Science.gov

Sample records for long-term solar activity

  1. Long-term persistence of solar activity

    NASA Technical Reports Server (NTRS)

    Ruzmaikin, Alexander; Feynman, Joan; Robinson, Paul

    1994-01-01

    We examine the question of whether or not the non-periodic variations in solar activity are caused by a white-noise, random process. The Hurst exponent, which characterizes the persistence of a time series, is evaluated for the series of C-14 data for the time interval from about 6000 BC to 1950 AD. We find a constant Hurst exponent, suggesting that solar activity in the frequency range from 100 to 3000 years includes an important continuum component in addition to the well-known periodic variations. The value we calculate, H approximately 0.8, is significantly larger than the value of 0.5 that would correspond to variations produced by a white-noise process. This value is in good agreement with the results for the monthly sunspot data reported elsewhere, indicating that the physics that produces the continuum is a correlated random process and that it is the same type of process over a wide range of time interval lengths.

  2. Long-term persistence of solar activity. [Abstract only

    NASA Technical Reports Server (NTRS)

    Ruzmaikin, Alexander; Feynman, Joan; Robinson, Paul

    1994-01-01

    The solar irradiance has been found to change by 0.1% over the recent solar cycle. A change of irradiance of about 0.5% is required to effect the Earth's climate. How frequently can a variation of this size be expected? We examine the question of the persistence of non-periodic variations in solar activity. The Huerst exponent, which characterizes the persistence of a time series (Mandelbrot and Wallis, 1969), is evaluated for the series of C-14 data for the time interval from about 6000 BC to 1950 AD (Stuiver and Pearson, 1986). We find a constant Huerst exponent, suggesting that solar activity in the frequency range of from 100 to 3000 years includes an important continuum component in addition to the well-known periodic variations. The value we calculate, H approximately equal to 0.8, is significantly larger than the value of 0.5 that would correspond to variations produced by a white-noise process. This value is in good agreement with the results for the monthly sunspot data reported elsewhere, indicating that the physics that produces the continuum is a correlated random process (Ruzmaikin et al., 1992), and that is is the same type of process over a wide range of time interval lengths. We conclude that the time period over which an irradiance change of 0.5% can be expected to occur is significantly shorter than that which would be expected for variations produced by a white-noise process.

  3. Magnetic Flux Transport and the Long-term Evolution of Solar Active Regions

    NASA Astrophysics Data System (ADS)

    Ugarte-Urra, Ignacio; Upton, Lisa; Warren, Harry P.; Hathaway, David H.

    2015-12-01

    With multiple vantage points around the Sun, Solar Terrestrial Relations Observatory (STEREO) and Solar Dynamics Observatory imaging observations provide a unique opportunity to view the solar surface continuously. We use He ii 304 Å data from these observatories to isolate and track ten active regions and study their long-term evolution. We find that active regions typically follow a standard pattern of emergence over several days followed by a slower decay that is proportional in time to the peak intensity in the region. Since STEREO does not make direct observations of the magnetic field, we employ a flux-luminosity relationship to infer the total unsigned magnetic flux evolution. To investigate this magnetic flux decay over several rotations we use a surface flux transport model, the Advective Flux Transport model, that simulates convective flows using a time-varying velocity field and find that the model provides realistic predictions when information about the active region's magnetic field strength and distribution at peak flux is available. Finally, we illustrate how 304 Å images can be used as a proxy for magnetic flux measurements when magnetic field data is not accessible.

  4. MAGNETIC FLUX TRANSPORT AND THE LONG-TERM EVOLUTION OF SOLAR ACTIVE REGIONS

    SciTech Connect

    Ugarte-Urra, Ignacio; Upton, Lisa; Warren, Harry P.; Hathaway, David H.

    2015-12-20

    With multiple vantage points around the Sun, Solar Terrestrial Relations Observatory (STEREO) and Solar Dynamics Observatory imaging observations provide a unique opportunity to view the solar surface continuously. We use He ii 304 Å data from these observatories to isolate and track ten active regions and study their long-term evolution. We find that active regions typically follow a standard pattern of emergence over several days followed by a slower decay that is proportional in time to the peak intensity in the region. Since STEREO does not make direct observations of the magnetic field, we employ a flux-luminosity relationship to infer the total unsigned magnetic flux evolution. To investigate this magnetic flux decay over several rotations we use a surface flux transport model, the Advective Flux Transport model, that simulates convective flows using a time-varying velocity field and find that the model provides realistic predictions when information about the active region's magnetic field strength and distribution at peak flux is available. Finally, we illustrate how 304 Å images can be used as a proxy for magnetic flux measurements when magnetic field data is not accessible.

  5. Long-term solar-terrestrial observations

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The results of an 18-month study of the requirements for long-term monitoring and archiving of solar-terrestrial data is presented. The value of long-term solar-terrestrial observations is discussed together with parameters, associated measurements, and observational problem areas in each of the solar-terrestrial links (the sun, the interplanetary medium, the magnetosphere, and the thermosphere-ionosphere). Some recommendations are offered for coordinated planning for long-term solar-terrestrial observations.

  6. Validation of Spacecraft Active Cavity Radiometer Total Solar Irradiance (TSI) Long Term Measurement Trends Using Proxy TSI Least Squares Analyses

    NASA Technical Reports Server (NTRS)

    Lee, Robert Benjamin, III; Wilson, Robert S.

    2003-01-01

    Long-term, incoming total solar irradiance (TSI) measurement trends were validated using proxy TSI values, derived from indices of solar magnetic activity. Spacecraft active cavity radiometers (ACR) are being used to measure longterm TSI variability, which may trigger global climate changes. The TSI, typically referred to as the solar constant, was normalized to the mean earth-sun distance. Studies of spacecraft TSI data sets confirmed the existence of a 0.1 %, long-term TSI variability component within a 10-year period. The 0.1% TSI variability component is clearly present in the spacecraft data sets from the 1984-2004 time frame. Typically, three overlapping spacecraft data sets were used to validate long-term TSI variability trends. However, during the years of 1978-1984, 1989-1991, and 1993-1996, three overlapping spacecraft data sets were not available in order to validate TSI trends. The TSI was found to vary with indices of solar magnetic activity associated with recent 10-year sunspot cycles. Proxy TSI values were derived from least squares analyses of the measured TSI variability with the solar indices of 10.7-cm solar fluxes, and with limb-darked sunspot fluxes. The resulting proxy TSI values were compared to the spacecraft ACR measurements of TSI variability to detect ACR instrument degradation, which may be interpreted as TSI variability. Analyses of ACR measurements and TSI proxies are presented primarily for the 1984-2004, Earth Radiation Budget Experiment (ERBE) ACR solar monitor data set. Differences in proxy and spacecraft measurement data sets suggest the existence of another TSI variability component with an amplitude greater than or equal to 0.5 Wm-2 (0.04%), and with a cycle of 20 years or more.

  7. Long -Term Variation In The Correlation Between Solar Activity And Earth Climate

    NASA Astrophysics Data System (ADS)

    Mehravani Behrouz, Masoud; Ajabshirizadeh, Ali

    The spots on surface of the sun are one of important indexes that make the solar activity clear . From 1610, according to the studies that have done about the sun, scientists have found that the number of these sunspots from each maximum to the next one is variable in a cycle of almost eleven years. Most of these scientists have found a positive correlation between different parameters of climatology and solar activity , but some have found negative correlation between them . In this study , according to the existent data about the sunspot number ( Wolf number ) and another parameter that bond with solar activity, apply numerical computation method and adjustment a prediction software with Neural Network method, curve of variation of temperature, rainfall and cloud cover of zone of Iran up to 2010 is predicted. With notice this subject that the variation in temperature is global, these data are useful to advance.

  8. On the high correlation between long-term averages of solar wind speed and geomagnetic activity

    NASA Technical Reports Server (NTRS)

    Crooker, N. U.; Feynman, J.; Gosling, J. T.

    1977-01-01

    Six-month and yearly averages of solar-wind speed from 1962 to 1975 are shown to be highly correlated with geomagnetic activity as measured by averages of the Ap index. On the same time scale the correlation between the southward component of the interplanetary magnetic field and geomagnetic activity is poor. Previous studies with hourly averages gave opposite results. The better correlation with the southward component on an hourly time scale is explained by its large variation compared with the relatively constant solar-wind speed. However, on a yearly time scale the magnitude of the variations in both parameters are about the same. This problem can be solved by invoking an energy transfer mechanism which is proportional to the first power of the southward component and a higher power of the solar-wind speed.

  9. Multiple dynamo modes as a mechanism for long-term solar activity variations

    NASA Astrophysics Data System (ADS)

    Käpylä, M. J.; Käpylä, P. J.; Olspert, N.; Brandenburg, A.; Warnecke, J.; Karak, B. B.; Pelt, J.

    2016-05-01

    Context. Solar magnetic activity shows both smooth secular changes, such as the modern Grand Maximum, and quite abrupt drops that are denoted as grand minima, such as the Maunder Minimum. Direct numerical simulations (DNS) of convection-driven dynamos offer one way of examining the mechanisms behind these events. Aims: In this work, we analyze a solution of a solar-like DNS that was evolved for roughly 80 magnetic cycles of 4.9 years and where epochs of irregular behavior are detected. The emphasis of our analysis is to find physical causes for such behavior. Methods: The DNS employed is a semi-global (wedge-shaped) magnetoconvection model. For the data analysis tasks we use Ensemble Empirical Mode Decomposition and phase dispersion methods, as they are well suited for analyzing cyclic (non-periodic) signals. Results: A special property of the DNS is the existence of multiple dynamo modes at different depths and latitudes. The dominant mode is solar-like (equatorward migration at low latitudes and poleward at high latitudes). This mode is accompanied by a higher frequency mode near the surface and at low latitudes, showing poleward migration, and a low-frequency mode at the bottom of the convection zone. The low-frequency mode is almost purely antisymmetric with respect to the equator, while the dominant mode has strongly fluctuating mixed parity. The overall behavior of the dynamo solution is extremely complex, exhibiting variable cycle lengths, epochs of disturbed and even ceased surface activity, and strong short-term hemispherical asymmetries. Surprisingly, the most prominent suppressed surface activity epoch is actually a global magnetic energy maximum; during this epoch the bottom toroidal magnetic field obtains a maximum, demonstrating that the interpretation of grand minima-type events is non-trivial. The hemispherical asymmetries are seen only in the magnetic field, while the velocity field exhibits considerably weaker asymmetry. Conclusions: We interpret

  10. Long-term prediction of solar and geomagnetic activity daily time series using singular spectrum analysis and fuzzy descriptor models

    NASA Astrophysics Data System (ADS)

    Mirmomeni, M.; Kamaliha, E.; Shafiee, M.; Lucas, C.

    2009-09-01

    Of the various conditions that affect space weather, Sun-driven phenomena are the most dominant. Cyclic solar activity has a significant effect on the Earth, its climate, satellites, and space missions. In recent years, space weather hazards have become a major area of investigation, especially due to the advent of satellite technology. As such, the design of reliable alerting and warning systems is of utmost importance, and international collaboration is needed to develop accurate short-term and long-term prediction methodologies. Several methods have been proposed and implemented for the prediction of solar and geomagnetic activity indices, but problems in predicting the exact time and magnitude of such catastrophic events still remain. There are, however, descriptor systems that describe a wider class of systems, including physical models and non-dynamic constraints. It is well known that the descriptor system is much tighter than the state-space expression for representing real independent parametric perturbations. In addition, the fuzzy descriptor models as a generalization of the locally linear neurofuzzy models are general forms that can be trained by constructive intuitive learning algorithms. Here, we propose a combined model based on fuzzy descriptor models and singular spectrum analysis (SSA) (FD/SSA) to forecast a number of geomagnetic activity indices in a manner that optimizes a fuzzy descriptor model for each of the principal components obtained from singular spectrum analysis and recombines the predicted values so as to transform the geomagnetic activity time series into natural chaotic phenomena. The method has been applied to predict two solar and geomagnetic activity indices: geomagnetic aa and solar wind speed (SWS) of the solar wind index. The results demonstrate the higher power of the proposed method-- compared to other methods -- for predicting solar activity.

  11. Long term solar activity and ionospheric prediction services rendered by the National Physical Laboratory, New Delhi

    NASA Technical Reports Server (NTRS)

    Reddy, B. M.; Aggarwal, S.; Lakshmi, D. R.; Shastri, S.; Mitra, A. P.

    1979-01-01

    The data base used in solar and ionospheric prediction services is described. Present prediction techniques are discussed and compared with actual observations. Future prediction techniques using computers are also discussed.

  12. SBUV/2 Long-Term Measurements of Solar Spectral Variability

    NASA Technical Reports Server (NTRS)

    DeLand, Matthew T.; Cebula, Richard P.

    1997-01-01

    The NOAA-11 SBUV/2 spectral solar data have been corrected for long-term instrument changes to produce a 5.5 year data record during solar cycle 22 (December 1988 - October 1994). Residual drifts in the data at long wavelengths are +/- 1% or less. At 200-205 nm, where solar variations drive stratospheric photochemistry, these data indicate long-term solar changes of 5-7% from the maximum of Cycle 22 in April 1991 through the end of the NOAA-11 data record. Comparisons of NOAA-11 data with UARS SUSIM and SOLSTICE for the period October 1991 - October 1994, when all 3 instruments were operating simultaneously, show that the observed long-term variations in 200-205 nm irradiance agree to within 2%. This result is consistent with predictions from the Mg-2 proxy index. The SBUV/2 instruments represent a valuable resource for long-term solar UV activity studies because of their overlapping data records. In addition to the NOAA-11 data presented here, the NOAA-9 SBUV/2 instrument began taking data in March 1985 and is still operating, providing a complete record of Cycle 22 behavior from a single instrument. Three additional SBUV/2 instruments are scheduled to be launched between 1997 and 2003, which should permit full coverage of solar cycle 23.

  13. Long-term solar irradiance variability: knowns and unknowns

    NASA Astrophysics Data System (ADS)

    Krivova, Natalie; Solanki, Sami K.; Dasi Espuig, Maria; Leng Yeo, Kok; Wu, Chi-Ju

    2016-07-01

    Long-term reconstructions of solar irradiance variability are crucial to our understanding of solar influence on climate. They are only possible with the help of suitable models, which in turn require a thorough understanding of the mechanisms of this variability. With the advance of such models, also the past reconstructions are becoming more reliable. Nevertheless, the remaining uncertainties spread out when extrapolating back over long periods of time, amplified by the increasingly poorer quality and reliability of the available data that bear information on past solar activity. We will discuss the progress and the reliability of irradiance reconstructions on time scales of decades to millennia.

  14. Characteristics of solar wind control on Jovian UV auroral activity deciphered by long-term Hisaki EXCEED observations: Evidence of preconditioning of the magnetosphere?

    NASA Astrophysics Data System (ADS)

    Kita, Hajime; Kimura, Tomoki; Tao, Chihiro; Tsuchiya, Fuminori; Misawa, Hiroaki; Sakanoi, Takeshi; Kasaba, Yasumasa; Murakami, Go; Yoshioka, Kazuo; Yamazaki, Atsushi; Yoshikawa, Ichiro; Fujimoto, Masaki

    2016-07-01

    While the Jovian magnetosphere is known to have the internal source for its activity, it is reported to be under the influence of the solar wind as well. Here we report the statistical relationship between the total power of the Jovian ultraviolet aurora and the solar wind properties found from long-term monitoring by the spectrometer EXCEED (Extreme Ultraviolet Spectroscope for Exospheric Dynamics) on board the Hisaki satellite. Superposed epoch analysis indicates that auroral total power increases when an enhanced solar wind dynamic pressure hits the magnetosphere. Furthermore, the auroral total power shows a positive correlation with the duration of a quiescent interval of the solar wind that is present before a rise in the dynamic pressure, more than with the amplitude of dynamic pressure increase. These statistical characteristics define the next step to unveil the physical mechanism of the solar wind control on the Jovian magnetospheric dynamics.

  15. Long-term reconstructions of total solar irradiance

    NASA Astrophysics Data System (ADS)

    Krivova, Natalie; Solanki, Sami K.; Dasi Espuig, Maria

    2012-07-01

    Solar irradiance is the main external driver of the Earth's climate, although its relative contribution compared to other internal and anthropogenic factors is not yet well determined. Variations of total solar irradiance have being measured for over three decades and are relatively well understood. Reconstructions of the irradiance into the past remain, however, rather uncertain. In particular, the magnitude of the secular change is highly debated. The reason is the lack of direct and well-sampled proxies of solar magnetic activity on time scales longer than a few decades. Reconstructions on time scales of centuries rely on sunspot observations available since 1610. Reconstructions on millennial time scales use concentrations of the cosmogenic isotopes in terrestrial archives. We will review long-term reconstructions of the solar irradiance using the SATIRE set of models, compare them with other recent models and discuss the remaining uncertainties.

  16. Interpretation of short and long-term oscillations of solar activity by alpha-omega dynamo model with two macro-cells of meridional fluxes

    NASA Astrophysics Data System (ADS)

    Popova, Elena

    2016-04-01

    Solar magnetic activity is related with generation strong magnetic fields in the depths of the Sun and manifested in sunspot occurrence on the solar surface. The amplitude and the spatial configuration of the magnetic field of our star are changing over the years. The most widely known variations of solar magnetic field are 11-years cycles and grand minima. The generation and evolution of the solar magnetic field and other stars is usually related to the dynamo mechanism. This mechanism is based on the consideration of the joint influence of the alpha-effect and differential rotation. Dynamo sources can be located at different depths (active layers) of the convection zone and can have different intensities. Based on such a system, the dynamical system with meridional fluxes in the case of the stellar dynamo with independent active layers has been constructed. We obtained quasi-biennial magnetic field oscillations for middle layer of the convective zone which can account for short term (2.5 years) oscillations often reported for 11 year solar cycles. Magnetic field waves from top and bottom layers of the convective zone are found generated with close frequencies whose interaction leads to beating effects responsible for the grand cycles (350-400 years) superimposed on a standard 22 year cycle. Using our model we made prediction of poloidal and toroidal fields on short (until 2040 year) and long-term timescale (until 3200 year) (V. V. Zharkova, S. J. Shepherd, E. Popova & S. I. Zharkov, Nature SR, 2015).

  17. Going Solar Yields Long-Term Economical, Educational Benefits

    ERIC Educational Resources Information Center

    von Moos, Brian

    2009-01-01

    Going solar is not an easy decision, but a long-term investment with a potentially substantial up-front cost. While some schools have enough capital in reserve, can raise bond money, or can solicit sufficient donations, many schools rely on creative financial programs to make a solar energy system economically feasible. Thinking about going solar…

  18. Long-term monthly statistics of mid-latitudinal NmF2 in the Northern geographic hemisphere during geomagnetically quiet and steadily low solar activity conditions

    NASA Astrophysics Data System (ADS)

    Pavlov, Anatoli; Pavlova, Nadezhda

    2016-07-01

    Long-term mid-latitude hourly values of NmF2 measured in 1957-2015 by 10 ionosondes (Point Arguello, Wallops Is., Boulder, de l'Ebre, Rome, Ottawa, Pruhonice, Dourbes, Slough, and Juliusruh) in the Northern geographic hemisphere were processed to select periods of geomagnetically quiet and low solar activity conditions to calculate several descriptive statistics of the noon NmF2 for each month, including the mathematical expectation, most probable value, arithmetic average, and arithmetic average median. The month-to-month variability of these descriptors allowed us to identify months of a year when they reach their extremes (maxima, minima). The calculated month-to-month variations of the NmF2 statistical parameters made it possible to study the winter anomaly and spring-autumn asymmetry in these statistical parameters.

  19. Long-term monthly statistics of mid-latitudinal NmF2 in the northern geographic hemisphere during geomagnetically quiet and steadily low solar activity conditions

    NASA Astrophysics Data System (ADS)

    Pavlov, A. V.; Pavlova, N. M.

    2016-05-01

    Long-term mid-latitude hourly values of NmF2 measured in 1957-2015 by 10 ionosondes in the Northern geographic hemisphere were processed to select periods of geomagnetically quiet and low solar activity conditions to calculate several descriptive statistics of the noon NmF2 for each month, including the mathematical expectation, most probable value, arithmetic average, and arithmetic average median. The month-to-month variability of these descriptors allowed us to identify months of a year when they reach their extremes (maxima, minima). The calculated month-to-month variations of the NmF2 statistical parameters made it possible to study the winter anomaly and spring-autumn asymmetry in these statistical parameters.

  20. Long-term Enhancements in Solar Wind Speed

    NASA Technical Reports Server (NTRS)

    Gazis, P. R.; Cuzzi, Jeff (Technical Monitor)

    1995-01-01

    Long-term enhancements in solar wind speed over timescales on the order of a year appear to be a common feature throughout the heliosphere over heliocentric distances that range from less than 0.72 AU to greater than 60. The origin of these events remains to be determined, but they are almost certainly associated with long-term variations at the solar wind source, in contrast with smaller-scale structures such as CIRs, MIRs, and GMIRs which are dynamical in origin. We present a survey of the long-term speed enhancements observed at the Pioneer Venus Orbiter (PVO), IMP 8, Voyager 2, and Pioneer 10 between 1974 and 1994 and compare this with published reports of smaller-scale events such as MIRs. We examine several of these long-term speed enhancements in detail to identify and characterize aspects of their structure, then describe how that structure evolves with heliocentric distance. Finally we discuss some of the implications of these events.

  1. Short and long term variations in the solar constant

    NASA Technical Reports Server (NTRS)

    Schatten, K. H.

    1981-01-01

    Short and long term variations in the solar constant are examined theoretically. The variations observed by the Solar Maximum Mission, lasting several days and associated with the passage of sunspot groups, strikingly demonstrates the well known lack of a bright ring effect around sunspots. This suggests that sunspot magnetic fields do not simply block the heat flowing upward into the photosphere. Rather, it is suggested that gravitational draining occurs; this cools sunspots and transports downward the heat that would otherwise flow into the photosphere. A model of sunspot temperature with depth shows modest support when compared with the empirical model of Van't Veer. Secular trends in the solar constant may occur and be associated with the influence of the convection zone magnetic field upon convective heat transport. As a start to understanding this problem, the Schwarzschild criterion has been modified to include the effects of magnetic field.

  2. LONG-TERM PERIODICITY VARIATIONS OF THE SOLAR RADIUS

    SciTech Connect

    Qu, Z. N.; Xie, J. L.

    2013-01-01

    In order to study the long-term periodicity variations of the solar radius, daily solar radius data from 1978 February to 2000 September at the Calern Observatory are used. Continuous observations of the solar radius are difficult due to the weather, seasonal effects, and instrument characteristics. Thus, to analyze these data, we first use the Dixon criterion to reject suspect values, then we measure the cross-correlation between the solar radius and sunspot numbers. The result indicates that the solar radius is in complete antiphase with the sunspot numbers and shows lead times of 74 months relative to the sunspot numbers. The Lomb-Scargle and date compensated discrete Fourier transform methods are also used to investigate the periodicity of the solar radius. Both methods yield similar significance periodicities around {approx}1 yr, {approx}2.6 yr, {approx}3.6 yr, and {approx}11 yr. Possible mechanisms for these periods are discussed. The possible physical cause of the {approx}11 yr period is the cyclic variation of the magnetic pressure of the concentrated flux tubes at the bottom of the solar convection zone.

  3. Long-term goals for solar thermal technology

    NASA Astrophysics Data System (ADS)

    Williams, T. A.; Dirks, J. A.; Brown, D. R.

    1985-05-01

    Long-term performance and cost goals for three solar thermal technologies are discussed. Pacific Northwest Laboratory (PNL) developed these goals in support of the Draft Five Year Research and Development Plan for the National Solar Thermal Technology Program (DOE 1984b). These technology goals are intended to provide targets that, if met, will lead to the widespread use of solar thermal technologies in the marketplace. Goals were developed for three technologies and two applications: central receiver and dish technologies for utility-generated electricity applications, and central receiver, dish, and trough technologies for industrial process heat applications. These technologies and applications were chosen because they are the primary technologies and applications that have been researched by DOE in the past. System goals were developed through analysis of future price projections for energy sources competing with solar thermal in the middle-to-late 1990's time frame. The system goals selected were levelized energy costs of 0.05/kWh for electricity and $9/MBtu for industrial process heat (1984 $). Component goals established to meet system goals were developed based upon projections of solar thermal component performance and cost which could be achieved in the same time frame.

  4. Long-term goals for solar thermal technology

    SciTech Connect

    Williams, T.A.; Dirks, J.A.; Brown, D.R.

    1985-05-01

    This document describes long-term performance and cost goals for three solar thermal technologies. Pacific Northwest Laboratory (PNL) developed these goals in support of the Draft Five Year Research and Development Plan for the National Solar Thermal Technology Program (DOE 1984b). These technology goals are intended to provide targets that, if met, will lead to the widespread use of solar thermal technologies in the marketplace. Goals were developed for three technologies and two applications: central receiver and dish technologies for utility-generated electricity applications, and central receiver, dish, and trough technologies for industrial process heat applications. These technologies and applications were chosen because they are the primary technologies and applications that have been researched by DOE in the past. System goals were developed through analysis of future price projections for energy sources competing with solar thermal in the middle-to-late 1990's time frame. The system goals selected were levelized energy costs of $0.05/kWh for electricity and $9/MBtu for industrial process heat (1984 $). Component goals established to meet system goals were developed based upon projections of solar thermal component performance and cost which could be achieved in the same time frame.

  5. Solar pulsations and long-term solar variability

    NASA Technical Reports Server (NTRS)

    Goode, P. R.; Logan, J. D.; Hill, H. A.

    1981-01-01

    The seismology of the solar atmosphere is important in relating changes in luminosity to variations in other observables. This approach has already led to the identification of properties which were not previously observed or recognized. Equally important results from solar seismology are expected in the future.

  6. The NASA's Long-Term Global Solar Energy Resource: Current Solar Resource Variability and Future Improvements

    NASA Astrophysics Data System (ADS)

    Stackhouse, P. W.; Cox, S. J.; Zhang, T.; Chandler, W.; Westberg, D.; Hoell, J. M.

    2011-12-01

    Considering the likelihood of global climate change and the global competition for energy resources, there is an increasing need to provide improved global Earth surface solar resource information. The improved long-term records are needed to better understand and quantify potential shifts in the solar resource with anticipated changes in climatic weather patterns. As part of the World Climate Research Programme's (WCRP) Global Energy and Water Cycle Experiment (GEWEX), NASA has an active Surface Radiation Budget project that has produced long-term global gridded estimates of the surface solar fluxes. These fluxes have been processed and made available to the solar energy community over the years through NASA's Surface meteorology and Solar Energy web site (SSE). This web site provides solar resource and accompanying meteorological variables specifically tailored to the renewable energy community spanning a 22 year period. The web application has been improved over time with usage growing nearly exponentially over the last few years. This paper presents the global and regional variability of the solar resource from the current data available at the SSE web application. The variability is compared for large different spatial scales and compared to other data sets where appropriate. We assess the interannual variability compared against surface sites and other satellite based data sets. These comparisons quantify the limits of usefulness of this data set. For instance, we find long-term linear trends that are dominated by satellite based artifacts in some areas, but agree well with surface measurements in others. Nevertheless, the extremes of solar variability are quantified and show agreement with surface observations good enough for most feasibility studies of solar energy systems. This presentation also contains a description of work currently on going to replace the current solar resource information available on SSE with a completely reprocessed version. The

  7. Long-term downward trend in total solar irradiance

    SciTech Connect

    Willson, R.C.; Hudson, H.S.; Frohlich, C.; Brusa, R.W.

    1986-11-28

    The first 5 years (from 1980 to 1985) of total solar irradiance observations by the first Active Cavity Radiometer Irradiance Monitor (ACRIM I) experiment on board the Solar Maximum Mission spacecraft show a clearly defined downward trends of -0.019% per year. The existence of this trend has been confirmed by the internal self-calibrations of ACRIM I, by independent measurements from sounding rockets and balloons, and by observations from the Nimbus-7 spacecraft. The trend appears to be due to unpredicted variations of solar luminosity on time scales of years, and it may be related to solar cycle magnetic activity.

  8. Long-term downward trend in total solar irradiance.

    PubMed

    Willson, R C; Hudson, H S; Frohlich, C; Brusa, R W

    1986-11-28

    The first 5 years (from 1980 to 1985) of total solar irradiance observations by the first Active Cavity Radiometer Irradiance Monitor (ACRIM I) experiment on board the Solar Maximum Mission spacecraft show a clearly defined downward trend of -0.019% per year. The existence of this trend has been confirmed by the internal self-calibrations of ACRIM I, by independent measurements from sounding rockets and balloons, and by observations from the Nimbus-7 spacecraft. The trend appears to be due to unpredicted variations of solar luminosity on time scales of years, and it may be related to solar cycle magnetic activity. PMID:17778952

  9. Long-term memories in online users' selecting activities

    NASA Astrophysics Data System (ADS)

    Pan, Xue; Hou, Lei; Stephen, Mutua; Yang, Huijie

    2014-07-01

    In this paper, we investigate the long-term memory effect in the behavior of online users. Two user-oriented online movie systems are used in this study. Due to the short length of the series, the balanced estimation of diffusion entropy approach is used to evaluate scaling-invariance in selecting activities of users in the two online movie systems. Our results indicate that persistence (long-term memory) exists widely in the movie selecting series. However, there is generally significant difference between a user's objective and subjective behaviors. Additionally, statistically, the long-term memory depends on activity levels, as results show that the much more active a users' group, the stronger the long-term memory will be. These findings provide a new criterion for constructing reasonable models, and can help understand how individuals' behaviors form a collective behavior of an online society.

  10. Long-term migration of the solar sector structure

    NASA Technical Reports Server (NTRS)

    Wolff, C. L.; Heath, D. F.

    1979-01-01

    The magnetic sector boundaries on the sun and in the solar wind are shown to have a high correlation with winter low pressure systems on earth. The vorticity-area index typically declines by about 10% during several days centered on the time when a sector boundary sweeps past the earth. Evidence that both the sector structure and solar activity levels can be understood as being under the influence of the same regular, internal solar mechanism is presented.

  11. Differing long-term evolutions of the solar open and closed magnetic fields

    NASA Astrophysics Data System (ADS)

    Dudok de Wit, Thierry; Watermann, Jurgen; Vieira, Luis Eduardo; Mursula, Kalevi

    During the last decade, there has been an ongoing debate around a possible tripling of the solar open magnetic flux over the 20th century. This result is based on 150 years of observations of the aa geomagnetic index, from which the open magnetic flux can be inferred. The aa index actually reveals the existence of two simultaneous 11-year cycles, as shown by Simon and Legrand in the 1980's. By studying the transfer function between the Sun and these two cycles, the relative contribution of both the solar open and closed magnetic fields can be inferred. Interestingly, the two exhibit quite different long-term evolutions. This may explain discrepancies between long-term reconstructions of solar activity based on sunspot numbers and on cosmogenic isotopes..

  12. Long-term performance and cost goals for solar thermal technology

    NASA Astrophysics Data System (ADS)

    Williams, T. A.

    1985-04-01

    Long term performance and cost goals recently developed for the solar thermal technology are described. These goals were developed in support of the draft 1985 to 1989 National Solar Thermal Technology Program Five Year Research and Development Plan, and are intended to aid in planning research activities needed to make solar thermal energy an option which is both technically and economically attractive (DOE 1984). Goals were developed for both utility electric applications and for industrial process heat applications. Solar thermal technology goals are intended to provide targets, which when met, would result in the widespread usage of solar thermal technologies in the marketplace. The goals described include system goals and component goals. System goals are energy price targets which must be met for solar thermal to be economically viable in a given market. Component goals are performance and cost targets for the primary elements of a solar thermal plant (concentrators, receivers, etc.) which would allow achievement of the system level goal.

  13. Quantitative study of long-term solar and climatic changes

    NASA Technical Reports Server (NTRS)

    Eddy, J. A.

    1982-01-01

    Long term variations in the diameter and the shape of the Sun were studied. Daily observations of the Sun's diameter made at the Greenwich Observatory between 1836 and 1953 were analysed and interpreted. The data was converted into digital form and then screened and processed. It was found that the horizontal diameter of the Sun measured at Greenwich appears to have decreased systematically between 1880 and 1953 at a rate of 1.2 plus or minus 0.6 minutes of arc per century.

  14. Applying activity-based costing in long-term care.

    PubMed

    Wodchis, W P

    1998-01-01

    As greater numbers of the elderly use health services, and as health care costs climb, effective financial tracking is essential. Cost management in health care can benefit if costs are linked to the care activities where they are incurred. Activity-based costing (ABC) provides a useful approach. The framework aligns costs (inputs), through activities (process), to outputs and outcomes. It allocates costs based on client care needs rather than management structure. The ABC framework was tested in a residential care facility and in supportive housing apartments. The results demonstrate the feasibility and advantages of ABC for long term care agencies, including community-based care. PMID:10339203

  15. Applying activity-based costing in long-term care.

    PubMed

    Wodchis, W P

    1998-01-01

    As greater numbers of the elderly use health services, and as health care costs climb, effective financial tracking is essential. Cost management in health care can benefit if costs are linked to the care activities where they are incurred. Activity-based costing (ABC) provides a useful approach. The framework aligns costs (inputs), through activities (process), to outputs and outcomes. It allocates costs based on client care needs rather than management structure. The ABC framework was tested in a residential care facility and in supportive housing apartments. The results demonstrate the feasibility and advantages of ABC for long term care agencies, including community-based care.

  16. The Importance of Long-Term Synoptic Observations and Data Sets for Solar Physics and Helioseismology

    NASA Astrophysics Data System (ADS)

    Elsworth, Yvonne; Broomhall, Anne-Marie; Gosain, Sanjay; Roth, Markus; Jefferies, Stuart M.; Hill, Frank

    2015-12-01

    A casual single glance at the Sun would not lead an observer to conclude that it varies. The discovery of the 11-year sunspot cycle was only made possible through systematic daily observations of the Sun over 150 years and even today historic sunspot drawings are used to study the behavior of past solar cycles. The origin of solar activity is still poorly understood as shown by the number of different models that give widely different predictions for the strength and timing of future cycles. Our understanding of the rapid transient phenomena related to solar activity, such as flares and coronal mass ejections (CMEs) is also insufficient and making reliable predictions of these events, which can adversely impact technology, remains elusive. There is thus still much to learn about the Sun and its activity that requires observations over many solar cycles. In particular, modern helioseismic observations of the solar interior currently span only 1.5 cycles, which is far too short to adequately sample the characteristics of the plasma flows that govern the dynamo mechanism underlying solar activity. In this paper, we review some of the long-term solar and helioseismic observations and outline some future directions.

  17. Correcting Radial Velocities for Long-Term Magnetic Activity Variations.

    PubMed

    Saar; Fischer

    2000-05-01

    We study stars in the Lick planetary survey for correlations between simultaneous measurements of high-precision radial velocities vr and magnetic activity (as measured in an SIR emission index from Ca ii lambda8662). We find significant correlations in approximately 30% of the stars. After removing linear trends between SIR and vr, we find that the dispersion in vr in these stars is decreased by an average of 17%, or approximately 45% of the dispersion above the measurement noise. F stars and less active stars with variable Ca ii H and K lines are the most successfully corrected. The magnitude of the slope of the SIR versus vr relations increases proportional to vsini and (excepting M dwarfs) tends to decrease with decreasing Teff. We argue that the main cause of these effects is modification of the mean line bisector shape brought on by long-term, magnetic activity-induced changes in the surface brightness and convective patterns. The correlations can be used to partially correct vr data for the effects of long-term activity variations, potentially permitting study of planets around some (higher mass) younger stars and planets producing smaller stellar reflex velocities. PMID:10790082

  18. Correcting Radial Velocities for Long-Term Magnetic Activity Variations.

    PubMed

    Saar; Fischer

    2000-05-01

    We study stars in the Lick planetary survey for correlations between simultaneous measurements of high-precision radial velocities vr and magnetic activity (as measured in an SIR emission index from Ca ii lambda8662). We find significant correlations in approximately 30% of the stars. After removing linear trends between SIR and vr, we find that the dispersion in vr in these stars is decreased by an average of 17%, or approximately 45% of the dispersion above the measurement noise. F stars and less active stars with variable Ca ii H and K lines are the most successfully corrected. The magnitude of the slope of the SIR versus vr relations increases proportional to vsini and (excepting M dwarfs) tends to decrease with decreasing Teff. We argue that the main cause of these effects is modification of the mean line bisector shape brought on by long-term, magnetic activity-induced changes in the surface brightness and convective patterns. The correlations can be used to partially correct vr data for the effects of long-term activity variations, potentially permitting study of planets around some (higher mass) younger stars and planets producing smaller stellar reflex velocities.

  19. Simulated long-term climate response to idealized solar geoengineering

    NASA Astrophysics Data System (ADS)

    Cao, Long; Duan, Lei; Bala, Govindasamy; Caldeira, Ken

    2016-03-01

    Solar geoengineering has been proposed as a potential means to counteract anthropogenic climate change, yet it is unknown how such climate intervention might affect the Earth's climate on the millennial time scale. Here we use the HadCM3L model to conduct a 1000 year sunshade geoengineering simulation in which solar irradiance is uniformly reduced by 4% to approximately offset global mean warming from an abrupt quadrupling of atmospheric CO2. During the 1000 year period, modeled global climate, including temperature, hydrological cycle, and ocean circulation of the high-CO2 simulation departs substantially from that of the control preindustrial simulation, whereas the climate of the geoengineering simulation remains much closer to that of the preindustrial state with little drift. The results of our study do not support the hypothesis that nonlinearities in the climate system would cause substantial drift in the climate system if solar geoengineering was to be deployed on the timescale of a millennium.

  20. Long-term activity recognition from wristwatch accelerometer data.

    PubMed

    Garcia-Ceja, Enrique; Brena, Ramon F; Carrasco-Jimenez, Jose C; Garrido, Leonardo

    2014-01-01

    With the development of wearable devices that have several embedded sensors, it is possible to collect data that can be analyzed in order to understand the user's needs and provide personalized services. Examples of these types of devices are smartphones, fitness-bracelets, smartwatches, just to mention a few. In the last years, several works have used these devices to recognize simple activities like running, walking, sleeping, and other physical activities. There has also been research on recognizing complex activities like cooking, sporting, and taking medication, but these generally require the installation of external sensors that may become obtrusive to the user. In this work we used acceleration data from a wristwatch in order to identify long-term activities. We compare the use of Hidden Markov Models and Conditional Random Fields for the segmentation task. We also added prior knowledge into the models regarding the duration of the activities by coding them as constraints and sequence patterns were added in the form of feature functions. We also performed subclassing in order to deal with the problem of intra-class fragmentation, which arises when the same label is applied to activities that are conceptually the same but very different from the acceleration point of view. PMID:25436652

  1. The Long-term Middle Atmospheric Influence of Very Large Solar Proton Events

    NASA Technical Reports Server (NTRS)

    Jackman, Charles H.; Marsh, Daniel R.; Vitt, Francis M.; Garcia, Rolando R.; Randall, Cora E.; Fleming, Eric L.; Frith, Stacey M.

    2008-01-01

    Long-term variations in ozone have been caused by both natural and humankind related processes. The humankind or anthropogenic influence on ozone originates from the chlorofluorocarbons and halons (chlorine and bromine) and has led to international regulations greatly limiting the release of these substances. Certain natural ozone influences are also important in polar regions and are caused by the impact of solar charged particles on the atmosphere. Such natural variations have been studied in order to better quantify the human influence on polar ozone. Large-scale explosions on the Sun near solar maximum lead to emissions of charged particles (mainly protons and electrons), some of which enter the Earth's magnetosphere and rain down on the polar regions. "Solar proton events" have been used to describe these phenomena since the protons associated with these solar events sometimes create a significant atmospheric disturbance. We have used the National Center for Atmospheric Research (NCAR) Whole Atmosphere Community Climate Model (WACCM) to study the long-term (> few months) influences of solar proton events from 1963 through 2004 on stratospheric ozone and temperature. There were extremely large solar proton events in 1972, 1989,2000,2001, and 2003. These events caused very distinctive polar changes in layers of the Earth's atmosphere known as the stratosphere (12-50 km; -7-30 miles) and mesosphere (50-90 km; 30-55 miles). The solar protons connected with these events created hydrogen- and nitrogen-containing compounds, which led to the polar ozone destruction. The nitrogen-containing compounds, called odd nitrogen, lasted much longer than the hydrogen-containing compounds and led to long-lived stratospheric impacts. An extremely active period for these events occurred in the five-year period, 2000- 2004, and caused increases in odd nitrogen which lasted for several months after individual events. Associated stratospheric ozone decreases of >lo% were calculated

  2. Long-term eruptive activity at a submarine arc volcano.

    PubMed

    Embley, Robert W; Chadwick, William W; Baker, Edward T; Butterfield, David A; Resing, Joseph A; de Ronde, Cornel E J; Tunnicliffe, Verena; Lupton, John E; Juniper, S Kim; Rubin, Kenneth H; Stern, Robert J; Lebon, Geoffrey T; Nakamura, Ko-ichi; Merle, Susan G; Hein, James R; Wiens, Douglas A; Tamura, Yoshihiko

    2006-05-25

    Three-quarters of the Earth's volcanic activity is submarine, located mostly along the mid-ocean ridges, with the remainder along intraoceanic arcs and hotspots at depths varying from greater than 4,000 m to near the sea surface. Most observations and sampling of submarine eruptions have been indirect, made from surface vessels or made after the fact. We describe here direct observations and sampling of an eruption at a submarine arc volcano named NW Rota-1, located 60 km northwest of the island of Rota (Commonwealth of the Northern Mariana Islands). We observed a pulsating plume permeated with droplets of molten sulphur disgorging volcanic ash and lapilli from a 15-m diameter pit in March 2004 and again in October 2005 near the summit of the volcano at a water depth of 555 m (depth in 2004). A turbid layer found on the flanks of the volcano (in 2004) at depths from 700 m to more than 1,400 m was probably formed by mass-wasting events related to the eruption. Long-term eruptive activity has produced an unusual chemical environment and a very unstable benthic habitat exploited by only a few mobile decapod species. Such conditions are perhaps distinctive of active arc and hotspot volcanoes. PMID:16724063

  3. Long-term eruptive activity at a submarine arc volcano

    USGS Publications Warehouse

    Embley, R.W.; Chadwick, W.W.; Baker, E.T.; Butterfield, D.A.; Resing, J.A.; De Ronde, C. E. J.; Tunnicliffe, V.; Lupton, J.E.; Juniper, S.K.; Rubin, K.H.; Stern, R.J.; Lebon, G.T.; Nakamura, K.-I.; Merle, S.G.; Hein, J.R.; Wiens, D.A.; Tamura, Y.

    2006-01-01

    Three-quarters of the Earth's volcanic activity is submarine, located mostly along the mid-ocean ridges, with the remainder along intraoceanic arcs and hotspots at depths varying from greater than 4,000 m to near the sea surface. Most observations and sampling of submarine eruptions have been indirect, made from surface vessels or made after the fact. We describe here direct observations and sampling of an eruption at a submarine arc volcano named NW Rota-1, located 60 km northwest of the island of Rota (Commonwealth of the Northern Mariana Islands). We observed a pulsating plume permeated with droplets of molten sulphur disgorging volcanic ash and lapilli from a 15-m diameter pit in March 2004 and again in October 2005 near the summit of the volcano at a water depth of 555 m (depth in 2004). A turbid layer found on the flanks of the volcano (in 2004) at depths from 700 m to more than 1,400 m was probably formed by mass-wasting events related to the eruption. Long-term eruptive activity has produced an unusual chemical environment and a very unstable benthic habitat exploited by only a few mobile decapod species. Such conditions are perhaps distinctive of active arc and hotspot volcanoes. ?? 2006 Nature Publishing Group.

  4. Long-term variation in the ionosphere and lower thermosphere as seen in the geomagnetic solar quiet daily variation

    NASA Astrophysics Data System (ADS)

    Shinbori, A.; Koyama, Y.; Hori, T.; Nose, M.; Otsuka, Y.

    2015-12-01

    In order to investigate characteristics of the long-term variation in the ionosphere and lower thermosphere, we analyzed the amplitude of geomagnetic solar quiet (Sq) field daily variation using 1-h geomagnetic field data obtained from 69 geomagnetic stations within the period of 1947-2013. In the present data analysis, we took advantage of the Inter-university Upper atmosphere Global Observation NETwork (IUGONET) products (metadata database and analysis software) for finding and handling the long-term observation data obtained at many observatories. The Sq amplitude observed at these geomagnetic stations showed a clear solar activity dependence and tended to be enhanced during each solar maximum phase. The Sq amplitude was the smallest around the minimum of solar cycle 23/24 in 2008-2009. This significant depression implies that the solar extreme ultraviolet (EUV) radiation responsible for ionization of the upper atmosphere decreased during this solar cycle minimum. In order to examine a global distribution of the long-term trend in the Sq amplitude, we derived the residual Sq amplitude from the deviation from the fitting curve between the solar F10.7 index and Sq amplitude. As a result, a majority of the trends in the residual Sq amplitude showed negative values over a wide region. This tendency was relatively strong in Europe, India, the eastern part of Canada, and New Zealand. Moreover, we estimate the neutral wind in the lower thermosphere from the Sq amplitude and height-integrated ionospheric conductivity in order to know the physical mechanism of the long-term trend in the residual Sq amplitude. As a result, the estimated thermospheric zonal and meridional winds showed a seasonal variation with a period of one year or less, but the solar activity dependence was unclear. This result suggests that the solar cycle dependence of the Sq amplitude may be mainly attributed to the variation of the ionospheric conductivity.

  5. Photometric Variations in Spotted Pleiades Stars as Probes of Long-Term Activity Cycles

    NASA Astrophysics Data System (ADS)

    Bardenett, E.; Milingo, J. B.; Marschall, L. A.; Backman, D. E.

    2004-12-01

    Through the collaborative efforts of undergraduates and faculty at Franklin & Marshall and Gettysburg Colleges, we present new photometric data for 3 K-type stars in the Pleiades. Continuing 8+ years of observations, this data contributes to the long-term study of photometric variations in these stars. These young stars have rotational light curves with V-band amplitudes of a few percent (up to 10% in the most active stars) due to large photospheric active regions or "starspots". Quantifying the level of starspot activity from year to year allows us to look for long-term trends analogous to the solar sunspot cycle. These observations were acquired with the National Undergraduate Research Observatory's (NURO) 31" telescope, which is operated by Lowell Observatory and Northern Arizona University. This work is supported by Franklin & Marshall College, the Delaware Space Grant Consortium, and Arizona Space Grant (NASA Space Grant programs).

  6. Long-term monthly statistics of the mid-latitude ionospheric E-layer peak electron density in the Northern geographic hemisphere during geomagnetically quiet and steadily low solar activity conditions

    NASA Astrophysics Data System (ADS)

    Pavlov, Anatoli; Pavlova, Nadezhda

    2016-07-01

    Long-term hourly values of the ionospheric E-layer peak electron density, NmE, measured during the time period of 1957-2014 by 4 mid-latitude ionosondes (Wallops Island, Boulder, de l'Ebre, and Rome) in the Northern geographic hemisphere were processed to select periods of geomagnetically quiet and low solar activity conditions to calculate several descriptive statistics of NmE close to noon for each month in a year, including the mathematical expectation of NmE, the standard deviations of NmE from the mathematically expected NmE, and the NmE variation coefficient. The month-to-month variability of these descriptors allowed us to identify months of a year when they reach their extremes (maxima, minima). We found that the most probable NmE cannot be considered as the best statistical parameter among the most probable NmE and the mathematically expected NmE in statistical studies of month-to-month variations of NmE. Depending on a choice of an ionosonde and a month, the calculated NmE variation coefficient changes from 5 to 12 %.

  7. Long-term stabilization of organic solar cells using hydroperoxide decomposers as additives

    NASA Astrophysics Data System (ADS)

    Turkovic, Vida; Engmann, Sebastian; Tsierkezos, Nikos; Hoppe, Harald; Madsen, Morten; Rubahn, Horst-Günter; Ritter, Uwe; Gobsch, Gerhard

    2016-03-01

    Stability of organic solar cells (OPV) remains a big problem on the way to their commercialization. Different approaches are being investigated: development of intrinsically more photochemically stable materials, optimization of encapsulation, and implementation of getter and UV blocking layers. In this study, we investigate stabilization of OPV devices using hydroperoxide decomposers as stabilizing additives. A set of five commercially available additives of organophosphorus, organosulfur, Ni chelate, and blocked thiol type are compared, ternary blended into the active layer, under exposure to aging under ISOS-3 degradation conditions. Improvements in long-term performance of OPV devices were observed upon stabilization with Advapak NEO-1120, lifetime was prolonged by a factor of 1.7, and accumulated power generation increased by a factor of 1.4. The stabilizing mechanisms are discussed using spectroscopic and microscopic measurements.

  8. Worldwide impact of aerosol's time scale on the predicted long-term concentrating solar power potential.

    PubMed

    Ruiz-Arias, Jose A; Gueymard, Christian A; Santos-Alamillos, Francisco J; Pozo-Vázquez, David

    2016-08-10

    Concentrating solar technologies, which are fuelled by the direct normal component of solar irradiance (DNI), are among the most promising solar technologies. Currently, the state-of the-art methods for DNI evaluation use datasets of aerosol optical depth (AOD) with only coarse (typically monthly) temporal resolution. Using daily AOD data from both site-specific observations at ground stations as well as gridded model estimates, a methodology is developed to evaluate how the calculated long-term DNI resource is affected by using AOD data averaged over periods from 1 to 30 days. It is demonstrated here that the use of monthly representations of AOD leads to systematic underestimations of the predicted long-term DNI up to 10% in some areas with high solar resource, which may result in detrimental consequences for the bankability of concentrating solar power projects. Recommendations for the use of either daily or monthly AOD data are provided on a geographical basis.

  9. Worldwide impact of aerosol's time scale on the predicted long-term concentrating solar power potential.

    PubMed

    Ruiz-Arias, Jose A; Gueymard, Christian A; Santos-Alamillos, Francisco J; Pozo-Vázquez, David

    2016-01-01

    Concentrating solar technologies, which are fuelled by the direct normal component of solar irradiance (DNI), are among the most promising solar technologies. Currently, the state-of the-art methods for DNI evaluation use datasets of aerosol optical depth (AOD) with only coarse (typically monthly) temporal resolution. Using daily AOD data from both site-specific observations at ground stations as well as gridded model estimates, a methodology is developed to evaluate how the calculated long-term DNI resource is affected by using AOD data averaged over periods from 1 to 30 days. It is demonstrated here that the use of monthly representations of AOD leads to systematic underestimations of the predicted long-term DNI up to 10% in some areas with high solar resource, which may result in detrimental consequences for the bankability of concentrating solar power projects. Recommendations for the use of either daily or monthly AOD data are provided on a geographical basis. PMID:27507711

  10. Towards an Improved High Resolution Global Long-Term Solar Resource Database

    NASA Technical Reports Server (NTRS)

    Stackhouse, Paul W.; Cox, Stephen J.; Chandler, William S.; Hoell, James M.; Zhang, Taiping; Westburg, David J.; Perez, Richard; Hemker, Charles; Schlemmer, James; Renne, D.; Sengupta, Manajit; Bates, John J.; Knapp, Kenneth

    2011-01-01

    This paper presents an overview of an ongoing project to develop and deliver a solar mapping processing system to the National Renewable Energy Laboratory (NREL) using the data sets that are planned for production at the National Climatic Data Center (NCDC). NCDC will be producing a long-term radiance and cloud property data set covering the globe every three hours at an approximate resolution of 10 x 10 km. NASA, the originators of the Surface meteorology and Solar Energy web portal are collaborating with SUNY-Albany to develop the production system and solar algorithms. The initial result will be a global long-term solar resource data set spanning over 25 years. The ultimate goal of the project is to also deliver this data set and production system to NREL for continual production. The project will also assess the impact of providing these new data to several NREL solar decision support tools.

  11. Future Long-term Measurements of Solar Spectral Irradiance Variability: Achievements and Lessons from the SORCE SIM

    NASA Astrophysics Data System (ADS)

    Richard, E. C.; Harder, J. W.; Pilewskie, P.; Woods, T. N.; Lykke, K.; Brown, S.

    2010-12-01

    In order to advance understanding of how natural and anthropogenic process affect Earth’s climate system there is a strong scientific importance of maintaining accurate, long-term records of climate forcing. The continuation of solar spectral irradiance (SSI) measurements are needed to characterize poorly understood wavelength dependent climate processes. A major challenge quantifying the influence of SSI variability relates directly to the radiometric absolute accuracy and long-term precision of the measurements. The strong reliance on radiative transfer modeling for interpretation and quantification of the deposition of solar radiation in the atmosphere makes it imperative that the spectral distribution of radiant energy entering the atmosphere be known to a high degree of absolute accuracy (tied directly to international standards). The Spectral Irradiance Monitor (SIM) is a solar spectral radiometer that continuously monitors the SSI across the wavelength region spanning the ultraviolet, visible and near infrared (200 nm - 2400 nm, a region encompassing 96% of the total solar irradiance). A future SIM instrument is included as part of the Total and Spectral Solar Irradiance Sensor (TSIS) to continue the measurement of SSI, which began with the SOlar Radiation and Climate Experiment (SORCE), launched in 2003. SORCE SIM measurements have now monitored SSI for a sufficiently long time and over a wide range in solar activity to quantify wavelength-dependent variability form the UV to the near IR. The analysis of the SORCE SIM measurements of solar spectral variability have resulted in a number of instrument design refinements central to maintaining the long-term calibration to SI irradiance standards and achieve the necessary measurement precision and long-term reproducibility (0.05-0.01% per year) to meet the needs for establishing a climate record of solar spectral irradiance into the future.

  12. Long-term stable polymer solar cells with significantly reduced burn-in loss.

    PubMed

    Kong, Jaemin; Song, Suhee; Yoo, Minji; Lee, Ga Young; Kwon, Obum; Park, Jin Kuen; Back, Hyungcheol; Kim, Geunjin; Lee, Seoung Ho; Suh, Hongsuk; Lee, Kwanghee

    2014-01-01

    The inferior long-term stability of polymer-based solar cells needs to be overcome for their commercialization to be viable. In particular, an abrupt decrease in performance during initial device operation, the so-called 'burn-in' loss, has been a major contributor to the short lifetime of polymer solar cells, fundamentally impeding polymer-based photovoltaic technology. In this study, we demonstrate polymer solar cells with significantly improved lifetime, in which an initial burn-in loss is substantially reduced. By isolating trap-embedded components from pristine photoactive polymers based on the unimodality of molecular weight distributions, we are able to selectively extract a trap-free, high-molecular-weight component. The resulting polymer component exhibits enhanced power conversion efficiency and long-term stability without abrupt initial burn-in degradation. Our discovery suggests a promising possibility for commercial viability of polymer-based photovoltaics towards real solar cell applications.

  13. Long-term measurements of solar spectral irradiance variability: toward the establishment of a climate record

    NASA Astrophysics Data System (ADS)

    Richard, Erik; Harder, Jerald; Pilewskie, Peter; Fontenla, Juan; Woods, Thomas; Brown, Steven; Lykke, Keith

    Knowledge of the top of the atmosphere (TOA) solar spectral irradiance (SSI) is crucial in interpreting the spectrally dependent radiative processes throughout Earth's climate system. Where this energy is deposited into the atmosphere and surface, how the climate responds to solar variability, and the mechanisms of climate response, are highly dependent on how the incident solar radiation is distributed with wavelength. In order to advance understanding of how natural and anthropogenic process affect Earth's climate system there is a strong scientific imperative to maintain accurate, long-term records of climate forcing and response. The contin-uation of SSI measurements provides a unique opportunity to characterize poorly understood wavelength dependent climate processes. Coupled chemistry-climate models require realistic assessments of the magnitudes and long-term trends in SSI for the interpretation and quantifi-cation of solar forcing in climate change scenarios. This places stringent requirements on the absolute calibration of the instrument (tied directly to international standards) and the ability to maintain that calibration on-orbit (long-term stability). The Spectral Irradiance Monitor (SIM) is a solar spectral radiometer that continuously monitors the SSI from 200 nm -2400 nm, a wavelength region encompassing 96% of the total solar irradiance. The SIM instrument is included as part of the Total and Spectral Solar Irradiance Sensor (TSIS) to continue the mea-surement of SSI, which began with the SOlar Radiation and Climate Experiment (SORCE), launched in 2003. SORCE SIM measurements have characterized SSI variability during the descending phase of Solar Cycle (SC) 23, but the determination of multi-solar cycle dependen-cies remains a key climatic uncertainty. Analysis of the measured spectral irradiance variability during the SORCE mission has resulted in a number of instrument design refinements central to maintaining, on-orbit, the long-term absolute

  14. Long-term temperature effects on GaAs solar cells

    NASA Technical Reports Server (NTRS)

    Heinbockel, J. H.; Hong, K. H.

    1979-01-01

    The thermal degradation of AlGaAs solar cells resulting from a long-term operation in a space environment is investigated. The solar cell degradation effects caused by zinc and aluminum diffusion as well as deterioration by arsenic evaporation are presented. Also, the results are presented of experimental testing and measurements of various GaAs solar cell properties while the solar cell was operating in the temperature range of 27 C to 350 C. In particular, the properties of light current voltage curves, dark current voltage curves, and spectral response characteristics are given. Finally, some theoretical models for the annealing of radiation damage over various times and temperatures are included.

  15. Future Long-term Measurements of Solar Spectral Irradiance by JPSS TSIS

    NASA Astrophysics Data System (ADS)

    Richard, E. C.; Harber, D.; Harder, J. W.; Pilewskie, P.; Brown, S.; Smith, A.; Lykke, K.

    2011-12-01

    To advance scientific understanding of how solar variability affects climate processes it is important to maintain accurate, long-term records of solar irradiance. Continuation of solar spectral irradiance (SSI) measurements is needed to characterize poorly understood wavelength-dependent climate processes. Measurement challenges in quantifying the influence of SSI variability on climate are achieving sufficient radiometric absolute accuracy and maintaining the long-term relative accuracy. The Total and Spectral Solar Irradiance Sensor (TSIS) is a dual-instrument package that will acquire solar irradiance as part of the Joint Polar Satellite System (JPSS). The TSIS Spectral Irradiance Monitor (SIM) instrument will continue the SSI measurements that began with the SORCE SIM in 2003. The TSIS SIM incorporates design and calibration improvements to better quantify long-term SSI variability. Specific improvements include the pre-launch SI-traceable calibration, the measurement precision, and the long-term relative stability needed to meet the requirements for establishing a climate record of SSI into the future. To quantify the absolute accuracy over the full spectral range, we have developed a SIM Radiometer Facility (SIMRF) utilizing the NIST Spectral Irradiance and Radiance Responsivity Calibrations using Uniform Sources (SIRCUS). This comprehensive facility includes tuneable laser light sources from the ultraviolet to the near infrared matched in radiant power to the solar spectrum and tied to a cryogenic radiometer traceable to the NIST Primary Optical Watt Radiometer (POWR). The full characterization and calibration follows a measurement equation approach at the unit-level for full validation of the end-to-end performance at the instrument-level to achieve a combined standard uncertainty of 0.25% .

  16. A long-term strategic plan for development of solar thermal electric technology

    SciTech Connect

    Williams, T.A.; Burch, G.D.; Chavez, J.M.; Mancini, T.R.; Tyner, C.E.

    1997-06-01

    Solar thermal electric (STE) technologies--parabolic troughs, power towers, and dish/engine systems--can convert sunlight into electricity efficiently and with minimum effect on the environment. These technologies currently range from developmental to early commercial stages of maturity. This paper summarizes the results of a recent strategic planning effort conducted by the US Department of Energy (DOE) to develop a long-term strategy for the development of STE technologies (DOE, 1996). The planning team led by DOE included representatives from the solar thermal industry, domestic utilities, state energy offices, and Sun-Lab (the cooperative Sandia National Laboratories/National Renewable Energy Laboratory partnership that supports the STE Program) as well as project developers. The plan was aimed at identifying specific activities necessary to achieve the DOE vision of 20 gigawatts of installed STE capacity by the year 2020. The planning team developed five strategies that both build on the strengths of, and opportunities for, STE technology and address weaknesses and threats. These strategies are to support future commercial opportunities for STE technologies; demonstrate improved performance and reliability of STE components and systems; reduce STE energy costs; develop advanced STE systems and applications; and address nontechnical barriers and champion STE power. The details of each of these strategies are discussed.

  17. A long-term strategic plan for development of solar thermal electric technology

    SciTech Connect

    Williams, T.A.; Burch, G.; Chavez, J.M.; Mancini, T.R.; Tyner, C.E.

    1997-06-01

    Solar thermal electric (STE) technologies--parabolic troughs, power towers, and dish/engine systems--can convert sunlight into electricity efficiently and with minimum effect on the environment. These technologies currently range from developmental to early commercial stages of maturity. This paper summarizes the results of a recent strategic planning effort conducted by the US department of Energy (DOE) to develop a long-term strategy for the development of STE technologies. The planning team led by DOE included representatives from the solar thermal industry, domestic utilities, state energy offices, and Sun{center_dot}Lab (the cooperative Sandia National laboratories/National Renewable Energy Laboratory partnership that supports the STE Program) as well as project developers. The plan was aimed at identifying specific activities necessary to achieve the DOE vision of 20 gigawatts of installed STE capability by the year 2020. The planning team developed five strategies that both build on the strengths of, and opportunities for, STE technology and address weaknesses and threats. These strategies are to: support future commercial opportunities for STE technologies; demonstrate improved performance and reliability of STE components and systems; reduce STE energy costs; develop advanced STE systems and applications; and address nontechnical barriers and champion STE power. The details of each of these strategies are discussed.

  18. Quasi-decadal variability of the stratosphere: Influence of long-term solar ultraviolet variations

    NASA Technical Reports Server (NTRS)

    Hood, L. L.; Jirikowic, J. L.; Mccormack, J. P.

    1993-01-01

    A multiple regression statistical model is applied to investigate the existence of upper-stratospheric ozone, temperature, and zonal wind responses to long-term (solar cycle) changes in solar ultraviolet radiation using 11.5 years of reprocessed Nimbus-7 Solar Backscattered Ultraviolet (SBUV) data and 12.4 years of National Meteorological Center (NMC) data. A positive solar cycle variation of independently measured ozone and temperature occurs with maximum amplitude near the low-latitude stratopause. The seasonal solar regression coefficients near 1 mb for both ozone and temperature occur at low latitudes supporting a role for photochemical and radiative forcing in their origin. Zonal wind perturbations that correlate with long-term solar ultraviolet variations are a strong function of season and pressure level. Above approximately 2 mbar, the largest solar-correlated zonal wind enhancements occur at middle winter latitudes near the time of winter solstice in both hemispheres. The Northern Hemisphere December enhancement at 1 mb was especially large, 23 +/- 9 m/s from solar minimum to maximum during the last solar cycle. The derived ozone, temperature, and zonal wind increases with increasing solar ultraviolet flux near the stratopause are larger than predicted by models that consider primarily photochemical and radiative processes. The higher ozone and temperature response amplitudes at low latitudes may be due to modified ozone transport and adiabatic temperature changes induced by the dynamical response. If the midlatitude winter solstice wind enhancements are solar induced, their high amplitudes require a positive feedback due to wave-mean flow interaction such that the planetary wave drag on the flow is reduced under solar maximum conditions.

  19. Long-term solar UV radiation reconstructed by Artificial Neural Networks (ANN)

    NASA Astrophysics Data System (ADS)

    Feister, U.; Junk, J.; Woldt, M.

    2008-01-01

    Artificial Neural Networks (ANN) are efficient tools to derive solar UV radiation from measured meteorological parameters such as global radiation, aerosol optical depths and atmospheric column ozone. The ANN model has been tested with different combinations of data from the two sites Potsdam and Lindenberg, and used to reconstruct solar UV radiation at eight European sites by more than 100 years into the past. Annual totals of UV radiation derived from reconstructed daily UV values reflect interannual variations and long-term patterns that are compatible with variabilities and changes of measured input data, in particular global dimming by about 1980-1990, subsequent global brightening, volcanic eruption effects such as that of Mt. Pinatubo, and the long-term ozone decline since the 1970s. Patterns of annual erythemal UV radiation are very similar at sites located at latitudes close to each other, but different patterns occur between UV radiation at sites in different latitude regions.

  20. Long term weathering effects on the thermal performance of the solaron (air) solar collector

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The test procedures and the results obtained during the evaluation test program on the Solaron Corporation air-type solar collector are presented. The tests were performed under simulated conditions, following long-term exposure to natural weathering conditions. The Solaron Model 2001, air-type solar collector has a gross area of 19 square feet and the weight is 160 pounds. The absorber plate is made of 24-gage steel, the coating is baked-on black paint, the cover consists of two sheets of 1/8-inch low-iron tempered glass, and the insulation is one thickness of 3 5/8-inch fiberglass batting.

  1. Long-term Trend of Solar Coronal Hole Distribution from 1975 to 2014

    NASA Astrophysics Data System (ADS)

    Fujiki, K.; Tokumaru, M.; Hayashi, K.; Satonaka, D.; Hakamada, K.

    2016-08-01

    We developed an automated prediction technique for coronal holes using potential magnetic field extrapolation in the solar corona to construct a database of coronal holes appearing from 1975 February to 2015 July (Carrington rotations from 1625 to 2165). Coronal holes are labeled with the location, size, and average magnetic field of each coronal hole on the photosphere and source surface. As a result, we identified 3335 coronal holes and found that the long-term distribution of coronal holes shows a similar pattern known as the magnetic butterfly diagram, and polar/low-latitude coronal holes tend to decrease/increase in the last solar minimum relative to the previous two minima.

  2. Progress Towards Deriving an Improved Long-Term Global Solar Resource

    NASA Technical Reports Server (NTRS)

    Cox, Stephen J.; Mikovitz, J. Colleen; Zhang, Taiping; Sorlie, Susan; Stackhouse, Paul W., Jr.; Perez, Richard; Hemker, Karl, Jr.; Schlemmer, James; Kivalov, Sergey; Renne, David; Sengupta, Manajit; Bates, John; Knapp, Kenneth

    2013-01-01

    This paper describes an ongoing project to provide the National Renewable Energy Laboratory (NREL) with a global long-term advanced global solar mapping production system for improved depiction of historical solar resources and to provide a mechanism for continual updates. This new production system is made possible by the efforts of NASA and NOAA 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 10 km, 3-hourly basis beginning July 1983. We provide a general overview of this project, samples of the new solar irradiance mapped data products, and comparisons to surface measurements. Samples of the use of the SUNY-Albany solar irradiance algorithm applied to the ISCCP data show very good agreement with high quality surface measurements. We identify the next steps in the production of the data set.

  3. Long Term Variation of Cosmic Ray Anisotropy and Soalr Activity

    NASA Astrophysics Data System (ADS)

    Richharia, M. K.; Shrivastava, S. K.; Jain, Alka; Jain, Manju

    The cosmic Ray CR intensity data recorded with Goose Bay Neutron Monitoring station have been investigate on 60 quietest days QD in a year for studying the variation in tri-diurnal and quart diurnal anisotropy during solar cycle 21 and 22 It has been observed that in spite of abrupt change in the amplitude and phase of tri-diurnal and quart diurnal anisotropy in CR intensity the amplitude is quite significant throughout period of investigation The tri-diurnal anisotropy clearly shows 11 year type of variation at Mid latitude neutron monitoring station

  4. Long-term variation in the upper atmosphere as seen in the geomagnetic solar quiet daily variation

    NASA Astrophysics Data System (ADS)

    Shinbori, Atsuki; Koyama, Yukinobu; Nose, Masahito; Hori, Tomoaki; Otsuka, Yuichi; Yatagai, Akiyo

    2014-12-01

    Characteristics of long-term variation in the amplitude of solar quiet (Sq) geomagnetic field daily variation have been investigated using 1-h geomagnetic field data obtained from 69 geomagnetic observation stations within the period of 1947 to 2013. The Sq amplitude observed at these geomagnetic stations showed a clear dependence on the 10- to 12-year solar activity cycle and tended to be enhanced during each solar maximum phase. The Sq amplitude was the smallest around the minimum of solar cycle 23/24 in 2008 to 2009. The relationship between the solar F10.7 index and Sq amplitude was approximately linear but about 53% of geomagnetic stations showed a weak nonlinear relation to the solar F10.7 index. In order to remove the effect of solar activity seen in the long-term variation of the Sq amplitude, we calculated a linear or second-order fitting curve between the solar F10.7 index and Sq amplitude during 1947 to 2013 and examined the residual Sq amplitude, which is defined as the deviation from the fitting curve. As a result, the majority of trends in the residual Sq amplitude that passed through a trend test showed negative values over a wide region. This tendency was relatively strong in Europe, India, the eastern part of Canada, and New Zealand. The relationship between the magnetic field intensity at 100-km altitude and residual Sq amplitude showed an anti-correlation for about 71% of the geomagnetic stations. Furthermore, the residual Sq amplitude at the equatorial station (Addis Ababa) was anti-correlated with the absolute value of the magnetic field inclination. This implies movement of the equatorial electrojet due to the secular variation of the ambient magnetic field.

  5. Long Term Activity Analysis in Surveillance Video Archives

    ERIC Educational Resources Information Center

    Chen, Ming-yu

    2010-01-01

    Surveillance video recording is becoming ubiquitous in daily life for public areas such as supermarkets, banks, and airports. The rate at which surveillance video is being generated has accelerated demand for machine understanding to enable better content-based search capabilities. Analyzing human activity is one of the key tasks to understand and…

  6. Solar Drivers of 11-yr and Long-Term Cosmic Ray Modulation

    NASA Technical Reports Server (NTRS)

    Cliver, E. W.; Richardson, I. G.; Ling, A. G.

    2011-01-01

    In the current paradigm for the modulation of galactic cosmic rays (GCRs), diffusion is taken to be the dominant process during solar maxima while drift dominates at minima. Observations during the recent solar minimum challenge the pre-eminence of drift: at such times. In 2009, the approx.2 GV GCR intensity measured by the Newark neutron monitor increased by approx.5% relative to its maximum value two cycles earlier even though the average tilt angle in 2009 was slightly larger than that in 1986 (approx.20deg vs. approx.14deg), while solar wind B was significantly lower (approx.3.9 nT vs. approx.5.4 nT). A decomposition of the solar wind into high-speed streams, slow solar wind, and coronal mass ejections (CMEs; including postshock flows) reveals that the Sun transmits its message of changing magnetic field (diffusion coefficient) to the heliosphere primarily through CMEs at solar maximum and high-speed streams at solar minimum. Long-term reconstructions of solar wind B are in general agreement for the approx. 1900-present interval and can be used to reliably estimate GCR intensity over this period. For earlier epochs, however, a recent Be-10-based reconstruction covering the past approx. 10(exp 4) years shows nine abrupt and relatively short-lived drops of B to < or approx.= 0 nT, with the first of these corresponding to the Sporer minimum. Such dips are at variance with the recent suggestion that B has a minimum or floor value of approx.2.8 nT. A floor in solar wind B implies a ceiling in the GCR intensity (a permanent modulation of the local interstellar spectrum) at a given energy/rigidity. The 30-40% increase in the intensity of 2.5 GV electrons observed by Ulysses during the recent solar minimum raises an interesting paradox that will need to be resolved.

  7. Long-term change in the organization of inventive activity.

    PubMed

    Lamoreaux, N R; Sokoloff, K L

    1996-11-12

    Relying on a quantitative analysis of the patenting and assignment behavior of inventors, we highlight the evolution of institutions that encouraged trade in technology and a growing division of labor between those who invented new technologies and those who exploited them commercially over the nineteenth and early-twentieth centuries. At the heart of this change in the organization of inventive activity was a set of familiar developments which had significant consequences for the supply and demand of inventions. On the supply side, the growing complexity and capital intensity of technology raised the amount of human and physical capital required for effective invention, making it increasingly desirable for individuals involved in this activity to specialize. On the demand side, the growing competitiveness of product markets induced firms to purchase or otherwise obtain the rights to technologies developed by others. These increasing incentives to differentiate the task of invention from that of commercializing new technologies depended for their realization upon the development of markets and other types of organizational supports for trade in technology. The evidence suggests that the necessary institutions evolved first in those regions of the country where early patenting activity had already been concentrated. A self-reinforcing process whereby high rates of inventive activity encouraged the evolution of a market for technology, which in turn encouraged greater specialization and productivity at invention as individuals found it increasingly feasible to sell and license their discoveries, appears to have been operating. This market trade in technological information was an important contributor to the achievement of a high level of specialization at invention well before the rise of large-scale research laboratories in the twentieth century. PMID:8917480

  8. Long-Term International Space Station (ISS) Risk Reduction Activities

    NASA Technical Reports Server (NTRS)

    Forroci, Michael P.; Gafka, George K.; Lutomski, Michael G.; Maher, Jacilyn S.

    2011-01-01

    As the assembly of the ISS nears completion, it is worthwhile to step back and review some of the actions pursued by the Program in recent years to reduce risk and enhance the safety and health of ISS crewmembers, visitors, and space flight participants. While the initial ISS requirements and design were intended to provide the best practicable levels of safety, it is always possible to further reduce risk given the determination, commitment, and resources to do so. The following is a summary of some of the steps taken by the ISS Program Manager, by our International Partners, by hardware and software designers, by operational specialists, and by safety personnel to continuously enhance the safety of the ISS, and to reduce risk to all crewmembers. While years of work went into the development of ISS requirements, there are many things associated with risk reduction in a Program like the ISS that can only be learned through actual operational experience. These risk reduction activities can be divided into roughly three categories: Areas that were initially noncompliant which have subsequently been brought into compliance or near compliance (i.e., Micrometeoroid and Orbital Debris [MMOD] protection, acoustics) Areas where initial design requirements were eventually considered inadequate and were subsequently augmented (i.e., Toxicity hazard level-4 materials, emergency procedures, emergency equipment, control of drag-throughs) Areas where risks were initially underestimated, and have subsequently been addressed through additional mitigation (i.e., Extravehicular Activity [EVA] sharp edges, plasma shock hazards). Due to the hard work and cooperation of many parties working together across the span of more than a decade, the ISS is now a safer and healthier environment for our crew, in many cases exceeding the risk reduction targets inherent in the intent of the original design. It will provide a safe and stable platform for utilization and discovery for years to come.

  9. Long term weathering effects on the thermal performance of the sunworks (liquid) solar collector

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The test procedures used and the results obtained during the evaluation test program of the Sunworks single-covered liquid solar collector are presented. The tests were performed under simulated conditions, following long-term exposure to natural weathering conditions. The sunworks collector is a flat-plate solar collector. The absorber plate is copper with copper tubes bonded by soft solder, and is coated with Enthon selective black with an absorptivity factor of .87 similar to .92 and an emissivity factor of .10 similar to .20. It has a single glass cover of 3/16 inches tempered glass and weighs about 115 pounds. The overall dimensions of the collector are 36 x 84 x 4 inches.

  10. Long-term differential energy spectrum for solar-flare iron-group particles

    NASA Technical Reports Server (NTRS)

    Blanford, G. E.; Fruland, R. M.; Morrison, D. A.

    1975-01-01

    A long-term solar-flare differential energy spectrum for iron-group nuclei from approximately 0.1 to approximately 600 MeV/amu is derived from track density profile measurements in sample 64455 and sample 68815. Measurements from uneroded surfaces were obtained from quench crystals of plagioclase in 64455, and a Kr-81/Kr method indicates that the exposure age of this sample is 2,010,000 yrs. The power laws which best fit the normalized track density data are reported; the energy spectrum consists of two power law curves smoothly joined together which in turn are smoothly connected to a modulated galactic cosmic-ray spectrum. Standard track production versus depth profiles can be used to determine solar-flare track exposure ages and erosion rates for lunar samples.

  11. Solar cycle dynamics of solar, magnetospheric, and heliospheric particles, and long-term atmospheric coupling: SAMPLEX

    NASA Technical Reports Server (NTRS)

    Mason, G. M. (Principal Investigator); Hamilton, D. C.; Blake, J. B.; Mewaldt, R. A.; Stone, E. C.; Baker, D. N.; VonRosenvinge, T. T.; Callis, L. B.; Klecker, B.; Hovestadt, D.; Scholer, M.

    1996-01-01

    This report summarizes science analysis activities by the SAMPEX mission science team during the period during the period July 1, 1995 through July 1, 1996. Bibliographic entries for 1995 and 1996 to date (July 1996) are included. The SAMPEX science team was extremely active, with 20 articles published or submitted to refereed journals, 18 papers published in their entirety in Conference Proceedings, and 53 contributed papers, seminars, and miscellaneous presentations. The bibliography at the end of this report constitutes the primary description of the research activity. Science highlights are given under the major activity headings of anomalous cosmic rays, solar energetic particles, magnetospheric precipitating electrons, trapped H and He isotopes, and data analysis activities.

  12. SeaWiFS long-term solar diffuser reflectance and sensor noise analyses

    SciTech Connect

    Eplee, Robert E. Jr.; Patt, Frederick S.; Barnes, Robert A.; McClain, Charles R

    2007-02-10

    The NASA Ocean Biology Processing Group's Calibration and Validation(Cal/Val) team has undertaken an analysis of the mission-long Sea-Viewing Wide Field-of-View Sensor (SeaWiFS)solar calibration time series to assess the long-term degradation of the solar diffuser reflectance over 9 years on orbit. The SeaWiFS diffuser is an aluminum plate coated with YB71 paint. The bidirectional reflectance distribution function of the diffuser was not fully characterized before launch,so the Cal/Val team has implemented a regression of the solar incidence angles and the drift in the node of the satellite's orbit against the diffuser time series to correct for solar incidence angle effects. An exponential function with a time constant of 200 days yields the best fit to the diffuser time series.The decrease in diffuser reflectance over the mission is wavelength dependent,ranging from 9% in the blue(412 nm) to 5% in the red and near infrared(670-865 nm). The Cal/Val team has developed a methodology for computing the signal-to-noise ratio (SNR) for SeaWiFS on orbit from the diffuser time series corrected for both the varying solar incidence angles and the diffuser reflectance degradation. A sensor noise model is used to compare on-orbit SNRs computed for radiances reflected from the diffuser with prelaunch SNRs measured at typical radiances specified for the instrument. To within the uncertainties in the measurements, the SNRs for SeaWiFS have not changed over the mission. The on-orbit performance of the SeaWiFS solar diffuser should offer insight into the long-term on-orbit performance of solar diffusers on other instruments, such as the Moderate-Resolution Imaging Spectrometer [currently flying on the Earth Observing System (EOS) Terra and Aqua satellites], the Visible and Infrared Radiometer Suite [scheduled to fly on the NASA National Polar-orbiting Operational Environmental Satellite System (NPOESS) and NPOESS Preparatory Project (NPP) satellites] and the Advanced Baseline

  13. Accelerometer's position independent physical activity recognition system for long-term activity monitoring in the elderly.

    PubMed

    Khan, Adil Mehmood; Lee, Young-Koo; Lee, Sungyoung; Kim, Tae-Seong

    2010-12-01

    Mobility is a good indicator of health status and thus objective mobility data could be used to assess the health status of elderly patients. Accelerometry has emerged as an effective means for long-term physical activity monitoring in the elderly. However, the output of an accelerometer varies at different positions on a subject's body, even for the same activity, resulting in high within-class variance. Existing accelerometer-based activity recognition systems thus require firm attachment of the sensor to a subject's body. This requirement makes them impractical for long-term activity monitoring during unsupervised free-living as it forces subjects into a fixed life pattern and impede their daily activities. Therefore, we introduce a novel single-triaxial-accelerometer-based activity recognition system that reduces the high within-class variance significantly and allows subjects to carry the sensor freely in any pocket without its firm attachment. We validated our system using seven activities: resting (lying/sitting/standing), walking, walking-upstairs, walking-downstairs, running, cycling, and vacuuming, recorded from five positions: chest pocket, front left trousers pocket, front right trousers pocket, rear trousers pocket, and inner jacket pocket. Its simplicity, ability to perform activities unimpeded, and an average recognition accuracy of 94% make our system a practical solution for continuous long-term activity monitoring in the elderly.

  14. Design and long-term monitoring of DSC/CIGS tandem solar module

    NASA Astrophysics Data System (ADS)

    Vildanova, M. F.; Nikolskaia, A. B.; Kozlov, S. S.; Shevaleevskiy, O. I.

    2015-11-01

    This paper describes the design and development of tandem dye-sensitized/Cu(In, Ga)Se (DSC/CIGS) PV modules. The tandem PV module comprised of the top DSC module and a bottom commercial 0,8 m2 CIGS module. The top DSC module was made of 10 DSC mini-modules with the field size of 20 × 20 cm2 each. Tandem DSC/CIGS PV modules were used for providing the long-term monitoring of energy yield and electrical parameters in comparison with standalone CIGS modules under outdoor conditions. The outdoor test facility, containing solar modules of both types and a measurement unit, was located on the roof of the Institute of Biochemical Physics in Moscow. The data obtained during monitoring within the 2014 year period has shown the advantages of the designed tandem DSC/CIGS PV-modules over the conventional CIGS modules, especially for cloudy weather and low-intensity irradiation conditions.

  15. Long-Term Dynamics of Small Bodies in the Solar System

    NASA Technical Reports Server (NTRS)

    Saunders, Steve (Technical Monitor); Holman, Matthew J.

    2005-01-01

    As part of the NASA Planetary Geology and Geophysics program Prof. Norm Murray (CITA) and I have been conducting investigations of the long-term dynamics of small bodies in the outer solar system. This grant, and its predecessor NAG5-7761, supported travel for collaboration by the Investigators and also supports Murray during an annual one month visit to the CfA for further collaboration. In the course of this grant we made a number of advances in solar system dynamics. For example, we developed an analytic model for the origin and consequence of chaos associated with three-body resonances in the asteroid belt. This has been shown to be important for the delivery of near Earth objects. We later extended this model to three-body resonances among planets. We were able to show that the numerically identified chaos among the outer planets results from a three-body resonance involving Jupiter, Saturn, and Uranus. The resulting paper was awarded the 1999 Newcomb Cleveland award from the AAAS. This award singles out one paper published in Science each year for distinction. This grant has also supported, in part, my participate in other solar system dynamics projects. The results from those collaborations are also listed.

  16. Long-Term Modeling of Solar Energy: Analysis of Concentrating Solar Power (CSP) and PV Technologies

    SciTech Connect

    Zhang, Yabei; Smith, Steven J.

    2007-08-16

    This report presents an overview of research conducted on solar energy technologies and their implementation in the ObjECTS framework. The topics covered include financing assumptions and selected issues related to the integration of concentrating thermal solar power (CSP) and photovoltaics PV technologies into the electric grid. A review of methodologies for calculating the levelized energy cost of capital-intensive technologies is presented, along with sensitivity tests illustrating how the cost of a solar plant would vary depending on financing assumptions. An analysis of the integration of a hybrid concentrating thermal solar power (CSP) system into the electric system is conducted. Finally a failure statistics analysis for PV plants illustrates the central role of solar irradiance uncertainty in determining PV grid integration characteristics.

  17. Long-Term Dynamics of Small Bodies in the Solar System

    NASA Technical Reports Server (NTRS)

    Holman, Matthew J.; Grant, John (Technical Monitor)

    2002-01-01

    As part of the NASA Planetary Geology and Geophysics program, Prof. Norm Murray (CITA (Canadian Institute of Theoretical Astrophysics)) and I have been conducting investigations of the long-term dynamics of small bodies in the outer solar system. This grant, and its successor NAG5-10365, supports travel for collaboration by the Investigators and also supports Murray during an annual one month visit to the CfA (Harvard-Smithsonian Center for Astrophysics) for further collaboration. In the course of this grant we made a number of advances in solar system dynamics. For example, we developed an analytic model for the origin and consequence of chaos associated with three-body resonances in the asteroid belt. This has been shown to be important for the delivery of near Earth objects (NEO). We later extended this model to three-body resonances among planets. We were able to show that the numerically identified chaos among the outer planets results from a three-body resonance involving Jupiter, Saturn, and Uranus. The resulting paper was awarded the 1999 Newcomb Cleveland award from the AAAS (American Association for the Advancement of Science). This award singles out one paper published in Science each year for distinction. A list of grant-related publications is presented, with abstracts included.

  18. LONG-TERM CHROMOSPHERIC ACTIVITY IN SOUTHERN M DWARFS: Gl 229 A AND Gl 752 A

    SciTech Connect

    Buccino, Andrea P.; Luoni, MarIa Luisa; Abrevaya, Ximena C.; Mauas, Pablo J. D.; DIaz, Rodrigo F.

    2011-02-15

    Several late-type stars present activity cycles similar to that of the Sun. However, these cycles have been mostly studied in F to K stars. Due to their small intrinsic brightness, M dwarfs are not usually the targets of long-term observational studies of stellar activity, and their long-term variability is generally not known. In this work, we study the long-term activity of two M dwarf stars: Gl 229 A (M1/2) and Gl 752 A (M2.5). We employ medium-resolution echelle spectra obtained at the 2.15 m telescope at the Argentinian observatory CASLEO between 2000 and 2010, and photometric observations obtained from the ASAS database. We analyze Ca II K line-core fluxes and the mean V magnitude with the Lomb-Scargle periodogram, and we obtain possible activity cycles of {approx}4 yr for Gl 229 A and {approx}7 yr for Gl 752 A.

  19. Tibial stress fractures in an active duty population: long-term outcomes.

    PubMed

    Kilcoyne, Kelly G; Dickens, Jonathan F; Rue, John-Paul

    2013-01-01

    Tibial stress fractures are a common overuse injury among military recruits. The purpose of this study was to determine what, if any, long-term effects that tibial stress fractures have on military personnel with respect to physical activity level, completion of military training, recurrence of symptoms, and active duty service. Twenty-six military recruits included in a previous tibial stress fracture study were contacted 10 years after initial injury and asked a series of questions related to any long-term consequences of their tibial stress fracture. Of the 13 patients available for contact, no patients reported any necessary limited duty while on active duty, and no patient reported being separated or discharged from the military as a result of stress fracture. Tibial stress fractures in military recruits are most often an isolated injury and do not affect ability to complete military training or reflect a long-term need for decreased physical activity.

  20. Effect of Long-Term Physical Activity Practice after Cardiac Rehabilitation on Some Risk Factors

    ERIC Educational Resources Information Center

    Freyssin, Celine, Jr.; Blanc, Philippe; Verkindt, Chantal; Maunier, Sebastien; Prieur, Fabrice

    2011-01-01

    The objective of this study was to evaluate the effects of long-term physical activity practice after a cardiac rehabilitation program on weight, physical capacity and arterial compliance. The Dijon Physical Activity Score was used to identify two groups: sedentary and active. Weight, distance at the 6-min walk test and the small artery elasticity…

  1. Developing Long-Term Physical Activity Participation: A Grounded Theory Study with African American Women

    ERIC Educational Resources Information Center

    Harley, Amy E.; Buckworth, Janet; Katz, Mira L.; Willis, Sharla K.; Odoms-Young, Angela; Heaney, Catherine A.

    2009-01-01

    Regular physical activity is linked to a reduced risk of obesity and chronic disease. African American women bear a disproportionate burden from these conditions and many do not get the recommended amount of physical activity. Long-term success of interventions to initiate and maintain a physically active lifestyle among African American women has…

  2. Worldwide impact of aerosol’s time scale on the predicted long-term concentrating solar power potential

    NASA Astrophysics Data System (ADS)

    Ruiz-Arias, Jose A.; Gueymard, Christian A.; Santos-Alamillos, Francisco J.; Pozo-Vázquez, David

    2016-08-01

    Concentrating solar technologies, which are fuelled by the direct normal component of solar irradiance (DNI), are among the most promising solar technologies. Currently, the state-of the-art methods for DNI evaluation use datasets of aerosol optical depth (AOD) with only coarse (typically monthly) temporal resolution. Using daily AOD data from both site-specific observations at ground stations as well as gridded model estimates, a methodology is developed to evaluate how the calculated long-term DNI resource is affected by using AOD data averaged over periods from 1 to 30 days. It is demonstrated here that the use of monthly representations of AOD leads to systematic underestimations of the predicted long-term DNI up to 10% in some areas with high solar resource, which may result in detrimental consequences for the bankability of concentrating solar power projects. Recommendations for the use of either daily or monthly AOD data are provided on a geographical basis.

  3. Worldwide impact of aerosol’s time scale on the predicted long-term concentrating solar power potential

    PubMed Central

    Ruiz-Arias, Jose A.; Gueymard, Christian A.; Santos-Alamillos, Francisco J.; Pozo-Vázquez, David

    2016-01-01

    Concentrating solar technologies, which are fuelled by the direct normal component of solar irradiance (DNI), are among the most promising solar technologies. Currently, the state-of the-art methods for DNI evaluation use datasets of aerosol optical depth (AOD) with only coarse (typically monthly) temporal resolution. Using daily AOD data from both site-specific observations at ground stations as well as gridded model estimates, a methodology is developed to evaluate how the calculated long-term DNI resource is affected by using AOD data averaged over periods from 1 to 30 days. It is demonstrated here that the use of monthly representations of AOD leads to systematic underestimations of the predicted long-term DNI up to 10% in some areas with high solar resource, which may result in detrimental consequences for the bankability of concentrating solar power projects. Recommendations for the use of either daily or monthly AOD data are provided on a geographical basis. PMID:27507711

  4. Motivational readiness for physical activity and quality of life in long-term lung cancer survivors.

    PubMed

    Clark, Matthew M; Novotny, Paul J; Patten, Christi A; Rausch, Sarah M; Garces, Yolanda I; Jatoi, Aminah; Sloan, Jeff A; Yang, Ping

    2008-07-01

    Little is known about the relationship between motivational readiness for physical activity and quality of life (QOL) in long-term lung cancer survivors. Long-term survivors are considered those who are living 5 years or more following a cancer diagnosis. This project examined the relationship between a self-report measure of motivational readiness for physical activity and QOL in a sample of 272 long-term lung cancer survivors. Participants (54% male, average age 70 years old) completed the mailed survey an average of 6 years after being diagnosed with lung cancer. Survey measures included the stage of change for physical activity and a set of single item QOL and symptom scales. Thirty-seven percent of respondents reported they currently engaged in regular physical activity (a total of 30 min or more per day, at least 5 days per week). Kruskal-Wallis tests revealed that those who reported engaging in regular physical activity reported a better overall QOL, better QOL on all five domains of QOL functioning (mental, physical, social, emotional, and spiritual), and fewer symptoms compared to those with a sedentary lifestyle. Physical activity level may have important QOL and symptom management benefits for long-term lung cancer survivors.

  5. Preserving a Unique Archive for Long-Term Solar Variability Studies

    NASA Astrophysics Data System (ADS)

    Webb, David F.; Hewins, Ian; McFadden, Robert; Emery, Barbara; Gibson, Sarah; Denig, William

    2016-05-01

    In 1964 (solar cycle 20) Patrick McIntosh began creating hand-drawn synoptic maps of solar activity, based on Hydrogen alpha (Hα) imaging measurements. These synoptic maps were unique because they traced the polarity inversion lines (PILs), connecting widely separated filaments, fibril patterns and plage corridors to reveal the large-scale organization of the solar magnetic field. He and his assistants later included coronal hole (CH) boundaries to the maps, usually from ground-based He-I 10830 images. They continued making these maps until 2010 (the start of solar cycle 24), yielding more than 40 years (~ 540 Carrington rotations) or nearly four complete solar cycles (SCs) of synoptic maps. The McIntosh collection of maps forms a unique and consistent set of global solar magnetic field data, and are unique tools for studying the structure and evolution of the large-scale solar fields and polarity boundaries, because: 1) they have excellent spatial resolution for defining polarity boundaries, 2) the organization of the fields into long-lived, coherent features is clear, and 3) the data are relatively homogeneous over four solar cycles. After digitization and archiving, these maps -- along with computer codes permitting efficient searches of the map arrays -- will be made publicly available at NOAA’s National Centers for Environmental Information (NCEI) in their final, searchable form. This poster is a progress report of the project so far and some suggested scientific applications.

  6. Analysis of Ca II K images aiming to determine long-term trends in solar irradiance variability

    NASA Astrophysics Data System (ADS)

    Kar, Anuradha; Ermolli, Ilaria; Krivova, Natalie; Solanki, Sami

    2013-04-01

    The change in radiative output of the Sun on time scales longer than a day is attributed to the variability in solar surface magnetic fields. Direct irradiance measurements are only available for less than four decades. To reconstruct long term trends in solar total and spectral irradiance, proxies of solar surface magnetism like sunspot, facular and network areas are needed. Currently, sunspot records alone are used for this purpose, from which the deduction of facular and network areas is rather indirect. Historical records of full disk images of the Sun taken in the Ca II K spectral line (393.3 nm) have the potential to provide far more direct information about the distribution and evolution of faculae and network elements. The latter appear as bright regions in the Ca II K spectroheliograms and their intensity is correlated with the magnetic field strength of the features on the solar surface. Solar full disk images in the Ca II K line have been recorded since the beginning of the 20th century at a number of solar observatories such as at Arcetri (Italy), Mount Wilson(California, US) and Kodaikanal (India). The images are available in digitized archives that contain the data processed for standard instrumental calibrations. To utilize these records for irradiance studies, the next step is to identify the bright magnetic features from the images using feature recognition techniques. We test different feature identification methods which are first applied to a set of recent images from the PSPT instrument at the Osservatorio Astronomico di Roma, taken during three periods characterized by high, medium and low levels of activity. Then the performance of these methods to historical images from Arcetri, Mt. Wilson and Kodaikanal archives is tested. The results will be presented and discussed here.

  7. Short-term and long-term treatment outcomes with Class III activator

    PubMed Central

    Ryu, Hyo-kyung; Chong, Hyun-Jeong; An, Ki-Yong

    2015-01-01

    Objective The purpose of this retrospective study was to investigate short-term and long-term skeletodental outcomes of Class III activator treatment. Methods A Class III activator treatment group (AG) comprised of 22 patients (9 boys, 13 girls) was compared with a Class III control group (CG) comprised of 17 patients (6 boys, 11 girls). The total treatment period was divided into three stages; the initial stage (T1), the post-activator treatment or post-mandibular growth peak stage (T2), and the long-term follow-up stage (T3). Cephalometric changes were evaluated statistically via the Mann-Whitney U-test and the Friedman test. Results The AG exhibited significant increases in the SNA angle, ANB angle, Wits appraisal, A point-N perpendicular, Convexity of A point, and proclination of the maxillary incisors, from T1 to T2. In the long-term follow-up (T1-T3), the AG exhibited significantly greater increases in the ANB angle, Wits appraisal, and Convexity of A point than the CG. Conclusions Favorable skeletal outcomes induced during the Class III activator treatment period were generally maintained until the long-term follow-up period of the post-mandibular growth peak stage. PMID:26445717

  8. Long-term memory consolidation depends on proteasome activity in the crab Chasmagnathus.

    PubMed

    Merlo, E; Romano, A

    2007-06-15

    Long-term memory formation depends on protein and mRNA synthesis that subserves synaptic reorganization. The removal of pre-existing inhibitory proteins by the ubiquitin-proteasome system (UPS) is proposed as a crucial step to support these modifications. The activation of the constitutive transcription factor nuclear factor kappaB (NF-kappaB) depends on the degradation of the inhibitor of NF-kappaB (IkappaB) by the UPS. Here we study the effect of a UPS inhibitor, MG132, on long-term memory consolidation and NF-kappaB activation in the learning paradigm of the crab Chasmagnathus, a model in which this transcription factor plays a key role. Here we found that administration of MG132 interferes with long-term memory but not with short-term memory, and no facilitatory effects were found. Then we studied the effect of the UPS inhibitor on NF-kappaB pathway, finding that MG132 blocks the activation of NF-kappaB induced by training. These results suggest that the UPS is necessary for long-term memory consolidation, allowing for the activation of NF-kappaB as one of the target molecular pathways.

  9. Stimulation of raphe (obscurus) nucleus causes long-term potentiation of phrenic nerve activity in cat.

    PubMed

    Millhorn, D E

    1986-12-01

    1. The respiratory response, measured as integrated phrenic nerve activity, during and for up to an hour following 10 min of continuous electrical stimulation of raphe obscurus was quantitated in anaesthetized, artificially ventilated cats whose carotid sinus nerves and vagus nerves had been cut. End-tidal PCO2 and body temperature were kept constant with servocontrollers. 2. Stimulation of raphe obscurus caused a significant increase in both phrenic tidal activity and respiratory frequency that persisted following cessation of the stimulus. This persistent facilitation is referred to as 'long-term potentiation' of respiration. 3. Control stimulations in the parenchyma of the medulla oblongata failed to stimulate respiration and cause the long-term potentiation. 4. Both the direct facilitatory effects of raphe obscurus stimulation on phrenic nerve activity and the long-term potentiation of respiration following the stimulus were prevented by pre-treating cats with methysergide, a serotonin receptor antagonist. 5. The results are discussed in terms of the raphe obscurus being the potential source of the long-term potentiation of respiration that occurs following stimulation of carotid body afferents (Millhorn, Eldridge & Waldrop, 1980a, b). PMID:3114470

  10. Stellar activity cycles from long-term data by robotic telescopes

    NASA Astrophysics Data System (ADS)

    Oláh, K.

    2014-03-01

    automated photometry+manual data from the literature, resulting in the detection of positive correlation between the rotational rates and cycle length(s) in the sense that faster rotating stars have shorter cycle(s). The long-term, B-V and U-B color index changes of active stars were thoroughly studied by Messina (2008). Direct connection between the magnetic behavior and the orbit of a system containing an active star is seldom observed; such examples are presented by Strassmeier et al. (2011) and Oláh et al. (2013). Based on the data from the DASCH (Digital Access to a Sky Century at Harvard) project, three active K-giants' long-term variability on the timescale of decades to 100 years have beed discovered by Tang et al. (2010). The ASAS database was used to study the cyclic behavior of field M-dwarf stars by Savanov (2012) who found no correlation between the rotation rates and cycle lengths of these objects, suggesting a different type of dynamo to those that drive the dynamo in the RS CVn systems and related active stars, e.g., in Oláh et al. (2009). Recently, Vida & Oláh (2013) determined cycles on the timescale of a year on fast rotating, late-type dwarf stars measured by the Kepler space telescope. However, despite the extremely high precision and time cadence, the Kepler data do not allow to study very long- term phenomena, such as the activity cycles of solar-like stars, due to the limited lifetime of the mission. One of the most important factors in studying stellar activity cycles is time, which cannot be overtaken by any means. It needs systematic, uninterrupted observations for dozens of years, preferably with the same instrument, to avoid systematic effects in the observed long-term variations. Another point is that most of the known magnetically active stars are quite bright objects needing a small telescope to be observed. The construction of automated photometric and spectroscopic telescopes is one of the major, and at the same time low

  11. Implications of solar irradiance variability upon long-term changes in the Earth's atmospheric temperatures

    NASA Technical Reports Server (NTRS)

    Lee, Robert B., III

    1992-01-01

    From 1979 through 1987, it is believed that variability in the incoming solar energy played a significant role in changing the Earth's climate. Using high-precision spacecraft radiometric measurements, the incoming total solar irradiance (total amount of solar power per unit area) and the Earth's mean, global atmospheric temperatures were found to vary in phase with each other. The observed irradiance and temperature changes appeared to be correlated with the 11-year cycle of solar magnetic activity. During the period from 1979 through 1985, both the irradiance and temperature decreased. From 1985 to 1987, they increased. The irradiance changed approximately 0.1 percent, while the temperature varied as much as 0.6 C. During the 1979-1987 period, the temperatures were forecasted to rise linearly because of the anthropogenic build-up of carbon dioxide and the hypothesized 'global warming', 'greenhouse effect', scenarios. Contrary to these scenarios, the temperatures were found to vary in a periodic manner in phase with the solar irradiance changes. The observed correlations between irradiance and temperature variabilily suggest that the mean, global temperature of the Earth may decline between 1990 and 1997 as solar magnetic activity decreases.

  12. How do solar magnetic fields influence the long term changes of some geomagnetic indeces?

    NASA Astrophysics Data System (ADS)

    Li, Y.; Luhmann, J. G.; Arge, C. N.; Ulrich, R.

    2001-05-01

    Lockwood et al. (Nature, June, 1999) and Stamper et al. (JGR, December, 1999) suggested that the increasing trend in geomagnetic activity seen in the aa index could be due to an increase in the Sun's magnetic field. Because this interpretation has implications for solar physics and climate studies, it is important to examine the connections between these indeces and the solar field, which affects geomagnetic activity through the solar wind. We use Mt. Wilson Observatory magnetograph data from 1967 to the present to study the photospheric field variations and the related variations at the source surface of a potential field model. We find that the source surface field behavior is not a straight forward mirror of the photospheric field. In particular, we find that the phase and amplitude of the source surface field strength variation with time, compared to the photospheric field variation, depends on heliolatitude. What is seen in a low latitude band around the ecliptic shows the desired increasing trend over the previous ~3 cycles that Lockwood, Stamper and coworkers require for their aa index simulations. However, this trend is not seen globally in either the photospheric or integrated source surface field. Thus our biased sampling of the solar field through the ecliptic solar wind is not a good measure from which to make conclusions about the global solar field.

  13. Solar Cycle Dynamics of Solar, Magnetospheric, and Heliospheric Particles, and Long-Term Atmospheric Coupling: SAMPEX

    NASA Technical Reports Server (NTRS)

    Mason, G. M.; Blake, J. B.; Mewaldt, R. A.; Stone, E. C.; Baker, D. N.; vonRosenvinge, T. T.; Callis, L. B.; Hamilton, D. C.; Klecker, B.; Hovestadt, D.; Scholer, M.

    1997-01-01

    This report summarizes science analysis activities by the SAMPEX mission science team during the period during the period July 1, 1997 through July 1, 1997. Bibliographic entries for 1996 and 1997 to date (July 1997) are included. The SAMPEX science team was extremely active, with 27 articles published or submitted to refereed journals, 17 papers published in their entirety in Conference Proceedings, and 74 contributed papers, seminars, and miscellaneous presentations. The bibliography at the end of this report constitutes the primary description of the research activity. Science highlights are given under the major activity headings, as well as other activities of the team.

  14. Long-term total solar irradiance variability during sunspot cycle 22

    NASA Technical Reports Server (NTRS)

    Lee, Robert B., III; Gibson, M. Alan; Wilson, Robert S.; Thomas, Susan

    1995-01-01

    Total solar irradiance measurements from the 1984-1993 Earth Radiation Budget Satellite (ERBS) active cavity radiometer and 1978-1993 Nimbus 7 transfer cavity radiometer spacecraft experiments are analyzed to detect the presence of 11-, 22-, and 80-year irradiance variability components. The analyses confirmed the existence of a significant 11-year irradiance variability component, associated with solar magnetic activity and the sunspot cycle. The analyses also suggest the presence of a 22- or 80-year variability component. The earlier Nimbus 7 and Solar Maximum Mission (SMM) spacecraft irradiance measurements decreased approximately 1.2 and 1.3 W/sq m, respectively, between 1980 and 1986. The Nimbus 7 values increased 1.2 W/sq m between 1986 and 1989. The ERBS irradiance measurements increased 1.3 W/sq m during 1986-1989, and then decreased 0.4 W/sq m (at an annual rate of 0.14 W/sq. m/yr) during 1990-1993. Considering the correlations between ERBS, Nimbus 7, and SMM irradiance trends and solar magnetic activity, the total solar irradiance should decrease to minimum levels by 1997 as solar activity decreases to minimum levels, and then increase to maximum levels by the year 2000 as solar activity rises. The ERBS measurements yielded 165.4 +/- 0.7 W/sq m as the mean irradiance value with measurement accuracies and precisions of 0.2% and 0.02%, respectively. The ERBS mean irradiance value is within 0.2% of the 1367.4, 1365.9, and 1366.9 W/sq m mean values for the SMM, Upper Atmosphere Research Satellite (UARS), and Space Shuttle Atmospheric Laboratory for Applications and Science (ATLAS 1) Solar Constant (SOLCON) active cavity radiometer spacecraft experiments, respectively. The Nimbus 7 measurements yielded 1372.1 W/sq m as the mean value with a measurement accuracy of 0.5%. Empirical irradiance model fits, based upon 10.7 -cm solar radio flux (F10) and photometric sunspot index (PSI), were used to assess the quality of the ERBS, Numbus 7, SMM, and the UARS

  15. Observing Campaign to Monitor Magnetically-Active Dwarfs for Long-Term Variability

    NASA Astrophysics Data System (ADS)

    Templeton, Matthew R.

    2009-10-01

    Dr. Styliani (Stella) Kafka of the Department of Terrestrial Magnetism, Carnegie Institute of Washington, requests AAVSO observers to perform long-term photometric monitoring on a number of magnetically active dwarf stars, with an observing frequency of one observation every three days taken with one or more filters. When multiple filters are available, the preferred observations are (in order of precedence): Rc, V, Ic, and B. Please observe such that you obtain a signal to noise of at least 50 (100 or higher is preferred). These objects are all nearby dwarfs known or suspected to have magnetic activity, primarily of the UV Ceti (flare star) or BY Draconis subtypes. Long-term photometric monitoring of these objects will be used in conjunction with other multiwavelength observations from ground-based facilities including the Magellan 6.5-meter and DuPont 2.5-meter telescopes in Chile to understand the long-term magnetic activity cycles of these stars. Such a study can reveal information about the physical natures of these stars, but also about their near space environments and habitability for life. These objects are red, and the variability amplitudes are low, often well below 0.1 magnitudes. The long-term variability due to stellar activity cycles may be much lower. Photometric accuracy rather than the number of observations are key to the success of this project. Unaccounted-for atmospheric effects such as extinction will likely overwhelm any long-term signal from these stars. Observers are strongly urged to fully calibrate their systems and to carefully reduce and transform their photometry to standard photometric passbands, including corrections for airmass/atmospheric extinction. Parameters for 40 objects are given. Observations should be submitted to the AAVSO International Database.

  16. Highly Efficient Organic Hole Transporting Materials for Perovskite and Organic Solar Cells with Long-Term Stability.

    PubMed

    Reddy, Saripally Sudhaker; Gunasekar, Kumarasamy; Heo, Jin Hyuck; Im, Sang Hyuk; Kim, Chang Su; Kim, Dong-Ho; Moon, Jong Hun; Lee, Jin Yong; Song, Myungkwan; Jin, Sung-Ho

    2016-01-27

    Small molecules based on N-atom-linked phenylcarbazole-fluorene as the main scaffold, end-capped with spirobifluorene derivatives, are developed as organic hole-transporting materials for highly efficient perovskite solar cells (PSCs) and bulk heterojunction (BHJ) inverted organic solar cells (IOSCs). The CzPAF-SBF-based devices show remarkable device performance with excellent long-term stability in PSCs and BHJ IOSCs with a maximum PCE of 17.21% and 7.93%, respectively.

  17. Is physical activity associated with appetite? A survey of long-term care residents.

    PubMed

    Dermott, Megann; McDaniel, Jennifer L; Weiss, Edward P; Tomazic, Terry J; Mattfeldt-Beman, Mildred

    2009-01-01

    The intent of this research was to explore the influence of physical activity on the appetite of older adults in long-term care. Given the impact of the anorexia of aging and the increasing numbers of older adults, this could have significant health implications. Residents (N = 93) of a long-term care, assisted living, and rehabilitation facility were surveyed using the "Appetite & Activity Questionnaire." There was no relationship found between physical activity and appetite regardless of the participants' sex or age. BMI appeared to correlate well with the amount of activity that was performed. The most salient finding was the near absence of physical activity, even in the presence of facilities, support personnel, and available time. PMID:19234996

  18. Solar Cycle Dynamics of Solar, Magnetospheric, and Heliospheric Particles, and Long-Term Atmospheric Coupling: SAMPEX

    NASA Technical Reports Server (NTRS)

    Mason, G. M.; Blake, J. B.; Mazur, J. E.; Mewaldt, R. A.; Stone, E. C.; Baker, D. N.; vonRosenvinge, T. T.; Callis, L. B.; Klecker, B.; Hovestadt, D.; Scholer, M.

    2000-01-01

    This final technical report summarizes science analysis activities by the SAMPEX mission science team during the period July 1, 1995 through September 30, 2000. Bibliographic entries for 1995 to date (October 2000) are included. The SAMPEX science team was extremely active, with 72 articles published or submitted to referred journals, 38 papers published in their entirety in Conference Proceedings, and 260 contributed papers, seminars, and miscellaneous presentations. The bibliography at the end of this report constitutes the primary description of the research activity. Science highlights are given under the major activity headings, as well as other activities of the team. One Ph.D. student, Mr. Daniel Williams, completed his thesis at California Institute of Technology based on data from the MAST instrument.

  19. Identifying Feasible Physical Activity Programs for Long-Term Care Homes in the Ontario Context

    PubMed Central

    Shakeel, Saad; Newhouse, Ian; Malik, Ali; Heckman, George

    2015-01-01

    Background Structured exercise programs for frail institutionalized seniors have shown improvement in physical, functional, and psychological health of this population. However, the ‘feasibility’ of implementation of such programs in real settings is seldom discussed. The purpose of this systematic review was to gauge feasibility of exercise and falls prevention programs from the perspective of long-term care homes in Ontario, given the recent changes in funding for publically funded physiotherapy services. Method Six electronic databases were searched by two independent researchers for randomized controlled trials that targeted long-term care residents and included exercise as an independent component of the intervention. Results A total of 39 studies were included in this review. A majority of these interventions were led by physiotherapist(s), carried out three times per week for 30–45 minutes per session. However, a few group-based interventions that were led by long-term care staff, volunteers, or trained non-exercise specialists were identified that also required minimal equipment. Conclusion This systematic review has identified ‘feasible’ physical activity and falls prevention programs that required minimal investment in staff and equipment, and demonstrated positive outcomes. Implementation of such programs represents cost-effective means of providing long-term care residents with meaningful gains in physical, psychological, and social health. PMID:26180563

  20. Elimination of dendritic spines with long-term memory is specific to active circuits

    PubMed Central

    Sanders, Jeff; Cowansage, Kiriana; Baumgärtel, Karsten; Mayford, Mark

    2012-01-01

    Structural changes in brain circuits active during learning are thought to be important for long-term memory storage. If these changes support long-term information storage they might be expected to be present at distant timepoints after learning, as well as specific to the circuit activated with learning, and sensitive to the contingencies of the behavioral paradigm. Here, we show such changes in the hippocampus as a result of contextual fear conditioning. There were significantly fewer spines specifically on active neurons of fear-conditioned mice. This spine loss did not occur in homecage mice or in mice exposed to the training context alone. Mice exposed to unpaired shocks showed a generalized reduction in spines. These learning-related changes in spine density could reflect a direct mechanism of encoding or alternately could reflect a compensatory adaptation to previously described enhancement in transmission due to glutamate receptor insertion. PMID:22956846

  1. Long-term Exposure to Air Pollution and Markers of Inflammation, Coagulation, and Endothelial Activation

    PubMed Central

    Hajat, Anjum; Allison, Matthew; Diez-Roux, Ana V.; Jenny, Nancy Swords; Jorgensen, Neal W.; Szpiro, Adam A.; Vedal, Sverre; Kaufman, Joel D.

    2015-01-01

    Background Air pollution is associated with cardiovascular disease, and systemic inflammation may mediate this effect. We assessed associations between long- and short-term concentrations of air pollution and markers of inflammation, coagulation, and endothelial activation. Methods We studied participants from the Multi-Ethnic Study of Atherosclerosis from 2000 to 2012 with repeat measures of serum C-reactive protein (CRP), interleukin-6 (IL-6), fibrinogen, D-dimer, soluble E-selectin, and soluble Intercellular Adhesion Molecule-1. Annual average concentrations of ambient fine particulate matter (PM2.5), individual-level ambient PM2.5 (integrating indoor concentrations and time–location data), oxides of nitrogen (NOx), nitrogen dioxide (NO2), and black carbon were evaluated. Short-term concentrations of PM2.5 reflected the day of blood draw, day prior, and averages of prior 2-, 3-, 4-, and 5-day periods. Random-effects models were used for long-term exposures and fixed effects for short-term exposures. The sample size was between 9,000 and 10,000 observations for CRP, IL-6, fibrinogen, and D-dimer; approximately 2,100 for E-selectin; and 3,300 for soluble Intercellular Adhesion Molecule-1. Results After controlling for confounders, 5 µg/m3 increase in long-term ambient PM2.5 was associated with 6% higher IL-6 (95% confidence interval = 2%, 9%), and 40 parts per billion increase in long-term NOx was associated with 7% (95% confidence interval = 2%, 13%) higher level of D-dimer. PM2.5 measured at day of blood draw was associated with CRP, fibrinogen, and E-selectin. There were no other positive associations between blood markers and short- or long-term air pollution. Conclusions These data are consistent with the hypothesis that long-term exposure to air pollution is related to some markers of inflammation and fibrinolysis. PMID:25710246

  2. Low-power sensor module for long-term activity monitoring.

    PubMed

    Leuenberger, Kaspar; Gassert, Roger

    2011-01-01

    Wearable sensor modules are a promising approach to collecting data on functional motor activities, both for repeated and long-term assessments, as well as to investigate the transfer of therapy to activities of daily living at home, but have so far either had limited sensing capabilities, or were not laid out for long-term monitoring. This paper presents ReSense, a miniature sensor unit optimized for long-term monitoring of functional activity. Inertial MEMS sensors capture accelerations along six degrees of freedom and a barometric pressure sensor serves as a precise altimeter. Data is written to an integrated memory card. The realized module measures Ø25 × 10 mm, weighs 10 g and can record continuously for 27 h at 25 Hz and over 22 h at 100 Hz. The integrated power-management system detects inactivity and extends the operating time by about a factor of two, as shown by initial 24 h recordings on five energetic healthy adults. The integrated barometric pressure sensor allowed to identify activities incorporating a change in altitude, such as going up/down stairs or riding an elevator. By taking into account data from the inertial sensors during the altitude changes, it becomes possible to distinguish between these two activities. PMID:22254785

  3. Long-term evolution in the global distribution of solar wind speed and density fluctuations during 1997-2009

    NASA Astrophysics Data System (ADS)

    Tokumaru, Munetoshi; Kojima, Masayoshi; Fujiki, Ken'ichi

    2012-06-01

    Interplanetary scintillation (IPS) observations made with the 327-MHz multistation system of the Solar-Terrestrial Environment Laboratory (STEL) are analyzed to investigate the global distribution of solar wind speed and density fluctuations (ΔNe) and their evolution during 1997-2009. This study aims at elucidating the evolution of ΔNe distribution during the cycle 23 and subsequent extended minimum, which is useful for improving understanding of the heliospheric response to the peculiar solar activity. The computer-assisted tomography (CAT) method is used in the present study to deconvolve the line-of-sight integration of STEL IPS observations. This CAT method enables retrieval of the quasi-stationary large-scale structure of the background solar wind. The results show that the high (low)-latitude region is dominated by reduced (enhanced) ΔNe plasma, being closely associated with the fast (slow) solar wind. The solar wind speed data show a distinct change with solar activity, and an excellent positive (negative) correlation is revealed between the fast (slow) wind area and the polar field strength of the Sun. In contrast, the ΔNe data do not show such a solar cycle variation, but instead reveal a significant increase in the fractional area of low-ΔNe region in 2004 preceded by a constant value with a small amount of fluctuation. This change is observed for all latitudes, distinctly after 2007 for low latitudes. Our finding is consistent with the long-term variation of the solar wind density revealed from in situ measurements at the Earth orbit, if ΔNe ∝ Ne (where Ne is the solar wind electron density), and also consistent with the coronal hole distribution during the last solar cycle. It is found that ΔNe is inversely correlated with the solar wind speed V. We obtain the best fit power law function ΔNe ∝ V-0.36±0.14 for V > 350 km/s, which is basically consistent with our earlier result. This fact suggests that the fractional density fluctuations

  4. Long-term activity of meteor showers from Comet 1P/Halley

    NASA Astrophysics Data System (ADS)

    Dubietis, A.

    2003-05-01

    Owing to the common origin of the Orionid and eta-Aquarid meteor showers, these produce similar observational characteristics despite distinct intersection geometry. From the observational data of the Visual Meteor Data Base (VMDB), which represents a homogeneous dataset gathered by a standardized visual observing technique, long-term population index and activity profiles were derived. Typical ZHRs are in the range of 15-30 for the Orionids, and 40-80 for the eta-Aquarids. It was found that there exists a approx. 12-year periodicity of the Orionids and a certain correlation between the long-term activity profiles of both showers. The paper also gives some insight into the filamentary structure and variations of the population index of the Orionids recovered from visual observations, illustrating the complexity of the meteoroid stream.

  5. The Role of Hippocampal NMDA Receptors in Long-Term Emotional Responses following Muscarinic Receptor Activation.

    PubMed

    Hoeller, Alexandre A; Costa, Ana Paula R; Bicca, Maíra A; Matheus, Filipe C; Lach, Gilliard; Spiga, Francesca; Lightman, Stafford L; Walz, Roger; Collingridge, Graham L; Bortolotto, Zuner A; de Lima, Thereza C M

    2016-01-01

    Extensive evidence indicates the influence of the cholinergic system on emotional processing. Previous findings provided new insights into the underlying mechanisms of long-term anxiety, showing that rats injected with a single systemic dose of pilocarpine--a muscarinic receptor (mAChR) agonist--displayed persistent anxiogenic-like responses when evaluated in different behavioral tests and time-points (24 h up to 3 months later). Herein, we investigated whether the pilocarpine-induced long-term anxiogenesis modulates the HPA axis function and the putative involvement of NMDA receptors (NMDARs) following mAChRs activation. Accordingly, adult male Wistar rats presented anxiogenic-like behavior in the elevated plus-maze (EPM) after 24 h or 1 month of pilocarpine injection (150 mg/kg, i.p.). In these animals, mAChR activation disrupted HPA axis function inducing a long-term increase of corticosterone release associated with a reduced expression of hippocampal GRs, as well as consistently decreased NMDAR subunits expression. Furthermore, in another group of rats injected with memantine--an NMDARs antagonist (4 mg/kg, i.p.)--prior to pilocarpine, we found inhibition of anxiogenic-like behaviors in the EPM but no further alterations in the pilocarpine-induced NMDARs downregulation. Our data provide evidence that behavioral anxiogenesis induced by mAChR activation effectively yields short- and long-term alterations in hippocampal NMDARs expression associated with impairment of hippocampal inhibitory regulation of HPA axis activity. This is a novel mechanism associated with anxiety-like responses in rats, which comprise a putative target to future translational studies. PMID:26795565

  6. The Role of Hippocampal NMDA Receptors in Long-Term Emotional Responses following Muscarinic Receptor Activation.

    PubMed

    Hoeller, Alexandre A; Costa, Ana Paula R; Bicca, Maíra A; Matheus, Filipe C; Lach, Gilliard; Spiga, Francesca; Lightman, Stafford L; Walz, Roger; Collingridge, Graham L; Bortolotto, Zuner A; de Lima, Thereza C M

    2016-01-01

    Extensive evidence indicates the influence of the cholinergic system on emotional processing. Previous findings provided new insights into the underlying mechanisms of long-term anxiety, showing that rats injected with a single systemic dose of pilocarpine--a muscarinic receptor (mAChR) agonist--displayed persistent anxiogenic-like responses when evaluated in different behavioral tests and time-points (24 h up to 3 months later). Herein, we investigated whether the pilocarpine-induced long-term anxiogenesis modulates the HPA axis function and the putative involvement of NMDA receptors (NMDARs) following mAChRs activation. Accordingly, adult male Wistar rats presented anxiogenic-like behavior in the elevated plus-maze (EPM) after 24 h or 1 month of pilocarpine injection (150 mg/kg, i.p.). In these animals, mAChR activation disrupted HPA axis function inducing a long-term increase of corticosterone release associated with a reduced expression of hippocampal GRs, as well as consistently decreased NMDAR subunits expression. Furthermore, in another group of rats injected with memantine--an NMDARs antagonist (4 mg/kg, i.p.)--prior to pilocarpine, we found inhibition of anxiogenic-like behaviors in the EPM but no further alterations in the pilocarpine-induced NMDARs downregulation. Our data provide evidence that behavioral anxiogenesis induced by mAChR activation effectively yields short- and long-term alterations in hippocampal NMDARs expression associated with impairment of hippocampal inhibitory regulation of HPA axis activity. This is a novel mechanism associated with anxiety-like responses in rats, which comprise a putative target to future translational studies.

  7. Physical activity and late effects in childhood acute lymphoblastic leukemia long-term survivors.

    PubMed

    Bertorello, N; Manicone, R; Galletto, C; Barisone, E; Fagioli, F

    2011-08-01

    In the present study the authors evaluated therapy-related long-term adverse effects and physical activity in a cohort of long-term survivors of childhood acute lymphoblastic leukemia (ALL), diagnosed in their center between March 1991 and August 2000, treated according to the AIEOP (Associazione Italiana di Ematologia e Oncologia Pediatrica) ALL 91 or 95 study protocol and regularly seen in the authors' long-term follow-up unit. The authors analyzed the long-term sequelae of major body systems in this cohort of subjects and administered an "ad hoc" questionnaire concerning sport. The authors found that 70 patients out of 102 (68.5%) showed no late effects, 10% presented only instrumental or neuropsychological test abnormalities, and 21.5% had 1 or more clinical late sequelae. None of the evidenced late effects represented a contraindication to do physical activity. Sixty-one percent of survivors do physical activity, most of them regularly. Sixty-one percent of males and 18.5% of females (P < .005) do competitive sport (sports rates are similar to those of the general age-matched population). Nearly all subjects spontaneously choose to do sport and think physical exercise is an important and useful resource for their health. The authors conclude that the more recent therapy regimens for leukemia treatment, excluding bone marrow transplantation, do not seem to cause such late effects as to prevent survivors from doing sport. Therefore, in the care of ALL survivors, physical activity is not only not contraindicated, but should also be promoted as much as possible. The development of specific educational programs is warranted as part of the care of cancer survivors.

  8. Long term variations and solar variability of atomic oxygen and hydrogen in the mesosphere / lower thermosphere

    NASA Astrophysics Data System (ADS)

    Ern, Manfred; Kaufmann, Martin; Lehmann, Catrin; Riese, Martin; Smith, Anne; Marsh, Daniel

    Global measurements of the hydroxyl mesospheric airglow as observed by the SCIAMACHY satellite instrument are presented. SCIAMACHY is mounted on ESA's Envisat launched in March 2002 into a polar, sun-synchronous orbit with an inclination of 98.7deg and an ascending node at 22:00 local solar time. Limb observations on the night side cover about 70 degrees in terms of latitude during each orbit, covering 30S-70N, depending on season. Based on these measurements altitude profiles of atomic oxygen and hydrogen are retrieved by means of an OH non-LTE model. These data are analyzed with respect to solar illumination conditions and global wave activity. A windowed space-time Fourier analysis is carried out to investigate seasonal changes in mesopause wave activity. First comparisons with simulations of the NCAR ROSE model are shown.

  9. Long-term reproductive and behavioral toxicity of anthracene to fish in the presence of solar ultraviolet radiation

    SciTech Connect

    Hall, A.T.; Oris, J.T.

    1994-12-31

    The long-term, low-level effects of anthracene in the presence of solar ultraviolet radiation (SUVR) were examined in the fathead minnow (Pimephales promelas). Adult fish exposed to anthracene exhibited reduced egg laying capacity, with altered oocyte maturation as a potential mechanism of action. Eggs and larvae maternally exposed to anthracene exhibited reduced hatching success and severe developmental abnormalities when incubated under SUVR. The combination of reduced egg output and developmental effects resulted in an inhibition in reproductive capacity in the range of 70--100%. Maternal transfer of anthracene to eggs was efficient; the BCF was 717 for maternally exposed eggs. However, anthracene deputation from eggs after oviposition with only maternal PAH exposure was rapid; anthracene half-life from eggs equaled 1.3 days. Exposure to anthracene under SUVR altered locomotor activity patterns in fathead minnows by inducing hyperactivity or hypoactivity during the light or dark phases of the photoperiod, respectively. Altered activity patterns indicated potential effects of anthracene on the nervous system and/or pineal gland. These alterations disrupted normal activity patterns and reproductive behaviors, and thus have major implications on a fish`s ability to survive and reproduce. Anthracene, a model phototoxic PAH, has many potential sites of toxic action, and any organism exposed to such contaminants will be an considerable SUVR-enhanced risk in the environment.

  10. Uncovering Camouflage: Amygdala Activation Predicts Long-Term Memory of Induced Perceptual Insight

    PubMed Central

    Ludmer, Rachel; Dudai, Yadin; Rubin, Nava

    2012-01-01

    What brain mechanisms underlie learning of new knowledge from single events? We studied encoding in long-term memory of a unique type of one-shot experience, induced perceptual insight. While undergoing an fMRI brain scan, participants viewed degraded images of real-world pictures where the underlying objects were hard to recognize (‘camouflage’), followed by brief exposures to the original images (‘solution’), which led to induced insight (“Aha!”). A week later, participants’ memory was tested; a solution image was classified as ‘remembered’ if detailed perceptual knowledge was elicited from the camouflage image alone. During encoding, subsequently remembered images enjoyed higher activity in mid-level visual cortex and medial frontal cortex, but most pronouncedly in the amygdala, whose activity could be used to predict which solutions will remain in long-term memory. Our findings extend the known roles of amygdala in memory to include promoting of long-term memory of the sudden reorganization of internal representations. PMID:21382558

  11. LONG-TERM VARIATION IN THE SUN’S ACTIVITY CAUSED BY MAGNETIC ROSSBY WAVES IN THE TACHOCLINE

    SciTech Connect

    Zaqarashvili, Teimuraz V.; Oliver, Ramon; Ballester, Jose Luis; Hanslmeier, Arnold; Carbonell, Marc; Gachechiladze, Tamar; Usoskin, Ilya G.

    2015-06-01

    Long-term records of sunspot number and concentrations of cosmogenic radionuclides (10Be and 14C) on the Earth reveal the variation of the Sun's magnetic activity over hundreds and thousands of years. We identify several clear periods in sunspot, 10Be, and 14C data as 1000, 500, 350, 200, and 100 years. We found that the periods of the first five spherical harmonics of the slow magnetic Rossby mode in the presence of a steady toroidal magnetic field of 1200–1300 G in the lower tachocline are in perfect agreement with the timescales of observed variations. The steady toroidal magnetic field can be generated in the lower tachocline either due to the steady dynamo magnetic field for low magnetic diffusivity or due to the action of the latitudinal differential rotation on the weak poloidal primordial magnetic field, which penetrates from the radiative interior. The slow magnetic Rossby waves lead to variations of the steady toroidal magnetic field in the lower tachocline, which modulate the dynamo magnetic field and consequently the solar cycle strength. This result constitutes a key point for long-term prediction of the cycle strength. According to our model, the next deep minimum in solar activity is expected during the first half of this century.

  12. Using larval fish community structure to guide long-term monitoring of fish spawning activity

    USGS Publications Warehouse

    Pritt, Jeremy J.; Roseman, Edward F.; Ross, Jason E.; DeBruyne, Robin L.

    2015-01-01

    Larval fishes provide a direct indication of spawning activity and may therefore be useful for long-term monitoring efforts in relation to spawning habitat restoration. However, larval fish sampling can be time intensive and costly. We sought to understand the spatial and temporal structure of larval fish communities in the St. Clair–Detroit River system, Michigan–Ontario, to determine whether targeted larval fish sampling can be made more efficient for long-term monitoring. We found that larval fish communities were highly nested, with lower river segments and late-spring samples containing the highest genus richness of larval fish. We created four sampling scenarios for each river system: (1) using all available data, (2) limiting temporal sampling to late spring, (3) limiting spatial sampling to lower river segments only, and (4) limiting both spatial and temporal sampling. By limiting the spatial extent of sampling to lower river sites and/or limiting the temporal extent to the late-spring period, we found that effort could be reduced by more than 50% while maintaining over 75% of the observed and estimated total genus richness. Similarly, limiting the sampling effort to lower river sites and/or the late-spring period maintained between 65% and 93% of the observed richness of lithophilic-spawning genera and invasive genera. In general, community composition remained consistent among sampling scenarios. Targeted sampling offers a lower-cost alternative to exhaustive spatial and temporal sampling and may be more readily incorporated into long-term monitoring.

  13. Determining the amount of physical activity needed for long-term weight control

    NASA Technical Reports Server (NTRS)

    Wier, L. T.; Ayers, G. W.; Jackson, A. S.; Rossum, A. C.; Poston, W. S.; Foreyt, J. P.

    2001-01-01

    OBJECTIVE: To evaluate prospectively the influence of habitual physical activity on body weight of men and women and to develop a model that defines the role of physical activity on longitudinal weight change. DESIGN AND SETTING: Occupational cohort study conducted for a mean of 5.5 y. SUBJECTS: A total of 496 (341 male and 155 female) NASA/Johnson Space Center employees who completed the 3 month education component of the employee health-related fitness program and remained involved for a minimum of 2 y. MEASUREMENTS: Body weights were measured at baseline (T1) and follow-up (T2), and habitual physical activity was obtained from the mean of multiple ratings of the 11-point (0-10) NASA Activity Scale (NAS) recorded quarterly between T1 and T2. Other measures included age, gender, VO(2 max) obtained from maximal treadmill testing, body mass index (BMI), and body fat percentage. RESULTS: Multiple regression demonstrated that mean NAS, T1 weight, aging and gender all influence long-term T2 weight. T1 age was significant for the men only. Independently, each increase in mean NAS significantly (P<0.01) reduced T2 weight in men (b=-0.91 kg; 95% CI:-1.4 to-0.42 kg) and women (b=-2.14 kg; 95% CI:-2.93 to-1.35 kg). Mean NAS had a greater effect on T2 weight as T1 weight increased, and the relationship was dose-dependent. CONCLUSIONS: Habitual physical activity is a significant source of long-term weight change. The use of self-reported activity level is helpful in predicting long-term weight changes and may be used by health care professionals when counseling patients about the value of physical activity for weight control.

  14. Intervention to increase physical activity in irritable bowel syndrome shows long-term positive effects

    PubMed Central

    Johannesson, Elisabet; Ringström, Gisela; Abrahamsson, Hasse; Sadik, Riadh

    2015-01-01

    AIM: To assess the long-term effects of physical activity on irritable bowel syndrome (IBS) symptoms and on quality of life, fatigue, depression and anxiety. METHODS: Seventy-six patients from a previous randomized controlled interventional study on increased physical activity in IBS were asked to participate in this long-term follow-up study. The included patients attended one visit in which they filled out questionnaires and they underwent a submaximal cycle ergometer test. The primary end point was the change in the IBS Severity Scoring System (IBS-SSS) at baseline, i.e., before the intervention and at follow-up. The secondary endpoints were changes in quality of life, fatigue, depression and anxiety. RESULTS: A total of 39 [32 women, median age 45 (28-61) years] patients were included in this follow-up. Median follow-up time was 5.2 (range: 3.8-6.2) years. The IBS symptoms were improved compared with baseline [IBS-SSS: 276 (169-360) vs 218 (82-328), P = 0.001]. This was also true for the majority of the dimensions of psychological symptoms such as disease specific quality of life, fatigue, depression and anxiety. The reported time of physical activity during the week before the visit had increased from 3.2 (0.0-10.0) h at baseline to 5.2 (0.0-15.0) h at follow-up, P = 0.019. The most common activities reported were walking, aerobics and cycling. There was no significant difference in the oxygen uptake 31.8 (19.7-45.8) mL per min per kg at baseline vs 34.6 (19.0-54.6) mL/min per kg at follow-up. CONCLUSION: An intervention to increase physical activity has positive long-term effects on IBS symptoms and psychological symptoms. PMID:25593485

  15. Properties of the long-term optical activity of the prototype polar AM Herculis

    NASA Astrophysics Data System (ADS)

    Šimon, Vojtěch

    2016-08-01

    AM Her displays strong long-term activity with the high and low states. This investigation uses AAVSO optical data for a time-series analysis of the long-term variations. Rapid changes of brightness (e.g. the orbital modulation) were smoothed out to emphasise the activity on super-orbital time-scale. I show that the character of this activity changed considerably on time-scales of years, which is reflected in a large evolution of the complicated histogram of the optical brightness. The high states are not the well-defined, narrow levels of brightness. I also show that AM Her displays transitions between the high and low states with the intermittently existing cycles. The longest uninterrupted series of transitions from the high to low state consists of seven episodes (about six years). The existence of this series can be controlled by the lifetime of the active regions on the donor, which modulates the mass transfer rate. I show that the episodes of the high and low states accumulate in clusters, which produces an additional cycle after smoothing by the moving averages. The cycles of activity of the donor can explain this modulation. A single isolated short episode of the low state does not imply a break of this cycle. I also argue that the specific properties of star spots and their migration caused by the differential rotation of the donor would be needed to explain the complex activity of AM Her.

  16. Long term results of mechanical prostheses for treatment of active infective endocarditis

    PubMed Central

    Guerra, J; Tornos, M; Permanyer-Miralda, G; Almirante, B; Murtra, M; Soler-Soler, J

    2001-01-01

    OBJECTIVE—To analyse the long term results of mechanical prostheses for treating active infective endocarditis.
DESIGN—Prospective cohort study of a consecutive series of patients diagnosed with infective endocarditis and operated on in the active phase of the infection for insertion of a mechanical prosthesis.
SETTING—Tertiary referral centre in a metropolitan area.
RESULTS—Between 1975 and 1997, 637 cases of infective endocarditis were diagnosed in the centre. Of these, 436 were left sided (with overall mortality of 20.3%). Surgical treatment in the active phase of the infection was needed in 141 patients (72% native, 28% prosthetic infective endocarditis). Mechanical prostheses were used in 131 patients. Operative mortality was 30.5% (40 patients). Ninety one survivors were followed up prospectively for (mean (SD)) 5.4 (4.5) years. Thirteen patients developed prosthetic valve dysfunction. Nine patients suffered reinfection: four of these (4%) were early and five were late. The median time from surgery for late reinfection was 1.4 years. During follow up, 12 patients died. Excluding operative mortality, actuarial survival was 86.6% at five years and 83.7% at 10 years; actuarial survival free from death, reoperation, and reinfection was 73.1% at five years and 59.8% at 10 years.
CONCLUSIONS—In patients surviving acute infective endocarditis and receiving mechanical prostheses, the rate of early reinfection compares well with reported results of homografts. In addition, prosthesis dysfunction rate is low and long term survival is good. These data should prove useful for comparison with long term studies, when available, using other types of valve surgery in active infective endocarditis.


Keywords: infective endocarditis; surgery; mechanical prosthesis PMID:11410564

  17. Effect of long-term physical activity practice after cardiac rehabilitation on some risk factors.

    PubMed

    Freyssin, Céline; Blanc, Philippe; Verkindt, Chantal; Maunier, Sébastien; Prieur, Fabrice

    2011-12-01

    The objective of this study was to evaluate the effects of long-term physical activity practice after a cardiac rehabilitation program on weight, physical capacity and arterial compliance. The Dijon Physical Activity Score was used to identify two groups: sedentary and active. Weight, distance at the 6-min walk test and the small artery elasticity indice were measured at the beginning, at the end of the rehabilitation program and at 18.3 ± 5.3 months after. After the cardiac rehabilitation, sedentary patients showed a significant increase in weight and a significant reduction in distance on the 6-min walk test and in the arterial compliance. Active patients did not show any alteration in these parameters. We concluded that, after a cardiac rehabilitation program, the sedentary lifestyle has a negative influence on weight, physical capacity and arterial compliance, which are major markers of risk factors. In contrast, the practice of physical activity preserves these parameters.

  18. A wearable sensor for unobtrusive, long-term assessment of electrodermal activity.

    PubMed

    Poh, Ming-Zher; Swenson, Nicholas C; Picard, Rosalind W

    2010-05-01

    Electrodermal activity (EDA) is a sensitive index of sympathetic nervous system activity. Due to the lack of sensors that can be worn comfortably during normal daily activity and over extensive periods of time, research in this area is limited to laboratory settings or artificial clinical environments. We developed a novel, unobtrusive, nonstigmatizing, wrist-worn integrated sensor, and present, for the very first time, a demonstration of long-term, continuous assessment of EDA outside of a laboratory setting. We evaluated the performance of our device against a Food and Drug Administration (FDA) approved system for the measurement of EDA during physical, cognitive, as well as emotional stressors at both palmar and distal forearm sites, and found high correlations across all the tests. We also evaluated the choice of electrode material by comparing conductive fabric with Ag/AgCl electrodes and discuss the limitations found. An important result presented in this paper is evidence that the distal forearm is a viable alternative to the traditional palmar sites for EDA measurements. Our device offers the unprecedented ability to perform comfortable, long-term, and in situ assessment of EDA. This paper opens up opportunities for future investigations that were previously not feasible, and could have far-reaching implications for diagnosis and understanding of psychological or neurological conditions. PMID:20172811

  19. Involvement of Microglia Activation in the Lead Induced Long-Term Potentiation Impairment

    PubMed Central

    Wang, Wen; Shen, Xue-Feng; Che, Hong-Lei; Guo, Yan-Yan; Zhao, Ming-Gao; Chen, Jing-Yuan; Luo, Wen-Jing

    2012-01-01

    Exposure of Lead (Pb), a known neurotoxicant, can impair spatial learning and memory probably via impairing the hippocampal long-term potentiation (LTP) as well as hippocampal neuronal injury. Activation of hippocampal microglia also impairs spatial learning and memory. Thus, we raised the hypothesis that activation of microglia is involved in the Pb exposure induced hippocampal LTP impairment and neuronal injury. To test this hypothesis and clarify its underlying mechanisms, we investigated the Pb-exposure on the microglia activation, cytokine release, hippocampal LTP level as well as neuronal injury in in vivo or in vitro model. The changes of these parameters were also observed after pretreatment with minocycline, a microglia activation inhibitor. Long-term low dose Pb exposure (100 ppm for 8 weeks) caused significant reduction of LTP in acute slice preparations, meanwhile, such treatment also significantly increased hippocampal microglia activation as well as neuronal injury. In vitro Pb-exposure also induced significantly increase of microglia activation, up-regulate the release of cytokines including tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β) and inducible nitric oxide synthase (iNOS) in microglia culture alone as well as neuronal injury in the co-culture with hippocampal neurons. Inhibiting the microglia activation with minocycline significantly reversed the above-mentioned Pb-exposure induced changes. Our results showed that Pb can cause microglia activation, which can up-regulate the level of IL-1β, TNF-α and iNOS, these proinflammatory factors may cause hippocampal neuronal injury as well as LTP deficits. PMID:22952811

  20. Energy development and environment - What about solar energy in a long term perspective?

    NASA Astrophysics Data System (ADS)

    Dessus, B.; Pharabod, F.

    The advantages and drawbacks of various solar technologies are compared. Emphasis is placed on the New Options for Energy (NOE) scenario, which attempts to mitigate the accumulation of atmospheric CO2 and of nuclear waste on earth. Supplies of various kinds of energy in the different regions of the world in the years 2020, 2060, and 2100 are predicted. The appropriate mix of solar technologies for different regions and the role of Solar Power Satellites (SPS) in the mix are addressed. An NOE scenario for a year 2100 solar mix is presented.

  1. The Contribution of the Solcon Instrument to the Long Term Total Solar Irradiance Observation

    NASA Technical Reports Server (NTRS)

    Dewitte, S.; Joukoff, A.; Crommelynck, D.; Lee, R. B., III; Helizon, R.

    1999-01-01

    On century time scales, the variation in the total solar irradiance received by the earth is believed to be a major climate change driver. Therefore accurate and time stable measurements of the total solar irradiance are necessary. We present the latest contribution of the SOLar CONstant (SOLCON) instrument to these measurements, namely its measurements during the International Extreme Ultraviolet Hitchhiker (IEH) 3 space shuttle flight, and its results: the verification of the ageing of the Earth Radiation Budget Satellite (ERBS), and the measurement of the Space Absolute Radiometric Reference (SARR) adjustment coefficients for the Variability of solar IRradiance and Gravity Oscillations (VIRGO) radiometers.

  2. Solar Diameter Monitor: an instrument to measure long-term changes.

    PubMed

    Brown, T M; Elmore, D F; Lacey, L; Hull, H

    1982-10-01

    Analyses of historical data suggest that the solar diameter may vary with time with an amplitude of a few tenths of a second of arc. The High Altitude Observatory has constructed a special purpose telescope, the Solar Diameter Monitor, designed to detect any such changes. The telescope is an f/50 transit instrument with an aperture of 10 cm and is almost completely automated to avoid observer bias. Each day at solar noon, it measures the sun's horizontal diameter by timing the solar disk transit time and the vertical diameter by comparing the image size to that of a stable length standard. Preliminary estimates suggest that these observations will allow a test of the solar diameter's constancy at the 1-sec of arc/century level in an observing time of 3-5 years. PMID:20396278

  3. Multitargeting activity of miR-24 inhibits long-term melatonin anticancer effects

    PubMed Central

    Sacconi, Andrea; Goeman, Frauke; Pallocca, Matteo; Pulito, Claudio; Korita, Etleva; Fanciulli, Maurizio; Muti, Paola; Blandino, Giovanni; Strano, Sabrina

    2016-01-01

    We have previously shown that melatonin exerts tumor suppressor activities by inducing the p38-p53 axis. This occurred within a few hours while no data are available on how melatonin pathway can be sustained on the long term. Here we show that miR-24, which has been demonstrated to target genes involved in the DNA repair process, targets p38, p53, PML and H2AX simultaneously. We show that long-term treatment with melatonin can decrease miR-24 levels post-transcriptionally, which pairs with a long-wave regulation of genes involved in cell proliferation, DNA damage, RNA metabolism and cell shape and transformation. Moreover, we show that melatonin can inhibit cell proliferation and migration, at least in part, by downregulating miR-24. Furthermore, we propose the involvement of hnRNP A1, which is downregulated by melatonin and involved in miRNA processing, in the regulation of miR-24 levels by melatonin. We conclude showing that miR-24 is upregulated in colon, breast and head and neck datasets and its levels negatively correlate with overall survival. PMID:26967561

  4. The development of ferritic-martensitic steels with reduced long-term activation

    NASA Astrophysics Data System (ADS)

    Ehrlich, K.; Kelzenberg, S.; Röhrig, H.-D.; Schäfer, L.; Schirra, M.

    1994-09-01

    Ferritic-martensitic 9-12% CrMoVNb steels of MANET type possess a number of advantageous properties for fusion reactor application. Their optimization has led to improved creep and fracture-toughness properties. New 9-10% CrWVTa alloys have been developed by KfK/IMF in collaboration with the SAARSTAHL GmbH which have a reduced long-term activation and show in addition superior fracture toughness properties. The calculation of dose rate and other radiological parameters with the presently available FISPACT/EAF codes, extended by KfK files for sequential reactions has shown that the long-term dose-rate in these alloys is governed by the remaining 'impurity level' of Nb and the alloying elements W and Ta. Sequential reactions — though relevant for single alloying elements like Cr, Mn, V and N — provide only a second order effect in Fe-based alloys. A challenge for the future materials development is the production of alloys with the desired narrow specification of elements and impurities, which necessitates new ways of steelmaking.

  5. Biomaterial modification of urinary catheters with antimicrobials to give long-term broadspectrum antibiofilm activity.

    PubMed

    Fisher, Leanne E; Hook, Andrew L; Ashraf, Waheed; Yousef, Anfal; Barrett, David A; Scurr, David J; Chen, Xinyong; Smith, Emily F; Fay, Michael; Parmenter, Christopher D J; Parkinson, Richard; Bayston, Roger

    2015-03-28

    Catheter-associated urinary tract infection (CAUTI) is the commonest hospital-acquired infection, accounting for over 100,000 hospital admissions within the USA annually. Biomaterials and processes intended to reduce the risk of bacterial colonization of the catheters for long-term users have not been successful, mainly because of the need for long duration of activity in flow conditions. Here we report the results of impregnation of urinary catheters with a combination of rifampicin, sparfloxacin and triclosan. In flow experiments, the antimicrobial catheters were able to prevent colonization by common uropathogens Proteus mirabilis, Staphylococcus aureus and Escherichia coli for 7 to 12weeks in vitro compared with 1-3days for other, commercially available antimicrobial catheters currently used clinically. Resistance development was minimized by careful choice of antimicrobial combinations. Drug release profiles and distribution in the polymer, and surface analysis were also carried out and the process had no deleterious effect on the mechanical performance of the catheter or its balloon. The antimicrobial catheter therefore offers for the first time a means of reducing infection and its complications in long-term urinary catheter users. PMID:25639970

  6. Multitargeting activity of miR-24 inhibits long-term melatonin anticancer effects.

    PubMed

    Mori, Federica; Ferraiuolo, Maria; Santoro, Raffaela; Sacconi, Andrea; Goeman, Frauke; Pallocca, Matteo; Pulito, Claudio; Korita, Etleva; Fanciulli, Maurizio; Muti, Paola; Blandino, Giovanni; Strano, Sabrina

    2016-04-12

    We have previously shown that melatonin exerts tumor suppressor activities by inducing the p38-p53 axis. This occurred within a few hours while no data are available on how melatonin pathway can be sustained on the long term. Here we show that miR-24, which has been demonstrated to target genes involved in the DNA repair process, targets p38, p53, PML and H2AX simultaneously. We show that long-term treatment with melatonin can decrease miR-24 levels post-transcriptionally, which pairs with a long-wave regulation of genes involved in cell proliferation, DNA damage, RNA metabolism and cell shape and transformation. Moreover, we show that melatonin can inhibit cell proliferation and migration, at least in part, by downregulating miR-24. Furthermore, we propose the involvement of hnRNP A1, which is downregulated by melatonin and involved in miRNA processing, in the regulation of miR-24 levels by melatonin. We conclude showing that miR-24 is upregulated in colon, breast and head and neck datasets and its levels negatively correlate with overall survival. PMID:26967561

  7. Study of long term effect of Solar UV and X-ray radiation on the VLF signals

    NASA Astrophysics Data System (ADS)

    Ray, Suman; Chakrabarti, Sandip Kumar; Sanki, Dipak

    2016-07-01

    Very Low Frequency (VLF) is one of the bands of Radio waves having frequencies lying between 3-30 KHz, with wavelengths 100-10 Km. It propagates through the Earth-ionosphere wave-guide which is formed by lower part of the ionosphere and upper part of Earth's surface. Ionosphere is the ionized component of upper atmosphere. In the present work, we have studied the long term effect of the high energy solar UV and X-ray radiation on the VLF signals. We have analyzed the VLF signal transmitted at 24 KHz from NAA (Cutler, Maine) and received at Moore Observatory in Brownsboro, Kentucky. Also we have collected X-ray and UV data to study the long term effect of UV and X-ray radiation on the VLF signal. We have analyzed the VLF signal for 2007 to 2015. We calculate the average diurnal peak amplitude of the VLF signal for each day and compare it with the UV and X-ray solar radiation. We found that the correlation coefficient of diurnal peak VLF signal amplitude with both solar X-ray and UV radiation is 0.7 indicating a strong correlation between these two phenomena.

  8. Application of micro-porous polycarbonate membranes in dye-sensitized solar cells: Cell performance and long-term stability

    NASA Astrophysics Data System (ADS)

    Lue, Shingjiang Jessie; Lo, Pei Wen; Hung, Ling-Yung; Tung, Yung Liang

    This research investigates the cell performance and long-term stability of dye-sensitized solar cells (DSSCs) containing micro-porous polycarbonate (PC) film as the frame work material to stabilize the electrolyte solution. The track-etched PC film has cylindrical pore geometry, which is beneficial for ion transport in the electrolyte trapped inside the PC film. The photovoltaic efficiency of the DSSC with 0.2-μm PC membrane is 5.75 ± 0.73% under irradiation of 100 mW cm -2, which is slightly lower than that (6.34 ± 0.44%) of cells without PC film. The differences in fill factor and open-circuit voltage between the DSSCs with and without PC film are not statistically significant. The long-term cell performance is carried out at continuous illumination of 100 mW cm -2 (1 sun) and in darkness at 60 °C for up to 1000 h. There is no significant efficiency difference between the cells with and without PC film in light soaking (4.33% vs. 4.52%) for 960 h. In darkness, however, the cells with PC film demonstrate much higher efficiency (at 2.37%) than cells without PC (0.85%) after 1000 h. The improved long-term efficiency data and the higher percentage of working cells confirm the superior lifetime and performance using the micro-porous PC film.

  9. Long Term Preservation of Earth Observation Data in Europe - Challenge and Cooperation Activities

    NASA Astrophysics Data System (ADS)

    Molch, K.; Albani, M.

    2014-12-01

    Earth observation data are unique snapshots of the Earth and the atmosphere. As such they constitute a humankind asset in their importance for monitoring changes in global environmental conditions. With spaceborne Earth observation (EO) missions dating back to the 1970s, 40 years worth of observations are now available in EO data archives worldwide. Data holdings are growing exponentially, e.g. with the Sentinel series of high resolution EO satellites of the European Copernicus Program - which introduces a new dimension of data volumes to be handled. As other EO data holders around the globe, the European Space Agency (ESA) and its member states are committed to keeping the valuable EO data assets safe, accessible, and useable for an unlimited timespan. Rapidly evolving information technology and changing user requirements call for a dedicated and coordinated approach to EO data long term preservation. In Europe collaborative EO data stewardship activities are coordinated by ESA within the ESA long term data preservation (LTDP) program. With a view to the entire data set life cycle of historic and current missions an active LTDP working group addresses a wide range of relevant technical and organizational topics. Studies investigate archiving and access technologies, user expectations, or applicable standards; guidelines and best practices recommend preservation workflows, steps to take in curating individual data sets, the composition of the preserved data set, or concepts for introducing persistent identifiers. Fostering an active international exchange, the activities and documents developed within this European LTDP framework extend beyond Europe by being introduced to the Group on Earth Observations (GEO) and the Committee on Earth Observation Satellites (CEOS). The paper describes the European LTDP cooperation framework, discusses individual focus areas and current activities, and highlights the interaction with global data stewardship initiatives.

  10. The impact of long-term hydrocarbon exposure on the structure, activity, and biogeochemical functioning of microbial mats.

    PubMed

    Aubé, Johanne; Senin, Pavel; Pringault, Olivier; Bonin, Patricia; Deflandre, Bruno; Bouchez, Olivier; Bru, Noëlle; Biritxinaga-Etchart, Edurne; Klopp, Christophe; Guyoneaud, Rémy; Goñi-Urriza, Marisol

    2016-10-15

    Photosynthetic microbial mats are metabolically structured systems driven by solar light. They are ubiquitous and can grow in hydrocarbon-polluted sites. Our aim is to determine the impact of chronic hydrocarbon contamination on the structure, activity, and functioning of a microbial mat. We compared it to an uncontaminated mat harboring similar geochemical characteristics. The mats were sampled in spring and fall for 2years. Seasonal variations were observed for the reference mat: sulfur cycle-related bacteria dominated spring samples, while Cyanobacteria dominated in autumn. The contaminated mat showed minor seasonal variation; a progressive increase of Cyanobacteria was noticed, indicating a perturbation of the classical seasonal behavior. Hydrocarbon content was the main factor explaining the differences in the microbial community structure; however, hydrocarbonoclastic bacteria were among rare or transient Operational Taxonomic Units (OTUs) in the contaminated mat. We suggest that in long-term contaminated systems, hydrocarbonoclastic bacteria cannot be considered a sentinel of contamination. PMID:27449831

  11. The impact of long-term hydrocarbon exposure on the structure, activity, and biogeochemical functioning of microbial mats.

    PubMed

    Aubé, Johanne; Senin, Pavel; Pringault, Olivier; Bonin, Patricia; Deflandre, Bruno; Bouchez, Olivier; Bru, Noëlle; Biritxinaga-Etchart, Edurne; Klopp, Christophe; Guyoneaud, Rémy; Goñi-Urriza, Marisol

    2016-10-15

    Photosynthetic microbial mats are metabolically structured systems driven by solar light. They are ubiquitous and can grow in hydrocarbon-polluted sites. Our aim is to determine the impact of chronic hydrocarbon contamination on the structure, activity, and functioning of a microbial mat. We compared it to an uncontaminated mat harboring similar geochemical characteristics. The mats were sampled in spring and fall for 2years. Seasonal variations were observed for the reference mat: sulfur cycle-related bacteria dominated spring samples, while Cyanobacteria dominated in autumn. The contaminated mat showed minor seasonal variation; a progressive increase of Cyanobacteria was noticed, indicating a perturbation of the classical seasonal behavior. Hydrocarbon content was the main factor explaining the differences in the microbial community structure; however, hydrocarbonoclastic bacteria were among rare or transient Operational Taxonomic Units (OTUs) in the contaminated mat. We suggest that in long-term contaminated systems, hydrocarbonoclastic bacteria cannot be considered a sentinel of contamination.

  12. 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.

  13. Long-term stability of dentoalveolar and skeletal changes after activator-headgear treatment.

    PubMed

    Lerstøl, Magnhild; Torget, Oystein; Vandevska-Radunovic, Vaska

    2010-02-01

    The aim of this study was to analyze the long-term stability of combined activator-headgear treatment on skeletal and dental structures in Class II patients. The material comprised 26 subjects, 10 girls and 16 boys. All had a molar Class II relationship, overjet > or =6 mm, and overbite > or =5 mm. They were treated in one practice with combined activator and headgear appliances. Lateral cephalometric radiographs and dental study casts were taken before treatment (T0, mean age 11.9 years), at the end of activator-headgear treatment (T1, mean age 15.9 years), and 12-15 years out of retention (T2, mean age 28.6 years). Nineteen cephalometric and nine dental cast variables were evaluated using a paired sample t-test between T0-T1, T1-T2, and T0-T2. At T1, the majority of the cephalometric measurements showed statistically significant changes. ANB was significantly reduced by 2.3 degrees due to a significant increase in SNB, but only small changes were observed in SNA. The interincisal angle increased as a result of significant retroclination of both maxillary and mandibular incisors. All patients achieved a Class I molar relationship and a significant reduction in overjet and overbite. At T2, the results showed only slight relapse from T1. However, the relapse did not compromise the significant improvement in almost all the cephalometric and dental variables. Combined activator-headgear treatment improved the skeletal and dental conditions and the results remained stable in the long term.

  14. Diverse impact of acute and long-term extracellular proteolytic activity on plasticity of neuronal excitability

    PubMed Central

    Wójtowicz, Tomasz; Brzdąk, Patrycja; Mozrzymas, Jerzy W.

    2015-01-01

    Learning and memory require alteration in number and strength of existing synaptic connections. Extracellular proteolysis within the synapses has been shown to play a pivotal role in synaptic plasticity by determining synapse structure, function, and number. Although synaptic plasticity of excitatory synapses is generally acknowledged to play a crucial role in formation of memory traces, some components of neural plasticity are reflected by nonsynaptic changes. Since information in neural networks is ultimately conveyed with action potentials, scaling of neuronal excitability could significantly enhance or dampen the outcome of dendritic integration, boost neuronal information storage capacity and ultimately learning. However, the underlying mechanism is poorly understood. With this regard, several lines of evidence and our most recent study support a view that activity of extracellular proteases might affect information processing in neuronal networks by affecting targets beyond synapses. Here, we review the most recent studies addressing the impact of extracellular proteolysis on plasticity of neuronal excitability and discuss how enzymatic activity may alter input-output/transfer function of neurons, supporting cognitive processes. Interestingly, extracellular proteolysis may alter intrinsic neuronal excitability and excitation/inhibition balance both rapidly (time of minutes to hours) and in long-term window. Moreover, it appears that by cleavage of extracellular matrix (ECM) constituents, proteases may modulate function of ion channels or alter inhibitory drive and hence facilitate active participation of dendrites and axon initial segments (AISs) in adjusting neuronal input/output function. Altogether, a picture emerges whereby both rapid and long-term extracellular proteolysis may influence some aspects of information processing in neurons, such as initiation of action potential, spike frequency adaptation, properties of action potential and dendritic

  15. Long Term Seismic Observation in Mariana by OBSs : Activity of Deep Earthquakes

    NASA Astrophysics Data System (ADS)

    Shiobara, H.; Mochizuki, K.; Ohki, S.; Kanazawa, T.; Fukao, Y.; Sugioka, H.; Suyehiro, K.

    2003-12-01

    In order to obtain the deep arc structural image of Mariana, a large-scale seismic observation by using 58 long-term ocean bottom seismometers (LTOBS) has been started since June 2003 for about one year. It is a part of the MARGINS program (US-JAPAN COLLABORATIVE RESEARCH: MULTI-SCALE SEISMIC IMAGING OF THE MARIANA SUBDUCTION FACTORY), and the aim of this observation is the crustal and mantle structure modeling by using passive and active seismic sources. The 50 and 8 LTOBSs are owned by LDEO and ERI, respectively, and they were deployed during the cruise of R/V Kaiyo (Jamstec), KY03-06. Prior to this experiment, we made a pilot long-term seismic array observation in the same area by using 10 LTOBSs, deployed in Oct. 2001 by R/V Yokosuka (Jamstec) and recovered in Feb. 2003 by R/V Kaiyo. This LTOBS has been developed by ERI, which has the PMD sensor (WB2023LP) and a titanium sphere housing (D=50cm) and was already used in several long-term observations (ex. trans-PHS array observation presented at the AGU fall meeting, 2000, S51B-02). Two of 10 LTOBSs could not be recovered due to malfunction of the releasing system, and one recovered had a trouble in the sensor control unit. But, seven others have obtained more than 11 months long data continuously. As passive source studies of these observations use characteristic deep earthquakes in this area, the activity of them will be introduced in this presentation, from the data obtained just above them. At the first step, difference of hypocenters of known events, listed on the PDE catalog, is examined. There are 59 events of epicenters within a circular area centered at 19° N, 145° E with radius of 1000km from the catalog during the observation. P and S arrivals are picked by using the WIN system, and the iasp91 model (only {VP} with {{VP}/{V_S}=1.732}) is used for the hypocenter determination. Station corrections are applied only for the sediment layer, estimated from several arrival time data of P and P-S converted

  16. Impact of microbial activity on the radioactive waste disposal: long term prediction of biocorrosion processes.

    PubMed

    Libert, Marie; Schütz, Marta Kerber; Esnault, Loïc; Féron, Damien; Bildstein, Olivier

    2014-06-01

    This study emphasizes different experimental approaches and provides perspectives to apprehend biocorrosion phenomena in the specific disposal environment by investigating microbial activity with regard to the modification of corrosion rate, which in turn can have an impact on the safety of radioactive waste geological disposal. It is found that iron-reducing bacteria are able to use corrosion products such as iron oxides and "dihydrogen" as new energy sources, especially in the disposal environment which contains low amounts of organic matter. Moreover, in the case of sulphate-reducing bacteria, the results show that mixed aerobic and anaerobic conditions are the most hazardous for stainless steel materials, a situation which is likely to occur in the early stage of a geological disposal. Finally, an integrated methodological approach is applied to validate the understanding of the complex processes and to design experiments aiming at the acquisition of kinetic data used in long term predictive modelling of biocorrosion processes.

  17. Predicting the ageing and the long-term durability of organic polymer solar cells

    NASA Astrophysics Data System (ADS)

    Gardette, Jean-Luc; Rivaton, Agnès; Thérias, Sandrine; Chambon, Sylvain; Manceau, Matthieu; Gaume, Julien

    2010-06-01

    Organic solar cells based on conductive polymers exhibit a unique combination of properties which include low cost, flexibility and large surface processability. Organic photovoltaic could then prevail for some applications alongside silicon, such as nomad or indoor. To achieve this objective, the sustainability of the initial properties in conditions of use of the cell is required, since it could be a lock to the emergence of these devices in the market. The polymers used in solar cells are indeed known to exhibit low resistance to environmental constraints, in particular to the combined action of sunlight, oxygen and water. We present recent results on both the accelerated artificial and the natural outdoors ageing of MDMO-PPV (Poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-Phenylenevinylene) and P3HT/PCBM blends poly(3-hexylthiophene) (P3HT) (methano-fullerene[6,6]-phenyl C61-butyric acid methyl ester) ([60] PCBM). The influence of various parameters such as the temperature and the presence of oxygen were studied. The modifications of the chemical structure of both the components of the blend were monitored by spectroscopic analysis (infrared, UV-visible), the morphology of the blends was analysed by AFM and XRD and the photovoltaic performances all along the exposure were recorded. Two important results have been pointed out: on one hand, the Achilles heel of the chemical structure of MDMO-PPV and P3HT under the impact of light has been evidenced. On the other hand, it has been shown that P3HT:PCBM blends are much more stable than MDMO:PCBM blends whatever the conditions of ageing are. Results show that a convenient encapsulation can ensure a promising lifetime of P3HT/PCBM blends in real conditions of use. This work also focuses on this last point and proposes to study and try to understand the behavior of the materials used in the active layer when submitted to photoaging and thermal aging in the absence of oxygen. To fulfil very good encapsulation, glass

  18. Covalent functionalization of graphene by azobenzene with molecular hydrogen bonds for long-term solar thermal storage

    PubMed Central

    Feng, Yiyu; Liu, Hongpo; Luo, Wen; Liu, Enzuo; Zhao, Naiqin; Yoshino, Katsumi; Feng, Wei

    2013-01-01

    Reduced graphene oxide-azobenzene (RGO-AZO) hybrids were prepared via covalent functionalization for long-term solar thermal storage. Thermal barrier (ΔEa) of cis to tran reversion and thermal storage (ΔH) were improved by molecular hydrogen bonds (H-bonds) through ortho- or para-substitution of AZO. Intramolecular H-bonds thermally stabilized cis-ortho-AZO on RGO with a long-term half-life of 5400 h (ΔEa = 1.2 eV), which was much longer than that of RGO-para-AZO (116 h). RGO-para-AZO with one intermolecular H-bond showed a high density of thermal storage up to 269.8 kJ kg−1 compared with RGO-ortho-AZO (149.6 kJ kg−1) with multiple intra- and intermolecular H-bonds of AZO according to relaxed stable structures. Thermal storage in experiment was the same order magnitude to theoretical data based on ΔH calculated by density functional theory and packing density. Photoactive RGO-AZO hybrid can be developed for high-performance solar thermal storage by optimizing molecular H-bonds. PMID:24247355

  19. Long-term solar UV radiation reconstructed by ANN modelling with emphasis on spatial characteristics of input data

    NASA Astrophysics Data System (ADS)

    Feister, U.; Junk, J.; Woldt, M.; Bais, A.; Helbig, A.; Janouch, M.; Josefsson, W.; Kazantzidis, A.; Lindfors, A.; den Outer, P. N.; Slaper, H.

    2008-06-01

    Artificial Neural Networks (ANN) are efficient tools to derive solar UV radiation from measured meteorological parameters such as global radiation, aerosol optical depths and atmospheric column ozone. The ANN model has been tested with different combinations of data from the two sites Potsdam and Lindenberg, and used to reconstruct solar UV radiation at eight European sites by more than 100 years into the past. Special emphasis will be given to the discussion of small-scale characteristics of input data to the ANN model. Annual totals of UV radiation derived from reconstructed daily UV values reflect interannual variations and long-term patterns that are compatible with variabilities and changes of measured input data, in particular global dimming by about 1980/1990, subsequent global brightening, volcanic eruption effects such as that of Mt. Pinatubo, and the long-term ozone decline since the 1970s. Patterns of annual erythemal UV radiation are very similar at sites located at latitudes close to each other, but different patterns occur between UV radiation at sites in different latitude regions.

  20. Towards more reliable long-term indices of geomagnetic activity: correcting a new inhomogeneity problem in early geomagnetic data

    NASA Astrophysics Data System (ADS)

    Holappa, Lauri; Mursula, Kalevi

    2016-07-01

    For the time before the space era our knowledge of the centennial evolution of solar wind (SW) and interplanetary magnetic field (IMF) is based on proxies derived from geomagnetic indices. The reliability of these proxies is dependent on the homogeneity of magnetic field data. In this paper we study the interhourly (IHV) and interdiurnal (IDV_{1d}) variability indices calculated from the data of two British observatories, Eskdalemuir and Lerwick, and compare them to the corresponding indices of the German Niemegk observatory. We find an excess of about 14 ± 4% (5.8 ± 2%) and 27 ± 10% (15 ± 6%) in the IHV (IDV_{1d}) in the indices of Eskdalemuir and Lerwick in 1935-1969. The timing of this excess accurately coincides with instrument changes made in these observatories, strongly supporting the interpretation that the excess is indeed caused by instrument related inhomogeneities in the data of Eskdalemuir and Lerwick. We show that the detected excess notably modifies the long-term trend of geomagnetic activity and the centennial evolution of IMF strength and solar wind speed estimated using these indices. We note that the detected inhomogeneity problem may not be limited to the data of the two studied observatories, but may be quite common to long series of geomagnetic measurements. These results question the reliability of the present measures of the centennial change in solar wind speed and IMF.

  1. Long-term effect of temperature on N2O emission from the denitrifying activated sludge.

    PubMed

    Wang, Xiaojun; Yang, Xiaoru; Zhang, Zhaoji; Ye, Xin; Kao, Chih Ming; Chen, Shaohua

    2014-03-01

    The long-term effect of various temperature (4°C, 12°C, 20°C, 25°C and 34°C) on nitrous oxide (N2O) emission from lab-scale denitrifying activated sludge was studied in terms of activation energy, abundance of functional gene nosZ and its transcription. Results showed that temperature had a positive effect on N2O emissions as well as the maximum biomass-specific reduction rates of N2O and NO3(-), ranging from 0.006% to 0.681% of (N2O + N2), 17.3-116.2 and 5.2-66.2 mg N g(-1) VSS h(-1), respectively. The activation energies (Ea) for N2O and NO3(-) reduction of 44.1 kJ mol(-1) and 54.9 kJ mol(-1), shed light on differences in denitrifying rate variation. The maximum NO3(-) reduction rates were more sensitive to temperature variation than the corresponding N2O reduction rates under long-term acclimation. As a result, the ratio between N2O and NO3(-) reduction rates declined to 1.87 at 34°C from 3.31 at 4°C, suggesting great potential capacity for N2O losses at high temperature. The copy numbers of denitrifiers as nosZ gene (×10(8) copies mL(-1)) and total bacteria as 16S rRNA gene (×10(10) copies mL(-1)) did not show obvious relationship with temperature, having relative abundance of 0.42% on average. The transcriptional regulation of nosZ gene, in the range of 10(8)-10(5) copies mL(-1), was affected by reductase activity, substrate concentration as well as its duration. The active nosZ gene expression was accompanied with low reductase capacity, high dissolved N2O and the duration of N2O accumulation. These results provide insights into activation energy and gene expression responsible for N2O emission.

  2. The Long-Term Market Potential of Concentrating Solar Power (CSP) Systems

    SciTech Connect

    Smith, Steven J.

    2012-10-30

    This chapter will examine the conditions under which thermal CSP systems might play a large role in the global energy system. CSP technologies, such as troughs or power towers, have a large advantage over other solar technologies in that they offer the potential for firm power delivery, mitigating intermittency issues. These systems require relatively cloud-free conditions to operate, which limits their geographic applicability.

  3. Long-term measurements of 36Cl to investigate potential solar influence on the decay rate

    NASA Astrophysics Data System (ADS)

    Kossert, Karsten; Nähle, Ole J.

    2014-03-01

    Recently, Jenkins et al. [6] reported on fluctuations in the detected decay events of 36Cl which were measured with a Geiger-Müller counter. Experimental data of 32Si measured by means of an end-window gas-flow proportional counter at the Brookhaven National Laboratory show similar periodicity, albeit a different amplitude. Jenkins et al. interpret the fluctuations as evidence of solar influence on the decay rates of beta-decaying radionuclides.

  4. Long-term variation of statistical properties of sunspot field strengths and their relation to the characteristics of solar cycles in 1917-2013

    NASA Astrophysics Data System (ADS)

    Tlatova, Kseniya; Pevtsov, Alexei; Tlatov, Andrey; Vasilieva, Valeria; Kalevi Mursula

    We use the digitized sunspot daily drawings from the Mount Wilson Observatory (MWO) from 1917—2013 to study the long-term variations in sunspot magnetic fields. Tabulated data include the heliographic coordinates, area and magnetic field strength of all sunspots on solar disk. Sunspot field strengths exhibit several trends, which can be of instrumental or truly solar in its nature. For example, in depth analysis of the sunspot field strength and the sunspot areas indicates long-term changes in the observing system at the MWO, when systematically larger number of measurements in sub-features (e.g., multiple umbrae) was made beginning mid-20th century. The final data set is used to study several properties of active regions including difference (in field strength and area) between leading and following sunspots, the orientation of magnetic field in sunspots and pores relative to vertical direction, and the Hale (polarity) and Joy (tilt) laws over the period of about ten solar cycles.

  5. Activation of Muscarinic M1 Acetylcholine Receptors Induces Long-Term Potentiation in the Hippocampus.

    PubMed

    Dennis, Siobhan H; Pasqui, Francesca; Colvin, Ellen M; Sanger, Helen; Mogg, Adrian J; Felder, Christian C; Broad, Lisa M; Fitzjohn, Steve M; Isaac, John T R; Mellor, Jack R

    2016-01-01

    Muscarinic M1 acetylcholine receptors (M1Rs) are highly expressed in the hippocampus, and their inhibition or ablation disrupts the encoding of spatial memory. It has been hypothesized that the principal mechanism by which M1Rs influence spatial memory is by the regulation of hippocampal synaptic plasticity. Here, we use a combination of recently developed, well characterized, selective M1R agonists and M1R knock-out mice to define the roles of M1Rs in the regulation of hippocampal neuronal and synaptic function. We confirm that M1R activation increases input resistance and depolarizes hippocampal CA1 pyramidal neurons and show that this profoundly increases excitatory postsynaptic potential-spike coupling. Consistent with a critical role for M1Rs in synaptic plasticity, we now show that M1R activation produces a robust potentiation of glutamatergic synaptic transmission onto CA1 pyramidal neurons that has all the hallmarks of long-term potentiation (LTP): The potentiation requires NMDA receptor activity and bi-directionally occludes with synaptically induced LTP. Thus, we describe synergistic mechanisms by which acetylcholine acting through M1Rs excites CA1 pyramidal neurons and induces LTP, to profoundly increase activation of CA1 pyramidal neurons. These features are predicted to make a major contribution to the pro-cognitive effects of cholinergic transmission in rodents and humans. PMID:26472558

  6. Activated mTORC1 promotes long-term cone survival in retinitis pigmentosa mice

    PubMed Central

    Venkatesh, Aditya; Ma, Shan; Le, Yun Z.; Hall, Michael N.; Rüegg, Markus A.; Punzo, Claudio

    2015-01-01

    Retinitis pigmentosa (RP) is an inherited photoreceptor degenerative disorder that results in blindness. The disease is often caused by mutations in genes that are specific to rod photoreceptors; however, blindness results from the secondary loss of cones by a still unknown mechanism. Here, we demonstrated that the mammalian target of rapamycin complex 1 (mTORC1) is required to slow the progression of cone death during disease and that constitutive activation of mTORC1 in cones is sufficient to maintain cone function and promote long-term cone survival. Activation of mTORC1 in cones enhanced glucose uptake, retention, and utilization, leading to increased levels of the key metabolite NADPH. Moreover, cone death was delayed in the absence of the NADPH-sensitive cell death protease caspase 2, supporting the contribution of reduced NADPH in promoting cone death. Constitutive activation of mTORC1 preserved cones in 2 mouse models of RP, suggesting that the secondary loss of cones is caused mainly by metabolic deficits and is independent of a specific rod-associated mutation. Together, the results of this study address a longstanding question in the field and suggest that activating mTORC1 in cones has therapeutic potential to prolong vision in RP. PMID:25798619

  7. Exchange Protein Activated by cAMP Enhances Long-Term Memory Formation Independent of Protein Kinase A

    ERIC Educational Resources Information Center

    Ma, Nan; Abel, Ted; Hernandez, Pepe J.

    2009-01-01

    It is well established that cAMP signaling within neurons plays a major role in the formation of long-term memories--signaling thought to proceed through protein kinase A (PKA). However, here we show that exchange protein activated by cAMP (Epac) is able to enhance the formation of long-term memory in the hippocampus and appears to do so…

  8. Relationship between Relativistic Electron Flux in the Inner Magnetosphere and ULF Pulsation on the Ground Associated with Long-term Variations of Solar Wind

    NASA Astrophysics Data System (ADS)

    Kitamura, K.; Nagatsuma, T.; Troshichev, O. A.; Obara, T.; Koshiishi, H.; Saita, S.; Yoshikawa, A.; Yumoto, K.

    2014-12-01

    In the present study the relativistic electron flux (0.59-1.18MeV) measured by Standard Dose Monitor (SDOM) onboard DRTS (KODAMA) satellite at the Geostationary Earth Orbit (GEO) is analyzed to investigate the long term (from 2002 to 2014) variations of the electron flux enhancement (REF) during the passage of Corotating Interaction Regions (CIRs) and/or Coronal Mass Ejection (CMEs). The long term variations of the REF clearly shows the 27-days period associated with the high speed solar wind velocity caused by the CIRs, whereas it is very few that the enhancement of REF lasts for several days after passage of CMEs. The 27-days period enhancement of REF represents the quite strong peak in 2003 when the high speed stream of the solar wind were quit active. We also conducted the same analysis for the Pc5 pulsations observed on the ground. The ground magnetic variations data globally observed by National Institute of Information and Communications Technology (NICT) and International Center for Space Weather Science and Education (ICSWSE) Kyushu University are used to investigate the long term variations of Pc5 power. The same signature in the REF variations is shown in the time variability of the Pc5 power on the ground. These results indicate that the solar wind condition strongly affects the acceleration process of the relativistic electron flux by the ULF wave. In particular the dependence of the REF and Pc5 variations on the sector structures and their seasonal variations strongly suggest that the relationship between Pc5 and REF variations could be controlled by the Russell-McPherron effect.

  9. The Solar Energy Institute: A long-term investment in America's youth

    SciTech Connect

    Arwood, J.W.

    1999-07-01

    Unlike students of a generation ago, today's high school students have had limited personal experience with the energy issues that influence their everyday lives. They have no personal knowledge of the Arab Oil Embargo or the long lines at gas pumps that students in the 1970s encountered. Unlike their counterparts of the 1980s, who demonstrated against nuclear power plant construction projects, today's students have had very little exposure to energy debates of any national or international consequence. What's more, they have only vague memories of the Persian Gulf War and the fight over energy supplies. Fearing that the absence of crucial, real-life experiences has negatively impacted the energy literacy of today's students, numerous entities have implemented programs designed to introduce young people to a cornucopia of diverse energy issues that affect every aspect of daily life. As part of this educational movement, the Arizona Department of Commerce Energy Office recognized the fact that young people face an increasingly uncertain energy picture and, as such, one must provide them an education that will allow them to make informed energy decisions in the future. To this end, the Energy Office founded the Solar Energy Institute. What the author has gathered from his two years of experience operating the Solar Energy Institute is that the energy IQ of America's youth, specifically their solar energy IQ, is deficient. The other conclusion he has been able to draw from the program of study is that this summer camp is having a positive impact on students' energy literacy as measured by test scores and a follow-up survey of participants.

  10. Short and long-term changes in gene expression mediated by the activation of TLR9

    PubMed Central

    Klaschik, Sven; Tross, Debra; Shirota, Hidekazu; Klinman, Dennis M.

    2009-01-01

    CpG DNA binds to Toll-like receptor 9 to stimulate a strong innate immune response. The magnitude, duration and scope of CpG-induced changes in gene expression is incompletely understood despite extensive studies of TLR9 mediated signal transduction pathways. In particular, the prolonged effects of CpG DNA on gene activation have not been investigated despite evidence that a single dose of CpG DNA alters immune reactivity for several weeks. This study used gene expression analysis to monitor changes in mRNA levels for 14 days, and identified the genes, pathways and functional groups triggered in vivo following CpG DNA administration. Two discrete peaks of gene activation (at 3 hr and 5 days) were observed after CpG injection. Both the behavior and function of genes activated during the second peak differed from those triggered shortly after CpG administration. Initial gene up-regulation corresponded to a period when TLR9 ligation stimulated genes functionally associated with the generation of innate and adaptive immune responses (e.g. the NF-kB and B-cell receptor pathways). The second peak reflected processes associated with cell division (e.g., cell cycle and DNA replication & repair). The complex bimodal pattern of gene expression elicited by CpG DNA administration provides novel insights into the long term effects of TLR9 engagement on genes associated with immunity and cell proliferation. PMID:20005572

  11. Pharmacological activation of CB1 receptor modulates long term potentiation by interfering with protein synthesis.

    PubMed

    Navakkode, Sheeja; Korte, Martin

    2014-04-01

    Cognitive impairment is one of the most important side effects associated with cannabis drug abuse, as well as the serious issue concerning the therapeutic use of cannabinoids. Cognitive impairments and neuropsychiatric symptoms are caused by early synaptic dysfunctions, such as loss of synaptic connections in different brain structures including the hippocampus, a region that is believed to play an important role in certain forms of learning and memory. We report here that metaplastic priming of synapses with a cannabinoid type 1 receptor (CB1 receptor) agonist, WIN55,212-2 (WIN55), significantly impaired long-term potentiation in the apical dendrites of CA1 pyramidal neurons. Interestingly, the CB1 receptor exerts its effect by altering the balance of protein synthesis machinery towards higher protein production. Therefore the activation of CB1 receptor, prior to strong tetanization, increased the propensity to produce new proteins. In addition, WIN55 priming resulted in the expression of late-LTP in a synaptic input that would have normally expressed early-LTP, thus confirming that WIN55 priming of LTP induces new synthesis of plasticity-related proteins. Furthermore, in addition to the effects on protein translation, WIN55 also induced synaptic deficits due to the ability of CB1 receptors to inhibit the release of acetylcholine, mediated by both muscarinic and nicotinic acetylcholine receptors. Taken together this supports the notion that the modulation of cholinergic activity by CB1 receptor activation is one mechanism that regulates the synthesis of plasticity-related proteins.

  12. Manipulation of long-term dynamics in a colloidal active matter system using speckle light fields

    NASA Astrophysics Data System (ADS)

    Pince, Ercag; Velu, Sabareesh K. P.; Callegari, Agnese; Elahi, Parviz; Gigan, Sylvain; Volpe, Giovanni; Volpe, Giorgio

    Particles undergoing a stochastic motion within a disordered medium is a ubiquitous physical and biological phenomena. Examples can be given from organelles performing tasks in the cytoplasm to large animals moving in patchy environment. Here, we use speckle light fields to study the anomalous diffusion in an active matter system consisting of micron-sized silica particles(diameter 5 μm) and motile bacterial cells (E. coli). The speckle light fields are generated by mode mixing inside a multimode optical fiber where a small amount of incident laser power is needed to obtain an effective disordered optical landscape for the purpose of optical manipulation. We experimentally show how complex potentials contribute to the long-term dynamics of the active matter system and observed an enhanced diffusion of particles interacting with the active bacterial bath in the speckle light fields. We showed that this effect can be tuned and controlled by varying the intensity and the statistical properties of the speckle pattern. Potentially, these results could be of interest for many technological applications, such as the manipulation of microparticles inside optically disordered media of biological interest.

  13. Plasticity of Neuron-Glial Transmission: Equipping Glia for Long-Term Integration of Network Activity

    PubMed Central

    Croft, Wayne; Dobson, Katharine L.; Bellamy, Tomas C.

    2015-01-01

    The capacity of synaptic networks to express activity-dependent changes in strength and connectivity is essential for learning and memory processes. In recent years, glial cells (most notably astrocytes) have been recognized as active participants in the modulation of synaptic transmission and synaptic plasticity, implicating these electrically nonexcitable cells in information processing in the brain. While the concept of bidirectional communication between neurons and glia and the mechanisms by which gliotransmission can modulate neuronal function are well established, less attention has been focussed on the computational potential of neuron-glial transmission itself. In particular, whether neuron-glial transmission is itself subject to activity-dependent plasticity and what the computational properties of such plasticity might be has not been explored in detail. In this review, we summarize current examples of plasticity in neuron-glial transmission, in many brain regions and neurotransmitter pathways. We argue that induction of glial plasticity typically requires repetitive neuronal firing over long time periods (minutes-hours) rather than the short-lived, stereotyped trigger typical of canonical long-term potentiation. We speculate that this equips glia with a mechanism for monitoring average firing rates in the synaptic network, which is suited to the longer term roles proposed for astrocytes in neurophysiology. PMID:26339509

  14. Solar image parameter data from the SDO: Long-term curation and data mining

    NASA Astrophysics Data System (ADS)

    Schuh, M. A.; Angryk, R. A.; Martens, P. C.

    2015-11-01

    The Solar Dynamics Observatory (SDO) mission captures thousands of images of the Sun per day, motivating the need for efficient and effective storage, representation, and search over a massive repository of data. This work investigates the general-purpose image parameter data produced by the SDO Feature Finding Team's trainable module, which operates at a fixed six minute cadence over all AIA channels. The data contains ten numerical measures computed for each image cell over a 64 × 64 grid for each image. We analyze all available data and metadata produced over the first three years and present comprehensive statistics and outliers while validating the cleanliness and usability of the data source for future research. We then utilize a database of automated solar event reports to create large-scale region-labeled datasets available to the public. We highlight the new-found potential for data-driven discovery by presenting several best-case labeling scenarios that establish a baseline for comparing machine learning classification and attribute (image parameter) evaluation results. Future work focuses on continued dataset curation and spatiotemporal data mining.

  15. Long-term variations of solar corpuscular fluxes based on lunar soil samples

    NASA Astrophysics Data System (ADS)

    Anufriev, G. S.

    2013-07-01

    We report the results of age determination of a lunar soil column, delivered by the Luna 16 mission in September 1970 from the Sea of Fertility. We elaborated and applied the soil age determination method using the kinetic parameter, the regolith accumulation rate. The age of the soil delivered by Luna 16 is about 90 Myr. The isotopic ratio of 3He/4He in the column is slightly higher than in the soil column delivered by the Luna 24 mission. The abundance of helium in the fine fraction of the soil (about 100 µm) is significantly higher and is close to the maximum abundance from the Luna 24 soil column. These differences are most likely associated with the variations of solar corpuscular fluxes. Based on the measurements of the helium isotope abundance in the samples of lunar soil columns, we have estimated the values of ancient solar fluxes of protons and helium and variations thereof in the time interval of up to 600 Myr. We demonstrate that during this epoch there were two strong bursts of the helium flux, about 80 and 470 Myr ago, respectively. The existence of the first peak was assumed earlier from the paleodendrochronological data.

  16. Long-term climbing fibre activity induces transcription of microRNAs in cerebellar Purkinje cells.

    PubMed

    Barmack, Neal H; Qian, Zuyuan; Yakhnitsa, Vadim

    2014-09-26

    Synaptic activation of central neurons is often evoked by electrical stimulation leading to post-tetanic potentiation, long-term potentiation or long-term depression. Even a brief electrical tetanus can induce changes in as many as 100 proteins. Since climbing fibre activity is often associated with cerebellar behavioural plasticity, we used horizontal optokinetic stimulation (HOKS) to naturally increase synaptic input to floccular Purkinje cells in mice for hours, not minutes, and investigated how this activity influenced the transcription of microRNAs, small non-coding nucleotides that reduce transcripts of multiple, complementary mRNAs. A single microRNA can reduce the translation of as many as 30 proteins. HOKS evoked increases in 12 microRNA transcripts in floccular Purkinje cells. One of these microRNAs, miR335, increased 18-fold after 24 h of HOKS. After HOKS stopped, miR335 transcripts decayed with a time constant of approximately 2.5 h. HOKS evoked a 28-fold increase in pri-miR335 transcripts compared with an 18-fold increase in mature miR335 transcripts, confirming that climbing fibre-evoked increases in miR335 could be attributed to increases in transcription. We used three screens to identify potential mRNA targets for miR335 transcripts: (i) nucleotide complementarity, (ii) detection of increased mRNAs following microinjection of miR335 inhibitors into the cerebellum, and (iii) detection of decreased mRNAs following HOKS. Two genes, calbindin and 14-3-3-θ, passed these screens. Transfection of N2a cells with miR335 inhibitors or precursors inversely regulated 14-3-3-θ transcripts. Immunoprecipitation of 14-3-3-θ co-immunoprecipitated PKC-γ and GABAAγ2. Knockdown of either 14-3-3-θ or PKC-γ decreased the serine phosphorylation of GABAAγ2, suggesting that 14-3-3-θ and PKC-γ under the control of miR335 homeostatically regulate the phosphorylation and insertion of GABAAγ2 into the Purkinje cell post-synaptic membrane. PMID:25135969

  17. Long-term facilitation of expiratory and sympathetic activities following acute intermittent hypoxia in rats

    PubMed Central

    Lemes, Eduardo V.; Aiko, Simone; Orbem, Caroline B.; Formentin, Cleiton; Bassi, Mirian; Colombari, Eduardo; Zoccal, Daniel B.

    2015-01-01

    Aim Acute intermittent hypoxia (AIH) promotes persistent increases in ventilation and sympathetic activity, referred as long-term facilitation (LTF). Augmented inspiratory activity is suggested as a major component of respiratory LTF. In the present study, we hypothesized that AIH also elicits a sustained increase in expiratory motor activity. We also investigated whether the expiratory LTF contributes to the development of sympathetic LTF after AIH. Methods Rats were exposed to AIH (10 × 6–7 % O2 for 45 s, every 5 min) and the cardiorespiratory parameters were evaluated during 60 min using in vivo and in situ approaches. Results In unanesthetized conditions (n=9), AIH elicited a modest but sustained increase in baseline mean arterial pressure (MAP, 104±2 vs 111±3 mmHg, P<0.05) associated with enhanced sympathetic and respiratory-related variabilities. In the in situ preparations (n=9), AIH evoked LTF in phrenic (33±12%), thoracic sympathetic (75±25%) and abdominal nerve activities (69±14%). The sympathetic overactivity after AIH was phase-locked with the emergence of bursts in abdominal activity during the late-expiratory phase. In anesthetized vagus-intact animals, AIH increased baseline MAP (113±3 vs 122±2 mmHg, P<0.05) and abdominal muscle activity (535±94%), which were eliminated after pharmacological inhibition of the retrotrapezoid nucleus/parafacial respiratory group (RTN/pFRG). Conclusion These findings indicate that increased expiratory activity is also an important component of AIH-elicited respiratory LTF. Moreover, the development of sympathetic LTF after AIH is linked to the emergence of active expiratory pattern and depends on the integrity of the neurones of the RTN/pFRG. PMID:26910756

  18. Long-Term Atmospheric Changes Caused by the Very Large Solar Proton Event in July 2000

    NASA Technical Reports Server (NTRS)

    Jackman, C. H.; Marsh, D. R.; Garcia, R. R.; Vitt, F. M.; Randall, C. E.; Fleming, F. L.; Labow, G. J.

    2007-01-01

    Solar cycle 23 was accompanied by eight very large solar proton events (SPEs) between 2000 and 2005, along with numerous smaller events. The very large SPE in July 2000, which was associated with the well-known 'Bastille Day Solar Storm,' caused very substantial changes in the polar mesosphere and stratosphere. Significant downward transport of the SPE-produced NO(x) from the polar lower mesosphere and upper stratosphere during the Southern Hemisphere winter period resulted in huge enhancements (>100%) in middle stratospheric NO(x) (NO+NO2) during September 2000 in the polar vortex, which were measured by UARS HALOE (C. E. Randall et al., Geophys. Res. Lett., 28,2385-2388,2001). We have used the Whole Atmosphere Community Climate Model (WACCM) to study the longer-term impact of the July 2000 SPE, the third largest SPE period in the past 40 years. This very large SPE provided a wonderful opportunity to study the downward transport of energetic particle precipitation effects in the middle atmosphere. Not surprisingly, the WACCM-simulated polar Northern Hemisphere influences from the July (mid-summer) 2000 SPE were significant for a few months, but the constituent changes were not transported below about 20 hPa. However in the polar Southern Hemisphere (SH) region, the persistent downward transport in the vortex during the months of July-August-September resulted in significant modeled influences for about a year past the SPE. The SH odd nitrogen family, NO(y) (N, NO, NO2, NO3, N2O5, HNO3, HO2NO2, ClONO2, BrONO2), was greatly enhanced by this SPE and these increases were transported to the lower stratosphere. The SPE-enhanced polar NO(y) resulted in long-lasting ozone decreases (from catalytic NO(y) destruction of ozone) and ozone increases (from NO(y) interference in the chlorine and bromine catalytic ozone destruction cycles). These ozone changes resulted in simulated SH polar stratospheric temperature decreases (1-2 K) and increases (1-3 K)..

  19. Paraoxonase activity and genetic polymorphisms in greenhouse workers with long term pesticide exposure.

    PubMed

    Hernández, Antonio F; Mackness, Bharti; Rodrigo, Lourdes; López, Olga; Pla, Antonio; Gil, Fernando; Durrington, Paul N; Pena, Gloria; Parrón, Tesifón; Serrano, José L; Mackness, Michael I

    2003-11-01

    Serum paraoxonase (PON1) is a high-density lipoprotein (HDL) associated protein, which plays a critical role in the pathogenesis of atherosclerosis, although it was primarily associated with the hydrolysis of organophosphorus compounds. PON1 was initially thought to be independent from physiological or pathological states, although recently some environmental factors have been reported to modulate its activity. In this study, we have investigated the promoter (PON1 -108C/T and -909 C/G) and coding region (PON1 192Q/R and 55L/M) polymorphisms, as well as PON1 activity towards different substrates (paraoxon, phenylacetate and diazoxon) in 102 individuals with long term low dose exposure to pesticides in a plastic greenhouse setting (sprayers), who are probably the group of agricultural workers with the highest exposure to pesticides. PON1 activity towards paraoxon was nonsignificantly decreased (up to 53.5%) in the sprayers subgroup exposed to organophosphates (n = 41) compared with nonsprayers acting as controls (n = 39). None of the genotypes studied was associated significantly with the subgroup of individuals exposed to organophosphates, although differences between sprayers and nonsprayers were observed in the PON1 -909 G/C polymorphism. Among the environmental factors that significantly predicted lower rates of PON1 activity towards paraoxon are, interestingly, the exposure to organophosphates and current smoking. By contrast, the utilization of protective clothing while spraying pesticides inside the greenhouses was positively associated with PON1 activity, very likely by preventing the pesticides from being absorbed. This study suggests that chronic exposure to pesticides might decrease PON1 activity and pinpoints the potential usefulness of monitoring PON1 activity in occupational settings where exposure to organophosphates occurs. PMID:14686479

  20. Gamma rays from pion decay - Evidence for long-term trapping of particles in solar flares

    NASA Technical Reports Server (NTRS)

    Mandzhavidze, Natalie; Ramaty, Reuven

    1992-01-01

    The energy spectrum and time dependence of the 50 MeV to 2 GeV gamma rays observed from the 1991 June 11 solar flare are analyzed. It is shown that the emission detected at the late phase of this flare with EGRET on the Compton Gamma-Ray Observatory can be explained by a model in which the bulk of the particles were accelerated during the impulsive phase and subsequently trapped in coronal magnetic loops. The observed spectrum was fit with a combination of pion decay radiation and primary electron bremsstrahlung. The 1991 June 11 data are compared with data for the 1982 June 3 and 1991 June 15 flares from which pion decay emission was also observed. The fact that the fluxes from these three flares are ordered in time in accordance with the predicted time dependence of emission produced by trapped particles provides support for the model.

  1. Long-term transportation noise annoyance is associated with subsequent lower levels of physical activity.

    PubMed

    Foraster, Maria; Eze, Ikenna C; Vienneau, Danielle; Brink, Mark; Cajochen, Christian; Caviezel, Seraina; Héritier, Harris; Schaffner, Emmanuel; Schindler, Christian; Wanner, Miriam; Wunderli, Jean-Marc; Röösli, Martin; Probst-Hensch, Nicole

    2016-05-01

    Noise annoyance (NA) might lead to behavioral patterns not captured by noise levels, which could reduce physical activity (PA) either directly or through impaired sleep and constitute a noise pathway towards cardiometabolic diseases. We investigated the association of long-term transportation NA and its main sources (aircraft, road, and railway) at home with PA levels. We assessed 3842 participants (aged 37-81) that attended the three examinations (SAP 1, 2, and 3 in years 1991, 2001 and 2011, respectively) of the population-based Swiss cohort on Air Pollution and Lung and Heart Diseases in Adults (SAPALDIA). Participants reported general 24-h transportation NA (in all examinations) and source-specific NA at night (only SAP 3) on an ICBEN-type 11-point scale. We assessed moderate, vigorous, and total PA from a short-questionnaire (SAP 3). The main outcome was moderate PA (active/inactive: cut-off≥150min/week). We used logistic regression including random effects by area and adjusting for age, sex, socioeconomic status, and lifestyles (main model) and evaluated potential effect modifiers. We analyzed associations with PA at SAP 3 a) cross-sectionally: for source-specific and transportation NA in the last year (SAP 3), and b) longitudinally: for 10-y transportation NA (mean of SAP 1+2), adjusting for prior PA (SAP 2) and changes in NA (SAP 3-2). Reported NA (score≥5) was 16.4%, 7.5%, 3%, and 1.1% for 1-year transportation, road, aircraft, and railway at SAP 3, respectively. NA was greater in the past, reaching 28.5% for 10-y transportation NA (SAP 1+2). The 10-y transportation NA was associated with a 3.2% (95% CI: 6%-0.2%) decrease in moderate PA per 1-NA rating point and was related to road and aircraft NA at night in cross-sectional analyses. The longitudinal association was stronger for women, reported daytime sleepiness or chronic diseases and it was not explained by objectively modeled levels of road traffic noise at SAP 3. In conclusion, long-term NA

  2. Evaluation of microbial activity for long-term performance assessments of deep geologic nuclear waste repositories.

    SciTech Connect

    Francis, Arokiasamy J.; Wang, Yifeng

    2005-06-01

    Microorganisms are ubiquitous in subsurface environments and play a major role in the biogeochemical recycling of various elements. In this paper, we have developed a general approach for a systematic evaluation of microbial impact on the long-term performance of the repository. We have demonstrated that data on microbial population alone are not sufficient for the evaluation of microbial impact on repository performance and a sensible approach for such evaluation must be based on the consideration of environmental constraints on microbial reaction pathways. We have applied our approach to both the Yucca Mountain (YM) repository and the Waste Isolation Pilot Plant (WIPP). We have demonstrated that the effect of microbial activity on the near-field chemistry in the Yucca Mountain repository is negligible because of limited nutrient supply and harsh environmental conditions created by waste emplacement. Whereas for the WIPP, we have shown that, due to the presence of a large quantity of organic materials and nutrients in the wastes, a significant microbial activity can potentially be stimulated and its impact on repository performance can be evaluated with carefully designed incubation experiments coupled with performance assessment calculations. The impact of microbial gas generation on disposal room chemistry in the WIPP can be mitigated by introducing MgO as a backfill material.

  3. Roche tomography of cataclysmic variables - VII. The long-term magnetic activity of AE Aqr

    NASA Astrophysics Data System (ADS)

    Hill, C. A.; Watson, C. A.; Steeghs, D.; Dhillon, V. S.; Shahbaz, T.

    2016-06-01

    We present a long-term study of the secondary star in the cataclysmic variable AE Aqr, using Roche tomography to indirectly image starspots on the stellar surface spanning 8 years of observations. The seven maps show an abundance of spot features at both high and low latitudes. We find that all maps have at least one large high-latitude spot region, and we discuss its complex evolution between maps, as well as its compatibility with current dynamo theories. Furthermore, we see the apparent growth in fractional spot coverage, fs, around 45° latitude over the duration of observations, with a persistently high fs near latitudes of 20°. These bands of spots may form as part of a magnetic activity cycle, with magnetic flux tubes emerging at different latitudes, similar to the `butterfly' diagram for the Sun. We discuss the nature of flux tube emergence in close binaries, as well as the activity of AE Aqr in the context of other stars.

  4. Long-term non-invasive and continuous measurements of legume nodule activity.

    PubMed

    Cabeza, Ricardo A; Liese, Rebecca; Fischinger, Stephanie A; Sulieman, Saad; Avenhaus, Ulrike; Lingner, Annika; Hein, Hans; Koester, Beke; Baumgarten, Vanessa; Dittert, Klaus; Schulze, Joachim

    2015-02-01

    Symbiotic nitrogen fixation is a process of considerable economic, ecological and scientific interest. The central enzyme nitrogenase reduces H(+) alongside N2 , and the evolving H2 allows a continuous and non-invasive in vivo measurement of nitrogenase activity. The objective of this study was to show that an elaborated set-up providing such measurements for periods as long as several weeks will produce specific insight into the nodule activity's dependence on environmental conditions and genotype features. A system was developed that allows the air-proof separation of a root/nodule and a shoot compartment. H2 evolution in the root/nodule compartment can be monitored continuously. Nutrient solution composition, temperature, CO2 concentration and humidity around the shoots can concomitantly be maintained and manipulated. Medicago truncatula plants showed vigorous growth in the system when relying on nitrogen fixation. The set-up was able to provide specific insights into nitrogen fixation. For example, nodule activity depended on the temperature in their surroundings, but not on temperature or light around shoots. Increased temperature around the nodules was able to induce higher nodule activity in darkness versus light around shoots for a period of as long as 8 h. Conditions that affected the N demand of the shoots (ammonium application, Mg or P depletion, super numeric nodules) induced consistent and complex daily rhythms in nodule activity. It was shown that long-term continuous measurements of nodule activity could be useful for revealing special features in mutants and could be of importance when synchronizing nodule harvests for complex analysis of their metabolic status. PMID:25640854

  5. Seasonal, interannual, and long-term variabilities in biomass burning activity over South Asia.

    PubMed

    Bhardwaj, P; Naja, M; Kumar, R; Chandola, H C

    2016-03-01

    The seasonal, interannual, and long-term variations in biomass burning activity and related emissions are not well studied over South Asia. In this regard, active fire location retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS), the retrievals of aerosol optical depth (AOD) from MODIS Terra, and tropospheric column NO2 from Ozone Monitoring Instrument (OMI) are used to understand the effects of biomass burning on the tropospheric pollution loadings over South Asia during 2003-2013. Biomass burning emission estimates from Global Fire Emission Database (GFED) and Global Fire Assimilation System (GFAS) are also used to quantify uncertainties and regional discrepancies in the emissions of carbon monoxide (CO), nitrogen oxide (NOx), and black carbon (BC) due to biomass burning in South Asia. In the Asian continent, the frequency of fire activity is highest over Southeast Asia, followed by South Asia and East Asia. The biomass burning activity in South Asia shows a distinct seasonal cycle that peaks during February-May with some differences among four (north, central, northeast, and south) regions in India. The annual biomass burning activity in north, central, and south regions shows an increasing tendency, particularly after 2008, while a decrease is seen in northeast region during 2003-2013. The increase in fire counts over the north and central regions contributes 24 % of the net enhancement in fire counts over South Asia. MODIS AOD and OMI tropospheric column NO2 retrievals are classified into high and low fire activity periods and show that biomass burning leads to significant enhancement in tropospheric pollution loading over both the cropland and forest regions. The enhancement is much higher (110-176 %) over the forest region compared to the cropland (34-62 %) region. Further efforts are required to understand the implications of biomass burning on the regional air quality and climate of South Asia.

  6. Long-term non-invasive and continuous measurements of legume nodule activity.

    PubMed

    Cabeza, Ricardo A; Liese, Rebecca; Fischinger, Stephanie A; Sulieman, Saad; Avenhaus, Ulrike; Lingner, Annika; Hein, Hans; Koester, Beke; Baumgarten, Vanessa; Dittert, Klaus; Schulze, Joachim

    2015-02-01

    Symbiotic nitrogen fixation is a process of considerable economic, ecological and scientific interest. The central enzyme nitrogenase reduces H(+) alongside N2 , and the evolving H2 allows a continuous and non-invasive in vivo measurement of nitrogenase activity. The objective of this study was to show that an elaborated set-up providing such measurements for periods as long as several weeks will produce specific insight into the nodule activity's dependence on environmental conditions and genotype features. A system was developed that allows the air-proof separation of a root/nodule and a shoot compartment. H2 evolution in the root/nodule compartment can be monitored continuously. Nutrient solution composition, temperature, CO2 concentration and humidity around the shoots can concomitantly be maintained and manipulated. Medicago truncatula plants showed vigorous growth in the system when relying on nitrogen fixation. The set-up was able to provide specific insights into nitrogen fixation. For example, nodule activity depended on the temperature in their surroundings, but not on temperature or light around shoots. Increased temperature around the nodules was able to induce higher nodule activity in darkness versus light around shoots for a period of as long as 8 h. Conditions that affected the N demand of the shoots (ammonium application, Mg or P depletion, super numeric nodules) induced consistent and complex daily rhythms in nodule activity. It was shown that long-term continuous measurements of nodule activity could be useful for revealing special features in mutants and could be of importance when synchronizing nodule harvests for complex analysis of their metabolic status.

  7. Seasonal, interannual, and long-term variabilities in biomass burning activity over South Asia.

    PubMed

    Bhardwaj, P; Naja, M; Kumar, R; Chandola, H C

    2016-03-01

    The seasonal, interannual, and long-term variations in biomass burning activity and related emissions are not well studied over South Asia. In this regard, active fire location retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS), the retrievals of aerosol optical depth (AOD) from MODIS Terra, and tropospheric column NO2 from Ozone Monitoring Instrument (OMI) are used to understand the effects of biomass burning on the tropospheric pollution loadings over South Asia during 2003-2013. Biomass burning emission estimates from Global Fire Emission Database (GFED) and Global Fire Assimilation System (GFAS) are also used to quantify uncertainties and regional discrepancies in the emissions of carbon monoxide (CO), nitrogen oxide (NOx), and black carbon (BC) due to biomass burning in South Asia. In the Asian continent, the frequency of fire activity is highest over Southeast Asia, followed by South Asia and East Asia. The biomass burning activity in South Asia shows a distinct seasonal cycle that peaks during February-May with some differences among four (north, central, northeast, and south) regions in India. The annual biomass burning activity in north, central, and south regions shows an increasing tendency, particularly after 2008, while a decrease is seen in northeast region during 2003-2013. The increase in fire counts over the north and central regions contributes 24 % of the net enhancement in fire counts over South Asia. MODIS AOD and OMI tropospheric column NO2 retrievals are classified into high and low fire activity periods and show that biomass burning leads to significant enhancement in tropospheric pollution loading over both the cropland and forest regions. The enhancement is much higher (110-176 %) over the forest region compared to the cropland (34-62 %) region. Further efforts are required to understand the implications of biomass burning on the regional air quality and climate of South Asia. PMID:26503008

  8. Long-term Measurements of Solar Proton Fluxes (1963-present) and the Subsequent Impact on Stratospheric Constituents

    NASA Technical Reports Server (NTRS)

    Jackman, Charles H.; Fleming, Eric L.

    2005-01-01

    The fluxes of solar protons have been measured by satellites for over forty years (1963-present). Eight Interplanetary Monitoring Platform (IMP) satellites measured solar proton fluxes from 1963-1993 and five NOAA Geostationary Operational Environmental Satellites (GOES) were used for the period 1994present. These high energy solar protons precipitate on the Earth's polar atmosphere sporadically, especially during solar proton events (SPEs), which typically last a few days. Solar protons with energies greater than 30 MeV are capable of reaching the stratosphere and causing increases in odd hydrogen (HOx) and odd nitrogen (NOy) constituents at polar latitudes (greater than 60 degrees geomagnetic). The enhanced HOx leads to short-lived ozone depletion (-days) due to the short lifetime of HOx constituents. The enhanced NOy leads to long-lived ozone changes because of the long lifetime of the NOy family in the stratosphere. Several very large SPEs (August 1972, August and October 1989, July and November 2000, September and November 2001, and October 2003) over the 1963-2004 time period were simulated in the GSFC two-dimensional chemistry and transport model and were predicted to cause significant polar upper stratospheric ozone depletion greater than 10%, which lasted for several weeks past the events. Several satellite instruments (BUV, SBUV, SBW/2, SAGE II, HALOE, etc.) have shown constituent changes as a result of SPEs. Long-term (greater than 40 year) model simulations of the influence of the solar protons and satellite measurements during and after some of the very large SPEs will be shown.

  9. Active Motor Training Has Long-term Effects on Infants’ Object Exploration

    PubMed Central

    Wiesen, Sarah E.; Watkins, Rachel M.; Needham, Amy Work

    2016-01-01

    Long-term changes in infants’ behavior as a result of active motor training were studied. Thirty-two infants completed three visits to the laboratory. At the first visit, infants were 3 months old and completed an object exploration assessment. Then the experimenter demonstrated the motor training procedures appropriate for the infant’s experimental condition, and parents took home custom infant mittens (either sticky or non-sticky) and a bag of lightweight toys to practice with their infants. Over the course of the following 2 weeks, infants participated in 10 sessions of either active (sticky) or passive (non-sticky) mittens training at home with their parents. Infants who participated in active mittens training wore mittens with the palms covered in Velcro, allowing them to pick up and move around small toys. Infants who participated in passive mittens training wore non-sticky mittens, and their parents moved the toys through their visual fields on their behalf. After completing the training, infants returned to the lab for the second visit. At visit two, infants participated in another object exploration assessment as well as a reaching assessment. Parents returned the training materials to the lab at the second visit, and were told not to continue any specific training regimen from this point forward. Two months later, when infants were about 5.5 months of age, they returned to the lab for a third visit. At the third visit, infants completed the same two assessments as during the second visit. The results of this study indicate that infants who participated in active motor training engaged in more sophisticated object exploration when compared to infants who received passive training. These findings are consistent with others in the literature showing that active motor training at 3 months of age facilitates the processes of object exploration and engagement. The current results and others reveal that the effects of early experience can last long after

  10. Active Motor Training Has Long-term Effects on Infants' Object Exploration.

    PubMed

    Wiesen, Sarah E; Watkins, Rachel M; Needham, Amy Work

    2016-01-01

    Long-term changes in infants' behavior as a result of active motor training were studied. Thirty-two infants completed three visits to the laboratory. At the first visit, infants were 3 months old and completed an object exploration assessment. Then the experimenter demonstrated the motor training procedures appropriate for the infant's experimental condition, and parents took home custom infant mittens (either sticky or non-sticky) and a bag of lightweight toys to practice with their infants. Over the course of the following 2 weeks, infants participated in 10 sessions of either active (sticky) or passive (non-sticky) mittens training at home with their parents. Infants who participated in active mittens training wore mittens with the palms covered in Velcro, allowing them to pick up and move around small toys. Infants who participated in passive mittens training wore non-sticky mittens, and their parents moved the toys through their visual fields on their behalf. After completing the training, infants returned to the lab for the second visit. At visit two, infants participated in another object exploration assessment as well as a reaching assessment. Parents returned the training materials to the lab at the second visit, and were told not to continue any specific training regimen from this point forward. Two months later, when infants were about 5.5 months of age, they returned to the lab for a third visit. At the third visit, infants completed the same two assessments as during the second visit. The results of this study indicate that infants who participated in active motor training engaged in more sophisticated object exploration when compared to infants who received passive training. These findings are consistent with others in the literature showing that active motor training at 3 months of age facilitates the processes of object exploration and engagement. The current results and others reveal that the effects of early experience can last long after

  11. Phrenic long-term facilitation requires PKCθ activity within phrenic motor neurons.

    PubMed

    Devinney, Michael J; Fields, Daryl P; Huxtable, Adrianne G; Peterson, Timothy J; Dale, Erica A; Mitchell, Gordon S

    2015-05-27

    Acute intermittent hypoxia (AIH) induces a form of spinal motor plasticity known as phrenic long-term facilitation (pLTF); pLTF is a prolonged increase in phrenic motor output after AIH has ended. In anesthetized rats, we demonstrate that pLTF requires activity of the novel PKC isoform, PKCθ, and that the relevant PKCθ is within phrenic motor neurons. Whereas spinal PKCθ inhibitors block pLTF, inhibitors targeting other PKC isoforms do not. PKCθ is highly expressed in phrenic motor neurons, and PKCθ knockdown with intrapleural siRNAs abolishes pLTF. Intrapleural siRNAs targeting PKCζ, an atypical PKC isoform expressed in phrenic motor neurons that underlies a distinct form of phrenic motor plasticity, does not affect pLTF. Thus, PKCθ plays a critical role in spinal AIH-induced respiratory motor plasticity, and the relevant PKCθ is localized within phrenic motor neurons. Intrapleural siRNA delivery has considerable potential as a therapeutic tool to selectively manipulate plasticity in vital respiratory motor neurons. PMID:26019328

  12. Long-Term file activity patterns in a UNIX workstation environment

    NASA Technical Reports Server (NTRS)

    Gibson, Timothy J.; Miller, Ethan L.

    1998-01-01

    As mass storage technology becomes more affordable for sites smaller than supercomputer centers, understanding their file access patterns becomes crucial for developing systems to store rarely used data on tertiary storage devices such as tapes and optical disks. This paper presents a new way to collect and analyze file system statistics for UNIX-based file systems. The collection system runs in user-space and requires no modification of the operating system kernel. The statistics package provides details about file system operations at the file level: creations, deletions, modifications, etc. The paper analyzes four months of file system activity on a university file system. The results confirm previously published results gathered from supercomputer file systems, but differ in several important areas. Files in this study were considerably smaller than those at supercomputer centers, and they were accessed less frequently. Additionally, the long-term creation rate on workstation file systems is sufficiently low so that all data more than a day old could be cheaply saved on a mass storage device, allowing the integration of time travel into every file system.

  13. Reduction of K+ Uptake in Glia Prevents Long-Term Depression Maintenance and Causes Epileptiform Activity

    PubMed Central

    Janigro, Damir; Gasparini, Sonia; D'Ambrosio, Raimondo; II, Guy McKhann; DiFrancesco, Dario

    2014-01-01

    Extracellular cesium causes synchronous, interictal-like bursting and prevents maintenance of long-term depression (LTD) in the CA1 hippocampal region. We have investigated the cellular mechanisms underlying cesium actions. Whole-cell recordings showed that brief (2 min) bath exposures to cesium caused pyramidal cell hyperpolarization associated with decreased membrane conductance attributable to blockade of an inward h-type current. After prolonged (>2 min) exposures, a late depolarizing response was observed; this effect was not associated with changes in cell membrane conductance. Recordings from interneurons revealed that Ih is expressed in a sub-population of cells and that cesium effects on interneurons expressing Ih are comparable to those observed in pyramidal cells. Consistent with this effect, cesium decreased the early component of the IPSP recorded in pyramidal cells. Interneurons lacking Ih were not affected by cesium but developed a depolarizing response when drug applications were paired to orthodromic stimulation. We concluded that cesium actions on LTD and cesium-induced epileptiform activity were not attributable exclusively to its direct effects on neurons. Recordings from hippocampal slice astrocytes revealed that cesium interfered with glial electrical responses during LTD induction. Cesium blocked glial inwardly rectifying potassium channels and increased the amplitude and duration of stimulation-evoked [K+]out increases. Thus, the effects of cesium on CA1 synchronization and synaptic plasticity appear to be mediated predominantly by blockade of glial voltage-dependent potassium uptake. PMID:9092603

  14. A note on periodicity of long-term variations of optical continuum in active galactic nuclei

    NASA Astrophysics Data System (ADS)

    Lu, Kai-Xing; Li, Yan-Rong; Bi, Shao-Lan; Wang, Jian-Min

    2016-06-01

    Graham et al. found a sample of active galactic nuclei (AGNs) and quasars from the Catalina Real-time Transient Survey (CRTS) that have long-term periodic variations in optical continuum. The nature of the periodicity remains uncertain. We investigate the periodic variability characteristics of the sample by testing the relations of the observed variability periods with AGN optical luminosity, black hole mass and accretion rates, and find no significant correlations. We also test the observed periods in several different aspects related to accretion discs surrounding single black holes, such as the Keplerian rotational periods of 5100 Å photon-emission regions and self-gravity dominated regions and the precessing period of warped discs. These tests shed new lights on understanding AGN variability in general. Under the assumption that the periodic behaviour is associated with supermassive black hole binary systems in particular, we compare the separations (r {D}_{bullet }) against characteristic radii of broad-line regions (R_riptscriptstyle BLR) of the binaries and find r {D}_{bullet }≈ 0.05R_riptscriptstyle BLR. This interestingly implies that these binaries have only circumbinary BLRs.

  15. Long-term chromospheric activity of non-eclipsing RS CVn-type stars

    NASA Astrophysics Data System (ADS)

    Buccino, A. P.; Mauas, P. J. D.

    2009-02-01

    Context: The IUE database provides several UV high and low-resolution spectra of RS CVn-type stars from 1978 to 1996. In particular, many of these stars were monitored continuously during several seasons by IUE. Aims: Our main purpose is to study the short and long-term chromospheric activity of the RS CVn systems most observed by IUE: HD 22 468 (V711 Tau, HR 1099, K1IV+G5V), HD 21 242 (UX Ari, K0IV+G5V), and HD 224 085 (II Peg, K2IV). Methods: We first obtained the Mount Wilson index S from the IUE high and low-resolution spectra. Secondly, we used the Lomb-Scargle periodogram to analyse the mean annual index < S> and the amplitude of the rotational modulation of the index S. Results: For HD 22 468 (V711 Tau, HR 1099), we find a possible chromospheric cycle with a period of ~18 years and a shorter cycle with a period of ~3 years, which could be associated to a chromospheric “flip-flop” cycle. The data of HD 224 085 (II Peg) also suggest a chromospheric cycle of ~21 years and a flip-flop cycle of ~9 years. Finally, we obtained a possible chromospheric cycle of ~7 years for HD 21 242 (UX Ari).

  16. Phrenic Long-Term Facilitation Requires PKCθ Activity within Phrenic Motor Neurons

    PubMed Central

    Devinney, Michael J.; Fields, Daryl P.; Huxtable, Adrianne G.; Peterson, Timothy J.; Dale, Erica A.

    2015-01-01

    Acute intermittent hypoxia (AIH) induces a form of spinal motor plasticity known as phrenic long-term facilitation (pLTF); pLTF is a prolonged increase in phrenic motor output after AIH has ended. In anesthetized rats, we demonstrate that pLTF requires activity of the novel PKC isoform, PKCθ, and that the relevant PKCθ is within phrenic motor neurons. Whereas spinal PKCθ inhibitors block pLTF, inhibitors targeting other PKC isoforms do not. PKCθ is highly expressed in phrenic motor neurons, and PKCθ knockdown with intrapleural siRNAs abolishes pLTF. Intrapleural siRNAs targeting PKCζ, an atypical PKC isoform expressed in phrenic motor neurons that underlies a distinct form of phrenic motor plasticity, does not affect pLTF. Thus, PKCθ plays a critical role in spinal AIH-induced respiratory motor plasticity, and the relevant PKCθ is localized within phrenic motor neurons. Intrapleural siRNA delivery has considerable potential as a therapeutic tool to selectively manipulate plasticity in vital respiratory motor neurons. PMID:26019328

  17. Long-term facilitation of genioglossus activity is present in normal humans during NREM sleep

    PubMed Central

    Chowdhuri, Susmita; Pierchala, Lisa; Aboubakr, Salah E.; Shkoukani, Mahdi; Badr, M. Safwan

    2008-01-01

    Episodic hypoxia (EH) is followed by increased ventilatory motor output in the recovery period indicative of long-term facilitation (LTF). We hypothesized that episodic hypoxia evokes LTF of genioglossus (GG) muscle activity in humans during non-rapid eye movement sleep (NREM) sleep. We studied 12 normal non-flow limited humans during stable NREM sleep. We induced 10 brief (3 minute) episodes of isocapnic hypoxia followed by 5 minutes of room air. Measurements were obtained during control, hypoxia, and at 5, 10, 20, 30 and 40 minutes of recovery, respectively, for minute ventilation (V̇I), supraglottic pressure (PSG), upper airway resistance (RUA) and phasic GG electromyogram (EMGGG). In addition, sham studies were conducted on room air. During hypoxia there was a significant increase in phasic EMGGG (202.7±24.1% of control, p<0.01) and in V̇I (123.0±3.3% of control, p<0.05); however, only phasic EMGGG demonstrated a significant persistent increase throughout recovery (198.9±30.9%, 203.6±29.9% and 205.4±26.4% of control, at 5, 10, and 20 minutes of recovery, respectively, p<0.01). In multivariate regression analysis, age and phasic EMGGG activity during hypoxia were significant predictors of EMGGG at recovery 20 minutes. No significant changes in any of the measured parameters were noted during sham studies. Conclusion: 1) EH elicits LTF of GG in normal non-flow limited humans during NREM sleep, without ventilatory or mechanical LTF. 2) GG activity during the recovery period correlates with the magnitude of GG activation during hypoxia, and inversely with age. PMID:17945544

  18. Impaired long-term habituation is dissociated from increased locomotor activity after sensorimotor cortex compression.

    PubMed

    Moreira, Tiago; Cebers, Gvido; Salehi, Mehdi; Wägner, Anna; Liljequist, Sture

    2006-02-15

    Behavioural habituation to a novel environment is a simple form of learning in rodents. We studied the habituation and locomotor activity (LMA) of Wistar rats subjected to unilateral, transient (30min) extradural compression (EC) of the right sensorimotor cortex. One group of rats was tested every 24h during the first 5 days (D1-D5) post-EC. Two other groups were tested for the first time in the LMA boxes on D3 and D6 post-EC and their performance was compared with the group tested on D1 (activity in a novel environment). Total and center locomotion, vertical activity and time spent in the center of the LMA box were reduced on D1 post-EC and normalized by D2. The EC-induced motor paresis was undetectable on the rotarod by D2 and on the beam-walking by D3. Total locomotion, vertical activity and time spent in the center of EC-rats significantly increased from D1 to D3. EC caused neurodegeneration in the cortex, caudate putamen and thalamus as detected by Fluoro-Jade staining. The size of the cortical damage decreased from D2 to D5 in the medial and caudal regions of the compressed hemisphere, in accordance with recovery of motor function. LMA provided additional information in the follow-up of recovery from brain injury and habituation to the environment. Thus, long-term, inter-session habituation was impaired from D1 to D3 but dissociated from increased LMA intra-session on D3, when the motor deficits provoked by EC were already undetectable in the rotarod and beam-walking tests. PMID:16337698

  19. Polyaniline hybridized surface defective ZnO nanorods with long-term stable photoelectrochemical activity

    NASA Astrophysics Data System (ADS)

    Bera, Susanta; Khan, Hasmat; Biswas, Indranil; Jana, Sunirmal

    2016-10-01

    We report surfactant/template free precursor solution based synthesis of polyaniline (PANI) hybridized surface defective ZnO nanorods by a two-step process. Initially, ZnO nanorods have been prepared at 95 °C, followed by hybridization (coating) of PANI onto the ZnO via in situ polymerization of aniline monomer, forming ZnO-PANI nanohybrid (ZP). The structural properties of ZP have been analyzed by X-ray diffraction (XRD) and transmission electron microscopic (TEM) studies. The presence of surface defects especially the oxygen vacancies in ZnO has been characterized by photoluminescence emission, high resolution TEM, X-ray photoelectron spectroscopy (XPS) and micro-Raman spectral measurements. The chemical interaction of PANI with ZnO has been examined by Fourier transform infrared (FTIR) and XPS analyses. A significant enhancement in visible absorption of ZP sample is found as evidenced from UV-vis diffused reflectance spectral study. BET nitrogen adsorption-desorption isotherm shows an improved textural property (pore size, pore volume) of ZP. Moreover, a long-term stable photoelectrochemical activity (PEC) of ZP is found compare to pristine ZnO. The synergic effect of PANI hybridization and the presence of surface defects in ZnO NRs can enhance the PEC by prolonging the recombination rate of photogenerated charge carriers. The effect can also provide large number of active sites to make electrolyte diffusion and mass transportation easier in the nanohybrid. This simple synthesis strategy can be adopted for PANI hybridization with different metal oxide semiconductors towards enhancing PEC activity of the hybrid materials.

  20. Ryanodine Receptor Activation Induces Long-Term Plasticity of Spine Calcium Dynamics

    PubMed Central

    Pannasch, Ulrike; Rückl, Martin; Rüdiger, Sten; Schmitz, Dietmar

    2015-01-01

    A key feature of signalling in dendritic spines is the synapse-specific transduction of short electrical signals into biochemical responses. Ca2+ is a major upstream effector in this transduction cascade, serving both as a depolarising electrical charge carrier at the membrane and an intracellular second messenger. Upon action potential firing, the majority of spines are subject to global back-propagating action potential (bAP) Ca2+ transients. These transients translate neuronal suprathreshold activation into intracellular biochemical events. Using a combination of electrophysiology, two-photon Ca2+ imaging, and modelling, we demonstrate that bAPs are electrochemically coupled to Ca2+ release from intracellular stores via ryanodine receptors (RyRs). We describe a new function mediated by spine RyRs: the activity-dependent long-term enhancement of the bAP-Ca2+ transient. Spines regulate bAP Ca2+ influx independent of each other, as bAP-Ca2+ transient enhancement is compartmentalized and independent of the dendritic Ca2+ transient. Furthermore, this functional state change depends exclusively on bAPs travelling antidromically into dendrites and spines. Induction, but not expression, of bAP-Ca2+ transient enhancement is a spine-specific function of the RyR. We demonstrate that RyRs can form specific Ca2+ signalling nanodomains within single spines. Functionally, RyR mediated Ca2+ release in these nanodomains induces a new form of Ca2+ transient plasticity that constitutes a spine specific storage mechanism of neuronal suprathreshold activity patterns. PMID:26098891

  1. Influence of Long-Term Zinc Administration on Spatial Learning and Exploratory Activity in Rats.

    PubMed

    Piechal, Agnieszka; Blecharz-Klin, Kamilla; Pyrzanowska, Justyna; Widy-Tyszkiewicz, Ewa

    2016-08-01

    Animal brain contains a significant amount of zinc, which is a cofactor for more than 300 enzymes. Moreover, it provides the basis for functioning of more than 2000 transcription factors, and it is necessary for memory formation and learning processes in the brain. The aim of this study was to investigate the effect of zinc supplementation on behavior in 3-month-old rats. For this purpose, the Morris water maze paradigm, hole-board, and T-maze were used. Wistar rats received a solution of ZnSO4 in drinking water at the doses of 16 mg/kg (Zn16 group) and 32 mg/kg (Zn32 group). In rats pretreated with the lower dose of zinc, the improvement of the mean escape latency was observed in comparison to the control group and Zn32 group. During memory task, both ZnSO4-supplemented groups showed an increase in crossings over the previous platform position. Furthermore, the exploratory activity in Zn16 group was improved in comparison to Zn32 and control group. In the brains of zinc-supplemented rats, we observed the higher content of zinc, both in the hippocampus and the prefrontal cortex. Hippocampal zinc level correlated positively with the mean annulus crossings of the Zn16 group during the probe trial. These findings show that the long-term administration of ZnS04 can improve learning, spatial memory, and exploratory activity in rats. Graphical Abstract Improvement of spatial learning, memory, and exploratory behavior.

  2. Episodic hypoxia evokes long-term facilitation of genioglossus muscle activity in neonatal rats

    PubMed Central

    McKay, Leanne C; Janczewski, Wiktor A; Feldman, Jack L

    2004-01-01

    The aim of this study was to determine if episodic hypoxia evokes persistent increases of genioglossus muscle (GG) activity, termed long-term facilitation (LTF), in neonatal rats in vivo. Experiments were performed on anaesthetized, spontaneously breathing, intubated neonatal rats (postnatal days (P) 3–7), divided into three groups. The first group (n = 8) was subjected to three 5-min periods of hypoxia (5% O2–95% N2) alternating with 5 min periods of room air. The second group (n = 8) was exposed to 15 min of continuous hypoxia. The third (n = 4) group was not exposed to hypoxia and served as a control. GG EMG activity and airflow were recorded before, during and for 60 min after episodic and continuous hypoxic exposure. During hypoxia, GG EMG burst amplitude and tidal volume (VT) significantly increased compared to baseline levels (episodic protocol: mean ±s.e.m.; 324 ± 59% of control and 0.13 ± 0.007 versus 0.09 ± 0.005 ml, respectively; continuous protocol: 259 ± 30% of control and 0.16 ± 0.005 versus 0.09 ± 0.007 ml, respectively; P < 0.05). After the episodic protocol, GG EMG burst amplitude transiently returned to baseline; over the next 60 min, burst amplitude progressively increased to levels significantly greater than baseline (238 ± 40% at 60 min; P < 0.05), without any significant increase in VT and respiratory frequency (P> 0.05). After the continuous protocol, there was no lasting increase in GG EMG burst amplitude. We conclude that LTF of upper airway muscles is an adaptive respiratory behaviour present from birth. PMID:15047768

  3. Urea as a long-term stable alternative to guanidium thiocyanate additive in dye-sensitized solar cell

    NASA Astrophysics Data System (ADS)

    Kim, Mi-Jeong; Park, Nam-Gyu

    2012-09-01

    Photovoltaic performance of 0.05 M urea-contained redox electrolyte is compared to that of 0.05 M guanidinium thiocyanate (GSCN)-contained one in dye-sensitized solar cell. No significant difference in the initial photovoltaic performance is observed, which means that the role of urea additive is similar to that of GSCN. Initial solar-to-electrical conversion efficiency of the device containing GSCN shows 7% that is diminished to 5.8% after 40 days, whereas the device containing urea exhibits stable photovoltaic performance showing that initial efficiency of 7.2% is almost remained unchanged after 40 days (7.1%). The lowered efficiency of the GSCN-contained device is mainly due to the decreased photocurrent density, which is ascribed to the formation of needle-shaped crystals on TiO2 layer. Infrared spectroscopic study confirms that the crystals are dye analogue, which is indicative of dye desorption in the presence of GSCN. On the other hand, no crystals are formed in the urea-contained electrolyte, which implies that dye desorption is negligible. Urea additive is thus found to be less reactive in dye desorption than GSCN, leading to long-term stability.

  4. Long-term measurement of indoor thermal environment and energy performance in a detached wooden house with passive solar systems

    SciTech Connect

    Ishikawa, Yoshimi; Yoshino, Hiroshi; Sasaki, Chikashi

    1998-07-01

    The indoor thermal environment, energy performance and energy consumption for a detached wooden house equipped with two passive solar systems, were investigated over a period of three years. The house with a floor area of 188 m{sup 2} was constructed in the autumn of 1993 in Sendai, Japan; and was well insulated and very airtight compared with other houses in Japan. There are six occupants. Heating equipment is comprises of a thermal storage space heater using night-time electricity and a vented firewood furnace on the first floor. Each room is ventilated all day by a central ventilation system. Two passive solar systems were incorporated: a concrete floor in the southern perimeter of the living room as a direct gain system, and an earth tube embedded around the circumference of the house to supply fresh air. The principal results obtained are as follows: (1) The indoor environment during the heating season was more thermally comfortable, compared with that or ordinary houses in Japan. (2) The concrete floor played a role of thermal storage, which absorbed and released heat for decreasing the fluctuation of room temperature. (3) The earth tube supplied air with lower temperature in the summer and higher temperature in the winter to the room, that the outdoor air temperature. This thermal performance did not decrease in spite of the long-term use. (4) The annual amount of energy consumption of this house was less than that of ordinary houses in the northern part of Japan.

  5. Long-term X-Ray Variability of Typical Active Galactic Nuclei in the Distant Universe

    NASA Astrophysics Data System (ADS)

    Yang, G.; Brandt, W. N.; Luo, B.; Xue, Y. Q.; Bauer, F. E.; Sun, M. Y.; Kim, S.; Schulze, S.; Zheng, X. C.; Paolillo, M.; Shemmer, O.; Liu, T.; Schneider, D. P.; Vignali, C.; Vito, F.; Wang, J.-X.

    2016-11-01

    We perform long-term (≈15 years, observed-frame) X-ray variability analyses of the 68 brightest radio-quiet active galactic nuclei (AGNs) in the 6 Ms Chandra Deep Field-South survey; the majority are in the redshift range of 0.6–3.1, providing access to penetrating rest-frame X-rays up to ≈10–30 keV. Of the 68 sources, 24 are optical spectral type I AGNs, and the rest (44) are type II AGNs. The timescales probed in this work are among the longest for X-ray variability studies of distant AGNs. Photometric analyses reveal widespread photon flux variability: 90% of AGNs are variable above a 95% confidence level, including many X-ray obscured AGNs and several optically classified type II quasars. We characterize the intrinsic X-ray luminosity ({L}{{X}}) and absorption ({N}{{H}}) variability via spectral fitting. Most (74%) sources show {L}{{X}} variability; the variability amplitudes are generally smaller for quasars. A Compton-thick candidate AGN shows variability of its high-energy X-ray flux, indicating the size of reflecting material to be ≲0.3 pc. {L}{{X}} variability is also detected in a broad absorption line quasar. The {N}{{H}} variability amplitude for our sample appears to rise as time separation increases. About 16% of sources show {N}{{H}} variability. One source transitions from an X-ray unobscured to obscured state, while its optical classification remains type I; this behavior indicates the X-ray eclipsing material is not large enough to obscure the whole broad-line region.

  6. Success rate, costs and long-term stability of treatment with activator/headgear combinations.

    PubMed

    Hedlund, Camilla; Feldmann, Ingalill

    2016-01-01

    The aims of this study were to evaluate treatment outcome with activator-headgear combinations carried out by general dental practitioners, overall costs, long-term stability and patients' satisfaction with treatment outcome. Patients who were recommended to start treatment in 2006 were included in this study (n = 97). Inclusion criteria were: Class II Division 1 with at least half a cusp width distal molar relationship, overjet ≥ 6 mm and presence of dental records. Data were collected, pre-treatment, post-treatment and 3 years after treatment for those with favorable outcome. Patients at follow-up completed a questionnaire about satisfaction with treatment outcome, perceived pain and discomfort during treatment, and subjective need for additional treatment. Eighty-five patients were analyzed, 52 boys and 33 girls (mean age 11.2 years SD 1.39). Thirty-five patients had successful treatment outcome, 15 partially successful and 35 had an unsuccessful outcome. Total costs for all 85 patients amounted to SEK 1 405 000 including both direct and indirect costs. Thirty-eight patients participated in the 3-year follow-up. Treatment outcomes were then categorized as successful in 28 patients, partially successful in 9 patients and 1 patient was judged as unsuccessful. Median values on VAS (0-100) for overall satisfaction with treatment and treatment outcome were high, 78 and 84 respectively. Median value for perceived pain and discomfort during treatment was 42. Just over half of the patients had a favorable treatment outcome. Patients with favorable outcome were stable over time and satisfied with treatment. PMID:27464383

  7. Copper speciation and microbial activity in long-term contaminated soils.

    PubMed

    Dumestre, A; Sauvé, S; McBride, M; Baveye, P; Berthelin, J

    1999-02-01

    Most soil quality guidelines do not distinguish among the various forms of metals in soils; insoluble, nonreactive, and nonbioavailable forms are deemed as hazardous as highly soluble, reactive, and toxic forms. The objective of this study was to better understand the long-term effects of copper on microorganisms in relation to its chemical speciation in the soil environment. Carbon mineralization processes and the global structure of different microbial communities (fungi, eubacteria, actinomycetes) are still affected after more than 50 years of copper contamination in 20 soils sampled from two different agricultural sites. The microbial respiration lag period (LP) preceding the beginning of mineralization process increases with the level of soil copper contamination and is not significantly affected by other environmental factors such as soil pH and soil organic matter (SOM) content. The total copper concentration showed the best correlation with the LP when each site is considered separately. However, when considering the whole set of data, soil solution free Cu2+ activity (pCu2+) is the best predictor of Cu toxicity determined by LP (quite likely because pCu2+ integrates the soil physicochemical variability). The maximum mineralization rate (MMR), even if well correlated with the pCu2+, appears not to be a good biomonitor of copper contamination in soils since it is highly sensitive to soil characteristics such as SOM content. This study emphasizes the importance of the physicochemical properties of the environment on soil heavy metal toxicity and on soil toxicological measurements. These properties must be characterized in soil toxicological studies with respect to (1) their interactions with heavy metals, and (2) their direct impact on the selected biological test. The measurement of pCu2+ to characterize the level of soil contamination and of lag period as a bioindicator of metal effects in the soil are recognized as useful tools for the evaluation of the

  8. The Calmodulin-Binding Transcription Activator CAMTA1 Is Required for Long-Term Memory Formation in Mice

    ERIC Educational Resources Information Center

    Bas-Orth, Carlos; Tan, Yan-Wei; Oliveira, Ana M. M.; Bengtson, C. Peter; Bading, Hilmar

    2016-01-01

    The formation of long-term memory requires signaling from the synapse to the nucleus to mediate neuronal activity-dependent gene transcription. Synapse-to-nucleus communication is initiated by influx of calcium ions through synaptic NMDA receptors and/or L-type voltage-gated calcium channels and involves the activation of transcription factors by…

  9. Factors that Influence Physical Activity in Long-Term Care: Perspectives of Residents, Staff, and Significant Others

    ERIC Educational Resources Information Center

    Benjamin, Kathleen; Edwards, Nancy; Guitard, Paulette; Murray, Mary Ann; Caswell, Wenda; Perrier, Marie Josee

    2011-01-01

    Physical activity has been linked to positive health outcomes for frail seniors. However, our understanding of factors that influence the physical activity of residents in the long-term care (LTC) setting is limited. This article describes our work with focus groups, one component of a multi-component study that examined factors influencing the…

  10. Surface EMG system for use in long-term vigorous activities

    NASA Astrophysics Data System (ADS)

    de Luca, G.; Bergman, P.; de Luca, C.

    The purpose of the project was to develop an advanced surface electromyographic (EMG) system that is portable, un-tethered, and able to detect high-fidelity EMG signals from multiple channels. The innovation was specifically designed to extend NASA's capability to perform neurological status monitoring for long-term, vigorous activities. These features are a necessary requirement of ground-based and in-flight studies planned for the International Space Station and human expeditions to Mars. The project consisted of developing 1) a portable EMG digital data logger using a handheld PC for acquiring the signal and storing the data from as many as 8 channels, and 2) an EMG electrode/skin interface to improve signal fidelity and skin adhesion in the presence of sweat and mechanical disturbances encountered during vigorous activities. The system, referred to as a MyoMonitor, was configured with a communication port for downloading the data from the data logger to the PC computer workstation. Software specifications were developed and implemented for programming of acquisition protocols, power management, and transferring data to the PC for processing and graphical display. The prototype MyoMonitor was implemented using a handheld PC that features a color LCD screen, enhanced keyboard, extended Lithium Ion battery and recharger, and 128 Mbytes of F ash Memory. The system was designed to be belt-worn,l thereby allowing its use under vigorous activities. The Monitor utilizes up to 8 differential surface EMG sensors. The prototype allowed greater than 2 hours of continuous 8-channel EMG data to be collected, or 17.2 hours of continuous single channel EMG data. Standardized tests in human subjects were conducted to develop the mechanical and electrical properties of the prototype electrode/interface system. Tests conducted during treadmill running and repetitive lifting demonstrated that the prototype interface significantly reduced the detrimental effects of sweat

  11. Fast stack activation procedure and effective long-term storage for high-performance polymer electrolyte membrane fuel cell

    NASA Astrophysics Data System (ADS)

    Yang, Seung Yong; Seo, Dong-Jun; Kim, Myeong-Ri; Seo, Min Ho; Hwang, Sun-Mi; Jung, Yong-Min; Kim, Beom-Jun; Yoon, Young-Gi; Han, Byungchan; Kim, Tae-Young

    2016-10-01

    Time-saving stack activation and effective long-term storage are one of most important issues that must be resolved for the commercialization of polymer electrolyte membrane fuel cell (PEMFC). Herein, we developed the cost-effective stack activation method to finish the whole activation within 30 min and the long-term storage method by using humidified N2 without any significant decrease in cell's performance for 30 days. Specifically, the pre-activation step with the direct injection of DI water into the stack and storage at 65 or 80 °C for 2 h increases the distinctive phase separation between the hydrophobic and hydrophilic regions in Nafion membrane, which significantly reduces the total activation time within 30 min. Additionally, the long-term storage with humidified N2 has no effect on the Pt oxidation and drying of Nafion membrane for 30 days due to its exergonic reaction in the cell. As a result, the high water content in Nafion membrane and the decrease of Pt oxidation are the critical factors that have a strong influence on the activation and long-term storage for high-performance PEMFC.

  12. Long-term effects of ammonia on the behavioral activity of the aquatic snail Potamopyrgus antipodarum (Hydrobiidae, Mollusca).

    PubMed

    Alonso, Alvaro; Camargo, Julio A

    2009-05-01

    An appropriate approach to assess the effect of toxicants on aquatic animals is to monitor behavioral endpoints, as they are a link between physiological and ecological processes. A group that can be exposed long-term to low toxic concentrations is benthic macroinvertebrates, as their mobility in aquatic ecosystems is relatively limited. Therefore, the study of behavioral long-term effects in this group is suitable from an ecological point of view, as behavioral effects can appear before mortality. During the last decades there has been an increase in ammonia concentrations in freshwater ecosystems, threatening aquatic animals. The present study focuses on the long-term effects (40 days) of nonionized ammonia on the behavioral activity of the aquatic snail Potamopyrgus antipodarum. One control and three ammonia concentrations (0.02, 0.07, and 0.13 mg N-NH(3)/L) were used in triplicate, and the activity of snails (as mean time to start normal movement) and immobility were recorded for each treatment after 0, 10, 20, 30, and 40 days of continuous exposure to nonionized ammonia. The results show that P. antipodarum presented a high tolerance to lethal long-term effects of nonionized ammonia, as no animal died during the bioassay. However, the behavioral activity of snails was a very sensitivity endpoint, as a mean nonionized ammonia concentration of 0.07 mg N-NH(3)/L affected P. antipodarum. The results are discussed and compared with the available literature on long-term effects of ammonia on freshwater macroinvertebrates. Additionally, the ammonia water quality criteria, NOECs, LOECs, and long-term LCs are discussed on the basis of the current available data for freshwater macroinvertebrates.

  13. Cortical Activation Patterns during Long-Term Memory Retrieval of Visually or Haptically Encoded Objects and Locations

    ERIC Educational Resources Information Center

    Stock, Oliver; Roder, Brigitte; Burke, Michael; Bien, Siegfried; Rosler, Frank

    2009-01-01

    The present study used functional magnetic resonance imaging to delineate cortical networks that are activated when objects or spatial locations encoded either visually (visual encoding group, n = 10) or haptically (haptic encoding group, n = 10) had to be retrieved from long-term memory. Participants learned associations between auditorily…

  14. Behavior Change Strategies for Successful Long-Term Weight Loss: Focusing on Dietary and Physical Activity Adherence, Not Weight Loss

    ERIC Educational Resources Information Center

    Hongu, Nobuko; Kataura, Martha P.; Block, Linda M.

    2011-01-01

    This article helps Extension professionals guide individuals in a successful long-term weight loss program. A program should focus on behavioral changes (improving eating habits and physical activity), not just weight loss. In order to do this, Extension professionals should implement behavior change strategies that motivate individuals to…

  15. Gender-Based Long-Term Surgical Outcome in Patients with Active Infective Aortic Valve Endocarditis.

    PubMed

    Dohmen, Pascal M; Binner, Christian; Mende, Meinhart; Daviewala, Piroze; Etz, Christian D; Borger, Michael Andrew; Misfeld, Martin; Eifert, Sandra; Mohr, Friedrich Wilhelm

    2016-01-01

    BACKGROUND The aim of this observational, single-center study was to evaluate the impact of gender on surgical outcome in patients with active infective endocarditis (AIE) of the aortic valve. MATERIAL AND METHODS Between October 1994 and January 2011, 755 patients (558 men and 297 women) underwent surgery for AIE at the Leipzig Heart Center, Germany, according to the modified Duke criteria. Data were collected before surgery and as the study was ongoing. Gender influence on survival was evaluated (Kaplan-Meier curves). Cox proportional models were used to evaluate gender differences in relation to early mortality (within 30 days) and late mortality (up to 10 years). RESULTS The early mortality rate was 15.0% among men and 23.0% among women, which was statistically significant different (p=0.01). In male patients, variables associated with overall mortality were age (HR 1.63, 95% CI 1.43-1.86; p<0.001), insulin-dependent diabetes mellitus (HR 2.02, 95% CI 1.48-2.75; p<0.001), preoperative low ejection fraction (OR 0.99, 95% CI 0.98-0.99; p=0.002), previous cardiac surgery (OR 1.62, 95% CI 1.22-2.13; p=0.001), preoperative ventilation (OR 1.77, 95% CI 1.14-2.75; p=0.012), preoperative dialysis (OR 1.89, 95% CI 1.20-2.98; p=0.006), NYHA Class IV (OR 1.56, 95% CI 1.12-2.15; p=0.008), and involvement of multiple valves (OR 1.65, 95% CI 1.24-2.19; p=0.001) had a statistically significant influence on the late mortality. Focus identification (OR 1.75, 95% CI 1.08-2.77; p=0.023), involvement of multiple valves (OR 1.52, 95% CI 1.02-2.26; p=0.040), preoperative dialysis (OR 3.65, 95% CI 1.96-6.77; p<0.001), and age (OR 1.53, 95% CI 1.28-1.82; p<0.004) were predictive risk factors for late mortality in women with AIE (OR 3.6, 95% CI 1.5-8.4; p<0.004). CONCLUSIONS This study demonstrated distinct gender-based differences in risk of mortality in patients with AIE (who were undergoing surgical treatment) with different early and long-term outcomes. PMID:27427831

  16. Threshold responses of songbirds to long-term timber management on an active industrial forest

    USGS Publications Warehouse

    Becker, D.A.; Wood, P.B.; Keyser, P.D.; Wigley, T.B.; Dellinger, R.; Weakland, C.A.

    2011-01-01

    Forest managers often seek to balance economic benefits from timber harvesting with maintenance of habitat for wildlife, ecosystem function, and human uses. Most research on the relationship between avian abundance and active timber management has been short-term, lasting one to two years, creating the need to investigate long-term avian responses and to identify harvest thresholds when a small change in habitat results in a disproportionate response in relative abundance and nest success. Our objectives were to identify trends in relative abundance and nest success and to identify landscape-scale disturbance thresholds for avian species and habitat guilds in response to a variety of harvest treatments (clear-cuts, heavy and light partial harvests) over 14 years. We conducted point counts and monitored nests at an industrial forest in the central Appalachians of West Virginia during 1996-1998, 2001-2003, and 2007-2009. Early successional species increased in relative abundance across all three time periods, whereas interior-edge and forest-interior guilds peaked in relative abundance mid-study after which the forest-interior guild declined. Of 41 species with >10 detections, four (10%) declined significantly, 13 (32%) increased significantly (only three species among all periods), and 9 (22%) peaked in abundance mid-study (over the entire study period, four species had no significant change in abundance, four declined, and one increased). Based on piecewise linear models, forest-interior and interior-edge guilds' relative abundance harvest thresholds were 28% total harvests (all harvests combined), 10% clear-cut harvests, and 18% light partial harvests, after which abundances declined. Harvest thresholds for the early successional guild were 42% total harvests, 11% clear-cut harvest, and 10% light partial harvests, and relative abundances increased after surpassing thresholds albeit at a reduced rate of increase after the clear-cut threshold. Threshold confidence

  17. Gender-Based Long-Term Surgical Outcome in Patients with Active Infective Aortic Valve Endocarditis

    PubMed Central

    Dohmen, Pascal M.; Binner, Christian; Mende, Meinhart; Daviewala, Piroze; Etz, Christian D.; Borger, Michael Andrew; Misfeld, Martin; Eifert, Sandra; Mohr, Friedrich Wilhelm

    2016-01-01

    Background The aim of this observational, single-center study was to evaluate the impact of gender on surgical outcome in patients with active infective endocarditis (AIE) of the aortic valve. Material/Methods Between October 1994 and January 2011, 755 patients (558 men and 297 women) underwent surgery for AIE at the Leipzig Heart Center, Germany, according to the modified Duke criteria. Data were collected before surgery and as the study was ongoing. Gender influence on survival was evaluated (Kaplan-Meier curves). Cox proportional models were used to evaluate gender differences in relation to early mortality (within 30 days) and late mortality (up to 10 years). Results The early mortality rate was 15.0% among men and 23.0% among women, which was statistically significant different (p=0.01). In male patients, variables associated with overall mortality were age (HR 1.63, 95% CI 1.43–1.86; p<0.001), insulin-dependent diabetes mellitus (HR 2.02, 95% CI 1.48–2.75; p<0.001), preoperative low ejection fraction (OR 0.99, 95% CI 0.98–0.99; p=0.002), previous cardiac surgery (OR 1.62, 95% CI 1.22–2.13; p=0.001), preoperative ventilation (OR 1.77, 95% CI 1.14–2.75; p=0.012), preoperative dialysis (OR 1.89, 95% CI 1.20–2.98; p=0.006), NYHA Class IV (OR 1.56, 95% CI 1.12–2.15; p=0.008), and involvement of multiple valves (OR 1.65, 95% CI 1.24–2.19; p=0.001) had a statistically significant influence on the late mortality. Focus identification (OR 1.75, 95% CI 1.08–2.77; p=0.023), involvement of multiple valves (OR 1.52, 95% CI 1.02–2.26; p=0.040), preoperative dialysis (OR 3.65, 95% CI 1.96–6.77; p<0.001), and age (OR 1.53, 95% CI 1.28–1.82; p<0.004) were predictive risk factors for late mortality in women with AIE (OR 3.6, 95% CI 1.5–8.4; p<0.004). Conclusions This study demonstrated distinct gender-based differences in risk of mortality in patients with AIE (who were undergoing surgical treatment) with different early and long-term outcomes. PMID

  18. Inter-trial neuronal activity in inferior temporal cortex: a putative vehicle to generate long-term visual associations.

    PubMed

    Yakovlev, V; Fusi, S; Berman, E; Zohary, E

    1998-08-01

    When monkeys perform a delayed match-to-sample task, some neurons in the anterior inferotemporal cortex show sustained activity following the presentation of specific visual stimuli, typically only those that are shown repeatedly. When sample stimuli are shown in a fixed temporal order, the few images that evoke delay activity in a given neuron are often neighboring stimuli in the sequence, suggesting that this delay activity may be the neural correlate of associative long-term memory. Here we report that stimulus-selective sustained activity is also evident following the presentation of the test stimulus in the same task. We use a neural network model to demonstrate that persistent stimulus-selective activity across the intertrial interval can lead to similar mnemonic representations (distributions of delay activity across the neural population) for neighboring visual stimuli. Thus, inferotemporal cortex may contain neural machinery for generating long-term stimulus-stimulus associations.

  19. Deciphering the Long-Term Trend of Atlantic Basin Intense Hurricanes: More Active Versus Less Active During the Present Epoch

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    1998-01-01

    During the interval of 1944-1997, 120 intense hurricanes (i.e., those of category 3 or higher on the Saffir-Simpson hurricane damage potential scale) were observed in the Atlantic basin, having an annual frequency of 0-7 events per year, being more active prior to the mid 1960's than thereafter (hence a possible two-state division: more active versus less active), and being preferentially lower during El Nino years as compared to non-El Nino years. Because decadal averages of the frequency of intense hurricanes closely resemble those of average temperature anomalies for northern hemispheric and global standards and of the average temperature at the Armagh Observatory (Northern Ireland), a proxy for climatic change, it is inferred that the long-term trends of the annual frequency of intense hurricanes and temperature may be statistically related. Indeed, on the basis of 4- and 10-yr moving averages, one finds that there exists strong linear associations between the annual frequency of intense hurricanes in the Atlantic basin and temperature (specially, when temperature slightly leads). Because the long-term leading trends of temperature are now decidedly upward, beginning about the mid 1980's, it is inferred that the long-term consequential trends of the annual frequency of intense hurricanes should now also be upward, having begun near 1990, suggesting that a return to the more active state probably has already occurred. However, because of the anomalous El Nino activity of the early to mid 1990's, the switch from the less active to the more active state essentially went unnoticed (a marked increase in the number of intense hurricanes was not observed until the 1995 and 1996 hurricane seasons, following the end of the anomalous El Nino activity). Presuming that a return to the more active state has, indeed, occurred, one expects the number of seasonal intense hurricanes during the present epoch (continuing through about 2012) to usually be higher than average (i

  20. Effects of long-term smoking on the activity and mRNA expression of CYP isozymes in rats

    PubMed Central

    He, Xiao-Meng; Zhou, Ying; Xu, Ming-Zhen; Li, Yang; Li, Hu-Qun

    2015-01-01

    Background To investigate the effect of long-term smoking on the activity and mRNA expression of cytochrome P450 (CYP) enzymes. Methods Sprague-Dawley rats were exposed to passive smoking 6 cigarettes per day for 180 days. A cocktail solution which contained phenacetin (20 mg/kg), tolbutamide (5 mg/kg), chlorzoxazone (20 mg/kg) and midazolam (10 mg/kg) was given orally to rats. Blood samples were collected at pre-specified time points and the concentrations of probe drugs in plasma were determined by HPLC-MS/MS. The corresponding pharmacokinetic parameters were calculated by DAS 3.0. In addition, real-time RT-PCR was used to analyze the mRNA expression of CYP1A2, CYP2C11, CYP2E1 and CYP3A1 in rat liver. Results There were no significant influences of pharmacokinetic profiles of chlorzoxazone in long-term smoking pretreated rats. But many pharmacokinetic profiles of phenacetin, tolbutamide, and midazolam in long-term smoking pretreated rats were affected significantly (P<0.05). The results suggested that long-term smoking had significant inhibition effects on CYP2C11 and CYP3A1 while CYP1A2 enzyme activity was induced. Furthermore, Long-term smoking had no effects on rat CYP2E1. The mRNA expression results were consistent with the pharmacokinetic results. Conclusions Alterations of CYP450 enzyme activities may fasten or slow down excretion with corresponding influence on drug efficacy or toxicity in smokers compared to nonsmokers, which may lead to clinical failures of lung cancer therapy or toxicity in smokers. PMID:26623094

  1. Long-term variability and impact on human health of biologically active UV radiation in Moscow

    NASA Astrophysics Data System (ADS)

    Zhdanova, Ekaterina; Chubarova, Natalia

    2014-05-01

    the developed classification for Moscow. Booth, C.R. and S. Madronich, 1994: Radiation amplification factors: improved formulation accounts for large increases in ultraviolet radiation associated with Antarctic ozone depletion. In: Ultraviolet Radiation in Antarctica: Measurements and Biological Research [Weiler, C.S. and P.A. Penhale (eds.)]. AGU Antarctic Research Series, 62, Washington, DC, USA, 39-42. Chubarova N.Y., 2008: UV variability in Moscow according to long-term UV measurements and reconstruction model. Atmos.Chem.Phys., 8, 3025-3031 Oriowo, M. et al., 2001:, Action spectrum for in vitro UV-induced cataract using whole lenses. Invest.Ophthalmol.&Vis.Sci, 42, 2596-2602. CIE, 1993: Reference Action Spectra for Ultraviolet Induced Erythema and Pigmentation of Different Human skin Types. CIE Research Note, CIE Technical Collection., N.3 CIE, 2006: Action spectrum for the production of previtamin D3 in human skin, Technical report 174, International commission on illumination

  2. Using Active Satellite Observations to Characterize Uncertatinty in Long Term Satellite Cloud Liquid Water Path Climatologies

    NASA Astrophysics Data System (ADS)

    Lebsock, M. D.

    2014-12-01

    Bias between the Advanced Microwave Scanning Radiometer-EOS (AMSR-E) version 2 and the Moderate Resolution Imaging Spectroradiometer (MODIS) collection 5.1 cloud liquid water path (Wc)products are explored with the aid of coincident active observations from the CloudSat radar and the CALIPSO lidar. In terms of detection, the active observations provide precise separation of cloudy from clear sky and precipitating from nonprecipitating clouds. In addition, they offer a unique quantification of precipitation water path (Wp) in warm clouds. They also provide an independent quantification of Wc that isbased on an accurate surface reference technique, which is an independent arbiter between the two passive approaches. The results herein establish the potential for CloudSat and CALIPSO to provide an independent assessment of bias between the conventional passive remote sensing methods from reflected solar and emitted microwave radiation. After applying a common data filter to the observations to account for sampling biases, AMSR-E is biased high relative to MODIS in the global mean by 26.4gm2. The RMS difference in the regional patterns is 32.4gm2, which highlights a large geographical dependence in the bias which is related to the tropical transitions from stratocumulus to cumulus cloud regimes. The contributions of four potential sources for this bias are investigated by exploiting the active observations: (1)bias in MODIS related to solar zenith angle dependence accounts for 2.3gm2, (2) bias in MODIS due to undersampling of cloud edges accounts for 4.2gm2, (3) a wind speed and water vapor-dependent "clear-sky bias" in the AMSR-E retrieval accounts for 6.3gm2, and (4) evidence suggests that much of the remaining 18gm2 bias is related to the assumed partitioning of the observed emission signal between cloud and precipitation water in the AMSR-E retrieval. This is most evident through the correlations between the regional mean patterns of Wp and the Wc bias within the

  3. Addressing solar modulation and long-term uncertainties in scaling secondary cosmic rays for in situ cosmogenic nuclide applications [rapid communication

    NASA Astrophysics Data System (ADS)

    Lifton, Nathaniel A.; Bieber, John W.; Clem, John M.; Duldig, Marc L.; Evenson, Paul; Humble, John E.; Pyle, Roger

    2005-10-01

    Solar modulation affects the secondary cosmic rays responsible for in situ cosmogenic nuclide (CN) production the most at the high geomagnetic latitudes to which CN production rates are traditionally referenced. While this has long been recognized (e.g., D. Lal, B. Peters, Cosmic ray produced radioactivity on the Earth, in: K. Sitte (Ed.), Handbuch Der Physik XLVI/2, Springer-Verlag, Berlin, 1967, pp. 551-612 and D. Lal, Theoretically expected variations in the terrestrial cosmic ray production rates of isotopes, in: G.C. Castagnoli (Ed.), Proceedings of the Enrico Fermi International School of Physics 95, Italian Physical Society, Varenna 1988, pp. 216-233), these variations can lead to potentially significant scaling model uncertainties that have not been addressed in detail. These uncertainties include the long-term (millennial-scale) average solar modulation level to which secondary cosmic rays should be referenced, and short-term fluctuations in cosmic ray intensity measurements used to derive published secondary cosmic ray scaling models. We have developed new scaling models for spallogenic nucleons, slow-muon capture and fast-muon interactions that specifically address these uncertainties. Our spallogenic nucleon scaling model, which includes data from portions of 5 solar cycles, explicitly incorporates a measure of solar modulation ( S), and our fast- and slow-muon scaling models (based on more limited data) account for solar modulation effects through increased uncertainties. These models improve on previously published models by better sampling the observed variability in measured cosmic ray intensities as a function of geomagnetic latitude, altitude, and solar activity. Furthermore, placing the spallogenic nucleon data in a consistent time-space framework allows for a more realistic assessment of uncertainties in our model than in earlier ones. We demonstrate here that our models reasonably account for the effects of solar modulation on measured

  4. Effect of long-term industrial waste effluent pollution on soil enzyme activities and bacterial community composition.

    PubMed

    Subrahmanyam, Gangavarapu; Shen, Ju-Pei; Liu, Yu-Rong; Archana, Gattupalli; Zhang, Li-Mei

    2016-02-01

    Although numerous studies have addressed the influence of exogenous pollutants on microorganisms, the effect of long-term industrial waste effluent (IWE) pollution on the activity and diversity of soil bacteria was still unclear. Three soil samples characterized as uncontaminated (R1), moderately contaminated (R2), and highly contaminated (R3) receiving mixed organic and heavy metal pollutants for more than 20 years through IWE were collected along the Mahi River basin, Gujarat, western India. Basal soil respiration and in situ enzyme activities indicated an apparent deleterious effect of IWE on microbial activity and soil function. Community composition profiling of soil bacteria using 16S rRNA gene amplification and denaturing gradient gel electrophoresis (DGGE) method indicated an apparent bacterial community shift in the IWE-affected soils. Cloning and sequencing of DGGE bands revealed that the dominated bacterial phyla in polluted soil were affiliated with Firmicutes, Acidobacteria, and Actinobacteria, indicating that these bacterial phyla may have a high tolerance to pollutants. We suggested that specific bacterial phyla along with soil enzyme activities could be used as relevant biological indicators for long-term pollution assessment on soil quality. Graphical Abstract Bacterial community profiling and soil enzyme activities in long-term industrial waste effluent polluted soils.

  5. Effect of long-term industrial waste effluent pollution on soil enzyme activities and bacterial community composition.

    PubMed

    Subrahmanyam, Gangavarapu; Shen, Ju-Pei; Liu, Yu-Rong; Archana, Gattupalli; Zhang, Li-Mei

    2016-02-01

    Although numerous studies have addressed the influence of exogenous pollutants on microorganisms, the effect of long-term industrial waste effluent (IWE) pollution on the activity and diversity of soil bacteria was still unclear. Three soil samples characterized as uncontaminated (R1), moderately contaminated (R2), and highly contaminated (R3) receiving mixed organic and heavy metal pollutants for more than 20 years through IWE were collected along the Mahi River basin, Gujarat, western India. Basal soil respiration and in situ enzyme activities indicated an apparent deleterious effect of IWE on microbial activity and soil function. Community composition profiling of soil bacteria using 16S rRNA gene amplification and denaturing gradient gel electrophoresis (DGGE) method indicated an apparent bacterial community shift in the IWE-affected soils. Cloning and sequencing of DGGE bands revealed that the dominated bacterial phyla in polluted soil were affiliated with Firmicutes, Acidobacteria, and Actinobacteria, indicating that these bacterial phyla may have a high tolerance to pollutants. We suggested that specific bacterial phyla along with soil enzyme activities could be used as relevant biological indicators for long-term pollution assessment on soil quality. Graphical Abstract Bacterial community profiling and soil enzyme activities in long-term industrial waste effluent polluted soils. PMID:26803661

  6. Impacts of human activities on coral reef ecosystems of southern Taiwan: a long-term study.

    PubMed

    Liu, Pi-Jen; Meng, Pei-Jie; Liu, Li-Lian; Wang, Jih-Terng; Leu, Ming-Yih

    2012-06-01

    In July 2001, the National Museum of Marine Biology and Aquarium, co-sponsored by the Kenting National Park Headquarters and Taiwan's National Science Council, launched a Long-Term Ecological Research (LTER) program to monitor anthropogenic impacts on the ecosystems of southern Taiwan, specifically the coral reefs of Kenting National Park (KNP), which are facing an increasing amount of anthropogenic pressure. We found that the seawater of the reef flats along Nanwan Bay, Taiwan's southernmost embayment, was polluted by sewage discharge at certain monitoring stations. Furthermore, the consequently higher nutrient and suspended sediment levels had led to algal blooms and sediment smothering of shallow water corals at some sampling sites. Finally, our results show that, in addition to this influx of anthropogenically-derived sewage, increasing tourist numbers are correlated with decreasing shallow water coral cover, highlighting the urgency of a more proactive management plan for KNP's coral reefs.

  7. Synoptic data for solar-terrestrial physics: The U.K. contribution to long-term monitoring

    NASA Astrophysics Data System (ADS)

    Willis, D. M.; Hewish, A.; Rishbeth, H.; Rycroft, M. J.

    1994-05-01

    In 1989 the Council of the Royal Society of London established a Study Group to investigate the current status and future requirements of solar-terrestrial monitoring in the United Kingdom. This paper summarizes the conclusions and recommendations of the U.K. Study Group. The rationale for regular synoptic monitoring of the solar terrestrial environment is reviewed briefly. Instruments used for solar-terrestrial monitoring in U.K.-supported research programs are listed, with special emphasis on research instruments that produce monitoring data. Some important applications of solar-terrestrial monitoring are outlined and criteria are presented for determining the priorities of various monitoring operations. High priority is attached to monitoring operations that are important for: (1) deriving geophysical models and reference systems; (2) calculating the principal solar-geophysical indices; (3) producing long time series of good data, especially at sites of particular geophysical interest; (4) detecting global changes; (5) contributing to real-time forecasts of solar-terrestrial conditions, or to longer-term predictions and planning; and (6) providing background data for other observations and experiments. The existing U.K. programs of solar-terrestrial monitoring make a highly prestigious contribution to national and international scientific activity. Synoptic measurements of the solar-terrestrial environment are crucial for underpinning present and future programs of basic, strategic and applied research. Therefore, a core program of synoptic monitoring must be maintained in the U.K. It is recommended that this core program should be financed centrally through the Research Councils and reviewed quinquennially.

  8. Genetic activation of ERK5 MAP kinase enhances adult neurogenesis and extends hippocampus-dependent long-term memory.

    PubMed

    Wang, Wenbin; Pan, Yung-Wei; Zou, Junhui; Li, Tan; Abel, Glen M; Palmiter, Richard D; Storm, Daniel R; Xia, Zhengui

    2014-02-01

    Recent studies have shown that inhibition of adult neurogenesis impairs the formation of hippocampus-dependent memory. However, it is not known whether increasing adult neurogenesis affects the persistence of hippocampus-dependent long-term memory. Furthermore, signaling mechanisms that regulate adult neurogenesis are not fully defined. We recently reported that the conditional and targeted knock-out of ERK5 MAP kinase in adult neurogenic regions of the mouse brain attenuates adult neurogenesis in the hippocampus and disrupts several forms of hippocampus-dependent memory. Here, we developed a gain-of-function knock-in mouse model to specifically activate endogenous ERK5 in the neurogenic regions of the adult brain. We report that the selective and targeted activation of ERK5 increases adult neurogenesis in the dentate gyrus by enhancing cell survival, neuronal differentiation, and dendritic complexity. Conditional ERK5 activation also improves the performance of challenging forms of spatial learning and memory and extends hippocampus-dependent long-term memory. We conclude that enhancing signal transduction of a single signaling pathway within adult neural stem/progenitor cells is sufficient to increase adult neurogenesis and improve the persistence of hippocampus-dependent memory. Furthermore, activation of ERK5 may provide a novel therapeutic target to improve long-term memory.

  9. Re-analysis of the long-term changes of the NIMBUS-7 radiometer and behaviour of total solar irradiance during solar cycle 21

    NASA Astrophysics Data System (ADS)

    Frohlich, C.

    2004-12-01

    Only one radiometer - called Hickey-Frieden (HF) - is within the ERB package on NIMBUS-7 for the measurement of total solar irradiance (TSI) and thus changes due to exposure to solar radiation cannot be directly determined by comparison with a less exposed radiometer on the same spacecraft. The geometry and optical property of the cavity of HF is, however, very similar to the PMO6-type radiometers, it is essentially a copy of it with increased size. For the PMO6V on VIRGO/SOHO two main effects have been identified, a rapid early increase and a slow decrease, normally termed degradation, which can be modelled with a hyperbolic function taking the actual dose into account (Fröhlich, 2003). The corrections used by Fröhlich and Lean (1998) for the composite were based on early results from VIRGO and used simple exponential functions. With the recent results from VIRGO a re-analysis of the long-term behaviour of HF is necessary. The results are not only important for solar radiometry from space, but also to improve the reliability of TSI before the start of ACRIM-I in early 1980. The latter will allow to better quantify the behaviour of solar cycle 21 and to compare it with the two recent ones which differ in several aspects. C. Fröhlich. Long-term behaviour of space radiometers. Metrologia, 40:60--65, 2003. C. Fröhlich and J. Lean. The sun's total irradiance: Cycles and trends in the past two decades and associated climate change uncertainties. Geophys. Res. Lett., 25:4377--4380, 1998.

  10. Spot activity on HD 89546 (FG UMa) from long-term photometry

    NASA Astrophysics Data System (ADS)

    Özdarcan, O.; Evren, S.; Henry, G. W.

    2012-02-01

    We present the analysis of 20 years of time-series BV photometry of the SB1 RS CVn binary HD 89546. The system's yearly mean V brightness, the B-V color index, the photometric period, and the light curve amplitude all show clear cyclic variability with an ≈9-year time scale. We also find some evidence for brightness variability on a time scale longer than the 20-year time span of our observations, perhaps indicating a longer cycle analogous to the solar Gleissberg cycle. We estimate the unspotted V magnitude of HD 89546 to be 7.154m, which is ≈0.2m brighter than the observed maximum brightness. Spot modelling of the system shows that spot temperature variations affect the observed B-V color as well as the V brightness. Two active longitudes are observed, centered around 180° and 360° longitude on the G9 III primary, each covering a longitude range of 120°. Furthermore, two inactive longitude zones are seen spanning only 60° between the two active longitudes. The longitudinal distribution of the spots exhibits no strong cyclic variability but does show rapid jumps of 120° that look like the flip-flop phenomenon. We estimate the differential rotation coefficient of the star as k=0.086 by considering the range of observed photometric period variations and assumed latitudinal spot variations over 45°. Based on data obtained with the Tennessee State University T3 0.4 m APT at Fairborn Observatory, operated by Tennessee State University, and T30 0.3 m telescope of the Ege University Observatory in Izmir.

  11. SWAP OBSERVATIONS OF THE LONG-TERM, LARGE-SCALE EVOLUTION OF THE EXTREME-ULTRAVIOLET SOLAR CORONA

    SciTech Connect

    Seaton, Daniel B.; De Groof, Anik; Berghmans, David; Nicula, Bogdan; Shearer, Paul

    2013-11-01

    The Sun Watcher with Active Pixels and Image Processing (SWAP) EUV solar telescope on board the Project for On-Board Autonomy 2 spacecraft has been regularly observing the solar corona in a bandpass near 17.4 nm since 2010 February. With a field of view of 54 × 54 arcmin, SWAP provides the widest-field images of the EUV corona available from the perspective of the Earth. By carefully processing and combining multiple SWAP images, it is possible to produce low-noise composites that reveal the structure of the EUV corona to relatively large heights. A particularly important step in this processing was to remove instrumental stray light from the images by determining and deconvolving SWAP's point-spread function from the observations. In this paper, we use the resulting images to conduct the first-ever study of the evolution of the large-scale structure of the corona observed in the EUV over a three year period that includes the complete rise phase of solar cycle 24. Of particular note is the persistence over many solar rotations of bright, diffuse features composed of open magnetic fields that overlie polar crown filaments and extend to large heights above the solar surface. These features appear to be related to coronal fans, which have previously been observed in white-light coronagraph images and, at low heights, in the EUV. We also discuss the evolution of the corona at different heights above the solar surface and the evolution of the corona over the course of the solar cycle by hemisphere.

  12. Propofol, but not etomidate, increases corticosterone levels and induces long-term alteration in hippocampal synaptic activity in neonatal rats.

    PubMed

    Xu, Changqing; Seubert, Christoph N; Gravenstein, Nikolaus; Martynyuk, Anatoly E

    2016-04-01

    Animal studies provide strong evidence that general anesthetics (GAs), administered during the early postnatal period, induce long-term cognitive and neurological abnormalities. Because the brain growth spurt in rodents is delayed compared to that in humans, a fundamental question is whether the postnatal human brain is similarly vulnerable. Sevoflurane and propofol, GAs that share positive modulation of the gamma-aminobutyric acid type A receptor (GABAAR) function cause marked increase in corticosterone levels and induce long-term developmental alterations in synaptic activity in rodents. If synaptogenesis is affected, investigation of mechanisms of the synaptic effects of GAs is of high interest because synaptogenesis in humans continues for several years after birth. Here, we compared long-term synaptic effects of etomidate with those of propofol. Etomidate and propofol both positively modulate GABAAR activity, but in contrast to propofol, etomidate inhibits the adrenal synthesis of corticosterone. Postnatal day (P) 4, 5, or 6 rats received five injections of etomidate, propofol, or vehicle control during 5h of maternal separation. Endocrine effects of the anesthetics were evaluated by measuring serum levels of corticosterone immediately after anesthesia or maternal separation. The frequency and amplitude of miniature inhibitory postsynaptic currents (mIPSCs) in hippocampal CA1 pyramidal neurons were measured at P24-40 and P≥80. Only propofol caused a significant increase in serum corticosterone levels (F(4.26)=17.739, P<0.001). In contrast to increased frequency of mIPSCs in the propofol group (F(4.23)=8.731, p<0.001), mIPSC activity in the etomidate group was not different from that in the vehicle groups. The results of this study together with previously published data suggest that anesthetic-caused increase in corticosterone levels is required for GABAergic GAs to induce synaptic effects in the form of a long-term increase in the frequency of hippocampal mIPSCs.

  13. Long-term Trends in Interplanetary Magnetic Field Strength and Solar Wind Structure during the 20th Century

    NASA Technical Reports Server (NTRS)

    Richardson, I. G.; Cliver, E. W.; Cane, H. V.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    Lockwood et al have recently reported an approximately 40% increase in the radial component of the interplanetary magnetic field (IMF) at Earth between 1964 and 1996. We argue that this increase does not constitute a secular trend but is largely the consequence of lower than average fields during solar cycle 20 (1964-1976) in comparison with surrounding cycles. For times after 1976 the average IMF strength has actually decreased slightly. Examination of the cosmic ray intensity, an indirect measure of the IMF strength, over the last five solar cycles (19-23) also indicates that cycle averages of the IMF strength have been relatively constant since approximately 1954. We also consider the origin of the well-documented increase in the geomagnetic alphaalpha index that occurred primarily during the first half of the twentieth century. We surmise that the coronal mass ejection (CME) rate for recent solar cycles was approximately twice as high as that for solar cycles 100 years ago. However, this change in the CME rate and the accompanying increase in 27-day recurrent storm activity reported by others are unable to account completely for the increase in alphaalpha. Rather, the CMEs and recurrent high-speed streams at the beginning of the twentieth century must have been embedded in a background of slow solar wind that was less geoeffective (having, for example, lower IMF strength and/or flow speed) than its modern counterpart.

  14. Forecasting life: a study of activity cycles in low-mass stars: lessons from long-term stellar light curves.

    PubMed

    Kafka, Stella

    2012-06-01

    Magnetic activity cycles are indirect traces of magnetic fields and can provide an insight on the nature and action of stellar dynamos and stellar magnetic activity. This, in turn, can determine local space weather and activity effects on stellar habitable zones. Using photometric monitoring of low-mass stars, we study the presence and properties of their magnetic activity cycles. We introduce long-term light curves of our sample stars, and discuss the properties of the observed trends, especially at spectral types where stars are fully convective (later than M3).

  15. 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 ...

  16. Long-term effectiveness and mediators of a need-supportive physical activity coaching among Flemish sedentary employees.

    PubMed

    Van Hoecke, Ann-Sophie; Delecluse, Christophe; Opdenacker, Joke; Lipkens, Luc; Martien, Sofie; Boen, Filip

    2013-09-01

    This study examined the long-term and mediation effects of a need-supportive coaching programme on physical activity. Sedentary employees (n = 92) of the university of Leuven received 4 months of physical activity coaching, based on the self-determination theory, by coaches with a bachelor's degree in kinesiology who are specializing in health-related physical activity (n = 30). The programme consisted of a limited number of individual contact moments (i.e. an intake session, three follow-up contacts and an out-take session), either face-to-face, by phone or by e-mail. Self-reported physical activity, social support, self-efficacy and autonomous motivation were assessed in the coaching group (n = 92) and a control group (n = 34) at three moments: before the intervention (i.e. pre-test), after the intervention (i.e. post-test) and 1 year after pre-test measurements (i.e. follow-up test). Results revealed significant 3 (time) × 2 (groups) interaction effects on strenuous and total physical activity. Moreover, whereas the control group remained stable from pre- to post-test, the coaching group increased significantly in moderate, strenuous and total physical activity. Additionally, the coaching group increased significantly in mild, moderate, strenuous and total physical activity from pre- to follow-up tests, whereas the control group did not change. Bootstrapping analyses indicated that self-efficacy and autonomous motivation significantly mediated the intervention effect on physical activity from pre- to post-test, while social support significantly mediated the long-term effect. This study provides evidence for the long-term effectiveness of a need-supportive physical activity programme that might be efficient at the community level.

  17. Activation of synaptic group II metabotropic glutamate receptors induces long-term depression at GABAergic synapses in CNS neurons.

    PubMed

    Tang, Zheng-Quan; Liu, Yu-Wei; Shi, Wei; Dinh, Emilie Hoang; Hamlet, William R; Curry, Rebecca J; Lu, Yong

    2013-10-01

    Metabotropic glutamate receptor (mGluR)-dependent homosynaptic long-term depression (LTD) has been studied extensively at glutamatergic synapses in the CNS. However, much less is known about heterosynaptic long-term plasticity induced by mGluRs at inhibitory synapses. Here we report that pharmacological or synaptic activation of group II mGluRs (mGluR II) induces LTD at GABAergic synapses without affecting the excitatory glutamatergic transmission in neurons of the chicken cochlear nucleus. Coefficient of variation and failure rate analysis suggested that the LTD was expressed presynaptically. The LTD requires presynaptic spike activity, but does not require the activation of NMDA receptors. The classic cAMP-dependent protein kinase A signaling is involved in the transduction pathway. Remarkably, blocking mGluR II increased spontaneous GABA release, indicating the presence of tonic activation of mGluR II by ambient glutamate. Furthermore, synaptically released glutamate induced by electrical stimulations that concurrently activated both the glutamatergic and GABAergic pathways resulted in significant and constant suppression of GABA release at various stimulus frequencies (3.3, 100, and 300 Hz). Strikingly, low-frequency stimulation (1 Hz, 15 min) of the glutamatergic synapses induced heterosynaptic LTD of GABAergic transmission, and the LTD was blocked by mGluR II antagonist, indicating that synaptic activation of mGluR II induced the LTD. This novel form of long-term plasticity in the avian auditory brainstem may play a role in the development as well as in temporal processing in the sound localization circuit.

  18. Spatial distribution of HTO activity in unsaturated soil depth in the vicinity of long-term release source

    SciTech Connect

    Golubev, A.; Golubeva, V.; Mavrin, S.

    2015-03-15

    Previous studies reported about a correlation between HTO activity distribution in unsaturated soil layer and atmospheric long-term releases of HTO in the vicinity of Savannah River Site. The Tritium Working Group of BIOMASS Programme has performed a model-model intercomparison study of HTO transport from atmosphere to unsaturated soil and has evaluated HTO activity distribution in the unsaturated soil layer in the vicinity of permanent atmospheric sources. The Tritium Working Group has also reported about such a correlation, however the conclusion was that experimental data sets are needed to confirm this conclusion and also to validate appropriate computer models. (authors)

  19. Evaluating, Migrating, and Consolidating Databases and Applications for Long-Term Surveillance and Maintenance Activities at the Rocky Flats Site

    SciTech Connect

    Surovchak, S.; Marutzky, S.; Thompson, B.; Miller, K.; Labonte, E.

    2006-07-01

    The U.S. Department of Energy (DOE) Office of Legacy Management (LM) is assuming responsibilities for long-term surveillance and maintenance (LTS and M) activities at the Rocky Flats Environmental Technology Site (RFETS) during fiscal year 2006. During the transition, LM is consolidating databases and applications that support these various functions into a few applications which will streamline future management and retrieval of data. This paper discussed the process of evaluating, migrating, and consolidating these databases and applications for LTS and M activities and provides lessons learned that will benefit future transitions. (authors)

  20. The calmodulin-binding transcription activator CAMTA1 is required for long-term memory formation in mice.

    PubMed

    Bas-Orth, Carlos; Tan, Yan-Wei; Oliveira, Ana M M; Bengtson, C Peter; Bading, Hilmar

    2016-06-01

    The formation of long-term memory requires signaling from the synapse to the nucleus to mediate neuronal activity-dependent gene transcription. Synapse-to-nucleus communication is initiated by influx of calcium ions through synaptic NMDA receptors and/or L-type voltage-gated calcium channels and involves the activation of transcription factors by calcium/calmodulin signaling in the nucleus. Recent studies have drawn attention to a new family of transcriptional regulators, the so-called calmodulin-binding transcription activator (CAMTA) proteins. CAMTAs are expressed at particularly high levels in the mouse and human brain, and we reasoned that, as calmodulin-binding transcription factors, CAMTAs may regulate the formation of long-term memory by coupling synaptic activity and calcium/calmodulin signaling to memory-related transcriptional responses. This hypothesis is supported by genetic studies that reported a correlation between Camta gene polymorphisms or mutations and cognitive capability in humans. Here, we show that acute knockdown of CAMTA1, but not CAMTA2, in the hippocampus of adult mice results in impaired performance in two memory tests, contextual fear conditioning and object-place recognition test. Short-term memory and neuronal morphology were not affected by CAMTA knockdown. Gene expression profiling in the hippocampus of control and CAMTA knockdown mice revealed a number of putative CAMTA1 target genes related to synaptic transmission and neuronal excitability. Patch clamp recordings in organotypic hippocampal slice cultures provided further evidence for CAMTA1-dependent changes in electrophysiological properties. In summary, our study provides experimental evidence that confirms previous human genetic studies and establishes CAMTA1 as a regulator of long-term memory formation.

  1. Inhibition of long-term memory formation by anti-ependymin antisera after active shock-avoidance learning in goldfish.

    PubMed

    Piront, M L; Schmidt, R

    1988-02-23

    Ependymins are acidic glycoprotein constituents of goldfish brain cytoplasm and extracellular fluid which are known to participate in biochemical reactions of long-term memory formation. In earlier experiments, anti-ependymin antisera were found to cause amnesia when injected into goldfish brain ventricles after the acquisition of a vestibulomotoric training task. To investigate whether they also inhibit memory consolidation after other learning events the anti-ependymin antisera were injected after an active shock-avoidance learning paradigm, as follows: goldfish were trained in a shuttle-box to cross a barrier in order to avoid electric shocks (unconditioned stimulus) applied shortly after a light signal (conditioned stimulus). Anti-ependymin antisera blocked retention of the learned avoidance when injected 0.5, 4.5 or 24 h after acquisition of the new behavior. They had no effect, however, when injected 72 h after learning. Apparently, long-term memory was already consolidated at this point. Antisera injected 0.5 or 72 h prior to training, also did not influence learning or memory. Thirteen percent of the goldfish fled the light stimulus spontaneously. These fish therefore did not experience the unconditioned stimulus and thus were unable to learn the task. When they were treated with the anti-ependymin antisera and tested 3 days later, the spontaneous escape reaction was not affected (active control group). The ability of anti-ependymin antisera to inhibit memory consolidation and their efficacy after administration at specific time intervals are very similar for the active shock-avoidance learning and for the vestibulomotoric training. We conclude that ependymins are not task-specific, but serve a general function in biochemical reactions essential for long-term memory formation.

  2. Energetic auroral and polar ion outflow at DE 1 altitudes Magnitude, composition, magnetic activity dependence, and long-term variations

    NASA Technical Reports Server (NTRS)

    Yau, A. W.; Lenchyshyn, L.; Shelley, E. G.; Peterson, W. K.

    1985-01-01

    Data acquired from the Dynamics Explorer I Energetic Ion Composition Spectrometer in the period from September 1981 to May 1984 are used to determine the magnitude of the terrestrial ion outflow in the 0.01-17 keV/el range. The data are also employed to investigate the mass composition and topology (local time and invariant latitude distributions) of the ion outflow, as well as the outflow's magnetic activity dependence and long-term variation. The relative importance of auroral versus polar cap upflowing ions as a source of energetic plasma for various parts of the magnetosphere is examined.

  3. Long-term ascorbic acid administration causes anticonvulsant activity during moderate and long-duration swimming exercise in experimental epilepsy.

    PubMed

    Tutkun, Erkut; Arslan, Gokhan; Soslu, Recep; Ayyildiz, Mustafa; Agar, Erdal

    2015-01-01

    The benefits of regular exercise on brain health are undeniable. Long-term exercise increases the production of reactive oxygen species in brain. Therefore, athletes often consume antioxidant supplements to remedy exercise-related damage and fatigue during exercise. The aim of this study is to evaluate the role of ascorbic acid in the effects of different intensities of swimming exercise on the brain susceptibility to experimental epilepsy in rats. Ascorbic acid was administered intraperitoneally (ip) during three different swimming exercise programme for 90 days (15 min, 30 min, 90 min/day). The anticonvulsant activity regarding the frequency of epileptiform activity appeared in the 80 min after 500 units intracortical penicillin injection in 30 min and 90 min/day exercise groups. The administration of ascorbic acid (100 mg/kg, ip) did not alter the anticonvulsant properties seen in the in short-duration (15 min/day) swimming exercise group. The amplitude of epileptiform activity also became significant in the 110 and 120 min after penicillin injection in the moderate (30 min/day) and long duration (60 min/day) groups, respectively. The results of the present study provide electrophysiologic evidence that long-term administration of ascorbic acid causes anticonvulsant activities in the moderate and long-duration swimming exercise. Antioxidant supplementation such as ascorbic acid might be suggested for moderate and long-duration swimming exercise in epilepsy. PMID:26232995

  4. Long-term activity in and among persons with transfemoral amputation.

    PubMed

    Halsne, Elizabeth G; Waddingham, Matthew G; Hafner, Brian J

    2013-01-01

    Although physical limitations associated with transfemoral amputation (TFA) have been studied in laboratory settings, little is known about habitual activity within free-living environments. A retrospective analysis of 12 mo of step activity data was performed to quantify activity levels, variations, and patterns in 17 adults with unilateral TFA. Yearly, seasonal, and monthly average daily step counts and coefficients of variation (CoVs) were examined to characterize mobility. Analysis by Medicare Functional Classification Level (MFCL) was performed to explore relationships between clinical classification and performance. Subjects averaged 1,540 prosthetic steps/day, and activity generally increased with MFCL. Activity between MFCL-2 and -3 subjects was not significantly different, suggesting that ability to engage in habitual physical activity may be similar for these groups. Relative variation (CoV) was 0.65 across subjects but was lower for those with higher activity levels. No significant differences in CoV by group were detected. Marked seasonal and monthly patterns in activity were identified. Warmer seasons and months generally promoted higher activity, but peak temperatures and humidity depressed activity. Results suggest that persons with TFA are greatly limited in regards to activity. Further, large variations within and between subjects may challenge the interpretation of step activity gathered over short periods of time.

  5. The antimicrobial efficacy of a new central venous catheter with long-term broad-spectrum activity.

    PubMed

    Schierholz, J M; Fleck, C; Beuth, J; Pulverer, G

    2000-07-01

    Indwelling vascular catheters are a major cause of nosocomial sepsis. Prevention of colonization of polymeric surfaces by continuous release of bactericidal, highly biocompatible antimicrobials incorporated into polymers has been investigated as a promising new approach. An antimicrobial polyurethane catheter was investigated by HPLC and various antimicrobial assays. Controlled drug delivery governed by the physico-chemical mass transfer from the polyurethane bulk provided long-term release of the antimicrobial substances from the material to the outer surface and catheter lumen. The in vitro activity of catheters coated with miconazole and rifampicin against 158 clinical isolates of catheter-associated infections was evaluated. Incubated in physiological NaCl at 37 degrees C, the half-life of inhibitory activity of catheters coated with miconazole or rifampicin exceeded 3 weeks. In static and dynamic adhesion assays, coated catheters were able to prevent colonization with Staphylococcus aureus, Staphylococcus epidermidis and enterococci. To produce catheters resistant to infection, a potent antimicrobial efficacy combined with an excellent biocompatibility over time is needed. The long lasting efficacy of the antimicrobial polyurethane alloy as well as the increased antifungal activity of miconazole combined with rifampicin may be regarded as a promising improvement for long-term central venous access.

  6. Activities to improve harmonization and quality of European VOC and NOx long-term monitoring within ACTRIS

    NASA Astrophysics Data System (ADS)

    Plass-Dülmer, Christian; Reimann, Stefan

    2013-04-01

    Variability and trend analysis of long-term monitoring data of VOC and NOx and comparison between different data sets require good and harmonized QA/QC and data evaluation procedures. Some 15 institutions and several associated partners have joined their efforts in networking activity NA4 of the European infrastructure project ACTRIS (Aerosols, Clouds, and Trace gases Research Infrastructure Network) to better harmonize and improve the quality of long-term VOC and NOx measurements. The objectives are closely related to the requirements of Global Atmosphere Watch (GAW, WMO) and EMEP. A survey of the existing European sites and measurement techniques has been compiled. Partners and associates were invited to participate in setting up drafted measurement guidelines, performing round robin experiments, and side-by-side intercomparison activities. Furthermore, forms for data and metadata submission were prepared in cooperation with EBAS and harmonized methods for data evaluation and uncertainty estimation were developed and suggested to be used in data submission to data centers. This presentation shall give an overview of the activities in NA4 and introduce two accompanying presentations concerning results of ACTRIS VOC and NOx intercomparisons.

  7. Alterations in antioxidant enzyme activities and proline content in pea leaves under long-term drought stress.

    PubMed

    Karataş, Ilhami; Öztürk, Lokman; Demir, Yavuz; Unlükara, Ali; Kurunç, Ahmet; Düzdemir, Oral

    2014-09-01

    The effects of long-term drought stress on chlorophyll, proline, protein and hydrogen peroxide (H2O2) contents, malondialdehyde (MDA) in terms of lipid peroxidation and on the changes in the activities of antioxidant enzymes such as superoxide dismutase (SOD, EC 1.15.1.1), ascorbate peroxidase (APX, EC 1.11.1.11), catalase (CAT, EC 1.11.1.6) and peroxidase (POX; EC 1.11.1.7) in the leaves of pea (Pisum sativum L.) were studied in field conditions. Chlorophyll and protein contents in leaves decreased significantly with increased drought stress. The proline content increased markedly under water deficit. MDA amounts were elevated as a result of water shortage, whereas H(2)O(2) content changed slightly in pea leaves exposed to drought stress. Drought stress markedly enhanced the activities of SOD, CAT and POX but slightly changed the activity of APX. We conclude that in field conditions, long-term water shortage increased the susceptibility to drought in peas.

  8. A novel cysteine-rich neurotrophic factor in Aplysia facilitates growth, MAPK activation, and long-term synaptic facilitation.

    PubMed

    Pu, Lu; Kopec, Ashley M; Boyle, Heather D; Carew, Thomas J

    2014-04-01

    Neurotrophins are critically involved in developmental processes such as neuronal cell survival, growth, and differentiation, as well as in adult synaptic plasticity contributing to learning and memory. Our previous studies examining neurotrophins and memory formation in Aplysia showed that a TrkB ligand is required for MAPK activation, long-term synaptic facilitation (LTF), and long-term memory (LTM) for sensitization. These studies indicate that neurotrophin-like molecules in Aplysia can act as key elements in a functionally conserved TrkB signaling pathway. Here we report that we have cloned and characterized a novel neurotrophic factor, Aplysia cysteine-rich neurotrophic factor (apCRNF), which shares classical structural and functional characteristics with mammalian neurotrophins. We show that apCRNF (1) is highly enriched in the CNS, (2) enhances neurite elongation and branching, (3) interacts with mammalian TrkB and p75(NTR), (4) is released from Aplysia CNS in an activity-dependent fashion, (5) facilitates MAPK activation in a tyrosine kinase dependent manner in response to sensitizing stimuli, and (6) facilitates the induction of LTF. These results show that apCRNF is a native neurotrophic factor in Aplysia that can engage the molecular and synaptic mechanisms underlying memory formation.

  9. The antimicrobial efficacy of a new central venous catheter with long-term broad-spectrum activity.

    PubMed

    Schierholz, J M; Fleck, C; Beuth, J; Pulverer, G

    2000-07-01

    Indwelling vascular catheters are a major cause of nosocomial sepsis. Prevention of colonization of polymeric surfaces by continuous release of bactericidal, highly biocompatible antimicrobials incorporated into polymers has been investigated as a promising new approach. An antimicrobial polyurethane catheter was investigated by HPLC and various antimicrobial assays. Controlled drug delivery governed by the physico-chemical mass transfer from the polyurethane bulk provided long-term release of the antimicrobial substances from the material to the outer surface and catheter lumen. The in vitro activity of catheters coated with miconazole and rifampicin against 158 clinical isolates of catheter-associated infections was evaluated. Incubated in physiological NaCl at 37 degrees C, the half-life of inhibitory activity of catheters coated with miconazole or rifampicin exceeded 3 weeks. In static and dynamic adhesion assays, coated catheters were able to prevent colonization with Staphylococcus aureus, Staphylococcus epidermidis and enterococci. To produce catheters resistant to infection, a potent antimicrobial efficacy combined with an excellent biocompatibility over time is needed. The long lasting efficacy of the antimicrobial polyurethane alloy as well as the increased antifungal activity of miconazole combined with rifampicin may be regarded as a promising improvement for long-term central venous access. PMID:10882687

  10. Long-term Results of a First-Generation Annealed Highly Cross-Linked Polyethylene in Young, Active Patients.

    PubMed

    Ranawat, Chitranjan S; Ranawat, Amar S; Ramteke, Alankar A; Nawabi, Danyal; Meftah, Morteza

    2016-01-01

    The survivorship of total hip arthroplasty in younger patients is dependent on the wear characteristics of the bearing surfaces. Long-term results with conventional polyethylene in young patients show a high failure rate. This study assessed the long-term results of a first-generation annealed highly cross-linked polyethylene (HCLPE) in uncemented total hip arthroplasty in young, active patients. Between 1999 and 2003, 112 total hip arthroplasty procedures performed in 91 patients with an average University of California Los Angeles activity score of 8 and mean age of 53 years (range, 24-65 years) were included from a prospective database. In all patients, a 28-mm metal femoral head on annealed HCLPE (Crossfire; Stryker, Mahwah, New Jersey) was used. At minimum 10-year follow-up (11.5±0.94 years), Kaplan-Meier survivorship was 97% for all failures (1 periprosthetic infection and 1 late dislocation) and 100% for mechanical failure (no revisions for osteolysis or loosening). This study showed low revision rates for wear-related failure and superior survivorship in young, active patients. Oxidation causing failure of the locking mechanism has not been a problem with Crossfire for up to 10 years. PMID:26811959

  11. Long-term study of cloud condensation nuclei (CCN) activation of the atmospheric aerosol in Vienna

    NASA Astrophysics Data System (ADS)

    Burkart, J.; Steiner, G.; Reischl, G.; Hitzenberger, R.

    2011-10-01

    During a total of 11 months, cloud condensation nuclei (CCN at super-saturation S 0.5%) and condensation nuclei (CN) concentrations were measured in the urban background aerosol of Vienna, Austria. For several months, number size distributions between 13.22 nm and 929 nm were also measured with a scanning mobility particle spectrometer (SMPS). Activation ratios (i.e. CCN/CN ratios) were calculated and apparent activation diameters obtained by integrating the SMPS size distributions. Variations in all CCN parameters (concentration, activation ratio, apparent activation diameter) are quite large on timescales of days to weeks. Passages of fronts influenced CCN parameters. Concentrations decreased with the passage of a front. No significant differences were found for fronts from different sectors (for Vienna mainly north to west and south to east). CCN concentrations at 0.5% S ranged from 160 cm-3 to 3600 cm-3 with a campaign average of 820 cm-3. Activation ratios were quite low (0.02-0.47, average: 0.13) and comparable to activation ratios found in other polluted regions (e.g. Cubison et al., 2008). Apparent activation diameters were found to be much larger (campaign average: 169 nm, range: (69-370) nm) than activation diameters for single-salt particles (around 50 nm depending on the salt). Contrary to CN concentrations, which are influenced by source patterns, CCN concentrations did not exhibit distinct diurnal patterns. Activation ratios showed diurnal variations counter-current to the variations of CN concentrations.

  12. Mineralogical impact on long-term patterns of soil nitrogen and phosphorus enzyme activities

    NASA Astrophysics Data System (ADS)

    Mikutta, Robert; Turner, Stephanie; Meyer-Stüve, Sandra; Guggenberger, Georg; Dohrmann, Reiner; Schippers, Axel

    2014-05-01

    Soil chronosequences provide a unique opportunity to study microbial activity over time in mineralogical diverse soils of different ages. The main objective of this study was to test the effect of mineralogical properties, nutrient and organic matter availability over whole soil pro-files on the abundance and activity of the microbial communities. We focused on microbio-logical processes involved in nitrogen and phosphorus cycling at the 120,000-year Franz Josef soil chronosequence. Microbial abundances (microbial biomass and total cell counts) and enzyme activities (protease, urease, aminopeptidase, and phosphatase) were determined and related to nutrient contents and mineralogical soil properties. Both, microbial abundances and enzyme activities decreased with soil depth at all sites. In the organic layers, microbial biomass and the activities of N-hydrolyzing enzymes showed their maximum at the intermediate-aged sites, corresponding to a high aboveground biomass. In contrast, the phosphatase activity increased with site age. The activities of N-hydrolyzing enzymes were positively correlated with total carbon and nitrogen contents, whereas the phosphatase activity was negatively correlated with the phosphorus content. In the mineral soil, the enzyme activities were generally low, thus reflecting the presence of strongly sorbing minerals. Sub-strate-normalized enzyme activities correlated negatively to clay content as well as poorly crystalline Al and Fe oxyhydroxides, supporting the view that the evolution of reactive sec-ondary mineral phases alters the activity of the microbial communities by constraining sub-strate availability. Our data suggest a strong mineralogical influence on nutrient cycling par-ticularly in subsoil environments.

  13. Long-term Synoptic Observations of the Sun.

    NASA Astrophysics Data System (ADS)

    Pevtsov, Alexei

    2015-08-01

    Does the solar activity vary with time, or it remains constant? How systematic or intermittent solar cycles are? Long-term observations of the Sun are the reason we know answers to these questions. Ultimately, the development of a better understanding of stellar cycles will require similar long-term observations of other sun-like stars. To facilitate international collaboration on synoptic long-term solar observations, IAU created a working group on “Coordination of Synoptic Observations of the Sun.” The working group provides a forum for discussion of all issues relevant to past, current, and future synoptic programs, preservation, calibration, and access to synoptic solar data products. This talk will provide a summary of recent activity by this IAU WG. It will also present a brief overview of recent research on sun-as-a-star conducted at the US National Solar Observatory.

  14. Long-term Observation of Soil Creep Activity around a Landslide Scar

    EPA Science Inventory

    Rate of sediment infilling into landslide scars by soil creep is needed to estimate the timing of subsequent landslide activity at a particular site. However, knowledge about the spatial distribution of its activity around the landslide scar is scarce. Additionally, there are few...

  15. Barriers to Physical Activity for People with Long-Term Neurological Conditions: A Review Study

    ERIC Educational Resources Information Center

    Mulligan, Hilda F.; Hale, Leigh A.; Whitehead, Lisa; Baxter, G. David

    2012-01-01

    People with disability are insufficiently physically active for health. This study identified the volume, quality, and findings of research that exposes environmental and personal barriers of physical activity participation for people with neurological conditions. CINAHL, Sport Discus, EMBASE, Medline, and AMED were systematically searched between…

  16. Long-Term Relationships between Synaptic Tenacity, Synaptic Remodeling, and Network Activity

    PubMed Central

    Minerbi, Amir; Kahana, Roni; Goldfeld, Larissa; Kaufman, Maya; Marom, Shimon; Ziv, Noam E.

    2009-01-01

    Synaptic plasticity is widely believed to constitute a key mechanism for modifying functional properties of neuronal networks. This belief implicitly implies, however, that synapses, when not driven to change their characteristics by physiologically relevant stimuli, will maintain these characteristics over time. How tenacious are synapses over behaviorally relevant time scales? To begin to address this question, we developed a system for continuously imaging the structural dynamics of individual synapses over many days, while recording network activity in the same preparations. We found that in spontaneously active networks, distributions of synaptic sizes were generally stable over days. Following individual synapses revealed, however, that the apparently static distributions were actually steady states of synapses exhibiting continual and extensive remodeling. In active networks, large synapses tended to grow smaller, whereas small synapses tended to grow larger, mainly during periods of particularly synchronous activity. Suppression of network activity only mildly affected the magnitude of synaptic remodeling, but dependence on synaptic size was lost, leading to the broadening of synaptic size distributions and increases in mean synaptic size. From the perspective of individual neurons, activity drove changes in the relative sizes of their excitatory inputs, but such changes continued, albeit at lower rates, even when network activity was blocked. Our findings show that activity strongly drives synaptic remodeling, but they also show that significant remodeling occurs spontaneously. Whereas such spontaneous remodeling provides an explanation for “synaptic homeostasis” like processes, it also raises significant questions concerning the reliability of individual synapses as sites for persistently modifying network function. PMID:19554080

  17. Effects of long term irrigation with polluted water and sludge amendment on some soil enzyme activities

    SciTech Connect

    Topac, F.O.; Baskaya, H.S.; Alkan, U.; Katkat, A.V.

    2008-01-15

    The objective of this study was to determine the effects of wastewater sludge-fly ash mixtures on urease, dehydrogenase, alkaline phosphatase and beta-glucosidase activities in soils. In order to evaluate the probable effects of previous soil management practices (irrigation with polluted water) on soil enzymes, two different soil samples which were similar in physical properties, but different in irrigation practice were used. The application of wastewater sludges supplemented with varying doses of fly ash increased potential enzyme activities for a short period of time (3 months) in comparison to unamended soils. However, the activity levels generally showed a decreasing trend with increasing ash ratios indicating the inhibitory effect of fly ash. The urease and dehydrogenase activities were particularly lower in soils irrigated from a polluted stream, indicating the negative effects of the previous soil management on soil microbial activity.

  18. Long-term effects of axotomy on neural activity during cat locomotion.

    PubMed

    Gordon, T; Hoffer, J A; Jhamandas, J; Stein, R B

    1980-06-01

    1. Neural activity was recorded from cats during locomotion on a treadmill using electrodes in Silastic cuffs placed around the sciatic nerve and the lateral gastrocnemius-soleus, medial gastrocnemius, common peroneal and tibial nerve branches. Each branch gave characteristic patterns of activity which were studied before and after it was cut distal to the recording cuffs. Sensory and motor components were separated and measured using cross-correlation techniques. The amplitude of the cross-correlation peaks was compared with the amplitude of compound action potentials evoked by electrical stimulation and recorded from the same sites in the anaesthetized animal. 2. Sensory activity declined rapidly following axotomy and did not recover unless reinnervation occurred. Sensory activity even 5 months after nerve section and resuture had recovered to only a fraction of the control values. This reduction is attributed to a decline in the evoked compound potentials and to many fibres being unsuccessful in regenerating to appropriate sensory organs. 3. Motor activity declined more than could be accounted for by a decline in evoked potentials over the first month after axotomy. The extra reduction represents a decline in the number of impulses generated by alpha-motoneurones after axotomy. If regeneration was permitted, motor activity recovered to higher levels than did the evoked potentials for the whole nerve. Even if regeneration was prevented by nerve ligation, motoneurones continued to generate activity at a stable level over a period of months during which whole nerve compound potentials continued to decline. 4. The modulation of motor activity in ligated nerves during the step cycle was still appropriate to the required movement. Thus, activity recorded from severed nerves in human amputees may be useful in controlling powered artificial limbs. The persistence of motor activity may be responsible for the lesser degree of atrophy found in motor fibres than in sensory

  19. Early Gelatinase Activity Is Not a Determinant of Long-Term Recovery after Traumatic Brain Injury in the Immature Mouse.

    PubMed

    Semple, Bridgette D; Noble-Haeusslein, Linda J; Gooyit, Major; Tercovich, Kayleen G; Peng, Zhihong; Nguyen, Trung T; Schroeder, Valerie A; Suckow, Mark A; Chang, Mayland; Raber, Jacob; Trivedi, Alpa

    2015-01-01

    The gelatinases, matrix metalloproteinases (MMP)-2 and MMP-9, are thought to be key mediators of secondary damage in adult animal models of brain injury. Moreover, an acute increase in these proteases in plasma and brain extracellular fluid of adult patients with moderate-to-severe traumatic brain injuries (TBIs) is associated with poorer clinical outcomes and mortality. Nonetheless, their involvement after TBI in the pediatric brain remains understudied. Using a murine model of TBI at postnatal day 21 (p21), approximating a toddler-aged child, we saw upregulation of active and pro-MMP-9 and MMP-2 by gelatin zymography at 48 h post-injury. We therefore investigated the role of gelatinases on long-term structural and behavioral outcomes after injury after acute inhibition with a selective gelatinase inhibitor, p-OH SB-3CT. After systemic administration, p-OH SB-3CT crossed the blood-brain barrier at therapeutically-relevant concentrations. TBI at p21 induced hyperactivity, deficits in spatial learning and memory, and reduced sociability when mice were assessed at adulthood, alongside pronounced tissue loss in key neuroanatomical regions. Acute and short-term post-injury treatment with p-OH SB-3CT did not ameliorate these long-term behavioral, cognitive, or neuropathological deficits as compared to vehicle-treated controls, suggesting that these deficits were independent of MMP-9 and MMP-2 upregulation. These findings emphasize the vulnerability of the immature brain to the consequences of traumatic injuries. However, early upregulation of gelatinases do not appear to be key determinants of long-term recovery after an early-life injury. PMID:26588471

  20. Early Gelatinase Activity Is Not a Determinant of Long-Term Recovery after Traumatic Brain Injury in the Immature Mouse

    PubMed Central

    Semple, Bridgette D.; Noble-Haeusslein, Linda J.; Gooyit, Major; Tercovich, Kayleen G.; Peng, Zhihong; Nguyen, Trung T.; Schroeder, Valerie A.; Suckow, Mark A.; Chang, Mayland; Raber, Jacob; Trivedi, Alpa

    2015-01-01

    The gelatinases, matrix metalloproteinases (MMP)-2 and MMP-9, are thought to be key mediators of secondary damage in adult animal models of brain injury. Moreover, an acute increase in these proteases in plasma and brain extracellular fluid of adult patients with moderate-to-severe traumatic brain injuries (TBIs) is associated with poorer clinical outcomes and mortality. Nonetheless, their involvement after TBI in the pediatric brain remains understudied. Using a murine model of TBI at postnatal day 21 (p21), approximating a toddler-aged child, we saw upregulation of active and pro-MMP-9 and MMP-2 by gelatin zymography at 48 h post-injury. We therefore investigated the role of gelatinases on long-term structural and behavioral outcomes after injury after acute inhibition with a selective gelatinase inhibitor, p-OH SB-3CT. After systemic administration, p-OH SB-3CT crossed the blood-brain barrier at therapeutically-relevant concentrations. TBI at p21 induced hyperactivity, deficits in spatial learning and memory, and reduced sociability when mice were assessed at adulthood, alongside pronounced tissue loss in key neuroanatomical regions. Acute and short-term post-injury treatment with p-OH SB-3CT did not ameliorate these long-term behavioral, cognitive, or neuropathological deficits as compared to vehicle-treated controls, suggesting that these deficits were independent of MMP-9 and MMP-2 upregulation. These findings emphasize the vulnerability of the immature brain to the consequences of traumatic injuries. However, early upregulation of gelatinases do not appear to be key determinants of long-term recovery after an early-life injury. PMID:26588471

  1. [Spinal circuit motor plasticity mechanisms in long-term sports activity adaptation].

    PubMed

    Andriianova, E Iu; Lanskaia, O V

    2014-01-01

    Man interacts with the environment through motor activities getting considerable sensor information from numerous internal and external sources. There is significant evidence of I-a afferents sensor information being critical in initiating of functional and morphological transformations in the periods of both development and maturation of cortex and spinal cord. Ia fibers ability to transmit sensor information, generated by muscle and motor activities, causes plastic changes in the central nervous system, enabling man to acquire new skills and movements and develop them. Therefore, understanding of activity-dependent neural plasticity mechanisms is of great importance in developing methods to perfect motor function, for example, in doing sports. This article presents the results of investigation of activity-dependent changes in spinal cord circuits in athletes. There are new data of cervical and lumbosacral motor spinal system plasticity as a result of various longterm sports activities. It is shown, in particular, that, in comparison with non-athletes, in the spinal cord of ski-racers and basketball-players the representation area of upper and lower extremities muscles alpha-motorneurons with high reflex excitability is extended. Moreover,.the direction of the extension was specified by the upper segments activity. Besides, the volume of some revealed signs of cervical and lumbosacral spinal cord plasticity in the ski-racers, involved into moderate cyclic activity, was higher than that in the basketball-players, whose movements are more various.

  2. Long-term study of cloud condensation nuclei (CCN) activation of the atmospheric aerosol in Vienna.

    PubMed

    Burkart, J; Steiner, G; Reischl, G; Hitzenberger, R

    2011-10-01

    During a total of 11 months, cloud condensation nuclei (CCN at super-saturation S 0.5%) and condensation nuclei (CN) concentrations were measured in the urban background aerosol of Vienna, Austria. For several months, number size distributions between 13.22 nm and 929 nm were also measured with a scanning mobility particle spectrometer (SMPS). Activation ratios (i.e. CCN/CN ratios) were calculated and apparent activation diameters obtained by integrating the SMPS size distributions. Variations in all CCN parameters (concentration, activation ratio, apparent activation diameter) are quite large on timescales of days to weeks. Passages of fronts influenced CCN parameters. Concentrations decreased with the passage of a front. No significant differences were found for fronts from different sectors (for Vienna mainly north to west and south to east). CCN concentrations at 0.5% S ranged from 160 cm(-3) to 3600 cm(-3) with a campaign average of 820 cm(-3). Activation ratios were quite low (0.02-0.47, average: 0.13) and comparable to activation ratios found in other polluted regions (e.g. Cubison et al., 2008). Apparent activation diameters were found to be much larger (campaign average: 169 nm, range: (69-370) nm) than activation diameters for single-salt particles (around 50 nm depending on the salt). Contrary to CN concentrations, which are influenced by source patterns, CCN concentrations did not exhibit distinct diurnal patterns. Activation ratios showed diurnal variations counter-current to the variations of CN concentrations.

  3. Responses of absolute and specific soil enzyme activities to long term additions of organic and mineral fertilizer.

    PubMed

    Zhang, Xinyu; Dong, Wenyi; Dai, Xiaoqin; Schaeffer, Sean; Yang, Fengting; Radosevich, Mark; Xu, Lili; Liu, Xiyu; Sun, Xiaomin

    2015-12-01

    Long-term phosphorus (P) and nitrogen (N) applications may seriously affect soil microbial activity. A long-term field fertilizer application trial was established on reddish paddy soils in the subtropical region of southern China in 1998. We assessed the effects of swine manure and seven different rates or ratios of NPK fertilizer treatments on (1) the absolute and specific enzyme activities per unit of soil organic carbon (SOC) or microbial biomass carbon (MBC) involved in C, N, and P transformations and (2) their relationships with soil environmental factors and soil microbial community structures. The results showed that manure applications led to increases in the absolute and specific activities of soil β-1,4-glucosidase(βG), β-1,4-N-acetylglucosaminidase (NAG), and leucine aminopeptidase (LAP). The absolute and specific acid phosphatase (AP) activities decreased as mineral P fertilizer application rates and ratios increased. Redundancy analysis (RDA) showed that there were negative correlations between absolute and specific AP activities, pH, and total P contents, while there were positive correlations between soil absolute and specific βG, NAG, and LAP enzyme activities, and SOC and total N contents. RDA showed that the contents of actinomycete and Gram-positive bacterium PLFA biomarkers are more closely related to the absolute and specific enzyme activities than the other PLFA biomarkers (P<0.01). Our results suggest that both the absolute and specific enzyme activities could be used as sensitive soil quality indicators that provide useful linkages with the microbial community structures and environmental factors. To maintain microbial activity and to minimize environmental impacts, P should be applied as a combination of inorganic and organic forms, and total P fertilizer application rates to subtropical paddy soils should not exceed 44 kg P ha(-1) year(-1). PMID:26196069

  4. Responses of absolute and specific soil enzyme activities to long term additions of organic and mineral fertilizer.

    PubMed

    Zhang, Xinyu; Dong, Wenyi; Dai, Xiaoqin; Schaeffer, Sean; Yang, Fengting; Radosevich, Mark; Xu, Lili; Liu, Xiyu; Sun, Xiaomin

    2015-12-01

    Long-term phosphorus (P) and nitrogen (N) applications may seriously affect soil microbial activity. A long-term field fertilizer application trial was established on reddish paddy soils in the subtropical region of southern China in 1998. We assessed the effects of swine manure and seven different rates or ratios of NPK fertilizer treatments on (1) the absolute and specific enzyme activities per unit of soil organic carbon (SOC) or microbial biomass carbon (MBC) involved in C, N, and P transformations and (2) their relationships with soil environmental factors and soil microbial community structures. The results showed that manure applications led to increases in the absolute and specific activities of soil β-1,4-glucosidase(βG), β-1,4-N-acetylglucosaminidase (NAG), and leucine aminopeptidase (LAP). The absolute and specific acid phosphatase (AP) activities decreased as mineral P fertilizer application rates and ratios increased. Redundancy analysis (RDA) showed that there were negative correlations between absolute and specific AP activities, pH, and total P contents, while there were positive correlations between soil absolute and specific βG, NAG, and LAP enzyme activities, and SOC and total N contents. RDA showed that the contents of actinomycete and Gram-positive bacterium PLFA biomarkers are more closely related to the absolute and specific enzyme activities than the other PLFA biomarkers (P<0.01). Our results suggest that both the absolute and specific enzyme activities could be used as sensitive soil quality indicators that provide useful linkages with the microbial community structures and environmental factors. To maintain microbial activity and to minimize environmental impacts, P should be applied as a combination of inorganic and organic forms, and total P fertilizer application rates to subtropical paddy soils should not exceed 44 kg P ha(-1) year(-1).

  5. Perspectives and experiences related to physical activity of elders in long-term-care settings.

    PubMed

    Phillips, Lorraine J; Flesner, Marcia

    2013-01-01

    This qualitative study investigated individual and situational factors influencing physical activity (PA) practices of elders in residential-care/assisted-living (RC/AL) communities. This article describes the results of focus-group interviews involving 47 residents across 6 RC/AL settings. Thematic analysis revealed 6 themes: staying active, past PA experiences, value of PA, barriers to PA, strategies to facilitate PA, and support needs to promote PA. Staying active meant walking indoors and out, attending chair-exercise programs, performing professionally prescribed home exercises, and using available exercise equipment. Past PA experiences shaped current preferences and practices. Participants agreed that exercise helped maintain physical functioning but recounted cognitive and situational barriers to PA. Lack of dedicated exercise space and short corridors hampered efforts to stay active. Participants wished for individualized home exercise programs and supervised exercise sessions. Future research should examine the extent to which the physical environment and PA programming in RC/AL communities affect elders' PA.

  6. Long-Term Global Morphology of Gravity Wave Activity Using UARS Data

    NASA Technical Reports Server (NTRS)

    Eckermann, Stephen D.; Bacmeister, Julio T.; Wu, Dong L.

    1998-01-01

    Progress in research into the global morphology of gravity wave activity using UARS data is described for the period March-June, 1998. Highlights this quarter include further progress in the analysis and interpretation of CRISTA temperature variances; model-generated climatologies of mesospheric gravity wave activity using the HWM-93 wind and temperature model; and modeling of gravity wave detection from space-based platforms. Preliminary interpretations and recommended avenues for further analysis are also described.

  7. Long-term effects of the trehalase inhibitor trehazolin on trehalase activity in locust flight muscle.

    PubMed

    Wegener, Gerhard; Macho, Claudia; Schlöder, Paul; Kamp, Günter; Ando, Osamu

    2010-11-15

    Trehalase (EC 3.2.1.28) hydrolyzes the main haemolymph sugar of insects, trehalose, into the essential cellular substrate glucose. Trehalase in locust flight muscle is bound to membranes that appear in the microsomal fraction upon tissue fractionation, but the exact location in vivo has remained elusive. Trehalase has been proposed to be regulated by a novel type of activity control that is based on the reversible transformation of a latent (inactive) form into an overt (active) form. Most trehalase activity from saline-injected controls was membrane-bound (95%) and comprised an overt form (∼25%) and a latent form (75%). Latent trehalase could be assayed only after the integrity of membranes had been destroyed. Trehazolin, a potent tight-binding inhibitor of trehalase, is confined to the extracellular space and has been used as a tool to gather information on the relationship between latent and overt trehalase. Trehazolin was injected into the haemolymph of locusts, and the trehalase activity of the flight muscle was determined at different times over a 30-day period. Total trehalase activity in locust flight muscle was markedly inhibited during the first half of the interval, but reappeared during the second half. Inhibition of the overt form preceded inhibition of the latent form, and the time course suggested a reversible precursor-product relation (cycling) between the two forms. The results support the working hypothesis that trehalase functions as an ectoenzyme, the activity of which is regulated by reversible transformation of latent into overt trehalase. PMID:21037064

  8. Predator and prey activity levels jointly influence the outcome of long-term foraging bouts.

    PubMed

    Sweeney, Kayla; Cusack, Brian; Armagost, Fawn; O'Brien, Timothy; Keiser, Carl N; Pruitt, Jonathan N

    2013-09-01

    Consistent interindividual differences in behavior (i.e., "behavioral types") may be a key factor in determining the outcome of species interactions. Studies that simultaneously account for the behavioral types of individuals in multiple interacting species, such as predator-prey systems, may be particularly strong predictors of ecological outcomes. Here, we test the predator-prey locomotor crossover hypothesis, which predicts that active predators are more likely to encounter and consume prey with the opposing locomotor tendency. We test this hypothesis using intraspecific behavioral variation in both a predator and prey species as predictors of foraging outcomes. We use the old field jumping spider, Phidippus clarus (Araneae, Salticidae), and the house cricket, Acheta domesticus (Orthoptera, Gryllidae), as a model predator-prey system in laboratory mesocosm trials. Stable individual differences in locomotor tendencies were identified in both P. clarus and A. domesticus, and the outcome of foraging bouts depended neither on the average activity level of the predator nor on the average activity level of prey. Instead, an interaction between the activity level of spiders and crickets predicted spider foraging success and prey survivorship. Consistent with the locomotor crossover hypothesis, predators exhibiting higher activity levels consumed more prey when in an environment containing low-activity prey items and vice versa. This study highlights 1) the importance of intraspecific variation in determining the outcome of predator-prey interactions and 2) that acknowledging behavioral variation in only a single species may be insufficient to characterize the performance consequences of intraspecific trait variants. PMID:23935257

  9. Repeated Isoflurane Exposures Impair Long-Term Potentiation and Increase Basal GABAergic Activity in the Basolateral Amygdala

    PubMed Central

    Long II, Robert P.; Aroniadou-Anderjaska, Vassiliki; Prager, Eric M.; Pidoplichko, Volodymyr I.; Figueiredo, Taiza H.; Braga, Maria F. M.

    2016-01-01

    After surgery requiring general anesthesia, patients often experience emotional disturbances, but it is unclear if this is due to anesthetic exposure. In the present study, we examined whether isoflurane anesthesia produces long-term pathophysiological alterations in the basolateral amygdala (BLA), a brain region that plays a central role in emotional behavior. Ten-week-old, male rats were administered either a single, 1 h long isoflurane (1.5%) anesthesia or three, 1 h long isoflurane exposures, separated by 48 h. Long-term potentiation (LTP) and spontaneous GABAergic activity in the BLA were studied 1 day, 1 week, and 1 month later. Single isoflurane anesthesia had no significant effect on the magnitude of LTP. In contrast, after repeated isoflurane exposures, LTP was dramatically impaired at both 1 day and 1 week after the last exposure but was restored by 1 month after the exposures. Spontaneous GABAA receptor-mediated IPSCs were increased at 1 day and 1 week after repeated exposures but had returned to control levels by 1 month after exposure. Thus, repeated exposures to isoflurane cause a long-lasting—but not permanent—impairment of synaptic plasticity in the BLA, which could be due to increased basal GABAergic activity. These pathophysiological alterations may produce emotional disturbances and impaired fear-related learning. PMID:27313904

  10. Repeated Isoflurane Exposures Impair Long-Term Potentiation and Increase Basal GABAergic Activity in the Basolateral Amygdala.

    PubMed

    Long Ii, Robert P; Aroniadou-Anderjaska, Vassiliki; Prager, Eric M; Pidoplichko, Volodymyr I; Figueiredo, Taiza H; Braga, Maria F M

    2016-01-01

    After surgery requiring general anesthesia, patients often experience emotional disturbances, but it is unclear if this is due to anesthetic exposure. In the present study, we examined whether isoflurane anesthesia produces long-term pathophysiological alterations in the basolateral amygdala (BLA), a brain region that plays a central role in emotional behavior. Ten-week-old, male rats were administered either a single, 1 h long isoflurane (1.5%) anesthesia or three, 1 h long isoflurane exposures, separated by 48 h. Long-term potentiation (LTP) and spontaneous GABAergic activity in the BLA were studied 1 day, 1 week, and 1 month later. Single isoflurane anesthesia had no significant effect on the magnitude of LTP. In contrast, after repeated isoflurane exposures, LTP was dramatically impaired at both 1 day and 1 week after the last exposure but was restored by 1 month after the exposures. Spontaneous GABAA receptor-mediated IPSCs were increased at 1 day and 1 week after repeated exposures but had returned to control levels by 1 month after exposure. Thus, repeated exposures to isoflurane cause a long-lasting-but not permanent-impairment of synaptic plasticity in the BLA, which could be due to increased basal GABAergic activity. These pathophysiological alterations may produce emotional disturbances and impaired fear-related learning.

  11. Effects of long-term salicylate administration on synaptic ultrastructure and metabolic activity in the rat CNS

    PubMed Central

    Yi, Bin; Hu, Shousen; Zuo, Chuantao; Jiao, Fangyang; Lv, Jingrong; Chen, Dongye; Ma, Yufei; Chen, Jianyong; Mei, Ling; Wang, Xueling; Huang, Zhiwu; Wu, Hao

    2016-01-01

    Tinnitus is associated with neural hyperactivity in the central nervous system (CNS). Salicylate is a well-known ototoxic drug, and we induced tinnitus in rats using a model of long-term salicylate administration. The gap pre-pulse inhibition of acoustic startle test was used to infer tinnitus perception, and only rats in the chronic salicylate-treatment (14 days) group showed evidence of experiencing tinnitus. After small animal positron emission tomography scans were performed, we found that the metabolic activity of the inferior colliculus (IC), the auditory cortex (AC), and the hippocampus (HP) were significantly higher in the chronic treatment group compared with saline group (treated for 14 days), which was further supported by ultrastructural changes at the synapses. The alterations all returned to baseline 14 days after the cessation of salicylate-treatment (wash-out group), indicating that these changes were reversible. These findings indicate that long-term salicylate administration induces tinnitus, enhanced neural activity and synaptic ultrastructural changes in the IC, AC, and HP of rats due to neuroplasticity. Thus, an increased metabolic rate and synaptic transmission in specific areas of the CNS may contribute to the development of tinnitus. PMID:27068004

  12. Repeated Isoflurane Exposures Impair Long-Term Potentiation and Increase Basal GABAergic Activity in the Basolateral Amygdala.

    PubMed

    Long Ii, Robert P; Aroniadou-Anderjaska, Vassiliki; Prager, Eric M; Pidoplichko, Volodymyr I; Figueiredo, Taiza H; Braga, Maria F M

    2016-01-01

    After surgery requiring general anesthesia, patients often experience emotional disturbances, but it is unclear if this is due to anesthetic exposure. In the present study, we examined whether isoflurane anesthesia produces long-term pathophysiological alterations in the basolateral amygdala (BLA), a brain region that plays a central role in emotional behavior. Ten-week-old, male rats were administered either a single, 1 h long isoflurane (1.5%) anesthesia or three, 1 h long isoflurane exposures, separated by 48 h. Long-term potentiation (LTP) and spontaneous GABAergic activity in the BLA were studied 1 day, 1 week, and 1 month later. Single isoflurane anesthesia had no significant effect on the magnitude of LTP. In contrast, after repeated isoflurane exposures, LTP was dramatically impaired at both 1 day and 1 week after the last exposure but was restored by 1 month after the exposures. Spontaneous GABAA receptor-mediated IPSCs were increased at 1 day and 1 week after repeated exposures but had returned to control levels by 1 month after exposure. Thus, repeated exposures to isoflurane cause a long-lasting-but not permanent-impairment of synaptic plasticity in the BLA, which could be due to increased basal GABAergic activity. These pathophysiological alterations may produce emotional disturbances and impaired fear-related learning. PMID:27313904

  13. Reversine Increases the Plasticity of Long-Term Cryopreserved Fibroblasts to Multipotent Progenitor Cells through Activation of Oct4

    PubMed Central

    Li, Xiangchen; Guo, Yu; Yao, Yaxin; Hua, Jinlian; Ma, Yuehui; Liu, Changqing; Guan, Weijun

    2016-01-01

    Reversine, a purine analog, had been evidenced that it could induce dedifferentiation of differentiated cells into multipotent progenitor cells. Here, we showed that reversine could increase the plasticity of long-term cryopreserved bovine fibroblasts, and reversine-treated cells achieved the ability to differentiate into all three germ layers cells, such as osteoblasts and adipocytes from mesoblast, neurocyte from ectoderm, hepatocytes and smooth muscle cells from endoderm. Moreover, treatment of reversine caused the grow arrest of fibroblasts at G2/M and distinct cell swelling resulting in the formation of polyploid cells. In parallel, reversine treatment induced a multipotency of fibroblasts might be attributed to the activation of histone modifications, especially the degression of DNA methylation. However, molecular and cellular experiments suggested that reversine treatment enhanced selectively the expression of pluripotent marker gene Oct4 and mesenchymal marker genes CD29, CD44 and CD73, but Sox2 and Nanog were not detected. Taken together, these results clearly demonstrate the ability of reversine to dedifferentiation of long-term cryopreserved somatic cells through activation of pluripotent gene Oct4. PMID:26722217

  14. Minocycline attenuates microglia activation and blocks the long-term epileptogenic effects of early-life seizures.

    PubMed

    Abraham, Jayne; Fox, Patrick D; Condello, Carlo; Bartolini, Alyssa; Koh, Sookyong

    2012-05-01

    Innate immunity mediated by microglia appears to play a crucial role in initiating and propagating seizure-induced inflammatory responses. To address the role of activated microglia in the pathogenesis of childhood epilepsy, we first examined the time course of microglia activation following kainic acid-induced status epilepticus (KA-SE) in Cx3cr1(GFP/+) transgenic mice whose microglia are fluorescently labeled. We then determined whether this seizure-induced microglia activation primes the central immune response to overreact and to increase the susceptibility to a second seizure later in life. We used an inhibitor of microglia activation, minocycline, to block the seizure-induced inflammation to determine whether innate immunity plays a causal role in mediating the long-term epileptogenic effects of early-life seizure. First status epilepticus was induced at postnatal day (P) 25 and a second status at P39. KA-SE at P25 caused nearly a two-fold increase in microglia activation within 24h. Significant seizure-induced activation persisted for 7 days and returned to baseline by 14 days. P39 animals with prior exposure to KA-SE not only responded with greater microglial activation in response to "second hit" of KA, but shorter latency to express seizures. Inhibition of seizure-induced inflammation by 7 day minocycline post-treatment abrogated both the exaggerated microglia activation and the increased susceptibility to the second seizure later in life. The priming effect of early-life seizures is accompanied by modified and rapidly reactivated microglia. Our results suggest that anti-inflammatory therapy after SE may be useful to block the epileptogenic process and mitigate the long-term damaging effects of early-life seizures. PMID:22366182

  15. Weight training, aerobic physical activities, and long-term waist circumference change in men

    PubMed Central

    Mekary, Rania A.; Grøntved, Anders; Despres, Jean-Pierre; De Moura, Leandro Pereira; Asgarzadeh, Morteza; Willett, Walter C.; Rimm, Eric B.; Giovannucci, Edward; Hu, Frank B.

    2014-01-01

    Objective Findings on weight training and waist circumference (WC) change are controversial. This study examined prospectively whether weight training, moderate-to-vigorous aerobic activity (MVAA), and replacement of one activity for another were associated with favorable changes in WC and body weight (BW). Methods Physical activity, WC, and BW were reported in 1996 and 2008 in a cohort of 10,500 healthy U.S. men in the Health Professionals Follow-up Study. We used multiple linear regression models (partition/substitution) to assess these associations. Results After adjusting for potential confounders, we observed a significant inverse dose-response relationship between weight training and WC change (P-trend<0.001). Less age-associated WC increase was seen with a 20 min/day activity increase; this benefit was significantly stronger for weight training (-0.67cm, 95%CI -0.93, -0.41) than for MVAA (-0.33cm, 95%CI -0.40, -0.27), other activities (-0.16cm, 95%CI -0.28, -0.03), or TV watching (0.08cm, 95%CI 0.05, 0.12). Substituting 20 min/day of weight training for any other discretionary activity had the strongest inverse association with WC change. MVAA had the strongest inverse association with BW change (-0.23kg, 95%CI -0.29, -0.17). Conclusions Among various activities, weight training had the strongest association with less WC increase. Studies on frequency /volume of weight training and WC change are warranted. PMID:25530447

  16. Predictors of long-term change of a physical activity promotion programme in primary care

    PubMed Central

    2014-01-01

    Background Further research is needed to improve the evidence regarding determinants of physical activity (PA) as a crucial step to plan higher effective intervention strategies. The goal of the present study is to identify socio-demographic and clinical characteristics of primary care (PHC) insufficiently active patients that are associated with longitudinal changes in the level of physical activity. Methods Longitudinal analysis of baseline socio-demographic and clinical predictors of physical activity change in insufficiently active PHC patients who participated in a PA-promoting multi-centre randomized clinical trial conducted from October 2003 through March 2006. The primary outcome measure was the self-reported physical activity assessed with the 7-day Physical Activity Recall (PAR), at baseline, 6, 12 and 24 months. Baseline covariates included sex, age, social class, anthropometric measures and other cardiovascular risk factors or associated diseases (Diabetes, HTA, tobacco use, etc.), and stage of readiness to change PA. Generalized linear mixed models were used to estimate longitudinal association of studied variables on PA change over the three follow-up measurements. Results A total of 3691 patients (85% of the 4317 recruited in the trial) with at least one follow-up measurement were included in the longitudinal analysis. At baseline, analysed patients (mean age: 50.6 years; 64.6% women) devoted 34.7 minutes and 2.36 metabolic equivalent hours per week (MET.h/week) to moderate and vigorous physical activity. Older age, male gender, higher social class, lower BMI, diagnosis of diabetes or hypertension, and measurement season were significant predictors of PA longitudinal change. The effect of baseline readiness to change on PA dose was modified by time, showing a positive gradient in favour of those with more readiness to change that increases significantly at 12 and 24 months (p-value interaction < .0001). Conclusions Identified baseline

  17. Urease immobilized polymer hydrogel: Long-term stability and enhancement of enzymatic activity.

    PubMed

    Kutcherlapati, S N Raju; Yeole, Niranjan; Jana, Tushar

    2016-02-01

    A method has been developed in which an enzyme namely urease was immobilized inside hydrogel matrix to study the stability and enzymatic activity in room temperature (∼27-30°C). This urease coupled hydrogel (UCG) was obtained by amine-acid coupling reaction and this procedure is such that it ensured the wider opening of mobile flap of enzyme active site. A systematic comparison of urea-urease assay and the detailed kinetic data clearly revealed that the urease shows activity for more than a month when stored at ∼27-30°C in case of UCG whereas it becomes inactive in case of free urease (enzyme in buffer solution). The aqueous microenvironment inside the hydrogel, unusual morphological features and thermal behaviour were believed to be the reasons for unexpected behaviour. UCG displayed enzyme activity at basic pH and up to 60°C. UCG showed significant enhancement in activity against thermal degradation compared to free urease. In summary, this method is a suitable process to stabilize the biomacromolecules in standard room temperature for many practical uses.

  18. Urease immobilized polymer hydrogel: Long-term stability and enhancement of enzymatic activity.

    PubMed

    Kutcherlapati, S N Raju; Yeole, Niranjan; Jana, Tushar

    2016-02-01

    A method has been developed in which an enzyme namely urease was immobilized inside hydrogel matrix to study the stability and enzymatic activity in room temperature (∼27-30°C). This urease coupled hydrogel (UCG) was obtained by amine-acid coupling reaction and this procedure is such that it ensured the wider opening of mobile flap of enzyme active site. A systematic comparison of urea-urease assay and the detailed kinetic data clearly revealed that the urease shows activity for more than a month when stored at ∼27-30°C in case of UCG whereas it becomes inactive in case of free urease (enzyme in buffer solution). The aqueous microenvironment inside the hydrogel, unusual morphological features and thermal behaviour were believed to be the reasons for unexpected behaviour. UCG displayed enzyme activity at basic pH and up to 60°C. UCG showed significant enhancement in activity against thermal degradation compared to free urease. In summary, this method is a suitable process to stabilize the biomacromolecules in standard room temperature for many practical uses. PMID:26520823

  19. Can administrative data identify active diagnoses for long-term care resident assessment?

    PubMed

    Berlowitz, Dan R; Hickey, Elaine C; Saliba, Debra

    2010-01-01

    Many veterans receive rehabilitation services in Department of Veterans Affairs (VA) nursing homes. Efficient methods for the identification of active diagnoses could facilitate care planning and outcomes assessment. We set out to determine whether diagnostic data from VA databases can be used to identify active diagnoses for Minimum Data Set (MDS) assessments. We evaluated diagnoses being considered for inclusion in MDS version 3.0 and present in at least 15% of a sample of VA nursing home residents. A research nurse following a standardized protocol identified active diagnoses from the medical records of 120 residents. A clinical nurse also identified active diagnoses in 58 of these patients. Inpatient and outpatient diagnoses from the VA National Patient Care Database were identified for the past year. We calculated kappa, sensitivity, and specificity values, considering the nurses' assessments the gold standard. We found that kappa values comparing research nurses and databases were generally poor, with only 8 of the 19 diagnoses having a value >0.60. Levels of agreement between the clinical nurse and administrative data were generally similar. We conclude that VA administrative data cannot be used to accurately identify active diagnoses for nursing home residents. How best to efficiently collect these important data remains uncertain.

  20. Predator and prey activity levels jointly influence the outcome of long-term foraging bouts

    PubMed Central

    2013-01-01

    Consistent interindividual differences in behavior (i.e., “behavioral types”) may be a key factor in determining the outcome of species interactions. Studies that simultaneously account for the behavioral types of individuals in multiple interacting species, such as predator–prey systems, may be particularly strong predictors of ecological outcomes. Here, we test the predator–prey locomotor crossover hypothesis, which predicts that active predators are more likely to encounter and consume prey with the opposing locomotor tendency. We test this hypothesis using intraspecific behavioral variation in both a predator and prey species as predictors of foraging outcomes. We use the old field jumping spider, Phidippus clarus (Araneae, Salticidae), and the house cricket, Acheta domesticus (Orthoptera, Gryllidae), as a model predator–prey system in laboratory mesocosm trials. Stable individual differences in locomotor tendencies were identified in both P. clarus and A. domesticus, and the outcome of foraging bouts depended neither on the average activity level of the predator nor on the average activity level of prey. Instead, an interaction between the activity level of spiders and crickets predicted spider foraging success and prey survivorship. Consistent with the locomotor crossover hypothesis, predators exhibiting higher activity levels consumed more prey when in an environment containing low-activity prey items and vice versa. This study highlights 1) the importance of intraspecific variation in determining the outcome of predator–prey interactions and 2) that acknowledging behavioral variation in only a single species may be insufficient to characterize the performance consequences of intraspecific trait variants. PMID:23935257

  1. Renal responses to long-term carotid baroreflex activation therapy in patients with drug-resistant hypertension.

    PubMed

    Alnima, Teba; de Leeuw, Peter W; Tan, Frans E S; Kroon, Abraham A

    2013-06-01

    Carotid baroreflex activation has been demonstrated to provide enduring reductions in arterial blood pressure. The aim of this study was to investigate the effect of long-term therapy on renal function. A total of 322 patients were enrolled in the Rheos Pivotal Trial. Group 1 consisted of 236 patients who started baroreflex activation therapy 1 month after device implantation, whereas in the 86 patients from group 2 the device was activated 6 months later. Serum creatinine and urine albumin/creatinine ratio were collected at screening (before device activation), and at months 6 and 12. Multilevel statistical analyses were adjusted for various covariables. Serum creatinine increased from 78 to 84 μmol/L, and glomerular filtration rate decreased from 92 to 87 mL/min per 1.73 m(2) in group 1 at month 6 (P<0.05). These values did not change any further after 12 months of therapy. Patients with highest glomerular filtration rate showed the greatest decrease in glomerular filtration. Group 2 showed the same trends as group 1 even before device activation at month 6. Systolic blood pressure reduction seemed to be significantly related to the change in glomerular filtration rate in both groups. Albumin/creatinine ratio did not change in both groups during follow-up. In conclusion, baroreflex activation therapy in hypertensive patients is associated with an initial mild decrease in glomerular filtration rate, which may be considered as a normal hemodynamic response to the drop in blood pressure. Long-term treatment does not result in further decrease in renal function, indicating baroreflex activation as a safe and effective therapy.

  2. Long-Term Norms and Cognitive Structures as Shapers of Television Viewer Activity.

    ERIC Educational Resources Information Center

    Thompson, Margaret; And Others

    1991-01-01

    Describes a study of high school students that examined responses to a music video dealing with teenage pregnancy. Students' motivations for viewing music videos, experiences with sex and pregnancy, and family communication patterns are related to the cognitive activities of thinking about the video content and relating it to their own lives. (20…

  3. Long-Term, Non-Computer, Communication Simulations as Course Integration Activities

    ERIC Educational Resources Information Center

    Hamilton, James P.

    2008-01-01

    This article offers a few guidelines for constructing effective simulations. It presents a sample class activity called simulated public hearing which aims to integrate the various elements of a public speaking course into a more comprehensive whole. Properly designed, simulated hearings have elements of persuasive, informative, and impromptu…

  4. Hippocampal inactivation with TTX impairs long-term spatial memory retrieval and modifies brain metabolic activity.

    PubMed

    Conejo, Nélida María; Cimadevilla, José Manuel; González-Pardo, Héctor; Méndez-Couz, Marta; Arias, Jorge Luis

    2013-01-01

    Functional inactivation techniques enable studying the hippocampal involvement in each phase of spatial memory formation in the rat. In this study, we applied tetrodotoxin unilaterally or bilaterally into the dorsal hippocampus to evaluate the role of this brain structure in retrieval of memories acquired 28 days before in the Morris water maze. We combined hippocampal inactivation with the assessment of brain metabolism using cytochrome oxidase histochemistry. Several brain regions were considered, including the hippocampus and other related structures. Results showed that both unilateral and bilateral hippocampal inactivation impaired spatial memory retrieval. Hence, whereas subjects with bilateral hippocampal inactivation showed a circular swim pattern at the side walls of the pool, unilateral inactivation favoured swimming in the quadrants adjacent to the target one. Analysis of cytochrome oxidase activity disclosed regional differences according to the degree of hippocampal functional blockade. In comparison to control group, animals with bilateral inactivation showed increased CO activity in CA1 and CA3 areas of the hippocampus during retrieval, while the activity of the dentate gyrus substantially decreased. However, unilateral inactivated animals showed decreased CO activity in Ammon's horn and the dentate gyrus. This study demonstrated that retrieval recruits differentially the hippocampal subregions and the balance between them is altered with hippocampal functional lesions.

  5. Reviewing or Retrieving: What Activity Best Promotes Long-Term Retention?

    ERIC Educational Resources Information Center

    Lindgren, Paul D.

    2012-01-01

    Research studies repeatedly emphasize the importance of vocabulary capabilities to a large variety of academic activities. This study compared a learning strategy that exclusively involved the visual review of vocabulary word-definition pairs to a strategy that, in addition, prompted participants to attempt free-recall retrieval of words to match…

  6. Activation of MAPK Is Necessary for Long-Term Memory Consolidation Following Food-Reward Conditioning

    ERIC Educational Resources Information Center

    Ribeiro, Maria J.; Schofield, Michael G.; Kemenes, Ildiko; O'Shea, Michael; Kemenes, Gyorgy; Benjamin, Paul R.

    2005-01-01

    Although an important role for the mitogen-activated protein kinase (MAPK) has been established for memory consolidation in a variety of learning paradigms, it is not known if this pathway is also involved in appetitive classical conditioning. We address this question by using a single-trial food-reward conditioning paradigm in the freshwater…

  7. Hippocampal inactivation with TTX impairs long-term spatial memory retrieval and modifies brain metabolic activity.

    PubMed

    Conejo, Nélida María; Cimadevilla, José Manuel; González-Pardo, Héctor; Méndez-Couz, Marta; Arias, Jorge Luis

    2013-01-01

    Functional inactivation techniques enable studying the hippocampal involvement in each phase of spatial memory formation in the rat. In this study, we applied tetrodotoxin unilaterally or bilaterally into the dorsal hippocampus to evaluate the role of this brain structure in retrieval of memories acquired 28 days before in the Morris water maze. We combined hippocampal inactivation with the assessment of brain metabolism using cytochrome oxidase histochemistry. Several brain regions were considered, including the hippocampus and other related structures. Results showed that both unilateral and bilateral hippocampal inactivation impaired spatial memory retrieval. Hence, whereas subjects with bilateral hippocampal inactivation showed a circular swim pattern at the side walls of the pool, unilateral inactivation favoured swimming in the quadrants adjacent to the target one. Analysis of cytochrome oxidase activity disclosed regional differences according to the degree of hippocampal functional blockade. In comparison to control group, animals with bilateral inactivation showed increased CO activity in CA1 and CA3 areas of the hippocampus during retrieval, while the activity of the dentate gyrus substantially decreased. However, unilateral inactivated animals showed decreased CO activity in Ammon's horn and the dentate gyrus. This study demonstrated that retrieval recruits differentially the hippocampal subregions and the balance between them is altered with hippocampal functional lesions. PMID:23724089

  8. Hippocampal Inactivation with TTX Impairs Long-Term Spatial Memory Retrieval and Modifies Brain Metabolic Activity

    PubMed Central

    Conejo, Nélida María; Cimadevilla, José Manuel; González-Pardo, Héctor; Méndez-Couz, Marta; Arias, Jorge Luis

    2013-01-01

    Functional inactivation techniques enable studying the hippocampal involvement in each phase of spatial memory formation in the rat. In this study, we applied tetrodotoxin unilaterally or bilaterally into the dorsal hippocampus to evaluate the role of this brain structure in retrieval of memories acquired 28 days before in the Morris water maze. We combined hippocampal inactivation with the assessment of brain metabolism using cytochrome oxidase histochemistry. Several brain regions were considered, including the hippocampus and other related structures. Results showed that both unilateral and bilateral hippocampal inactivation impaired spatial memory retrieval. Hence, whereas subjects with bilateral hippocampal inactivation showed a circular swim pattern at the side walls of the pool, unilateral inactivation favoured swimming in the quadrants adjacent to the target one. Analysis of cytochrome oxidase activity disclosed regional differences according to the degree of hippocampal functional blockade. In comparison to control group, animals with bilateral inactivation showed increased CO activity in CA1 and CA3 areas of the hippocampus during retrieval, while the activity of the dentate gyrus substantially decreased. However, unilateral inactivated animals showed decreased CO activity in Ammon's horn and the dentate gyrus. This study demonstrated that retrieval recruits differentially the hippocampal subregions and the balance between them is altered with hippocampal functional lesions. PMID:23724089

  9. Long-term aerobic exercise increases redox-active iron through nitric oxide in rat hippocampus.

    PubMed

    Chen, Qian; Xiao, De-Sheng

    2014-01-30

    Adult hippocampus is highly vulnerable to iron-induced oxidative stress. Aerobic exercise has been proposed to reduce oxidative stress but the findings in the hippocampus are conflicting. This study aimed to observe the changes of redox-active iron and concomitant regulation of cellular iron homeostasis in the hippocampus by aerobic exercise, and possible regulatory effect of nitric oxide (NO). A randomized controlled study was designed in the rats with swimming exercise treatment (for 3 months) and/or an unselective inhibitor of NO synthase (NOS) (L-NAME) treatment. The results from the bleomycin-detectable iron assay showed additional redox-active iron in the hippocampus by exercise treatment. The results from nonheme iron content assay, combined with the redox-active iron content, showed increased storage iron content by exercise treatment. NOx (nitrate plus nitrite) assay showed increased NOx content by exercise treatment. The results from the Western blot assay showed decreased ferroportin expression, no changes of TfR1 and DMT1 expressions, increased IRP1 and IRP2 expression, increased expressions of eNOS and nNOS rather than iNOS. In these effects of exercise treatment, the increased redox-active iron content, storage iron content, IRP1 and IRP2 expressions were completely reversed by L-NAME treatment, and decreased ferroportin expression was in part reversed by L-NAME. L-NAME treatment completely inhibited increased NOx and both eNOS and nNOS expression in the hippocampus. Our findings suggest that aerobic exercise could increase the redox-active iron in the hippocampus, indicating an increase in the capacity to generate hydroxyl radicals through the Fenton reactions, and aerobic exercise-induced iron accumulation in the hippocampus might mainly result from the role of the endogenous NO.

  10. Long-term weathering effects on the thermal performance of the Libbey-Owens-Ford (liquid) solar collector

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Thermal performance tests were conducted on the Libbey-Owens-Ford liquid collector, following long term exposure to natural weathering conditions. Visual inspection of the collector, prior to the retest, indicated noticeable clouding of the inner cover glass, probably resulting from outgassing of the insulation. The absorber plate also showed some discoloration. The test results indicated that performance degradation had occurred at inlet temperatures significantly above ambient. The change in the slope of the efficiency curve, from the original data, is a direct indicator of an increase in the collector heat loss coefficient.

  11. Long-term effects of engineered nanoparticles on enzyme activity and functional bacteria in wastewater treatment plants.

    PubMed

    Zheng, Xiong; Huang, Haining; Su, Yinglong; Wei, Yuanyuan; Chen, Yinguang

    2015-01-01

    The pervasive use of engineered nanoparticles (NPs) in a wide range of fields raises concerns about their potential environmental impacts. Previous studies confirmed that some NPs had already entered wastewater treatment plants (WWTPs). Wastewater nutrient removal depends on the metabolisms of activated sludge bacteria and their related key enzymes. Therefore, this study compared the possible influences of Al2O3, SiO2, TiO2, and ZnO NPs on the key enzymes activities and microbial community structures involved in wastewater treatment facilities. It was found that long-term exposure to these NPs significantly affected the microbial communities and changed the relative abundances of key functional bacteria, such as ammonia-oxidizing bacteria. Also, the gene expressions and catalytic activities of essential enzymes, such as ammonia monooxygenase, nitrite oxidoreductase, nitrate reductase, and nitrite reductase, were decreased, which finally resulted in a lower efficiency of biological nitrogen removal.

  12. Long-term effects of engineered nanoparticles on enzyme activity and functional bacteria in wastewater treatment plants.

    PubMed

    Zheng, Xiong; Huang, Haining; Su, Yinglong; Wei, Yuanyuan; Chen, Yinguang

    2015-01-01

    The pervasive use of engineered nanoparticles (NPs) in a wide range of fields raises concerns about their potential environmental impacts. Previous studies confirmed that some NPs had already entered wastewater treatment plants (WWTPs). Wastewater nutrient removal depends on the metabolisms of activated sludge bacteria and their related key enzymes. Therefore, this study compared the possible influences of Al2O3, SiO2, TiO2, and ZnO NPs on the key enzymes activities and microbial community structures involved in wastewater treatment facilities. It was found that long-term exposure to these NPs significantly affected the microbial communities and changed the relative abundances of key functional bacteria, such as ammonia-oxidizing bacteria. Also, the gene expressions and catalytic activities of essential enzymes, such as ammonia monooxygenase, nitrite oxidoreductase, nitrate reductase, and nitrite reductase, were decreased, which finally resulted in a lower efficiency of biological nitrogen removal. PMID:26114277

  13. Effects of drying on nitrification activity in zeoponic medium used for long-term space missions

    NASA Technical Reports Server (NTRS)

    McGilloway, R. L.; Weaver, R. W.

    2004-01-01

    One component of a proposed life support system is the use of zeoponic substrates, which slowly release NH4+ into "soil" solution, for the production of plants. Nitrifying bacteria that convert NH4+ to NO3- are among the important microbial components of these systems. Survival of nitrifying bacteria in dry zeoponic substrates is needed, because the substrate would likely be stored in an air-dry state between croppings. Substrate was enriched for nitrifying bacteria and allowed to air-dry in a laminar flow hood. Stored substrate was analyzed for nitrifier survivability by measuring nitrifier activity at the beginning, 3 days, 1, 2, and 3 weeks. After rewetting, activity was approximately 9 micrograms N g-1 h-1 regardless of storage time. Nitrification rates did not decrease during storage. It seems unlikely that drying between plantings would result in practical reductions in nitrification, and reinoculation with nitrifying bacteria would not be necessary.

  14. Long-Term Global Morphology of Gravity Wave Activity Using UARS Data

    NASA Technical Reports Server (NTRS)

    Eckermann, Stephen D.; Bacmeister, Julio T.; Wu, Dong L.

    1998-01-01

    This is the first quarter's report on research to extract global gravity-wave data from satellite data and to model those observations synoptically. Preliminary analysis of global maps of extracted middle atmospheric temperature variance from the CRISTA instrument is presented, which appear to contain gravity-wave information. Corresponding simulations of global gravity-wave and mountain-wave activity during this mission period are described using global ray-tracing and mountain-wave models, and interesting similarities among simulated data and CRISTA data are noted. Climatological simulations of mesospheric gravity-wave activity using the HWM-03 wind-temperature climatology are also reported, for comparison with UARS MLS data. Preparatory work on modeling of gravity wave observations from space-based platforms and subsequent interpretation of the MLS gravity-wave product are also described. Preliminary interpretation and relation to the research objectives are provided, and further action for the next quarter's research is recommended.

  15. Opioid ligands having delayed long-term antagonist activity: potential pharmacotherapies for opioid abuse.

    PubMed

    Husbands, Stephen M; Lewis, John W

    2003-03-01

    Buprenorphine is a partial agonist at the micro -opioid receptor with long duration of action and also exhibits delayed antagonist activity. Buprenorphine is finding increasing use as a treatment agent for opioid abuse, though its low efficacy is not well tolerated by all addicts. There is interest in developing a higher efficacy version of buprenorphine and in this mini-review some of the ligands recently discovered, that share with buprenorphine a profile of agonism followed by delayed antagonism, are discussed.

  16. Amygdala-ventral striatum circuit activation decreases long-term fear

    PubMed Central

    Correia, Susana S; McGrath, Anna G; Lee, Allison; Graybiel, Ann M; Goosens, Ki A

    2016-01-01

    In humans, activation of the ventral striatum, a region associated with reward processing, is associated with the extinction of fear, a goal in the treatment of fear-related disorders. This evidence suggests that extinction of aversive memories engages reward-related circuits, but a causal relationship between activity in a reward circuit and fear extinction has not been demonstrated. Here, we identify a basolateral amygdala (BLA)-ventral striatum (NAc) pathway that is activated by extinction training. Enhanced recruitment of this circuit during extinction learning, either by pairing reward with fear extinction training or by optogenetic stimulation of this circuit during fear extinction, reduces the return of fear that normally follows extinction training. Our findings thus identify a specific BLA-NAc reward circuit that can regulate the persistence of fear extinction and point toward a potential therapeutic target for disorders in which the return of fear following extinction therapy is an obstacle to treatment. DOI: http://dx.doi.org/10.7554/eLife.12669.001 PMID:27671733

  17. Modelling of RBMK-1500 SNF storage casks activation during very long term storage.

    PubMed

    Narkunas, Ernestas; Smaizys, Arturas; Poskas, Povilas; Ragaisis, Valdas

    2016-09-01

    Existing interim spent nuclear fuel storage facility (SNFSF) at Ignalina nuclear power plant in Lithuania is fully loaded with CASTOR(®)RBMK-1500 and CONSTOR(®)RBMK-1500 storage casks. The planned lifetime of these casks is 50 years and the first loaded cask was moved to the SNFSF in 1999. The start of operation of disposal facility in Lithuania is foreseen later than the planned interim storage ends. So, the possibilities to extend the storage period over 50 years should be considered. Therefore, the casks decommissioning issues should be taken into account, as due to prolonged neutron irradiation casks materials could became activated. This paper presents modelling results of storage casks neutron activation during 300 year storage period. Modelling results show, that after 50 years of storage, side-wall and bottom of CASTOR(®)RBMK-1500 cask are activated above clearance criteria. However, for 100-300 year storage period all of the casks components could be free released. PMID:27344524

  18. Modelling of RBMK-1500 SNF storage casks activation during very long term storage.

    PubMed

    Narkunas, Ernestas; Smaizys, Arturas; Poskas, Povilas; Ragaisis, Valdas

    2016-09-01

    Existing interim spent nuclear fuel storage facility (SNFSF) at Ignalina nuclear power plant in Lithuania is fully loaded with CASTOR(®)RBMK-1500 and CONSTOR(®)RBMK-1500 storage casks. The planned lifetime of these casks is 50 years and the first loaded cask was moved to the SNFSF in 1999. The start of operation of disposal facility in Lithuania is foreseen later than the planned interim storage ends. So, the possibilities to extend the storage period over 50 years should be considered. Therefore, the casks decommissioning issues should be taken into account, as due to prolonged neutron irradiation casks materials could became activated. This paper presents modelling results of storage casks neutron activation during 300 year storage period. Modelling results show, that after 50 years of storage, side-wall and bottom of CASTOR(®)RBMK-1500 cask are activated above clearance criteria. However, for 100-300 year storage period all of the casks components could be free released.

  19. Long-Term Starspot Activity of the Eclipsing Variable System CG Cyg

    NASA Astrophysics Data System (ADS)

    Kozhevnikova, A. V.; Alekseev, I. Yu.; Kozhevnikov, V. P.; Svechnikov, M. A.

    2005-07-01

    Photometric observations of the eclipsing variable system CG Cyg (G9+K3, P=0 d .63), which belongs to a group of short-period, chromospherically active RS CVn type stars with the same type of activity as the sun, have been made over two seasons in 2003 and 2004. The spotting of the star’s surface is modelled using the original observations together with photometric data published since 1965. In every season the spots were concentrated near the equator and covered up to 18% of the star’s entire surface, while the temperature difference between the quiescent photosphere and the spotted regions was 2100 K. Cyclical variations in the total area and average latitude of the spots, as well as flip-flop of the active longitudes, are suspected. Latitudinal drift of the spots during a cycle and differential rotation of the star are discovered. The following orbital elements are obtained: M1 = 0.93 M⊙, M2 = 0.81 M⊙, R1 = 1.01 R⊙, and R2 = 0.82 R⊙.

  20. Amygdala-ventral striatum circuit activation decreases long-term fear

    PubMed Central

    Correia, Susana S; McGrath, Anna G; Lee, Allison; Graybiel, Ann M; Goosens, Ki A

    2016-01-01

    In humans, activation of the ventral striatum, a region associated with reward processing, is associated with the extinction of fear, a goal in the treatment of fear-related disorders. This evidence suggests that extinction of aversive memories engages reward-related circuits, but a causal relationship between activity in a reward circuit and fear extinction has not been demonstrated. Here, we identify a basolateral amygdala (BLA)-ventral striatum (NAc) pathway that is activated by extinction training. Enhanced recruitment of this circuit during extinction learning, either by pairing reward with fear extinction training or by optogenetic stimulation of this circuit during fear extinction, reduces the return of fear that normally follows extinction training. Our findings thus identify a specific BLA-NAc reward circuit that can regulate the persistence of fear extinction and point toward a potential therapeutic target for disorders in which the return of fear following extinction therapy is an obstacle to treatment. DOI: http://dx.doi.org/10.7554/eLife.12669.001

  1. The hippocampus remains activated over the long term for the retrieval of truly episodic memories.

    PubMed

    Harand, Caroline; Bertran, Françoise; La Joie, Renaud; Landeau, Brigitte; Mézenge, Florence; Desgranges, Béatrice; Peigneux, Philippe; Eustache, Francis; Rauchs, Géraldine

    2012-01-01

    The role of the hippocampus in declarative memory consolidation is a matter of intense debate. We investigated the neural substrates of memory retrieval for recent and remote information using functional magnetic resonance imaging (fMRI). 18 young, healthy participants learned a series of pictures. Then, during two fMRI recognition sessions, 3 days and 3 months later, they had to determine whether they recognized or not each picture using the "Remember/Know" procedure. Presentation of the same learned images at both delays allowed us to track the evolution of memories and distinguish consistently episodic memories from those that were initially episodic and then became familiar or semantic over time and were retrieved without any contextual detail. Hippocampal activation decreased over time for initially episodic, later semantic memories, but remained stable for consistently episodic ones, at least in its posterior part. For both types of memories, neocortical activations were observed at both delays, notably in the ventromedial prefrontal and anterior cingulate cortices. These activations may reflect a gradual reorganization of memory traces within neural networks. Our data indicate maintenance and strengthening of hippocampal and cortico-cortical connections in the consolidation and retrieval of episodic memories over time, in line with the Multiple Trace theory (Nadel and Moscovitch, 1997). At variance, memories becoming semantic over time consolidate through strengthening of cortico-cortical connections and progressive disengagement of the hippocampus. PMID:22937055

  2. Assessing the impact of long term frozen storage of faecal samples on protein concentration and protease activity

    PubMed Central

    Morris, Laura S.; Marchesi, Julian R.

    2016-01-01

    Background The proteome is the second axis of the microbiome:host interactome and proteases are a significant aspect in this interaction. They interact with a large variety of host proteins and structures and in many situations are implicated in pathogenesis. Furthermore faecal samples are commonly collected and stored frozen so they can be analysed at a later date. So we were interested to know whether long term storage affected the integrity of proteases and total protein and whether historical native faecal samples were still a viable option for answering research questions around the functional proteome. Methods Faecal samples were collected from 3 healthy volunteers (3 biological replicates) and processed in order to be stored at both − 20 °C and − 80 °C and in a variety of storage buffers. Protein extraction, protein content and protease activity were assessed at the time of collection, after 24 h, 1 week, 1 month, 3 months 6 months and finally 1 year. Results Beadbeating impacted the quantity of protein extracted, while sodium azide did not impact protease assays. Long term storage of extracted proteins showed that both total protein and protease activity were affected when they were stored as extracted protein. Intact faecal samples were shown to maintain both protein levels and protease activity regardless of time and temperature. Conclusions Beadbeating increases the protein and protease activity when extracting from a faecal sample, however, the extracted protein is not stable and activity is lost, even with a suitable storage buffer. The most robust solution is to store the proteins in an intact frozen native faecal matrix and extract at the time of assay or analysis, this approach was shown to be suitable for samples in which, there are low levels of protease activity and which had been frozen for a year. PMID:26853125

  3. In vivo long-term magnetic resonance imaging activity of ferritin-based magnetic nanoparticles versus a standard contrast agent.

    PubMed

    Valero, Elsa; Fiorini, Silvia; Tambalo, Stefano; Busquier, Heriberto; Callejas-Fernández, José; Marzola, Pasquina; Gálvez, Natividad; Domínguez-Vera, José M

    2014-07-10

    New long-circulating maghemite nanoparticles of 4 and 6 nm, coated with an apoferritin protein capsid, exhibit useful properties to act as magnetic resonance imaging (MRI) contrast agents. A full in vivo study of the so-called apomaghemites reveals that their long-term MRI properties are better than those of a standard superparamagnetic iron oxide (SPIO) widely used in biomedical applications. The biodistribution of apomaghemites and standard SPIO was investigated by MRI in mice at two different concentrations, 6 and 2.5 mg of Fe·kg(-1), over 60 days. Significant differences are found at low dose (2.5 mg of Fe·kg(-1)). Thus, whereas apomaghemites are active for MR bioimaging of liver for 45 days, standard SPIO is not effective beyond 7 days. On the basis of our data, we may concluded that apomaghemites can act as new long-term MRI liver contrast agents, allowing first the diagnosis of a liver pathology and then monitoring after treatment without the need for a second injection.

  4. Long-term variations of atmospheric wave activity in the mesosphere and lower thermosphere region over the equatorial Pacific

    NASA Astrophysics Data System (ADS)

    Tsuda, T.; Yoshida, S.; Isoda, F.; Nakamura, T.; Nuryanto, A.; Manurung, S.; Sobari, O.; Vincent, R. A.; Reid, I. M.

    2002-05-01

    We have analyzed long-term variations of the wind velocity variance of ultra-fast Kelvin (UFK) waves (3.0-3.8d) and gravity waves in two wave period ranges; 30-35h (0.7-0.8c/d) and 8-11h(2.1-2.9c/d), in the equatorial mesosphere and lower thermosphere region using meteor wind radar (MWR) observations in Jakarta (JKT) (6°S107°E) from November 1992 to June 1998, as well as two medium frequency (MF) radars at Christmas Island (2°N157°W) and Pontianak (0.03°N109°E) from January 1996 to July 1997. The long-term variations of the wind variance of these waves at JKT showed enhancements twice a year in 1993-1995, mostly coinciding with the westward wind phase of MSAO or the transition period of MSAO from eastward to westward wind. The activity of both UFK and gravity waves became significantly weak in 1996-1997. In particular, the UFK wave variance became simultaneously smaller at JKT and the two MF radar sites, indicating that this peculiar event had a global scale.

  5. Changing patterns of the long-term activity of the intermediate polar V1223 Sgr

    NASA Astrophysics Data System (ADS)

    Šimon, Vojtěch

    2014-11-01

    High and low states represent a large variety of features in the optical activity of some types of cataclysmic variables. Here, we examine them in the intermediate polar V1223 Sgr. We use the photographic observations from the Bamberg Observatory and from Garnavich and Szkody, and the CCD ASAS-3 and NSVS data. One plate or CCD image was usually obtained per night. These data span 78 years. We use the histograms of brightness to set the separation between the high and low states in V1223 Sgr at the level of 13.9 mag(B). The profile of this statistical distribution is dominated by a broad bump with the peak-to-peak amplitude of more than 1 mag(B). This is the result of co-adding various episodes of the high states, sometimes with the brightness varying on a timescale of months even during a single episode. The high state is not any uniquely defined level of brightness. Groups of the low states represent tails from such bumps rather than forming specific levels of brightness. The fuzzy boundaries of the bright side of the statistical distributions of brightness show that the system cannot find equilibrium of the mass transfer even in the high state. We show that V1223 Sgr underwent a large change of its high/low state activity; we ascribe it to the changes of the stellar activity of the donor. The episodes of the low states with mutually similar depth and profile were observed to recur with a cycle of 1092 days in the data mapping the years from 1999 to 2009; this behavior was discordant with the typical recurrence times present before. In our scenario, this cycle is driven by the changing aspect of some structure (e.g. a sequence of star spots migrating across the L1 point) on the donor. Because of the differential rotation of the donor, this configuration cyclically influences the mass flow to the accretion disk.

  6. Squid have nociceptors that display widespread long-term sensitization and spontaneous activity after bodily injury.

    PubMed

    Crook, Robyn J; Hanlon, Roger T; Walters, Edgar T

    2013-06-12

    Bodily injury in mammals often produces persistent pain that is driven at least in part by long-lasting sensitization and spontaneous activity (SA) in peripheral branches of primary nociceptors near sites of injury. While nociceptors have been described in lower vertebrates and invertebrates, outside of mammals there is limited evidence for peripheral sensitization of primary afferent neurons, and there are no reports of persistent SA being induced in primary afferents by noxious stimulation. Cephalopod molluscs are the most neurally and behaviorally complex invertebrates, with brains rivaling those of some vertebrates in size and complexity. This has fostered the opinion that cephalopods may experience pain, leading some governments to include cephalopods under animal welfare laws. It is not known, however, if cephalopods possess nociceptors, or whether their somatic sensory neurons exhibit nociceptive sensitization. We demonstrate that squid possess nociceptors that selectively encode noxious mechanical but not heat stimuli, and that show long-lasting peripheral sensitization to mechanical stimuli after minor injury to the body. As in mammals, injury in squid can cause persistent SA in peripheral afferents. Unlike mammals, the afferent sensitization and SA are almost as prominent on the contralateral side of the body as they are near an injury. Thus, while squid exhibit peripheral alterations in afferent neurons similar to those that drive persistent pain in mammals, robust changes far from sites of injury in squid suggest that persistently enhanced afferent activity provides much less information about the location of an injury in cephalopods than it does in mammals.

  7. Long-term physical activity: an exogenous risk factor for sporadic amyotrophic lateral sclerosis?

    PubMed Central

    Harwood, Ceryl A.; Westgate, Kate; Gunstone, Sue; Brage, Soren; Wareham, Nicholas J.; McDermott, Christopher J.; Shaw, Pamela J.

    2016-01-01

    Abstract Objectives: To conduct a geographically defined, UK-based case-control study, to examine any association between physical activity (PA) and amyotrophic lateral sclerosis (ALS). Methods: A novel historical PA questionnaire was designed, validated, and subsequently administered in individual face-to-face interviews of 175 newly diagnosed sporadic ALS cases and 317 age- and sex-matched community controls. Historical PA energy expenditure and time spent in vigorous-intensity PA were derived from questionnaire data and compared between cases and controls. Results: Participation in an extra 10kJ/kg/day of PA (equivalent to approximately 45minutes brisk walking) was consistently associated with an increased risk of ALS, with the strongest association observed for adulthood exercise-related PA (OR 1.47, 95% CI 1.10-1.97). An extra 10mins/day of vigorous PA was also associated with the odds of ALS (OR 1.03, 95% CI 1·01-1·05). Results were slightly attenuated following adjustment for smoking and educational attainment. Conclusions: To our knowledge this is the first study to demonstrate a positive association between ALS and PA participation using a specifically designed and validated historical PA questionnaire. Despite the well-established health benefits of PA, a high activity lifestyle may also be associated with elevated risk of ALS. Large-scale prospective studies in the future may help to confirm this association. PMID:26998882

  8. A Wearable Patch to Enable Long-Term Monitoring of Environmental, Activity and Hemodynamics Variables.

    PubMed

    Etemadi, Mozziyar; Inan, Omer T; Heller, J Alex; Hersek, Sinan; Klein, Liviu; Roy, Shuvo

    2016-04-01

    We present a low power multi-modal patch designed for measuring activity, altitude (based on high-resolution barometric pressure), a single-lead electrocardiogram, and a tri-axial seismocardiogram (SCG). Enabled by a novel embedded systems design methodology, this patch offers a powerful means of monitoring the physiology for both patients with chronic cardiovascular diseases, and the general population interested in personal health and fitness measures. Specifically, to the best of our knowledge, this patch represents the first demonstration of combined activity, environmental context, and hemodynamics monitoring, all on the same hardware, capable of operating for longer than 48 hours at a time with continuous recording. The three-channels of SCG and one-lead ECG are all sampled at 500 Hz with high signal-to-noise ratio, the pressure sensor is sampled at 10 Hz, and all signals are stored to a microSD card with an average current consumption of less than 2 mA from a 3.7 V coin cell (LIR2450) battery. In addition to electronic characterization, proof-of-concept exercise recovery studies were performed with this patch, suggesting the ability to discriminate between hemodynamic and electrophysiology response to light, moderate, and heavy exercise. PMID:25974943

  9. Long-term effect of continuing sports activity in competitive athletes with frequent ventricular premature complexes and apparently normal heart.

    PubMed

    Delise, Pietro; Sitta, Nadir; Lanari, Emanuela; Berton, Giuseppe; Centa, Monica; Allocca, Giuseppe; Cati, Arianna; Biffi, Alessandro

    2013-11-01

    The long-term outcome of athletes with frequent ventricular premature complexes (VPCs) and apparently normal heart has not been fully clarified. To evaluate the clinical and prognostic significance of VPCs and the influence of continuing sports activity during follow-up, we studied 120 healthy athletes (96 men; median age 16 years) in whom frequent VPCs (>100 VPCs/24 hours) were discovered by chance during preparticipation screening. All athletes were followed up for a median of 84 months. During follow-up, 96 underwent serial 24-hour Holter recording and 62 underwent serial echocardiography. The median number of VPCs/24 hours on basal Holter was 3,760. During follow-up, 81 athletes continued sports activity, whereas 39 did not. No athlete died or developed overt heart disease. The median number of VPCs/24 hours decreased in both athletes who continued sports activity and those who did not (from 3,805 to 1,124, p <0.0001 and from 5,787 to 1,298, p <0.0001, respectively). During follow-up, left ventricular ejection fraction slightly decreased to <55% in 9 of 62 athletes who, in respect to the remaining 53, had more VPCs/24 hours both in the basal state (12,000 vs 3,880) and during follow-up (10,702 vs 1,368), and a longer follow-up (95 vs 36 months). In conclusion, (1) frequent VPCs in athletes without heart disease have a long-term benign prognostic significance, (2) sporting activity does not modify this benign outcome, (3) during follow-up, the burden of VPCs decreases whether or not subjects continue sports activity, and (4) in 14.5% of athletes, ejection fraction slightly decreases over time.

  10. Implications of subzero metabolic activity on long-term microbial survival in terrestrial and extraterrestrial permafrost.

    PubMed

    Amato, Pierre; Doyle, Shawn M; Battista, John R; Christner, Brent C

    2010-10-01

    The survival of microorganisms over extended time frames in frozen subsurface environments may be limited by chemical (i.e., via hydrolysis and oxidation) and ionizing radiation-induced damage to chromosomal DNA. In an effort to improve estimates for the survival of bacteria in icy terrestrial and extraterrestrial environments, we determined rates of macromolecular synthesis at temperatures down to -15°C in bacteria isolated from Siberian permafrost (Psychrobacter cryohalolentis K5 and P. arcticus 273-4) and the sensitivity of P. cryohalolentis to ionizing radiation. Based on experiments conducted over ≈400 days at -15°C, the rates of protein and DNA synthesis in P. cryohalolentis were <1 to 16 proteins cell(-1) d(-1) and 83 to 150 base pairs (bp) cell(-1) d(-1), respectively; P. arcticus synthesized DNA at rates of 20 to 1625 bp cell(-1) d(-1) at -15°C under the conditions tested. The dose of ionizing radiation at which 37% of the cells survive (D(37)) of frozen suspensions of P. cryohalolentis was 136 Gy, which was ∼2-fold higher (71 Gy) than identical samples exposed as liquid suspensions. Laboratory measurements of [(3)H]thymidine incorporation demonstrate the physiological potential for DNA metabolism at -15°C and suggest a sufficient activity is possible to offset chromosomal damage incurred in near-subsurface terrestrial and martian permafrost. Thus, our data imply that the longevity of microorganisms actively metabolizing within permafrost environments is not constrained by chromosomal DNA damage resulting from ionizing radiation or entropic degradation over geological time.

  11. Long-term benefit of PD-L1 blockade in lung cancer associated with JAK3 activation

    PubMed Central

    Van Allen, Eliezer M.; Golay, Hadrien G.; Liu, Yan; Koyama, Shohei; Wong, Karrie; Taylor-Weiner, Amaro; Giannakis, Marios; Harden, Maegan; Rojas-Rudilla, Vanesa; Chevalier, Aaron; Thai, Tran; Lydon, Christine; Mach, Stacy; Wong, Joshua A.; Rabin, Alexandra R.; Helmkamp, Joshua; Sholl, Lynette; Carter, Scott L.; Oxnard, Geoffrey; Janne, Pasi; Getz, Gad; Lindeman, Neal; Hammerman, Peter S.; Garraway, Levi A.; Hodi, F. Stephen; Rodig, Scott; Dranoff, Glenn; Wong, Kwok-Kin; Barbie, David A.

    2015-01-01

    PD-1 immune checkpoint blockade occasionally results in durable clinical responses in advanced metastatic cancers. However, mechanism-based predictors of response to this immunotherapy remain incompletely characterized. We performed comprehensive genomic profiling on a tumor and germline sample from a patient with refractory lung adenocarcinoma who achieved marked long-term clinical benefit from anti-PD-L1 therapy. We discovered activating somatic and germline amino acid variants in JAK3 that promoted PD-L1 induction in lung cancer cells and in the tumor immune microenvironment. These findings suggest that genomic alterations that deregulate cytokine receptor signal transduction could contribute to PD-L1 activation and engagement of the PD-1 immune checkpoint in lung cancer. PMID:26014096

  12. Long Term Optical and Infrared Reverberation Mapping of High and Low Luminosity Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Gorjian, Varoujan; Barth, Aaron; Brandt, Niel; Dawson, Kyle; Green, Paul; Ho, Luis; Horne, Keith; Jiang, Linhua; Joner, Mike; Kenney, John; McGreer, Ian; Nordgren, Tyler; Schneider, Donald; Shen, Yue; Tao, Charling

    2016-08-01

    Previous Spitzer reverberation monitoring projects looking for UV/optical light absorbed and re-emitted in the IR by dust have been limited to very low luminosity active galactic nuclei (AGN) that could potentially show reverberation within a single cycle (~1 year). Cycle 11-12's two year baseline allowed for the reverberation mapping of 17 high luminosity quasars from the Sloan Digital Sky Survey Reverberation Mapping project. By combining ground based monitoring from Pan-STARRS, CFHT, and Steward Observatory telescopes with Spitzer data we have for the first time detected dust reverberation in quasars. We propose to continue this project to capitalize on the continuing optical motnoring from the ground and to increase the confidence in the detected lags. Additionally, the Call for Proposals asks for up to 1000 hours of observations in the Spitzer CVZ to accommodate battery charging needs. We propose to add to our quasar sample five lower luminosity Seyfert galaxies from the Pan-STARRS ground based optical survey that are in the Spitzer CVZ, which will increase the luminosity range of AGN we are studying and, combined with additional ground based observatories, provide for a continuous monitoring campaign lasting 2 years and thus provide the most detailed study of dust around AGN to date.

  13. Long term validation of Robust Satellite Techniques (RST) for thermal volcanic activity monitoring

    NASA Astrophysics Data System (ADS)

    Marchese, Francesco; Filizzola, Carolina; Genzano, Nicola; Mazzeo, Giuseppe; Paciello, Rossana; Pergola, Nicola; Tramutoli, Valerio

    2010-05-01

    A multi-temporal scheme of satellite data analysis, named RST (Robust Satellite Techniques), already successfully used to study and monitor several active volcanoes, has recently been tested on a long time series of NOAA-AVHRR records acquired over Mount Etna area for a full assessment of its performances. Satellite records acquired at different time of pass (e.g. day/night, winter/summer), from 1995 to 2008 (14 years of satellite records analyzed), processed following RST prescriptions, have been strictly validated using ground based information reported in the volcano bulletins freely available on the web. In this work results of this detailed validation analysis will be presented, discussing performances of such an approach for an automatic satellite monitoring of thermal volcanic features. Moreover, RST capabilities in detecting even abrupt changes in thermal signal related to the beginning of new eruptive events, by using data provided by geostationary satellite like MSG-SEVIRI, will be investigated, for a possible implementation of such an approach within an integrated Early Warning System devoted to volcanic hazard mitigation.

  14. Long-term variability of active galactic nuclei from the "Planck" catalog

    NASA Astrophysics Data System (ADS)

    Volvach, A. E.; Kardashev, N. S.; Larionov, M. G.; Volvach, L. N.

    2016-07-01

    A complete sample of 104 bright active galactic nuclei (AGNs) from the "Planck" catalog (early results) were observed at 36.8 GHz with the 22-m radio telescope of the Crimean Astrophysical Observatory (CrAO).Variability indices of the sources at this frequency were determined based on data from theWMAP space observatory, theMetsa¨ hovi RadioObservatory (Finland), and the CrimeanAstrophysical Observatory. New observational results confirm that the variability of these AGNs is stronger in the millimeter than at other radio wavelengths. The variability indices probably change as a result of the systematic decrease in the AGN flux densities in the transition to the infrared. Some radio sources demonstrate significant flux-density variations, including decreases, which sometimes cause them to fall out of the analysed sample. The change of the variability index in the millimeter is consistent with the suggestion that this variability is due to intrinsic processes in binary supermassive black holes at an evolutionary stage close to coalescence. All 104 of the sources studied are well known objects that are included in various radio catalogs and have flux densities exceeding 1 Jy at 36.8 GHz.

  15. Long-term activation of the innate immune system in atherosclerosis.

    PubMed

    Christ, Anette; Bekkering, Siroon; Latz, Eicke; Riksen, Niels P

    2016-08-01

    Efforts to reverse the pathologic consequences of vulnerable plaques are often stymied by the complex treatment resistant pro-inflammatory environment within the plaque. This suggests that pro-atherogenic stimuli, such as LDL cholesterol and high fat diets may impart longer lived signals on (innate) immune cells that persist even after reversing the pro-atherogenic stimuli. Recently, a series of studies challenged the traditional immunological paradigm that innate immune cells cannot display memory characteristics. Epigenetic reprogramming in these myeloid cell subsets, after exposure to certain stimuli, has been shown to alter the expression of genes upon re-exposure. This phenomenon has been termed trained innate immunity or innate immune memory. The changed responses of 'trained' innate immune cells can confer nonspecific protection against secondary infections, suggesting that innate immune memory has likely evolved as an ancient mechanism to protect against pathogens. However, dysregulated processes of immunological imprinting mediated by trained innate immunity may also be detrimental under certain conditions as the resulting exaggerated immune responses could contribute to autoimmune and inflammatory diseases, such as atherosclerosis. Pro-atherogenic stimuli most likely cause epigenetic modifications that persist for prolonged time periods even after the initial stimulus has been removed. In this review we discuss the concept of trained innate immunity in the context of a hyperlipidemic environment and atherosclerosis. According to this idea the epigenome of myeloid (progenitor) cells is presumably modified for prolonged periods of time, which, in turn, could evoke a condition of continuous immune cell over-activation.

  16. Long-term Global Morphology of Gravity Wave Activity Using UARS Data

    NASA Technical Reports Server (NTRS)

    Eckermann, Stephen D.; Jackman, C. (Technical Monitor)

    2000-01-01

    An extensive body of research this quarter is documented. Further methodical analysis of temperature residuals in Cryogenic Limb Array Etalon Spectrometer (CLAES) Version 8 level 3AT data show signatures during December 1992 at middle and high northern latitudes that, when compared to Naval Research Laboratory/Mountain Wave Forecast Model (NRL)/(MWFM) mountain wave hindcasts, reveal evidence of long mountain waves in these data over Eurasia, Greenland, Scandinavia and North America. The explicit detection of gravity waves in limb-scanned Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) temperatures is modeled at length, to derive visibility functions. These insights are used to convert CRISTA gravity wave temperature residuals into data that more closely resemble gravity wave fluctuations detected in data from other satellite instruments, such as Microwave Limb Sounder (MLS), Limb Infrared Monitor of the Stratosphere (LIMS) and Global Positioning System/Meteorology (GPS)/(MET). Finally, newly issued mesospheric temperatures from inversion of CRISTA 15gin emissions are analyzed using a new method that uses separate Kalman fits to the ascending and descending node data. This allows us to study global gravity wave amplitudes at two local times, 12 hours apart. In the equatorial mesosphere, where a large diurnal tidal temperature signal exists, we see modulations of gravity wave activity that are consistent with gravity wave-tidal interactions produced by tidal temperature variability.

  17. LONG-TERM OPTICAL CONTINUUM COLOR VARIABILITY OF NEARBY ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Sakata, Yu; Minezaki, Takeo; Yoshii, Yuzuru; Uchimoto, Yuka Katsuno; Sugawara, Shota; Kobayashi, Yukiyasu; Koshida, Shintaro; Aoki, Tsutomu; Tomita, Hiroyuki; Enya, Keigo; Suganuma, Masahiro

    2010-03-01

    We examine whether the spectral energy distribution of optical continuum emission of active galactic nuclei (AGNs) changes during flux variation, based on accurate and frequent monitoring observations of 11 nearby Seyfert galaxies and QSOs carried out in the B, V, and I bands for seven years by the MAGNUM telescope. The multi-epoch flux data in any two different bands obtained on the same night show a very tight linear flux-to-flux relationship for all target AGNs. The flux of the host galaxy within the photometric aperture is carefully estimated by surface brightness fitting to available high-resolution Hubble Space Telescope images and MAGNUM images. The flux of narrow emission lines in the photometric bands is also estimated from available spectroscopic data. We find that the non-variable component of the host galaxy plus narrow emission lines for all target AGNs is located on the fainter extension of the linear regression line of multi-epoch flux data in the flux-to-flux diagram. This result strongly indicates that the spectral shape of AGN continuum emission in the optical region ({approx}4400-7900 A) does not systematically change during flux variation. The trend of spectral hardening that optical continuum emission becomes bluer as it becomes brighter, which has been reported by many studies, is therefore interpreted as the domination of the variable component of the nearly constant spectral shape of an AGN as it brightens over the non-variable component of the host galaxy plus narrow lines, which is usually redder than AGN continuum emission.

  18. Long term monitoring of geomorphological changes caused by torrent activity using terrestrial laser scanning

    NASA Astrophysics Data System (ADS)

    Prokop, A.; Chiari, M.

    2012-04-01

    Torrential processes present a serious hazard in alpine regions. Especially sediment transport is responsible for most torrent related damages. The material incorporated in torrents is inherently complex, varying from clay sized solids to boulders of several meters of diameter. For geoscientists it is important to predict possible triggering zones and deposition areas or run out lengths. Run out analysis is an especially important component for hazard assessment in alpine watersheds, which includes prediction of potential hazard areas and mapping the distribution of hazard intensity parameters such as the thickness of the deposit. In this study terrestrial laser scanning has been applied to investigate the spatial distribution of erosion and deposition of bed load material over a 4000 m long reach of a torrent. Within the monitoring period a new open check dam was built at the study site after removing the old one. Due to the open construction it was expected, that during flood events sediment is stored behind the check dam, but during smaller flood events the deposition area should be self-emptied again. The measurements were carried out to investigate if the new check dam functioned as expected. Therefore the reach has been scanned 6 times during the last 3 years. Several monitoring activities before and after torrent events required global data registration using differential GPS. Tachymetry connected areas with missing GPS reception to GPS measured ones. Terrestrial laser scanning provided dense 3d-data. The RIEGL LMS-Z420i was chosen due to its long range, high accuracy and high scanning speed of the measurements. The accuracy of the measurement was in a range of 8 cm. The objectives of the TLS survey of the torrent deposit were to determine the volume of the deposited mass as well as to detect zones of erosion and deposition of material by the creation of high resolution DEM's. The results of the measurements taken at the test site in Carinthia, Austria are

  19. Effect of long-term unilateral activity on bone mineral density of female junior tennis players.

    PubMed

    Haapasalo, H; Kannus, P; Sievänen, H; Pasanen, M; Uusi-Rasi, K; Heinonen, A; Oja, P; Vuori, I

    1998-02-01

    distal radius), no significant BMD differences were found between the players and controls in any Tanner stage. In the correlation analysis, the Tanner I and II players (mean ages 9.4 and 10.8 years) showed no significant associations between any of the predictive variables and the side-to-side BMD differences, while in Tanner stages III, IV, and V, such associations could be found; the total amount of training hours during the playing career and the number of training sessions per week showed a significant and systematic correlation (rs ranging from 0.43 to 0.80) with the side-to-side BMD differences in several measured bone sites. In conclusion, this study suggests that in a majority of female junior tennis players, the benefit of unilateral activity on bone density does not become clearly evident until the adolescent growth spurt or Tanner stage III. The total amount of training during the player's career and the current training frequency (sessions per week) seem to best explain the training effect on bone tissue, leaving, however, room for speculation on the still unknown factors that modulate the loading response of a growing bone. PMID:9495526

  20. Characteristics of long-term variation in the amlitude of the geomagnetic solar quiet (Sq) daily variation using the Inter-university Upper atmosphere Gobal Observation NETwork (IUGONET) data analysis system

    NASA Astrophysics Data System (ADS)

    Shinbori, A.; Koyama, Y.; Nose, M.; Hori, T.; Otsuka, Y.; Yatagai, A. I.

    2014-12-01

    Characteristics of long-term variation in the amplitude of solar quiet geomagnetic field daily variation (Sq) have been investigated using 1-hour geomagnetic field data obtained from 69 geomagnetic stations in a period of 1947-2013. In the present data analysis, we took advantage of the IUGONET data analysis system. The Sq amplitude clearly showed a 10-12 year solar activity dependence and it tended to enhance during each solar maximum. During the minimum of solar cycle 23/24 in 2008-2009, the Sq amplitude became the smallest in the investigated period. The relationship between the solar F10.7 index and Sq amplitude is approximately linear but 64 percent of geomagnetic stations show a weak nonlinear dependence on the solar F10.7 index. In order to remove the effect of solar activity seen in the long-term variation of the Sq amplitude, we calculated a linear or second order fitting curve between the solar F10.7 index and Sq amplitude during 1947-2013, and examined the residual Sq amplitude, which is defined as the deviation from the fitting curve. As a result, a majority of the trends in the residual Sq amplitude that passed through a trend test showed a negative value in a wide region. This tendency was relatively strong in Europe, India, the eastern part of Canada, and New Zealand. The relationship between the magnetic field intensity and residual Sq amplitude showed an anti-correlation for about 71 percent of geomagnetic stations. On the other hand, the residual Sq amplitude in the equatorial station (Addis Ababa) was anti-correlated with the absolute value of the magnetic field inclination. This implies the movement of the equatorial electrojet due to the secular variation of the ambient magnetic field.

  1. Changes in the long-term hydrological regimes and the impacts of human activities in the main Wei River, China

    NASA Astrophysics Data System (ADS)

    Zhang, Hongbo; Huang, Qiang; Zhang, Qiang; Gu, Lei; Chen, Keyu; Yu, Qijun

    2016-03-01

    Under the combined influence of climate changes and human activities, the hydrological regime of the Wei River shows remarkable variations which have caused many issues in the Wei River in recent decades, such as a lack of freshwater, water pollution, disastrous flooding and channel sedimentation. Hence, hydrological regime changes and potential human-induced impacts have been drawing increasing attention from local government and hydrologists. This study investigates hydrological regime changes in the natural and measured runoff series at four hydrological stations on the main Wei River and quantifies features of their long-term change by analysing their historical annual and seasonal runoff data using several approaches, i.e., continuous wavelet transform, cross-wavelet, wavelet coherence, trend-free pre-whitening Mann-Kendall test and detrended fluctuation analysis. By contrasting two different analysis results between natural and measured river runoff series, the impacts of human activities on the long-term hydrological regime were investigated via the changes of spatio-temporal distribution in dominant periods, the trends and long-range memory of river runoff. The results show : (a) that periodic properties of the streamflow changes are the result of climate, referring to precipitation changes in particular, while human activities play a minor role; (b) a significant decreasing trend can be observed in the natural streamflow series along the entire main stream of the Wei River and the more serious decrease emerging in measured flow should result from human-induced influences in recent decades; and (c) continuous decreasing streamflow in the Wei River will trigger serious shortages of freshwater in the future, which may challenge the sustainability and safety of water resources development in the river basin, and should be paid great attention before 2020.

  2. Projections of long-term changes in solar radiation based on CMIP5 climate models and their influence on energy yields of photovoltaic systems

    NASA Astrophysics Data System (ADS)

    Wild, Martin; Folini, Doris; Henschel, Florian; Müller, Björn

    2015-04-01

    Traditionally, for the planning and assessment of solar energy systems, the amount of solar radiation (sunlight) incident on the Earth's surface is assumed to be constant over the years. However, with changing climate and air pollution levels, solar resources may no longer be stable over time and undergo substantial decadal changes. Observational records covering the past decades confirm long-term changes in this quantity. Here we examine, how the latest generation of climate models used for the 5th IPCC report projects potential changes in surface solar radiation over the coming decades, and how this may affect, in combination with the expected greenhouse warming, solar power output from photovoltaic (PV) systems. For this purpose, projections up to the mid 21th century from 39 state of the art climate models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) are analysed globally and for selected key regions with major solar power production capacity. The large model ensemble allows to assess the degree of consistency of their projections. Models are largely consistent in the sign of the projected changes in solar radiation under cloud-free conditions as well as in surface temperatures over most of the globe, while still reasonably consistent over a considerable part of the globe in the sign of changes in cloudiness and associated changes in solar radiation. A first order estimate of the impact of solar radiation and temperature changes on energy yields of PV systems under the RPC8.5 scenario indicates statistically significant decreases in PV outputs in large parts of the world, but notable exceptions with positive trends in parts of Europe and the South-East of China. Projected changes between 2006 and 2049 under the RCP8.5 scenario overall are on the order of 1 % per decade for horizontal planes, but may be larger for tilted or tracked planes as well as on shorter (decadal) timescales. Related References: Wild, M., Folini, D., Henschel, F., and M

  3. Multi-decade Measurements of the Long-Term Trends of Atmospheric Species by High-Spectral-Resolution Infrared Solar Absorption Spectroscopy

    NASA Technical Reports Server (NTRS)

    Rinsland, Curtis P.; Chiou, Linda; Goldman, Aaron; Hannigan, James W.

    2010-01-01

    Solar absorption spectra were recorded for the first time in 5 years with the McMath Fourier transform spectrometer at the US National solar Observatory on Kitt Peak in southern Arizona, USA (31.91 N latitude, 111.61 W longitude, 2.09 km altitude). The solar absorption spectra cover 750-1300 and 1850-5000 cm(sup -1) and were recorded on 20 days during March-June 2009. The measurements mark the continuation of a long-term record of atmospheric chemical composition measurements that have been used to quantify seasonal cycles and long-term trends of both tropospheric and stratospheric species from observations that began i 1977. Fits to the measured spectra have been performed, and they indicate the spectra obtained since return to operational status are nearly free of channeling and the instrument line shape function is well reproduced taking into account the measurement parameters. We report updated time series measurements of total columns for six atmospheric species and their analysis for seasonal cycles and long-term trends. An sn example, the time series fit shows a decrease in the annual increase rate i Montreal-Protocol-regulated chlorofluorocarbon CCL2F2 from 1.51 plus or minus 0.38% yr(sup -1) at the beginning of the time span to -1.54 plus or minus 1.28 yr(sup -1) at the end of the time span, 1 sigma, and hence provides evidence for the impact of those regulations on the trend.

  4. Metabotropic glutamate receptor 3 activation is required for long-term depression in medial prefrontal cortex and fear extinction.

    PubMed

    Walker, Adam G; Wenthur, Cody J; Xiang, Zixiu; Rook, Jerri M; Emmitte, Kyle A; Niswender, Colleen M; Lindsley, Craig W; Conn, P Jeffrey

    2015-01-27

    Clinical studies have revealed that genetic variations in metabotropic glutamate receptor 3 (mGlu3) affect performance on cognitive tasks dependent upon the prefrontal cortex (PFC) and may be linked to psychiatric conditions such as schizophrenia, bipolar disorder, and addiction. We have performed a series of studies aimed at understanding how mGlu3 influences PFC function and cognitive behaviors. In the present study, we found that activation of mGlu3 can induce long-term depression in the mouse medial PFC (mPFC) in vitro. Furthermore, in vivo administration of a selective mGlu3 negative allosteric modulator impaired learning in the mPFC-dependent fear extinction task. The results of these studies implicate mGlu3 as a major regulator of PFC function and cognition. Additionally, potentiators of mGlu3 may be useful in alleviating prefrontal impairments associated with several CNS disorders. PMID:25583490

  5. Metabotropic glutamate receptor 3 activation is required for long-term depression in medial prefrontal cortex and fear extinction

    PubMed Central

    Walker, Adam G.; Wenthur, Cody J.; Xiang, Zixiu; Rook, Jerri M.; Emmitte, Kyle A.; Niswender, Colleen M.; Lindsley, Craig W.; Conn, P. Jeffrey

    2015-01-01

    Clinical studies have revealed that genetic variations in metabotropic glutamate receptor 3 (mGlu3) affect performance on cognitive tasks dependent upon the prefrontal cortex (PFC) and may be linked to psychiatric conditions such as schizophrenia, bipolar disorder, and addiction. We have performed a series of studies aimed at understanding how mGlu3 influences PFC function and cognitive behaviors. In the present study, we found that activation of mGlu3 can induce long-term depression in the mouse medial PFC (mPFC) in vitro. Furthermore, in vivo administration of a selective mGlu3 negative allosteric modulator impaired learning in the mPFC-dependent fear extinction task. The results of these studies implicate mGlu3 as a major regulator of PFC function and cognition. Additionally, potentiators of mGlu3 may be useful in alleviating prefrontal impairments associated with several CNS disorders. PMID:25583490

  6. Adrenergic α₁ receptor activation is sufficient, but not necessary for phrenic long-term facilitation.

    PubMed

    Huxtable, A G; MacFarlane, P M; Vinit, S; Nichols, N L; Dale, E A; Mitchell, G S

    2014-06-01

    Acute intermittent hypoxia (AIH; three 5-min hypoxic episodes) causes a form of phrenic motor facilitation (pMF) known as phrenic long-term facilitation (pLTF); pLTF is initiated by spinal activation of Gq protein-coupled 5-HT2 receptors. Because α1 adrenergic receptors are expressed in the phrenic motor nucleus and are also Gq protein-coupled, we hypothesized that α1 receptors are sufficient, but not necessary for AIH-induced pLTF. In anesthetized, paralyzed, and ventilated rats, episodic spinal application of the α1 receptor agonist phenylephrine (PE) elicited dose-dependent pMF (10 and 100 μM, P < 0.05; but not 1 μM). PE-induced pMF was blocked by the α1 receptor antagonist prazosin (1 mM; -20 ± 20% at 60 min, -5 ± 21% at 90 min; n = 6). Although α1 receptor activation is sufficient to induce pMF, it was not necessary for AIH-induced pLTF because intrathecal prazosin (1 mM) did not alter AIH-induced pLTF (56 ± 9% at 60 min, 78 ± 12% at 90 min; n = 9). Intravenous (iv) prazosin (150 μg/kg) appeared to reduce pLTF (21 ± 9% at 60 min, 26 ± 8% at 90 min), but this effect was not significant. Hypoglossal long-term facilitation was unaffected by intrathecal prazosin, but was blocked by iv prazosin (-4 ± 14% at 60 min, -13 ± 18% at 90 min), suggesting different LTF mechanisms in different motor neuron pools. In conclusion, Gq protein-coupled α1 adrenergic receptors evoke pMF, but they are not necessary for AIH-induced pLTF.

  7. Long-term gene therapy with thrombospondin 2 inhibits TGF-β activation, inflammation and angiogenesis in chronic allograft nephropathy.

    PubMed

    Daniel, Christoph; Vogelbacher, Regina; Stief, Andrea; Grigo, Christina; Hugo, Christian

    2013-01-01

    We recently identified Thrombospondin-2 (TSP-2) as a regulator of matrix remodelling and inflammation in experimental kidney disease by using TSP-2 null mice and successfully proved TSP-2 overexpression as a therapeutic concept in a short term glomerulonephritis model in the rat. In this current study, we investigated if long-term TSP-2 overexpression is also capable to ameliorate the progression of chronic kidney disease in the setting of the chronic allograft nephropathy F344-Lewis model in the rat. Two weeks after renal transplantation, two rat thigh muscles were transfected once only with either a TSP-2 overexpressing plasmid (n = 8) or a luciferase-expressing plasmid as control (n = 8). Rats were monitored for renal function, histological changes and gene expression in the graft for up to 30 weeks after transplantation. Unexpectedly, only in the TSP-2 treated group 2 rats died before the end of the experiment and renal function tended to be worsened in the TSP-2 group compared to the luciferase-treated controls. In addition, glomerular sclerosis and tubular interstitial injury as well as cortical fibronectin deposition was significantly increased in the TSP-2 treated kidneys despite reduced TGF-β activation and marked anti-inflammatory (macrophages, T-cells and B-cells) effects in this group. Long-term TSP-2 therapy impaired repair of renal endothelium, as demonstrated by significant higher glomerular and peritubular endothelial rarefaction and reduced endothelial cell proliferation in the transplanted kidneys from TSP-2 treated rats compared to controls. This TSP-2 effect was associated with decreased levels of renal VEGF but not VEGF1 receptor. In conclusion, despite its anti-inflammatory and TGF-β activation blocking effects, TSP-2 gene therapy did not ameliorate but rather worsened experimental chronic allograft nephropathy most likely via its anti-angiogenic properties on the renal microvasculature.

  8. Long-Term Gene Therapy with Thrombospondin 2 Inhibits TGF-β Activation, Inflammation and Angiogenesis in Chronic Allograft Nephropathy

    PubMed Central

    Daniel, Christoph; Vogelbacher, Regina; Stief, Andrea; Grigo, Christina; Hugo, Christian

    2013-01-01

    We recently identified Thrombospondin-2 (TSP-2) as a regulator of matrix remodelling and inflammation in experimental kidney disease by using TSP-2 null mice and successfully proved TSP-2 overexpression as a therapeutic concept in a short term glomerulonephritis model in the rat. In this current study, we investigated if long-term TSP-2 overexpression is also capable to ameliorate the progression of chronic kidney disease in the setting of the chronic allograft nephropathy F344-Lewis model in the rat. Two weeks after renal transplantation, two rat thigh muscles were transfected once only with either a TSP-2 overexpressing plasmid (n = 8) or a luciferase-expressing plasmid as control (n = 8). Rats were monitored for renal function, histological changes and gene expression in the graft for up to 30 weeks after transplantation. Unexpectedly, only in the TSP-2 treated group 2 rats died before the end of the experiment and renal function tended to be worsened in the TSP-2 group compared to the luciferase-treated controls. In addition, glomerular sclerosis and tubular interstitial injury as well as cortical fibronectin deposition was significantly increased in the TSP-2 treated kidneys despite reduced TGF-β activation and marked anti-inflammatory (macrophages, T-cells and B-cells) effects in this group. Long-term TSP-2 therapy impaired repair of renal endothelium, as demonstrated by significant higher glomerular and peritubular endothelial rarefaction and reduced endothelial cell proliferation in the transplanted kidneys from TSP-2 treated rats compared to controls. This TSP-2 effect was associated with decreased levels of renal VEGF but not VEGF1 receptor. In conclusion, despite its anti-inflammatory and TGF-β activation blocking effects, TSP-2 gene therapy did not ameliorate but rather worsened experimental chronic allograft nephropathy most likely via its anti-angiogenic properties on the renal microvasculature. PMID:24376766

  9. Indoor test and long-term weathering effects on the thermal performance of the solar energy system (liquid) solar collector. [Marshall Space Flight Center solar test facility and solar simulator

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The procedures used and the results obtained during the evaluation test program on a liquid solar collector are presented. The narrow flat plate collector with reflective concentrating mirrors uses water as the working fluid. The double-covered collector weighs 137 pounds and has overall dimensions of about 35" by 77" by 6.75". The test program was conducted to obtain the following information: thermal performance data under simulated conditions, structural behavior under static load, and the effects of long term exposure to natural weathering.

  10. Pain in long-term breast cancer survivors: the role of body mass index, physical activity, and sedentary behavior.

    PubMed

    Forsythe, Laura P; Alfano, Catherine M; George, Stephanie M; McTiernan, Anne; Baumgartner, Kathy B; Bernstein, Leslie; Ballard-Barbash, Rachel

    2013-01-01

    Although pain is common among post-treatment breast cancer survivors, studies that are longitudinal, identify a case definition of clinically meaningful pain, or examine factors contributing to pain in survivors are limited. This study describes longitudinal patterns of pain in long-term breast cancer survivors, evaluating associations of body mass index (BMI), physical activity, sedentary behavior with mean pain severity and above-average pain. Women newly diagnosed with stages 0-IIIA breast cancer (N = 1183) were assessed, on average, 6 months (demographic/clinical characteristics), 30 months (demographics), 40 months (demographics, pain), 5 years (BMI, physical activity, and sedentary behavior), and 10 years (demographics, pain, BMI, physical activity, and sedentary behavior) post-diagnosis. This analysis includes survivors who completed pain assessments 40 months post-diagnosis (N = 801), 10 years post-diagnosis (N = 563), or both (N = 522). Above-average pain was defined by SF-36 bodily pain scores ≥1/2 standard deviation worse than age-specific population norms. We used multiple regression models to test unique associations of BMI, physical activity, and sedentary behavior with pain adjusting for demographic and clinical factors. The proportion of survivors reporting above-average pain was higher at 10 years than at 40 months (32.3 vs. 27.8 %, p < 0.05). Approximately one-quarter of survivors reported improved pain, while 9.0 % maintained above-average pain and 33.1 % reported worsened pain. Cross-sectionally at 10 years, overweight and obese survivors reported higher pain than normal-weight survivors and women meeting physical activity guidelines were less likely to report above-average pain than survivors not meeting these guidelines (p < 0.05). Longitudinally, weight gain (>5 %) was positively associated, while meeting physical activity guidelines was inversely associated, with above-average pain (OR, 95 % CI = 1.76, 1.03-3.01 and 0.40, 0

  11. Long-term effects of fertilizer on soil enzymatic activity of wheat field soil in Loess Plateau, China.

    PubMed

    Hu, Weigang; Jiao, Zhifang; Wu, Fasi; Liu, Yongjun; Dong, Maoxing; Ma, Xiaojun; Fan, Tinglu; An, Lizhe; Feng, Huyuan

    2014-12-01

    The effects of long-term (29 years) fertilization on local agro-ecosystems in the Loess Plateau of northwest China, containing a single or combinations of inorganic (Nitrogen, N; Phosphate, P) and organic (Mature, M Straw, S) fertilizer, including N, NP, SNP, M, MNP, and a control. The soil enzymes, including dehydrogenase, urease, alkaline phosphatase, invertase and glomalin, were investigated in three physiological stages (Jointing, Dough, and Maturity) of wheat growth at three depths of the soil profile (0-15, 16-30, 31-45 cm). We found that the application of farmyard manure and straw produced the highest values of soil enzymatic activity, especially a balanced applied treatment of MNP. Enzymatic activity was lowest in the control. Values were generally highest at dough, followed by the jointing and maturity stages, and declined with soil profile depth. The activities of the enzymes investigated here are significantly correlated with each other and are correlated with soil nutrients, in particular with soil organic carbon. Our results suggest that a balanced application of fertilizer nutrients and organic manure (especially those containing P) has positive effects on multiple soil chemical parameters, which in turn enhances enzyme activity. We emphasize the role of organic manure in maintaining soil organic matter and promoting biological activity, as its application can result in a substantial increase in agricultural production and can be sustainable for many years.

  12. Long-term effects of fertilizer on soil enzymatic activity of wheat field soil in Loess Plateau, China.

    PubMed

    Hu, Weigang; Jiao, Zhifang; Wu, Fasi; Liu, Yongjun; Dong, Maoxing; Ma, Xiaojun; Fan, Tinglu; An, Lizhe; Feng, Huyuan

    2014-12-01

    The effects of long-term (29 years) fertilization on local agro-ecosystems in the Loess Plateau of northwest China, containing a single or combinations of inorganic (Nitrogen, N; Phosphate, P) and organic (Mature, M Straw, S) fertilizer, including N, NP, SNP, M, MNP, and a control. The soil enzymes, including dehydrogenase, urease, alkaline phosphatase, invertase and glomalin, were investigated in three physiological stages (Jointing, Dough, and Maturity) of wheat growth at three depths of the soil profile (0-15, 16-30, 31-45 cm). We found that the application of farmyard manure and straw produced the highest values of soil enzymatic activity, especially a balanced applied treatment of MNP. Enzymatic activity was lowest in the control. Values were generally highest at dough, followed by the jointing and maturity stages, and declined with soil profile depth. The activities of the enzymes investigated here are significantly correlated with each other and are correlated with soil nutrients, in particular with soil organic carbon. Our results suggest that a balanced application of fertilizer nutrients and organic manure (especially those containing P) has positive effects on multiple soil chemical parameters, which in turn enhances enzyme activity. We emphasize the role of organic manure in maintaining soil organic matter and promoting biological activity, as its application can result in a substantial increase in agricultural production and can be sustainable for many years. PMID:25134679

  13. Preventing Long-Term Risk of Obesity for Two Generations: Prenatal Physical Activity Is Part of the Puzzle

    PubMed Central

    Ruchat, Stephanie-May; Mottola, Michelle F.

    2012-01-01

    Background. The period surrounding pregnancy has been identified as a risk period for overweight/obesity in both mother and child because of excessive gestational weight gain (GWG). The promotion of a healthy GWG is therefore of paramount importance in the context of the prevention of obesity in the current and next generations. Objective. To provide a comprehensive overview of the effect of prenatal physical activity interventions, alone or in combination with nutritional counselling, on GWG and to address whether preventing excessive GWG decreases the incidence of infant high birth weight and/or postpartum weight retention. Method. A search of the PubMed database was conducted to identify all relevant studies. Nineteen studies were included in this review: 13 interventions combining physical activity, nutrition, and GWG counselling and 6 interventions including physical activity alone. Results. Prenatal lifestyle interventions promoting healthy eating and physical activity habits appear to be the most effective approach to prevent excessive GWG. Achievement of appropriate GWG may also decrease the incidence of high infant birth weight and postpartum weight retention. Conclusion. Healthy eating habits during pregnancy, combined with an active lifestyle, may be important elements in the prevention of long-term risk of obesity for two generations. PMID:23316363

  14. Postsynaptic activity reverses the sign of the acetylcholine-induced long-term plasticity of GABAA inhibition

    PubMed Central

    Domínguez, Soledad; Fernández de Sevilla, David; Buño, Washington

    2014-01-01

    Acetylcholine (ACh) regulates forms of plasticity that control cognitive functions but the underlying mechanisms remain largely unknown. ACh controls the intrinsic excitability, as well as the synaptic excitation and inhibition of CA1 hippocampal pyramidal cells (PCs), cells known to participate in circuits involved in cognition and spatial navigation. However, how ACh regulates inhibition in function of postsynaptic activity has not been well studied. Here we show that in rat PCs, a brief pulse of ACh or a brief stimulation of cholinergic septal fibers combined with repeated depolarization induces strong long-term enhancement of GABAA inhibition (GABAA-LTP). Indeed, this enhanced inhibition is due to the increased activation of α5βγ2 subunit-containing GABAA receptors by the GABA released. GABAA-LTP requires the activation of M1-muscarinic receptors and an increase in cytosolic Ca2+. In the absence of PC depolarization ACh triggered a presynaptic depolarization-induced suppression of inhibition (DSI), revealing that postsynaptic activity gates the effects of ACh from presynaptic DSI to postsynaptic LTP. These results provide key insights into mechanisms potentially linked with cognitive functions, spatial navigation, and the homeostatic control of abnormal hyperexcitable states. PMID:24938789

  15. Antitumor activity and long-term fate of chimeric antigen receptor-positive T cells in patients with neuroblastoma.

    PubMed

    Louis, Chrystal U; Savoldo, Barbara; Dotti, Gianpietro; Pule, Martin; Yvon, Eric; Myers, G Doug; Rossig, Claudia; Russell, Heidi V; Diouf, Oumar; Liu, Enli; Liu, Hao; Wu, Meng-Fen; Gee, Adrian P; Mei, Zhuyong; Rooney, Cliona M; Heslop, Helen E; Brenner, Malcolm K

    2011-12-01

    We generated MHC-independent chimeric antigen receptors (CARs) directed to the GD2 antigen expressed by neuroblastoma tumor cells and treated patients with this disease. Two distinguishable forms of this CAR were expressed in EBV-specific cytotoxic T lymphocytes (EBV-CTLs) and activated T cells (ATCs). We have previously shown that EBV-CTLs expressing GD2-CARs (CAR-CTLs) circulated at higher levels than GD2-CAR ATCs (CAR-ATCs) early after infusion, but by 6 weeks, both subsets became low or undetectable. We now report the long-term clinical and immunologic consequences of infusions in 19 patients with high-risk neuroblastoma: 8 in remission at infusion and 11 with active disease. Three of 11 patients with active disease achieved complete remission, and persistence of either CAR-ATCs or CAR-CTLs beyond 6 weeks was associated with superior clinical outcome. We observed persistence for up to 192 weeks for CAR-ATCs and 96 weeks for CAR-CTLs, and duration of persistence was highly concordant with the percentage of CD4(+) cells and central memory cells (CD45RO(+)CD62L(+)) in the infused product. In conclusion, GD2-CAR T cells can induce complete tumor responses in patients with active neuroblastoma; these CAR T cells may have extended, low-level persistence in patients, and such persistence was associated with longer survival. This study is registered at www.clinialtrials.gov as #NCT00085930.

  16. Sports Activity after Low-contact-stress Total Knee Arthroplasty - A long term follow-up study.

    PubMed

    Vielgut, Ines; Leitner, Lukas; Kastner, Norbert; Radl, Roman; Leithner, Andreas; Sadoghi, Patrick

    2016-04-19

    The purpose of this study was to provide comprehensive long-term data about sports activity levels in patients following total knee arthroplasty (TKA) and to determine the impact of pre-operative function, pain and specific performed sports on the results. 236 patients who have undergone TKA for severe osteoarthritis of the knee were asked to provide specific information regarding exercised types of sports before surgery and after at least 10 years following TKA. Pre- and postoperative function and pain were evaluated by the use of Tegner-, WOMAC- and VAS Score. After a mean of 14.9 years, a significant improvement regarding pain and function was observed. Pre-operative Tegner- and WOMAC scores revealed significant positive correlations with the post-operative Tegner-Score. Accordingly, a high percentage of patients (70.9%) stayed actively involved in sports. Nevertheless, the number of performing patients has decreased according to the sports impact. 71.3% continued practising low-impact-, 43.7% intermediate-impact sports whereas only 16.4% kept performing high impact sports. We conclude that TKA is highly effective in long-time pain reduction as well as improvement of function. Additionally, we found considerable sports activities preserved in the investigated series. However, sports activities in particular, seem to decrease according to the impact of sports.

  17. Antitumor activity and long-term fate of chimeric antigen receptor–positive T cells in patients with neuroblastoma

    PubMed Central

    Savoldo, Barbara; Dotti, Gianpietro; Pule, Martin; Yvon, Eric; Myers, G. Doug; Rossig, Claudia; Russell, Heidi V.; Diouf, Oumar; Liu, Enli; Liu, Hao; Wu, Meng-Fen; Gee, Adrian P.; Mei, Zhuyong; Rooney, Cliona M.; Heslop, Helen E.; Brenner, Malcolm K.

    2011-01-01

    We generated MHC-independent chimeric antigen receptors (CARs) directed to the GD2 antigen expressed by neuroblastoma tumor cells and treated patients with this disease. Two distinguishable forms of this CAR were expressed in EBV-specific cytotoxic T lymphocytes (EBV-CTLs) and activated T cells (ATCs). We have previously shown that EBV-CTLs expressing GD2-CARs (CAR-CTLs) circulated at higher levels than GD2-CAR ATCs (CAR-ATCs) early after infusion, but by 6 weeks, both subsets became low or undetectable. We now report the long-term clinical and immunologic consequences of infusions in 19 patients with high-risk neuroblastoma: 8 in remission at infusion and 11 with active disease. Three of 11 patients with active disease achieved complete remission, and persistence of either CAR-ATCs or CAR-CTLs beyond 6 weeks was associated with superior clinical outcome. We observed persistence for up to 192 weeks for CAR-ATCs and 96 weeks for CAR-CTLs, and duration of persistence was highly concordant with the percentage of CD4+ cells and central memory cells (CD45RO+CD62L+) in the infused product. In conclusion, GD2-CAR T cells can induce complete tumor responses in patients with active neuroblastoma; these CAR T cells may have extended, low-level persistence in patients, and such persistence was associated with longer survival. This study is registered at www.clinialtrials.gov as #NCT00085930. PMID:21984804

  18. Sports Activity after Low-contact-stress Total Knee Arthroplasty – A long term follow-up study

    PubMed Central

    Vielgut, Ines; Leitner, Lukas; Kastner, Norbert; Radl, Roman; Leithner, Andreas; Sadoghi, Patrick

    2016-01-01

    The purpose of this study was to provide comprehensive long-term data about sports activity levels in patients following total knee arthroplasty (TKA) and to determine the impact of pre-operative function, pain and specific performed sports on the results. 236 patients who have undergone TKA for severe osteoarthritis of the knee were asked to provide specific information regarding exercised types of sports before surgery and after at least 10 years following TKA. Pre- and postoperative function and pain were evaluated by the use of Tegner-, WOMAC- and VAS Score. After a mean of 14.9 years, a significant improvement regarding pain and function was observed. Pre-operative Tegner- and WOMAC scores revealed significant positive correlations with the post-operative Tegner-Score. Accordingly, a high percentage of patients (70.9%) stayed actively involved in sports. Nevertheless, the number of performing patients has decreased according to the sports impact. 71.3% continued practising low-impact-, 43.7% intermediate-impact sports whereas only 16.4% kept performing high impact sports. We conclude that TKA is highly effective in long-time pain reduction as well as improvement of function. Additionally, we found considerable sports activities preserved in the investigated series. However, sports activities in particular, seem to decrease according to the impact of sports. PMID:27090945

  19. Activation of the transcription factor NF-kappaB by retrieval is required for long-term memory reconsolidation.

    PubMed

    Merlo, Emiliano; Freudenthal, Ramiro; Maldonado, Héctor; Romano, Arturo

    2005-01-01

    Several studies support that stored memories undergo a new period of consolidation after retrieval. It is not known whether this process, termed reconsolidation, requires the same transcriptional mechanisms involved in consolidation. Increasing evidence supports the participation of the transcription factor NF-kappaB in memory. This was initially demonstrated in the crab Chasmagnathus model of associative contextual memory, in which re-exposure to the training context induces a well characterized reconsolidation process. Here we studied the role of NF-kappaB in reconsolidation. NF-kappaB was specifically activated in trained animals re-exposed to the training context but not to a different context. NF-kappaB was not activated when animals were re-exposed to the context after a weak training protocol insufficient to induce long-term memory. A specific inhibitor of the NF-kappaB pathway, sulfasalazine, impaired reconsolidation when administered 20 min before re-exposure to the training context but was not effective when a different context was used. These findings indicate for the first time that NF-kappaB is activated specifically by retrieval and that this activation is required for memory reconsolidation, supporting the view that this molecular mechanism is required in both consolidation and reconsolidation.

  20. A long-term study of the impact of solar flares on ionospheric characteristics measured by digisondes and GNSS receivers

    NASA Astrophysics Data System (ADS)

    Tripathi, Sharad Chandra; Haralambous, Haris; Das, Tanmay

    2016-07-01

    Solar Flares are highly transient phenomena radiating over a wide spectrum of wavelengths with EUV and X-rays imposing the most significant effect on ionospheric characteristics. This study presents an attempt to examine qualitatively and quantitatively these effects as measured by digisondes and GNSS receivers on a global scale. For this purpose we have divided the whole globe in three sectors (American, African-European and Asian) based on longitude. We have extracted data for ionospheric characteristics by scaling, manually, the ionograms being provided by DIDBase (Digital Ionogram Database) as provided by the Global Ionospheric Radio Observatory (GIRO) during X-class flares for an approximate period of a solar cycle . We have also used TEC data extracted from GPS observations from collocated IGS Stations. Spectral analysis of Solar Flares are added to the methodology to compare the effects in terms of spectral characteristics.

  1. Long-Term Variations in the Occurrence and Effective Solar Transmission of Clouds as Determined from Surface-Based Total Irradiance Observations

    SciTech Connect

    Dutton, Ellsworth G.; Farhadi, A.; Stone, R. S.; Long, Charles N.; Nelson, D. W.

    2004-02-11

    Time series of cloud solar transmission and cloud occurrence frequency are developed for the past 27 years at four globally remote and climatically diverse surface locations. A new methodology is developed that objectively segregates times of cloud-free conditions from those times when clouds are detected in high-time-resolution total solar irradiance observations that are obtained from pyranometers. The methodology for cloud detection depends on the magnitude and short-term variability of observed departures from clear-sky conditions. Expected clear-sky irradiances are based on interpolated clear-sky observations. Results of the new cloud detection methodology are compared to four independent cloud detection methods. An effective cloud transmission is determined as the ratio of observed irradiance in the presence of clouds to that expected in the absence of clouds. Selective forward scattering by clouds toward the observation site results in computed effective transmissions frequently being >1.0. It is shown that conditional temporal averaging of effective cloud transmission over periods of three days or more virtually eliminates the unrealistic cloud transmissions exceeding 1.0. Such temporal averaging of the surface measurements is advantageous for comparing against other area-wide cloud transmission estimates, such as those determined from satellite or by numerical climate models. The cloud occurrence frequency and the effective solar transmission for long-term observational records are summarized into monthly and annual averages, and their long-term variability is investigated. Temporal variations in frequency distributions of transmission are used to determine which clouds are responsible for changes in mean cloudiness. A statistically significant upward trend in cloud occurrence frequency, from 76% to 82% between 1976 and 2001, is detected at Barrow, Alaska, where clouds having solar transmission near 0.2 exhibit the largest increase. At the South Pole

  2. A Theoretical Framework for Utilizing Long-Term Measurements of Radiation and Clouds for Solar Energy Research

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Xie, Y.

    2015-12-01

    One of the greatest challenges facing solar energy research is accurately predicting global horizontal irradiance (GHI) for photovoltaic (PV) modules and direct normal irradiance (DNI) for concentrated solar power (CSP) plants at the surface with a high temporal resolution. Addressing this solar energy challenge is tied ultimately to the quantitative relationship between the direct, diffuse and total radiation reaching the surface and clouds in the atmosphere, which remains elusive. Here we will first introduce a theoretical framework that relates DNI and GHI to cloud fraction and cloud albedo through two dimensionless numbers: the relative cloud radiative forcing for the direct radiation (defined as the difference between the clear sky and all sky direct downwelling radiative fluxes normalized by the clear sky direct downwelling radiative fluxes) is primarily determined by cloud fraction; the ratio of the relative cloud radiative forcing for the total downwelling radiation to the relative cloud radiative forcing for the direct radiation is primarily determined by cloud albedo. We then use decade-long measurements of partitioned radiation and cloud properties at the ARM sites to validate the theoretical relationships between the two dimensionless radiation-based parameters and cloud properties. We will also explore the potentials and challenges of using the relationships between cloud properties and radiation partition at the surface for solar energy research, opening new avenues to utilizing ARM measurements.

  3. Investigation of solar wind dependence of the plasma sheet based on long-term Geotail/LEP data evaluation

    NASA Astrophysics Data System (ADS)

    Saeki, R.; Seki, K.; Saito, Y.; Shinohara, I.; Miyashita, Y.; Imada, S.; Machida, S.

    2014-12-01

    It is observationally known that the plasma density and temperature in plasma sheet are significantly changed by solar wind conditions [e.g., Terasawa et al., 1997]. Thus it is considered that the plasma sheet plasma is originated from the solar wind, and several entry mechanisms have been suggested. When the interplanetary magnetic field (IMF) is southward, the solar wind plasma enters the plasma sheet mainly through magnetic reconnection at the dayside magnetopause. In contrast, for the northward IMF, the double-lobe reconnection [Song et al., 1999], abnormal diffusion [Johnson and Cheng., 1997], and plasma mixing through the Kelvin-Helmholtz instability caused by viscous interaction [Hasegawa et al., 2004] have been proposed. Relative contribution of each process is, however, far from understood. In the present study, we use magnetotail observations by the Geotail spacecraft at radial distances of 10-32 Re during 12-year period from 1995 to 2006 to investigate properties of the plasma sheet. We conducted a statistical analysis with calibrated LEP-EA [Mukai et al., 1994] ion and electron data. We selected central plasma sheet observations and derived electron and ion temperature and density using the same method and criteria as Terasawa et al. [1997]. In addition, OMNI solar-wind data are used. The results show that the plasma sheet density (both ion and electron temperatures) has a good correlation with the solar wind density (kinetic energy) over the whole solar cycle. We find clear dawn-dusk asymmetry in the temperature ratio Ti/Te, i.e., the average Ti/Te is higher on the duskside than the dawn. The density also shows the dawn-dusk asymmetry and higher on the duskside than on the dawnside. A previous study by Wang et al. [2012] showed that Ti/Te is high (typically 5-10) in the magnetosheath. The statistical results, therefore, suggest that the shocked solar wind plasma can easily enter the duskside plasma sheet rather than the dawnside. We will discuss the

  4. A long-term change of the AR/KR/XE fractionation in the solar corpuscular radiation

    NASA Technical Reports Server (NTRS)

    Wieler, R.; Baur, H.; Signer, P.

    1993-01-01

    Solar noble gases in an ilmenite separate from breccia 79035 (antiquity greater than 1 Ga) were analyzed by closed system stepped etching (CSSE). All five gases show the familiar two-component structure: first solar-wind (SW) gases are released, followed by gases from solar energetic particles (SEP). Element patterns in 79035 are similar to those of 71501 ilmenite. SW-He-Ne were partly lost, but SEP-He-Ne-Ar are retained (nearly) unfractionated. Constant Ar/Kr/Xe ratios indicate that ilmenites contain an unfractionated sample of the heavy SW-SEP noble gases. Ar/Kr/Xe ratios in the solar corpuscular radiation are, however, different from 'solar system' values, whereby the Kr/Xe difference in 79035 is about twice as large as in 71501. We propose that Xe is less fractionated than Kr and Ar, though its first ionization potential (FIP) is higher than the 'cutoff' at approximately 11.5 eV, above which all elements in SEP are usually assumed to be depleted by a roughly constant factor. SW-Ne may be isotopically slightly heavier in the ancient SW trapped by 79035, as proposed earlier. In this work we extend our previous CSSE studies of solar noble gases including Kr and Xe to a lunar sample irradiated at least 1 Ga ago (breccia 79035, ilmenite separate, 42-64 microns). This sample was particularly gently etched in the first steps. Surprisingly, the first three steps, each releasing less than or equal to 0.5% of the total 36-Ar, showed an SEP-like trapped component plus relatively large concentrations of cosmogenic gases. Steps 4ff contain much less cosmogenic and more solar gas with a SW-like isotope pattern. Thus, a very minor easily etchable phase that has completely lost its SW-gases must be responsible for steps 1-3. We will not discuss these steps here and refer to the actual step 4 as the 'initial' etching step.

  5. Using smartphones to collect time-activity data for long-term personal-level air pollution exposure assessment.

    PubMed

    Glasgow, Mark L; Rudra, Carole B; Yoo, Eun-Hye; Demirbas, Murat; Merriman, Joel; Nayak, Pramod; Crabtree-Ide, Christina; Szpiro, Adam A; Rudra, Atri; Wactawski-Wende, Jean; Mu, Lina

    2016-06-01

    Because of the spatiotemporal variability of people and air pollutants within cities, it is important to account for a person's movements over time when estimating personal air pollution exposure. This study aimed to examine the feasibility of using smartphones to collect personal-level time-activity data. Using Skyhook Wireless's hybrid geolocation module, we developed "Apolux" (Air, Pollution, Exposure), an Android(TM) smartphone application designed to track participants' location in 5-min intervals for 3 months. From 42 participants, we compared Apolux data with contemporaneous data from two self-reported, 24-h time-activity diaries. About three-fourths of measurements were collected within 5 min of each other (mean=74.14%), and 79% of participants reporting constantly powered-on smartphones (n=38) had a daily average data collection frequency of <10 min. Apolux's degree of temporal resolution varied across manufacturers, mobile networks, and the time of day that data collection occurred. The discrepancy between diary points and corresponding Apolux data was 342.3 m (Euclidian distance) and varied across mobile networks. This study's high compliance and feasibility for data collection demonstrates the potential for integrating smartphone-based time-activity data into long-term and large-scale air pollution exposure studies.

  6. Sustained Dorsal Hippocampal Activity is Not Obligatory for Either the Maintenance or Retrieval of Long-Term Spatial Memory

    PubMed Central

    Broadbent, Nicola J.; Squire, Larry R.; Clark, Robert E.

    2011-01-01

    Memories are initially stored in a labile state and are subject to modification by a variety of treatments, including disruption of hippocampal function. We infused a sodium channel blocker (or CNQX) to inactivate the rat dorsal hippocampus reversibly for 1 week following training on a task of spatial memory (the water maze). Previous work with conventional lesions has established that the dorsal hippocampus is essential for both the acquisition and expression of memory in this task. The question in the present study was whether chronic disruption of neuronal activity in the dorsal hippocampus after training would abolish memory or whether memory would survive extended disruption of hippocampal activity. As expected from earlier work, we found that performance was impaired during the infusion period. The critical test occurred 1 week after the lesion was reversed. We found that retention of the water maze recovered to control levels. Accordingly, sustained hippocampal activity following training is not obligatory for either the maintenance of long-term spatial memory or its subsequent retrieval. PMID:19921702

  7. RGTA OTR4120, a heparan sulfate mimetic, is a possible long-term active agent to heal burned skin.

    PubMed

    Garcia-Filipe, S; Barbier-Chassefiere, V; Alexakis, C; Huet, E; Ledoux, D; Kerros, M E; Petit, E; Barritault, D; Caruelle, J P; Kern, P

    2007-01-01

    Burn-related skin fibrosis leads to loss of tissue function and hypertrophic scar formation with damaging consequences for the patient. There is therefore a great need for an efficient agent to treat burned skin. We report that ReGeneraTing Agent (RGTA) reduces burn-induced skin alteration. The tissue-regenerating effect of RGTA OTR4120 was evaluated after 1-6 days and after 10 months in a rat skin burn model. This effect was also examined in vitro using fibroblasts isolated from control and 6-day-old burned skins. We measured production of dermal collagen I, III, and V and activities of metalloproteinases 2 and 9 (MMP-2 and MMP-9). Ratio of collagen III over collagen I production increased 6 days after the burn, because of a decrease in collagen I production. After 10 months, ratio of collagen III over collagen I in burn sites was still increased compared with control skin, because of an increase in collagen III production. Both abnormalities were corrected by OTR4120. OTR4120 increased pro- and active MMP-2 and MMP-9, compared with healthy and burned controls and therefore accelerated remodeling. Similar data were obtained with cultured fibroblasts from healthy and burned skins. OTR4120 enhanced healing in short- and long-term after burns, reducing the formation of fibrotic tissue, and then represents a potential agent to improve burned skin healing.

  8. V-band Photometry Of By Draconis-type Variables; Probing Long-term Activity Cycles In Three Pleiades Members

    NASA Astrophysics Data System (ADS)

    Milingo, Jackie; Thomson, A. D.; Truong, P. N.; Marschall, L. A.; Backman, D. E.

    2007-05-01

    Through the collaborative efforts of undergraduates and faculty at Gettysburg and Franklin & Marshall Colleges, we present the compilation of 10 years of differential photometry for three K-type stars in the Pleiades. These young stars have rotational light curves with V-band amplitudes of a few percent (10% in the most active) due to BY Draconis-type behavior (modulation due to rotation of a star with non-uniform surface brightness). With 10 years of photometry reduced, measured, and compiled we are now in a position to probe the V-band variations in these stars for indications of the extent of brightness asymmetry in the photosphere, and characteristics of the long-term activity of these stars. These observations were acquired at the National Undergraduate Research Observatory, operated by Lowell Observatory and Northern Arizona University. This work is supported by Gettysburg College, the Pennsylvania Space Grant Consortium, Arizona Space Grant, NSF grant AST-0354056, and by the Nantucket Maria Mitchell Association.

  9. Long term effect of alkali types on waste activated sludge hydrolytic acidification and microbial community at low temperature.

    PubMed

    Jin, Baodan; Wang, Shuying; Xing, Liqun; Li, Baikun; Peng, Yongzhen

    2016-01-01

    The effect of four alkali reagents (NaOH, KOH, Ca(OH)2, mixed alkali) on waste activated sludge (WAS) hydrolytic acidification and microbial community was studied in semi-continuous fermentation systems at low temperature (15°C) over long term operational time (65day). The results showed that protein and polysaccharide of NaOH (124.26, 11.92) was similar to that of KOH (109.53, 11.30), both were higher than Ca(OH)2 (70.66, 3.74) and mixed alkali (90.66, 8.71). The short chain fatty acids (SCFAs) of NaOH (231.62) was higher than KOH (220.62mg chemical oxygen demand (COD)/g VSS). Although Ca(OH)2 system had strong acidification capacity, the shortage of SCFAs occurred due to the low activity of hydrolase. Illumina MiSeq sequencing revealed that Tissierella and Erysipelothrix were enriched in the NaOH and Ca(OH)2 systems, where Peptostreptococcaceae incertae_sedis was enriched in the NaOH and KOH systems, less Anaerolinea was involved in Ca(OH)2 condition. PMID:26546788

  10. Inspiratory activation is not required for episodic hypoxia-induced respiratory long-term facilitation in postnatal rats

    PubMed Central

    Tadjalli, Arash; Duffin, James; Li, Yan Mei; Hong, Hyunwook; Peever, John

    2007-01-01

    Episodic hypoxia causes repetitive inspiratory activation that induces a form of respiratory plasticity termed long-term facilitation (LTF). While LTF is a function of the hypoxic exposures and inspiratory activation, their relative importance in evoking LTF is unknown. The aims of this study were to: (1) dissociate the relative roles played by episodic hypoxia and respiratory activation in LTF; and (2) determine whether the magnitude of LTF varies as a function of hypoxic intensity. We did this by examining the effects of episodic hypoxia in postnatal rats (15–25 days old), which unlike adult rats exhibit a prominent hypoxia-induced respiratory depression. We quantified inspiratory phrenic nerve activity generated by the in situ working-heart brainstem before, during and for 60 min after episodic hypoxia. We demonstrate that episodic hypoxia evokes LTF despite the fact that it potently suppresses inspiratory activity during individual hypoxic exposures (P < 0.05). Specifically, we show that after episodic hypoxia (three 5 min periods of 10% O2) respiratory frequency increased to 40 ± 3.3% above baseline values over the next 60 min (P < 0.001). Continuous hypoxia (15 min of 10% O2) had no lasting effects on respiratory frequency (P > 0.05). To determine if LTF magnitude was affected by hypoxic intensity, the episodic hypoxia protocol was repeated under three different O2 tensions. We demonstrate that the magnitude and time course of LTF depend on hypoxic severity, with more intense hypoxia inducing a more potent degree of LTF. We conclude that inspiratory activation is not required for LTF induction, and that hypoxia per se is the physiological stimulus for eliciting hypoxia-induced respiratory LTF. PMID:17932158

  11. 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

  12. Long-term Trend of Sunspot Numbers

    NASA Astrophysics Data System (ADS)

    Gao, P. X.

    2016-10-01

    Using the Hilbert–Huang Transform method, we investigate the long-term trend of yearly mean total sunspot numbers in the time interval of 1700–2015, which come from the World Data Center—the sunspot Index and long-term solar observations. The main findings of this study are summarized below. (1) From the adaptive trend, which is extracted from the yearly mean total sunspot numbers, we can find that the value gradually increases during the time period 1700–1975, then decreases gradually from 1975 to 2015. (2) The Centennial Gleissberg Cycle is extracted from the yearly mean total sunspot numbers and confirms that a new grand minimum is in progress; the Dalton Minimum, the Gleissberg Minimum, and low level of solar activity during solar cycle 24 (the part of the new grand minimum) all can be understood as minima of the Centennial Gleissberg Cycle. (3) Based on the adaptive (overall) trend, and the 100-year and longer timescale trend of yearly mean total sunspot numbers, we can infer that the level of solar activity during the new grand minimum may be close to that during the Gleissberg Minimum, slightly higher than that during the Dalton Minimum, and significantly higher than that during the Maunder Minimum. Our results do not support the suggestion that a new grand minimum, somewhat resembling the Maunder Minimum, is in progress.

  13. Active Traction Force Response to Long-Term Cyclic Stretch Is Dependent on Cell Pre-stress.

    PubMed

    Cirka, Heather; Monterosso, Melissa; Diamantides, Nicole; Favreau, John; Wen, Qi; Billiar, Kristen

    2016-04-26

    Mechanical stimulation is recognized as a potent modulator of cellular behaviors such as proliferation, differentiation, and extracellular matrix assembly. However, the study of how cell-generated traction force changes in response to stretch is generally limited to short-term stimulation. The goal of this work is to determine how cells actively alter their traction force in response to long-term physiological cyclic stretch as a function of cell pre-stress. We have developed, to our knowledge, a novel method to assess traction force after long-term (24 h) uniaxial or biaxial cyclic stretch under conditions of high cell pre-stress with culture on stiff (7.5 kPa) polyacrylamide gels (with or without transforming growth factor β1 (TGF-β1)) and low pre-stress by treating with blebbistatin or culture on soft gels (0.6 kPa). In response to equibiaxial stretch, valvular interstitial cells on stiff substrates decreased their traction force (from 300 nN to 100 nN) and spread area (from 3000 to 2100 μm(2)). With uniaxial stretch, the cells had similar decreases in traction force and area and reoriented perpendicular to the stretch. TGF-β1-treated valvular interstitial cells had higher pre-stress (1100 nN) and exhibited a larger drop in traction force with uniaxial stretch, but the percentage changes in force and area with stretch were similar to the non-TGF-β1-treated group. Cells with inhibited myosin II motors increased traction force (from 41 nN to 63 nN) and slightly reoriented toward the stretch direction. In contrast, cells cultured on soft gels increased their traction force significantly, from 15 nN to 45 nN, doubled their spread area, elongated from an initially rounded morphology, and reoriented perpendicular to the uniaxial stretch. Contractile-moment measurements provided results consistent with total traction force measurements. The combined results indicate that the change in traction force in response to external cyclic stretch is dependent upon the

  14. Pairing of pre- and postsynaptic activities in cerebellar Purkinje cells induces long-term changes in synaptic efficacy in vitro.

    PubMed

    Crepel, F; Jaillard, D

    1991-01-01

    1. An in vitro slice preparation of rat cerebellar cortex was used to analyse long-lasting modifications of synaptic transmission at parallel fibre (PF)-Purkinje cell (PC) synapses. These use-dependent changes were induced by pairing PF-mediated EPSPs evoked at low frequency (1 Hz) with different levels of membrane polarization (or bioelectrical activities) of PCs for 15 min. 2. Experiments were performed on forty-eight PCs recorded intracellularly in a conventional perfused chamber, and in fifty other cells maintained in a static chamber either in the presence (n = 21) or in the absence (n = 29) of 400 nM-phorbol 12,13-dibutyrate (PDBu). 3. In these three experimental conditions, PF-mediated EPSPs were always measured on PCs maintained at a holding potential of -75 mV, and further hyperpolarized by constant hyperpolarizing pulses. This allowed us both to test the input resistance of PCs and to avoid their firing during PF-mediated EPSPs. 4. In all cells retained for the present study, latencies of PF-mediated EPSPs evoked at 0.2 Hz were stable during the pre-pairing period, and the same was true for their amplitude and time course. 5. In the perfused chamber, pairing of PF-mediated EPSPs with the same hyperpolarization of PCs as that used for measurements of synaptic responses had no effect on these EPSPs in 30% of PCs. It induced long-term depression (LTD) and long-term potentiation (LTP) in 23 and 47% of the tested cells respectively (n = 17). 6. In the perfused chamber, pairing of PF-mediated EPSPs with moderate depolarization of PCs (n = 19) giving rise to a sustained firing of sodium spikes significantly favoured the appearance of LTP as compared to the previous pairing protocol. However, there were still 27 and 15% of cells which showed no modification and LTD respectively. 7. In contrast, pairing of PF-mediated EPSPs with calcium (Ca2+) spikes evoked by strong depolarization of PCs (n = 12) led to LTD of synaptic transmission in nearly half of the tested

  15. Long-term variations of estimated global solar radiation and the influencing factors in Hunan province, China during 1980-2013

    NASA Astrophysics Data System (ADS)

    Zou, Ling; Lin, Aiwen; Wang, Lunche; Xia, Xiangao; Gong, Wei; Zhu, Hongji; Zhao, Zhenzhen

    2016-04-01

    Long-term variation of estimated global solar radiation (E g↓) and its relationship with total cloud cover (TCC), low cloud cover (LCC), water vapor content (WVC) and aerosol optical depth (AOD) were investigated based on the observations at 21 meteorological stations in Hunan province, China. Long-term variations of all variables were calculated for each station; the Mann-Kendall trend test was used to detect the significant level of temporal development trend for each variable; the Pearson correlation analysis was used to measure their linear relationships. Annual E g↓ generally decreased at the rate of -2.11 × 10-3 MJ m-2 decade-1 in Hunan province during 1980-2013. Seasonal mean E g↓ decreased at the rate of -11.99 × 10-3, -4.71 × 10-3 and -4.51 × 10-3 MJ m-2 decade-1 in summer, autumn and winter, respectively, while the increasing trend was observed in spring (15.74 × 10-3 MJ m-2 decade-1). The annual variation of E g↓ in Hunan province was dominantly determined by the variations of AOD (0.33 × 10-3 decade-1) and LCC (0.24 % p decade-1). But the spatial variation of E g↓ in Hunan province was complex. All 21 stations were divided into four groups according to the long-term trends of E g↓, TCC, LCC, AOD and WVC. An increasing E g↓ was observed at stations in group 1, which was determined by the variability of TCC. The variability of AOD and TCC might contribute to the increasing E g↓ in group 2. There were decreasing trends of E g↓ for the stations in group 3 and group 4, which were largely determined by the increases of AOD and LCC.

  16. Long-term leaching behavior of phenol in cement/activated-carbon solidified/stabilized hazardous waste.

    PubMed

    Liu, Jianguo; Nie, Xiaoqin; Zeng, Xianwei; Su, Zhaoji

    2013-01-30

    The long-term leaching behavior of phenol in solidified/stabilized (S/S) hazardous wastes cured for 28 d with different amounts of activated carbon (AC) was investigated using synthetic inorganic acid (H(2)SO(4):HNO(3) = 2:1, pH = 3.2), acetic acid buffer (HAc/NaAc, pH = 4.93), and deionized water as leachants to simulate the leaching of phenol in three exposure scenarios: acid-precipitation, co-disposal, and neutral-precipitation. Phenol immobilization was enhanced by AC adsorption and impaired by the growth of micropores with increasing amount of AC; thus the optimal added amount of AC to be to added S/S wastes was 2%. The leaching behavior of phenol in co-disposal scenario was unpredictable due to inadequate ionization of HAc in the HAc-NaAc buffer solution. The findings indicated that S/S products should be disposed of in hazardous waste landfills rather than municipal solid waste landfills. PMID:23270892

  17. Long-term follow-up after high-activity 125I brachytherapy for pediatric brain tumors.

    PubMed

    Sneed, P K; Russo, C; Scharfen, C O; Prados, M D; Malec, M K; Larson, D A; Lamborn, K R; Lamb, S A; Voss, B; Weaver, K A; Phillips, T L; Gutin, P H; Wara, W M; Edwards, M S

    1996-06-01

    A retrospective review including long-term follow-up (4.6-12.0 years) was performed of all 28 pediatric patients who underwent high-activity 125I brachytherapy at the University of California, San Francisco, for primary or recurrent brain tumors from 1980 until 1991. There were 4 glioblastomas, 11 high-grade nonglioblastoma multiforme (NGM) malignant gliomas, 10 contrast-enhancing low-grade NGM, 2 choroid plexus carcinomas, and 1 rhabdomyosarcoma. The 13 survivors included 7 of 8 patients with primary high-grade NGM, 2 of 3 patients with primary low-grade NGM, and 3 of 7 patients with recurrent low-grade NGM. Necrosis (with or without tumor) was identified in 17 of 22 reoperated patients. The mean Karnofsky performance status was 88 +/- 9 at the time of brachytherapy, 87 +/- 7 at 3 years, and 87 +/- 9 in 11 patients alive at 6-12 years. Brachytherapy is a useful modality for treating selected pediatric brain tumors, and although focal necrosis is a common sequela, it does not tend to have a major impact on the Karnofsky performance status, if the implant site is amenable to reoperation.

  18. Effects of memantine on hippocampal long-term potentiation, gamma activity, and sensorimotor gating in freely moving rats.

    PubMed

    Ma, Jingyi; Mufti, Asfandyar; Stan Leung, L

    2015-09-01

    Memantine, an uncompetitive N-methyl-D-aspartate receptor antagonist, is used for treatment of patients with Alzheimer's disease. The mechanisms of memantine in relieving cognitive and behavioral symptoms are unclear, and this study attempts to elucidate its action on network and synaptic functions of the hippocampus. The effects of memantine on electrographic activity and hippocampal long-term potentiation (LTP) were investigated in freely moving rats. Basal dendritic excitation on hippocampal CA1 pyramidal cells showed a robust LTP after theta-frequency primed bursts, and the LTP was higher after 5-10 mg/kg intraperitoneal (ip) memantine pretreatment, as compared with saline pretreatment. Injection of scopolamine (5 mg/kg ip) before memantine failed to block the LTP-enhancing effect of memantine. Memantine as compared with saline pretreatment did not affect the LTP after an afterdischarge induced by high-frequency (200-Hz) train stimulation. Memantine (5 or 10 mg/kg ip) significantly enhanced gamma oscillations in the hippocampal local field potentials of 40-100 Hz during walking and awake immobility. Memantine at 10 mg/kg ip, but not at 5 mg/kg ip, increased prepulse inhibition of the acoustic startle response, while both 5 and 10 mg/kg ip memantine enhanced the acoustic startle response as compared with saline-injected rats. These electrophysiological and behavioral effects of memantine are unique among N-methyl-D-aspartate receptor antagonists but are consistent with memantine's effects in improving cognitive and sensorimotor functions of Alzheimer's patients.

  19. Reducing long term sickness absence by an activating intervention in adjustment disorders: a cluster randomised controlled design

    PubMed Central

    van der Klink, J J L; Blonk, R; Schene, A; van Dijk, F J H

    2003-01-01

    Aims: To compare an innovative activating intervention with "care as usual" (control group) for the guidance of employees on sickness leave because of an adjustment disorder. It was hypothesised that the intervention would be more effective than care as usual in lowering the intensity of symptoms, increasing psychological resources, and decreasing sickness leave duration. Methods: A prospective, cluster randomised controlled trial was carried out with 192 patients on first sickness leave for an adjustment disorder. Symptom intensity, sickness duration, and return to work rates were measured at 3 months and 12 months. Analyses were performed on an intention to treat basis. Results: At 3 months, significantly more patients in the intervention group had returned to work compared with the control group. At 12 months all patients had returned to work, but sickness leave was shorter in the intervention group than in the control group. The recurrence rate was lower in the intervention group. There were no differences between the two study groups with regard to the decrease of symptoms. At baseline, symptom intensity was higher in the patients than in a normal reference population, but decreased over time in a similar manner in both groups to approximately normal levels. Conclusion: The experimental intervention for adjustment disorders was successful in shortening sick leave duration, mainly by decreasing long term absenteeism. PMID:12771395

  20. Long-term kinetics of T cell production in HIV-infected subjects treated with highly active antiretroviral therapy

    PubMed Central

    Fleury, S.; Rizzardi, G. P.; Chapuis, A.; Tambussi, G.; Knabenhans, C.; Simeoni, E.; Meuwly, J.-Y.; Corpataux, J.-M.; Lazzarin, A.; Miedema, F.; Pantaleo, G.

    2000-01-01

    The long-term kinetics of T cell production following highly active antiretroviral therapy (HAART) were investigated in blood and lymph node in a group of HIV-infected subjects at early stage of established infection and prospectively studied for 72 wk. Before HAART, CD4 and CD8 T cell turnover was increased. However, the total number of proliferating CD4+ T lymphocytes, i.e., CD4+Ki67+ T lymphocytes, was not significantly different in HIV-infected (n = 73) and HIV-negative (n = 15) subjects, whereas proliferating CD8+Ki67+ T lymphocytes were significantly higher in HIV-infected subjects. After HAART, the total body number of proliferating CD4+Ki67+ T lymphocytes increased over time and was associated with an increase of both naive and memory CD4+ T cells. The maximal increase (2-fold) was observed at week 36, whereas at week 72 the number of proliferating CD4+ T cells dropped to baseline levels, i.e., before HAART. The kinetics of the fraction of proliferating CD4 and CD8 T cells were significantly correlated with the changes in the total body number of these T cell subsets. These results demonstrate a direct relationship between ex vivo measures of T cell production and quantitative changes in total body T lymphocyte populations. This study provides advances in the delineation of the kinetics of T cell production in HIV infection in the presence and/or in the absence of HAART. PMID:10805798

  1. Extended-release PEG-luciferin allows for long-term imaging of firefly luciferase activity in vivo.

    PubMed

    Chandran, Sachin S; Williams, Simon A; Denmeade, Samuel R

    2009-01-01

    Bioluminescence has gained favour in the last decade as an approach for observing tumours in vivo in a non-destructive manner. This very sensitive technique is based on light emission by the reaction of luciferin with the enzyme luciferase, as measured by a photodetector. Ever since the development of recombinant tumour cell lines that have been engineered to produce luciferase, a vast number of experiments have been carried out examining tumour growth, tumour metastasis and the effect of therapeutic regimens in such cases. A primary stumbling block, however, is the relatively short circulatory half-life of luciferin. In this paper, we propose the PEGylation of 6-amino-D-luciferin to extend its in vivo circulatory half-life, thus making the possibility of long-term observations in animals possible. The covalent attachment was through a carbamate linker that is known to hydrolyse in vivo, releasing the parent compound. Based on our studies, longer emission of the PEGylated luciferin was observed, as compared to free luciferin in mice bearing PC3 prostate tumours expressing luciferase. This result suggests that this reagent can be used in applications requiring extended monitoring of luciferase activation in vivo. PMID:18780328

  2. Long-term leaching behavior of phenol in cement/activated-carbon solidified/stabilized hazardous waste.

    PubMed

    Liu, Jianguo; Nie, Xiaoqin; Zeng, Xianwei; Su, Zhaoji

    2013-01-30

    The long-term leaching behavior of phenol in solidified/stabilized (S/S) hazardous wastes cured for 28 d with different amounts of activated carbon (AC) was investigated using synthetic inorganic acid (H(2)SO(4):HNO(3) = 2:1, pH = 3.2), acetic acid buffer (HAc/NaAc, pH = 4.93), and deionized water as leachants to simulate the leaching of phenol in three exposure scenarios: acid-precipitation, co-disposal, and neutral-precipitation. Phenol immobilization was enhanced by AC adsorption and impaired by the growth of micropores with increasing amount of AC; thus the optimal added amount of AC to be to added S/S wastes was 2%. The leaching behavior of phenol in co-disposal scenario was unpredictable due to inadequate ionization of HAc in the HAc-NaAc buffer solution. The findings indicated that S/S products should be disposed of in hazardous waste landfills rather than municipal solid waste landfills.

  3. Differences in root functions during long-term drought adaptation: comparison of active gene sets of two wheat genotypes.

    PubMed

    Sečenji, M; Lendvai, Á; Miskolczi, P; Kocsy, G; Gallé, Á; Szucs, A; Hoffmann, B; Sárvári, É; Schweizer, P; Stein, N; Dudits, D; Györgyey, J

    2010-11-01

    In an attempt to shed light on the role of root systems in differential responses of wheat genotypes to long-term water limitation, transcriptional differences between two wheat genotypes (Triticum aestivum L., cv. Plainsman V and landrace Kobomugi) were identified during adaptation to moderate water stress at the tillering stage. Differences in organ sizes, water-use efficiency and seed production were detected in plants grown in soil, and root functions were characterised by expression profiling. The molecular genetic background of the behaviour of the two genotypes during this stress was revealed using a cDNA macroarray for transcript profiling of the roots. During a 4-week period of moderate water deficit, a set of up-regulated genes displaying transiently increased expression was identified in young plantlets, mostly in the second week in the roots of Kobomugi, while transcript levels remained constantly high in roots of Plainsman V. These genes encode proteins with various functions, such as transport, protein metabolism, osmoprotectant biosynthesis, cell wall biogenesis and detoxification, and also regulatory proteins. Oxidoreductases, peroxidases and cell wall-related genes were induced significantly only in Plainsman V, while induction of stress- and defence-related genes was more pronounced in Kobomugi. Real-time qPCR analysis of selected members of the glutathione S-transferase gene family revealed differences in regulation of family members in the two genotypes and confirmed the macroarray results. The TaGSTZ gene was stress-activated only in the roots of Kobomugi.

  4. Long-term effect of the antibiotic cefalexin on methane production during waste activated sludge anaerobic digestion.

    PubMed

    Lu, Xueqin; Zhen, Guangyin; Liu, Yuan; Hojo, Toshimasa; Estrada, Adriana Ledezma; Li, Yu-You

    2014-10-01

    Long-term experiments herein were conducted to investigate the effect of cefalexin (CLX) on methane production during waste activated sludge (WAS) anaerobic digestion. CLX exhibited a considerable inhibition in methane production during the initial 25 days while the negative effect attenuated subsequently and methane production recovered depending on CLX doses used (600 and 1000 mg/L). The highest methane yield reached 450 mL at 1000 mg-CLX/L after 157 days of digestion, 63.8% higher than CLX-free one. Stimulated excretion of extracellular polymeric substances (EPS) by CLX served as microbial protecting layers, creating a suitable environment for microbes' growth and fermentation. Further examination via ultraviolet visible (UV-Vis) spectra also verified the elevated slime EPS, LB-EPS and TB-EPS indicated by UV-254 in the presence of CLX. Unlike the commonly accepted adverse effect, this study demonstrated the beneficial role of CLX in methane production, providing new insights into its true environmental impacts.

  5. Long-term community dynamics of small landbirds with and without exposure to extensive disturbance from military training activities.

    PubMed

    Rivers, James W; Gipson, Philip S; Althoff, Donald P; Pontius, Jeffrey S

    2010-02-01

    Military training activities are known to impact individual species, yet our understanding of how such activities influence animal communities is limited. In this study, we used long-term data in a case study approach to examine the extent to which the local small landbird community differed between a site in northeast Kansas that experienced intensive disturbance from military training activities (Ft. Riley Military Installation) and a similar, nearby site that experienced minimal human disturbance (Konza Prairie Biological Station). In addition, we characterized how the regional pool of potential colonizers influenced local community dynamics using Breeding Bird Survey data. From 1991 to 2001, most species of small terrestrial landbirds (73%) recorded during breeding surveys were found at both sites and the mean annual richness at Ft. Riley (39.0 +/- 2.86 [SD]) was very similar to that of Konza Prairie (39.4 +/- 2.01). Richness was maintained at relatively constant levels despite compositional changes because colonizations compensated local extinctions at both sites. These dynamics were driven primarily by woodland species that exhibited stochastic losses and gains and were present at a low local and regional abundance. Our results suggest that military training activities may mimic natural disturbances for some species in this area because the small landbird community did not differ markedly between sites with and sites without extensive human disturbance. Although our results suggest that military training is not associated with large changes in the avian community, additional studies are needed to determine if this pattern is found in other ecological communities.

  6. Long-Term Community Dynamics of Small Landbirds with and Without Exposure to Extensive Disturbance from Military Training Activities

    NASA Astrophysics Data System (ADS)

    Rivers, James W.; Gipson, Philip S.; Althoff, Donald P.; Pontius, Jeffrey S.

    2010-02-01

    Military training activities are known to impact individual species, yet our understanding of how such activities influence animal communities is limited. In this study, we used long-term data in a case study approach to examine the extent to which the local small landbird community differed between a site in northeast Kansas that experienced intensive disturbance from military training activities (Ft. Riley Military Installation) and a similar, nearby site that experienced minimal human disturbance (Konza Prairie Biological Station). In addition, we characterized how the regional pool of potential colonizers influenced local community dynamics using Breeding Bird Survey data. From 1991 to 2001, most species of small terrestrial landbirds (73%) recorded during breeding surveys were found at both sites and the mean annual richness at Ft. Riley (39.0 ± 2.86 [SD]) was very similar to that of Konza Prairie (39.4 ± 2.01). Richness was maintained at relatively constant levels despite compositional changes because colonizations compensated local extinctions at both sites. These dynamics were driven primarily by woodland species that exhibited stochastic losses and gains and were present at a low local and regional abundance. Our results suggest that military training activities may mimic natural disturbances for some species in this area because the small landbird community did not differ markedly between sites with and sites without extensive human disturbance. Although our results suggest that military training is not associated with large changes in the avian community, additional studies are needed to determine if this pattern is found in other ecological communities.

  7. Our changing atmosphere: evidence based on long-term infrared solar observations at the Jungfraujoch since 1950.

    PubMed

    Zander, R; Mahieu, E; Demoulin, P; Duchatelet, P; Roland, G; Servais, C; De Mazière, M; Reimann, S; Rinsland, C P

    2008-03-01

    The Institute of Astrophysics of the University of Liège has been present at the High Altitude Research Station Jungfraujoch, Switzerland, since the late 1940s, to perform spectrometric solar observations under dry and weakly polluted high-mountain conditions. Several solar atlases of photometric quality, extending altogether from the near-ultra-violet to the middle-infrared, were produced between 1956 and 1994, first with grating spectrometers then with Fourier transform instruments. During the early 1970s, scientific concerns emerged about atmospheric composition changes likely to set in as a consequence of the growing usage of nitrogen-containing agricultural fertilisers and the industrial production of chlorine-bearing compounds such as the chlorofluorocarbons and hydro-chlorofluorocarbons. Resulting releases to the atmosphere with ensuing photolysis in the stratosphere and catalytic depletion of the protective ozone layer prompted a worldwide consortium of chemical manufacturing companies to solicit the Liège group to help in clarifying these concerns by undertaking specific observations with its existing Jungfraujoch instrumentation. The following pages evoke the main steps that led from quasi full sun-oriented studies to priority investigations of the Earth's atmosphere, in support of both the Montreal and the Kyoto Protocols.

  8. Role of morphology and crystallinity of nanorod and planar electron transport layers on the performance and long term durability of perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Fakharuddin, Azhar; Di Giacomo, Francesco; Ahmed, Irfan; Wali, Qamar; Brown, Thomas M.; Jose, Rajan

    2015-06-01

    High efficiency is routinely reported in CH3NH3PbI3-xClx sensitized mesoscopic solar cells (PSCs) employing planar and scaffold architectures; however, a systematic comparison of their photovoltaic performance under similar experimental conditions and their long term stability have so far not been discussed. In this paper, we compare the performance and durability of PSCs employing these two device configurations and conclude that although a planar architecture routinely provides high initial photoconversion efficiency (PCE), particularly high open-circuit voltage (VOC), a scaffold is crucial to achieve long term durable performance of such devices. In a comparative study of scaffold (rutile nanorods, NRs) vs. planar devices, the efficiency in latter dropped off by one order of magnitude in ∼300 h despite their similar initial PCE of ∼12%. We compared the performance and the durability of two types of scaffolds, i.e., pristine and TiCl4 treated NRs, and observed that the pristine NRs showed >10% improvement in the PCE after ∼1300 h whereas the cells employing post-treated NR scaffold retained ∼60% of initial value. We address the origin of the different photovoltaic performance of planar and scaffold devices in the context of photoanode morphology and its possible effect on the cell durability.

  9. Modeling Cu Migration in CdTe Solar Cells Under Device-Processing and Long-Term Stability Conditions: Preprint

    SciTech Connect

    Teeter, G.; Asher, S.

    2008-05-01

    An impurity migration model for systems with material interfaces is applied to Cu migration in CdTe solar cells. In the model, diffusion fluxes are calculated from the Cu chemical potential gradient. Inputs to the model include Cu diffusivities, solubilities, and segregation enthalpies in CdTe, CdS and contact materials. The model yields transient and equilibrium Cu distributions in CdTe devices during device processing and under field-deployed conditions. Preliminary results for Cu migration in CdTe photovoltaic devices using available diffusivity and solubility data from the literature show that Cu segregates in the CdS, a phenomenon that is commonly observed in devices after back-contact processing and/or stress conditions.

  10. Modeling Cu Migration in CdTe Solar Cells Under Device-Processing and Long-Term Stability Conditions (Poster)

    SciTech Connect

    Teeter, G.; Asher, S.

    2008-05-01

    An impurity migration model for systems with material interfaces is applied to Cu migration in CdTe solar cells. In the model, diffusion fluxes are calculated from the Cu chemical potential gradient. Inputs to the model include Cu diffusivities, solubilities, and segregation enthalpies in CdTe, CdS and contact materials. The model yields transient and equilibrium Cu distributions in CdTe devices during device processing and under field-deployed conditions. Preliminary results for Cu migration in CdTe PV devices using available diffusivity and solubility data from the literature show that Cu segregates in the CdS, a phenomenon that is commonly observed in devices after back-contact processing and/or stress conditions.

  11. K6PC-5, a novel sphingosine kinase activator, improves long-term ultraviolet light-exposed aged murine skin.

    PubMed

    Park, Hwa-young; Youm, Jong-Kyung; Kwon, Mi Jung; Park, Byeong Deog; Lee, Seung Hun; Choi, Eung Ho

    2008-10-01

    Sphingosine-1-phosphate (S1P), which is formed by phosphorylation of sphingosine through a process catalysed by sphingosine kinase (SK), is a multifunctional mediator of a variety of cellular responses including proliferation, differentiation, motility, and survival. K6PC-5, which was recently synthesized as a novel SK activator, is expected to increase S1P levels. Indeed studies have already demonstrated that K6PC-5 exhibits anti-aging effects on intrinsic aged murine skin by increasing fibroblasts, collagen synthesis, dermal thickness, and epidermal differentiation. However, photoaging and intrinsic aging have highly different clinical and histopathological properties. In this study, we developed a photoaged murine model by exposing mice that were 56 weeks old to ultraviolet (UV)B and UVA radiation for 8 weeks. We then investigated whether K6PC-5, as an SK activator, had anti-aging effects on photoaged murine skin in addition to its effects on intrinsic aged murine skin and determined the mechanism. K6PC-5 increased dermal collagen density in photoaged skin through increases in fibroblasts and collagen production. Photoaged murine skin treated with K6PC-5 showed an increase in stratum corneum (SC) integrity with increased corneodesmosome density and an improvement in barrier recovery rate. Matrix metalloproteinase 13 remained unchanged. These results indicate that topical application of K6PC-5 improves photoaged skin by improving skin barrier and increasing fibroblast count and function. In conclusion, K6PC-5, as an S1P activator, improves long-term UV-exposed aged skin as well as intrinsic aged skin. PMID:18341573

  12. A long-term study of new particle formation in a coastal environment: meteorology, gas phase and solar radiation implications.

    PubMed

    Sorribas, M; Adame, J A; Olmo, F J; Vilaplana, J M; Gil-Ojeda, M; Alados-Arboledas, L

    2015-04-01

    New particle formation (NPF) was investigated at a coastal background site in Southwest Spain over a four-year period using a Scanning Particle Mobility Sizer (SMPS). The goals of the study were to characterise the NPF and to investigate their relationship to meteorology, gas phase (O3, SO2, CO and NO2) and solar radiation (UVA, UVB and global). A methodology for identifying and classifying the NPF was implemented using the wind direction and modal concentrations as inputs. NPF events showed a frequency of 24% of the total days analysed. The mean duration was 9.2±4.2 h. Contrary to previous studies conducted in other locations, the NPF frequency reached its maximum during cold seasons for approximately 30% of the days. The lowest frequency took place in July with 10%, and the seasonal wind pattern was found to be the most important parameter influencing the NPF frequency. The mean formation rate was 2.2±1.7 cm(-3) s(-1), with a maximum in the spring and early autumn and a minimum during the summer and winter. The mean growth rate was 3.8±2.4 nm h(-1) with higher values occurring from spring to autumn. The mean and seasonal formation and growth rates are in agreement with previous observations from continental sites in the Northern Hemisphere. NPF classification of different classes was conducted to explore the effect of synoptic and regional-scale patterns on NPF and growth. The results show that under a breeze regime, the temperature indirectly affects NPF events. Higher temperatures increase the strength of the breeze recirculation, favouring gas accumulation and subsequent NPF appearance. Additionally, the role of high relative humidity in inhibiting the NPF was evinced during synoptic scenarios. The remaining meteorological variables (RH), trace gases (CO and NO), solar radiation, PM10 and condensation sink, showed a moderate or high connection with both formation and growth rates. PMID:25618818

  13. A long-term study of new particle formation in a coastal environment: meteorology, gas phase and solar radiation implications.

    PubMed

    Sorribas, M; Adame, J A; Olmo, F J; Vilaplana, J M; Gil-Ojeda, M; Alados-Arboledas, L

    2015-04-01

    New particle formation (NPF) was investigated at a coastal background site in Southwest Spain over a four-year period using a Scanning Particle Mobility Sizer (SMPS). The goals of the study were to characterise the NPF and to investigate their relationship to meteorology, gas phase (O3, SO2, CO and NO2) and solar radiation (UVA, UVB and global). A methodology for identifying and classifying the NPF was implemented using the wind direction and modal concentrations as inputs. NPF events showed a frequency of 24% of the total days analysed. The mean duration was 9.2±4.2 h. Contrary to previous studies conducted in other locations, the NPF frequency reached its maximum during cold seasons for approximately 30% of the days. The lowest frequency took place in July with 10%, and the seasonal wind pattern was found to be the most important parameter influencing the NPF frequency. The mean formation rate was 2.2±1.7 cm(-3) s(-1), with a maximum in the spring and early autumn and a minimum during the summer and winter. The mean growth rate was 3.8±2.4 nm h(-1) with higher values occurring from spring to autumn. The mean and seasonal formation and growth rates are in agreement with previous observations from continental sites in the Northern Hemisphere. NPF classification of different classes was conducted to explore the effect of synoptic and regional-scale patterns on NPF and growth. The results show that under a breeze regime, the temperature indirectly affects NPF events. Higher temperatures increase the strength of the breeze recirculation, favouring gas accumulation and subsequent NPF appearance. Additionally, the role of high relative humidity in inhibiting the NPF was evinced during synoptic scenarios. The remaining meteorological variables (RH), trace gases (CO and NO), solar radiation, PM10 and condensation sink, showed a moderate or high connection with both formation and growth rates.

  14. Long term (2007-2013) observations of columnar aerosol optical properties and retrieved size distributions over Anantapur, India using multi wavelength solar radiometer

    NASA Astrophysics Data System (ADS)

    Raja Obul Reddy, K.; Balakrishnaiah, G.; Rama Gopal, K.; Siva Kumar Reddy, N.; Chakradhar Rao, T.; Lokeswara Reddy, T.; Nazeer Hussain, S.; Vasudeva Reddy, M.; Reddy, R. R.; Boreddy, S. K. R.; Suresh Babu, S.

    2016-10-01

    This paper presents the long - term observational studies on aerosol optical properties measured at Sri Krishnadevaraya University (SKU) campus (14° 62‧ N, 77° 65‧ E, 331m asl), Anantapur, in southern India during 2007-2013 using a ground based Multi - Wavelength solar Radiometer (MWR). Seasonal mean values of Aerosol Optical Depth (AOD) for the whole study period were observed to be 0.34 ± 0.03, 0.45 ± 0.04, 0.24 ± 0.04, and 0.31 ± 0.03 during the winter, summer, monsoon and post - monsoon, respectively. Annual mean values of Ångström exponent (α) (turbidity coefficient (β)) varied from 0.68 ± 0.25 (0.18 ± 0.03) to 1.1 ± 0.12 (0.32 ± 0.12) during 2007-2013. However, high values of α in the range of 0.8-1.1 were observed during the winter, while low values in the range 0.3-0.7 were noticed during the monsoon. The frequency distribution of AODs during winter in the range of 0.2-0.4 is about 78%, while summer these were shifted from 0.3 to 0.6 around ∼70%, which indicated the dust strongly affects this region. The accumulated frequencies of Ångström exponent (α) less than 1.0 and greater than 1.0 were about 69% and 31%, respectively, occurred in the summer months indicates the dominance of coarse particles. Columnar size distributions, retrieved from the spectral optical depths, in general, show a bimodal log normal distribution in the optically active size range. The seasonal mean effective radius (Reff) was found to be high in monsoon (∼0.61 μm) and low in winter (∼0.38 μm). The highest mean mass loading values are lies between 475 ± 36 to 769 ± 49 mg m-2 during the summer, whereas the lowest value in the range 204 ± 19 to 278 ± 23 mg m-2 during the monsoon. The difference between α and curvature effect have been studied as a function of AOD on seasonal basis. Finally, to understand the contribution of long range transported aerosols, we have investigated this analysis making use of back trajectories obtained from the HYSPLIT

  15. Alpha5GABAA receptor activity sets the threshold for long-term potentiation and constrains hippocampus-dependent memory.

    PubMed

    Martin, Loren J; Zurek, Agnieszka A; MacDonald, John F; Roder, John C; Jackson, Michael F; Orser, Beverley A

    2010-04-14

    Synaptic plasticity, which is the neuronal substrate for many forms of hippocampus-dependent learning, is attenuated by GABA type A receptor (GABA(A)R)-mediated inhibition. The prevailing notion is that a synaptic or phasic form of GABAergic inhibition regulates synaptic plasticity; however, little is known about the role of GABA(A)R subtypes that generate a tonic or persistent inhibitory conductance. We studied the regulation of synaptic plasticity by alpha5 subunit-containing GABA(A)Rs (alpha5GABA(A)Rs), which generate a tonic inhibitory conductance in CA1 pyramidal neurons using electrophysiological recordings of field and whole-cell potentials in hippocampal slices from both wild-type and null mutant mice for the alpha5 subunit of the GABA(A)R (Gabra5(-/-) mice). In addition, the strength of fear-associated memory was studied. The results showed that alpha5GABA(A)R activity raises the threshold for induction of long-term potentiation in a highly specific band of stimulation frequencies (10-20 Hz) through mechanisms that are predominantly independent of inhibitory synaptic transmission. The deletion or pharmacological inhibition of alpha5GABA(A)Rs caused no change in baseline membrane potential or input resistance but increased depolarization during 10 Hz stimulation. The encoding of hippocampus-dependent memory was regulated by alpha5GABA(A)Rs but only under specific conditions that generate moderate but not robust forms of fear-associated learning. Thus, under specific conditions, alpha5GABA(A)R activity predominates over synaptic inhibition in modifying the strength of both synaptic plasticity in vitro and certain forms of memory in vivo. PMID:20392949

  16. Impact of Long-Term Endurance Training vs. Guideline-Based Physical Activity on Brain Structure in Healthy Aging.

    PubMed

    Wood, Katelyn N; Nikolov, Robert; Shoemaker, J Kevin

    2016-01-01

    Brain structure is a fundamental determinant of brain function, both of which decline with age in the adult. Whereas short-term exercise improves brain size in older adults, the impact of endurance training on brain structure when initiated early and sustained throughout life, remains unknown. We tested the hypothesis that long-term competitive aerobic training enhances cortical and subcortical mass compared to middle to older-aged healthy adults who adhere to the minimum physical activity guidelines. Observations were made in 16 masters athletes (MA; 53 ± 6 years, VO2max = 55 ± 10 ml/kg/min, training > 15 years), and 16 active, healthy, and cognitively intact subjects (HA; 58 ± 9 years, VO2max = 38 ± 7 ml/kg/min). T1-weighted structural acquisition at 3T enabled quantification of cortical thickness and subcortical gray and white matter volumes. Cardiorespiratory fitness correlated strongly with whole-brain cortical thickness. Subcortical volumetric mass at the lateral ventricles, R hippocampus, R amygdala, and anterior cingulate cortex, correlated with age but not fitness. In a region-of-interest (ROI) group-based analysis, MA expressed greater cortical thickness in the medial prefrontal cortex, pre and postcentral gyri, and insula. There was no effect of group on the rate of age-related cortical or subcortical decline. The current data suggest that lifelong endurance training that produces high levels of cardiorespiratory fitness, builds cortical reserve early in life, and sustains this benefit over the 40-70 year age span. This reserve likely has important implications for neurological health later in life. PMID:27445798

  17. Expansion and long-term culture of human spermatogonial stem cells via the activation of SMAD3 and AKT pathways

    PubMed Central

    Guo, Ying; Liu, Linhong; Sun, Min; Hai, Yanan; Li, Zheng

    2015-01-01

    Spermatogonial stem cells (SSCs) can differentiate into spermatids, reflecting that they could be used in reproductive medicine for treating male infertility. SSCs are able to become embryonic stem-like cells with the potentials of differentiating into numerous cell types of the three germ layers and they can transdifferentiate to mature and functional cells of other lineages, highlighting significant applications of human SSCs for treating human diseases. However, human SSCs are very rare and a long-term culture system of human SSCs has not yet established. This aim of study was to isolate, identify and culture human SSCs for a long period. We isolated GPR125-positive spermatogonia with high purity and viability from adult human testicular tissues utilizing the two-step enzymatic digestion and magnetic-activated cell sorting with antibody against GPR125. These freshly isolated cells expressed a number of markers for SSCs, including GPR125, PLZF, GFRA1, RET, THY1, UCHL1 and MAGEA4, but not the hallmarks for spermatocytes and spermatozoa, e.g. SYCP1, SYCP3, PRM1, and TNP1. The isolated human SSCs could be cultured for two months with a significant increase of cell number with the defined medium containing growth factors and hydrogel. Notably, the expression of numerous SSC markers was maintained during the cultivation of human SSCs. Furthermore, SMAD3 and AKT phosphorylation was enhanced during the culture of human SSCs. Collectively, these results suggest that human SSCs can be cultivated for a long period and expanded whilst retaining an undifferentiated status via the activation of SMAD3 and AKT pathways. This study could provide sufficient cells of SSCs for their basic research and clinic applications in reproductive and regenerative medicine. PMID:26088866

  18. Silver Nanoparticles Modified by Gelatin with Extraordinary pH Stability and Long-Term Antibacterial Activity

    PubMed Central

    Sivera, Martin; Kvitek, Libor; Soukupova, Jana; Panacek, Ales; Prucek, Robert; Vecerova, Renata; Zboril, Radek

    2014-01-01

    The potential for application of any nanoparticles, including silver nanoparticles (AgNPs), is strongly dependent on their stability against aggregation. Therefore, improvement of this parameter is a key task, especially in the case of AgNPs, because a correlation between size and biological activity has been demonstrated. In the present work, a natural stabilizer, gelatin, was investigated for the stabilization of AgNPs in an aqueous dispersion. The particles were prepared via a modified Tollens process, and the gelatin modifier was added prior to the reducing agent. The stability against aggregation of the AgNPs prepared by this method was more than one order of magnitude higher (on the basis of the critical coagulation concentration (CCC)) than that of AgNPs prepared via a similar method but without the assistance of gelatin. Their high stability against aggregation was confirmed over wide pH range (from 2 to 13) in which the particles did not exhibit rapid aggregation; such stability has not been previously reported for AgNPs. Additionally, gelatin not only fulfills the role of a unique stabilizer but also positively influences the modified Tollens process used to prepare the AgNPs. The diameter of the gelatin-modified AgNPs was substantially smaller in comparison to those prepared without gelatin. The polydispersity of the dispersion significantly narrowed. Moreover, the gelatin-stabilized AgNPs exhibited long-term stability against aggregation and maintained high antibacterial activity when stored for several months under ambient conditions. PMID:25098570

  19. Biochemical responses and mitochondrial mediated activation of apoptosis on long-term effect of aspartame in rat brain.

    PubMed

    Ashok, Iyaswamy; Sheeladevi, Rathinasamy

    2014-01-01

    Aspartame, an artificial sweetener, is very widely used in many foods and beverages. But there are controversies about its metabolite which is marked for its toxicity. Hence it is believed to be unsafe for human use. Previous studies have reported on methanol exposure with involvements of free radicals on excitotoxicity of neuronal apoptosis. Hence, this present study is proposed to investigate whether or not chronic aspartame (FDA approved Daily Acceptable Intake (ADI),40 mg/kg bwt) administration could release methanol, and whether or not it can induce changes in brain oxidative stress status and gene and protein expression of anti-apoptotic Bcl-2 and pro-apoptotic Bax and caspase-3 in the rat brain region. To mimic the human methanol metabolism, Methotrexate (MTX)-treated Wistar strain male albino rats were used and after the oral administration of aspartame, the effects were studied along with controls and MTX-treated controls. Aspartame exposure resulted with a significant increase in the enzymatic activity in protein carbonyl, lipid peroxidation levels, superoxide dismutase, glutathione-S-transferase, glutathione peroxidase and catalase activity in (aspartame MTX)-treated animals and with a significant decrease in reduced glutathione, glutathione reductase and protein thiol, pointing out the generation of free radicals. The gene and protein expression of pro apoptotic marker Bax showed a marked increase whereas the anti-apoptotic marker Bcl-2 decreased markedly indicating the aspartame is harmful at cellular level. It is clear that long term aspartame exposure could alter the brain antioxidant status, and can induce apoptotic changes in brain.

  20. Impact of Long-Term Endurance Training vs. Guideline-Based Physical Activity on Brain Structure in Healthy Aging

    PubMed Central

    Wood, Katelyn N.; Nikolov, Robert; Shoemaker, J. Kevin

    2016-01-01

    Brain structure is a fundamental determinant of brain function, both of which decline with age in the adult. Whereas short-term exercise improves brain size in older adults, the impact of endurance training on brain structure when initiated early and sustained throughout life, remains unknown. We tested the hypothesis that long-term competitive aerobic training enhances cortical and subcortical mass compared to middle to older-aged healthy adults who adhere to the minimum physical activity guidelines. Observations were made in 16 masters athletes (MA; 53 ± 6 years, VO2max = 55 ± 10 ml/kg/min, training > 15 years), and 16 active, healthy, and cognitively intact subjects (HA; 58 ± 9 years, VO2max = 38 ± 7 ml/kg/min). T1-weighted structural acquisition at 3T enabled quantification of cortical thickness and subcortical gray and white matter volumes. Cardiorespiratory fitness correlated strongly with whole-brain cortical thickness. Subcortical volumetric mass at the lateral ventricles, R hippocampus, R amygdala, and anterior cingulate cortex, correlated with age but not fitness. In a region-of-interest (ROI) group-based analysis, MA expressed greater cortical thickness in the medial prefrontal cortex, pre and postcentral gyri, and insula. There was no effect of group on the rate of age-related cortical or subcortical decline. The current data suggest that lifelong endurance training that produces high levels of cardiorespiratory fitness, builds cortical reserve early in life, and sustains this benefit over the 40–70 year age span. This reserve likely has important implications for neurological health later in life. PMID:27445798

  1. An exploration of the effectiveness of artificial mini-magnetospheres as a potential Solar Storm shelter for long term human space missions

    NASA Astrophysics Data System (ADS)

    Bamford, Ruth; Kellett, Barry; Bradford, John; Todd, Tom N.; Stafford-Allen, Robin; Alves, E. Paulo; Silva, Luis; Collingwood, Cheryl; Crawford, Ian A.; Bingham, Robert

    2014-12-01

    In this paper we explore the effectiveness of an artificial mini-magnetosphere as a potential radiation shelter for long term human space missions. Our study includes the differences that the plasma environment makes to the efficiency of the shielding from the high energy charged particle component of solar and cosmic rays, which radically alters the power requirements. The incoming electrostatic charges are shielded by fields supported by the self captured environmental plasma of the solar wind, potentially augmented with additional density. The artificial magnetic field generated on board acts as the means of confinement and control. Evidence for similar behaviour of electromagnetic fields and ionised particles in interplanetary space can be gained by the example of the enhanced shielding effectiveness of naturally occurring "mini-magnetospheres" on the moon. The shielding effect of surface magnetic fields of the order of ~100s nanoTesla is sufficient to provide effective shielding from solar proton bombardment that culminate in visible discolouration of the lunar regolith known as "lunar swirls". Supporting evidence comes from theory, laboratory experiments and computer simulations that have been obtained on this topic. The result of this work is, hopefully, to provide the tools for a more realistic estimation of the resources versus effectiveness and risk that spacecraft engineers need to work with in designing radiation protection for long-duration human space missions.

  2. Continuous, Long-term, Cyclic, Varied Eruptive Activity Observed at NW Rota-1 Submarine Volcano, Mariana Arc

    NASA Astrophysics Data System (ADS)

    Chadwick, B.; Dziak, R. P.; Baker, E. T.; Cashman, K. V.; Embley, R. W.; Ferrini, V.; de Ronde, C. E.; Butterfield, D. A.; Deardorff, N.; Haxel, J. H.; Matsumoto, H.; Fowler, M. J.; Walker, S. L.; Bobbitt, A. M.; Merle, S. G.

    2009-12-01

    the slow extrusion in 2009, a portable hydrophone recorded rhythmic sounds similar to those recorded during explosive activity in 2006 but at lower sound levels. The burst-and-pause pattern in the acoustic data indicates that cyclic magmatic gas build-up and release is the dominant driver of the long-term eruptive activity at NW Rota-1 over a wide range of eruption rates.

  3. Long-Term Uplift in the Altiplano-Puna Neovolcanic Zone: Evidence of an Active Magmatic Diapir?

    NASA Astrophysics Data System (ADS)

    Fialko, Y.; Pearse, J.

    2012-12-01

    We present InSAR observations of a long-term uplift in the Altiplano-Puna neovolcanic zone (central Andes, South America). Previous observations revealed a a massive Ultra Low Velocity Zone (ULVZ) at depth of 17-19 km (Zandt et al., 2003), and surface deformation that was attributed to Uturuncu, a dormant volcano in the middle of the Altiplano-Puna neovolcanic zone (Pritchard and Simons, 2002). Our time series analysis of combined data from different sensors (ERS-1/2 and ENVISAT), satellite tracks, and observation modes (fine beam and ScanSAR) reveals that the central uplift has persisted at a nearly constant rate of ~1 cm/yr over the last two decades, and is surrounded by a broad zone of subsidence. We use the satellite line-of-sight velocities from different look directions to constrain the depth and geometry of the inferred sources of magmatic unrest. Inversions based on elastic half-space models indicate that the inflation source is located well below the brittle-ductile transition, and likely resides at the depth of the seismically imaged ULVZ. We investigated the effects of inelastic deformation in the ambient crust using finite element models. The models incorporated laboratory-derived rheologies of the ambient crust, and geotherms appropriate for an active neo-volcanic zone such as the one in the Altiplano-Puna province. Based on a large number of numerical simulations constrained by the observed surface velocities, we conclude that the ongoing uplift and peripheral subsidence result from a large mid-crustal diapir fed by a partially molten source region in the middle crust. The observed pattern of surface deformation due to the Altiplano-Puna ULVZ is remarkably similar to that due to the Socorro Magma Body (SMB) in central New Mexico, USA (Pearse and Fialko, 2010), suggesting a common process. mosaic of the mean LOS velocity showing uplift and peripheral subsidence due to the inferred mid-crustal diapir.

  4. Short- and Long-Term Theory-Based Predictors of Physical Activity in Women Who Participated in a Weight-Management Program

    ERIC Educational Resources Information Center

    Wasserkampf, A.; Silva, M. N.; Santos, I. C.; Carraça, E. V.; Meis, J. J. M.; Kremers, S. P. J.; Teixeira, P. J.

    2014-01-01

    This study analyzed psychosocial predictors of the Theory of Planned Behavior (TPB) and Self-Determination Theory (SDT) and evaluated their associations with short- and long-term moderate plus vigorous physical activity (MVPA) and lifestyle physical activity (PA) outcomes in women who underwent a weight-management program. 221 participants (age…

  5. Different Phases of Long-Term Memory Require Distinct Temporal Patterns of PKA Activity after Single-Trial Classical Conditioning

    ERIC Educational Resources Information Center

    Michel, Maximilian; Kemenes, Ildiko; Muller, Uli; Kemenes, Gyorgy

    2008-01-01

    The cAMP-dependent protein kinase (PKA) is known to play a critical role in both transcription-independent short-term or intermediate-term memory and transcription-dependent long-term memory (LTM). Although distinct phases of LTM already have been demonstrated in some systems, it is not known whether these phases require distinct temporal patterns…

  6. The long-term behavior of the main peak of the dayside ionosphere of Venus during solar cycle 21 and its implications on the effect of the solar cycle upon the electron temperature in the main peak region

    NASA Technical Reports Server (NTRS)

    Kliore, Arvydas J.; Mullen, Luke F.

    1989-01-01

    Results are presented on the long-term behavior of the main peak electron density in the Venus ionosphere during the solar cycle 21, based on 104 radio occultation measurements of the vertical electron density profile in the dayside ionosphere of Venus carried out aboard the Pioneer Venus Orbiter spacecraft (along with published data on 11 Venera 9-10 measurements). The equation representing the electron temperature at h = 140 km is presented. The results imply that the electron temperature at h = 140 km decreased by about 25 percent from solar maximum to solar minimum, compared to a decrease of 50-75 percent above 200 km found by Kliore and Mullen (1989).

  7. Solar activity over different timescales

    NASA Astrophysics Data System (ADS)

    Obridko, Vladimir; Nagovitsyn, Yuri

    The report deals with the “General History of the Sun” (multi-scale description of the long-term behavior of solar activity): the possibility of reconstruction. Time scales: • 100-150 years - the Solar Service. • 400 - instrumental observations. • 1000-2000 years - indirect data (polar auroras, sunspots seen with the naked eye). • Over-millennial scale (Holocene) -14С (10Be) Overview and comparison of data sets. General approaches to the problem of reconstruction of solar activity indices on a large timescale. North-South asymmetry of the sunspot formation activity. 200-year cycle over the “evolution timescales”.The relative contribution of the large-scale and low-latitude. components of the solar magnetic field to the general geomagnetic activity. “Large-scale” and low-latitude sources of geomagnetic disturbances.

  8. Long-term parenteral nutrition

    PubMed Central

    Ladefoged, Karin; Jarnum, Stig

    1978-01-01

    Nineteen patients (11 women and eight men) aged 20-68 received long-term parenteral nutrition, mostly at home, for six to 63 months (mean 19 months). Indications for LTPN were extensive, active Crohn's disease in three patients, intestinocutaneous fistulas in three, and short-bowel syndrome in the remaining 13 patients. Subclavian or intra-atrial (Broviac) catheters were most commonly used, for which the average life was four and seven months respectively. Complications of long-term parenteral nutrition included pneumothorax in four out of 48 subclavian vein punctures. Catheter-induced thrombosis of central veins was shown by phlebography 17 times in nine patients, and eight episodes of total occlusion occurred. Two of these patients had pulmonary infarction. Nineteen episodes of catheter sepsis occurred in 11 patients, but only one was fatal. Complications related to intestinal disease included intra-abdominal abscesses and intestinal fistulas, and disturbances of liver function. Five patients died, though in only two was death related to long-term parenteral nutrition. One of these patients died from catheter sepsis, the other had subdural haematoma possibly caused by anticoagulant treatment. Eight of the 14 surviving patients still needed parenteral nutrition. All received a disability pension, but six had an acceptable quality of life with almost normal social activities. Despite problems such as difficulties in maintaining standardised infusion programmes, it was concluded that long-term parenteral nutrition at home is practicable and consistent with an acceptable quality of life. ImagesFIG 2 PMID:98199

  9. Underwater deployment of the polyphenylene oxide dosimeter combined with a neutral density filter to measure long-term solar UVB exposures.

    PubMed

    Schouten, P W; Parisi, A V

    2012-07-01

    Numerous studies have conclusively shown how solar ultraviolet radiation (UV) (290-400 nm) has a negative impact upon underwater ecosystems. As a consequence of this, UV must be accurately evaluated in aquatic locations by employing a non-invasive measurement technique in order to better understand the damage it causes on both a macro and micro scale and provide solutions on how to manage its impact over both short and long time scales. Specifically, the UVB (290-320 nm) has the highest potential for causing stress to marine organisms. This manuscript details the deployment of a cost-effective and easily useable UVB detection dosimeter based on polyphenylene oxide (PPO) combined with a neutral density filter (NDF) derived from polyethylene. A long-term calibration regime performed over an extensive solar zenith angle range (SZA) in summer at a semi-tropical location showed that the PPO dosimeter used in conjunction with a polyethylene NDF could measure UVB exposures underwater up to 125 h in daylight (11-12 days approximately) before reaching near total saturation, providing an exposure limit as much as seven times greater that what was previously achievable with PPO dosimeters deployed without an NDF and approximately 42 times larger than those measured previously with polysulphone dosimeters. PMID:22551692

  10. The effect of acute and long-term physical activity on extracellular matrix and serglycin in human skeletal muscle

    PubMed Central

    Hjorth, Marit; Norheim, Frode; Meen, Astri J; Pourteymour, Shirin; Lee, Sindre; Holen, Torgeir; Jensen, Jørgen; Birkeland, Kåre I; Martinov, Vladimir N; Langleite, Torgrim M; Eckardt, Kristin; Drevon, Christian A; Kolset, Svein O

    2015-01-01

    Remodeling of extracellular matrix (ECM), including regulation of proteoglycans in skeletal muscle can be important for physiological adaptation to exercise. To investigate the effects of acute and long-term exercise on the expression of ECM-related genes and proteoglycans in particular, 26 middle-aged, sedentary men underwent a 12 weeks supervised endurance and strength training intervention and two acute, 45 min bicycle tests (70% VO2max), one at baseline and one after 12 weeks of training. Total gene expression in biopsies from m. vastus lateralis was measured with deep mRNA sequencing. After 45 min of bicycling approximately 550 gene transcripts were >50% upregulated. Of these, 28 genes (5%) were directly related to ECM. In response to long-term exercise of 12 weeks 289 genes exhibited enhanced expression (>50%) and 20% of them were ECM related. Further analyses of proteoglycan mRNA expression revealed that more than half of the proteoglycans expressed in muscle were significantly enhanced after 12 weeks intervention. The proteoglycan serglycin (SRGN) has not been studied in skeletal muscle and was one of few proteoglycans that showed increased expression after acute (2.2-fold, P < 0.001) as well as long-term exercise (1.4-fold, P < 0.001). Cultured, primary human skeletal muscle cells expressed and secreted SRGN. When the expression of SRGN was knocked down, the expression and secretion of serpin E1 (SERPINE1) increased. In conclusion, acute and especially long-term exercise promotes enhanced expression of several ECM components and proteoglycans. SRGN is a novel exercise-regulated proteoglycan in skeletal muscle with a potential role in exercise adaptation. PMID:26290530

  11. An Initial Evaluation of a Long-Term, Sustainable, Integrated Community-Based Physical Activity Program for Adults with Intellectual Disability

    ERIC Educational Resources Information Center

    Lante, Kerrie A.; Walkley, Jeff W.; Gamble, Merrilyn; Vassos, Maria V.

    2011-01-01

    Background: Physical activity (PA) programs for adults with intellectual disability (ID) have positive impacts, at least in the short term. No research has been reported on the effect of long-term engagement in PA programs for adults with ID. This paper explores the physical and psychosocial benefits gained by two individuals with mild ID who…

  12. Exploring Behavioral Markers of Long-Term Physical Activity Maintenance: A Case Study of System Identification Modeling within a Behavioral Intervention

    ERIC Educational Resources Information Center

    Hekler, Eric B.; Buman, Matthew P.; Poothakandiyil, Nikhil; Rivera, Daniel E.; Dzierzewski, Joseph M.; Aiken Morgan, Adrienne; McCrae, Christina S.; Roberts, Beverly L.; Marsiske, Michael; Giacobbi, Peter R., Jr.

    2013-01-01

    Efficacious interventions to promote long-term maintenance of physical activity are not well understood. Engineers have developed methods to create dynamical system models for modeling idiographic (i.e., within-person) relationships within systems. In behavioral research, dynamical systems modeling may assist in decomposing intervention effects…

  13. Prior Activation of Inositol 1,4,5-Trisphosphate Receptors Suppresses the Subsequent Induction of Long-Term Potentiation in Hippocampal CA1 Neurons

    ERIC Educational Resources Information Center

    Fujii, Satoshi; Yamazaki, Yoshihiko; Goto, Jun-Ichi; Fujiwara, Hiroki; Mikoshiba, Katsuhiko

    2016-01-01

    We investigated the role of inositol 1,4,5-trisphosphate receptors (IP3Rs) activated by preconditioning low-frequency afferent stimulation (LFS) in the subsequent induction of long-term potentiation (LTP) in CA1 neurons in hippocampal slices from mature guinea pigs. Induction of LTP in the field excitatory postsynaptic potential or the population…

  14. Cost-Effectiveness of a Long-Term Internet-Delivered Worksite Health Promotion Programme on Physical Activity and Nutrition: A Cluster Randomized Controlled Trial

    ERIC Educational Resources Information Center

    Robroek, Suzan J. W.; Polinder, Suzanne; Bredt, Folef J.; Burdorf, Alex

    2012-01-01

    This study aims to evaluate the cost-effectiveness of a long-term workplace health promotion programme on physical activity (PA) and nutrition. In total, 924 participants enrolled in a 2-year cluster randomized controlled trial, with departments (n = 74) within companies (n = 6) as the unit of randomization. The intervention was compared with a…

  15. Widespread blunting of hypothalamic and amygdala-septal activity and behavior in rats with long-term hyperglycemia.

    PubMed

    Moreno-Cortés, M L; Gutiérrez-García, A G; Guillén-Ruiz, G; Romo-González, T; Contreras, C M

    2016-09-01

    Anxiety and depression in diabetic patients contributes to a poor prognosis, but possible causal relationships have been controversial. Anxiety, fear, and anhedonia are mediated by interactions between different deep structures of the temporal lobe (e.g., amygdala complex and hippocampus) and other forebrain-related structures (e.g., lateral septal nucleus). Connections between these structures and the hypothalamic orexinergic system are necessary for the maintenance of energy and wakefulness. However, few studies have explored the impact of long-term hyperglycemia in these structures on anxiety. We induced long-term hyperglycemia (glucose levels of ∼500mg/dl) in Wistar rats by injecting them with alloxan and simultaneously protecting them from hyperglycemia by injecting them daily with a low dose of insulin (i.e., just enough insulin to avoid death), thus maintaining hyperglycemia and ketonuria for as long as 6 weeks. Compared with controls, long-term hyperglycemic rats exhibited a significant reduction of Fos expression in the lateral septal nucleus and basolateral amygdala, but no differences were found in cerebellar regions. Orexin-A cells appeared to be inactive in the lateral hypothalamus. No differences were found in sucrose consumption or behavior in the elevated plus maze compared with the control group, but a decrease in general locomotion was observed. These data indicate a generalized blunting of the metabolic brain response, accompanied by a decrease in locomotion but no changes in hedonic- or anxiety-like behavior.

  16. Ambient Ozone Control in a Photochemically Active Region: Short-Term Despiking or Long-Term Attainment?

    PubMed

    Ou, Jiamin; Yuan, Zibing; Zheng, Junyu; Huang, Zhijiong; Shao, Min; Li, Zekun; Huang, Xiaobo; Guo, Hai; Louie, Peter K K

    2016-06-01

    China has made significant progress decreasing the ambient concentrations of most air pollutants, but ozone (O3) is an exception. O3 mixing ratios during pollution episodes are far higher than the national standard in the Pearl River Delta (PRD), thus greater evidence-based control efforts are needed for O3 attainment. By using a validated O3 modeling system and the latest regional emission inventory, this study illustrates that control strategies for short-term O3 despiking and long-term attainment in the PRD may be contradictory. VOC-focused controls are more efficient for O3 despiking in urban and industrial areas, but significant NOx emission reductions and a subsequent transition to a NOx-limited regime are required for O3 attainment. By tracking O3 changes along the entire path toward long-term attainment, this study recommends to put a greater focus on NOx emission controls region-wide. Parallel VOC reductions around the Nansha port are necessary in summertime and should be extended to the urban and industrial areas in fall with a flexibility to be strengthened on days forecasted to have elevated O3. Contingent VOC-focused controls on top of regular NOx-focused controls would lay the groundwork for striking a balance between short-term despiking and long-term attainment of O3 concentrations in the PRD. PMID:27135547

  17. X-RAY, FUV, AND UV OBSERVATIONS OF {alpha} CENTAURI B: DETERMINATION OF LONG-TERM MAGNETIC ACTIVITY CYCLE AND ROTATION PERIOD

    SciTech Connect

    DeWarf, L. E.; Guinan, E. F.; Datin, K. M.

    2010-10-10

    Over the last couple of decades we have been carrying out a study of stellar magnetic activity, dynamos, atmospheric physics, and spectral irradiances from a sample of solar-type G0-5 V stars with different ages. One of the major goals of this program is to study the evolution of the Sun's X-ray through NUV spectral irradiances with age. Of particular interest is the determination of the young Sun's elevated levels of high-energy fluxes because of the critical roles that X-ray (coronal) through FUV (transition region (TR), chromospheric) emissions play on the photochemical and photoionization evolution (and possible erosion) of early, young planetary atmospheres and ionospheres. Motivated by the current exoplanetary search missions (such as Kepler and CoRoT, along with the planned Space Interferometry Mission and Darwin/Terrestrial Planet Finder missions) that are hunting for Earth-size planets in the habitable zones (liquid water) of nearby main-sequence G-M stars, we are expanding our program to cooler, less luminous, but very importantly, much more numerous main-sequence K-type stars, such as {alpha} Centauri B. The long life (2-3x longer than the Sun) and slow evolution of K stars provide nearly constant energy sources for possible hosted planets. This program parallels our 'Sun in Time' program, but extends the study to stars with deeper convective zone depths. Presented here are X-ray (coronal; ROSAT, Chandra, XMM-Newton), UV (TR; International Ultraviolet Explorer (IUE)), NUV (chromospheric; IUE), and recently acquired FUV (TR/chromospheric; FUSE Cycles 7/8) observations of the K1 V star {alpha} Cen B (HD 128621; V = 1.33; (B - V) = +0.88; {tau} = 5.6 {+-} 0.6 Gyr). These combined high-energy measures provide a more complete look into the nature of {alpha} Cen B's magnetic activity and X-ray-UV radiances. We find that {alpha} Cen B has exhibited significant long-term variability in X-ray through NUV emission fluxes, indicating a solar-like long-term activity

  18. Acute Stress, But not Corticosterone, Disrupts Short- and Long-Term Synaptic Plasticity in Rat Dorsal Subiculum Via Glucocorticoid Receptor Activation

    PubMed Central

    MacDougall, Matthew J.; Howland, John G.

    2015-01-01

    The subiculum (SUB) serves as the major output structure of the hippocampus; therefore, exploring synaptic plasticity within this region is of great importance for understanding the dynamics of hippocampal circuitry and hippocampal–cortical interactions. Previous research has shown exposure to acute stress dramatically alters synaptic plasticity within the hippocampus proper. Using in vivo electrophysiological recordings in urethane-anesthetized adult male Sprague–Dawley rats, we tested the effects of either acute restraint stress (30 min) or corticosterone (CORT) injections (3 mg/kg; s.c.) on short- and long-term forms of synaptic plasticity in the Cornu Ammonis 1–SUB pathway. Paired-pulse facilitation and two forms of long-term plasticity (long-term potentiation and late-developing potentiation) were significantly reduced after exposure to acute stress but not CORT treatment. Measurements of plasma CORT confirmed similar levels of circulating hormone in animals exposed to either acute stress or CORT treatment. The disruptive effects of acute stress on both short- and long-term forms of synaptic plasticity are mediated by glucocorticoid receptor (GR) activation as these disruptions were blocked by pre-treatment with the selective GR antagonist RU38486 (10 mg/kg; s.c.). The present results highlight the susceptibility of subicular plasticity to acute stress and provide evidence that GR activation is necessary but not sufficient for mediating these alterations. PMID:22918985

  19. Long-term efficacy and safety of once-daily mesalazine granules for the treatment of active ulcerative colitis.

    PubMed

    Böhm, Stephan Karl; Kruis, Wolfgang

    2014-01-01

    demonstrated that OD administration of 5-ASA is as effective as conventional dosing in mild to moderate active UC. The three 5-ASA products MMX, Salofalk(®), and Pentasa(®) employed in those studies so far have not shown differences in efficacy between OD and conventional dosing. No differences regarding safety outcomes have been detected between OD and conventional dosing, including incidence of adverse events, serious adverse events, or withdrawal from treatment due to an adverse event. Although the majority of patients prefer OD dosing to conventional dosing, it was not possible to detect differences in adherence between OD and multiple dose regimens in the clinical trial setting. Well-designed and controlled large-scale community-based studies are necessary to further investigate and prove the point of improved long-term adherence and treatment efficacy in OD dosing.

  20. Long-term efficacy and safety of once-daily mesalazine granules for the treatment of active ulcerative colitis

    PubMed Central

    Böhm, Stephan Karl; Kruis, Wolfgang

    2014-01-01

    demonstrated that OD administration of 5-ASA is as effective as conventional dosing in mild to moderate active UC. The three 5-ASA products MMX, Salofalk®, and Pentasa® employed in those studies so far have not shown differences in efficacy between OD and conventional dosing. No differences regarding safety outcomes have been detected between OD and conventional dosing, including incidence of adverse events, serious adverse events, or withdrawal from treatment due to an adverse event. Although the majority of patients prefer OD dosing to conventional dosing, it was not possible to detect differences in adherence between OD and multiple dose regimens in the clinical trial setting. Well-designed and controlled large-scale community-based studies are necessary to further investigate and prove the point of improved long-term adherence and treatment efficacy in OD dosing. PMID:25285021

  1. Reliability of 1.8-meter solar radio telescope at Metsähovi Radio Observatory for long-term solar monitoring

    NASA Astrophysics Data System (ADS)

    Uunila, Minttu; Kallunki, Juha

    2015-09-01

    Our aim is to prove that long time series of solar observations measured with Metsähovi Radio Observatory's 1.8-meter solar radio telescope, RT-1.8, at 11.2 GHz are reliable, and that the data can be used for solar cyclicity studies. We give a detailed description of RT-1.8 and its calibration. We compare 14 years of Metsähovi Radio Observatory's solar data from solar cycles 23 and 24 to both Dominion Radio Astrophysical Observatory (DRAO 2015), Penticton, Canada 2.8 GHz and Nobeyama Solar Radio Observatory (NSRO 2015), Nobeyama, Japan 9.4 and 17.0 GHz data. Our results show high correlation between all data sets.

  2. Effects of Long-Term Acupuncture Treatment on Resting-State Brain Activity in Migraine Patients: A Randomized Controlled Trial on Active Acupoints and Inactive Acupoints

    PubMed Central

    Zhao, Ling; Liu, Jixin; Zhang, Fuwen; Dong, Xilin; Peng, Yulin; Qin, Wei; Wu, Fumei; Li, Ying; Yuan, Kai; von Deneen, Karen M.; Gong, Qiyong; Tang, Zili; Liang, Fanrong

    2014-01-01

    Background Acupuncture has been commonly used for preventing migraine attacks and relieving pain during a migraine, although there is limited knowledge on the physiological mechanism behind this method. The objectives of this study were to compare the differences in brain activities evoked by active acupoints and inactive acupoints and to investigate the possible correlation between clinical variables and brain responses. Methods and Results A randomized controlled trial and resting-state functional magnetic resonance imaging (fMRI) were conducted. A total of eighty migraineurs without aura were enrolled to receive either active acupoint acupuncture or inactive acupoint acupuncture treatment for 8 weeks, and twenty patients in each group were randomly selected for the fMRI scan at the end of baseline and at the end of treatment. The neuroimaging data indicated that long-term active acupoint therapy elicited a more extensive and remarkable cerebral response compared with acupuncture at inactive acupoints. Most of the regions were involved in the pain matrix, lateral pain system, medial pain system, default mode network, and cognitive components of pain processing. Correlation analysis showed that the decrease in the visual analogue scale (VAS) was significantly related to the increased average Regional homogeneity (ReHo) values in the anterior cingulate cortex in the two groups. Moreover, the decrease in the VAS was associated with increased average ReHo values in the insula which could be detected in the active acupoint group. Conclusions Long-term active acupoint therapy and inactive acupoint therapy have different brain activities. We postulate that acupuncture at the active acupoint might have the potential effect of regulating some disease-affected key regions and the pain circuitry for migraine, and promote establishing psychophysical pain homeostasis. Trial Registration Chinese Clinical Trial Registry ChiCTR-TRC-13003635 PMID:24915066

  3. Sustainable development and next generation's health: a long-term perspective about the consequences of today's activities for food safety.

    PubMed

    Frazzoli, Chiara; Petrini, Carlo; Mantovani, Alberto

    2009-01-01

    Development is defined sustainable when it meets the needs of the present without compromising the ability of future generations to meet their own needs. Pivoting on social, environmental and economic aspects of food chain sustainability, this paper presents the concept of sustainable food safety based on the prevention of risks and burden of poor health for generations to come. Under this respect, the assessment of long-term, transgenerational risks is still hampered by serious scientific uncertainties. Critical issues to the development of a sustainable food safety framework may include: endocrine disrupters as emerging contaminants that specifically target developing organisms; toxicological risks assessment in Countries at the turning point of development; translating knowledge into toxicity indexes to support risk management approaches, such as hazard analysis and critical control points (HACCP); the interplay between chemical hazards and social determinants. Efforts towards the comprehensive knowledge and management of key factors of sustainable food safety appear critical to the effectiveness of the overall sustainability policies.

  4. Non-invasive long-term recordings of cortical 'direct current' (DC-) activity in humans using magnetoencephalography.

    PubMed

    Mackert, B M; Wübbeler, G; Burghoff, M; Marx, P; Trahms, L; Curio, G

    1999-10-01

    Recently, biomagnetic fields below 0.1 Hz arising from nerve or muscle injury currents have been measured non-invasively using superconducting quantum interference devices (SQUIDs). Here we report first long-term recordings of cortical direct current (DC) fields in humans based on a horizontal modulation (0.4 Hz) of the body and, respectively, head position beneath the sensor array: near-DC fields with amplitudes between 90 and 540 fT were detected in 5/5 subjects over the auditory cortex throughout prolonged stimulation periods (here: 30 s) during which subjects were listening to concert music. These results prove the feasibility to record non-invasively low amplitude near-DC magnetic fields of the human brain and open the perspective for studies on DC-phenomena in stroke, such as anoxic depolarization or periinfarct depolarization, and in migraine patients.

  5. The Effect of Novel Research Activities on Long-term Survival of Temporarily Captive Steller Sea Lions (Eumetopias jubatus).

    PubMed

    Shuert, Courtney; Horning, Markus; Mellish, Jo-Ann

    2015-01-01

    Two novel research approaches were developed to facilitate controlled access to, and long-term monitoring of, juvenile Steller sea lions for periods longer than typically afforded by traditional fieldwork. The Transient Juvenile Steller sea lion Project at the Alaska SeaLife Center facilitated nutritional, physiological, and behavioral studies on the platform of temporary captivity. Temporarily captive sea lions (TJs, n = 35) were studied, and were intraperitoneally implanted with Life History Transmitters (LHX tags) to determine causes of mortality post-release. Our goal was to evaluate the potential for long-term impacts of temporary captivity and telemetry implants on the survival of study individuals. A simple open-population Cormack-Jolly-Seber mark-recapture model was built in program MARK, incorporating resightings of uniquely branded study individuals gathered by several contributing institutions. A priori models were developed to weigh the evidence of effects of experimental treatment on survival with covariates of sex, age, capture age, cohort, and age class. We compared survival of experimental treatment to a control group of n = 27 free-ranging animals (FRs) that were sampled during capture events and immediately released. Sex has previously been show to differentially affect juvenile survival in Steller sea lions. Therefore, sex was included in all models to account for unbalanced sex ratios within the experimental group. Considerable support was identified for the effects of sex, accounting for over 71% of total weight for all a priori models with delta AICc <5, and over 91% of model weight after removal of pretending variables. Overall, most support was found for the most parsimonious model based on sex and excluding experimental treatment. Models including experimental treatment were not supported after post-hoc considerations of model selection criteria. However, given the limited sample size, alternate models including effects of experimental

  6. The Effect of Novel Research Activities on Long-term Survival of Temporarily Captive Steller Sea Lions (Eumetopias jubatus)

    PubMed Central

    Shuert, Courtney; Horning, Markus; Mellish, Jo-Ann

    2015-01-01

    Two novel research approaches were developed to facilitate controlled access to, and long-term monitoring of, juvenile Steller sea lions for periods longer than typically afforded by traditional fieldwork. The Transient Juvenile Steller sea lion Project at the Alaska SeaLife Center facilitated nutritional, physiological, and behavioral studies on the platform of temporary captivity. Temporarily captive sea lions (TJs, n = 35) were studied, and were intraperitoneally implanted with Life History Transmitters (LHX tags) to determine causes of mortality post-release. Our goal was to evaluate the potential for long-term impacts of temporary captivity and telemetry implants on the survival of study individuals. A simple open-population Cormack-Jolly-Seber mark-recapture model was built in program MARK, incorporating resightings of uniquely branded study individuals gathered by several contributing institutions. A priori models were developed to weigh the evidence of effects of experimental treatment on survival with covariates of sex, age, capture age, cohort, and age class. We compared survival of experimental treatment to a control group of n = 27 free-ranging animals (FRs) that were sampled during capture events and immediately released. Sex has previously been show to differentially affect juvenile survival in Steller sea lions. Therefore, sex was included in all models to account for unbalanced sex ratios within the experimental group. Considerable support was identified for the effects of sex, accounting for over 71% of total weight for all a priori models with delta AICc <5, and over 91% of model weight after removal of pretending variables. Overall, most support was found for the most parsimonious model based on sex and excluding experimental treatment. Models including experimental treatment were not supported after post-hoc considerations of model selection criteria. However, given the limited sample size, alternate models including effects of experimental

  7. The Effect of Novel Research Activities on Long-term Survival of Temporarily Captive Steller Sea Lions (Eumetopias jubatus).

    PubMed

    Shuert, Courtney; Horning, Markus; Mellish, Jo-Ann

    2015-01-01

    Two novel research approaches were developed to facilitate controlled access to, and long-term monitoring of, juvenile Steller sea lions for periods longer than typically afforded by traditional fieldwork. The Transient Juvenile Steller sea lion Project at the Alaska SeaLife Center facilitated nutritional, physiological, and behavioral studies on the platform of temporary captivity. Temporarily captive sea lions (TJs, n = 35) were studied, and were intraperitoneally implanted with Life History Transmitters (LHX tags) to determine causes of mortality post-release. Our goal was to evaluate the potential for long-term impacts of temporary captivity and telemetry implants on the survival of study individuals. A simple open-population Cormack-Jolly-Seber mark-recapture model was built in program MARK, incorporating resightings of uniquely branded study individuals gathered by several contributing institutions. A priori models were developed to weigh the evidence of effects of experimental treatment on survival with covariates of sex, age, capture age, cohort, and age class. We compared survival of experimental treatment to a control group of n = 27 free-ranging animals (FRs) that were sampled during capture events and immediately released. Sex has previously been show to differentially affect juvenile survival in Steller sea lions. Therefore, sex was included in all models to account for unbalanced sex ratios within the experimental group. Considerable support was identified for the effects of sex, accounting for over 71% of total weight for all a priori models with delta AICc <5, and over 91% of model weight after removal of pretending variables. Overall, most support was found for the most parsimonious model based on sex and excluding experimental treatment. Models including experimental treatment were not supported after post-hoc considerations of model selection criteria. However, given the limited sample size, alternate models including effects of experimental

  8. Stimulation of gene expression and activity of antioxidant related enzyme in Sprague Dawley rat kidney induced by long-term iron toxicity.

    PubMed

    Budak, Harun; Kocpinar, Enver Fehim; Gonul, Nurdan; Ceylan, Hamid; Erol, Huseyin Serkan; Erdogan, Orhan

    2014-11-01

    The trace elements such as iron are vital for various enzyme activities and for other cellular proteins, but iron toxicity causes the production of reactive oxygen species (ROS) that causes alterations in morphology and function of the nephron. The present study was designed to determine the effect of long-term iron overload on the renal antioxidant system and to determine any possible correlation between enzymatic and molecular levels. Our data showed that reduced glutathione (GSH) levels, which is a marker for oxidative stress, strikingly decreased with a long-term iron overload in rat kidney. While renal mRNA levels of glucose 6-phosphate dehydrogenase (G6pd), 6-phosphogluconate dehydrogenase (6pgd) and glutathione peroxidase (Gpx) were significantly affected in the presence of ferric iron, no changes were seen for glutathione reductase (Gsr) and glutathione S-transferases (Gst). While the iron affected the enzymatic activity of G6PD, GSR, GST, and GPX, it had no significant effect on 6PGD activity in the rat kidney. In conclusion, we reported here that the gene expression of G6pd, 6pgd, Gsr, Gpx, and Gst did not correlate to enzyme activity, and the actual effect of long-term iron overload on renal antioxidant system is observed at protein level. Furthermore, the influence of iron on the renal antioxidant system is different from its effect on the hepatic antioxidant system. PMID:25038477

  9. Forgetting of long-term memory requires activation of NMDA receptors, L-type voltage-dependent Ca2+ channels, and calcineurin

    PubMed Central

    Sachser, Ricardo Marcelo; Santana, Fabiana; Crestani, Ana Paula; Lunardi, Paula; Pedraza, Lizeth Katherine; Quillfeldt, Jorge Alberto; Hardt, Oliver; de Oliveira Alvares, Lucas

    2016-01-01

    In the past decades, the cellular and molecular mechanisms underlying memory consolidation, reconsolidation, and extinction have been well characterized. However, the neurobiological underpinnings of forgetting processes remain to be elucidated. Here we used behavioral, pharmacological and electrophysiological approaches to explore mechanisms controlling forgetting. We found that post-acquisition chronic inhibition of the N-methyl-D-aspartate receptor (NMDAR), L-type voltage-dependent Ca2+ channel (LVDCC), and protein phosphatase calcineurin (CaN), maintains long-term object location memory that otherwise would have been forgotten. We further show that NMDAR activation is necessary to induce forgetting of object recognition memory. Studying the role of NMDAR activation in the decay of the early phase of long-term potentiation (E-LTP) in the hippocampus, we found that ifenprodil infused 30 min after LTP induction in vivo blocks the decay of CA1-evoked postsynaptic plasticity, suggesting that GluN2B-containing NMDARs activation are critical to promote LTP decay. Taken together, these findings indicate that a well-regulated forgetting process, initiated by Ca2+ influx through LVDCCs and GluN2B-NMDARs followed by CaN activation, controls the maintenance of hippocampal LTP and long-term memories over time. PMID:26947131

  10. Bacterial response to a continuous long-term exposure of silver nanoparticles at sub-ppm silver concentrations in a membrane bioreactor activated sludge system.

    PubMed

    Zhang, Chiqian; Liang, Zhihua; Hu, Zhiqiang

    2014-03-01

    Silver nanoparticles (nanosilver or AgNPs) have excellent antimicrobial properties. Because of their increasing use, there is a concern about the potential impact of AgNPs in wastewater treatment systems. This study investigated the long-term effects of AgNPs (continuous loading for more than 60 days) on membrane bioreactor (MBR) activated sludge performance. At the influent AgNP concentration of 0.10 mg Ag/L, there was no significant difference in effluent water quality or bacterial activities before and after AgNP exposure. Nitrifying bacterial community structure was relatively stable before and after the long-term AgNP loading. Both ammonia-oxidizing bacteria (AOB) Nitrosomonas spp. and Nitrosospira spp. were present while Nitrospira spp. was the dominant nitrite-oxidizing bacterial species throughout this study. Abundance of silver resistance gene silE in the MBR, however, increased by 50-fold 41 days after the AgNP exposure, and then decreased with continuous AgNP exposure. The long-term nanosilver exposure did not change the membrane fouling rate although extracellular polymeric substances (EPS) concentration increased significantly after nanosilver dosing. The results suggest that AgNPs at the influent concentrations of 0.10 mg/L and below have almost no impact on activated sludge wastewater treatment performance, as activated sludge can effectively reduce nanosilver toxicity by adsorbing or precipitating AgNPs and silver ions (Ag(+)) released from the dissolution of AgNPs. PMID:24210505

  11. Forgetting of long-term memory requires activation of NMDA receptors, L-type voltage-dependent Ca2+ channels, and calcineurin.

    PubMed

    Sachser, Ricardo Marcelo; Santana, Fabiana; Crestani, Ana Paula; Lunardi, Paula; Pedraza, Lizeth Katherine; Quillfeldt, Jorge Alberto; Hardt, Oliver; Alvares, Lucas de Oliveira

    2016-01-01

    In the past decades, the cellular and molecular mechanisms underlying memory consolidation, reconsolidation, and extinction have been well characterized. However, the neurobiological underpinnings of forgetting processes remain to be elucidated. Here we used behavioral, pharmacological and electrophysiological approaches to explore mechanisms controlling forgetting. We found that post-acquisition chronic inhibition of the N-methyl-D-aspartate receptor (NMDAR), L-type voltage-dependent Ca(2+) channel (LVDCC), and protein phosphatase calcineurin (CaN), maintains long-term object location memory that otherwise would have been forgotten. We further show that NMDAR activation is necessary to induce forgetting of object recognition memory. Studying the role of NMDAR activation in the decay of the early phase of long-term potentiation (E-LTP) in the hippocampus, we found that ifenprodil infused 30 min after LTP induction in vivo blocks the decay of CA1-evoked postsynaptic plasticity, suggesting that GluN2B-containing NMDARs activation are critical to promote LTP decay. Taken together, these findings indicate that a well-regulated forgetting process, initiated by Ca(2+) influx through LVDCCs and GluN2B-NMDARs followed by CaN activation, controls the maintenance of hippocampal LTP and long-term memories over time.

  12. Short- and long-term effects of solar ultraviolet radiation on the red algae Porphyridium cruentum (S. F. Gray) Nägeli.

    PubMed

    Villafañe, Virginia E; Gao, Kunshan; Helbling, E Walter

    2005-04-01

    During spring 2002 and fall 2003 we carried out experiment in tropical southern China to determine the short- and long-term effects of solar ultraviolet radiation (UVR, 280-400 nm) on photosynthesis and growth in the unicellular red alga Porphyridium cruentum. During the experimentation, cells of P. cruentum were exposed to three radiation treatments: (a) samples exposed to PAR (400-700 nm) + UV-A (315-400 nm) + UV-B (280-315 nm)(PAB treatment); (b) samples exposed to PAR + UV-A (PA treatment) and, (c) samples exposed only to PAR (P treatment). To assess the short-term impact of UVR as a function of irradiance, we determined photosynthesis versus irradiance (Pvs.E) curves. From these curves the maximum carbon uptake rate (P(max)) and the light saturation parameter (E(k)) were obtained, with values of approximately 12.8-14.4 microg C (microg chl a)(-1) h(-1), and approximately 250 micromol m(-2) s(-1), respectively. A significant UVR effect on assimilation numbers was observed when samples were exposed at irradiances higher than E(k), with samples exposed to full solar radiation having significant less carbon fixation than those exposed only to PAR. Biological weighting functions of P. cruentum were used to evaluate the UVR impact per unit energy received by the cells; the data indicate that the species is as sensitive as natural phytoplankton from the southern China Sea; however, it is much more resistant than Antarctic assemblages. When evaluating the combined effects of mixing speed and UVR, it was seen that samples rotating fast within the upper mixed layer were less inhibited by UVR as compared to those under slow mixing or in fixed samples. Growth of P. cruentum over a week-long experiment was not affected by neither UVR nor UV-A; additionally, low photoinhibition was found at the end as compared to that at the beginning of this experiment. Our results thus indicate that, although on short-term basis P. cruentum is affected by solar UVR, it can acclimate to

  13. Long-term weathering effects on the thermal performance of the solargenics (liquid) solar collector at outdoor conditions. [Marshall Space Flight Center Solar test facility

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The test procedures and the results obtained during the evaluation of a single-covered liquid solar collector are presented. The tests were performed under outdoor natural conditions. The collector was under stagnation conditions for a total of approximately ten months. The solar collector is a liquid, single-glazed, flat plate collector, and is about 240 inches long, and 3.8 inches in depth.

  14. Long-term safety evaluation of bimatoprost ophthalmic solution 0.03%: a pooled analysis of six double-masked, randomized, active-controlled clinical trials

    PubMed Central

    Wirta, David; VanDenburgh, Amanda M; Weng, Emily; Whitcup, Scott M; Kurstjens, Sef; Beddingfield, Frederick C

    2011-01-01

    Background: Bimatoprost ophthalmic solution 0.03% was approved in the US for reducing intraoccular pressure (IOP) based on two double-masked, active-controlled clinical trials. Four additional long-term studies (≥12 months) were conducted; however, the aggregate safety profile of the six studies has not been reported. Methods: Adverse events (AEs) were pooled from six double-masked, active-controlled, long-term clinical trials in which subjects received bimatoprost 0.03% once daily (QD) or twice daily (BID) as an eyedrop. AE terms were converted to MedDRA (V.11.0) Preferred Terms and analyzed. Results: In total, 1409 patients received more than one dose of bimatoprost 0.03% QD or BID. Most AEs were mild in severity and reported by 86.7% (QD) and 94.8% (BID) of subjects (≤12 months of treatment). AEs reported through month 12 (aggregate incidence of ≥5%) were conjunctival hyperemia, increased eyelash growth, eye pruritus, periocular skin hyperpigmentation, eye irritation, dry eye, and hypertrichosis. AE onset was generally reported within four months of treatment. The cumulative incidence of common AEs in the QD treatment group at 24–48 months was similar to that measured at 12 months of treatment. Conclusion: Bimatoprost 0.03% has a favorable safety and tolerability profile as characterized by six long-term studies. Common AEs were due to the known pharmacological activity of bimatoprost and reversible with treatment cessation. PMID:21691584

  15. Insolation data manual: Long-term monthly averages of solar radiation, temperature, degree-days, and global KT for 248 National Weather Service stations and direct normal solar radiation data manual: Long-term, monthly mean, daily totals for 235 National Weather Service stations

    NASA Astrophysics Data System (ADS)

    1990-07-01

    The Insolation Data Manual presents monthly averaged data which describes the availability of solar radiation at 248 National Weather Service (NWS) stations, principally in the United States. Monthly and annual average daily insolation and temperature values have been computed from a base of 24 to 25 years of data, generally from 1952 to 1975, and listed for each location. Insolation values represent monthly average daily totals of global radiation on a horizontal surface and are depicted using the three units of measurement: kJ/sq m per day, Btu/sq ft per day and langleys per day. Average daily maximum, minimum and monthly temperatures are provided for most locations in both Celsius and Fahrenheit. Heating and cooling degree-days were computed relative to a base of 18.3 C (65 F). For each station, global KT (cloudiness index) values were calculated on a monthly and annual basis. Global KT is an index of cloudiness and indicates fractional transmittance of horizontal radiation, from the top of the atmosphere to the earth's surface. The second section of this volume presents long-term monthly and annual averages of direct normal solar radiation for 235 NWS stations, including a discussion of the basic derivation process. This effort is in response to a generally recognized need for reliable direct normal data and the recent availability of 23 years of hourly averages for 235 stations. The relative inaccessibility of these data on microfiche further justifies reproducing at least the long-term averages in a useful format. In addition to a definition of terms and an overview of the ADIPA model, a discussion of model validation results is presented.

  16. The hypothalamic-pituitary-luteal axis in women: effects of long-term orally active opioid antagonist (naltrexone) administration.

    PubMed

    Fulghesu, A M; Lanzone, A; Apa, R; Guido, M; Ciampelli, M; Cucinelli, F; Caruso, A; Mancuso, S

    1997-01-01

    Aim of our study is to assess the effect of a long-term oral opiate antagonist treatment during the luteal phase on the hypothalamic-pituitary-ovarian axis. Fourteen normovulatory women participated to the study. Immediately after the ovulation, the patients were randomly divided in two groups: in the first one women received naltrexone 50 mg/die orally (Antaxone Zambon Italy) from day 1 of the luteal phase for 7 days. In the second patients were treated with placebo for the same period and served as control group. On day 7, patients were hospitalized for a pulse pattern study followed by a GnRH test. LH, FSH, Estradiol, Progesterone were assayed. The naltrexone administration strongly increased the number as well as the amplitude of the gonadotropin pulses. The circulating P levels were also significantly higher in treated patients. The GnRH injection significantly increases the gonadotropin secretion in all patients. The stimulated LH and FSH secretion was significantly greater in treated patients when compared to controls. Such discharge of LH determined a significant increase of progesterone production in controls, but failed to stimulate the corpus luteum in treated patients. In conclusion the present paper strengthen an important role of the opioidergic system in the regulation of GnRH pulsatility in luteal phase. Moreover, our findings confirms the sensibility of the corpus luteum to LH and the possibility to stimulate the P secretion during the luteal phase.

  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. 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.

  19. Alterations in task-induced activity and resting-state fluctuations in visual and DMN areas revealed in long-term meditators.

    PubMed

    Berkovich-Ohana, Aviva; Harel, Michal; Hahamy, Avital; Arieli, Amos; Malach, Rafael

    2016-07-15

    Recently we proposed that the information contained in spontaneously emerging (resting-state) fluctuations may reflect individually unique neuro-cognitive traits. One prediction of this conjecture, termed the "spontaneous trait reactivation" (STR) hypothesis, is that resting-state activity patterns could be diagnostic of unique personalities, talents and life-styles of individuals. Long-term meditators could provide a unique experimental group to test this hypothesis. Using fMRI we found that, during resting-state, the amplitude of spontaneous fluctuations in long-term mindfulness meditation (MM) practitioners was enhanced in the visual cortex and significantly reduced in the DMN compared to naïve controls. Importantly, during a visual recognition memory task, the MM group showed heightened visual cortex responsivity, concomitant with weaker negative responses in Default Mode Network (DMN) areas. This effect was also reflected in the behavioral performance, where MM practitioners performed significantly faster than the control group. Thus, our results uncover opposite changes in the visual and default mode systems in long-term meditators which are revealed during both rest and task. The results support the STR hypothesis and extend it to the domain of local changes in the magnitude of the spontaneous fluctuations. PMID:27109713

  20. Alterations in task-induced activity and resting-state fluctuations in visual and DMN areas revealed in long-term meditators.

    PubMed

    Berkovich-Ohana, Aviva; Harel, Michal; Hahamy, Avital; Arieli, Amos; Malach, Rafael

    2016-07-15

    Recently we proposed that the information contained in spontaneously emerging (resting-state) fluctuations may reflect individually unique neuro-cognitive traits. One prediction of this conjecture, termed the "spontaneous trait reactivation" (STR) hypothesis, is that resting-state activity patterns could be diagnostic of unique personalities, talents and life-styles of individuals. Long-term meditators could provide a unique experimental group to test this hypothesis. Using fMRI we found that, during resting-state, the amplitude of spontaneous fluctuations in long-term mindfulness meditation (MM) practitioners was enhanced in the visual cortex and significantly reduced in the DMN compared to naïve controls. Importantly, during a visual recognition memory task, the MM group showed heightened visual cortex responsivity, concomitant with weaker negative responses in Default Mode Network (DMN) areas. This effect was also reflected in the behavioral performance, where MM practitioners performed significantly faster than the control group. Thus, our results uncover opposite changes in the visual and default mode systems in long-term meditators which are revealed during both rest and task. The results support the STR hypothesis and extend it to the domain of local changes in the magnitude of the spontaneous fluctuations.

  1. [Radiometers performance attenuation and data correction in long-term observation of total radiation and photosynthetically active radiation in typical forest ecosystems in China].

    PubMed

    Zhu, Zhi-Lin; Sun, Xiao-Min; Yu, Gui-Rui; Wen, Xue-Fa; Zhang, Yi-Ping; Han, Shi-Jie; Yan, Jun-Hua; Wang, Hui-Min

    2011-11-01

    Based on the total radiation and photosynthetically active radiation (PAR) observations with net radiometer (CNR1) and quantum sensor (Li-190SB) in 4 ChinaFLUX forest sites (Changbaishan, Qianyanzhou, Dinghushan, and Xishuangbanna) in 2003-2008, this paper analyzed the uncertainties and the radiometers performance changes in long-term and continuous field observation. The results showed that the 98% accuracy of the total radiation measured with CNR1 (Q(cNR1)) could satisfy the technical criterion for the sites except Xishuangbanna where the Q(CNR1) was averagely about 7% lower than Q(CM11), the radiation measured with high accuracy pyranometer CM11. For most sites, though the temperature had definite effects on the performance of CNR1, the effects were still within the allowable range of the accuracy of the instrument. Besides temperature, the seasonal fog often occurred in tropical rain forests in Xishuangbanna also had effects on the performance of CNR1. Based on the long-term variations of PAR, especially its ratio to total radiation in the 4 sites, it was found that quantum sensor (Li-190SB) had obvious performance attenuation, with the mean annual attenuation rate being about 4%. To correct the observation error caused by Li-190SB, an attempt was made to give a post-correction of the PAR observations, which could basically eliminate the quantum sensor's performance attenuation due to long-term field measurement.

  2. Long-term effect of irrigation with water from sewage treatment plant on AMF biodiversity and microbial activities.

    NASA Astrophysics Data System (ADS)

    Alguacil, M. M.; Torrecillas, E.; Lozano, Z.; Torres, M. P.; Garcia-Orenes, F.; Roldan, A.

    2012-04-01

    Shortage of water is one of the most important environmental problem in the Mediterranean areas that implicates the search for strategies for saving good quality water. The use of treated waste water for the irrigation of agricultural land can be a good solution for this problem because it reduces the utilization of fresh water and potentially could improve soil key parameters, but can modify physical-chemical and biological properties of the same. The aim of this work was to study the effect of long-term irrigation with treated waste water on microbial diversity, mainly arbuscular mycorrhizal fungi (AMF) of the soil and other properties related with the microbial community. The experiment was developed in an agricultural area with Citrus orchard, located in Alicante in the southeast Spain. Here, we tested whether the communities of AMF as well as soil microbial properties were affected by irrigation with water coming from sewage treatment plant during 40 years in a soil. To carry out this study the soil properties (dehydrogenase, urease, protease-BAA, acid phosphatase, β-glucosidase, glomalin related soil protein, microbial biomass C and aggregate stability) and AMF diversity (the AM fungal small sub-unit (SSU) rRNA genes were subjected to PCR, cloning, sequencing and phylogenetic analyses) were analysed in the soil from two different plots with the same soil but with different type of irrigation (irrigated with fresh water and irrigated with treated water). The first results did not show significant differences in some soil properties between soil irrigated with water treated or not.

  3. Workshop on Solar Activity, Solar Wind, Terrestrial Effects, and Solar Acceleration

    NASA Technical Reports Server (NTRS)

    1992-01-01

    A summary of the proceedings from the workshop are presented. The areas covered were solar activity, solar wind, terrestrial effects, and solar acceleration. Specific topics addressed include: (1) solar cycle manifestations, both large and small scale, as well as long-term and short-term changes, including transients such as flares; (2) sources of solar wind, as identified by interplanetary observations including coronal mass ejections (CME's) or x-ray bright points, and the theory for and evolution of large-scale and small-scale structures; (3) magnetosphere responses, as observed by spacecraft, to variable solar wind and transient energetic particle emissions; and (4) origin and propagation of solar cosmic rays as related to solar activity and terrestrial effects, and solar wind coronal-hole relationships and dynamics.

  4. Divergent short- and long-term effects of acute stress in object recognition memory are mediated by endogenous opioid system activation.

    PubMed

    Nava-Mesa, Mauricio O; Lamprea, Marisol R; Múnera, Alejandro

    2013-11-01

    Acute stress induces short-term object recognition memory impairment and elicits endogenous opioid system activation. The aim of this study was thus to evaluate whether opiate system activation mediates the acute stress-induced object recognition memory changes. Adult male Wistar rats were trained in an object recognition task designed to test both short- and long-term memory. Subjects were randomly assigned to receive an intraperitoneal injection of saline, 1 mg/kg naltrexone or 3 mg/kg naltrexone, four and a half hours before the sample trial. Five minutes after the injection, half the subjects were submitted to movement restraint during four hours while the other half remained in their home cages. Non-stressed subjects receiving saline (control) performed adequately during the short-term memory test, while stressed subjects receiving saline displayed impaired performance. Naltrexone prevented such deleterious effect, in spite of the fact that it had no intrinsic effect on short-term object recognition memory. Stressed subjects receiving saline and non-stressed subjects receiving naltrexone performed adequately during the long-term memory test; however, control subjects as well as stressed subjects receiving a high dose of naltrexone performed poorly. Control subjects' dissociated performance during both memory tests suggests that the short-term memory test induced a retroactive interference effect mediated through light opioid system activation; such effect was prevented either by low dose naltrexone administration or by strongly activating the opioid system through acute stress. Both short-term memory retrieval impairment and long-term memory improvement observed in stressed subjects may have been mediated through strong opioid system activation, since they were prevented by high dose naltrexone administration. Therefore, the activation of the opioid system plays a dual modulating role in object recognition memory.

  5. Long-Term Activation of Group I Metabotropic Glutamate Receptors Increases Functional TRPV1-Expressing Neurons in Mouse Dorsal Root Ganglia

    PubMed Central

    Masuoka, Takayoshi; Kudo, Makiko; Yoshida, Junko; Ishibashi, Takaharu; Muramatsu, Ikunobu; Kato, Nobuo; Imaizumi, Noriko; Nishio, Matomo

    2016-01-01

    Damaged tissues release glutamate and other chemical mediators for several hours. These chemical mediators contribute to modulation of pruritus and pain. Herein, we investigated the effects of long-term activation of excitatory glutamate receptors on functional expression of transient receptor potential vaniloid type 1 (TRPV1) in dorsal root ganglion (DRG) neurons and then on thermal pain behavior. In order to detect the TRPV1-mediated responses in cultured DRG neurons, we monitored intracellular calcium responses to capsaicin, a TRPV1 agonist, with Fura-2. Long-term (4 h) treatment with glutamate receptor agonists (glutamate, quisqualate or DHPG) increased the proportion of neurons responding to capsaicin through activation of metabotropic glutamate receptor mGluR1, and only partially through the activation of mGluR5; engagement of these receptors was evident in neurons responding to allylisothiocyanate (AITC), a transient receptor potential ankyrin type 1 (TRPA1) agonist. Increase in the proportion was suppressed by phospholipase C (PLC), protein kinase C, mitogen/extracellular signal-regulated kinase, p38 mitogen-activated protein kinase or transcription inhibitors. Whole-cell recording was performed to record TRPV1-mediated membrane current; TRPV1 current density significantly increased in the AITC-sensitive neurons after the quisqualate treatment. To elucidate the physiological significance of this phenomenon, a hot plate test was performed. Intraplantar injection of quisqualate or DHPG induced heat hyperalgesia that lasted for 4 h post injection. This chronic hyperalgesia was attenuated by treatment with either mGluR1 or mGluR5 antagonists. These results suggest that long-term activation of mGluR1/5 by peripherally released glutamate may increase the number of neurons expressing functional TRPV1 in DRG, which may be strongly associated with chronic hyperalgesia. PMID:27064319

  6. Regulation of Synaptic Rac1 Activity, Long-Term Potentiation Maintenance, and Learning and Memory by BCR and ABR Rac GTPase-Activating Proteins

    PubMed Central

    Oh, Daeyoung; Han, Seungnam; Seo, Jinsoo; Lee, Jae-Ran; Choi, Jeonghoon; Groffen, John; Kim, Karam; Cho, Yi Sul; Choi, Han-Saem; Shin, Hyewon; Woo, Jooyeon; Won, Hyejung; Park, Soon Kwon; Kim, Soo-Young; Jo, Jihoon; Whitcomb, Daniel J.; Cho, Kwangwook; Kim, Hyun; Bae, Yong Chul; Heisterkamp, Nora; Choi, Se-Young; Kim, Eunjoon

    2016-01-01

    Rho family small GTPases are important regulators of neuronal development. Defective Rho regulation causes nervous system dysfunctions including mental retardation and Alzheimer’s disease. Rac1, a member of the Rho family, regulates dendritic spines and excitatory synapses, but relatively little is known about how synaptic Rac1 is negatively regulated. Breakpoint cluster region (BCR) is a Rac GTPase-activating protein known to form a fusion protein with the c-Abl tyrosine kinase in Philadelphia chromosome-positive chronic myelogenous leukemia. Despite the fact that BCR mRNAs are abundantly expressed in the brain, the neural functions of BCR protein have remained obscure. We report here that BCR and its close relative active BCR-related (ABR) localize at excitatory synapses and directly interact with PSD-95, an abundant postsynaptic scaffolding protein. Mice deficient for BCR or ABR show enhanced basal Rac1 activity but only a small increase in spine density. Importantly, mice lacking BCR or ABR exhibit a marked decrease in the maintenance, but not induction, of long-term potentiation, and show impaired spatial and object recognition memory. These results suggest that BCR and ABR have novel roles in the regulation of synaptic Rac1 signaling, synaptic plasticity, and learning and memory, and that excessive Rac1 activity negatively affects synaptic and cognitive functions. PMID:20962234

  7. The long-term effectiveness of need-supportive physical activity counseling compared with a standard referral in sedentary older adults.

    PubMed

    Van Hoecke, Ann-Sophie; Delecluse, Christophe; Bogaerts, An; Boen, Filip

    2014-04-01

    This study compared the long-term effectiveness of three physical activity counseling strategies among sedentary older adults: a 1-contact referral (REFER), a 1-contact individualized walking program (WALK), and multiple-contact, individually tailored, and need-supportive coaching based on the self-determination theory (COACH). Participants (n = 442) completed measurements before (pretest), immediately after (posttest), and 1 yr after (follow-up test) a 10-wk intervention. Linear mixed models demonstrated significant time-by-condition interaction effects from pre- to posttest. More specifically, WALK and COACH yielded larger increases in daily steps and self-reported physical activity than REFER. Similarly, self-reported physical activity increased more from pre- to follow-up test in WALK and COACH compared with REFER. Autonomous motivation mediated the effect of perceived need-support on physical activity, irrespective of counseling strategy. These results demonstrate the long-term effectiveness of both a 1-contact individualized walking program and a more time-consuming, need-supportive coaching, especially in comparison with a standard referral to local opportunities.

  8. Long term environmental tobacco smoke activates nuclear transcription factor-kappa B, activator protein-1, and stress responsive kinases in mouse brain.

    PubMed

    Manna, Sunil K; Rangasamy, Thirumalai; Wise, Kimberly; Sarkar, Shubhashish; Shishodia, Shishir; Biswal, Shyam; Ramesh, Govindarajan T

    2006-05-28

    Environmental tobacco smoke (ETS) is a key mediator of several diseases. Tobacco smoke contains a mixture of over 4700 chemical components many of which are toxic and have been implicated in the etiology of oxidative stress related diseases such as chronic obstructive pulmonary disease, Parkinson's disease, asthma, cancer and cardiovascular disease. However, the mechanism of action of cigarette smoke in the onset of these diseases is still largely unknown. Previous studies have revealed that the free radicals generated by cigarette smoke may contribute to many of these chronic health problems and this study sought to address the role of environmental tobacco smoke in oxidative stress related damage in different regions of the mouse brain. In this study, male mice were exposed for 7h/day, 7 days/week, for 6 months. Our results show that tobacco smoke led to increased generation of reactive oxygen species with an increase in NF-kappaB activation. Gel shift analysis also revealed the elevated level of the oxidative stress sensitive proinflammatory nuclear transcription factor-kappa B and activator protein-1 in different regions of the brain of cigarette smoke exposed mice. Tobacco smoke led to activation of COX-2 in all the regions of the brain. Activation of mitogen activated protein kinase and c-Jun N-terminal kinase were also observed in various regions of brain of ETS exposed mice. Overall our results indicate that exposure to long-term cigarette smoke induces oxidative stress leading to activation of stress induced kinases and activation of proinflammatory transcription factors.

  9. Assessing role activities of individuals receiving long-term hemodialysis: psychometric testing of the revised Inventory of Functional Status-Dialysis (IFS-Dialysis).

    PubMed

    Thomas-Hawkins, Charlotte

    2005-08-01

    The purpose of the study was to examine the reliability and validity of the revised IFS-Dialysis, a theory-based self-report measure of the extent to which individuals receiving long-term hemodialysis are actually performing role activities. The IFS-Dialysis was administered to 186 individuals receiving hemodialysis. Chronbach's alpha was used to assess internal consistency reliability, and structural equation modeling was used to assess the construct validity of the revised measure. Alpha reliability for the total instrument was 0.88, and subscale alpha coefficients ranged from 0.75 to 0.85. Construct validity of the IFS-Dialysis was supported by the significant relationship of each item to its respective subscale latent variable, and model testing indicated a good fit of the measurement model to the data. The IFS-Dialysis can be used to obtain clinical assessments of the extent to which individuals receiving long-term hemodialysis treatments are engaging in role activities. Interventions can then be implemented to facilitate an optimal level of activity performance for each individual.

  10. Virus burden in long-term survivors of human immunodeficiency virus (HIV) infection is a determinant of anti-HIV CD8+ lymphocyte activity.

    PubMed

    Ferbas, J; Kaplan, A H; Hausner, M A; Hultin, L E; Matud, J L; Liu, Z; Panicali, D L; Nerng-Ho, H; Detels, R; Giorgi, J V

    1995-08-01

    Persons infected with human immunodeficiency virus (HIV) for > 8 years were studied to delineate virologic and immunologic attributes of long-term survival. Whereas those with 300-700 CD4+ cells/microL often had circulating cytotoxic T lymphocytes (CTL) against HIV antigens, those with > 1000 CD4+ cells/microL did not. The subjects with > 1000 CD4+ cells/microL had low virus burden, low levels of Gag-specific CTL precursors, and minimal CD8+ cell activation. Overall, elevated levels of CD8+ cells, CD38 antigen expression on CD8+ cells, and anti-HIV functions were correlated with increased virus burden, provirus load, and HIV plasma RNA levels. A factor that suppressed HIV replication was spontaneously secreted from CD8+ cells of most subjects but not from those with high CD4+ cell counts. CD8+ cell activities, therefore, may reflect chronic viral stimulation of the immune system. Long-term survivors with high levels of CD4+ cells maintained control of viral replication but lacked the CD8+ cell activities.

  11. NLRP3 inflammasome activation by mitochondrial reactive oxygen species plays a key role in long-term cognitive impairment induced by paraquat exposure.

    PubMed

    Chen, Liuji; Na, Ren; Boldt, Erin; Ran, Qitao

    2015-09-01

    Exposure to environmental toxins such as pesticides is implicated in increasing Alzheimer's disease risk. In this study, we investigated the long-term effects of paraquat exposure on cognition of Alzheimer's disease animal model APP/PS1 mice and wild-type (WT) mice. Our results showed that APP/PS1 mice had exacerbated cognition impairment and elevated Aβ levels at 5 months after paraquat exposure, and that WT mice had cognition impairment at 5 and 16 months after paraquat exposure. In addition, increased mitochondrial oxidative stress and augmented brain inflammation were observed in both paraquat-exposed APP/PS1 mice and WT mice. Interestingly, activation of NLRP3 inflammasome, which triggers inflammation in response to mitochondrial stress, was enhanced in paraquat-exposed mice. Moreover, transgenic mice overexpressing Prdx3, a key enzyme in detoxifying mitochondrial H2O2, had suppressed NLRP3 inflammasome activation, reduced brain inflammation, and attenuated cognition impairment after paraquat exposure. Together, our results indicate that NLRP3 inflammasome activation induced by mitochondrial reactive oxygen species plays a key role in mediating paraquat-induced long-term cognition decline by elevating brain inflammation. PMID:26119225

  12. A long-term, prospective, cohort study on the performance of right ventricular pacing leads: comparison of active-fixation with passive-fixation leads

    PubMed Central

    Liu, Lie; Tang, Jiaojiao; Peng, Hu; Wu, Shulin; Lin, Chunying; Chen, Dongli; Zhang, Qianhuan; Liang, Yuanhong; Chen, Silin; Chen, Yan; Wei, Huiqiang

    2015-01-01

    Active-fixation pacing leads allow the use of selective pacing sites. We evaluated their long-term performance versus passive-fixation leads in 199 newly implanted patients (n = 100 active and n = 99 passive). Postoperative pacing thresholds in the active group were higher than in the passive group (0.85 ± 0.31 V vs. 0.53 ± 0.21 V at baseline, P < 0.001). The active thresholds fell to 0.72 ± 0.23 V at 5 years with a significant drop at one month (0.68 ± 0.53 V, P = 0.003). The passive thresholds slightly increased to 0.72 ± 0.31 V at five years. Differences between groups were significant until three years (all P < 0.05). Active impedances were generally lower than passive impedances (600.44 ± 94.31Ω vs. 683.14 ± 110.98Ω at baseline), and both showed significant reductions at one month to 537.96 ± 147.43Ω in the active group, and after three months to 643.85 ± 82.40Ω in the passive group (both P < 0.01 vs. baseline). Impedance differences between groups were significant until four years (all P < 0.05). Adverse events included thresholds over 1 V, 5 of 6 active and 2 of 5 passive leads returned to below 1 V. One active left ventricular lead dislodged. One passive left subclavian lead insulation fracture occurred. Thus Active fixation pacing leads are stable in a five-year long-term follow up. There was no difference between active and passive leads in terms of electrical performance. PMID:25563218

  13. Solar activity secular cycles

    NASA Astrophysics Data System (ADS)

    Kramynin, A. P.; Mordvinov, A. V.

    2013-12-01

    Long-term variations in solar activity secular cycles have been studied using a method for the expansion of reconstructed sunspot number series Sn( t) for 11400 years in terms of natural orthogonal functions. It has been established that three expansion components describe more than 98% of all Sn( t) variations. In this case, the contribution of the first expansion component is about 92%. The averaged form of the 88year secular cycle has been determined based on the form of the first expansion coordinate function. The quasi-periodicities modulating the secular cycle have been revealed based on the time function conjugate to the first function. The quasi-periodicities modulating the secular cycle coincide with those observed in the Sn( t) series spectrum. A change in the secular cycle form and the time variations in this form are described by the second and third expansion components, the contributions of which are about 4 and 2%, respectively. The variations in the steepness of the secular cycle branches are more pronounced in the 200-year cycle, and the secular cycle amplitude varies more evidently in the 2300-year cycle.

  14. Long-Term Effects of Physically Active Academic Lessons on Physical Fitness and Executive Functions in Primary School Children

    ERIC Educational Resources Information Center

    de Greeff, J. W.; Hartman, E.; Mullender-Wijnsma, M. J.; Bosker, R. J.; Doolaard, S.; Visscher, C.

    2016-01-01

    Integrating physical activity into the curriculum has potential health and cognitive benefits in primary school children. The aim of this study was to investigate the effects of physically active academic lessons on cardiovascular fitness, muscular fitness and executive functions. In the current randomized controlled trial, 499 second and third…

  15. Long-term behaviour of starspots. III - Active longitudes on the long-period RS CVn star HK Lacertae

    NASA Technical Reports Server (NTRS)

    Olah, K.; Hall, D. S.; Henry, G. W.

    1991-01-01

    Thirteen years of photometry were used to study active longitudes on the surface of HK Lacertae. The decaying and forming phenomena of active areas in the years of 1980-1981, 1983-1984, and 1988-1989 are shown. New activity centers suddenly occur near the same orbital phase (0.6) and have lifetimes of several (greater than 6) years. The average rotational period of HK Lac is 24.2852 d; compared to the orbital period of 24.4284 d, this implies a 32 degree/year drift of the active areas on the stellar surface. Two possible interpretations for the period difference are discussed: pseudosynchronism and rigidity of magnetic patterns. The active longitudes on HK Lac are compared with similar phenomena found on the sun.

  16. The influence of patients' attributions of the immediate effects of treatment of depression on long-term effectiveness of behavioural activation and antidepressant medication.

    PubMed

    Moradveisi, Latif; Huibers, Marcus J H; Arntz, Arnoud

    2015-06-01

    Patients' attributions of effects of treatment are important, as these can affect long-term outcome. Most studies so far focused on the influence of attributions to medication for anxiety and depression disorders. We investigated the effects of patients' attributions made after acute treatment on the long-term outcome of antidepressant medication (ADM) and psychological treatment (behavioural activation, BA). Data are based on a randomized trial testing the effectiveness of BA vs. ADM for major depression (MDD) in Iran. Patients with MDD (N = 100) were randomized to BA (N = 50) or ADM (N = 50). Patients' attributions were assessed at post-test (after completion of the treatments). Scores on an attribution questionnaire were factor analysed, and factor scores were retained as predictors of depressive symptoms at 1-year follow-up. Regression analysis was used to test whether attributions predicted depressive symptoms at 1-yr follow-up, controlling for symptom level, condition, and their interaction at post-test. Belief in coping efficacy was the only attribution factor significantly predicting 1-year HRSD scores, controlling for condition, post-test HRSD and their interaction. It also mediated the condition differences at follow-up. Credit to self was the single attribution factor that predicted BDI follow-up scores, controlling for condition, posttest BDI, and their interaction. It partially mediated the condition differences on the BDI at follow-up. Attribution to increased coping capacities and giving credit to self appear essential. In the long-term (at 1 year follow-up), the difference in outcome between BA and ADM (with BA being superior to ADM) is at least partially mediated by attributions.

  17. Long-term Outcomes of the FRESH START Trial: Exploring the Role of Self-efficacy in Cancer Survivors’ Maintenance of Dietary Practices and Physical Activity

    PubMed Central

    Mosher, Catherine E.; Lipkus, Isaac; Sloane, Richard; Snyder, Denise C.; Lobach, David F.; Demark-Wahnefried, Wendy

    2012-01-01

    Objective This study examined whether changes in self-efficacy explain the effects of a mailed print intervention on long-term dietary practices of breast and prostate cancer survivors. The relationship between change in self-efficacy and long-term physical activity (PA) also was examined. Methods Breast and prostate cancer survivors (N=543) from 39 U.S. states and two Canadian provinces participated in the FRESH START intervention trial. Participants were randomly assigned to receive a 10-month program of mailed print materials on diet and PA available in the public domain or a 10-month program of tailored materials designed to increase fruit and vegetable (F&V) intake, decrease fat intake, and/or increase PA. Changes in self-efficacy for F&V intake and fat restriction were analyzed as potential mediators of the intervention’s effects on diet at 2-year follow-up. Because we previously found that change in self-efficacy for PA did not vary by group assignment, the relationship between change in self-efficacy and PA at 2-year follow-up was examined across study conditions. Results Results suggest that change in self-efficacy for fat restriction partially explained the intervention’s effect on fat intake (mean indirect effect=-.28), and change in self-efficacy for F&V consumption partially explained the intervention’s effect on daily F&V intake (mean indirect effect=.11). Change in self-efficacy for fat restriction partially accounted for the intervention’s impact on overall diet quality among men only (mean indirect effect=.60). Finally, change in self-efficacy for PA predicted PA at 2-year follow-up. Conclusions Findings suggest that self-efficacy may influence long-term maintenance of healthy lifestyle practices among cancer survivors. PMID:22544562

  18. Relationship of long-term highly active antiretroviral therapy on salivary flow rate and CD4 Count among HIV-infected patients

    PubMed Central

    Kumar, J Vijay; Baghirath, P Venkat; Naishadham, P Parameswar; Suneetha, Sujai; Suneetha, Lavanya; Sreedevi, P

    2015-01-01

    Objectives: To determine if long-term highly active antiretroviral therapy (HAART) therapy alters salivary flow rate and also to compare its relation of CD4 count with unstimulated and stimulated whole saliva. Materials and Methods: A cross-sectional study was performed on 150 individuals divided into three groups. Group I (50 human immunodeficiency virus (HIV) seropositive patients, but not on HAART therapy), Group II (50 HIV-infected subjects and on HAART for less than 3 years called short-term HAART), Group III (50 HIV-infected subjects and on HAART for more than or equal to 3 years called long-term HAART). Spitting method proposed by Navazesh and Kumar was used for the measurement of unstimulated and stimulated salivary flow rate. Chi-square test and analysis of variance (ANOVA) were used for statistical analysis. Results: The mean CD4 count was 424.78 ± 187.03, 497.82 ± 206.11 and 537.6 ± 264.00 in the respective groups. Majority of the patients in all the groups had a CD4 count between 401 and 600. Both unstimulated and stimulated whole salivary (UWS and SWS) flow rates in Group I was found to be significantly higher than in Group II (P < 0.05). Unstimulated salivary flow rate between Group II and III subjects were also found to be statistically significant (P < 0.05). ANOVA performed between CD4 count and unstimulated and stimulated whole saliva in each group demonstrated a statistically significant relationship in Group II (P < 0.05). There were no significant results found between CD4 count and stimulated whole saliva in each groups. Conclusion: The reduction in CD4 cell counts were significantly associated with salivary flow rates of HIV-infected individuals who are on long-term HAART. PMID:26097309

  19. Relative desirability of leisure activities and work parameters in a simulation of isolated work stations. [long term space flight simulation

    NASA Technical Reports Server (NTRS)

    Sullins, W. R., Jr.; Rogers, J. G.

    1974-01-01

    The kinds of activities that are attractive to man in long duration isolation are delineated considering meaningful work as major activity and a choice of leisure/living provisions. The dependent variables are the relative distribution between various work, leisure, and living activities where external constraints on the subject's freedom of choice are minimized. Results indicate that an average of at least five hours per day of significant meaningful work is required for satisfactory enjoyment of the situation; most other parameters of the situation have less effects on overall performance and satisfaction

  20. Short- and long-term changes in anterior cingulate activation during resolution of task-set competition.

    PubMed

    Woodward, Todd S; Ruff, Christian C; Ngan, Elton T C

    2006-01-12

    Alternating between task sets involves detection that the current task set is unfavorable, initiation of a change in set, and application of the new task set while fine-tuning to optimally adjust to the demands of the environment. Functional magnetic resonance imaging (fMRI) studies of cognitive flexibility consistently report activation of the anterior cingulate cortex and/or adjacent pre-supplementary motor regions (ACC/pre-SMA, medial Brodmann's areas 24/32/6), suggesting that these cortical regions are involved in switching task set. In the current study, our objective was to probe whether ACC/pre-SMA activation would decrease for a number of trials following a switch in task set, implying longer-term involvement in fine-tuning adjustments. By measuring activation when switching between word reading and color naming in response to Stroop stimuli, ACC/pre-SMA activation was observed when actively countering the influence of the irrelevant task set, and this activation decreased as a function of the number of trials since a task switch. Basal ganglia and thalamic regions also displayed a decreased response over successive trials after task switches. These findings suggest that the ACC/pre-SMA are not only involved in generating a new course of action, but are also involved (along with subcortical regions) in fine-tuning operations that resolve competition between task sets over subsequent repetitions of the same task. PMID:16376861

  1. Lower cytotoxicity, high stability, and long-term antibacterial activity of a poly(methacrylic acid)/isoniazid/rifampin nanogel against multidrug-resistant intestinal Mycobacterium tuberculosis.

    PubMed

    Chen, Tao; Li, Qiang; Guo, Lina; Yu, Li; Li, Zhenyan; Guo, Huixin; Li, Haicheng; Zhao, Meigui; Chen, Liang; Chen, Xunxun; Zhong, Qiu; Zhou, Lin; Wu, Ting

    2016-01-01

    To overcome the undesirable side effects and reduce the cytotoxicity of isoniazid (INH) and rifampin (RMP) in the digestive tract, a poly(methacrylic acid) (PMAA) nanogel was developed as a carrier of INH and RMP. This PMAA/INH/RMP nanogel was prepared as a treatment for intestinal tuberculosis caused by multidrug-resistant Mycobacterium tuberculosis (MTB). The morphology, size, and in vitro release properties were evaluated in a simulated gastrointestinal medium, and long-term antibacterial performance, cytotoxicity, stability, and activity of this novel PMAA/INH/RMP nanogel against multidrug-resistant MTB in the intestine were investigated. Our results indicate that the PMAA/INH/RMP nanogel exhibited extended antibacterial activity by virtue of its long-term release of INH and RMP in the simulated gastrointestinal medium. Further, this PMAA/INH/RMP nanogel exhibited lower cytotoxicity than did INH or RMP alone, suggesting that this PMAA/INH/RMP nanogel could be a more useful dosage form than separate doses of INH and RMP for intestinal MTB. The novel aspects of this study include the cytotoxicity study and the three-phase release profile study, which might be useful for other researchers in this field.

  2. Ectopic AP4 expression induces cellular senescence via activation of p53 in long-term confluent retinal pigment epithelial cells.

    PubMed

    Wang, Yiping; Wong, Matthew Man-Kin; Zhang, Xiaojian; Chiu, Sung-Kay

    2015-11-15

    When cells are grown to confluence, cell-cell contact inhibition occurs and drives the cells to enter reversible quiescence rather than senescence. Confluent retinal pigment epithelial (RPE) cells exhibiting contact inhibition was used as a model in this study to examine the role of overexpression of transcription factor AP4, a highly expressed transcription factor in many types of cancer, in these cells during long-term culture. We generated stable inducible RPE cell clones expressing AP4 or AP4 without the DNA binding domain (DN-AP4) and observed that, when cultured for 24 days, RPE cells with a high level of AP4 exhibit a large, flattened morphology and even cease proliferating; these changes were not observed in DN-AP4-expressing cells or non-induced cells. In addition, AP4-expressing cells exhibited senescence-associated β-galactosidase activity and the senescence-associated secretory phenotype. We demonstrated that the induced cellular senescence was mediated by enhanced p53 expression and that AP4 regulates the p53 gene by binding directly to two of the three E-boxes present on the promoter of the p53 gene. Moreover, we showed that serum is essential for AP4 in inducing p53-associated cellular senescence. Collectively, we showed that overexpression of AP4 mediates cellular senescence involving in activation of p53 in long-term post-confluent RPE cells.

  3. Long-term effects of 4-year longitudinal school-based physical activity intervention on the physical fitness of children and youth during 7-year followup assessment.

    PubMed

    Jurak, Gregor; Cooper, Ashley; Leskosek, Bojan; Kovac, Marjeta

    2013-12-01

    Many school-based physical activity (PA) interventions have been developed, but only a few have assessed their long-term effects. A PA intervention taking place in the first four years of some Slovenian primary schools entails an enhanced physical education (PE) curriculum, including two extra lessons of PE per week, a wider selection of PE content, and additional outdoor education delivered by both a specialist PE teacher and a general teacher. The effects of the intervention on children's physical fitness (motor tasks and anthropometry) were evaluated within a quasi-experimental study. In total, 324 children from nine Slovenian primary schools either received the enhanced curriculum (intervention (n=160)) or standard PE (control (n=164)), and were followed for a four-year intervention period and seven years post intervention. Data from the SLOFIT database were used to compare differences in the physical fitness of children each year. Linear Mixed Models were used to test the influence of the PA intervention. Over an 11-year period, the PA intervention group significantly differed in all motor tasks, but not in anthropometric measures or body mass index, after controlling for year of measurement and sex. Differences between the control and intervention groups decreased with time. This study highlights the importance of tracking the long term effects of PA interventions. PA intervention in the first four years of Slovenian primary school offers the possibility of improving physical performance in children; initiatives aiming to increase their performance (physical fitness, physical activity) and health outcomes are warranted.

  4. Context-specific activation of hippocampus and SN/VTA by reward is related to enhanced long-term memory for embedded objects.

    PubMed

    Loh, Eleanor; Kumaran, Dharshan; Koster, Raphael; Berron, David; Dolan, Ray; Duzel, Emrah

    2016-10-01

    Animal studies indicate that hippocampal representations of environmental context modulate reward-related processing in the substantia nigra and ventral tegmental area (SN/VTA), a major origin of dopamine in the brain. Using functional magnetic resonance imaging (fMRI) in humans, we investigated the neural specificity of context-reward associations under conditions where the presence of perceptually similar neutral contexts imposed high demands on a putative hippocampal function, pattern separation. The design also allowed us to investigate how contextual reward enhances long-term memory for embedded neutral objects. SN/VTA activity underpinned specific context-reward associations in the face of perceptual similarity. A reward-related enhancement of long-term memory was restricted to the condition where the rewarding and the neutral contexts were perceptually similar, and in turn was linked to co-activation of the hippocampus (subfield DG/CA3) and SN/VTA. Thus, an ability of contextual reward to enhance memory for focal objects is closely linked to context-related engagement of hippocampal-SN/VTA circuitry. PMID:26708279

  5. Context-specific activation of hippocampus and SN/VTA by reward is related to enhanced long-term memory for embedded objects.

    PubMed

    Loh, Eleanor; Kumaran, Dharshan; Koster, Raphael; Berron, David; Dolan, Ray; Duzel, Emrah

    2016-10-01

    Animal studies indicate that hippocampal representations of environmental context modulate reward-related processing in the substantia nigra and ventral tegmental area (SN/VTA), a major origin of dopamine in the brain. Using functional magnetic resonance imaging (fMRI) in humans, we investigated the neural specificity of context-reward associations under conditions where the presence of perceptually similar neutral contexts imposed high demands on a putative hippocampal function, pattern separation. The design also allowed us to investigate how contextual reward enhances long-term memory for embedded neutral objects. SN/VTA activity underpinned specific context-reward associations in the face of perceptual similarity. A reward-related enhancement of long-term memory was restricted to the condition where the rewarding and the neutral contexts were perceptually similar, and in turn was linked to co-activation of the hippocampus (subfield DG/CA3) and SN/VTA. Thus, an ability of contextual reward to enhance memory for focal objects is closely linked to context-related engagement of hippocampal-SN/VTA circuitry.

  6. Human midbrain precursors activate the expected developmental genetic program and differentiate long-term to functional A9 dopamine neurons in vitro. Enhancement by Bcl-X(L).

    PubMed

    Seiz, Emma G; Ramos-Gómez, Milagros; Courtois, Elise T; Tønnesen, Jan; Kokaia, Merab; Liste Noya, Isabel; Martínez-Serrano, Alberto

    2012-11-15

    Understanding the molecular programs of the generation of human dopaminergic neurons (DAn) from their ventral mesencephalic (VM) precursors is of key importance for basic studies, progress in cell therapy, drug screening and pharmacology in the context of Parkinson's disease. The nature of human DAn precursors in vitro is poorly understood, their properties unstable, and their availability highly limited. Here we present positive evidence that human VM precursors retaining their genuine properties and long-term capacity to generate A9 type Substantia nigra human DAn (hVM1 model cell line) can be propagated in culture. During a one month differentiation, these cells activate all key genes needed to progress from pro-neural and pro-dopaminergic precursors to mature and functional DAn. For the first time, we demonstrate that gene cascades are correctly activated during differentiation, resulting in the generation of mature DAn. These DAn have morphological and functional properties undistinguishable from those generated by VM primary neuronal cultures. In addition, we have found that the forced expression of Bcl-X(L) induces an increase in the expression of key developmental genes (MSX1, NGN2), maintenance of PITX3 expression temporal profile, and also enhances genes involved in DAn long-term function, maintenance and survival (EN1, LMX1B, NURR1 and PITX3). As a result, Bcl-X(L) anticipates and enhances DAn generation.

  7. Long-term operation of biological activated carbon pre-treatment for microfiltration of secondary effluent: Correlation between the organic foulants and fouling potential.

    PubMed

    Pramanik, Biplob Kumar; Roddick, Felicity A; Fan, Linhua

    2016-03-01

    The impact of long-term (>2 years) biological activated carbon (BAC) treatment for mitigating organic fouling in the microfiltration of biologically treated secondary effluent was investigated. Correlation between the organic constituents and hydraulic filtration resistance was investigated to identify the major components responsible for fouling. Over two years operation, the removal efficiency for dissolved organic carbon (DOC) by the BAC treatment was fairly consistent (30 ± 3%), although the reduction in UVA254 gradually decreased from 56 to 34%. BAC treatment effectively decreased the organic foulants in the effluent and so contributed to the mitigation of membrane fouling as shown by reduction in the unified membrane fouling index (UMFI). BAC consistently removed biopolymers whereas the removal of humic substances decreased from 52 to 25% after two years of BAC operation, and thus led to a gradual decrease in UMFI reduction efficiency from 78 to 43%. This was due to gradual reduction in adsorption capacity of the activated carbon as confirmed by analysis of its pore size distribution. Hence humics also played an important role in membrane fouling. However, there was a good correlation between protein and carbohydrate contents with hydraulically reversible and irreversible filtration resistance, compared with UVA254, turbidity and DOC. Although the mitigation of membrane fouling decreased over time, this study demonstrated that the long-term use of BAC pre-treatment of biologically treated secondary effluent prior to microfiltration has potential to reduce the need for frequent chemical cleaning and so increase membrane life span.

  8. Long-term effects of rapamycin treatment on insulin mediated phosphorylation of Akt/PKB and glycogen synthase activity

    SciTech Connect

    Varma, Shailly; Shrivastav, Anuraag; Changela, Sheena; Khandelwal, Ramji L.

    2008-04-01

    Protein kinase B (Akt/PKB) is a Ser/Thr kinase that is involved in the regulation of cell proliferation/survival through mammalian target of rapamycin (mTOR) and the regulation of glycogen metabolism through glycogen synthase kinase 3{beta} (GSK-3{beta}) and glycogen synthase (GS). Rapamycin is an inhibitor of mTOR. The objective of this study was to investigate the effects of rapamycin pretreatment on the insulin mediated phosphorylation of Akt/PKB phosphorylation and GS activity in parental HepG2 and HepG2 cells with overexpression of constitutively active Akt1/PKB-{alpha} (HepG2-CA-Akt/PKB). Rapamycin pretreatment resulted in a decrease (20-30%) in the insulin mediated phosphorylation of Akt1 (Ser 473) in parental HepG2 cells but showed an upregulation of phosphorylation in HepG2-CA-Akt/PKB cells. Rictor levels were decreased (20-50%) in parental HepG2 cells but were not significantly altered in the HepG2-CA-Akt/PKB cells. Furthermore, rictor knockdown decreased the phosphorylation of Akt (Ser 473) by 40-60% upon rapamycin pretreatment. GS activity followed similar trends as that of phosphorylated Akt and so with rictor levels in these cells pretreated with rapamycin; parental HepG2 cells showed a decrease in GS activity, whereas as HepG2-CA-Akt/PKB cells showed an increase in GS activity. The changes in the levels of phosphorylated Akt/PKB (Ser 473) correlated with GS and protein phoshatase-1 activity.

  9. Long-term degradation of resin-based cements in substances present in the oral environment: influence of activation mode

    PubMed Central

    da SILVA, Eduardo Moreira; NORONHA-FILHO, Jaime Dutra; AMARAL, Cristiane Mariote; POSKUS, Laiza Tatiana; GUIMARÃES, José Guilherme Antunes

    2013-01-01

    Indirect restorations in contact with free gingival margins or principally within the gingival sulcus, where the presence of organic acids produced by oral biofilm is higher, may present faster degradation of the resin-based cement pellicle. Objectives: To investigate the degradation of four resin-based cements: Rely X ARC (R), Variolink II (V), enforce (E) and All Cem (A), after immersion in distilled water (DW), lactic acid (LA) and artificial saliva (AS) and to analyze the influence of the activation mode on this response. Material and Methods: Two activation modes were evaluated: chemical (Ch) and dual (D). In the dual activation, a two-millimeter thick ceramic disk (IPS empress System) was interposed between the specimen and light-curing unit tip. Specimens were desiccated, immersed in distilled water, artificial saliva and lactic acid 0.1 M at 37ºC for 180 days, weighed daily for the first 7 days, and after 14, 21, 28, 90 and 180 days and were desiccated again. Sorption and solubility (µg/mm3) were calculated based on ISO 4049. The data were submitted to multifactor analysis of variance (MANOVA) and Tukey's HSD test for media comparisons (α=0.05). Results: Sorption was higher after immersion in LA (p<0.05) and increased significantly with time (p<0.05). Sorption was influenced by the activation mode: Ch>D (p<0.05). The lowest solubility was presented by R (p<0.05). Conclusions: Lactic acid increased the degradation of resin-based cements. Moreover, the physical component of activation, i.e., light-activation, contributed to a low degradation of resin-based cements. PMID:23857651

  10. Long-Term Stability of Motor Cortical Activity: Implications for Brain Machine Interfaces and Optimal Feedback Control

    PubMed Central

    Flint, Robert D.; Scheid, Michael R.; Wright, Zachary A.; Solla, Sara A.

    2016-01-01

    The human motor system is capable of remarkably precise control of movements—consider the skill of professional baseball pitchers or surgeons. This precise control relies upon stable representations of movements in the brain. Here, we investigated the stability of cortical activity at multiple spatial and temporal scales by recording local field potentials (LFPs) and action potentials (multiunit spikes, MSPs) while two monkeys controlled a cursor either with their hand or directly from the brain using a brain–machine interface. LFPs and some MSPs were remarkably stable over time periods ranging from 3 d to over 3 years; overall, LFPs were significantly more stable than spikes. We then assessed whether the stability of all neural activity, or just a subset of activity, was necessary to achieve stable behavior. We showed that projections of neural activity into the subspace relevant to the task (the “task-relevant space”) were significantly more stable than were projections into the task-irrelevant (or “task-null”) space. This provides cortical evidence in support of the minimum intervention principle, which proposes that optimal feedback control (OFC) allows the brain to tightly control only activity in the task-relevant space while allowing activity in the task-irrelevant space to vary substantially from trial to trial. We found that the brain appears capable of maintaining stable movement representations for extremely long periods of time, particularly so for neural activity in the task-relevant space, which agrees with OFC predictions. SIGNIFICANCE STATEMENT It is unknown whether cortical signals are stable for more than a few weeks. Here, we demonstrate that motor cortical signals can exhibit high stability over several years. This result is particularly important to brain–machine interfaces because it could enable stable performance with infrequent recalibration. Although we can maintain movement accuracy over time, movement components that are

  11. Effects of long-term preservation of Frankia strains on infectivity, effectivity, and in vitro nitrogenase activity

    SciTech Connect

    Fontaine, M.S.; Young, P.H.; Torrey, J.G.

    1986-04-01

    Frankia strain HFP ArI3 which had been preserved for 27 months by being lyophilized, frozen in glycerol, or stored in complex medium was successfully used as an inoculum after being subcultured for inducing nodulation and nitrogen fixation of Alnus rubra. Glycerol-preserved HFPArI3 produced significantly lower rates of nitrogenase activity than did lyophilized or complex-medium-preserved inocula. Bacteria that had been preserved by all three methods were successfully induced to fix atmospheric nitrogen by being cultured in nitrogen-free medium. Subculturing of these cells in nitrogen-free medium a second and third time yielded increasing rates of nitrogenase activity. Initial nitrogenase activity was detected on days 5, 4, and 3 during the first, second, and third subcultures after preservation, respectively. Maximum activity was observed on days 11, 10, and 8 during the first, second, and third subcultures, respectively. A description is given of standard culture techniques used in our laboratory for Frankia isolates, and methods used to distribute Frankia cultures by mail are described.

  12. The Effect of Long-Term Storage on the Physiochemical and Bactericidal Properties of Electrochemically Activated Solutions

    PubMed Central

    Robinson, Gareth; Thorn, Robin; Reynolds, Darren

    2013-01-01

    Electrochemically activated solutions (ECAS) are generated by electrolysis of NaCl solutions, and demonstrate broad spectrum antimicrobial activity and high environmental compatibility. The biocidal efficacy of ECAS at the point of production is widely reported in the literature, as are its credentials as a “green biocide.” Acidic ECAS are considered most effective as biocides at the point of production and ill suited for extended storage. Acidic ECAS samples were stored at 4 °C and 20 °C in glass and polystyrene containers for 398 days, and tested for free chlorine, pH, ORP and bactericidal activity throughout. ORP and free chlorine (mg/L) in stored ECAS declined over time, declining at the fastest rate when stored at 20 °C in polystyrene and at the slowest rate when stored at 4 °C in glass. Bactericidal efficacy was also affected by storage and ECAS failed to produce a 5 log10 reduction on five occasions when stored at 20 °C. pH remained stable throughout the storage period. This study represents the longest storage evaluation of the physiochemical parameters and bactericidal efficacy of acidic ECAS within the published literature and reveals that acidic ECAS retain useful bactericidal activity for in excess of 12 months, widening potential applications. PMID:23263673

  13. Characterisation of eye-lens DNases: long term persistence of activity in post apoptotic lens fibre cells.

    PubMed

    Arruti, C; Chaudun, E; De Maria, A; Courtois, Y; Counis, M F

    1995-01-01

    Fibre cells in the ocular lens exhibit a constitutive apoptotic process of nuclear degradation that includes chromatin breakage, generating a ladder pattern of DNA fragments. This process is intrinsic to the normal terminal differentiation program. Despite the loss of nucleus and cytoplasmic organelles, the terminal differentiated fibre cells remain in the lens during the whole life span of the individual. The lens cells thus provide a unique system in which to determine the presence and fate of endonucleases once the chromatin has been cleaved. We report here on the presence of DNase activity in nucleated and anucleated lens cells. Using a nuclease gel assay and double-stranded DNA as substrate, we found active 30 and 60 kDa DNases. The enzymatic activities were Ca(2+), Mg(2+) dependent, and active at neutral pH. The relative amount of these forms changed during development and aging of the lens fibre cells. Both forms were inhibited by Zn(2+), aurintricarboxylic acid, and G-actin. The proteins were also separated by SDS-PAGE, renatured after removing SDS and incubated in the presence of native DNA adsorbed to a membrane. Therefore it was possible to demonstrate, by means of a nick translation reaction, that the enzymes produced single strand cuts. Based on these findings we propose that these chick lens nucleases are probably related to DNase I.

  14. Characterisation of eye-lens DNases: long term persistence of activity in post apoptotic lens fibre cells.

    PubMed

    Arruti, C; Chaudun, E; De Maria, A; Courtois, Y; Counis, M F

    1995-01-01

    Fibre cells in the ocular lens exhibit a constitutive apoptotic process of nuclear degradation that includes chromatin breakage, generating a ladder pattern of DNA fragments. This process is intrinsic to the normal terminal differentiation program. Despite the loss of nucleus and cytoplasmic organelles, the terminal differentiated fibre cells remain in the lens during the whole life span of the individual. The lens cells thus provide a unique system in which to determine the presence and fate of endonucleases once the chromatin has been cleaved. We report here on the presence of DNase activity in nucleated and anucleated lens cells. Using a nuclease gel assay and double-stranded DNA as substrate, we found active 30 and 60 kDa DNases. The enzymatic activities were Ca(2+), Mg(2+) dependent, and active at neutral pH. The relative amount of these forms changed during development and aging of the lens fibre cells. Both forms were inhibited by Zn(2+), aurintricarboxylic acid, and G-actin. The proteins were also separated by SDS-PAGE, renatured after removing SDS and incubated in the presence of native DNA adsorbed to a membrane. Therefore it was possible to demonstrate, by means of a nick translation reaction, that the enzymes produced single strand cuts. Based on these findings we propose that these chick lens nucleases are probably related to DNase I. PMID:17180015

  15. Long-Term Monitoring of Soil Microbiological Activities in Two Forest Sites in South Tyrol in the Italian Alps

    PubMed Central

    Margesin, Rosa; Minerbi, Stefano; Schinner, Franz

    2014-01-01

    We monitored microbiological properties in two forest sites over a period of 17 years (1993–2010) within the International Cooperative Programme on Integrated Monitoring of Air Pollution Effects on Ecosystems (ICP IM). The two study sites were located in South Tyrol in the Italian Alps at altitudes of 1,737 m a.s.l. (subalpine site IT01) and 570 m a.s.l. (submontane site IT02). Soil samples were collected in the late spring and autumn of 1993, 2000, and 2010, and were characterized by measuring respiration, key enzyme activities involved in the C, N, P, and S cycles and litter degradation, and the abundance of viable bacterial and fungal populations. Over the study period, an increase in mean annual air temperatures at both sites (+0.6°C and +0.8°C at IT01 and IT02, respectively) was calculated from trendlines. Significantly lower mean annual air temperatures, higher temperature fluctuations, and higher annual precipitation rates were observed at site IT01 than at site IT02. Subalpine site IT01 was characterized by significantly lower microbial activity (respiration, enzymes) and abundance than those at submontane site IT02. The year of sampling had a significant effect on all the parameters investigated, except for nitrification. Fungal abundance decreased consistently over the study period, while no consistent trend was noted among the other parameters investigated. Season only affected a few of the measured microbiological parameters: respiration and bacterial numbers were significantly higher in the spring than in the autumn, while the opposite was noted for xylanase and phosphatase activities. Soil fungi contributed essentially to xylanase and protease activities, while soil bacteria were mainly involved in degradation processes that required the activity of sulfatase. PMID:25008018

  16. Long-term monitoring of soil microbiological activities in two forest sites in South tyrol in the italian alps.

    PubMed

    Margesin, Rosa; Minerbi, Stefano; Schinner, Franz

    2014-09-17

    We monitored microbiological properties in two forest sites over a period of 17 years (1993-2010) within the International Cooperative Programme on Integrated Monitoring of Air Pollution Effects on Ecosystems (ICP IM). The two study sites were located in South Tyrol in the Italian Alps at altitudes of 1,737 m a.s.l. (subalpine site IT01) and 570 m a.s.l. (submontane site IT02). Soil samples were collected in the late spring and autumn of 1993, 2000, and 2010, and were characterized by measuring respiration, key enzyme activities involved in the C, N, P, and S cycles and litter degradation, and the abundance of viable bacterial and fungal populations. Over the study period, an increase in mean annual air temperatures at both sites (+0.6°C and +0.8°C at IT01 and IT02, respectively) was calculated from trendlines. Significantly lower mean annual air temperatures, higher temperature fluctuations, and higher annual precipitation rates were observed at site IT01 than at site IT02. Subalpine site IT01 was characterized by significantly lower microbial activity (respiration, enzymes) and abundance than those at submontane site IT02. The year of sampling had a significant effect on all the parameters investigated, except for nitrification. Fungal abundance decreased consistently over the study period, while no consistent trend was noted among the other parameters investigated. Season only affected a few of the measured microbiological parameters: respiration and bacterial numbers were significantly higher in the spring than in the autumn, while the opposite was noted for xylanase and phosphatase activities. Soil fungi contributed essentially to xylanase and protease activities, while soil bacteria were mainly involved in degradation processes that required the activity of sulfatase.

  17. Long-Term Effects of Irrigation with Waste Water on Soil AM Fungi Diversity and Microbial Activities: The Implications for Agro-Ecosystem Resilience

    PubMed Central

    del Mar Alguacil, Maria; Torrecillas, Emma; Torres, Pilar; García-Orenes, Fuensanta; Roldán, Antonio

    2012-01-01

    The effects of irrigation with treated urban wastewater (WW) on the arbuscular mycorrhizal fungi (AMF) diversity and soil microbial activities were assayed on a long-term basis in a semiarid orange-tree orchard. After 43 years, the soil irrigated with fresh water (FW) had higher AMF diversity than soils irrigated with WW. Microbial activities were significantly higher in the soils irrigated with WW than in those irrigated with FW. Therefore, as no negative effects were observed on crop vitality and productivity, it seems that the ecosystem resilience gave rise to the selection of AMF species better able to thrive in soils with higher microbial activity and, thus, to higher soil fertility. PMID:23094075

  18. Long-term effects of irrigation with waste water on soil AM fungi diversity and microbial activities: the implications for agro-ecosystem resilience.

    PubMed

    Alguacil, Maria del Mar; Torrecillas, Emma; Torres, Pilar; García-Orenes, Fuensanta; Roldán, Antonio

    2012-01-01

    The effects of irrigation with treated urban wastewater (WW) on the arbuscular mycorrhizal fungi (AMF) diversity and soil microbial activities were assayed on a long-term basis in a semiarid orange-tree orchard. After 43 years, the soil irrigated with fresh water (FW) had higher AMF diversity than soils irrigated with WW. Microbial activities were significantly higher in the soils irrigated with WW than in those irrigated with FW. Therefore, as no negative effects were observed on crop vitality and productivity, it seems that the ecosystem resilience gave rise to the selection of AMF species better able to thrive in soils with higher microbial activity and, thus, to higher soil fertility. PMID:23094075

  19. BDNF modulates heart contraction force and long-term homeostasis through truncated TrkB.T1 receptor activation

    PubMed Central

    Fulgenzi, Gianluca; Tomassoni-Ardori, Francesco; Babini, Lucia; Becker, Jodi; Barrick, Colleen; Puverel, Sandrine

    2015-01-01

    Brain-derived neurotrophic factor (BDNF) is critical for mammalian development and plasticity of neuronal circuitries affecting memory, mood, anxiety, pain sensitivity, and energy homeostasis. Here we report a novel unexpected role of BDNF in regulating the cardiac contraction force independent of the nervous system innervation. This function is mediated by the truncated TrkB.T1 receptor expressed in cardiomyocytes. Loss of TrkB.T1 in these cells impairs calcium signaling and causes cardiomyopathy. TrkB.T1 is activated by BDNF produced by cardiomyocytes, suggesting an autocrine/paracrine loop. These findings unveil a novel signaling mechanism in the heart that is activated by BDNF and provide evidence for a global role of this neurotrophin in the homeostasis of the organism by signaling through different TrkB receptor isoforms. PMID:26347138

  20. An X-ray Study of The Red Dwarf Next Door: The Long-Term Activity of Proxima Cen

    NASA Astrophysics Data System (ADS)

    Guinan, Edward

    2010-09-01

    As the nearest star & outlying member of the alpha Cen system, Proxima Cen has well determined physical properties & an age ~5-6 Gyr. From its mass and late spectral type (M5.5 V), Proxima is expected to be fully convective & have a different dynamo from the Sun. Analysis of years of photometry reveals: P-rot = 83.7-d & an activity cycle of ~7.6 yrs. Also X-ray data from ROSAT, XMM and Chandra show a corresponding coronal X-ray cycle with an expected minimum during 2010/11. We propose an LETGS observation to extend (& better define) its coronal activity cycle. These data will be used to carry out a detailed physical analysis of the changes in its coronal properties over its cycle. We also will search for flares & analyze separately. Supporting photometry and spectroscopy also will be made.

  1. The acute and the long-term effects of nigral lipopolysaccharide administration on dopaminergic dysfunction and glial cell activation.

    PubMed

    Iravani, Mahmoud M; Leung, Clement C M; Sadeghian, Mona; Haddon, Claire O; Rose, Sarah; Jenner, Peter

    2005-07-01

    Sustained reactive microgliosis may contribute to the progressive degeneration of nigral dopaminergic neurons in Parkinson's disease (PD), in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) exposed human and in non-human primates. However, the temporal relationship between glial cell activation and nigral cell death is relatively unexplored. Consequently, the effects of acute (24 h) and chronic (30 days) glial cell activation induced by unilateral supranigral lipopolysaccharide (LPS) administration were studied in rats. At 24 h, LPS administration caused a marked reduction in the number of tyrosine hydroxylase-immunoreactive (TH-ir) neurons in the substantia nigra (SN) but striatal TH-ir was unaffected. By 30 days, the loss of TH-positive neurons in the LPS-treated nigra was no greater than at 24 h although a heterogeneous loss of striatal TH-ir was present. The loss of nigrostriatal neurons was of functional significance, as at 30 days, LPS-treated rats exhibited ipsiversive circling in response to (+)-amphetamine administration. At 24 h, there was a moderate increase in glial fibrillary acidic protein (GFAP)-ir astrocytes in the SN but a marked elevation of p47phox positive OX-42-ir microglia, and intense inducible nitric oxide synthase (iNOS)-ir and 3-nitrotyrosine (3-NT)-ir was present. However, by 30 days the morphology of OX-42-ir microglia returned to a resting state, the numbers were greatly reduced and no 3-NT-ir was present. At 30 days, GFAP-ir astrocytes were markedly increased in number and iNOS-ir was present in fibrillar astrocyte-like cells. This study shows that acute glial activation leading to dopaminergic neuron degeneration is an acute short-lasting response that does not itself perpetuate cell death or lead to prolonged microglial activation.

  2. Long-term sulphur starvation of Arabidopsis thaliana modifies mitochondrial ultrastructure and activity and changes tissue energy and redox status.

    PubMed

    Ostaszewska, Monika; Juszczuk, Izabela M; Kołodziejek, Izabella; Rychter, Anna M

    2014-04-15

    Sulphur, as a constituent of amino acids (cysteine and methionine), iron-sulphur clusters, proteins, membrane sulpholipids, glutathione, glucosinolates, coenzymes, and auxin precursors, is essential for plant growth and development. Absence or low sulphur concentration in the soil results in severe growth retardation. Arabidopsis thaliana plants grown hydroponically for nine weeks on Knop nutrient medium without sulphur showed morphological symptoms of sulphur deficiency. The purpose of our study was to investigate changes that mitochondria undergo and the role of the highly branched respiratory chain in survival during sulphur deficiency stress. Ultrastructure analysis of leaf mesophyll cells of sulphur-deficient Arabidopsis showed heterogeneity of mitochondria; some of them were not altered, but the majority had swollen morphology. Dilated mitochondria displayed a lower matrix density and fewer cristae compared to control mitochondria. Disintegration of the inner and outer membranes of some mitochondria from the leaves of sulphur-deficient plants was observed. On the contrary, chloroplast ultrastructure was not affected. Sulphur deficiency changed the respiratory activity of tissues and isolated mitochondria; Complex I and IV capacities and phosphorylation rates were lower, but external NAD(P)H dehydrogenase activity increased. Higher external NAD(P)H dehydrogenase activity corresponded to increased cell redox level with doubled NADH/NAD ratio in the leaf and root tissues. Sulphur deficiency modified energy status in the tissues of Arabidopsis plants. The total concentration of adenylates (expressed as ATP+ADP), measured in the light, was lower in the leaves and roots of sulphur-deficient plants than in the controls, which was mainly due to the severely decreased ATP levels. We show that the changes in mitochondrial ultrastructure are compensated by the modifications in respiratory chain activity. Although mitochondria of Arabidopsis tissues are affected by

  3. Nitrate inhibition of legume nodule growth and activity. I. Long term studies with a continuous supply of nitrate

    SciTech Connect

    Streeter, J.G.

    1985-02-01

    The synthesis and accumulation of nitrite has been suggested as a causative factor in the inhibition of legume nodules supplied with nitrate. Plants were grown in sand culture with a moderate level of nitrate (2.1 to 6.4 millimolar) supplied continuously from seed germination to 30 to 50 days after planting. In a comparison of nitrate treatments, a highly significant negative correlation between nitrite concentration in soybean (Glycine max (L.) Merr.) nodules and nodule fresh weight per shoot dry weight was found even when bacteroids lacked nitrate reductase (NR). However, in a comparison of two Rhizobium japonicum strains, there was only 12% as much nitrite in nodules formed by NR/sup -/ R. japonicum as in nodules formed by NR/sup +/ R. japonicum, and growth and acetylene reduction activity of both types of nodules was about equally inhibited. The very small concentration of nitrite found in P. vulgaris nodules was probably below that required for the inhibition of nitrogenase based on published in vitro experiments, and yet the specific acetylene reduction activity was inhibited 83% by nitrate. The overall results do not support the idea that nitrite plays a role in the inhibition of nodule growth and nitrogenase activity by nitrate.

  4. Long-term ¹³⁷Cs activity monitoring of mushrooms in forest ecosystems of the Czech Republic.

    PubMed

    Škrkal, J; Rulík, P; Fantínová, K; Burianová, J; Helebrant, J

    2013-12-01

    This paper reports on results of activity mass concentration analyses performed in various forest mushrooms in the Czech Republic within 1986 and 2011. The estimated effective half-life of (137)Cs and its environmental half-life (i.e. the effective half-life minus the effect of physical decay) were found to be 5.6 ± 0.6 and 6.9 ± 0.7 y, respectively. Non-homogeneity in (137)Cs surface contamination over the country's territory and fungus species-based (137)Cs accumulation capacity then account for a span of up to 4 orders of magnitude in activity mass concentrations measured each year after the Chernobyl accident. The highest geometric activity mass concentration (Bq kg(-1) of dry weight) means of (137)Cs (obtained from samples between years 2004 and 2011) were measured in Suillaceae (1050 Bq kg(-1)) and Boletus badius (930 Bq kg(-1)), the lowest in Agaricus (1 Bq kg(-1)). The geometric mean of all mushrooms amounted to 230 Bq kg(-1), being 440 Bq kg(-1) in Boletales, 150 Bq kg(-1) in Russulales and 21 Bq kg(-1) in Agaricales. Geometric standard deviation levels were generally high. The highest Cs accumulation capacity was observed in Boletales (namely in Suillaceae), while the lowest in Agaricales, being over 3 orders of magnitude lower than in Suillaceae.

  5. Long term storage of Pleurotus ostreatus and Trametes versicolor isolates using different cryopreservation techniques and its impact on laccase activity.

    PubMed

    Eichlerová, Ivana; Homolka, Ladislav; Tomšovský, Michal; Lisá, Ludmila

    2015-12-01

    The strain Pleurotus ostreatus Florida f6, its 45 basidiospore-derived isolates (both monokaryons and dikaryons prepared in our laboratory), Trametes versicolor strain CCBAS 614 and 22 other T. versicolor isolates obtained from the sporocarps collected in distant localities were successfully preserved for 12 y using perlite and straw cryopreservation protocols. All tested isolates survived a 12-year storage in liquid nitrogen (LN) and their laccase production and Poly B411 decolorization capacity was preserved. Also mycelium extension rate and the types of colony appearance of individual isolates remained unchanged. Different cryopreservation techniques were also tested for the short time (24 h) and the long time (6 m) storage of the culture liquid with extracellular laccase produced by T. versicolor strain CCBAS 614. The results showed that 10 % glycerol was the most suitable cryopreservant. The absence of the cryopreservant did not cause high loss of laccase activity in the samples; the presence of DMSO (5 or 10 %) in LN-stored samples caused mostly a decrease of laccase activity. For the preservation of laccase activity in the liquid culture the storage in the freezer at -80 °C is more convenient than the storage in liquid nitrogen. PMID:26615755

  6. Long term storage of Pleurotus ostreatus and Trametes versicolor isolates using different cryopreservation techniques and its impact on laccase activity.

    PubMed

    Eichlerová, Ivana; Homolka, Ladislav; Tomšovský, Michal; Lisá, Ludmila

    2015-12-01

    The strain Pleurotus ostreatus Florida f6, its 45 basidiospore-derived isolates (both monokaryons and dikaryons prepared in our laboratory), Trametes versicolor strain CCBAS 614 and 22 other T. versicolor isolates obtained from the sporocarps collected in distant localities were successfully preserved for 12 y using perlite and straw cryopreservation protocols. All tested isolates survived a 12-year storage in liquid nitrogen (LN) and their laccase production and Poly B411 decolorization capacity was preserved. Also mycelium extension rate and the types of colony appearance of individual isolates remained unchanged. Different cryopreservation techniques were also tested for the short time (24 h) and the long time (6 m) storage of the culture liquid with extracellular laccase produced by T. versicolor strain CCBAS 614. The results showed that 10 % glycerol was the most suitable cryopreservant. The absence of the cryopreservant did not cause high loss of laccase activity in the samples; the presence of DMSO (5 or 10 %) in LN-stored samples caused mostly a decrease of laccase activity. For the preservation of laccase activity in the liquid culture the storage in the freezer at -80 °C is more convenient than the storage in liquid nitrogen.

  7. Chronic, long-term social stress can cause decreased microtubule protein network activity and dynamics in cerebral cortex of male Wistar rats.

    PubMed

    Eskandari Sedighi, Ghazaleh; Riazi, Gholam Hossein; Vaez Mahdavi, Mohammad Reza; Cheraghi, Tayebe; Atarod, Deyhim; Rafiei, Shahrbanoo

    2015-03-01

    Social stress is viewed as a factor in the etiology of a variety of psychopathologies such as depression and anxiety. Animal models of social stress are well developed and widely used in studying clinical and physiological effects of stress. Stress is known to significantly affect learning and memory, and this effect strongly depends on the type of stress, its intensity, and duration. It has been demonstrated that chronic and acute stress conditions can change neuronal plasticity, characterized by retraction of apical dendrites, reduction in axonogenesis, and decreased neurogenesis. Various behavioral studies have also confirmed a decrease in learning and memory upon exposure of animals to long-term chronic stress. On the other hand, the close relationship between microtubule (MT) protein network and neuroplasticity controlling system suggests the possibility of MT protein alterations in high stressful conditions. In this work, we have studied the kinetics, activity, and dynamicity changes of MT proteins in the cerebral cortex of male Wistar rats that were subjected to social instability for 35 and 100 days. Our results indicate that MT protein network dynamicity and polymerization ability is decreased under long-term (100 days) social stress conditions.

  8. Activation of presynaptic and postsynaptic ryanodine-sensitive calcium stores is required for the induction of long-term depression at GABAergic synapses in the neonatal rat hippocampus.

    PubMed

    Caillard, O; Ben-Ari, Y; Gaïarsa, J L

    2000-09-01

    The role of internal calcium stores in the induction of long-term depression at GABAergic synapses was investigated in the neonatal rat hippocampus. Whole-cell recordings of CA3 pyramidal neurons were performed on hippocampal slices from neonatal (2-4 d old) rats. In control conditions, tetanic stimulation (TS) evoked an NMDA-dependent long-term depression of GABA(A) receptor-mediated postsynaptic responses (LTD(GABA-A)). LTD(GABA-A) was prevented when the cells were loaded with ruthenium red, a blocker of Ca2+-induced Ca2+ release (CICR) stores, whereas loading the cells with heparin, a blocker of IP3-induced Ca2+ release stores, had no effect. The effects of ryanodine, another compound that interferes with CICR stores, were also investigated. Intracellular injection of ryanodine prevented the induction of LTD(GABA-A) only when the TS was preceded by depolarizing pulses that increase intracellular Ca2+ concentration. When applied in the bath, ryanodine prevented the induction of LTD(GABA-A). Altogether, these results suggest that ryanodine acts as a Ca2+-dependent blocker of CICR stores and that the induction of LTD(GABA-A) required the activation of both presynaptic and postsynaptic CICR stores.

  9. [The Impact of Diseases (ICD-10) and Impairments of Activity and Participation (ICF) on the Long-Term Care Insurance in Germany (SGB XI)].

    PubMed

    Schmitt, J

    2006-07-01

    On the basis of a representative sample of expert records from the Medical Review Board of the statutory care insurance funds (MDK) it could be shown that in the year 2003 more diseases of dementia had been examined for the long-term care insurance. The diagnois of dementia is statistically significant as a determinat of exposition related to get benefit from the care insuance. Help assistance which is needed after suffering form fraturs of bones are significant too, but related to get no benefits. In Germany the expert records of the long-term care insurance investigate the help assistance defined by the Social Code (SGB XI) which is needed in the daily live of the disabled and handicaped people. The classification of the SGB XI for daily performances offers the required transparency by using the mulitvariate logistic regression analysis with the predictor to get benefits from the care insurance. The help assistance estimated in the sample was recoded with the International Classification of Functioning, Disability and Health (ICF). Within this classification activity and participation in daily life of disabled and handicapped people are investigated. It was found that there could be more subdivions for these performances. A new analysis of the body function recorded in the ICF could be of interest to explain significant variables relating to the amount of help assistance.

  10. Long-term activation of the pro-coagulant response after neoadjuvant chemoradiation and major cancer surgery

    PubMed Central

    Byrne, M; Reynolds, J V; O'Donnell, J S; Keogan, M; White, B; Byrne, M; Murphy, S; Maher, S G; Pidgeon, G P

    2009-01-01

    Background: The association between cancer, major surgery and venous thromboembolism (VTE) is well established. Multimodal therapy is increasingly being used as standard treatment for localised gastrointestinal cancer. The aim of this study was to examine the markers of pro-coagulation response and VTE risk in an exemplar multimodal model of pre-operative combination chemotherapy and radiation therapy, followed by complex cancer surgery. Methods: Consecutive patients (n=36) with localised oesophageal cancer were studied at baseline after the first and second cycles of chemoradiation, and on post-operative days 1–28, and at 3, 6 and 9 months. Factors regulating the pro- and anti-coagulant response, as well as pro-inflammatory markers including NFκB activation in peripheral blood mononuclear cells, were examined. All patients received enoxaparin 40 mg s.c. postoperatively up to discharge, and underwent pulmonary CT-pulmonary angiography and venography on day 10 postoperatively. Results: Four (11%) non-fatal thromboembolic events were documented, all after hospital discharge. Neoadjuvant therapy before surgery activated factor VIII (FVIII) and pro-inflammatory NFκB, and increased D-dimers, pro-thrombin fragment 1+2 (F1+2) and the thrombin-anti-thrombin complex (TAT). Surgery significantly (P<0.05) increased pro-thrombin time (PT), activated partial thromboplastin time, fibrinogen, D-dimers, TAT, F1+2 and FVIII up to 6 months. Conclusion: These data highlight the linked pro-coagulant and immunoinflammatory pathways in the multimodal management of oesophageal cancer, and suggest that the duration of current standard thromboprophylaxis regimens warrants further study. PMID:19953092

  11. Increased dopaminergic and 5-hydroxytryptaminergic activities in male rat brain following long-term treatment with anabolic androgenic steroids

    PubMed Central

    Thiblin, Ingemar; Finn, Anja; Ross, Svante B; Stenfors, Carina

    1999-01-01

    The effects of treating groups of rats with four different anabolic androgenic steroids (AAS) (testosterone, nandrolone, methandrostenolone, and oxymetholone) on 5-hydroxytryptamine (5-HT) and dopamine (DA) neurones in different brain regions were examined. The AAS was injected six times with 1 week's interval and the rats were sacrificed 2 days after the final injection. 5-HT and its metabolite 5-hydroxyindoleacetic acid (5-HIAA), DA and its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were measured. The effect on DA and 5-HT synthesis rate was analysed as the accumulation of 3,4-dihydroxyphenyl-alanine (DOPA) and 5-hydroxytryptophan (5-HTP), respectively, after inhibition of the amino acid decarboxylase with NSD-1015 (3-hydroxy-benzylhydrazine dihydrochloride). Additionally, the monoamine oxidase (MAO) activity was analysed in the hypothalamus. The DOPAC+HVA/DA ratio was increased in the striatum in all treatment groups. However, the synthesis rate of DA was significantly increased only in the methandrostenolone treated group. The 5-HIAA/5-HT ratio was increased in all treatment groups in the hippocampus, in the frontal cortex in the methandrostenolone-treated animals and in the hypothalamus in the testosterone- and oxymetholone-treated rats, while the 5-HT synthesis rate was not affected by the AAS-treatments. The MAO-A activity was increased in the oxymetholone-treated rats while the other treatment groups were unaffected. The MAO-B activity was not changed. The results indicate that relatively high doses of AAS increase dopaminergic and 5-hydroxytryptaminergic metabolism in male rat brain, probably due to enhanced turnover in these monaminergic systems. PMID:10217522

  12. Increased dopaminergic and 5-hydroxytryptaminergic activities in male rat brain following long-term treatment with anabolic androgenic steroids.

    PubMed

    Thiblin, I; Finn, A; Ross, S B; Stenfors, C

    1999-03-01

    1. The effects of treating groups of rats with four different anabolic androgenic steroids (AAS) (testosterone, nandrolone, methandrostenolone, and oxymetholone) on 5-hydroxytryptamine (5-HT) and dopamine (DA) neurones in different brain regions were examined. The AAS was injected six times with 1 week's interval and the rats were sacrificed 2 days after the final injection. 5-HT and its metabolite 5-hydroxyindoleacetic acid (5-HIAA), DA and its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were measured. The effect on DA and 5-HT synthesis rate was analysed as the accumulation of 3,4-dihydroxyphenyl-alanine (DOPA) and 5-hydroxytryptophan (5-HTP), respectively, after inhibition of the amino acid decarboxylase with NSD-1015 (3-hydroxy-benzylhydrazine dihydrochloride). Additionally, the monoamine oxidase (MAO) activity was analysed in the hypothalamus. 2. The DOPAC + HVA/DA ratio was increased in the striatum in all treatment groups. However, the synthesis rate of DA was significantly increased only in the methandrostenolone treated group. 3. The 5-HIAA/5-HT ratio was increased in all treatment groups in the hippocampus, in the frontal cortex in the methandrostenolone-treated animals and in the hypothalamus in the testosterone- and oxymetholone-treated rats, while the 5-HT synthesis rate was not affected by the AAS-treatments. 4. The MAO-A activity was increased in the oxymetholone-treated rats while the other treatment groups were unaffected. The MAO-B activity was not changed. 5. The results indicate that relatively high doses of AAS increase dopaminergic and 5-hydroxytryptaminergic metabolism in male rat brain, probably due to enhanced turnover in these monaminergic systems. PMID:10217522

  13. Sustainability of the Catalytic Activity of a Silica-Titania Composite (STC) for Long-Term Indoor Air Quality Control

    NASA Technical Reports Server (NTRS)

    Coutts, Janelle L.; Levine, Lanfang H.; Richards, Jeffrey T.

    2011-01-01

    TiO2-assisted photocatalytic oxidation (PCO) is an emerging technology for indoor air quality control and is also being evaluated as an alternative trace contaminant control technology for crew habitats in space exploration. Though there exists a vast range of literature on the development of photocatalysts and associated reactor systems, including catalyst performance and performance-influencing factors, the critical question of whether photocatalysts can sustain their initial catalytic activity over an extended period of operation has not been adequately addressed. For a catalyst to effectively serve as an air quality control product, it must be rugged enough to withstand exposure to a multitude of low concentration volatile organic compounds (VOCs) over long periods of time with minimal loss of activity. The objective of this study was to determine the functional lifetime of a promising photocatalyst - the silica-titania composite (STC) from Sol Gel Solutions, LLC in a real-world scenario. A bench-scale STC-packed annular reactor under continuous irradiation by a UV-A fluorescent black-light blue lamp ((lambda)max = 365 nm) was exposed to laboratory air continuously at an apparent contact time of 0.27 sand challenged with a known concentration of ethanol periodically to assess any changes in catalytic activity. Laboratory air was also episodically spiked with halocarbons (e.g., octafluoropropane), organosulfur compounds (e.g., sulfur hexafluoride), and organosilicons (e.g., siloxanes) to simulate accidental releases or leaks of such VOCs. Total organic carbon (TOC) loading and contaminant profiles of the laboratory air were also monitored. Changes in STC photocatalytic performance were evaluated using the ethanol mineralization rate, mineralization efficiency, and oxidation intermediate (acetaldehyde) formation. Results provide insights to any potential catalyst poisoning by trace halocarbons and organosulfur compounds.

  14. Patient-reported outcomes of caries prophylaxis among Swedish caries active adults in a long-term perspective.

    PubMed

    Flink, Håkan; Tegelberg, Åke; Arnetz, Judy; Birkhed, Dowen

    2016-01-01

    The aim of this study was to measure patient-reported outcomes of caries prophylaxis and to compare them with previously documented efforts in dental offices. A questionnaire was mailed to 134 caries active (CA) and 40 caries inactive (CI) adult patients treated at a Swedish public dental service clinic. The overall response rate was 69%. The questionnaire included items regarding patient perceived caries prophylaxis in relation to: 1) treatment and recommendations given by the dental personnel, 2) performed self-care and 3) perceived and expected effects.The responses were studied for their association to clinical data, extracted retrospectively from the patients' dental records.The mean follow up time was > 16 years. Information about caries prophylaxis (p = 0.01) and recommendations for self-care (p = 0.04) were given more often to the CA group than to the CI group. Supplementary examinations and recommendations of self-care risk treatments were more frequent in the CA group (p < 0.001). CA patients also made more frequent extra efforts at home to avoid caries by changing their eating habits (p < 0.001), improving their oral hygiene (p = 0.04) and using extra fluoride (p = 0.001). In the CA group, 60% did not considerthat the extra prophylaxis efforts had made them caries inactive, and 40% were not satisfied with the outcome. Most patients (> 90%) hoped that the outcome of caries prophylactics would be a reduced number of cavities.The patient-perceived experiences of caries prophylaxis-were in concordance with dental records. Both the dentists and the caries active middle-aged Swedish adults were aware of the need for extra prophylaxis.The caries active patients perceived having made extra home care efforts, but had not experienced that they had become free from caries. PMID:27464386

  15. Long-term simulation of the activated sludge process at the Hanover-Gümmerwald pilot WWTP.

    PubMed

    Makinia, Jacek; Rosenwinkel, Karl-Heinz; Spering, Volker

    2005-04-01

    The aim of this study was to obtain a validated model, consisting of the Activated Sludge Model No. 3 (ASM3) and the EAWAG bio-P module, which could be used as a decision tool for estimating the maximum allowable peak flow to wastewater treatment plants during stormwater conditions. The databases used for simulations originated from the Hanover-Gummerwald pilot plant subjected to a series of controlled, short-term hydraulic shock loading experiments. The continuous influent wastewater composition was generated using on-line measurements of only three parameters (COD, N-NH4+, P-PO4 3-). Model predictions were compared with on-line data from different locations in the activated sludge system including the aerobic zone (concentrations of N-NH4+, N-NO3-) and secondary effluent (concentrations of P-PO4 3-). The simulations confirmed experimental results concerning the capabilities of the system for handling increased flows during stormwater events. No (or minor) peaks of N-NH4+ were predicted for the line with the double dry weather flowrate, whereas peaks of N-NH4+ at the line with the quadruple dry weather flowrate were normally exceeding 8 g Nm(-3) (similar to the observations).

  16. Long-Term Follow-Up of the Telemonitoring Weight-Reduction Program “Active Body Control”

    PubMed Central

    Stumm, Gabriele; Blaik, Alexandra; Kropf, Siegfried; Westphal, Sabine; Hantke, Tanja Katrin; Luley, Claus

    2016-01-01

    The Active Body Control (ABC) weight-reduction program is based on telemonitoring of physical activity and nutrition together with telecoaching by weekly counseling letters sent by post or by e-mail. The study presented here reports the results of a 1-year follow-up of 49 patients with the metabolic syndrome who had lost weight with the aid of the ABC program in the preceding year. The weight regain after the second year in patients not receiving any further care (“ABC discontinued” group; n = 24) and the potential benefit of continuing with the ABC program with monthly counseling letters (“ABC continued” group; n = 25) were investigated. The relative weight changes after the first year had been, respectively, −13.4% and −11.4% in the “ABC discontinued” and “ABC continued” groups, and after the second year they decreased by, respectively, 4.4 and 2.8%. However, this difference in weight regains between the two groups was not statistically significant. It is concluded that three-quarters of the weight loss after 1 year is maintained after the second year. The decision whether to continue with the ABC program after 1 year should be made individually. PMID:27088096

  17. Optimal warm-up stimuli of muscle activation to enhance short and long-term acute jumping performance.

    PubMed

    Saez Saez de Villarreal, Eduardo; González-Badillo, Juan J; Izquierdo, Mikel

    2007-07-01

    The aim of this study was to determine the effect of different types of active warm-up stimuli of muscle activation on explosive jumping performance after short (5 min postwarm-up) and long (6 h postwarm-up) recovery periods following warm-up. Twelve trained volleyball players (21-24 years) performed different types of specific warm-up stimuli (WP) after baseline measurements [e.g., countermovement jump (CMJ) without and with extra load and Drop jump (DJ)] on randomized separate occasions: (1) three sets of five jumps with extra load (WP1), (2) two sets of four reps at 80% of 1RM parallel squat (1RM(PS)) and two sets of two reps at 85% of 1RM(PS) (WP2), (3) two sets of four reps at 80% of 1RM(PS) and two sets of two reps at 90% of 1RM(PS) and two sets of one rep at 95% of 1RM(PS) (WP3), (4) three sets of five DJs (WP4), (5) specified warm-up for a volleyball match (WP5), (6) three sets of five reps at 30% 1RM(PS) (WP6), and (7) an experimental condition of no active warm-up. Height in DJ significantly improved (P < 0.05) after WP1 (4.18%), WP2 (2.98%), WP3 (5.47%), and WP5 (4.49%). Maximal power output during CMJ with extra load significantly improved (P < 0.05) after WP2 (11.39%), WP5 (10.90%), WP3 (9%), and WP1 (2.47%). High-intensity dynamic loading (e.g., 80-95% 1RM), as well as specific volleyball warm-up protocol bring about the greatest effects on subsequent neuromuscular explosive responses. Acute positive effects on jumping performance after warm-up were maintained after long recovery periods (e.g., 6 h following warm-up), particularly when prior high-intensity dynamic actions were performed. PMID:17394010

  18. Geomagnetic activity: Dependence on solar wind parameters

    NASA Technical Reports Server (NTRS)

    Svalgaard, L.

    1977-01-01

    Current ideas about the interaction between the solar wind and the earth's magnetosphere are reviewed. The solar wind dynamic pressure as well as the influx of interplanetary magnetic field lines are both important for the generation of geomagnetic activity. The influence of the geometry of the situation as well as the variability of the interplanetary magnetic field are both found to be important factors. Semi-annual and universal time variations are discussed as well as the 22-year cycle in geomagnetic activity. All three are found to be explainable by the varying geometry of the interaction. Long term changes in geomagnetic activity are examined.

  19. Long-term modulation of tyrosine hydroxylase activity and expression by endothelin-1 and -3 in the rat anterior and posterior hypothalamus.

    PubMed

    Perfume, Guadalupe; Nabhen, Sabrina L; Barrera, Karla Riquelme; Otero, María G; Bianciotti, Liliana G; Vatta, Marcelo S

    2008-03-01

    Brain catecholamines are involved in the regulation of biological functions, including cardiovascular activity. The hypothalamus presents areas with high density of catecholaminergic neurons and the endothelin system. Two hypothalamic regions intimately related with the cardiovascular control are distinguished: the anterior (AHR) and posterior (PHR) hypothalamus, considered to be sympathoinhibitory and sympathoexcitatory regions, respectively. We previously reported that endothelins (ETs) are involved in the short-term tyrosine hydroxylase (TH) regulation in both the AHR and PHR. TH is crucial for catecholaminergic transmission and is tightly regulated by well-characterized mechanisms. In the present study, we sought to establish the effects and underlying mechanisms of ET-1 and ET-3 on TH long-term modulation. Results showed that in the AHR, ETs decreased TH activity through ET(B) receptor activation coupled to the nitric oxide, phosphoinositide, and CaMK-II pathways. They also reduced total TH level and TH phosphorylated forms (Ser 19 and 40). Conversely, in the PHR, ETs increased TH activity through a G protein-coupled receptor, likely an atypical ET receptor or the ET(C) receptor, which stimulated the phosphoinositide and adenylyl cyclase pathways, as well as CaMK-II. ETs also increased total TH level and the Ser 19, 31, and 40 phosphorylated sites of the enzyme. These findings support that ETs are involved in the long-term regulation of TH activity, leading to reduced sympathoinhibition in the AHR and increased sympathoexcitation in the PHR. Present and previous studies may partially explain the cardiovascular effects produced by ETs when applied to the brain.

  20. Long-term modulation of tyrosine hydroxylase activity and expression by endothelin-1 and -3 in the rat anterior and posterior hypothalamus.

    PubMed

    Perfume, Guadalupe; Nabhen, Sabrina L; Barrera, Karla Riquelme; Otero, María G; Bianciotti, Liliana G; Vatta, Marcelo S

    2008-03-01

    Brain catecholamines are involved in the regulation of biological functions, including cardiovascular activity. The hypothalamus presents areas with high density of catecholaminergic neurons and the endothelin system. Two hypothalamic regions intimately related with the cardiovascular control are distinguished: the anterior (AHR) and posterior (PHR) hypothalamus, considered to be sympathoinhibitory and sympathoexcitatory regions, respectively. We previously reported that endothelins (ETs) are involved in the short-term tyrosine hydroxylase (TH) regulation in both the AHR and PHR. TH is crucial for catecholaminergic transmission and is tightly regulated by well-characterized mechanisms. In the present study, we sought to establish the effects and underlying mechanisms of ET-1 and ET-3 on TH long-term modulation. Results showed that in the AHR, ETs decreased TH activity through ET(B) receptor activation coupled to the nitric oxide, phosphoinositide, and CaMK-II pathways. They also reduced total TH level and TH phosphorylated forms (Ser 19 and 40). Conversely, in the PHR, ETs increased TH activity through a G protein-coupled receptor, likely an atypical ET receptor or the ET(C) receptor, which stimulated the phosphoinositide and adenylyl cyclase pathways, as well as CaMK-II. ETs also increased total TH level and the Ser 19, 31, and 40 phosphorylated sites of the enzyme. These findings support that ETs are involved in the long-term regulation of TH activity, leading to reduced sympathoinhibition in the AHR and increased sympathoexcitation in the PHR. Present and previous studies may partially explain the cardiovascular effects produced by ETs when applied to the brain. PMID:18094067

  1. Microbial community and metabolism activity in a bioelectrochemical denitrification system under long-term presence of p-nitrophenol.

    PubMed

    Chen, Dan; Yang, Kai; Wei, Li; Wang, Hongyu

    2016-10-01

    Bioelectrochemical denitrification system (BEDS) is a promising technology for nitrate removal from wastewaters. The hazards and effects concerning p-nitrophenol (PNP) towards BEDS lack enough investigations and possess great research prospects. This study investigated how PNP affected the nitrate removal efficiency, microbial communities, functional denitrifying genes abundances, nitrate and nitrite reductase activities, diffusible signal factors (DSF) release, and extracellular polymeric substances (EPS) production in the BEDS. Results indicated that nitrate removal efficiency decreased with initial PNP concentration increased from 0 to 100mg/L. Phylum Firmicutes and class Clostridia were the main contributors for denitrification process in this BEDS. The abundances of the denitrifying genes nirS, nirK, napA, and narG all presented decreased trends with increasing PNP. In addition, the concentrations of nitrate reductase (NR), nitrite reductase (NIR), and EPS obviously decreased, while the concentration of DSF increased with increasing PNP, which demonstrated that higher PNP would inhibit the biofilm formation. PMID:27367815

  2. 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.

  3. Short and long-term lifestyle coaching approaches used to address diverse participant barriers to weight loss and physical activity adherence

    PubMed Central

    2014-01-01

    Background Individual barriers to weight loss and physical activity goals in the Diabetes Prevention Program, a randomized trial with 3.2 years average treatment duration, have not been previously reported. Evaluating barriers and the lifestyle coaching approaches used to improve adherence in a large, diverse participant cohort can inform dissemination efforts. Methods Lifestyle coaches documented barriers and approaches after each session (mean session attendance = 50.3 ± 21.8). Subjects were 1076 intensive lifestyle participants (mean age = 50.6 years; mean BMI = 33.9 kg/m2; 68% female, 48% non-Caucasian). Barriers and approaches used to improve adherence were ranked by the percentage of the cohort for whom they applied. Barrier groupings were also analyzed in relation to baseline demographic characteristics. Results Top weight loss barriers reported were problems with self-monitoring (58%); social cues (58%); holidays (54%); low activity (48%); and internal cues (thought/mood) (44%). Top activity barriers were holidays (51%); time management (50%); internal cues (30%); illness (29%), and motivation (26%). The percentage of the cohort having any type of barrier increased over the long-term intervention period. A majority of the weight loss barriers were significantly associated with younger age, greater obesity, and non-Caucasian race/ethnicity (p-values vary). Physical activity barriers, particularly thought and mood cues, social cues and time management, physical injury or illness and access/weather, were most significantly associated with being female and obese (p < 0.001 for all). Lifestyle coaches used problem-solving with most participants (≥75% short-term; > 90% long term) and regularly reviewed self-monitoring skills. More costly approaches were used infrequently during the first 16 sessions (≤10%) but increased over 3.2 years. Conclusion Behavioral problem solving approaches have short and long term dissemination potential

  4. 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

  5. Long-term deforestation in NW Spain: linking the Holocene fire history to vegetation change and human activities

    NASA Astrophysics Data System (ADS)

    Kaal, Joeri; Carrión Marco, Yolanda; Asouti, Eleni; Martín Seijo, Maria; Martínez Cortizas, Antonio; Costa Casáis, Manuela; Criado Boado, Felipe

    2011-01-01

    The Holocene fire regime is thought to have had a key role in deforestation and shrubland expansion in Galicia (NW Spain) but the contribution of past societies to vegetation burning remains poorly understood. This may be, in part, due to the fact that detailed fire records from areas in close proximity to archaeological sites are scarce. To fill this gap, we performed charcoal analysis in five colluvial soils from an archaeological area (Campo Lameiro) and compared the results to earlier studies from this area and palaeo-ecological literature from NW Spain. This analysis allowed for the reconstruction of the vegetation and fire dynamics in the area during the last ca 11 000 yrs. In the Early Holocene, Fabaceae and Betula sp. were dominant in the charcoal record. Quercus sp. started to replace these species around 10 000 cal BP, forming a deciduous forest that prevailed during the Holocene Thermal Maximum until ˜5500 cal BP. Following that, several cycles of potentially fire-induced forest regression with subsequent incomplete recovery eventually led to the formation of an open landscape dominated by shrubs (Erica sp. and Fabaceae). Major episodes of forest regression were (1) ˜5500-5000 cal BP, which marks the mid-Holocene cooling after the Holocene Thermal Maximum, but also the period during which agropastoral activities in NW Spain became widespread, and (2) ˜2000-1500 cal BP, which corresponds roughly to the end of the Roman Warm Period and the transition from the Roman to the Germanic period. The low degree of chronological precision, which is inherent in fire history reconstructions from colluvial soils, made it impossible to distinguish climatic from human-induced fires. Nonetheless, the abundance of synanthropic pollen indicators (e.g. Plantago lanceolata and Urtica dioica) since at least ˜6000 cal BP strongly suggests that humans used fire to generate and maintain pasture.

  6. Correlates of Adherence and Treatment Failure Among Kenyan Patients on Long-term Highly Active Anti-Retroviral Therapy

    PubMed Central

    Ochieng, Washingtone; Kitawi, Rose C.; Nzomo, Timothy J.; Mwatelah, Ruth S.; Kimulwo, Maureen J.; Ochieng, Dorothy J.; Kinyua, Joyceline; Lagat, Nancy; Onyango, Kevin O.; Lwembe, Raphael M.; Mwamburi, Mkaya; Ogutu, Bernhards R.; Oloo, Florence A.; Aman, Rashid

    2015-01-01

    Background Universal access to highly active antiretroviral therapy (HAART) is still elusive in most developing nations. We asked whether peer support influenced adherence and treatment outcome and if a single viral load (VL) could define treatment failure in a resource-limited setting. Methods A multi-center longitudinal and cross-sectional survey of VL, CD4 T-cells and adherence in 546 patients receiving HAART for up to 228 months. VL and CD4 counts were determined using m2000 Abbott RealTime HIV-1 assay and FACS respectively. Adherence was assessed based on pill-count and on self-report. Results Respectively, 55.8%, 22.2% and 22% of the patients had good, fair and poor adherence. Adherence, peer support and regimen but not HIV disclosure, age or gender, independently correlated with VL and durability of treatment in a multivariate analysis (p<0.001). Treatment failure was 35.9% using sequential VL but ranged between 27% and 35% using alternate single VL cross-sectional definitions. More patients failed stavudine (41.2%) than zidovudine (37.4%) or tenofovir (28.8%, P=0.043) treatment arms. Peer support correlated positively with adherence (χ2, p<0.001), with non-adherence highest in the stavudine arm. VL before the time of regimen switch was comparable between patients switching and those not switching treatment. Moreover, 36% of those switching still failed second-line regimen. Conclusion Weak adherence support and inaccessible VL testing threaten to compromise the success of HAART scale-up in Kenya. To hasten ART monitoring and decision-making, we suggest strengthening patient-focused adherence programs, optimizing and aligning regimen to WHO standards, and a single point-of-care VL testing when multiple tests are unavailable. PMID:26009836

  7. Changes in Soil Carbon and Enzyme Activity As a Result of Different Long-Term Fertilization Regimes in a Greenhouse Field

    PubMed Central

    Zhang, Lili; Chen, Wei; Burger, Martin; Yang, Lijie; Gong, Ping; Wu, Zhijie

    2015-01-01

    In order to discover the advantages and disadvantages of different fertilization regimes and identify the best management practice of fertilization in greenhouse fields, soil enzyme activities involved in carbon (C) transformations, soil chemical characteristics, and crop yields were monitored after long-term (20-year) fertilization regimes, including no fertilizer (CK), 300 kg N ha-1 and 600 kg N ha-1 as urea (N1 and N2), 75 Mg ha-1 horse manure compost (M), and M with either 300 or 600 kg N ha-1 urea (MN1 and MN2). Compared with CK, fertilization increased crop yields by 31% (N2) to 69% (MN1). However, compared with CK, inorganic fertilization (especially N2) also caused soil acidification and salinization. In the N2 treatment, soil total organic carbon (TOC) decreased from 14.1±0.27 g kg-1 at the beginning of the long-term experiment in 1988 to 12.6±0.11 g kg-1 (P<0.05). Compared to CK, N1 and N2 exhibited higher soil α-galactosidase and β-galactosidase activities, but lower soil α-glucosidase and β-glucosidase activities (P<0.05), indicating that inorganic fertilization had different impacts on these C transformation enzymes. Compared with CK, the M, MN1 and MN2 treatments exhibited higher enzyme activities, soil TOC, total nitrogen, dissolved organic C, and microbial biomass C and N. The fertilization regime of the MN1 treatment was identified as optimal because it produced the highest yields and increased soil quality, ensuring sustainability. The results suggest that inorganic fertilizer alone, especially in high amounts, in greenhouse fields is detrimental to soil quality. PMID:25706998

  8. Long-term study of the impact of methotrexate on serum cytokines and lymphocyte subsets in patients with active rheumatoid arthritis: correlation with pharmacokinetic measures

    PubMed Central

    Kremer, Joel M; Lawrence, David A; Hamilton, Robert; McInnes, Iain B

    2016-01-01

    Objective To describe changes in immune parameters observed during long-term methotrexate (MTX) therapy in patients with active rheumatoid arthritis (RA) and explore correlations with simultaneously measured MTX pharmacokinetic (PKC) parameters. Design Prospective, open-label, long-term mechanism of action study. Setting University clinic. Methods MTX was initiated at a single weekly oral dose of 7.5 mg and dose adjusted for efficacy and toxicity for the duration of the study. Standard measures of disease activity were performed at baseline and every 6–36 months. Serum cytokine measurements in blood together with lymphocyte surface immunophenotypes and stimulated peripheral blood mononuclear cell (PBMC) cytokine production were assessed at each clinical evaluation. Results Cytokine concentrations exhibited multiple significant correlations with disease activity measures over time. The strongest correlations observed were for interleukin (IL)-6 (r=0.45, p<0.0001 for swollen joints and r=0.32, p=0.002 for tender joints) and IL-8 (r=0.25, p=0.01 for swollen joints). Significant decreases from baseline were observed in serum IL-1B, IL-6 and IL-8 concentrations. The most significant changes were observed for IL-6 (p<0.001). Significant increases from baseline were observed in IL-2 release from PBMCs ex vivo (p<0.01). In parallel, multiple statistically significant correlations were observed between MTX PKC measures and immune parameters. The change in swollen joint count correlated inversely with the change in area under the curve (AUC) for MTX (r=−0.63, p=0.007). Conclusions MTX therapy of patients with RA is accompanied by a variety of changes in serum cytokine expression, which in turn correlate strongly with clinical disease activity and MTX pharmacokinetics (PKCs). These data strongly support the notion that MTX mediates profound and functionally relevant effects on the immunological hierarchy in the RA lesion. PMID:27335660

  9. Changes in soil carbon and enzyme activity as a result of different long-term fertilization regimes in a greenhouse field.

    PubMed

    Zhang, Lili; Chen, Wei; Burger, Martin; Yang, Lijie; Gong, Ping; Wu, Zhijie

    2015-01-01

    In order to discover the advantages and disadvantages of different fertilization regimes and identify the best management practice of fertilization in greenhouse fields, soil enzyme activities involved in carbon (C) transformations, soil chemical characteristics, and crop yields were monitored after long-term (20-year) fertilization regimes, including no fertilizer (CK), 300 kg N ha-1 and 600 kg N ha-1 as urea (N1 and N2), 75 Mg ha-1 horse manure compost (M), and M with either 300 or 600 kg N ha-1 urea (MN1 and MN2). Compared with CK, fertilization increased crop yields by 31% (N2) to 69% (MN1). However, compared with CK, inorganic fertilization (especially N2) also caused soil acidification and salinization. In the N2 treatment, soil total organic carbon (TOC) decreased from 14.1±0.27 g kg-1 at the beginning of the long-term experiment in 1988 to 12.6±0.11 g kg-1 (P<0.05). Compared to CK, N1 and N2 exhibited higher soil α-galactosidase and β-galactosidase activities, but lower soil α-glucosidase and β-glucosidase activities (P<0.05), indicating that inorganic fertilization had different impacts on these C transformation enzymes. Compared with CK, the M, MN1 and MN2 treatments exhibited higher enzyme activities, soil TOC, total nitrogen, dissolved organic C, and microbial biomass C and N. The fertilization regime of the MN1 treatment was identified as optimal because it produced the highest yields and increased soil quality, ensuring sustainability. The results suggest that inorganic fertilizer alone, especially in high amounts, in greenhouse fields is detrimental to soil quality.

  10. Changes in soil carbon and enzyme activity as a result of different long-term fertilization regimes in a greenhouse field.

    PubMed

    Zhang, Lili; Chen, Wei; Burger, Martin; Yang, Lijie; Gong, Ping; Wu, Zhijie

    2015-01-01

    In order to discover the advantages and disadvantages of different fertilization regimes and identify the best management practice of fertilization in greenhouse fields, soil enzyme activities involved in carbon (C) transformations, soil chemical characteristics, and crop yields were monitored after long-term (20-year) fertilization regimes, including no fertilizer (CK), 300 kg N ha-1 and 600 kg N ha-1 as urea (N1 and N2), 75 Mg ha-1 horse manure compost (M), and M with either 300 or 600 kg N ha-1 urea (MN1 and MN2). Compared with CK, fertilization increased crop yields by 31% (N2) to 69% (MN1). However, compared with CK, inorganic fertilization (especially N2) also caused soil acidification and salinization. In the N2 treatment, soil total organic carbon (TOC) decreased from 14.1±0.27 g kg-1 at the beginning of the long-term experiment in 1988 to 12.6±0.11 g kg-1 (P<0.05). Compared to CK, N1 and N2 exhibited higher soil α-galactosidase and β-galactosidase activities, but lower soil α-glucosidase and β-glucosidase activities (P<0.05), indicating that inorganic fertilization had different impacts on these C transformation enzymes. Compared with CK, the M, MN1 and MN2 treatments exhibited higher enzyme activities, soil TOC, total nitrogen, dissolved organic C, and microbial biomass C and N. The fertilization regime of the MN1 treatment was identified as optimal because it produced the highest yields and increased soil quality, ensuring sustainability. The results suggest that inorganic fertilizer alone, especially in high amounts, in greenhouse fields is detrimental to soil quality. PMID:25706998

  11. Hydrogen peroxide generation and antioxidant enzyme activities in the leaves and roots of wheat cultivars subjected to long-term soil drought stress.

    PubMed

    Huseynova, Irada M; Aliyeva, Durna R; Mammadov, Alamdar Ch; Aliyev, Jalal A

    2015-08-01

    The dynamics of the activity of catalase, ascorbate peroxidase, guaiacol peroxidase, and benzidine peroxidase, as well as the level of hydrogen peroxide in the vegetative organs of durum wheat (Triticum durum Desf.) cultivars was studied under long-term soil drought conditions. It was established that hydrogen peroxide generation occurred at early stages of stress in the tolerant variety Barakatli-95, whereas in the susceptible variety Garagylchyg-2 its significant amounts were accumulated only at later stages. Garagylchyg-2 shows a larger reduction of photochemical activity of PS II in both genotypes at all stages of ontogenesis under drought stress than Barakatli-95. The highest activity of catalase which plays a leading role in the neutralization of hydrogen peroxide was observed in the leaves and roots of the drought-tolerant variety Barakatli-95. Despite the fact that the protection system also includes peroxidases, the activity of these enzymes even after synthesis of their new portions is substantially lower compared with catalase. Native PAGE electrophoresis revealed the presence of one isoform of CAT, seven isoforms of APX, three isoforms of GPO, and three isoforms of BPO in the leaves, and also three isoforms of CAT, four isoforms of APX, two isoforms of GPO, and six isoforms of BPO in the roots of wheat. One isoform of CAT was found in the roots when water supply was normal and three isoforms were observed under drought conditions. Stress associated with long-term soil drought in the roots of wheat has led to an increase in the heterogeneity due to the formation of two new sedentary forms of catalase: CAT2 and CAT3.

  12. Long-term effect of municipal solid waste amendment on microbial abundance and humus-associated enzyme activities under semiarid conditions.

    PubMed

    Bastida, Felipe; Kandeler, Ellen; Hernández, Teresa; García, Carlos

    2008-05-01

    Microbial ecology is the key to understanding the function of soil biota for organic matter cycling after a single amendment of organic waste in semiarid soils. Therefore, in this paper, the long-term effect (17 years) of adding different doses of a solid municipal waste to an arid soil on humus-enzyme complexes, a very stable and long-lasting fraction of soil enzymes, as well as on microbial and plant abundance, was studied. Humic substances were extracted by 0.1 M pH 7 sodium pyrophosphate from soil samples collected in experimental plots amended with different doses of a solid municipal waste (0, 65, 130, 195, and 260 t/ha) 17 years before. The activity of different hydrolases related with the C (beta-glucosidase), N (urease), and P (alkaline phosphatase) cycles and with the formation of humic substances (o-diphenol oxidase) were determined in this extract. The density and diversity of plant cover in the plots, as well as the fungal and bacterial biomass (by analyzing phopholipid fatty acids) were also determined. In general, the amended plots showed greater humic substance-related enzymatic activity than the unamended plots. This activity increased with the dose but only up to a certain level, above which it leveled off or even diminished. Plant diversity and cover density followed the same trend. Fungal and bacterial biomass also benefited in a dose-dependent manner. Different signature molecules representing gram+ and gram- bacteria, and those corresponding to monounsaturated and saturated fatty acids showed a similar behavior. The results demonstrate that organic amendment had a noticeable long-term effect on the vegetal development, humic substances-related enzyme activity and on the development of bacteria and fungi in semiarid conditions.

  13. Long-term treadmill exercise improves spatial memory of male APPswe/PS1dE9 mice by regulation of BDNF expression and microglia activation.

    PubMed

    Xiong, J Y; Li, S C; Sun, Y X; Zhang, X S; Dong, Z Z; Zhong, P; Sun, X R

    2015-11-01

    Increasing evidence suggests that physical activity could delay or attenuate the symptoms of Alzheimer's disease (AD). But the underlying mechanisms are still not fully understood. To investigate the effect of long-term treadmill exercise on the spatial memory of AD mice and the possible role of β-amyloid, brain-derived neurotrophic factor (BDNF) and microglia in the effect, male APPswe/PS1dE9 AD mice aged 4 months were subjected to treadmill exercise for 5 months with 6 sessions per week and gradually increased load. A Morris water maze was used to evaluate the spatial memory. Expression levels of β-amyloid, BDNF and Iba-1 (a microglia marker) in brain tissue were detected by immunohistochemistry. Sedentary AD mice and wildtype C57BL/6J mice served as controls. The results showed that 5-month treadmill exercise significantly decreased the escape latencies (P < 0.01 on the 4th day) and improved the spatial memory of the AD mice in the water maze test. Meanwhile, treadmill exercise significantly increased the number of BDNF-positive cells and decreased the ratios of activated microglia in both the cerebral cortex and the hippocampus. However, treadmill exercise did not sig