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1

Long-term persistence of solar activity  

NASA Technical Reports Server (NTRS)

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.

Ruzmaikin, Alexander; Feynman, Joan; Robinson, Paul

1994-01-01

2

Long-term solar activity influences on South American rivers  

Microsoft Academic Search

River streamflows are excellent climatic indicators since they integrate precipitation over large areas. Here we follow up on our previous study of the influence of solar activity on the flow of the Paraná River, in South America. We find that the unusual minimum of solar activity in recent years have a correlation on very low levels in the Paraná's flow,

Pablo J. D. Mauas; Andrea P. Buccino; Eduardo Flamenco

2011-01-01

3

Long-term solar activity influences on South American rivers  

NASA Astrophysics Data System (ADS)

River streamflows are excellent climatic indicators since they integrate precipitation over large areas. Here we follow up on our previous study of the influence of solar activity on the flow of the Paraná River, in South America. We find that the unusual minimum of solar activity in recent years have a correlation on very low levels in the Paraná's flow, and we report historical evidence of low water levels during the Little Ice Age. We also study data for the streamflow of three other rivers (Colorado, San Juan and Atuel), and snow levels in the Andes. We obtained that, after eliminating the secular trends and smoothing out the solar cycle, there is a strong positive correlation between the residuals of both the Sunspot Number and the streamflows, as we obtained for the Paraná. Both results put together imply that higher solar activity corresponds to larger precipitation, both in summer and in wintertime, not only in the large basin of the Paraná, but also in the Andean region north of the limit with Patagonia.

Mauas, Pablo J. D.; Buccino, Andrea P.; Flamenco, Eduardo

2011-02-01

4

Chaotic mean wind in turbulent thermal convection and long-term correlations in solar activity  

E-print Network

It is shown that correlation function of the mean wind velocity in a turbulent thermal convection (Rayleigh number $Ra \\sim 10^{11}$) exhibits exponential decay with a very long correlation time, while corresponding largest Lyapunov exponent is certainly positive. These results together with the reconstructed phase portrait indicate presence of a chaotic component in the examined mean wind. Telegraph approximation is also used to study relative contribution of the chaotic and stochastic components to the mean wind fluctuations and an equilibrium between these components has been studied. Since solar activity is based on the thermal convection processes, it is reasoned that the observed solar activity long-term correlations can be an imprint of the mean wind chaotic properties. In particular, correlation function of the daily sunspots number exhibits exponential decay with a very long correlation time and corresponding largest Lyapunov exponent is certainly positive, also relative contribution of the chaotic and stochastic components follows the same pattern as for the convection mean wind.

A. Bershadskii

2009-12-25

5

Long-Term Evolution Of Emissivity And Heating In A Solar Active Region  

NASA Astrophysics Data System (ADS)

We study the evolution of the heating and emissivity of an active region from its birth throughout its decay during six solar rotations (July-Nov. 1996). We analyse multi-wavelength and multi-instrument data obtained from SOHO (EIT, SUMER, CDS, MDI), Yohkoh (SXT), GOES and 10.7cm radio data from DRAO, Canada. We take one "snapshot" per rotation at the time of the central meridian passage (CMP) of the AR, outside of time of flares, which appears to be representative enough to allow us to make some general conclusions about the long-term evolution. Deriving physical parameters like intensity (flux), temperature and emission measure of the entire AR vs. time, we formulate mathematically the change in radiation emitted by the decaying AR at several wavelengths. Combining the emissivity data with the evolution of magnetic flux density as the flux is being dispersed by small- and larger-scale convective motions, we make an attempt to understand the physics behind the emission and heating. We also analyse the effects of flaring on the heating of the AR, and study whether and how the flare properties evolve during the life of the active region.

van Driel-Gesztelyi, L.; Thompson, B.; Démoulin, P.; Orlando, S.; Bocchialini, K.; Oláh, K.; Kövári, Z.; Deforest, C.; Khan, J.; Fludra, A.; Mandrini, C.

1999-10-01

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)

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.

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

2003-01-01

7

On the long-term evolution of solar active regions from full Sun observations, magnetic flux transport and hydrodynamic modeling  

NASA Astrophysics Data System (ADS)

With their multiple vantage points around the Sun, STEREO and SDO observations provide a unique opportunity to view the solar surface continuously. We use data from these observatories to study the long-term evolution of solar active regions in He II 304 A. We show that active regions follow a universal pattern of emergence over several days followed by a decay that is proportional to the peak intensity in the region. We find that magnetic surface flux transport simulations are able to reproduce this evolution. Since STEREO does not make direct observations of the magnetic field, we use the flux-luminosity relationship to infer the total unsigned magnetic flux from the He 304 A images. We also illustrate the use of far-side imaging to introduce solar active regions into magnetic surface flux transport simulations. We finally show how these models can be used to determine the long-term coronal emission evolution in active regions by coupling extrapolations of the magnetic flux transport simulations field with EBTEL solutions to the hydrodynamic loop equations.

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

2015-04-01

8

Long-Term Evolution Of Emissivity And Heating In A Solar Active Region  

Microsoft Academic Search

We study the evolution of the heating and emissivity of an active region from its birth throughout its decay during six solar rotations (July-Nov. 1996). We analyse multi-wavelength and multi-instrument data obtained from SOHO (EIT, SUMER, CDS, MDI), Yohkoh (SXT), GOES and 10.7cm radio data from DRAO, Canada. We take one \\

L. van Driel-Gesztelyi; B. Thompson; P. Démoulin; S. Orlando; K. Bocchialini; K. Oláh; Z. Kövári; C. Deforest; J. Khan; A. Fludra; C. Mandrini

1999-01-01

9

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

NASA Technical Reports Server (NTRS)

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.

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

1979-01-01

10

Long-term variations in the north-south asymmetry of solar activity and solar cycle prediction, III: Prediction for the amplitude of solar cycle 25  

NASA Astrophysics Data System (ADS)

The combined Greenwich and Solar Optical Observing Network (SOON) sunspot group data during 1874-2013 are analysed and studied the relatively long-term variations in the annual sums of the areas of sunspot groups in 0°-10°, 10°-20°, and 20°-30° latitude intervals of the Sun’s northern and southern hemispheres. The variations in the corresponding north-south differences are also studied. Long periodicities in these parameters are determined from the fast Fourier transform (FFT), maximum entropy method (MEM), and Morlet wavelet analysis. It is found that in the difference between the sums of the areas of the sunspot groups in 0°-10° latitude intervals of northern and southern hemispheres, there exist ?9-year periodicity during the high activity period 1940-1980 and ?12-year periodicity during the low activity period 1890-1939. It is also found that there exists a high correlation (85% from 128 data points) between the sum of the areas of the sunspot groups in 0°-10° latitude interval of the southern hemisphere during a Qth year (middle year of 3-year smoothed time series) and the annual mean International Sunspot Number (RZ) of (Q+9)th year. Implication of these results is discussed in the context of solar activity prediction and predicted 50±10 for the amplitude of solar cycle 25, which is about 31% lower than the amplitude of cycle 24.

Javaraiah, J.

2015-01-01

11

Long-term reconstructions of total solar irradiance  

NASA Astrophysics Data System (ADS)

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.

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

2012-07-01

12

The Long-Term Hemispheric Sunspot Activity  

NASA Astrophysics Data System (ADS)

Sunspot activity is usually represented by either sunspot numbers (SN) or sunspot areas (SA). The smoothed monthly mean SA and SN in the northern and southern hemispheres from 1945 January to 2008 March are used to investigate the characteristics of long-term hemispheric sunspot activity. Although sunspot activity (SA and SN) is found to begin one month earlier in the northern hemisphere than in the southern hemisphere on the average of the considered time interval, the shift is so small that no long-term systematic phase shift is statistically acceptable as a first-order effect, as suggested by White & Trotter. Sunspot activity never peaks at the same time in the two hemispheres. Although the Schwabe cycle appears in hemispheric sunspot activity, its period length slightly varies during the considered time interval and seems to be longer in the southern hemisphere than in the northern hemisphere on the average. Sunspot activity is asymmetrically distributed in the hemispheres, but the largest hemispheric diversity usually does not appear around the maximum time of a cycle. The diversity of SA, respectively, in the northern and southern hemispheres runs on the Sun similarly and synchronously as the diversity of SN does. Sunspot activity is slightly asynchronous in the hemispheres.

Li, K. J.; Gao, P. X.; Zhan, L. S.; Shi, X. J.

2009-01-01

13

Simulation of long term solar power feed-in and solar balancing potential in European countries Simulation of long term solar power feed-in and  

E-print Network

-in with respect to the transmission grid , EMS2014-331 3 / 18 #12;Simulation of long term solar power feedSimulation of long term solar power feed-in and solar balancing potential in European countries Simulation of long term solar power feed-in and solar balancing potential in European countries Kabitri Nag

Heinemann, Detlev

14

Long-term goals for solar thermal technology  

Microsoft Academic Search

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

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

1985-01-01

15

Going Solar Yields Long-Term Economical, Educational Benefits  

ERIC Educational Resources Information Center

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

von Moos, Brian

2009-01-01

16

Analysis of Solar Irradiation Anomalies in Long Term Over India  

NASA Astrophysics Data System (ADS)

India has a high potential for solar energy applications due to its geographic position within the Sun Belt and the large number of cloudless days in many regions of the country. However, certain regions of India, particularly those largely populated, can exhibit large aerosol loading in the atmosphere as a consequence of anthropogenic emissions that could have a negative feedback in the solar resource potential. This effect, named as solar dimming, has already been observed in India, and in some other regions in the world, by some authors using ground data from the last two decades. The recent interest in the promotion of solar energy applications in India highlights the need of extending and improving the knowledge of the solar radiation resources in this country, since most of the long term measurements available correspond to global horizontal radiation and most of them are also located big cities or highly populated areas. In addition, accurate knowledge on the aerosol column quantification and on its dynamical behavior with high spatial resolution is particularly important in the case of India, due to their impact on direct normal irradiation. Long term studies of solar irradiation over India can be performed using monthly means of global hemispheric irradiation measurements from the Indian Meteorological Department. Ground data are available from 1964 till today through the World Radiation Data Centre that publish these values in the web. This work shows a long term analysis of solar irradiation in India using anomalies techniques and trends in ten places over India. Most of the places have exhibit a decreasing trend and negative anomalies confirming thus the darkening effect already reported by solar dimming studies. The analysis of anomalies has also found two periods of different behavior. From 1964 till 1988 the anomalies observed were positive and the last 20 years seems to be a period of negative anomalies. This observation is also consequent with solar dimming effect, apparently increased during the last two decades due to the increase of aerosol loading in the atmosphere. These results remark the important of having accurate knowledge of atmospheric aerosol loading and its dynamics over India with high spatial resolution in the framework of solar energy deployment in the country. It is worth to mention that greater anomalies and a noticeable decreasing trend found in Calcutta could be correlated with the highly population rate, and thus the greater the population density of the area the greater the negative anomalies and the decreasing trend of solar irradiation monthly means.

Cony, M.; Polo, J.; Martin, L.; Navarro, A.; Serra, I.

2012-04-01

17

Long-term memories in online users' selecting activities  

NASA Astrophysics Data System (ADS)

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.

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

2014-07-01

18

Long-term goals for solar thermal technology  

SciTech Connect

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.

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

1985-05-01

19

The shear-induced alpha-effect and long-term variations in solar dynamo  

E-print Network

The consequences of the shear-induced alpha effect to the long-term modulation of magnetic activity are examined with the help of the axisymmetric numerical dynamo model that includes the self-consistent description of the angular momentum balance, heat transport and magnetic field generation in the spherical shell. We find that the shear contributions to alpha effect can complicate the long-term behaviour of the large-scale magnetic activity and differential rotation in nonlinear dynamo. Additionally we consider the impact secular magnetic activity variations to the secular modulations of the solar luminosity and radius.

V. V. Pipin

2007-12-17

20

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

NASA Astrophysics Data System (ADS)

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 project was funded under the NASA Applied Science program between NASA, NREL, the State University of New York/Albany (SUNY) and the NOAA National Climatic Data Center (NCDC) to provide NREL with a global long-term advanced global solar mapping production system for improved depiction of historical solar resources and variability and to provide a mechanism for continual updates of solar resource information. Underlying this new data set will be a completely reprocessed 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. The new version of the ISCCP data features an improved long-term calibration process and pixel resolution up to 10 km. Thus, working with SUNY, NASA will develop and test an improved production system that will enable the longest-term global solar resource database to date. Lastly, we will identify the next steps in the production of the data set including some pathways to reduce the uncertainties identified in the current data set.

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

2011-12-01

21

Long term myriocin treatment increases MRP1 transport activity.  

PubMed

We investigated the effect of myriocin treatment, which extensively depletes sphingolipids from cells, on multidrug resistance-related protein 1 (MRP1) efflux activity in MRP1 expressing cells and isolated plasma membrane vesicles. Our data reveal that both short term (3 days) and long term (7 days) treatment effectively reduce the cellular sphingolipid content to the same level. Intriguingly, a two-fold increase in MRP1-mediated efflux activity was observed following long term treatment, while short term treatment had no impact. Very similar data were obtained with plasma membrane vesicles isolated from myriocin-treated cells. Exploiting the cell-free vesicle system, Michaelis-Menten analysis revealed that the intrinsic MRP1 activity remained unaltered; however, the fraction of active transporter molecules increased. We demonstrate that the latter effect is due to an enhanced recruitment of MRP1 into lipid raft fractions, thereby promoting MRP1 activity. PMID:23178537

Meszaros, Peter; Klappe, Karin; van Dam, Annie; Ivanova, Pavlina T; Milne, Stephen B; Myers, David S; Brown, H Alex; Permentier, Hjalmar; Hoekstra, Dick; Kok, Jan W

2013-02-01

22

Long-term variations in total solar irradiance  

NASA Technical Reports Server (NTRS)

For more than a decade total solar irradiance has been monitored simultaneously from space by different satellites. The detection of total solar irradiance variations by satellite-based experiments during the past decade and a half has stimulated modeling efforts to help identify their causes and to provide estimates of irradiance data, using `proxy' indicators of solar activity, for time intervals when no satellite observations exist. In this paper total solar irradiance observed by the Nimbus-7/Earth Radiation Budget (ERB), Solar Maximum Mission (SMM)/Active Cavity Radiometer Irradiance Monitor (ACRIM) 1, and Upper Atmosphere Research Satellite (UARS)/ACRIM 2 radiometers is modeled with the Photometric Sunspot Index and the Mg II core-to-wing ratio. Since the formation of the Mg II line is very similar to that of the Ca II K line, the Mg core-to-wing ratio, derived from the irradiance observations of the Nimbus-7 and NOAA9 satellites, is used as a proxy for the bright magnetic elements. It is shown that the observed changes in solar irradiance are underestimated by the proxy models at the time of maximum and during the beginning of the declining portion of solar cycle 22 similar to behavior just before the maximum of solar cycle 21. This disagreement between total irradiance observations and their model estimates is indicative of the fact that the underlying physical mechanism of the changes observed in the solar radiative output is not well-understood. Furthermore, the uncertainties in the proxy data used for irradiance modeling and the resulting limitation of the models should be taken into account, especially when the irradiance models are used for climatic studies.

Pap, Judit M.; Willson, Richard C.; Froelich, Claus; Donnelly, Richard F.; Puga, Larry

1994-01-01

23

Long-term perspective on the development of solar energy  

Microsoft Academic Search

We use dynamic optimization methods to analyze the development of solar technologies in light of the increasing scarcity and environmental pollution associated with fossil fuel combustion. Learning from solar R&D efforts accumulates in the form of knowledge to gradually reduce the cost of solar energy, while the scarcity and pollution externalities associated with fossil fuel combustion come into effect through

Yacov Tsur; Amos Zemel

2000-01-01

24

Respiratory neural activity during long-term facilitation.  

PubMed

Intermittent hypoxia results in a long-term facilitation (LTF) of respiratory efferent activity. The studies reviewed here presented data from both anesthetized and decerebrate, paralyzed, vagotomized, artificially ventilated adult cats. Multiple arrays of tungsten microelectrodes were used to record the concurrent responses of brain stem neurons that contribute to respiratory motor pattern generation. Spike trains were analyzed with firing rate histograms, peristimulus time histograms, cycle triggered histograms, spike triggered averages with multiunit phrenic efferent activity, cross correlation histograms, joint peristimulus time histograms and the gravity method. These studies addressed several hypotheses. (1) There is parallel processing of input from carotid chemoreceptors to the brain stem. (2) Respiratory related midline neurons are involved in the induction and maintenance of LTF. (3) There is a change in effective connectivity of brain stem neurons with LTF. (4) Neural networks involved in the induction and maintenance of LTF have patterns of synchrony that recur with a frequency greater than expected by chance. PMID:10963769

Morris, K F; Baekey, D M; Shannon, R; Lindsey, B G

2000-07-01

25

Long-term activity recognition from wristwatch accelerometer data.  

PubMed

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

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

2014-01-01

26

Long-Term Activity Recognition from Wristwatch Accelerometer Data *  

PubMed Central

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

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

2014-01-01

27

Long Term Variations of the Solar Cycle: Forecast of the Future Cycles (P20)  

NASA Astrophysics Data System (ADS)

Deviating from the traditional dynamo mechanism, we model the solar cycle as a forced and damped harmonic oscillator and from all the 22 cycles (1755-1996), we obtain long-term amplitudes, frequencies, phases and decay factor. For all the solar cycles, we find that amplitude and frequencies of the sinusoidal part remain constant and a very small decay factor from the transient part. These results suggest persistent MHD oscillations that might be compatible with long-period (~ 22 yr) Alfvenic oscillations. The Maunder-minimum type of solar activity, with a period of ~ 100 years, is explained as a result of coupled poloidal and toroidal MHD oscillations. Using the obtained amplitudes, frequencies and the phases of the previous 22 solar cycles, we forecast the amplitude (maximum sunspot number) and period of the present solar cycle (23) that match very well with the observations. The period of the present cycle is found to be 11.73 years. With these encouraging results, we forecast the profiles of future 15 solar cycles. Important findings are : (i) the period and amplitude of the cycle 24 are 9.34 years and 116 (plus or minus 12), (ii) the period and amplitude of the cycle 25 are 12.49 years and 110 (plus or minus 11) and, (iii) the sun might experience a very low ( around 60) sunspot activity during 2089- 2100 AD (cycle 31).

Hiremath, K. M.

2006-11-01

28

Stellar activity and the long-term use of robotic telescopes  

NASA Astrophysics Data System (ADS)

A number of automated and robotic telescopes are nowadays devoted to the systematic monitoring of magnetically active stars and binary systems at several astronomical institutions, all over the world, and their number is steadily increasing. Standard equipments include wide- and narrow-band photometers and, more recently, spectroscopic capabilities. The long-term time series that those telescopes are providing turn out to be of paramount importance in order to significantly progress in our understanding of solar-like stellar activity of magnetic origin, that seemingly affect most of late-type dwarfs and subgiants. Our principal aim is to illustrate which key parameters, that can be derived from such long-term time series, determine the appearance and evolution of stellar activity phenomena in different astrophysical environments other than solar, and their role in determining the physical characteristics of starspots, their surface distribution, filling factor, migration in latitude and longitude, and evolution in time. By using spots as tracers of stellar rotation, reliable data on stellar differential rotation, the prime motor of magnetic activity, can be derived. Moreover, the activity cycle is the additional fundamental parameter that can be provided by long-term time series. In order to properly address the study of stellar activity, an internationally coordinated network of 1-2 m class robotic telescopes dedicated to multi-wavelength systematic observations should be established.

Rodonò, M.; Messina, S.; Lanza, A. F.; Cutispoto, G.

2004-10-01

29

Terrestrial Solar Power Plants - Current Perspectives and Long Term Visions  

NASA Astrophysics Data System (ADS)

For terrestrial photovoltaic systems to be viable alternatives to satellite-borne solar generators, two conditions are necessary: Low-cost power generation and low-loss power transmission. This review will deal mainly with the power generation aspect of Very Large Scale terrestrial PV systems, for which it will be argued that system costs of less than $1000/kW may be achievable via the use of concentrator photovoltaic (CPV) technology. Such system costs should be directly competitive with fossil-fuelled ground-based power plants without the need for subsidies. As such, they could be readily integrated into the existing terrestrial grid systems in appropriate parts of the world. Regarding the transmission aspect, technological improvements are to be expected in low-loss long- distance cables - possibly via the discovery of hightemperature superconducting materials. This could enable the creation of a trans-equatorial power grid that, like satellite-borne systems, would ensure that the sun always shines on the generators. Key words: terrestrial solar energy, photovoltaics, dishconcentrators, low-cost electricity

Faiman, D.

2004-12-01

30

Long-term thermal performance of a two-phase thermosyphon solar water heater  

Microsoft Academic Search

This article investigates experimentally the long-term thermal performance of a two-phase thermosyphon solar water heater and compares the results with the conventional systems. Experimental investigations are conducted to obtain the system thermal efficiencies from the hourly, daily and long-term performance tests. Different heat transfer mechanisms, including natural convection, geyser boiling, nucleate boiling and film-wise condensation, are observed in the two-phase

Bo-Ren Chen; Yu-Wei Chang; Wen-Shing Lee; Sih-Li Chen

2009-01-01

31

Predicting the Long-Term Behavior of a Micro-Solar Power System  

Microsoft Academic Search

Micro-solar power system design is challenging because it must address long-term system behavior under highly variable solar energy conditions and consider a large space of design options. Several micro-solar power systems and models have been made, validating particular points in the whole design space. We provide a general architecture of micro-solar power systems---comprising key components and interconnections among the components---and

Jaein Jeong; David Culler

32

Sunspot Unit Areas: A New Parameter to Describe the Long-term Solar Variability  

E-print Network

-scale explosive energy releases in the form of solar flares and coronal mass ejections (CMEs). Studies have shownSunspot Unit Areas: A New Parameter to Describe the Long-term Solar Variability K.J. Li1,2 , J. Qiu2 , T.W. Su1 and P.X. Gao1 National Astronomical Observatories/Yunnan Observatory, CAS, Kunming

33

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

NASA Technical Reports Server (NTRS)

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 to last for up to five months past the largest events. However, the computed total column ozone and stratospheric temperature changes connected with the solar events were not found to be statistically significant. Thus, solar proton events do not likely contribute significantly to measured total column ozone fluctuations and stratospheric temperature changes.

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

2008-01-01

34

Activity Preferences and Satisfaction Among Older Adults in a Veterans Administration Long-Term Care Facility  

Microsoft Academic Search

Activities can be a nonpharmacological intervention for depression in long-term care. To address the activity needs of men, 183 residents of a VA long-term care facility were surveyed about activity interests, past and present, and activity satisfaction. With a 30% return rate, residents reported 85% overall satisfaction with activities and identified television as the most preferred activity, past and present.

Jacqueline Kracker; Kelly Kearns; Frederick J. Kier; Kimberly A. Christensen

2011-01-01

35

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

NASA Technical Reports Server (NTRS)

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.

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

36

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

PubMed

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. PMID:25483206

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

37

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

NASA Astrophysics Data System (ADS)

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.

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

2014-12-01

38

Long-term temperature effects on GaAs solar cells  

NASA Technical Reports Server (NTRS)

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.

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

1979-01-01

39

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

SciTech Connect

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.

Williams, T.A. [National Renewable Energy Lab., Golden, CO (United States); Burch, G.D. [Dept. of Energy, Washington, DC (United States); Chavez, J.M.; Mancini, T.R.; Tyner, C.E. [Sandia National Labs., Albuquerque, NM (United States)

1997-06-01

40

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

SciTech Connect

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.

Williams, T.A. [National Renewable Energy Lab., Golden, CO (United States); Burch, G. [USDOE, Washington, DC (United States); Chavez, J.M.; Mancini, T.R.; Tyner, C.E. [Sandia National Labs., Albuquerque, NM (United States)

1997-06-01

41

Long-term reliability of screen printed CdS/CdTe solar-cell modules  

NASA Astrophysics Data System (ADS)

Long-term reliability tests have been carried out screen-printed CdS/CdTe solar-cell modules under rooftop conditions in three countries at different latitudes (Japan, India and Australia). Test results on 118 modules, over periods of 140 to 800 days, have shown that such modules are fundamentally stable under these conditions. The only exception was one large module tested in India. The degradation of this module appears to have resulted from water which was able to enter because of poor sealing. Studies on waterproofing are necessary if the long-term reliability of screen-printed CdS/CdTe solar-cell modules is to be improved.

Nakano, A.; Ikegami, S.; Matsumoto, H.; Uda, H.; Komatsu, Y.

1986-05-01

42

Mitigating the Long term Operating Extreme Load through Active Control  

NASA Astrophysics Data System (ADS)

The parameters influencing the long term extreme operating design loads are identified through the implementation of a Design of Experiment (DOE) method. A function between the identified critical factors and the ultimate out-of-plane loads on the blade is determined. Variations in the initial blade azimuth location are shown to affect the extreme blade load magnitude during operation in normal turbulence wind input. The simultaneously controlled operation of generator torque variation and pitch variation at low blade pitch angles is detected to be responsible for very high loads acting on the blades. Through gain scheduling of the controller (modifications of the proportional Kp and the integral K gains) the extreme loads are mitigated, ensuring minimum instantaneous variations in the power production for operation above rated wind speed. The response of the blade load is examined for different values of the integral gain as resulting in rotor speed error and the rate of change of rotor speed. Based on the results a new load case for the simulation of extreme loads during normal operation is also presented.

Koukoura, Christina; Natarajan, Anand

2014-12-01

43

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

Microsoft Academic Search

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

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

1997-01-01

44

Hybrid solar\\/wind power system probabilistic modelling for long-term performance assessment  

Microsoft Academic Search

This paper presents a probabilistic approach based on the convolution technique to assess the long-term performance of a hybrid solar–wind power system (HSWPS) for both stand-alone and grid-linked applications. To estimate energy performance of HSWPS the reliability analysis is performed by the use of the energy index of reliability (EIR) directly related to energy expected not supplied (EENS). Analytical expressions

G. Tina; S. Gagliano; S. Raiti

2006-01-01

45

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

NASA Technical Reports Server (NTRS)

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.

1979-01-01

46

Variations in the solar fluxes of helium and protons on the long-term scale  

NASA Astrophysics Data System (ADS)

A reconstruction of data on ancient (to ˜600 Ma ago) solar fluxes of protons and helium has been performed on the basis of isotopic investigations of helium and neon in lunar soil samples from columns delivered by the automatic stations Luna-16 and Luna-24 in 1970 and 1976. Recent investigations have shown the presence of long-term climate variations, which can be explained in the context of solar-terrestrial links. However, the "space" impact, simultaneously with the Sun's influence on the Earth, takes place in the form of cosmic ray irradiation and as an influence on the Earth that is exerted by the flux of cosmic dust and meteorites (including the very large ones at the early stage of the Earth evolution). Therefore the existence of long-term variability of solar corpuscular fluxes may serve as direct evidence of the manifestation of solar-terrestrial links. The possibility of finding these links appears on the basis of the revealed variations of solar wind fluxes with an age from the contemporary level to the level of ˜600 Ma ago.

Anufriev, G. S.

2014-11-01

47

On a long-term dynamics of the magnetised solar tachocline  

E-print Network

We investigate the confinement and long-term dynamics of the magnetised solar tachocline. Starting from first principles, we derive the values of turbulent transport coefficients and then explore the implications for the confinement and long-term dynamics of the tachocline. For reasonable parameter values, the turbulent eddy viscosity is found to be negative, with turbulence enhancing the radial shear in the tachocline. Both magnetic diffusivity and thermal diffusivity are severely quenched, with the values much smaller than the magnitude of the eddy viscosity. The effect of the meridional circulation on momentum transport via the hyperviscosity becomes important when the radial shear becomes large (larger than the presently inferred value) due to the negative viscosity.

Eun-Jin Kim; Nicolas Leprovost

2006-12-04

48

Progress Towards Deriving an Improved Long-Term Global Solar Resource  

NASA Technical Reports Server (NTRS)

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.

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

49

Long term health implications of fitness and physical activity patterns  

Microsoft Academic Search

Northern Ireland has the highest incidence of coronary heart disease (CHD) in the world. The physical fitness, activity patterns, health knowledge, attitudes, and dietary habits of a random, stratified sample of 3211 Northern Irish children, comprising 1540 boys and 1671 girls, age range 11-18 years were examined. At all ages boys were significantly more active than girls. The most important

C Riddoch; J M Savage; N Murphy; G W Cran; C Boreham

1991-01-01

50

Long-term variation in the upper atmosphere as seen in the geomagnetic solar quiet (Sq) daily variation  

NASA Astrophysics Data System (ADS)

It has been well-known that geomagnetic solar quiet (Sq) daily variation is produced by the global ionospheric currents flowing in the E-region, which are generated by dynamo process via interaction between the neutral wind and ionospheric plasma in a region of the lower thermosphere and ionosphere. Then, to investigate the Sq amplitude is essential for understanding the long-term variations in the ionospheric conductivity and neutral wind of the lower thermosphere and ionosphere. Recently, Elias et al. [2010] reported that the Sq amplitude tends to increase by 5.4-9.9 % in the middle latitudes in a period of 1961-2001. They mentioned that the long-term variation of ionospheric conductivity associated with geomagnetic secular variation mainly determines the Sq trend, but that the rest component is due to ionospheric conductivity enhancement associated with cooling effect in the thermosphere due to increasing greenhouse gas. In the present study, we clarify the characteristics of the long-term variation in the Sq amplitude using the long-term observation data of geomagnetic field and neutral wind. In the present analysis, we used the F10.7 solar flux as a good indicator of the variation in the solar irradiance in the EUV and UV range as well as geomagnetic field data with time resolution of 1 hour observed at 184 geomagnetic stations. The definition of the Sq amplitude is the difference of the H-component between the maximum and minimum every day when the Kp index is less than 4. As a result, the long-term variation in the Sq amplitude at all the geomagnetic stations shows a strong correlation with the solar F10.7 flux which depends on 11-year solar activity. The relationship between the Sq amplitude and F10.7 flux was not linear but nonlinear. This nonlinearity could be interpreted as the decrease of production rate of electrons and ions in the ionosphere for the strong EUV and UV fluxes as already reported by Balan et al. [1993]. In order to minimize the solar activity dependence on the Sq amplitude, we calculated second orders of fitting curve between the F10.7 flux and Sq amplitude during 1950-2011, and examined the residual Sq amplitude defined as the deviation from the fitting curve. The residual Sq amplitude clearly shows increase and decrease trends with the periods of 20 years. Then, it seems that the trends in the residual Sq and Sqp fields are related to the long-term variation in the ionospheric conductivities associated with the secular variation of the ambient magnetic field and the upper atmosphere (for example, plasma and neutral densities). In order to verify qualitatively the above signatures, we need to investigate the long-term variation in the ionospheric conductivities using a calculation tool developed by the IUGONET project.

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

2012-12-01

51

Long Term Activity Analysis in Surveillance Video Archives  

ERIC Educational Resources Information Center

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…

Chen, Ming-yu

2010-01-01

52

Long-Term Extra-tropical Land Temperature Variability and Its Association with Solar and Volcanic Forcing  

NASA Astrophysics Data System (ADS)

It has long been hypothesized that a significant fraction of observed Northern Hemisphere (NH) temperature variability at multi-decadal to centennial time scales can be attributed to variations in solar activity. This argument has been supported by some modeling experiments that used long-term changes in solar irradiance, explosive volcanism, and anthropogenic trace gases to model temperature changes over the past 1,000 years. The modeled temperatures based on these radiative forcings often compare reasonably well to proxy-based NH temperature reconstructions covering the past 1,000 years, with solar forcing being important up to the mid-20th century, after which anthropogenic forcing dominates. Volcanic forcing is also important, but it operates in a more impulsive, episodic fashion. Consequently, its impact on proxy estimates of NH temperatures over the past 1,000 years may episodically distort and even overwhelm the effects of solar forcing on temperatures, thus breaking down what would otherwise be the appearance of a strong solar influence on past temperatures. While this problem can be investigated with models, the level of radiative forcing attributed to both solar and volcanic effects is still poorly constrained. Here, we statistically investigate the combined influences of solar and volcanic forcing in a land-only, extra-tropical NH temperature reconstruction. This record has been shown to have a strong statistical association with instrumental annual temperatures over the same region of the NH. Using estimates of solar irradiance and volcanic forcing, we show evidence for a centennial time-scale influence of solar forcing on past temperatures on the order of 700-1,000 years ago during a period of relatively high solar activity and little explosive volcanism. After that time, the frequency of explosive volcanism increases substantially, during a period of generally reduced solar activity, which appears to overwhelm solar forcing. In an effort to better reveal the underlying solar signal in the temperature reconstruction, we try to factor out the volcanic forcing signal, with limited success. It appears, therefore, that the emergence of solar forcing as a long-term agent of temperature change over extra-tropical NH land areas is highly dependent both on the magnitude of its forcing and on the frequency and timing of explosive volcanism as a competing agent of temperature variability and change.

Cook, E. R.

2004-12-01

53

Long term health implications of fitness and physical activity patterns.  

PubMed Central

Northern Ireland has the highest incidence of coronary heart disease (CHD) in the world. The physical fitness, activity patterns, health knowledge, attitudes, and dietary habits of a random, stratified sample of 3211 Northern Irish children, comprising 1540 boys and 1671 girls, age range 11-18 years were examined. At all ages boys were significantly more active than girls. The most important finding was an appreciable decline in physical activity levels after the age of 14 years reaching extremely low levels in older girls. While 75% of exercise taken was not related to school, physical education classes constituted the only exercise taken by one third of pupils. Girls had healthier nutritional habits and were more inclined to employ weight control measures than boys. There was a preponderance of children with a higher body mass index indicating a tendency to obesity in the child population. Over 20% of school leavers of both sexes regularly smoked cigarettes and 20% regularly drank alcohol. The postulated relationship between childhood inactivity, adult sedentary lifestyle, and increased risk of CHD raises serious cause for concern regarding the future cardiovascular health of many children. PMID:1776891

Riddoch, C; Savage, J M; Murphy, N; Cran, G W; Boreham, C

1991-01-01

54

Long-term-average, solar cycle, and seasonal response of magnetospheric energetic electrons to the solar wind speed  

NASA Astrophysics Data System (ADS)

Among the interplanetary activity parameters the solar wind speed is the one best correlated with the energetic electron fluxes in the inner magnetosphere. We examine the radial and temporal characteristics of the 2-6 MeV electron response, approximating it in this paper with linear filters. The filter response is parameterized by the time delay (?), measured from the time of solar wind impact, and the L shell (L). We examine solar cycle and seasonal effects using an 8-year-long database of Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX)/ Proton Electron Telescope (PET) measurements at the radial range L = 1.1-10. The main peak P1 of the long-term-average response is at (?, L) = (2, 5.3) and has a simultaneous response over a wide range of radial distances, ?L = 5. The duration of the response after the peak is inversely proportional to the L shell. The central part of the inner magnetosphere (L = 3.7-5.75) has a much more prolonged response (>10 days) than other parts. Prior to the main response, P1, a brief response, P0, of typically lower amplitude appears at (?, L) = (0, 3), probably as a quasi-adiabatic response to the compression of the magnetosphere by the solar wind pressure. Over the solar cycle the variation in solar wind input results in a systematic change of the position, amplitude, radial extent, and duration of the two peaks: during solar wind minimum the quasi-adiabatic peak disappears, and the radial size of the responding region decreases; both are responses to low-density, high-speed streams. During solar minimum, the duration is at least 3 days (30%) longer than average, probably due to the sustained solar wind input. Systematic variations appear also as a function of season due to several magnetic and fluid effects. During equinoxes the coupling is stronger, and the duration is longer (by at least 2 days) compared to solstices. Between the two equinoxes the fall response has a significantly higher amplitude and longer duration than the spring equinox response. This is at least partly due to the higher GSE By component during the observation time, which acts to increase the effective GSM Bz component according to the Russell-McPherron effect. The seasonal modulation of the response is consistent with the variation in the fluxes themselves [, 1999]. The modulation is discussed in terms of the equinoctial and axial hypotheses [, 1970; , 1973; , 2000].

Vassiliadis, D.; Klimas, A. J.; Kanekal, S. G.; Baker, D. N.; Weigel, R. S.

2002-11-01

55

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

NASA Technical Reports Server (NTRS)

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.

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

2011-01-01

56

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

NASA Technical Reports Server (NTRS)

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.

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

2011-01-01

57

Solar irradiance at the earth's surface: long-term behavior observed at the South Pole  

NASA Astrophysics Data System (ADS)

This research examines a 17-year database of UV-A (320-400 nm) and visible (400-600 nm) solar irradiance obtained by a scanning spectroradiometer located at the South Pole. The goal is to define the variability in solar irradiance reaching the polar surface, with emphasis on the influence of cloudiness and on identifying systematic trends and possible links to the solar cycle. To eliminate changes associated with the varying solar elevation, the analysis focuses on data averaged over 30-35 day periods centered on each year's austral summer solstice. The long-term average effect of South Polar clouds is a small attenuation, with the mean measured irradiances being about 5-6% less than the clear-sky values, although at any specific time clouds may reduce or enhance the signal that reaches the sensor. The instantaneous fractional attenuation or enhancement is wavelength dependent, where the percent deviation from the clear-sky irradiance at 400-600 nm is typically 2.5 times that at 320-340 nm. When averaged over the period near each year's summer solstice, significant correlations appear between irradiances at all wavelengths and the solar cycle as measured by the 10.7 cm solar radio flux. An approximate 1.8 ± 1.0% decrease in ground-level irradiance occurs from solar maximum to solar minimum for the wavelength band 320-400 nm. The corresponding decrease for 400-600 nm is 2.4 ± 1.9%. The best-estimate declines appear too large to originate in the sun. If the correlations have a geophysical origin, they suggest a small variation in atmospheric attenuation with the solar cycle over the period of observation, with the greatest attenuation occurring at solar minimum.

Frederick, J. E.; Hodge, A. L.

2011-02-01

58

Solar irradiance at the Earth's surface: long-term behavior observed at the South Pole  

NASA Astrophysics Data System (ADS)

This research examines a 17-year database of UV-A (320-400 nm) and visible (400-600 nm) solar irradiance obtained by a scanning spectroradiometer located at the South Pole. The goal is to define the variability in solar irradiance reaching the polar surface, with emphasis on the influence of cloudiness and on identifying systematic trends and possible links to the solar cycle. To eliminate changes associated with the varying solar elevation, the analysis focuses on data averaged over 30-35 day periods centered on each year's austral summer solstice. The long-term average effect of South Polar clouds is a small attenuation, with the mean measured irradiances being about 5-6% less than the clear-sky values, although at any specific time clouds may reduce or enhance the signal that reaches the sensor. The instantaneous fractional attenuation or enhancement is wavelength dependent, where the percent deviation from the clear-sky irradiance at 400-600 nm is typically 2.5 times that at 320-340 nm. When averaged over the period near each year's summer solstice, significant correlations appear between irradiances at all wavelengths and the solar cycle as measured by the 10.7 cm solar radio flux. An approximate 1.8 ± 1.0% decrease in ground-level irradiance occurs from solar maximum to solar minimum for the wavelength band 320-400 nm. The corresponding decrease for 400-600 nm is 2.4 ± 1.9%. The best-estimate declines appear too large to originate in the sun. If the correlations have a geophysical origin, they suggest a small variation in atmospheric attenuation with the solar cycle over the period of observation, with the greatest attenuation occurring at solar minimum.

Frederick, J. E.; Hodge, A. L.

2010-11-01

59

Long-term variation in the upper atmosphere as seen in the amplitude of the geomagnetic solar quiet daily variation  

NASA Astrophysics Data System (ADS)

It has been well-known that geomagnetic solar quiet (Sq) daily variation is produced by global ionospheric currents flowing in the E-region from middle latitudes to the magnetic equator. These currents are generated by a dynamo process via interaction between the neutral wind and ionospheric plasma in a region of the thermosphere and ionosphere. From the Ohm's equation, the ionospheric currents strongly depend on the ionospheric conductivity, polarization electric field and neutral wind. Then, to investigate the Sq amplitude is essential for understanding the long-term variations in the ionospheric conductivity and neutral wind of the thermosphere and ionosphere. Elias et al. [2010] found that the Sq amplitude tends to increase by 5.4-9.9 % in the middle latitudes from 1961 to 2001. They mentioned that the long-term variation of ionospheric conductivity associated with geomagnetic secular variation mainly determines the Sq trend, but that the rest component is ionospheric conductivity enhancement associated with cooling effects in the thermosphere due to increasing the greenhouse gases. In this talk, we clarify the characteristics of the long-term variation in the Sq amplitude using the long-term observation data of geomagnetic field and neutral wind. These observation data have been provided by the IUGONET (Inter-university Upper atmosphere Global Observation NETwork) project. In the present analysis, we used the F10.7 flux as an indicator of the variation in the solar irradiance in the EUV and UV range, geomagnetic field data with time resolution of 1 hour. The definition of the Sq amplitude is the difference of the H-component between the maximum and minimum per day when the Kp index is less than 4. As a result, the Sq amplitude at all the stations strongly depends on 11-year solar activity, and tends to enhance more during the high activities (19- and 22- solar cycles) than during the low activity (20-solar cycle). The Fourier spectra of the F10.7 flux and Sq amplitude at Guam (13.59N, 144.87E) showed that the common peaks appear at the periods of 5.5, 7,5 and 10.5 years with the coherence of more than 0.9 while the spectrum peaks around 0.5 and 1.0 year appear only in the Sq amplitude. The former peak of the Sq amplitude is due to the solar activity while the latter is a cause of the upper atmosphere variation. In order to minimize the solar activity dependence of the Sq amplitude, we calculated the residual Sq amplitude using a second degree polynomial curve between the F10.7 and Sq amplitude during 1957-2010, and examined the residual Sq field defined as the deviation from the fitting curve. The residual Sq amplitude showed a clear tendency to increase and decrease during the periods of 1957-1992 and 1993-2010, respectively. It should be noted that the residual Sq amplitude around 2010 is almost the same level as that around 1970. In order to verify qualitatively the above signatures, we need to investigate the long-term variation in the ionospheric conductivities calculated with the IRI-2007 and MSIS-00 models.

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

2011-12-01

60

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

NASA Technical Reports Server (NTRS)

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.

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

61

Predicting the Long-Term Behavior of a Micro-Solar Power System JAEIN JEONG, Cisco Systems  

E-print Network

35 Predicting the Long-Term Behavior of a Micro-Solar Power System JAEIN JEONG, Cisco Systems DAVID CULLER, University of California, Berkeley Micro-solar power system design is challenging because it must of design options. Several micro-solar power systems and models have been made, validating particular points

California at Berkeley, University of

62

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

SciTech Connect

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.

Buccino, Andrea P.; Luoni, MarIa Luisa; Abrevaya, Ximena C.; Mauas, Pablo J. D. [Instituto de Astronomia y Fisica del Espacio (CONICET), C.C. 67 Sucursal 28, C1428EHA-Buenos Aires (Argentina); DIaz, Rodrigo F., E-mail: abuccino@iafe.uba.ar [Institut d'Astrophysique de Paris, 98bis, blvd Arago, F-75014 Paris (France)

2011-02-15

63

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

ERIC Educational Resources Information Center

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…

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

2011-01-01

64

Developing Long-Term Physical Activity Participation: A Grounded Theory Study With African American Women  

Microsoft Academic Search

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 not been realized. By clearly elucidating the process

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

2009-01-01

65

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

ERIC Educational Resources Information Center

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…

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

2009-01-01

66

Long-term response of stratospheric ozone and temperature to solar variability  

NASA Astrophysics Data System (ADS)

The long-term variability in stratospheric ozone mass mixing ratio (O3) and temperature (T) from 1979 to 2013 is investigated using the latest reanalysis product delivered by the European Centre for Medium-Range Weather Forecasts (ECMWF), i.e., ERA-Interim. Moreover, using the Mg II index time series for the same time period, the response of the stratosphere to the 11-year Schwabe solar cycle is investigated. Results reveal the following features: (i) upward (downward) trends characterize zonally averaged O3 anomalies in the upper (middle to lower stratosphere) stratosphere, while prevailing downward trends affect the T field. Mg II index data exhibit a weaker 24th solar cycle (though not complete) when compared with the previous two; (ii) correlations between O3 and Mg II, T and Mg II, and O3 and T are consistent with photochemical reactions occurring in the stratosphere and large-scale transport; and (iii) wavelet cross-spectra between O3 and Mg II index show common power for the 11-year period, particularly in tropical regions around 30-50 hPa, and different relative phase in the upper and lower stratosphere. A comprehensive insight into the actual processes accounting for the observed correlation between ozone and solar UV variability would be gained from an improved bias correction of ozone measurements provided by different satellite instruments, and from the observations of the time behavior of the solar spectral irradiance.

Bordi, I.; Berrilli, F.; Pietropaolo, E.

2015-03-01

67

Post-parturition and late lactation urine : long-term effects of exposure on mouse activity  

E-print Network

Post-parturition and late lactation urine : long-term effects of exposure on mouse activity infant mice were exposed for 10 consecutive days to urine from post-parturitional and late-lactational exposed to urine from late-lactational donors was associated with reduced activity when compared with mice

Paris-Sud XI, Université de

68

2006 Nature Publishing Group Long-term eruptive activity at a submarine arc  

E-print Network

© 2006 Nature Publishing Group Long-term eruptive activity at a submarine arc volcano Robert W , Douglas A. Wiens12 & Yoshihiko Tamura13 Three-quarters of the Earth's volcanic activity is submarine of submarine eruptions have been indirect, made from surface vessels or made after the fact1­6 . We describe

Chadwick, Bill

69

Continuous assessment of work activities and posture in long-term care nurses  

Microsoft Academic Search

The high prevalence of low back injuries in nursing has prompted the use of mechanical lift assists while overall assessment of activities and postures remains limited. The purpose of this study was to chronicle trunk posture and work tasks of long-term healthcare professionals. An inclinometer monitored trunk posture for 27 workers, 20 of whom were also observed continuously throughout their

Joanne N. Hodder; Michael W. R. Holmes; Peter J. Keir

2010-01-01

70

Amygdala Activity at Encoding Correlated with Long-Term, Free Recall of Emotional Information  

Microsoft Academic Search

Positron emission tomography of cerebral glucose metabolism in adult human subjects was used to investigate amygdaloid complex (AC) activity associated with the storage of long-term memory for emotionally arousing events. Subjects viewed two videos (one in each of two separate positron emission tomography sessions, separated by 3-7 days) consisting either of 12 emotionally arousing film clips (``E'' film session) or

Larry Cahill; Richard J. Haier; James Fallon; Michael T. Alkire; Cheuk Tang; David Keator; Joseph Wu; James L. McGaugh

1996-01-01

71

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

Microsoft Academic Search

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

Yabei Zhang; Steven J. Smith

2007-01-01

72

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

SciTech Connect

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.

Zhang, Yabei; Smith, Steven J.

2007-08-16

73

Stellar activity cycles from long-term data by robotic telescopes  

NASA Astrophysics Data System (ADS)

All results about stellar activity cycles stem from decades-long systematic observations that were done by small telescopes. Without these equipments we would not know much, if anything, about stellar activity cycles, like those we see and observe easily on the nearest star, the Sun. In the early 80's of the last century systematic photometric monitoring of active stars began with automated photometric telescopes (APTs), some of which continue the observations to date. The Vienna-Potsdam APT now works for about two decades (Strassmeier et al. 1997), similarly to the 4-College Consortium APT (Dukes et al. 1995), while the Catania APT (Rodono et al. 2001) was closed down a few years ago. These small tools with the same setups for decades do not cost much and are relatively cheap to maintain. The longest continuous photometric datasets of a few objects from APTs span now over 30 years, which, together with earlier, manually-obtained data allow to study those activity cycles of stars which are in the order of 10 years or shorter: to be sure in the timescale of a cycle it should be observed repeatedly at least 2-3 times. The spectroscopic automated telescope STELLA (Strassmeier et al. 2004), built in the first decade of this century, measured already a few dozens of radial velocity curves for long-period binary stars and measured their activity levels (Strassmeier et al. 2012); these results can be gathered only by robotic telescopes. Only with STELLA it is possible to study the decades-long behavior of starspots on active giants with long rotational periods via Doppler Imaging. As the databases were growing it became clear that stars, just as the Sun, had multiple cycles. It was also found that stellar cycles showed systematic changes and that the cycle lengths correlated with the rotational periods of the stars. Extensive summaries of stellar activity cycles are found in Baliunas et al. (1995) using the Mt. Wilson Ca-index survey, and Oláh et al. (2009) based on 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-cost, investments in astronomy. These telescopes and their equipments should be preserved and used as lon

Oláh, K.

2014-03-01

74

A tropomyosin-related kinase B ligand is required for ERK activation, long-term synaptic facilitation, and long-term memory in Aplysia  

PubMed Central

BDNF, which acts through tropomyosin-related kinase B (TrkB) receptors during mammalian development, also enhances long-term synaptic facilitation (LTF) in adult Aplysia. Because LTF is a substrate for long-term memory (LTM) in Aplysia, we examined the requirement of a secreted TrkB ligand in LTM formation at molecular, synaptic, and behavioral levels. Using an extracellular fusion protein that sequesters secreted TrkB ligands, we show that TrkB function is required for serotonin-induced activation of extracellular signal-regulated kinase, tail nerve shock-induced LTF in the CNS, and tail shock-induced LTM but is not necessary for short-term synaptic facilitation or short-term memory. These results show that a secreted growth factor, acting through a TrkB signaling cascade, is critical for the induction of long-lasting plasticity and memory formation in Aplysia. PMID:16963562

Sharma, Shiv K.; Sherff, Carolyn M.; Stough, Shara; Hsuan, Vickie; Carew, Thomas J.

2006-01-01

75

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

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

76

Effects of Long-term Organic Amendments and Soil Solarization on Pepper and Watermelon Growth, Yield, and Soil Fertility  

Microsoft Academic Search

Many vegetable growers rely on methyl bromide or other soil fumigants to manage soil pathogens, nematodes, and weeds. Nonchemical alternatives such as solariza- tion and organic amendments are as yet largely unproven, but do offer promise of more sustainable solutions. The objective of this study was to evaluate the effects of long-term organic amendments and soil solarization on soil chemical

Monica Ozores-Hampton; Philip A. Stansly; Robert McSorley; Thomas A. Obreza

77

Non-linear analysis of the long-term behaviour of solar filaments  

NASA Astrophysics Data System (ADS)

The correlation dimension and K2 entropy of solar filaments are investigated using the Carte Synoptique catalogue of solar filaments from 1919 March to 1989 December. It is found that the correlation dimension of full-disc, low-latitude (<50°) and high-latitude (?50°) filament numbers is about 4.05 ± 0.35, 4.1 ± 0.45 and 4.0 ± 0.4, respectively and shows very similar fractal properties when compared with values derived from Wolf sunspot numbers. All K2 entropies of full-disc, low-latitude and high-latitude filament numbers are positive, though larger than the K2 entropy of Wolf sunspot numbers. On the basis of the correlation dimension, positive K2 entropy, chaotic solar dynamo and solar filament-sunspot relationship, it is concluded that the coronal activity of the high layer of the Sun described by solar filament numbers is chaotic and has very complex behaviour.

Zou, Peng; Li, Qi-Xiu; Wu, Nan

2014-01-01

78

Optimisation of long-term activated-sludge treatment of winery wastewater  

Microsoft Academic Search

The results obtained in work carried out in order to verify the overall efficiency of full-scale, long-term, activated-sludge treatment of winery wastewater are presented. The analytical data showed the high removal of COD (average 98%; min. 97.6; max. 99.1) during the whole experimentation period and with various working parameters. The effluent had chemico-physical values in conformity with Table A of

R. Marchetti

1995-01-01

79

Working-Memory Capacity as Long-Term Memory Activation: An Individual-Differences Approach  

Microsoft Academic Search

One explanation of the correlation often observed between working-memory span scores and reading comprehension is that individuals differ in level of activation available for long-term memory units. Two experiments used the fan manipulation to test this idea. In Experiment 1, high- and low-working-memory Ss learned a set of unrelated sentences varying in the number of shared concepts (fan) and then

Judy Cantor; Randall W. Engle

1993-01-01

80

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

NASA Technical Reports Server (NTRS)

This report summarizes science analysis activities by the SAMPEX mission science team during the period during the period July 1, 1997 through July 1, 1998. Bibliographic entries for 1997 and 1998 to date (July 1998) are included. The SAMPEX science team was extremely active, with 20 articles published or submitted to refereed journals, 11 papers published in their entirety in Conference Proceedings, and 49 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.

Mason, G. M.; Blake, J. B.; Mewaldt, R. A.; Stone, E. C.; Baker, D. N.

1998-01-01

81

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

NASA Technical Reports Server (NTRS)

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.

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

82

Long term endurance test and contact degradation of CIGS solar cells  

NASA Astrophysics Data System (ADS)

CIGS is the most promising technology for thin-film solar cells with record efficiencies of 20.4 % on laboratory scale and 17.8 % aperture area efficiency on a 900 cm² module. Another important factor besides the cell efficiency is the reliability and long term stability of the manufactured modules, which can be assessed by accelerated ageing. In this contribution the accelerated ageing of CIGS mini modules has been investigated. Therefore, modules were dark annealed under dry heat conditions at different temperatures. During the endurance test a positive or negative bias was applied to the cells. In regular intervals the IV- and CV-characteristics were measured at room temperature. After an overall stress time of 3500 h the IV-characteristics were determined under different illumination conditions (intensity, spectral illumination). Our previous publications suggest a barrier at the back contact to explain the observed parameter drifts. This contribution is focused on the influence of different bias conditions during the endurance test on the generation of a back diode and on the change of the acceptor concentration. These parameter drifts have an impact on the open circuit voltage, fill factor and on the appearance of a cross over between dark and illuminated IV-characteristics. The interpretation of the observed parameter drifts was supported by SCAPS simulations based on the above mentioned back barrier model. As an outcome of the simulations signatures for the existence of a back barrier diode were established. IVmeasurements, temperature dependent Voc measurements and SunsVoc measurements are helpful means to detect such back diodes.

Ott, Thomas; Schönberger, Francillina; Walter, Thomas; Hariskos, Dimitrios; Kiowski, Oliver; Schäffler, Raymund

2013-09-01

83

Long-term correlation in single calcium-activated potassium channel kinetics  

NASA Astrophysics Data System (ADS)

Ion channels are protein molecules found in biological membranes, which can assume distinct open and closed conformational states, a phenomenon called ion channel kinetics. The transitions from one state to another are dependent on the potential energy barrier that separates them and can be controlled by the electrical field, ions and/or drugs. Both Markovian and fractal models have been used for modeling the ion channel kinetics. Ion single channel records are characterized by successive openings and closings, which are correlated in time. Here the rescaled range analysis ( R/S Hurst analysis) is used to test for the occurrence of long-term correlation in the kinetics of a calcium-activated potassium channel of Leydig cells. A Hurst coefficient H=0.640±0.064 ( n=5) was found for the single calcium-activated potassium channel clamped at -80 mV and exposed to a free Ca 2+ concentration equal to 10 nM. This numerical value indicates the presence of long-term correlation (memory) in this kinetic process. However, when the R/ S analysis was applied to ion channel data simulated using Markovian and fractal models, it could not account for the long-term correlation previously found in the experimental data. In summary, in this work we show that: (i) opening and closing dwell times for the single calcium-activated potassium channel of Leydig cells present long-term correlation and (ii) Markovian and fractal models, which describe well the dwell time distributions, are not adequate to describe the memory found in the kinetics of this channel.

Campos de Oliveira, R. A.; Barbosa, C. T. F.; Consoni, L. H. A.; Rodrigues, A. R. A.; Varanda, W. A.; Nogueira, R. A.

2006-05-01

84

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

NASA Technical Reports Server (NTRS)

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.

Lee, Robert B., III

1992-01-01

85

Different patterns of electrical activity lead to long-term potentiation by activating different intracellular pathways.  

PubMed

Deciphering and storing information coded in different firing patterns are important properties of neuronal networks, as they allow organisms to respond and adapt to external and internal events. Here we report that hippocampal CA1 pyramidal neurons respond to brief bursts of high-frequency stimulation (HFS) and ? burst stimulation (TBS) with long-lasting enhanced responses (long-term potentiation [LTP]), albeit by engaging different signaling pathways. TBS induces LTP through calpain-1-mediated suprachiasmatic nucleus circadian oscillatory protein degradation, ERK activation, and actin polymerization, whereas HFS requires adenosine A2 receptors, PKA, and actin polymerization. TBS- but not HFS-induced LTP is impaired in calpain-1 knock-out mice. However, TBS-induced LTP and learning impairment in knock-out mice are restored by activating the HFS pathway. Thus, different patterns of rhythmic activities trigger potentiation by activating different pathways, and cross talks between these can be used to restore LTP and learning when elements of the pathways are impaired. PMID:25589756

Zhu, Guoqi; Liu, Yan; Wang, Yubin; Bi, Xiaoning; Baudry, Michel

2015-01-14

86

Physical activity for prevention of osteoporosis in patients with severe haemophilia on long-term prophylaxis.  

PubMed

Physical activity has been considered as an important factor for bone density and as a factor facilitating prevention of osteoporosis. Bone density has been reported to be reduced in haemophilia. To examine the relation between different aspects of physical activity and bone mineral density (BMD) in patients with severe haemophilia on long-term prophylaxis. The study group consisted of 38 patients with severe haemophilia (mean age 30.5 years). All patients received long-term prophylaxis to prevent bleeding. The bone density (BMD g cm(-2)) of the total body, lumbar spine, total hip, femoral neck and trochanter was measured by dual energy X-ray absorptiometry. Physical activity was assessed using the self-report Modifiable Activity Questionnaire, an instrument which collects information about leisure and occupational activities for the prior 12 months. There was only significant correlation between duration and intensity of vigorous physical activity and bone density at lumber spine L1-L4; for duration (r = 0.429 and P = 0.020) and for intensity (r = 0.430 and P = 0.019); whereas no significant correlation between all aspects of physical activity and bone density at any other measured sites. With adequate long-term prophylaxis, adult patients with haemophilia are maintaining bone mass, whereas the level of physical activity in terms of intensity and duration play a minor role. These results may support the proposition that the responsiveness to mechanical strain is probably more important for bone mass development in children and during adolescence than in adults and underscores the importance of early onset prophylaxis. PMID:20113364

Khawaji, M; Astermark, J; Akesson, K; Berntorp, E

2010-05-01

87

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

NASA Technical Reports Server (NTRS)

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.

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

2001-01-01

88

Calibration Of a Century of Polar Field Measurements and what this Tells us About the Long-term Variability of the Solar and Heliospheric Magnetic Field  

NASA Astrophysics Data System (ADS)

In addition to the well known 11-year periodicity, the solar cycle also presents long-term modulations of its amplitude and period which play a determinant role in the evolution of space weather and climate. To this date, the efforts at understanding long-term solar variability have focused on the active parts of the cycle using sunspot properties as their main source of data. However, the recent extend minimum of sunspot cycle 23 has shown us that the quiet parts of the cycle are equally important and thus long-term databases complementary to sunspot properties are necessary. Here we show how to consolidate Mount Wilson Observatory polar faculae data from four observational campaigns (1906-1964, Sheeley 1966; 1960-1975, Sheeley 1976; 1975-1990, Sheeley 1991; 1985-2007, Sheeley 2008), validate it through a comparison with facular data counted automatically from MDI intensitygrams, and calibrate it against polar field measurements taken by the Wilcox Solar Observatory (1977-2011) and average polar field and total polar flux calculated using MDI line-of-sight magnetograms (1996-2011). We also show that the consolidated polar facular measurements are in excellent agreement with both polar field and polar flux estimates, making them an ideal proxy to study the evolution of the polar magnetic field since 1906 and use this proxy to study the role of polar flux in the evolution of the solar cycle and the Heliospheric Magnetic Field (HMF).

Munoz-Jaramillo, Andres; Sheeley, N. R.; Zhang, J.; DeLuca, E. E.

2012-05-01

89

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

SciTech Connect

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.

Hall, A.T. [Sandoz Agro, Inc., Des Plaines, IL (United States); Oris, J.T. [Miami Univ. Oxford, OH (United States)

1994-12-31

90

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

PubMed Central

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

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

2015-01-01

91

Long-term-average, solar cycle, and seasonal response of magnetospheric energetic electrons to the solar wind speed  

E-print Network

to the solar wind speed D. Vassiliadis,1 A. J. Klimas,2 S. G. Kanekal,3 D. N. Baker,3 and R. S. Weigel4. [1] Among the interplanetary activity parameters the solar wind speed is the one best correlated is parameterized by the time delay (t), measured from the time of solar wind impact, and the L shell (L). We

92

Caspase-3 Activation via Mitochondria Is Required for Long-Term Depression and AMPA Receptor Internalization  

E-print Network

NMDA receptor-dependent synaptic modifications, such as long-term potentiation (LTP) and long-term depression (LTD), are essential for brain development and function. LTD occurs mainly by the removal of AMPA receptors from ...

Li, Zheng

93

Long-term changes in excitability induced by protein kinase C activation in Aplysia sensory neurons.  

PubMed

Protein kinases A (PKA) and C (PKC) play a central role as intracellular transducers during simple forms of learning in Aplysia. These two proteins seem to cooperate in mediating the different forms of plasticity underlying behavioral modifications of defensive reflexes in a state- and time-dependent manner. Although short- and long-term changes in the synaptic efficacy of the connections between mechanosensory neurons and motoneurons of the reflex have been well characterized, there is also a distinct intermediate phase of plasticity that is not as well understood. Biochemical and physiological experiments have suggested a role for PKC in the induction and expression of this form of facilitation. In this report, we demonstrate that PKC activation can induce both intermediate- and long-term changes in the excitability of sensory neurons (SNs). Short application of 4beta-phorbol ester 12,13-dibutyrate (PDBU), a potent activator of PKC, produced a long-lasting increase in the number of spikes fired by SNs in response to depolarizing current pulses. This effect was observed in isolated cell culture and in the intact ganglion; it was blocked by a selective PKC inhibitor (chelerythrine). Interestingly, the increase in excitability measured at an intermediate-term time point (3 h) after treatment was independent of protein synthesis, while it was disrupted at the long-term (24 h) time point by the general protein synthesis inhibitor, anisomycin. In addition to suggesting that PKC as well as PKA are involved in long-lasting excitability changes, these findings support the idea that memory formation involves multiple stages that are mechanistically distinct at the biochemical level. PMID:9497402

Manseau, F; Sossin, W S; Castellucci, V F

1998-03-01

94

Enhanced photovoltaic properties and long-term stability in plasmonic dye-sensitized solar cells via noncorrosive redox mediator.  

PubMed

We demonstrate the localized surface plasmon resonance (LSPR) effect, which can enhance the photovoltaic properties of dye-sensitized solar cells (DSSCs), and the long-term stability of size-controlled plasmonic structures using a noncorrosive redox mediator. Gold nanoparticles (Au NPs) were synthesized with a phase transfer method based on ligand exchange. This synthetic method is advantageous because the uniformly sized Au NPs, can be mass produced and easily applied to DSSC photoanodes. The plasmonic DSSCs showed an 11% improvement of power conversion efficiency due to the incorporation of 0.07 wt % Au NPs, compared to the reference DSSCs without Au NPs. The improved efficiency was primarily due to the enhanced photocurrent generation by LSPR effect. With the cobalt redox mediator, the long-term stability of the plasmonic structures also significantly increased. The plasmonic DSSCs with cobalt(II/III) tris(2,2'-bipyridine) ([Co(bpy)3](2+/3+)) redox mediator maintained the LSPR effect with stable photovoltaic performance for 1000 h. This is, to our knowledge, the first demonstration of the long-term stability of plasmonic nanostructures in plasmonic DSSCs based on liquid electrolytes. As a result, the enhanced long-term stability of plasmonic NPs via a noncorrosive redox mediator will increase the feasibility of plasmonic DSSCs. PMID:25296336

Jung, Heesuk; Koo, Bonkee; Kim, Jae-Yup; Kim, Taehee; Son, Hae Jung; Kim, BongSoo; Kim, Jin Young; Lee, Doh-Kwon; Kim, Honggon; Cho, Jinhan; Ko, Min Jae

2014-11-12

95

Methodology for Using Long-Term Accelerometry Monitoring to Describe Daily Activity Patterns in COPD  

PubMed Central

We sought to develop procedures for computerized analysis of long-term, high-resolution activity monitoring data that allow accurate assessment of the time course of activity levels suitable for use in chronic obstructive pulmonary disease (COPD) patients. Twenty-two COPD patients utilizing long-term oxygen recruited from 5 sites of the COPD Clinical Research Network wore a triaxial accelerometer (RT3, Stayhealthy, Monrovia, CA) during waking hours over a14 day period. Computerized algorithms were composed allowing minute-by-minute activity data to be analyzed to determine, for each minute, whether the monitor was being worn. Temporal alignment allowed determination of average time course of activity level, expressed as average vector magnitude units (VMU, the vectorial sum of activity counts in three orthogonal directions) per minute, for each hour of the day. Mid-day activity was quantified as average VMU/minute between 10AM and 4PM for minutes the monitor was worn. Over the 14 day monitoring period, subjects wore the monitor an average of 11.4±3.0 hours·day?1. During midday hours, subjects wore the monitor 76.3% of the time and generated an average activity level of 112±55 VMU·min?1. Increase in precision of activity estimates with longer monitoring periods was demonstrated. This analysis scheme allows a detailed temporal pattern of activity to be defined from triaxial accelerometer recordings and has the potential to facilitate comparisons among subjects and between subject groups. This trial is registered at ClinicalTrials.gov (NCT00325754). PMID:19378225

Hecht, Ariel; Ma, Shuyi; Porszasz, Janos; Casaburi, Richard

2010-01-01

96

Cholinergic Pairing with Visual Activation Results in Long-Term Enhancement of Visual Evoked Potentials  

PubMed Central

Acetylcholine (ACh) contributes to learning processes by modulating cortical plasticity in terms of intensity of neuronal activity and selectivity properties of cortical neurons. However, it is not known if ACh induces long term effects within the primary visual cortex (V1) that could sustain visual learning mechanisms. In the present study we analyzed visual evoked potentials (VEPs) in V1 of rats during a 4–8 h period after coupling visual stimulation to an intracortical injection of ACh analog carbachol or stimulation of basal forebrain. To clarify the action of ACh on VEP activity in V1, we individually pre-injected muscarinic (scopolamine), nicotinic (mecamylamine), ?7 (methyllycaconitine), and NMDA (CPP) receptor antagonists before carbachol infusion. Stimulation of the cholinergic system paired with visual stimulation significantly increased VEP amplitude (56%) during a 6 h period. Pre-treatment with scopolamine, mecamylamine and CPP completely abolished this long-term enhancement, while ?7 inhibition induced an instant increase of VEP amplitude. This suggests a role of ACh in facilitating visual stimuli responsiveness through mechanisms comparable to LTP which involve nicotinic and muscarinic receptors with an interaction of NMDA transmission in the visual cortex. PMID:19543405

Kang, Jun Il; Vaucher, Elvire

2009-01-01

97

Long-term weathering effects on the thermal performance of the Lennox/Honeywell (liquid) solar collector  

NASA Technical Reports Server (NTRS)

The test procedures used and the results obtained during the evaluation test program of the Lennox/Honeywell double covered liquid solar collector. The tests were performed under simulated conditions, following long-term exposure to natural weathering conditions. The Lennox/Honeywell collector is a flat-plate solar collector. The absorber plate is steel with copper tubes bonded on the upper surface, and is coated with black chrome. Visual inspection of the collector indicated slight discoloration of the absorber plate. Results indicate that performance degradation had occurred. Absorptivity and/or transmissivity decreased as a result of the weathering.

1978-01-01

98

SWAP Observations of the Long-Term, Large-Scale Evolution of the EUV Solar Corona  

E-print Network

The Sun Watcher with Active Pixels and Image Processing (SWAP) EUV solar telescope on board the Project for On-Board Autonomy 2 (PROBA2) spacecraft has been regularly observing the solar corona in a bandpass near 17.4 nm since February 2010. With a field-of-view of 54x54 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 (PSF) 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 persiste...

Seaton, Daniel B; Shearer, Paul; Berghmans, David; Nicula, Bogdan

2013-01-01

99

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

PubMed

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

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

100

Long-term effects of silver nanoparticles on reproductive activity of rabbit buck.  

PubMed

Using the rabbit as an animal model, this study evaluated the long-term effect of silver nanoparticles (NPs) administered intravenously (0.6 mg/kg bw) on reproductive activity and sperm quality. Semen analysis was performed by optical microscopy and sperm motility evaluation by computer assisted sperm analyzer (CASA). Mitochondria oxygen consumption, light and transmission electron microscopy of rabbit testis and ejaculated sperm were also carried out. Throughout the experiment NP-treated rabbits showed higher seminal reactive oxygen species (ROS), less motile sperm, and lower curvilinear velocity and oxygen consumption than control animals. In contrast, libido, serum testosterone, sperm concentration, and semen volume were hardly affected by NPs. Transmission electron microscopy analysis did not show any evident morphological damage in testes; however, Ag NPs are visible in spermatids and ejaculated sperm. These preliminary results show that Ag NPs can reach the testes, compromising sperm motility, sperm speed, and acrosome and mitochondria shape and function. PMID:24547726

Castellini, Cesare; Ruggeri, Silvia; Mattioli, Simona; Bernardini, Giovanni; Macchioni, Lara; Moretti, Elena; Collodel, Giulia

2014-06-01

101

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

PubMed

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. PMID:24177136

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

2014-06-01

102

Decreased protein phosphatase 2A activity in hippocampal long-term potentiation.  

PubMed

Using autophosphorylated Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) as substrate, we now find that long-term potentian (LTP) induction and maintenance are also associated with a significant decrease in calyculin A-sensitive protein phosphatase (protein phosphatase 2A) activity, without changes in Mg2+-dependent protein phosphatase (protein phosphatase 2C) activity. This decrease in protein phosphatase 2A activity was prevented when LTP induction was inhibited by treatment with calmidazolium or D-2-amino-5-phosphonopentanoic acid. In addition, the application of high-frequency stimulation to 32P-labeled hippocampal slices resulted in increases in the phosphorylation of a 55-kDa protein immunoprecipitated with anti-phosphatase 2A antibodies. Use of a specific antibody revealed that the 55-kDa protein is the B'alpha subunit of protein phosphatase 2A. Following purification of brain protein phosphatase 2A, the B'alpha subunit was phosphorylated by CaM kinase II, an event that led to the reduction of protein phosphatase 2A activity. These results suggest that the decreased activity in protein phosphatase 2A following LTP induction contributes to the maintenance of constitutively active CaM kinase II and to the long-lasting increase in phosphorylation of synaptic components implicated in LTP. PMID:10646534

Fukunaga, K; Muller, D; Ohmitsu, M; Bakó, E; DePaoli-Roach, A A; Miyamoto, E

2000-02-01

103

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

ERIC Educational Resources Information Center

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…

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

2009-01-01

104

Improving the long-term stability of PBDTTPD polymer solar cells through material purification aimed at  

E-print Network

from high Mn PBDTTPD achieve power conversion efficiencies (PCE) as high as 7.3%, the short and tandem solar cells have demonstrated efficiencies exceeding 10%. In addition to a high efficiency, OPV impurities play in OPV lifetime is unknown. In solar cells made from a high efficiency polymer, we observe

McGehee, Michael

105

Long-term durability of sol–gel porous coatings for solar glass covers  

Microsoft Academic Search

The application of antireflective coatings to the glass covers of solar thermal collectors, allows to increase the efficiency of the whole system. In this sense, sol–gel silica porous coatings have been deposited on borosilicate glass and solar transmittance values as high as 0.97 have been obtained. The densification process of the films has been studied and the optimal heat treatment

G. San Vicente; R. Bayón; N. Germán; A. Morales

2009-01-01

106

Outcome of long term active surveillance for estrogen receptor-positive ductal carcinoma in situ  

PubMed Central

Introduction An option for active surveillance is not currently offered to patients with ductal carcinoma in situ (DCIS); however a small number of women decline standard surgical treatment for noninvasive cancer. The purpose of this study was to assess outcomes in a cohort of 14 well-informed women who elected non-surgical active surveillance with endocrine treatment alone for estrogen receptor-positive DCIS. Methods Retrospective review of 14 women, 12 of whom were enrolled in an IRB-approved single-arm study of 3 months of neoadjuvant endocrine therapy prior to definitive surgical management. The patients in this report withdrew from the parent study opting instead for active surveillance with endocrine treatment and imaging. Results 8 women had surgery at a median follow up of 28.3 months (range 10.1–70 months), 5 had stage I IDC at surgical excision, and 3 had DCIS alone. 6 women remain on surveillance without evidence of invasive disease for a median of 31.8 months (range 11.8–80.8 months). Conclusion Long-term active surveillance for DCIS is feasible in a well-informed patient population, but is associated with risk of invasive cancer at surgical excision. PMID:21843942

Meyerson, Anna F.; Lessing, Juan N.; Itakura, Kaoru; Hylton, Nola M.; Wolverton, Dulcy E.; Joe, Bonnie N.; Esserman, Laura J.; Hwang, E. Shelley

2014-01-01

107

Long-term starspot activity of the eclipsing binaries BH Vir and WY Cnc  

NASA Astrophysics Data System (ADS)

We present the results of multicolor photometry of the two spotted, short-period, late-type RS CVn stars BH Vir and WY Cnc. We have derived the parameters of the binaries’ components, and refined their masses, radii, and luminosities. A strong flare of WY Cnc was detected for the first time, and pre-flare variations of the star’s activity studied. Our observations and published data spanning 40 years are analyzed using a zone starspot model. We demonstrate that the spots are always concentrated near the equators and at intermediate latitudes, with maximum spotted areas as large as 29% for BH Vir and 21% for WY Cnc. The temperature differences between spotted regions and the quiet photosphere were 2300 K (BH Vir) and 1800 K (WY Cnc). The detected long-term brightness variations of BH Vir suggest the existence of an activity cycle with a probable period of 22 years. Both stars have starspots concentrated at two active longitudes separated by approximately half of the orbital period during all the studied seasons; these longitudes remained the same (0° and 184°) for BH Vir over 40 years, whereas they migrated in the direction of the stellar rotation at a rate of 3.8°/yr for WY Cnc, suggesting a cycle of 47 years for the migration of the active longitudes.

Kozhevnikova, A. V.; Alekseev, I. Yu.; Heckert, P. A.; Kozhevnikov, V. P.

2007-11-01

108

The chromospherically active binary star EI Eridani II. Long-term Doppler imaging  

E-print Network

Data from 11 years of continuous spectroscopic observations of the active RS CVn-type binary star EI Eridani - gained at NSO/McMath-Pierce, KPNO/Coude Feed and during the MUSICOS 98 campaign - were used to obtain 34 Doppler maps in three spectroscopic lines for 32 epochs, 28 of which are independent of each other. Various parameters are extracted from our Doppler maps: average temperature, fractional spottedness, and longitudinal and latitudinal spot-occurrence functions. We find that none of these parameters show a distinct variation nor a correlation with the proposed activity cycle as seen from photometric long-term observations. This suggests that the photometric brightness cycle may not necessarily be due to just a cool spot cycle. The general morphology of the spot pattern remains persistent over the whole period of 11 years. A large cap-like polar spot was recovered from all our images. A high degree of variable activity was noticed near latitudes of approx. 60-70 degrees where the appendages of the polar spot emerged and dissolved.

A. Washuettl; K. G. Strassmeier; M. Weber

2008-11-19

109

Therapeutic intraspinal stimulation to generate activity and promote long-term recovery  

PubMed Central

Neuroprosthetic approaches have tremendous potential for the treatment of injuries to the brain and spinal cord by inducing appropriate neural activity in otherwise disordered circuits. Substantial work has demonstrated that stimulation applied to both the central and peripheral nervous system leads to immediate and in some cases sustained benefits after injury. Here we focus on cervical intraspinal microstimulation (ISMS) as a promising method of activating the spinal cord distal to an injury site, either to directly produce movements or more intriguingly to improve subsequent volitional control of the paretic extremities. Incomplete injuries to the spinal cord are the most commonly observed in human patients, and these injuries spare neural tissue bypassing the lesion that could be influenced by neural devices to promote recovery of function. In fact, recent results have demonstrated that therapeutic ISMS leads to modest but sustained improvements in forelimb function after an incomplete spinal cord injury (SCI). This therapeutic spinal stimulation may promote long-term recovery of function by providing the necessary electrical activity needed for neuron survival, axon growth, and synaptic stability. PMID:24578680

Mondello, Sarah E.; Kasten, Michael R.; Horner, Philip J.; Moritz, Chet T.

2014-01-01

110

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

PubMed Central

Reduced graphene oxide-azobenzene (RGO-AZO) hybrids were prepared via covalent functionalization for long-term solar thermal storage. Thermal barrier (?Ea) of cis to tran reversion and thermal storage (?H) 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 (?Ea = 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 ?H 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

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

2013-01-01

111

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

NASA Astrophysics Data System (ADS)

Reduced graphene oxide-azobenzene (RGO-AZO) hybrids were prepared via covalent functionalization for long-term solar thermal storage. Thermal barrier (?Ea) of cis to tran reversion and thermal storage (?H) 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 (?Ea = 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 ?H 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.

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

2013-11-01

112

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

PubMed

Reduced graphene oxide-azobenzene (RGO-AZO) hybrids were prepared via covalent functionalization for long-term solar thermal storage. Thermal barrier (?Ea) of cis to tran reversion and thermal storage (?H) 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 (?Ea = 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 ?H 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

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

2013-01-01

113

Long-term radiation effects on GaAs solar cell characteristics  

NASA Technical Reports Server (NTRS)

This report investigates preliminary design considerations which should be considered for a space experiment involving Gallium Arsenide (GaAs) solar cells. The electron radiation effects on GaAs solar cells were conducted in a laboratory environment, and a statistical analysis of the data is presented. In order to augment the limited laboratory data, a theoretical investigation of the effect of radiation on GaAs solar cells is also developed. The results of this study are empirical prediction equations which can be used to estimate the actual damage of electrical characteristics in a space environment. The experimental and theoretical studies also indicate how GaAs solar cell parameters should be designed in order to withstand the effects of electron radiation damage.

Heinbockel, J. H.; Doviak, M. J.

1978-01-01

114

The Long Term Evolution, Kinematics and Sediment Flux from an Active Earthflow  

NASA Astrophysics Data System (ADS)

Large, slow moving earthflows are pervasive in many rapidly eroding landscapes world wide. In the coast ranges of northern California, some earthflows are active (moving up to 2m/yr), but much of the landscape is imprinted with the ubiquitous subtle headscarps, toes and deflated transport zones from multiple generations of earthflows and landslides in various stages of dormancy. To better understand earthflow transport history and evolution, we aim to constrain the long term sediment flux, kinematics and topographic development of an individual earthflow. We undertake a multi-proxy study, focused on a 1.5km-long active earthflow entering Kekawaka Ck, an 85km2 tributary of the Eel River, southwest Trinity County, California. This classical earthflow has a steep amphitheater-like accumulation area which feeds into a narrow, elongate transport zone, and terminates at the creek in a bulbous toe. Combining high resolution digital topography from LiDAR, total station surveying, and a sequence of orthorectified historical aerial photographs, we generated displacement vectors of earthflow movement spanning the past 6 decades. The earthflow has a complex history of movement, with rates of activity varying through time and across the different kinematic zones of the earthflow complex. Horizontal movement rates range from 0.2-1m/yr and are greatest in the narrow mid-section of the earthflow, consistent with the dictates of mass conservation. Given direct observations of earthflow width and thickness at the hillslope-channel interface, we estimate the modern sediment flux attributable to mass movement to be 650 +/- 200 m3/yr. To extend our analysis to the millennial scale, we measured inventories of meteoric 10-Be in 4 soil pits down the flow axis, and one pit on unfailed terrain above the headscarp. The 10-Be depth profiles show how adjacent slopes enriched with >15kyr of 10-Be detach from the headscarp as the earthflow margin retrogresses upslope. These slump blocks disintegrate and undergo variable mixing as they become incorporated into the steep flow accumulation zone, prior to consolidating into the fast moving narrow neck of the earthflow. 10-Be inventories systematically increase with distance downslope from the headscarp, the elongate transport zone acting like a conveyor belt. The most distal pit contains >2100 years of accumulated 10-Be, and can be used to infer a long term flow velocity of 0.3m/yr. The earthflow's headscarp has reached the ridgeline, limiting further expansion.

Mackey, B. H.; Roering, J. J.; McKean, J. A.

2008-12-01

115

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)

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.

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

116

Leisure time physical activity and long-term cardiovascular and cancer outcomes: the Busselton Health Study.  

PubMed

The study aimed to investigate whether meeting leisure time physical activity recommendations was associated with reduced incident and fatal cancer or cardiovascular disease (CVD) in a community-based cohort of middle- to late-aged adults with long-term follow-up. At baseline, 2,320 individuals were assessed on a large number of lifestyle and clinical parameters including their level of physical activity per week, other risk factors (e.g. smoking and alcohol use) various anthropometric measures, blood tests and medical history. Individuals were linked to hospital and mortality registry data to identify future cancer and cardiovascular events (fatal and non-fatal) out to 15 years of follow-up. Cox regression analyses adjusted for relevant confounders identified a priori were used to estimate risk for all-cause, cancer-specific and CVD-specific mortality. In the full cohort an estimated 21 % decreased risk for all-cause mortality (HR 0.79; 95 % CI 0.66-0.96) and 22 % decreased risk for fatal/non-fatal CVD events (HR 0.78; 95 % CI 0.66-0.92) was associated with baseline self-reported physical activity levels of 150 min or more. After exclusion of those with chronic co-morbidities (CVD, cancer, diabetes, chronic obstructive pulmonary disease, hypertension treatment) at baseline, lower risk for fatal/non-fatal CVD events remained significantly associated with 150 min or more of physical activity (HR 0.77; 95 % CI 0.62-0.96). Results from this well established prospective community-based cohort study support the role of leisure time physical activity in reducing all-cause mortality and CVD events (fatal/nonfatal) in the broader population studied. The data also suggest that physical activity associated reductions in risk for CVD events (fatal/nonfatal) were not overly impacted by prevalent key non-communicable diseases. PMID:25354993

Gunnell, Anthony S; Knuiman, Matthew W; Divitini, Mark L; Cormie, Prue

2014-11-01

117

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

PubMed

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

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

118

Solar cell packaged by a microlens array and its long-term optical efficiency enhancement  

NASA Astrophysics Data System (ADS)

A technique of mounting a microlens array (MLA) on a solar cell as an encapsulation layer is presented. The uniform cylinder-shaped MLA was fabricated through simple and cost-effective micromachining processes. The efficiency of the triple-junction InGaP/GaAs/Ge solar cell was considerably enhanced by replacing a bare glass cover with the developed MLA as a surface protection layer. This is attributed to efficient conveyance of the refractive light into bare photoactive regions of the solar cell to avoid the gridlines. Under the optimal mounting condition with an optimal height of optical spacer, the MLA effect was maximized resulting in a 16.8% increase in power conversion efficiency (PCE) than that of the control device. The efficiency of the MLA-packaged solar cell remained for a long time without degradation. The MLA can therefore replace a conventional glass (or film) as a means of encapsulation layer to enhance photovoltaic performances of GaAs-based solar cells.

Nam, Minwoo; Kim, Kangho; Lee, Jaejin; Yang, Sang Sik; Lee, Kee-Keun

2013-03-01

119

Solar thermal systems long-term performance predictions using closed-form solutions  

Microsoft Academic Search

In this paper, a closed-loop feedback control system representation of solar thermal system is derived for each of the various modes of operation. Analysis of the transfer functions resulted in identifying the various system parameters which must be optimized in order to obtain the maximum system response to a continuous input weather function. Using a stochastic weather model, which has

D. K. Anand; R. B. Abarcar; S. R. Venkateswaran

1979-01-01

120

Long-term Stellar Activity Variations of Stars from the HARPS M-dwarf Sample: Comparison Between Activity Indices  

NASA Astrophysics Data System (ADS)

We used four known chromospheric activity indicators to measure long-term activity variations in a sample of 23 M-dwarf stars from the HARPS planet search program. We compared the indices using weighted Pearson correlation coefficients and found that in general (i) the correlation between SCaI I and Na I is very strong and does not depend on the activity level of the stars, (ii) the correlation between our SCaI I and H? seems to depend on the activity level of the stars, and (iii) there is no strong correlation between SCaI I and He I for these type of stars.

Gomes da Silva, J.; Santos, N. C.; Bonfils, X.

2011-12-01

121

Long-term effects of maternal immune activation on depression-like behavior in the mouse.  

PubMed

Depression is a debilitating mental disease affecting a large population worldwide, the pathophysiological mechanisms of which remain incompletely understood. Prenatal infection and associated activation of the maternal immune system (MIA) are prominently related to an increased risk for the development of several psychiatric disorders including schizophrenia and autism in the offsprings. However, the role of MIA in the etiology of depression and its neurobiological basis are insufficiently investigated. Here we induced MIA in mice by challenge with polyinosinic:polycytidylic phosphate salt-a synthetic analog of double-stranded RNA, which enhances maternal levels of the cytokine interleukin-6 (IL-6)-and demonstrate a depression-like behavioral phenotype in adult offsprings. Adult offsprings additionally show deficits in cognition and hippocampal long-term potentiation (LTP) accompanied by disturbed proliferation of newborn cells in the dentate gyrus and compromised neuronal maturation and survival. The behavioral, neurogenic and functional deficiencies observed are associated with reduced hippocampal expression of vascular endothelial growth factor (VEGF)A-VEGFR2. IL-6-STAT3-dependent aberrant VEGFA-VEGFR2 signaling is proposed as neurobiological mechanism mediating the effects of MIA on the developing fetal brain and ensuing consequences in adulthood. PMID:24548878

Khan, D; Fernando, P; Cicvaric, A; Berger, A; Pollak, A; Monje, F J; Pollak, D D

2014-01-01

122

Active fixation leads--long-term threshold reduction using a drug-infused ceramic collar.  

PubMed

Previous investigators, including our group, have reported the threshold reduction benefits of steroid-releasing leads. To date, all published literature has been for the passive fixation versions. The application of steroids should also enhance the performance of active fixation leads. We have developed and tested an atrial and a ventricular Accufix lead with a dexamethasone acetate-releasing, porous ceramic collar (DA DEC). A long-term sheep study has shown a significant reduction in thresholds (THR) when compared to standard Accufix leads without the collar (ACC) for atrial (ATR) and ventricular (VENT) versions (bipolar THR [0.5 msec] at 24 weeks: VENT DA DEC = 0.51 +/- 0.07, VENT ACC = 1.49 +/- 1.03; ATR DA DEC = 1.31 +/- 1.14, ATR ACC = 2.99 +/- 1.31). All other parameters tested, including pacing and sensing impedance as well as polarization overpotential, were similar for the two groups. The Accufix DEC leads therefore have excellent potential for low energy stimulation. PMID:1721172

Anderson, N; Mathivanar, R; Skalsky, M; Tunstell, A; Ng, M; Harman, D

1991-11-01

123

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

E-print Network

Context. The IUE database provides a large number of 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 22468 (V711 Tau, HR 1099, K1IV+G5V), HD 21242 (UX Ari, K0IV+G5V) and HD 224085 (II Peg, K2IV). Methods. We first obtain the Mount Wilson index S from the IUE high and low-resolution spectra. Secondly, we analyse with the Lomb-Scargle periodogram the mean annual index S and the amplitude of its rotational modulation. Results. For HD 22468 (V711 Tau, HR 1099), we found 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 224085 (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 21242 (UX Ari).

Andrea P. Buccino; Pablo J. D. Mauas

2008-12-19

124

Long-Term file activity patterns in a UNIX workstation environment  

NASA Technical Reports Server (NTRS)

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.

Gibson, Timothy J.; Miller, Ethan L.

1998-01-01

125

An hybrid neuro-wavelet approach for long-term prediction of solar wind  

NASA Astrophysics Data System (ADS)

Nowadays the interest for space weather and solar wind forecasting is increasing to become a main relevance problem especially for telecommunication industry, military, and for scientific research. At present the goal for weather forecasting reach the ultimate high ground of the cosmos where the environment can affect the technological instrumentation. Some interests then rise about the correct prediction of space events, like ionized turbulence in the ionosphere or impacts from the energetic particles in the Van Allen belts, then of the intensity and features of the solar wind and magnetospheric response. The problem of data prediction can be faced using hybrid computation methods so as wavelet decomposition and recurrent neural networks (RNNs). Wavelet analysis was used in order to reduce the data redundancies so obtaining representation which can express their intrinsic structure. The main advantage of the wavelet use is the ability to pack the energy of a signal, and in turn the relevant carried informations, in few significant uncoupled coefficients. Neural networks (NNs) are a promising technique to exploit the complexity of non-linear data correlation. To obtain a correct prediction of solar wind an RNN was designed starting on the data series. As reported in literature, because of the temporal memory of the data an Adaptative Amplitude Real Time Recurrent Learning algorithm was used for a full connected RNN with temporal delays. The inputs for the RNN were given by the set of coefficients coming from the biorthogonal wavelet decomposition of the solar wind velocity time series. The experimental data were collected during the NASA mission WIND. It is a spin stabilized spacecraft launched in 1994 in a halo orbit around the L1 point. The data are provided by the SWE, a subsystem of the main craft designed to measure the flux of thermal protons and positive ions.

Napoli, Christian; Bonanno, Francesco; Capizzi, Giacomo

2011-06-01

126

Seasonal cycle and long-term trend of solar energy fluxes through Arctic sea ice  

NASA Astrophysics Data System (ADS)

Arctic sea ice has not only decreased in volume during the last decades, but has also changed in its physical properties towards a thinner and more seasonal ice cover. These changes strongly impact the energy budget, and might affect the ice-associated ecosystems. In this study, we quantify solar shortwave fluxes through sea ice for the entire Arctic during all seasons. To focus on sea-ice-related processes, we exclude fluxes through open water, scaling linearly with sea ice concentration. We present a new parameterization of light transmittance through sea ice for all seasons as a function of variable sea ice properties. The maximum monthly mean solar heat flux under the ice of 30 × 105 Jm-2 occurs in June, enough heat to melt 0.3 m of sea ice. Furthermore, our results suggest that 96% of the annual solar heat input through sea ice occurs during only a 4-month period from May to August. Applying the new parameterization to remote sensing and reanalysis data from 1979 to 2011, we find an increase in transmitted light of 1.5% yr-1 for all regions. This corresponds to an increase in potential sea ice bottom melt of 63% over the 33-year study period. Sensitivity studies reveal that the results depend strongly on the timing of melt onset and the correct classification of ice types. Assuming 2 weeks earlier melt onset, the annual transmitted solar radiation to the upper ocean increases by 20%. Continuing the observed transition from a mixed multi-year/first-year sea ice cover to a seasonal ice cover results in an increase in light transmittance by an additional 18%.

Arndt, S.; Nicolaus, M.

2014-11-01

127

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

SciTech Connect

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.

Smith, Steven J.

2012-10-30

128

Long-term evolution of a high-latitude active region  

Microsoft Academic Search

We describe the decay phase of one of the largest active regions of solar cycle 22 that developed by the end of June 1987. The center of both polarities of the magnetic fields of the region systematically shifted north and poleward throughout the decay phase. In addition, a substantial fraction of the trailing magnetic fields migrated equatorward and south of

William H. Marquette; Sara F. Martin

1988-01-01

129

SEASONAL PHOSPHATASE ACTIVITY IN THREE CHARACTERISTIC SOILS OF THE ENGLISH UPLANDS POLLUTED BY LONG-TERM ATMOSPHERIC NITROGEN DEPOSITION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Phosphomonoesterase activities were determined monthly during a seasonal cycle in three characteristic soil types of the English uplands that have been subject to long-term atmospheric nitrogen deposition. Activities (µmol para-nitrophenol per gram soil dry wt per hour) ranged between 83.9 - 307 in...

130

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

ERIC Educational Resources Information Center

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…

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

2011-01-01

131

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

SciTech Connect

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.

Arwood, J.W.

1999-07-01

132

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

NASA Astrophysics Data System (ADS)

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.

Anufriev, G. S.

2013-07-01

133

Long term accuracy of solar irradiance measurements: a common analysis of several datasets for the SOLID project.  

NASA Astrophysics Data System (ADS)

Since the 60's, numerous instrument have been sent in space to measure the solar irradiance at different wavelengths. These observations have been used to build or validate models that predict the irradiance at unobserved times or wavelengths. However, as it is well known, the stability of instruments in space is difficult to maintain and there are significant disagreements between various observations and models. We will present an ongoing effort made within the SOLID project to consistently assess the long term accuracy of several irradiance datasets. In more details, we compare several datasets with empirical models at different time scales in a -as much as possible- similar way to detect behaviors that could hardly be attributed to the Sun. The research leading to these results has received funding from the European Community's Seventh Framework Program (FP7 2012) under grant agreement n° 313188 (SOLID).

Kretzschmar, Matthieu; Scholl, Micha; Dudok de Wit, Thierry

2014-05-01

134

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

NASA Technical Reports Server (NTRS)

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)..

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

2007-01-01

135

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

NASA Technical Reports Server (NTRS)

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.

Jackman, Charles H.; Fleming, Eric L.

2005-01-01

136

Analytical treatment of long-term observations of the day-night asymmetry for solar neutrinos  

E-print Network

The Earth's density distribution can be approximately considered piecewise continuous at the scale of two-flavor oscillations of typical solar neutrinos, such as the beryllium-7 and boron-8 neutrinos. This quite general assumption appears to be enough to analytically calculate the day-night asymmetry factor for such neutrinos. Using the explicit time averaging procedure, we show that, within the leading-order approximation, this factor is determined by the electron density within about one oscillation length under the detector, namely, in the Earth's crust (and upper mantle for high-energy neutrinos). We also evaluate the effect of the inner Earth's structure on the observed asymmetry and show that it is suppressed and mainly comes from the neutrinos observed near the winter and summer solstices. As a result, we arrive at the strict interval constraint on the asymmetry, which is valid within quite a wide class of Earth models.

S. S. Aleshin; O. G. Kharlanov; A. E. Lobanov

2013-02-28

137

Analytical treatment of long-term observations of the day-night asymmetry for solar neutrinos  

E-print Network

The Earth's density distribution can be approximately considered piecewise continuous at the scale of two-flavor oscillations of typical solar neutrinos, such as the beryllium-7 and boron-8 neutrinos. This quite general assumption appears to be enough to analytically calculate the day-night asymmetry factor for such neutrinos. Using the explicit time averaging procedure, we show that, within the leading-order approximation, this factor is determined by the electron density within about one oscillation length under the detector, namely, in the Earth's crust (and upper mantle for high-energy neutrinos). We also evaluate the effect of the inner Earth's structure on the observed asymmetry and show that it is suppressed and mainly comes from the neutrinos observed near the winter and summer solstices. As a result, we arrive at the strict interval constraint on the asymmetry, which is valid within quite a wide class of Earth models.

Aleshin, S S; Lobanov, A E; 10.1103/PhysRevD.87.045025

2013-01-01

138

Is medial temporal lobe activation specific for encoding long-term memories?  

Microsoft Academic Search

Several neuroimaging studies have consistently demonstrated the critical involvement of prefrontal cortices and medial temporal lobes during long-term encoding. While the contribution of prefrontal lobes to working memory is well established, the role of the MTL structures remains controversial. To address this issue, we registered the neuromagnetic brain patterns of eight adult volunteers while they performed two working memory tasks

Pablo Campo; Fernando Maestú; Tomás Ortiz; Almudena Capilla; Santiago Fernández; Alberto Fernández

2005-01-01

139

Surface EMG system for use in long-term vigorous activities  

NASA Astrophysics Data System (ADS)

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 accumulation on signal fidelity. The average number of artifacts contaminating the EMG signals during treadmill running was reduced approximat ely three-fold by the prototype electrode/interface, when compared to methods currently available. Peel adhesion of the interface to the skin was significantly improved for treadmill running. Similarly, the artifacts from controlled impacts on the electrode housing were significantly reduced for both treadmill running and for the repetitive lifting task.

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

140

Atmospheric science is the study of short-term weather and long-term climate, involving activities such as weather  

E-print Network

Atmospheric science is the study of short-term weather and long-term climate, involving activities such as weather forecasting, climate projections, air quality modeling, data analysis, and basic and applied. The program maintains strong ties with regional employers in both the private sector and the National Weather

Saldin, Dilano

141

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

NASA Technical Reports Server (NTRS)

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.e., greater than or equal to 2), except during El Nino-related seasons when the number usually will be less than average.

Wilson, Robert M.

1998-01-01

142

Associations between long-term physical activity, waist circumference and weight gain: a 30-year longitudinal twin study  

Microsoft Academic Search

Background and objective:Physical activity level and obesity are both partly determined by genes and childhood environment. To determine the associations between long-term leisure-time physical activity, weight gain and waist circumference and whether these are independent of genes and childhood effects.Design and subjects:The study design is a 30-year follow-up twin study in Finland. For this study, 146 twin pairs were comprehensively

K Waller; J Kaprio; U M Kujala

2008-01-01

143

Long-term magnetic activity of a sample of M-dwarf stars from the HARPS program. I. Comparison of activity indices  

NASA Astrophysics Data System (ADS)

Context. The search for extra-solar planets similar to Earth is becoming a reality, but as the level of the measured radial-velocity reaches the sub-m s-1, stellar intrinsic sources of noise capable of hiding the signal of these planets from scrutiny become more important. Aims: Other stars are known to have magnetic cycles similar to that of the Sun. The relationship between these activity variations and the observed radial-velocity is still not satisfactorily understood. Following our previous work, which studied the correlation between activity cycles and long-term velocity variations for K dwarfs, we now expand it to the lower end of the main sequence. In this first paper our aim is to assess the long-term activity variations in the low end of the main sequence, having in mind a planetary search perspective. Methods: We used a sample of 30 M0-M5.5 stars from the HARPS M-dwarf planet search program with a median timespan of observations of 5.2 years. We computed chromospheric activity indicators based on the Ca ii H and K, H?, He i D3, and Na i D1 and D2 lines. All data were binned to average out undesired effects such as rotationally modulated atmospheric inhomogeneities. We searched for long-term variability of each index and determined the correlations between them. Results: While the SCa II, H?, and Na i indices showed significant variability for a fraction of our stellar sample (39%, 33%, and 37%, respectively), only 10% of our stars presented significant variability in the He i index. We therefore conclude that this index is a poor activity indicator at least for this type of stars. Although the H? shows good correlation with SCa II for the most active stars, the correlation is lost when the activity level decreases. This result appears to indicate that the Ca ii - H? correlation is dependent on the activity level of the star. The Na i lines correlate very well with the SCa II index for the stars with low activity levels we used, and are thus a good chromospheric activity proxy for early-M dwarfs. We therefore strongly recommend the use of the Na i activity index because the signal-to-noise ratio in the sodium lines spectral region is always higher than for the calcium lines. Based on observations made with the HARPS instrument on the ESO 3.6-m telescope at La Silla Observatory under programme ID 072.C-0488(E).

Gomes da Silva, J.; Santos, N. C.; Bonfils, X.; Delfosse, X.; Forveille, T.; Udry, S.

2011-10-01

144

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

NASA Astrophysics Data System (ADS)

Measurements of erythemally weighted UV irradiance (Qer) have been performed at the Meteorological Observatory of Moscow State University since 1999 with the UVB-1 YES pyranometers. These types of devices are broadband with a spectral sensitivity curve close to the action spectrum of erythema. Main uncertainties of UVB-1 YES measurements include the difference in spectral curves of the instrument and the action spectrum of erythema, as well as the deviation from the cosine law. These uncertainties were taken into account in the database of Qer measurements (Chubarova, 2008. Additional corrections of UVB-1 measurements at low ambient temperatures have been made. We analyze interannual, seasonal and diurnal Qer changes over the time period 1999-2012. In addition, the comparisons with the results of UV reconstruction model (Chubarova, 2008) are made. This model allows us to evaluate relative changes in Qer due to variations in total ozone, effective cloud amount transmission, aerosol and cloud optical thickness since 1968. It is important to note that the main reason for UV irradiance monitoring development is the strong influence of UV irradiance on the biosphere and especially on human health mainly on human skin (CIE, 1993, CIE, 2006) and eyes (Oriowo, M. et al., 2001). Based on the detailed studies we have shown the possibility of utilizing UVB-1 pyranometers for measuring the eye-damage UV radiation. Parallel measurements by the Bentham DTM-300 spectrometer and the UVB-1 YES pyranometer at the Innsbruck Medical University (Austria) have provided us the calibration factor in eye-damage units for this broadband instrument. Influence of main geophysical factors on different types of UV irradiance is estimated by means the RAF ideology (Booth, Madronich, 1994). We discuss the responses of different types of biologically active UV radiation to the impact of various atmospheric factors. The UV conditions (deficiency, optimum, excess for human) are analyzed according to 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

Zhdanova, Ekaterina; Chubarova, Natalia

2014-05-01

145

Long-term Follow-up of 414 HIV-Infected Romanian Children and Adolescents Receiving Lopinavir\\/ Ritonavir-Containing Highly Active Antiretroviral Therapy  

Microsoft Academic Search

BACKGROUND. There are no published reports of the long-term safety and effective- ness of highly active antiretroviral therapy for children and adolescents living in resource-limited settings or of large cohorts of HIV-infected children and adoles- cents treated long-term (48 weeks) with lopinavir\\/ritonavir-containing highly active antiretroviral therapy. OBJECTIVES. The purpose of this work was to evaluate the long-term outcomes of treatment

Mark W. Kline; Sorin Rugina; Margareta Ilie; Rodica F. Matusa; Ana-Maria Schweitzer; Nancy R. Calles; Heidi L. Schwarzwald

146

Long-term effects of municipal solid waste compost application on soil enzyme activities and microbial biomass  

Microsoft Academic Search

A long-term field experiment utilising barley received four different treatments prior to sowing: municipal solid waste (MSW) compost at either 20tha?1 (C20) or 80tha?1 (C80); cow manure (MA) at 20tha?1; mineral fertilizer (MIN) or NPK (400kgha?1); and NH4NO3 (150kgha?1). The effects of these applications on soil enzyme activities and microbial biomass at crop harvest were measured after nine years. In

J. C Garc??a-Gil; C Plaza; P Soler-Rovira; A Polo

2000-01-01

147

Hot Jupiters and Hot Spots: The Short and Long-term Chromospheric Activity on Stars with Giant Planets  

Microsoft Academic Search

We monitored the chromospheric activity in the Ca II H & K lines of 13\\u000asolar-type stars (including the Sun); 8 of them over three years at the CFHT\\u000aand 5 in a single run at the VLT. Ten of the 13 targets have close planetary\\u000acompanions. All of the stars observed at the CFHT show long-term (months to\\u000ayears)

E. Shkolnik; G. A. H. Walker; D. A. Bohlender; M. Kürster

2004-01-01

148

The long-term evolution of active regions, multi-wavelength flux and heating studies: observations and theory  

NASA Astrophysics Data System (ADS)

Analyzing the long-term evolution of active regions (ARs) permits to quantify the link between their atmospheric emission (from optical to X-rays) and the magnetic field. Multi-wavelength studies provide the full story, and not just a snapshot, of the phenomena and they allow us analyze how the atmosphere changes as the field strength decreases (with the dispersion of the AR).

Démoulin, P.

149

Long-term sexual activity status and influencing factors in men after surgery for hypospadias  

PubMed Central

The aim of this study was to compare the long-term postoperative status of hypospadiac patients by analysing their sexual psychology, sexual behaviour, sexual function and influencing factors. A total of 130 hypospadiac patients hospitalized between January 1988 and December 2007 were followed up with questionnaires using Zung's Self-rating Depression Scale (SDS), Self-rating Anxiety Scale (SAS), a self-designed sexual function questionnaire and a 5-item version of the International Index of Erectile Function (IIEF-5). The surveys served to evaluate the effects of hypospadias type, number of operations and surgical procedures on sexual psychology, sexual behaviour and sexual function. The control group consisted of 50 healthy adults. The postoperative SDS / SAS scores and occurrences of depression/anxiety in hypospadiac patients were significantly higher than those of normal controls (P < 0.001). Patients with proximal hypospadias and multiple procedures differed from those with distal hypospadias and a single procedure in all parameters of sexual psychology (P < 0.05). The average penile lengths and circumferences of hypospadiac patients under either erect or flaccid conditions were significantly shorter than those of normal controls (P < 0.001). A similar difference existed between patients with distal and proximal hypospadias (P < 0.01). There was no significant difference in any parameter of sexual function between patients with different numbers of operations and surgical procedures. Hypospadiac patients were clearly impaired in sexual psychology and penile development. The severity of hypospadias and number of operations were key factors that influenced the sexual psychology of patients. This finding indicated the importance of long-term follow-up and psychological counselling for hypospadiac patients postoperatively. PMID:19377489

Wang, Wen-Wei; Tu, Xiang-An; Deng, Chun-Hua; Mo, Jia-Cong; Zhao, Liang; Chen, Ling-Wu

2009-01-01

150

Surface electromagnetic impedance and geomagnetic activity: results of long term observation  

NASA Astrophysics Data System (ADS)

The magnetotelluric (MT) method is one of the most useful geophysical tool to discover even the deep subsurface structures. The target function of the MT data processing is the surface electromagnetic (EM) impedance. In case of practical MT exploration the surface EM impedance is computed based on a simplification related to the nature of the ionospheric source of the surface EM signals. Assuming that the ionospheric current systems result in homogeneous surface electromagnetic variations, the uncertainty of the computed surface electromagnetic impedance tensor depends only the duration of the EM observation. However the surface EM field can only be approached by plane waves in certain time periods and besides given uncertainty. The EM impedance may be sensitive to magnetospheric and -indirectly- interplanetary circumstances and solar activity. Four years continuous observation of telluric and surface geomagnetic components allowed to perform a representative survey to discover if geomagnetic activity has any effect on observed EM impedance tensor. Geomagnetic indices (Dst, ULF-index, ASY-H, SYM-H) have been used to classify dates according to geomagnetic activity. Processing to estimate the mean surface EM impedance tensor has been performed in each dataset, each class separately. The sensitivity and the characteristics of the answer of the EM impedance tensor to the geomagnetic disturbances seems to be definite. This presentation aims to briefly summarize the preliminary results of our study based on the unique dataset of the Széchenyi István Geophysical Obsevatory (Intermagnet code:NCK). In addition, pointing out the limitations of the routine way of practical MT data processing and interpretation is an important duty of this study. This study was supported by the TAMOP-4.2.2.C-11/1/KONV-2012-0015 (Earth-system) project sponsored by the EU and European Social Foundation.

Lemperger, István; Menvielle, Menvielle; Wesztergom, Viktor; Bencze, Pál; Szendr?i, Judit; Novák, Attila; Kis, Árpád; Szalai, Sándor

2014-05-01

151

Doxorubicin attenuates serotonin-induced long-term synaptic facilitation by phosphorylation of p38 mitogen-activated protein kinase.  

PubMed

Doxorubicin (DOX) is an anthracycline used widely for cancer chemotherapy. Its primary mode of action appears to be topoisomerase II inhibition, DNA cleavage, and free radical generation. However, in non-neuronal cells, DOX also inhibits the expression of dual-specificity phosphatases (also referred to as MAPK phosphatases) and thereby inhibits the dephosphorylation of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (p38 MAPK), two MAPK isoforms important for long-term memory (LTM) formation. Activation of these kinases by DOX in neurons, if present, could have secondary effects on cognitive functions, such as learning and memory. The present study used cultures of rat cortical neurons and sensory neurons (SNs) of Aplysia to examine the effects of DOX on levels of phosphorylated ERK (pERK) and phosphorylated p38 (p-p38) MAPK. In addition, Aplysia neurons were used to examine the effects of DOX on long-term enhanced excitability, long-term synaptic facilitation (LTF), and long-term synaptic depression (LTD). DOX treatment led to elevated levels of pERK and p-p38 MAPK in SNs and cortical neurons. In addition, it increased phosphorylation of the downstream transcriptional repressor cAMP response element-binding protein 2 in SNs. DOX treatment blocked serotonin-induced LTF and enhanced LTD induced by the neuropeptide Phe-Met-Arg-Phe-NH2. The block of LTF appeared to be attributable to overriding inhibitory effects of p-p38 MAPK, because LTF was rescued in the presence of an inhibitor (SB203580 [4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)-1H-imidazole]) of p38 MAPK. These results suggest that acute application of DOX might impair the formation of LTM via the p38 MAPK pathway. PMID:25274809

Liu, Rong-Yu; Zhang, Yili; Coughlin, Brittany L; Cleary, Leonard J; Byrne, John H

2014-10-01

152

Doxorubicin Attenuates Serotonin-Induced Long-Term Synaptic Facilitation by Phosphorylation of p38 Mitogen-Activated Protein Kinase  

PubMed Central

Doxorubicin (DOX) is an anthracycline used widely for cancer chemotherapy. Its primary mode of action appears to be topoisomerase II inhibition, DNA cleavage, and free radical generation. However, in non-neuronal cells, DOX also inhibits the expression of dual-specificity phosphatases (also referred to as MAPK phosphatases) and thereby inhibits the dephosphorylation of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (p38 MAPK), two MAPK isoforms important for long-term memory (LTM) formation. Activation of these kinases by DOX in neurons, if present, could have secondary effects on cognitive functions, such as learning and memory. The present study used cultures of rat cortical neurons and sensory neurons (SNs) of Aplysia to examine the effects of DOX on levels of phosphorylated ERK (pERK) and phosphorylated p38 (p-p38) MAPK. In addition, Aplysia neurons were used to examine the effects of DOX on long-term enhanced excitability, long-term synaptic facilitation (LTF), and long-term synaptic depression (LTD). DOX treatment led to elevated levels of pERK and p-p38 MAPK in SNs and cortical neurons. In addition, it increased phosphorylation of the downstream transcriptional repressor cAMP response element-binding protein 2 in SNs. DOX treatment blocked serotonin-induced LTF and enhanced LTD induced by the neuropeptide Phe-Met-Arg-Phe-NH2. The block of LTF appeared to be attributable to overriding inhibitory effects of p-p38 MAPK, because LTF was rescued in the presence of an inhibitor (SB203580 [4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)-1H-imidazole]) of p38 MAPK. These results suggest that acute application of DOX might impair the formation of LTM via the p38 MAPK pathway. PMID:25274809

Liu, Rong-Yu; Zhang, Yili; Coughlin, Brittany L.; Cleary, Leonard J.

2014-01-01

153

Novel approaches to mid-long term weather and climate forecast based on the solar-geomagnetic signal  

NASA Astrophysics Data System (ADS)

Two possibilities are discussed concerning the use of data on solar-geomagnetic activity for meteorological forecasting (cloudiness, temperature and precipitation). The first possibility is consideration of quasicyclic recurrence of large solar flares and geomagnetic storms with periods of 2 - 5 years. For the periods shorter than one year the second possibility is taking into account: the negative correlation of total global cloud cover with the number of solar spots and positive correlation with the total solar irradiance (TSI) - the contribution of short wave radiation of faculae fields. To justify the mechanism of solar-tropospheric links, it is obviously necessary to provide explanation for the observed dependence of weather and climate on usual cyclic activity of the Sun. Meteorologists and even geophysicists have found no significant correlation between atmospheric parameters and either number of solar spots or variations of solar constant. It was found that temperature did not display any variability with the 11-year period (the basic solar cycle). Instead stable quasi-periodic variations of temperature of air within 2 - 5.5 years and also for the precipitation periods in the interval 2 to 6 years were observed. Each 11-year cycle displays two maxima for the probability of solar X-ray and extreme UV flares and for probability of medium and strong geomagnetic storms (2 to 4 years for the flares and 2 to 6 years for significant magnetic storms), and those induced by solar flares, the latter, as a rule, between the maximum points of the number of geomagnetic storms. On a timescale of about a year or shorter, a correlation is revealed between the occurrence of the total cloudiness and the sunspot and faculae activity (number of solar spots and the value of the solar constant - TSI). From the number of sunspots and the data concerning faculae fields, on the basis of the known statistics for the lifetime of these formation in the solar photosphere, it is possible to forecasting the variation in the area of cloud and consequently the thermal radiative balance of the Earth (the temperature anomalies) for several months ahead. The physics of these manifestations of the effect of the "solar signal" on the troposphere is also related with our radio-optical three-stage trigger mechanism. The microwave radiation generated by ionosphere under the influence of the enhanced solar and geomagnetic activity (increased fluxes of the ionizing solar radiation during solar flares and of electrons precipitated from radiation belts during magnetic storms) affects the cluster condensation process of origination and further evolution of optically thin cloudiness, including the formation of precipitation in the course of «sowing» by crystals from upper-layer clouds. These clouds cause a net warming due to their relative transparence at short wavelengths but opacity in the infrared region (where there is flux of the thermal radiation coming out from the underlying surface).

Avakyan, Sergey; Baranova, Lubov

154

A long-term perspective on anthropogenic activities and management strategies in a prairie wetland  

NASA Astrophysics Data System (ADS)

Multiple stressors to shallow lake/wetland ecosystems have the ability to control the relative stability of alternative states (clear, macrophyte-dominated or turbid, algal dominated). As a consequence, the use of remedial biomanipulations to induce trophic cascades and shift a turbid lake to a clear state is often only a temporary solution. Here we show the instability of short-term manipulations in the shallow Lake Christina (a Class V wetland in the prairie ecoregion of western Minnesota, USA) is governed by the long-term state following a regime shift in the lake. During the modern, managed period of the lake, three top-down manipulations (fish kills) were undertaken inducing temporary (5-10 years) unstable clear-water states. Paleoecological remains of diatoms, along with proxies of primary production (total chlorophyll a and total organic carbon accumulation rate) and trophic state (total P) from sediment records clearly show a single regime shift in the lake during the early 1950s; following this shift, the functioning of the lake ecosystem is dominated by a persistent turbid state. We find that multiple stressors contributed to the regime shift. First, the lake began to eutrophy (from agricultural land use and/or increased waterfowl populations), leading to a dramatic increase in primary production. Soon after, the construction of a dam in 1936 effectively doubled the depth of the lake, compounded by increases in regional humidity; this resulted in an increase in planktivorous and benthivorous fish reducing phytoplankton grazers. These factors further conspired to increase the stability of a turbid regime during the modern managed period, such that switches to a clear-water state were inherently unstable and the lake consistently returned to a turbid state. We conclude that while top-down manipulations have had measurable impacts on the lake state, they have not been effective in providing a return to an ecosystem similar to the stable historical period. Our work offers an example of a well-studied ecosystem forced by multiple stressors into a new long-term managed period, where manipulated clearwater states are temporary, managed features.

Hobbs, J. M.; Hobbs, W.; LaFrancois, T.; Edlund, M.; Theissen, K. M.; Zimmer, K.; Hanson, M.

2012-12-01

155

Activation of Synaptic Group II Metabotropic Glutamate Receptors Induces Long-Term Depression at GABAergic Synapses in CNS Neurons  

PubMed Central

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. PMID:24089501

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

2013-01-01

156

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

NASA Technical Reports Server (NTRS)

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.

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

1985-01-01

157

Effect of the long-term care prevention project on the motor functions and daily life activities of the elderly  

PubMed Central

[Purpose] The purpose of this study was to verify the effects of the long-term care prevention project and develop an effective program. [Subjects] A total of 81 elderly people (age, 79 ± 5.1?years; height, 149.2 ± 9.2?cm; weight, 54.2 ± 11.4?kg). [Methods] Grip, knee extension muscular strength, 10?m walking speed, and Timed Up and Go time were measured for evaluation of motor functions, and the “Locomo 25”, a 25-question risk assessment questionnaire, was used as the judgment criterion for evaluation of daily life activities, with measurements being taken at the beginning of the project and after three months. [Results] In the motor functions evaluation, significant differences were observed in 10?m walking speed, Timed Up and Go time, and knee extension strength. In the daily life activities evaluation, scores for pain, rising movement, standing movement, indoor walking, outdoor walking, and fear of falling were significantly reduced. In addition, a significant correlation was also observed between motor functions and daily life activities. [Conclusion] The result of this study indicated that the long-term care prevention project is effective in maintaining or improving muscular strength and mitigating pain in the elderly and that it is an effective program for maintaining daily life activities. We were also able to show that it would be effective to develop programs with a low exercise intensity that can be performed on a continuing by the elderly. PMID:25642073

Wada, Yoshihiro; Sakuraba, Keisyoku; Kubota, Atsushi

2015-01-01

158

Effect of the long-term care prevention project on the motor functions and daily life activities of the elderly.  

PubMed

[Purpose] The purpose of this study was to verify the effects of the long-term care prevention project and develop an effective program. [Subjects] A total of 81 elderly people (age, 79 ± 5.1?years; height, 149.2 ± 9.2?cm; weight, 54.2 ± 11.4?kg). [Methods] Grip, knee extension muscular strength, 10?m walking speed, and Timed Up and Go time were measured for evaluation of motor functions, and the "Locomo 25", a 25-question risk assessment questionnaire, was used as the judgment criterion for evaluation of daily life activities, with measurements being taken at the beginning of the project and after three months. [Results] In the motor functions evaluation, significant differences were observed in 10?m walking speed, Timed Up and Go time, and knee extension strength. In the daily life activities evaluation, scores for pain, rising movement, standing movement, indoor walking, outdoor walking, and fear of falling were significantly reduced. In addition, a significant correlation was also observed between motor functions and daily life activities. [Conclusion] The result of this study indicated that the long-term care prevention project is effective in maintaining or improving muscular strength and mitigating pain in the elderly and that it is an effective program for maintaining daily life activities. We were also able to show that it would be effective to develop programs with a low exercise intensity that can be performed on a continuing by the elderly. PMID:25642073

Wada, Yoshihiro; Sakuraba, Keisyoku; Kubota, Atsushi

2015-01-01

159

Long-term motor activity recording of dogs and the effect of sleep deprivation  

Microsoft Academic Search

Summary Motor activity of laboratory dogs was recorded for several weeks with an ambulatory monitoring device. The effect of 24 h sleep deprivation (SD) on motor activity during recovery was investigated. A clear rest-activity rhythm was established. The dogs exhibited a similar mean daily rest-activity pattern: 1) rest occurred mainly in the dark; 2) the amimals were most active after

I. Tobler; H. Sigg

1986-01-01

160

SWAP Observations of the Long-term, Large-scale Evolution of the Extreme-ultraviolet Solar Corona  

NASA Astrophysics Data System (ADS)

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.

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

2013-11-01

161

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

SciTech Connect

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.

Seaton, Daniel B.; De Groof, Anik; Berghmans, David; Nicula, Bogdan [Royal Observatory of Belgium-SIDC, Avenue Circulaire 3, B-1180 Brussels (Belgium); Shearer, Paul [Department of Mathematics, 2074 East Hall, University of Michigan, 530 Church Street, Ann Arbor, MI 48109-1043 (United States)

2013-11-01

162

A Wearable Sensor for Unobtrusive, Long-Term Assessment of Electrodermal Activity  

E-print Network

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 ...

Poh, Ming-Zher

163

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

PubMed

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. PMID:23047611

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

2014-09-01

164

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

PubMed

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. PMID:24639488

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

2014-04-01

165

A Review of the Recent NASA Long-Term Orbital Debris Environment Projection and Active Debris Removal Modeling Activities  

NASA Technical Reports Server (NTRS)

The NASA Orbital Debris Program Office (ODPO) developed a high fidelity debris evolutionary model, LEGEND (a LEO-to-GEO Environment Debris model), in 2004 to enhance its capability to better model the near-Earth environment. LEGEND can mimic the growth of the historical debris population and project it into the future based on user-defined scenarios. The first major LEGEND study concluded that even without any future launches, the LEO population would continue to increase due to mutual collisions among existing objects. In reality, the increase will be worse than this prediction because of ongoing satellite launches and unexpected major breakups. Even with a full implementation of the commonly-adopted mitigation measures, the LEO population growth is inevitable. To preserve the near-Earth environment for future generations, active debris removal (ADR) must be considered. A follow-up LEGEND ADR study was completed recently. The main results indicate that (1) the mass and collision probability of each object can be used to establish an effective removal selection criterion and (2) a removal rate of 5 objects per year is sufficient to stabilize the LEO environment. Due to the limitation of removal techniques, however, different target selection criteria (in size, altitude, inclination, etc.) may be more practical. A careful evaluation of the effectiveness of different proposed techniques must be carried out to maximize the long-term benefit to the environment.

Liou, J.C.

2009-01-01

166

A Long-Term Evaluation of Sensing Modalities for Activity Recognition  

E-print Network

characterize a number of issues important for designing activity detection systems that may not have been this work that impact how one might design a home activity recognition system. In addition, we highlight-world conditions. 2 Related Work Although there are different commercial systems available for activity monitoring

Philipose, Matthai

167

Solar Activity  

NSDL National Science Digital Library

This educational brief provides an overview of solar activity, including a description of Earth's magnetosphere and of various solar phenomena such as the solar wind, Coronal Mass Ejections (CMEs), sunspots, solar flares, and others. A list of links to additional material is also provided.

168

Long-Term Effects of a Physical Activity Intervention in High School Girls  

PubMed Central

Background Physical activity decreases during childhood and adolescence, and physical activity levels are significantly lower in females than males, particularly during adolescence. Schools are attractive settings in which to implement interventions designed to promote physical activity in girls and young women, but few studies have tested the sustained effects of such interventions. Design Cross-sectional. Data were collected in 2002–2003 and analyzed in 2006–2007. Setting/Participants 1594 adolescent girls in 22 high schools. Intervention The intervention, Lifestyle Education for Activity Program (LEAP), was designed to increase physical activity in 9th grade girls through two channels: changes in instructional practices and changes in the school environment. This study (LEAP 2) examined the extent to which effects of the intervention were maintained when the girls were in 12th grade. Main Outcome Measures Number of 30-minute blocks per day of vigorous physical activity. Results Girls in the intervention schools that most fully implemented and maintained the intervention were more likely than girls in the other schools to participate in an average of one or more blocks of vigorous physical activity per day (p=0.04; OR=1.49; 95% CI=1.01, 2.20). Conclusions A comprehensive physical activity intervention that is fully implemented and maintained can increase participation in vigorous physical activity by high school girls. PMID:17888853

Pate, Russell R.; Saunders, Ruth; Dishman, Rod K.; Addy, Cheryl; Dowda, Marsha; Ward, Dianne S.

2007-01-01

169

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

PubMed Central

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. PMID:21977003

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

2011-01-01

170

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

171

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

ERIC Educational Resources Information Center

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…

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

2012-01-01

172

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...

173

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

SciTech Connect

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.

Topac, F.O.; Baskaya, H.S.; Alkan, U.; Katkat, A.V. [Uludag University, Bursa (Turkey)

2008-01-15

174

Relationship between long-term phase advances in high-latitude VLF wave propagation and solar energetic particle fluxes  

NASA Astrophysics Data System (ADS)

Anomalous advances of OMEGA VLF navigation system (10.2-kHz) signals during three extended periods (totaling 60 days) of solar cosmic ray event activity during 1982 are examined and compared with energetic proton, alpha particle, and electron precipitation into the polar cap ionosphere. Time profiles of the OMEGA 10.2-kHz Hawaii-to-Norway path phase advance are found to be almost congruent with the time profiles of the logarithms of the energetic proton fluxes precipitating into the polar cap as determined from instruments aboard the polar orbiting NOAA-6 satellite and the GOES-2 geostationary satellite. Although both energetic alpha particles and electrons contribute to the anomalous phase advance experienced by the 10.2-kHz Hawaii-to-Norway OMEGA signal, a simple, empirical algorithm reasonably relates the observed phase advance to the observed differential fluxes of 6-MeV solar cosmic ray protons.

Sauer, Herbert H.; Spjeldvik, Walther N.; Steele, F. Kenneth

1987-06-01

175

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

PubMed

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. PMID:25702462

Andriianova, E Iu; Lanskaia, O V

2014-01-01

176

Long-term fluctuations in volcanic activity: implications for future environmental impact  

E-print Network

, acidic lake (pH ranging from to reduce impacts on communities and economies. Although phreatic eruptions through acidic crater lakes typically present a limited hazard, activity associated with a catastrophic drop in lake level

Williams-Jones, Glyn

177

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

NASA Technical Reports Server (NTRS)

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.

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

1998-01-01

178

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

PubMed

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

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

2013-09-01

179

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

PubMed Central

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

2013-01-01

180

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

PubMed Central

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 characteristics such as readiness to change and risk factors can guide physicians to prioritize time and intervention efforts for maximizing their impact on insufficiently active PHC patients. PMID:24491081

2014-01-01

181

Long-term activation in a 15 MeV radiotherapy accelerator.  

PubMed

The high energy electrons produced by linear accelerators can generate several radioisotopes by means of photonuclear reactions. The activity produced in the head of a 15 MV Mevatron Siemens 77 medical linear accelerator was measured by high resolution gamma-ray spectrometry, during its decommissioning 1 year after the last clinical use. The activity of 54Mn, 57Co, 60Co, 181W, and 65Zn was measured while the activity of other radioisotopes which emit soft beta or gamma rays such as 59Ni, 63Ni, and 55Fe was inferred by appropriate scaling factors. The number of pieces requiring particular care is limited, their mass does not exceed some tens of kilograms, and their volume is of the order of some thousands of cm3. Moreover, these materials are metals and the emitted radiation can be easily shielded, so that storage should not create particular problems. PMID:18697527

Brusa, A; Cesana, A; Stucchi, C; Terrani, M; Zanellati, F

2008-07-01

182

Long term activation in a 15 MeV radiotherapy accelerator  

SciTech Connect

The high energy electrons produced by linear accelerators can generate several radioisotopes by means of photonuclear reactions. The activity produced in the head of a 15 MV Mevatron Siemens 77 medical linear accelerator was measured by high resolution gamma-ray spectrometry, during its decommissioning 1 year after the last clinical use. The activity of {sup 54}Mn, {sup 57}Co, {sup 60}Co, {sup 181}W, and {sup 65}Zn was measured while the activity of other radioisotopes which emit soft {beta} or {gamma} rays such as {sup 59}Ni, {sup 63}Ni, and {sup 55}Fe was inferred by appropriate scaling factors. The number of pieces requiring particular care is limited, their mass does not exceed some tens of kilograms, and their volume is of the order of some thousands of cm{sup 3}. Moreover, these materials are metals and the emitted radiation can be easily shielded, so that storage should not create particular problems.

Brusa, A.; Cesana, A.; Stucchi, C.; Terrani, M.; Zanellati, F. [Health Physics Department, National Cancer Institute of Milan, Milan 20133 (Italy); Nuclear Engineering Department, Politecnico di Milano, Milan 20133 (Italy); Health Physics Department, National Cancer Institute of Milan, Milan 20133 (Italy); Nuclear Engineering Department, Politecnico di Milano, Milan 20133 (Italy); Health Physics Department, National Cancer Institute of Milan, Milan 20133 (Italy)

2008-07-15

183

Activity and long-term stability of PEDOT as Pt catalyst support for the DMFC anode  

Microsoft Academic Search

The feasibility of using poly(3,4-ethylenedioxythiophene) (PEDOT) as Pt catalyst support for direct methanol fuel cell (DMFC)\\u000a anodes was investigated. Measurements with freshly prepared Pt-PEDOT\\/C electrodes showed poor activity for methanol oxidation\\u000a in a half-cell and a DMFC. A substantial enhancement in that activity was evident after either electrochemical over-oxidation\\u000a of PEDOT or long-time storage of the Pt-PEDOT\\/C gas diffusion electrode

J.-F. Drillet; R. Dittmeyer; K. Jüttner

2007-01-01

184

Stability and antimicrobial activity of allyl isothiocyanate during long-term storage in an oil-in-water emulsion.  

PubMed

This study investigated the stability and antimicrobial activity of allyl isothiocyanate (AITC) in medium chain triglyceride (MCT) or soybean oil (SBO) dispersed in an oil-in-water (o/w) system during long-term storage. Oil type, content, and oxidative stability affect the stability and antimicrobial activity of AITC during storage. High oil content is favorable for AITC stability in the emulsion. Notably, AITC with MCT is more stable than AITC with SBO with the same oil content. Consequently, AITC with MCT is more effective than AITC with SBO in inhibiting G(-) bacteria (E. coli O157:H7, Salmonella enterica, and Vibrio parahaemolyticus) and G(+) bacteria (Staphylococcus aureus and Listeria monocytogenes). PMID:20629866

Liu, Tai-Ti; Yang, Tsung-Shi

2010-06-01

185

Long-Term Heavy Ketamine Use is Associated with Spatial Memory Impairment and Altered Hippocampal Activation.  

PubMed

Ketamine, a non-competitive N-methyl-d-aspartate receptor antagonist, is rising in popularity as a drug of abuse. Preliminary evidence suggests that chronic, heavy ketamine use may have profound effects on spatial memory but the mechanism of these deficits is as yet unclear. This study aimed to examine the neural mechanism by which heavy ketamine use impairs spatial memory processing. In a sample of 11 frequent ketamine users and 15 poly-drug controls, matched for IQ, age, years in education. We used fMRI utilizing an ROI approach to examine the neural activity of three regions known to support successful navigation; the hippocampus, parahippocampal gyrus, and the caudate nucleus during a virtual reality task of spatial memory. Frequent ketamine users displayed spatial memory deficits, accompanied by and related to, reduced activation in both the right hippocampus and left parahippocampal gyrus during navigation from memory, and in the left caudate during memory updating, compared to controls. Ketamine users also exhibited schizotypal and dissociative symptoms that were related to hippocampal activation. Impairments in spatial memory observed in ketamine users are related to changes in medial temporal lobe activation. Disrupted medial temporal lobe function may be a consequence of chronic ketamine abuse and may relate to schizophrenia-like symptomatology observed in ketamine users. PMID:25538631

Morgan, Celia J A; Dodds, Chris M; Furby, Hannah; Pepper, Fiona; Fam, Johnson; Freeman, Tom P; Hughes, Emer; Doeller, Christian; King, John; Howes, Oliver; Stone, James M

2014-01-01

186

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

ERIC Educational Resources Information Center

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…

Hamilton, James P.

2008-01-01

187

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

ERIC Educational Resources Information Center

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…

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

2005-01-01

188

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

ERIC Educational Resources Information Center

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…

Thompson, Margaret; And Others

1991-01-01

189

Long-Term Heavy Ketamine Use is Associated with Spatial Memory Impairment and Altered Hippocampal Activation  

PubMed Central

Ketamine, a non-competitive N-methyl-d-aspartate receptor antagonist, is rising in popularity as a drug of abuse. Preliminary evidence suggests that chronic, heavy ketamine use may have profound effects on spatial memory but the mechanism of these deficits is as yet unclear. This study aimed to examine the neural mechanism by which heavy ketamine use impairs spatial memory processing. In a sample of 11 frequent ketamine users and 15 poly-drug controls, matched for IQ, age, years in education. We used fMRI utilizing an ROI approach to examine the neural activity of three regions known to support successful navigation; the hippocampus, parahippocampal gyrus, and the caudate nucleus during a virtual reality task of spatial memory. Frequent ketamine users displayed spatial memory deficits, accompanied by and related to, reduced activation in both the right hippocampus and left parahippocampal gyrus during navigation from memory, and in the left caudate during memory updating, compared to controls. Ketamine users also exhibited schizotypal and dissociative symptoms that were related to hippocampal activation. Impairments in spatial memory observed in ketamine users are related to changes in medial temporal lobe activation. Disrupted medial temporal lobe function may be a consequence of chronic ketamine abuse and may relate to schizophrenia-like symptomatology observed in ketamine users. PMID:25538631

Morgan, Celia J. A.; Dodds, Chris M.; Furby, Hannah; Pepper, Fiona; Fam, Johnson; Freeman, Tom P.; Hughes, Emer; Doeller, Christian; King, John; Howes, Oliver; Stone, James M.

2014-01-01

190

Long-Term Fitness Training Improves the Circadian Rest-Activity Rhythm in Healthy Elderly Males  

Microsoft Academic Search

In old age, the circadian timing system loses optimal functioning. This process is even accelerated in Alzheimer's disease. Because pharmacological treatment of day-night rhythm disturbances usually is not very effective and may have considerable side effects, nonpharmacological treatments deserve attention. Bright light therapy has been shown to be effective. It is known from animal studies that increased activity, or an

Eus J. W. Van Someren; Cees Lijzenga; Majid Mirmiran; Dick F. Swaab

1997-01-01

191

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

PubMed Central

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

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

2013-01-01

192

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

PubMed

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. PMID:24184442

Chen, Qian; Xiao, De-Sheng

2014-01-30

193

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

NASA Technical Reports Server (NTRS)

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.

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

1998-01-01

194

Long-term growth of human WGA-activated T-lymphocytes without feeder cells.  

PubMed

Human wheat germ agglutinin (WGA)-activated T-lymphocytes from either peripheral blood or spleen could be propagated for several weeks in the presence of culture supernatants from human mononuclear cells obtained after a 1-day stimulation with WGA and after a subsequent 3-day culture without mitogen. The continuous T-cell growth in this culture system required alternate exposition of the cells to the above supernatants, both with and without WGA, but proceeded in the absence of feeder cells. After 3 weeks of propagation most cells displayed the CD4+ phenotype, expressed IL2 receptors, and responded to PHA, Con A, and WGA. It has been shown that WGA-activated T-cells could be cloned by limiting dilution and propagated using the above culture system. PMID:2569939

Siwicki, J K

1989-09-01

195

Long-term starspot evolution, activity cycle and orbital period variation of SZ Piscium  

Microsoft Academic Search

A sequence of V-band light curves of the active close binary SZ Piscium (F8 V-IV+ K1 IV), extending from 1957 to 1998, is presented and analysed to derive the spot distribution and evolution on the component stars. In our modelling approach the Roche geometry and Kurucz's atmospheric models were adopted. The resulting maps of the spot surface distribution were regularized

A. F. Lanza; M. Rodonò; L. Mazzola; S. Messina

2001-01-01

196

IgG immunoadsorption reduces systemic lupus erythematosus activity and proteinuria: a long term observational study  

PubMed Central

Objective: To analyse the effects of rigorous immunoglobulin removal by immunoadsorption (IAS) on proteinuria (primary outcome variable), disease activity (SIS, SLEDAI, ECLAM), and autoantibodies to double stranded DNA (anti-dsDNA) in active systemic lupus erythematosus (SLE). Methods: 16 patients with severe SLE and renal disease, in whom cyclophosphamide was contraindicated or failed to halt disease progression, were treated with IAS for 3 months. Patients achieving at least 20% improvement in two or more of the outcome measures were considered responders and offered a 9 months' extension period. Results: Within 3 months, 14 patients responded and 11 opted for an extension. Proteinuria decreased from 6.7 (4.6) g/day (mean (SD)) at baseline to 4.3 (3.5) g/day at 3 months and 2.9 (2.4) g/day at 12 months (p<0.001). From baseline to 3 and 12 months, disease activity improved independently of scoring by SIS (15 (5) to 5 (2) and to 5 (2), p<0.0001), SLEDAI (21 (7) to 5 (4) and to 5 (4), p<0.0001), or ECLAM (7 (2) to 2 (1) and to 3 (1), p<0.0001). Anti-dsDNA fell from 391 (647) IU/ml to 146 (218) and to 53 (50) IU/ml at 3 and 12 months, respectively. Steroids could be tapered from 117 (159) mg/day at baseline to 29 (17) mg/day at 3 months and 9 (2) mg/day at 12 months. IAS was not associated with an excess of infections. However, one patient died of septicaemia after 1 month of treatment. Conclusion: In this negatively selected cohort of patients with SLE, IAS was associated with a significant response shown by reduced proteinuria, improved global disease activity, decreased anti-dsDNA, and lower glucocorticoid dosages, suggesting therapeutic benefit. PMID:15640267

Stummvoll, G; Aringer, M; Smolen, J; Schmaldienst, S; Jimenez-Boj, E; Horl, W; Graninger, W; Derfler, K

2005-01-01

197

A PC-based system for long-term monitoring of animal activity  

Microsoft Academic Search

This paper describes a PC-based animal locomotor and sound activities synchronous analysis and recording system. In the former, using video recording and image analysis techniques, the geometric locations of an animal in a cage and its bodily displacement areas between consecutive time in two-dimensions were detected. Tremendous data reduction rate has also been obtained (512×512:4), which facilitates our PC computer

B. M. Wu; F. H. Y. Chan; F. K. Lam; M. C. Lam; P. W. F. Poon; A. M. S. Poon

1998-01-01

198

Long-term antibacterial efficacy of air plasma-activated water  

NASA Astrophysics Data System (ADS)

Indirect air dielectric barrier discharge in close proximity to water creates an acidified, nitrogen-oxide containing solution known as plasma-activated water (PAW), which remains antibacterial for several days. Suspensions of E. coli were exposed to PAW for either 15 min or 3 h over a 7-day period after PAW generation. Both exposure times yielded initial antibacterial activity corresponding to a ~5-log reduction in cell viability, which decreased at differing rates over 7 days to negligible activity and a 2.4-log reduction for 15 min and 3 h exposures, respectively. The solution remained at pH ~2.7 for this period and initially included hydrogen peroxide, nitrate and nitrite anions. The solution composition varied significantly over this time, with hydrogen peroxide and nitrite diminishing within a few days, during which the antibacterial efficacy of 15 min exposures decreased significantly, while that of 3 h exposures produced a 5-log reduction or more. These results highlight the complexity of PAW solutions where multiple chemical components exert varying biological effects on differing time scales.

Traylor, Matthew J.; Pavlovich, Matthew J.; Karim, Sharmin; Hait, Pritha; Sakiyama, Yukinori; Clark, Douglas S.; Graves, David B.

2011-11-01

199

Long-term ¹³?Cs activity monitoring of mushrooms in forest ecosystems of the Czech Republic.  

PubMed

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. PMID:23838098

Škrkal, J; Rulík, P; Fantínová, K; Burianová, J; Helebrant, J

2013-12-01

200

Long-term lidar observations of wintertime gravity wave activity over northern Sweden  

NASA Astrophysics Data System (ADS)

This paper presents an analysis of gravity wave activity over northern Sweden as deduced from 18 years of wintertime lidar measurements at Esrange (68° N, 21° E). Gravity wave potential energy density (GWPED) was used to characterize the strength of gravity waves in the altitude regions 30-40 km and 40-50 km. The obtained values exceed previous observations reported in the literature. This is suggested to be due to Esrange's location downwind of the Scandinavian mountain range and due to differences in the various methods that are currently used to retrieve gravity wave parameters. The analysis method restricted the identification of the dominating vertical wavelengths to a range from 2 to 13 km. No preference was found for any wavelength in this window. Monthly mean values of GWPED show that most of the gravity waves' energy dissipates well below the stratopause and that higher altitude regions show only small dissipation rates of GWPED. Our analysis does not reproduce the previously reported negative trend in gravity wave activity over Esrange. The observed inter-annual variability of GWPED is connected to the occurrence of stratospheric warmings with generally lower wintertime mean GWPED during years with major stratospheric warmings. A bimodal GWPED occurrence frequency indicates that gravity wave activity at Esrange is affected by both ubiquitous wave sources and orographic forcing.

Ehard, B.; Achtert, P.; Gumbel, J.

2014-11-01

201

Occupational Physical Activities and Long-Term Functional and Radiographic Outcomes in Patients With Ankylosing Spondylitis  

PubMed Central

Objective We sought to identify specific occupational activities associated with functional limitations and radiographic damage in patients with longstanding ankylosing spondylitis (AS). Methods We asked patients diagnosed with AS for ?20 years to report all past occupations, which we mapped to specific physical activities using the Occupational Information Network, which is the US Department of Labor job classification database. For each occupation reported, we obtained ratings for 13 physical abilities of the worker and 13 aspects of the work environment or work tasks (work context) thought to be most relevant to patients with AS. Averages for each measure, weighted by the number of years in each job, were related to the degree of functional limitation as assessed by the Bath AS Functional Index (BASFI) and to the extent of spinal radiographic damage as assessed by the Bath AS Radiology Index for the spine (BASRI-s). Results Among 397 patients, those with a history of jobs requiring dynamic flexibility (the ability to repeatedly bend, stretch, twist, or reach) had more functional limitations than those whose past jobs required little or no dynamic flexibility (adjusted mean BASFI score 48.3 in the top quartile versus 38.1 in all others). Those whose past jobs required more dynamic flexibility, extent flexibility, and exposure to whole body vibration also had significantly higher BASRI-s scores. Conclusion Bending, twisting, and stretching are the occupational activities associated with greater functional limitations and radiographic damage in patients with longstanding AS. Exposure to whole body vibration was also associated with more radiographic damage. PMID:18512723

Ward, Michael M.; Reveille, John D.; Learch, Thomas J.; Davis, John C.; Weisman, Michael H.

2009-01-01

202

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

NASA Astrophysics Data System (ADS)

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.

Šimon, Vojt?ch

2014-11-01

203

Measuring social activities and social function in long-term cancer survivors who received hematopoietic stem cell transplantation  

PubMed Central

Objective Cancer survivors report deficits in social functioning even years after completing treatment. Commonly used measures of social functioning provide incomplete understanding of survivors’ social behavior. This study describes social activities of survivors and evaluates the psychometric properties of the Social Activity Log (SAL) in a cohort of long-term survivors of hematopoietic stem cell transplantation (HSCT) for cancer. Methods One hundred two 5–20 year survivors completed the SAL, Short Form-36 Health Survey (SF-36), and other patient reported outcomes. Principal components analysis determined the factor structure of the SAL along with correlations and regressions to establish validity. Results Principal component analysis yielded three factors in the SAL: “non-contact events” (eg, telephone calls), “regular events” (eg, played cards),” and “special events” (eg, concerts), which explained 59% of the total variance. The SAL possessed good internal consistency (Cronbach’s ? = 0.82). SF-36 social function and SAL were moderately correlated (r = .31). In linear regressions, physical function and depression explained 16% of the variance in the SAL (P<.001), while physical function, depression and fatigue predicted 55% of the variance in SF-36 social function (P<.001). Conclusions Results support the use of the SAL as a measure of social activity in cancer survivors who received HSCT. Whereas the SAL is designed to measure social behaviors, SF-36 social function assesses subjective experience and is more strongly associated with depression and fatigue. The SAL appears to be a promising tool to understand the behavioral social deficits reported by long-term survivors of cancer. PMID:19358230

Syrjala, Karen L.; Stover, Allison C.; Yi, Jean C.; Artherholt, Samantha B.; Abrams, Janet R.

2011-01-01

204

Response to Pneumococcal Polysaccharide Vaccination in HIV-Positive Individuals on Long Term Highly Active Antiretroviral Therapy  

PubMed Central

Background and objectives Streptococcus pneumoniae continues to cause serious infections in HIV-positive individuals in the era of highly active anti-retroviral therapy. This led to the recommendation to revaccinate HIV-positive individuals with PPV23 five years after primary vaccination. The benefits of revaccination and the impact of long term highly active anti-retroviral therapy (HAART) on antigen-specific B cell reconstitution have remained unclear thus far and were investigated. Design and methods We assessed antibody levels, opsonophagocytic activity and phenotype of pneumococcal polysaccharide (PPS) specific-B cells post-revaccination in long term HAART cohorts stratified according to CD4 count as group A (CD4>200) and group B (CD4<200). Anti-PPS IgG, IgM and functional antibody response against vaccine serotypes 14 and 23F were measured by ELISA and opsonophagocytic assay followed by phenotypic analysis of PPS14 and 23F-specific B cells using fluorescently labeled PPS. Results Significant increases in total and functional antibody titers were noted in groups A and B post-vaccination concomitant with significant rise in PPS-specific IgM memory B cells, a critical B cell subset required for protection against PPS although the overall response remained significantly diminished compared to HIV-negative volunteers. Conclusion Comparable increases in opsonophagocytic titers between study groups A and B concomitant with a comparable rise in PPS-specific IgM memory B cells indicate revaccination to be beneficial regardless of the degree of CD4 T cell reconstitution. These findings emphasize the importance of defining effective vaccination practices amongst high-risk individuals.

Iyer, Anita S; Leggat, David J; Ohtola, Jennifer A; Duggan, Joan M; Georgescu, Claudiu A; Al Rizaiza, Adeeb A; Khuder, Sadik A; Khaskhely, Noor M; Westerink, Julie

2015-01-01

205

Chronic active hepatitis in children. A clinical and immunological long-term study.  

PubMed

Six girls and one boy with cronic active hepatitis (CAH) of unknown etiology were between 9 and 15 years at the clinical onset of their illness. After beginning immunosuppressive therapy the course of their disease was followed from one to ten years. All had markedly increased IgG, high titres of smooth muscle antibodies (SMA) and antinuclear antibodies of IgG class in the earliest serum specimens tested. Therapy resulted in an improved sense of well-being and a decrease in SGOT, IgG and titres of SMA. Very high titres of measles antibodies were observed in all cases. In one of the cases CAH manifested itself after measles and in another after rubella infection. The first case in our series of patients died of liver failure after 5 years of illness. The other patients have survived and are able to live a normal life. The possibility of CAH should be considered when children develop symptoms of hepatitis. Longterm immunosuppressive treatment with regular clinical and laboratory evaluation is important. Estimation of titres of SMA is an additional parameter of value in following of the activity of CAH in these young patients. PMID:831383

Lidman, K; Biberfeld, G; Sterner, G; Norberg, R

1977-01-01

206

Performance change during long-term ozonation aimed at augmenting denitrification and decreasing waste activated sludge.  

PubMed

Partial ozonation of return activated sludge for waste sludge minimization and soluble COD production was examined. Two nitrifying sequencing batch reactors, one control and one ozonated, were operated under alternating anoxic/aerobic conditions. During the first steady-state period of 95-136 d of ozonation, the amount of wasted solids decreased with the ozone dose up to 25%, generating soluble COD by cell lysis. However, during a subsequent period of 190-232 d of continuous ozonation, the effect of solids destruction and COD production decreased by 50%. The investigations of extracellular polymers content and floc shape analyses showed that, after prolonged daily ozone treatment, sludge floc structure becomes stronger, denser, and more ozone-resistant. The findings suggest that, for prolonged operation of partial sludge ozonation, an increase in ozone doses may be required to continuously maintain the expected solids destruction level. This in turn will increase the operational costs of the treatment. PMID:18848718

Dytczak, Magdalena A; Oleszkiewicz, Jan A

2008-11-01

207

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

PubMed

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. PMID:21087159

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

2010-10-01

208

Solar Week Monday: Do the Activity - Measuring Solar Activity  

NSDL National Science Digital Library

This is an online lesson associated with activities during Solar Week, a twice-yearly event in March and October during which classrooms are able to interact with scientists studying the Sun. Outside of Solar Week, information, activities, and resources are archived and available online at any time. This is an activity about measurements of solar activity. Learners will observe an image of the Sun and sketch major features, plot data to begin to recognize patterns of solar activity, look for long-term patterns in graphed data, compare X-ray and visible light images of the Sun to find solar features common to both sets of images, and make a prediction of what the Sun will look like in a visible light image after observing an X-ray image taken on the same day. This activity is scheduled to occur during Monday of Solar Week.

2012-08-03

209

Metabotropic glutamate receptor 3 activation is required for long-term depression in medial prefrontal cortex and fear extinction.  

PubMed

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

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

210

Long-term morphological evolution of a morphologically active man-made stream in the Netherlands  

NASA Astrophysics Data System (ADS)

Around 1770, a straight artificial canal (Gelderns-Nierskanaal) has been constructed between the River Niers and the River Meuse, crossing the border between Germany and the Netherlands, with the purpose of reducing flood risk in the downstream reaches of the River Niers. Whereas the German part of the canal is kept straight throughout time, the Dutch part was left unprotected and developed into a morphodynamically active stream featuring a meandering planform. The current planform and in-channel morphology are analyzed using airborne LiDAR data and historical topographic maps. Around the turn of the 18th century, the first attempts were made to make detailed topographic maps. From this time on, at least 16 topographic maps of the area around the stream were made. With the use of these historical topographic maps, a reconstruction is made of the planimetric shape of the stream over a period of 240 years. The LiDAR data show old meander belts at several places around the stream. Those belts compare well with the topographic maps. The sinuosity increases from upstream to downstream. This could be a consequence of the valley slope, where the upper part is flat and the slope increases in downstream direction. Besides, the LiDAR data show that erosion resulted in an incised valley, with dimensions to 50 m in width and 6 m in depth. Both the datasets are combined to make an estimate of the historical sediment budget of the stream.

Eekhout, J.; Hoitink, T.

2010-12-01

211

Persistent Long-Term Facilitation at an Identified Synapse Becomes Labile with Activation of Short-Term Heterosynaptic Plasticity  

PubMed Central

Short-term and long-term synaptic plasticity are cellular correlates of learning and memory of different durations. Little is known, however, how these two forms of plasticity interact at the same synaptic connection. We examined the reciprocal impact of short-term heterosynaptic or homosynaptic plasticity at sensorimotor synapses of Aplysia in cell culture when expressing persistent long-term facilitation (P-LTF) evoked by serotonin [5-hydroxytryptamine (5-HT)]. Short-term heterosynaptic plasticity induced by 5-HT (facilitation) or the neuropeptide FMRFa (depression) and short-term homosynaptic plasticity induced by tetanus [post-tetanic potentiation (PTP)] or low-frequency stimulation [homosynaptic depression (HSD)] of the sensory neuron were expressed in both control synapses and synapses expressing P-LTF in the absence or presence of protein synthesis inhibitors. All forms of short-term plasticity failed to significantly affect ongoing P-LTF in the absence of protein synthesis inhibitors. However, P-LTF reversed to control levels when either 5-HT or FMRFa was applied in the presence of rapamycin. In contrast, P-LTF was unaffected when either PTP or HSD was evoked in the presence of either rapamycin or anisomycin. These results indicate that synapses expressing persistent plasticity acquire a “new” baseline and functionally express short-term changes as naive synapses, but the new baseline becomes labile following selective activations—heterosynaptic stimuli that evoke opposite forms of plasticity—such that when presented in the presence of protein synthesis inhibitors produce a rapid reversal of the persistent plasticity. Activity-selective induction of a labile state at synapses expressing persistent plasticity may facilitate the development of therapies for reversing inappropriate memories. PMID:24695698

Schacher, Samuel

2014-01-01

212

Brain activation patterns in major depressive disorder and work stress-related long-term sick leave among Swedish females.  

PubMed

Deficits in executive functioning and working memory associated with frontal lobe dysfunction are prominent in depression and work-related long-term sick leave (LTSL). This study used functional magnetic resonance imaging (fMRI) to investigate potential differences in brain activation patterns in these conditions. In addition, the function of the hypothalamic-pituitary-adrenal (HPA) axis was examined and compared between groups. Since there is a clear overrepresentation of women in these diagnostic groups, and to ensure a more homogenous sample population, only women were included. To examine the neural correlates of relevant cognitive processes in patients on sick leave >90 days due to work-related LTSL, recently diagnosed patients with major depression Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV criteria, untreated), and healthy controls (n = 10, each group), a 2-back working memory task and a visual long-term memory task were administered during fMRI scanning. HPA axis functioning was investigated using a diurnal curve of saliva cortisol and a dexamethasone suppression test. Task performance was comparable among the three groups. Multivariate image analysis revealed that both memory tasks engaged a similar brain network in all three groups, including the prefrontal and parietal cortex. During the 2-back task, LTSL patients had significant frontal hypoactivation compared to controls and patients with depression. Saliva cortisol measurements showed a flattening of the diurnal rythmicity in LTSL patients compared to patients with depression and healthy contols. Taken together, these findings indicate that work stress-related LTSL and major depression are dissociable in terms of frontal activation and diurnal cortisol rhythmicity. PMID:22217254

Sandström, Agneta; Säll, Roland; Peterson, Jonas; Salami, Alireza; Larsson, Anne; Olsson, Tommy; Nyberg, Lars

2012-09-01

213

Long term monitoring of geomorphological changes caused by torrent activity using terrestrial laser scanning  

NASA Astrophysics Data System (ADS)

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 presented and the geomorphologic changes of the channel bed caused by the new check dam are discussed.

Prokop, A.; Chiari, M.

2012-04-01

214

Long-term activity-induced changes in the brain : a study of translational regulation and structural plasticity  

E-print Network

Long-lasting changes must take place in the brain to store the skills and memories that have been learned by the organism throughout its history. Long-term memory (LTM), and its cellular correlate, the late-phase of long-term ...

Govindarajan, Arvind

2005-01-01

215

Remote long-term registrations of sleep-wake rhythms, core body temperature and activity in marmoset monkeys.  

PubMed

Initial studies in the day active marmoset monkey (Callithrix jacchus) indicate that the sleep-wake cycle of these non-human primates resembles that of humans and therefore conceivably represent an appropriate model for human sleep. The methods currently employed for sleep studies in marmosets are limited. The objective of this study was to employ and validate the use of specific remote monitoring system technologies that enable accurate long-term recordings of sleep-wake rhythms and the closely related rhythms of core body temperature (CBT) and locomotor activity in unrestrained group-housed marmosets. Additionally, a pilot sleep deprivation (SD) study was performed to test the recording systems in an applied experimental setup. Our results show that marmosets typically exhibit a monophasic sleep pattern with cyclical alternations between NREM and REM sleep. CBT displays a pronounced daily rhythm and locomotor activity is primarily restricted to the light phase. SD caused an immediate increase in NREM sleep time and EEG slow-wave activity as well as a delayed REM sleep rebound that did not fully compensate for REM sleep that had been lost during SD. In conclusion, the combination of two innovative technical approaches allows for simultaneous measurements of CBT, sleep cycles and activity in multiple subjects. The employment of these systems represents a significant refinement in terms of animal welfare and will enable many future applications and longitudinal studies of circadian rhythms in marmosets. PMID:22850608

Hoffmann, Kerstin; Coolen, Alex; Schlumbohm, Christina; Meerlo, Peter; Fuchs, Eberhard

2012-12-01

216

Long-term effects of fertilizer on soil enzymatic activity of wheat field soil in Loess Plateau, China.  

PubMed

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

Hu, Weigang; Jiao, Zhifang; Wu, Fasi; Liu, Yongjun; Dong, Maoxing; Ma, Xiaojun; Fan, Tinglu; An, Lizhe; Feng, Huyuan

2014-12-01

217

Long-term stratospheric carbon tetrafluoride (CF4) increase inferred from 19852004 infrared space-based solar occultation measurements  

E-print Network

-based solar occultation measurements C. P. Rinsland,1 E. Mahieu,2 R. Zander,2 R. Nassar,3 P. Bernath,3 C determined from infrared high spectral resolution solar occultation Fourier transform spectrometer-term stratospheric carbon tetrafluoride (CF4) increase inferred from 1985­2004 infrared space-based solar occultation

Nassar, Ray

218

Abdel Wahab M., El-Metwally M., Hassan R., Lefvre M., Oumbe A., Wald L., 2008. Assessing surface solar irradiance in Northern Africa desert climate and its long-term variations from Meteosat images. International  

E-print Network

solar irradiance in Northern Africa desert climate and its long-term variations from Meteosat images in Northern Africa desert climate and its long-term variations from Meteosat images MAGDY ABDEL WAHAB¶, MOSSAD and flora life in the desert climate in Northern Africa. Of particular interest nowadays to the four nations

Paris-Sud XI, Université de

219

Postsynaptic activity reverses the sign of the acetylcholine-induced long-term plasticity of GABAA inhibition.  

PubMed

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 ?5??2 subunit-containing GABAA receptors by the GABA released. GABAA-LTP requires the activation of M1-muscarinic receptors and an increase in cytosolic Ca(2+). 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

Domínguez, Soledad; Fernández de Sevilla, David; Buño, Washington

2014-07-01

220

Postsynaptic activity reverses the sign of the acetylcholine-induced long-term plasticity of GABAA inhibition  

PubMed Central

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 ?5??2 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

Domínguez, Soledad; Fernández de Sevilla, David; Buño, Washington

2014-01-01

221

Multi-decade Measurements of the Long-Term Trends of Atmospheric Species by High-Spectral-Resolution Infrared Solar Absorption Spectroscopy  

NASA Technical Reports Server (NTRS)

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.

Rinsland, Curtis P.; Chiou, Linda; Goldman, Aaron; Hannigan, James W.

2010-01-01

222

Long-term outcome of patients with active ankylosing spondylitis with etanercept-sustained efficacy and safety after seven years  

PubMed Central

Introduction Data from clinical studies on the long-term efficacy and safety of anti-tumor necrosis factor (TNF)-? therapy in patients with ankylosing spondylitis (AS) are scarce. This is the first report on continuous treatment with the TNF? fusion protein etanercept over seven years (y). Methods Overall, 26 patients with active AS were initially treated with etanercept 2 × 25 mg s.c./week with no concomitant disease modifying anti-rheumatic drugs (DMARDs) or steroids. The clinical response was assessed by standardized parameters. The primary outcome was the proportion of patients in the Spondyloarthritis International Society (ASAS) partial remission at seven years. AS disease activity scores (ASDAS) for status and improvement were compared to conventional outcome measures. Results Overall, 21/26 patients (81%) completed two years of treatment and 16/26 patients (62%) completed seven years. In the completer analysis, 31% patients were in ASAS partial remission at seven years, while 44% patients showed an ASDAS inactive disease status. Mean Bath AS activity index (BASDAI) scores, which were elevated at baseline (6.3 ± 0.9), showed constant improvement and remained low: 3.1 ± 2.5 at two years and 2.5 ± 2.2 at seven years, while ASDAS also improved (3.9 ± 0.7 at baseline, 1.8 ± 0.9 at two years, 1.6 ± 0.8 at seven years), all P <0.001. From the 10 dropouts, only 5 patients discontinued treatment due to adverse events. Patients who completed the study had lower baseline Bath AS function index (BASFI) scores vs. patients who discontinued. No other clinical parameter at baseline could predict any long-term outcome. Conclusions This study confirms the clinical efficacy and safety of etanercept in patients with active AS over seven years of continuous treatment. After seven years, more than half of the initially treated patients remained on anti-TNF therapy, and one-third were in partial remission. Trial Registration ClinicalTrials.gov: NCT01289743 PMID:23786760

2013-01-01

223

Long-term investigations of radiocaesium activity concentrations in carps in north Croatia after the Chernobyl accident  

E-print Network

Long-term investigations of radiocaesium activity concentrations in carps in the Republic of Croatia are presented. The radiocaesium levels in carps decreased exponentially and the effective ecological half-life of 137Cs in carps was estimated to be about 1 year for 1987-2002 period and 5 years for 1993-2005 period. The observed 134Cs:137Cs activity ratio in carps has been found to be similar to the ratio that has been observed in other environmental samples. Concentration factor for carps (wet weight) was roughly estimated to be 128 +/- 74 Lkg-1, which is in reasonable agreement with model prediction based on K+ concentrations in water. Estimated annual effective doses received by 134Cs and 137Cs intake due to consumption of carps for an adult member of Croatian population are small, per caput dose for the 1987 - 2005 estimated to be 0.5 +/- 0.2 microSv. Due to minor freshwater fish consumption in Croatia and low radiocaesium activity concentrations in carps, it can be concluded that carps consumption was no...

Franic, Z

2007-01-01

224

Occipital cortex activation by long-term repetitive tactile stimulation is necessary for object recognition in blinds: a case report.  

PubMed

Tactile vision has been approached from a variety of angles using different techniques. So far, a certain kind of object (and text) recognition has been shown, though seeing as such has not been achieved yet, and it remains unclear. Trough repetitive passive tactile stimulation perceptual processing is transferred from temporo-parietal to occipital areas, which affects object recognition. We report the results of passive tactile stimulation, as well as rTMS, applied to a 50 year old left handed blind male with over 97% loss of vision, who suffers from Peter's anomaly and microphthalmia. After 15 weeks of passive tactile stimulation, the subject showed increased activity in occipital areas associated with the development of visual-like perception which remained unchanged after three months without passive tactile stimulation. Inhibitory rTMS over the visual cortex led to noticeable reduction of spatial recognition performance and visual sensations in this subject. Stable changes in occipital cortical activity can be associated with subjective sensations of seeing. Once occipital activation has been achieved, it is necessary for spatial object recognition. Both facts highlight the implication of occipital areas in tactile vision and the cortical plasticity of passive tactile long-term stimulation in people with blindness. PMID:23819463

Ortiz, Tomás; Poch, Joaquín; Santos, Juan M; Martínez, Ana M; Ortiz-Terán, Laura; Requena, Carmen; Barcia, Juan A; de Erausquin, Gabriel A; Pascual-Leone, Alvaro

2014-06-01

225

X-ray, FUV, and UV Observations of ? Centauri B: Determination of Long-term Magnetic Activity Cycle and Rotation Period  

NASA Astrophysics Data System (ADS)

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 ? Centauri B. The long life (2-3× 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 ? Cen B (HD 128621; V = 1.33; (B - V) = +0.88; ? = 5.6 ± 0.6 Gyr). These combined high-energy measures provide a more complete look into the nature of ? Cen B's magnetic activity and X-ray-UV radiances. We find that ? Cen B has exhibited significant long-term variability in X-ray through NUV emission fluxes, indicating a solar-like long-term activity cycle of P cycle = 8.84 ± 0.4 years. In addition, analysis of the short-term rotational modulation of mean light due to the effects of magnetically active regions has yielded a well-determined rotation period of P rotation = 36.2 ± 1.4 days. ? Cen B is the only old main-sequence K star with a reliably determined age and rotation period, and for early K stars, as in the case of the Sun for G2 V stars, is an important calibrator for stellar age/rotation/activity relations.

DeWarf, L. E.; Datin, K. M.; Guinan, E. F.

2010-10-01

226

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)

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.

1979-01-01

227

Long-term evaluation of three-dimensional heliocentric solar sail trajectories with arbitrary fixed sail setting  

Microsoft Academic Search

The solar radiation effects upon the orbital behaviour of an arbitrarily shaped spacecraft (or a solar sail in particular) in a general fixed orientation with respect to the local coordinate frame are investigated. Through introduction of a quasi-angle in the osculating plane, the motion of the orbital plane becomes uncoupled from the in-plane perturbations. Exact solutions in the form of

J. C. Van Der Ha; V. J. Modi

1979-01-01

228

Short-term and long-term effects on carbon storage of pulse feeding on acclimated or unacclimated activated sludge.  

PubMed

This study was aimed to investigate the effect of different feeding patterns on the physiological state of the activated sludge and related microbial composition in an SBR (SRT of 2 days, acetate as the sole carbon source, aerobic conditions). The activated sludge was acclimated to two subsequent feeding patterns, namely to continuous feeding throughout the reaction phase and then to pulse feeding. FISH and microscopy staining procedure (Nile blue) were used to investigate the microbial composition, in combination with quantitative determination of storage. At steady state, storage was significant even under continuous feeding whereas pulse feeding brought a strong increase of both rate and yield of storage. Short-term and long-term effects were clearly distinguishable: the immediate adaptation of biomass coming from continuous feeding to a single spike accounted for a significant portion of the overall increase of both rate and yield of polymer storage that was obtained after long acclimation to pulse feeding. On the contrary, after either type of feeding, both cultures were mainly constituted from the members of Thauera/Azoarcus group. Thus, the same dominant group preferably consumed the acetate via storage or growth depending on acclimation conditions. Our study clearly showed that a progressive increase of storage capacity is not necessarily due to a shift of microbial composition. PMID:21496858

Ci?gin, Asli Seyhan; Orhon, Derin; Rossetti, Simona; Majone, Mauro

2011-05-01

229

Midazolam inhibits hippocampal long-term potentiation and learning through dual central and peripheral benzodiazepine receptor activation and neurosteroidogenesis  

PubMed Central

Benzodiazepines (BDZs) enhance ?-aminobutyric acid-A (GABAA) receptor inhibition by direct actions on central BDZ receptors (CBRs). Although some BDZs also bind mitochondrial receptors (translocator protein 18kDa, TSPO) and promote the synthesis of GABA-enhancing neurosteroids, the role of neurosteroids in the clinical effects of BDZs is unknown. In rat hippocampal slices, we compared midazolam, an anesthetic BDZ with clonazepam, an anticonvulsant/anxiolytic BDZ that activates CBRs selectively. Midazolam, but not clonazepam, increased neurosteroid levels in CA1 pyramidal neurons without changing TSPO immunostaining. Midazolam, but not clonazepam, also augmented a form of spike inhibition following stimulation adjacent to the pyramidal cell layer and inhibited induction of long-term potentiation. These effects were prevented by finasteride, an inhibitor of neurosteroid synthesis, or 17PA (17-phenyl-(3?, 5?)-androst-16-en-3-ol), a blocker of neurosteroid effects on GABAA receptors. Moreover, the synaptic effects were mimicked by a combination of clonazepam with FGIN, a selective TSPO agonist, or a combination of clonazepam with exogenous allopregnanolone. Consistent with these in vitro results, finasteride abolished the effects of midazolam on contextual fear learning when administrated one day prior to midazolam injection. Thus, dual activation of CBRs and TSPO appears to result in unique actions of clinically-important BDZs. Furthermore, endogenous neurosteroids are shown to be important regulators of pyramidal neuron function and synaptic plasticity. PMID:21159950

Tokuda, Kazuhiro; O’Dell, Kazuko A.; Izumi, Yukitoshi; Zorumski, Charles F.

2010-01-01

230

Long term treatment of rheumatoid arthritis with high doses of intravenous immunoglobulins: effects on disease activity and serum cytokines.  

PubMed Central

OBJECTIVE--To evaluate the effects of long term treatment of rheumatoid arthritis (RA) with high doses of intravenous immunoglobulins (IVIg). METHODS--Ten patients with active RA and prior unsuccessful treatment with at least one slow acting antirheumatic drug were treated with 400 mg/kg of IVIg for the first three days and then once a month for 12 months. Clinical evaluation and laboratory analysis were performed every month. Serum levels of tumour necrosis factor alpha (TNF alpha), soluble interleukin-2 receptor (sIL-2R), IL-1 alpha, IL-1 beta, IL-6 and interferon gamma (IFN gamma) were measured at baseline and at three monthly intervals for 15 months. RESULTS--Although laboratory parameters were not influenced by the treatment, a late but significant clinical improvement was observed after six months. Serial measurement of cytokines revealed a rapid and persistent decrease in serum TNF alpha and a late and significant reduction in sIL-2R concentrations. CONCLUSION--This study suggests that IVIg can ameliorate the symptoms and improve the functional capability of RA patients. This effect is associated with a partial modulation of serum concentrations of inflammatory cytokines and, more interestingly, with a late decrease in sIL-2R which correlated with the late reduction in disease activity. PMID:7794045

Muscat, C; Bertotto, A; Ercolani, R; Bistoni, O; Agea, E; Cesarotti, M; Fiorucci, G; Spinozzi, F; Gerli, R

1995-01-01

231

Influence of lightweight ambulatory oxygen on oxygen use and activity patterns of COPD patients receiving long-term oxygen therapy.  

PubMed

Lightweight ambulatory oxygen devices are provided on the assumptions that they enhance compliance and increase activity, but data to support these assumptions are lacking. We studied 22 patients with severe chronic obstructive pulmonary disease receiving long-term oxygen therapy (14 men, average age = 66.9 y, FEV(1) = 33.6%pred, PaO(2) at rest = 51.7 torr) who were using E-cylinders as their portable oxygen. Subjects were recruited at 5 sites and studied over a 2-week baseline period and for 6 months after randomizing them to either continuing to use 22-lb E-cylinders towed on a cart or to carrying 3.6-lb aluminum cylinders. Utilizing novel electronic devices, ambulatory and stationary oxygen use was monitored continuously over the 2 weeks prior to and the 6 months following randomization. Subjects wore tri-axial accelerometers to monitor physical activity during waking hours for 2-3 weeks prior to, and at 3 and 6 months after, randomization. Seventeen subjects completed the study. At baseline, subjects used 17.2 hours of stationary and 2.5 hours of ambulatory oxygen daily. At 6 months, ambulatory oxygen use was 1.4 ± 1.0 hrs in those randomized to E-cylinders and 1.9 ± 2.4 hrs in those using lightweight oxygen (P = NS). Activity monitoring revealed low activity levels prior to randomization and no significant increase over time in either group. In this group of severe chronic obstructive pulmonary disease patients, providing lightweight ambulatory oxygen did not increase either oxygen use or activity. Future efforts might focus on strategies to encourage oxygen use and enhance activity in this patient group. This trial is registered at ClinicalTrials.gov (NCT003257540). PMID:22292592

Casaburi, Richard; Porszasz, Janos; Hecht, Ariel; Tiep, Brian; Albert, Richard K; Anthonisen, Nicholas R; Bailey, William C; Connett, John E; Cooper, J Allen; Criner, Gerard J; Curtis, Jeffrey; Dransfield, Mark; Lazarus, Stephen C; Make, Barry; Martinez, Fernando J; McEvoy, Charlene; Niewoehner, Dennis E; Reilly, John J; Scanlon, Paul; Scharf, Steven M; Sciurba, Frank C; Woodruff, Prescott

2012-02-01

232

Short-lived tectonic switch mechanism for long-term pulses of volcanic activity after mega-thrust earthquakes  

NASA Astrophysics Data System (ADS)

Eruptive rates in volcanic arcs increase significantly after subduction mega-thrust earthquakes. Over short to intermediate time periods the link between mega-thrust earthquakes and arc response can be attributed to dynamic triggering processes or static stress changes, but a fundamental mechanism that controls long-term pulses of volcanic activity after mega-thrust earthquakes has not been proposed yet. Using geomechanical, geological, and geophysical arguments, we propose that increased eruption rates over longer timescales are due to the relaxation of the compressional regime that accompanies mega-thrust subduction zone earthquakes. More specifically, the reduction of the horizontal stress ?h promotes the occurrence of short-lived strike-slip kinematics rather than reverse faulting in the volcanic arc. The relaxation of the pre-earthquake compressional regime facilitates magma mobilisation by providing a short-circuit pathway to shallow depths by significantly increasing the hydraulic properties of the system. The timescale for the onset of strike-slip faulting depends on the degree of shear stress accumulated in the arc during inter-seismic periods, which in turn is connected to the degree of strain-partitioning at convergent margins. We performed Coulomb stress transfer analysis to determine the order of magnitude of the stress perturbations in present-day volcanic arcs in response to five recent mega-thrust earthquakes; the 2005 M8.6, 2007 M8.5, and 2007 M7.9 Sumatra earthquakes; the 2010 M8.8 Maule, Chile earthquake; and the 2011 M9.0 Tohoku, Japan earthquake. We find that all but one the shallow earthquakes that occurred in the arcs of Sumatra, Chile and Japan show a marked lateral component. We suggests that the long-term response of volcanic arcs to subduction zone mega-thrust earthquakes will be manifested as predominantly strike-slip seismic events, and that these future earthquakes may be followed closely by indications of rising magma to shallower depths, e.g. surface inflation and seismic swarms.

Lupi, M.; Miller, S. A.

2014-01-01

233

Short-lived tectonic switch mechanism for long-term pulses of volcanic activity after mega-thrust earthquakes  

NASA Astrophysics Data System (ADS)

Eruptive rates in volcanic arcs increase significantly after mega-thrust earthquakes in subduction zones. Over short to intermediate time periods the link between mega-thrust earthquakes and arc response can be attributed to dynamic triggering processes or static stress changes, but a fundamental mechanism that controls long-term pulses of volcanic activity after mega-thrust earthquakes has not been proposed yet. Using geomechanical, geological, and geophysical arguments, we propose that increased eruption rates over longer timescales are due to the relaxation of the compressional regime that accompanies mega-thrust subduction zone earthquakes. More specifically, the reduction of the horizontal stress ?h promotes the occurrence of short-lived strike-slip kinematics rather than reverse faulting in the volcanic arc. The relaxation of the pre-earthquake compressional regime facilitates magma mobilization by providing a short-circuit pathway to shallow depths by significantly increasing the hydraulic properties of the system. The timescale for the onset of strike-slip faulting depends on the degree of shear stress accumulated in the arc during inter-seismic periods, which in turn is connected to the degree of strain-partitioning at convergent margins. We performed Coulomb stress transfer analysis to determine the order of magnitude of the stress perturbations in present-day volcanic arcs in response to five actual mega-thrust earthquakes; the 2005 M8.6, 2007 M8.5, and 2007 M7.9 Sumatra earthquakes; the 2010 M8.8 Maule, Chile earthquake; and the 2011 M9.0 Tohoku, Japan earthquake. We find that all, but one, the shallow earthquakes that occurred in the arcs of Sumatra, Chile and Japan show a marked lateral component. Our hypothesis suggests that the long-term response of volcanic arcs to subduction zone mega-thrust earthquakes will be manifested as predominantly strike-slip seismic events, and that these future earthquakes will be followed closely by seismic swarms, inflation, and other indications of a rising magma source.

Lupi, M.; Miller, S. A.

2013-06-01

234

Long-Term Community Dynamics of Small Landbirds with and Without Exposure to Extensive Disturbance from Military Training Activities  

NASA Astrophysics Data System (ADS)

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.

Rivers, James W.; Gipson, Philip S.; Althoff, Donald P.; Pontius, Jeffrey S.

2010-02-01

235

Modeling the long-term durability of concrete barriers in the context of low-activity waste storage  

NASA Astrophysics Data System (ADS)

The paper investigates the long-term durability of concrete barriers in contact with a cementitious wasteform designed to immobilize low-activity nuclear waste. The high-pH pore solution of the wasteform contains high concentration level of sulfate, nitrate, nitrite and alkalis. The multilayer concrete/wasteform system was modeled using a multiionic reactive transport model accounting for coupling between species, dissolution/ precipitation reactions, and feedback effect. One of the primary objectives was to investigate the risk associated with the presence of sulfate in the wasteform on the durability of concrete. Simulation results showed that formation of expansive phases, such as gypsum and ettringite, into the concrete barrier was not extensive. Based on those results, it was not possible to conclude that concrete would be severely damaged, even after 5,000 years. Lab work was performed to provide data to validate the modeling results. Paste samples were immersed in sulfate contact solutions and analyzed to measure the impact of the aggressive environment on the material. The results obtained so far tend to confirm the numerical simulations.

Protière, Y.; Samson, E.; Henocq, P.

2013-07-01

236

Long-Term Variations in the Occurrence and Effective Solar Transmission of Clouds as Determined from Surface-Based Total Irradiance Observations  

SciTech Connect

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, decadal time scale oscillations in both cloud characteristics are detected, but no particular cloud category is identified as the source of that oscillation.

Dutton, Ellsworth G.; Farhadi, A.; Stone, R. S.; Long, Charles N.; Nelson, D. W.

2004-02-11

237

Long Term Ecological Resources  

NSDL National Science Digital Library

Students analyze data on temperature and precipitation collected from 26 different Long Term Ecological Research sites and compare them with annual net primary productivity. The students then form an ecological rule to explain their results.

Scott Cooper

238

Asenapine alters the activity of monoaminergic systems following its subacute and long-term administration: An in vivo electrophysiological characterization.  

PubMed

Asenapine is a tetracyclic atypical antipsychotic used for treatment of schizophrenia and mania. Previous in vivo electrophysiological studies demonstrated antagonistic action of asenapine at dopamine D2, serotonin (5-HT)2A, and ?2-adrenergic receptors. Here, we assessed monoamine system activities after two-day and 21-day asenapine administration at a dosage (0.1mg/kg/day) resulting in clinically relevant plasma levels. In the ventral tegmental area (VTA), asenapine increased the number of spontaneously active dopamine neurons, while firing parameters remained unchanged. Asenapine partially prevented the D2 autoreceptor-mediated inhibitory response to apomorphine after two days of administration. This effect was lost after 21 days of administration, suggesting adaptive changes leading to D2 receptor sensitization. Asenapine increased the firing activity of noradrenergic neurons in the locus coeruleus (LC) after 21, but not two days of administration. Furthermore, it potently blocked 5-HT2A receptors while ?2-adrenergic receptors were unaffected by this drug regimen. Both acute and long-term asenapine administration partially blocked ?2-adrenergic receptors in the CA3 region of the hippocampus, and noradrenergic tone on ?1- and ?2-adrenoceptors remained unchanged. In the dorsal raphe nucleus, asenapine increased the firing rate of 5-HT neurons after two, but not 21 days of administration. In addition, responsiveness of 5-HT1A autoreceptors was unaltered by asenapine. In the hippocampus, 21-day asenapine administration increased serotonergic tone by partial agonistic action on postsynaptic 5-HT1A and terminal 5-HT1B receptors. Taken together, asenapine had profound effects on both catecholamine systems, potently blocked 5-HT2A receptors, and enhanced 5-HT tone, effects that could be important in treatment of mood disorders and schizophrenia. PMID:25656272

Oosterhof, Chris A; El Mansari, Mostafa; Blier, Pierre

2015-04-01

239

Long-term accelerating foreshock activity may indicate the occurrence time of a strong shock in the Western Hellenic Arc  

NASA Astrophysics Data System (ADS)

In the decades prior to the occurrence of the 1899 ( Ms = 6.6) and 1947 ( Ms = 7.0) main shocks in the Western Hellenic Arc (WHA) the rate of occurrence of foreshocks ( Ms ? 5.2) within a radius of 100 km around the epicenters can generally be said to have accelerated. After a long period of very low foreshock activity (stage I), the process culminates in a final rapid acceleration of foreshocks some months before the main shocks (stage II), while the last two months are quiescent (stage III). These three stages are in good correspondence with the three stages of crustal deformation and several precursors to the main shock as predicted by the dilatancy model. The data fit very well power law equations similar to those found for short-term foreshocks of ordinary earthquakes and those associated with the creation of artificial lakes. The position of the rupture zones of past WHA strong shocks implies that the eastern part of the segment is the most probable location for the next strong shock in the arc. A process of accelerating seismic activity, similar to that which preceded the 1899 and 1947 shocks, has been under way since 1966 around this part of the segment. A comparison between changes in the power law curves for the earlier earthquakes and the one now expected, indicates that the latter is now 3-8 months "overdue". Assuming that the long-term accelerating foreshock activity is a seismotectonic peculiarity of the WHA segment, I suggest that the preparation of the next rupture in the WHA has entered a highly mature stage, and that there will very probably be an earthquake in this area within the next few months.

Papadopoulos, Gerassimos A.

1988-09-01

240

Long term potentiation is impaired in membrane glycoprotein CD200-deficient mice: a role for Toll-like receptor activation.  

PubMed

The membrane glycoprotein CD200 is expressed on several cell types, including neurons, whereas expression of its receptor, CD200R, is restricted principally to cells of the myeloid lineage, including microglia. The interaction between CD200 and CD200R maintains microglia and macrophages in a quiescent state; therefore, CD200-deficient mice express an inflammatory phenotype exhibiting increased macrophage or microglial activation in models of arthritis, encephalitis, and uveoretinitis. Here, we report that lipopolysaccharide (LPS) and Pam(3)CysSerLys(4) exerted more profound effects on release of the proinflammatory cytokines, interleukin (IL)-1?, IL-6, and tumor necrosis factor-? (TNF?), in glia prepared from CD200(-/-) mice compared with wild type mice. This effect is explained by the loss of CD200 on astrocytes, which modulates microglial activation. Expression of Toll-like receptors 4 and 2 (TLR4 and -2) was increased in glia prepared from CD200(-/-) mice, and the evidence indicates that microglial activation, assessed by the increased numbers of CD11b(+) cells that stained positively for both MHCII and CD40, was enhanced in CD200(-/-) mice compared with wild type mice. These neuroinflammatory changes were associated with impaired long term potentiation (LTP) in CA1 of hippocampal slices prepared from CD200(-/-) mice. One possible explanation for this is the increase in TNF? in hippocampal tissue prepared from CD200(-/-) mice because TNF? application inhibited LTP in CA1. Significantly, LPS and Pam(3)CysSerLys(4), at concentrations that did not affect LTP in wild type mice, inhibited LTP in slices prepared from CD200(-/-) mice, probably due to the accompanying increase in TLR2 and TLR4. Thus, the neuroinflammatory changes that result from CD200 deficiency have a negative impact on synaptic plasticity. PMID:21835925

Costello, Derek A; Lyons, Anthony; Denieffe, Stephanie; Browne, Tara C; Cox, F Fionnuala; Lynch, Marina A

2011-10-01

241

Carotid chemoafferent activity is not necessary for all phrenic long-term facilitation following acute intermittent hypoxia  

PubMed Central

Phrenic long-term facilitation (pLTF) is a form of respiratory plasticity induced by acute intermittent hypoxia (AIH) or episodic carotid chemoafferent neuron activation. Surprisingly, residual pLTF is expressed in carotid denervated rats. However, since carotid denervation eliminates baroreceptor feedback and causes profound hypotension during hypoxia in anesthetized rats, potential contributions of these uncontrolled factors or residual chemoafferent neuron activity to residual pLTF cannot be ruled out. Since ATP is necessary for hypoxic carotid chemotransduction, we tested the hypothesis that functional peripheral chemoreceptor denervation (with intact baroreceptors) via systemic P2X receptor antagonism blocks hypoxic phrenic responses and AIH-induced pLTF in anesthetized rats. Pyridoxal-phosphate-6-azophenyl-2?,4?-disulfonic acid (PPADS; 100 mg/kg i.v.), a non-selective P2X receptor antagonist, was administered to anesthetized, vagotomized, paralyzed and ventilated male Sprague–Dawley rats prior to AIH (3, 5 min episodes of 10% O2; 5 min intervals). Although PPADS strongly attenuated the short-term hypoxic phrenic response (20±4% vs. 113±15% baseline; P < 0.001), pLTF was reduced but not eliminated 60 min post-AIH (25±4% vs. 51±11% baseline; n = 8 and 7, respectively; P < 0.002). Thus, AIH initiates residual pLTF out of proportion to the diminished hypoxic phrenic response and chemoafferent neuron activation. Although the mechanism of residual pLTF following functional chemo-denervation remains unclear, possible mechanisms involving direct effects of hypoxia on the CNS are discussed. PMID:21093615

Sibigtroth, C.M.; Mitchell, G.S.

2015-01-01

242

Activation instead of blocking mesolimbic dopaminergic reward circuitry is a preferred modality in the long term treatment of reward deficiency syndrome (RDS): a commentary  

Microsoft Academic Search

BACKGROUND AND HYPOTHESIS: Based on neurochemical and genetic evidence, we suggest that both prevention and treatment of multiple addictions, such as dependence to alcohol, nicotine and glucose, should involve a biphasic approach. Thus, acute treatment should consist of preferential blocking of postsynaptic Nucleus Accumbens (NAc) dopamine receptors (D1-D5), whereas long term activation of the mesolimbic dopaminergic system should involve activation

Kenneth Blum; Amanda Chen; Thomas JH Chen; Eric R Braverman; Jeffrey Reinking; Seth H Blum; Kimberly Cassel; Bernard W Downs; Roger L Waite; Lonna Williams; Thomas J Prihoda; Mallory M Kerner; Tomas Palomo; David E Comings; Howard Tung; Patrick Rhoades; Marlene Oscar-Berman

2008-01-01

243

Effects of resistance and functional-skills training on habitual activity and constipation among older adults living in long-term care facilities: a randomized controlled trial  

Microsoft Academic Search

BACKGROUND: Large-scale RCTs comparing different types of exercise training in institutionalised older people are scarce, especially regarding effects on habitual physical activity and constipation. This study investigated the effects of different training protocols on habitual physical activity and constipation of older adults living in long-term care facilities. METHODS: A randomized controlled trial with 157 participants, aged 64 to 94 years,

Marijke JM Chin A Paw; Mireille NM van Poppel; Willem van Mechelen

2006-01-01

244

A comparison of the short and long term effects of insecticidal lectins on the activities of soluble and brush border enzymes of tomato moth larvae ( Lacanobia oleracea)  

Microsoft Academic Search

When fed in semi-artificial diet in short- and long-term bioassays, the lectins from snowdrop (Galanthus nivalis; GNA) and jackbean (Canavalia ensiformis; Con A) affected the activities of soluble and brush border membrane (BBM) enzymes in the midgut of Lacanobia oleracea larvae. In the short term both lectins increased gut protein levels and BBM aminopeptidase activity. The lectins also increased trypsin

Elaine Fitches; John A Gatehouse

1998-01-01

245

Silver Nanoparticles Modified by Gelatin with Extraordinary pH Stability and Long-Term Antibacterial Activity  

PubMed Central

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

Sivera, Martin; Kvitek, Libor; Soukupova, Jana; Panacek, Ales; Prucek, Robert; Vecerova, Renata; Zboril, Radek

2014-01-01

246

Biochemical responses and mitochondrial mediated activation of apoptosis on long-term effect of aspartame in rat brain.  

PubMed

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. PMID:25009784

Ashok, Iyaswamy; Sheeladevi, Rathinasamy

2014-01-01

247

Dayside magnetic ULF power at high latitudes: A possible long-term proxy for the solar wind velocity?  

Microsoft Academic Search

We examine the occurrence of dayside high-latitude magnetic variations with periods between 2 and 10 min statistically using data from around 20 magnetic stations in Greenland, Scandinavia, and Canada, many of which have been in operation for a full solar cycle. We derive time series of the power spectral density (psd) in two different frequency bands: 2-4 min period and

Susanne Vennerstrøm

1999-01-01

248

A long-term change of the AR/KR/XE fractionation in the solar corpuscular radiation  

NASA Technical Reports Server (NTRS)

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.

Wieler, R.; Baur, H.; Signer, P.

1993-01-01

249

Different Phases of Long-Term Memory Require Distinct Temporal Patterns of PKA Activity after Single-Trial Classical Conditioning  

ERIC Educational Resources Information Center

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…

Michel, Maximilian; Kemenes, Ildiko; Muller, Uli; Kemenes, Gyorgy

2008-01-01

250

Long-term magnetic activity of a sample of M-dwarf stars from the HARPS program . II. Activity and radial velocity  

NASA Astrophysics Data System (ADS)

Owing to their low mass and luminosity, M dwarfs are ideal targets if one hopes to find low-mass planets similar to Earth using the radial velocity (RV) method. However, stellar magnetic cycles could add noise or even mimic the RV signal of a long-period companion. We extend our previous study of the correlation between activity cycles and long-term RV variations for K dwarfs to the lower-end of the main sequence. Our objective is to detect any correlations between long-term activity variations and the observed RV of a sample of M dwarfs. We use a sample of 27 M-dwarfs with a median observational timespan of 5.9 years. The cross-correlation function (CCF) with its parameters RV, bisector inverse slope (BIS), full width at half maximum (FWHM), and contrast are computed from the HARPS spectrum. The activity index is derived using the Na i D doublet. These parameters are compared with the activity level of the stars to search for correlations. We detect RV variations up to ~5 m s-1 that we can attribute to activity cycle effects. However, only 36% of the stars with long-term activity variability appear to have had their RV affected by magnetic cycles, on the typical timescale of ~6 years. Therefore, we suggest a careful analysis of activity data when searching for extrasolar planets using long-timespan RV data. Based on observations made with the HARPS instrument on the ESO 3.6-m telescope at La Silla Observatory under programme ID 072.C-0488(E).Tables with the data used for Figs. A.1-A.27 are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/541/A9Appendix A is available in electronic form at http://www.aanda.org

Gomes da Silva, J.; Santos, N. C.; Bonfils, X.; Delfosse, X.; Forveille, T.; Udry, S.; Dumusque, X.; Lovis, C.

2012-05-01

251

Short-term activation of liver X receptors inhibits osteoblasts but long-term activation does not have an impact on murine bone in vivo.  

PubMed

Liver X receptors (LXRs) are nuclear receptors that play a crucial role in the transcriptional control of lipid metabolism. Pharmacological LXR activation is an attractive concept for the treatment of atherosclerosis. Genetic LXR deficiency in mice has been shown to have an effect on bone turnover and structure and LXR activation is known to influence the osteogenic differentiation of bone marrow stromal cells. Therefore, therapeutic pharmacological LXR activation may have relevant effects on bone. Here, using two synthetic LXR ligands, T0901317 and GW3965, we investigated the effect of LXR activation on murine osteoblasts and the influence of long-term LXR activation on bone in vivo in mice. Short term (48 h) in vitro treatment of primary murine osteoblasts with T0901317 resulted in a dose-dependent decrease of osteocalcin and alkaline phosphatase mRNA and protein. In vivo, a 6-day treatment of C57BL/6J mice with T0901317 led to a 40% reduction of serum osteocalcin concentrations. Long-term (12-week) oral administration of T0901317 or GW3965 influenced the expression of established LXR target genes in liver and intestine, but did not alter trabecular and cortical bone structure or bone turnover as determined by total skeleton radiography, histomorphometric analysis of lumbar vertebral trabecular bone, micro CT analysis of femur cortical bone and biochemical determination of bone formation and resorption markers. We conclude that short-term pharmacological LXR activation has the potential to profoundly influence osteoblast function, but that long-term LXR activation in vivo has no adverse effects on the murine skeleton. PMID:20817130

Prawitt, Janne; Beil, F Timo; Marshall, Robert P; Bartelt, Alexander; Ruether, Wolfgang; Heeren, Joerg; Amling, Michael; Staels, Bart; Niemeier, Andreas

2011-02-01

252

Effects of long-term elevated CO2, warming, and prolonged drought on Pleurozium-associated diazotrophic activity and abundance  

NASA Astrophysics Data System (ADS)

Nitrogen (N2) fixation is the primary natural influx of N to terrestrial ecosystems, and changes in N2 fixation may have consequences for primary productivity and thus ecosystem function. We studied the activity and abundance of diazotrophs associated with the feather moss Pleurozium schreberi in a temperate heathland, after seven years of global change manipulations, including elevated atmospheric CO2 (510 ppm), increased temperature (0.5-1.5 ° C), and prolonged pre-summer droughts (4-6 weeks /year). Acetylene reduction assay was carried out monthly to monitor N2 fixation rates throughout one year, while nif H copy abundance, serving as a diazotroph abundance estimate, was measured by quantitative polymerase chain reaction (q-PCR). Prolonged summer droughts significantly increased both N2 fixation and nif H copy abundance, contrasting previous studies that demonstrate a direct negative correlation between N2 fixation and water availability. A shift in the relative abundance of N2-fixing bacteria from the green, upper parts of the moss stem to the lower, brown parts was observed. This shift could make diazotrophs less sensitive to desiccation, enabling N2 fixation to be upheld for longer during drought and thus causing higher abundance. Increased temperature likewise had a positive effect on the diazotroph abundance, although this did not translate into increased activity. Possibly, warming protects diazotrophs during extreme cold events, while actual N2 fixation is limited by water, disregarding a rise in potential N2 fixation caused by higher abundance. Increased CO2 caused no significant diazotroph response. Our study showed that long-term increase in temperature and recurrent drought events cause higher diazotroph abundance in Pleurozium schreberi and thus enhance the potential N2 fixations rate. Furthermore, our results indicate that diazotrophs may alter colonization patterns and thereby actively remain in the moss fraction less likely affected by desiccation. In consequence, Pleurozium-associated N2 fixation may become an even more important contributor of N for terrestrial ecosystems in a predicted future climate.

Dyrnum, Kristine; Priemé, Anders; Michelsen, Anders

2014-05-01

253

Long-term soil microbial community and enzyme activity responses to an integrated cropping-livestock system in a semi-arid region  

Technology Transfer Automated Retrieval System (TEKTRAN)

This study is part of a larger long-term project to develop and evaluate integrated crop and livestock systems in order to reduce dependence on underground water sources by optimizing cotton (Gossypium hirsutum) production in the Texas High Plains of U.S. Microbial communities and activities were e...

254

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

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…

Robroek, Suzan J. W.; Polinder, Suzanne; Bredt, Folef J.; Burdorf, Alex

2012-01-01

255

Modeling Cu Migration in CdTe Solar Cells Under Device-Processing and Long-Term Stability Conditions (Poster)  

SciTech Connect

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.

Teeter, G.; Asher, S.

2008-05-01

256

Modeling Cu Migration in CdTe Solar Cells Under Device-Processing and Long-Term Stability Conditions: Preprint  

SciTech Connect

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.

Teeter, G.; Asher, S.

2008-05-01

257

A long-term study of new particle formation in a coastal environment: Meteorology, gas phase and solar radiation implications.  

PubMed

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±4.2h. 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±1.7cm(-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±2.4nmh(-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

Sorribas, M; Adame, J A; Olmo, F J; Vilaplana, J M; Gil-Ojeda, M; Alados-Arboledas, L

2015-04-01

258

Long-term testing  

NASA Astrophysics Data System (ADS)

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

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

259

Active layer thickness and thaw subsidence in permafrost terrain: results from long-term observations near Barrow, Alaska  

NASA Astrophysics Data System (ADS)

Patterns of active-layer thickness (ALT) on the North Slope of Alaska are highly variable, both spatially and temporally. Although geographic patterns of ALT repeat themselves from year to year, ALT is an integrated response to a large number of parameters. Thaw penetration into an ice-rich layer at the base of the active layer is accompanied by loss of volume (thaw consolidation) and results in subsidence at the ground surface. Differential thaw settlement occurs annually in permafrost environments as the layer of annual thaw (the active layer) develops. Significant ice segregation can occur at the bottom of the active layer during "cold" periods, due predominantly to freezing from below in the autumn and winter. This study examines trends in seasonal thawing of soils and vertical movements of the ground surface associated with formation and ablation of ice near the permafrost table in the Barrow region. The core thaw depth data set consists of ALT measurements conducted under the Circumpolar Active Layer Monitoring (CALM) program. The Barrow CALM site, represented by a regular 1 km2 grid, was established in the early 1990s. The reported ALT observations were initiated in 1992 and are measured annually in late August. Additional ALT measurements are available from a series of 10 x 10 meter plots established in 1962 as part of the Cold Regions Research and Engineering Laboratory (CRREL) research program at Barrow. Annual observations were made between 1962 and 1970. Measurements were reestablished in 1991 under the CALM program, following the original methodology. Field investigations to track interannual vertical movements associated with formation and ablation of ice near the permafrost table were initiated in 2003. Measurements continue annually at several CRREL plots representative of different elements of the tundra landscape. Observations were made at the end of the thawing season using Differential Global Positioning Systems (DGPS) technology. Results from data analysis indicate that long-term changes in ALT are accompanied by pronounced interannual variability. No significant trends are observed in the active-layer record over the last 20 years. The values from the 1960s are generally higher than in the 1990s and are very similar to those of the 2000s. Following below-average thaw in 1991-1993, there was a general increase in ALT, followed by stabilization in the thawing regime during 1999-2011. The sampled areas showed net subsidence of the ground surface over the period of observation (2003-2011), reducing average surface elevation by 0.13 m. To evaluate the integrated thermal response of this permafrost landscape to climatic forcing, site-average annual thaw depth values were correlated with the square root of DDT, estimated from site-specific air temperature records and accumulated by the date of thaw depth and surface elevation measurements. The linear best-fit regression equation was used, in conjunction with the DDT record, to estimate the vertical position of the ground surface years prior to 2003, when DGPS surveys were initiated. Results indicate that over the 18 year period the elevation of the permafrost table has decreased by 0.33 m. Only 36% (0.12 m) of this change is attributable to increased active-layer thickness, while 64% (0.21m) is attributable to subsidence of the ground surface.

Shiklomanov, N. I.; Streletskiy, D. A.; Nelson, F. E.

2012-12-01

260

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)

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.

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

261

Solar and wind energy resources in Northern Hungary, including bi-variate distribution and long-term tendencies  

NASA Astrophysics Data System (ADS)

Spatial interpolation and mapping of renewable energy resources is an important task of potential estimation in case of atmospheric renewable energy sources. Its first steps, concerning global radiation measured at horizontal surfaces (not on optimally tilted ones) and near-surface wind speed measured at 10 m height above the surface (not at 60-120 m of contemporary wind-turbines). Based on these standard meteorological observations, experts of the Hungarian Meteorological Service elaborated a series of digital maps with 0.1 x 0.1 deg resolution compiled in the framework of the CarpatClim Project (www.carpatclim-eu.org). The grid-point values are based on homogenised data using MASH theory and software (SZENTIMREY, 1999). The interpolation has been performed by the MISH theory and software (SZENTIMREY and BIHARI, 2006). The study tackles the solar and wind energy in four aspects. Firstly, a trial for validation of the gridded data is provided by comparison a single station, Eger for 2001-2010 (global radiation) and 1996-2010 (wind speed cube). The horizontal distance between the closest grid-point and the station is less than 1 km. Gridded global radiation data perform very well comparing to the observations, based on various statistical parameters of the distribution, whereas for the wind speed cube, used as indicator of available energy, there is a considerable bias between the two sets of data. Secondly, the annual cycles of the area-mean global radiation and wind-speed are presented, based on the gridded data of a selected ca. 50x50 km2 (6x8 grid-points) region. Both the averages and standard deviations of the diurnal mean values are presented for the 1981-2010 reference period. Presenting the maps of the distribution within this area is our third aspect, considering both averages and standard deviations. Finally the point-wise trends are drown for both energy sources in the single grid-point used in the aspect one in 1981-2010, and also in the nearby located station for comparison. The trend of solar energy is positive, whereas the trend for wind energy (speed cube) is negative in the given 30 year period. Since these three decades exhibited mainly warming in the Northern Hemisphere, these trends might also be interpreted as responses to the large-scale forcing, though the observed behaviour does not necessarily mean causal relationship with the global tendencies. After these univariate analyses, correlation The study has been supported by the TÁMOP-4.2.2.A-11/1/KONV-2012-0016 Project in Hungary. Keywords: global radiation, wind energy, statistics, mapping, common distribution, climate change

Mika, Janos; Dobi-Wantuch, Ildiko; Tóth-Tarjányi Zsuzsanna, Zsuzsanna; Molnar, Zsofia; Kitti Csabai, Edina; Razsi, Andras

2014-05-01

262

Long term effect of curcumin in regulation of glycolytic pathway and angiogenesis via modulation of stress activated genes in prevention of cancer.  

PubMed

Oxidative stress, an important factor in modulation of glycolytic pathway and induction of stress activated genes, is further augmented due to reduced antioxidant defense system, which promotes cancer progression via inducing angiogenesis. Curcumin, a naturally occurring chemopreventive phytochemical, is reported to inhibit carcinogenesis in various experimental animal models. However, the underlying mechanism involved in anticarcinogenic action of curcumin due to its long term effect is still to be reported because of its rapid metabolism, although metabolites are accumulated in tissues and remain for a longer time. Therefore, the long term effect of curcumin needs thorough investigation. The present study aimed to analyze the anticarcinogenic action of curcumin in liver, even after withdrawal of treatment in Dalton's lymphoma bearing mice. Oxidative stress observed during lymphoma progression reduced antioxidant enzyme activities, and induced angiogenesis as well as activation of early stress activated genes and glycolytic pathway. Curcumin treatment resulted in activation of antioxidant enzyme super oxide dismutase and down regulation of ROS level as well as activity of ROS producing enzyme NADPH:oxidase, expression of stress activated genes HIF-1?, cMyc and LDH activity towards normal level. Further, it lead to significant inhibition of angiogenesis, observed via MMPs activity, PKC? and VEGF level, as well as by matrigel plug assay. Thus findings of this study conclude that the long term effect of curcumin shows anticarcinogenic potential via induction of antioxidant defense system and inhibition of angiogenesis via down regulation of stress activated genes and glycolytic pathway in liver of lymphoma bearing mice. PMID:24932681

Das, Laxmidhar; Vinayak, Manjula

2014-01-01

263

Lipid Profile Disorders Induced by Long-Term Cessation of Physical Activity in Previously Highly Endurance Trained Subjects  

Microsoft Academic Search

The objective of this study was to describe long-term detrain- ing effects on lipid profile in previously highly endurance- trained athletes. The study design was longitudinal, with a 2-yr follow-up study of changes in lipid profile during hard training and detraining. Ten subjects trained for 2 yr (22 h\\/wk; two 47-wk training periods with a 5-wk recovery period), and the

CYRIL PETIBOIS; HENRI GIN; GERARD DELERIS

264

The influence of weather conditions on the activity of high-arctic arthropods inferred from long-term observations  

PubMed Central

Background Climate change is particularly pronounced in the High Arctic and a better understanding of the repercussions on ecological processes like herbivory, predation and pollination is needed. Arthropods play an important role in the high-arctic ecosystem and this role is determined by their density and activity. However, density and activity may be sensitive to separate components of climate. Earlier emergence due to advanced timing of snowmelt following climate change may expose adult arthropods to unchanged temperatures but higher levels of radiation. The capture rate of arthropods in passive open traps like pitfall trap integrates density and activity and, therefore, serves as a proxy of the magnitude of such arthropod-related ecological processes. We used arthropod pitfall trapping data and weather data from 10 seasons in high-arctic Greenland to identify climatic effects on the activity pattern of nine arthropod taxa. Results We were able to statistically separate the variation in capture rates into a non-linear component of capture date (density) and a linear component of weather (activity). The non-linear proxy of density always accounted for more of the variation than the linear component of weather. After accounting for the seasonal phenological development, the most important weather variable influencing the capture rate of flying arthropods was temperature, while surface-dwelling species were principally influenced by solar radiation. Conclusion Consistent with previous findings, air temperature best explained variation in the activity level of flying insects. An advancement of the phenology in this group due to earlier snowmelt will make individuals appear earlier in the season, but parallel temperature increases could mean that individuals are exposed to similar temperatures. Hence, the effect of climatic changes on the activity pattern in this group may be unchanged. In contrast, we found that solar radiation is a better proxy of activity levels than air temperature in surface-dwelling arthropods. An advancement of the phenology may expose surface-dwelling arthropods to higher levels of solar radiation, which suggest that their locomotory performance is enhanced and their contribution to ecological processes is increased. PMID:18454856

Høye, Toke T; Forchhammer, Mads C

2008-01-01

265

X-RAY, FUV, AND UV OBSERVATIONS OF {alpha} CENTAURI B: DETERMINATION OF LONG-TERM MAGNETIC ACTIVITY CYCLE AND ROTATION PERIOD  

SciTech Connect

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 cycle of P{sub cycle} = 8.84 {+-} 0.4 years. In addition, analysis of the short-term rotational modulation of mean light due to the effects of magnetically active regions has yielded a well-determined rotation period of P{sub rotation} = 36.2 {+-} 1.4 days. {alpha} Cen B is the only old main-sequence K star with a reliably determined age and rotation period, and for early K stars, as in the case of the Sun for G2 V stars, is an important calibrator for stellar age/rotation/activity relations.

DeWarf, L. E.; Guinan, E. F.; Datin, K. M., E-mail: Laurence.DeWarf@Villanova.ed [Department of Astronomy and Astrophysics, Villanova University, 800 Lancaster Avenue, Villanova, PA 19085 (United States)

2010-10-10

266

Long-term efficacy and safety of once-daily mesalazine granules for the treatment of active ulcerative colitis  

PubMed Central

In 1977, 5-aminosalicylic acid (5-ASA) was discovered as a therapeutically active moiety of sulfasalazine (SASP) and was launched for topical and oral therapy of ulcerative colitis (UC) in 1984. As a first-step, delivery systems had to be developed to protect 5-ASA against absorption in the upper gastrointestinal tract, resulting in different and competing strategies (azo compounds, controlled release, and pH-dependent release). In a second step, at the beginning of the new century, coinciding with the expiration of patent protection for the first 5-ASA formulations, two component composite release mechanisms (pH-dependent and controlled release) were developed. Furthermore, the drug was formulated as granules instead of tablets, allowing higher unit strengths compared with tablets. Neither Salofalk Granu-Stix®, nor MMX 5-ASA, nor Pentasa® granules have initially been developed for once-daily (OD) dosing. A review of the achievements of 20 years of 5-ASA development has demonstrated that 5-ASA has equal efficacy compared with SASP at best, that there are no measurable differences in efficacy between various 5-ASA preparations, and that in a group of patients tolerating SASP, adverse event profiles of SASP and 5-ASA did not differ significantly, with SASP being the far cheaper substance. Therefore, drug adherence came into focus as a new goal for improving UC therapy. Although adherence is a complex and multifactorial construct, a simple dosing schedule may contribute to higher drug adherence and better efficacy of treatment. Simultaneously, the US 5-ASA market, estimated to be worth US$1.4 billion, is expected to grow continuously. Naturally, this very competitive market is not only driven by scientific progress but also by commercial interests. Thus, patents for minor changes to the formulation may serve as protection against drug companies trying to launch generic versions. Randomized controlled trials performed on OD dosing in induction of remission have 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

Böhm, Stephan Karl; Kruis, Wolfgang

2014-01-01

267

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

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

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

268

Synaptic long-term potentiation and depression in the rat medial vestibular nuclei depend on neural activation of estrogenic and androgenic signals.  

PubMed

Estrogenic and androgenic steroids can be synthesised in the brain and rapidly modulate synaptic transmission and plasticity through direct interaction with membrane receptors for estrogens (ERs) and androgens (ARs). We used whole cell patch clamp recordings in brainstem slices of male rats to explore the influence of ER and AR activation and local synthesis of 17?-estradiol (E2) and 5?-dihydrotestosterone (DHT) on the long-term synaptic changes induced in the neurons of the medial vestibular nucleus (MVN). Long-term depression (LTD) and long-term potentiation (LTP) caused by different patterns of high frequency stimulation (HFS) of the primary vestibular afferents were assayed under the blockade of ARs and ERs or in the presence of inhibitors for enzymes synthesizing DHT (5?-reductase) and E2 (P450-aromatase) from testosterone (T). We found that LTD is mediated by interaction of locally produced androgens with ARs and LTP by interaction of locally synthesized E2 with ERs. In fact, the AR block with flutamide prevented LTD while did not affect LTP, and the blockade of ERs with ICI 182,780 abolished LTP without influencing LTD. Moreover, the block of P450-aromatase with letrozole not only prevented the LTP induction, but inverted LTP into LTD. This LTD is likely due to the local activation of androgens, since it was abolished under blockade of ARs. Conversely, LTD was still induced in the presence of finasteride the inhibitor of 5?-reductase demonstrating that T is able to activate ARs and induce LTD even when DHT is not synthesized. This study demonstrates a key and opposite role of sex neurosteroids in the long-term synaptic changes of the MVN with a specific role of T-DHT for LTD and of E2 for LTP. Moreover, it suggests that different stimulation patterns can lead to LTD or LTP by specifically activating the enzymes involved in the synthesis of androgenic or estrogenic neurosteroids. PMID:24265837

Scarduzio, Mariangela; Panichi, Roberto; Pettorossi, Vito Enrico; Grassi, Silvarosa

2013-01-01

269

Memantine restores long term potentiation impaired by tonic N-methyl- d-aspartate (NMDA) receptor activation following reduction of Mg 2+ In hippocampal slices  

Microsoft Academic Search

This study compared the ability of memantine and (+)MK-801 to counteract deficits in the induction of long term potentiation (LTP) following reduction of Mg2+ in hippocampal slices—a model of increased synaptic noise due to tonic N-methyl-d-aspartate (NMDA) receptor activation. Decreasing Mg2+ from 1 mM to 10 ?M for 60 min enhanced baseline field excitatory post-synaptic potential (fEPSP) slopes (87.2±10.6% above

Tadeusz Frankiewicz; Chris G. Parsons

1999-01-01

270

Effects of long-term waste water irrigation on soil organic matter, soil microbial biomass and its activities in central Mexico  

Microsoft Academic Search

The effect of long-term waste water irrigation (up to 80?years) on soil organic matter, soil microbial biomass and its activities\\u000a was studied in two agricultural soils (Vertisols and Leptosols) irrigated for 25, 65 and 80?years respectively at Irrigation\\u000a District 03 in the Valley of Mezquital near Mexico City. In the Vertisols, where larger amounts of water have been applied\\u000a than

J. K. Friedel; T. Langer; C. Siebe; K. Stahr

2000-01-01

271

Long-term application of compost influences microbial biomass and enzyme activities in a tropical Aeric Endoaquept planted to rice under flooded condition  

Microsoft Academic Search

In a field study, long-term application of compost to a tropical Aeric Endoaquept under continuous rice growing in a rice–rice–fallow sequence resulted in the stimulation of microbial biomass and select soil enzyme activities. Mean seasonal soil microbial biomass-C (Cmic) increased by 42%, 39% and 89% in inorganic fertilizer, compost and compost+inorganic fertilizer treatments, respectively, over the unamended control. Cmic content

Dali R. Nayak; Y. Jagadeesh Babu; T. K. Adhya

2007-01-01

272

Role of colony-stimulating activity in murine long-term bone marrow cultures: evidence for its production and consumption by the adherent cells  

Microsoft Academic Search

The involvement of colony-stimulating activity (CSA) in murine long-term bone marrow cultures (LTBMC) was studied using bilayer agar cultures. The supernatants of LTBMC were removed. a layer of dense agar was spread over the cells adherent to the bottom of the flask. and fresh myeloid cells were plated as source of CFU-C in an upper agar layer. Large numbers of

Jean-MiChel Heard; Serge Fichelson; Bruno Varet

1982-01-01

273

Differential roles of Ca(2+)/calmodulin-dependent protein kinase II and mitogen-activated protein kinase activation in hippocampal long-term potentiation.  

PubMed

The roles of Ca(2+)/calmodulin-dependent protein kinase II (CaM kinase II) and mitogen-activated protein kinase (MAPK) in long-term potentiation (LTP) were investigated in the CA1 area of hippocampal slices, using electrophysiological and biochemical approaches. A brief high-frequency stimulation, but not low-frequency stimulation, delivered to Schaffer collateral/commissural afferents produced a stable LTP and activated both CaM kinase II and 42 kDa MAPK. Different from the activity of CaM kinase II, the increase in MAPK activity was transient. At a concentration of 50 microM, but not of 30 microM, PD098059, a potent inhibitor of MAPK kinase, markedly inhibited the induction of LTP. Although the two concentrations had similar inhibitory effects on MAPK activity, only 50 microM PD098059 suppressed the activation of CaM kinase II. Application of calmidazolium, an antagonist of calmodulin, blocked both CaM kinase II activation and the LTP induction without affecting the increase in 42 kDa MAPK activity. Application of neurotrophin brain-derived neurotrophic factor (BDNF) promoted the induction of LTP, with concomitant activation of CaM kinase II. Under the same conditions, BDNF failed to activate MAPK in hippocampal slices. These results indicate that, although the LTP induction is accompanied by increases in two kinase activities, only CaM kinase II activation is required for this event. PMID:10493730

Liu, J; Fukunaga, K; Yamamoto, H; Nishi, K; Miyamoto, E

1999-10-01

274

Long-term regulation of serotonergic activity in the rat brain via activation of protein kinase A.  

PubMed Central

Serotonergic neurons located at the base of the mammalian brain innervate practically every region of the brain and the spinal cord. These neurons exhibit spontaneous electrical discharges in a rhythmical way. Their firing frequency is modulated by serotonin autoreceptors which also regulate intracellular cAMP levels. We have investigated how elevated levels of cAMP alter the development and the functional properties of serotonergic neurons in culture. To study the influence of cAMP on the expression of genes underlying serotonergic activity, a quantitative RT-PCR approach using internal standards was developed. Cultures of embryonic rat brain serotonergic neurons were continuously treated with cAMP analogues. Increased cAMP levels had three effects. First, the neuronal morphology was changed towards that typical for mature serotonergic neurons. Second, the expression of tryptophan hydroxylase, the rate-limiting enzyme in serotonin production, was increased in dibutyryl-cAMP treated cultures. Third, the expression of the inhibitory autoreceptor (5-HT1A) was down-regulated. These results suggest the existence of a mechanism by which the neurons react to synaptic input regulating intracellular cAMP levels. Increased cAMP concentrations affect the development and cause a prolonged activation of serotonergic transmission. Since 5-HT1A receptors inhibit cAMP formation, their down-regulation argues against a negative feedback control in this system, consistent with observations in vivo. Images PMID:8384555

Foguet, M; Hartikka, J A; Schmuck, K; Lübbert, H

1993-01-01

275

[Stapedectomy: long term results].  

PubMed

Stapedectomy, with its most innovatory variations, constitutes the treatment of choice for otoesclerosis. Short term results are spectacular, getting GAP closures of less than 5 dB approximatelly in 94% patients, variations depending on the authors. Long term follow up check results show a gradual auditory deterioration. The aim of this study is to audiometric evolution of patients operated of stapedectomy 7 to 10 years ago in our department and to correlate the results with those obtained by other authors, in an attempt to unify conclusions. PMID:12185900

Hernández Montero, E; Fraile Rodrigo, J; Marín Garrido, C; Sampériz, L Carmen; Llorente Arenas, E; Naya Gálvez, M J; Ortiz García, A

2002-04-01

276

Long-term conditions.  

PubMed

Technology enabled care services (TECS), which include technologies such as telehealth, telecare, telemedicine and self-care apps, are designed to help people manage long-term conditions and retain as much independence as possible. The NHS Commissioning Assembly has published TECS Resource for Commissioners, a toolkit that raises awareness of the range of TECS available and their benefits to patients and professionals, supports commissioners to collaborate with providers to implement TECS, and advises how to create a TECS strategy, oversee implementation plans and ensure effective evaluation. The publication is at tinyurl.com/khsebyr. PMID:25806457

2015-03-25

277

Investigation of ionic conductivity and long-term stability of a LiI and KI coupled diphenylamine quasi-solid-state dye-sensitized solar cell.  

PubMed

In this work, enhancement of ionic conductivity and long-term stability through the addition of diphenylamine (DPA) in poly(ethylene oxide) (PEO) is demonstrated. Potassium iodide (KI) is adopted as the crystal growth inhibitor, and DPA is used as a charge transport enhancer in the electrolyte. The modified electrolyte is used with titanium dioxide (TiO2) nanoparticles, which is systematically tuned to obtain high surface area. The dye-sensitized solar cell (DSSC) showed a photocurrent of 14 mAcm2 with a total conversion efficiency of 5.8% under one sun irradiation. DPA enhances the interaction of the TiO2 nanoparticle film and the I-/I3- electrolyte leading to high ionic conductivity (3.5 × 10-3 Scm-1), without compromising on the electrochemical and mechanical stability. Electrochemical impedance spectroscopy (EIS) studies show that electron transport and electron lifetime are enhanced in the DPA added electrolyte due to reduced sublimation of iodine. The most promising feature of the electrolyte is increased device stability with 89% of the overall efficiency preserved even after 40 days. PMID:21648469

Agarwala, S; Peh, C K N; Ho, G W

2011-07-01

278

Long-term calorie restriction decreases metabolic cost of movement and prevents decrease of physical activity during aging in the rhesus monkeys  

PubMed Central

Background Short-term (<1 year) calorie restriction (CR) has been reported to decrease physical activity and metabolic rate in humans and non-human primate models; however, studies examining the very long-term (>10 year) effect of CR on these parameters are lacking. Objective The objective of this study was to examine metabolic and behavioral adaptations to long-term CR longitudinally in rhesus macaques. Design Eighteen (10 male, 8 female) control (C) and 24 (14 male, 10 female) age matched CR rhesus monkeys between 19.6 and 31.9 years old were examined after 13 and 18 years of moderate adult-onset CR. Energy expenditure (EE) was examined by doubly labeled water (DLW; TEE) and respiratory chamber (24hrEE). Physical activity was assessed both by metabolic equivalent (MET) in a respiratory chamber and by an accelerometer. Metabolic cost of movements during 24h were also calculated. Age and fat-free mass were included as covariates. Results Adjusted total and 24hr EE were not different between C and CR. Sleeping metabolic rate was significantly lower, and physical activity level was higher in CR than in C independent from the CR-induced changes in body composition. The duration of physical activity above 1.6 METs was significantly higher in CR than in C, and CR had significantly higher accelerometer activity counts than C. Metabolic cost of movements during 24h were significantly lower in CR than in C. The accelerometer activity counts were significantly decreased after seven years in C animals, but not in CR animals. Conclusions The results suggest that long-term CR decreases basal metabolic rate, but maintains higher physical activity with lower metabolic cost of movements compared with C. PMID:23954367

Yamada, Yosuke; Colman, Ricki J; Kemnitz, Joseph W.; Baum, Scott T.; Anderson, Rozalyn M.; Weindruch, Richard; Schoeller, Dale A.

2013-01-01

279

Divergent short- and long-term effects of acute stress in object recognition memory are mediated by endogenous opioid system activation.  

PubMed

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. PMID:24036398

Nava-Mesa, Mauricio O; Lamprea, Marisol R; Múnera, Alejandro

2013-11-01

280

Focal epileptiform activity in the prefrontal cortex is associated with long-term attention and sociability deficits  

PubMed Central

There is a well-described association between childhood epilepsy and pervasive cognitive and behavioral deficits. Often these children not only have ictal EEG events, but also frequent interictal abnormalities. The precise role of these interictal discharges in cognition remains unclear. In order to understand the relationship between frequent epileptiform discharges during neurodevelopment and cognition later in life, we developed a model of frequent focal interictal spikes (IIS). Postnatal day (p) 21 rats received injections of bicuculline methiodine into the prefrontal cortex (PFC). Injections were repeated in order to achieve 5 consecutive days of transient inhibitory/excitatory imbalance resulting in IIS. Short-term plasticity (STP) and behavioral outcomes were studied in adulthood. IIS is associated with a significant increase in STP bilaterally in the PFC. IIS rats did not show working memory deficits, but rather showed marked inattentiveness without significant alterations in motivation, anxiety or hyperactivity. Rats also demonstrated significant deficits in social behavior. We conclude that GABAergic blockade during early-life and resultant focal IIS in the PFC disrupt neural networks and are associated with long-term consequences for behavior at a time when IIS are no longer present, and thus may have important implications for ADHD and autism spectrum disorder associated with childhood epilepsy. PMID:24269731

Hernan, Amanda E.; Alexander, Abigail; Jenks, Kyle R.; Barry, Jeremy; Lenck-Santini, Pierre-Pascal; Isaeva, Elena; Holmes, Gregory L.; Scott, Rod C.

2015-01-01

281

Focal epileptiform activity in the prefrontal cortex is associated with long-term attention and sociability deficits.  

PubMed

There is a well-described association between childhood epilepsy and pervasive cognitive and behavioral deficits. Often these children not only have ictal EEG events, but also frequent interictal abnormalities. The precise role of these interictal discharges in cognition remains unclear. In order to understand the relationship between frequent epileptiform discharges during neurodevelopment and cognition later in life, we developed a model of frequent focal interictal spikes (IIS). Postnatal day (p) 21 rats received injections of bicuculline methiodine into the prefrontal cortex (PFC). Injections were repeated in order to achieve 5 consecutive days of transient inhibitory/excitatory imbalance resulting in IIS. Short-term plasticity (STP) and behavioral outcomes were studied in adulthood. IIS is associated with a significant increase in STP bilaterally in the PFC. IIS rats did not show working memory deficits, but rather showed marked inattentiveness without significant alterations in motivation, anxiety or hyperactivity. Rats also demonstrated significant deficits in social behavior. We conclude that GABAergic blockade during early-life and resultant focal IIS in the PFC disrupt neural networks and are associated with long-term consequences for behavior at a time when IIS are no longer present, and thus may have important implications for ADHD and autism spectrum disorder associated with childhood epilepsy. PMID:24269731

Hernan, Amanda E; Alexander, Abigail; Jenks, Kyle R; Barry, Jeremy; Lenck-Santini, Pierre-Pascal; Isaeva, Elena; Holmes, Gregory L; Scott, Rod C

2014-03-01

282

A relationship between reduced nucleus accumbens shell and enhanced lateral hypothalamic orexin neuronal activation in long-term fructose bingeing behavior.  

PubMed

Fructose accounts for 10% of daily calories in the American diet. Fructose, but not glucose, given intracerebroventricularly stimulates homeostatic feeding mechanisms within the hypothalamus; however, little is known about how fructose affects hedonic feeding centers. Repeated ingestion of sucrose, a disaccharide of fructose and glucose, increases neuronal activity in hedonic centers, the nucleus accumbens (NAc) shell and core, but not the hypothalamus. Rats given glucose in the intermittent access model (IAM) display signatures of hedonic feeding including bingeing and altered DA receptor (R) numbers within the NAc. Here we examined whether substituting fructose for glucose in this IAM produces bingeing behavior, alters DA Rs and activates hedonic and homeostatic feeding centers. Following long-term (21-day) exposure to the IAM, rats given 8-12% fructose solutions displayed fructose bingeing but unaltered DA D1R or D2R number. Fructose bingeing rats, as compared to chow bingeing controls, exhibited reduced NAc shell neuron activation, as determined by c-Fos-immunoreactivity (Fos-IR). This activation was negatively correlated with orexin (Orx) neuron activation in the lateral hypothalamus/perifornical area (LH/PeF), a brain region linking homeostatic to hedonic feeding centers. Following short-term (2-day) access to the IAM, rats exhibited bingeing but unchanged Fos-IR, suggesting only long-term fructose bingeing increases Orx release. In long-term fructose bingeing rats, pretreatment with the Ox1R antagonist SB-334867 (30 mg/kg; i.p.) equally reduced fructose bingeing and chow intake, resulting in a 50% reduction in calories. Similarly, in control rats, SB-334867 reduced chow/caloric intake by 60%. Thus, in the IAM, Ox1Rs appear to regulate feeding based on caloric content rather than palatability. Overall, our results, in combination with the literature, suggest individual monosaccharides activate distinct neuronal circuits to promote feeding behavior. Specifically, long-term fructose bingeing activates a hyperphagic circuit composed in part of NAc shell and LH/PeF Orx neurons. PMID:24736531

Rorabaugh, Jacki M; Stratford, Jennifer M; Zahniser, Nancy R

2014-01-01

283

A Relationship between Reduced Nucleus Accumbens Shell and Enhanced Lateral Hypothalamic Orexin Neuronal Activation in Long-Term Fructose Bingeing Behavior  

PubMed Central

Fructose accounts for 10% of daily calories in the American diet. Fructose, but not glucose, given intracerebroventricularly stimulates homeostatic feeding mechanisms within the hypothalamus; however, little is known about how fructose affects hedonic feeding centers. Repeated ingestion of sucrose, a disaccharide of fructose and glucose, increases neuronal activity in hedonic centers, the nucleus accumbens (NAc) shell and core, but not the hypothalamus. Rats given glucose in the intermittent access model (IAM) display signatures of hedonic feeding including bingeing and altered DA receptor (R) numbers within the NAc. Here we examined whether substituting fructose for glucose in this IAM produces bingeing behavior, alters DA Rs and activates hedonic and homeostatic feeding centers. Following long-term (21-day) exposure to the IAM, rats given 8–12% fructose solutions displayed fructose bingeing but unaltered DA D1R or D2R number. Fructose bingeing rats, as compared to chow bingeing controls, exhibited reduced NAc shell neuron activation, as determined by c-Fos-immunoreactivity (Fos-IR). This activation was negatively correlated with orexin (Orx) neuron activation in the lateral hypothalamus/perifornical area (LH/PeF), a brain region linking homeostatic to hedonic feeding centers. Following short-term (2-day) access to the IAM, rats exhibited bingeing but unchanged Fos-IR, suggesting only long-term fructose bingeing increases Orx release. In long-term fructose bingeing rats, pretreatment with the Ox1R antagonist SB-334867 (30 mg/kg; i.p.) equally reduced fructose bingeing and chow intake, resulting in a 50% reduction in calories. Similarly, in control rats, SB-334867 reduced chow/caloric intake by 60%. Thus, in the IAM, Ox1Rs appear to regulate feeding based on caloric content rather than palatability. Overall, our results, in combination with the literature, suggest individual monosaccharides activate distinct neuronal circuits to promote feeding behavior. Specifically, long-term fructose bingeing activates a hyperphagic circuit composed in part of NAc shell and LH/PeF Orx neurons. PMID:24736531

Rorabaugh, Jacki M.; Stratford, Jennifer M.; Zahniser, Nancy R.

2014-01-01

284

Short and long-term lifestyle coaching approaches used to address diverse participant barriers to weight loss and physical activity adherence  

PubMed Central

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? 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 for many kinds of participant barriers. Given minimal resources, increased attention to training lifestyle coaches in the consistent use of these approaches appears warranted. PMID:24521153

2014-01-01

285

Long-term MF radar observations of solar tides in the low-latitude mesosphere: Interannual variability and comparisons with the GSWM  

NASA Astrophysics Data System (ADS)

Long-term MF radar wind measurements in the 80-100 km height range made at three equatorial and subtropical sites (Adelaide, Christmas Island, and Kauai) are used to produce climatologies and to study interannual variability of solar tides. Twelve years of data were available for Adelaide and up to 6 years at the other sites and are analyzed in 30-day intervals. The climatological values are compared with the Global Scale Wave Model (GSWM). Good agreement between the measured and model amplitudes and phases is found for the diurnal tide, but the semidiurnal model values agree less well with the observations. The diurnal tidal amplitudes and phases show strong seasonal variability. Maximum amplitudes are attained in March, and subsidiary maxima are observed in July/August and October, while the phase shows an annual cycle at Adelaide and Kauai, with the phase advancing by ˜4-6 hours from summer to winter. Amplitudes of the semidiurnal tide rarely exceed 10 m s-1. The phases undergo rapid shifts around the equinoxes at Adelaide and Kauai, but there is a more complicated phase variation at Christmas Island. The diurnal tide shows strong interannual variability in amplitude, especially near the March equinox. There appears to be an association with the quasi-biennial oscillation (QBO) in zonal winds in the equatorial stratosphere, with the amplitudes being larger than the climatological average in years when the stratospheric winds are eastward and smaller than average when the QBO is in its westward phase. In contrast, the phase of the diurnal tide, as well as the semidiurnal tide, shows little systematic interannual variability.

Vincent, R. A.; Kovalam, S.; Fritts, D. C.; Isler, J. R.

1998-04-01

286

Long term variation of the solar diurnal anisotropy of galactic cosmic rays observed with the Nagoya multi-directional muon detector  

E-print Network

We analyze the three dimensional anisotropy of the galactic cosmic ray (GCR) intensities observed independently with a muon detector at Nagoya in Japan and neutron monitors over four solar activity cycles. We clearly see the phase of the free-space diurnal anisotropy shifting toward earlier hours around solar activity minima in A>0 epochs, due to the reduced anisotropy component parallel to the mean magnetic field. The average parallel component is consistent with a rigidity independent spectrum, while the perpendicular component increases with GCR rigidity. We suggest that this harder spectrum of the perpendicular component is due to contribution from the drift streaming. We find that the bidirectional latitudinal density gradient is positive in A>0 epoch, while it is negative in A0 and A0. We also find, however, that parallel mean free path (radial gradient) appears to persistently increase (decreasing) in the last three cycles of weakening solar activity. We suggest that simple differences between these pa...

Munakata, K; Kato, C; Kota, J

2014-01-01

287

Long-term effect of irrigation with water from sewage treatment plant on AMF biodiversity and microbial activities.  

NASA Astrophysics Data System (ADS)

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, ?-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.

Alguacil, M. M.; Torrecillas, E.; Lozano, Z.; Torres, M. P.; Garcia-Orenes, F.; Roldan, A.

2012-04-01

288

The long-term hospitalization experience following military service in the 1991 Gulf War among veterans remaining on active duty, 1994–2004  

PubMed Central

Background Despite more than a decade of extensive, international efforts to characterize and understand the increased symptom and illness-reporting among veterans of the 1991 Gulf War, concern over possible long-term health effects related to this deployment continue. The purpose of this study was to describe the long-term hospitalization experience of the subset of U.S. Gulf War veterans still on active duty between 1994 and 2004. Methods Gulf War veterans on active duty rosters as of October 1, 1994, were identified (n = 211 642) and compared with veterans who had separated from military service and then assessed for attrition at three-year intervals during a 10-year follow-up period, examining demographic and military service characteristics, Gulf War exposure variables, and hospitalization data. Cox proportional hazard modeling was used to evaluate independent predictors of all-cause hospitalization among those still on active duty and to estimate cumulative probability of hospitalization, 1994–2004, by service branch. Results Members of our 1994 active duty cohort were more likely to be officers, somewhat older, and married compared with those who had separated from the military after serving in the 1991 Gulf War. Selected war-related exposures or experiences did not appear to influence separation with the exception of in-theater presence during the brief ground combat phase. Overall the top three diagnostic categories for hospitalizations were musculo-skeletal, injury and poisoning, and digestive disorders. Diseases of the circulatory system and symptoms, signs, and ill-defined conditions increased proportionately over time. In-theater hospitalization was the only significant independent predictor of long-term hospitalization risk among selected war-related exposures or experiences examined. The cumulative probability of hospitalization was highest for Army and lowest for Marines. Conclusion Our results were generally consistent with a previous hospitalization study of US Gulf War veterans for the period August 1991 to July 1999. Although lack of a comparison group for our study limits interpretation of overall findings, intra-cohort analyses showed no significant associations between long-term hospitalization and war-related exposures or experiences, with the exception of in-theater hospitalization, within our active duty subset of 1991 Gulf War veterans. PMID:18271971

Hooper, Tomoko I; DeBakey, Samar F; Nagaraj, Barbara E; Bellis, Kimberly S; Smith, Besa; Smith, Tyler C; Gackstetter, Gary D

2008-01-01

289

Temporal synaptic tagging by I(h) activation and actin: involvement in long-term facilitation and cAMP-induced synaptic enhancement.  

PubMed

Presynaptic I(h) channels become activated during a tetanus through membrane hyperpolarization resulting from Na(+) accumulation and electrogenic Na(+)/K(+) exchange. I(h) activation is obligatory for inducing long-term facilitation (LTF), a long-lasting synaptic strengthening. cAMP-induced synaptic enhancement also requires I(h) activation, and both processes are sensitive to actin depolymerization. Other mechanisms are responsible for expression of the responses. Once initiated, continued response to cAMP is I(h) and actin independent. Moreover, LTF-induced activation of I(h) renders subsequent cAMP enhancement insensitive to both I(h) blockers and actin depolymerization. This actin-stabilized "temporal synaptic tagging" set by I(h) activation is prolonged when I(h) is activated concurrent with an elevation in presynaptic calcium concentration ([Ca(2+)]i), permitting the further strengthening of synapses given appropriate additional stimuli. PMID:11856533

Beaumont, Vahri; Zhong, Ning; Froemke, Robert C; Ball, Robin W; Zucker, Robert S

2002-02-14

290

Long-term melatonin administration attenuates low-LET ?-radiation-induced lymphatic tissue injury during the reproductively active and inactive phases of Indian palm squirrels (Funambulus pennanti)  

PubMed Central

A comparative analysis of low linear energy transfer (LET) ?-radiation-induced damage in the lymphatic tissue of a tropical seasonal breeder, Indian palm squirrel (Funambulus pennanti), during its reproductively active phase (RAP) and inactive phase (RIP) was performed with simultaneous investigation of the effects of long-term melatonin pre-treatment (100 ?g/100 g body weight). A total of 120 squirrels (60 during RAP and 60 during RIP) were divided into 12 groups and sacrificed at 4, 24, 48, 72 and 168 h following 5 Gy ?-radiation exposure; control groups were excluded from exposure. Total leukocyte count and absolute lymphocyte count (ALC) and melatonin only of peripheral blood, stimulation index, thiobarbituric-acid-reactive substances (TBARS) level, superoxide dismutase (SOD) activity, and the apoptotic index of spleen as analysed by terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick-end labelling (TUNEL) noted at observed time-points were significantly reduced in melatonin pre-treated groups during RAP and RIP. Long-term melatonin pre-treatment mitigated radiation-induced alterations more prominently during RIP, as assessed by ALC, TBARS, SOD, TUNEL and caspase-3 activity, at some time-points. Our results demonstrate an inhibitory role of melatonin on caspase-3 activity in splenocytes during RAP and RIP following ?-radiation-induced caspase-mediated apoptosis. Hence, we propose that melatonin might preserve the viability of immune cells of a seasonal breeder against background radiation, which is constantly present in the environment. PMID:20139262

Sharma, S; Haldar, C; Chaube, S K; Laxmi, T; Singh, S S

2010-01-01

291

The long term dynamics of the solar radiative zone associated to new results from SoHO and young solar analogs  

E-print Network

The Standard Solar Model (SSM) is no more sufficient to interpret all the observations of the radiative zone obtained with the SoHO satellite. We recall our present knowledge of this internal region and compare the recent results to models beyond the SSM assumptions. Then we discuss the missing processes and quantify some of them in using young analog observations to build a more realistic view of our star. This progress will be useful for solar-like stars observed by COROT and KEPLER.

Sylvaine Turck-Chieze; Sebastien Couvidat; Antonio Eff-Darwich; Vincent Duez; Rafael A. Garcia; Stephane Mathis; Savita Mathur; Laurent Piau; David Salabert

2011-09-19

292

Adenosine monophosphate-activated kinase, AMPK, is involved in the maintenance of the quality of extended boar semen during long-term storage.  

PubMed

Boar semen preservation for later use in artificial insemination is performed by diluting semen in an appropriate medium and then lowering the temperature to decrease spermatozoa metabolism. The adenosine monophosphate-activated kinase, AMPK, is a key cell energy sensor that controls cell metabolism and recently has been identified in boar spermatozoa. Our aim was to investigate the role of AMPK in spermatozoa functional parameters including motility, mitochondrial membrane potential, plasma membrane integrity, acrosome integrity, and cell viability during long-term boar semen storage at 17 °C in Beltsville thawing solution. Boar seminal doses were diluted in Beltsville thawing solution in the presence or absence of different concentrations of AMPK inhibitor, compound C (1, 10, and 30 ?M) and evaluations were performed at 1, 2, 4, 7, or 10 days. Data demonstrate that AMPK becomes phosphorylated at threonine(172) (active) during storage of boar semen reaching maximum levels at Day 7. Moreover, AMPK inhibition during boar semen storage causes: (1) a potent inhibition of spermatozoa motility; (2) a reduction in the percentage of spermatozoa showing high mitochondria membrane potential; (3) a rise in the percentage of spermatozoa displaying high plasma membrane scrambling; and (4) a loss of acrosomal membrane integrity. Our study suggests that AMPK activity plays an important role in the maintenance of the spermatozoa quality during long-term storage of boar semen. PMID:23773688

Martin-Hidalgo, David; Hurtado de Llera, Ana; Yeste, Marc; Cruz Gil, M; Bragado, M Julia; Garcia-Marin, Luis J

2013-09-01

293

A long-term, prospective, cohort study on the performance of right ventricular pacing leads: comparison of active-fixation with passive-fixation leads.  

PubMed

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 ± 94.31? vs. 683.14 ± 110.98? at baseline), and both showed significant reductions at one month to 537.96 ± 147.43? in the active group, and after three months to 643.85 ± 82.40? 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

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

294

Marked dissociation between hypothalamic-pituitary-adrenal activation and long-term behavioral effects in rats exposed to immobilization or cat odor.  

PubMed

Exposure of rodents to cats or certain cat odors results in long-term behavioral effects reminiscent of enhanced anxiety that have been considered to model post-traumatic stress disorder. However, other severe stressors such as tail-shock or immobilization in wooden boards (IMO) appear to induce shorter lasting changes in anxiety. In addition, there are controversial results regarding the effects of urine/feces odors. In the present work, we studied in two experiments the relationship between the degree of stress experienced by the animals during exposure to IMO, urine odors or fur odors (as assessed by hypothalamic-pituitary-adrenal activation and plasma glucose) and the short- and long-term behavioral consequences. In the first experiment, rats were individually exposed for 15 min to a novel environment (white large cages) containing either clean cat litter (controls) or litter soiled by cats (urine odors). Half of the rats in each condition were left to freely explore the environment whereas the others were subjected to immobilization (IMO) within the cages. Although ACTH, corticosterone and glucose responses to IMO were much stronger than those to the white cages with clean litter or urine odors (which did not differ from each other), no effect of treatments on anxiety-like behavior in the elevated plus-maze (EPM) were found one week later. However, previous IMO exposure did cause sensitization of the ACTH response to the EPM. In the second experiment, the response to white large cages containing either no odor (controls), litter soiled by cats (urine odor) or a cloth impregnated with cat odor (fur odor) was compared. Urine and fur odors elicited similar ACTH and corticosterone responses that were higher than those of controls, but plasma glucose levels were slightly higher in rats exposed to fur odor. When compared to controls, activity was only diminished in the novel cages containing fur odor. Similarly, fur odor-exposed rats, but not those exposed to urine odor, showed signs of enhanced anxiety in the EPM seven days later, although the ACTH response to the EPM was similar in the three groups. The present data demonstrate: (a) a marked dissociation between the degree of ACTH, corticosterone and glucose responses to stressors and their long-term anxiety-like effects; (b) that the type of cat odor is critical in determining the short-term and long-term physiological and behavioral consequences of exposure; and (c) that plasma ACTH released during brief exposure to the EPM does not appear to reflect anxiety-like behavior. PMID:18644680

Muñoz-Abellán, C; Andero, R; Nadal, R; Armario, A

2008-09-01

295

Long term perspectives in energy resources  

Microsoft Academic Search

Long term perspectives in global energy use patterns and energy resources are considered. The potential contributions of natural gas and coal, oil, nuclear energy, hydroelectric energy, and alternative energy resources (geothermal, wind, biomass, solar) are evaluated. It is concluded that fossile fuels will continue to provide the bulk of the world's energy through the upcoming decades. The political uncertainty of

C. Destival

1978-01-01

296

Thirteen Years of Observations at Alaskan CALM Sites: Long-Term Active Layer and Ground Surface Temperature Trends  

Microsoft Academic Search

Active layer monitoring is an important component of efforts to assess the affects of global change in permafrost environments. In this study we used data from 13 (1995-2007) years of spatially oriented field observations at a series of 16 representative Circumpolar Active Layer Monitoring (CALM) sites in northern Alaska to examine temporal and spatial trends in active layer thickness and

Dmitry A. Streletskiy; Nikolay I. Shiklomanov; Frederick E. Nelson; Anna E. Klene

297

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

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

Mosher, Catherine E.; Lipkus, Isaac; Sloane, Richard; Snyder, Denise C.; Lobach, David F.; Demark-Wahnefried, Wendy

2012-01-01

298

Observing Changes of Surface Solar Irradiance in Oregon: A Comparison of Satellite and Ground-Based Long-Term Time-Series  

NASA Astrophysics Data System (ADS)

Significant increases over time are found in direct normal irradiance (DNI) in Oregon using both ground and satellite-derived measurements of DNI. Linear regression of all locations in both data sets shows strong positive trends of .4% to .6% per year. Ground measurements are analyzed from 1980 (and at one site from 1978) until 2004. These 25 years of ground measurements come from three climatically diverse sites in the state of Oregon using an Eppley Normal Incidence Pyrheliometer (NIP). The NIP is a good candidate for long term trend analysis as its responsivity remains consistent over time. The sensitivity of the Eppley Precision Spectral Pyranometer (PSP) which measures total radiation, on the other hand, degrades over time, approximately .5% to 2% per year. This uniquely long data set is compared to DNI calculated from the International Satellite Cloud Climatology Project (ISCCP). The ISCCP D series applied here has 280 km x 280 km boxes, each of which includes one of the ground based sites, giving cloud and atmospheric input data from 1983 until 2001. Radiative transfer calculations are done using the two-stream method from the library for radiative transfer (libRadtran). The three hourly satellite observations allow comparison of different time integration periods. Besides annual average comparisons, monthly averages are examined to look for seasonal variation and confirm that the observations show a regional trend. Ground measurements of DNI for this length of time are rare, making this study a unique opportunity to test the capability to calculate direct normal irradiance based on ISCCP results. The agreement of the ISCCP derived irradiances to the measurements is very good: the trends differ between .08 and .3 W/m{2 depending on the site. From 1998 through 2002 satellite data were used to produce a solar radiation database on a 0.1i° grid. Comparisons between the modeled beam irradiance for the coordinates of the ground based station will be compared to the average for the area of the ISCCP grid to check how representative each ground site is of the ISCCP box. The successful verification of ISCCP for this application at three independent sites in this region allows us to use this approach to also analyze similar changes over other regions. Comparing these two methods of obtaining direct irradiance also provides valuable information about the sources of seasonal and inter-annual changes in cloud cover and other atmospheric constituents.

Riihimaki, L. D.; Vignola, F. E.; Lohmann, S.; Meyer, R.

2005-12-01

299

Long-Term Activation upon Brief Exposure to Xanomleline Is Unique to M1 and M4 Subtypes of Muscarinic Acetylcholine Receptors  

PubMed Central

Xanomeline is an agonist endowed with functional preference for M1/M4 muscarinic acetylcholine receptors. It also exhibits both reversible and wash-resistant binding to and activation of these receptors. So far the mechanisms of xanomeline selectivity remain unknown. To address this question we employed microfluorometric measurements of intracellular calcium levels and radioligand binding to investigate differences in the short- and long-term effects of xanomeline among muscarinic receptors expressed individually in Chinese hamster ovary cells. 1/One-min exposure of cells to xanomeline markedly increased intracellular calcium at hM1 and hM4, and to a lesser extent at hM2 and hM3 muscarinic receptors for more than 1 hour. 2/Unlike the classic agonists carbachol, oxotremorine, and pilocarpine 10-min exposure to xanomeline did not cause internalization of any receptor subtype. 3/Wash-resistant xanomeline selectively prevented further increase in intracellular calcium by carbachol at hM1 and hM4 receptors. 4/After transient activation xanomeline behaved as a long-term antagonist at hM5 receptors. 5/The antagonist N-methylscopolamine (NMS) reversibly blocked activation of hM1 through hM4 receptors by xanomeline. 6/NMS prevented formation of xanomeline wash-resistant binding and activation at hM2 and hM4 receptors and slowed them at hM1, hM3 and hM5 receptors. Our results show commonalities of xanomeline reversible and wash-resistant binding and short-time activation among the five muscarinic receptor subtypes. However long-term receptor activation takes place in full only at hM1 and hM4 receptors. Moreover xanomeline displays higher efficacy at hM1 and hM4 receptors in primary phasic intracellular calcium release. These findings suggest the existence of particular activation mechanisms specific to these two receptors. PMID:24558448

Šantr??ková, Eva; Doležal, Vladimír; El-Fakahany, Esam E.; Jakubík, Jan

2014-01-01

300

Short- and long-term nutritional modulation of acetyl-CoA carboxylase activity in selected tissues of rainbow trout (Oncorhynchus mykiss).  

PubMed

Acetyl-CoA carboxylase (ACoAC) catalyses the carboxylation of acetyl-CoA into malonyl-CoA. This product plays a pivotal role in the regulation of energy metabolism since it is both a substrate for fatty acid synthesis and an inhibitor of the oxidative pathway. The present study was initiated to analyse the modulation of ACoAC activity in liver and selected extrahepatic tissues of rainbow trout (Oncorhynchus mykiss) by dietary changes as a contribution to the understanding of the nutritional control of lipid metabolism in fish. Short-term effects of food intake were studied by measuring ACoAC activity in the liver and dorsal white muscle at different time intervals after a meal. Only slight variations were observed in the muscle during the period 2-72 h after the meal. The long-term effects of an increase in dietary lipids or carbohydrates levels were examined by measuring ACoAC activity in the liver, adipose tissue, intestine, kidney, red muscle, dorsal and ventral white muscles of trout after 3 months of feeding with different diets. ACoAC activity is stimulated by a high-digestible starch diet in the abdominal adipose tissue and the white muscle. A high-lipid diet decreases ACoAC activity in the liver and the intestine, but not in other tissues. Contrary to mammals, a rapid adaptation of ACoAC activity to food supply is not effective in rainbow trout. However, a long-term nutritional control of ACoAC activity does occur in this species, but the target tissue differs with the predominant non-protein energy sources in the diet. The present results suggest the potential existence of two ACoAC isoforms with different tissue distribution as has been observed in mammals and birds. PMID:12828797

Rollin, Xavier; Médale, Françoise; Gutieres, Stéphanie; Blanc, Denise; Kaushik, Sadasivam J

2003-06-01

301

TISSUE-PLASMINOGEN ACTIVATOR IS INDUCED AS AN IMMEDIATE-EARLY GENE DURING SEIZURE, KINDLING, AND LONG-TERM POTENTIATION  

EPA Science Inventory

Activity-dependent genes in brain have been identified using differential screening of hippocampal cDNA library from rats exposed to metrazol seizures under conditions of superconduction. Five immediate early genes whose expression is elevated by neural activity were identified. ...

302

Long-Term Exposure to Concentrated Ambient PM2.5 Increases Mouse Blood Pressure through Abnormal Activation of the Sympathetic Nervous System: A Role for Hypothalamic Inflammation  

PubMed Central

Background: Exposure to particulate matter ? 2.5 ?m in diameter (PM2.5) increases blood pressure (BP) in humans and animal models. Abnormal activation of the sympathetic nervous system may have a role in the acute BP response to PM2.5 exposure. The mechanisms responsible for sympathetic nervous system activation and its role in chronic sustenance of hypertension in response to PM2.5 exposure are currently unknown. Objectives: We investigated whether central nervous system inflammation may be implicated in chronic PM2.5 exposure-induced increases in BP and sympathetic nervous system activation. Methods: C57BL/6J mice were exposed to concentrated ambient PM2.5 (CAPs) for 6 months, and we analyzed BP using radioactive telemetric transmitters. We assessed sympathetic tone by measuring low-frequency BP variability (LF-BPV) and urinary norepinephrine excretion. We also tested the effects of acute pharmacologic inhibitors of the sympathetic nervous system and parasympathetic nervous system. Results: Long-term CAPs exposure significantly increased basal BP, paralleled by increases in LF-BPV and urinary norepinephrine excretion. The increased basal BP was attenuated by the centrally acting ?2a agonist guanfacine, suggesting a role of increased sympathetic tone in CAPs exposure–induced hypertension. The increase in sympathetic tone was accompanied by an inflammatory response in the arcuate nucleus of the hypothalamus, evidenced by increased expression of pro-inflammatory genes and inhibitor kappaB kinase (IKK)/nuclear factor–kappaB (NF-?B) pathway activation. Conclusion: Long-term CAPs exposure increases BP through sympathetic nervous system activation, which may involve hypothalamic inflammation. Citation: Ying Z, Xu X, Bai Y, Zhong J, Chen M, Liang Y, Zhao J, Liu D, Morishita M, Sun Q, Spino C, Brook RD, Harkema JR, Rajagopalan S. 2014. Long-term exposure to concentrated ambient PM2.5 increases mouse blood pressure through abnormal activation of the sympathetic nervous system: a role for hypothalamic inflammation. Environ Health Perspect 122:79–86;?http://dx.doi.org/10.1289/ehp.1307151 PMID:24240275

Xu, Xiaohua; Bai, Yuntao; Zhong, Jixin; Chen, Minjie; Liang, Yijia; Zhao, Jinzhuo; Liu, Dongyao; Morishita, Masako; Sun, Qinghua; Spino, Catherine; Brook, Robert D.; Harkema, Jack R.; Rajagopalan, Sanjay

2013-01-01

303

Long-term behaviour of starspots. III - Active longitudes on the long-period RS CVn star HK Lacertae  

NASA Technical Reports Server (NTRS)

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.

Olah, K.; Hall, D. S.; Henry, G. W.

1991-01-01

304

Suppression of poly (ADP-ribose) polymerase activation by 3-aminobenzamide in a rat model of myocardial infarction: long-term morphological and functional consequences  

PubMed Central

Recent studies demonstrated that inhibition or genetic inactivation of the enzyme poly (ADP-ribose) polymerase (PARP) is beneficial in myocardial reperfusion injury. PARP activation in the reperfused myocardium has been assumed, but not directly demonstrated. Furthermore, the issue whether pharmacological PARP inhibition affords long-term functional benefit in the reperfused myocardium has not been explored. These questions were addressed in the present study. In a rat model of myocardial ischemia (1?h) and reperfusion (up to 24?h), there was a marked and significant activation of PARP in the ischemic borderzone, as determined by poly(ADP-ribose) (PAR) immunohistochemistry. PAR localized to the nuclei of myocytes and infiltrating mononuclear cells. In the core of the infarction, necrotic tissues and diffuse PAR staining were observed. PARP activation remained markedly detectable 24?h after reperfusion. The PARP inhibitor 3-aminobenzamide (20?mg?kg?1 intraperitoneally 10?min before reperfusion, and every 2?h thereafter for 6?h) markedly reduced the activation of the enzyme in myocytes. 3-aminobenzamide significantly protected against myocardial morphological and functional alterations at 24?h post-reperfusion. Notably, infarct size was reduced, circulating creatine kinase activity was attenuated, and myocardial contractility (dP dt?1) was restored by 3-aminobenzamide. Our results demonstrate a significant and prolonged activation of PARP in the reperfused myocardium, localizing to the necrotic area and the ischaemic borderzone. Furthermore, the studies demonstrate that PARP inhibition affords long-term beneficial morphological and functional effects in the reperfused myocardium. These data strengthen the notion that pharmacological PARP inhibition is a viable novel experimental approach for protection against myocardial reperfusion injury. PMID:11498530

Liaudet, Lucas; Szabó, Éva; Timashpolsky, Leonid; Virág, László; Cziráki, Attila; Szabó, Csaba

2001-01-01

305

Solar activity secular cycles  

NASA Astrophysics Data System (ADS)

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.

Kramynin, A. P.; Mordvinov, A. V.

2013-12-01

306

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)

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

Sullins, W. R., Jr.; Rogers, J. G.

1974-01-01

307

Peripheral blood monocyte and T-lymphocyte activation levels at diagnosis predict long-term survival in head and neck squamous cell carcinoma patients.  

PubMed

This study was performed to determine whether peripheral blood (PB) monocyte and/or lymphocyte activation at diagnosis were associated with long-term prognosis in patients with head and neck squamous cell carcinoma (HNSCC), and to what extent such prognostic properties relate to human papilloma virus (HPV)-associated tumor infection of the included patients. This was a long-term prospective study describing patient survival in relation to PB T lymphocyte and monocyte activation in patients observed for up to 14 years following diagnosis. Sixty-four patients from a consecutive cohort of newly diagnosed HNSCC patients along with 16 non-cancer control patients were included over a period of almost 2 years. Monocyte responsiveness was assessed at diagnosis (N = 56 HNSCC/16 non-cancer controls) by measuring net levels of spontaneous vs lipopolysaccharide-induced monocyte chemotactic protein (MCP)-1 secretion in vitro. PB T lymphocyte activation was determined (N = 58 HNSCC/16 controls) by measuring the percentage of T cells expressing CD69 by flow cytometry. Whether HPV infection or not was determined by PCR analysis on formalin fixed paraffin-embedded tumor tissue. Tumor HPV-positive patients had better prognosis than HPV-negative patients. A low net MCP-1 response in monocytes predicted increased survival (Relative risk (RR) = 2.1; Confidence interval (CI): 1.1-4.0; p < 0.05). A low percentage of CD69 positive T lymphocytes also predicted better prognosis (RR = 2.6; CI: 1.3-5.0; p = 0.005). The predictive power of MCP-1 monocyte and CD69 T lymphocyte measures were retained when adjusted for age and gender of the patients and shown to be independent of each other (N = 50 HNSCC/16 controls). The results were similar in HPV tumor-positive and -negative patients. Patients with high monocyte- and/or T lymphocyte activation status had low survival with 8% 5 year overall survival (OS) compared to 65% 5 year OS for patients with dual low activation levels (RR = 0.27; CI: 0.14-0.56; p < 0.001), mostly secondary to disease-specific survival. Both tumor HPV-positive and -negative HNSCC patients with high percentage of CD69 positive T lymphocytes and/or high monocyte MCP-1 secretion had low long-term survival. The data suggest that the general inflammatory and adaptive immune systems are independently linked to the clinical aggressiveness of both tumor HPV-negative and -positive HNSCC patients. PMID:25801083

Aarstad, Hans Jørgen; Vintermyr, Olav K; Ulvestad, Elling; Aarstad, Helene H; Kross, Kenneth W; Heimdal, John H

2015-04-01

308

Admission Lipoprotein-Associated Phospholipase A2 Activity Is Not Associated with Long-Term Clinical Outcomes after ST-Segment Elevation Myocardial Infarction  

PubMed Central

Background Lipoprotein-associated phospholipase A2 (Lp-PLA2) activity is a biomarker predicting cardiovascular diseases in a real-world. However, the prognostic value in patients undergoing primary percutaneous coronary intervention (pPCI) for ST-segment elevation myocardial infarction (STEMI) on long-term clinical outcomes is unknown. Methods Lp-PLA2 activity was measured in samples obtained prior to pPCI from consecutive STEMI patients in a high-volume intervention center from 2005 until 2007. Five years all-cause mortality was estimated with the Kaplan-Meier method and compared among tertiles of Lp-PLA2 activity during complete follow-up and with a landmark at 30 days. In a subpopulation clinical endpoints were assessed at three years. The prognostic value of Lp-PLA2, in addition to the Thrombolysis In Myocardial Infarction or multimarker risk score, was assessed in multivariable Cox regression. Results The cohort (n?=?987) was divided into tertiles (low <144, intermediate 144–179, and high >179 nmol/min/mL). Among the tertiles differences in baseline characteristics associated with long-term mortality were observed. However, no significant differences in five years mortality in association with Lp-PLA2 activity levels were found; intermediate versus low Lp-PLA2 (HR 0.97; CI 95% 0.68–1.40; p?=?0.88) or high versus low Lp-PLA2 (HR 0.75; CI 95% 0.51–1.11; p?=?0.15). Both in a landmark analysis and after adjustments for the established risk scores and selection of cases with biomarkers obtained, non-significant differences among the tertiles were observed. In the subpopulation no significant differences in clinical endpoints were observed among the tertiles. Conclusion Lp-PLA2 activity levels at admission prior to pPCI in STEMI patients are not associated with the incidence of short and/or long-term clinical endpoints. Lp-PLA2 as an independent and clinically useful biomarker in the risk stratification of STEMI patients still remains to be proven. PMID:24788873

Woudstra, Pier; Damman, Peter; Kuijt, Wichert J.; Kikkert, Wouter J.; Grundeken, Maik J.; van Brussel, Peter M.; Stroobants, An K.; van Straalen, Jan P.; Fischer, Johan C.; Koch, Karel T.; Henriques, José P. S.; Piek, Jan J.; Tijssen, Jan G. P.; de Winter, Robbert J.

2014-01-01

309

CaMKII, but not protein kinase A, regulates Rpt6 phosphorylation and proteasome activity during the formation of long-term memories  

PubMed Central

CaMKII and Protein Kinase A (PKA) are thought to be critical for synaptic plasticity and memory formation through their regulation of protein synthesis. Consistent with this, numerous studies have reported that CaMKII, PKA and protein synthesis are critical for long-term memory formation. Recently, we found that protein degradation through the ubiquitin-proteasome system is also critical for long-term memory formation in the amygdala. However, the mechanism by which ubiquitin-proteasome activity is regulated during memory formation and how protein degradation interacts with known intracellular signaling pathways important for learning remain unknown. Recently, evidence has emerged suggesting that both CaMKII and PKA are capable of regulating proteasome activity in vitro through the phosphorylation of proteasome regulatory subunit Rpt6 at Serine-120, though whether they regulate Rpt6 phosphorylation and proteasome function in vivo remains unknown. In the present study we demonstrate for the first time that fear conditioning transiently modifies a proteasome regulatory subunit and proteasome catalytic activity in the mammalian brain in a CaMKII-dependent manner. We found increases in the phosphorylation of proteasome ATPase subunit Rpt6 at Serine-120 and an enhancement in proteasome activity in the amygdala following fear conditioning. Pharmacological manipulation of CaMKII, but not PKA, in vivo significantly reduced both the learning-induced increase in Rpt6 Serine-120 phosphorylation and the increase in proteasome activity without directly affecting protein polyubiquitination levels. These results indicate a novel role for CaMKII in memory formation through its regulation of protein degradation and suggest that CaMKII regulates Rpt6 phosphorylation and proteasome function both in vitro and in vivo. PMID:24009566

Jarome, Timothy J.; Kwapis, Janine L.; Ruenzel, Wendy L.; Helmstetter, Fred J.

2013-01-01

310

Long-Term Plasticity in the Regulation of Olfactory Bulb Activity by Centrifugal Fibers from Piriform Cortex  

PubMed Central

Olfactory bulb granule cells are activated synaptically via two main pathways. Mitral/tufted (M/T) cells form dendrodendritic synapses on granule cells that can be activated by antidromic stimulation of the lateral olfactory tract (LOT). Centrifugal fibers originating from the association fiber (AF) system in piriform cortex (PC) make axodendritic synapses on granule cells within the granule cell layer (GCL) that can be activated by orthodromic stimulation of AF axons in the PC. We explored functional plasticity in the AF pathway by recording extracellularly from individual M/T cells and presumed granule cells in male Long–Evans rats under urethane anesthesia while testing their response to LOT and AF stimulation. Presumed granule cells driven synaptically by LOT stimulation (type L cells) were concentrated in the superficial half of the GCL and were activated at short latencies, whereas those driven synaptically by AF stimulation (type A cells) were concentrated in the deep half of the GCL and were activated at longer latencies. Type A cells were readily detected only in animals in which the AF input to the GCL had been previously potentiated by repeated high-frequency stimulation. An additional bout of high-frequency stimulation administered under urethane caused an immediate increase in the number of action potentials evoked in type A cells by AF test stimulation and a concomitant increase in inhibition of M/T cells. These results underscore the importance of the role played in olfactory processing by PC regulation of OB activity and document the long-lasting potentiation of that regulation by repeated high-frequency AF activation. PMID:25031407

Cauthron, Joy L.

2014-01-01

311

Antioxidant activity in mature branches of ponderosa pine (Pinus ponderosa) under long-term, low concentration ozone exposure  

SciTech Connect

Antioxidant activity (superoxide dismutase, peroxidases and glutathione) is being examined in mature needle tissue of ponderosa pine exposed to elevated levels of ozone (O{sub 3}). Trees used in this study are 8-14 year-old clones produced from buds from a 70 year-old tree grafted onto seedling rootstock. Trees are exposed to O{sub 3} using a newly developed branch exposure chamber (BEC). Ozone treatments are charcoal-filtered, ambient and 2x ambient concentrations. A non-chambered branch will determine the effect of exposure chamber. Superoxide dismutase (SOD) activity measured in current-year needles in February via nitrobluetetrazolium (NBT) reduction was 138.5 {plus minus} 15 (SD) units mg{sup {minus}1} protein. The activity of guaiacol-oxidizing peroxidases was 89 {plus minus} 19 (SD) {Delta}A{sub 470} min{sup {minus}1} mg{sup {minus}1} protein. Ascorbate peroxidase and the ratio of oxidized to reduced glutathione (GSSG/GSH) are also being monitored. Antioxidant activity will be measured monthly across the ozone season (March to November) and during natural ozone episodes. Cellular antioxidant activity will be related to needle photosynthesis, respiration and stomatal conductance measured using a Licor 6200 portable photosynthesis apparatus.

Benes, S.E.; Murphy, T.M.; Laeuchli, A. (Univ. of California, Davis (USA)); Anderson, P.D.; Houpis, J.L.J. (Lawrence Livermore National Laboratory, CA (USA))

1990-05-01

312

Long-term effects of rapamycin treatment on insulin mediated phosphorylation of Akt/PKB and glycogen synthase activity  

SciTech Connect

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.

Varma, Shailly [Department of Biochemistry, College of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5 (Canada); Shrivastav, Anuraag [Department of Pathology and Laboratory Medicine, College of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5 (Canada); Health Research Division, Saskatchewan Cancer Agency, Saskatoon, SK S7N 4H4 (Canada); Changela, Sheena [Department of Biochemistry, College of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5 (Canada); Khandelwal, Ramji L. [Department of Biochemistry, College of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5 (Canada)], E-mail: ramji.khandelwal@usask.ca

2008-04-01

313

Geomagnetic activity: Dependence on solar wind parameters  

NASA Technical Reports Server (NTRS)

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.

Svalgaard, L.

1977-01-01

314

BACTERIAL ACTIVITY, COMMUNITY STRUCTURE, AND DEGREE OF SPATIAL HEREROGENEITY ON THE SMALL SCALE AT A LONG-TERM CONTAMINATED SITE  

Technology Transfer Automated Retrieval System (TEKTRAN)

In an anthropogenically disturbed soil, (88% sand, 8% silt, 4% clay) 150 mg samples were studied to examine the fine scale relationship of bacterial activity and community structure to heavy metal contaminants. The soils had been contaminated for over 40 years with aromatic solvents, lead (Pb), and...

315

Effects of long-term preservation of Frankia strains on infectivity, effectivity, and in vitro nitrogenase activity  

SciTech Connect

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.

Fontaine, M.S.; Young, P.H.; Torrey, J.G.

1986-04-01

316

Effects of long-term preservation of frankia strains on infectivity, effectivity, and in vitro nitrogenase activity.  

PubMed

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 HFP ArI3 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. PMID:16347033

Fontaine, M S; Young, P H; Torrey, J G

1986-04-01

317

Long-term monitoring of soil microbiological activities in two forest sites in South tyrol in the italian alps.  

PubMed

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

Margesin, Rosa; Minerbi, Stefano; Schinner, Franz

2014-09-17

318

Changes in Soil Carbon and Enzyme Activity As a Result of Different Long-Term Fertilization Regimes in a Greenhouse Field  

PubMed Central

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 ?-galactosidase and ?-galactosidase activities, but lower soil ?-glucosidase and ?-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

Zhang, Lili; Chen, Wei; Burger, Martin; Yang, Lijie; Gong, Ping; Wu, Zhijie

2015-01-01

319

Changes in soil carbon and enzyme activity as a result of different long-term fertilization regimes in a greenhouse field.  

PubMed

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 ?-galactosidase and ?-galactosidase activities, but lower soil ?-glucosidase and ?-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

Zhang, Lili; Chen, Wei; Burger, Martin; Yang, Lijie; Gong, Ping; Wu, Zhijie

2015-01-01

320

Long-term starspot activity of three short-period RS CVn stars: BH Vir, WY Cnc and CG Cyg  

NASA Astrophysics Data System (ADS)

We present starspot analyses of CG Cyg, BH Vir and WY Cnc on the basis of our new photometric observations as well as published photometric data spanning almost 40 years. The spotted regions were concentrated at low latitudes up to 32°, the spots covered up to 29% of the stellar surface and all three stars show non-axisymmetric spot distributions (active longitude structures separated by approximately half the orbital period). We found that the variations in the brightness and spottedness of CG Cyg are probably cyclic with a period of about 20 years. We detected a large flare on WY Cnc (1.02×1035 erg in the B band) and analysed the WY Cnc spot activity before and during the flare.

Kozhevnikova, A. V.; Alekseev, I. Yu.; Heckert, P. A.; Kozhevnikov, V. P.

2007-02-01

321

Physical Activity in Relation to Long-term Weight Maintenance After Intentional Weight Loss in Premenopausal Women  

Microsoft Academic Search

The type and amount of physical activity (PA) needed for prevention of weight regain are not well understood. We prospectively examined the associations between patterns of discretionary PA and 6-year maintenance of intentional weight loss among 4,558 healthy premenopausal women who were 26–45 years old in 1991 and had lost >5% of their body weight in the previous 2 years.

Rania A. Mekary; Diane Feskanich; Frank B. Hu; Walter C. Willett; Alison E. Field

2010-01-01

322

Soil microbial activity, nitrogen cycling, and long-term changes in organic carbon pools as related to fallow tillage management  

Microsoft Academic Search

Two experiments were established in 1969 and 1970 near Sidney, NE, to determine the effect of moldboard plow (plow), sub-tillage (sub-till), and no-tillage (no-till) fallow management on soil properties, biological activities, and carbon and nitrogen cycling. One experiment was on land which had been broken from sod in 1920, seeded to crested wheatgrass [Agropyron cristatum (L.) Gaertn.] from 1957 to

J. W Doran; E. T Elliott; K Paustian

1998-01-01

323

Nitrate inhibition of legume nodule growth and activity. I. Long term studies with a continuous supply of nitrate  

SciTech Connect

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.

Streeter, J.G.

1985-02-01

324

Sustainability of the Catalytic Activity of a Silica-Titania Composite (STC) for Long-Term Indoor Air Quality Control  

NASA Technical Reports Server (NTRS)

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.

Coutts, Janelle L.; Levine, Lanfang H.; Richards, Jeffrey T.

2011-01-01

325

Increased dopaminergic and 5-hydroxytryptaminergic activities in male rat brain following long-term treatment with anabolic androgenic steroids  

PubMed Central

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

Thiblin, Ingemar; Finn, Anja; Ross, Svante B; Stenfors, Carina

1999-01-01

326

Long-term environmental stewardship.  

SciTech Connect

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.

Nagy, Michael David

2010-08-01

327

Presynaptic long-term plasticity  

PubMed Central

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

Yang, Ying; Calakos, Nicole

2013-01-01

328

Changes in the properties and biological activity of crusty solonetzes in the Baraba Lowland under the long-term impact of gypsum  

NASA Astrophysics Data System (ADS)

A single application of gypsum to crusty hydromorphic low- and high-sodium solonetzes led to the destruction of the columnar structure and the formation of a valuable crumb-granular structure after 25 years. The surface crust disappeared from the reclaimed solonetzes, whereas its thickness in the control soils was about 10 cm. The long-term impact of gypsum also resulted in lower bulk density values in the upper soil meter, especially in the high-sodium solonetz. The number of microorganisms accumulating available nitrogen- and carbon-bearing compounds increased, and the urease and proteolytic activities of the soil became more pronounced. In the upper 20 cm of the reclaimed solonetzes, the microbiological transformation of the plant remains into the soil organic matter became more intensive, thus attesting to the development of the soddy process. The favorable effects of gypsum increased with an increase in the rate of its application.

Semendyaeva, N. V.; Korobova, L. N.; Elizarov, N. V.

2014-11-01

329

Verapamil does not modify catalytic activity of CYP450 in rainbow trout after long-term exposure.  

PubMed

Little is known about the effects of the cardiovascular drug verapamil (VRP) on metabolic processes in fish. Most calcium channel blockers including VRP are metabolized by cytochrome P450 (CYP450) enzymes. In this study we investigated the in vivo effect of VRP on some CYP450-mediated reactions in juvenile rainbow trout (Oncorhynchus mykiss). Fish were exposed to sublethal concentrations of VRP (0.5, 27 and 270 ?g l(-1)) for 0, 21, and 42 day. The following CYP450-mediated reactions were studied in hepatic microsomes: O-dealkylation of ethoxyresorufin, methoxyresorufin, and pentoxyresorufin, hydroxylation of coumarin, tolbutamide, and p-nitrophenol, and O-debenzylation of 7-benzyloxy-4-trifluoromethylcoumarin. The amounts of products of these reactions did not differ among fish exposed to different levels of VRP and control fish. This suggests that the levels of VPR used did not alter catalytic activity of the selected CYP450 enzymes. In conclusion, none of the investigated CYP450-mediated reactions has potential as a biomarker to monitor VRP contamination of the aquatic environment. PMID:22244749

Burkina, V; Zamaratskaia, G; Randak, T; Li, Z H; Fedorova, G; Pickova, J; Zlabek, V

2012-05-01

330

Development of magnetic particle techniques for long-term culture of bone cells with intermittent mechanical activation.  

PubMed

Magnetic particles were coated with RGD and adhered to primary human osteoblasts. During a 21-day culture, the osteoblasts plus adhered magnetic particles underwent a daily exposure to a time-varying magnetic field via a permanent NdFeB magnet, thus applying a direct mechanical stress to the cells (Bmax approximately 60 mT). After 21 days, preliminary results show that the cells plus magnetic particles were viable and had proliferated. A von-kossa stain showed mineralized bone matrix produced at 21 days in the experimental group whereas the control groups showed no mineralized matrix production. Real-time reverse transcription-polymerase chain reaction at 21 days showed an upregulation of osteopontin from the experimental group in comparison to the control group of cells with adhered particles and no magnet applied. These preliminary results indicate that adherence of RGD-coated 4.5 microm ferromagnetic particles to primary human osteoblasts does not initiate cell necrosis up to 21 days in vitro. Also, mechanical stimulation of human osteoblasts by magnetic particle technology appears to have an influence on osteoblastic activity. PMID:16689213

Cartmell, Sarah H; Dobson, Jon; Verschueren, Sarah B; El Haj, Alicia J

2002-06-01

331

Lytic activity by temperate phages of Pseudomonas aeruginosa in long-term cystic fibrosis chronic lung infections.  

PubMed

Pseudomonas aeruginosa is the most common bacterial pathogen infecting the lungs of cystic fibrosis (CF) patients. The transmissible Liverpool epidemic strain (LES) harbours multiple inducible prophages (LES?2; LES?3; LES?4; LES?5; and LES?6), some of which are known to confer a competitive advantage in an in vivo rat model of chronic lung infection. We used quantitative PCR (Q-PCR) to measure the density and dynamics of all five LES phages in the sputa of 10 LES-infected CF patients over a period of 2 years. In all patients, the densities of free-LES phages were positively correlated with the densities of P. aeruginosa, and total free-phage densities consistently exceeded bacterial host densities 10-100-fold. Further, we observed a negative correlation between the phage-to-bacterium ratio and bacterial density, suggesting a role for lysis by temperate phages in regulation of the bacterial population densities. In 9/10 patients, LES?2 and LES?4 were the most abundant free phages, which reflects the differential in vitro induction properties of the phages. These data indicate that temperate phages of P. aeruginosa retain lytic activity after prolonged periods of chronic infection in the CF lung, and suggest that temperate phage lysis may contribute to regulation of P. aeruginosa density in vivo.The ISME Journal advance online publication, 2 December 2014; doi:10.1038/ismej.2014.223. PMID:25461970

James, Chloe E; Davies, Emily V; Fothergill, Joanne L; Walshaw, Martin J; Beale, Colin M; Brockhurst, Michael A; Winstanley, Craig

2014-12-01

332

Influence of Martian regolith analogs on the activity and growth of methanogenic archaea, with special regard to long-term desiccation  

PubMed Central

Methanogenic archaea have been studied as model organisms for possible life on Mars for several reasons: they can grow lithoautotrophically by using hydrogen and carbon dioxide as energy and carbon sources, respectively; they are anaerobes; and they evolved at a time when conditions on early Earth are believed to have looked similar to those of early Mars. As Mars is currently dry and cold and as water might be available only at certain time intervals, any organism living on this planet would need to cope with desiccation. On Earth there are several regions with low water availability as well, e.g., permafrost environments, desert soils, and salt pans. Here, we present the results of a set of experiments investigating the influence of different Martian regolith analogs (MRAs) on the metabolic activity and growth of three methanogenic strains exposed to culture conditions as well as long-term desiccation. In most cases, concentrations below 1 wt% of regolith in the media resulted in an increase of methane production rates, whereas higher concentrations decreased the rates, thus prolonging the lag phase. Further experiments showed that methanogenic archaea are capable of producing methane when incubated on a water-saturated sedimentary matrix of regolith lacking nutrients. Survival of methanogens under these conditions was analyzed with a 400 day desiccation experiment in the presence of regolith analogs. All tested strains of methanogens survived the desiccation period as it was determined through reincubation on fresh medium and via qPCR following propidium monoazide treatment to identify viable cells. The survival of long-term desiccation and the ability of active metabolism on water-saturated MRAs strengthens the possibility of methanogenic archaea or physiologically similar organisms to exist in environmental niches on Mars. The best results were achieved in presence of a phyllosilicate, which provides insights of possible positive effects in habitats on Earth as well. PMID:25852668

Schirmack, Janosch; Alawi, Mashal; Wagner, Dirk

2015-01-01

333

Influence of Martian regolith analogs on the activity and growth of methanogenic archaea, with special regard to long-term desiccation.  

PubMed

Methanogenic archaea have been studied as model organisms for possible life on Mars for several reasons: they can grow lithoautotrophically by using hydrogen and carbon dioxide as energy and carbon sources, respectively; they are anaerobes; and they evolved at a time when conditions on early Earth are believed to have looked similar to those of early Mars. As Mars is currently dry and cold and as water might be available only at certain time intervals, any organism living on this planet would need to cope with desiccation. On Earth there are several regions with low water availability as well, e.g., permafrost environments, desert soils, and salt pans. Here, we present the results of a set of experiments investigating the influence of different Martian regolith analogs (MRAs) on the metabolic activity and growth of three methanogenic strains exposed to culture conditions as well as long-term desiccation. In most cases, concentrations below 1 wt% of regolith in the media resulted in an increase of methane production rates, whereas higher concentrations decreased the rates, thus prolonging the lag phase. Further experiments showed that methanogenic archaea are capable of producing methane when incubated on a water-saturated sedimentary matrix of regolith lacking nutrients. Survival of methanogens under these conditions was analyzed with a 400 day desiccation experiment in the presence of regolith analogs. All tested strains of methanogens survived the desiccation period as it was determined through reincubation on fresh medium and via qPCR following propidium monoazide treatment to identify viable cells. The survival of long-term desiccation and the ability of active metabolism on water-saturated MRAs strengthens the possibility of methanogenic archaea or physiologically similar organisms to exist in environmental niches on Mars. The best results were achieved in presence of a phyllosilicate, which provides insights of possible positive effects in habitats on Earth as well. PMID:25852668

Schirmack, Janosch; Alawi, Mashal; Wagner, Dirk

2015-01-01

334

Adipose tissue-derived mesenchymal stem cells in long-term dialysis patients display downregulation of PCAF expression and poor angiogenesis activation.  

PubMed

We previously demonstrated that mesenchymal stem cells (MSCs) differentiate into functional kidney cells capable of urine and erythropoietin production, indicating that they may be used for kidney regeneration. However, the viability of MSCs from dialysis patients may be affected under uremic conditions. In this study, we isolated MSCs from the adipose tissues of end-stage kidney disease (ESKD) patients undergoing long-term dialysis (KD-MSCs; mean: 72.3 months) and from healthy controls (HC-MSCs) to compare their viability. KD-MSCs and HC-MSCs were assessed for their proliferation potential, senescence, and differentiation capacities into adipocytes, osteoblasts, and chondrocytes. Gene expression of stem cell-specific transcription factors was analyzed by PCR array and confirmed by western blot analysis at the protein level. No significant differences of proliferation potential, senescence, or differentiation capacity were observed between KD-MSCs and HC-MSCs. However, gene and protein expression of p300/CBP-associated factor (PCAF) was significantly suppressed in KD-MSCs. Because PCAF is a histone acetyltransferase that mediates regulation of hypoxia-inducible factor-1? (HIF-1?), we examined the hypoxic response in MSCs. HC-MSCs but not KD-MSCs showed upregulation of PCAF protein expression under hypoxia. Similarly, HIF-1? and vascular endothelial growth factor (VEGF) expression did not increase under hypoxia in KD-MSCs but did so in HC-MSCs. Additionally, a directed in vivo angiogenesis assay revealed a decrease in angiogenesis activation of KD-MSCs. In conclusion, long-term uremia leads to persistent and systematic downregulation of PCAF gene and protein expression and poor angiogenesis activation of MSCs from patients with ESKD. Furthermore, PCAF, HIF-1?, and VEGF expression were not upregulated by hypoxic stimulation of KD-MSCs. These results suggest that the hypoxic response may be blunted in MSCs from ESKD patients. PMID:25025381

Yamanaka, Shuichiro; Yokote, Shinya; Yamada, Akifumi; Katsuoka, Yuichi; Izuhara, Luna; Shimada, Yohta; Omura, Nobuo; Okano, Hirotaka James; Ohki, Takao; Yokoo, Takashi

2014-01-01

335

Long-Term Impact of Community-Based Information, Education and Communication Activities on Food Hygiene and Food Safety Behaviors in Vietnam: A Longitudinal Study  

PubMed Central

Background Ingestion of contaminated water or food is a major contributor to childhood diarrhea in developing countries. In Vietnam, the use of community-based information, education and communication (IEC) activities could be a sustainable strategy to improve food hygiene and food safety behaviors. This study thus examined the long-term impact of community-based IEC activities on food hygiene and food safety behaviors. Methods In this longitudinal study, we interviewed caregivers of children aged between six months and four years in suburban Hanoi. Baseline data were collected in January 2006 (n?=?125). After conducting IEC interventions, we collected a 1st set of evaluation data in January 2007 (n?=?132). To examine the long-term impact of the interventions, we then collected a 2nd set of evaluation data in January 2008 (n?=?185). Changes in childhood diarrhea prevalence, IEC coverage, and food hygiene and food safety behaviors were assessed over a two-year period using bivariate and logistic regression analyses. Effective IEC channels were determined through multiple linear regression analysis. Results Childhood diarrhea was significantly reduced from 21.6% at baseline to 7.6% at the 1st post-intervention evaluation (P?=?0.002), and to 5.9% at the 2nd evaluation. Among 17 food hygiene and food safety behaviors measured, a total of 11 behaviors were improved or maintained by the 2nd evaluation. Handwashing after toilet use was significantly improved at both evaluation points. Overall, 3 food safety behaviors and 7 food hygiene behaviors were found to have significantly improved at the 1st and at the 2nd evaluations, respectively. Flip chart communication administered by community groups was identified to be the most effective IEC channel for effecting behavior change (P?=?0.018). Conclusions Flip chart communication administered by community groups is effective for improving multiple food hygiene and food safety behaviors in sustainable ways, and should be included in water and health promotion programs. PMID:23950978

Takanashi, Kumiko; Quyen, Dao To; Le Hoa, Nguyen Thi; Khan, Nguyen Cong; Yasuoka, Junko; Jimba, Masamine

2013-01-01

336

The effect of long-term nitrate treatment on SRB activity, corrosion rate and bacterial community composition in offshore water injection systems.  

PubMed

Biogenic production of hydrogen sulphide (H(2)S) is a problem for the oil industry as it leads to corrosion and reservoir souring. Continuous injection of a low nitrate concentration (0.25-0.33 mM) replaced glutaraldehyde as corrosion and souring control at the Veslefrikk and Gullfaks oil field (North Sea) in 1999. The response to nitrate treatment was a rapid reduction in number and activity of sulphate-reducing bacteria (SRB) in the water injection system biofilm at both fields. The present long-term study shows that SRB activity has remained low at < or =0.3 and < or =0.9 microg H(2)S/cm(2)/day at Veslefrikk and Gullfaks respectively, during the 7-8 years with continuous nitrate injection. At Veslefrikk, 16S rRNA gene based community analysis by PCR-DGGE showed that bacteria affiliated to nitrate-reducing sulphide-oxidizing Sulfurimonas (NR-SOB) formed major populations at the injection well head throughout the treatment period. Downstream of deaerator the presence of Sulfurimonas like bacteria was less pronounced, and were no longer observed 40 months into the treatment period. The biofilm community during nitrate treatment was highly diverse and relative stable for long periods of time. At the Gullfaks field, a reduction in corrosion of up to 40% was observed after switch to nitrate treatment. The present study show that nitrate injection may provide a stable long-term inhibition of SRB in sea water injection systems, and that corrosion may be significantly reduced when compared to traditional biocide treatment. PMID:18752014

Bødtker, Gunhild; Thorstenson, Tore; Lillebø, Bente-Lise P; Thorbjørnsen, Bente E; Ulvøen, Rikke Helen; Sunde, Egil; Torsvik, Terje

2008-12-01

337

Linking people with long-term health conditions to healthy community activities: development of Patient-Led Assessment for Network Support (PLANS)  

PubMed Central

ObjectiveTo combine insights from service users with long-term conditions (LTCs) to assist the development of a community referral intervention designed to promote engagement and improve access to health-relevant resources. BackgroundSocial deprivation and reduced access to resources have been causally linked with social isolation and the ability to manage LTCs. Participation in meaningful activity has been associated with positive health benefits, and strategies to promote access to community activities have shown some potential to improve outcomes for people with LTCs. This suggests the need to develop an engagement and referral intervention in partnership with service users and community groups as part of mainstream self-care support. MethodA series of focus groups and interviews with members of community groups in Greater Manchester designed as an iterative and collaborative approach to elicit the role of personal and community networks that support long-term condition management (LTCM) to develop a community referral tool. ResultsParticipants reported a broad range of resources relevant to LTCM that often went beyond the usual concerns associated with self-care. This helped to inform a tool (PLANS) to tailor access to types of community-based resources which can support LTCM. ConclusionsUnderstanding the everyday challenges of living with a LTC highlighted the importance of connecting and engaging with localized support for people. In response to this, we developed an intervention (PLANS) which tailors access to local resources based on personal preferences, needs and acceptability to encourage service users to engage with sustainable health choices. PMID:23731452

Blickem, Christian; Kennedy, Anne; Vassilev, Ivaylo; Morris, Rebecca; Brooks, Helen; Jariwala, Praksha; Blakeman, Tom; Rogers, Anne

2013-01-01

338

Adipose Tissue-Derived Mesenchymal Stem Cells in Long-Term Dialysis Patients Display Downregulation of PCAF Expression and Poor Angiogenesis Activation  

PubMed Central

We previously demonstrated that mesenchymal stem cells (MSCs) differentiate into functional kidney cells capable of urine and erythropoietin production, indicating that they may be used for kidney regeneration. However, the viability of MSCs from dialysis patients may be affected under uremic conditions. In this study, we isolated MSCs from the adipose tissues of end-stage kidney disease (ESKD) patients undergoing long-term dialysis (KD-MSCs; mean: 72.3 months) and from healthy controls (HC-MSCs) to compare their viability. KD-MSCs and HC-MSCs were assessed for their proliferation potential, senescence, and differentiation capacities into adipocytes, osteoblasts, and chondrocytes. Gene expression of stem cell-specific transcription factors was analyzed by PCR array and confirmed by western blot analysis at the protein level. No significant differences of proliferation potential, senescence, or differentiation capacity were observed between KD-MSCs and HC-MSCs. However, gene and protein expression of p300/CBP-associated factor (PCAF) was significantly suppressed in KD-MSCs. Because PCAF is a histone acetyltransferase that mediates regulation of hypoxia-inducible factor-1? (HIF-1?), we examined the hypoxic response in MSCs. HC-MSCs but not KD-MSCs showed upregulation of PCAF protein expression under hypoxia. Similarly, HIF-1? and vascular endothelial growth factor (VEGF) expression did not increase under hypoxia in KD-MSCs but did so in HC-MSCs. Additionally, a directed in vivo angiogenesis assay revealed a decrease in angiogenesis activation of KD-MSCs. In conclusion, long-term uremia leads to persistent and systematic downregulation of PCAF gene and protein expression and poor angiogenesis activation of MSCs from patients with ESKD. Furthermore, PCAF, HIF-1?, and VEGF expression were not upregulated by hypoxic stimulation of KD-MSCs. These results suggest that the hypoxic response may be blunted in MSCs from ESKD patients. PMID:25025381

Yamanaka, Shuichiro; Yokote, Shinya; Yamada, Akifumi; Katsuoka, Yuichi; Izuhara, Luna; Shimada, Yohta; Omura, Nobuo; Okano, Hirotaka James; Ohki, Takao; Yokoo, Takashi

2014-01-01

339

Long term operation of high concentration powdered activated carbon membrane bio-reactor for advanced water treatment.  

PubMed

A pilot scale experiment was conducted to evaluate the performance of a membrane bioreactor filled with high concentration powdered activated carbon. This hybrid system has great potential to substitute for existing GAC or O3/BAC processes in the drinking water treatment train. The system was installed at a water treatment plant located downstream of the Nakdong river basin, Korea. Effluent of rapid sand filter was used as influent of the system which consists of PAC bio-reactor, submerged MF membrane module and air supply facility. PAC concentration of 20 g/L was maintained at the beginning of the experiment and it was increased to 40 g/L. The PAC has not been changed during the operational periods. The membrane was a hollow fiber type with pore sizes of 0.1 and 0.4 microm. It was apparent that the high PAC concentration could prevent membrane fouling. 40 g/L PAC was more effective to reduce the filtration resistance than 20 g/L. At the flux of 0.36 m/d, TMP was maintained less than 40 kPa for about 3 months by intermittent suction type operation (12 min suction/3 min idling). Adsorption was the dominant role to remove DOC at the initial operational period. However the biological effect was gradually increased after around 3 months operation. Constant DOC removal could be maintained at about 40% without any trouble and then a tremendous reduction of DBPs (HAA5 and THM) higher than 85% was achieved. Full nitrification was observed at the controlled influent ammonia nitrogen concentration of 3 and 7 mg/L. pH was an important parameter to keep stable ammonia oxidation. From almost two years of operation, it is clear that the PAC membrane bioreactor is highly applicable for advanced water treatment under the recent situation of more stringent DBPs regulation in Korea. PMID:15566190

Seo, G T; Moon, C D; Chang, S W; Lee, S H

2004-01-01

340

Long-term deforestation in NW Spain: linking the Holocene fire history to vegetation change and human activities  

NASA Astrophysics Data System (ADS)

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.

Kaal, Joeri; Carrión Marco, Yolanda; Asouti, Eleni; Martín Seijo, Maria; Martínez Cortizas, Antonio; Costa Casáis, Manuela; Criado Boado, Felipe

2011-01-01

341

Linking short- and long-term deformation along an active margin: regional tectono-geomorphic patterns in light of the 2010 Maule Chile earthquake (M8.8)  

NASA Astrophysics Data System (ADS)

Strongly coupled subduction zones are known to have generated some of the largest earthquakes on Earth (megathrust earthquakes). These regions are also associated with an array of tectonic landforms, including multiple marine and fluvial terraces, which are intimately coupled with the long-term effects of seismogenic processes. Thus understanding the parameters that control the along-strike propagation of megathrust earthquake ruptures combined with the analysis of tectonic landforms is fundamental for the assessment of seismic hazards and risk mitigation. Here we report on the 2010 Maule earthquake that ruptured ~500 km of the central Chile margin. Modeling of GPS data during the interseismic and co-seismic periods have revealed segmentation in two main areas of high slip release and coupling. However, the spatiotemporal persistence of these segments and their relation with mechanical properties of the forearc is still poorly understood. To elucidate the relationships between short-term rupture segments and long-term tectono-geomorphic entities of the forearc we quantified permanent, long-term deformation using marine terraces in the Maule rupture zone and evaluate its relation with inter- and co-seismic patterns. We used the MIS-5 marine terrace, an ubiquitous geomorphic reference surface along the coast of central Chile, which we correlated with LiDAR images, field observations and new OSL ages. Furthermore, we evaluated the mechanisms of uplift by forward modeling of plate boundary slip. Coeval terraces are sharply offset across discrete crustal faults and also deformed in areas of broad crustal warping with wavelengths of ~100 km, reflecting activity of deep-seated structures within the interplate zone, both at the southern and northern sectors of the Maule rupture, where uplift rates reach 1.8 mm/yr. The central part, in turn, is characterized by a lesser degree of permanent uplift. Based on the similarities between seismic-cycle deformation and historical earthquake ruptures we propose that the southern sector of the Maule rupture zone constitutes a stable, discrete seismotectonic boundary. In contrast, the northern sector constitutes a rather diffuse boundary that may prevent rupture propagation of some earthquakes. Our modeling results suggest that in the north slip at the plate interface must be deeper than that inferred for the 2010 event to uplift the coast.

Jara-Muñoz, Julius; Melnick, Daniel; Brill, Dominik; Strecker, Manfred

2014-05-01

342

Long-Term Effects of Highly Active Antiretroviral Therapy on CD4+ Cell Evolution among Children and Adolescents Infected with HIV: 5 Years and Counting  

PubMed Central

Background Lower percentages of CD4+ T lymphocytes are associated with adverse clinical outcomes among children and adolescents infected with human immunodeficiency virus (HIV). CD4+ lymphocyte percentage generally increases with receipt of highly active antiretroviral therapy (HAART), but long-term follow-up is required to assess whether these increases in CD4+ cell percentage are maintained and whether they lead to normal CD4+ cell percentages in children with severe immunosuppression. Methods The study population included 1236 children and adolescents perinatally infected with HIV who were enrolled in a US-based multicenter prospective cohort study (Pediatric AIDS Clinical Trials Group 219/219C) and who were not receiving HAART at study initiation. We estimated the effects of HAART, HAART with protease inhibitors, and HAART with nonnucleoside reverse-transcriptase inhibitors on CD4+ cell percentage, using marginal structural models to account for confounding by severity. Results Initiation of any type of HAART increased CD4+ cell percentage by 2.34% (95% confidence interval, 1.35%–3.33%) in the first year, relative to noninitiation of HAART. The substantial increases in CD4+ cell percentage observed after the first year of experience with these combination therapies were followed by relatively smaller increases that continued for 5 years after initiation. Although larger increases in CD4+ cell percentage were observed among children with a greater degree of immunosuppression at baseline, the mean CD4+ cell percentage after 5 years of HAART did not reach normal levels. Conclusions Our study supports the initiation of HAART in children before severe immunosuppression occurs for long-term maintenance of normal CD4+ cell percentages. This beneficial result must be weighed against the evidence of potential adverse events associated with the prolonged use of such therapy. PMID:18426371

Patel, Kunjal; Hernán, Miguel A.; Williams, Paige L.; Seeger, John D.; McIntosh, Kenneth; Van Dyke, Russell B.; Seage, George R.

2011-01-01

343

Associations of Dietary Intake and Physical Activity with Sleep Disordered Breathing in the Apnea Positive Pressure Long-term Efficacy Study (APPLES)  

PubMed Central

The purpose of this study was to examine whether dietary habits and physical activity patterns were independently associated with severity of sleep disordered breathing (SDB) in adults diagnosed with obstructive sleep apnea. Data collected from 320 adults participating in an ancillary study of The Apnea Positive Pressure Long-term Efficacy Study were analyzed as a cross-sectional assessment at study baseline. The respiratory disturbance index (RDI) was used as a measure of the severity of sleep disordered breathing. Separate linear regression models were fitted using RDI as the independent variable and various preselected components of dietary intake and physical activity as the dependent variables. The results indicated that even after adjusting for BMI, age, and daytime sleepiness, subjects with very severe and extremely severe SDB (RDI ? 50) consumed a diet that was higher in cholesterol, protein, total fat, and total saturated fatty acids. These findings were most evident among women. For all participants, those with RDI ? 50 in comparison to those < 50, on average consumed 88.16 more mg of cholesterol per day (95% CI: 44.45 to 131.86, p < 0.001). Among the women participants only, those with RDI ? 50 in comparison to those < 50, on average consumed 21.96 more grams of protein (95% CI: 2.64 to 41.29, p = 0.026), 27.75 more grams of total fat (95% CI: 3.38 to 52.11, p = 0.026), and 9.24 more grams of saturated fatty acids (95% CI: 0.67 to 17.80, p = 0.035). Furthermore, those with an RDI ? 50 had a 224.58 greater caloric expenditure than those with RDI < 50 from all activities including work and sleep (95% CI: 40.98 to 408.18, p = 0.017). Although significant results were seen in a reduction of physical activity from recreational activities, this finding was explained by the increase in BMI associated with higher levels of RDI. Citation: Vasquez MM; Goodwin JL; Drescher AA; Smith TW; Quan SF. Associations of dietary intake and physical activity with sleep disordered breathing in the apnea positive pressure long-term efficacy study (APPLES). J Clin Sleep Med 2008;4(5):411–418. PMID:18853696

Vasquez, Monica M.; Goodwin, James L.; Drescher, Amy A.; Smith, Terry W.; Quan, Stuart F.

2008-01-01

344

Long term anti-tumour necrosis factor ? monotherapy in rheumatoid arthritis: effect on radiological course and prognostic value of markers of cartilage turnover and endothelial activation  

PubMed Central

Objectives: To investigate the effect of prolonged neutralisation of tumour necrosis factor ? (TNF?) on the radiological course in rheumatoid arthritis (RA). To assess whether the radiological course can be predicted by clinical variables or biological markers of cartilage and synovium turnover and of endothelial activation. Patients and methods: Forty seven patients with active RA enrolled at our centre in monotherapy trials with adalimumab (D2E7), a fully human anti-TNF? monoclonal antibody, were studied for two years. Radiographs of hands and feet obtained at baseline and after one and two years were scored in chronological order by a single, blinded observer using the modified Sharp method. Radiological course was classified as stable or progressive using the smallest detectable difference as cut off point. The relation between radiological course and serum markers of cartilage and synovium turnover (metalloproteinases (MMP-1 and MMP-3), cartilage oligomeric matrix protein (COMP), human cartilage glycoprotein-39 (HC gp-39)), endothelial activation (soluble E-selectin and intercellular adhesion molecule (ICAM-1)), and integrated measures of disease activity were assessed using univariate and multivariate analysis. Results: Radiological evaluation was performed in 36 patients with paired sets of radiographs at baseline and two years. After two years a total of 15/36 (42%) presented no radiological progression. More patients with stable radiological course were still receiving anti-TNF? treatment after two years (13/15 (87%) v 11/21 (52%); p=0.03) and had lower baseline COMP and sICAM-1 levels (p=0.01 and 0.04, respectively) than those in the group with progressive disease. In a logistic regression model the combination of sustained TNF neutralisation and baseline COMP and sICAM-1 levels was predictive for radiological outcome (p=0.03). C reactive protein and disease activity score area under the curve were significantly correlated with changes in radiological scores after two years (r=0.40 and 0.37, p<0.05). Long term TNF? neutralisation decreased the levels of COMP, sICAM, MMPs, and HC gp-39, but not sE-selectin. Conclusion: The results suggest that long term monotherapy with anti-TNF? has a positive effect on radiological outcome and modulates cartilage and synovium turnover as measured by biological markers. Baseline serum sICAM-1 levels and COMP levels may be helpful to identify patients with progressive or non-progressive radiological outcome. PMID:11874832

den Broeder, A A; Joosten, L; Saxne, T; Heinegard, D; Fenner, H; Miltenburg, A; Frasa, W; van Tits, L J; Buurman, W; van Riel, P L C M; van de Putte, L B A; Barrera, P

2002-01-01

345

Soil microbiological properties and enzymatic activities of long-term post-fire recovery in dry and semiarid Aleppo pine (Pinus halepensis M.) forest stands  

NASA Astrophysics Data System (ADS)

Wildfires affecting forest ecosystems and post-fire silvicultural treatments may cause considerable changes in soil properties. The capacity of different microbial groups to recolonize soil after disturbances is crucial for proper soil functioning. The aim of this work was to investigate some microbial soil properties and enzyme activities in semiarid and dry Aleppo pine (Pinus halepensis M.) forest stands. Different plots affected by a wildfire event 17 years ago without or with post-fire silvicultural treatments five years after the fire event were selected. A mature Aleppo pine stand unaffected by wildfire and not thinned was used as a control. Physicochemical soil properties (soil texture, pH, carbonates, organic matter, electrical conductivity, total N and P), soil enzymes (urease, phosphatase, ?-glucosidase and dehydrogenase activities), soil respiration and soil microbial biomass carbon were analysed in the selected forests areas and plots. The main finding was that long time after this fire event produces no differences in the microbiological soil properties and enzyme activities of soil after comparing burned and thinned, burned and not thinned, and mature plots. Thus, the long-term consequences and post-fire silvicultural management in the form of thinning have a significant effect on the site recovery after fire. Moreover, significant site variation was generally seen in soil enzyme activities and microbiological parameters. We conclude that total vegetation restoration normalises microbial parameters, and that wildfire and post-fire silvicultural treatments are not significant factors of soil properties after 17 years.

Hedo, J.; Lucas-Borja, M. E.; Wic, C.; Andrés Abellán, M.; de Las Heras, J.

2014-10-01

346

Microcalorimetric study of the effects of long-term fertilization on soil microbial activity in a wheat field on the Loess Plateau.  

PubMed

The effects of the long-term inorganic (nitrogen, N; phosphate, P) and organic (manure, M; straw, S) fertilizers/managemenet individually and in combinations (N, NP, SNP, M, and MNP) on soil microbial activity were investigated in a wheat field on the Loess Plateau, China. Microcalorimetry was used to determine microbial activity under different treatments. Nearly 30 years of consecutive fertilization has altered the culturable population of soil bacteria and fungi, the highest ones were detected in the treatments of manure and MNP, followed by the NP and SNP treatments. The microbial growth rate constant (?/h(-1)) was significantly greater in the MNP treatment than all the other treatments. The total heat exchange values (Q/J) were the highest in the MNP and NP treatments, which were significantly different from the N and M treatments. The peak height (P(t)/?W) were significantly higher in MNP and NP treatments than in the remaining treatments. The peak time values (t(p)/h) among the MNP, NP, SNP and M, N and CK treatments were significantly different. In general, comparing with control, soil microbial activity was much higher in MNP, NP and SNP treatments, all including the phosphate fertilizer. Our results showed that the application of inorganic fertilizer and organic manure have positive effects on multiple soil chemical parameters, soil microorganism abundance and activity, and hence crop yield. PMID:25134677

Zhang, Qi; Liu, Xiaomei; Ma, Xiaojun; Fang, Jian; Fan, Tinglu; Wu, Fasi; An, Lizhe; Feng, Huyuan

2014-12-01

347

Influences of a DRD2 polymorphism on updating of long-term memory representations and caudate BOLD activity: Magnification in aging.  

PubMed

A number of genetic polymorphisms are related to individual differences in cognitive performance. Striatal dopamine (DA) functions, associated with cognitive performance, are linked to the TaqIA polymorphism of the DRD2/ANKK1 gene. In humans, presence of an A1 allele of the DRD2/ANKK1-TaqIA polymorphism is related to reduced density of striatal DA D2 receptors. The resource-modulation hypothesis assumes that aging-related losses of neurochemical and structural brain resources modulate the extent to which genetic variations affect cognitive functioning. Here, we tested this hypothesis using functional MRI during long-term memory (LTM) updating in younger and older carriers and noncarriers of the A1-allele of the TaqIa polymorphism. We demonstrate that older A1-carriers have worse memory performance, specifically during LTM updating, compared to noncarriers. Moreover, A1-carriers exhibited less blood oxygen level-dependent (BOLD) activation in left caudate nucleus, a region critical to updating. This effect was only seen in older adults, suggesting magnification of genetic effects on functional brain activity in aging. Further, a positive relationship between caudate BOLD activation and updating performance among non-A1 carriers indicated that caudate activation was behaviorally relevant. These results demonstrate a link between the DRD2/ANKK1-TaqIA polymorphism and neurocognitive deficits related to LTM updating, and provide novel evidence that this effect is magnified in aging. Hum Brain Mapp, 2014. © 2014 Wiley Periodicals, Inc. PMID:25486867

Persson, Jonas; Rieckmann, Anna; Kalpouzos, Grégoria; Fischer, Håkan; Bäckman, Lars

2014-12-01

348

Anandamide, cannabinoid type 1 receptor, and NMDA receptor activation mediate non-Hebbian presynaptically expressed long-term depression at the first central synapse for visceral afferent fibers.  

PubMed

Presynaptic long-term depression (LTD) of synapse efficacy generally requires coordinated activity between presynaptic and postsynaptic neurons and a retrograde signal synthesized by the postsynaptic cell in an activity-dependent manner. In this study, we examined LTD in the rat nucleus tractus solitarii (NTS), a brainstem nucleus that relays homeostatic information from the internal body to the brain. We found that coactivation of N-methyl-D-aspartate receptors (NMDARs) and type 1 cannabinoid receptors (CB1Rs) induces LTD at the first central excitatory synapse between visceral fibers and NTS neurons. This LTD is presynaptically expressed. However, neither postsynaptic activation of NMDARs nor postsynaptic calcium influx are required for its induction. Direct activation of NMDARs triggers cannabinoid-dependent LTD. In addition, LTD is unaffected by blocking 2-arachidonyl-glycerol synthesis, but its induction threshold is lowered by preventing fatty acid degradation. Altogether, our data suggest that LTD in NTS neurons may be entirely expressed at the presynaptic level by local anandamide synthesis. PMID:23904599

Khlaifia, Abdessattar; Farah, Hanad; Gackiere, Florian; Tell, Fabien

2013-07-31

349

Short- and long-term A3 adenosine receptor activation inhibits the Na+/H+ exchanger NHE3 activity and expression in opossum kidney cells.  

PubMed

The renal function of the A(3) adenosine receptor (A3AR) is poorly characterized. In this study, we report that the A3AR-selective agonist, 1-[2-chloro-6-[[(3-iodophenyl)methyl]amino]-9H-purine-9-yl]-1-deoxy-N-methyl-b-D-ribofuranuronamide (2-Cl-IBMECA) regulates the Na+/H+ exchanger-3 (NHE3) in a dose- and time-dependent fashion. In opossum kidney (OK) cells, 2-Cl-IBMECA at high (10(-6) M) and low (10(-8) M) dose inhibits NHE3 by a multiphasic time course with an acute phase of NHE3 inhibition from 15 min to 1 h, followed by a chronic phase of NHE3 inhibition from 24 to 48 h. Pre-incubation with either the selective A3AR-antagonist MRS1523 (10(-7) M) or the protein kinase C inhibitor, Calphostin C (10(-8) M) completely blocked 10(-6) M 2-Cl-IBMECA-induced acute (15 min) and chronic (24 h) phases of NHE3 inhibition. In contrast, the acute inhibitory phase (15 min) of 10(-8) M 2-Cl-IBMECA was completely prevented only when Calphostin C (10(-8) M) was added in conjunction with the protein kinase A inhibitor, H89 (10(-7) M). Acute (15 or 30 min depending on the A3AR-agonist concentration) A3AR-dependent inhibition of NHE3 activity was accompanied by decrease in cell surface NHE3 protein with no change in total NHE3 antigen. Chronic (24 h) A3AR-mediated down-regulation of NHE3 was associated with reduction of surface NHE3, decreased total NHE3 protein (70%) and a paradoxical rise of NHE3 RNA (40%). In summary, these results indicate that A3AR directly regulates NHE3 at multiple levels in a complex pattern. A3AR-dependent short- and long-term inhibition of NHE3 may be a fundamental mechanism of net sodium and fluid balance. PMID:18286509

Di Sole, Francesca; Cerull, Robert; Babich, Victor; Casavola, Valeria; Helmle-Roth, Corinna; Burckhardt, Gerhard

2008-07-01

350

The Inhibitory Effect of Interleukin1b on Long-Term Potentiation Is Coupled with Increased Activity of Stress-Activated Protein Kinases  

Microsoft Academic Search

Long-term potentiation (LTP) in perforant path-granule cell synapses is decreased in aged rats, stressed rats, and rats injected intracerebroventricularly with the proinflammatory cy- tokine interleukin-1b (IL-1b). One factor that is common to these experimental conditions is an increase in the concentration of IL-1b in the dentate gyrus, suggesting a causal relationship between the compromise in LTP and increased IL-1b concentra-

E. Vereker; E. O'Donnell; M. A. Lynch

2000-01-01

351

Basics (Long-Term Care)  

MedlinePLUS

... Term Care? Expand Long-term Care Considerations for LGBT Adults Expand Health Disparities Impacting LTC Expand Caregivers ... on Alzheimer's Disease Lesbian, Gay, Bisexual and Transgender (LGBT) community Home About Us Accessibility Disclaimer Privacy Contact ...

352

Medicare (Long-Term Care)  

MedlinePLUS

... term Care Services – Skilled Nursing Medicare does not pay the largest part of long-term care services ... 100 days . For the first 20 days, Medicare pays 100 percent of your costs. For days 21 ...

353

Adenosine monophosphate activated protein kinase (AMPK), a mediator of estradiol-induced apoptosis in long-term estrogen deprived breast cancer cells.  

PubMed

Estrogens stimulate growth of hormone-dependent breast cancer but paradoxically induce tumor regress under certain circumstances. We have shown that long-term estrogen deprivation (LTED) enhances the sensitivity of hormone dependent breast cancer cells to estradiol (E2) so that physiological concentrations of estradiol induce apoptosis in these cells. E2-induced apoptosis involve both intrinsic and extrinsic pathways but precise mechanisms remain unclear. We found that exposure of LTED MCF-7 cells to E2 activated AMP activated protein kinase (AMPK). In contrast, E2 inhibited AMPK activation in wild type MCF-7 cells where E2 prevents apoptosis. As a result of AMPK activation, the transcriptional activity of FoxO3, a downstream factor of AMPK, was up-regulated in E2 treatment of LTED. Increased activity of FoxO3 was demonstrated by up-regulation of three FoxO3 target genes, Bim, Fas ligand (FasL), and Gadd45?. Among them, Bim and FasL mediate intrinsic and extrinsic apoptosis respectively and Gadd45? causes cell cycle arrest at the G2/M phase. To further confirm the role of AMPK in apoptosis, we used AMPK activator AICAR in wild type MCF-7 cells and examined apoptosis, proliferation and expression of Bim, FasL, and Gadd45?. The effects of AICAR on these parameters recapitulated those observed in E2-treated LTED cells. Activation of AMPK by AICAR also increased expression of Bax in MCF-7 cells and its localization to mitochondria, which is a required process for apoptosis. These results reveal that AMPK is an important factor mediating E2-induced apoptosis in LTED cells, which is implicative of therapeutic potential for relapsing breast cancer after hormone therapy. PMID:25721362

Chen, Haiyan; Wang, Ji-Ping; Santen, Richard J; Yue, Wei

2015-06-01

354

Myosin II ATPase activity mediates the long-term potentiation-induced exodus of stable F-actin bound by drebrin A from dendritic spines.  

PubMed

The neuronal actin-binding protein drebrin A forms a stable structure with F-actin in dendritic spines. NMDA receptor activation causes an exodus of F-actin bound by drebrin A (DA-actin) from dendritic spines, suggesting a pivotal role for DA-actin exodus in synaptic plasticity. We quantitatively assessed the extent of DA-actin localization to spines using the spine-dendrite ratio of drebrin A in cultured hippocampal neurons, and found that (1) chemical long-term potentiation (LTP) stimulation induces rapid DA-actin exodus and subsequent DA-actin re-entry in dendritic spines, (2) Ca(2+) influx through NMDA receptors regulates the exodus and the basal accumulation of DA-actin, and (3) the DA-actin exodus is blocked by myosin II ATPase inhibitor, but is not blocked by myosin light chain kinase (MLCK) or Rho-associated kinase (ROCK) inhibitors. These results indicate that myosin II mediates the interaction between NMDA receptor activation and DA-actin exodus in LTP induction. Furthermore, myosin II seems to be activated by a rapid actin-linked mechanism rather than slow MLC phosphorylation. Thus the myosin-II mediated DA-actin exodus might be an initial event in LTP induction, triggering actin polymerization and spine enlargement. PMID:24465547

Mizui, Toshiyuki; Sekino, Yuko; Yamazaki, Hiroyuki; Ishizuka, Yuta; Takahashi, Hideto; Kojima, Nobuhiko; Kojima, Masami; Shirao, Tomoaki

2014-01-01

355

The Long Term Impact of Cataract Surgery on Quality of Life, Activities and Poverty: Results from a Six Year Longitudinal Study in Bangladesh and the Philippines  

PubMed Central

Background Cataract surgery has been shown to improve quality of life and household economy in the short term. However, it is unclear whether these benefits are sustained over time. This study aims to assess the six year impact of cataract surgery on health related quality of life (HRQoL), daily activities and economic poverty in Bangladesh and The Philippines. Methods and Findings This was a longitudinal study. At baseline people aged ?50 years with visual impairment due to cataract (‘cases’) and age-, sex-matched controls without visual impairment were interviewed about vision specific and generic HRQoL, daily activities and economic indicators (household per capita expenditure, assets and self-rated wealth). Cases were offered free or subsidised cataract surgery. Cases and controls were re-interviewed approximately one and six years later. At baseline across the two countries there were 455 cases and 443 controls. Fifty percent of cases attended for surgery. Response rates at six years were 47% for operated cases and 53% for controls. At baseline cases had poorer health and vision related QoL, were less likely to undertake productive activities, more likely to receive assistance with activities and were poorer compared to controls (p<0.05). One year after surgery there were significant increases in HRQoL, participation and time spent in productive activities and per capita expenditure and reduction in assistance with activities so that the operated cases were similar to controls. These increases were still evident after six years with the exception that time spent on productive activities decreased among both cases and controls. Conclusion Cataract causing visual loss is associated with reduced HRQoL and economic poverty among older adults in low-income countries. Cataract surgery improves the HRQoL of the individual and economy of the household. The findings of this study suggest these benefits are sustained in the long term. PMID:24747192

Danquah, Lisa; Kuper, Hannah; Eusebio, Cristina; Rashid, Mamunur Akm; Bowen, Liza; Foster, Allen; Polack, Sarah

2014-01-01

356

Long-term operation of a novel pilot-scale six tanks alternately operating activated sludge process in treating domestic wastewater.  

PubMed

The performance of a new pilot-scale six tanks activated sludge process has been evaluated for 303 d, receiving real domestic wastewater with a flow rate of 15-24.4 L/h. Partial nitrification via nitrite and microbial community structure were investigated in this system. The result shows that the nitrite accumulation rate was achieved successfully over 94% in the last aerobic compartment through a combination of short hydraulic retention time and low dissolved oxygen (DO) level. Fluorescence in situ hybridization analysis was used to correlate ammonia-oxidizing bacteria (AOB) numbers with nutrient removal via nitrite. It was shown that in response to complete and partial nitrification modes, the numbers of AOB population were 7.7 x 10(7) cells/g mixed liquor suspended solids (MLSS) and 5.31 x 10(8) cells/g MLSS, respectively. The morphology of the sludge indicated that there is a small rod-shaped and spherical cluster which was mainly dominantly bacterial according to scanning electron microscope. Higher pollutant removal efficiencies of 86.2%, 98%, and 96.1%, for total nitrogen, NH4+ - N, and total phosphorus, respectively, were achieved by a long-term operation of the six tanks activated sludge process at a low DO concentration and low chemical oxygen demand to nitrogen ratio which were approximately equal to the complete nitrification-ldenitrification with the addition of an external carbon source at a concentration of 1.5-2.5 mg/L. PMID:24956781

Mohammed, R N; Abu-Alhail, S; Xi-Wu, L

2014-08-01

357

Asynchronous Pre- and Postsynaptic Activity Induces Associative Long-Term Depression in Area CA1 of the Rat Hippocampus in vitro  

NASA Astrophysics Data System (ADS)

Associative long-term depression (LTD) was induced in hippocampal slice cultures with repeated low-frequency (0.3 Hz) stimulation of the Schaffer collateral pathway, only when such stimuli were preceded by intracellular injection of brief depolarizing current pulses in the postsynaptic CA1 pyramidal cell. The decrease in excitatory postsynaptic potential amplitude lasted >30 min, could be reversed by induction of potentiation, could be induced at previously potentiated inputs, was input-specific, and did not require activation or potentiation of other inputs. The magnitude of the depression depended upon the time interval between depolarization and stimulation and upon the duration of the depolarizing pulse. LTD was not observed in neurons impaled with electrodes containing a Ca2+ chelator. LTD could not be induced in the presence of an N-methyl-D-aspartate receptor antagonist, suggesting that voltage-dependent Ca2+ influx is necessary but not sufficient for LTD induction. We conclude that associative LTD results when synaptic activity follows postsynaptic depolarization within a circumscribed time window.

Debanne, Dominique; Gahwiler, Beat H.; Thompson, Scott M.

1994-02-01

358

Long-Term Effect of a School-Based Physical Activity Program (KISS) on Fitness and Adiposity in Children: A Cluster-Randomized Controlled Trial  

PubMed Central

Background School-based intervention studies promoting a healthy lifestyle have shown favorable immediate health effects. However, there is a striking paucity on long-term follow-ups. The aim of this study was therefore to assess the 3 yr-follow-up of a cluster-randomized controlled school-based physical activity program over nine month with beneficial immediate effects on body fat, aerobic fitness and physical activity. Methods and Findings Initially, 28 classes from 15 elementary schools in Switzerland were grouped into an intervention (16 classes from 9 schools, n?=?297 children) and a control arm (12 classes from 6 schools, n?=?205 children) after stratification for grade (1st and 5th graders). Three years after the end of the multi-component physical activity program of nine months including daily physical education (i.e. two additional lessons per week on top of three regular lessons), short physical activity breaks during academic lessons, and daily physical activity homework, 289 (58%) participated in the follow-up. Primary outcome measures included body fat (sum of four skinfolds), aerobic fitness (shuttle run test), physical activity (accelerometry), and quality of life (questionnaires). After adjustment for grade, gender, baseline value and clustering within classes, children in the intervention arm compared with controls had a significantly higher average level of aerobic fitness at follow-up (0.373 z-score units [95%-CI: 0.157 to 0.59, p?=?0.001] corresponding to a shift from the 50th to the 65th percentile between baseline and follow-up), while the immediate beneficial effects on the other primary outcomes were not sustained. Conclusions Apart from aerobic fitness, beneficial effects seen after one year were not maintained when the intervention was stopped. A continuous intervention seems necessary to maintain overall beneficial health effects as reached at the end of the intervention. Trial Registration ControlledTrials.com ISRCTN15360785 PMID:24498404

Meyer, Ursina; Schindler, Christian; Zahner, Lukas; Ernst, Dominique; Hebestreit, Helge; van Mechelen, Willem; Rocca, Hans-Peter Brunner-La; Probst-Hensch, Nicole; Puder, Jardena J.; Kriemler, Susi

2014-01-01

359

Total knee replacement in young, active patients: long-term follow-up and functional outcome: a concise follow-up of a previous report.  

PubMed

Concern exists regarding the long-term durability and effectiveness of total knee arthroplasty in young patients. We reviewed our experience with total knee arthroplasty in patients fifty-five years old and younger with severe osteoarthritis to determine the long-term outcomes. One hundred and fourteen total knee arthroplasties were performed in eighty-eight patients at an average patient age of fifty-one years. Clinical outcomes, survival analysis, and radiographs were all reviewed at the most recent follow-up. One hundred and eight knees (eighty-four patients) were followed up from May 2011 to 2012. At thirty years, survivorship without revision for any cause was 70.1% (twenty-five revisions) and survivorship with failure defined as aseptic revision of the tibial or femoral components was 82.5%. At thirty years, a significant difference existed in the survivorship free from tibial or femoral aseptic revision (p = 0.003) between the non-modular Insall-Burstein I component (92.3%) and the modular Insall-Burstein II component (68.3%). All patients were evaluated at an average time from the index total knee arthroplasty to the latest follow-up of 25.1 years (range, twenty to thirty-five years). Clinical evaluation was obtained in thirty-six patients with forty-five total knee arthroplasties. The average Hospital for Special Surgery score had improved from 57.9 points preoperatively to 85.3 points. The average Knee Society score was 87.4 points and the average Knee Society functional score was 62.1 points; the average knee motion was 110°. The mean Tegner and Lysholm activity score improved from 1.5 points preoperatively to 3.0 points. Radiographic review of forty-two knees that had undergone total knee arthroplasty demonstrated a mean 3.2° of valgus, with no cases of radiographically loose components. Total knee arthroplasty with use of a cemented posterior stabilized system, particularly a non-modular Insall-Burstein I design, was an effective treatment option with durable results for end-stage symptomatic osteoarthritis in this young cohort. These data should provide comparison for modern total knee arthroplasties and alternative procedures in young patients. PMID:25232089

Long, William J; Bryce, Christopher D; Hollenbeak, Christopher S; Benner, Rodney W; Scott, W Norman

2014-09-17

360

Long-Term Vision and Non-Vision Dominant Behavioral Deficits in the 2-VO Rats Are Accompanied by Time and Regional Glial Activation in the White Matter  

PubMed Central

The permanent occlusion of common carotid arteries (2-VO) in rats has been shown to induce progressive and long-lasting deficits in cognitive performance, however, whether these aberrant behaviors are attributed to visual dysfunction or cognitive impairment and what are the underlying mechanisms, remain controversial. In the present study, vision dominant (Morris water maze) and non-vision dominant (voice-cued fear conditioning) behavioral tests were assigned to comprehensively evaluate the influence of 2-VO lesion on cognitive behaviors. In the Morris water maze test, escape latencies of 2-VO rats were markedly increased in both hidden and unfixed visible platform tasks, which were accompanied by severe retinal damage. In the voice-cued fear conditioning test, significant reduction in the percentage of freezing behavior was observed at 60 days after 2-VO lesion. Chronic lesion by 2-VO failed to cause noticeable changes in the grey matter, as indicated by intact hippocampal and prefrontal cortical structures, sustained synaptic protein levels and glial cell numbers. In contrast, aberrant arrangement of myelinated axons was observed in the optic tract, but not in the corpus callosum and inner capsule of 2-VO rats. Concurrently, marked astrocyte proliferation and microglia activation in the optic tract occurred at 3 days after 2-VO lesion, and continued for up to 60 days. Differently, robust glial activation was observed in the corpus callosum at 3 days after 2-VO surgery, and then gradually returned to the baseline level at 14 and 60 days. Our study reported for the first time about the effect of 2-VO on the long-term cognitive impairment in the non-vision dominant fear conditioning test, which may be more applicable than the Morris water maze test for assessing 2-VO associated cognitive function. The time and region specific glial activation in the white matter may relate to retinal impairment, even behavioral deficits, in the setting of chronic cerebral hypoperfusion. PMID:24968196

Ruan, Zhi; Lei, Yun; Chen, Yu Ting; Zhang, Hai Yan

2014-01-01

361

Circadian activity rhythms and voluntary ethanol intake in male and female ethanol-preferring rats: effects of long-term ethanol access.  

PubMed

Chronic alcohol (ethanol) intake alters fundamental properties of the circadian clock. While previous studies have reported significant alterations in free-running circadian period during chronic ethanol access, these effects are typically subtle and appear to require high levels of intake. In the present study we examined the effects of long-term voluntary ethanol intake on ethanol consumption and free-running circadian period in male and female, selectively bred ethanol-preferring P and HAD2 rats. In light of previous reports that intermittent access can result in escalated ethanol intake, an initial 2-week water-only baseline was followed by either continuous or intermittent ethanol access (i.e., alternating 15-day epochs of ethanol access and ethanol deprivation) in separate groups of rats. Thus, animals were exposed to either 135 days of continuous ethanol access or to five 15-day access periods alternating with four 15-day periods of ethanol deprivation. Animals were maintained individually in running-wheel cages under continuous darkness throughout the experiment to allow monitoring of free-running activity and drinking rhythms, and 10% (v/v) ethanol and plain water were available continuously via separate drinking tubes during ethanol access. While there were no initial sex differences in ethanol drinking, ethanol preference increased progressively in male P and HAD2 rats under both continuous and intermittent-access conditions, and eventually exceeded that seen in females. Free-running period shortened during the initial ethanol-access epoch in all groups, but the persistence of this effect showed complex dependence on sex, breeding line, and ethanol-access schedule. Finally, while females of both breeding lines displayed higher levels of locomotor activity than males, there was little evidence for modulation of activity level by ethanol access. These results are consistent with previous findings that chronic ethanol intake alters free-running circadian period, and show further that the development of chronobiological tolerance to ethanol may vary by sex and genotype. PMID:25281289

Rosenwasser, Alan M; McCulley, Walter D; Fecteau, Matthew

2014-11-01

362

Activation instead of blocking mesolimbic dopaminergic reward circuitry is a preferred modality in the long term treatment of reward deficiency syndrome (RDS): a commentary  

PubMed Central

Background and hypothesis Based on neurochemical and genetic evidence, we suggest that both prevention and treatment of multiple addictions, such as dependence to alcohol, nicotine and glucose, should involve a biphasic approach. Thus, acute treatment should consist of preferential blocking of postsynaptic Nucleus Accumbens (NAc) dopamine receptors (D1-D5), whereas long term activation of the mesolimbic dopaminergic system should involve activation and/or release of Dopamine (DA) at the NAc site. Failure to do so will result in abnormal mood, behavior and potential suicide ideation. Individuals possessing a paucity of serotonergic and/or dopaminergic receptors, and an increased rate of synaptic DA catabolism due to high catabolic genotype of the COMT gene, are predisposed to self-medicating any substance or behavior that will activate DA release, including alcohol, opiates, psychostimulants, nicotine, gambling, sex, and even excessive internet gaming. Acute utilization of these substances and/or stimulatory behaviors induces a feeling of well being. Unfortunately, sustained and prolonged abuse leads to a toxic" pseudo feeling" of well being resulting in tolerance and disease or discomfort. Thus, a reduced number of DA receptors, due to carrying the DRD2 A1 allelic genotype, results in excessive craving behavior; whereas a normal or sufficient amount of DA receptors results in low craving behavior. In terms of preventing substance abuse, one goal would be to induce a proliferation of DA D2 receptors in genetically prone individuals. While in vivo experiments using a typical D2 receptor agonist induce down regulation, experiments in vitro have shown that constant stimulation of the DA receptor system via a known D2 agonist results in significant proliferation of D2 receptors in spite of genetic antecedents. In essence, D2 receptor stimulation signals negative feedback mechanisms in the mesolimbic system to induce mRNA expression causing proliferation of D2 receptors. Proposal and conclusion The authors propose that D2 receptor stimulation can be accomplished via the use of Synapatmine™, a natural but therapeutic nutraceutical formulation that potentially induces DA release, causing the same induction of D2-directed mRNA and thus proliferation of D2 receptors in the human. This proliferation of D2 receptors in turn will induce the attenuation of craving behavior. In fact as mentioned earlier, this model has been proven in research showing DNA-directed compensatory overexpression (a form of gene therapy) of the DRD2 receptors, resulting in a significant reduction in alcohol craving behavior in alcohol preferring rodents. Utilizing natural dopaminergic repletion therapy to promote long term dopaminergic activation will ultimately lead to a common, safe and effective modality to treat Reward Deficiency Syndrome (RDS) behaviors including Substance Use Disorders (SUD), Attention Deficit Hyperactivity Disorder (ADHD), Obesity and other reward deficient aberrant behaviors. This concept is further supported by the more comprehensive understanding of the role of dopamine in the NAc as a "wanting" messenger in the meso-limbic DA system. PMID:19014506

Blum, Kenneth; Chen, Amanda Lih Chuan; Chen, Thomas JH; Braverman, Eric R; Reinking, Jeffrey; Blum, Seth H; Cassel, Kimberly; Downs, Bernard W; Waite, Roger L; Williams, Lonna; Prihoda, Thomas J; Kerner, Mallory M; Palomo, Tomas; Comings, David E; Tung, Howard; Rhoades, Patrick; Oscar-Berman, Marlene

2008-01-01

363

The summit activity at Mt. Etna from 1995 to 2001: a multidisciplinary approach to investigate the long-term processes in the plumbing system  

NASA Astrophysics Data System (ADS)

The integration of volcanologic observations with petrologic, microgravity and ground deformation data acquired at Etna from 1995 to 2001, provide the opportunity to investigate the long-term dynamics of Mt. Etna during a period when the activity was restricted to the summit craters. Temporal patterns of major and trace elements indicate that the variability of bulk rocks composition is due to fractional crystallization and mixing between residing and new intruding magmas. Microgravity data show that from late-1996 to mid-1999 and from late-2000 to mid-2001, phases of strong gravity decrease occurred, centered on the upper southeastern sector of the volcano. The gravity decreases coincide with increases in the rate of the seismic strain release. Ground deformation show, from 1994 to the onset of the 2001 eruption, an almost continuous expansion of the volcano mainly due to magma accumulation into the western sector of the volcano. Therefore, the anti-correlation between gravity and seismicity in the eastern flank is not strictly connected to movements of magma and/or change of its chemical and physical properties. Conversely, these data suggest an increase of micro-fracturing along the NNW-SSE structural trend, implying a local density (gravity) decrease coupled with an increase in the release of seismic energy. From 1996 to 1999 the ascent of conspicuous magma volumes promoted the reactivation of the South-East and Voragine summit craters, that showed an intense explosive and effusive activity until the end of 1999. The increase in the rate of fracturing from late-2000 to mid-2001 enhanced the formation of a preferential path for magma ascent to the surface and the onset of the July 2001 flank eruption.

Carbone, Daniele; Corsaro, Rosa Anna; Guglielmino, Francesco; Puglisi, Giuseppe

2014-05-01

364

Factors to be Considered in Long-Term Monitoring of a Former Nuclear Test Site in a Geophysically Active and Water-rich Environment  

NASA Astrophysics Data System (ADS)

The US Department of Energy (USDOE) is currently undertaking an ambitious program of environmental remediation of the surface of Amchitka Island in the western Aleutians, where three underground nuclear tests were conducted during 1963-1971. Among these tests was Cannikin, at approximately 5 megatons the largest nuclear device ever exploded underground by the United States and equivalent in seismic energy release to a magnitude 7 earthquake. The blast caused about 1 m of uplift of the Bering Sea coastline in the 3-km-wide fault-bounded block within which it was detonated. The impending final transfer of stewardship of this area to the US Fish and Wildlife Service as part of the Alaska Maritime National Wildlife Refuge raises anew the question of the potential for transport of radionuclides from the shot cavity, located at 1791 m depth in mafic laharic breccias, into the accessible environment. In particular, there is concern about whether such contaminants could become concentrated in the marine food chain that is used for subsistence by Alaskan Natives (and by the broader international community through the North Pacific and Bering Fisheries). Both possible transport pathways in the form of faults and transport medium in the form of abundant water are present. Since the pre-plate tectonics paradigm days of active testing, the scientific community's understanding of the tectonic context of the Aleutian Islands has grown tremendously. Recently, the first direct measurements of motion within the arc have been made. How this new understanding should guide plans for long-term monitoring of the site is an important question. Convergence due to subduction of the North Pacific plate beneath North America ranges from near-normal at the Alaska Peninsula and eastern Aleutian islands to highly oblique in the west. Amchitka itself can be seen as a subaerial portion of a 200-km-long Rat Island arc crest segment. This fragment has torn from the Andreanof Islands to the east at Amchitka Pass and has rotated 25 degrees clockwise about a pole near Kiska Volcano, in the right-lateral shear of the western arc. The island is cut by ENE trending normal faults that are down-dropped to the northwest and reflect arc-parallel extension. Quaternary-age normal faulting decreases in intensity northwestward from Amchitka Pass, but is nevertheless present in the vicinity of and was activated by the nuclear tests. Westward translation of the island is probably more than the rate of 1 cm/year measured at Umnak Island 900 km to the east, and less than 3 cm/year measured at Attu 400 km to the west. The University of Alaska is receiving support under the USDOE-funded CRESP II program (Consortium for Risk Evaluation with Stakeholder Participation; IRM, New Brunswick,NJ.) to develop a research plan leading to long term stewardship of the site in collaboration with key researchers and stakeholders. A GPS network was established by us to define movement of and deformation within Amchitka; the present state of test-induced ground fractures, up to 2 km in length and 5.7 m in vertical displacement, was documented; and deep core samples from the shot region, acquired 30 years ago, were shipped to the mainland for further analysis.

Eichelberger, J.; Hill, G.; Patrick, M.; Freymueller, J.; Barnes, D.; Kelley, J.; Layer, P.

2001-12-01

365

A Strategy to Conduct an Analysis of the Long-Term Performance of Low-Activity Waste Glass in a Shallow Subsurface Disposal System at Hanford  

SciTech Connect

Privatized services are being procured to vitrify low-activity tank wastes for eventual disposal in a shallow subsurface facility at the Hanford Site. Over 500,000 metric tons of low-activity waste glass will be generated, which is among the largest volumes of waste within the U.S. Department of Energy (DOE) complex and is one of the largest inventories of long-lived radionuclides planned for disposal in a low-level waste facility. Before immobilized waste can be disposed, DOE must approve a "performance assessment," which is a document that describes the impacts of the disposal facility on public health and environmental resources. Because the release rate of radionuclides from the glass waste form is a key factor determining these impacts, a sound scientific basis for determining their long-term release rates must be developed if this disposal action is to be accepted by regulatory agencies, stakeholders, and the public. In part, the scientific basis is determined from a sound testing strategy. The foundation of the proposed testing strategy is a well accepted mechanistic model that is being used to calculate the glass corrosion behavior over the geologic time scales required for performance assessment. This model requires that six parameters be determined, and the testing program is defined by an appropriate set of laboratory experiments to determine these parameters, and is combined with a set of field experiments to validate the model as a whole. Three general classes of laboratory tests are proposed in this strategy: 1) characterization, 2) accelerated, and 3) service condition. Characterization tests isolate and provide specific information about processes or parameters in theoretical models. Accelerated tests investigate corrosion behavior that will be important over the regulated service life of a disposal system within a laboratory time frame of a few years or less. Service condition tests verify that the techniques used in accelerated tests do not change the alteration mechanisms. The recommended characterization tests are single-pass flow-through tests using a batch reactor design, Accelerated and service conditions tests include product consistency and pressurized unsaturated flow (PUF) tests. Nonradioactive glasses will be used for the majority of the laboratory testing (-80%), with the remainder performed with glasses containing a selected set of key radionuclides. Additionally, a series of PUF experiments with a natural analog of basaltic glass is recommended to confirm that the alteration products observed under accelerated conditions in the PUF tests are similar to those found associated with the natural analog. This will provide additional confidence in using the PUF test results to infer long-term corrosion behavior. Field tests are proposed as a unique way to validate the glass corrosion and contaminant transport models being used in the performance assessment. To better control the test conditions, the field tests are to be performed in lysimeters (corrugated steel containers buried flush with the ground surface). Lysimeters provide a way to combine a glass, Hanford soil, and perhaps other engineered materials in a well-controlled test, but on a scale that is not practicable in the laboratory. The recommended field tests include some experiments where a steady flow rate of water is artificially applied. These tests use a glass designed to have a high corrosion rate so that it is easier to monitor contaminant release and transport. Existing lysimeters at the Hanford Site can be used for these experiments or new lysimeters that have been equipped with the latest in monitoring equipment and located near the proposed disposal site.

BP McGrail, WL Ebert, DH Bacon, DM Strachan

1998-02-18

366

Inhibition of PKC-dependent extracellular Ca2+ entry contributes to the depression of contractile activity in long-term pressure-overloaded endothelium-denuded rat aortas  

PubMed Central

We examined the contractile responsiveness of rat thoracic aortas under pressure overload after long-term suprarenal abdominal aortic coarctation (lt-Srac). Endothelium-dependent angiotensin II (ANG II) type 2 receptor (AT2R)-mediated depression of contractions to ANG II has been reported in short-term (1 week) pressure-overloaded rat aortas. Contractility was evaluated in the aortic rings of rats subjected to lt-Srac or sham surgery (Sham) for 8 weeks. ANG I and II levels and AT2R protein expression in the aortas of lt-Srac and Sham rats were also evaluated. lt-Srac attenuated the contractions of ANG II and phenylephrine in the aortas in an endothelium-independent manner. However, lt-Srac did not influence the transient contractions induced in endothelium-denuded aortic rings by ANG II, phenylephrine, or caffeine in Ca2+-free medium or the subsequent tonic constrictions induced by the addition of Ca2+ in the absence of agonists. Thus, the contractions induced by Ca2+ release from intracellular stores and Ca2+ influx through stored-operated channels were not inhibited in the aortas of lt-Srac rats. Potassium-elicited contractions in endothelium-denuded aortic rings of lt-Srac rats remained unaltered compared with control tissues. Consequently, the contractile depression observed in aortic tissues of lt-Srac rats cannot be explained by direct inhibition of voltage-operated Ca2+ channels. Interestingly, 12-O-tetradecanoylphorbol-13-acetate-induced contractions in endothelium-denuded aortic rings of lt-Srac rats were depressed in the presence but not in the absence of extracellular Ca2+. Neither levels of angiotensins nor of AT2R were modified in the aortas after lt-Srac. The results suggest that, in rat thoracic aortas, lt-Srac selectively inhibited protein kinase C-mediated activation of contraction that is dependent on extracellular Ca2+ entry. PMID:25098618

Padilla, J.; López, R.M.; López, P.; Castillo, M.C.; Querejeta, E.; Ruiz, A.; Castillo, E.F.

2014-01-01

367

Long-term reduction of cocaine self-administration in rats treated with adenoviral vector-delivered cocaine hydrolase: evidence for enzymatic activity.  

PubMed

A new pharmacokinetic approach treating cocaine addiction involves rapidly metabolizing cocaine before it reaches brain reward centers using mutated human butyrylcholinesterase (BChE) or cocaine hydrolase (CocH). Recent work has shown that helper-dependent adenoviral (hdAD) vector-mediated plasma CocH reduced the locomotor-activating effects of cocaine and prevented reinstatement of cocaine-seeking behavior up to 6 months in rats. The present study investigated whether hdAD-CocH could decrease ongoing intravenous cocaine (0.4 mg/kg) self-administration. The hdAD-CocH vector was injected into self-administering rats, and after accumulation of plasma CocH, there was a dramatic reduction in cocaine infusions earned under a fixed ratio 1 schedule of reinforcement that lasted for the length of the study (>2 months). Pretreatment with the selective BChE and CocH inhibitor iso-OMPA (1.5 mg/kg) restored cocaine intake; therefore, the decline in self-administration was likely due to rapid CocH-mediated cocaine metabolism. Direct measurements of cocaine levels in plasma and brain samples taken after the conclusion of behavioral studies provided strong support for this conclusion. Further, rats injected with hdAD-CocH did not experience a deficit in operant responding for drug reinforcement and self-administered methamphetamine (0.05 mg/kg) at control levels. Overall, these outcomes suggest that viral gene transfer can yield plasma CocH levels that effectively diminish long-term cocaine intake and may have potential treatment implications for cocaine-dependent individuals seeking to become and remain abstinent. PMID:24407266

Zlebnik, Natalie E; Brimijoin, Stephen; Gao, Yang; Saykao, Amy T; Parks, Robin J; Carroll, Marilyn E

2014-05-01

368

Sex and genotype dependence on the effects of long?term high environmental temperatures on cellular enzyme activities from chicken organs  

Microsoft Academic Search

The effects of long term hyperthermia on enzyme levels in the chicken heart and breast muscles, brain, kidney, liver and lung, in relation to sex and degree of feathering, were studied. The enzymes studied were alanine and aspartate amino?transferases, alkaline phosphatase, creatine kinase, lactic dehydrogenase and gamma?glutamyltransferase. Double heterozygote frizzled naked neck and normally feathered male and female broilers were

E. Bogin; H. C. Peh; Y. Avidar; B. Israeli; E. Kevkhaye; P. Lombardi; A. Cahaner

1997-01-01

369

Is long term virological response related to CCR 5 32 deletion in HIV infected patients started on highly active antiretroviral therapy?  

E-print Network

Is long term virological response related to CCR 5 32 deletion in HIV infected patients started, antiretroviral therapy, CCR5 32 deletion, virological response Corresponding author : Dr. Jean to have a sustained virological response if all plasma HIV-RNA measurements between month 4 and years 3

Boyer, Edmond

370

Long-term data archiving  

SciTech Connect

Long term data archiving has much value for chemists, not only to retain access to research and product development records, but also to enable new developments and new discoveries. There are some recent regulatory requirements (e.g., FDA 21 CFR Part 11), but good science and good business both benefit regardless. A particular example of the benefits of and need for long term data archiving is the management of data from spectroscopic laboratory instruments. The sheer amount of spectroscopic data is increasing at a scary rate, and the pressures to archive come from the expense to create the data (or recreate it if it is lost) as well as its high information content. The goal of long-term data archiving is to save and organize instrument data files as well as any needed meta data (such as sample ID, LIMS information, operator, date, time, instrument conditions, sample type, excitation details, environmental parameters, etc.). This editorial explores the issues involved in long-term data archiving using the example of Raman spectral databases. There are at present several such databases, including common data format libraries and proprietary libraries. However, such databases and libraries should ultimately satisfy stringent criteria for long term data archiving, including readability for long times into the future, robustness to changes in computer hardware and operating systems, and use of public domain data formats. The latter criterion implies the data format should be platform independent and the tools to create the data format should be easily and publicly obtainable or developable. Several examples of attempts at spectral libraries exist, such as the ASTM ANDI format, and the JCAMP-DX format. On the other hand, proprietary library spectra can be exchanged and manipulated using proprietary tools. As the above examples have deficiencies according to the three long term data archiving criteria, Extensible Markup Language (XML; a product of the World Wide Web Consortium, an independent standards body) as a new data interchange tool is being investigated and implemented. In order to facilitate data archiving, Raman data needs calibration as well as some other kinds of data treatment. Figure 1 illustrates schematically the present situation for Raman data calibration in the world-wide Raman spectroscopy community, and presents some of the terminology used.

Moore, David Steven [Los Alamos National Laboratory

2009-01-01

371

Solar Terrestrial Activity Report  

NSDL National Science Digital Library

This chock-full of data page is hosted by the DX-listeners club (folks who search for distant radio signals). At the top is a graph of solar flux, sunspot number, and planetary A index, measured every five days, from October 30, 2000 to the present. Next come links to more data and graphs on solar energy, cycles, etc. Recent Solar and Geomagnetic Data, Solar Wind, and Electron Fluence Charts are updated daily. Also on-site are data for Solar Cycles 1-23; a Graphical Comparison of Cycles 21, 22 and 23; a Graphical Comparison of Cycles 10, 13, 17, 20 and 23; and Historical Solar and Geomagnetic data charts 1954-2000. In addition, users will find data and data links including active solar region maps, geomagnetic forecasts, and reports of recent solar activities such as flares and coronal mass injections.

372

Modelling the effects of solar activity onto the Greek national electric grid  

NASA Astrophysics Data System (ADS)

We study both the short term and long term effects of solar activity on the large transformers (150kV and 400kV) of the Greek national electric grid. We use data analysis and various analytic and statistical methods and models. Contrary to the common belief in PPC Greece, we see that there are considerable both short term (immediate) and long term effects of solar activity onto large transformers in a mid-latitude country like Greece. Our results can be summarized as follows: For the short term effects: During 1989-2010 there were 43 "stormy days" (namely days with for example Ap >= 100) and we had 19 failures occurring during a stormy day plus or minus 3 days and 51 failures occurring during a stormy day plus or minus 7 days. All these failures can be directly related to Geomagnetically Induced Currents (GIC's). Explicit cases are presented. For the long term effects we have two main results: The maximum number of transformer failures occur 3-4 years after the maximum of solar activity. There is statistical correlation between solar activity expressed using various newly defined long term solar activity indices and the annual number of transformer failures. These new long term solar activity indices were defined using both local (from geomagnetic stations in Greece) and global (planetary averages) geomagnetic data. Applying both linear and non-linear statistical regression we compute the regression equations and the corresponding coefficients of determination.

Zois, I. P.

2014-03-01

373

Soil organic carbon (SOC) accumulation in rice paddies under long-term agro-ecosystem experiments in southern China - VI. Changes in microbial community structure and respiratory activity  

NASA Astrophysics Data System (ADS)

Biological stabilization within accumulated soil organic carbon (SOC) has not been well understood, while its role in physical and chemical protection as well as of chemical recalcitrance had been addressed in Chinese rice paddies. In this study, topsoil samples were collected and respiratory activity measured in situ following rice harvest under different fertilization treatments of three long-term experimental sites across southern China in 2009. The SOC contents, microbial biomass carbon (SMBC) and nitrogen (SMBN) were analysed using chemical digestion and microbial community structure assessment via clony dilute plate counting methods. While SOC contents were consistently higher under compound chemical fertilization (Comp-Fert) or combined organic and inorganic fertilization (Comb-Fert) compared to N fertilization only (N-Fert), there was significantly higher fungal-bacterial ratio under Comb-Fert than under N-Fert and Comp-Fert. When subtracting the background effect under no fertilization treatment (Non-Fert), the increase both in SMBC and SMBN under fertilization treatment was found very significantly correlated to the increase in SOC over controls across the sites. Also, the ratio of culturable fungal to bacterial population numbers (F/B ratio) was well correlated with soil organic carbon contents in all samples across the sites studied. SOC accumulation favoured a build-up the microbial community with increasing fungal dominance in the rice paddies under fertilization treatments. While soil respiration rates were high under Comb-Fert as a result of enhanced microbial community build-up, the specific soil respiratory activity based on microbial biomass carbon was found in a significantly negatively correlation with the SOC contents for overall samples. Thus, a fungal-dominated microbial community seemed to slow SOC turnover, thereby favouring SOC accumulation under Comp-Fert or under Comb-Fert in the rice paddies. Therefore, the biological stabilization process is of importance in SOC sequestration in the rice paddies, operating with physical and chemical protection and chemical recalcitrance. However, sufficient understanding and prediction of SOM dynamics needs further quantitative characterization of the simultaneous operation of several mechanisms.

Liu, D.; Liu, X.; Liu, Y.; Li, L.; Pan, G.; Crowley, D.; Tippkötter, R.

2011-02-01

374

Insolation data manual: long-term monthly averages of solar radiation, temperature, degree-days and global anti K/sub T/ for 248 national weather service stations  

SciTech Connect

Monthly averaged data is presented which describes the availability of solar radiation at 248 National Weather Service stations. Monthly and annual average daily insolation and temperature values have been computed from a base of 24 to 25 years of data. 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/sup 0/C (65/sup 0/F). For each station, global anti K/sub T/ (cloudiness index) were calculated on a monthly and annual basis. (MHR)

Knapp, C L; Stoffel, T L; Whitaker, S D

1980-10-01

375

Adolescent political activism and long-term happiness: a 21-year longitudinal study on the development of micro- and macrosocial worries.  

PubMed

Utilizing latent growth modeling, the long-term development of worries among peace movement supporters is examined. Data originate from a seven-wave German longitudinal study started in 1985 with on average 14-year-olds. Waves were interspersed 3 and a half years each. Activists are assumed to have lower (self-related) microworries (Hypothesis 1) and higher macroworries (concerned with larger entities; Hypothesis 2) than nonactivists at the onset of the study. Nonactivists who appraised the threat of nuclear war as high in 1985 are assumed to report worse mental health than their activist age-mates 21 years later (Hypothesis 3). Activists are assumed to express relatively more macroworries than nonactivists in midadulthood (Hypothesis 4). All four hypotheses were confirmed. Results are interpreted in a stress-coping (Lazarus) and resource (Elder) framework, suggesting that refraining from acting out against a perceived sociopolitical threat is a long-term risk for a positive mental health trajectory. PMID:21307181

Boehnke, Klaus; Wong, Becky

2011-03-01

376

Long-term total sleep deprivation decreases the default spontaneous activity and connectivity pattern in healthy male subjects: a resting-state fMRI study  

PubMed Central

Objective The aim of this study is to use resting-state functional connectivity (rsFC) and amplitude of low-frequency fluctuation (ALFF) methods to explore intrinsic default-mode network (DMN) impairment after sleep deprivation (SD) and its relationships with clinical features. Methods Twelve healthy male subjects underwent resting-state functional magnetic resonance imaging twice: once following rested wakefulness (RW) and the other following 72 hours of total SD. Before the scans, all subjects underwent the attention network test (ANT). The independent component analysis (ICA), rsFC, and ALFF methods were used to examine intrinsic DMN impairment. Receiver operating characteristic (ROC) curve was used to distinguish SD status from RW status. Results Compared with RW subjects, SD subjects showed a lower accuracy rate (RW =96.83%, SD =77.67%; P<0.001), a slower reaction time (RW =695.92 ms; SD =799.18 ms; P=0.003), a higher lapse rate (RW =0.69%, SD =19.29%; P<0.001), and a higher intraindividual coefficient of variability in reaction time (RW =0.26, SD =0.33; P=0.021). The ICA method showed that, compared with RW subjects, SD subjects had decreased rsFC in the right inferior parietal lobule (IPL, BA40) and in the left precuneus (PrC)/posterior cingulate cortex (PCC) (BA30, 31). The two different areas were selected as regions of interest (ROIs) for future rsFC analysis. Compared with the same in RW subjects, in SD subjects, the right IPL showed decreased rsFC with the left PrC (BA7) and increased rsFC with the left fusiform gyrus (BA37) and the left cluster of middle temporal gyrus and inferior temporal gyrus (BA37). However, the left PrC/PCC did not show any connectivity differences. Compared with RW subjects, SD subjects showed lower ALFF area in the left IPL (BA39, 40). The left IPL, as an ROI, showed decreased rsFC with the right cluster of IPL and superior temporal gyrus (BA39, 40). ROC curve analysis showed that the area under the curve (AUC) value of the left IPL was 0.75, with a cutoff point of 0.834 (mean ALFF signal value). Further diagnostic analysis exhibited that the AUC alone discriminated SD status from RW status, with 75% sensitivity and 91.7% specificity. Conclusion Long-term SD disturbed the spontaneous activity and connectivity pattern of DMN. PMID:25834451

Dai, Xi-Jian; Liu, Chun-Lei; Zhou, Ren-Lai; Gong, Hong-Han; Wu, Bin; Gao, Lei; Wang, Yi-Xiang J

2015-01-01

377

Long-Term Post-Stroke Changes Include Myelin Loss, Specific Deficits in Sensory and Motor Behaviors and Complex Cognitive Impairment Detected Using Active Place Avoidance  

PubMed Central

Persistent neurobehavioral deficits and brain changes need validation for brain restoration. Two hours middle cerebral artery occlusion (tMCAO) or sham surgery was performed in male Sprague-Dawley rats. Neurobehavioral and cognitive deficits were measured over 10 weeks included: (1) sensory, motor, beam balance, reflex/abnormal responses, hindlimb placement, forepaw foot fault and cylinder placement tests, and (2) complex active place avoidance learning (APA) and simple passive avoidance retention (PA). Electroretinogram (ERG), hemispheric loss (infarction), hippocampus CA1 neuronal loss and myelin (Luxol Fast Blue) staining in several fiber tracts were also measured. In comparison to Sham surgery, tMCAO surgery produced significant deficits in all behavioral tests except reflex/abnormal responses. Acute, short lived deficits following tMCAO were observed for forelimb foot fault and forelimb cylinder placement. Persistent, sustained deficits for the whole 10 weeks were exhibited for motor (p<0.001), sensory (p<0.001), beam balance performance (p<0.01) and hindlimb placement behavior (p<0.01). tMCAO produced much greater and prolonged cognitive deficits in APA learning (maximum on last trial of 604±83% change, p<0.05) but only a small, comparative effect on PA retention. Hemispheric loss/atrophy was measured 10 weeks after tMCAO and cross-validated by two methods (e.g., almost identical % ischemic hemispheric loss of 33.4±3.5% for H&E and of 34.2±3.5% for TTC staining). No visual dysfunction by ERG and no hippocampus neuronal loss were detected after tMCAO. Fiber tract damage measured by Luxol Fast Blue myelin staining intensity was significant (p<0.01) in the external capsule and striatum but not in corpus callosum and anterior commissure. In summary, persistent neurobehavioral deficits were validated as important endpoints for stroke restorative research in the future. Fiber myelin loss appears to contribute to these long term behavioral dysfunctions and can be important for cognitive behavioral control necessary for complex APA learning. PMID:23505432

Li, Jie; Ooi, Evelyn; Bloom, Jonathan; Poon, Carrie; Lax, Daniel; Rosenbaum, Daniel M.; Barone, Frank C.

2013-01-01

378

Long-term follow-up with Granulocyte and Monocyte Apheresis re-treatment in patients with chronically active inflammatory bowel disease  

Microsoft Academic Search

BACKGROUND: Patients with IBD and chronic inflammation refractory to conventional therapy often demonstrate higher risk of serious complications. Combinations of immunosuppression and biological treatment as well as surgical intervention are often used in this patient group. Hence, there is need for additional treatment options. In this observational study, focused on re-treatment and long-term results, Granulocyte\\/Monocyte Adsorption (GMA, Adacolumn®) treatment has

Annelie Lindberg; Michael Eberhardson; Mats Karlsson; Per Karlén

2010-01-01

379

Long term results of early active extension and passive flexion mobilization following one-stage tendon grafting for neglected injuries of the flexor digitorum profundus in children  

Microsoft Academic Search

We retrospectively reviewed the long-term clinical outcomes of one-stage flexor tendon grafting for seven paediatric patients with isolated flexor digitorum profundus (FDP) tendon injuries in Zones 1 or 2. Free tendon grafts (one palmaris longus tendons and six plantaris tendons) were used for reconstruction by Pulvertaft’s procedure. The ages of the patients at reconstruction ranged from 7 to 15 (mean

Hiroshi Yamazaki; Hiroyuki Kato; Shigeharu Uchiyama; Norimasa Iwasaki; Hisamitsu Ishikura; Akio Minami

2011-01-01

380

Diversity and Activity of Cellulose-Decomposing Bacteria, Isolated from a Sandy and a Loamy Soil after Long-Term Manure Application  

Microsoft Academic Search

The community of culturable cellulolytic bacteria was analyzed in two long-term experimental field sites on Albic Luvisol\\u000a (silty sand) and Haplic Phaeozem (loam), with and without farmyard manure treatment. Against the backdrop of significant differences\\u000a in soil properties, the bacterial community structure differed clearly between sites and was affected by manure application\\u000a as analyzed by T-RFLP of 16S rDNA. The

Andreas Ulrich; Gabriele Klimke; Stephan Wirth

2008-01-01