isolating the waste by keeping the waste away from flowing water. The FBS, consisting of a layer of highly conductive, fine-grained material overlying a sloped gravel layer, is proposed to isolate high-level radioactive waste (HLW) at a candidate disposal facility located in the unsaturated zone at Yucca Mountain in Nevada. A series of laboratory experiments were conducted to (a) assure that the FBS of a specific design can divert the anticipated maximum advective flow (under ideal conditions as well as for the case of a disturbed interface between the two layers caused by, for example, improper initial emplacement or faulting due to seismic activity), (b) investigate water inhibition into the gravel, and (c) measure the diffusion coefficient of the tuff gravel under partially saturated conditions. The main results show that (a) the FBS used in the study can divert point-source flow rates as high as 2.6 {times} 10{sup 5} {ell}/yr; (b) this FBS will continue performing with offsets of the interface as great as 50 cm or more; (c) after 12 months of testing, moisture penetrates the gravel only several grain diameters; and (d) the gravel effective diffusion coefficient is <10{sup {minus}11} cm{sup 2}/s under such low partial saturations. These results indicate that a properly designed FBS can be successful at isolating the HLW under the anticipated range of environmental conditions that exist both now and in the future at Yucca Mountain.

  16. Long-Term Reliability of SiGe/Si HBTs From Accelerated Lifetime Testing

    NASA Technical Reports Server (NTRS)

    Bhattacharya, Pallab

    2001-01-01

    Accelerated lifetime tests were performed on double-mesa structure Si(0.7)Ge(0.3)/Si npn heterojunction bipolar transistors, grown by molecular beam epitaxy, in the temperature range of 175 C-275 C. The transistors (with 5x20 sq micron emitter area) have DC current gains approx. 40-50 and f(sub T) and f(sub max) of up to 22 GHz and 25 GHz, respectively. It is found that a gradual degradation in these devices is caused by the recombination enhanced impurity diffusion (REID) of boron atoms from the p-type base region and the associated formation of parasitic energy barriers to electron transport from the emitter to collector layers. This REED has been quantitatively modeled and explained, to the first order of approximation, and the agreement with the measured data is good. The mean time to failure (MTTF) of these devices at room temperature under 1.35 x 10(exp 4) A/sq cm current density operation is estimated from the extrapolation of the Arrhenius plots of device lifetime versus reciprocal temperature. The results of the reliability tests offer valuable feedback for SiGe heterostructure design in order to improve the long-term reliability of the devices and circuits made with them. Hot electron induced degradation of the base-emitter junction was also observed during the accelerated lifetime testing. In order to improve the HBT reliability endangered by the hot electrons, deuterium sintered techniques have been proposed. The preliminary results from this study show that a deuterium-sintered HBT is, indeed, more resistant to hot-electron induced base-emitter junction degradation.

  17. Atomic oxygen ground-based accelerated tests of spacecraft materials and structures for long-term LEO missions

    NASA Astrophysics Data System (ADS)

    Chernik, Vladimir; Novikov, Lev; Smirnova, Tatyana; Shumov, Andrey

    Spacecraft materials are degradated during long-term low earth orbit (LEO) flight. The Internation Space Station (ISS) is planed to be prolonged the term of action up to 20-25 years. To specify so long life one requires a validation of spacecraft material behaviour conservation for the period. The LEO environment includes atomic oxygen (AO) destructive incident flow. The appropriate AO fluence is proposed to be as high as 10E22-10E23 atom O/sq cm. The simulative ground-based test is evident to be acceptable if its duration is not too long usually under several hundreds of hours. In that case the rate of the test acceleration exceeds 100-200. One way to accelerate test is to increase oxygen particles energy. We test materials under oxygen plasma beam, formed by a magnetoplasmadynamic accelerator, with the oxygen particle energy of 20 -30 eV. In this way we determine an AO effective fluence by a kapton equivalent technique. The beam varies from LEO incident flow by energy, flux and rates of the oxygen dissociation / ionization/ excitation. To evaluate the test adequacy we measured and compared with LEO data erosion yields of a number of polymer materials, applied on spacecraft external surfaces. There were: polyimide (kapton), polyamide (nylon), polyethylene, polyvinyl fluoride (tedlar), polysteren, polymethyl methacrylate, epoxy, polyethylene terephthalate (mylar), graphite. Their relative erosion yields, measured and normalized by polyimide in this way, practically coincide with the data of flight experiments on the ISS. The results ground to use our plasma mode for accelerated tests of spacecraft material durability for long-term LEO flights. We tested quite a number of polymer-based materials and structures usable on ISS and another LEO spacecrafts. The effective AO fluencies ran up to 3,5 10E22 atom O/sq cm corresponding to the ISS flight duration about 20 years. We studied material behaviors like mass and thickness losses, erosion yield, surface morphology

  18. Long-term animal experiments with an intraventricular axial flow blood pump.

    PubMed

    Yamazaki, K; Kormos, R L; Litwak, P; Tagusari, O; Mori, T; Antaki, J F; Kameneva, M; Watach, M; Gordon, L; Mukuo, H; Umezu, M; Tomioka, J; Outa, E; Griffith, B P; Koyanagai, H

    1997-01-01

    A miniature intraventricular axial flow blood pump (IVAP) is undergoing in vivo evaluation in calves. The IVAP system consists of a miniature (phi 13.9 mm) axial flow pump that resides within the left ventricular (LV) chamber and a brushless DC motor. The pump is fabricated from titanium alloy, and the pump weight is 170 g. It produces a flow rate of over 5 L/min against 100 mmHg pressure at 9,000 rpm with an 8 W total power consumption. The maximum total efficiency exceeds 17%. A purged lip seal system is used in prototype no. 8, and a newly developed "Cool-Seal" (a low temperature mechanical seal) is used in prototype no. 9. In the Cool-Seal system, a large amount of purge flow is introduced behind the seal faces to augment convective heat transfer, keeping the seal face temperature at a low level for prevention of heat denaturation of blood proteins. The Cool-Seal system consumes < 10 cc purge fluid per day and has greatly extended seal life. The pumps were implanted in three calves (26, 30, and 168 days of support). The pump was inserted through a left thoracotomy at the fifth intercostal space. Two pursestring sutures were placed on the LV apex, and the apex was cored with a myocardial punch. The pump was inserted into the LV with the outlet cannula smoothly passing through the aortic valve without any difficulty. Only 5 min elapsed between the time of chest opening and initiation of pumping. Pump function remained stable throughout in all experiments. No cardiac arrhythmias were detected, even at treadmill exercise tests. The plasma free hemoglobin level remained in the acceptable range. Post mortem examination did not reveal any interference between the pump and the mitral apparatus. No major thromboembolism was detected in the vital organs in Cases 1 or 2, but a few small renal infarcts were detected in Case 3.

  19. Effects of Repeated Testing on Short- and Long-Term Memory Performance across Different Test Formats

    ERIC Educational Resources Information Center

    Stenlund, Tova; Sundström, Anna; Jonsson, Bert

    2016-01-01

    This study examined whether practice testing with short-answer (SA) items benefits learning over time compared to practice testing with multiple-choice (MC) items, and rereading the material. More specifically, the aim was to test the hypotheses of "retrieval effort" and "transfer appropriate processing" by comparing retention…

  20. Effects of Repeated Testing on Short- and Long-Term Memory Performance across Different Test Formats

    ERIC Educational Resources Information Center

    Stenlund, Tova; Sundström, Anna; Jonsson, Bert

    2016-01-01

    This study examined whether practice testing with short-answer (SA) items benefits learning over time compared to practice testing with multiple-choice (MC) items, and rereading the material. More specifically, the aim was to test the hypotheses of "retrieval effort" and "transfer appropriate processing" by comparing retention…

  1. Reconstruction of the thoracic wall-long-term follow-up including pulmonary function tests.

    PubMed

    Daigeler, Adrien; Druecke, Daniel; Hakimi, Mitra; Duchna, Hans-Werner; Goertz, Ole; Homann, Heinz-Herbert; Lehnhardt, Marcus; Steinau, Hans-Ulrich

    2009-07-01

    Thoracic wall reconstructions have become a standard procedure for the reconstructive plastic surgeon in the larger hospital setting, but detailed reports about long-term results including pulmonary function and physical examination are rare. The data of 92 consecutive patients with full thickness chest wall resections were acquired from patient's charts and contact to patients, their relatives or general practitioners, with special reference to treatment and clinical course. At a mean follow-up of 5.5 years, 36 patients were examined physically and interviewed. Twenty-seven of them underwent additional pulmonary function tests. Kaplan-Meier method was used to calculate survival. Regression tests were undertaken to identify factors influencing the outcome. Postoperative complications were observed in 42.4%, but neither mesh implantation nor the size of the defect contributed significantly. The 5-year mortality was worse for patients with recurrent mamma carcinoma (90.6%) than for patients with soft tissue sarcoma (56.3%). No medical history or operation parameter (resection size and localization) besides the general patients' conditions increased mortality. Pulmonary function parameters were only moderately reduced and not significantly affected by the resections' size or its localization. Majority of patients suffer from sensation disorders and motion-dependent pain, which contributed significantly to hypoxemia. Quality-of-life parameters were significantly reduced compared to the healthy control group but similar to the control group with cancer according to the Short Form-36 protocol. We could not detect a relevant decrease in quality of life comparing post- to preoperative values. Thoracic wall reconstruction provides sufficient thoracic wall stability to maintain pulmonary function, but postoperative pain and sensation disorders are considerable. However, chest wall repair can contribute to palliation and even cure after full-thickness resections.

  2. Long-term laser induced contamination tests of optical elements under vacuum at 351nm

    NASA Astrophysics Data System (ADS)

    Leinhos, Uwe; Mann, Klaus; Bayer, Armin; Dette, Jens-Oliver; Schöneck, Matthias; Endemann, Martin; Wernham, Denny; Petazzi, Federico; Tighe, Adrian; Alves, Jorge; Thibault, Dominique

    2010-11-01

    Photon-induced contamination of optical surfaces is a major obstacle for space-bound laser applications. At Laser-Laboratorium Göttingen, a setup was developed that allows monitoring transmission, reflection and fluorescence of laser-irradiated optical components under well-controlled vacuum conditions, in order to assess their possible optical degradation due to radiation-induced contaminant deposition in orbit. In cooperation with the European Space Agency ESA optical elements for the ADM-Aelolus mission were investigated. In order to perform global wind-profile observation based on Doppler-LIDAR, the satellite ADM-Aelolus will be launched in 2011 and injected into an orbit 400 km above Earth's surface. ADM-Aeolus will be the first satellite ever that is equipped with a UV-laser (emitting at a wavelength of 355 nm) and a reflector telescope. For both high-reflecting mirrors and an anti-reflective coated windows long-term irradiation tests (up to 500 million laser pulses per test run) were performed at a base pressure < 10-9 mbar, using a XeF excimer laser (λ=351 nm, repetition rate 1kHz). At this, samples of polymers used inside the satellite (insulators for cabling, adhesives, etc.) were installed into the chamber, and the interaction of their degassing with the sample surfaces under laser irradiation was investigated. Optical degradation associated with contaminant adsorption was detected on the irradiated sample sites as a function of various parameters, including pulse repetition rate, view factor and coating material

  3. A test of our society: how and for whom we finance long-term care.

    PubMed

    Merrill, J

    1992-01-01

    Financing long-term care remains an issue of great national interest, but little action. This lack of action is due to a lack of consensus regarding both what we mean by long-term care and what roles the private and public sectors should play. Different solutions have been offered, some focusing on the public sector and others on the private. The reality is that financing the needed care will require participation of both sectors, as well as a redefinition of their roles that makes them complementary rather than competitive, as is now the case. This partnership can take many forms, but must, at a minimum, reflect an explicit societal commitment to what our population is entitled to with respect to long-term care; develop the infrastructure that meets the total--as opposed to only the medical--needs of the population; and make more efficient use of the resources that can be brought to bear on the problem.

  4. Genetic Testing For Alzheimer’s And Long-Term Care Insurance

    PubMed Central

    Taylor, Donald H.; Cook-Deegan, Robert M.; Hiraki, Susan; Roberts, J. Scott; Blazer, Dan G.; Green, Robert C.

    2010-01-01

    A genetic marker known as apolipoprotein E provides a clear signal of a person’s risk of developing Alzheimer’s disease and thus that person’s future need for long-term care. People who find that they have the variant of the trait that increases Alzheimer’s disease risk are more likely to purchase long-term care insurance after receiving this information. If the information is widely introduced into the insurance market, coverage rates could be affected in different ways, depending on who possesses that information. Policymakers will eventually need to confront the issue of the use of this and other markers in the pricing of long-term care insurance. PMID:20048367

  5. Lunar heat-flow experiment: Long term temperature observations on the lunar surface at Apollo sites 15 and 17

    NASA Technical Reports Server (NTRS)

    Peters, K.

    1975-01-01

    Several investigators of the Apollo lunar experiments have observed gradual increases in the mean temperatures recorded by various surface thermometers. Similar effects were noticed in the temperatures of the thermometers of the Apollo 15 and 17 Heat Flow Experiments. An analysis of the long term temperature histories of the heat flow experiment thermometers is presented. These data show that no change in mean surface temperature at the Apollo 15 and 17 sites has occurred, and suggest that the slow increase in mean temperatures of thermometers in the electronics housing are due to changes in radiative properties of the housing's surfaces.

  6. Enhanced long-term organics and nitrogen removal and associated microbial community in intermittently aerated subsurface flow constructed wetlands.

    PubMed

    Fan, Jinlin; Zhang, Jian; Guo, Wenshan; Liang, Shuang; Wu, Haiming

    2016-08-01

    The long-term enhanced removal efficiency of organics and nitrogen in subsurface flow constructed wetlands (SSF CWs) with and without intermittent aeration for decentralized domestic wastewater was evaluated, and the function of intermittent aeration on microbial community was also investigated in this study. The high and long-term 95.6% COD, 96.1% NH4(+)-N and 85.8% TN removal efficiencies were achieved in experimental intermittently aerated SSF CW compared with non-aerated SSF CW. Aerated SSF CWs also exhibited the excellent removal performance when comparatively comparing with other strategies and techniques applied in CWs. In addition, fluorescence in situ hybridization (FISH) analysis revealed that associated microbial abundance significantly increased owing to intermittent aeration. These results indicated intermittent aeration CWs might be an effective and sustainable strategy for wastewater treatment in rural areas, but require further full-scale investigation in future.

  7. Long-term explosive degassing and debris flow activity at West Mata submarine volcano

    NASA Astrophysics Data System (ADS)

    Dziak, R. P.; Bohnenstiehl, D. R.; Baker, E. T.; Matsumoto, H.; Caplan-Auerbach, J.; Embley, R. W.; Merle, S. G.; Walker, S. L.; Lau, T.-K.; Chadwick, W. W.

    2015-03-01

    West Mata is a 1200 m deep submarine volcano where explosive boninite eruptions were observed in 2009. The acoustic signatures from the volcano's summit eruptive vents Hades and Prometheus were recorded with an in situ (~25 m range) hydrophone during ROV dives in May 2009 and with local (~5 km range) moored hydrophones between December 2009 and August 2011. The sensors recorded low frequency (1-40 Hz), short duration explosions consistent with magma bubble bursts from Hades, and broadband, 1-5 min duration signals associated with episodes of fragmentation degassing from Prometheus. Long-term eruptive degassing signals, recorded through May 2010, preceded a several month period of declining activity. Degassing episodes were not recorded acoustically after early 2011, although quieter effusive eruption activity may have continued. Synchronous optical measurements of turbidity made between December 2009 and April 2010 indicate that turbidity maxima resulted from occasional south flank slope failures triggered by the collapse of accumulated debris during eruption intervals.

  8. Long-term leaching tests with high ash fusion Maryland coal slag

    SciTech Connect

    Browman, M.G. )

    1991-03-01

    The main objective of this project was to investigate the potential environmental impact of the storage or disposal of coal gasification residues. In this regard, this investigation examined the quality of leachate produced during the long-term outdoor storage slag generated at the TVA 200-t/d Texaco gasifier in Muscle Shoals, Alabama. Evaluative laboratory extraction tests were also conducted on both the coarse and fine slag. Leachate quality was tracked in both the surface water and the water at depth after it percolated through the slag pile (leachate well water) by measuring pH and conductivity on a weekly basis and toxic trace elements and other chemical species quarterly or at longer intervals. The major species observed in the leachate well water were Ca and Mg cations as well as sulfate anions. The average electrical conductivity measured in the leachate well water was 2503 {mu}mhos/cm. The measured pH decreased from an initial value of 8.2 and stabilized at about 7.1 with occasional excursions to values as low as 6.3 during dry periods. Concurrently, sulfate concentrations averaged 1083 mg/l with occasional peaks as high as 2600 mg/l. Fe and Mn concentrations measured in the leachate well waters averaged 2.0 and 1.68 mg/l, respectively. Concentrations of species for which Primary Maximum Contaminant Limits (MCLs) for public drinking water supplies have been established were generally below the primary limits with the exception of Se and F which exceeded the limits occasionally. Concentrations of Fe, Mn, sulfate, and total dissolved solids were markedly above the Secondary MCLs set for these species. 35 refs., 2 figs., 21 tabs.

  9. Test of a motor theory of long-term auditory memory.

    PubMed

    Schulze, Katrin; Vargha-Khadem, Faraneh; Mishkin, Mortimer

    2012-05-01

    Monkeys can easily form lasting central representations of visual and tactile stimuli, yet they seem unable to do the same with sounds. Humans, by contrast, are highly proficient in auditory long-term memory (LTM). These mnemonic differences within and between species raise the question of whether the human ability is supported in some way by speech and language, e.g., through subvocal reproduction of speech sounds and by covert verbal labeling of environmental stimuli. If so, the explanation could be that storing rapidly fluctuating acoustic signals requires assistance from the motor system, which is uniquely organized to chain-link rapid sequences. To test this hypothesis, we compared the ability of normal participants to recognize lists of stimuli that can be easily reproduced, labeled, or both (pseudowords, nonverbal sounds, and words, respectively) versus their ability to recognize a list of stimuli that can be reproduced or labeled only with great difficulty (reversed words, i.e., words played backward). Recognition scores after 5-min delays filled with articulatory-suppression tasks were relatively high (75-80% correct) for all sound types except reversed words; the latter yielded scores that were not far above chance (58% correct), even though these stimuli were discriminated nearly perfectly when presented as reversed-word pairs at short intrapair intervals. The combined results provide preliminary support for the hypothesis that participation of the oromotor system may be essential for laying down the memory of speech sounds and, indeed, that speech and auditory memory may be so critically dependent on each other that they had to coevolve.

  10. An intelligent flow control system for long term fluid restriction in small animals.

    PubMed

    Zheng, Can; Li, Meihua; Kawada, Toru; Uemura, Kazunori; Inagaki, Masashi; Sugimachi, Masaru

    2013-01-01

    Fluid retention is one of the most common symptoms in patients with chronic heart failure. Although fluid restriction may be a therapeutic strategy, the degree of fluid restriction necessary for the best therapeutic outcome remains unknown partly due to the lack of proper experimental method to restrict water consumption in small animals. The traditional methods that allow animals to access water only in a limited time window or within pre-determined daily volume can be stressful because the animals may become thirsty during the time of water deprivation. To provide a less stressful water restriction paradigm, we designed a feedback-control system of drinking flow to modulate the drinking behavior of small animals. This system consisted of an infrared droplet sensor for monitoring the drinking flow and a computer controlled electric valve to regulate the water availability. A light signal which synchronized with the command for opening the valve was set to establish a conditioned reflex. An animal test indicated that rats were adaptable to a precisely programmed water supply. This system may warrant investigation into the consequences of fluid restriction in chronic experimental animal study.

  11. Development and Testing of a Simple Calibration Technique for Long-Term Hydrological Impact Assessment (L-THIA) Model

    NASA Astrophysics Data System (ADS)

    Muthukrishnan, S.; Harbor, J.

    2001-12-01

    models that focus strictly on surface runoff, is that many users are interested in predictions of runoff that match observations of flow in streams and rivers. To make L-THIA more useful for the planners and engineers alike, a simple, long-term calibration method based on linear regression of L-THIA predicted and observed surface runoff has been developed and tested here. The results from Little Eagle Creek (LEC) in Indiana show that such calibrations are successful and valuable. This method can be used to calibrate other simple rainfall-runoff models too.

  12. Simulating soil C dynamics with EPIC: Model description and testing against long-term data

    SciTech Connect

    Izaurralde, R Cesar C.; Williams, Jimmy R.; Mcgill, William B.; Rosenberg, Norman J.; Quiroga Jakas, Maria C.

    2006-01-01

    Soil carbon sequestration (SCS) has emerged as a technology with significant potential to help stabilize atmospheric CO2 concentrations and thus reduce the threat of global warming. Methods and models are needed to evaluate and recommend SCS practices based on their effects on carbon dynamics and environmental quality. EPIC (Environment Policy Integrated Climate) is a widely used and tested model for simulating many agroecosystem processes including plant growth, crop yield, tillage, wind and water erosion, runoff, soil density, and leaching. Here we describe new C and N modules developed in EPIC built on concepts from the Century model to connect the simulation of soil C dynamics to crop management, tillage methods, and erosion processes. The added C and N routines interact directly with soil moisture, temperature, erosion, tillage, soil density, leaching, and translocation functions in EPIC. Equations were also added to describe the effects of soil texture on soil C stabilization. Lignin concentration is modeled as a sigmoidal function of plant age. EPIC was tested against data from a Conservation Reserve Program (CRP) 6-yr experiment at five sites in three U.S. Great Plains states and a 61-y long-term agronomic experiment in Canada. Mean Square Deviations (MSD) calculated for CRP sites were less than 0.01 kg C2 m2, except for one site where it reached 0.025 kg2 C2 m. MSD values in the 61-y experiment ranged between 0.047 and 0.077 kg C2 m2. In conclusion, the version of the EPIC model presented and tested here contains the necessary algorithms to simulate SCS and improve understanding of the interactions among soil erosion, C dynamics, and tillage. A strength of the model as tested is its ability to explain the variability in crop production, C inputs and SOC and N cycling over a wised range soil, cropping and climatic conditions over periods from 6 to 61 years. For example, at the Breton site over 61 years, EPIC accounted for 69% of the variability in grain

  13. Tracing long-term vadose zone processes at the Nevada Test Site, USA.

    PubMed

    Hunt, James R; Tompson, Andrew F B

    2005-11-15

    The nuclear weapons testing programme of the USA has released radionuclides to the subsurface at the Nevada Test Site. One of these tests has been used to study the hydrological transport of radionuclides for over 25 years in groundwater and the deep unsaturated zone. Ten years after the weapon's test, a 16 year groundwater pumping experiment was initiated to study the mobility of radionuclides from that test in an alluvial aquifer. The continuously pumped groundwater was released into an unlined ditch where some of the water infiltrated into the 200 m deep vadose zone. The pumped groundwater had well-characterized tritium activities that were utilized to trace water migration in the shallow and deep vadose zones. Within the near-surface vadose zone, tritium levels in the soil water are modelled by a simple one-dimensional, analytical wetting front model. In the case of the near-surface soils at the Cambric Ditch experimental site, water flow and salt accumulation appear to be dominated by rooted vegetation, a mechanism not included within the wetting front model. Simulation results from a two-dimensional vadose groundwater flow model illustrate the dominance of vertical flow in the vadose zone and the recharge of the aquifer with the pumped groundwater. The long-time series of hydrological data provides opportunities to understand contaminant transport processes better in the vadose zone with an appropriate level of modelling.

  14. Tracing long-term vadose zone processes at the Nevada Test Site, USA

    NASA Astrophysics Data System (ADS)

    Hunt, James R.; Tompson, Andrew F. B.

    2005-11-01

    The nuclear weapons testing programme of the USA has released radionuclides to the subsurface at the Nevada Test Site. One of these tests has been used to study the hydrological transport of radionuclides for over 25 years in groundwater and the deep unsaturated zone. Ten years after the weapon's test, a 16 year groundwater pumping experiment was initiated to study the mobility of radionuclides from that test in an alluvial aquifer. The continuously pumped groundwater was released into an unlined ditch where some of the water infiltrated into the 200 m deep vadose zone. The pumped groundwater had well-characterized tritium activities that were utilized to trace water migration in the shallow and deep vadose zones. Within the near-surface vadose zone, tritium levels in the soil water are modelled by a simple one-dimensional, analytical wetting front model. In the case of the near-surface soils at the Cambric Ditch experimental site, water flow and salt accumulation appear to be dominated by rooted vegetation, a mechanism not included within the wetting front model. Simulation results from a two-dimensional vadose groundwater flow model illustrate the dominance of vertical flow in the vadose zone and the recharge of the aquifer with the pumped groundwater. The long-time series of hydrological data provides opportunities to understand contaminant transport processes better in the vadose zone with an appropriate level of modelling. Copyright

  15. Tracing long-term vadose zone processes at the Nevada Test Site, USA

    PubMed Central

    Hunt, James R.; Tompson, Andrew F. B.

    2010-01-01

    The nuclear weapons testing programme of the USA has released radionuclides to the subsurface at the Nevada Test Site. One of these tests has been used to study the hydrological transport of radionuclides for over 25 years in groundwater and the deep unsaturated zone. Ten years after the weapon’s test, a 16 year groundwater pumping experiment was initiated to study the mobility of radionuclides from that test in an alluvial aquifer. The continuously pumped groundwater was released into an unlined ditch where some of the water infiltrated into the 200 m deep vadose zone. The pumped groundwater had well-characterized tritium activities that were utilized to trace water migration in the shallow and deep vadose zones. Within the near-surface vadose zone, tritium levels in the soil water are modelled by a simple one-dimensional, analytical wetting front model. In the case of the near-surface soils at the Cambric Ditch experimental site, water flow and salt accumulation appear to be dominated by rooted vegetation, a mechanism not included within the wetting front model. Simulation results from a two-dimensional vadose groundwater flow model illustrate the dominance of vertical flow in the vadose zone and the recharge of the aquifer with the pumped groundwater. The long-time series of hydrological data provides opportunities to understand contaminant transport processes better in the vadose zone with an appropriate level of modelling. PMID:21785525

  16. Long-term memory: disruption by inhibitors of protein synthesis and cytoplasmic flow

    SciTech Connect

    Flood, J.F.; Landry, D.W.; Bennett, E.L.; Jarvik, M.E.

    1981-01-01

    Colchicine (60 ..mu..g/kg), an inhibitor of axoplasmic transport, administered subcutaneously to mice has no detectable effect on retention when given shortly after active avoidance training, nor did a pertaining injection of anisomycin (ANI) have an amnesic effect. However, when ANI was administered shortly prior to training and colchicine was administered after training, retention performance was impaired. The amnesic effect was dependent on the time at which colchicine was administered. The amnesic effect was also obtained when ANI was combined with either vinblastine (6 ..mu..g/kg) or podophyllotoxin (3 ..mu..g/kg), drugs that inhibit axoplasmic transport. Intracerebral injections of colchicine (60 ng to 60 pg) caused amnesia in subjects pretreated with ANI, but not in subjects pretreated with saline. Lumicolchicine, an isomer of colchicine, which has similar central nervous system effects but has a low binding affinity for microtubule protein, did not impair retention in ANI pretreated mice. It is suggested that axonal transport of recently synthesized protein is required for long-term memory storage.

  17. The design, fabrication, and testing of WETF high-quality, long-term-storage, secondary containment vessels

    SciTech Connect

    Kane J. Fisher

    2000-03-01

    Los Alamos National Laboratory's Weapons Engineering Tritium Facility (WETF) requires secondary containment vessels to store primary tritium containment vessels. The primary containment vessel provides the first boundary for tritium containment. The primary containment vessel is stored within a secondary containment vessel that provides the secondary boundary for tritium containment. WETF requires high-quality, long-term-storage, secondary tritium containment vessels that fit within a Mound-designed calorimeter. In order to qualify the WETF high-quality, long-term-storage, secondary containment vessels for use at WETF, steps have been taken to ensure the appropriate design, adequate testing, quality in fabrication, and acceptable documentation.

  18. Tests of the protein-synthesis hypothesis of formation of long-term memory

    SciTech Connect

    Rosenzweig, M.R.; Bennett, E.L.; Flood, J.F.

    1980-09-01

    A major hypothesis has been that synthesis of protein is required for formation of long-term memory. Results of many studies conducted during the past decade have supported this hypothesis, but different limitations have been suggested and competing interpretations have been offered. Several alternative hypotheses have also been proposed and data have been offered in favor of them. We will review some of the results both for and against the protein-synthesis hypothesis.

  19. Long-term sealing ability of Pulp Canal Sealer, AH-Plus, GuttaFlow and Epiphany.

    PubMed

    Bouillaguet, S; Shaw, L; Barthelemy, J; Krejci, I; Wataha, J C

    2008-03-01

    To evaluate the long-term sealing ability of four contemporary endodontic sealers [Pulp Canal Sealer (PCS), AH-Plus, GuttaFlow and Epiphany] using a fluid filtration technique. The palatal roots of 40 human maxillary molar teeth were selected and the root canal was prepared using a crown-down technique (apical size 40, 6% taper). Roots were irrigated with 3% NaOCl, 17% EDTA solution and rinsed with distilled water. Canals were filled with either PCS, AH-Plus, GuttaFlow or Epiphany using a single-cone technique (n = 8). Twenty-four hours after filling, the roots were connected to an automatic flow-recording device (Flodec System) filled with double-distilled water under pressure (0.2 bar) to measure leakage. Flow rates were assessed at 6, 12 or 24-h and after 1-year of storage. None of the materials fully prevented fluid flow. Fluid flow decreased after 6 h and decreased further after 12 h. After 24 h, PCS and AH-Plus allowed significantly more fluid flow than GuttaFlow and Epiphany. After 1 year, PCS allowed significantly more fluid flow than the other materials. No significant changes in leakage occurred between 24 h and 1 year. GuttaFlow and Epiphany allowed less fluid movement along filled straight roots.

  20. The Franck Test for Gender Identity: Correlation with Occupation and Long-Term Stability of Score in Normal Men.

    ERIC Educational Resources Information Center

    Berg, Roland

    1985-01-01

    A correlation was found between high (independent) occupational positions and masculine scores on the Franck Drawing Completion Test (FDCT). Acceptable individual long-term stability was also evident. The FDCT appears to be useful in assessing gender identity. (Author/ABB)

  1. Organotypic cultures as tool to test long-term effects of chemicals on the nervous system.

    PubMed

    Peña, F

    2010-01-01

    The study of neuroscience has vastly benefited from the use of brain slices. This preparation has been fundamental for the understanding of the cellular basis of nervous system function as well as for the study of the mechanisms involved in neuronal network dysfunction. This experimental model provides flexible access, and control of, specific neural circuits and maintains their basic properties, allowing them to reproduce most of their natural network activities. Brain slices permit the combination of sophisticated techniques such as electrophysiology, fluorescence imaging, pharmacology, molecular biology, etc. More recently, the development of organotypic brain slice cultures has expanded the use of modern technical approaches to the study neuronal networks, while increasing their possibilities of evaluating long-term effects of acute experimental conditions, as well as the effects of chronic treatments on neuronal network function in vitro. Here, I will provide an overview of the use of organotypic cultures to understand neuronal network function and dysfunction, as well as the pharmacological approaches used for these studies. As a final example, I will review the studies performed in organotypic cultures regarding the deleterious effects of long-term amyloid beta application on neuronal networks in vitro, as well as the use of drugs that may prevent or revert their deleterious effects on nervous system function. Overall, this review will provide elements to support the use of organotypic cultures as a very reliable model to explore long-term neuropharmacological studies in vitro.

  2. From Gaged to Ungaged- Predicting Long-term Environmental Flows, and Ecosystems Responses.

    NASA Astrophysics Data System (ADS)

    Sengupta, A.; Adams, S. K.; Stein, E. D.; Mazor, R.; Bledsoe, B. P.

    2015-12-01

    Modern management needs, such as water supply, quality, and ecosystem protection place numerous demands on instream flows. Many regions are interested in developing numeric flow criteria as a way of ensuring maintenance of flow patterns that protect biological resources while meeting other demands. Developing flow criteria requires the capacity to generate reliable time series of the daily flow at any stream reach of interest and to relate flow patterns to biological indicators of stream health. Most stream reaches are not gaged, and it is impractical to develop detailed models for all reaches where flow alteration needs to be evaluated. We present a novel mechanistic approach to efficiently predict flows and flow alteration at all ungaged stream locations within a region of interest. We used an "ensemble approach" whereby a series of regionally representative models were developed and calibrated. New sites of interest are assigned to one of the ensemble models based on similarity of catchment properties. For southern California, we selected 43 gaged sites representing the range of geomorphology, and watershed characteristics of streams in the region. For each gaged site, we developed a hydrologic model (HEC-HMS) to predict daily flows for a period representing dry, wet and normal precipitation. The final goal is to relate flow alterations to ecological responses, the models were calibrated to three separate performance metrics that reflect conditions important for instream biological communities- proportion of low flow days, flashiness and Nash Sutcliffe efficiency for overall model performance. We cross-validated the models using a "jack-knife" approach. Models were assigned to novel 840 bioassessment sites based on the results of a Random Forest model that identified catchment properties that most affected the runoff patterns. Daily flow data for existing and "reference conditions" was simulated for a 23-year period for current and reference (undeveloped

  3. Endotoxic shock after long-term resuscitation of hemorrhage/reperfusion injury decreased splanchnic blood flow and eicosanoid release.

    PubMed Central

    Myers, S I; Tumage, R H; Kadesky, K M; Seelig, A R; Bartula, L

    1996-01-01

    OBJECTIVE: The authors examine the hypothesis that hemorrhage/reperfusion injury predisposes the splanchnic bed to decreased prostacyclin (PGl2) release and blood flow after subsequent endotoxin challenge. SUMMARY BACKGROUND DATA: Prostacyclin is a potent vasodilator that has been demonstrated to be an important regulator of splanchnic blood flow. Previous studies have demonstrated that during resuscitation from severe hemorrhage, there is a marked reduction in intestinal PGl2 levels, which is associated with reduced splanchnic perfusion. METHODS: Anesthetized Sprague-Dawley rats underwent hemorrhage to a mean arterial pressure of 30 mmHg for 30 minutes followed by the reinfusion of shed blood. Then the animals were maintained on total parenteral nutrition (TPN) for 10 days, after which time they received 20 mg/kg Escherichia coli endotoxin intraperitoneally. Aortic and superior mesenteric artery (SMA) blood flow was monitored with a Doppler flow probe. The splanchnic bed was excised and perfused in vitro for measurement of venous effluent eicosanoid concentrations. Controls consisted of animals that received TPN and endotoxin but did not undergo hemorrhage and resuscitation (sham). RESULTS: Total parenteral nutrition support of sham animals followed by endotoxin challenge did not alter splanchnic eicosanoid release or blood flow. Hemorrhage/reperfusion animals supported by long-term TPN and challenged with endotoxin demonstrated a threefold decrease in splanchnic prostacyclin metabolite (6-keto-PGF1 alpha) release and a 50% decrease in SMA blood flow. CONCLUSIONS: Hemorrhage/reperfusion injury predisposes the splanchnic bed from rats sustained with long-term TPN to decreased release of PGl2 and SMA blood flow when challenged with endotoxin as a second injury. PMID:8757386

  4. Flow regimes and long-term water exchange of the Himmerfjärden estuary

    NASA Astrophysics Data System (ADS)

    Engqvist, Anders; Stenström, Petter

    2009-06-01

    A numerical model of processes determining the water exchange encountered in Baltic coastal archipelagos is calibrated and validated against salinity and temperature field data spanning two decades with approximately bi-weekly resolution assessed in the Himmerfjärden estuary. This area is resolved into 17 basins interconnected by 38 individual straits of varying geometrical properties using GIS-based methods. All formulations of the strait exchange flows are free from parameters that need calibration and permit computations of the flow through a strait contraction with or without a coincident sill under a flow classification scheme, of which the first one (a) consists of two groups of multiple layers including aspirated layers from levels beneath the sill crest. The other regimes are as follows. (b) Pure barotropic flow; (c) rotationally controlled flow and (d) plug-flow, which serves as resort solution for flow situations that cannot be solved with (a) and also for computation of the barotropic part of the total flow. For long canals where friction effects act to reduce the flow, a fifth exchange regime is used. The vertical mixing formulation is based on energy balances between supplied wind energy and its work against buoyancy forces. The values of semi-empirical parameters involved in the mixing scheme have been established by calibration against measured data of the first decade period. A statistical evaluation is performed comparing the model results with the measurements of the second decade. It is found that the accuracy of the model is yet limited by the poor temporal resolution in the boundary and the thermal forcing. The overall accuracy of this approach is found to be comparable to earlier model studies in the same area. Since the exchange flows are now based on first principles and are applied to four times more basins, it seems that this more articulated model approach can confidently be applied to more complex archipelago areas.

  5. Why Does a Shift in Precipitation from Snow Towards Rain Lead to a Decrease in Long Term Mean River Flow?

    NASA Astrophysics Data System (ADS)

    Woods, Ross

    2017-04-01

    Empirical evidence suggests that a shift in precipitation from snow towards rain leads to a strong decrease in long term mean river flow, for a diverse set of snow-dominated catchments across the USA (Berghuijs et al, 2014, Nature Climate Change). Mutually inconsistent hypotheses have been proposed, but no comprehensive explanations are available to explain the observations. Why does less snow apparently lead to less river flow and more evaporation? Is it caused by changes in snow cover, soil freezing, infiltration processes, timing of plant water uptake or something else? Which processes are important where? Solving this scientific puzzle will have significant follow-on impacts for hydrological models, flood risk assessment, seasonal water forecasts, and climate change impacts on water availability, ecosystem functions and other systems impacted by long-term reductions in river flow and evaporation, and their feedbacks to the water cycle. A large international research collaboration (CHIPPER, 34 groups from 14 countries) has formed to make a joint contribution to improved understanding of links between the phase of precipitation and the hydrological cycle, with a particular focus on water balance. This presentation will review progress since 2014 on the topic, outline intended future lines of investigation, and invite feedback and additional collaborations.

  6. Periodic "flow-stop" perfusion microchannel bioreactors for mammalian and human embryonic stem cell long-term culture.

    PubMed

    Korin, Natanel; Bransky, Avishay; Dinnar, Uri; Levenberg, Shulamit

    2009-02-01

    The present study examines the use of automated periodic "flow-stop" perfusion systems for long-term culture of mammalian cells in a microchannel bioreactor. The method is used to culture Human Foreskin Fibroblasts (HFF) and Human Umbilical Vein Endothelial Cells (HUVEC) for long periods of time (>7 d) in a microchannel (height 100 mum). Design parameters, mass transport and shear stress issues are theoretically examined via numerical simulations. Cell growth and morphology are experimentally monitored and an enhanced growth rate was measured compared to constant perfusion micro-reactors and to traditional culture in Petri dishes. Moreover, we demonstrate the use of the method to co-culture undifferentiated colonies of human Embryonic Stem Cells (hESC) on HFF feeder cells in microchannels. The successful hESC-HFF co-culture in the microbioreactor is achieved due to two vital characteristics of the developed method-short temporal exposure to flow followed by long static incubation periods. The short pulsed exposure to shear enables shear sensitive cells (e.g., hESC) to withstand the medium renewal flow. The long static incubation period may enable secreted factors (e.g., feeder cells secreted factors) to accumulate locally. Thus the developed method may be suitable for long-term culture of sensitive multi-cellular complexes in microsystems.

  7. Long-term flow forecasts based on climate and hydrologic modeling: Uruguay River basin

    NASA Astrophysics Data System (ADS)

    Tucci, Carlos Eduardo Morelli; Clarke, Robin Thomas; Collischonn, Walter; da Silva Dias, Pedro Leite; de Oliveira, Gilvan Sampaio

    2003-07-01

    This paper describes a procedure for predicting seasonal flow in the Rio Uruguay drainage basin (area 75,000 km2, lying in Brazilian territory), using sequences of future daily rainfall given by the global climate model (GCM) of the Brazilian agency for climate prediction (Centro de Previsão de Tempo e Clima, or CPTEC). Sequences of future daily rainfall given by this model were used as input to a rainfall-runoff model appropriate for large drainage basins. Forecasts of flow in the Rio Uruguay were made for the period 1995-2001 of the full record, which began in 1940. Analysis showed that GCM forecasts underestimated rainfall over almost all the basin, particularly in winter, although interannual variability in regional rainfall was reproduced relatively well. A statistical procedure was used to correct for the underestimation of rainfall. When the corrected rainfall sequences were transformed to flow by the hydrologic model, forecasts of flow in the Rio Uruguay basin were better than forecasts based on historic mean or median flows by 37% for monthly flows and by 54% for 3-monthly flows.

  8. Analysis on the Long Term Effect of Trial Test Road Constructed on Batu Pahat Soft Clay (BPSC) at Recess UTHM

    NASA Astrophysics Data System (ADS)

    Idrus, M. M. M.; Edayu, A. E.; Adnan, Z.; Ismail, B.

    2016-07-01

    The reinforcement used in soil for construction of roads on the soft clay is very important as it will determine the level of service of the road after it was built. Damage or defects on the road surface to be an indicator of the level of the road has dropped and shows the deformation of the road. For this research, an analysis has carried out on the long-term effect of trial test road constructed on Batu Pahat Soft Clay (BPSC) at RECESS UTHM. Through this research, the reinforcement using Rawell Geosynthetic Clay Liner (RGCL) was the best with the stability is 14964 N, a low flow is 2.69mm, stiffness modulus is 1766 MPa, the peak load is 739.4 N and a lower horizontal deformation which is 1.71 µm compared Woven Geotextile section and section without geotextile [1] [9]. In terms of deformation can be seen clearly from physical observations that section without geotextile suffered significant damage than others. Settlement of road can also be analyzed by a longitudinal section that plotted based on the result of leveling work. After that, settlements are more visible way on the right side of the road trial. Through lab tests conducted, it indicate that the coring samples obtained from sites of each section meets the specifications set by the Jabatan Kerja Raya (JKR) in terms of stability, flow and stiffness [1]. Through this study, a trial road built on soft soil can be used as a test site because of the uniqueness of these roads which has three different types of reinforcements.

  9. Continuous-flow total artificial heart supports long-term survival of a calf.

    PubMed

    Frazier, O H; Cohn, William E; Tuzun, Egemen; Winkler, Jo Anna; Gregoric, Igor D

    2009-01-01

    The development and clinical use of continuous-flow left ventricular assist devices (LVADs) stimulated our interest in developing a total heart replacement with continuous-flow rotary blood pumps. We constructed a continuous-flow total artificial heart (CFTAH) from 2 HeartMate II axial-flow LVADs and used this CFTAH to replace the native heart of a calf. The purpose of this experiment was to study the effects of total continuous flow on physiologic parameters at rest and during exercise after the animal recovered from surgery. We monitored pulmonary and systemic pump performance, and we assessed arterial blood gases, hemodynamic and biochemical variables, and neurohormone levels during the 7 weeks of CFTAH support. At day 36 after CFTAH implantation, the calf was exercised on a treadmill at increasing speeds for 40 minutes; total oxygen consumption, pump flow, blood pressure, and respiratory rate were monitored. Baseline hematologic levels were altered postoperatively but returned to normal by 2 weeks. We saw no signs of hemolysis or thrombosis during CFTAH support. The calf had a normal physiologic response to treadmill exercise. The animal gained weight and appeared to function normally during the study. The CFTAH operated within design specifications throughout the study. Homeostasis, end-organ and vasomotor function, and the ability to exercise are not adversely affected by 7 weeks of totally pulseless circulation in a calf.

  10. Continuous-Flow Total Artificial Heart Supports Long-Term Survival of a Calf

    PubMed Central

    Frazier, O. H.; Cohn, William E.; Tuzun, Egemen; Winkler, Jo Anna; Gregoric, Igor D.

    2009-01-01

    The development and clinical use of continuous-flow left ventricular assist devices (LVADs) stimulated our interest in developing a total heart replacement with continuous-flow rotary blood pumps. We constructed a continuous-flow total artificial heart (CFTAH) from 2 HeartMate II axial-flow LVADs and used this CFTAH to replace the native heart of a calf. The purpose of this experiment was to study the effects of total continuous flow on physiologic parameters at rest and during exercise after the animal recovered from surgery. We monitored pulmonary and systemic pump performance, and we assessed arterial blood gases, hemodynamic and biochemical variables, and neurohormone levels during the 7 weeks of CFTAH support. At day 36 after CFTAH implantation, the calf was exercised on a treadmill at increasing speeds for 40 minutes; total oxygen consumption, pump flow, blood pressure, and respiratory rate were monitored. Baseline hematologic levels were altered postoperatively but returned to normal by 2 weeks. We saw no signs of hemolysis or thrombosis during CFTAH support. The calf had a normal physiologic response to treadmill exercise. The animal gained weight and appeared to function normally during the study. The CFTAH operated within design specifications throughout the study. Homeostasis, end-organ and vasomotor function, and the ability to exercise are not adversely affected by 7 weeks of totally pulseless circulation in a calf. PMID:20069083

  11. Long-term agroecosystem research in the central Mississippi river basin: goodwater creek experimental watershed flow data.

    PubMed

    Baffaut, Claire; Sadler, E John; Ghidey, Fessehaie

    2015-01-01

    Flow monitoring in Goodwater Creek Experimental Watershed started in 1971 at three nested watersheds ranging from 12 to 73 km. Since then, runoff or stream flow has been measured at 14 plots, three fields, and 12 additional stream sites ranging from 0.0034 to 6067 km in the Central Mississippi River Basin. Long-term data sets are important to document the changes resulting from anthropogenic and natural drivers. The data set presented here documents discharge across a range of catchment sizes in an area known for its high runoff potential. It constitutes the flow database of the Central Mississippi River Basin site of the Long-Term Agricultural Research network. Like the other sites of this network, data are accessible through the STEWARDS web interface (). Here we (i) describe the data collection methods, (ii) document the data available at plot, field, and watershed scales, and (iii) provide the main characteristics of discharge. General characteristics of discharge per unit area for different cropping system management systems show that in this claypan soil setting, management and tillage of row crop systems do not affect surface flow during the growing season (April-October). Data from fields and stream sites show the dampening of peak flow values and lengthening of storm hydrographs caused by mixed land uses and longer times of concentration. Overall, stream flow accounts for a third of the precipitation, of which 80% is from surface runoff and 20% is from groundwater. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  12. Femoral head blood flow in long-term steroid therapy: study of rabbit model

    SciTech Connect

    Wang, G.J.; Hubbard, S.L.; Reger, S.I.; Miller, E.D.; Stamp, W.G.

    1983-12-01

    Using a rabbit model, previous studies showed steroid-induced hyperlipidemia with subsequent fatty embolization of the subchondral arteries and hypertrophy of the marrow fat cells, followed by elevation of femoral head pressure from the normal level of 25 cm to nearly 60 cm H2O after eight weeks of treatment. This has led us to believe that pressure changes lead to decreased blood flow in the femoral head. In our study of 22 New Zealand white adult rabbits, weighing an average of 4.0 kg, 14 received a weekly dose of 12.45 mg of methylprednisolone (Depo-Medrol), and eight served as control. Femoral head blood flow was established using the radioactive microsphere technique. Control and cortisone-treated rabbits had femoral head blood flow measured 6, 8 and 10 weeks after treatment. The average blood flow in the control femoral heads averaged 0.2039 +/- 0.076 ml/min/gm, with no difference in the left side and the right side. In the treated group, the average blood flow at ten weeks was 0.162 +/- 0.039 ml/min/gm on the right and 0.164 +/- 0.037 ml/min/gm on the left, which was significantly different. This is parallel to unpredictable clinical findings in human beings.

  13. Long-term methanol vehicle test program. Final subcontract report, 1 November 1992--1 February 1995

    SciTech Connect

    Jones, J.C.; Maxwell, T.T.

    1995-09-01

    Work was sperformed to determine effects of methanol fuel on engine performance and exhaust emissions during long-term use in a 1988 Chevrolet Corsica. Engine wear, gasket performance, fuel economy, emissions level, oil consumption, and overall vehicle performance were monitored over 22,000 miles. Baselines were established at the beginning for comparison: engine was disassembled, bearing/ring clearances and cam profiles were measured. Higher flow rate fuel injectors from AC Rochester were installed and the computer system calibrated for M100 fuel. The vehicle durability test increased oil consumption by 26% under cold-start conditions, 9% under hot start. Oil consumption under hot start was higher than under cold start by as much as 56%; effect of component temperatures on oil viscosity appears to be the cause. It is recommended that oil consumption of a gasoline-fueled vehicle be measured in order to normalize the effect of methanol operation on oil consumption, and to study the effect of steady-state and transient conditions on oil consumption.

  14. Testing long-term memory in animal models of schizophrenia: suggestions from CNTRICS.

    PubMed

    Bussey, Timothy J; Barch, Deanna M; Baxter, Mark G

    2013-11-01

    This paper reports the results of discussions at the fourth meeting of Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia (CNTRICS) meeting, held over two days in Washington, DC in April 2011. The meeting focused on animal paradigms for assessing the cognitive constructs relevant to schizophrenia identified in previous CNTRICS meetings. This report focuses on the outcome of discussions in the general area of long-term memory. A number of candidate animal paradigms were discussed. Two of these - one for rodents and one for non-human primates - were recommended as particularly promising for further development. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Simulation of long-term debris flow sediment transport based on a slope stability and a debris flow routing model

    NASA Astrophysics Data System (ADS)

    Müller, T.; Hoffmann, T.

    2012-04-01

    Debris flows play a crucial role in the coupling of hillslope-sediment sources and channels in mountain environments. In most landscape evolution models (LEMs), the sediment transport by debris flows is (if at all) often represented by simple empirical rules. This generally results from the mismatch of the coarse resolution of the LEMs and the small scale impacts of debris flow processes. To extend the accuracy and predictive power of LEMs, either a higher resolution of LEMs in combination with process-based debris flow models or a better parametrisation of subpixel scale debris flow processes is necessary. Furthermore, the simulation of sediment transport by debris flows is complicated by their episodic nature and unknown factors controlling the frequency and magnitude of events. Here, we present first results using a slope stability model (SINMAP) and an event-based debris flow routing model (SCIDDICA-S4c) to simulate the effects of debris flows in LEMs. The model was implemented in the XULU modelling platform developed by the Department of Computer Science at the University of Bonn. The combination of the slope stability model and the event-based routing and mass balance model enables us to simulate the triggering and routing of debris flow material through the iteration of single events over several thousand years. Although a detailed calibration and validation remains to be done, the resulting debris flow-affected areas in a test elevation model correspond well with data gained from a geomorphological mapping of the corresponding area, justifying our approach. The increased computation speed allows to run high resolution LEM in convenient short time at relatively low cost. This should encourage the development of more detailed LEMs, in which process-based models should be incorporated.

  16. The long term response of stream flow to climatic warming in headwater streams of interior Alaska

    Treesearch

    Jeremy B. Jones; Amanda J. Rinehart

    2010-01-01

    Warming in the boreal forest of interior Alaska will have fundamental impacts on stream ecosystems through changes in stream hydrology resulting from upslope loss of permafrost, alteration of availability of soil moisture, and the distribution of vegetation. We examined stream flow in three headwater streams of the Caribou-Poker Creeks Research Watershed (CPCRW) in...

  17. MODELING LONG-TERM NITRATE BASE-FLOW LOADING FROM TWO AGRICULTURAL WATERSHEDS

    EPA Science Inventory

    Nitrate contamination of ground water from agricultural practices may be contributing to the eutrophication of the Chesapeake Bay, degrading water quality and aquatic habitats. Groundwater flow and nitrate transport and fate are modeled, using MODFLOW and MT3D computer models, in...

  18. MODELING LONG-TERM NITRATE BASE-FLOW LOADING FROM TWO AGRICULTURAL WATERSHEDS

    EPA Science Inventory

    Nitrate contamination of ground water from agricultural practices may be contributing to the eutrophication of the Chesapeake Bay, degrading water quality and aquatic habitats. Groundwater flow and nitrate transport and fate are modeled, using MODFLOW and MT3D computer models, in...

  19. Impact of the 2008 Wenchuan earthquake in China on subsequent long-term debris flow activities in the epicentral area

    NASA Astrophysics Data System (ADS)

    Zhang, S.; Zhang, L. M.

    2017-01-01

    The 2008 Wenchuan earthquake triggered the largest number of landslides among the recent strong earthquake events around the world. The loose landslide materials were retained on steep terrains and deep gullies. In the period from 2008 to 2015, numerous debris flows occurred during rainstorms along the Provincial Road 303 (PR303) near the epicentre of the earthquake, causing serious damage to the reconstructed highway. Approximately 5.24 × 106 m3 of debris-flow sediment was deposited shortly after the earthquake. This paper evaluates the evolution of the debris flows that occurred after the Wenchuan earthquake, which helps understand long-term landscape evolution and cascading effects in regions impacted by mega earthquakes. With the aid of a GIS platform combined with field investigations, we continuously tracked movements of the loose deposit materials in all the debris flow gullies along an 18 km reach of PR303 and the characteristics of the regional debris flows during several storms in the past seven years. This paper presents five important aspects of the evolution of debris flows: (1) supply of debris flow materials; (2) triggering rainfall; (3) initiation mechanisms and types of debris flows; (4) runout characteristics; and (5) elevated riverbed due to the deposited materials from the debris flows. The hillslope soil deposits gradually evolved into channel deposits and the solid materials in the channels moved towards the ravine mouth. Accordingly, channelized debris flows became dominant gradually. Due to the decreasing source material volume and changes in debris flow characteristics, the triggering rainfall tends to increase from 30 mm h- 1 in 2008 to 64 mm h- 1 in 2013, and the runout distance tends to decrease over time. The runout materials blocked the river and elevated the riverbed by at least 30 m in parts of the study area. The changes in the post-seismic debris flow activity can be categorized into three stages, i.e., active, unstable, and

  20. Expertise in cognitive psychology: testing the hypothesis of long-term working memory in a study of soccer players.

    PubMed

    Postal, Virginie

    2004-10-01

    This experiment compared several theories of expertise and exceptional performances in cognitive psychology. One current conception assumes that experts in a specific domain have developed a long-term working memory, which accounts for the difference in memory performance between experts and novices. The principal characteristics of this memory are the speed with which processes of storage and retrieval function and the existence of retrieval structures that allow a temporary activation of the knowledge store in long-term memory. Other authors such as Vicente and Wang argue this notion does not account for memory performance that is not intrinsic to the domain of expertise. We attempt to clarify the two viewpoints and to focus on this debate by testing the hypothesis of long-term working memory using soccer as the domain of expertise and by comparing the cognitive performance of participants who have different expertise (novices, supporters, players, and coaches). 35 male participants were administered a new version of the Reading Span test to assess their long-term working memory according to two conditions. In the first condition (structured condition), the last word of each sentence was related to the soccer domain, and these words were related to each other in such a manner that they represented a part of the game. In the second condition (unstructured condition), the last word of each sentence was related to soccer but these words did not represent part of the game. Analysis showed that the sentence span increased as a function of expertise for the structured condition but not for the unstructured condition. The results were interpreted in the framework of the constraint attunement hypothesis proposed by Vicente in 1992 and the long-term working memory hypothesis proposed by Ericsson and Kintsch in 1995.

  1. Using Uncertainty to Guide Characterization, Closure and Long-term Management of an Underground Nuclear Test Site

    SciTech Connect

    Chapman, J.; Pohll, G.; Hassan, A.; Pohlmann, K.

    2007-01-09

    groundwater model as a result of the new data. The revised model was deemed acceptable by both DOE and the State of Nevada, and has been used to determine the contaminant boundary for the site, the calculation of which required choices regarding risk or concentration metrics and whether to focus on the uncertainty of where the contaminants might be or where the groundwater is free of contaminants. The model was also used to develop an optimum monitoring system, the installation of which provided another opportunity to reduce uncertainty as data were collected for model validation. The short-term validation process, and long-term monitoring, provide data that can feed back into the stochastic flow and transport model to cull poorly performing model realizations and reduce uncertainty in the model predictions.

  2. Startup and long term operation of enhanced biological phosphorus removal in continuous-flow reactor with granules.

    PubMed

    Li, Dong; Lv, Yufeng; Zeng, Huiping; Zhang, Jie

    2016-07-01

    The startup and long term operation of enhanced biological phosphorus removal (EBPR) in a continuous-flow reactor (CFR) with granules were investigated in this study. Through reducing the settling time from 9min to 3min gradually, the startup of EBPR in a CFR with granules was successfully realized in 16days. Under continuous-flow operation, the granules with good phosphorus and COD removal performance were stably operated for more than 6months. And the granules were characterized with particle size of around 960μm, loose structure and good settling ability. During the startup phase, polysaccharides (PS) was secreted excessively by microorganisms to resist the influence from the variation of operational mode. Results of relative quantitative PCR indicated that granules dominated by polyphosphate-accumulating organisms (PAOs) were easier accumulated in the CFR because more excellent settling ability was needed in the system.

  3. Fixation and long-term storage of human lymphocytes for surface marker analysis by flow cytometry.

    PubMed

    Lal, R B; Edison, L J; Chused, T M

    1988-05-01

    A method to preserve stained human lymphocytes for subsequent cell surface analysis by flow cytometry (FCM) is described. Cells stained with fluorescein isothiocyanate (FITC) and phycoerythrin (PE)-conjugated monoclonal antibodies and then fixed in 1% paraformaldehyde, followed by extensive washing and resuspension in 1% BSA medium, could be stored at 4 degrees C for at least 2 weeks prior to FCM analysis without significant alteration in the light scatter or fluorescence properties of the cells. Furthermore, the method was also suitable for analyzing lymphocytes that express T-cell activation markers in certain disease conditions. In addition, we have identified monoclonal antibody combinations that discriminate different lymphocyte subsets that are satisfactory for multiparameter analysis after 2 weeks of storage. This method should prove useful for enumerating lymphocyte subsets in field study sites remote from flow cytometry laboratories.

  4. Improving Long-term Post-wildfire hydrologic simulations using ParFlow

    NASA Astrophysics Data System (ADS)

    Lopez, S. R.; Kinoshita, A. M.

    2015-12-01

    Wildfires alter the natural hydrologic processes within a watershed. After vegetation is burned, the combustion of organic material and debris settles into the soil creating a hydrophobic layer beneath the soil surface with varying degree of thickness and depth. Vegetation regrowth rates vary as a function of radiative exposure, burn severity, and precipitation patterns. Hydrologic models used by the Burned Area Emergency Response (BAER) teams use input data and model calibration constraints that are generally either one-dimensional, empirically-based models, or two-dimensional, conceptually-based models with lumped parameter distributions. These models estimate runoff measurements at the watershed outlet; however, do not provide a distributed hydrologic simulation at each point within the watershed. This work uses ParFlow, a three-dimensional, distributed hydrologic model to (1) correlate burn severity with hydrophobicity, (2) evaluate vegetation recovery rate on water components, and (3) improve flood prediction for managers to help with resource allocation and management operations in burned watersheds. ParFlow is applied to Devil Canyon (43 km2) in San Bernardino, California, which was 97% burned in the 2003 Old Fire. The model set-up uses a 30m-cell size resolution over a 6.7 km by 6.4 km lateral extent. The subsurface reaches 30 m and is assigned a variable cell thickness. Variable subsurface thickness allows users to explicitly consider the degree of recovery throughout the stages of regrowth. Burn severity maps from remotely sensed imagery are used to assign initial hydrophobic layer parameters and thickness. Vegetation regrowth is represented with satellite an Enhanced Vegetation Index. Pre and post-fire hydrologic response is evaluated using runoff measurements at the watershed outlet, and using water component (overland flow, lateral flow, baseflow) measurements.

  5. Estimating long-term behavior of periodically driven flows without trajectory integration

    NASA Astrophysics Data System (ADS)

    Froyland, Gary; Koltai, Péter

    2017-05-01

    Periodically driven flows are fundamental models of chaotic behavior and the study of their transport properties is an active area of research. A well-known analytic construction is the augmentation of phase space with an additional time dimension; in this augmented space, the flow becomes autonomous or time-independent. We prove several results concerning the connections between the original time-periodic representation and the time-extended representation, focusing on transport properties. In the deterministic setting, these include single-period outflows and time-asymptotic escape rates from time-parameterized families of sets. We also consider stochastic differential equations with time-periodic advection term. In this stochastic setting one has a time-periodic generator (the differential operator given by the right-hand-side of the corresponding time-periodic Fokker-Planck equation). We define in a natural way an autonomous generator corresponding to the flow on time-extended phase space. We prove relationships between these two generator representations and use these to quantify decay rates of observables and to determine time-periodic families of sets with slow escape rate. Finally, we use the generator on the time-extended phase space to create efficient numerical schemes to implement the various theoretical constructions. These ideas build on the work of Froyland et al (2013 SIAM J. Numer. Anal. 51 223-47), and no expensive time integration is required. We introduce an efficient new hybrid approach, which treats the space and time dimensions separately.

  6. Greenhouse Gases in the South Atlantic: Testing and Automation of Instrumentation for Long-Term Monitoring

    NASA Astrophysics Data System (ADS)

    Lowry, D.; Fisher, R.; Sriskantharajah, S.; Lanoisellé, M.; Etchells, A.; Manning, A.; Nisbet, E.

    2009-04-01

    Understanding ocean uptake of atmospheric CO2 by the Southern Ocean is important for modelling of future global warming scenarios, particularly since it was recently proposed that this sink was reducing (Le Quéré, et al., 2007). To help our understanding of this problem a new project aims to flask sample air from 5 South Atlantic sites and set up continuous monitoring at the 2 most accessible of these: Ascension Island and the Falklands. Flask sample measurements will include CO2 and CH4 mixing ratios and the ^13C measurement of both of these gases using the rapid continuous flow trace gas analysis system at Royal Holloway, University of London (RHUL). Routine precisions are ±0.03 per mil and ±0.05 per mil for CO2 and CH4, respectively (Fisher et al., 2006). A time series of ^13C in CH4 was maintained for Ascension Island from 2000-2005 and a time series for methane isotopes commenced for the Falkland Islands in autumn 2007. To meet the continuous monitoring requirements of the new project, three Picarro G1301 CO2 / CH4 / H2O Cavity Ring Down Spectrometers (CRDS) were installed at RHUL in October 2008 for testing, calibration and the development of an automated air inlet system suitable for analysis of calibration gases at the remote sites. Initial testing included calibration with NOAA calibrated and target gases, validation of the Picarro-defined H2O-correction of CO2, and derivation of an H2O-correction for CH4. Continuing checks on the H2O correction are made by having 2 instruments side-by-side taking air from the same inlet, but one having a combined Nafion / Mg-perchlorate drying system that utilizes the analysis system exhaust gas for the reverse flow through the Nafion and maintains water-levels at 0.05% for more than 2 weeks. These instruments are connected to the same air inlet as a GC measuring CH4 mixing ratio and a LiCor 6252 measuring CO2 mixing ratio at 30-minute and 1-minute intervals respectively. The third CRDS instrument is connected to a

  7. Are longitudinal ice-surface structures on the Antarctic Ice Sheet indicators of long-term ice-flow configuration?

    NASA Astrophysics Data System (ADS)

    Glasser, N. F.; Jennings, S. J. A.; Hambrey, M. J.; Hubbard, B.

    2014-07-01

    Continent-wide mapping of longitudinal ice-surface structures on the Antarctic Ice Sheet reveals that they originate in the interior of the ice sheet and are arranged in arborescent networks fed by multiple tributaries. Longitudinal ice-surface structures can be traced continuously down-ice for distances of up to 1200 km. They are co-located with fast-flowing glaciers and ice streams that are dominated by basal sliding rates above tens of m yr-1 and are strongly guided by subglacial topography. Longitudinal ice-surface structures dominate regions of converging flow, where ice flow is subject to non-coaxial strain and simple shear. Associating these structures with the AIS' surface velocity field reveals (i) ice residence times of ~ 2500 to 18 500 years, and (ii) undeformed flow-line sets for all major flow units analysed except the Kamb Ice Stream and the Institute and Möller Ice Stream areas. Although it is unclear how long it takes for these features to form and decay, we infer that the major ice-flow and ice-velocity configuration of the ice sheet may have remained largely unchanged for several thousand years, and possibly even since the end of the last glacial cycle. This conclusion has implications for our understanding of the long-term landscape evolution of Antarctica, including large-scale patterns of glacial erosion and deposition.

  8. Regression method for estimating long-term mean annual ground-water recharge rates from base flow in Pennsylvania

    USGS Publications Warehouse

    Risser, Dennis W.; Thompson, Ronald E.; Stuckey, Marla H.

    2008-01-01

    A method was developed for making estimates of long-term, mean annual ground-water recharge from streamflow data at 80 streamflow-gaging stations in Pennsylvania. The method relates mean annual base-flow yield derived from the streamflow data (as a proxy for recharge) to the climatic, geologic, hydrologic, and physiographic characteristics of the basins (basin characteristics) by use of a regression equation. Base-flow yield is the base flow of a stream divided by the drainage area of the basin, expressed in inches of water basinwide. Mean annual base-flow yield was computed for the period of available streamflow record at continuous streamflow-gaging stations by use of the computer program PART, which separates base flow from direct runoff on the streamflow hydrograph. Base flow provides a reasonable estimate of recharge for basins where streamflow is mostly unaffected by upstream regulation, diversion, or mining. Twenty-eight basin characteristics were included in the exploratory regression analysis as possible predictors of base-flow yield. Basin characteristics found to be statistically significant predictors of mean annual base-flow yield during 1971-2000 at the 95-percent confidence level were (1) mean annual precipitation, (2) average maximum daily temperature, (3) percentage of sand in the soil, (4) percentage of carbonate bedrock in the basin, and (5) stream channel slope. The equation for predicting recharge was developed using ordinary least-squares regression. The standard error of prediction for the equation on log-transformed data was 9.7 percent, and the coefficient of determination was 0.80. The equation can be used to predict long-term, mean annual recharge rates for ungaged basins, providing that the explanatory basin characteristics can be determined and that the underlying assumption is accepted that base-flow yield derived from PART is a reasonable estimate of ground-water recharge rates. For example, application of the equation for 370

  9. Acute and long-term effects of blood flow restricted training on heat shock proteins and endogenous antioxidant systems.

    PubMed

    Cumming, K T; Ellefsen, S; Rønnestad, B R; Ugelstad, I; Raastad, T

    2016-10-10

    Blood flow restricted exercise (BFRE) with low loads has been demonstrated to induce considerable stress to exercising muscles. Muscle cells have developed a series of defensive systems against exercise-induced stress. However, little is known about acute and long-term effects of BFRE training on these systems. Nine previously untrained females trained low-load BFRE and heavy load strength training (HLS) on separate legs and on separate days to investigate acute and long-term effects on heat shock proteins (HSP) and endogenous antioxidant systems in skeletal muscles. BFRE and HLS increased muscle strength similarly by 12 ± 7% and 12 ± 6%, respectively, after 12 weeks of training. Acutely after the first BFRE and HLS exercise session, αB-crystallin and HSP27 content increased in cytoskeletal structures, accompanied by increased expression of several HSP genes. After 12 weeks of training, this acute HSP response was absent. Basal levels of αB-crystallin, HSP27, HSP70, mnSOD, or GPx1 remained unchanged after 12 weeks of training, but HSP27 levels increased in the cytoskeleton. Marked translocation of HSP to cytoskeletal structures at the commencement of training indicates that these structures are highly stressed from BFRE and HLS. However, as the muscle gets used to this type of exercise, this response is abolished.

  10. Long-term mechanical life testing of polymeric post insulators for distribution and a comparison to porcelain

    SciTech Connect

    Cherney, E.A. )

    1988-07-01

    The paper presents the results and analyses of long-term cantilever strength tests on polymeric line post insulators. The time-to-failure data for static cantilever loads are represented by the Weibull distribution. The life distribution, obtained from the maximum likelihood estimates of the accelerated failure times, fits an exponential model. An extrapolation of the life distribution to normal loads provides an estimate of the strength rating and mechanical equivalence to porcelain line post insulators.

  11. Prospective analysis of long term control of mild hypertension on cerebral blood flow

    SciTech Connect

    Meyer, J.S.; Rogers, R.L.; Mortel, K.F.

    1985-11-01

    A group of 12 otherwise normal elderly volunteers (mean age = 69.8 years), were detected to have mild hypertension. Cerebral blood flow (CBF) values were measured using 133Xe inhalation method prior to initiating medical treatment and repeated at 6, 12, 24 and 36 months after BP was adequately controlled and restored to normal (below 150/90). Results indicate that CBF values increased markedly during follow-up intervals at 6, 12 and 24 months but not at 36 months. Hypertension is known to be a risk factor for stroke and 4 of the 12 subjects subsequently developed symptoms of cerebrovascular disease (stroke, multi-infarct dementia or transient ischemic attacks) despite control of hypertension. Analyses separating asymptomatic and symptomatic groups indicated that the eight asymptomatic patients continued to maintain increased CBF levels throughout the entire three year interval, whereas the 4 symptomatic patients developed declines in CBF which began, and progressively decreased below the initial pretreatment values, during the second and third years.

  12. Long-Term Trends in River Flow From Semiarid Rangelands: Degradation and Recovery

    NASA Astrophysics Data System (ADS)

    Wilcox, B. P.; Huang, Y.; Narasimhan, B.

    2007-05-01

    In the last 100 years or so, desertification, degradation, and woody plant encroachment have altered huge tracts of semiarid rangelands. It is expected that the changes thus brought about significantly affect water balance in these regions; and in fact, at the headwater-catchment and smaller scales, such effects are reasonably well documented. For larger scales, however, there is surprisingly little documentation of hydrological change. In this paper, we evaluate the extent to which streamflow from large watersheds in central Texas has changed concurrent with the dramatic shifts in vegetation cover (conversion from grasslands to woodlands) that have taken place during the last century. Our study focused on the three watersheds that supply the major tributaries of the Concho River-those of the North Concho (3279 km2), the Middle Concho (5398 km2), and the South Concho (1070 km2). Using data from the period of record (1926-2005), we found that annual streamflow for the North Concho decreased by about 70% between 1960 and 2005. Not only did we find no downtrend in precipitation that might explain this reduced flow, we found no corresponding change in annual streamflow for the other two basins. When we analyzed trends in baseflow and stormflow separately, however, we found that in spite of large increases in mesquite and juniper cover, baseflow for all the watersheds has remained essentially consistent since 1960 (and may even have increased). At the same time, stormflows (floods) were fewer and of smaller magnitude. In other words, the same amount of precipitation, on average, generated less stormflow after 1960 than before. We suggest that these lower stormflows result from generally higher soil infiltrability due to the greater density of both woody and herbaceous plants. There is no indication that the decline in streamflow is related to diminished baseflows caused by extraction of subsurface water by woody plants.

  13. Testing causes for long-term changes in carbon cycling and climate during the early Paleogene

    NASA Astrophysics Data System (ADS)

    Komar, N.; Zeebe, R. E.; Dickens, G. R.

    2013-12-01

    The late Paleocene to the early Eocene (˜58-52 Ma) was marked by significant changes in global climate and carbon cycling. Among the evidence for these changes, stable isotope records reveal a prominent decrease of δ13C and δ18O (in both surface and deep ocean), indicating a reorganization in the long-term global carbon cycle and a long-term warming trend (˜4°C), respectively. Concurrently, deep-sea carbonate records at several sites indicate a deepening of the calcite compensation depth (CCD). Here, we investigate possible causes (e.g., increased volcanic degassing, decreased net organic burial, and accelerated dissociation of gas hydrate) for these observations, but from a new perspective. The basic model employed is a modified version of GEOCARB III. However, we have coupled this well-known geochemical model to LOSCAR, a model that enables simulation of seawater carbonate chemistry, the CCD, and ocean δ13C. We have also added a gas hydrate capacitor that can account for the storage and release of methane from the seafloor over millions of years. We further consider accurate input data (e.g., δ13C of carbonate) on a currently accepted time scale that spans an interval much longer than the perturbation. Several different scenarios are investigated with the goal of consistency amongst inferred changes in temperature, the CCD, and surface ocean and deep ocean δ13C. The results strongly suggest that a decrease in net organic carbon burial drove carbon cycle changes during the late Paleocene and early Eocene, although an increase in volcanic activity might have contributed. Importantly, a drop in net organic carbon burial may represent increased oxidation of previously deposited organic carbon, such as stored in peat or gas hydrates. The model successfully recreates trends in Earth surface warming, as inferred from δ18O records, the CCD, and δ13C. At the moment, however, our coupled modeling effort cannot reproduce the magnitude of change in all these

  14. The effect of long-term supplementation of vitamin C on pulpal blood flow in streptozotocin-induced diabetic rats.

    PubMed

    Amatyakul, Supathra; Chakraphan, Daroonwan; Chotpaibulpan, Siriporn; Patumraj, Suthiluk

    2003-01-01

    To examine the effect of vitamin C on blood flow in diabetic dental pulp, the animal model of streptozotocin (STZ)-induced diabetic rats (i.v. injection of STZ 55 mg/kg BW) was used. Male Sprague-Dawley rats weighing 200-250 g were divided into 3 groups: non-diabetes (CON), diabetes (STZ), and diabetes supplemented by vitamin C (STZ+Vit C). Vitamin C was supplemented by drinking water (1 g/l). At 12 weeks (wks) and 24 wks after the STZ injection, the laser Doppler flow-meter (Model ALF 21, USA) was used to measure pulpal blood flow (PBF) while the animals were anesthetized with sodium pentobarbital (50 mg/kg BW). The experimental results showed that at 12 and 24 wks after the STZ injection, hyperglycemia hypertension and loss of body weight were significantly developed. Simultaneously, decreased plasma vitamin C level was demonstrated significantly in STZ rats. The reduction of pulpal blood flow (PBF) in the lower incisors was observed in STZ rats at both monitored time points. Interestingly, the supplementation of vitamin C for 24 wks restored PBF. In conclusion, the present study demonstrated that long-term supplementation of vitamin C, a natural antioxidant, could markedly prevent the diabetic-induced reduction in PBF.

  15. Long-term change of a small ice cap in Greenland: a dynamic perspective from numerical flow modelling

    NASA Astrophysics Data System (ADS)

    Vieli, A.; Adamson, K.; Lane, T. P.

    2016-12-01

    Small ice caps at the periphery of the Greenland ice sheet are often close to the limit of existence and therefore respond far more sensitively to climate change than the land-margin of the neighboring ice sheet. However, their past evolution and dynamic behavior is poorly understood and their use as climate indicators therefore remains limited. We here aim to provide a long-term reconstruction of Lyngmarksbreen, a small (32km2) ice cap on Disko Island in West Greenland, from the pre-little ice age (LIA, starting at about 1200 AD) to present. We use a 2-dim. time-dependent numerical flow model (SIA) in combination with geomorphological mapping, exposure dating and historical observations to simulate its long-term evolution. We specifically focus on retreat since the LIA, which is well constrained by geomorphological length records of several small outlet glaciers and data from local and regional climate stations (Qeqertassuaq and Ilulisat). We also explore aspects related to flow dynamics and find that the dynamic state of this ice cap is far from being balanced and is highly sensitive to the surface elevation mass balance feedback resulting in an asynchronous response of the different outlets. This sensitivity can partly be explained by low surface slopes and a very limited elevation extent of the ice cap. Our investigations further suggest that redistribution of snow through wind-drift is strongly affecting the surface mass balance and hence the evolution of the ice cap. Over the last century the ice cap almost continuously retreated and today almost no accumulation area remains. As a consequence, this ice cap will likely vanish within the next few decades.

  16. Long-term evolution of a small ice cap in Greenland: a dynamic perspective from numerical flow modelling

    NASA Astrophysics Data System (ADS)

    Vieli, Andreas; Lane, Timothy; Adamson, Kathryn

    2017-04-01

    Small ice caps at the periphery of the Greenland ice sheet are often close to the limit of existence and are therefore expected to respond more sensitively to climate change than the land-margin of the neighboring ice sheet. However, their past evolution and dynamic behavior is poorly understood and their use as climate indicators therefore remains so far limited. We here aim to provide a long-term dynamic reconstruction of Lyngmarksbraeen, a small (32km2) ice cap on Disko Island in West Greenland, with a particular focus on the little ice age (LIA, since 1200AD). We use a 2-dim. time-dependent numerical flow model (SIA) and a PDD-mass balance model in combination with historical observations, geomorphological mapping and exposure dating to simulate its long-term evolution and dynamic behaviour. We specifically focus on retreat since the LIA, which is well constrained by geomorphological evidence and historical maps and length records of several small outlet glaciers and data from local and regional climate stations (Qeqertarssuaq and Ilulisat). We also explore aspects related to flow dynamics and find that the dynamic state of this ice cap is, at any time, far from being balanced and is highly sensitive to the surface elevation mass balance feedback and results in an asynchronous response of the different outlets and hysteresis-type behaviour. The modelling is able to reproduce the observed LIA-extent and the almost continuous retreat over the last hundred years well. It further indicates that the ice cap was already dynamically inert since the 1960s. Today, the ice cap has lost almost its entire accumulation area and even without any further warming in the future, the ice cap is expected to vanish within a couple of decades.

  17. Diesel fuel long term storage and treatment- recommended tests and practices (U)

    SciTech Connect

    Gross, R.

    2009-06-05

    The Clean Air Act (1970) is the comprehensive federal law that regulates air emissions from stationary and mobile sources. Among other things, this law authorized the Environmental Protection Agency (EPA) to establish National Ambient Air Quality Standards to protect public health and public welfare and to regulate emissions of hazardous air pollutants. In recent years, EPA regulations have forced oil refineries into producing a very low sulfur diesel fuel and incentives for adding up to 5% bio-diesel. These changes to the fuel oil formulation are beneficial to air quality and to energy conservation, but adversely impact heat content, long term storage stability, engine power, and injection system reliability. Diesel engines typically have a high incidence of injector failure resulting from poor diesel fuel quality. Since standby diesel engines do not run continuously it is necessary to implement periodic surveillance's to ensure the quality of diesel fuel is acceptable for reliable operation when a loss of power occurs. The information contained in this document is a compilation of best practices to be used as a guide for maintenance of a reliable diesel fuel system.

  18. Interactions of Flow, Sediment Transport, and Vegetation in the Long-Term Evolution of Arroyos

    NASA Astrophysics Data System (ADS)

    Perignon, M. C.; Griffin, E. R.; Tucker, G. E.; Friedman, J. M.; Overeem, I.

    2014-12-01

    Arroyos in the Southwestern United States have experienced multiple cut-and-fill cycles in the late Quaternary. Extensive studies fo the Lower Rio Puerco, New Mexico, USA, show that it has most recently progressed from an (1) unincised state with a broad floodplain in the mid 1800s, through a period of (2) incision, forming a deep gully with steep walls by the early 1900s, and to the (3) present-day stage of arroyo widening and filling. The arroyo cycle is driven by a combination of autogenic processes and external forcings, although the relative influence of each process is under debate. We use the morphodynamic model ANUGA to explore the influences of discharge, sediment transport, and vegetation on the geomorphic evolution of the Lower Rio Puerco through the arroyo cycle. The predictive power of the numerical model is first established by using it to hind-cast the morphologic evolution of a reach of the river during a large flood in 2006, and comparing the model predictions to real-world magnitudes and patterns of topographic change recorded for this event by multi-temporal airborne lidar. The morphodynamic model is then used to simulate the response of this stream to floods in the past. A comprehensive dataset of the topography and hydrology of the Lower Rio Puerco since the 1920s is used to reproduce the morphology of the arroyo at multiple points in time, and historical descriptions serve to extrapolate these into the 19th century. We test the sensitivity of the reconstructed landscapes to changes in peak discharge, sediment supply, and the distribution and characteristics of vegetation in order to determine the relative influence of each forcing in the evolution of the stream, and to understand how the interactions of different processes could drive its progression through the arroyo cycle.

  19. Evaluating long-term trends in mean- and high- river flows using a network of reference stations in Ireland

    NASA Astrophysics Data System (ADS)

    Wilby, R. L.; Murphy, C.; Harrigan, S.; Hall, J.

    2012-12-01

    This paper describes the development of a reference hydrometric network for Ireland established primarily for the detection of climate driven trends in mean and high river flows. Thirty-five stations were identified for inclusion in the network plus a further 8 from the UK Benchmark Network. Their average record length is 40 years with a minimum of 28 and maximum of 63 years. Time series were derived for eight river flow indices: annual and seasonal mean flows and the annual maximum 1-, 10- and 30-day flows. Mann Kendall and Theil Sen statistics were applied to all indices using fixed and variable start/end dates. Trends in the winter mean are found to be highly dependent on the chosen period of analysis with the longest records showing increased flows. Contrary to expectations (of regional climate change scenarios), increases are also evident for long-term summer mean flows. High flow metrics exhibit positive and persistent trends that are less affected by inter-annual variability and period of record. Overall, there is strong spatial coherence in these patterns of change, linked to temporal variations in precipitation. Our results highlight the dangers of using conventional fixed periods such as 1961-1990 for trend detection, recognising that there is always a trade-off between record length, density of the network, and geographic coverage. Furthermore, outliers at the beginning of the record can be an artefact of the original motivation for installing the gauging station(s). In this case, water resource concerns during a markedly dry period in the mid-1970s favour positive trends over subsequent decades. Future work will focus on detection times for climate change signals and the identification of sentinel sites for discerning early signs of anthropogenic climate change across Ireland. Broader lessons for monitoring and detection of anthropogenic climate change signals will also be distilled.

  20. Testing the NMDA, long-term potentiation, and cholinergic hypotheses of spatial learning.

    PubMed

    Cain, D P

    1998-03-01

    The problems and issues associated with the use of pharmacological antagonists in studies on learning and memory are considered in a review of the role of N-methyl-D-aspartate (NMDA) receptors, NMDA receptor-mediated long-term potentiation (LTP), and muscarinic receptors in spatial learning in the water maze. The evidence indicates that neither NMDA nor muscarinic receptors, nor NMDA receptor-mediated LTP, are required for spatial learning, although they might normally contribute to it. Detailed behavioral analyses have indicated that the water maze task is more complex than generally has been appreciated, and has a number of dissociable components. Naive rats trained under NMDA or muscarinic antagonism display sensorimotor disturbances that interfere with their ability to acquire the task. Rats made familiar with the general requirements of the task can learn the location of a hidden platform readily under NMDA or muscarinic antagonism. The ability of a rat to acquire the water maze task depends on its ability to apply instinctive behaviors to performance of the task in an adaptive manner. The instinctive behaviors undergo modification as the rat learns the general strategies required in the task. The evidence suggests that at least some of the plastic changes involved in acquiring the task occur in existing neural circuits situated in widespread areas of the brain, including sensory and motor structures in the cortex and elsewhere, and are therefore difficult to distinguish from existing sensorimotor mechanisms. More generally, the findings indicate the difficulty of inferring the occurrence or nonoccurrence of learning from behavior, and the difficulty of causally linking the action of particular receptor populations with the formation of specific memories.

  1. A joint stochastic-deterministic approach for long-term and short-term modelling of monthly flow rates

    NASA Astrophysics Data System (ADS)

    Stojković, Milan; Kostić, Srđan; Plavšić, Jasna; Prohaska, Stevan

    2017-01-01

    The authors present a detailed procedure for modelling of mean monthly flow time-series using records of the Great Morava River (Serbia). The proposed procedure overcomes a major challenge of other available methods by disaggregating the time series in order to capture the main properties of the hydrologic process in both long-run and short-run. The main assumption of the conducted research is that a time series of monthly flow rates represents a stochastic process comprised of deterministic, stochastic and random components, the former of which can be further decomposed into a composite trend and two periodic components (short-term or seasonal periodicity and long-term or multi-annual periodicity). In the present paper, the deterministic component of a monthly flow time-series is assessed by spectral analysis, whereas its stochastic component is modelled using cross-correlation transfer functions, artificial neural networks and polynomial regression. The results suggest that the deterministic component can be expressed solely as a function of time, whereas the stochastic component changes as a nonlinear function of climatic factors (rainfall and temperature). For the calibration period, the results of the analysis infers a lower value of Kling-Gupta Efficiency in the case of transfer functions (0.736), whereas artificial neural networks and polynomial regression suggest a significantly better match between the observed and simulated values, 0.841 and 0.891, respectively. It seems that transfer functions fail to capture high monthly flow rates, whereas the model based on polynomial regression reproduces high monthly flows much better because it is able to successfully capture a highly nonlinear relationship between the inputs and the output. The proposed methodology that uses a combination of artificial neural networks, spectral analysis and polynomial regression for deterministic and stochastic components can be applied to forecast monthly or seasonal flow rates.

  2. Laboratory testing on the removal of the veterinary antibiotic doxycycline during long-term liquid pig manure and digestate storage.

    PubMed

    Widyasari-Mehta, Arum; Suwito, Hanna Resti Kartika Ayu; Kreuzig, Robert

    2016-04-01

    The veterinary antibiotic doxycycline (DOXY) is today frequently applied in conventional pig husbandry for the control of respiratory diseases. After the treatment, pigs excrete major amounts of DOXY as the unchanged active substance. Thus, DOXY residues were found in liquid manures and digestates of biogas plants at concentrations of mg kg(-1) dry weight. In order to assess the impact of field applications of contaminated manures and digestates on the entry of DOXY residues into arable and grassland soils, thorough information about the removal of DOXY during long-term storage of farm fertilizers is required. Since this aspect has been only less investigated for manures but not for digestates, first long-term storage simulation tests were performed at laboratory scale. Within the 170-d incubation periods under strictly anaerobic conditions, doxycycline was removed in liquid pig manure by 61% and in digestate by 76%. The calculated half-lives of 120 d and 91 d thus emphasized the persistence of doxycycline in both matrices. Due to the substance specific properties of DOXY, this removal was caused neither by mineralization, epimerization nor biotransformation. According to the high affinity of DOXY to manure and digestate solids, however, the formation of non-extractable residues has to be taken into account as the predominant concentration determining process. This was indicated by the sequential extraction procedure applied. Hence, these results confirmed that a full removal capacity for doxycycline cannot be reached through the long-term storage of farm fertilizers.

  3. Usefulness of a 50-meter round walking test for fall prediction in the elderly requiring long-term care.

    PubMed

    Hachiya, Mizuki; Murata, Shin; Otao, Hiroshi; Ihara, Takehiko; Mizota, Katsuhiko; Asami, Toyoko

    2015-12-01

    [Purpose] This study aimed to verify the usefulness of a 50-m round walking test developed as an assessment method for walking ability in the elderly. [Subjects] The subjects were 166 elderly requiring long-term care individuals (mean age, 80.5 years). [Methods] In order to evaluate the factors that had affected falls in the subjects in the previous year, we performed the 50-m round walking test, functional reach test, one-leg standing test, and 5-m walking test and measured grip strength and quadriceps strength. [Results] The 50-m round walking test was selected as a variable indicating fall risk based on the results of multiple logistic regression analysis. The cutoff value of the 50-m round walking test for determining fall risk was 0.66 m/sec. The area under the receiver operating characteristic curve was 0.64. The sensitivity of the cutoff value was 65.7%, the specificity was 63.6%, the positive predictive value was 55.0%, the negative predictive value was 73.3%, and the accuracy was 64.5%. [Conclusion] These results suggest that the 50-m round walking test is a potentially useful parameter for the determination of fall risk in the elderly requiring long-term care.

  4. Long-Term Testing of Rhodium-Based Catalysts for Mixed Alcohol Synthesis – 2013 Progress Report

    SciTech Connect

    Gerber, Mark A.; Gray, Michel J.; Thompson, Becky L.

    2013-09-23

    The U.S. Department of Energy’s Pacific Northwest National Laboratory has been conducting research since 2005 to develop a catalyst for the conversion of synthesis gas (carbon monoxide and hydrogen) into mixed alcohols for use in liquid transportation fuels. Initially, research involved screening possible catalysts based on a review of the literature, because at that time, there were no commercial catalysts available. The screening effort resulted in a decision to focus on catalysts containing rhodium and manganese. Subsequent research identified iridium as a key promoter for this catalyst system. Since then, research has continued to improve rhodium/manganese/iridium-based catalysts, optimizing the relative and total concentrations of the three metals, examining baseline catalysts on alternative supports, and examining effects of additional promoters. Testing was continued in FY 2013 to evaluate the performance and long-term stability of the best catalysts tested to date. Three tests were conducted. A long-term test of over 2300 hr duration at a single set of operating conditions was conducted with the best carbon-supported catalyst. A second test of about 650 hr duration at a single set of operating conditions was performed for comparison using the same catalyst formulation on an alternative carbon support. A third test of about 680 hr duration at a single set of operating conditions was performed using the best silica-supported catalyst tested to date.

  5. Tests of US rock salt for long-term stability of CAES reservoirs

    SciTech Connect

    Gehle, R.M.; Thoms, R.L.

    1986-01-01

    This is a report on laboratory tests to assess the effects of compressed air energy storage (CAES) on rock salt within the US. The project included a conventional laboratory test phase, with triaxial test machines, and a bench-scale test phase performed in salt mines in southern Louisiana. Limited numerical modeling also was performed to serve as a guide in selecting test layouts and for interpreting test data.

  6. A dynamic multi-organ-chip for long-term cultivation and substance testing proven by 3D human liver and skin tissue co-culture.

    PubMed

    Wagner, Ilka; Materne, Eva-Maria; Brincker, Sven; Süssbier, Ute; Frädrich, Caroline; Busek, Mathias; Sonntag, Frank; Sakharov, Dmitry A; Trushkin, Evgeny V; Tonevitsky, Alexander G; Lauster, Roland; Marx, Uwe

    2013-09-21

    Current in vitro and animal tests for drug development are failing to emulate the systemic organ complexity of the human body and, therefore, to accurately predict drug toxicity. In this study, we present a multi-organ-chip capable of maintaining 3D tissues derived from cell lines, primary cells and biopsies of various human organs. We designed a multi-organ-chip with co-cultures of human artificial liver microtissues and skin biopsies, each a (1)/100,000 of the biomass of their original human organ counterparts, and have successfully proven its long-term performance. The system supports two different culture modes: i) tissue exposed to the fluid flow, or ii) tissue shielded from the underlying fluid flow by standard Transwell® cultures. Crosstalk between the two tissues was observed in 14-day co-cultures exposed to fluid flow. Applying the same culture mode, liver microtissues showed sensitivity at different molecular levels to the toxic substance troglitazone during a 6-day exposure. Finally, an astonishingly stable long-term performance of the Transwell®-based co-cultures could be observed over a 28-day period. This mode facilitates exposure of skin at the air-liquid interface. Thus, we provide here a potential new tool for systemic substance testing.

  7. Long-term ground penetrating radar monitoring of a small volume DNAPL release in a natural groundwater flow field.

    PubMed

    Hwang, Yong Keun; Endres, Anthony L; Piggott, Scott D; Parker, Beth L

    2008-04-04

    An earlier field experiment at Canadian Forces Base Borden by Brewster and Annan [Geophysics 59 (1994) 1211] clearly demonstrated the capability of ground penetrating radar (GPR) reflection profiling to detect and monitor the formation of DNAPL layers in the subsurface. Their experiment involved a large volume release (770 L) of tetrachloroethylene into a portion of the sand aquifer that was hydraulically isolated from groundwater flow by sheet pile walls. In this study, we evaluated the ability of GPR profiling to detect and monitor much smaller volume releases (50 L). No subsurface confining structure was used in this experiment; hence, the DNAPL impacted zone was subjected to the natural groundwater flow regime. This condition allowed us to geophysically monitor the DNAPL mass loss over a 66 month period. Reflectivity variations on the GPR profiles were used to infer the presence and evolution of the solvent layers. GPR imaging found significant reflectivity increases due to solvent layer formation during the two week period immediately after the release. These results demonstrated the capacity of GPR profiling for the detection and monitoring of lesser volume DNAPL releases that are more representative of small-scale industrial spills. The GPR imaged solvent layers subsequently reduced in both areal extent and reflectivity after 29 months and almost completely disappeared by the end of the 66 month monitoring period. Total DNAPL mass estimates based on GPR profiling data indicated that the solvent mass was reduced to 34%-36% of its maximum value after 29 months; only 4%-9% of the solvent mass remained in the study area after 66 months. These results are consistent with independent hydrogeological estimates of remaining DNAPL mass based on the downgradient monitoring of the dissolved solvent phase. Hence, we have concluded that the long-term GPR reflectivity changes of the DNAPL layers are likely the result from the dissolution of chlorinated solvents residing

  8. The role of long-term memory in a test of visual working memory: Proactive facilitation but no proactive interference.

    PubMed

    Oberauer, Klaus; Awh, Edward; Sutterer, David W

    2017-01-01

    We report 4 experiments examining whether associations in visual working memory are subject to proactive interference from long-term memory (LTM). Following a long-term learning phase in which participants learned the colors of 120 unique objects, a working memory (WM) test was administered in which participants recalled the precise colors of 3 concrete objects in an array. Each array in the WM test consisted of 1 old (previously learned) object with a new color (old-mismatch), 1 old object with its old color (old-match), and 1 new object. Experiments 1 to 3 showed that WM performance was better in the old-match condition than in the new condition, reflecting a beneficial contribution from LTM. In the old-mismatch condition, participants sometimes reported colors associated with the relevant shape in LTM, but the probability of successful recall was equivalent to that in the new condition. Thus, information from LTM only intruded in the absence of reportable information in WM. Experiment 4 tested for, and failed to find, proactive interference from the preceding trial in the WM test: Performance in the old-mismatch condition, presenting an object from the preceding trial with a new color, was equal to performance with new objects. Experiment 5 showed that long-term memory for object-color associations is subject to proactive interference. We conclude that the exchange of information between LTM and WM appears to be controlled by a gating mechanism that protects the contents of WM from proactive interference but admits LTM information when it is useful. (PsycINFO Database Record

  9. O2 evolution and cyclic electron flow around photosystem I in long-term ground batch culture of Euglena gracilis

    NASA Astrophysics Data System (ADS)

    An, Yanjun; Wang, Suqin; Hao, Zongjie; Zhou, Yiyong; Liu, Yongding

    2014-12-01

    Based on the purpose of better exploring the function of green producers in the closed aquatic biological life support system, the condition of dynamic O2 evolution and performance of cyclic electron flow around photosystem I (CEF-PSI) in long-term ground batch culture of Euglena gracilis were studied, the relationship between linear electron flow (LEF) and CEF-PSI was revealed, the function of CEF-PSI was investigated. Excellent consistency in O2 evolution pattern was observed in cultures grown in both closed and open containers, O2 evolution was strictly suppressed in phase 1, but the rate of it increased significantly in phase 2. CEF-PSI was proposed to be active during the whole course of cultivation, even in the declining phase 3, it still operated at the extent of 47-55%. It is suggested that the relationship between LEF and CEF-PSI is not only competition but also reciprocity. CEF-PSI was proposed to contribute to the considerable growth in phase 1; it was also suggested to play an important protective role against photosystem II (PSII) photoinhibition at the greatly enhanced level (approximately 80-95%) on the 2nd day. Our results in this research suggest that E. gracilis had very particular photosynthetic characteristics, the strict O2 evolution suppression in the initial culture phase might be a special light acclimation behavior, and CEF-PSI could be an important mechanism involved in this kind of adaptation to the changeable light environment.

  10. Constrained prose recall and the assessment of long-term forgetting: the case of ageing and the Crimes Test.

    PubMed

    Baddeley, Alan; Rawlings, Bruce; Hayes, Amie

    2014-01-01

    It has become increasingly clear that some patients with apparently normal memory may subsequently show accelerated long-term forgetting (ALF), with dramatic loss when retested. We describe a constrained prose recall task that attempts to lay the foundations for a test suitable for detecting ALF sensitively and economically. Instead of the usual narrative structure of prose recall tests, it employs a matrix structure involving four episodes, each describing a minor crime, with each crime involving the binding into a coherent episode of a specified range of features, involving the victim, the crime, the criminal and the location, allowing a total of 80 different probed recall questions to be generated. These are used to create four equivalent 20-item tests, three of which are used in the study. After a single verbal presentation, young and elderly participants were tested on three occasions, immediately, and by telephone after a delay of 6 weeks, and at one of a varied range of intermediate points. The groups were approximately matched on immediate test; both showed systematic forgetting which was particularly marked in the elderly. We suggest that constrained prose recall has considerable potential for the study of long-term forgetting.

  11. The effects of test-enhanced learning on long-term retention in AAN annual meeting courses.

    PubMed

    Larsen, Douglas P; Butler, Andrew C; Aung, Wint Y; Corboy, John R; Friedman, Deborah I; Sperling, Michael R

    2015-02-17

    We measured the long-term retention of knowledge gained through selected American Academy of Neurology annual meeting courses and compared the effects of repeated quizzing (known as test-enhanced learning) and repeated studying on that retention. Participants were recruited from 4 annual meeting courses. All participants took a pretest. This randomized, controlled trial utilized a within-subjects design in which each participant experienced 3 different postcourse activities with each activity performed on different material. Each key information point from the course was randomized in a counterbalanced fashion among participants to one of the 3 activities: repeated short-answer quizzing, repeated studying, and no further exposure to the materials. A final test covering all information points from the course was taken 5.5 months after the course. Thirty-five participants across the 4 courses completed the study. Average score on the pretest was 36%. Performance on the final test showed that repeated quizzing led to significantly greater long-term retention relative to both repeated studying (55% vs 46%; t[34] = 3.28, SEM = 0.03, p = 0.01, d = 0.49) and no further exposure (55% vs 44%; t[34] = 3.16, SEM = 0.03, p = 0.01, d = 0.58). Relative to the pretest baseline, repeated quizzing helped participants to retain almost twice as much of the knowledge acquired from the course compared to repeated studying or no further exposure. Whereas annual meeting continuing medical education (CME) courses lead to long-term gains in knowledge, when repeated quizzing is added, retention is significantly increased. CME planners may consider adding repeated quizzing to increase the impact of their courses. © 2015 American Academy of Neurology.

  12. The effects of test-enhanced learning on long-term retention in AAN annual meeting courses

    PubMed Central

    Butler, Andrew C.; Aung, Wint Y.; Corboy, John R.; Friedman, Deborah I.; Sperling, Michael R.

    2015-01-01

    Objective: We measured the long-term retention of knowledge gained through selected American Academy of Neurology annual meeting courses and compared the effects of repeated quizzing (known as test-enhanced learning) and repeated studying on that retention. Methods: Participants were recruited from 4 annual meeting courses. All participants took a pretest. This randomized, controlled trial utilized a within-subjects design in which each participant experienced 3 different postcourse activities with each activity performed on different material. Each key information point from the course was randomized in a counterbalanced fashion among participants to one of the 3 activities: repeated short-answer quizzing, repeated studying, and no further exposure to the materials. A final test covering all information points from the course was taken 5.5 months after the course. Results: Thirty-five participants across the 4 courses completed the study. Average score on the pretest was 36%. Performance on the final test showed that repeated quizzing led to significantly greater long-term retention relative to both repeated studying (55% vs 46%; t[34] = 3.28, SEM = 0.03, p = 0.01, d = 0.49) and no further exposure (55% vs 44%; t[34] = 3.16, SEM = 0.03, p = 0.01, d = 0.58). Relative to the pretest baseline, repeated quizzing helped participants to retain almost twice as much of the knowledge acquired from the course compared to repeated studying or no further exposure. Conclusions: Whereas annual meeting continuing medical education (CME) courses lead to long-term gains in knowledge, when repeated quizzing is added, retention is significantly increased. CME planners may consider adding repeated quizzing to increase the impact of their courses. PMID:25609761

  13. Long-Term Stability of Teacher Certification Test Objective Job Analysis Ratings.

    ERIC Educational Resources Information Center

    Silvestro, John R.; And Others

    Public school ratings of the importance of subject-matter test objectives associated with teacher certification tests were examined by means of a job-analysis survey conducted in 1986 and a similar survey conducted in 1993. It was predicted that there would be a high degree of change in the importance ratings assigned to these test objectives…

  14. Correlation of short-term to long-term oxidation testing for alumina forming alloys and coatings

    NASA Astrophysics Data System (ADS)

    Stiger, Matthew J.

    Engineering long cyclic oxidation life of high temperature materials requires success on two fronts. First a slow growing protective oxide scale must form during the elevated temperature exposure. To satisfy this aspect, alumina-forming alloys and coatings are widely accepted as leading materials for use in this environment and are the focus of this discussion. The second aspect is the formation of an adherent oxide that resists spallation during thermal cycling. The driving force for spallation is the stored elastic strain energy that develops from stresses in the oxide scale. Once this stored elastic strain energy exceeds the oxide-substrate interfacial toughness, cracking and subsequent spallation occurs followed by rapid oxidation of the substrate. With advances in alloy and coating development resulting in higher operating temperatures and increased service lives, researchers are faced with excessive laboratory time and cost required to perform a long-term cyclic oxidation test. The challenge is to predict long-term oxidation behavior from short-term experiments. Since the rate limiting step to high temperature oxidation is a thermally activated process, previous investigations were performed at increased exposure temperatures for rapid degradation of the alloys and coatings to rank material performance. Others have mechanically induced oxide spallation to give insight on the adherence of oxide scales prior to spontaneous failure. In this investigation, short-term testing is employed to gain insight on long-term performance and to determine inputs into a cyclic oxidation model for life-time prediction. This model operates in an iterative process where one iteration is a thermal cycle. The amount of oxide formed during the high temperature segment is calculated followed by the amount that is lost due to scale spallation during cooling. Retained oxide at the end of this cycle is used as the starting point for the following iteration. The two inputs into this

  15. A multi-organ chip co-culture of neurospheres and liver equivalents for long-term substance testing.

    PubMed

    Materne, Eva-Maria; Ramme, Anja Patricia; Terrasso, Ana Paula; Serra, Margarida; Alves, Paula Marques; Brito, Catarina; Sakharov, Dmitry A; Tonevitsky, Alexander G; Lauster, Roland; Marx, Uwe

    2015-07-10

    Current in vitro and animal tests for drug development are failing to emulate the systemic organ complexity of the human body and, therefore, often do not accurately predict drug toxicity, leading to high attrition rates in clinical studies (Paul et al., 2010). The phylogenetic distance between humans and laboratory animals is enormous, this affects the transferability of animal data on the efficacy of neuroprotective drugs. Therefore, many neuroprotective treatments that have shown promise in animals have not been successful when transferred to humans (Dragunow, 2008; Gibbons and Dragunow, 2010). We present a multi-organ chip capable of maintaining 3D tissues derived from various cell sources in a combined media circuit which bridges the gap in systemic and human tests. A steady state co-culture of human artificial liver microtissues and human neurospheres exposed to fluid flow over two weeks in the multi-organ chip has successfully proven its long-term performance. Daily lactate dehydrogenase activity measurements of the medium and immunofluorescence end-point staining proved the viability of the tissues and the maintenance of differentiated cellular phenotypes. Moreover, the lactate production and glucose consumption values of the tissues cultured indicated that a stable steady-state was achieved after 6 days of co-cultivation. The neurospheres remained differentiated neurons over the two-week cultivation in the multi-organ chip, proven by qPCR and immunofluorescence of the neuronal markers βIII-tubulin and microtubule-associated protein-2. Additionally, a two-week toxicity assay with a repeated substance exposure to the neurotoxic 2,5-hexanedione in two different concentrations induced high apoptosis within the neurospheres and liver microtissues, as shown by a strong increase of lactate dehydrogenase activity in the medium. The principal finding of the exposure of the co-culture to 2,5-hexanedione was that not only toxicity profiles of two different doses

  16. Long term follow up of newborns tested with the auditory response cradle.

    PubMed Central

    Bhattacharya, J; Bennett, M J; Tucker, S M

    1984-01-01

    The auditory response cradle is being used in a mass hearing screening project. Babies are assessed in the first week after birth by the fully automatic, microprocessor controlled cradle. The test, lasting from two to 10 minutes, compares physiological auditory responses to natural behaviour measured in control trials. More than 5000 babies have been tested and full follow up information at the age of 7 to 9 months is available from over two thirds of these. Less detailed information is available for 71% and 64% of those babies who have been followed up at 18 months and three years of age respectively. A total of 439 of 5553 neonates tested failed the first screening test. Eighty eight (1 X 6%) failed a second screening test while still in the maternity unit but 61 of these were subsequently shown to be normal, giving a false positive rate of 1 X 1%. The babies who failed the screening tests included 9 with sensorineural hearing loss, three with secretory otitis media, and three with abnormal auditory brain stem response tests. One child who passed the initial screening tests was found to have a moderately severe hearing loss at the age of 18 months. Images Figure PMID:6540071

  17. Military chemical warfare agent human subjects testing: part 2--long-term health effects among participants of U.S. military chemical warfare agent testing.

    PubMed

    Brown, Mark

    2009-10-01

    Military chemical warfare agent testing from World War I to 1975 produced thousands of veterans with concerns about how their participation affected their health. A companion article describes the history of these experiments, and how the lack of clinical data hampers evaluation of long-term health consequences. Conversely, much information is available about specific agents tested and their long-term health effects in other populations, which may be invaluable for helping clinicians respond effectively to the health care and other needs of affected veterans. The following review describes tested agents and their known long-term health consequences. Although hundreds of chemicals were tested, they fall into only about a half-dozen pharmaceutical classes, including common pharmaceuticals; anticholinesterase agents including military nerve agents and pesticides; anticholinergic glycolic acid esters such as atropine; acetylcholine reactivators such as 2-PAM; psychoactive compounds including cannabinoids, phencyclidine, and LSD; and irritants including tear gas and riot control agents.

  18. Surgical Placement of Catheters for Long-term Cardiovascular Exercise Testing in Swine.

    PubMed

    De Wijs-Meijler, Daphne P M; Stam, Kelly; van Duin, Richard W B; Verzijl, Annemarie; Reiss, Irwin K; Duncker, Dirk J; Merkus, Daphne

    2016-02-09

    This protocol describes the surgical procedure to chronically instrument swine and the procedure to exercise swine on a motor-driven treadmill. Early cardiopulmonary dysfunction is difficult to diagnose, particularly in animal models, as cardiopulmonary function is often measured invasively, requiring anesthesia. As many anesthetic agents are cardiodepressive, subtle changes in cardiovascular function may be masked. In contrast, chronic instrumentation allows for measurement of cardiopulmonary function in the awake state, so that measurements can be obtained under quiet resting conditions, without the effects of anesthesia and acute surgical trauma. Furthermore, when animals are properly trained, measurements can also be obtained during graded treadmill exercise. Flow probes are placed around the aorta or pulmonary artery for measurement of cardiac output and around the left anterior descending coronary artery for measurement of coronary blood flow. Fluid-filled catheters are implanted in the aorta, pulmonary artery, left atrium, left ventricle and right ventricle for pressure measurement and blood sampling. In addition, a 20 G catheter is positioned in the anterior interventricular vein to allow coronary venous blood sampling. After a week of recovery, swine are placed on a motor-driven treadmill, the catheters are connected to pressure and flow meters, and swine are subjected to a five-stage progressive exercise protocol, with each stage lasting 3 min. Hemodynamic signals are continuously recorded and blood samples are taken during the last 30 sec of each exercise stage. The major advantage of studying chronically instrumented animals is that it allows serial assessment of cardiopulmonary function, not only at rest but also during physical stress such as exercise. Moreover, cardiopulmonary function can be assessed repeatedly during disease development and during chronic treatment, thereby increasing statistical power and hence limiting the number of animals

  19. Non-destructive testing on aramid fibres for the long-term assessment of interventions on heritage structures

    NASA Astrophysics Data System (ADS)

    Ceravolo, R.; De Marchi, A.; Pinotti, E.; Surace, C.; Zanotti Fragonara, L.

    2015-07-01

    High strength fibre reinforced polymers (FRPs) are composite materials made of fibres such as carbon, aramid and/or glass, and a resin matrix. FRPs are commonly used for structural repair and strengthening interventions and exhibit high potential for applications to existing constructions, including heritage buildings. In regard to aramid fibres, uncertainties about the long-term behaviour of these materials have often made the designers reluctant to use them in structural engineering. The present study describes simple and non-destructive nonlinearity tests for assessing damage or degradation of structural properties in Kevlar fibres. This was obtained by using high precision measurements to detect small deviations in the dynamic response measured on fibres and ropes. The change in dynamic properties was then related to a damage produced by exposure of the sample to UV rays for a defined time period, which simulated long-term sun exposure. In order to investigate the sensitivity of such an approach to damage detection, non-linearity characterisation tests were conducted on aramid fibres in both damaged and undamaged states. With the purpose of carrying out dynamic tests on small fibre specimens, a dedicated instrumentation was designed and built in cooperation with the Metrology Laboratory of the Department of Electronics at the Politecnico di Torino.

  20. Integrated Corrosion Facility for long-term testing of candidate materials for high-level radioactive waste containment

    SciTech Connect

    Estill, J.C.; Dalder, E.N.C.; Gdowski, G.E.; McCright, R.D.

    1994-10-01

    A long-term-testing facility, the Integrated Corrosion Facility (I.C.F.), is being developed to investigate the corrosion behavior of candidate construction materials for high-level-radioactive waste packages for the potential repository at Yucca Mountain, Nevada. Corrosion phenomena will be characterized in environments considered possible under various scenarios of water contact with the waste packages. The testing of the materials will be conducted both in the liquid and high humidity vapor phases at 60 and 90{degrees}C. Three classes of materials with different degrees of corrosion resistance will be investigated in order to encompass the various design configurations of waste packages. The facility is expected to be in operation for a minimum of five years, and operation could be extended to longer times if warranted. A sufficient number of specimens will be emplaced in the test environments so that some can be removed and characterized periodically. The corrosion phenomena to be characterized are general, localized, galvanic, and stress corrosion cracking. The long-term data obtained from this study will be used in corrosion mechanism modeling, performance assessment, and waste package design. Three classes of materials are under consideration. The corrosion resistant materials are high-nickel alloys and titanium alloys; the corrosion allowance materials are low-alloy and carbon steels; and the intermediate corrosion resistant materials are copper-nickel alloys.

  1. Modeling performance of a two-dimensional capsule in a microchannel flow: long-term lateral migration.

    PubMed

    Li, Hua; Ma, Gang

    2010-08-01

    The long-term lateral migration of a two-dimensional elastic capsule in a microchannel is studied numerically in this paper. The numerical method combines a finite volume technique for solving the fluid problem with a front tracking technique for capturing and tracking the capsule membrane. The capsule is modeled as a liquid medium enclosed by a thin membrane which has linear elastic properties. The capsule, whose initial shape is circle and which starts from a near-center position or a near-wall position, experiences tilting and membrane tank-treading, and migrates laterally when moving along the surrounding flow. The lateral migration demonstrates the existence of lift effect of surrounding flow on moving capsule. Before capsule approaches to the microchannel centerline closely, lower membrane dilation modulus and lower viscosity ratio tend to result in faster lateral migration. The initial position also influences the performance behavior of capsule, despite the lateral migration of capsule is a quasisteady process. Small difference in capsule behavior when capsule is not near to the microchannel centerline might lead to significant difference in capsule behavior when capsule approaches closely to the centerline. When capsules are near to microchannel wall, the effect of the wall on capsule behavior might dominate, leading to relatively faster lateral migration. When capsules are not far from microchannel centerline, the effect of the nonlinearity of Poiseuille flow might dominate, resulting in relatively slower lateral movement. When capsules are located closely to the centerline, they behave differently, where the reason still remains poorly understood and it will be one of our future studies. The comparison between the capsule behavior from the present simulation and that by the migration law proposed by Coupier [Phys. Fluids 20, 111702 (2008)] shows that the behavioral agreement for near-wall capsule is better than that for near-center capsule, and the best

  2. Long-term test results from a West Valley actinide-doped reference glass

    SciTech Connect

    Fortner, J.A.; Gerding, T.J.; Bates, J.K.

    1995-07-01

    Results from drip tests designed to simulate unsaturated conditions in the proposed Yucca Mountain Repository are reported for an actinide-doped glass (reference glass ATM-10) used as a model waste form. These tests have been ongoing for nearly 7 years, with data collected on solution composition (including transuranics), colloid formation and disposition, glass corrosion layers, and solid secondary phases. This test is unique because of its long elapsed time, high content of thorium and transuranics, use of actual groundwater from the proposed site area, use of contact between the glass and sensitized stainless steel in the test, and the variety of analytical procedures applied to the components. Some tests have been terminated, and scanning electron microscopy (SEM) and analytical transmission electron microscopy (AEM) were used to directly measure glass corrosion and identify secondary phases. Other tests remain ongoing, with periodic sampling of the water that had contacted the glass. The importance of integrated testing has been demonstrated, as complex interactions between the glass, the groundwater, and the sensitized stainless steel have been observed. Secondary phases include smectite clay, iron silicates, and brockite. Actinides, except neptunium, concentrate into stable secondary phases. The release of actinides is then controlled by the behavior of these phases.

  3. Long-term field and laboratory leaching tests of cemented radioactive wastes.

    PubMed

    Ojovan, Michael I; Varlackova, Galina A; Golubeva, Zoya I; Burlaka, Olga N

    2011-03-15

    Experiments with real and simulated radioactive cementitious wasteforms were set up to compare the leaching behaviour of cementitious wasteforms containing nuclear power plant operational waste in field and laboratory test conditions. Experiments revealed that the average annual (137)Cs leach rate in deionised water was about thirty-five times greater compared with the measured average value for the 1st year of the field test. Cumulative leached fraction of (137)Cs for 1st year (3.74%) was close to values reported in literature for similar laboratory experiments in deionised water, however more than two orders of magnitude higher than the 1st year leached fraction of (137)Cs in the repository test (0.01%). Therefore, to compare field and laboratory test results, a scaling factor is required in order to account for surface to volume factor difference, multiplied by a temperature factor and a leach rate decrease coefficient related to the ground water composition.

  4. Electrochemical Test Method for Evaluating Long-Term Propellant-Material Compatibility

    DTIC Science & Technology

    1978-12-01

    INSTRUCTIONS BEFORE COMPLETING FORM 2.GV CESSION NO.,. ftECIPIENT’S CATALOG NUMMEPI COVERED ý ,LECTROCHEMICALJEST METHOD FOR EVALUATING Fnl~pt LoNG -TERN...effects of each of these configurations were evaluated with respect to baseline tests where the metal was in the form of either a slug or a strip. The...system components beyond the limitations of real-time testing and evaluation. In the case of unmanned satellites, components which are in contact with

  5. Long-term stability of ethanol solutions for breath-alcohol tests.

    PubMed

    Kucmanic, John

    2009-01-01

    Aqueous alcohol solutions in conjunction with a simulator are used commonly to calibrate and check the operation of breath-alcohol instruments. In Ohio, these solutions expire one year from the date of manufacture. This study was undertaken to review and report the stability of several batches of solution that had been manufactured from 2003 to 2007 and were statutorily expired. Eight batches of solution, each with a theoretical breath-alcohol target value of 0.100 g/210 L, were tested on paired Intoxilyzer 8000s using Guth model 590 simulators. This model of simulator required only 250 mL of solution per simulator. Therefore, each batch was evaluated by testing a single bottle of solution that had remained sealed since its manufacture. Five tests were performed on each instrument, and the acceptable criterion was limited to +/- 0.005 g/210 L of the established target value. A current batch of solution was also examined to verify the performance of the instrument before study sample testing commenced and at the completion of testing. All batches and bottles produced acceptable results within the acceptable limit for each target value. It can be concluded that the stability of the wet bath solution packaged in high-density polyethylene bottles with a theoretical concentration of 0.100 g/210 L is in excess of five years and surpasses the statutory expiration term of one year from the date of manufacture when stored at normal room temperatures.

  6. LONG-TERM STABILITY TESTING RESULTS USING SURROGATES AND SORBENTS FOR SAVANNAH RIVER SITE ORGANIC AND AQUEOUS WASTESTREAMS - 10016

    SciTech Connect

    Burns, H.

    2009-11-10

    The U.S. Department of Energy (DOE) has tasked MSE Technology Applications, Inc. (MSE) with evaluating the long-term stability of various commercially available sorbent materials to solidify two organic surrogate wastestreams (both volatile and nonvolatile), a volatile organic surrogate with a residual aqueous phase, an aqueous surrogate, and an aqueous surrogate with a residual organic phase. The Savannah River Site (SRS) Legacy and F-Canyon plutonium/uranium extraction (PUREX) process waste surrogates constituted the volatile organic surrogates, and various oils constituted the nonvolatile organic surrogates. The aqueous surrogates included a rainwater surrogate and an aqueous organic surrogate. MSE also evaluated the PUREX surrogate with a residual aqueous component with and without aqueous type sorbent materials. Solidification of the various surrogate wastestreams listed above was performed from 2004 to 2006 at the MSE Test Facility located in Butte, Montana. This paper summarizes the comparison of the initial liquid release test (LRT) values with LRT results obtained during subsequent sampling events in an attempt to understand and define the long-term stability characteristics for the solidified wastestreams.

  7. Test-Enhanced Learning in the Classroom: Long-Term Improvements from Quizzing

    ERIC Educational Resources Information Center

    Roediger, Henry L., III; Agarwal, Pooja K.; McDaniel, Mark A.; McDermott, Kathleen B.

    2011-01-01

    Three experiments examined whether quizzing promotes learning and retention of material from a social studies course with sixth grade students from a suburban middle school. The material used in the experiments was the course material students were to learn and some of the dependent measures were the actual tests on which students received grades.…

  8. Leachate Testing and Evaluation for Estuarine Sediments. Long-Term Effects of Dredging Operations Program.

    DTIC Science & Technology

    1996-03-01

    input concentration approach is, as a practical matter, easier to accomplish. Levenspiel (1972) describes tracer testing and interpretation of results in...approximation analysis," Journal of Hydraulic Engineering American Soci- ety of Civil Engineers 110(12), 1700-1717. Levenspiel , 0. (1972). Chemical

  9. Electrochemical characterizations of microtubular solid oxide fuel cells under a long-term testing at intermediate temperature operation

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Toshiaki; Galloway, Kevin V.; Yoon, Jieon; Sammes, Nigel M.

    2011-03-01

    We report the long-term stability of a microtubular solid oxide fuel cell (SOFC) operable at ∼500 °C. The SOFC consists of NiO-Gd doped ceria (GDC) as the anode as well as the tubular support, GDC as an electrolyte and La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF)-GDC as the cathode. A single tubular cell with a diameter of approximately 1.8 mm and an effective electrode length of approximately 20 mm generated 150 mW cm-2 and 340 mW cm-2 at 500 °C and 550 °C, respectively, under the operation conditions of 0.7 V and humidified H2 fuel flow. The cell exhibited good stability with a degradation rate of 0.25%/100 h under operation conditions of 200 mA and 0.75 V.

  10. Long term testing of start-stop cycles on high temperature PEM fuel cell stack

    NASA Astrophysics Data System (ADS)

    Kannan, Arvind; Kabza, Alexander; Scholta, Joachim

    2015-03-01

    A PEM fuel cell with an operating temperature above 100 °C is desired for increasing the kinetics of reactions, reduced sensitivity to impurities of the fuel, as well as for the reduction of the requirements on thermal and water management systems. High Temperature Polymer Electrolyte Membrane Fuel Cells (HT-PEMFC) can effectively be combined with CHP systems to offer a simple system design and higher overall system efficiencies. For HT-PEMFC systems, the development of elaborated start/stop strategies is essential in mitigation of fuel cell degradation during these events. A 5 cell co-flow stack is assembled with BASF P1100W membrane electrode assembly (MEA) with an active area of 163.5 cm2. Continuous operation and more than 1500 start stop cycles have been performed in order to study the degradation effects of both continuous operation and of repeated start stops using a protective start-stop algorithm, which is designed to avoid the formation of aggressive cell potentials. The repeated use of this procedure led to a degradation of 26 μV/cycle at a current density of 0.25 A cm-2 and 11 μV/cycle at a current density of 0.03 A cm-2. At open circuit voltage (OCV), a higher degradation rate of 133 μV/cycle was observed.

  11. Long-term leaching test of organo-contaminated cement-clay pastes.

    PubMed

    Zampori, L; Stampino, P Gallo; Dotelli, G

    2009-10-30

    The aim of the present work is to investigate the effect of a prolonged leaching test (more than a year) on the microstructure of solidified cementitious wasteforms. A set of four different cement-based monoliths (Ap, Bp, Cp and Dp) was prepared, and for each series an uncontaminated sample was prepared as reference (A-D). An organoclay was added in all pastes as pre-sorbent material for the pollutant; a model liquid organic pollutant, 2-chloroaniline (2-CA), was added only in the contaminated ones and different types of admixtures, chosen among those typically employed in the concrete mix-design, were used. After the first 28 days of curing, all the monoliths, contaminated and uncontaminated, underwent a dynamic leach testing (DLT) for more than 1 year in deionized water.

  12. Long term storage test of titanium material with liquid fluorine propellant

    NASA Technical Reports Server (NTRS)

    Denson, J. R.; English, W. D.; Roth, J.; Toy, A.

    1979-01-01

    The compatibility of 6AL-4V Ti with propellant grade GF2 and LF2 at 77 K for up to 3 years was investigated. Titanium double coupons, annealed or heat treated, with 16 or 64 RMS finishes, were immersed in F2 in individual Pyrex capsules and stored under LN2 for 29 and 39 months. Pre and post immersion tests were performed on the propellant and coupons. Chemical analysis of the propellant did not reveal any significant changes due to titanium corrosion. Gravimetric, visual, microscopic, and metallurgical examination with pitting analysis did not reveal gross corrosion of the titanium although pitting appears to be greater after 39 months exposure. The increase in pit size and number raises the possibility of unpredictable crack propagation instability. Fracture toughness tests are necessary to define this possibility.

  13. [Functional test with potassium chloride following long-term space mission].

    PubMed

    Grigor'ev, A I; Noskov, V B

    1997-01-01

    To look into the potassiuretic function of kidneys in 11 cosmonauts on the second day post recovery after six-month MIR missions, functional testing with potassium chloride was performed. The following standard procedure was used before and after the missions: during morning hours fasting test-subjects consumed a 10% solution of potassium chloride in the amount of 0.55 ml/kg or 0.75 mmol of potassium per a kilogram of body mass with some additional liquid in the amount of 10 ml/kg of body mass. Later on, urine was collected for four hours. Administration of the potassium loading test after missions did not reveal any significant group-average changes in potassium excretion as compared with pre-flight levels; meanwhile, calcium excretion was increased. Reduced blood concentrations of potassium were determined in each of the cosmonauts immediately after landing. The main contributor to retaining of the renal potassiuretic function after prolonged missions appears to be the effective inflight physical countermeasures against the musculoskeletal deconditioning of the human body.

  14. Long-term static testing of an FRP prototype highway structure

    NASA Astrophysics Data System (ADS)

    Lee, J.; Hollaway, L.; Thorne, A.; Head, P.

    In recent years it has become apparent that the labour and maintenance costs of highway structures fabricated from conventional constructional materials (i.e. steel and concrete) are rising, and therefore the whole life cost of these structures is being significantly affected. Highway structures manufactured from advanced composite materials provide a viable solution to reduce substantially both the labour and the maintenance costs, whilst providing structures that behave in accordance with the present British code of practice for highway structures. The principle objectives of the investigations were to undertake experimentally and to verify, where applicable, numerically the suitability of advanced fibre-reinforced polymer (FRP) composite materials manufactured in the form of box beams for use as highway structures. It was also important to research into any unique behaviour exhibited by the FRP structures while under test and to develop relevant theoretical models and formulae to characterize completely this behaviour. The composite box beam showed no signs of global deterioration and generally behaved as predicted; the short term stiffness of the beam measured at specific times during the test did not decrease to any extent. There was some local flexural cracking in the connectors at the position of the applied loads, but this can be eliminated by design. The creep and deflections of the beam at the end of the test were well within acceptable limits.

  15. Corrosion of metals in wood : comparing the results of a rapid test method with long-term exposure tests across six wood treatments

    Treesearch

    Samuel L. Zelinka; Donald S. Stone

    2011-01-01

    This paper compares two methods of measuring the corrosion of steel and galvanized steel in wood: a long-term exposure test in solid wood and a rapid test method where fasteners are electrochemically polarized in extracts of wood treated with six different treatments. For traditional wood preservatives, the electrochemical extract method correlates with solid wood...

  16. A field assessment of long-term laboratory sediment toxicity tests with the amphipod Hyalella azteca

    USGS Publications Warehouse

    Ingersoll, Christopher G.; Wang, Ning; Hayward, Jeannie M. R.; Jones, John R.; Jones, Susan B.; Ireland, D. Scott

    2005-01-01

    Response of the amphipod Hyalella azteca exposed to contaminated sediments for 10 to 42 d in laboratory toxicity tests was compared to responses observed in controlled three-month invertebrate colonization exposures conducted in a pond. Sediments evaluated included a sediment spiked with dichlorodiphenyldichloroethane (DDD) or dilutions of a field sediment collected from the Grand Calumet River (GCR) in Indiana (USA) (contaminated with organic compounds and metals). Consistent effects were observed at the highest exposure concentrations (400 ??g DDD/goc [DDD concentrations normalized to grams of organic carbon (goc) in sedimentl or 4% GCR sediment) on survival, length, and reproduction of amphipods in the laboratory and on abundance of invertebrates colonizing sediments in the field. Effect concentrations for DDD observed for 10-d length and 42-d reproduction of amphipods (e.g., chronic value [ChV] of 66 ??g DDD/goc and 25% inhibition concentration [IC25] of 68 ??g DDD/goc for reproduction) were similar to the lowest effect concentrations for DDD measured on invertebrates colonizing sediment the field. Effect concentrations for GCR sediment on 28-d survival and length and 42-d reproduction and length of amphipods (i.e., ChVs of 0.20-0.66% GCR sediment) provided more conservative effect concentrations compared to 10-d survival or length of amphipods in the laboratory or the response of invertebrates colonizing sediment in the field (e.g., ChVs of 2.2% GCR sediment). Results of this study indicate that use of chronic laboratory toxicity tests with H. azteca and benthic colonization studies should be used to provide conservative estimates of impacts on benthic communities exposed to contaminated sediments. Bioaccumulation of DDD by oligochaetes colonizing the DDD-spiked sediment was similar to results of laboratory sediment tests previously conducted with the oligochaete Lumbriculus variegates, confirming that laboratory exposures can be used to estimate

  17. Changing the philosophy of care in long-term care: testing of the restorative care intervention.

    PubMed

    Resnick, Barbara; Gruber-Baldini, Ann L; Galik, Elizabeth; Pretzer-Aboff, Ingrid; Russ, Karin; Hebel, J Richard; Zimmerman, Sheryl

    2009-04-01

    The purpose of this study was to test the effectiveness of a 12-month restorative care (Res-Care) intervention on the beliefs related to Res-Care, knowledge of Res-Care, observed performance of Res-Care with residents, and job satisfaction among nursing assistants (NAs) in nursing home (NH) settings. This was a randomized controlled trial including 12 sites and used a repeated measure design with follow-up testing done at 4 and 12 months. An intention-to-treat principle was followed in all analyses, and generalized estimating equations were used to perform repeated measures. A total of 556 NAs consented to participate and completed baseline assessments (265 in treatment and 258 in control sites), 427 completed 4-month follow-up (218 in treatment and 195 in control sites), and 357 completed 12-month follow-up (168 in treatment and 158 in control sites). There was a statistically significant increase in the treatment group participants' outcome expectations related to Res-Care activities (p = .04) and performance of Res-Care (p < .001) at 4 months, and an increase in knowledge of Res-Care (p < .001) and job satisfaction (p < .001) at 12 months. There was no difference between the groups with regard to self-efficacy expectations. This study provides an important step in understanding the implementation of a Res-Care philosophy in NH settings and the benefit this can have for NAs.

  18. Long-term photothermal/humidity testing of photovoltaic module polymer insulations and cover films

    NASA Technical Reports Server (NTRS)

    Mon, G.; Gonzales, C.; Willis, P.; Jetter, E.; Sugimura, R.

    1990-01-01

    The life expectancies of Tedlar and other polymer films considered for use as cover materials in terrestrial photovoltaic (PV) modules were investigated by exposing them for more than 13,000 h on an outdoor test stand and for up to 10,000 h in several accelerated multistress environments. Visual observations and diagnostic analyses of weight and mechanical strength losses were periodically conducted to assess the nature and rate of degradation of mechanical properties and to assess the effects of film thickness and UV stabilizer content. Spectroscopic analyses of pristine and degraded materials linked weight and mechanical property losses to the underlying photothermal/photooxidation chemistry. It is shown that heavy doses of UV stabilizers prolong, while elevated temperatures shorten, the useful life of these materials; humidity plays only a minor role. The most heavily UV-stabilized films are expected to operate usefully in a PV module front-cover application for only five to ten years. The performance of none of the tested films appears consistent with the 20-30 year life goals of the PV industry.

  19. Long-term photothermal/humidity testing of photovoltaic module polymer insulations and cover films

    NASA Technical Reports Server (NTRS)

    Mon, G.; Gonzales, C.; Willis, P.; Jetter, E.; Sugimura, R.

    1990-01-01

    The life expectancies of Tedlar and other polymer films considered for use as cover materials in terrestrial photovoltaic (PV) modules were investigated by exposing them for more than 13,000 h on an outdoor test stand and for up to 10,000 h in several accelerated multistress environments. Visual observations and diagnostic analyses of weight and mechanical strength losses were periodically conducted to assess the nature and rate of degradation of mechanical properties and to assess the effects of film thickness and UV stabilizer content. Spectroscopic analyses of pristine and degraded materials linked weight and mechanical property losses to the underlying photothermal/photooxidation chemistry. It is shown that heavy doses of UV stabilizers prolong, while elevated temperatures shorten, the useful life of these materials; humidity plays only a minor role. The most heavily UV-stabilized films are expected to operate usefully in a PV module front-cover application for only five to ten years. The performance of none of the tested films appears consistent with the 20-30 year life goals of the PV industry.

  20. Long-term exposure to a ‘safe’ dose of bisphenol A reduced protein acetylation in adult rat testes

    NASA Astrophysics Data System (ADS)

    Chen, Zhuo; Zuo, Xuezhi; He, Dongliang; Ding, Shibin; Xu, Fangyi; Yang, Huiqin; Jin, Xin; Fan, Ying; Ying, Li; Tian, Chong; Ying, Chenjiang

    2017-01-01

    Bisphenol A (BPA), a typical environmental endocrine-disrupting chemical, induces epigenetic inheritance. Whether histone acetylation plays a role in these effects of BPA is largely unknown. Here, we investigated histone acetylation in male rats after long-term exposure to a ‘safe’ dose of BPA. Twenty adult male rats received either BPA (50 μg/kg·bw/day) or a vehicle diet for 35 weeks. Decreased protein lysine-acetylation levels at approximately ~17 kDa and ~25 kDa, as well as decreased histone acetylation of H3K9, H3K27 and H4K12, were detected by Western blot analysis of testes from the treated rats compared with controls. Additionally, increased protein expression of deacetylase Sirt1 and reduced binding of Sirt1, together with increased binding of estrogen receptor β (ERβ) to caveolin-1 (Cav-1), a structural protein component of caveolar membranes, were detected in treated rats compared with controls. Moreover, decreased acetylation of Cav-1 was observed in the treated rats for the first time. Our study showed that long-term exposure to a ‘safe’ dose of BPA reduces histone acetylation in the male reproductive system, which may be related to the phenotypic paternal-to-offspring transmission observed in our previous study. The evidence also suggested that these epigenetic effects may be meditated by Sirt1 via competition with ERβ for binding to Cav-1.

  1. Long-term exposure to a ‘safe’ dose of bisphenol A reduced protein acetylation in adult rat testes

    PubMed Central

    Chen, Zhuo; Zuo, Xuezhi; He, Dongliang; Ding, Shibin; Xu, Fangyi; Yang, Huiqin; Jin, Xin; Fan, Ying; Ying, Li; Tian, Chong; Ying, Chenjiang

    2017-01-01

    Bisphenol A (BPA), a typical environmental endocrine-disrupting chemical, induces epigenetic inheritance. Whether histone acetylation plays a role in these effects of BPA is largely unknown. Here, we investigated histone acetylation in male rats after long-term exposure to a ‘safe’ dose of BPA. Twenty adult male rats received either BPA (50 μg/kg·bw/day) or a vehicle diet for 35 weeks. Decreased protein lysine-acetylation levels at approximately ~17 kDa and ~25 kDa, as well as decreased histone acetylation of H3K9, H3K27 and H4K12, were detected by Western blot analysis of testes from the treated rats compared with controls. Additionally, increased protein expression of deacetylase Sirt1 and reduced binding of Sirt1, together with increased binding of estrogen receptor β (ERβ) to caveolin-1 (Cav-1), a structural protein component of caveolar membranes, were detected in treated rats compared with controls. Moreover, decreased acetylation of Cav-1 was observed in the treated rats for the first time. Our study showed that long-term exposure to a ‘safe’ dose of BPA reduces histone acetylation in the male reproductive system, which may be related to the phenotypic paternal-to-offspring transmission observed in our previous study. The evidence also suggested that these epigenetic effects may be meditated by Sirt1 via competition with ERβ for binding to Cav-1. PMID:28067316

  2. An Update of the Nation's Long-Term Strategic Needs for NASA's Aeronautics Test Facilities

    NASA Technical Reports Server (NTRS)

    Anton, Philip S.; Raman, Raj; Osburg, Jan; Kallimani, James G.

    2009-01-01

    The National Aeronautics and Space Administration's (NASA's) major wind tunnel (WT), propulsion test (PT), and simulation facilities exist to serve NASA's and the nation's aeronautics needs. RAND Corporation researchers conducted a prior study of these facilities from 2002 to 2003, identifying (1) NASA's continuing ability to serve national needs, (2) which facilities appear strategically important from an engineering perspective given the vehicle classes the nation investigates and produces, and (3) management challenges and issues. This documented briefing (DB) is the final report from a new, one-year study (conducted from September 2006 through January 2008), partially updating the prior assessment. The study focuses on updating the list of facilities in the prior study that were deemed to be strategically important (again, from an engineering perspective) in serving those needs. This update also adds a new assessment of national needs for six major aeronautics simulators at NASA and lists those deemed strategically important.

  3. Long Term Field Test of Polymer Insulator on 77kV Transmission Line

    NASA Astrophysics Data System (ADS)

    Tanaka, Nobuya; Kuroyagi, Toshiyuki; Niihara, Sadao

    As an anti-Vandalism measure, polymer insulator which is light and shows good performance in contamination withstand voltage is already adopted to many new power transmission lines mainly in U.S.A. However, it is said that aging deterioration is promoted by ultraviolet rays, ozone, leakage current and partial discharge because polymer insulator is made of organic materials. It is important that we seize the characteristics of aging deterioration to maintain power transmission lines. As polymer insulator for power transmission lines is more expensive than ceramic one, it is scarely used in Japan, and there is no data in the field. In this study, we installed polymer insulator to 77kV power transmission line and carried out field test for nine years from 1997 to 2006 and investigated electrical and mechanical characteristics of them.

  4. An Update of the Nation's Long-Term Strategic Needs for NASA's Aeronautics Test Facilities

    NASA Technical Reports Server (NTRS)

    Anton, Philip S.; Raman, Raj; Osburg, Jan; Kallimani, James G.

    2009-01-01

    The National Aeronautics and Space Administration's (NASA's) major wind tunnel (WT), propulsion test (PT), and simulation facilities exist to serve NASA's and the nation's aeronautics needs. RAND Corporation researchers conducted a prior study of these facilities from 2002 to 2003, identifying (1) NASA's continuing ability to serve national needs, (2) which facilities appear strategically important from an engineering perspective given the vehicle classes the nation investigates and produces, and (3) management challenges and issues. This documented briefing (DB) is the final report from a new, one-year study (conducted from September 2006 through January 2008), partially updating the prior assessment. The study focuses on updating the list of facilities in the prior study that were deemed to be strategically important (again, from an engineering perspective) in serving those needs. This update also adds a new assessment of national needs for six major aeronautics simulators at NASA and lists those deemed strategically important.

  5. [Long-term application of the multiple sclerosis functional composite test in Debrecen, Hungary].

    PubMed

    Mezei, Zsolt; Bereczki, Dániel; Csiba, László; Csépány, Tünde

    2006-11-20

    The multiple sclerosis functional composite (MSFC) has been recommended by the National Multiple Sclerosis Society as a new clinical outcome measure. It is based on measurements in three clinical dimensions: leg function/ambulation (timed 25-foot walk), arm function (9 hole peg test) and cognitive function (paced auditory serial addition test). Scores on component measures are converted to standard scores (Z-scores), that reflect patient performance. This method has not yet been introduced into routine clinical practice. Since March 2000 over the five years period the MSFC calculation was applied to 17 patients with relapsing-remitting multiple sclerosis (age mean: 37.4 +/- 10.8 years, duration of the disease: 5.5 +/- 4.9 years, EDSS: 2.7 +/- 1.4) seen at the neuroimmunological outpatient clinic to evaluate its usefulness and its correlation with the traditionally applied expanded disability status scale (EDSS). Thirteen patients received immunomodulatory treatment (interferon beta and glatiramer acetate), one patient received immunosuppressant therapy (azathioprine), and there was one patient, who developed secondary-progressive phase and we changed the interferon treatment to mitoxantrone. MSFC and EDSS were measured at 3., 6., 9, 12., 18 and 60 months of follow-up. The prospective study confirmed a strong correlation between EDSS and MSFC in multiple sclerosis. The MSFC was more sensitive to clinical changes than EDSS. Our results after 18 months of follow up are already published. After five years arm/hand function and leg function/ambulation were the most sensitive measures for disease progression. In contrast with the literature we did not experience correlation with cognitive changes. We demonstrated strong correlation between MSFC and EDSS after a longer period. MSFC is a simple method, suitable for follow-up of multiple sclerosis patients in everyday clinical practice.

  6. Long-Term Fuid Flow Measurements From Widely Varied Oceanic Settings Elucidate Near-Surface Hydrologic Environments

    NASA Astrophysics Data System (ADS)

    Tryon, M. D.; Brown, K. M.

    2003-12-01

    The quantification of aqueous flux rates from various ocean floor environments has been a goal of numerous scientific programs for more than a decade with increasing focus on gas hydrate regions. Six years ago we developed the Chemical and Aqueous Transport (CAT) meter to collect long-term temporal records of low to moderate aqueous flow rates in sedimented ocean floor environments and, more specifically, to quantify to mass flux associated with the formation of gas hydrates. Since that time thirty of these instruments have been built and over a hundred deployments accomplished in a variety of hydrate and non-hydrate settings. We present here an overview of the results of these deployments and compare and contrast the flow records from these varied hydrological environments. Specific environments include: Gas Hydrates (Hydrate Ridge and the Eel River area on the Cascadia convergent margin, and Bush Hill in northern Gulf of Mexico), Hydrothermal (Japan's Sagami Bay and the incoming plate offshore Costa Rica's Nicoya Peninsula, TicoFlux area), and the tectonically active convergent margin off Nicoya and Osa. One of the most important outcomes of this research is the realization that fluid flow across the seabed/ocean interface is often dominated by shallow subsurface and oceanographic processes which vary significantly over time. These processes can be as simple as the diurnal pressure gradients caused by the rise and fall of tides to highly complex processes associated with the formation and transport of subsurface free gas. These processes have been both a boon and a bane to our research. Tidal oscillations have tended to mask the net flow in many very low flux settings. The high degree of spatial and temporal variation in some environments have revealed the extreme difficulty of quantifying the more widespread mass flux associated with the underlying tectonic processes. Yet, the nature of these variations have allowed us to better constrain the fundamental

  7. Generation of Bentonite Colloids Under Repository-relevant Conditions in the CFM Long-term In situ Test, Grimsel Test Site, Switzerland

    NASA Astrophysics Data System (ADS)

    Lanyon, G. W.; Blechschmidt, I.; Schaefer, T.; Kontar, K.; Steiner, P.; Martin, A. J.

    2014-12-01

    Colloid-associated radionuclide transport from the Engineered Barrier System may influence the performance of geological repositories for radioactive waste in fractured host rocks. The Colloid Formation and Migration (CFM) experiment at the Grimsel Test Site (GTS) in Switzerland is studying colloid generation from a solid bentonite source in a shear zone under repository-relevant conditions in the CFM Long-term In situ Test (LIT). Hydraulic gradients in the shear zone are controlled by a tunnel-packer system maintaining stable repository relevant flow-velocities. The tunnel-packer system controls inflow from the MI shear zone to an IAEA radioprotection controlled zone in the AU tunnel at GTS [1]. After detailed characterisation of the shear zone including colloid/radionuclide migration tests [2] over scales from 0.1-6m, a solid bentonite source was installed in a borehole intersecting the shear zone in May 2014. The source was installed on a purpose-built packer system that can be overcored at the end of the experiment. The bentonite source includes labelled synthetic clays, radionuclide and dye tracers to better characterise colloid generation and near-field solute/colloid-associated radionuclide transport. Three near-field boreholes intersect the shear zone within 10cm of the bentonite source to allow sampling of the groundwater around the bentonite. The experimental setup and first results from monitoring of the LIT are presented. [1] I. Blechschmidt, A. Martin. (2012) In-situ tracer tests and models developed to understand flow paths in a shear zone at the Grimsel Test Site, Switzerland, Abstract H33J-1472 presented at 2012 Fall Meeting, AGU, San Francisco, Calif., 3-7 Dec. [2] T. Schäfer, et al. (2013) The latest results on colloid associated radionuclide migration from the CFM Project, Grimsel Test Site (GTS, Switzerland). Abstract H31G-1277 presented at 2013 Fall Meeting, AGU, San Francisco, Calif., 9-13 Dec.

  8. Development of mobile sensor for volcanic observation "HOMURA": Test campaigns for a long-term operation

    NASA Astrophysics Data System (ADS)

    Kaneko, K.; Iwahori, K.; Ito, K.; Sagi, H.

    2016-12-01

    Unmanned robots are useful to observe volcanic phenomena near active volcanic vents, to learn symptoms and transitions of eruptions, and to mitigate volcanic disasters. We have been trying to develop a practical UGV robot for flexible observation of active volcanic vents. We named this system "Homura". In this presentation, we report results of test campaigns of Homura for observation in a volcanic field. We have developed a prototype of Homura, which is a small robot vehicle with six wheels (75 x 43 x 31 cm and a weight of about 12 kg). It is remotely controlled with mobile phone radio waves; it can move in volcanic fields and send real time data of sensors (camera and gas sensors) equipped in the vehicle to the base station. Homura has a small solar panel (4 W). Power consumption of Homura is about 4 W in operation of sensors and less than 0.1 W in idle state, so that Homura can work outdoors for a long time by intermittent operation.We carried out two test campaigns of Homura at Iwo-yama to examine if Homura can work for a few month in natural volcanic fields (however, it had no solar panel in these campaigns). Iwo-yama is one of craters in the Kirishima volcanic field, SW Japan; the area within 1 km from the crater was an off-limit area from Oct., 2014 to May, 2015 and from Feb. to Mar., 2016 because of strong volcanic seismicity. On Feb. 19th, 2015 and Mar. 7th, 2016, we carried and put Homura at the rim of the crater. Unfortunately, mobile phone connectivity was not entirely stable around Iwo-yama. Then, we did not move Homura and only obtain real time data of the sensors. In the two campaigns, we operated Homura at our office for a few hours every day for 49 and 37 days, respectively. Although the weather was often bad (rain, fog, or cold temperature) during the campaigns, Homura perfectly worked. The results of these campaigns indicate that Homura is useful as s simple monitoring station in volcanic fields where mobile phone connection is available.

  9. Long-Term Care

    MedlinePlus

    ... this page please turn Javascript on. Long-Term Care What Is Long-Term Care? Long-term care involves a variety of services ... the Escape (Esc) button on your keyboard.) Most Care Provided at Home Long-term care is provided ...

  10. Cardiopulmonary exercise testing variables as predictors of long-term outcome in thoracic sarcoidosis

    PubMed Central

    Lopes, A.J.; Menezes, S.L.S.; Dias, C.M.; Oliveira, J.F.; Mainenti, M.R.M.; Guimarães, F.S.

    2012-01-01

    Cardiopulmonary exercise testing (CPET) plays an important role in the assessment of functional capacity in patients with interstitial lung disease. The aim of this study was to identify CPET measures that might be helpful in predicting the vital capacity and diffusion capacity outcomes of patients with thoracic sarcoidosis. A longitudinal study was conducted on 42 nonsmoking patients with thoracic sarcoidosis (median age = 46.5 years, 22 females). At the first evaluation, spirometry, the measurement of single-breath carbon monoxide diffusing capacity (DLCOsb) and CPET were performed. Five years later, the patients underwent a second evaluation consisting of spirometry and DLCOsb measurement. After 5 years, forced vital capacity (FVC)% and DLCOsb% had decreased significantly [95.5 (82-105) vs 87.5 (58-103) and 93.5 (79-103) vs 84.5 (44-102), respectively; P < 0.0001 for both]. In CPET, the peak oxygen uptake, maximum respiratory rate, breathing reserve, alveolar-arterial oxygen pressure gradient at peak exercise (P(A-a)O2), and Δ SpO2 values showed a strong correlation with the relative differences for FVC% and DLCOsb% (P < 0.0001 for all). P(A-a)O2 ≥22 mmHg and breathing reserve ≤40% were identified as significant independent variables for the decline in pulmonary function. Patients with thoracic sarcoidosis showed a significant reduction in FVC% and DLCOsb% after 5 years of follow-up. These data show that the outcome measures of CPET are predictors of the decline of pulmonary function. PMID:22331135

  11. Long-term consequences of non-intentional flows of substances: Modelling non-intentional flows of lead in the Dutch economic system and evaluating their environmental consequences

    SciTech Connect

    Elshkaki, Ayman Voet, Ester van der; Holderbeke, Mirja van; Timmermans, Veerle

    2009-06-15

    Substances may enter the economy and the environment through both intentional and non-intentional flows. These non-intentional flows, including the occurrence of substances as pollutants in mixed primary resources (metal ores, phosphate ores and fossil fuels) and their presence in re-used waste streams from intentional use may have environmental and economic consequences in terms of pollution and resource availability. On the one hand, these non-intentional flows may cause pollution problems. On the other hand, these flows have the potential to be a secondary source of substances. This article aims to quantify and model the non-intentional flows of lead, to evaluate their long-term environmental consequences, and compare these consequences to those of the intentional flows of lead. To meet this goal, the model combines all the sources of non-intentional flows of lead within one model, which also includes the intentional flows. Application of the model shows that the non-intentional flows of lead related to waste streams associated with intentional use are decreasing over time, due to the increased attention given to waste management. However, as contaminants in mixed primary resources application, lead flows are increasing as demand for these applications is increasing.

  12. Long-term consequences of non-intentional flows of substances: modelling non-intentional flows of lead in the Dutch economic system and evaluating their environmental consequences.

    PubMed

    Elshkaki, Ayman; van der Voet, Ester; Holderbeke, Mirja Van; Timmermans, Veerle

    2009-06-01

    Substances may enter the economy and the environment through both intentional and non-intentional flows. These non-intentional flows, including the occurrence of substances as pollutants in mixed primary resources (metal ores, phosphate ores and fossil fuels) and their presence in re-used waste streams from intentional use may have environmental and economic consequences in terms of pollution and resource availability. On the one hand, these non-intentional flows may cause pollution problems. On the other hand, these flows have the potential to be a secondary source of substances. This article aims to quantify and model the non-intentional flows of lead, to evaluate their long-term environmental consequences, and compare these consequences to those of the intentional flows of lead. To meet this goal, the model combines all the sources of non-intentional flows of lead within one model, which also includes the intentional flows. Application of the model shows that the non-intentional flows of lead related to waste streams associated with intentional use are decreasing over time, due to the increased attention given to waste management. However, as contaminants in mixed primary resources application, lead flows are increasing as demand for these applications is increasing.

  13. Contribution of Pharmacogenetic Testing to Modeled Medication Change Recommendations in a Long-Term Care Population with Polypharmacy.

    PubMed

    Sugarman, Elaine A; Cullors, Ali; Centeno, Joel; Taylor, David

    2016-12-01

    Among long-term care facility residents, polypharmacy is common, and often appropriate, given the need to treat multiple, complex, chronic conditions. Polypharmacy has, however, been associated with increased healthcare costs, adverse drug events, and drug interactions. The current study evaluates the potential medication cost savings of adding personalized pharmacogenetic information to traditional medication management strategies. One hundred and twelve long-term care residents completed pharmacogenetic testing for targeted variants in the following genes: CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP3A4/CYP3A5, HTR2A, HTR2C, SLC6A4, SLC6A2 COMT, OPRM1, SLCO1B1, VKORC1 and MTHFR. Following reporting of the IDgenetix Polypharmacy(®) test results, an internal medication management assessment was performed by a licensed clinical pharmacist to identify potential opportunities for regimen optimization through medication changes or discontinuations. The medication cost differences before and after the pharmacogenetic-guided review were assessed. Medication review following pharmacogenetic result reporting identified 54 patients (48.2%) with a total of 132 drug change recommendations (45 reductions; 87 replacements) and an average of 2.4 proposed medication changes (range 1-6) per patient. Medication cost savings related to the identified reduction and replacement opportunities exceeded the cost of testing and are estimated to be US$ 1300 (year 2016 cost) per patient annually assuming full implementation. Compared with traditional medication review, pharmacogenetic testing resulted in a 38% increase in the number of patients with current medication change opportunities and also offered valuable genetic information that could be referenced to personalize future prescribing decisions for all patients.

  14. Analysis of the immune system of multiple myeloma patients achieving long-term disease control by multidimensional flow cytometry.

    PubMed

    Pessoa de Magalhães, Roberto J; Vidriales, María-Belén; Paiva, Bruno; Fernandez-Gimenez, Carlos; García-Sanz, Ramón; Mateos, Maria-Victoria; Gutierrez, Norma C; Lecrevisse, Quentin; Blanco, Juan F; Hernández, Jose; de las Heras, Natalia; Martinez-Lopez, Joaquin; Roig, Monica; Costa, Elaine Sobral; Ocio, Enrique M; Perez-Andres, Martin; Maiolino, Angelo; Nucci, Marcio; De La Rubia, Javier; Lahuerta, Juan-Jose; San-Miguel, Jesús F; Orfao, Alberto

    2013-01-01

    Multiple myeloma remains largely incurable. However, a few patients experience more than 10 years of relapse-free survival and can be considered as operationally cured. Interestingly, long-term disease control in multiple myeloma is not restricted to patients with a complete response, since some patients revert to having a profile of monoclonal gammopathy of undetermined significance. We compared the distribution of multiple compartments of lymphocytes and dendritic cells in the bone marrow and peripheral blood of multiple myeloma patients with long-term disease control (n=28), patients with newly diagnosed monoclonal gammopathy of undetermined significance (n=23), patients with symptomatic multiple myeloma (n=23), and age-matched healthy adults (n=10). Similarly to the patients with monoclonal gammopathy of undetermined significance and symptomatic multiple myeloma, patients with long-term disease control showed an expansion of cytotoxic CD8(+) T cells and natural killer cells. However, the numbers of bone marrow T-regulatory cells were lower in patients with long-term disease control than in those with symptomatic multiple myeloma. It is noteworthy that B cells were depleted in patients with monoclonal gammopathy of undetermined significance and in those with symptomatic multiple myeloma, but recovered in both the bone marrow and peripheral blood of patients with long-term disease control, due to an increase in normal bone marrow B-cell precursors and plasma cells, as well as pre-germinal center peripheral blood B cells. The number of bone marrow dendritic cells and tissue macrophages differed significantly between patients with long-term disease control and those with symptomatic multiple myeloma, with a trend to cell count recovering in the former group of patients towards levels similar to those found in healthy adults. In summary, our results indicate that multiple myeloma patients with long-term disease control have a constellation of unique immune changes

  15. Short and long term outcomes of 200 patients supported by continuous-flow left ventricular assist devices

    PubMed Central

    Tsiouris, Athanasios; Paone, Gaetano; Nemeh, Hassan W; Borgi, Jamil; Williams, Celeste T; Lanfear, David E; Morgan, Jeffrey A

    2015-01-01

    AIM: To study the institutional experience over 8 years with 200 continuous-flow (CF) - left ventricular assist devices (LVAD). METHODS: We evaluated our institution’s LVAD database and analyzed all patients who received a CF LVAD as a bridge to transplant (BTT) or destination therapy from March 2006 until June 2014. We identified 200 patients, of which 179 were implanted with a HeartMate II device (Thoratec Corp., Pleasanton, CA) and 21 received a Heartware HVAD (HeartWare Inc., Framingham, MA). RESULTS: The mean age of our LVAD recipients was 59.3 years (range 17-81), 76% (152/200) were males, and 49% were implanted for the indication of BTT. The survival rate for our LVAD patients at 30 d, 6 mo, 12 mo, 2 years, 3 years, and 4 years was 94%, 86%, 78%, 71%, 62% and 45% respectively. The mean duration of LVAD support was 581 d (range 2-2595 d). Gastrointestinal bleeding (was the most common adverse event (43/200, 21%), followed by right ventricular failure (38/200, 19%), stroke (31/200, 15%), re exploration for bleeding (31/200, 15%), ventilator dependent respiratory failure (19/200, 9%) and pneumonia (15/200, 7%). Our driveline infection rate was 7%. Pump thrombosis occurred in 6% of patients. Device exchanged was needed in 6% of patients. On multivariate analysis, preoperative liver dysfunction, ventilator dependent respiratory failure, tracheostomy and right ventricular failure requiring right ventricular assist device support were significant predictors of post LVAD survival. CONCLUSION: Short and long term survival for patients on LVAD support are excellent, although outcomes still remain inferior compared to heart transplantation. The incidence of driveline infections, pump thrombosis and pump exchange have declined significantly in recent years. PMID:26635927

  16. Using earth-tide induced water pressure changes to measure in situ permeability: A comparison with long-term pumping tests

    NASA Astrophysics Data System (ADS)

    Allègre, Vincent; Brodsky, Emily E.; Xue, Lian; Nale, Stephanie M.; Parker, Beth L.; Cherry, John A.

    2016-04-01

    Good constraints on hydrogeological properties are an important first step in any quantitative model of groundwater flow. Field estimation of permeability is difficult as it varies over orders of magnitude in natural systems and is scale-dependent. Here we directly compare permeabilities inferred from tidal responses with conventional large-scale, long-term pumping tests at the same site. Tidally induced water pressure changes recorded in wells are used to infer permeability at ten locations in a densely fractured sandstone unit. Each location is either an open-hole well or a port in a multilevel monitoring well. Tidal response is compared at each location to the results of two conventional, long-term and large scale pumping tests performed at the same site. We obtained consistent values between the methods for a range of site-specific permeabilities varying from ˜10-15 m2 to 10-13 m2 for both open wells with large open intervals and multilevel monitoring well. We conclude that the tidal analysis is able to capture passive and accurate estimates of permeability.

  17. Long-term Testing Results for the 2008 Installation of LED Luminaires at the I-35 West Bridge in Minneapolis

    SciTech Connect

    Kinzey, Bruce R.; Davis, Robert G.

    2014-09-30

    This document reports the long-term testing results from an extended GATEWAY project that was first reported in “Demonstration Assessment of Light-Emitting Diode (LED) Roadway Lighting at the I-35W Bridge, in Minneapolis, MN,” August 2009. That original report presented the results of lighting the newly reconstructed I 35W Bridge using LEDs in place of conventional high-pressure sodium (HPS) roadway luminaires, comparing energy use and illuminance levels with a simulated baseline condition. That installation was an early stage implementation of LED lighting and remains one of the oldest installations in continued operation today. This document provides an update of the LED system’s performance since its installation in September 2008.

  18. Long-term extracorporeal circulation management: the role of low- and high-range heparin ACT tests.

    PubMed

    Herbst, Daniel; Najm, Hani K; Jha, Kumar Neerod

    2008-12-01

    Modern management of extracorporeal circulation, especially during long-term support of post-cardiac surgical patients, remains challenging and requires optimal care of the patient's fluid balance and coagulation hemostasis for its successful outcome. The activated clotting time assay is one of the tests used to manage extracorporeal circulation and is available in a low- and high-range level. The question of which assay is more appropriate for procedures that require low to moderate heparin dosing is still unclear. We report our experience with a neonate diagnosed with hypoplastic left heart syndrome who needed emergent extracorporeal membrane oxygenation support for 13 days after Norwood stage I palliation using a Sano shunt. Although successful, bleeding complications prompted us to review our strategy for management of coagulation hemostasis.

  19. The Cambric Ditch at the Nevada Test Site as a Long-term Vadose Zone Test Bed

    NASA Astrophysics Data System (ADS)

    Tompson, A. F.; Hunt, J. R.; Hudson, G. B.

    2004-12-01

    Atomic weapons testing at the Nevada Test Site introduced many tracers for quantifying hydrologic transport processes in arid climates. The particular experiment at the Cambric site in Frenchman Flat represents an ongoing 29-year field test that could never be repeated and continues to offer opportunities for vadose zone studies. The Cambric test released the energy yield equivalent of 0.75 kt of TNT when it was detonated 294 m below the land surface and 73 m below the water table in Frenchman Flat in May 1965. Beginning in 1975, groundwater was pumped steadily from a well located 91 m from the detonation point in order to elicit information on radionuclide migration. The pumping well effluent was monitored, discharged to an unlined ditch, and allowed to flow towards a dry lake 1.6 km away. Approximately one third of this flow was lost to infiltration. Over the next 16 years, pumped groundwater was shown to contain tritium, fission products (technetium-99, iodine-129) and activation products (chlorine-36), all of which can be used to trace water flow in the vadose zone. Bromide was also added as an additional tracer into the ditch. Multi-year records exist for water migration in the shallow vadose zone along with temperature profiles. Over the course of the pumping experiment, vegetation developed in and near the ditch, providing an additional pathway for water loss by transpiration and selective radionuclide transport. Significant water has not flowed in the ditch since 1991 and the site remains an ideal analog site for the studying drying in arid climates, the adaptability of vegetation under changing water conditions, and the use of helium-3 as a tracer of soil-atmosphere exchange and vadose zone - groundwater interactions. In addition, there is evidence that tritiated water and chlorine-36 have infiltrated over 200 meters vertically in the vadose zone and have become a source term for groundwater contamination. The Cambric Ditch remains as a field site ideally

  20. Improving effects of long-term growth hormone treatment on monoaminergic neurotransmission and related behavioral tests in aged rats.

    PubMed

    Esteban, Susana; Garau, Celia; Aparicio, Sara; Moranta, David; Barceló, Pere; Ramis, Margarita; Tresguerres, Jesús A F; Rial, Rubén

    2010-12-01

    An age-related decline in cognitive functions and physical performance has been associated with reductions in growth hormone (GH) secretion and brain neurotransmitter function. In vivo experiments were performed to study the long-term effects of exogenously administered GH on the central monoaminergic neurotransmitters serotonin, dopamine, and noradrenaline and behavioral tests in old Wistar rats. The accumulation of 5-hydroxytryptophan (5-HTP) and L-3,4-dihydroxyphenylalanine (DOPA) after decarboxylase inhibition was used as a measure of the rate of tryptophan and tyrosine hydroxylation in vivo. Also, the content of the neurotransmitters serotonin, dopamine, and noradrenaline and some metabolites was measured by high-pressure liquid chromatography (HPLC) in the hippocampus and striatum, brain regions involved in adult memory processing and motor coordination. The age-related decline observed in all the neurochemical parameters in control rats was significantly reversed after repeated subcutaneous administration of GH (2 mg/kg per day, 4 weeks). Thus, GH treatment exerted a long-term effect on serotonin, dopamine, and noradrenaline neurotransmission by enhancing neurotransmitter synthesis and metabolism in aged rats. The results obtained after examining working memory tasks in the eight-radial maze and motor ability in the Rotarod treadmill in aged rats were consistent with these neurochemical data; both tests were significantly improved after chronic GH treatment. Overall, these in vivo findings suggest that the positive effects induced by GH on serotonin, dopamine, and noradrenaline neurotransmitters might explain, at least in part, the effects of chronic GH treatment in improving cognitive and motor ability in aged rats, and could aid in preventing or delaying deficits in monoamines associated with learning or motor disabilities.

  1. Development of a flow controller for long-term sampling of gases and vapors using evacuated canisters.

    PubMed

    Rossner, Alan; Farant, Jean Pierre; Simon, Philippe; Wick, David P

    2002-11-15

    Anthropogenic activities contribute to the release of a wide variety of volatile organic compounds (VOC) into microenvironments. Developing and implementing new air sampling technologies that allow for the characterization of exposures to VOC can be useful for evaluating environmental and health concerns arising from such occurrences. A novel air sampler based on the use of a capillary flow controller connected to evacuated canisters (300 mL, 1 and 6 L) was designed and tested. The capillary tube, used to control the flow of air, is a variation on a sharp-edge orifice flow controller. It essentially controls the velocity of the fluid (air) as a function of the properties of the fluid, tube diameter and length. A model to predict flow rate in this dynamic system was developed. The mathematical model presented here was developed using the Hagen-Poiseuille equation and the ideal gas law to predict flow into the canisters used to sample for long periods of time. The Hagen-Poiseuille equation shows the relationship between flow rate, pressure gradient, capillary resistance, fluid viscosity, capillary length and diameter. The flow rates evaluated were extremely low, ranging from 0.05 to 1 mL min(-1). The model was compared with experimental results and was shown to overestimate the flow rate. Empirical equations were developed to more accurately predict flow for the 300 mL, 1 and 6 L canisters used for sampling periods ranging from several hours to one month. The theoretical and observed flow rates for different capillary geometries were evaluated. Each capillary flow controller geometry that was tested was found to generate very reproducible results, RSD < 2%. Also, the empirical formulas developed to predict flow rate given a specified diameter and capillary length were found to predict flow rate within 6% of the experimental data. The samplers were exposed to a variety of airborne vapors that allowed for comparison of the effectiveness of capillary flow controllers to

  2. Evaluation of the resilience of a full-scale down-flow hanging sponge reactor to long-term outages at a sewage treatment plant in India.

    PubMed

    Onodera, Takashi; Takayama, Daisuke; Ohashi, Akiyoshi; Yamaguchi, Takashi; Uemura, Shigeki; Harada, Hideki

    2016-10-01

    Resilience to process outages is an essential requirement for sustainable wastewater treatment systems in developing countries. In this study, we evaluated the ability of a full-scale down-flow hanging sponge (DHS) reactor to recover after a 10-day outage. The DHS tested in this study uses polyurethane sponge as packing material. This full-scale DHS reactor has been tested over a period of about 4 years in India with a flow rate of 500 m(3)/day. Water was not supplied to the DHS reactor that was subjected to the 10-day outage; however, the biomass did not dry out because the sponge was able to retain enough water. Soon after the reactor was restarted, a small quantity of biomass, amounting to only 0.1% of the total retained biomass, was eluted. The DHS effluent achieved satisfactory removal of suspended solids, chemical oxygen demand, and ammonium nitrogen within 90, 45, and 90 min, respectively. Conversely, fecal coliforms in the DHS effluent did not reach satisfactory levels within 540 min; instead, the normal levels of fecal coliforms were achieved within 3 days. Overall, the tests demonstrated that the DHS reactor was sufficiently robust to withstand long-term outages and achieved steady state soon after restart. This reinforces the suitability of this technology for developing countries. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Study on the installation method for the long-term observatory based on the field test during Chikyu Expedition 319

    NASA Astrophysics Data System (ADS)

    Kitada, K.; Araki, E.; Kimura, T.; Saffer, D. M.; Byrne, T.; McNeill, L. C.; Toczko, S.; Eguchi, N. O.; Takahashi, K.

    2009-12-01

    In future IODP expeditions, a series of long-term borehole observatories that combine elements of CORKs (e.g., ODP Leg 196 in the Nankai Trough) and NEREID (ODP Leg 186 at Japan Trench), will be installed into the three holes along the NanTroSEIZE transect offshore the Kii Peninsula of southern Honshu, Japan (Sites C0002, C0009 and C0010). The three boreholes are located within and above regions of contrasting behavior of the megasplay fault zone and plate boundary (i.e., a site ~6-7 km above the “locked” seismogenic plate boundary [Site C0009], a site above the updip edge of the locked zone [Site C0002], and a shallow site in the megasplay fault zone and footwall where slip is presumed to be aseismic [Site C0010]). These observatories aim to monitor seismic activity, slow slip behavior, and possibly interseismic strain accumulation at the plate boundary and megasplay faults across a range of pressure, temperature, and kinematic conditions. Currently, the planned observation system for the boreholes consists of an array of sensors designed to monitor slow crustal deformation (e.g., strain, tilt, and pore pressure as a proxy for strain), seismic events including very low frequency earthquakes, hydrologic transients associated with strain events, ambient pore pressure, and temperature. In order to realize these long-term borehole observatories, one of the primary challenges is to install high- precision, sensitive sensors into the borehole without damaging them. In particular, strong vibration can damage sensors during the lowering on drill pipe through the water column, especially in areas of strong ocean currents such as the Nankai Trough. During IODP Expedition 319 from May - August 2009 , we conducted a simulation of the planned future borehole sensor installation at Site C0010 after casing operations, as part of the preparation for long-term borehole observatories in future NanTroSEIZE expeditions. This test had two main objectives: (1) to evaluate

  4. Preferential flow paths in paraglacial catchments: first order controls on the long-term stability of 'biodiversity hotspots' in a changing climate

    NASA Astrophysics Data System (ADS)

    Grocott, Michael; Kettridge, Nick; Bradley, Chris; Milner, Alexander

    2016-04-01

    PFPs are a fundamental first order control upon the occurrence of 'biodiversity hotspots' within paraglacial floodplains, and highlights their role as an important conduit for hillslope-floodplain connectivity. Given the expected changes in the hydrological dynamics of paraglacial catchments this research raises questions about the long-term stability of GW-fed streams, and whether the increasing relative importance of groundwater sources (e.g. from colluvium) can sustain flow of GW-fed streams. In addition glacial retreat and associated long-term declines in sediment yields could have negative implications for the development and renewal of PFPs across paraglacial floodplains, which would be detrimental to the persistence of 'biodiversity hotspots'.

  5. OECD MCCI project long-term 2-D molten core concrete interaction test design report, Rev. 0. September 30, 2002.

    SciTech Connect

    Farmer, M. T.; Kilsdonk, D. J.; Lomperski, S.; Aeschliman, R. W.; Basu, S.

    2011-05-23

    The Melt Attack and Coolability Experiments (MACE) program at Argonne National Laboratory addressed the issue of the ability of water to cool and thermally stabilize a molten core-concrete interaction when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. As a follow-on program to MACE, The Melt Coolability and Concrete Interaction Experiments (MCCI) project is conducting reactor material experiments and associated analysis to achieve the following two technical objectives: (1) resolve the ex-vessel debris coolability issue through a program that focuses on providing both confirmatory evidence and test data for the coolability mechanisms identified in MACE integral effects tests, and (2) address remaining uncertainties related to long-term two-dimensional molten core-concrete interactions under both wet and dry cavity conditions. Achievement of these two objectives will demonstrate the efficacy of severe accident management guidelines for existing plants, and provide the technical basis for better containment designs for future plants. In terms of the first program objective, the Small-Scale Water Ingression and Crust Strength (SSWICS) test series has been initiated to provide fundamental information on the ability of water to ingress into cracks and fissures that form in the debris during quench, thereby augmenting the otherwise conduction-limited heat transfer process. A test plan for Melt Eruption Separate Effects Tests (MESET) has also been developed to provide information on the extent of crust growth and melt eruptions as a function of gas sparging rate under well-controlled experiment conditions. In terms of the second program objective, the project Management Board (MB) has approved startup activities required to carry out

  6. HYPOXIA IN CHESAPEAKE BAY, 1950-2001: LONG-TERM CHANGE IN RELATION TO NUTRIENT LOADING AND RIVER FLOW

    EPA Science Inventory

    A 52-yr record of dissolved oxygen in Chesapeake Bay (1950 to 2001) and a record of nitrate (NO3-) loading by the Susquehanna River spanning a longer period (1903, 1945 to 2001) were assembled to describe the long-term pattern of hypoxia and anoxia in Chesapeake Bay an...

  7. HYPOXIA IN CHESAPEAKE BAY, 1950-2001: LONG-TERM CHANGE IN RELATION TO NUTRIENT LOADING AND RIVER FLOW

    EPA Science Inventory

    A 52-yr record of dissolved oxygen in Chesapeake Bay (1950 to 2001) and a record of nitrate (NO3-) loading by the Susquehanna River spanning a longer period (1903, 1945 to 2001) were assembled to describe the long-term pattern of hypoxia and anoxia in Chesapeake Bay an...

  8. Preparatory work required for a long-term district recirculation test in a gassy underground metal-non metal mine

    SciTech Connect

    Pritchard, C.J.

    1995-12-31

    Federal mine safety regulations prohibit the recirculation of face air In a gassy Class III metal-non metal mine. Tg Soda Ash, Inc, operates a 2.0M ton/yr (2.2 million st/yr) underground gassy Class III trona mine in southwest Wyoming, currently liberating approximately 5,700 m{sup 3}/day (200,000 ft{sup 3}/day) of methane. Because of the low methane emissions and the incombustibility of trona, it was decided that Tg would be an excellent environment to test recirculation at a U.S. gassy mine, for possible future use by industry. A research program was begun with the cooperation of MSHA, the U.S. Bureau of Mines, the University of Utah, and Tg. Initial testing centered around re-using shop air underground. Next, conduct a continuous miner section recirculation test to see how the face contamination was affected by 305m (1,000 ft) and 610m (2,000 ft) recirculation distances. A district test followed to examine the effects of the critical parameter - respirable dust. Finally, a long-term program to study respirable trona dust transportation and deposition In mine airways to plan for district fan siting and effects on face air dust levels.

  9. Multi-configuration electromagnetic induction measurements at long term agricultural test sites in Germany with different fertilizer and irrigation managements

    NASA Astrophysics Data System (ADS)

    Kaufmann, Manuela Sarah; von Hebel, Christian; Brogi, Cosimo; Baumecker, Michael; Döring, Thomas; Amelung, Wulf; Vereecken, Harry; van der Kruk, Jan

    2017-04-01

    Electromagnetic induction (EMI) data are often being used to investigate large scale soil properties including clay content, soil water content, and salinity changes for a wide range of applications. For agricultural sites, different management practices such as organic/mineral fertilization, tillage, and/or irrigation are important when interpreting the measured apparent electrical conductivity (ECa). Here, we present EMI data recorded at two long term field experiment (LTFE) agricultural test sites in Thyrow near Berlin (Germany), where different long term fertilizer and irrigation management practices were applied. We used two fixed-boom multi-coil EMI instruments that simultaneously measure over nine different depths of investigation (DOI), recording information ranging between the very shallow (0-0.25 m) ploughing zone including the organic matter and the surface soil (A-Horizon) down to the relatively deep (0-2.7 m) subsoil (B-Horizon) or even substratum (C-Horizon). At both test sites, the prevailing sandy to silty sand in the A- and B-Horizon is underlain by a glacial till C-Horizon resulting in generally low ECa values between 0.5 and 5 mS/m. At one test site, a "static nutrient deficiency experiment" is performed since 1937, where organic fertilizer (farm yard manure) and mineral fertilizers (nitrogen-phosphate-potassium (NPK) and liming) are applied at specific grids. Comparing the fertilizer application grid to the measured EMI data, the lowest ECa values coincide to unfertilized grids whereas the ECa values increase with liming, farm yard manure, and NPK. The visually observed correlation between ECa and the liming treatment was possibly due to the increased pH of the soil, because the fertilizer application increases ion contents that increase the soil electrical conductivity. At the second test site, a "Static Irrigation and Fertilizer Experiment" is conducted, where next to the fertilizer treatment (farm yard manure and nitrogen) part of the field

  10. Long-term stability of cardiovascular and catecholamine responses to stress tests: an 18-year follow-up study.

    PubMed

    Hassellund, Skjalg S; Flaa, Arnljot; Sandvik, Leiv; Kjeldsen, Sverre E; Rostrup, Morten

    2010-01-01

    Cardiovascular (CV) hyperreactivity to stress must be reasonably stable if it is considered to be important in the development of hypertension and CV disease. The aim of the present study was to assess long-term stability of blood pressure, heart rate, epinephrine, and norepinephrine responses to a cold pressor test and a mental arithmetic stress test. Eighty-one subjects selected from the first (n=30), 50th (n=30), and 95th to 99th (n=39) percentiles of the mean blood pressure distribution at a military draft procedure were tested on 2 occasions 18 years apart. Stress responses were measured during a cold pressor test (hand immersed in ice water for 1 minute) and during a mental stress test (subtraction for 5 minutes). Intra-arterial blood pressure measurements and arterial catecholamine samples were taken at the initial examination. At follow-up, noninvasive Finapres beat-to-beat blood pressure measurements and venous plasma catecholamine samples were used. The 18-year correlations of the CV and epinephrine absolute responses during mental stress ranged from 0.6 to 0.8. The entry/follow-up correlation of systolic blood pressure during the mental stress test (95% CI: 0.69 to 0.86) was significantly higher than during the cold pressor test (95% CI: 0.30 to 0.65), and responses to mental stress overall appeared to be more stable than responses to the cold pressor test. Our study suggests that CV and sympathoadrenal reactivity, specifically to mental stress, are relatively stable individual characteristics. These results support one of the necessary preconditions to consider hyperreactivity involved in the development of hypertension and CV disease.

  11. Testing promotes long-term learning via stabilizing activation patterns in a large network of brain areas.

    PubMed

    Keresztes, Attila; Kaiser, Daniel; Kovács, Gyula; Racsmány, Mihály

    2014-11-01

    The testing effect refers to the phenomenon that repeated retrieval of memories promotes better long-term retention than repeated study. To investigate the neural correlates of the testing effect, we used event-related functional magnetic resonance imaging methods while participants performed a cued recall task. Prior to the neuroimaging experiment, participants learned Swahili-German word pairs, then half of the word pairs were repeatedly studied, whereas the other half were repeatedly tested. For half of the participants, the neuroimaging experiment was performed immediately after the learning phase; a 1-week retention interval was inserted for the other half of the participants. We found that a large network of areas identified in a separate 2-back functional localizer scan were active during the final recall of the word pair associations. Importantly, the learning strategy (retest or restudy) of the word pairs determined the manner in which the retention interval affected the activations within this network. Recall of previously restudied memories was accompanied by reduced activation within this network at long retention intervals, but no reduction was observed for previously retested memories. We suggest that retrieval promotes learning via stabilizing cue-related activation patterns in a network of areas usually associated with cognitive and attentional control functions.

  12. Anxiolytic effects of short- and long-term administration of cacao mass on rat elevated T-maze test.

    PubMed

    Yamada, Takashi; Yamada, Yasushi; Okano, Yasuyo; Terashima, Takehiko; Yokogoshi, Hidehiko

    2009-12-01

    We demonstrated the effects of short- and long-term administration of cacao mass on anxiety in the elevated T-maze test, which is an animal model of anxiety. In the first study, we administered cacao mass (100 mg/100 g body weight) per os and immediately performed the elevated T-maze test. Short-term cacao mass significantly abolished delayed avoidance latency compared with the control but did not change escape latency. This result suggested that cacao mass administration reduced conditional fear-relating behavior. Short-term cacao mass administration did not affect the concentration of brain monoamines, emotion-related neurotransmitters such as norepinephrine, serotonin and dopamine, in the rat brain. In the next study, we fed a cacao mass-containing diet to rats for 2 weeks and performed the elevated T-maze test. Contrary to short-term administration, chronic consumption of cacao mass tended to increase avoidance latency and did not change escape latency. Brain serotonin concentration and its turnover were enhanced by chronic consumption of cacao mass. These results suggested that chronic consumption of cacao did not affect fear-related behavior but was involved in brain monoamine metabolism. In conclusion, we suggest that short-term cacao mass consumption showed an anxiolytic effect but chronic consumption did not.

  13. Curcuma comosa improves learning and memory function on ovariectomized rats in a long-term Morris water maze test

    PubMed Central

    Su, Jian; Sripanidkulchai, Kittisak; Wyss, J. Michael; Sripanidkulchai, Bungorn

    2010-01-01

    Aim of the study Curcuma comosa extract and some purified compounds from this plant have been reported to have estrogenic-like effects, and estrogen improves learning in some animals and potentially in postmenopausal women; therefore, this study tested the hypothesis that Curcuma comosa and estrogen have similar beneficial effects on spatial learning and memory. Materials and methods Curcuma comosa hexane extract, containing 0.165 mg of (4E,6E)-1,7-diphenylhepta-4,6-dien-3-one per mg of the crude extract, was orally administered to ovariectomized Wistar rats at the doses of 250 or 500 mg/kg body weight. 17β-estradiol (10 μg/kg body weight, subcutaneously) was used as a positive control. Thirty days after the initiation of treatment, animals were tested in a Morris water maze for spatial learning and memory. They were re-tested every 30 days and a final probe trial was run on day 119. Results Compared to control rats, OVX rats displayed significant memory impairment for locating the platform in the water maze from day 67 after the surgery, onward. In contrast, OVX rats treated with either Curcuma comosa or estrogen were significantly protected from this decline in cognitive function. Further, the protection of cognitive effects by Curcuma comosa was larger at higher dose. Conclusions These results suggest that long-term treatment with Curcuma comosa has beneficial effects on learning and memory function in rats. PMID:20420894

  14. Long-term assessment of the seal provided by root-end filling materials in large cavities through capillary flow porometry.

    PubMed

    De Bruyne, M A A; De Bruyne, R J E; De Moor, R J G

    2006-06-01

    To evaluate the long-term sealing ability of a variety of materials when used as root-end fillings. A total of 140 standardized horizontal bovine root sections (external diameter: 7 mm, height: 3 mm; internal diameter: 2.5 mm) were divided into seven groups, filled with either gutta-percha with AH26, Ketac Fil, Fuji IX, Tooth-Colored MTA, IRM, Ketac Fil with conditioner or Fuji IX with conditioner and submitted to capillary flow porometry at 1 and 6 months to assess minimum, mean flow and maximum pore diameters. Results of the different materials and results by material were analysed statistically using non-parametric tests; the level of significance was set at 0.05. There were no significant differences between the minimum pore diameters associated with the materials at each time. At 1 month the mean flow pore diameters of Ketac Fil were significantly larger than those of gutta-percha, Ketac Fil with conditioner, Fuji IX with conditioner and IRM. There were significant differences between the maximum pore diameters at 1 month (all>IRM; Fuji IX>gutta-percha, Ketac Fil with conditioner, Fuji IX with conditioner) and 6 months (Fuji IX>gutta-percha, IRM; Ketac Fil>gutta-percha, IRM). There were significant differences in the minimum pore diameters between the different points in time for each material except IRM, in the mean flow pore diameters for each material and in the maximum pore diameters for each material except MTA. All materials were associated with capillary flow. IRM root-end fillings had through pores that were smaller than those associated with other materials. Conventionally setting glass-ionomer cements had the largest pores, although dentine conditioning improved their performance. The seal of all materials improved after 6 months.

  15. The Professional Nurse Self-Assessment Scale: Psychometric testing in Norwegian long term and home care contexts.

    PubMed

    Finnbakk, Elisabeth; Wangensteen, Sigrid; Skovdahl, Kirsti; Fagerström, Lisbeth

    2015-01-01

    Nurses' clinical competence is vital to ensure safe and high quality care, and the continuous assessment of nurses' clinical competence is of major concern. A validated instrument for the self-assessment of nurses' clinical competence at different educational levels across specialties and countries is lacking. The aim of this study was to test the reliability and construct validity of the new Professional Nurse Self-Assessment Scale (ProffNurse SAS) questionnaire in long term and home care contexts in Norway. The questionnaire is based on the Nordic Advanced Practice Nursing model, in which the nurse-patient relationship is central. The study has a cross-sectional survey design. A purposive sample of 357 registered nurses who worked in long term and home care contexts in two geographical regions encompassing eight municipalities and three counties was included. The respondents completed the 74-item ProffNurse SAS questionnaire and demographic background data was collected. Data collection was conducted in two phases: first region autumn 2011 and second region spring 2012. Exploratory factor analyses (EFA) were used to test the psychometric properties of the questionnaire and included the following steps: assessment of the factorality of the data, factor extraction by Principal Component Analysis (PCA), oblimin (oblique) factor rotation, and interpretation. Cronbach's alpha was used to estimate the internal consistency. The PCA revealed a six-component structure, reducing the number of items in the questionnaire from 74 to 51. Based on the content of the highest-loading items, the six components were named: Direct Clinical Practice, Professional Development, Ethical Decision-Making, Clinical Leadership, Cooperation and Consultation, and Critical Thinking. The Cronbach's alpha values ranged from 0.940 (highest; Direct Clinical Practice) to 0.737 (lowest; Critical Thinking), leading to the estimation that the ProffNurse SAS is reliable. The six components support the

  16. A test-retest dataset for assessing long-term reliability of brain morphology and resting-state brain activity.

    PubMed

    Huang, Lijie; Huang, Taicheng; Zhen, Zonglei; Liu, Jia

    2016-03-15

    We present a test-retest dataset for evaluation of long-term reliability of measures from structural and resting-state functional magnetic resonance imaging (sMRI and rfMRI) scans. The repeated scan dataset was collected from 61 healthy adults in two sessions using highly similar imaging parameters at an interval of 103-189 days. However, as the imaging parameters were not completely identical, the reliability estimated from this dataset shall reflect the lower bounds of the true reliability of sMRI/rfMRI measures. Furthermore, in conjunction with other test-retest datasets, our dataset may help explore the impact of different imaging parameters on reliability of sMRI/rfMRI measures, which is especially critical for assessing datasets collected from multiple centers. In addition, intelligence quotient (IQ) was measured for each participant using Raven's Advanced Progressive Matrices. The data can thus be used for purposes other than assessing reliability of sMRI/rfMRI alone. For example, data from each single session could be used to associate structural and functional measures of the brain with the IQ metrics to explore brain-IQ association.

  17. A test-retest dataset for assessing long-term reliability of brain morphology and resting-state brain activity

    PubMed Central

    Huang, Lijie; Huang, Taicheng; Zhen, Zonglei; Liu, Jia

    2016-01-01

    We present a test-retest dataset for evaluation of long-term reliability of measures from structural and resting-state functional magnetic resonance imaging (sMRI and rfMRI) scans. The repeated scan dataset was collected from 61 healthy adults in two sessions using highly similar imaging parameters at an interval of 103–189 days. However, as the imaging parameters were not completely identical, the reliability estimated from this dataset shall reflect the lower bounds of the true reliability of sMRI/rfMRI measures. Furthermore, in conjunction with other test-retest datasets, our dataset may help explore the impact of different imaging parameters on reliability of sMRI/rfMRI measures, which is especially critical for assessing datasets collected from multiple centers. In addition, intelligence quotient (IQ) was measured for each participant using Raven’s Advanced Progressive Matrices. The data can thus be used for purposes other than assessing reliability of sMRI/rfMRI alone. For example, data from each single session could be used to associate structural and functional measures of the brain with the IQ metrics to explore brain-IQ association. PMID:26978040

  18. The role of long-term memory in digit-symbol test performance in young and older adults.

    PubMed

    Stephens, R; Kaufman, A

    2009-03-01

    The psychological functions assessed by substitution tests, and the age-related performance decline, are not well understood. Here several aspects of long-term memory were manipulated across younger and older adults. A 45-page Digit-Symbol test was employed. Each page contained a 9-item digit symbol code-table and 9 response items. There were 9 study conditions with each condition deployed across 5 pages, or trials, of the test. The conditions were formed by crossing two within-subjects factors, each with 3 levels. The first factor, Digit Order, pertained to having the code table digits in numerical order vs. a pseudo-random order fixed across trials vs. a pseudo-random order that varied across trials. The second factor, Symbol Pairing, pertained to having a fixed digit-symbol pairing across trials vs. having a varying digit-symbol pairing across trials vs. having a novel set of 9 symbols introduced on each of the 5 trials. Including the additional factor, Age, resulted in a 2 x 3 x 3 mixed randomised block design. The older group was slowed, F(1, 22) = 17.267, p < .001, and overall-performance was poorer when the digits were arranged non-numerically, F(1,44) = 55.403, p < .001. An Age by Symbol-Order interaction indicated that use of novel symbols disadvantaged only the older participants, F(1, 44) = 6.577, p = .014. While there was no evidence that incidental paired-associate learning or spatial memory affect digit-symbol performance, symbol familiarity may be important to digit symbol test completion in older adults. The benefit of ordinally arranged digits in the coding table highlights a fundamental process difference between Digit-Symbol and Symbol-Digit test formats.

  19. Molecular demographic history of the annual sunflowers Helianthus annuus and H. petiolaris--large effective population sizes and rates of long-term gene flow.

    PubMed

    Strasburg, Jared L; Rieseberg, Loren H

    2008-08-01

    Hybridization between distinct species may lead to introgression of genes across species boundaries, and this pattern can potentially persist for extended periods as long as selection at some loci or genomic regions prevents thorough mixing of gene pools. However, very few reliable estimates of long-term levels of effective migration are available between hybridizing species throughout their history. Accurate estimates of divergence dates and levels of gene flow require data from multiple unlinked loci as well as an analytical framework that can distinguish between lineage sorting and gene flow and incorporate the effects of demographic changes within each species. Here we use sequence data from 18 anonymous nuclear loci in two broadly sympatric sunflower species, Helianthus annuus and H. petiolaris, analyzed within an "isolation with migration" framework to make genome-wide estimates of the ages of these two species, long-term rates of gene flow between them, and effective population sizes and historical patterns of population growth. Our results indicate that H. annuus and H. petiolaris are approximately one million years old and have exchanged genes at a surprisingly high rate (long-term N(ef)m estimates of approximately 0.5 in each direction), with somewhat higher rates of introgression from H. annuus into H. petiolaris than vice versa. In addition, each species has undergone dramatic population expansion since divergence, and both species have among the highest levels of genetic diversity reported for flowering plants. Our results provide the most comprehensive estimate to date of long-term patterns of gene flow and historical demography in a nonmodel plant system, and they indicate that species integrity can be maintained even in the face of extensive gene flow over a prolonged period.

  20. MOLECULAR DEMOGRAPHIC HISTORY OF THE ANNUAL SUNFLOWERS HELIANTHUS ANNUUS AND H. PETIOLARIS—LARGE EFFECTIVE POPULATION SIZES AND RATES OF LONG-TERM GENE FLOW

    PubMed Central

    Strasburg, Jared L.; Rieseberg, Loren H.

    2008-01-01

    Hybridization between distinct species may lead to introgression of genes across species boundaries, and this pattern can potentially persist for extended periods as long as selection at some loci or genomic regions prevents thorough mixing of gene pools. However, very few reliable estimates of long-term levels of effective migration are available between hybridizing species throughout their history. Accurate estimates of divergence dates and levels of gene flow require data from multiple unlinked loci as well as an analytical framework that can distinguish between lineage sorting and gene flow and incorporate the effects of demographic changes within each species. Here we use sequence data from 18 anonymous nuclear loci in two broadly sympatric sunflower species, Helianthus annuus and H. petiolaris, analyzed within an “isolation with migration” framework to make genome-wide estimates of the ages of these two species, long-term rates of gene flow between them, and effective population sizes and historical patterns of population growth. Our results indicate that H. annuus and H. petiolaris are approximately one million years old and have exchanged genes at a surprisingly high rate (long-term Nef m estimates of approximately 0.5 in each direction), with somewhat higher rates of introgression from H. annuus into H. petiolaris than vice versa. In addition, each species has undergone dramatic population expansion since divergence, and both species have among the highest levels of genetic diversity reported for flowering plants. Our results provide the most comprehensive estimate to date of long-term patterns of gene flow and historical demography in a nonmodel plant system, and they indicate that species integrity can be maintained even in the face of extensive gene flow over a prolonged period. PMID:18462213

  1. Effect of long-term in vitro testing on the properties of bioactive glass-polysulfone composites.

    PubMed

    Oréfice, Rodrigo; West, Jon; Latorre, Guy; Hench, Larry; Brennan, Anthony

    2010-03-08

    The combination of bioactive ceramics and polymers can allow the preparation of composites with tailorable mechanical properties and bioactive behavior. In these composites, bioactive ceramics can act as a source of both reinforcement and bioactivity, while the polymer matrix can add toughness and processability to the material. On the other hand, the effect of using a highly dimensional unstable phase as a reinforcing agent on the long-term properties of the composite is a major concern regarding the lifetime of possible applications. In this work, a bioactive glass-polysulfone particulate composite was prepared by hot-pressing at 215 degrees C a mixture of polysulfone and different concentrations of bioactive glass particles (Bioglass 45S5, particle size range: 125-106 microm) to yield composites having 20 and 40 vol % of bioactive glass particles. The obtained composites were exposed to a simulated body fluid at 37 degrees C for different periods of time ranging from 1 h to 60 days. After the test, the mechanical properties of the composites were investigated by a four-point bending test, while DMS (dynamic mechanical spectroscopy) was used to identify the effect of water on the structure and behavior of the composite. The interface between glass particles and the polymer was also investigated by SEM/EDX and diffuse reflection infrared spectroscopy. The results showed that a decay in the mechanical properties of the composites within the first 20 h of test can occur. Otherwise, after this initial decay, no more pronounced reduction in properties could be noted. The analyses of the fracture surface of composites tested in vitro indicated the hydration of the surface of the particles. Therefore, it was concluded that water migration through the interface of the composite causes surface dissolution of glass particles and formation of voids, which were responsible for the observed decay in mechanical properties. Composites with modified interfaces revealed less

  2. Lipogenesis and lipid peroxidation in rat testes after long-term treatment with sucrose and tannic acid in drinking water.

    PubMed

    Mašek, T; Starčević, K

    2017-05-01

    We studied the influence of long-term treatment with sucrose and tannic acid in drinking water on the fatty acid profile and lipid peroxidation in rat testes. Male Wistar rats were supplemented with sucrose (30% w/v) or with sucrose and tannic acid (sucrose 30% w/v, tannic acid 0.1% w/v) in drinking water. The treatment with sucrose elevated blood glucose levels in the plasma (p < .05) and decreased the testis weight (p < .05) and testis index (p < .05) of the rats. Sucrose treatment increased monounsaturated fatty acids (MUFA) and C22:6n3, and decreased n6 fatty acids in testis tissue. Lipid peroxidation was significantly increased after sucrose administration in plasma (p < .05) and testis tissue (p < .01). The addition of tannic acid led to the decrease in lipid peroxidation in the plasma (p < .05) and testis (p < .05), a further increase in MUFA and decrease in n6 fatty acids. In conclusion, sucrose significantly altered the testis fatty acid profile with an increase in MUFA and C22:6n3, and a decrease in n6 fatty acids. Tannic acid attenuated oxidative stress and hyperglycaemia, but it did not improve pathological changes in the fatty acid composition of the testis. © 2016 Blackwell Verlag GmbH.

  3. Testing the generalized complementary relationship of evaporation with continental-scale long-term water-balance data

    NASA Astrophysics Data System (ADS)

    Szilagyi, Jozsef; Crago, Richard; Qualls, Russell J.

    2016-09-01

    The original and revised versions of the generalized complementary relationship (GCR) of evaporation (ET) were tested with six-digit Hydrologic Unit Code (HUC6) level long-term (1981-2010) water-balance data (sample size of 334). The two versions of the GCR were calibrated with Parameter-Elevation Regressions on Independent Slopes Model (PRISM) mean annual precipitation (P) data and validated against water-balance ET (ETwb) as the difference of mean annual HUC6-averaged P and United States Geological Survey HUC6 runoff (Q) rates. The original GCR overestimates P in about 18% of the PRISM grid points covering the contiguous United States in contrast with 12% of the revised version. With HUC6-averaged data the original version has a bias of -25 mm yr-1 vs the revised version's -17 mm yr-1, and it tends to more significantly underestimate ETwb at high values than the revised one (slope of the best fit line is 0.78 vs 0.91). At the same time it slightly outperforms the revised version in terms of the linear correlation coefficient (0.94 vs 0.93) and the root-mean-square error (90 vs 92 mm yr-1).

  4. Evidence of long-term gene flow and selection during domestication from analyses of Eurasian wild and domestic pig genomes.

    PubMed

    Frantz, Laurent A F; Schraiber, Joshua G; Madsen, Ole; Megens, Hendrik-Jan; Cagan, Alex; Bosse, Mirte; Paudel, Yogesh; Crooijmans, Richard P M A; Larson, Greger; Groenen, Martien A M

    2015-10-01

    Traditionally, the process of domestication is assumed to be initiated by humans, involve few individuals and rely on reproductive isolation between wild and domestic forms. We analyzed pig domestication using over 100 genome sequences and tested whether pig domestication followed a traditional linear model or a more complex, reticulate model. We found that the assumptions of traditional models, such as reproductive isolation and strong domestication bottlenecks, are incompatible with the genetic data. In addition, our results show that, despite gene flow, the genomes of domestic pigs have strong signatures of selection at loci that affect behavior and morphology. We argue that recurrent selection for domestic traits likely counteracted the homogenizing effect of gene flow from wild boars and created 'islands of domestication' in the genome. Our results have major ramifications for the understanding of animal domestication and suggest that future studies should employ models that do not assume reproductive isolation.

  5. Long-term oxygen therapy.

    PubMed

    Christopher, Kent L; Porte, Phillip

    2011-02-01

    This article provides an overview of the status of long-term oxygen therapy (LTOT). In the United States, payment cutbacks are occurring as a result of congressionally mandated competitive bidding and capped rental programs. These Medicare programs are discussed. These legislative and regulatory changes may result in reduced patient access to appropriate oxygen-delivery systems that meet medical needs, including optimal ambulation. Prescribing LTOT is addressed in this article, as is the need for adequate patient education. The importance of appropriate monitoring and reassessment is presented. The use of an LTOT collaborative care model is discussed. Although the new intermittent flow oxygen-delivery systems have potential benefits, there is consensus that each patient should be tested on the specific device because of variability in delivery and patient response. Feasible locations for patient education and monitoring are identified.

  6. Synthesis, characterization, and detection of new oxandrolone metabolites as long-term markers in sports drug testing.

    PubMed

    Guddat, S; Fußhöller, G; Beuck, S; Thomas, A; Geyer, H; Rydevik, A; Bondesson, U; Hedeland, M; Lagojda, A; Schänzer, W; Thevis, M

    2013-10-01

    The discovery and implementation of the long-term metabolite of metandienone, namely 17β-hydroxymethyl-17α-methyl-18-norandrost-1,4,13-trien-3-one, to doping control resulted in hundreds of positive metandienone findings worldwide and impressively demonstrated that prolonged detection periods significantly increase the effectiveness of sports drug testing. For oxandrolone and other 17-methyl steroids, analogs of this metabolite have already been described, but comprehensive characterization and pharmacokinetic data are still missing. In this report, the synthesis of the two epimeric oxandrolone metabolites-17β-hydroxymethyl-17α-methyl-18-nor-2-oxa-5α-androsta-13-en-3-one and 17α-hydroxymethyl-17β-methyl-18-nor-2-oxa-5α-androsta-13-en-3-one-using a fungus (Cunninghamella elegans) based protocol is presented. The reference material was fully characterized by liquid chromatography nuclear magnetic resonance spectroscopy and high resolution/high accuracy mass spectrometry. To ensure a specific and sensitive detection in athlete's urine, different analytical approaches were followed, such as liquid chromatography-tandem mass spectrometry (QqQ and Q-Orbitrap) and gas chromatography-tandem mass spectrometry, in order to detect and identify the new target analytes. The applied methods have demonstrated good specificity and no significant matrix interferences. Linearity (R(2) > 0.99) was tested, and precise results were obtained for the detection of the analytes (coefficient of variation <20%). Limits of detection (S/N) for confirmatory and screening analysis were estimated at 1 and 2 ng/mL of urine, respectively. The assay was applied to oxandrolone post-administration samples to obtain data on the excretion of the different oxandrolone metabolites. The studied specimens demonstrated significantly longer detection periods (up to 18 days) for the new oxandrolone metabolites compared to commonly targeted metabolites such as epioxandrolone or 18-nor

  7. Long-term retention of a divided attention psycho-motor test combining choice reaction test and postural balance test: A preliminary study.

    PubMed

    Rossi, R; Pascolo, P B

    2015-09-01

    Driving in degraded psychophysical conditions, such as under the influence of alcohol or drugs but also in a state of fatigue or drowsiness, is a growing problem. The current roadside tests used for detecting drugs from drivers suffer various limitations, while impairment is subjective and does not necessarily correlate with drug metabolite concentration found in body fluids. This work is a validation step towards the study of feasibility of a novel test conceived to assess psychophysical conditions of individuals performing at-risk activities. Motor gestures, long-term retention and learning phase related to the protocol are analysed in unimpaired subjects. The protocol is a divided attention test, which combines a critical tracking test achieved with postural movements and a visual choice reaction test. Ten healthy subjects participated in a first set of trials and in a second set after about six months. Each session required the carrying out of the test for ten times in order to investigate learning effect and performance over repetitions. In the first set the subjects showed a learning trend up to the third trial, whilst in the second set of trials they showed motor retention. Nevertheless, the overall performance did not significantly improve. Gestures are probably retained due to the type of tasks and the way in which the instructions are conveyed to the subjects. Moreover, motor retention after a short training suggests that the protocol is easy to learn and understand. Implications for roadside test usage and comparison with current tests are also discussed.

  8. Frequency and clinical meaning of long-term degenerative changes after lumbar discectomy visualized on imaging tests

    PubMed Central

    Galasso, Olimpio; Attingenti, Paolo; Federico, Gianluigi; Milano, Carlo

    2009-01-01

    The aim of this retrospective controlled study was to evaluate radiographic degeneration in the lumbar spine of patients who had undergone lumbar discectomy minimum 21 years earlier and its clinical meaning. Indeed, no previous investigation on degenerative changes occurring after lumbar discectomy with a comparable long follow-up has been published. The study participants consisted of 50 patients who had undergone discectomy for lumbar disc herniation. The mean length of follow-up was 25.3 ± 3.0 years. Patients were assessed by Short Form-36 Health Survey (SF-36), Oswestry Disability Index, and a study-specific questionnaire. Radiographic views of the lumbar spine were obtained from all patients and compared to those of 50 asymptomatic controls. A five-step published classification was used to assess the increasing severity of radiographic changes. CT or MRI scans were also available for 27 patients who had undergone discectomy. Moderate to severe radiographic changes were present in 45 patients (90%) and 34 controls (68%), respectively (P = 0.013). The most prevalent MRI/CT changes were loss of disc height (89%), facet joint arthritis (89%), and endplate changes (57%). Thirty-two of 33 subjects (97%) reporting pain during the last 12 months had significant degeneration on their radiographs, and the frequency of changes was higher with respect to subjects without pain (P = 0.040). In conclusion, standard lumbar discectomy frequently leads to long-term degenerative changes on imaging tests. The presence of moderate to severe degeneration is associated with self-reported pain. PMID:19894068

  9. Comparative test of ecological assessment methods of lowland streams based on long-term monitoring data of macrophytes.

    PubMed

    Wiegleb, Gerhard; Gebler, Daniel; van de Weyer, Klaus; Birk, Sebastian

    2016-01-15

    Ecological assessment of water courses is required by the European Water Framework Directive (WFD). Assessment by means of macrophytes is impeded by insufficient knowledge on the relations between assessment scores and the dynamics of environmental parameters. Data from a long-term observation of macrophyte dynamics over 21 years in two lowland rivers were used for testing the performance of six widely used assessment methods. Six sample sites situated in two lowland streams were selected. Four sites were classified as of moderate habitat quality and two sites as of poor habitat quality in the context of WFD. Assessment methods generally showed a poor performance in recognizing the ecological status of the annual observations. Status was more often over- than underestimated. Performance of methods differed among individual rivers and among river zones. Assessment scores mostly showed a steady decline, even though all sites obviously remained in the same habitat quality class throughout the observation period. Variation of most environmental factors was largely unrelated to assessment scores. Fluctuations of assessment scores were partly related to single natural disturbance events such as high discharge. Increased shading by marginal trees was reflected negatively by most assessment scores. Assessment scores were highly correlated with species richness and total abundance. The best overall performance was shown by the North-Rhine Westphalian (NRW) method. In contrast to single metric methods it can be adapted to individual properties of a reach in a flexible way. Macrophyte assessment based on the pressure-impact framework did not lead to a satisfying result in our case study. Improvement of species assessment scores and inclusion of functional properties such as growth form may help to overcome the present difficulties. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Understanding the microscopic deformation mechanism and macroscopic mechanical behavior of nanocrystalline Ni by the long-term stress relaxation test

    NASA Astrophysics Data System (ADS)

    Shen, Xixun; Zhang, Congcong; Zeng, Tao; Cheng, Danhong; Lian, Jianshe

    2014-05-01

    The long-term stress relaxation tests with a relaxation time of about 7 h are performed on the bulk dense nanocrystalline Ni (with a mean grain size of 27 nm) pre-deformed at strain rate from 4.17 s-1- 4.17 × 10-6 s-1, where a phenomenon that the initial relaxation behavior of nc Ni depends on itself deformation history. That is, the nc Nis pre-deformed at higher strain rate (not less than 4.17 × 10-3 s-1) exhibit a three-staged relaxation process from the initial near linear rapidly stress delayed (LRSD) stage and the subsequent lumber nonlinear stress delayed (LNSD) one and the final near linear slowly stress delayed (LSSD) one while only the later two stages are observed for the nc Nis pre-deformed at low strain rate. The three-stage relaxation behavior is attributed to the transition from the initial dislocation-dominated plasticity to the mixture of dislocation motion and diffusion-based GB activity and finally to the entire diffusion-based GB activity including GB sliding or grain rotation in the rate-controlling deformation mechanism, which was illuminated by the attained three-staged strain rate sensitivity and activation volume and the exhaustion of mobile density of deformed nc Ni in the first two stages of relaxation. Such rate-controlling deformation mechanism well interpreted the macroscopic tensile mechanical behavior of nc Ni and simultaneously an optimizing strategy in improving the ductility of nc Ni is also mentioned.

  11. The geochemical release feature of Tl in Tl-rich pyrite mine wastes: a long-term leaching test.

    PubMed

    Li, Jinwen; Chen, Nan; Rajan, Ivy; Sun, Zhehua; Wu, Huiming; Chen, Diyun; Kong, Lingjun

    2017-05-01

    Identifying and revealing the geochemical behaviour of Tl during mine waste weathering are very important to assess the potential environmental impact of Thallium (Tl) from open mine-waste piles. Herein, two methods including the modified BCR sequential extraction and the long-term humidity cell tests (HCT) were employed to understand the Tl chemical fractions and to stimulate intense chemical weathering process, respectively. The results from BCR sequential extraction showed that the Tl concentration in the studied sample was 18.78 mg/kg, containing 1.878 mg/kg oxidisable, 0.282 mg/kg acid exchangeable and 1.596 mg/kg reducible Tl. The acid exchangeable fraction contributed to a particular potential risk to the aquatic marine life in the early stages and the Fe/Mn oxidisable fraction posed a potential risk being dissolved into solution at low pH (i.e. acidic conditions). The variations of Tl concentration in leachates were classified as two period as the pH values decrease. In the first period, the Tl concentrations decreased positively with pH value with poor correlation between pH value and SO4(2-) concentration in leachates. Drastic release of Tl was observed in the early period once the material was exposed to air and water, being ascribe to the acid exchangeable fraction bound to carbonate as dissolved by acid. During the second period, three increased peaks of Tl concentration (11.02, 16.03, 43.15 μg/L) and four increased peaks of SO4(2-) concentration (315, 390, 899.61 and 2670 mg/L) were observed. A good correlation (R (2) = 0.8384) between the concentrations of Tl and SO4(2-) was observed, indicating the Tl was mainly released from the oxidation of sulphide.

  12. Hearing Loss and Cognitive-Communication Test Performance of Long-Term Care Residents With Dementia: Effects of Amplification

    ERIC Educational Resources Information Center

    Hopper, Tammy; Slaughter, Susan E.; Hodgetts, Bill; Ostevik, Amberley; Ickert, Carla

    2016-01-01

    Purpose: The study aims were (a) to explore the relationship between hearing loss and cognitive-communication performance of individuals with dementia, and (b) to determine if hearing loss is accurately identified by long-term care (LTC) staff. The research questions were (a) What is the effect of amplification on cognitive-communication test…

  13. Testing the Long-Term Efficacy of a Prevention Program for Improving Marital Conflict in Community Families

    ERIC Educational Resources Information Center

    Faircloth, W. Brad; Schermerhorn, Alice C.; Mitchell, Patricia M.; Cummings, Jennifer S.; Cummings, E. Mark

    2011-01-01

    Family-focused prevention programs for community samples have potentially broad, clinically relevant implications but few studies have examined whether any program benefits continue to be observed over the long term. Although benefits of a marital conflict focused parent education program, the Happy Couples and Happy Kids (i.e., HCHK) program,…

  14. Hearing Loss and Cognitive-Communication Test Performance of Long-Term Care Residents With Dementia: Effects of Amplification

    ERIC Educational Resources Information Center

    Hopper, Tammy; Slaughter, Susan E.; Hodgetts, Bill; Ostevik, Amberley; Ickert, Carla

    2016-01-01

    Purpose: The study aims were (a) to explore the relationship between hearing loss and cognitive-communication performance of individuals with dementia, and (b) to determine if hearing loss is accurately identified by long-term care (LTC) staff. The research questions were (a) What is the effect of amplification on cognitive-communication test…

  15. Development of testing and analysis methodology to assess the long term durability of polymeric composites at high temperatures

    NASA Technical Reports Server (NTRS)

    Johnson, W. Steven

    1990-01-01

    A workshop was held to help assess the state-of-the-art in evaluating the long term durability of polymeric matrix composites (PMCs) and to recommend future activities. Design and evaluation of PMCs at elevated temperatures were discussed. The workshop presentations, the findings of the workshop sessions are briefly summarized.

  16. KENNEDY SPACE CENTER, FLA. - Dr. Paul Hintze (left) explains to Center Director Jim Kennedy a project he is working at the KSC Beach Corrosion Test Site. Hitze is doing post-graduate work for the National Research Council. The test facility site was established in the 1960s and has provided more than 30 years of historical information on the long-term performance of many materials in use at KSC and other locations around the world. Located 100 feet from the Atlantic Ocean approximately 1 mile south of the Space Shuttle launch sites, the test facility includes an atmospheric exposure site, a flowing seawater exposure site, and an on-site electrochemistry laboratory and monitoring station. The beach laboratory is used to conduct real-time corrosion experiments and provides for the remote monitoring of surrounding weather conditions. The newly added flowing seawater immersion facility provides for the immersion testing of materials and devices under controlled conditions.

    NASA Image and Video Library

    2003-08-21

    KENNEDY SPACE CENTER, FLA. - Dr. Paul Hintze (left) explains to Center Director Jim Kennedy a project he is working at the KSC Beach Corrosion Test Site. Hitze is doing post-graduate work for the National Research Council. The test facility site was established in the 1960s and has provided more than 30 years of historical information on the long-term performance of many materials in use at KSC and other locations around the world. Located 100 feet from the Atlantic Ocean approximately 1 mile south of the Space Shuttle launch sites, the test facility includes an atmospheric exposure site, a flowing seawater exposure site, and an on-site electrochemistry laboratory and monitoring station. The beach laboratory is used to conduct real-time corrosion experiments and provides for the remote monitoring of surrounding weather conditions. The newly added flowing seawater immersion facility provides for the immersion testing of materials and devices under controlled conditions.

  17. A Nonlinear Dynamic Approach Reveals a Long-Term Stroke Effect on Cerebral Blood Flow Regulation at Multiple Time Scales

    PubMed Central

    Hu, Kun; Lo, Men-Tzung; Peng, Chung-Kang; Liu, Yanhui; Novak, Vera

    2012-01-01

    Cerebral autoregulation (CA) is an important vascular control mechanism responsible for relatively stable cerebral blood flow despite changes of systemic blood pressure (BP). Impaired CA may leave brain tissue unprotected against potentially harmful effects of BP fluctuations. It is generally accepted that CA is less effective or even inactive at frequencies >∼0.1 Hz. Without any physiological foundation, this concept is based on studies that quantified the coupling between BP and cerebral blood flow velocity (BFV) using transfer function analysis. This traditional analysis assumes stationary oscillations with constant amplitude and period, and may be unreliable or even invalid for analysis of nonstationary BP and BFV signals. In this study we propose a novel computational tool for CA assessment that is based on nonlinear dynamic theory without the assumption of stationary signals. Using this method, we studied BP and BFV recordings collected from 39 patients with chronic ischemic infarctions and 40 age-matched non-stroke subjects during baseline resting conditions. The active CA function in non-stroke subjects was associated with an advanced phase in BFV oscillations compared to BP oscillations at frequencies from ∼0.02 to 0.38 Hz. The phase shift was reduced in stroke patients even at > = 6 months after stroke, and the reduction was consistent at all tested frequencies and in both stroke and non-stroke hemispheres. These results provide strong evidence that CA may be active in a much wider frequency region than previously believed and that the altered multiscale CA in different vascular territories following stroke may have important clinical implications for post-stroke recovery. Moreover, the stroke effects on multiscale cerebral blood flow regulation could not be detected by transfer function analysis, suggesting that nonlinear approaches without the assumption of stationarity are more sensitive for the assessment of the coupling of nonstationary

  18. Physiological basis and long-term clinical outcome of discordance between fractional flow reserve and coronary flow velocity reserve in coronary stenoses of intermediate severity.

    PubMed

    van de Hoef, Tim P; van Lavieren, Martijn A; Damman, Peter; Delewi, Ronak; Piek, Martijn A; Chamuleau, Steven A J; Voskuil, Michiel; Henriques, José P S; Koch, Karel T; de Winter, Robbert J; Spaan, Jos A E; Siebes, Maria; Tijssen, Jan G P; Meuwissen, Martijn; Piek, Jan J

    2014-06-01

    Discordance between fractional flow reserve (FFR) and coronary flow velocity reserve (CFVR) may reflect important coronary pathophysiology but usually remains unnoticed in clinical practice. We evaluated the physiological basis and clinical outcome associated with FFR/CFVR discordance. We studied 157 intermediate coronary stenoses in 157 patients, evaluated by FFR and CFVR between April 1997 and September 2006 in which revascularization was deferred. Long-term follow-up was performed to document the occurrence of major adverse cardiac events: cardiac death, myocardial infarction, or target vessel revascularization. Discordance between FFR and CFVR occurred in 31% and 37% of stenoses at the 0.75, and 0.80 FFR cut-off value, respectively, and was characterized by microvascular resistances during basal and hyperemic conditions. Follow-up duration amounted to 11.7 years (Q1-Q3, 9.9-13.3 years). Compared with concordant normal results of FFR and CFVR, a normal FFR with an abnormal CFVR was associated with significantly increased major adverse cardiac events rate throughout 10 years of follow-up, regardless of the FFR cut-off applied. In contrast, an abnormal FFR with a normal CFVR was associated with equivalent clinical outcome compared with concordant normal results: ≤ 3 years when FFR <0.75 was depicted abnormal and throughout 10 years of follow-up when FFR ≤ 0.80 was depicted abnormal. Discordance of CFVR with FFR originates from the involvement of the coronary microvasculature. Importantly, the risk for major adverse cardiac events associated with FFR/CFVR discordance is mainly attributable to stenoses where CFVR is abnormal. This emphasizes the requirement of intracoronary flow assessment in addition to coronary pressure for optimal risk stratification in stable coronary artery disease. © 2014 American Heart Association, Inc.

  19. Short and long-term tests of elastomers with hot hostile fluids. Environmental Compatibility Test Program final report

    SciTech Connect

    Friese, G.J.

    1982-12-30

    Equipment manufacturers and elastomer houses were called to find the best currently available high-temperature elastomers. Tensile specimens of 46 such compounds were immersion tested for five days in six 190C fluids of interest: isobutane, brine, ASTM No. 1 oil, ASTM No. 3 oil, Pacer DHT-185M synthetic oil, and Chevron Cylinder Grade 460X oil. The best eight were selected based upon the least change in mechanical properties. These eight were then simultaneously tested (a) by immersion in five 190C fluids for six months and (b) as 0-rings for 46 hours at 190C, 230C, and 265C (accelerated ageing) in three fluids and at a differential pressure of 21 MPa. Based upon these 0-ring tests, four compounds were selected for testing as 0-rings in three 204C fluids at 21 MPa differential pressure. The data were evaluated and conclusions were drawn. Conclusions and recommendations are provided. There was immersion testing of primarily L'Garde compounds in brine and CL3 mineral oil for 6 months at 190C. L'Garde had formulated several compounds specifically for 260C brine, and their applicability to a specific problem was assessed early in the program.

  20. A Serendipitous, Long-term Infiltration Experiment: Water and Radionuclide Circulation Beneath the CAMBRIC Trench at the Nevada Test Site.

    NASA Astrophysics Data System (ADS)

    Maxwell, R. M.; Tompson, A. F.; Carle, S. F.; Zavarin, M.; Kollet, S. J.

    2005-12-01

    Underground atomic weapons testing at the Nevada Test Site introduced numerous radionuclides that may be used to characterize subsurface hydrologic transport processes in arid climates. Beginning in 1975, groundwater adjacent to the CAMBRIC test, conducted beneath Frenchman Flat in 1965, was pumped steadily for 16 years to elicit experimental information on the migration of residual radioactivity through the saturated zone. Radionuclides in the pumping well effluent, including tritium, 36Cl, and 85Kr, were extensively monitored prior to their discharge into an unlined ditch flowing toward a dry lake bed over a kilometer away. We have applied a large (6km x 6km x 1km) and highly resolved (4 m) variably saturated flow model to investigate infiltration into the 220-m vadose zone underlying the ditch as well as subsequent groundwater recharge and well recirculation processes. A Lagrangian particle-tracking model has been used to compute flow pathways and estimate radionuclide travel and residence times in various parts of the system based upon the flow model. Results are consistent with rising tritium levels observed in a monitoring well since 1991. They suggest that recirculation of the ditch effluent through the vadose zone, into groundwater, and back to the test cavity and pumping well are responsible for diluted, tritium-based groundwater age dates observed in 2000 at these locations, as well as for increased tailing effects observed in the pumping well elution curves. Altogether, the models and experimental observations provide an improved basis to understand both historical and future movements of test-related radionuclides in groundwater near CAMBRIC. This work was conducted under the auspices of the U. S. Department of Energy by the University of California, Lawrence Livermore National Laboratory (LLNL) under contract W-7405-Eng-48. This work was funded by the UGTA program of the U. S. Department of Energy.

  1. Long-Term Performance of Transuranic Waste Inadvertently Disposed in a Shallow Land Burial Trench at the Nevada Test Site

    SciTech Connect

    Gregory J. Shott; Vefa Yucel

    2009-07-16

    In 1986, 21 m3 of transuranic (TRU) waste was inadvertently disposed in a shallow land burial trench at the Area 5 Radioactive Waste Management Site on the Nevada Test Site. U.S. Department of Energy (DOE) TRU waste must be disposed in accordance with Title 40, Code of Federal Regulations (CFR), Part 191, Environmental Radiation Protection Standard for Management and Disposal of Spent Nuclear Fuel, High-Level, and Transuranic Radioactive Wastes. The Waste Isolation Pilot Plant is the only facility meeting these requirements. The National Research Council, however, has found that exhumation of buried TRU waste for disposal in a deep geologic repository may not be warranted when the effort, exposures, and expense of retrieval are not commensurate with the risk reduction achieved. The long-term risks of leaving the TRU waste in-place are evaluated in two probabilistic performance assessments. A composite analysis, assessing the dose from all disposed waste and interacting sources of residual contamination, estimates an annual total effective dose equivalent (TEDE) of 0.01 mSv, or 3 percent of the dose constraint. A 40 CFR 191 performance assessment also indicates there is reasonable assurance of meeting all requirements. The 40 CFR 191.15 annual mean TEDE for a member of the public is estimated to reach a maximum of 0.055 mSv at 10,000 years, or approximately 37 percent of the 0.15 mSv individual protection requirement. In both assessments greater than 99 percent of the dose is from co-disposed low-level waste. The simulated probability of the 40 CFR 191.13 cumulative release exceeding 1 and 10 times the release limit is estimated to be 0.0093 and less than 0.0001, respectively. Site characterization data and hydrologic process modeling support a conclusion of no groundwater pathway within 10,000 years. Monte Carlo uncertainty analysis indicates that there is reasonable assurance of meeting all regulatory requirements. Sensitivity analysis indicates that the results

  2. The Impact of Structure on Word Meaning and Fill-in-The-Blank Tests Procedures on Short-Term and Long-Term Retention of Vocabulary Items

    ERIC Educational Resources Information Center

    Fazeli, Seyed Hossein

    2009-01-01

    The purpose of research described in the current study to investigate the impact of structure knowing on two types of test, i.e. word-meaning test and fill-in-the-blank test, their correlation and procedures on both short-term and long-term retention of vocabulary items. The importance of the present study, to test the condition that learners are…

  3. Use of double-mass curves to determine drawdown in a long-term aquifer test in north-central Volusia County, Florida

    USGS Publications Warehouse

    Rutledge, A.T.

    1985-01-01

    A test well withdrew water from the upper Floridan aquifer system at an average of 530 gallons per minute from June 1978 to July 1979. Ground-water levels were monitored in wells open to the upper Floridan (artesian) aquifer system and in wells open to the surficial (water-table) aquifer. Double-mass curves were used to separate drawdown from natural water-level fluctuations. Drawdowns in the Floridan were 4.3 feet at a site 350 feet away from the pumped well, 4.1 feet at a site 1,000 feet away, 1.0 foot at a site 1.0 mile away, and 0.4 foot at a site 5.8 miles away. After an initial drawdown of 0.2 foot at a surficial aquifer well 1,000 feet from the pumped well, there was some recovery, and long-term drawdown averaged less than 0.2 foot. In a five-day aquifer test during a period of no rainfall in 1976, the ratio of surficial aquifer drawdown to Floridan aquifer system drawdown reached equilibrum at 0.05. The results of the long-term test indicate that this ratio is the upper limit of long-term drawdown because of capture of evapotranspiration and runoff during the long-term test. (USGS)

  4. Evaluation of Short-Term and Long-Term Migration Testing from Can Coatings into Food Simulants: Epoxy and Acrylic-Phenolic Coatings.

    PubMed

    Paseiro-Cerrato, Rafael; DeVries, Jonathan; Begley, Timothy H

    2017-03-29

    Traditionally, migration testing during 10 days at 40 °C has been considered sufficient and appropriate for simulating the potential migration of substances from food-contact materials into foods. However, some packages, such as food cans, may be stored holding food for extended time periods (years). This study attempts to verify whether common testing conditions accurately estimate long-term migration. Two types of can coatings, epoxy and acrylic-phenolic, were subjected to short-term and long-term migration testing (1 day-1.5 years) using food simulants (water, 3% acetic acid, 50% ethanol, and isooctane) at 40 °C. Using HPLC-DAD/CAD, HPLC-MS, UHPLC-HRMS (where HRMS is accurate mass, mass spectrometry), and DART-HRMS, we identified potential migrants before starting the experiment: BPA, BADGE, BADGE derivatives, benzoguanamine, and other relevant marker compounds. During the experiment using a water-based food simulant, migrants remained stable. Most of the cans in contact with 3% acetic acid did not survive the experimental conditions. Tracked migrants were not detected in isooctane. In the presence of 50% ethanol, the traditional migration test during 10 days at 40 °C did not predict migration during long-term storage. These results suggest that migration protocols should be modified to account for long-term storage.

  5. Development of hot dry rock technology at Hijiori test site: Program for a long-term circulation test

    SciTech Connect

    Tenma, Norio; Iwakiri, Shunichi; Matsunaga, Isao

    1998-10-01

    Since 1985, the New Energy and Industrial Technology Development Organization (NEDO) has continued the development of hot dry rock power generation in Hijiori Hot Dry Rock test site, Yamagata prefecture, Japan, as part of the Sunshine Project and succeeding New Sunshine Project sponsored by the Agency of Industrial Science and Technology (AIST), a branch of the Ministry of International Trade and Industry (MITI). The objective of this project is to identify the feasibility of a Hot Dry Rock power generation system in Japan. Thus, the research and development being undertaken at Hijiori HDR test site is aiming to establish hot rock drilling technology, logging borehole technology for evaluating the state of the rock around the well, hydraulic fracturing technology for creating artificial fractures in rock, fracture mapping technology for surveying the reservoir area, and reservoir evaluation technology for predicting reservoir longevity.

  6. Long-term in vivo carcinogenicity tests of potassium bromate, sodium hypochlorite, and sodium chlorite conducted in Japan.

    PubMed

    Kurokawa, Y; Takayama, S; Konishi, Y; Hiasa, Y; Asahina, S; Takahashi, M; Maekawa, A; Hayashi, Y

    1986-11-01

    Long-term in vivo carcinogenicity tests of potassium bromate (KBrO3), sodium hypochlorite (NaClO), and sodium chlorite (NaClO2) have been conducted in Japan from 1977 to 1985. In these investigations, groups of approximately 50 male and 50 female F344 rats or B6C3F1 mice were given solutions of the compounds as their drinking water ad libitum at two dose levels determined on the basis of preliminary 13-week tests. Control animals were given distilled water. The carcinogenic potential of KBrO3 was tested by administering doses of 500 or 250 ppm to rats for 110 weeks. Significantly elevated incidences of renal cell tumors in males and females and mesotheliomas of the peritoneum in males as compared to controls were observed. When female mice were given KBrO3 at doses of 1000 or 500 ppm for 78 weeks, no significant differences in tumor incidences between experimental and control groups were apparent. NaClO was administered to male and female rats, respectively, at doses of 1000 or 500 ppm and 2000 or 1000 ppm for 104 weeks. In mice, NaClO was given at doses of 1000 or 500 ppm to either sex for 103 weeks. The incidences of tumors in NaClO-treated and control animals of both sexes were not significantly different in both rat and mouse studies. NaClO2 was given to rats of both sexes at a dose of 600 or 300 ppm for 85 weeks. No statistically significant differences were observed in the incidences of tumor formation between NaClO2-treated and control groups of both sexes. NaClO2 was administered to mice at a concentration of 500 or 250 ppm for 85 weeks. In males, the combined incidences of hyperplastic nodules and hepatocellular carcinomas of the liver in a low-dose group, and adenomas and adenocarcinomas of the lung in a high-dose group, were marginally increased compared to controls (p less than 0.05). However, these incidences in treated males were within the range of values of historical control data in our program. We concluded that KBrO3 was carcinogenic in rats of

  7. Long-term in vivo carcinogenicity tests of potassium bromate, sodium hypochlorite, and sodium chlorite conducted in Japan.

    PubMed Central

    Kurokawa, Y; Takayama, S; Konishi, Y; Hiasa, Y; Asahina, S; Takahashi, M; Maekawa, A; Hayashi, Y

    1986-01-01

    Long-term in vivo carcinogenicity tests of potassium bromate (KBrO3), sodium hypochlorite (NaClO), and sodium chlorite (NaClO2) have been conducted in Japan from 1977 to 1985. In these investigations, groups of approximately 50 male and 50 female F344 rats or B6C3F1 mice were given solutions of the compounds as their drinking water ad libitum at two dose levels determined on the basis of preliminary 13-week tests. Control animals were given distilled water. The carcinogenic potential of KBrO3 was tested by administering doses of 500 or 250 ppm to rats for 110 weeks. Significantly elevated incidences of renal cell tumors in males and females and mesotheliomas of the peritoneum in males as compared to controls were observed. When female mice were given KBrO3 at doses of 1000 or 500 ppm for 78 weeks, no significant differences in tumor incidences between experimental and control groups were apparent. NaClO was administered to male and female rats, respectively, at doses of 1000 or 500 ppm and 2000 or 1000 ppm for 104 weeks. In mice, NaClO was given at doses of 1000 or 500 ppm to either sex for 103 weeks. The incidences of tumors in NaClO-treated and control animals of both sexes were not significantly different in both rat and mouse studies. NaClO2 was given to rats of both sexes at a dose of 600 or 300 ppm for 85 weeks. No statistically significant differences were observed in the incidences of tumor formation between NaClO2-treated and control groups of both sexes. NaClO2 was administered to mice at a concentration of 500 or 250 ppm for 85 weeks. In males, the combined incidences of hyperplastic nodules and hepatocellular carcinomas of the liver in a low-dose group, and adenomas and adenocarcinomas of the lung in a high-dose group, were marginally increased compared to controls (p less than 0.05). However, these incidences in treated males were within the range of values of historical control data in our program. We concluded that KBrO3 was carcinogenic in rats of

  8. Long Term Prognosis

    MedlinePlus

    ... TERM PROGNOSIS The long-term outlook of pediatric cardiomyopathy continues to be unpredictable because it occurs with ... a child also depends on the type of cardiomyopathy and the stage the disease is first diagnosed. ...

  9. Long-term agroecosystem research in the Central Mississippi River Basin: Goodwater Creek Experimental Watershed flow data

    USDA-ARS?s Scientific Manuscript database

    Flow monitoring in Goodwater Creek Experimental Watershed started in 1971 at three nested watersheds ranging from 12 to 73 km2 in drainage area. Since then, flow has been measured at 14 plots, 3 fields, and 12 additional stream sites ranging from 0.0034 to 6067 km2 in the Central Mississippi River B...

  10. Changes in long-term flow regimes in Mekong River and their implications in riverine ecosystems and reservoir operation

    NASA Astrophysics Data System (ADS)

    Dongnan, L.; Long, D.; Zhao, J.; Lu, H.; Hong, Y.

    2016-12-01

    Human activities, such as dam construction, significantly alter the flow regimes in Mekong River, especially after the completion of two large dams, namely, Xiaowan and Nuozadu, in 2010 and 2014, respectively. Streamflow data from 1960 to 2014 obtained from six stations located along the Mekong mainstream are divided into three periods, i.e., the pre-impact period (1960-1991), the transition period (1992-2009), and the impacted period (2010-2014). The flow regimes are investigated using eco-low metrics and the indicators of hydrologic alteration (IHA). Principal component analysis is applied to select key indices from IHA. Results show that damming the upstream area reduced the annual streamflow in upstream Chiang Saen gauging station, whereas no clear effect was observed in downstream Stung Treng station. Operation of dams reduces the streamflow in wet seasons and increases the streamflow in dry seasons, leading to unique seasonal variation in streamflow in terms of eco-flow metrics in Chiang Saen gauging station from 2010 to 2014. In addition, no notable change has been observed in the date of occurrence of extreme flows. In upstream Chiang Saen gauging station, the maximum flow values decreased significantly in the year corresponding to the completion of the Manwan, Dachaoshan, and Jinghong Dams. The construction and operation of dams clearly exerted significant impacts on low pulse duration. The 90-day maximum flow, high and low pulse duration, number of fluctuations, and date of the occurrence of maximum flow are selected to reflect flow regimes in Mekong River. On one hand, changes in flow regimes influence the riverine ecosystems; on the other hand, these changes are beneficial in downstream irrigation, flood management, and navigation. The results of this study provide reference for reservoir operation in upstream regions, taking into consideration both the ecological and economic benefits of such operation, as well as for maximizing the interests of

  11. Sediment mobilization deposits from episodic subsurface fluid flow - A new tool to reveal long-term earthquake records?

    NASA Astrophysics Data System (ADS)

    Reusch, Anna; Moernaut, Jasper; Anselmetti, Flavio S.; Strasser, Michael

    2016-04-01

    Subsurface fluid flow can be affected by earthquakes: increased spring activity, mud volcano eruptions, groundwater fluctuations, changes in geyser frequency and other forms of altered subsurface fluid flow have been documented during, after, or even prior to earthquakes. Recently discovered giant pockmarks on the bottom of Lake Neuchâtel, Switzerland, are the lake-floor expression of subsurface fluid flow. They discharge karstic groundwater from the Jura Mountains and experience episodically increased subsurface fluid flow documented by subsurface sediment mobilization deposits at the levees of the pockmarks. In this study, we present the spatio-temporal distribution of event deposits from phases of sediment expulsion and their time correlative multiple mass-transport deposits. We report striking evidence for five events of concurrent multiple subsurface sediment deposits and multiple mass-transport deposits since Late Glacial times, for which we propose past earthquakes as trigger. Comparison of this new event catalogue with historic earthquakes and other independent paleoseismic records suggests that initiation of sediment expulsion requires a minimum macroseismic intensity of VII. Thus, our study presents for the first time sedimentary deposits resulting from increased subsurface fluid flow as new paleoseismic proxy. Comparable processes must also be relevant for other mountain front ranges and coastal mountain ranges, where groundwater flow triggers subsurface sediment mobilization and discharges into lacustrine and marine settings.

  12. Test-Retest Reliability of 10 Hz Conditioning Electrical Stimulation Inducing Long-Term Potentiation (LTP)-Like Pain Amplification in Humans

    PubMed Central

    Xia, Weiwei; Mørch, Carsten Dahl; Andersen, Ole Kæseler

    2016-01-01

    Background 10 Hz conditioning electrical stimulation (CES) has been shown to induce long-term potentiation (LTP)-like pain amplification similar to traditional 100 Hz CES in healthy humans. The aim of this study was to assess the test-retest reliability and to estimate sample sizes required for future crossover and parallel study designs. Methods The 10 Hz paradigm (500 rectangular pulses lasting 50 s) was repeated on two separate days with one week interval in twenty volunteers. Perceptual intensities to single electrical stimulation (SES) at the conditioned skin site and to mechanical stimuli (pinprick and light stroking) in immediate vicinity to the conditioned skin site were recorded. Superficial blood flow (SBF) was assessed as indicator of neurogenic inflammation. All outcome measures were assessed with 10 min interval three times before and six times after the CES. The coefficient of variation and intra-class correlation coefficient were calculated within session and between sessions. Sample sizes were estimated for future crossover (Ncr) and parallel (Np) drug testing studies expected to detect a 30% decrease for the individual outcome measure following 10 Hz CES. Results Perceptual intensity ratings to light stroking (Ncr = 2, Np = 33) and pinprick stimulation (491 mN) (Ncr = 6, Np = 54) increased after CES and showed better reliability in crossover than parallel design. The SBF increased after CES, and then declined until reaching a plateau 20 minutes postCES. SBF showed acceptable reliability both in crossover and parallel designs (Ncr = 3, Np = 13). Pain ratings to SES were reliable, but with large estimated sample sizes (Ncr = 634, Np = 11310) due to the minor pain amplification. Conclusions The reliability of 10 Hz CES was acceptable in inducing LTP-like effects in the assessments of superficial blood flow, heterotopic mechanical hyperalgesia, and dysesthesia in terms of sample sizes for future crossover study designs. PMID:27529175

  13. Net profit flow per country from 1980 to 2009: The long-term effects of foreign direct investment.

    PubMed

    Akkermans, Dirk H M

    2017-01-01

    The paper aims at describing and explaining net profit flows per country for the period 1980-2009. Net profit flows result from Foreign Direct Investment (FDI) stock and profit repatriation: inward stock creating a profit outflow and outward FDI stock a profit inflow. Profit flows, especially 'normal' ones are not commonly researched. According to world-system theory, countries are part of a system characterised by a core, semi-periphery and periphery, as shown by network analyses of trade relations. Network analyses based on ownership relations of TransNational Corporations (TNCs) show that the top 50 firms that control about 40% of the world economy are almost exclusively located in core countries. So, we may expect a hierarchy in net profit flows with core countries on top and the periphery at the bottom. FDI outflows from the core countries especially rose in the 1990s, so we may expect that the difference has grown in time. A dataset on 'net profit flow' per country is developed. There are diverging developments in net profit flows since the 1980s, as expected: ever more positive for core countries, negative and ever lower for semi-peripheral and peripheral countries, in particular from the 1990s onwards. A fixed effects quantile regression using publicly available data confirms the prediction that peripheral countries share a unique characteristic: their outward investments do not have a positive influence on net profit flow as is the case with semi-peripheral and core countries. The most probable explanation is that peripheral outward investments are indirectly owned by firms located in core and semi-peripheral countries, so all peripheral profit inflows end up in those countries.

  14. Net profit flow per country from 1980 to 2009: The long-term effects of foreign direct investment

    PubMed Central

    2017-01-01

    Aim of the paper The paper aims at describing and explaining net profit flows per country for the period 1980–2009. Net profit flows result from Foreign Direct Investment (FDI) stock and profit repatriation: inward stock creating a profit outflow and outward FDI stock a profit inflow. Profit flows, especially ‘normal’ ones are not commonly researched. Theoretical background According to world-system theory, countries are part of a system characterised by a core, semi-periphery and periphery, as shown by network analyses of trade relations. Network analyses based on ownership relations of TransNational Corporations (TNCs) show that the top 50 firms that control about 40% of the world economy are almost exclusively located in core countries. So, we may expect a hierarchy in net profit flows with core countries on top and the periphery at the bottom. FDI outflows from the core countries especially rose in the 1990s, so we may expect that the difference has grown in time. Data and results A dataset on 'net profit flow' per country is developed. There are diverging developments in net profit flows since the 1980s, as expected: ever more positive for core countries, negative and ever lower for semi-peripheral and peripheral countries, in particular from the 1990s onwards. A fixed effects quantile regression using publicly available data confirms the prediction that peripheral countries share a unique characteristic: their outward investments do not have a positive influence on net profit flow as is the case with semi-peripheral and core countries. The most probable explanation is that peripheral outward investments are indirectly owned by firms located in core and semi-peripheral countries, so all peripheral profit inflows end up in those countries. PMID:28654644

  15. Validated Metrics of Quick Flow Improve Assessments of Streamflow Generation Processes at the Long-Term Sleepers River Research Site

    NASA Astrophysics Data System (ADS)

    Sebestyen, S. D.; Shanley, J. B.

    2015-12-01

    There are multiple approaches to quantify quick flow components of streamflow. Physical hydrograph separations of quick flow using recession analysis (RA) are objective, reproducible, and easily calculated for long-duration streamflow records (years to decades). However, this approach has rarely been validated to have a physical basis for interpretation. In contrast, isotopic hydrograph separation (IHS) and end member mixing analysis using multiple solutes (EMMA) have been used to identify flow components and flowpath routing through catchment soils. Nonetheless, these two approaches are limited by data from limited and isolated periods (hours to weeks) during which more-intensive grab samples were analyzed. These limitations oftentimes make IHS and EMMA difficult to generalize beyond brief windows of time. At the Sleepers River Research Watershed (SRRW) in northern Vermont, USA, we have data from multiple snowmelt events over a two decade period and from multiple nested catchments to assess relationships among RA, IHS, and EMMA. Quick flow separations were highly correlated among the three techniques, which shows links among metrics of quick flow, water sources, and flow path routing in a small (41 ha), forested catchment (W-9) The similarity in responses validates a physical interpretation for a particular RA approach (the Ekhardt recursive RA filter). This validation provides a new tool to estimate new water inputs and flowpath routing for more and longer periods when chemical or isotopic tracers may not have been measured. At three other SRRW catchments, we found similar strong correlations among the three techniques. Consistent responses across four catchments provide evidence to support other research at the SRRW that shows that runoff generation mechanisms are similar despite differences in catchment sizes and land covers.

  16. KENNEDY SPACE CENTER, FLA. - Louis MacDowell (right), Testbed manager, explains to Center Director Jim Kennedy the use of astmospheric calibration specimens. Placed at various locations, they can rank the corrosivity of the given environment. The KSC Beach Corrosion Test Site was established in the 1960s and has provided more than 30 years of historical information on the long-term performance of many materials in use at KSC and other locations around the world. Located 100 feet from the Atlantic Ocean approximately 1 mile south of the Space Shuttle launch sites, the test facility includes an atmospheric exposure site, a flowing seawater exposure site, and an on-site electrochemistry laboratory and monitoring station. The beach laboratory is used to conduct real-time corrosion experiments and provides for the remote monitoring of surrounding weather conditions. The newly added flowing seawater immersion facility provides for the immersion testing of materials and devices under controlled conditions.

    NASA Image and Video Library

    2003-08-21

    KENNEDY SPACE CENTER, FLA. - Louis MacDowell (right), Testbed manager, explains to Center Director Jim Kennedy the use of astmospheric calibration specimens. Placed at various locations, they can rank the corrosivity of the given environment. The KSC Beach Corrosion Test Site was established in the 1960s and has provided more than 30 years of historical information on the long-term performance of many materials in use at KSC and other locations around the world. Located 100 feet from the Atlantic Ocean approximately 1 mile south of the Space Shuttle launch sites, the test facility includes an atmospheric exposure site, a flowing seawater exposure site, and an on-site electrochemistry laboratory and monitoring station. The beach laboratory is used to conduct real-time corrosion experiments and provides for the remote monitoring of surrounding weather conditions. The newly added flowing seawater immersion facility provides for the immersion testing of materials and devices under controlled conditions.

  17. Analytical results of a long-term aquifer test conducted near the Rio Grande, Albuquerque, New Mexico, with a section on piezometric-extensometric test results

    USGS Publications Warehouse

    Thorn, Conde R.; Heywood, Charles E.

    2001-01-01

    The City of Albuquerque, New Mexico, is interested in gaining a better understanding, both quantitative and qualitative, of the aquifer system in and around Albuquerque. Currently (2000), the City of Albuquerque and surrounding municipalities are completely dependent on ground-water reserves for their municipal water supply. This report presents the results of a long-term aquifer test conducted near the Rio Grande in Albuquerque. The long-term aquifer test was conducted during the winter of 1994-95. The City of Albuquerque Griegos 1 water production well was pumped continuously for 54 days at an average pumping rate of 2,331 gallons per minute. During the 54-day pumping and a 30-day recovery period, water levels were recorded in a monitoring network that consisted of 3 production wells and 19 piezometers located at nine sites. These wells and piezometers were screened in river alluvium and (or) the upper and middle parts of the Santa Fe Group aquifer system. In addition to the measurement of water levels, aquifer-system compaction was monitored during the aquifer test by an extensometer. Well-bore video and flowmeter surveys were conducted in the Griegos 1 water production well at the end of the recovery period to identify the location of primary water- producing zones along the screened interval. Analytical results from the aquifer test presented in this report are based on the methods used to analyze a leaky confined aquifer system and were performed using the computer software package AQTESOLV. Estimated transmissivities for the Griegos 1 and 4 water production wells ranged from 10,570 to 24,810 feet squared per day; the storage coefficient for the Griegos 4 well was 0.0025. A transmissivity of 13,540 feet squared per day and a storage coefficient of 0.0011 were estimated from the data collected from a piezometer completed in the production interval of the Griegos 1 well.

  18. Search for a more adequate test to predict the long-term migration from the PVC gaskets of metal lids into oily foods in glass jars.

    PubMed

    Graubardt, Nadine; Biedermann, Maurus; Fiselier, Katell; Bolzoni, Luciana; Pedrelli, Turno; Cavalieri, Chiara; Simoneau, Cathérine; Grob, Koni

    2009-07-01

    As shown previously, the conventional testing procedure for simulating long-term migration from the gaskets of metal closures into oily foods does not adequately reflect reality. It appears to be impossible to accelerate migration to the extent that the situation at the end of the shelf life of a product can be anticipated in a few days or weeks. Therefore, we investigated whether long-term migration could be extrapolated from migration rates determined for new lids. Jars were kept in the normal upright position. Since heat treatment may have a strong temporary impact, migration during the initial heating for pasteurization or sterilization and storage at ambient temperature were determined using different lids. Commercial products were recalled from sales points throughout Europe to determine the real migration over extended periods of time and for jars with differing histories. This migration was compared with data from the short-term testing to investigate whether an empirical relationship could be derived. The results show that the short-term test enables the comparison of lids and plasticizers in the initial phase of migration, but that long-term extrapolation presupposes more complex kinetic modeling. The results also demonstrate that the legal relevance of "official" testing methods should be reconsidered to avoid conflict when food contact materials comply with migration limits in the test but not in actual application.

  19. Drought-induced changes in flow regimes lead to long-term losses in mussel-provided ecosystem services.

    PubMed

    Vaughn, Caryn C; Atkinson, Carla L; Julian, Jason P

    2015-03-01

    Extreme hydro-meteorological events such as droughts are becoming more frequent, intense, and persistent. This is particularly true in the south central USA, where rapidly growing urban areas are running out of water and human-engineered water storage and management are leading to broad-scale changes in flow regimes. The Kiamichi River in southeastern Oklahoma, USA, has high fish and freshwater mussel biodiversity. However, water from this rural river is desired by multiple urban areas and other entities. Freshwater mussels are large, long-lived filter feeders that provide important ecosystem services. We ask how observed changes in mussel biomass and community composition resulting from drought-induced changes in flow regimes might lead to changes in river ecosystem services. We sampled mussel communities in this river over a 20-year period that included two severe droughts. We then used laboratory-derived physiological rates and river-wide estimates of species-specific mussel biomass to estimate three aggregate ecosystem services provided by mussels over this time period: biofiltration, nutrient recycling (nitrogen and phosphorus), and nutrient storage (nitrogen, phosphorus, and carbon). Mussel populations declined over 60%, and declines were directly linked to drought-induced changes in flow regimes. All ecosystem services declined over time and mirrored biomass losses. Mussel declines were exacerbated by human water management, which has increased the magnitude and frequency of hydrologic drought in downstream reaches of the river. Freshwater mussels are globally imperiled and declining around the world. Summed across multiple streams and rivers, mussel losses similar to those we document here could have considerable consequences for downstream water quality although lost biofiltration and nutrient retention. While we cannot control the frequency and severity of climatological droughts, water releases from reservoirs could be used to augment stream flows and

  20. Drought-induced changes in flow regimes lead to long-term losses in mussel-provided ecosystem services

    PubMed Central

    Vaughn, Caryn C; Atkinson, Carla L; Julian, Jason P

    2015-01-01

    Extreme hydro-meteorological events such as droughts are becoming more frequent, intense, and persistent. This is particularly true in the south central USA, where rapidly growing urban areas are running out of water and human-engineered water storage and management are leading to broad-scale changes in flow regimes. The Kiamichi River in southeastern Oklahoma, USA, has high fish and freshwater mussel biodiversity. However, water from this rural river is desired by multiple urban areas and other entities. Freshwater mussels are large, long-lived filter feeders that provide important ecosystem services. We ask how observed changes in mussel biomass and community composition resulting from drought-induced changes in flow regimes might lead to changes in river ecosystem services. We sampled mussel communities in this river over a 20-year period that included two severe droughts. We then used laboratory-derived physiological rates and river-wide estimates of species-specific mussel biomass to estimate three aggregate ecosystem services provided by mussels over this time period: biofiltration, nutrient recycling (nitrogen and phosphorus), and nutrient storage (nitrogen, phosphorus, and carbon). Mussel populations declined over 60%, and declines were directly linked to drought-induced changes in flow regimes. All ecosystem services declined over time and mirrored biomass losses. Mussel declines were exacerbated by human water management, which has increased the magnitude and frequency of hydrologic drought in downstream reaches of the river. Freshwater mussels are globally imperiled and declining around the world. Summed across multiple streams and rivers, mussel losses similar to those we document here could have considerable consequences for downstream water quality although lost biofiltration and nutrient retention. While we cannot control the frequency and severity of climatological droughts, water releases from reservoirs could be used to augment stream flows and

  1. Testing Periodic Local Position Invariance Using Long-Term Comparison of the Syrte Atomic Fountains and H-Masers

    NASA Astrophysics Data System (ADS)

    Tobar, M. E.; Stanwix, P. L.; McFerran, J. J.; Guena, J.; Abgrall, M.; Bize, S.; Clairon, A.; Laurent, Ph.; Rosenbusch, P.; Rovera, D.; Santarelli, G.

    2014-01-01

    The frequencies of Cs and Rb fountain clocks have been compared to various H-masers to search for periodic changes correlated with the gravitational potential and boost with respect to the cosmic microwave background. The data span about eight years and the main sources of long-term noise are the offsets and linear drifts associated with the H-masers. To circumvent these effects we apply a numerical derivative to the data, which significantly reduces the standard error. We determine a limit for the Local Position Invariance (LPI) coefficient with respect to gravity to be 4.8×10-6 and 10-5 for a Cs-H and Rb-H comparison, respectively. From the same data the boost LPI coefficients were measured to parts in 1011. From these results and others, independent limits on all coefficients of the boost violation vector with respect to fundamental constant invariance were determined to parts in 1010.

  2. Identifying external influences on discharge time series: Long term variability of the Danube River flow and its relation to precipitation and temperature

    NASA Astrophysics Data System (ADS)

    Szolgayová, Elena; Blöschl, Günter; Bucher, Christian

    2013-04-01

    Studies analysing the impact of climate related drivers, such as precipitation and temperature on discharge have become widely popular in the past years. It is especially interesting to see the impact of these factors from the long term perspective and the influence of these drivers on possible long range dependence in the discharge time series. In this work we use cross - wavelet analysis in order to improve the understanding of interdependencies between discharge and the above named climate related drivers and to observe the long term variability of the river flows and its relation to temperature and precipitations. Analysis of the cross - wavelet spectra thus can help to explain the influence of the specific geographical conditions of the region on the discharge. Using the cross - wavelets thus helps to explain the long term behaviour and long range dependence in discharge from the process point of view. Such analysis obviously has to be done case based, observing the interaction between the discharge and the respective driver for different frequency intervals at different periods in time for a discharge gauging station separately. We consider daily and monthly discharge time series from five discharge gauging stations of the Danube River in Germany, Austria and Slovakia and the areal average precipitation over their catchments and temperature time series for the respective discharge gauge. The cross - wavelets are used to analyze the general impact of precipitation on discharge using generated discharge and precipitation data in each station. A simple dual kernel convolution model is used to generate discharge from precipitation. From thus obtained data sets the cross - wavelet spectra are constructed and analysed in order to understand how does precipitation influence discharge, especially in the lower frequencies. The influence of different behavioral patterns in precipitation (simulating possible different physiographic conditions in the catchment), such as

  3. A Serendipitous, Long-Term Infiltration Experiment: Water and Tritium Circulation Beneath the CAMBRIC Ditch at the Nevada Test Site

    SciTech Connect

    Maxwell, R M; Tompson, A B; Kollet, S J

    2008-11-20

    Underground nuclear weapons testing at the Nevada Test Site introduced numerous radionuclides that may be used to characterize subsurface hydrologic transport processes in arid climates. A sixteen year pumping experiment designed to examine radionuclide migration away from the CAMBRIC nuclear test, conducted in groundwater beneath Frenchman Flat in 1965, gave rise to an unintended second experiment involving radionuclide infiltration through the vadose zone, as induced by seepage of pumping effluents beneath an unlined discharge trench. The combined experiments have been reanalyzed using a detailed, three-dimensional numerical model of transient, variably saturated flow and mass transport, tailored specifically for large scale and efficient calculations. Simulations have been used to estimate radionuclide travel and residence times in various parts of the system for comparison with observations in wells. Model predictions of mass transport were able to clearly demonstrate radionuclide recycling behavior between the ditch and pumping well previously suggested by isotopic age dating information; match travel time estimates for radionuclides moving between the ditch, the water table, and monitoring wells; and provide more realistic ways in which to interpret the pumping well elution curves. Collectively, the results illustrate the utility of integrating detailed numerical modeling with diverse observational data in developing accurate interpretations and forecasts of contaminant migration processes.

  4. A serendipitous, long-term infiltration experiment: Water and tritium circulation beneath the CAMBRIC trench at the Nevada Test Site

    NASA Astrophysics Data System (ADS)

    Maxwell, Reed M.; Tompson, Andrew F. B.; Kollet, Stefan

    2009-08-01

    Underground nuclear weapons testing at the Nevada Test Site introduced numerous radionuclides that may be used subsequently to characterize subsurface hydrologic transport processes in arid climates. In 1965, a unique, 16-year pumping experiment designed to examine radionuclide migration away from the CAMBRIC nuclear test, conducted in the saturated zone beneath Frenchman Flat, Nevada, USA, gave rise to an unintended second experiment involving radionuclide infiltration through the vadose zone, as induced by seepage of pumping effluents beneath an unlined discharge trench. The combined experiments have been reanalyzed using a detailed, three-dimensional numerical model of transient, variably saturated flow and mass transport in a heterogeneous subsurface, tailored specifically for large-scale and efficient calculations. Simulations have been used to estimate tritium travel and residence times in various parts of the system for comparison with observations in wells. Model predictions of mass transport were able to clearly demonstrate radionuclide recycling behavior between the trench and pumping well previously suggested by isotopic age dating information; match travel time estimates for radionuclides moving between the trench, the water table, and monitoring and pumping wells; and provide more realistic ways in which to interpret the pumping well elution curves. Collectively, the results illustrate the utility of integrating detailed numerical modeling with diverse observational data in developing more accurate interpretations of contaminant migration processes.

  5. A serendipitous, long-term infiltration experiment: water and tritium circulation beneath the CAMBRIC trench at the Nevada Test Site.

    PubMed

    Maxwell, Reed M; Tompson, Andrew F B; Kollet, Stefan

    2009-08-11

    Underground nuclear weapons testing at the Nevada Test Site introduced numerous radionuclides that may be used subsequently to characterize subsurface hydrologic transport processes in arid climates. In 1965, a unique, 16-year pumping experiment designed to examine radionuclide migration away from the CAMBRIC nuclear test, conducted in the saturated zone beneath Frenchman Flat, Nevada, USA, gave rise to an unintended second experiment involving radionuclide infiltration through the vadose zone, as induced by seepage of pumping effluents beneath an unlined discharge trench. The combined experiments have been reanalyzed using a detailed, three-dimensional numerical model of transient, variably saturated flow and mass transport in a heterogeneous subsurface, tailored specifically for large-scale and efficient calculations. Simulations have been used to estimate tritium travel and residence times in various parts of the system for comparison with observations in wells. Model predictions of mass transport were able to clearly demonstrate radionuclide recycling behavior between the trench and pumping well previously suggested by isotopic age dating information; match travel time estimates for radionuclides moving between the trench, the water table, and monitoring and pumping wells; and provide more realistic ways in which to interpret the pumping well elution curves. Collectively, the results illustrate the utility of integrating detailed numerical modeling with diverse observational data in developing more accurate interpretations of contaminant migration processes.

  6. The role of episodic fire-related debris flows on long-term (103-104) sediment yields in the Middle Fork Salmon River Watershed, in central Idaho

    NASA Astrophysics Data System (ADS)

    Riley, K. E.; Pierce, J. L.; Hopkins, A.

    2010-12-01

    Episodic fire-related debris flows contribute large amounts of sediment and large woody debris to streams. This study evaluates fire-related sedimentation from small steep tributaries of the Middle Fork Salmon River (MFSR) in central Idaho to evaluate the timing, frequency, and magnitude of episodic fire-related sedimentation on long-term (10 3-10 4) sediment yields. The MFSR lies within the Northern Rocky Mountains and encompasses a range of ecosystems including high elevation (~3,000 -1,700 m) subalpine pine and spruce forests, mid-elevation (2650 - 1130 m) montane Douglas-fir and ponderosa pine-dominated forests and low elevation (~ 1,800 - 900 m) sagebrush steppe. Recent debris flow events in tributaries of the MFSR appear to primarily result from increased surface runoff, rilling, and progressive sediment bulking following high severity fires. This study estimates: 1) the volume of sediment delivered by four recent (1997-2008) fire-related debris flow events using real time kinematic GPS surveys, and 2) the timing of Holocene fire-related debris flow events determined by 14C dating charcoal fragments preserved in buried burned soils and within fire-related deposits. Our measured volumes of the four recent debris flow events are compared to two empirically derived volume estimates based on remotely sensed spatial data (burn severity and slope), measured geometric data (longitudinal profile, cross sectional area, flow banking angle), and precipitation records. Preliminary stratigraphic profiles in incised alluvial fans suggest that a large percentage of alluvial fan thickness is composed of fire-related deposits suggesting fire-related hillslope erosion is a major process delivering sediment to alluvial fans and to the MFSR. Fire-related deposits from upper basins compose ~71% of total alluvial fan thickness, while fire-related deposits from lower basins make up 36% of alluvial fan thickness. However, lower basins are less densely vegetated with small diameter

  7. An alternative design for long-term stability testing of large molecules: a scientific discussion paper from an EBF Topic Team.

    PubMed

    Pihl, Susanne; Andersen, Lene; Bruzelius, Katharina; Schiebl, Christine; Golob, Michaela

    2015-12-01

    Long-term stability testing of drug candidates in biological matrix is a key parameter in bioanalytical method validation. The European Bioanalysis Forum formed a Topic Team to evaluate the use of isochronic design for long-term stability testing of large molecules. Isochronic design is based on storage of samples at a reference temperature (below -130°C) where the samples are considered stable. The stability samples are stored at the intended storage temperature and then transferred to the reference temperature, while a set of reference samples is stored the entire storage period at the reference temperature. Stability and reference samples will then be analyzed in one run at the end of the storage period. The mean concentrations of the stability samples are compared either to their nominal concentrations or to the mean concentrations of the reference samples. The design minimizes day-to-day variation, reduces workload and adds to the flexibility in the laboratory.

  8. Bivalent response to long-term storage in liquid-preserved boar semen: a flow cytometric analysis.

    PubMed

    Henning, Heiko; Petrunkina, Anna M; Harrison, Robin A P; Waberski, Dagmar

    2012-07-01

    The fertility of liquid-preserved boar semen declines during storage at 17°C, insemination trials even indicating early losses in fertilizing ability within the first 24-48 h of storage. Standard semen parameters barely reflect these changes in semen quality, and new approaches for assessment of functional changes in stored spermatozoa are needed. Capacitation, the essential prefertilization step for spermatozoa in the female genital tract, is specifically induced in vitro by bicarbonate. Therefore, we have investigated changes in responsiveness of boar spermatozoa to bicarbonate during storage. Ejaculates of 14 boars were diluted in Beltsville thawing solution, cooled to 17°C and stored for 12, 24, 72, 120, and 168 h before investigation. At each time, basic semen quality was characterized by sperm motility and viability. Subsequently, washed subsamples were incubated in variants of an in vitro fertilization (IVF) medium and assessed for kinetic changes of viability (plasma membrane integrity) and intracellular calcium concentration using flow cytometry in combination with propidium iodide and Fluo-3. By this means, it was possible to determine specific effects of bicarbonate and calcium on sperm subpopulations over incubation time. During storage, standard semen parameters remained on a high level. However, flow cytometric analysis of sperm responses to capacitating and control media revealed two opposing effects of storage. There was a loss of response to bicarbonate in part of the live sperm population but an increasing degree of instability in the rest. Assessment of response to capacitating media by flow cytometry appears a markedly more sensitive way of monitoring sperm functionality during storage than the standard semen parameters of motility and viability.

  9. Long-term effects of triethylenemelamine exposure on mouse testis cells and sperm chromatin structure assayed by flow cytometry

    SciTech Connect

    Evenson, D.P.; Baer, R.K.; Jost, L.K. )

    1989-01-01

    The toxic and potentially mutagenic actions of triethylenemelamine (TEM) on mouse body and testis weights, testicular cell kinetics, sperm production, sperm head morphology, and sperm chromatin structure were assessed in two experiments. The first experiment examined effects of four dose levels of TEM, assayed 1, 4, or 10 wk after toxic exposure. In the second study, effects from five dosage levels were measured at 1, 4, and 10 wk, and the highest dosage level was evaluated over 44 wk. TEM produced an expected dose related loss of spermatogenic activity and subsequent recovery as determined by dual-parameter (DNA, RNA) flow cytometry (FCM) measurements of testicular cells. Both testicular weights and caudal sperm reserves remained generally below controls after 44 wk recovery following exposure to the highest dosage. Chromatin structure alterations, defined as increased susceptibility to DNA denaturation in situ, and sperm head morphology were highly correlated with dose and with each other. Sperm head morphology and sperm chromatic structure remained abnormal at 44 wk for the 1.0 mg/kg TEM dosage, suggesting that the abnormalities, present long after the initial toxic response, may be a result of mutation. This study demonstrates that flow cytometry provides a unique, rapid, and efficient means to measure effects of reproductive toxins and potential mutagens.

  10. Simulation of Life Testing Procedures for Estimating Long-Term Degradation and Lifetime of AlGaN/GaN HEMTs (Postprint)

    DTIC Science & Technology

    2009-10-01

    failure region. Overestimating the activation energy for failure leads to overly optimistic operating lifetime predictions . II. MODEL To model these effects...in general, will be much less for smaller devices. It is shown that the error in E′a and A ′ becomes a much greater problem for lifetime prediction ...AFRL-RX-WP-TP-2009-4331 SIMULATION OF LIFE TESTING PROCEDURES FOR ESTIMATING LONG-TERM DEGRADATION AND LIFETIME OF AlGaN/GaN HEMTs

  11. [Effects of Long-term Implementation of the Flow-Sediment Regulation Scheme on Grain and Clay Compositions of Inshore Sediments in the Yellow River Estuary].

    PubMed

    Wang, Miao-miao; Sun, Zhi-gao; Lu, Xiao-ning; Wang, Wei; Wang, Chuan-yuan

    2015-04-01

    Based on the laser particle size and X-ray diffraction (XRD) analysis, 28 sediment samples collected from the inshore region of the Yellow River estuary in October 2013 were determined to discuss the influence of long-term implementation of the flow-sediment regulation scheme (FSRS, initiated in 2002) on the distributions of grain size and clay components (smectite, illite, kaolinite and chlorite) in sediments. Results showed that, after the FSRS was implemented for more than 10 years, although the proportion of sand in inshore sediments of the Yellow River estuary was higher (average value, 23.5%) than those in sediments of the Bohai Sea and the Yellow River, silt was predominated (average value, 59.1%) and clay components were relatively low (average value, 17.4%). The clay components in sediments of the inshore region in the Yellow River estuary were close with those in the Yellow River. The situation was greatly changed due to the implementation of FSRS since 2002, and the clay components were in the order of illite > smectite > chlorite > kaolinite. This study also indicated that, compared to large-scale investigation in Bohai Sea, the local study on the inshore region of the Yellow River estuary was more favorable for revealing the effects of long-term implementation of the FSRS on sedimentation environment of the Yellow River estuary.

  12. Long term operation of continuous-flow system with enhanced biological phosphorus removal granules at different COD loading.

    PubMed

    Li, Dong; Lv, Yufeng; Zeng, Huiping; Zhang, Jie

    2016-09-01

    In this study, a continuous-flow system with enhanced biological phosphorus removal (EBPR) granules was operated at different COD concentrations (200, 300 and 400mgL(-)(1)) to investigate the effect of COD loading on this system. The results showed that when the COD concentration in influent was increased to 400mgL(-)(1), the anaerobic COD removal efficiency and total phosphorus removal efficiency reduced obviously and the settling ability of granules deteriorated due to the proliferation of filamentous bacteria. Moreover, high COD loading inhibited the EPS secretion and destroyed the stability of granules. Results of high-through pyrosequencing indicated that filamentous bacteria had a competitive advantage over polyphosphate-accumulating organisms (PAOs) at high COD loading. The performance of system, settling ability of granules and proportion of PAOs gradually recovered to the initial level after the COD concentration was reduced to 200mgL(-)(1) on day 81. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Estimation of long-term Ca(2+) loss through outlet flow from an agricultural watershed and the influencing factors.

    PubMed

    Zhang, Wenzhao; Yin, Chunmei; Chen, Chunlan; Chen, Anlei; Xie, Xiaoli; Fu, Xingan; Hou, Haijun; Wei, Wenxue

    2016-06-01

    Soil Ca(2+) loss from agricultural lands through surface runoff can accelerate soil acidification and render soil degradation, but the characteristics of Ca(2+) loss and influencing factors in watershed scale are unclear. This study was carried out in a watershed with various land uses in a subtropical region of China. The outlet flow was automatically monitored every 5 min all year round, and the water samples were collected twice a year from 2001 to 2011. The concentrations of Ca(2+), Mg(2+), K(+), total nitrogen (TN), and total phosphorus (TP) of water samples were measured. The dynamic losses of the nutrients through the outlet flow were estimated, and the relationships between the nutrient losses and rainfall intensity as well as antecedent soil moisture were investigated. The results showed that great variations of nutrient concentrations and losses appeared during the investigation period. The average concentrations of Ca(2+), Mg(2+), K(+), TN, and TP were 0.43, 0.08, 0.10, 0.19, and 0.003 mmol L(-1), respectively. The average Ca(2+) loss reached 1493.79 mol ha(-1) year(-1) and was several times higher than for Mg(2+), K(+), and TN, about 140 times higher than for TP. Rainfall intensity had remarkable effects on Ca(2+) concentration (P < 0.01) and loss (P < 0.05) when it reached rainstorm level (50 mm day(-1)), while a quadratic relationship was observed between antecedent soil moisture and Ca(2+) concentration only when rainfall intensity was less than 50 mm day(-1). In a word, much greater amounts of Ca(2+) were lost from the watershed, and this may be one important contributor to the increasing acidification of acidic soils in subtropical regions.

  14. Time trends in radiocaesium in the Japanese diet following nuclear weapons testing and Chernobyl: Implications for long term contamination post-Fukushima.

    PubMed

    Smith, Jim T; Tagami, Keiko; Uchida, Shigeo

    2017-12-01

    Estimation of time changes in radiocaesium in foodstuffs is key to predicting the long term impact of the Fukushima accident on the Japanese diet. We have modelled >4000 measurements, spanning 50 years, of (137)Cs in foodstuffs and whole diet in Japan after nuclear weapons testing (NWT) and the Chernobyl accident. Broadly consistent long term trends in (137)Cs activity concentrations are seen between different agricultural foodstuffs; whole diet follows this general trend with remarkably little variation between averages for different regions of Japan. Model blind tests against post-NWT data for the Fukushima Prefecture showed good predictions for radiocaesium in whole diet, spinach and Japanese radish (for which good long term test data were available). For the post-Fukushima period to 2015, radiocaesium in the average diet followed a declining time trend consistent with that seen after NWT and Chernobyl. Data for different regions post-Fukushima show a high degree of mixing of dietary foodstuffs between regions: significant over-estimates of average dietary (137)Cs were made when it was assumed that only regionally-produced food was consumed. Predictions of mean committed effective internal doses from dietary (137)Cs (2011 to 2061) in non-evacuated parts of the Fukushima Prefecture show that average internal dose is relatively low. This study focused on average regional ingestion dose rates and does not attempt to make site specific predictions. However, temporal trends identified could form a basis for site specific predictions of long term activity concentrations in agricultural products and diet both outside and (to assess potential re-use) inside currently evacuated areas. Copyright © 2017. Published by Elsevier B.V.

  15. An intervention to promote patient participation and self-management in long term conditions: development and feasibility testing

    PubMed Central

    2010-01-01

    Background There is worldwide interest in managing the global burden of long-term conditions. Current health policy places emphasis on self-management and supporting patient participation as ways of improving patient outcomes and reducing costs. However, achieving genuine participation is difficult. This paper describes the development of an intervention designed to promote participation in the consultation and facilitate self-management in long-term conditions. In line with current guidance on the development of complex interventions, our aim was to develop and refine the initial intervention using qualitative methods, prior to more formal evaluation. Methods We based the intervention on published evidence on effective ways of improving participation. The intervention was developed, piloted and evaluated using a range of qualitative methods. Firstly, focus groups with stakeholders (5 patients and 3 clinicians) were held to introduce the prototype and elucidate how it could be improved. Then individual 'think aloud' and qualitative interviews (n = 10) were used to explore how patients responded to and understood the form and provide further refinement. Results The literature highlighted that effective methods of increasing participation include the use of patient reported outcome measures and values clarification exercises. The intervention (called PRISMS) integrated these processes, using a structured form which required patients to identify problems, rate their magnitude and identify their priority. PRISMS was well received by patients and professionals. In the individual qualitative interviews the main themes that emerged from the data related to (a) the content of the PRISMS (b) the process of completing PRISMS and how it could be operationalised in practice and (c) the outcomes of completing PRISMS for the patient. A number of different functions of PRISMS were identified by patients including its use as an aide-memoire, to provide a focus to consultations, to

  16. Occurrence and elimination of antibiotic resistance genes in a long-term operation integrated surface flow constructed wetland.

    PubMed

    Fang, Hansun; Zhang, Qin; Nie, Xiangping; Chen, Baowei; Xiao, Yuandong; Zhou, Qiubai; Liao, Wei; Liang, Ximei

    2017-04-01

    Wetland construction is a recommended domestic sewage treatment technique, owing to its simplicity and cost efficiency. Concentrations of 14 antibiotic resistance genes (ARGs) in an integrated surface flow constructed wetland (ICW) steadily operated over 10 years were investigated in the winter and summer. Domestic sewage was observed to be the primary source of ARGs in the ICW, and 77.8% and 59.5% removal rates of total targeted ARGs in the ICW were achieved in the winter and summer, respectively. Concentrations of five ARGs (sul1, tetA, tetC, tetE, and qnrS) in the winter and of six ARGs (sul1, sul3, tetA, tetC, tetE, and qnrS) in the summer were increased throughout the treatment process. Strong correlations were found between ARGs in water and those found in sediments, especially in the summer, indicating that ARGs may be exchanged between water and sediment. Strong positive correlations were also observed between concentrations of intI1 and several ARGs, implying that mobile genetic elements may play a key role in the dissemination of ARGs in an ICW. Our study results suggest aqueous ARGs could be effectively removed via an ICW and that ICWs can also act as reservoirs of specific ARGs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Using the Sonoran Desert test site to monitor the long-term radiometric stability of the Landsat TM/ETM+ and Terra MODIS sensors

    USGS Publications Warehouse

    Angal, A.; Xiong, X.; Choi, T.; Chander, G.; Wu, A.

    2009-01-01

    Pseudo-invariant ground targets have been extensively used to monitor the long-term radiometric calibration stability of remote sensing instruments. The NASA MODIS Characterization Support Team (MCST), in collaboration with members from the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center, has previously demonstrated the use of pseudo-invariant ground sites for the long-term stability monitoring of Terra MODIS and Landsat 7 ETM+ sensors. This paper focuses on the results derived from observations made over the Sonoran Desert. Additionally, Landsat 5 TM data over the Sonoran Desert site were used to evaluate the temporal stability of this site. Top-ofatmosphere (TOA) reflectances were computed for the closely matched TM, ETM+, and MODIS spectral bands over selected regions of interest. The impacts due to different viewing geometries, or the effect of test site Bi-directional Reflectance Distribution Function (BRDF), are also presented. ?? 2009 SPIE.

  18. Long-Term Results from Evaluation of Advanced New Construction Packages in Test Homes: Lake Elsinore, California

    SciTech Connect

    Stecher, D.; Brozyna, K.

    2013-08-01

    This report presents the long-term evaluation results from a hot-dry climate project that examines the room-to-room temperature conditions that exist in a high performance envelope, the performance of a simplified air distribution system, and a comparison of modeled energy performance with measured energy use. The project, a prototype house built by K. Hovnanian Homes' Ontario Group, is located in Lake Elsinore, Riverside County, California, and achieves a 50% level of whole house source energy savings with respect to the Building America (BA) Benchmark Definition 2009 (Hendron and Engebrecht 2010). Temperature measurements in three rooms indicate that the temperature difference between the measured locations and the thermostat were within recommendations 90.3% of the time in heating mode and 99.3% of the time in cooling mode. The air distribution system is operating efficiently with average delivered temperatures adequate to facilitate proper heating and cooling and only minor average temperature differences observed between the system's plenum and farthest register. Monitored energy use results for the house indicate that it is using less energy than predicted from modeling. A breakdown of energy use according to end use determined little agreement between comparable values.

  19. Long-Term Results from Evaluation of Advanced New Construction Packages in Test Homes: Lake Elsinore, Californi

    SciTech Connect

    Stecher, D.; Brozyna, K.

    2013-08-01

    This report presents the long-term evaluation results from a hot-dry climate project that examines the room-to-room temperature conditions that exist in a high performance envelope, the performance of a simplified air distribution system, and a comparison of modeled energy performance with measured energy use. The project, a prototype house built by K. Hovnanian Homes’ Ontario Group, is located in Lake Elsinore, Riverside County, California, and achieves a 50% level of whole house source energy savings with respect to the Building America (BA) Benchmark Definition 2009 (Hendron and Engebrecht 2010). Temperature measurements in three rooms indicate that the temperature difference between the measured locations and the thermostat were within recommendations 90.3% of the time in heating mode and 99.3% of the time in cooling mode. The air distribution system is operating efficiently with average delivered temperatures adequate to facilitate proper heating and cooling and only minor average temperature differences observed between the system’s plenum and farthest register. Monitored energy use results for the house indicate that it is using less energy than predicted from modeling. A breakdown of energy use according to end use determined little agreement between comparable values.

  20. Study Design to Test the Hypothesis That Long-Term Space Travel Harms the Human and Animal Immune Systems

    NASA Technical Reports Server (NTRS)

    Shearer, William T.; Lugg, Desmond J.; Ochs, H. D.; Pierson, Duane L.; Reuben, James M.; Rosenblatt, Howard M.; Sams, Clarence; Smith, C. Wayne; Smith, E. Obrian; Smolen, James E.

    1999-01-01

    The potential threat of immunosuppression and abnormal inflammatory responses in long-term space travel, leading to unusual predilection for opportunistic infections, malignancy, and death, is of ma or concern to the National Aeronautics and Space Administration (NASA) Program. This application has been devised to seek answers to questions of altered immunity in space travel raised by previous investigations spanning 30-plus years. We propose to do this with the help of knowledge gained by the discovery of the molecular basis of many primary and secondary immunodeficiency diseases and by application of molecular and genetic technology not previously available. Two areas of immunity that previously received little attention in space travel research will be emphasized: specific antibody responses and non-specific inflammation and adhesion. Both of these areas of research will not only add to the growing body of information on the potential effects of space travel on the immune system, but be able to delineate any functional alterations in systems important for antigen presentation, specific immune memory, and cell:cell and cell:endothelium interactions. By more precisely defining molecular dysfunction of components of the immune system, it is hoped that targeted methods of prevention of immune damage in space could be devised.

  1. Study Design to Test the Hypothesis That Long-Term Space Travel Harms the Human and Animal Immune Systems

    NASA Technical Reports Server (NTRS)

    Shearer, William T.; Lugg, Desmond J.; Ochs, H. D.; Pierson, Duane L.; Reuben, James M.; Rosenblatt, Howard M.; Sams, Clarence; Smith, C. Wayne; Smith, E. Obrian; Smolen, James E.

    1999-01-01

    The potential threat of immunosuppression and abnormal inflammatory responses in long-term space travel, leading to unusual predilection for opportunistic infections, malignancy, and death, is of ma or concern to the National Aeronautics and Space Administration (NASA) Program. This application has been devised to seek answers to questions of altered immunity in space travel raised by previous investigations spanning 30-plus years. We propose to do this with the help of knowledge gained by the discovery of the molecular basis of many primary and secondary immunodeficiency diseases and by application of molecular and genetic technology not previously available. Two areas of immunity that previously received little attention in space travel research will be emphasized: specific antibody responses and non-specific inflammation and adhesion. Both of these areas of research will not only add to the growing body of information on the potential effects of space travel on the immune system, but be able to delineate any functional alterations in systems important for antigen presentation, specific immune memory, and cell:cell and cell:endothelium interactions. By more precisely defining molecular dysfunction of components of the immune system, it is hoped that targeted methods of prevention of immune damage in space could be devised.

  2. Body Size and Geographic Range Do Not Explain Long Term Variation in Fish Populations: A Bayesian Phylogenetic Approach to Testing Assembly Processes in Stream Fish Assemblages

    PubMed Central

    Jacquemin, Stephen J.; Doll, Jason C.

    2014-01-01

    We combine evolutionary biology and community ecology to test whether two species traits, body size and geographic range, explain long term variation in local scale freshwater stream fish assemblages. Body size and geographic range are expected to influence several aspects of fish ecology, via relationships with niche breadth, dispersal, and abundance. These traits are expected to scale inversely with niche breadth or current abundance, and to scale directly with dispersal potential. However, their utility to explain long term temporal patterns in local scale abundance is not known. Comparative methods employing an existing molecular phylogeny were used to incorporate evolutionary relatedness in a test for covariation of body size and geographic range with long term (1983 – 2010) local scale population variation of fishes in West Fork White River (Indiana, USA). The Bayesian model incorporating phylogenetic uncertainty and correlated predictors indicated that neither body size nor geographic range explained significant variation in population fluctuations over a 28 year period. Phylogenetic signal data indicated that body size and geographic range were less similar among taxa than expected if trait evolution followed a purely random walk. We interpret this as evidence that local scale population variation may be influenced less by species-level traits such as body size or geographic range, and instead may be influenced more strongly by a taxon’s local scale habitat and biotic assemblages. PMID:24691075

  3. Testing a Model of Self-Management of Fluid Intake in Community-Residing Long-Term Indwelling Urinary Catheter Users

    PubMed Central

    Wilde, Mary H.; Crean, Hugh F.; McMahon, James M.; McDonald, Margaret V.; Tang, Wan; Brasch, Judith; Fairbanks, Eileen; Shah, Shivani; Zhang, Feng

    2015-01-01

    Background Urinary tract infection and blockage are serious and recurrent challenges for people with long-term indwelling catheters, and these catheter problems cause worry and anxiety when they disrupt normal daily activities. Objectives The goal was to determine whether urinary catheter-related self-management behaviors focusing on fluid intake would mediate fluid intake related self-efficacy toward decreasing catheter-associated urinary tract infection (CAUTI) and/or catheter blockage. Method The sample involved data collected from 180 adult community-living, long-term indwelling urinary catheter users. The authors tested a model of fluid intake self-management (F-SMG) related to fluid intake self-efficacy (F-SE) for key outcomes of CAUTI and blockage. To account for the large number of zeros in both outcomes, a zero inflated negative binomial (ZINB) structural equation model was tested. Results Structurally, F-SE was positively associated with F-SMG, suggesting that higher F-SE predicts more (higher) F-SMG; however, F-SMG was not associated with either the frequency of CAUTI’s or the presence or absence of CAUTI. F-SE was positively related to F-SMG and F-SMG predicted less frequency of catheter blockage, but neither F-SE nor F-SMG predicted the presence or absence of blockage. Discussion Further research is needed to better understand determinants of CAUTI in long-term catheter users and factors which might influence or prevent its occurrence. Increased confidence (self-efficacy) and self-management behaviors to promote fluid intake could be of value in long-term urinary catheter users to decrease catheter blockage. PMID:26938358

  4. Synthesis of published and unpublished corrosion data from long term tests of fasteners embedded in wood : calculation of corrosion rates and the effect of corrosion on lateral joint strength

    Treesearch

    Samuel L. Zelinka; Douglas R. Rammer

    2011-01-01

    In the past 5 years, several accelerated test methods have been developed to measure the corrosion of metals in contact with wood. It is desirable to contrast these accelerated results against those of long term exposure tests. While there have been several published long-term exposure tests performed on metals in treated wood, the data from these studies could not be...

  5. Possible Long-Term Health Effects of Short-Term Exposure to Chemical Agents. Volume 3. Current Health Status of Test Subjects

    DTIC Science & Technology

    1985-12-31

    AD-A163 614 ’Poss-ible Long-Term Health Effects of Short-Term Exposure to Chemical Agents Volume 3 Final Report Current Health Status of Test ...Short-Term Exposure to Chemical Agents Vol. 3--Current Health Status of Test Subjects 1.2PRSONAU AUITORS) Committee on Toxicology, Board on Toxicolo y...Effects of Chemical Agents Used in Human Testing --Morbidity Studies" (DAMD17-83-C-3185-- (over) _____________________ CODSS. SUBJECT TERMS (ConteW an en e

  6. CAREER: Hydrothermal vent flow and temperature fluctuations: exploring long-term variability through an integrated research and education program

    NASA Astrophysics Data System (ADS)

    Di Iorio, D.

    2011-12-01

    An acoustic scintillation system was built in partnership with ASL Environmental Sciences (Sidney BC Canada), which provided a unique opportunity for two engineering undergraduate students to live and work abroad. The acoustic instrumentation was tested in coastal waters and then deployed to study deep-sea hydrothermal plume dynamics. Undergraduate students were involved in the deployment of instrumentation and the development of processing software to give vertical velocities and temperature fluctuations from a vigorous hydrothermal vent. A graduate student thesis has yielded insights into the vertical and azimuthal dependence of entrainment and into plume bending and rise height. Teachers and Ocean Science Bowl students also participated in research cruises describing physical oceanography of estuaries, coastal waters, and deep-sea hydrothermal vents and participated in data collection, processing and analysis. Teachers used the knowledge they gained to develop creative educational curricula at their schools, to present their experiences at national conferences and to publish an article in the National Science Teachers Association - The Science Journal. One of the teachers was recently recognized with the Presidential Award for Excellence in Mathematics and Science Teaching. Working with the ocean bowl team at Oconee County High School has led to top ten placements in the national championships in 2005 (fourth place) and 2006 (sixth place). In order to increase quantitative methods in an undergraduate class, students acquire data from an ocean observatory and analyze the data for specific quantities of interest. One such project led to the calculation of the upper ocean heat content for the Greenland Sea using 7 years of Argo profiles, which showed a 0.04oC/year trend. These results were then published in JGR.

  7. Short-term and long-term evapotranspiration rates at ecological restoration sites along a large river receiving rare flow events

    USGS Publications Warehouse

    Shanafield, Margaret; Jurado, Hugo Gutierrez; Burgueño, Jesús Eliana Rodríguez; Hernández, Jorge Ramírez; Jarchow, Christopher; Nagler, Pamela L.

    2017-01-01

    Many large rivers around the world no longer flow to their deltas, due to ever greater water withdrawals and diversions for human needs. However, the importance of riparian ecosystems is drawing increasing recognition, leading to the allocation of environmental flows to restore river processes. Accurate estimates of riparian plant evapotranspiration (ET) are needed to understand how the riverine system responds to these rare events and achieve the goals of environmental flows. In 2014, historic environmental flows were released into the Lower Colorado River at Morelos Dam (Mexico); this once perennial but now dry reach is the final stretch to the mighty Colorado River Delta. One of the primary goals was to supply native vegetation restoration sites along the reach with water to help seedlings establish and boost groundwater levels to foster the planted saplings. Patterns in ET before, during, and after the flows are useful for evaluating whether this goal was met and understanding the role that ET plays in this now ephemeral river system. Here, diurnal fluctuations in groundwater levels and MODIS data were used to compare estimates of ET specifically at three native vegetation restoration sites during 2014 planned flow events, while MODIS data was used to evaluate long-term (2002 – 2016) ET responses to restoration efforts at these sites. Overall, ET was generally 0 - 10 mm d-1 across sites and although daily ET values from groundwater data were highly variable, weekly averaged estimates were highly correlated with MODIS-derived estimates at most sites. The influence of the 2014 flow events was not immediately apparent in the results, although the process of clearing vegetation and planting native vegetation at the restoration sites was clearly visible in the results.

  8. Assessment of endothelial dysfunction by flow-mediated dilatation in men on long-term androgen deprivation therapy for prostate cancer.

    PubMed

    Gilbert, Stephen E; Tew, Garry A; Bourke, Liam; Winter, Edward M; Rosario, Derek J

    2013-09-01

    What is the central question of this study? Androgen deprivation therapy (ADT) for prostate cancer has been linked with increased cardiovascular risk, but the mechanisms are unclear. Is there evidence that endothelial dysfunction, as evidenced by reduced flow-mediated dilatation (FMD), is associated with ADT? What is the main finding and its importance? Reduction in FMD with preservation of glyceryl trinitrate-mediated dilatation indicates endothelial dysfunction in men with prostate cancer on long-term ADT compared with well-matched control subjects. Vascular endothelial dysfunction associated with long-term ADT for prostate cancer might explain the observed epidemiological increases in adverse cardiovascular events. Assessment of FMD may be useful in the monitoring of cardiovascular risk in men with prostate cancer on ADT. Androgen deprivation therapy (ADT) in men with prostate cancer has been linked to an increased incidence of cardiovascular events and mortality, but the underpinning mechanisms are unclear. Endothelial dysfunction is considered a precursor for cardiovascular disease. Previous studies have reported variably on the association between ADT and endothelial function. This blinded case-control study examined endothelial function, using high-resolution ultrasound to measure flow-mediated dilatation (FMD) and glyceryl trinitrate (GTN)-mediated-dilatation in the brachial artery, in 20 men with prostate cancer (69 ± 7 years old) treated by ADT (median duration 22 months, range 6-133 months) and 20 men without prostate cancer (69 ± 5 years old) matched for age, physical activity, coexistent cardiovascular disease and body mass index. The magnitude of dilatation was calculated traditionally and allometrically scaled, adjusting for baseline diameter. There were no differences between groups for resting vascular measures (means ± SD). Flow-mediated dilatation was lower in men on ADT than in control subjects (3.9 ± 2.1 versus 5.9 ± 3.8% for traditional

  9. Prognostic value of the pilocarpine test to identify patients who may obtain long-term relief from xerostomia by acupuncture treatment.

    PubMed

    Blom, M; Kopp, S; Lundeberg, T

    1999-05-01

    Xerostomia (dry mouth) is a clinical symptom due to a number of factors, including Sjögren syndrome and radiation treatment to the head and neck region. It has been reported that acupuncture increases the salivary flow rate (SFR) in healthy subjects and in patients with xerostomia. A prognostic tool that would allow the care provider to identify patients who may respond to acupuncture treatment will aid in early intervention and thus lead to normalized SFR or relief of symptoms. To determine the prognostic value of a test using pilocarpine chloride to identify those patients with xerostomia who may achieve a long-term increase in SFR in response to acupuncture. Cohort clinical study of 10 months' duration. School of dentistry in a large, urban, research institute. Thirty-two consecutive patients with xerostomia due to radiation treatment (n = 21) or Sjögren syndrome (n=11). Salivary flow rates for unstimulated whole saliva and paraffin-chewing stimulated whole saliva were measured before and after the administration of individualized doses of pilocarpine. All patients were then given 24 acupuncture treatments and followed up at 1 and 6 months. The effects of acupuncture treatment on SFR were recorded and response compared with the results of the pilocarpine test. Sensitivity, specificity, and positive and negative predictive value of the pilocarpine test based on changes in SFR, defined as a 20% increase or greater, following acupuncture treatment, compared with response to the pilocarpine test. At the 1-month follow-up, 18 (72%) of 25 patients with a positive pilocarpine test result had defined significant changes in SFR; 4 (67%) of 6 patients with a negative pilocarpine test result had an unchanged SFR. At this point, the sensitivity of the pilocarpine test was 0.90 (95% confidence interval [CI], 0.68-0.99) and the specificity was 0.36 (95% CI, 0.11-0.69). The positive predictive value was 0.72 (95% CI, 0.51-0.88), and the negative predictive value was 0.67 (95

  10. Normalizing rainfall/debris-flow thresholds along the U.S. Pacific coast for long-term variations in precipitation climate

    USGS Publications Warehouse

    Wilson, Raymond C.

    1997-01-01

    Broad-scale variations in long-term precipitation climate may influence rainfall/debris-flow threshold values along the U.S. Pacific coast, where both the mean annual precipitation (MAP) and the number of rainfall days (#RDs) are controlled by topography, distance from the coastline, and geographic latitude. Previous authors have proposed that rainfall thresholds are directly proportional to MAP, but this appears to hold only within limited areas (< 1?? latitude), where rainfall frequency (#RDs) is nearly constant. MAP-normalized thresholds underestimate the critical rainfall when applied to areas to the south, where the #RDs decrease, and overestimate threshold rainfall when applied to areas to the north, where the #RDs increase. For normalization between climates where both MAP and #RDs vary significantly, thresholds may best be described as multiples of the rainy-day normal, RDN = MAP/#RDs. Using data from several storms that triggered significant debris-flow activity in southern California, the San Francisco Bay region, and the Pacific Northwest, peak 24-hour rainfalls were plotted against RDN values, displaying a linear relationship with a lower bound at about 14 RDN. RDN ratios in this range may provide a threshold for broad-scale regional forecasting of debris-flow activity.

  11. The long-term effect of anti TNF-alpha treatment on temporomandibular joints, oral mucosa, and salivary flow in patients with active rheumatoid arthritis: a pilot study.

    PubMed

    Moen, Ketil; Kvalvik, Anne Grimstvedt; Hellem, Sølve; Jonsson, Roland; Brun, Johan G

    2005-10-01

    The objective of this study was to evaluate the long-term effects of anti-TNF-alpha treatment on temporomandibular joints (TMJs), oral mucosa, and salivary flow in RA. Seventeen patients received infusions of TNF-alpha blocking agents after 0, 2, and 6 weeks, and then every 8 weeks until week 54 (follow-up). Clinical dysfunction index (Di) for the TMJ system, salivary flow, disease activity score (DAS28), and other medical assessments were calculated at weeks 0 and 54. Median Di was 5.0 (range 0-21) at baseline and 1.0 (range 0-6) (P = .001) at follow-up. Mean salivary flow was 3.2 mL/15 minutes at baseline and 4.6 at follow-up (P = .055). Two (11.7%) of the patients developed oral candidiasis during the period of treatment. The median DAS28 was 6.2 (range, 4.7-7.7) at baseline and 4.1 (range, 1.6-6.8) at follow-up (P = .001). We conclude that anti-TNF-alpha blocking treatments have beneficial effects on oral as well as general manifestations of RA.

  12. The effect of short-term and long-term femoral artery ligation on rat calf muscle oxygen tension, blood flow, metabolism and function.

    PubMed

    Angersbach, D; Jukna, J J; Nicholson, C D; Ochlich, P; Wilke, R

    1988-01-01

    The effect of short-term (1 day-1 week) and long-term (6-12 weeks) femoral artery ligation on the oxygen tension (pO2), blood flow, metabolism and function of rat gastrocnemius muscle has been examined. Femoral artery ligation reduced resting blood flow, pO2 and pH. Concomitantly, the concentration of high energy phosphates was reduced and the muscle lactate concentration increased. The fatigue developed by the gastrocnemius/plantaris muscle, during a 10 min period of isometric exercise, was increased and the associated hyperaemia was attenuated. The surgery, performed to ligate the artery, induced an increase in the plasma fibrinogen concentration and whole blood viscosity. As the time interval increased after the femoral artery ligation there was a progressive reduction of the magnitude of the effects. Ten weeks after ligation resting muscle concentrations of high energy phosphates and lactate, whole blood viscosity and muscle pH had normalized. However, resting muscle blood flow, pO2, ability to sustained isometric exercise and the exercise induced hyperaemia were still reduced compared to intact animals. Comparison with literature data reveals that the changes produced by chronic femoral artery ligation in rat calf muscle mimic those seen in man with intermittent claudication.

  13. Rapid stress-testing vs. long-term aging: a case study of 980-nm emitting single-spatial mode lasers

    NASA Astrophysics Data System (ADS)

    Tomm, Jens W.; Hempel, Martin; Venables, David; Rossin, Victor; Zucker, Erik; Elsaesser, Thomas

    2016-03-01

    The degradation behaviors of 980-nm emitting nominally identical single-spatial mode lasers are studied during continuous wave long-term operation and during single-pulse stress tests. Both tests activate internal catastrophic optical damage as sudden degradation mechanism limiting the device lifetime. In case of high power stress-testing, the mechanism that initializes this effect is a spatial widening of the optical mode, resulting in increased absorption outside the waveguide. A similar disturbance to the optical mode is caused by defects that are generated during long-term operation. Thus two very different aging regimes eventually result in the same degradation scenario. We find that single-pulse stress-testing allows for activation of several degradation mechanisms in a device one after the other. Moreover, it becomes possible to distinguish between effects induced by gradual degradation and such that are independent on operation time. Thus stress-testing is considered a complementary tool, which might pave the way towards more economic device testing.

  14. The Role of Test Expectancy in the Build-Up of Proactive Interference in Long-Term Memory

    ERIC Educational Resources Information Center

    Weinstein, Yana; Gilmore, Adrian W.; Szpunar, Karl K.; McDermott, Kathleen B.

    2014-01-01

    We examined the hypothesis that interpolated testing in a multiple list paradigm protects against proactive interference by sustaining test expectancy during encoding. In both experiments, recall on the last of 5 word lists was compared between 4 conditions: a tested group who had taken tests on all previous lists, an untested group who had not…

  15. Long-term effects of stimulant exposure on cerebral blood flow response to methylphenidate and behavior in attention-deficit hyperactivity disorder.

    PubMed

    Schrantee, Anouk; Bouziane, C; Bron, E E; Klein, S; Bottelier, M A; Kooij, J J S; Rombouts, S A R B; Reneman, L

    2017-03-20

    Stimulant prescription rates for attention deficit hyperactivity disorder (ADHD) are increasing, even though potential long-term effects on the developing brain have not been well-studied. A previous randomized clinical trial showed short-term age-dependent effects of stimulants on the DA system. We here assessed the long-term modifying effects of age-of-first-stimulant treatment on the human brain and behavior. 81 male adult ADHD patients were stratified into three groups: 1) early stimulant treatment (EST; <16 years of age) 2) late stimulant treatment (LST: ≥23 years of age) and 3) stimulant treatment naive (STN; no history of stimulant treatment). We used pharmacological magnetic resonance imaging (phMRI) to assess the cerebral blood flow (CBF) response to an oral methylphenidate challenge (MPH, 0.5 mg/kg), as an indirect measure of dopamine function in fronto-striatal areas. In addition, mood and anxiety scores, and recreational drug use were assessed. Baseline ACC CBF was lower in the EST than the STN group (p = 0.03), although CBF response to MPH was similar between the three groups (p = 0.23). ADHD symptom severity was higher in the STN group compared to the other groups (p < 0.01). In addition, the EST group reported more depressive symptoms (p = 0.04), but not anxiety (p = 0.26), and less recreational drug use (p = 0.04). In line with extensive pre-clinical data, our data suggest that early, but not late, stimulant treatment long-lastingly affects the human brain and behavior, possibly indicating fundamental changes in the dopamine system.

  16. New Rapid Evaluation for Long-Term Behavior in Deep Geological Repository by Geotechnical Centrifuge—Part 2: Numerical Simulation of Model Tests in Isothermal Condition

    NASA Astrophysics Data System (ADS)

    Sawada, Masataka; Nishimoto, Soshi; Okada, Tetsuji

    2017-01-01

    In high-level radioactive waste disposal repositories, there are long-term complex thermal, hydraulic, and mechanical (T-H-M) phenomena that involve the generation of heat from the waste, the infiltration of ground water, and swelling of the bentonite buffer. The ability to model such coupled phenomena is of particular importance to the repository design and assessments of its safety. We have developed a T-H-M-coupled analysis program that evaluates the long-term behavior around the repository (called "near-field"). We have also conducted centrifugal model tests that model the long-term T-H-M-coupled behavior in the near-field. In this study, we conduct H-M-coupled numerical simulations of the centrifugal near-field model tests. We compare numerical results with each other and with results obtained from the centrifugal model tests. From the comparison, we deduce that: (1) in the numerical simulation, water infiltration in the rock mass was in agreement with the experimental observation. (2) The constant-stress boundary condition in the centrifugal model tests may cause a larger expansion of the rock mass than in the in situ condition, but the mechanical boundary condition did not affect the buffer behavior in the deposition hole. (3) The numerical simulation broadly reproduced the measured bentonite pressure and the overpack displacement, but did not reproduce the decreasing trend of the bentonite pressure after 100 equivalent years. This indicates the effect of the time-dependent characteristics of the surrounding rock mass. Further investigations are needed to determine the effect of initial heterogeneity in the deposition hole and the time-dependent behavior of the surrounding rock mass.

  17. Interlaboratory Evaluation of Hyalella Azteca and Chironomus Tentans Short-term and Long-term Sediment Toxicity Tests

    EPA Science Inventory

    This paper presents the results of interlaboratory toxicity tests on sediment toxicity methods for use in routine testing and this data has been presented in an EPA report and this is a summary of that data.

  18. Interlaboratory Evaluation of Hyalella Azteca and Chironomus Tentans Short-term and Long-term Sediment Toxicity Tests

    EPA Science Inventory

    This paper presents the results of interlaboratory toxicity tests on sediment toxicity methods for use in routine testing and this data has been presented in an EPA report and this is a summary of that data.

  19. Test Methodology Development for Experimental Structural Assessment of ASC Planar Spring Material for Long-Term Durability

    NASA Technical Reports Server (NTRS)

    Yun, Gunjin; Abdullah, A. B. M.; Binienda, Wieslaw; Krause, David L.; Kalluri, Sreeramesh

    2014-01-01

    A vibration-based testing methodology has been developed that will assess fatigue behavior of the metallic material of construction for the Advanced Stirling Convertor displacer (planar) spring component. To minimize the testing duration, the test setup is designed for base-excitation of a multiplespecimen arrangement, driven in a high-frequency resonant mode; this allows completion of fatigue testing in an accelerated period. A high performance electro-dynamic exciter (shaker) is used to generate harmonic oscillation of cantilever beam specimens, which are clasped on the shaker armature with specially-designed clamp fixtures. The shaker operates in closed-loop control with dynamic specimen response feedback provided by a scanning laser vibrometer. A test coordinator function synchronizes the shaker controller and the laser vibrometer to complete the closed-loop scheme. The test coordinator also monitors structural health of the test specimens throughout the test period, recognizing any change in specimen dynamic behavior. As this may be due to fatigue crack initiation, the test coordinator terminates test progression and then acquires test data in an orderly manner. Design of the specimen and fixture geometry was completed by finite element analysis such that peak stress does not occur at the clamping fixture attachment points. Experimental stress evaluation was conducted to verify the specimen stress predictions. A successful application of the experimental methodology was demonstrated by validation tests with carbon steel specimens subjected to fully-reversed bending stress; high-cycle fatigue failures were induced in such specimens using higher-than-prototypical stresses

  20. Scheduling viability tests for seeds in long-term storage based on a Bayesian Multi-Level Model

    USDA-ARS?s Scientific Manuscript database

    Genebank managers conduct viability tests on stored seeds so they can replace lots that have viability near a critical threshold, such as 50 or 85% germination. Currently, these tests are typically scheduled at uniform intervals; testing every 5 years is common. A manager needs to balance the cost...

  1. Midterm and long-term follow-up of cerebral aneurysms treated with flow diverter devices: a single-center experience.

    PubMed

    Piano, Mariangela; Valvassori, Luca; Quilici, Luca; Pero, Guglielmo; Boccardi, Edoardo

    2013-02-01

    The introduction of flow diverter devices is revolutionizing the endovascular approach to cerebral aneurysms. Midterm and long-term results of angiographic, cross-sectional imaging and clinical follow-up are still lacking. The authors report their experience with endovascular treatment of intracranial aneurysms using both the Pipeline embolization device and Silk stents. From October 2008 to July 2011 a consecutive series of 104 intracranial aneurysms in 101 patients (79 female, 22 male; average age 53 years) were treated. Three of the 104 aneurysms were ruptured and 101 were unruptured. Silk stents were implanted in 47 of the aneurysms and Pipeline stents in the remaining 57. In 14 cases a combination of flow diverter devices and coils were used to treat larger aneurysms (maximum diameter > 15 mm). Patients underwent angiographic follow-up examination at 6 months after treatment, with or without CT or MRI, and at 1 year using CT or MRI, with or without conventional angiography. In all cases placement of flow diverter stents was technically successful. The mortality and morbidity rates were both 3%. Adverse events without lasting clinical sequelae occurred in 20% of cases. Angiography performed at 6 months after treatment showed complete aneurysm occlusion in 78 of 91 cases (86% of evaluated aneurysms) and subocclusion in 11 (12%); only in 2 cases were the aneurysms unchanged. Fifty-three aneurysms were evaluated at 1 year after treatment. None of these aneurysms showed recanalization, and 1 aneurysm, which was incompletely occluded at the 6-month follow-up examination, was finally occluded. Aneurysmal sac shrinkage was observed in 61% of assessable aneurysms. Parent artery reconstruction using flow diverter devices is a feasible, safe, and successful technique for the treatment of endovascular treatment of cerebral aneurysms.

  2. [The Brumory test, an incidental long-term memory task designed for foreign, non-French-speaking people with low educational level].

    PubMed

    Vanderaspoilden, V; Nury, D; Frisque, J; Peigneux, P

    2015-12-01

    Cognitive assessment among foreign patients is a growing need for several reasons: foreign patients have a different culture, they have an insufficient command of the language of the consulting center, and the available cognitive tools are largely unsuitable. For these reasons, we developed a non-verbal test of long-term memory called the Brumory test. This test is based on incident encoding of 48 colored images followed by retrieval by recognition. We compared the performance of indigenous participants with that of immigrant participants (mainly from Morocco). Immigrant participants did not speak French properly and had a low educational level. The results indicate no significant difference in memory performance between the two groups of participants. Moreover, the instructions were easily understood by immigrant participants, despite the fact they do not master French. We conclude that the Brumory test is an appropriate test to assess memory among foreign non-French-speaking patients people with low educational level.

  3. Effect of long-term exposure of 2.4 GHz radiofrequency radiation emitted from Wi-Fi equipment on testes functions.

    PubMed

    Dasdag, Suleyman; Taş, Muzaffer; Akdag, Mehmet Zulkuf; Yegin, Korkut

    2015-03-01

    The aim of this study was to investigate long-term effects of radiofrequency radiation (RFR) emitted from a Wireless Fidelity (Wi-Fi) system on testes. The study was carried out on 16 Wistar Albino adult male rats by dividing them into two groups such as sham (n: 8) and exposure (n: 8). Rats in the exposure group were exposed to 2.4 GHz RFR radiation for 24 h/d during 12 months (1 year). The same procedure was applied to the rats in the sham control group except the Wi-Fi system was turned off. Immediately after the last exposure, rats were sacrificed and reproductive organs were removed. Motility (%), concentration (×10(6)/mL), tail defects (%), head defects (%) and total morphologic defects (%) of sperms and weight of testes (g), left epididymis (g), prostate (g), seminal vesicles (g) were determined. Seminiferous tubules diameter (μm) and tunica albuginea thickness (μm) were also measured. However, the results were evaluated by using Johnsen's score. Head defects increased in the exposure group (p < 0.05) while weight of the epididymis and seminal vesicles, seminiferous tubules diameter and tunica albuginea thickness were decreased in the exposure group (p < 0.01, p < 0.001, p < 0.0001). However, other alterations of other parameters were not found significant (p > 0.05). In conclusion, we observed that long-term exposure of 2.4 GHz RF emitted from Wi-Fi (2420 μW/kg, 1 g average) affects some of the reproductive parameters of male rats. We suggest Wi-Fi users to avoid long-term exposure of RF emissions from Wi-Fi equipment.

  4. Sperm characteristics and ultrastructure of testes of rats after long-term treatment with the methanol subfraction of Carica papaya seeds

    PubMed Central

    Manivannan, Boomi; Mittal, Ruchi; Goyal, Shipra; Ansari, Abdul S.; Lohiya, Nirmal K.

    2009-01-01

    The contraceptive efficacy of Carica papaya seeds after short-term evaluation has been well established. We have examined the safety and mechanism of contraception in rats after long-term treatment with the methanol subfraction (MSF) of C. papaya seeds. The test substance was administered orally to the male albino rats (n = 40) at 50 mg per kg body weight each day for 360 days. Control animals (n = 40) received olive oil as a vehicle. Recovery was assessed up to 120 days after treatment withdrawal. Sperm parameters, serum testosterone levels, fertility, histology and ultrastructure of the testis, haematology and serum clinical chemistry were evaluated to establish the safety and efficacy of the test substance. Safety of long-term treatment was evidenced by unaltered health status, organ weight, haematology and clinical chemistry, and by an increase in body weight. The mechanism of contraception was shown by reduction in nuclear and cytoplasmic volume, normal nuclear characteristics and vacuolization in the cytoplasmic organelles of the Sertoli cells, as well as nuclear degeneration in spermatocytes and spermatids indicating disturbed spermatogenesis. Leydig cells were normal. Initial effects were observed in Sertoli cells at 60 days of treatment. Spermatocytes and spermatids were affected after 120–240 days of treatment. A significant decline in sperm count and viability, total inhibition of sperm motility, increased numbers of sperm abnormalities, normal serum testosterone levels and 100% sterility were evident after 60 days of treatment. All the altered parameters, including percent fertility, were restored to control level 120 days after treatment withdrawal. It is concluded that the MSF is safe for long-term treatment and the mechanism of contraception is shown by its effect on spermatid differentiation in the testis, possibly mediated by the Sertoli cell factors. PMID:19648937

  5. Test-retest reliability of a new questionnaire for the retrospective assessment of long-term lithium use in bipolar disorder.

    PubMed

    Tighe, Sarah K; Ritchey, Megan; Schweizer, Barbara; Goes, Fernando S; MacKinnon, Dean; Mondimore, Francis; Raymond DePaulo, J; McMahon, Francis J; Schulze, Thomas G; Zandi, Peter P; Potash, James B

    2015-03-15

    The identification of predictors of treatment response holds tremendous potential for the improvement of clinical outcomes in bipolar disorder (BP). The goal of this project is to evaluate the test-retest reliability of a new clinical tool, the Lithium Questionnaire (LQ), for the retrospective assessment of long-term lithium use in research participants with BP. Twenty-nine individuals with BP-I (n=27), major depression (n=1), or schizoaffective disorder (n=1) were recruited for participation. The LQ was administered to all participants at two time-points, spaced 17 months apart on average, and used to determine each subject׳s score on the Retrospective Criteria of Long-Term Treatment Response in Research Subjects with Bipolar Disorder Scale, or the Alda Scale. Scores were confirmed through a best-estimate procedure, and test-retest reliability (intra-class correlation coefficient [ICC]) of the LQ was calculated. The correlation between the total Alda Scale scores at the two time-points was in the moderate range (ICC=0.60). Relevant clinical factors such as age or presence of Axis I psychiatric comorbidity did not influence the reliability. The validity of the LQ was not examined. Inclusion of two participants with non-BP diagnoses may have affected the LQ׳s reliability, but re-analysis of our data after exclusion of these participants did not influence the reliability. The absence of measures of mood and cognition at time of LQ may be a limitation of this work. The LQ holds promise for the standardization of the retrospective assessment of long-term treatment in BP. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Solute transport processes in a karst vadose zone characterized by long-term tracer tests (the cave system of Postojnska Jama, Slovenia)

    NASA Astrophysics Data System (ADS)

    Kogovsek, Janja; Petric, Metka

    2014-11-01

    The processes influencing the solute transport in the karst vadose zone were studied by long-term tracer tests with artificial tracers. The results of three successive tracer tests with different modes of injection were compared. Tracer breakthrough curves were monitored at three drips of different hydrological types inside one of the cave galleries of the system of Postojnska Jama over several years. Comparison of the results indicates the highly significant influence of preceding hydrological conditions (dry vs wet), injection mode (artificial flushing vs natural infiltration by subsequent rainfall, and on a bare rock vs on an overlying layer) and geologic heterogeneities within the vadose zone on solute transport in the karst vadose zone. Injection with artificial flushing resulted in rapid infiltration and the tracer traversed almost one hundred meters of bedrock in hours. However, the majority of tracer can be stored within less permeable parts of the vadose zone and then gradually flushed out after additional abundant and intensive precipitation in the period of several years. Long-continued sampling in each of the tests proved to be important for reliable characterization of the long-term solute transport dynamics.

  7. Long Term Performance Retention Test Using High Power COTS NiCd and NiMH Cells

    NASA Technical Reports Server (NTRS)

    Hall, Dan; Darcy, Eric; Strangways, Brad; Nelson, Tim

    2003-01-01

    This slide presentation reviews the tests and results for performance retention of high powered commercial off the shelf (COTS) NiCd, and NiMH cells. Electromechanical actuators for space flight requires short duration high power batteries. The concern is that NiCd battery designs demonstrate an unfavorable power degradation after long periods of inactivity. Cycling can recover some of the decay, but this reduces the readiness that these batteries must have. Two 5-cell SubC stick test batteries ere chosen using NiCd and NiMH were tested and then the differences for charge maintenance were compared.

  8. The effects of prolonged administration of norepinephrine reuptake inhibitors on long-term potentiation in dentate gyrus, and on tests of spatial and object recognition memory in rats.

    PubMed

    Walling, Susan G; Milway, J Stephen; Ingram, Matthew; Lau, Catherine; Morrison, Gillian; Martin, Gerard M

    2016-02-01

    Phasic norepinephrine (NE) release events are involved in arousal, novelty detection and in plasticity processes underlying learning and memory in mammalian systems. Although the effects of phasic NE release events on plasticity and memory are prevalently documented, it is less understood what effects chronic NE reuptake inhibition and sustained increases in noradrenergic tone, might have on plasticity and cognitive processes in rodent models of learning and memory. This study investigates the effects of chronic NE reuptake inhibition on hippocampal plasticity and memory in rats. Rats were administered NE reuptake inhibitors (NRIs) desipramine (DMI; 0, 3, or 7.5mg/kg/day) or nortriptyline (NTP; 0, 10 or 20mg/kg/day) in drinking water. Long-term potentiation (LTP; 200 Hz) of the perforant path-dentate gyrus evoked potential was examined in urethane anesthetized rats after 30-32 days of DMI treatment. Short- (4-h) and long-term (24-h) spatial memory was tested in separate rats administered 0 or 7.5mg/kg/day DMI (25-30 days) using a two-trial spatial memory test. Additionally, the effects of chronically administered DMI and NTP were tested in rats using a two-trial, Object Recognition Test (ORT) at 2- and 24-h after 45 and 60 days of drug administration. Rats administered 3 or 7.5mg/kg/day DMI had attenuated LTP of the EPSP slope but not the population spike at the perforant path-dentate gyrus synapse. Short- and long-term memory for objects is differentially disrupted in rats after prolonged administration of DMI and NTP. Rats that were administered 7.5mg/kg/day DMI showed decreased memory for a two-trial spatial task when tested at 4-h. In the novel ORT, rats receiving 0 or 7.5mg/kg/day DMI showed a preference for the arm containing a Novel object when tested at both 2- and 24-h demonstrating both short- and long-term memory retention of the Familiar object. Rats that received either dose of NTP or 3mg/kg/day DMI showed impaired memory at 2-h, however this

  9. Extending periodic eddy covariance latent heat fluxes through tree sap-flow measurements to estimate long-term total evaporation in a peat swamp forest

    NASA Astrophysics Data System (ADS)

    Clulow, A. D.; Everson, C. S.; Mengistu, M. G.; Price, J. S.; Nickless, A.; Jewitt, G. P. W.

    2015-05-01

    A combination of measurement and modelling was used to find a pragmatic solution to estimate the annual total evaporation from the rare and indigenous Nkazana Peat Swamp Forest (PSF) on the east coast of Southern Africa to improve the water balance estimates within the area. Actual total evaporation (ETa) was measured during three window periods (between 7 and 9 days each) using an eddy covariance (EC) system on a telescopic mast above the forest canopy. Sap flows of an understory tree and an emergent tree were measured using a low-maintenance heat pulse velocity system for an entire hydrological year (October 2009 to September 2010). An empirical model was derived, describing the relationship between ETa from the Nkazana PSF and sap-flow measurements. These overlapped during two of the window periods (R2 = 0.92 and 0.90), providing hourly estimates of ETa from the Nkazana PSF for a year, totalling 1125 mm (while rainfall was 650 mm). In building the empirical model, it was found that to include the understory tree sap flow provided no benefit to the model performance. In addition, the relationship between the emergent tree sap flow with ETa between the two field campaigns was consistent and could be represented by a single empirical model (R2 = 0.90; RMSE = 0.08 mm h-1). During the window periods of EC measurement, no single meteorological variable was found to describe the Nkazana PSF ETa satisfactorily. However, in terms of evaporation models, the hourly FAO Penman-Monteith reference evaporation (ETo) best described ETa during the August 2009 (R2 = 0.75), November 2009 (R2 = 0.85) and March 2010 (R2 = 0.76) field campaigns, compared to the Priestley-Taylor potential evaporation (ETp) model (R2 = 0.54, 0.74 and 0.62 during the respective field campaigns). From the extended record of ETa (derived in this study from sap flow) and ETo, a monthly crop factor (Kc) was derived for the Nkazana PSF, providing a method of estimating long-term swamp forest water-use from

  10. Techniques for control of long-term reliability of complex integrated circuits. I - Reliability assurance by test vehicle qualification.

    NASA Technical Reports Server (NTRS)

    Van Vonno, N. W.

    1972-01-01

    Development of an alternate approach to the conventional methods of reliability assurance for large-scale integrated circuits. The product treated is a large-scale T squared L array designed for space applications. The concept used is that of qualification of product by evaluation of the basic processing used in fabricating the product, providing an insight into its potential reliability. Test vehicles are described which enable evaluation of device characteristics, surface condition, and various parameters of the two-level metallization system used. Evaluation of these test vehicles is performed on a lot qualification basis, with the lot consisting of one wafer. Assembled test vehicles are evaluated by high temperature stress at 300 C for short time durations. Stressing at these temperatures provides a rapid method of evaluation and permits a go/no go decision to be made on the wafer lot in a timely fashion.

  11. Long-Term Immersion Testing of Alloy 22 and Titanium Grade 7 Double U-bend Specimens

    SciTech Connect

    Evans, K J; Stuart, M L; Hailey, P D; Rebak, R B

    2007-02-08

    Double U-bend specimens of Alloy 22 (N06022) and Titanium Grade 7 (R52400) were exposed to a naturally aerated concentrated Basic Saturated Water (BSW) electrolyte at 105 C for over six years. Different type of discoloration of the Ti Gr 7 and Alloy 22 specimens was observed. General Corrosion was minimal and not distinguishable under a scanning electron microscope. None of the tested specimens suffered environmentally assisted cracking (EAC) or localized corrosion under the tested conditions. The specimens retained their residual stress after the long environmental exposure.

  12. Mid- and long-term anxiety levels associated with presymptomatic testing of Huntington's disease, Machado-Joseph disease, and familial amyloid polyneuropathy.

    PubMed

    Lêdo, Susana; Leite, Ângela; Souto, Teresa; Dinis, Maria A; Sequeiros, Jorge

    2016-02-05

    To study anxiety as a variable of the mid- and long-term psychological impact of pre-symptomatic testing for three autosomal dominant late-onset disorders - Huntington's disease (HD), Machado-Joseph disease (MJD) and familial amyloid polyneuropathy (FAP) TTR V30M - in a Portuguese sample. This cross-sectional study included 203 participants: 170 (83.7%) underwent pre-symptomatic testing for FAP, 29 (14.3%) for HD, and 4 (2%) for MJD. Of the 203 participants, 73 (36.0%) were asymptomatic carriers, 29 (14.5%) were symptomatic carriers, 9 (4.5%) were diagnosed with FAP and had a liver transplant, and 89 (44.5%) were non-carriers. Most were women (58.1%) and married (66.5%). The anxiety variable was assessed using the Zung Self-Rating Anxiety Scale (SAS). The anxiety scores were higher for symptomatic carriers and for those who underwent psychological support consultations over the years. For symptomatic carriers, the mean scores were superior to 40 points, which reflects clinical anxiety. Although it was not possible to differentiate between the mid- and long-term psychological impacts, this study supports the conclusion that the proximity to the age of symptoms onset might be a trigger for anxiety.

  13. Assessment of dynamic and long-term performance of an innovative multi-story timber building via structural monitoring and dynamic testing

    NASA Astrophysics Data System (ADS)

    Omenzetter, Piotr; Morris, Hugh; Worth, Margaret; Gaul, Andrew; Jager, Simon; Desgeorges, Yohann

    2012-04-01

    An innovative three-story timber building, using self-centering, post-tensioned timber shear walls as the main horizontal load resisting system and lightweight non-composite timber-concrete floors, has recently been completed in Nelson, New Zealand. It is expected to be the trailblazer for similar but taller structures to be more widely adopted. Performance based standards require an advanced understanding of building responses and in order to meet the need for in-situ performance data the building has been subjected to forced vibration testing and instrumented for continuous monitoring using a total of approximately 90 data channels to capture its dynamic and long-term responses. The first part of the paper presents a brief discussion of the existing research on the seismic performance of timber frame buildings and footfall induced floor vibrations. An outline of the building structural system, focusing on the novel design solutions, is then discussed. This is followed by the description of the monitoring system. The analysis of monitoring results starts with a discussion of the monitoring of long-term deformations. Next, the assessment of the floor vibration serviceability performance is outlined. Then, the forced vibration tests conducted on the whole building at different construction stages are reviewed. The system identification results from seismic shaking records are also discussed. Finally, updating of a finite element model of the building is conducted.

  14. Long-term high-velocity oxidation and hot corrosion testing of several NiCrAl and FeCrAl base oxide dispersion strengthened alloys

    NASA Technical Reports Server (NTRS)

    Lowell, C. E.; Deadmore, D. L.; Whittenberger, J. D.

    1982-01-01

    Several oxide dispersion strengthened (ODS) alloys have been tested for cyclic, long-term, high gas-velocity resistance to oxidation at 1100 C and hot corrosion at 900 C. Both nominally Ni-16Cr-4Al and Fe-20Cr-4.5Al ODS alloys were subjected up to about 2500 cycles, where each cycle consisted of 1 hr in a hot, Mach 0.3 combusted gas stream followed by a 3-min quench in an ambient temperature, Mach 0.3 air blast. For comparison to existing technology, a coated superalloy was simultaneously tested. The ODS iron alloy exhibited clearly superior behavior, surviving 3800 oxidation and 2300 hot corrosion cycles essentially unscathed. While the ODS nickel alloys exhibited adequate oxidation resistance, the long-term hot corrosion resistance could be marginal, since the best life for such alloys under these conditions was only about 1100 cycles. However, the hot corrosion resistance of the ODS Ni-base alloys is excellent in comparison to that of traditional superalloys.

  15. Long-term high-velocity oxidation and hot corrosion testing of several NiCrAl and FeCrAl base oxide dispersion strengthened alloys

    NASA Technical Reports Server (NTRS)

    Lowell, C. E.; Deadmore, D. L.; Whittenberger, J. D.

    1982-01-01

    Several oxide dispersion strengthened (ODS) alloys have been tested for cyclic, long-term, high gas-velocity resistance to oxidation at 1100 C and hot corrosion at 900 C. Both nominally Ni-16Cr-4Al and Fe-20Cr-4.5Al ODS alloys were subjected up to about 2500 cycles, where each cycle consisted of 1 hr in a hot, Mach 0.3 combusted gas stream followed by a 3-min quench in an ambient temperature, Mach 0.3 air blast. For comparison to existing technology, a coated superalloy was simultaneously tested. The ODS iron alloy exhibited clearly superior behavior, surviving 3800 oxidation and 2300 hot corrosion cycles essentially unscathed. While the ODS nickel alloys exhibited adequate oxidation resistance, the long-term hot corrosion resistance could be marginal, since the best life for such alloys under these conditions was only about 1100 cycles. However, the hot corrosion resistance of the ODS Ni-base alloys is excellent in comparison to that of traditional superalloys.

  16. Long term out-of-pile thermocouple tests in conditions representative for nuclear gas-cooled high temperature reactors

    SciTech Connect

    Laurie, M.; Fourrez, S.; Fuetterer, M. A.; Lapetite, J. M.

    2011-07-01

    During irradiation tests at high temperature, failure of commercial Inconel 600 sheathed thermocouples is commonly encountered. To understand and remedy this problem, out-of-pile tests were performed with thermocouples in carburizing atmospheres which can be assumed to be at least locally representative for High Temperature Reactors. The objective was to screen those thermocouples which would consecutively be used under irradiation. Two such screening tests have been performed with a set of thermocouples embedded in graphite (mainly conventional Type N thermocouples and thermocouples with innovative sheaths) in a dedicated furnace with helium flushing. Performance indicators such as thermal drift, insulation and loop resistance were monitored and compared to those from conventional Type N thermocouples. Several parameters were investigated: niobium sleeves, bending, thickness, sheath composition, temperature as well as the chemical environment. After the tests, Scanning Electron Microscopy (SEM) examinations were performed to analyze possible local damage in wires and in the sheath. The present paper describes the two experiments, summarizes results and outlines further work, in particular to further analyze the findings and to select suitable thermocouples for qualification under irradiation. (authors)

  17. Final report: Long Term Test of a Gear-Type Pump for the Am/Cm Project

    SciTech Connect

    Duignan, M.R.

    1998-04-01

    At the request of the Immobilization Technology section, the Experimental Thermal Fluids group carried out a test to determine the operational characteristics of a gear-type pump. This pump was under consideration as a replacement for the air-lift melter feed pumping system of the Americium and Curium Project.

  18. Urine drug testing results and paired oral fluid comparison from patients enrolled in long-term medication-assisted treatment in Tennessee.

    PubMed

    Miller, Katie L; Puet, Brandi L; Roberts, Ali; Hild, Cheryl; Carter, Jason; Black, David L

    2017-05-01

    Urine drug testing is recommended for individuals receiving medication-assisted treatment. It provides objective information for practitioners to consider and may serve as a protective factor against drug-related mortality. The primary objective of our study was to describe urine drug testing results for patients undergoing long-term medication-assisted treatment (≥6months). The secondary objective was to provide further evidence to establish oral fluid as a reliable alternative to urine. All subjects (n=639) included in the study were enrolled in one of five treatment centers in the state of Tennessee, and all urine specimens were positive for either methadone or buprenorphine. Nicotine (87%), caffeine (70%), marijuana (15%), alcohol (14%) and gabapentin (10%) were the most prevalent substances identified through urine drug testing. The presence of non-maintenance opioids (prescription and/or heroin) may represent relapse; these drugs were present in 10% of specimens tested. Evidence of illicit drug use (cocaine, heroin, marijuana and/or methamphetamine) was detected in 19% specimens. For 126 of the 639 subjects included in the study, paired oral fluid and urine test results were compared for agreement. Of the total paired urine and oral fluid tests, approximately 7% were positive for a drug in both specimen types and 91% were negative in both, resulting in an overall agreement of 98%. The study demonstrates continued use of illicit and commercially available medications in a medication-assisted treatment population undergoing long-term treatment. The results affirm the reliability of oral fluid as an alternative specimen type for compliance testing in this population. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. A statistically compiled test battery for feasible evaluation of knee function after rupture of the Anterior Cruciate Ligament - derived from long-term follow-up data.

    PubMed

    Schelin, Lina; Tengman, Eva; Ryden, Patrik; Häger, Charlotte

    2017-01-01

    Clinical test batteries for evaluation of knee function after injury to the Anterior Cruciate Ligament (ACL) should be valid and feasible, while reliably capturing the outcome of rehabilitation. There is currently a lack of consensus as to which of the many available assessment tools for knee function that should be included. The present aim was to use a statistical approach to investigate the contribution of frequently used tests to avoid redundancy, and filter them down to a proposed comprehensive and yet feasible test battery for long-term evaluation after ACL injury. In total 48 outcome variables related to knee function, all potentially relevant for a long-term follow-up, were included from a cross-sectional study where 70 ACL-injured (17-28 years post injury) individuals were compared to 33 controls. Cluster analysis and logistic regression were used to group variables and identify an optimal test battery, from which a summarized estimator of knee function representing various functional aspects was derived. As expected, several variables were strongly correlated, and the variables also fell into logical clusters with higher within-correlation (max ρ = 0.61) than between clusters (max ρ = 0.19). An extracted test battery with just four variables assessing one-leg balance, isokinetic knee extension strength and hop performance (one-leg hop, side hop) were mathematically combined to an estimator of knee function, which acceptably classified ACL-injured individuals and controls. This estimator, derived from objective measures, correlated significantly with self-reported function, e.g. Lysholm score (ρ = 0.66; p<0.001). The proposed test battery, based on a solid statistical approach, includes assessments which are all clinically feasible, while also covering complementary aspects of knee function. Similar test batteries could be determined for earlier phases of ACL rehabilitation or to enable longitudinal monitoring. Such developments, established on a well

  20. Copper release kinetics from a long-term contaminated acid soil using a stirred flow chamber: effect of ionic strength and pH.

    PubMed

    Fernández-Calviño, David; Bermúdez-Couso, Alipio; Garrido-Rodríguez, Beatriz; Peña Rodríguez, Susana; Arias-Estévez, Manuel

    2012-02-01

    The effect of pH and ionic strength on copper release in a long-term Cu-polluted soil was studied using a stirred flow chamber. The presence of Ca(2+) and Na(+) was also evaluated. More copper was released as the ionic strength increased, and it was significantly higher in the presence of Ca(2+) than in the presence of Na(+). The maximum amount of Cu that could be released under experimental conditions increased logarithmically as the ionic strength increased, and the release rate parameters were not significantly correlated with ionic strength values. The maximum amount of Cu that could be released was similar for solutions with pH values between 5.5 and 8.5. For solutions with a pH value below 4.5, the amount of Cu released increased exponentially as the pH decreased. The release rate parameters and Cu release pattern were affected by pH, especially for more acidic solutions (pH values of 2.5 and 3.5).

  1. Long-term measurement of stream flow and salinity in a tidal river by the use of the fluvial acoustic tomography system

    NASA Astrophysics Data System (ADS)

    Kawanisi, Kiyosi; Razaz, Mahdi; Kaneko, Arata; Watanabe, Satoshi

    2010-01-01

    SummaryLong-term variation of stream flow of a tidal river was measured by an innovative technology, called the fluvial acoustic tomography (FAT). The reciprocal sound transmission was performed between two acoustic stations, located on both sides of the river. Even in the tidal river with the periodic intrusion of salt wedges, the cross-sectional average velocities along the river stream axis, estimated from the travel time difference data, were consistent with the average velocities, observed by an array of moored downward-looking ADCPs. The cross-sectional average salinity was also estimated by using the mean travel time data collected from the reciprocal sound transmission, the mean values of temperature measured by the conductivity-temperature ( C- T) sensors, and the ray simulation result. The derived salinity data from the FAT are comparable with that obtained by the C- T sensors. It is concluded that the fluvial acoustic tomography (FAT) is a prospective method for the continuous monitoring of tidal river discharge and temperature/salinity variations.

  2. Realizing the cognitive potential of children 5-7 with a mathematics focus: post-test and long-term effects of a 2-year intervention.

    PubMed

    Shayer, Michael; Adhami, Mundher

    2010-09-01

    In the context of the British Government's policy directed on improving standards in schools, this paper presents research on the effects of a programme intended to promote the cognitive development of children in the first 2 years of primary school (Y1 & 2, aged 5-7 years). The programme is based on earlier work dealing with classroom-based interventions with older children at both primary and secondary levels of schooling. The hypothesis tested is that it is possible to increase the cognitive ability of children by assisting teachers towards that aim in the context of mathematics. A corollary hypothesis is that such an increase would result in an increase in long-term school achievement. The participants were 8 teachers in one local education authority (LEA) and 10 teachers in another. Data were analysed on 275 children present at Year 1 pre-test in 2002 and at long-term Key Stage 2 post-test in 2008. Two intervention methods were employed: a Y1 set of interactive activities designed around Piagetian concrete operational schemata, and mathematics lessons in both Y1 and Y2 designed from a theory-base derived from both Piaget and Vygotsky. At post-test in 2004, the mean effect sizes for cognitive development of the children - assessed by the Piagetian test Spatial Relations - were 0.71 SD in one LEA and 0.60 SD in the other. Five classes achieved a median increase of 1.3 SD. The mean gains over pre-test in 2002 for all children in Key Stage 1 English in 2004 were 0.51 SD, and at Key Stage 2 English in 2008 - the long-term effect - were 0.36 SD, an improvement of 14 percentile points. The main hypothesis was supported by the data on cognitive development. The corollary hypothesis is supported by the gains in English. The implications of this study are that relative intelligence can be increased and is not fixed, and that children can be led into collaborating with each other to the benefit of their own thinking, and that there does exist a theory-based methodology

  3. Assessing long-term effects of eslicarbazepine acetate on lipid metabolism profile, sodium values and liver function tests.

    PubMed

    Ley, M; Principe, A; Jiménez-Conde, J; Rocamora, R

    2015-09-01

    Older dibenzazepines with a carboxamide substitution have been demonstrated to cause deleterious effects on lipid metabolism profile, as well as frequent hyponatremia. The aim of our study is to assess the effects of eslicarbazepine acetate, a novel AED, on lipid metabolism profile, sodium values and liver function tests, as well as to compare them with previous effects of carbamazepine and oxcarbazepine. This report describes a retrospective cohort study of 108 patients who were treated with eslicarbazepine. Of these patients, 52% had switched to eslicarbazepine from prior treatment with carbamazepine or oxcarbazepine. Laboratory values concerning lipid metabolism profile, liver function tests and sodium were assessed before and after beginning/switching treatment. Patients who began treatment or whose treatment for dyslipidemia was modified during the study period were excluded from the analysis. Co-medications that could impact lipid metabolism profile, sodium or hepatic function were kept stable during the study period. The mean total cholesterol of the entire group decreased significantly from prior pathological to normal values after beginning/switching treatment. The percentage of patients with pathological values decreased. Patients switching from prior carboxamides also showed significant reductions in mean LDL and triglycerides. Patients beginning treatment without prior carboxamides did not develop dyslipidemia after titration. A tendency for an increased percentage of patients with hyponatremia was detected in both groups. Compared with older carboxamides, eslicarbazepine acetate exhibits a safer profile related to lipid metabolism. No relevant changes were detected in liver function tests. Consequently, a vascular risk factor could be avoided in patients with chronic epilepsy, while hyponatremia still needs to be ruled out. Prospective studies are still needed. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Potential for Local Fertilization: A Benthocosm Test of Long-Term and Short-Term Effects of Mussel Excretion on the Plankton

    PubMed Central

    Granados, Monica; Duffy, Sean; Robert, Pauline; Péquin, Bérangère; Mohit, Vani; McKindsey, Christopher W.; Archambault, Philippe; Myrand, Bruno; Lovejoy, Connie; Tremblay, Réjean; Plourde, Stéphane; Fussmann, Gregor F.

    2016-01-01

    Mussel aquaculture has expanded worldwide and it is important to assess its impact on the water column and the planktonic food web to determine the sustainability of farming practices. Mussel farming may affect the planktonic food web indirectly by excreting bioavailable nutrients in the water column (a short-term effect) or by increasing nutrient effluxes from biodeposit-enriched sediments (a long-term effect). We tested both of these indirect effects in a lagoon by using plankton-enclosing benthocosms that were placed on the bottom of a shallow lagoon either inside of a mussel farm or at reference sites with no history of aquaculture. At each site, half of the benthocosms were enriched with seawater that had held mussels (excretion treatment), the other half received non-enriched seawater as a control treatment. We monitored nutrients ([PO43-] and [NH4+]), dissolved oxygen and plankton components (bacteria, the phytoplankton and the zooplankton) over 5 days. We found a significant relationship between long-term accumulation of mussel biodeposits in sediments, water-column nutrient concentrations and plankton growth. Effects of mussel excretion were not detected, too weak to be significant given the spatial and temporal variability observed in the lagoon. Effects of mussels on the water column are thus likely to be coupled to benthic processes in such semi-enclosed water bodies. PMID:27249793

  5. Potential for Local Fertilization: A Benthocosm Test of Long-Term and Short-Term Effects of Mussel Excretion on the Plankton.

    PubMed

    Cherif, Mehdi; Granados, Monica; Duffy, Sean; Robert, Pauline; Péquin, Bérangère; Mohit, Vani; McKindsey, Christopher W; Archambault, Philippe; Myrand, Bruno; Lovejoy, Connie; Tremblay, Réjean; Plourde, Stéphane; Fussmann, Gregor F

    2016-01-01

    Mussel aquaculture has expanded worldwide and it is important to assess its impact on the water column and the planktonic food web to determine the sustainability of farming practices. Mussel farming may affect the planktonic food web indirectly by excreting bioavailable nutrients in the water column (a short-term effect) or by increasing nutrient effluxes from biodeposit-enriched sediments (a long-term effect). We tested both of these indirect effects in a lagoon by using plankton-enclosing benthocosms that were placed on the bottom of a shallow lagoon either inside of a mussel farm or at reference sites with no history of aquaculture. At each site, half of the benthocosms were enriched with seawater that had held mussels (excretion treatment), the other half received non-enriched seawater as a control treatment. We monitored nutrients ([PO43-] and [NH4+]), dissolved oxygen and plankton components (bacteria, the phytoplankton and the zooplankton) over 5 days. We found a significant relationship between long-term accumulation of mussel biodeposits in sediments, water-column nutrient concentrations and plankton growth. Effects of mussel excretion were not detected, too weak to be significant given the spatial and temporal variability observed in the lagoon. Effects of mussels on the water column are thus likely to be coupled to benthic processes in such semi-enclosed water bodies.

  6. Regional long-term production modeling from a single well test, Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope

    SciTech Connect

    Anderson, Brian J.; Kurihara, Masanori; White, Mark D.; Moridis, George J.; Wilson, Scott J.; Pooladi-Darvish, Mehran; Gaddipati, Manohar; Masuda, Yoshihiro; Collett, Timothy S.; Hunter, Robert B.; Narita, Hideo; Rose, Kelly; Boswell, Ray

    2011-02-01

    Following the results from the open-hole formation pressure response test in the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well (Mount Elbert well) using Schlumberger's Modular Dynamics Formation Tester (MDT) wireline tool, the International Methane Hydrate Reservoir Simulator Code Comparison project performed long-term reservoir simulations on three different model reservoirs. These descriptions were based on 1) the Mount Elbert gas hydrate accumulation as delineated by an extensive history-matching exercise, 2) an estimation of the hydrate accumulation near the Prudhoe Bay L-pad, and 3) a reservoir that would be down-dip of the Prudhoe Bay L-pad and therefore warmer and deeper. All of these simulations were based, in part, on the results of the MDT results from the Mount Elbert Well. The comparison group's consensus value for the initial permeability of the hydrate-filled reservoir (k = 0.12 mD) and the permeability model based on the MDT history match were used as the basis for subsequent simulations on the three regional scenarios. The simulation results of the five different simulation codes, CMG STARS, HydrateResSim, MH-21 HYDRES, STOMP-HYD, and TOUGH+HYDRATE exhibit good qualitative agreement and the variability of potential methane production rates from gas hydrate reservoirs is illustrated. As expected, the predicted methane production rate increased with increasing in situ reservoir temperature; however, a significant delay in the onset of rapid hydrate dissociation is observed for a cold, homogeneous reservoir and it is found to be repeatable. The inclusion of reservoir heterogeneity in the description of this cold reservoir is shown to eliminate this delayed production. Overall, simulations utilized detailed information collected across the Mount Elbert reservoir either obtained or determined from geophysical well logs, including thickness (37 ft), porosity (35%), hydrate saturation (65%), intrinsic permeability (1000 mD), pore water

  7. Regional long-term production modeling from a single well test, Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope

    USGS Publications Warehouse

    Anderson, B.J.; Kurihara, M.; White, M.D.; Moridis, G.J.; Wilson, S.J.; Pooladi-Darvish, M.; Gaddipati, M.; Masuda, Y.; Collett, T.S.; Hunter, R.B.; Narita, H.; Rose, K.; Boswell, R.

    2011-01-01

    Following the results from the open-hole formation pressure response test in the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well (Mount Elbert well) using Schlumberger's Modular Dynamics Formation Tester (MDT) wireline tool, the International Methane Hydrate Reservoir Simulator Code Comparison project performed long-term reservoir simulations on three different model reservoirs. These descriptions were based on 1) the Mount Elbert gas hydrate accumulation as delineated by an extensive history-matching exercise, 2) an estimation of the hydrate accumulation near the Prudhoe Bay L-pad, and 3) a reservoir that would be down-dip of the Prudhoe Bay L-pad and therefore warmer and deeper. All of these simulations were based, in part, on the results of the MDT results from the Mount Elbert Well. The comparison group's consensus value for the initial permeability of the hydrate-filled reservoir (k = 0.12 mD) and the permeability model based on the MDT history match were used as the basis for subsequent simulations on the three regional scenarios. The simulation results of the five different simulation codes, CMG STARS, HydrateResSim, MH-21 HYDRES, STOMP-HYD, and TOUGH+HYDRATE exhibit good qualitative agreement and the variability of potential methane production rates from gas hydrate reservoirs is illustrated. As expected, the predicted methane production rate increased with increasing in situ reservoir temperature; however, a significant delay in the onset of rapid hydrate dissociation is observed for a cold, homogeneous reservoir and it is found to be repeatable. The inclusion of reservoir heterogeneity in the description of this cold reservoir is shown to eliminate this delayed production. Overall, simulations utilized detailed information collected across the Mount Elbert reservoir either obtained or determined from geophysical well logs, including thickness (37 ft), porosity (35%), hydrate saturation (65%), intrinsic permeability (1000 mD), pore water

  8. Changing Flows, Chaning Livelihoods: Long-Term Changes in Hydro-Ecology and Socio-Economy in the Saskatchewan River Delta, Canada

    NASA Astrophysics Data System (ADS)

    Strickert, G. E.; Jardine, T.; Patrick, B.; Abu, R.; Andrews, E. J.; Reed, M.; Steelman, T.; Massie, M.

    2015-12-01

    The Saskatchewan River Delta is North America's largest inland delta, covering 10,000 km2 at the interface of the Great Plains and Boreal forest. Historically, it was the most productive fish and wildlife habitat in the region [BP1] and as such, traditional livelihoods in the local Cree and Métis community were supported by a flourishing fur trade, dense moose populations, and commercial and subsistence fisheries. But water resource development upstream has truncated flood peaks and introduced hydro-peaking with adverse consequences for biological production and these livelihoods. Local science and traditional knowledge, combined with a growing wealth of western science measurements are painting a picture of long-term ecological change. Remote sensing techniques coupled with hydrometric data show strong correlations between surface water coverage area and in-channel flow, thus enabling backcasting and forecasting of inundation patterns. The implications of losses of hydrological connectivity are evaluated using environmental DNA and stable isotope markers of fish movement and avian origins, with a focus on species that are most important for the economy and culture of the delta's people. The work aims to contribute to the setting of environmental flows and the re-licensing of major dams in 2015, as well as to support the development of a community-led water stewardship planning process that is now underway, with a goal of identifying threats to the delta and to make recommendations on threat mitigation. This presentation will describe how this community-informed, interdisciplinary approach aims to understand linkages between water, wildlife and people in this vital ecosystem. [BP1]In what region? This is a redundant statement if talking about the River Delta region. Maybe just take out first half of sentence.

  9. Long-Term Agroecosystem Research in the Central Mississippi River Basin: SWAT Simulation of Flow and Water Quality in the Goodwater Creek Experimental Watershed.

    PubMed

    Baffaut, Claire; John Sadler, E; Ghidey, Fessehaie; Anderson, Stephen H

    2015-01-01

    Starting in 1971, stream flow and climatologic data have been collected in the Goodwater Creek Experimental Watershed, which is part of the Central Mississippi River Basin (CMRB) Long-Term Agroecosystem Research (LTAR) site. Since 1992, water quality and socio-economic data have complemented these data sets. Previous modeling efforts highlighted the challenges created by the presence of a claypan. Specific changes were introduced in the Soil and Water Assessment Tool (SWAT) (i) to better simulate percolation through and saturation above the claypan and (ii) to simulate the spatial and temporal distributions of the timing of field operations throughout the watershed. Our objectives were to document the changes introduced into the code, demonstrate that these changes improved simulation results, describe the model's parameterization, calibration, and validation, and assess atrazine [6-chloro--ethyl-'-(1-methylethyl)-1,3,5-triazine-2,4-diamine] management practices in the hydrologic context of claypan soils. Model calibration was achieved for 1993 to 2010 at a daily time step for flow and at a monthly time step for water quality constituents. The new percolation routines ensured correct balance between surface runoff and groundwater. The temporal heterogeneity of atrazine application ensured the correct frequency of daily atrazine loads. Atrazine incorporation by field cultivation resulted in a 17% simulated reduction in atrazine load without a significant increase in sediment yields. Reduced atrazine rates produced proportional reductions in simulated atrazine transport. The model can be used to estimate the impact of other drivers, e.g., changing aspects of climate, land use, cropping systems, tillage, or management practices, in this context. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  10. Modeling the distributed effects of forest thinning on the long-term water balance and stream flow extremes for a semi-arid basin in the southwestern US

    NASA Astrophysics Data System (ADS)

    Moreno, H. A.; Gupta, H. V.; White, D. D.; Sampson, D. A.

    2015-10-01

    To achieve water resources sustainability in the water-limited Southwestern US, it is critical to understand the potential effects of proposed forest thinning on the hydrology of semi-arid basins, where disturbances to headwater catchments can cause significant changes in the local water balance components and basin-wise stream flows. In Arizona, the Four Forest Restoration Initiative (4FRI) is being developed with the goal of restoring 2.4 million acres of ponderosa pine along the Mogollon Rim. Using the physically based, spatially distributed tRIBS model, we examine the potential impacts of the 4FRI on the hydrology of Tonto Creek, a basin in the Verde-Tonto-Salt (VTS) system, which provides much of the water supply for the Phoenix Metropolitan Area. Long-term (20 year) simulations indicate that forest removal can trigger significant shifts in the spatio-temporal patterns of various hydrological components, causing increases in net radiation, surface temperature, wind speed, soil evaporation, groundwater recharge, and runoff, at the expense of reductions in interception and shading, transpiration, vadose zone moisture and snow water equivalent, with south facing slopes being more susceptible to enhanced atmospheric losses. The net effect will likely be increases in mean and maximum stream flow, particularly during El Niño events and the winter months, and chiefly for those scenarios in which soil hydraulic conductivity has been significantly reduced due to thinning operations. In this particular climate, forest thinning can lead to net loss of surface water storage by vegetation and snow pack, increasing the vulnerability of ecosystems and populations to larger and more frequent hydrologic extreme conditions on these semi-arid systems.

  11. Biodiversity–ecosystem functioning relationships in long-term time series and palaeoecological records: deep sea as a test bed

    PubMed Central

    Wei, Chih-Lin; Danovaro, Roberto; Myhre, Sarah E.

    2016-01-01

    The link between biodiversity and ecosystem functioning (BEF) over long temporal scales is poorly understood. Here, we investigate biological monitoring and palaeoecological records on decadal, centennial and millennial time scales from a BEF framework by using deep sea, soft-sediment environments as a test bed. Results generally show positive BEF relationships, in agreement with BEF studies based on present-day spatial analyses and short-term manipulative experiments. However, the deep-sea BEF relationship is much noisier across longer time scales compared with modern observational studies. We also demonstrate with palaeoecological time-series data that a larger species pool does not enhance ecosystem stability through time, whereas higher abundance as an indicator of higher ecosystem functioning may enhance ecosystem stability. These results suggest that BEF relationships are potentially time scale-dependent. Environmental impacts on biodiversity and ecosystem functioning may be much stronger than biodiversity impacts on ecosystem functioning at long, decadal–millennial, time scales. Longer time scale perspectives, including palaeoecological and ecosystem monitoring data, are critical for predicting future BEF relationships on a rapidly changing planet. PMID:27114583

  12. Biodiversity-ecosystem functioning relationships in long-term time series and palaeoecological records: deep sea as a test bed.

    PubMed

    Yasuhara, Moriaki; Doi, Hideyuki; Wei, Chih-Lin; Danovaro, Roberto; Myhre, Sarah E

    2016-05-19

    The link between biodiversity and ecosystem functioning (BEF) over long temporal scales is poorly understood. Here, we investigate biological monitoring and palaeoecological records on decadal, centennial and millennial time scales from a BEF framework by using deep sea, soft-sediment environments as a test bed. Results generally show positive BEF relationships, in agreement with BEF studies based on present-day spatial analyses and short-term manipulative experiments. However, the deep-sea BEF relationship is much noisier across longer time scales compared with modern observational studies. We also demonstrate with palaeoecological time-series data that a larger species pool does not enhance ecosystem stability through time, whereas higher abundance as an indicator of higher ecosystem functioning may enhance ecosystem stability. These results suggest that BEF relationships are potentially time scale-dependent. Environmental impacts on biodiversity and ecosystem functioning may be much stronger than biodiversity impacts on ecosystem functioning at long, decadal-millennial, time scales. Longer time scale perspectives, including palaeoecological and ecosystem monitoring data, are critical for predicting future BEF relationships on a rapidly changing planet. © 2016 The Author(s).

  13. Analysis of long-term mechanical grooming on large-scale test panels coated with an antifouling and a fouling-release coating.

    PubMed

    Hearin, John; Hunsucker, Kelli Z; Swain, Geoffrey; Stephens, Abraham; Gardner, Harrison; Lieberman, Kody; Harper, Michael

    2015-01-01

    Long-term grooming tests were conducted on two large-scale test panels, one coated with a fluorosilicone fouling-release (FR) coating, and one coated with a copper based ablative antifouling (AF) coating. Mechanical grooming was performed weekly or bi-weekly using a hand operated, electrically powered, rotating brush tool. The results indicate that weekly grooming was effective at removing loose or heavy biofilm settlement from both coatings, but could not prevent the permanent establishment of low-profile tenacious biofilms. Weekly grooming was very effective at preventing macrofouling establishment on the AF coating. The effectiveness of weekly grooming at preventing macrofouling establishment on the FR coating varied seasonally. The results suggest that frequent mechanical grooming is a viable method to reduce the fouling rating of ships' hulls with minimal impact to the coating. Frequent grooming could offer significant fuel savings while reducing hull cleaning frequencies and dry dock maintenance requirements.

  14. Elimination of long-term variations from chaotic light curves

    NASA Astrophysics Data System (ADS)

    Plachy, E.; Kolláth, Z.

    2013-11-01

    We performed a comparative dynamical investigation of chaotic test data using the global flow reconstruction method. We demonstrate that large-amplitude, long-term variations may have a disturbing effect for the analysis. The Empirical Mode Decomposition method (EMD) and the Fourier filtering were tested to remove the additional variations. Test results show that the elimination of these variations significantly increased the robustness of the reconstructions.

  15. Functional Sensory-Motor Performance Following Long Term Space Flight: The First Results of "Field Test" Experiment

    NASA Technical Reports Server (NTRS)

    Tomilovskaya, E. S.; Rukavishnikov, I. V.; Kofman, I. S.; Kitov, V. V.; Grishin, A. P.; Yu, N.; Lysova.; Cerisano, J. M.; Kozlovskaya, I. B.; Reschke, M. F.

    2014-01-01

    quantifying the coordination and timing of relatively simple basic movements - transition from seated and prone positions to standing, walking, stepping over obstacles, tandem walking, muscle compliance, as well as characteristics of postural sway and orthostatic tolerance. Testing for changes in these parameters have been initiated in the medical tent at the landing site. The first set of experiments showed that during the first hour after landing, cosmonauts and astronauts were able to execute (although slower and with more effort than preflight) simple movements such as egress from a seated or prone position and also to remain standing for 3.5 minutes without exhibiting pronounced cardiovascular changes. More challenging tests, however, demonstrated a prominent reduction in coordination - the obstacle task, for example, was performed at much slower speed and with a marked overestimation of the obstacle height and tandem walking was greatly degraded suggesting significant changes in proprioception, brainstem and vestibular function. There is some speculation that the neural changes, either from the bottom-up or top down may be long lasting; requiring compensatory responses that will modify or mask the adverse responses we have observed. Furthermore, these compensatory responses may actually be beneficial, helping achieve a more rapid adaptation to both weightlessness and a return to earth.

  16. Association Between Concentrations of Hemoglobin Determined by Fecal Immunochemical Tests and Long-term Development of Advanced Colorectal Neoplasia.

    PubMed

    Grobbee, Esmée J; Schreuders, Eline H; Hansen, Bettina E; Bruno, Marco J; Lansdorp-Vogelaar, Iris; Spaander, Manon C W; Kuipers, Ernst J

    2017-07-28

    Colorectal cancer (CRC) screening using quantitative fecal immunochemical tests (FITs) is rapidly gaining ground worldwide. FITs are invariably used in a dichotomous manner using pre-specified cut-off values. To optimize FIT-based screening programs, we investigated the association between fecal hemoglobin (fHb) concentrations below the FIT cut-off value and later development of colorectal advanced neoplasia. We analyzed data collected from a population-based study of 9561 average-risk subjects (50-74 yrs old) in the Netherlands who were offered 4 rounds of FIT screening for CRC from November 2006 through December 2014. We analyzed data from 7663 participants screened at least once and found to have a negative FIT result at baseline (below the cut-off value of 10 μg Hb/ g feces). Participants were followed for a median 4.7 yrs (interquartile range, 2.0-6.1 yrs); CRCs diagnosed outside the screening program were identified from the Dutch Comprehensive Cancer Centre database. Hazard ratios for advanced neoplasia were determined using Cox proportional hazard regression analyses. Logistic regression techniques were used to calculate risks of advanced neoplasia after consecutive fHb concentrations below the cut-off value. After 8 years of follow up, participants with baseline concentrations of 8-10 μg fHb/g had a higher cumulative incidence of advanced neoplasia (33%) than participants with 0 μg fHb/g (5%) (P<.001). Multi-variate hazard ratios increased from 1.2 for subjects with concentrations of 0-2 μg fHb/g to 8.2 for subjects with concentrations of 8-10 μg fHb/g (P<.001). Participants with 2 consecutive fHb concentrations of 8 μg Hb/g had a 14-fold increase in risk of advanced neoplasia compared to participants with 2 consecutive fHb concentrations of 0 μg Hb/g (P<.001). In a population-based study of average-risk individuals with a FIT result below the cut-off value, we associated baseline concentrations of 8-10 μg fHb/g with an increased risk of advanced

  17. Developing a scale to measure family dynamics related to long-term care, and testing that scale in a multicenter cross-sectional study.

    PubMed

    Kusaba, Tesshu; Sato, Kotaro; Matsui, Yoshinori; Matsuda, Satoshi; Ando, Takashi; Sakushima, Ken; Wakita, Takafumi; Fukuma, Shingo; Fukuhara, Shunichi

    2014-07-10

    As Japan's population ages, more frail elderly people are cared for by members of their family. The dynamics within such families are difficult to study, in part because they are difficult to quantify. We developed a scale for assessing family dynamics related to long-term care. Here we report on the development of that scale, and we present the results of reliability testing and validation testing. Two primary-care specialists drafted questions about family dynamics, and discussed them with other primary-care physicians and clinical researchers. The final questionnaire asked about four problems or undesirable situations: disengagement (emotional distance), scapegoating (inappropriate blame), transfer of problems across generations (transfer of unnecessary burden from older to younger generations, trans-generationally displaced revenge), and undesirable behavior (co-dependence). Next, at six general-medicine clinics, doctors evaluated families that had a caregiver and a patient requiring long-term care. The results were analyzed by factor analysis. Cronbach's α was computed, and criterion-related validation tests were done with three types of criteria: relationship before caregiving, ability to do activities of daily living (ADL), and the duration of care. Results were obtained from 199 families. Among the caregivers, 79% were women and their mean age was 63 years. Among the patients, 71% were women and their mean age was 84 years. The results of factor analysis indicated that the scale was unidimensional. Cronbach's α was 0.73. Not having a good relationship before caregiving was associated with significantly worse family dynamics scores, as was greater dependence regarding ADL. We developed a scale that enables physicians to assess the dynamics of families with a patient and a family caregiver. The scale's scores are reliable and the results of validation testing were generally good. This scale holds promise as a tool both for research and for primary

  18. Developing a scale to measure family dynamics related to long-term care, and testing that scale in a multicenter cross-sectional study

    PubMed Central

    2014-01-01

    Background As Japan’s population ages, more frail elderly people are cared for by members of their family. The dynamics within such families are difficult to study, in part because they are difficult to quantify. We developed a scale for assessing family dynamics related to long-term care. Here we report on the development of that scale, and we present the results of reliability testing and validation testing. Methods Two primary-care specialists drafted questions about family dynamics, and discussed them with other primary-care physicians and clinical researchers. The final questionnaire asked about four problems or undesirable situations: disengagement (emotional distance), scapegoating (inappropriate blame), transfer of problems across generations (transfer of unnecessary burden from older to younger generations, trans-generationally displaced revenge), and undesirable behavior (co-dependence). Next, at six general-medicine clinics, doctors evaluated families that had a caregiver and a patient requiring long-term care. The results were analyzed by factor analysis. Cronbach’s α was computed, and criterion-related validation tests were done with three types of criteria: relationship before caregiving, ability to do activities of daily living (ADL), and the duration of care. Results Results were obtained from 199 families. Among the caregivers, 79% were women and their mean age was 63 years. Among the patients, 71% were women and their mean age was 84 years. The results of factor analysis indicated that the scale was unidimensional. Cronbach’s α was 0.73. Not having a good relationship before caregiving was associated with significantly worse family dynamics scores, as was greater dependence regarding ADL. Conclusions We developed a scale that enables physicians to assess the dynamics of families with a patient and a family caregiver. The scale’s scores are reliable and the results of validation testing were generally good. This scale holds promise as a

  19. Mild subclinical hypothyroidism in thalassaemia major: prevalence, multigated radionuclide test, clinical and laboratory long-term follow-up study.

    PubMed

    De Sanctis, Vincenzo; De Sanctis, Elena; Ricchieri, Paola; Gubellini, Erika; Gilli, Giuseppe; Gamberini, Maria Rita

    2008-10-01

    From 1990 to 1991, the Pediatric and Adolescent Endocrine Outpatient Clinic of Arcispedale S. Anna admitted 97 thalassaemia major (TM) patients for endocrine evaluation. Their mean age was 14.2+/-5.7 years (range 5-28 years). Sixty-eight (70%) had normal thyroid function and twenty-one (21.6%) were discharged with a diagnosis of hypothyroidism of different degrees of severity. Thirteen patients out of 21 (61.9%) were females. Twelve patients (57.1%) fulfilled the criteria for subclinical hypothyroidism (SH). Their mean age was 15.7+/-3.5 years (range 9-22 years). A positive direct correlation was observed between the following variables: TSH and serum ferritin, TG and basal TSH, basal TSH and peak levels after TRH stimulation test. In 6 out of 12 TM patients (50%) with SH type a, the basal ejection fraction assessed by MUGA scan was normal; 1 TM patient (8.3%) showed mild abnormality and 5 TM patients (41.6%) showed severe abnormalities. A normal response during exercise (increase in LVEF greater than 5 percentage units) occurred in 10 patients (83.3%). Global or segmental left ventricular dysfunction at rest and during exercise were found in 8 patients (66.6%) and 10 patients (83.3%), respectively. These cardiac abnormalities were more common in TM patients with severe iron overload and poor compliance to DFX treatment (group A: serum ferritin above 2500 ng/ml) compared to TM patients with mild-moderate iron overload (group B: serum ferritin below 2500 ng/ml). In the control group of TM patients (group C) with normal thyroid function the assessment of MUGA scan was normal in all subjects at rest and after exercise. Global or segmental left ventricular dysfunction was observed only during exercise in 50% of TM patients with normal thyroid function (group C). Our patients with SH exhibited three different thyroid function patterns during follow-up: a. 3 (25%) of 12 studied TM patients showed a normalization of serum TSH levels b. 2 patients (16.6%) showed

  20. Long-Term Motor Deficits after Controlled Cortical Impact in Rats Can Be Detected by Fine Motor Skill Tests but Not by Automated Gait Analysis.

    PubMed

    Schönfeld, Lisa-Maria; Jahanshahi, Ali; Lemmens, Evi; Schipper, Sandra; Dooley, Dearbhaile; Joosten, Elbert; Temel, Yasin; Hendrix, Sven

    2017-01-15

    Animal models with constant, long-lasting motor deficits together with the right tests to assess behavioral abnormalities are needed to study the effectiveness of potential therapies to restore motor functions. In the current study, controlled cortical impact (CCI) was applied in rats to induce damage to the forelimb area of the motor cortex and the dorsal striatum. Motor behavior was assessed before and after CCI, using fine motor skill tests such as the adhesive removal test, the cylinder test, and the Montoya staircase test as well as the automated gait analysis system CatWalk XT over a 6 week period. CCI caused a variety of unilateral motor deficits, which were characterized in detail by using the selected fine motor skill tests. In striking contrast to previous studies on CCI in mice, neither forelimb impairments, nor general changes in gait, were detected with the CatWalk XT. These data suggest that the adhesive removal test, the cylinder test, and the Montoya staircase test are the methods of choice to detect long-term unilateral motor deficits in rats after CCI, whereas the use of automated gait analysis systems might not be suitable to measure these behavioral deviations.

  1. Target and non-target analysis of migrants from PVC-coated cans using UHPLC-Q-Orbitrap MS: evaluation of long-term migration testing.

    PubMed

    Vaclavikova, Marta; Paseiro-Cerrato, Rafael; Vaclavik, Lukas; Noonan, Gregory O; DeVries, Jonathan; Begley, Timothy H

    2016-01-01

    A simple, rapid and sensitive method for analyzing multi-target and non-target additives in polyvinyl chloride (PVC) food can coatings using ultra-high-performance liquid chromatography coupled to quadrupole-orbital ion-trap mass spectrometry was developed. This procedure was used to study the behaviour of a cross-linking agent, benzoguanamine (BGA), two slip agents, oleamide and erucamide, and 18 other commonly used plasticisers including phthalates, adipates, sebacates, acetyl tributyl citrate and epoxidised soybean or linseed oils. This optimised method was used to detect these analytes in food simulants (water and 3% acetic acid) in a long-term migration test of PVC-coated food cans for a period ranging from 1 day to 1.5 years at 40°C. Although very low detection limits (5 ng ml(-1)) were obtained for the majority of compounds, none of the monitored plasticisers and slip agents was detected in simulants extracted from cans over the period of the test. However, the presence of BGA in both aqueous food simulants was confirmed based on high-resolution mass spectrometry, product ion spectra and analysis of a reference standard. The BGA concentration in both simulants continued to increase with storage time: after 1.5 years storage in aqueous food simulants at 40°C, BGA was detected at concentrations up to 84 µg dm(-2). We believe this is the first study describing the long-term migration capacity of BGA from any vinyl coating material intended for use in PVC-coated food cans. Our results may have implications for migration test protocols for food cans that will be stored for extended time periods.

  2. Long-term effect of vasectomy on the biochemical composition of testes and sex accessory organs of the Indian desert gerbil, Meriones hurrianae Jerdon.

    PubMed

    Lohiya, N K; Dixit, V P

    1975-02-01

    A long-term vasoligation operation in gerbils, Meriones hurrianae Jerdon did not reveal any consistent change in the weights of androgen dependent organs such as seminal vesicles, ventral prostate, epididymes and perineal complex (levator ani muscle and penis). Histological structure of the testis and caput epididymis remains normal after vasectomy. There was no effect of bilateral vasectomy on androgen production of the testes as reflected by fructose content of coagulating gland. No compensatory hypertrophy of the contralateral testis was observed in unilaterally vasectomized gerbils. The RNA content of the testis and epididymis and ascorbic acid content of adrenal gland did not show appreciable change. No change in protein content of the testis was found but a significant increase was observed in the protein content of epididymis after the operation.

  3. A retrospective study of long-term psychosocial consequences and satisfaction after carrier testing in childhood in an autosomal recessive disease: aspartylglucosaminuria.

    PubMed

    Järvinen, O; Hietala, M; Aalto, A M; Arvio, M; Uutela, A; Aula, P; Kääriäinen, H

    2000-12-01

    Genetic carrier testing of children is usually not recommended. However, there are no data concerning long-term psychological consequences, experience, and satisfaction of those tested as well as their recall of the test results. We evaluated these items retrospectively 10-24 years after carrier testing performed in childhood. Study material comprised 25 families with aspatylglucosaminuria (AGU), an autosomal recessive disorder, with 35 healthy sibs from all parts of Finland tested for carriership during childhood between 1973 and 1987. Of these sibs, 25 participated in our study. The questionnaire comprised multiple-choice and open-ended questions. The psychosocial well-being of the study subjects measured by the RAND 36 item Health Survey 1.0 (RAND) was, in general, at least as good as that of controls, and showed no significant differences between carriers and non-carriers (p > 0.154). All tested individuals were satisfied with the fact that they had been tested and stated that the decision to perform carrier testing on a child can be made by the parents. Of the 25 tested, 23 knew and understood their test result correctly at the time of our study. Most of the tested individuals (60%) stated that the best time for carrier testing would be in the childhood or in the teen years. This study indicates that carrier testing in childhood for an autosomal recessive disorder (AGU) had caused no measurable disturbance of quality of life in adulthood, and those tested reported being satisfied. However, we do not recommend testing in childhood, as the result is not needed prior to the time for reproductive decisions.

  4. Evaluation of a deposit in the vicinity of the PBU L-106 Site, North Slope, Alaska, for a potential long-term test of gas production from hydrates

    SciTech Connect

    Moridis, G.J.; Reagan, M.T.; Boyle, K.L.; Zhang, K.

    2010-05-01

    As part of the effort to investigate the technical feasibility of gas production from hydrate deposits, a long-term field test (lasting 18-24 months) is under consideration in a project led by the U.S. Department of Energy. We evaluate a candidate deposit involving the C-Unit in the vicinity of the PBU-L106 site in North Slope, Alaska. This deposit is stratigraphically bounded by impermeable shale top and bottom boundaries (Class 3), and is characterized by high intrinsic permeabilities, high porosity, high hydrate saturation, and a hydrostatic pressure distribution. The C-unit deposit is composed of two hydrate-bearing strata separated by a 30-ft-thick shale interlayer, and its temperatrure across its boundaries ranges between 5 and 6.5 C. We investigate by means of numerical simulation involving very fine grids the production potential of these two deposits using both vertical and horizontal wells. We also explore the sensitivity of production to key parameters such as the hydrate saturation, the formation permeability, and the permeability of the bounding shale layers. Finally, we compare the production performance of the C-Unit at the PBU-L106 site to that of the D-Unit accumulation at the Mount Elbert site, a thinner, single-layer Class 3 deposit on the North Slope of Alaska that is shallower, less-pressurized and colder (2.3-2.6 C). The results indicate that production from horizontal wells may be orders of magnitude larger than that from vertical ones. Additionally, production increases with the formation permeability, and with a decreasing permeability of the boundaries. The effect of the hydrate saturation on production is complex and depends on the time frame of production. Because of higher production, the PBU-L106 deposit appears to have an advantage as a candidate for the long-term test.

  5. Optimizing Eating Performance for Long-Term Care Residents With Dementia: Testing the Impact of Function-Focused Care for Cognitively Impaired.

    PubMed

    Liu, Wen; Galik, Elizabeth; Nahm, Eun-Shim; Boltz, Marie; Resnick, Barbara

    2015-12-01

    The objective of this study was to evaluate the impact of a well-developed theory-based function-focused care for cognitively impaired (FFC-CI) intervention on eating performance among long-term care (LTC) residents with moderate-to-severe cognitive impairment. A secondary analysis of longitudinal data from 2 cluster-randomized controlled trials that originally tested the impact of FFC-CI on all function and physical activities. Participants were 199 residents with moderate-to-severe cognitive impairment from 4 nursing homes and 4 assisted living facilities. Data at baseline, and 3 and 6 months were used. Resident outcome data used in this analysis included eating performance conceptualized using the single self-care "feeding" item in the Barthel Index, cognitive function by Mini-Mental State Examination, sitting balance conceptualized using the single "chair sit-sitting balance" item in the Tinetti Gait and Balance scale, physical capability by Physical Capability Scale, depression by Cornell Scale for Depression in Dementia, and agitation by Cohen-Mansfield Agitation Inventory (short form). At baseline, almost one-third (32.2%) of the 199 residents needed help with eating. There was no significant change with regard to eating performance over time in both groups, and no significant treatment by time difference between groups in eating performance (P = .195). Current findings support a need to revise the FFC-CI to better address eating performance. Future work may benefit from a stronger focus on eating performance rather than the more commonly addressed functional tasks, such as bathing, dressing, and ambulation. In addition, the inclusion of a more heterogeneous group of LTC residents with regard to eating performance is needed to test the impact of the revised approach on eating performance. Copyright © 2015 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

  6. Mechanical behavior and failure analysis of prosthetic retaining screws after long-term use in vivo. Part 3: Preload and tensile fracture load testing.

    PubMed

    Al Jabbari, Youssef S; Fournelle, Raymond; Ziebert, Gerald; Toth, Jeffrey; Iacopino, Anthony M

    2008-04-01

    The aim of this study was to determine the preload and tensile fracture load values of prosthetic retaining screws after long-term use in vivo compared to unused screws (controls). Additionally, the investigation addressed whether the preload and fracture load values of prosthetic retaining screws reported by the manufacturer become altered after long-term use in vivo. For preload testing, 10 new screws (controls) from Nobel Biocare (NB) and 73 used retaining screws [58 from NB and 15 from Sterngold (SG)] were subjected to preload testing. For tensile testing, eight controls from NB and 58 used retaining screws (46 from NB and 12 from SG) were subjected to tensile testing. Used screws for both tests were in service for 18-120 months. A custom load frame, load cell, and torque wrench setup were used for preload testing. All 83 prosthetic screws were torqued once to 10 Ncm, and the produced preload value was recorded (N) using an X-Y plotter. Tensile testing was performed on a universal testing machine and the resulting tensile fracture load value was recorded (N). Preload and tensile fracture load values were analyzed with 2-way ANOVA and Tukey post-hoc tests. There was a significant difference between preload values for screws from NB and screws from SG (p < 0.001). The preload values for gold alloy screws from NB decreased as the number of years in service increased. There was a significant difference between tensile fracture values for the three groups (gold alloy screws from NB and SG and palladium alloy screws from NB) at p < 0.001. The tensile fracture values for gold alloy screws from NB and SG decreased as the number of years in service increased. In fixed detachable hybrid prostheses, perhaps as a result of galling, the intended preload values of prosthetic retaining screws may decrease with increased in-service time. The reduction of the fracture load value may be related to the increase of in-service time; however, the actual determination of this

  7. Prefrontal blood flow and oxygenation measured by NIRS during long-term memory tasks are impaired by acute hyperglycemia (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Harris, R. Luke; Bell, Lindsay; Reimer, Andrea; Pettersen, Jacqueline A.; Siakaluk, Paul; Duffels, Brian

    2017-02-01

    Our goal was to use 2-channel frequency domain near-infrared spectroscopy (NIRS) to investigate the hemodynamic and metabolic mechanisms underlying hyperglycemia-associated long-term memory impairment. We hypothesized that prefrontal cortex (PFC) oxygen saturation (%Sat) and perfusion (tHb, i.e. total hemoglobin) would decrease due to hyperglycemia during learning, and then increase during recall. During learning, participants' blood glucose was manipulated with beverages containing either 47.4 mg saccharine control (CON, n = 10), or 50 g dextrose + 23.7 mg saccharine (GLC, n = 10). In the Symbol-Digit Modalities Test (SMDT) participants matched nine symbols to corresponding digits (1-9 inclusive), completing 105 learning and 15 testing trials on day 1 and 15 testing trials on day 2. From learning to recall, CON SMDT performance was unchanged, but GLC SMDT performance was decreased 11% (P = 0.0173). There were significant interactions (2-way ANOVA) between the CON-GLC treatment effects and the learning-recall effects for both PFC perfusion and oxygen saturation. Specifically, comparing learning to recall, CON exhibited no tHb differences but for GLC there was a large tHb decrease during learning with a partial recovery toward CON values during recall (P = 0.0012); and, comparing learning to recall, CON exhibited a large %Sat decrease but GLC exhibited a large %Sat increase (P = 0.021). We speculate that, during learning, after overnight fasting (CON) the PFC demands more hemodynamic and metabolic resources and "works" harder, but with readily available sugar (GLC) the PFC exhibits decreased "effort."

  8. Long-Term Continuous Monitoring of Fluid Chemistry and Flux at the Bush Hill Gas Hydrate Field, Gulf of Mexico Using a New Flow Meter, The MOSQUITO

    NASA Astrophysics Data System (ADS)

    Solomon, E.; Kastner, M.; Jannasch, H.; Weinstein, Y.; Robertson, G.; Aubrey, A.

    2004-12-01

    Long-term monitoring of fluid, solute, and methane fluxes that influence marine gas hydrate formation and dissociation has important implications for the seafloor biochemical environment, ocean chemistry, and potentially the atmosphere. Four newly designed flux meters called the MOSQUITO (Multiple Orifice Sampler and Quantitative Injection Tracer Observer) and two temperature loggers were deployed adjacent to the Bush Hill hydrate mound in the northern Gulf of Mexico (GC185) in order to understand how chemistry, physics, biology, and subsurface hydrology dynamically influence the growth and dissociation of the hydrate mound. The MOSQUITO contains a network of osmotic samplers and a tracer injection device, each connected to a titanium capillary tube that penetrates the sediment. The tracer is injected as a point source, and fluid chemistry and tracer concentrations are continuously sampled simultaneously at multiple depths below the seafloor in a three dimensional array with respect to the tracer injection point. Bottom water chemistry is also sampled continuously. Vertical and horizontal flow rates as low as 1 cm/yr are determined by modeling the variability in tracer concentration at each depth over time. MOSQUITOs can be deployed at passive margins, ridge crests, ridge flanks, subduction zones, and lakes. MOSQUITOs were deployed over a period of 430 days from June 2002 to August 2003 and were sampled at weekly resolution. The temperature loggers were attached to the MOSQUITOs and recorded seafloor temperature every 40 minutes. Three MOSQUITOs were deployed within 3 m of the hydrate mound and ˜ 5 m apart, adjacent to transient methane seeps; in a mussel field, in a bacterial mat, and in a tubeworm field. The fourth MOSQUITO was placed ˜150 m southwest of the hydrate mound to monitor background fluid flow, geochemistry, and temperature. The average bottom water temperature over the 430-day deployment period was 7.94° C, with minimum temperatures occurring every

  9. Long term perfusion system supporting adipogenesis

    PubMed Central

    Abbott, Rosalyn D.; Raja, Waseem K.; Wang, Rebecca Y.; Stinson, Jordan A.; Glettig, Dean L.; Burke, Kelly A.; Kaplan, David L.

    2015-01-01

    Adipose tissue engineered models are needed to enhance our understanding of disease mechanisms and for soft tissue regenerative strategies. Perfusion systems generate more physiologically relevant and sustainable adipose tissue models, however adipocytes have unique properties that make culturing them in a perfusion environment challenging. In this paper we describe the methods involved in the development of two perfusion culture systems (2D and 3D) to test their applicability for long term in vitro adipogenic cultures. It was hypothesized that a silk protein biomaterial scaffold would provide a 3D framework, in combination with perfusion flow, to generate a more physiologically relevant sustainable adipose tissue engineered model than 2D cell culture. Consistent with other studies evaluating 2D and 3D culture systems for adipogenesis we found that both systems successfully model adipogensis, however 3D culture systems were more robust, providing the mechanical structure required to contain the large, fragile adipocytes that were lost in 2D perfused culture systems. 3D perfusion also stimulated greater lipogenesis and lipolysis and resulted in decreased secretion of LDH compared to 2D perfusion. Regardless of culture configuration (2D or 3D) greater glycerol was secreted with the increased nutritional supply provided by perfusion of fresh media. These results are promising for adipose tissue engineering applications including long term cultures for studying disease mechanisms and regenerative approaches, where both acute (days to weeks) and chronic (weeks to months) cultivation are critical for useful insight. PMID:25843606

  10. A statistically compiled test battery for feasible evaluation of knee function after rupture of the Anterior Cruciate Ligament – derived from long-term follow-up data

    PubMed Central

    2017-01-01

    Purpose Clinical test batteries for evaluation of knee function after injury to the Anterior Cruciate Ligament (ACL) should be valid and feasible, while reliably capturing the outcome of rehabilitation. There is currently a lack of consensus as to which of the many available assessment tools for knee function that should be included. The present aim was to use a statistical approach to investigate the contribution of frequently used tests to avoid redundancy, and filter them down to a proposed comprehensive and yet feasible test battery for long-term evaluation after ACL injury. Methods In total 48 outcome variables related to knee function, all potentially relevant for a long-term follow-up, were included from a cross-sectional study where 70 ACL-injured (17–28 years post injury) individuals were compared to 33 controls. Cluster analysis and logistic regression were used to group variables and identify an optimal test battery, from which a summarized estimator of knee function representing various functional aspects was derived. Results As expected, several variables were strongly correlated, and the variables also fell into logical clusters with higher within-correlation (max ρ = 0.61) than between clusters (max ρ = 0.19). An extracted test battery with just four variables assessing one-leg balance, isokinetic knee extension strength and hop performance (one-leg hop, side hop) were mathematically combined to an estimator of knee function, which acceptably classified ACL-injured individuals and controls. This estimator, derived from objective measures, correlated significantly with self-reported function, e.g. Lysholm score (ρ = 0.66; p<0.001). Conclusions The proposed test battery, based on a solid statistical approach, includes assessments which are all clinically feasible, while also covering complementary aspects of knee function. Similar test batteries could be determined for earlier phases of ACL rehabilitation or to enable longitudinal monitoring. Such

  11. The Entrance test of physics and Workbook in teaching of physics at secondary vocational school within long-term pedagogical research

    NASA Astrophysics Data System (ADS)

    Kerlínová, Věra

    2017-01-01

    Within the long-term pedagogical research ongoing since the school year 2008/2009 to 2015/2016 at the secondary vocational school in Bohumín was through of Entrance test of physics, which included curriculum of the sixth to ninth year of elementary school, regularly finding out, in which parts of Entrance test - Unit conversions, International System of Units, Properties of matter, Mechanics, Thermodynamics, Electricity and Magnetism, Optics, Atoms and Universe - pupils of the 1st years of secondary vocational school, technical and non-technical, reach a higher number of correct answers, in which dominates the wrong answers and which parts of the test pupils are better left out completely. It turned out that the results of these tests are very informative not only for theoretical and practical teaching, but also technical and other science subjects. The results of the Entrance tests are also a valuable source of information for continuous innovation Workbook of Physics - Mechanics for the 1st year of secondary vocational schools [1] - whose the first version began during the school year 2007/2008 and which was tested within pre-research in school years 2008/2009, 2009/2010 and within research in school year 2010/2011. On the basis of feedbacks getting from research the Workbook is regularly expanded, innovated and updated. The Workbook consists of parts dedicated to physical concepts, physical tasks, proposals to physical experiments, pupils comments from viewed video projection and documentary films, examples from the world of science and technology, examples from practice and real life, physical terminology in English, quizzes, competitions, interesting things and links related to discussed curriculum. The Workbook is divided into thematic sections, chapters and subchapters similar as physics textbooks for pupils of the 1st years of Secondary Schools in the Czech Republic. In the Workbook there are included tasks on fill in the words, polynomial tasks with

  12. Usability testing, initial implementation, and formative evaluation of an evidence-based intervention: lessons from a demonstration project to reduce long-term foster care.

    PubMed

    Akin, Becci A; Bryson, Stephanie A; Testa, Mark F; Blase, Karen A; McDonald, Tom; Melz, Heidi

    2013-12-01

    The field of child welfare faces an undersupply of evidence-based interventions to address long-term foster care. The Permanency Innovations Initiative is a five-year federal demonstration project intended to generate evidence to reduce long stays in foster care for those youth who encounter the most substantial barriers to permanency. This article describes a systematic and staged approach to implementation and evaluation of a PII project that included usability testing as one of its key activities. Usability testing is an industry-derived practice which analyzes early implementation processes and evaluation procedures before they are finalized. This article describes the iterative selection, testing, and analysis of nine usability metrics that were designed to assess three important constructs of the project's initial implementation and evaluation: intervening early, obtaining consent, and engaging parents. Results showed that seven of nine metrics met a predetermined target. This study demonstrates how findings from usability testing influenced the initial implementation and formative evaluation of an evidence-supported intervention. Implications are discussed for usability testing as a quality improvement cycle that may contribute to better operationalized interventions and more reliable, valid, and replicable evidence. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Postdischarge international normalized ratio testing and long-term clinical outcomes of patients with heart failure receiving warfarin: findings from the ADHERE registry linked to Medicare claims.

    PubMed

    Qualls, Laura G; Greiner, Melissa A; Eapen, Zubin J; Fonarow, Gregg C; Mills, Roger M; Klaskala, Winslow; Hernandez, Adrian F; Curtis, Lesley H

    2013-12-01

    Effective warfarin thromboprophylaxis requires maintaining anticoagulation within the recommended international normalized ratio (INR) range. INR testing rates and associations between testing and outcomes are not well understood. INR testing rates after hospitalization for acute decompensated heart failure are suboptimal, and testing is associated with lower risks of mortality and adverse clinical events. We conducted a retrospective cohort study of patients who were long-term warfarin users and were hospitalized for heart failure, had a medical history of atrial fibrillation or valvular heart disease, and were enrolled in fee-for-service Medicare. INR testing was defined as ≥1 outpatient INR test within 45 days after discharge. Using Cox proportional hazards models, we examined associations between testing and all-cause mortality, all-cause readmission, and adverse clinical events at 1 year. Among 8558 patients, 7722 (90.2%) were tested. After 1 year, tested patients had lower all-cause mortality (23.5% vs 32.6%; P < 0.001) and fewer myocardial infarctions (2.0% vs 3.3%; P = 0.02). These differences remained significant after multivariable adjustment with hazard ratios of 0.72 (95% confidence interval [CI]: 0.63-0.84; P < 0.001) and 0.58 (95% CI: 0.41-0.83; P = 0.003), respectively. Differences in all-cause readmission, thromboembolic events, ischemic stroke, and bleeding events were not statistically significant. Postdischarge outpatient INR testing in patients with heart failure complicated by atrial fibrillation or valvular heart disease was high. INR testing was associated with improved survival and fewer myocardial infarctions at 1 year but was not independently associated with other adverse clinical events. © 2013 Wiley Periodicals, Inc.

  14. Cross-flow microfiltration with periodical back-washing for photocatalytic degradation of pharmaceutical and diagnostic residues-evaluation of the long-term stability of the photocatalytic activity of TiO2.

    PubMed

    Doll, Tusnelda E; Frimmel, Fritz H

    2005-03-01

    The combination of semiconductor photocatalysis with cross-flow microfiltration accompanied by periodical back-washing was investigated in a pilot plant. The investigation included the testing of membrane materials because the membrane must resist the abrasion and the periodical back-washing. Another objective of this investigation was to assess the potential of two different TiO(2) materials (Hombikat UV100 and P25) for continuous photocatalytic degradation of persistent organic pollutants. The study focused on the long-term stability of the photocatalytic activity of TiO(2) during its continuous application. The combination of photocatalysis and cross-flow microfiltration allowed the separation and reuse of TiO(2) after the photocatalytic degradation of clofibric acid, carbamazepine and iomeprol. The investigations showed that the photocatalytic activity of P25 and Hombikat UV100 was constant during continuous usage over several days. This study indicates the high potential of the combination of heterogeneous photocatalytic oxidation processes with cross-flow microfiltration accompanied by periodical back-washing of the membrane. Thus environmentally relevant pharmaceuticals and X-ray contrast media can be transformed and mineralized in a continuous water treatment process.

  15. 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.

  16. Erection capability is potentiated by long-term sildenafil treatment: role of blood flow-induced endothelial nitric-oxide synthase phosphorylation.

    PubMed

    Musicki, Biljana; Champion, Hunter C; Becker, Robyn E; Liu, Tongyun; Kramer, Melissa F; Burnett, Arthur L

    2005-07-01

    Despite demonstrated clinical efficacy of sildenafil for the temporary treatment of erectile dysfunction, the possibility that sildenafil used long-term durably augments erectile ability remains unclear. We investigated whether continuous long-term administration of sildenafil at clinically relevant levels to aged rats "primes" the penis for improved erectile ability and involves nitric oxide (NO) or RhoA/Rho-kinase signaling pathways. In aged, but not young rats, sildenafil prolonged erection and increased the protein expressions of phosphorylated endothelial NO synthase (eNOS) at serine-1177 and phosphorylated Akt at serine-473 in penes. Only in the young rat penis, protein expressions of phosphodiesterase-5 and phosphomyosin phosphatase target subunit 1, a marker of Rho-kinase activity, were increased by sildenafil. Sildenafil inhibited phosphodiesterase-5 activity in penes of young and aged rats coincident with assayed free plasma levels of the drug equivalent to clinically therapeutic measurements. We conclude that erectile ability can be enhanced under preconditions of erectile impairment by long-term inhibition of phosphodiesterase-5 and that the effect is mediated by Akt-dependent eNOS phosphorylation. The lack of erectile ability enhancement in young rats by long-term phosphodiesterase-5 inhibition may relate to restrained NO signaling by phosphodiesterase-5 up-regulation, lack of incremental Akt and eNOS phosphorylation, and heightened Rho-kinase signaling in the penis.

  17. Sediment Waves Beneath the West Pacific Warm Pool on Eauripik Rise: A Direct Indicator of Long-Term Bottom Current Flow

    NASA Astrophysics Data System (ADS)

    Baldwin, K.; Mountain, G. S.; Rosenthal, Y.

    2015-12-01

    Variations in ocean dynamics of the western Pacific warm pool (WPWP) have significant impacts on global climate, and understanding this relationship can improve predictions of future climate trends. We report on progress towards establishing a history of water column structure and air-sea interaction of this critical part of the global climate system. Sites proposed and now approved for future drilling by IODP Exp. 363 were surveyed with 2D high-resolution multi-channel seismic grids during cruise 1313 of the R/V Roger Revelle in September 2013. Here we describe observations at proposed site WP2 on the northern Eauripik Rise, near the northern limb of the WPWP. Approximately 400 m of buried sediment waves, with amplitudes of 10-20 m and wavelengths of 1-2 km, are prevalent throughout the ~ 10 x 15 km survey grid. Abyssal sediment waves provide direct evidence of circulation in the deep sea, and can be tied to indirect circulation indicators in sediment cores. Additionally, changes in circulation indicated by changes in bedform geometry can be associated with climatic oscillations. The sediment waves were mapped, characterized, and converted to depth using seismic stacking velocities. Biostratigraphy at DSDP Site 62, 450 km south of WP2 on Eauripik Rise provided age constraints on several horizons correlated between these locations. The oldest waves at WP2 (~ 15 Ma; 400 mbsf) migrate north and increase in amplitude upsection until a key horizon at roughly 280 mbsf is reached. At this level wave migration stops, though wave heights continue to decrease until at seafloor all seismic evidence of current-controlled deposition has disappeared. This morphologic shift, suggested from available data to occur ~10 Ma, indicates a change from strong, long-term current-controlled sedimentation to conditions with little to no bottom current flow. Drilling at WP2 will pinpoint the time of this change and will aid the understanding of the evolution of the WPWP since the middle

  18. FIELD TEST PROGRAM FOR LONG-TERM OPERATION OF A COHPAC SYSTEM FOR REMOVING MERCURY FROM COAL-FIRED FLUE GAS

    SciTech Connect

    Jean Bustard; Charles Lindsey; Paul Brignac; Travis Starns; Sharon Sjostrom; Trent Taylor; Cindy Larson

    2003-10-31

    system. The overall objective is to evaluate the long-term effects of sorbent injection on mercury capture and COHPAC performance. The work is being done on one-half of the gas stream at Alabama Power Company's Plant Gaston Unit 3 (nominally 135 MW). Data from the testing will be used to determine: (1) If sorbent injection into a high air-to-cloth ratio baghouse is a viable, long-term approach for mercury control; and (2) Design criteria and costs for new baghouse/sorbent injection systems that will use a similar, polishing baghouse (TOXECON{trademark}) approach.

  19. FIELD TEST PROGRAM FOR LONG-TERM OPERATION OF A COHPAC SYSTEM FOR REMOVING MERCURY FROM COAL-FIRED FLUE GAS

    SciTech Connect

    Jean Bustard; Charles Lindsey; Paul Brignac; Travis Starns; Sharon Sjostrom; Trent Taylor; Cindy Larson

    2004-01-29

    generating plant that is equipped with a COHPAC{trademark} system. The overall objective is to evaluate the long-term effects of sorbent injection on mercury capture and COHPAC{trademark} performance. The work is being done on one-half of the gas stream at Alabama Power Company's Plant Gaston Unit 3 (nominally 135 MW). Data from the testing will be used to determine: (1) If sorbent injection into a high air-to-cloth ratio baghouse is a viable, long-term approach for mercury control; and (2) Design criteria and costs for new baghouse/sorbent injection systems that will use a similar, polishing baghouse (TOXECON{trademark}) approach.

  20. Field Test Program for Long-Term Operation of a COHPAC System for Removing Mercury from Coal-Fired Flue Gas

    SciTech Connect

    Jean Bustard; Charles Lindsey; Paul Brignac; Travis Starns; Sharon Sjostrom; Cindy Larson

    2006-04-24

    generating plant that is equipped with a COHPAC{reg_sign} system. The overall objective is to evaluate the long-term effects of sorbent injection on mercury capture and COHPAC{reg_sign} performance. The work is being done on one-half of the gas stream at Alabama Power Company's Plant Gaston Unit 3 (nominally 135 MW). Data from the testing will be used to determine: (1) If sorbent injection into a high air-to-cloth ratio baghouse is a viable, long-term approach for mercury control; and (2) Design criteria and costs for new baghouse/sorbent injection systems that will use a similar, polishing baghouse (TOXECON{trademark}) approach.

  1. FIELD TEST PROGRAM FOR LONG-TERM OPERATION OF A COHPAC SYSTEM FOR REMOVING MERCURY FROM COAL-FIRED FLUE GAS

    SciTech Connect

    Jean Bustard; Charles Lindsey; Paul Brignac; Travis Starns; Sharon Sjostrom; Tom Millar

    2003-07-30

    overall objective is to evaluate the long-term effects of sorbent injection on mercury capture and COHPAC performance. The work is being done on one-half of the gas stream at Alabama Power Company's Plant Gaston Unit 3 (nominally 135 MW). Data from the testing will be used to determine: (1) If sorbent injection into a high air-to-cloth ratio baghouse is a viable, long-term approach for mercury control; and (2) Design criteria and costs for new baghouse/sorbent injection systems that will use a similar, polishing baghouse (TOXECON) approach.

  2. Field Test Program for Long-Term Operation of a COHPAC System for Removing Mercury from Coal-Fired Flue Gas

    SciTech Connect

    Jean Bustard; Charles Lindsey; Paul Brignac; Travis Starns; Sharon Sjostrom; Trent Taylor; Cindy Larson

    2005-01-24

    generating plant that is equipped with a COHPAC{reg_sign} system. The overall objective is to evaluate the long-term effects of sorbent injection on mercury capture and COHPAC{reg_sign} performance. The work is being done on one-half of the gas stream at Alabama Power Company's Plant Gaston Unit 3 (nominally 135 MW). Data from the testing will be used to determine: (1) If sorbent injection into a high air-to-cloth ratio baghouse is a viable, long-term approach for mercury control; and (2) Design criteria and costs for new baghouse/sorbent injection systems that will use a similar, polishing baghouse (TOXECON{trademark}) approach.

  3. Field Test Program for Long-Term Operation of a COHPAC System for Removing Mercury from Coal-Fired Flue Gas

    SciTech Connect

    Jean Bustard; Charles Lindsey; Paul Brignac: Travis Starns; Sharon Sjostrom; Trent Taylor; Cindy Larson

    2005-04-28

    generating plant that is equipped with a COHPAC{reg_sign} system. The overall objective is to evaluate the long-term effects of sorbent injection on mercury capture and COHPAC{reg_sign} performance. The work is being done on one-half of the gas stream at Alabama Power Company's Plant Gaston Unit 3 (nominally 135 MW). Data from the testing will be used to determine: (1) If sorbent injection into a high air-to-cloth ratio baghouse is a viable, long-term approach for mercury control; and (2) Design criteria and costs for new baghouse/sorbent injection systems that will use a similar, polishing baghouse (TOXECON{trademark}) approach.

  4. FIELD TEST PROGRAM FOR LONG-TERM OPERATION OF A COHPAC SYSTEM FOR REMOVING MERCURY FROM COAL-FIRED FLUE GAS

    SciTech Connect

    Jean Bustard

    2003-06-13

    long term effects of sorbent injection on mercury capture and COHPAC performance. The work is being done on 1/2 of the gas stream at Alabama Power's Plant Gaston Unit 3 (nominally 135 MW). Data from the testing will be used to determine: (1) Is sorbent injection into a high air-to-cloth ratio baghouse a viable, long term approach for mercury control; and (2) Design criteria and costs for new baghouse/sorbent injection systems that will use a similar, polishing baghouse (TOXECON) approach.

  5. Field Test Program for Long-Term Operation of a COHPAC System for Removing Mercury from Coal-Fired Flue Gas

    SciTech Connect

    Jean Bustard; Charles Lindsey; Paul Brignac; Travis Starns; Sharon Sjostrom; Cindy Larson

    2006-01-27

    generating plant that is equipped with a COHPAC{reg_sign} system. The overall objective is to evaluate the long-term effects of sorbent injection on mercury capture and COHPAC{reg_sign} performance. The work is being done on one-half of the gas stream at Alabama Power Company's Plant Gaston Unit 3 (nominally 135 MW). Data from the testing will be used to determine: (1) If sorbent injection into a high air-to-cloth ratio baghouse is a viable, long-term approach for mercury control; and (2) Design criteria and costs for new baghouse/sorbent injection systems that will use a similar, polishing baghouse (TOXECON{trademark}) approach.

  6. Field Test Program for Long-Term Operation of a COHPAC System for Removing Mercury from Coal-Fired Flue Gas

    SciTech Connect

    Jean Bustard; Charles Lindsey; Paul Brignac; Travis Starns; Sharon Sjostrom; Trent Taylor; Cindy Larson

    2004-10-25

    generating plant that is equipped with a COHPAC{reg_sign} system. The overall objective is to evaluate the long-term effects of sorbent injection on mercury capture and COHPAC{reg_sign} performance. The work is being done on one-half of the gas stream at Alabama Power Company's Plant Gaston Unit 3 (nominally 135 MW). Data from the testing will be used to determine: (1) If sorbent injection into a high air-to-cloth ratio baghouse is a viable, long-term approach for mercury control; and (2) Design criteria and costs for new baghouse/sorbent injection systems that will use a similar, polishing baghouse (TOXECON{trademark}) approach.

  7. Field Test Program for Long-Term Operation of a COHPAC System for Removing Mercury from Coal-Fired Flue Gas

    SciTech Connect

    Jean Bustard; Charles Lindsey; Paul Brignac; Travis Starns; Sharon Sjostrom; Cindy Larson

    2005-10-24

    generating plant that is equipped with a COHPAC{reg_sign} system. The overall objective is to evaluate the long-term effects of sorbent injection on mercury capture and COHPAC{reg_sign} performance. The work is being done on one-half of the gas stream at Alabama Power Company's Plant Gaston Unit 3 (nominally 135 MW). Data from the testing will be used to determine: (1) If sorbent injection into a high air-to-cloth ratio baghouse is a viable, long-term approach for mercury control; and (2) Design criteria and costs for new baghouse/sorbent injection systems that will use a similar, polishing baghouse (TOXECON{trademark}) approach.

  8. FIELD TEST PROGRAM FOR LONG-TERM OPERATION OF A COHPAC SYSTEM FOR REMOVING MERCURY FROM COAL-FIRED FLUE GAS

    SciTech Connect

    Jean Bustard; Charles Lindsey

    2003-01-24

    long term effects of sorbent injection on mercury capture and COHPAC performance. The work is being done on 1/2 of the gas stream at Alabama Power's Plant Gaston Unit 3 (nominally 135 MW). Data from the testing will be used to determine: (1) Is sorbent injection into a high air-to-cloth ratio baghouse a viable, long term approach for mercury control; and (2) Design criteria and costs for new baghouse/sorbent injection systems that will use a similar, polishing baghouse (TOXECON) approach.

  9. Field Test Program for Long-Term Operation of a COHPAC System for Removing Mercury from Coal-Fired Flue Gas

    SciTech Connect

    Jean Bustard; Charles Lindsey; Paul Brignac; Travis Starns; Sharon Sjostrom; Trent Taylor; Cindy Larson

    2004-08-06

    generating plant that is equipped with a COHPAC{reg_sign} system. The overall objective is to evaluate the long-term effects of sorbent injection on mercury capture and COHPAC{reg_sign} performance. The work is being done on one-half of the gas stream at Alabama Power Company's Plant Gaston Unit 3 (nominally 135 MW). Data from the testing will be used to determine: (1) If sorbent injection into a high air-to-cloth ratio baghouse is a viable, long-term approach for mercury control; and (2) Design criteria and costs for new baghouse/sorbent injection systems that will use a similar, polishing baghouse (TOXECON{trademark}) approach.

  10. Field Test Program for Long-Term Operation of a COHPAC System for Removing Mercury from Coal-Fired Flue Gas

    SciTech Connect

    Jean Bustard; Charles Lindsey; Paul Brignac; Travis Starns; Sharon Sjostrom; Cindy Larson

    2005-07-14

    generating plant that is equipped with a COHPAC{reg_sign} system. The overall objective is to evaluate the long-term effects of sorbent injection on mercury capture and COHPAC{reg_sign} performance. The work is being done on one-half of the gas stream at Alabama Power Company's Plant Gaston Unit 3 (nominally 135 MW). Data from the testing will be used to determine: (1) If sorbent injection into a high air-to-cloth ratio baghouse is a viable, long-term approach for mercury control; and (2) Design criteria and costs for new baghouse/sorbent injection systems that will use a similar, polishing baghouse (TOXECON{trademark}) approach.

  11. Field Test Program for Long-Term Operation of a COHPAC System for Removing Mercury from Coal-Fired Flue Gas

    SciTech Connect

    Jean Bustard; Charles Lindsey; Paul Brignac; Travis Starns; Sharon Sjostrom; Trent Taylor; Cindy Larson

    2004-06-04

    generating plant that is equipped with a COHPAC{reg_sign} system. The overall objective is to evaluate the long-term effects of sorbent injection on mercury capture and COHPAC{reg_sign} performance. The work is being done on one-half of the gas stream at Alabama Power Company's Plant Gaston Unit 3 (nominally 135 MW). Data from the testing will be used to determine: (1) If sorbent injection into a high air-to-cloth ratio baghouse is a viable, long-term approach for mercury control; and (2) Design criteria and costs for new baghouse/sorbent injection systems that will use a similar, polishing baghouse (TOXECON{trademark}) approach.

  12. Establishing a Long-term 30 Year Global Solar Resource at 10 km Resolution: Preliminary Results From Test Processing and Continuing Plans

    NASA Astrophysics Data System (ADS)

    Stackhouse, P. W.; Mikovitz, J. C.; Cox, S. J.; Zhang, T.; Perez, R.; Schlemmer, J.; Sengupta, M.; Knapp, K. R.

    2014-12-01

    As renewable energy system become more prevalent, improved global long-term, up-to-date records are needed to better understand and quantify the solar resource and variability. Toward this end, a project involving NASA, DOE NREL, SUNY-Albany and the NOAA National Climatic Data Center (NCDC) was initiated to provide NREL with a solar resource mapping production system for improved depiction of global long-term solar resources that provides the capacity for continual updates. This new production system is made possible by the efforts of NOAA and NASA to completely reprocess the International Satellite Cloud Climatology Project (ISCCP) data set that provides satellite visible and infrared radiances together with retrieved cloud and surface properties on a 3-hourly basis beginning from July 1983 at an effective 10 km resolution. Thus, working with SUNY and NCDC, NASA will develop and test an improved production system that will yield an operational production system for NREL to continually update the Earth's solar resource. In this presentation, we provide a general overview of this project together with samples of the new solar irradiance mapped data products and comparisons to surface measurements at various locations across the world. Here, a three-year prototype of the anticipated ISCCP data set called GridSat is used to assess the algorithms and demonstrate the production system. GridSat maps together cross-calibrated visible and IR reflectances from all the world's geosynchronous satellites at 10 km and 3-hourly respectively. The results are shown and discussed in comparison to existing solar data products. Additionally, the solar irradiance values are compared to various Baseline Surface Radiation Network surface site measurements and other high quality surface measurements. The statistics of the agreement between the measurements and new satellite estimates are also reviewed. The team is now testing a beta release of the revised ISCCP data set through the NOAA

  13. Decision document for performing a long-term pumping test at the S-3 Site, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect

    1995-02-01

    One of the principal problems confronting the remediation of Bear Creek Valley is the cleanup of contaminated groundwater. The S-3 Site is one of the locations in the valley where groundwater is most contaminated, and contamination from the S-3 Site has also caused extensive contamination of downgradient groundwater. This groundwater plume, therefore, has a high priority in the Bear Creek Valley remedial process. Pumping and treating groundwater was identified early in the feasibility study as a likely remedial alternative for the S-3 Site groundwater plume. The hydrology and geochemistry of the plume are extremely complex. There is a high degree of uncertainty in the current understanding of how the aquifer will react physically and chemically to pumping, making evaluation of a pump-and-treat alternative impractical at the present time. Before a pump-and-treat alternative can be evaluated, its technical practicability, effectiveness, and projected cost must be determined. A long-term pumping test (LTPT) at the S-3 Site has been proposed so that the information necessary to carry out this evaluation can be collected. This document constitutes the first phase in the planning process for this test.

  14. An empirical test of the 'shark nursery area concept' in Texas bays using a long-term fisheries-independent data set

    USGS Publications Warehouse

    Froeschke, John T.; Stunz, Gregory W.; Sterba-Boatwright, Blair; Wildhaber, Mark L.

    2010-01-01

    Using a long-term fisheries-independent data set, we tested the 'shark nursery area concept' proposed by Heupel et al. (2007) with the suggested working assumptions that a shark nursery habitat would: (1) have an abundance of immature sharks greater than the mean abundance across all habitats where they occur; (2) be used by sharks repeatedly through time (years); and (3) see immature sharks remaining within the habitat for extended periods of time. We tested this concept using young-of-the-year (age 0) and juvenile (age 1+ yr) bull sharks Carcharhinus leucas from gill-net surveys conducted in Texas bays from 1976 to 2006 to estimate the potential nursery function of 9 coastal bays. Of the 9 bay systems considered as potential nursery habitat, only Matagorda Bay satisfied all 3 criteria for young-of-the-year bull sharks. Both Matagorda and San Antonio Bays met the criteria for juvenile bull sharks. Through these analyses we examined the utility of this approach for characterizing nursery areas and we also describe some practical considerations, such as the influence of the temporal or spatial scales considered when applying the nursery role concept to shark populations.

  15. Long-term Cost-Effectiveness of Diagnostic Tests for Assessing Stable Chest Pain: Modeled Analysis of Anatomical and Functional Strategies.

    PubMed

    Bertoldi, Eduardo G; Stella, Steffan F; Rohde, Luis E; Polanczyk, Carisi A

    2016-05-01

    Several tests exist for diagnosing coronary artery disease, with varying accuracy and cost. We sought to provide cost-effectiveness information to aid physicians and decision-makers in selecting the most appropriate testing strategy. We used the state-transitions (Markov) model from the Brazilian public health system perspective with a lifetime horizon. Diagnostic strategies were based on exercise electrocardiography (Ex-ECG), stress echocardiography (ECHO), single-photon emission computed tomography (SPECT), computed tomography coronary angiography (CTA), or stress cardiac magnetic resonance imaging (C-MRI) as the initial test. Systematic review provided input data for test accuracy and long-term prognosis. Cost data were derived from the Brazilian public health system. Diagnostic test strategy had a small but measurable impact in quality-adjusted life-years gained. Switching from Ex-ECG to CTA-based strategies improved outcomes at an incremental cost-effectiveness ratio of 3100 international dollars per quality-adjusted life-year. ECHO-based strategies resulted in cost and effectiveness almost identical to CTA, and SPECT-based strategies were dominated because of their much higher cost. Strategies based on stress C-MRI were most effective, but the incremental cost-effectiveness ratio vs CTA was higher than the proposed willingness-to-pay threshold. Invasive strategies were dominant in the high pretest probability setting. Sensitivity analysis showed that results were sensitive to costs of CTA, ECHO, and C-MRI. Coronary CT is cost-effective for the diagnosis of coronary artery disease and should be included in the Brazilian public health system. Stress ECHO has a similar performance and is an acceptable alternative for most patients, but invasive strategies should be reserved for patients at high risk. © 2016 Wiley Periodicals, Inc.

  16. A spatially supported forced-choice recognition test reveals children’s long-term memory for newly learned word forms

    PubMed Central

    Gordon, Katherine R.; McGregor, Karla K.

    2014-01-01

    Children’s memories for the link between a newly trained word and its referent have been the focus of extensive past research. However, memory for the word form itself is rarely assessed among preschool-age children. When it is, children are typically asked to verbally recall the forms, and they generally perform at floor on such tests. To better measure children’s memory for word forms, we aimed to design a more sensitive test that required recognition rather than recall, provided spatial cues to off-set the phonological memory demands of the test, and allowed pointing rather than verbal responses. We taught 12 novel word-referent pairs via ostensive naming to sixteen 4- to 6-year-olds and measured their memory for the word forms after a week-long retention interval using the new spatially supported form recognition test. We also measured their memory for the word-referent links and the generalization of the links to untrained referents with commonly used recognition tests. Children demonstrated memory for word forms at above chance levels; however, their memory for forms was poorer than their memory for trained or generalized word-referent links. When in error, children were no more likely to select a foil that was a close neighbor to the target form than a maximally different foil. Additionally, they more often selected correct forms that were among the first six than the last six to be trained. Overall, these findings suggest that children are able to remember word forms after a limited number of ostensive exposures and a long-term delay. However, word forms remain more difficult to learn than word-referent links and there is an upper limit on the number of forms that can be learned within a given period of time. PMID:24639660

  17. Long-term environmental stewardship.

    SciTech Connect

    Nagy, Michael David

    2010-08-01

    The purpose of this Supplemental Information Source Document is to effectively describe Long-Term Environmental Stewardship (LTES) at Sandia National Laboratories/New Mexico (SNL/NM). More specifically, this document describes the LTES and Long-Term Stewardship (LTS) Programs, distinguishes between the LTES and LTS Programs, and summarizes the current status of the Environmental Restoration (ER) Project.

  18. Long-term urethral catheterisation.

    PubMed

    Turner, Bruce; Dickens, Nicola

    This article discusses long-term urethral catheterisation, focusing on the relevant anatomy and physiology, indications for the procedure, catheter selection and catheter care. It is important that nurses have a good working knowledge of long-term catheterisation as the need for this intervention will increase with the rise in chronic health conditions and the ageing population.

  19. Presynaptic long-term plasticity

    PubMed Central

    Yang, Ying; Calakos, Nicole

    2013-01-01

    Long-term synaptic plasticity is a major cellular substrate for learning, memory, and behavioral adaptation. Although early examples of long-term synaptic plasticity described a mechanism by which postsynaptic signal transduction was potentiated, it is now apparent that there is a vast array of mechanisms for long-term synaptic plasticity that involve modifications to either or both the presynaptic terminal and postsynaptic site. In this article, we discuss current and evolving approaches to identify presynaptic mechanisms as well as discuss their limitations. We next provide examples of the diverse circuits in which presynaptic forms of long-term synaptic plasticity have been described and discuss the potential contribution this form of plasticity might add to circuit function. Finally, we examine the present evidence for the molecular pathways and cellular events underlying presynaptic long-term synaptic plasticity. PMID:24146648

  20. Packaging Reliability Effect of ENIG and ENEPIG Surface Finishes in Board Level Thermal Test under Long-Term Aging and Cycling.

    PubMed

    Shen, Chaobo; Hai, Zhou; Zhao, Cong; Zhang, Jiawei; Evans, John L; Bozack, Michael J; Suhling, Jeffrey C

    2017-04-26

    This study illustrates test results and comparative literature data on the influence of isothermal aging and thermal cycling associated with Sn-1.0Ag-0.5Cu (SAC105) and Sn-3.0Ag-0.5Cu (SAC305) ball grid array (BGA) solder joints finished with ENIG and ENEPIG on the board side and ENIG on the package side compared with ImAg plating on both sides. The resulting degradation data suggests that the main concern for 0.4 mm pitch 10 mm package size BGA is package side surface finish, not board side. That is, ENIG performs better than immersion Ag for applications involving long-term isothermal aging. SAC305, with a higher relative fraction of Ag₃Sn IMC within the solder, performs better than SAC105. SEM and polarized light microscope analysis show cracks propagated from the corners to the center or even to solder bulk, which eventually causes fatigue failure. Three factors are discussed: IMC, grain structure, and Ag₃Sn particle. The continuous growth of Cu-Sn intermetallic compounds (IMC) and grains increase the risk of failure, while Ag₃Sn particles seem helpful in blocking the crack propagation.

  1. Long-term testing of a high-temperature proton exchange membrane fuel cell short stack operated with improved polybenzimidazole-based composite membranes

    NASA Astrophysics Data System (ADS)

    Pinar, F. Javier; Cañizares, Pablo; Rodrigo, Manuel A.; Úbeda, Diego; Lobato, Justo

    2015-01-01

    In this work, the feasibility of a 150 cm2 high-temperature proton exchange membrane fuel cell (HT-PEMFC) stack operated with modified proton exchange membranes is demonstrated. The short fuel cell stack was manufactured using a total of three 50 cm2 membrane electrode assemblies (MEAs). The PEM technology is based on a polybenzimidazole (PBI) membrane. The obtained results were compared with those obtained using a HT-PEMFC stack with unmodified membranes. The membranes were cast from a PBI polymer synthesized in the laboratory, and the modified membranes contained 2 wt.% micro-sized TiO2 as a filler. Long-term tests were performed in both constant and dynamic loading modes. The fuel cell stack with 2 wt.% TiO2 composite PBI membranes exhibited an irreversible voltage loss of less than 2% after 1100 h of operation. In addition, the acid loss was reduced from 2% for the fuel cell stack with unmodified membranes to 0.6% for the fuel cell stack with modified membranes. The results demonstrate that introducing filler into the membranes enhances the durability and stability of this type of fuel cell technology. Moreover, the fuel cell stack system also exhibits very rapid and stable power and voltage output responses under dynamic load regimes.

  2. Long-term decrease of atmospheric test {sup 137}Cs in the soil-prairie plant-milk pathway in southern Chile

    SciTech Connect

    Schuller, P. Ellies, A.; Handl, J.

    1998-07-01

    The time dependency of nuclear test {sup 137}Cs in soil, prairie plants, and milk was observed on pastures of seven dairy farms in the 10th Region, Chile, from 1982 to 1997, without any appreciable deposition of radioactive fallout after 1983. Whereas the {sup 137}Cs concentration in the soil decreased at a rate close to that of the radionuclide`s physical decay during the whole observation period, the rate of decrease of the {sup 137}Cs concentration in the prairie plants and in the milk, having been very rapid between 1982--1990, became slower between 1991--1997. The effective half-lives of the concentration in plants were found to be 5.6 y and 12 y during the first and second observation periods, respectively. Similar half-lives of 5.5 y and 13 y were found for the concentration decline in milk during each period. These data clearly demonstrate a reduction in the long-term decrease of the {sup 137}Cs plant uptake, and consequently in the decrease of the {sup 137}Cs concentration in milk, resulting from a decline of {sup 137}Cs availability for prairie plants in the Hapludand soils over the whole 15-y observation period.

  3. Advanced coal technology by-products: Long-term results from landfill test cells and their implications for reuse or disposal applications

    SciTech Connect

    Weinberg, A.; Harness, J.L.

    1994-06-01

    New air pollution regulations under the 1991 Clean Air Act and other legislation are motivating continued development and implementation, of cleaner, more efficient processes for converting coal to electrical power. These clean coal processes produce solid by-products which differ in important respects from conventional pulverized coal combustion ash. Clean coal by-products` contain both residual sorbent and captured SO{sub 2} control products, as well as the mineral component of the coal. The Department of Energy/Morgantown Energy Technology Center has contracted Radian Corporation to construct and monitor landfill test cells with a several different advanced coal combustion by-products at three locations around the US; data from these sites provide a unique picture of the long-term field behavior of clean coal combustion by-products. The field testing sites were located in western Colorado, northern Ohio, and central Illinois. Fluidized bed combustion and lime injection residues are characterized by high lime and calcium sulfate contents` contributed by reacted and unreacted sorbent materials, and produce an leachate, when wetted. Compared with conventional coal fly ash, the clean coal technology ashes have been noted for potential difficulties when wetted, including corrosivity, heat generation, cementation, and swelling on hydration. On the other hand, the high lime content and chemical reactivity of clean coal residues offer potential benefits in reuse as a cementitious material.The results of three years of data collection suggest a fairly consistent pattern of behavior for the calcium-based dry sorbent systems involved in the project, despite differences in the initial of the by-products, differences in the methods of placement, and differences in climate at the test sites.

  4. Arsenic Removal from Groundwater by Solar Driven Inline-Electrolytic Induced Co-Precipitation and Filtration-A Long Term Field Test Conducted in West Bengal.

    PubMed

    Otter, Philipp; Malakar, Pradyut; Jana, Bana Bihari; Grischek, Thomas; Benz, Florian; Goldmaier, Alexander; Feistel, Ulrike; Jana, Joydev; Lahiri, Susmita; Alvarez, Juan Antonio

    2017-10-02

    Arsenic contamination in drinking water resources is of major concern in the Ganga delta plains of West Bengal in India and Bangladesh. Here, several laboratory and field studies on arsenic removal from drinking water resources were conducted in the past and the application of strong-oxidant-induced co-precipitation of arsenic on iron hydroxides is still considered as the most promising mechanism. This paper suggests an autonomous, solar driven arsenic removal setting and presents the findings of a long term field test conducted in West Bengal. The system applies an inline-electrolytic cell for in situ chlorine production using the natural chloride content of the water and by that substituting the external dosing of strong oxidants. Co-precipitation of As(V) occurs on freshly formed iron hydroxide, which is removed by Manganese Greensand Plus(®) filtration. The test was conducted for ten months under changing source water conditions considering arsenic (187 ± 45 µg/L), iron (5.5 ± 0.8 mg/L), manganese (1.5 ± 0.4 mg/L), phosphate (2.4 ± 1.3 mg/L) and ammonium (1.4 ± 0.5 mg/L) concentrations. Depending on the system setting removal rates of 94% for arsenic (10 ± 4 µg/L), >99% for iron (0.03 ± 0.03 mg/L), 96% for manganese (0.06 ± 0.05 mg/L), 72% for phosphate (0.7 ± 0.3 mg/L) and 84% for ammonium (0.18 ± 0.12 mg/L) were achieved-without the addition of any chemicals/adsorbents. Loading densities of arsenic on iron hydroxides averaged to 31 µgAs/mgFe. As the test was performed under field conditions and the here proposed removal mechanisms work fully autonomously, it poses a technically feasible treatment alternative, especially for rural areas.

  5. Factors to be Considered in Long-Term Monitoring of a Former Nuclear Test Site in a Geophysically Active and Water-rich Environment

    NASA Astrophysics Data System (ADS)

    Eichelberger, J.; Hill, G.; Patrick, M.; Freymueller, J.; Barnes, D.; Kelley, J.; Layer, P.

    2001-12-01

    The US Department of Energy (USDOE) is currently undertaking an ambitious program of environmental remediation of the surface of Amchitka Island in the western Aleutians, where three underground nuclear tests were conducted during 1963-1971. Among these tests was Cannikin, at approximately 5 megatons the largest nuclear device ever exploded underground by the United States and equivalent in seismic energy release to a magnitude 7 earthquake. The blast caused about 1 m of uplift of the Bering Sea coastline in the 3-km-wide fault-bounded block within which it was detonated. The impending final transfer of stewardship of this area to the US Fish and Wildlife Service as part of the Alaska Maritime National Wildlife Refuge raises anew the question of the potential for transport of radionuclides from the shot cavity, located at 1791 m depth in mafic laharic breccias, into the accessible environment. In particular, there is concern about whether such contaminants could become concentrated in the marine food chain that is used for subsistence by Alaskan Natives (and by the broader international community through the North Pacific and Bering Fisheries). Both possible transport pathways in the form of faults and transport medium in the form of abundant water are present. Since the pre-plate tectonics paradigm days of active testing, the scientific community's understanding of the tectonic context of the Aleutian Islands has grown tremendously. Recently, the first direct measurements of motion within the arc have been made. How this new understanding should guide plans for long-term monitoring of the site is an important question. Convergence due to subduction of the North Pacific plate beneath North America ranges from near-normal at the Alaska Peninsula and eastern Aleutian islands to highly oblique in the west. Amchitka itself can be seen as a subaerial portion of a 200-km-long Rat Island arc crest segment. This fragment has torn from the Andreanof Islands to the east at

  6. Atlanto-occipital catheterization of young rats for long-term drug delivery into the lumbar subarachnoid space combined with in vivo testing and electrophysiology in situ.

    PubMed

    Kopach, Olga; Krotov, Volodymyr; Voitenko, Nana

    2017-10-01

    Catheterization has been widely used in neuroscience and pain research for local drug delivery. Though different modifications were developed, the use of young animals for spinal catheterization remains limited because of a little success rate. A reliable technique is needed to catheterize young animals aimed for in vivo testing combined with spinal cord electrophysiology, often limited by animal age, to facilitate pain research. We describe intrathecal catheterization of young rats (3-week-old) through atlanto-occipical approach for long-lasting drug delivery into the lumbar subarachnoid space. The technique represents a surgical approach of minimized invasiveness that requires PE-10 catheter and few equipment of standard laboratory use. Behavioral assessments revealed that spinal catheterization does not change peripheral sensitivity of different modalities (thermal and mechanical) and gives no rise to locomotive deficit or anxiety-like behavior in young rats. The long-term administration of genetic material (oligodeoxynucleotides given up to 4days), examined both in vivo and in situ, produced no adverse effects on basal peripheral sensitivity, but changed the AMPA receptor-mediated currents in sensory interneurons of the spinal cord. Dissimilar to already described methods, the method is designed for the use of young rats for behavioral testing in vivo and/or spinal cord electrophysiology in situ. A practical method for spinal catheterization of young animals designed for studies in vivo and in situ is proposed. The method is rapid and effective and should facilitate investigation of therapeutic effects on both systemic and subcellular levels, as an advantage over the existing methods. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. An evaluation of the effects of long-term cell phone use on the testes via light and electron microscope analysis.

    PubMed

    Çelik, Serkan; Aridogan, I Atilla; Izol, Volkan; Erdoğan, Seyda; Polat, Sait; Doran, Saban

    2012-02-01

    To investigate whether the low-intensity electromagnetic waves transmitted by cell phones cause histopathological or ultrastructural changes in the testes of rats. Wistar-Kyoto male rats were placed into either a control group or a group that was exposed to an electromagnetic field (EMF). Two cell phones with Specific Absorbation Rate values of 1.58 were placed and left off in cages that housed 15 rats included in the control group, and four cell phones were placed and left on in cages that housed 30 rats included in the experimental group. After 3 months, weights, seminiferous tubule diameters, and spermatogenic cell conditions of all testes of the rats were evaluated. One half of each testis was examined also under an electron microscope. No significant differences were observed between the testis weights, seminiferous tubule diameters, and histopathological evaluations between rats that had and had not been exposed to EMF. Electron microscope analysis revealed that the membrana propria thickness and the collagen fiber contents were increased and the capillary veins extended in the experimental group. Common vacuolization in the cytoplasm of the Sertoli cells, growth of electron-dense structures, and existence of large lipid droplets were noted as the remarkable findings of this study. Although the cells that had been exposed to long-term, low-dose EMF did not present any findings that were contrary to the control conditions, the changes observed during ultrastructural examination gave the impression that significant changes may occur if the study period were to be extended. Longer studies are needed to better understand the effects of EMFs on testis tissue. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Long-term pumping test to study the impact of an open-loop geothermal system on seawater intrusion in a coastal aquifer: the case study of Bari (Southern Italy)

    NASA Astrophysics Data System (ADS)

    Clementina Caputo, Maria; Masciale, Rita; Masciopinto, Costantino; De Carlo, Lorenzo

    2016-04-01

    The high cost and scarcity of fossil fuels have promoted the increased use of natural heat for a number of direct applications. Just as for fossil fuels, the exploitation of geothermal energy should consider its environmental impact and sustainability. Particular attention deserves the so-called open loop geothermal groundwater heat pump (GWHP) system, which uses groundwater as geothermal fluid. From an economic point of view, the implementation of this kind of geothermal system is particularly attractive in coastal areas, which have generally shallow aquifers. Anyway the potential problem of seawater intrusion has led to laws that restrict the use of groundwater. The scarcity of freshwater could be a major impediment for the utilization of geothermal resources. In this study a new methodology has been proposed. It was based on an experimental approach to characterize a coastal area in order to exploit the low-enthalpy geothermal resource. The coastal karst and fractured aquifer near Bari, in Southern Italy, was selected for this purpose. For the purpose of investigating the influence of an open-loop GWHP system on the seawater intrusion, a long-term pumping test was performed. The test simulated the effects of a prolonged withdrawal on the chemical-physical groundwater characteristics of the studied aquifer portion. The duration of the test was programmed in 16 days, and it was performed with a constant pumping flowrate of 50 m3/h. The extracted water was outflowed into an adjacent artificial channel, by means of a piping system. Water depth, temperature and electrical conductivity of the pumped water were monitored for 37 days, including also some days before and after the pumping duration. The monitored parameters, collected in the pumping and in five observation wells placed 160 m down-gradient with respect to the groundwater flow direction, have been used to estimate different scenarios of the impact of the GWHP system on the seawater intrusion by mean of a

  9. Decision-analytic modeling to evaluate the long-term effectiveness and cost-effectiveness of HPV-DNA testing in primary cervical cancer screening in Germany.

    PubMed

    Sroczynski, Gaby; Schnell-Inderst, Petra; Mühlberger, Nikolai; Lang, Katharina; Aidelsburger, Pamela; Wasem, Jürgen; Mittendorf, Thomas; Engel, Jutta; Hillemanns, Peter; Petry, Karl Ulrich; Krämer, Alexander; Siebert, Uwe

    2010-04-27

    Persistent infections with high-risk types of human papillomavirus (HPV) are associated with the development of cervical neoplasia. Compared to cytology HPV testing is more sensitive in detecting high-grade cervical cancer precursors, but with lower specificity. HPV based primary screening for cervical cancer is currently discussed in Germany. Decisions should be based on a systematic evaluation of the long-term effectiveness and cost-effectiveness of HPV based primary screening. What is the long-term clinical effectiveness (reduction in lifetime risk of cervical cancer and death due to cervical cancer, life years gained) of HPV testing and what is the cost-effectiveness in Euro per life year gained (LYG) of including HPV testing in primary cervical cancer screening in the German health care context? How can the screening program be improved with respect to test combination, age at start and end of screening and screening interval and which recommendations should be made for the German health care context? A previously published and validated decision-analytic model for the German health care context was extended and adapted to the natural history of HPV infection and cervical cancer in order to evaluate different screening strategies that differ by screening interval, and tests, including cytology alone, HPV testing alone or in combination with cytology, and HPV testing with cytology triage for HPV-positive women. German clinical, epidemiological and economic data were used. In the absence of individual data, screening adherence was modelled independently from screening history. Test accuracy data were retrieved from international meta-analyses. Predicted outcomes included reduction in lifetime-risk for cervical cancer cases and deaths, life expectancy, lifetime costs, and discounted incremental cost-effectiveness ratios (ICER). The perspective of the third party payer and 3% annual discount rate were adopted. Extensive sensitivity analyses were performed in order

  10. Long-Term Impacts of Educational Interventions

    ERIC Educational Resources Information Center

    Deming, David James

    2010-01-01

    The school accountability movement has led to a marked increase in the use of standardized test scores to measure school and teacher productivity, yet little is known about the correlation between test score gains and improvements in long-term outcomes. In the first chapter of my dissertation, I study the impact of a school choice policy in…

  11. Long-Term Impacts of Educational Interventions

    ERIC Educational Resources Information Center

    Deming, David James

    2010-01-01

    The school accountability movement has led to a marked increase in the use of standardized test scores to measure school and teacher productivity, yet little is known about the correlation between test score gains and improvements in long-term outcomes. In the first chapter of my dissertation, I study the impact of a school choice policy in…

  12. Long-term effects of nicotine on the forced swimming test in mice: an experimental model for the study of depression caused by smoke.

    PubMed

    Mannucci, Carmen; Tedesco, Michele; Bellomo, Maria; Caputi, Achille P; Calapai, Gioacchino

    2006-10-01

    Large evidence showing an association between depression and tobacco smoking is known. Nicotine is the active chemical responsible for smoking addiction, and its withdrawal may induce in smokers greater sensitivity to stress. Our aim has been to investigate the links between tobacco addiction and depression by studying the long-term effects of repeated administration of nicotine followed by dependence, to forced swimming test, serotonin content and 5-HT(1A) expression in diencephalon. Dependence has been induced by daily subcutaneous injection in mice of nicotine (2mg/kg four injections daily) for 15 days and assessed after nicotine withdrawal with an abstinence scale; control animals received daily subcutaneous injection of saline for the same period. Experiments on forced swimming test have been carried out at t=0 (last day of nicotine or saline treatment), and 15, 30, 45 and 60 days after saline or nicotine withdrawal. Both control mice and nicotine mice have been pre-treated with oral 5-hydroxy-tryptophan (12.5-50mg/kg), precursor of serotonin, before forced swimming test. Nicotine mice have shown on forced swimming test a significant increase of immobility time compared to control mice. This increase was not evident in nicotine mice treated with 5-hydroxy-tryptophan and treatment with the selective serotonin receptorial antagonist WAY 100635 (WAY) abolished 5-hydroxy-tryptophan effects. Evaluation of diencephalic serotonin, performed at t=0 showed an increase of diencephalic serotonin content, while serotonin measured 15, 30, 45 and 60 days after nicotine withdrawal, was significantly reduced in nicotine mice compared to control mice. Western blot analysis showed a great reduction of 5-HT(1A) receptor expression in nicotine mice measured at t=0 (last day of treatment) and at 15 and 30 days after nicotine withdrawal compared to control mice. Our results show that (i) behavioural alterations estimated with forced swimming test and (ii) changes in diencephalic

  13. Long-term corrosion studies

    SciTech Connect

    Gdowski, G.

    1998-05-29

    The scope of this activity is to assess the long-term corrosion properties of metallic materials under consideration for fabricating waste package containers. Three classes of metals are to be assessed: corrosion resistant, intermediate corrosion resistant, and corrosion allowance. Corrosion properties to be evaluated are general, pitting and crevice corrosion, stress-corrosion cracking, and galvanic corrosion. The performance of these materials will be investigated under conditions that are considered relevant to the potential emplacement site. Testing in four aqueous solutions, and vapor phases above them, and at two temperatures are planned for this activity. (The environmental conditions, test metals, and matrix are described in detail in Section 3.0.) The purpose and objective of this activity is to obtain the kinetic and mechanistic information on degradation of metallic alloys currently being considered for waste package containers. This information will be used to provide assistance to (1) waste package design (metal barrier selection) (E-20-90 to E-20-92), (2) waste package performance assessment activities (SIP-PA-2), (3) model development (E-20-75 to E-20-89). and (4) repository license application.

  14. The Long-term Effect of Bacille Calmette-Guérin Vaccination on Tuberculin Skin Testing: A 55-Year Follow-Up Study.

    PubMed

    Mancuso, James D; Mody, Rupal M; Olsen, Cara H; Harrison, Lee H; Santosham, Mathuram; Aronson, Naomi E

    2017-08-01

    Bacille Calmette-Guérin (BCG) vaccination is known to cause false-positive tuberculin skin test (TST) results from cross-reactions with mycobacterial antigens. However, the duration of BCG vaccination influence on the TST is poorly characterized. The objective of this study was to assess the long-term effect of BCG vaccination on TST reactivity. Data on TST reactivity were prospectively collected during 1935 to 1947 as part of a clinical trial among Native Americans/Alaskan Natives and were retrospectively collected thereafter between 1948 and 1998. TST induration of ≥ 10 mm was defined as a positive reaction. Kaplan-Meier analysis and multivariate Cox regression were used to compare the time to TST conversion and reversion between the BCG and placebo groups. BCG vaccination after infancy was associated with an increased risk of TST reactivity in the first 15 years after vaccination (adjusted hazard ratio [HR], 2.33). This association remained during the interval 16 to 55 years after vaccination, although the effect was attenuated (adjusted HR, 1.26). Age at vaccination modestly impacted the effect of BCG on TST results in the first 15 years. Positive TST results among the BCG-vaccinated group were more likely to revert to negative results during the first 15 years but not in the latter period. This study provides evidence that BCG vaccination after infancy may influence TST results beyond the 10-year period conventionally accepted by the Centers for Disease Control and Prevention (CDC), extending up to 55 years after vaccination. This suggests that BCG vaccination should be taken into account when interpreting TST results regardless of the time elapsed since vaccination. Published by Elsevier Inc.

  15. Long-term impact of pre-operative physical rehabilitation protocol on the 6-min walk test of patients with adolescent idiopathic scoliosis: A randomized clinical trial.

    PubMed

    Dos Santos Alves, V L; Stirbulov, R; Avanzi, O

    2015-01-01

    Monitored physical activities in patients with adolescent idiopathic scoliosis (AIS) have been shown to improve physical performance, endurance and cardiopulmonary function and may be assessed by the 6-min walk test (6MWT). We aimed to evaluate the long-term results of the 6MWT after a rehabilitation protocol employed before surgical correction for AIS. This prospective randomized clinical trial studied the impact of a 4-month pre-operative physical rehabilitation protocol on post-operative cardiopulmonary function and physical endurance, by using the 6MWT, in patients with AIS submitted to surgical correction, comparing them to matched controls without physical rehabilitation. Studied variables were heart and respiratory rate, systolic and diastolic blood pressure, peripheral blood oxygen saturation, Borg score, and distance walked. Patients were assessed at baseline, after 4 months of rehabilitation, and 3, 6 and 12 months post-operatively. A total of 50 patients with AIS were included in the study and allocated blindly, by simple randomization, into either one of the two groups, with 25 patients each: study group (pre-operative physical rehabilitation) and control group. The physical rehabilitation protocol promoted significant progressive improvement in heart and respiratory rate, peripheral blood oxygen saturation, distance walked, and level of effort assessed by the Borg scale after surgery. Post-surgical recovery, evaluated by 6MWT, was significantly better in patients who underwent a 4-month pre-operative physical rehabilitation protocol. Copyright © 2013 Sociedade Portuguesa de Pneumologia. Published by Elsevier España, S.L.U. All rights reserved.

  16. Long-Term Carbon Injection Field Test for 90% Mercury Removal for a PRB Unit a Spray Dryer and Fabric Filter

    SciTech Connect

    Sjostrom, Sharon; Amrhein, Jerry

    2009-04-30

    The power industry in the U.S. is faced with meeting regulations to reduce the emissions of mercury compounds from coal-fired plants. Injecting a sorbent such as powdered activated carbon (PAC) into the flue gas represents one of the simplest and most mature approaches to controlling mercury emissions from coal-fired boilers. The purpose of this test program was to evaluate the long-term mercury removal capability, long-term mercury emissions variability, and operating and maintenance (O&M) costs associated with sorbent injection on a configuration being considered for many new plants. Testing was conducted by ADA Environmental Solutions (ADA) at Rocky Mountain Power’s (RMP) Hardin Station through funding provided by DOE/NETL, RMP, and other industry partners. The Hardin Station is a new plant rated at 121 MW gross that was first brought online in April of 2006. Hardin fires a Powder River Basin (PRB) coal and is configured with selective catalytic reduction (SCR) for NOx control, a spray dryer absorber (SDA) for SO2 control, and a fabric filter (FF) for particulate control. Based upon previous testing at PRB sites with SCRs, very little additional mercury oxidation from the SCR was expected at Hardin. In addition, based upon results from DOE/NETL Phase II Round I testing at Holcomb Station and results from similarly configured sites, low native mercury removal was expected across the SDA and FF. The main goal of this project was met—sorbent injection was used to economically and effectively achieve 90% mercury control as measured from the air heater (AH) outlet to the stack for a period of ten months. This goal was achieved with DARCO® Hg-LH, Calgon FLUEPAC®-MC PLUS and ADA Power PAC PREMIUM brominated activated carbons at nominal loadings of 1.5–2.5 lb/MMacf. An economic analysis determined the twenty-year levelized cost to be 0.87 mills/kW-hr, or $15,000/lb Hg removed. No detrimental effects on other equipment or plant operations were observed. The