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1

Long-term solar activity predictions  

NASA Technical Reports Server (NTRS)

The need for long term solar activity predictions is addressed. The spatial organization of solar activity is described including applications for predictions, and ancient evidence for solar variability. Methods of predicting sunspot numbers are discussed. The inherent accuracy of the methods varies considerably, but a typical error bar 20%. The accuracy of sunspot cycle predictions is considered along with long term predictions of great solar events.

Mcintosh, P. S.; Brown, G. M.; Buhmann, R.; Clark, T.; Fougere, P. F.; Hunter, H.; Lincoln, J. V.; Sargent, H. H., III; Timothy, J. G.; Lin, Y. Z.

1979-01-01

2

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

3

Long term variability of solar magnetic activity: the solar-stellar connection  

NASA Astrophysics Data System (ADS)

Long term variability of solar magnetic activity: the solar-stellar connection S.K. Solanki Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany The dominant time-scales of solar variability are the solar rotation period and in particular the length of the solar cycle, but variations of solar activity on longer time scales are also present. Variations of stellar activity are also well documented on time scales up to stellar activity cycles, although secular variations on longer time scales are somewhat less well established, due to the limited length of the available observational time series. Multi-wavelength observations of solar variability is mainly limited to the space age, while direct observations of sunspots are available back to the year 1610, i.e. over the whole era of telescopic astronomy. In the last decades considerable progress has been made in extending our knowledge of solar activity to pre-telescopic times, using records of the concentration of cosmogenic isotopes in terrestrial archives.Such studies have shown, e.g., that in addition to grand minima, the Sun has also enjoyed times of significantly anhanced activity, so called grand maxima. The recent decades formed a particularly prominent such grand maximum. The current peculiar minimum has shown strong indications that we are in the process of leaving this last grand maximum. There is also strong evidence that there are significant secular changes of the magnetic flux and other active phenomena. Although the period over which we have data on stellar activity is far shorter than for the Sun, these data allow stars of different types to be sampled (i.e. stars with different activity levels, of different spectral types, at different evolutionary stages, etc.) that display the full variety of active phenomena, including cycles, but also chaotic variability. After an overview of our knowledge and understanding of the longer-term evolution of solar activity, comparisons with observations of stellar activity time series are presented and some implications for our understanding of stellar activity variations are deduced.

Solanki, Sami K.

4

Comparison of long-term trend of solar radius with sunspot activity and flare index  

NASA Astrophysics Data System (ADS)

Results are presented from a study of solar radius measurements taken with the solar astrolabe at the TUBITAK National Observatory (TUG) over seven years, 2001-2007. The data series with standard deviation of 0.35 arcsec shows the long-term variational trend with 0.04 arcsec/year. On the other hand, the data series of solar radius are compared with the data of sunspot activity and H- ? flare index for the same period. Over the seven year trend, we have found significant linear anti-correlations between the solar radius and other indicators such as sunspot numbers, sunspot areas, and H- ? flare index. While the solar radius displays the strongest anti-correlation (-0.7676) with sunspot numbers, it shows a significant anti-correlation of -0.6365 with sunspot areas. But, the anti-correlation between the solar radius and H- ? flare index is found to be -0.4975, slightly lower than others. In addition, we computed Hurst exponent of the data sets ranging between 0.7214 and 0.7996, exhibiting the persistent behavior for the long term trend. In the light of the strong correlations with high significance, we may suggest that there are a causal relationship between the solar radius and solar time series such as sunspot activity and H- ? flare index.

Kilic, H.; Golbasi, O.

2011-07-01

5

Long-term Variations of The Solar Activity -- Lower Atmosphere Relationship  

NASA Astrophysics Data System (ADS)

Long-term variations of the air temperature in St.Petersburg, Stockholm, Salzburg and English Midlands are considered. There is shown that in the regions under consider- ation the air temperature distinctly depends on the intensity of the lower atmospheric zonal circulation (Blinova index and North Atlantic Oscillation index (NAO)). In turn, the NAO-index is shown to depend on the solar activity. However, this dependence is rather complicated and exhibits long-period variations associated with secular varia- tions of the solar activity. A possible mechanism of this phenomena is discussed.

Zaitseva, S.; Akhremtchik, S.; Pudovkin, M.; Besser, B.; Rijnbeek, R.

6

Long-Term Solar Irradiance Variability  

NASA Technical Reports Server (NTRS)

Measurements of the solar energy throughout the solar spectrum and understanding its variability provide important information about the physical processes and structural changes in the solar interior and in the solar atmosphere...The aim of this paper is to discuss the solar-cycle-related long-term changes in solar total and UV irradiances. The spaceborne irradiance observations are compared to ground-based indices of solar magnetic activity, such as the Photometric Sunspot Index, full disk magnetic flux, and the Mt. Wilson Magnetic Plage Strength Index.

Pap, J. M.

1996-01-01

7

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

2009-08-27

8

Long-term solar-terrestrial observations  

NASA Technical Reports Server (NTRS)

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

1988-01-01

9

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

10

Simulation of Long-term Changes in the Surface Ozone and Aerosol Concentrations Based on the Solar Activity Data  

NASA Astrophysics Data System (ADS)

Based on the long-term data obtained during previous studies we have found an interrelationship the surface ozone and aerosol content with solar activity. Variation of the concentration of both these atmospheric components have a period close to 11 years that has a 2(3)-year phase lag with respect to solar activity. Analyzing possible causes of such behaviour we discarded hypotheses of the anthropogenic origin of the trend and post-volcanic influence of El Chichon and Penatubo eruptions. It turned out, that variation of aerosol number concentration correlates with atmospheric circulation forms (W, E, and C), which are governed by solar activity. Then we analysed sequentially an ozone mechanism and variations of incoming ultraviolet radiation to determine possible causes of this phenomenon. As a result we found an intermediate process, which consists in the influence of increasing UV radiation on plants. At the beginning of UV radiation increase it is observed suppression of the vegetation. After 1- or 2-year adaptation period its productivity becomes stronger that leads to the emission of additional amount of ozone and aerosol precursors. This hypothesis has been verified using Normalized Difference Vegetation Index (NDVI) and gave good results. Prediction of the long-term changes in the surface ozone and aerosol concentrations has been done based on this hypothesis. This work was funded by Presidium of RAS (Program No. 16), Brunch of Geology, Geophysics and Mining Sciences of RAS (Program No 5), Russian Foundation for Basic Research (grant No 08-05-92499), and Federal Agency for Science and Innovation (State Contract ? 02.518.11.7153).

Belan, Boris; Antokhin, Pavel; Arshinov, Mikhail; Belan, Sergey; Slyadneva, Tatyana; Tolmachev, Gennadii

2010-05-01

11

Long-term solar-terrestrial observations  

NASA Astrophysics Data System (ADS)

In the fall of 1985, the Committee on Solar-Terrestrial Research (CSTR) created a panel to study the requirements for long-term monitoring and archiving of solar-terrestrial data. The panel comprised specialists in all four areas that constitute solar-terrestrial science: the sun, interplanetary medium, magnetosphere-thermosphere-ionosphere, and upper atmosphere. It interviewed many individuals from the solar-terrestrial monitoring and data archiving communities, along with administrators and directors from appropriate government agencies. It circulated nearly 500 questionnaires to obtain information and opinions from the broader community to learn which observational data should be considered essential over the long term to support the operational and research needs of solar-terrestrial science. This report summarizes the panel's principal findings, and the panel's recommendations follow. A separate section listing the critical observational needs by area is presented together with the scientific rationale for each area. The recommendations are defended in terms of this explicit scientific rationale and the multifold uses of current and long-term solar-terrestrial observations for continued operational solar-terrestrial forecasts and services.

12

On the Physical Origin of the Cycles in Long-term Modulation of Solar Activity  

Microsoft Academic Search

By a Morlet wavelet analysis in sub harmonics of the 11 year fundamental frequency of sunspot number as a proxy for the toroidal component of solar dynamo magnetic field the evolution for the last 400 years of four well defined cycles- a decadal, a semi-secular, the Gleissberg and the Suess ones - in the modulation of this component of the

S. Duhau; C. de Jager

2007-01-01

13

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

14

Long-term changes in the North-South asymmetry of solar activity: a nonlinear dynamics characterization using visibility graphs  

NASA Astrophysics Data System (ADS)

Solar activity is characterized by complex dynamics superimposed to an almost periodic, about 11 years cycle. One of its main features is the presence of a marked, time-varying hemispheric asymmetry, the deeper reasons of which have not yet been completely uncovered. Traditionally, this asymmetry has been studied by considering amplitude and phase differences. Here, we use visibility graphs, a novel tool of nonlinear time series analysis, to obtain complementary information on hemispheric asymmetries in dynamical properties. Our analysis provides deep insights into the potentials and limitations of this method, revealing a complex interplay between factors relating to statistical and dynamical properties, i.e., effects due to the probability distribution and the regularity of observed fluctuations. We demonstrate that temporal changes in the hemispheric predominance of the graph properties lag those directly associated with the total hemispheric sunspot areas. Our findings open a new dynamical perspective on studying the North-South sunspot asymmetry, which is to be further explored in future work.

Zou, Y.; Donner, R. V.; Marwan, N.; Small, M.; Kurths, J.

2014-04-01

15

Long-term changes in the North-South asymmetry of solar activity: a nonlinear dynamics characterization using visibility graphs  

NASA Astrophysics Data System (ADS)

Solar activity is characterized by complex dynamics superimposed to an almost periodic, about 11-years cycle. One of its main features is the presence of a marked, time-varying hemispheric asymmetry, the deeper reasons of which have not yet been completely uncovered. Traditionally, this asymmetry has been studied by considering amplitude and phase differences. Here, we use visibility graphs, a novel tool of nonlinear time series analysis, to obtain complementary information on hemispheric asymmetries in dynamical properties. Our analysis provides deep insights into the potentials and limitations of this method, revealing a complex interplay between factors relating to statistical and dynamical properties, i.e., effects due to the probability distribution and the regularity of observed fluctuations. We demonstrate that temporal changes in the hemispheric predominance of the graph properties lag those directly associated with the total hemispheric sunspot areas. Our findings open a new dynamical perspective on studying the North-South sunspot asymmetry, which is to be further explored in future work.

Zou, Yong; Donner, Reik; Marwan, Norbert; Small, Michael; Kurths, Jürgen

2014-05-01

16

The long-term dynamical evolution of the solar system  

Microsoft Academic Search

The dynamical evolution of the solar system once the planets have acquired most of their material and settled into nearly circular, nearly coplanar orbits is traced. A brief review of those aspects of the dynamics of the Hamiltonian systems relevant to the gravitational N-body problem is presented, with emphasis on recent developments which pertain to the long-term evolution of orbits.

Martin J. Duncan; Thomas Quinn

1993-01-01

17

On the Long-Term Modulation of Solar Differential Rotation  

NASA Astrophysics Data System (ADS)

Long-term modulation of solar differential rotation was studied with data from Mt. Wilson and our original observations during Solar Cycles 16 through 23. The results are that i) the global B-value ( i.e. latitudinal gradient of differential rotation) is modulated with a period of about six or seven solar cycles, ii) the B-values of the northern and southern hemispheres are also modulated with a period similar to the global one, but iii) they show quasi-oscillatory behavior with a phase shift between them. We examined the yearly fluctuations of the B-values in every solar cycle with reference to the phase of the sunspot cycle and found that the B-values in the sunspot-minimum years show large and erratic variations, while those in the sunspot-maximum years show small fluctuations. Positive correlation between the former B-values and the latter was found. We discuss the independent long-term behavior of solar differential rotation between the northern and southern solar hemispheres and the implication for the solar dynamo.

Suzuki, M.

2014-11-01

18

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

19

Solar Spectral Irradiance variations: the long-term view  

NASA Astrophysics Data System (ADS)

Solar Spectral Irradiance variations: the long-term view S.K. Solanki Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany The total and spectral irradiance of the Sun are prime candidates for external forcing of the Earth's climate system. Whereas variations of total solar irradiance have been observed and modelled with great success, our corresponding knowledge of the variation of spectral irradi-ance is, by comparison, still in its infancy. Although, on short time-scales multiple measured time series and models are now available, on longer time-scales models are the only source of information. Until recently even the models were rather restricted, being either based purely on proxies, or limited in spectral range. A new generation of models is now available, which goes beyond the limitations of the earlier approaches. An overview of the models and their results is given, with the emphasis being placed on the most recent ones.

Solanki, Sami K.

20

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

21

Long-term migration of the solar sector structure  

NASA Technical Reports Server (NTRS)

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

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

1979-01-01

22

Long-term downward trend in total solar irradiance  

Microsoft Academic Search

The first 5 years (from 1980 to 1985) of total solar irradiance observations by the first Active Cavity Radiometer Irradiance Monitor (ACRIM I) experiment on board the Solar Maximum Mission spacecraft show a clearly defined downward trends of -0.019% per year. The existence of this trend has been confirmed by the internal self-calibrations of ACRIM I, by independent measurements from

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

1986-01-01

23

Long-term Consequences of Childhood ADHD on Criminal Activities  

Microsoft Academic Search

Background: Attention Deficit\\/Hyperactivity Disorder (ADHD) is one of the most prevalent mental health problems facing children. Little is known of the long-term consequences of ADHD on young adult outcomes. Aims of the Study: We examine the associations between childhood ADHD symptoms and criminal activities as a young adult. Methods: We use a nationally representative study of US adolescents and logistic

Jason Fletcher; Barbara Wolfe

2009-01-01

24

Long-term performance of the Hunn passive solar residence  

SciTech Connect

Detailed performance and annual energy consumption data are reported, as well as occupant observations and conclusions, for three heating seasons in the Hunn hybrid passive/active solar residence located in Los Alamos, New Mexico. The performance data were gathered by the Los Alamos National Laboratory and include hourly storage wall and interior temperature data for a midwinter period, an interior air-temperature histogram, and measured auxiliary energy consumption and solar heating fraction for each heating season. Also, energy and cost savings over the three-year period are estimated.

Hunn, B.D.

1981-01-01

25

TOWARDS AN IMPROVED HIGH RESOLUTION GLOBAL LONG-TERM SOLAR RESOURCE DATABASE  

E-print Network

TOWARDS AN IMPROVED HIGH RESOLUTION GLOBAL LONG- TERM SOLAR RESOURCE DATABASE Paul W. Stackhouse and test an improved production system that will enable the longest-term global solar resource database

Perez, Richard R.

26

Applying activity-based costing in long-term care.  

PubMed

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

Wodchis, W P

1998-01-01

27

Study of spatial and temporal structure of long-term effects of solar activity and cosmic ray variations on the lower atmosphere circulation  

NASA Astrophysics Data System (ADS)

The spatial and temporal structure of the effects of solar activity (SA) and galactic cosmic ray (GCR) flux variations on the lower atmosphere circulation has been studied based on NCEP/NCAR reanalysis archive for 1948-2006 and MSLP (Climatic Research Unit, UK) data for 1873-2000. It has been shown that the GCR effects on pressure variations are characterized by a strong latitudinal and regional dependence, which is determined by specific features of the tropospheric circulation in the studied regions. The distribution of the correlation coefficients for mean yearly values of atmospheric pressure with the GCR flux intensity is closely related to the position of the main climatological fronts. The periodic (˜60 years) changes in the correlation sign of the pressure at high and middle latitudes with Wolf numbers have been revealed. It has been suggested that the changes of the sign of SA/GCR effects on atmospheric pressure are caused by the changes of the macrocirculation epochs, which, in turn, may be related to large-scale processes on the Sun.

Veretenenko, S. V.; Ogurtsov, M. G.

2012-09-01

28

Long-Term Total Solar Irradiance (TSI) Variability Trends: 1984-2004  

NASA Technical Reports Server (NTRS)

The incoming total solar irradiance (TSI), typically referred to as the solar constant, is being studied to identify long-term TSI changes, which may trigger global climate changes. The TSI is normalized to the mean earth-sun distance. Studies of spacecraft TSI data sets confirmed the existence of 0.1 %, long-term TSI variability component with a period of 10 years. The component varied directly with solar magnetic activity associated with recent 10-year sunspot cycles. The 0.1 % TSI variability component is clearly present in the spacecraft data sets from the 1984-2004, Earth Radiation Budget Experiment (ERBE) active cavity radiometer (ACR) solar monitor; 1978-1993, Nimbus-7 HF; 1980-1989, Solar Maximum Mission [SMM] ACRIM; 1991-2004, Upper Atmosphere Research Satellite (UARS) ACRIM; 1996-2003, Solar and Heliospheric Observatory (SOHO)/VIRGO, Space Science (ATLAS), 2000-2004, ACRIMSAT; and 2003-2004 SOlar Radiation and Climate Experiment (SORCE) active cavity radiometer (ACR) missions. From October 1984, through March 2004, the ERBS/ERBE solar monitor was used to produce the longest continuous data set of total solar irradiance (TSI) variability measurements. The solar monitor is located on Shuttle Atmospheric Laboratory for Applications and the NASA Earth Radiation Budget Satellite (ERBS). Maximum TSI values occurred during the 1989-1991, and 1998-2002, time frames; while minimum [quiet sun] TSI levels occurred during 1986 and 1996. Recent ERBS measurements indicate that the TSI is decreasing to forecasted, minimum levels by 2006. Using the discontinuous non-operational Nimbus-7, SMM ACRIM, and UARS ACRIM mission TSI data sets, Wilson and Mordvinor (2003) suggested the existence of an additional long-term TSI variability component, 0.05 %, with a period longer than a decade. Analyses of the ERBS/ERBE data set do not support the Wilson and Mordvinor analyses approach because it used the Nimbus-7 data set which exhibited a significant ACR response shift of 0.7 Wm-2

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

2004-01-01

29

Maintenance of a long term total solar irradiance data series  

NASA Technical Reports Server (NTRS)

The dispersion of the measurements that contributed to the previously defined space absolute radiometric reference (SARR) is investigated by objective statistical analysis. The estimated standard deviation with which the reference is known is 0.22 W/sq m, corresponding to 0.016 percent of its mean value. Several updates are made in the SARR referenced total solar irradiance data series, which was previously obtained from November 1978 until December 1993. The shift in 1898-1990 of the NIMBUS 7 instrument identified by Lee in 1995 is investigated and taken into account, resulting in new values for the NIMBUS 7 measurements before 1990 and in a new SARR adjustment coefficient for the active cavity radiometer irradiance monitoring (ACRIM) 1 instrument. The data series is extended to the present by adding level 1 data of DIARAD/VIRGO on board SOHO. A preliminary SARR coefficient for level 1 DIARAD/VIRGO was obtained by comparison with SARR referenced ACRIM 2 data.

Dewitte, S.; Crommelynck, D.; Joukoff, A.

1997-01-01

30

Comparing Sunspot Area and Sunspot Number as Proxies for Long-term Solar Irradiance Variation  

NASA Technical Reports Server (NTRS)

Because relevant observations from space began only in 1979 with Nimbus-7, it is impossible to correlate direct measurements of small changes in solar irradiance with terrestrial temperature over a number of solar cycles. Yet there is recent evidence that some feature of solar change over a cycle may have a larger influence on climate than would result from merely introducing the additional amount of heat delivered to Earth's atmosphere at solar minimum. It would be useful to check this possibility over several solar cycles. To do this, we would need a sufficiently reliable proxy for irradiance change that at least survives a test against the space observations. Sunspot area is a fairly straightforward parameter to measure, and is associated with the extent of magnetic activity known to correlate strongly with solar irradiance change. We have tested the use of sunspot area as a long-term proxy for solar irradiance change, using observations made at the Coimbra Solar Observatory, from which we obtain both statistically weighted sunspot numbers and sunspot areas over the period 1980-1992. These are both correlated with solar irradiance values measured from Nimbus-7 spacecraft over the same time period, to see if sunspot area offers affords a strong positive correlation and also a distinct advantage over sunspot number as a useful proxy that can then be compared with terrestrial temperature records. Preliminary results yield a positive correlation of 0.71 for sunspot area, but further tests are being conducted and will be reported.

Jordan, Stuart D.; Garcia, A. G.; Oegerle, William (Technical Monitor)

2002-01-01

31

III. VALUE OF LONG-TERM SOLAR RADIATION DATA Long-term solar radiation data sets are scarce  

E-print Network

start to show patterns and trends in solar radiation. Statistically these variations are complex and do the relationship between solar and other renewable resources with a high degree of statistical confidence indicator of the amount of useful energy that a solar energy system can collect. The variations of monthly

Oregon, University of

32

Long-term response of total ozone content at different latitudes of the Northern and Southern Hemispheres caused by solar activity during 1958-2006 (results of regression analysis)  

NASA Astrophysics Data System (ADS)

Solar activity influences on atmospheric photochemical system via its changebale electromag-netic flux with eleven-year period and also by energetic particles during solar proton event (SPE). Energetic particles penetrate mostly into polar regions and induce additional produc-tion of NOx and HOx chemical compounds, which can destroy ozone in photochemical catalytic cycles. Solar irradiance variations cause in-phase variability of ozone in accordance with photo-chemical theory. However, real ozone response caused by these two factors, which has different physical nature, is not so clear on long-term time scale. In order to understand the situation multiply linear regression statistical method was used. Three data series, which covered the period 1958-2006, have been used to realize such analysis: yearly averaged total ozone at dif-ferent latitudes (World Ozone Data Centre, Canada, WMO); yearly averaged proton fluxes with E¿ 10 MeV ( IMP, GOES, METEOR satellites); yearly averaged numbers of solar spots (Solar Data). Then, before the analysis, the data sets of ozone deviations from the mean values for whole period (1958-2006) at each latitudinal belt were prepared. The results of multiply regression analysis (two factors) revealed rather complicated time-dependent behavior of ozone response with clear negative peaks for the years of strong SPEs. The magnitudes of such peaks on annual mean basis are not greater than 10 DU. The unusual effect -positive response of ozone to solar proton activity near both poles-was discovered by statistical analysis. The pos-sible photochemical nature of found effect is discussed. This work was supported by Russian Science Foundation for Basic Research (grant 09-05-009949) and by the contract 1-6-08 under Russian Sub-Program "Research and Investigation of Antarctica".

Krivolutsky, Alexei A.; Nazarova, Margarita; Knyazeva, Galina

33

Long-term physical activity trends in breast cancer survivors  

PubMed Central

Background Physical activity is associated with reduced mortality and higher quality of life in breast cancer survivors; however, limited data on the prevalence of activity and long-term trends after diagnosis are available. Methods A multi-ethnic cohort of 631 women (18–64 years) with stage 0-IIIA breast cancer were followed for 10 years. Recreational aerobic activity (MET-hrs/week) was ascertained for the year before diagnosis (baseline), 24 months, 5 and 10 years after enrollment. Women were classified according to U.S. physical activity guidelines (?150 mins/week moderate or ?75 mins/week vigorous activity). The odds ratios (OR) for meeting guidelines at 5 and 10 years according to baseline factors was estimated using logistic regression. The change in MET-hrs/wk was predicted using linear regression. Results Pre-diagnosis, 34% of women met physical activity guidelines; 34.0%, 39.5%, and 21.4% met guidelines at 24 months, 5 years, and 10 years post-enrollment, respectively. Fewer than 8% of survivors met guidelines at all follow-up periods. Over 10 years, recreational aerobic activity decreased by a mean(SD) 4.3(16.2) MET-hrs/wk.. Meeting guidelines pre-diagnosis was strongly associated with meeting guidelines at 5 years [OR (95% CI): 2.76 (1.85–4.1)] and 10 years [OR (95% CI): 3.35 (2.13–5.28)]. No other demographic or prognostic factors were significantly associated with the 10-year change in MET-hrs/wk. Conclusion The vast majority of early breast cancer survivors do not meet national exercise recommendations 10 years post-diagnosis. Impact Physical activity levels are low in breast cancer survivors across the 10 years post-diagnosis, yet the predictors of activity in this population remain poorly understood. PMID:23576689

Mason, Caitlin; Alfano, Catherine M.; Smith, Ashley Wilder; Wang, C.Y.; Neuhouser, Marian L.; Duggan, Catherine; Bernstein, Leslie; Baumgartner, Kathy B.; Baumgartner, Richard N.; Ballard-Barbash, Rachel; McTiernan, Anne

2013-01-01

34

Long-term eruptive activity at a submarine arc volcano  

USGS Publications Warehouse

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

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

2006-01-01

35

Improvement on the long-term stability of flexible plastic dye-sensitized solar cells  

Microsoft Academic Search

We investigate the long-term stability of performance for plastic dye-sensitized solar cells (DSSCs) based on organic iodides (TBAI or PMII) in methoxypropionitrile-based electrolytes. Plastic DSSCs containing TBAI maintain 96.9% of baseline efficiency under more than 1000h prolonged one sun light irradiation and thermal stress (60°C) aging. The factors of device long-term stability, such as the effects of organic iodides, cell-sealing

Kun-Mu Lee; Wei-Hao Chiu; Ming-De Lu; Wen-Feng Hsieh

36

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

37

Long-term middle atmospheric influence of very large solar proton events  

Microsoft Academic Search

The Whole Atmosphere Community Climate Model (WACCM3) has been used to study the long-term (more than a few months) effects of solar proton events (SPEs). Extremely large solar proton events occurred in 1972, 1989, 2000, 2001, and 2003 and caused some longer-lasting atmospheric changes. The highly energetic solar protons produced odd hydrogen (HOx) and odd nitrogen (NOy), which then led

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

2009-01-01

38

Chaotic response of global climate to long-term solar forcing variability  

E-print Network

It is shown that global climate exhibits chaotic response to solar forcing variability in a vast range of timescales: from annual to multi-millennium. Unlike linear systems, where periodic forcing leads to periodic response, nonlinear chaotic response to periodic forcing can result in exponentially decaying broad-band power spectrum with decay rate T_e equal to the period of the forcing. It is shown that power spectrum of a reconstructed time series of Northern Hemisphere temperature anomaly for the past 2,000 years has an exponentially decaying broad-band part with T_e = 11 yr, i.e. the observed decay rate T_e equals the mean period of the solar activity. It is also shown that power spectrum of a reconstruction of atmospheric CO_2 time fluctuations for the past 650,000 years, has an exponentially decaying broad-band part with T_e = 41,000 years, i.e. the observed decay rate T_e equals the period of the obliquity periodic forcing. A possibility of a chaotic solar forcing of the climate has been also discussed. These results clarify role of solar forcing variability in long-term global climate dynamics (in particular in the unsolved problem of the glaciation cycles) and help in construction of adequate dynamic models of the global climate.

A. Bershadskii

2009-03-16

39

Long-term changes in the solar photosphere associated with changes in the coronal source flux  

NASA Astrophysics Data System (ADS)

Using sunspot observations from Greenwich and Mount Wilson, we show that the latitudinal spread of sunspot groups has increased since 1874, in a manner that closely mirrors the long-term (˜100 year) changes in the coronal source flux, Fs, as inferred from geomagnetic activity. This latitude spread is shown to be well correlated with the flux emergence rate required by the model of the coronal source flux variation by Solanki et al. [2000]. The time constant for the decay of this open flux is found to be 3.6±0.8 years. Using this value, and quantifying the photospheric flux emergence rate using the latitudinal spread of sunspot groups, the model reproduces the observed coronal source flux variation. The ratio of the 100-year drift to the solar cycle amplitude for the flux emergence rate is found to be half of the same ratio for Fs.

Foster, S.; Lockwood, M.

2001-04-01

40

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

41

Thermosiphon solar domestic water heating systems: long-term performance prediction using artificial neural networks  

Microsoft Academic Search

The objective of this work is to use artificial neural networks (ANN) for the long-term performance prediction of thermosiphonic type solar domestic water heating (SDWH) systems. Thirty SDWH systems have been tested and modelled according to the procedures outlined in the standard ISO 9459-2 at three locations in Greece. From these, data from 27 of the systems were used for

Soteris A Kalogirou; Sofia Panteliou

2000-01-01

42

Solar Magnetic Flux and Long-term Changes In The Space Weather, 1700-2000  

NASA Astrophysics Data System (ADS)

Some new results are presented about long-term (since the year 1700) behavior of the solar open field magnetic flux and its geoeffectiviness. The time dependent flux model introduced by Solanki et al. (2000) has been applied to the variations of geomagnetic aa-index series (1844-2000) and auroral occurrence rate (1700-1980). Their charac- teristic secular variations (Gleissberg cycle, about 90 yrs) as well as the 11-year solar periodicity follow closely to the flux model variations.

Nevanlinna, H.

43

Stratospheric chemical and thermal response to long-term variability in solar UV irradiance  

Microsoft Academic Search

Taking into account the thermal feedback effect on the reaction rates, a theoretical analysis of the chemical response of the stratosphere to the possible long-term variability of solar ultraviolet irradiance is presented. The variability, related to the 11-year solar cycle, is introduced in a two-dimensional stratosphere model simulating the zonally averaged distribution of chemical species related to oxygen, hydrogen, nitrogen

G. Brasseur; P. C. Simon

1981-01-01

44

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

E-print Network

Magnetospheric Physics: Energetic particles, trapped; 2784 Magnetospheric Physics: Solar wind/ magnetosphereLong-term-average, solar cycle, and seasonal response of magnetospheric energetic electrons to the solar wind speed D. Vassiliadis,1 A. J. Klimas,2 S. G. Kanekal,3 D. N. Baker,3 and R. S. Weigel4

45

Improvement on the long-term stability of flexible plastic dye-sensitized solar cells  

NASA Astrophysics Data System (ADS)

We investigate the long-term stability of performance for plastic dye-sensitized solar cells (DSSCs) based on organic iodides (TBAI or PMII) in methoxypropionitrile-based electrolytes. Plastic DSSCs containing TBAI maintain 96.9% of baseline efficiency under more than 1000 h prolonged one sun light irradiation and thermal stress (60 °C) aging. The factors of device long-term stability, such as the effects of organic iodides, cell-sealing conditions, and the sheet resistance of indium tin oxide coated polyethylene naphthalate substrate (ITO/PEN) are discussed via using electrochemical impedance spectroscopy and electrical resistance measurement.

Lee, Kun-Mu; Chiu, Wei-Hao; Lu, Ming-De; Hsieh, Wen-Feng

2011-10-01

46

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

47

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

48

Saturn suprathermal O2+ and mass-28+ molecular ions: Long-term seasonal and solar variation  

NASA Astrophysics Data System (ADS)

Suprathermal singly charged molecular ions, O2+ (at ~32 Da/e) and the Mass-28 ion group 28M+ (ions at ~28 Da/e, with possible contributions from C2H5+, HCNH+, N2+, and/or CO+), are present throughout Saturn's ~4-20 Rs (1 Saturn radius, Rs = 60,268 km) near-equatorial magnetosphere from mid-2004 until mid-2012. These ~83-167 keV/e heavy ions measured by Cassini's CHarge-Energy-Mass Spectrometer have long-term temporal profiles that differ from each other and differ relative to the dominant water group ions, W+ (O+, OH+, H2O+, and H3O+). O2+/W+, initially ~0.05, declined steadily until equinox in mid-2009 by a factor of ~6, and 28M+/W+, initially ~0.007, declined similarly until early-2007 by a factor of ~2. The O2+/W+ decline is consistent with Cassini's in situ ring-ionosphere thermal ion measurements, and with proposed and modeled seasonal photolysis of Saturn's rings for thermal O2 and O2+. The water ice-dominated main rings and Enceladus plume depositions thereon are the two most likely O2+ sources. Enceladus' dynamic plumes, though, have no known long-term dependence. After declining, O2+/W+ and 28M+/W+ levels remained low until late-2011 when O2+/W+ increased, but 28M+/W+ did not. The O2+/W+ increase was steady and became statistically significant by mid-2012, indicating a clear increase after a decline, that is, a possibly delayed O2+ "seasonal" recovery. Ring insolation is driven by solar UV flux which itself varies with the sun's 11 year activity cycle. The O2+/W+ and 28M+/W+ declines are consistent with seasonal ring insolation. No O2+/W+ response to the late-2008 solar-cycle UV minimum and recovery is evident. However, the O2+/W+ recovery from the postequinox baseline levels in late-2011 coincided with a strong solar UV enhancement. We suggest a scenario/framework in which the O2+ observations can be understood.

Christon, S. P.; Hamilton, D. C.; Difabio, R. D.; Mitchell, D. G.; Krimigis, S. M.; Jontof-Hutter, D. S.

2013-06-01

49

Long-term changes in composition of solar particles implanted in extraterrestrial materials  

NASA Technical Reports Server (NTRS)

Analysis of lunar surface samples for elements implanted therein by solar corpuscular radiation reveals evidence for the following compositional changes over a time period between 1.5 and 3 Gyr: 50-percent decreases in the ratios He-4/Ar-36 and Xe/Ar-36; a 20-percent increase in the ratio He-3/He-4; a 3-percent increase in the ratio Ne-20/Ne-22; and a 50-percent increase in the ratio N-15/N-14. The causes of these changes are not resolved at this time but may include (1) a change in acceleration conditions of the solar wind, (2) a change in flux of solar energetic particles relative to that of the solar wind, and (3) a change in composition of the solar convective zone. There is good evidence for a long-term decrease in the solar-wind flux.

Kerridge, J. F.; Signer, P.; Wieler, R.; Becker, R. H.; Pepin, R. O.

1991-01-01

50

Long-term performance of solar-assisted heat pump water heater  

Microsoft Academic Search

A long-term reliability test of an integral-type solar-assisted heat pump water heater (ISAHP) was carried out. The prototype has been running continuously for more than 13,000 h with total running time >20,000 h during the past 5 yr. The measured energy consumption is 0.019 kWh\\/l of hot water at 57 oC that is much less than the backup electric energy

B. J Huang; C. P Lee

2004-01-01

51

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

52

Analytic models for predicting the long-term performance of solar photovoltaic systems  

Microsoft Academic Search

Analytic models based on calculations for one repetitive day are presented for predicting the long-term performance of photovoltaic systems. For highly time-dependent loads, a general one-repetitive day simulation technique is described. For the special but practical cases of constant load distributions, simple closed-form solutions are derived for monthly solar fraction and dumped energy as functions of the important system variables.

J. M. Gordon; P. Zoglin

1986-01-01

53

Measurements of long-term changes in atmospheric OCS (carbonyl sulfide) from infrared solar observations  

Microsoft Academic Search

Multi-decade atmospheric OCS (carbonyl sulfide) infrared measurements have been analyzed with the goal of quantifying long-term changes and evaluating the consistency of the infrared atmospheric OCS remote-sensing measurement record. Solar-viewing grating spectrometer measurements recorded in April 1951 at the Jungfraujoch station (46.5°N latitude, 8.0°E longitude, 3.58km altitude) show evidence for absorption by lines of the strong ?3 band of OCS

Curtis P. Rinsland; Linda Chiou; Emmanuel Mahieu; Rodolphe Zander; Chris D. Boone; Peter F. Bernath

2008-01-01

54

Coincident Activity of Converging Pathways Enables Simultaneous Long-Term Potentiation and Long-Term Depression in Hippocampal CA1 Network In Vivo  

Microsoft Academic Search

Memory is believed to depend on activity-dependent changes in the strength of synapses, e.g. long-term potentiation (LTP) and long-term depression (LTD), which can be determined by the sequence of coincident pre- and postsynaptic activity, respectively. It remains unclear, however, whether and how coincident activity of converging efferent pathways can enable LTP and LTD in the pathways simultaneously. Here, we report

Zhifang Dong; Huili Han; Jun Cao; Xia Zhang; Lin Xu; Bai Lu

2008-01-01

55

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

56

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

57

Long-term stabilization of organic solar cells using hindered phenols as additives.  

PubMed

We report on the improvement of long-term stability of organic solar cells (OPV) using hindered phenol based antioxidants as stabilizing additives. A set of seven commercially available hindered phenols are investigated for use in bulk-heterojunction OPV. Polymer:fullerene films based on poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) are characterized with respect to the initial power conversion efficiency and the long-term stability improvement under illumination in ambient conditions. FTIR spectroscopy is used to trace chemical degradation over time. OPV performance is recorded under ISOS-3 conditions, and an improved long-term performance of OPV devices, manifested in increased accumulated power generation (APG), is found for octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate. Using this additive, APG is increased by a factor of 3 compared to the reference. Observed differences in the stabilization of tested additives are discussed in terms of energetic trap states formation within the HOMO/LUMO gap of the photoactive material, morphological changes, and chemical structure. PMID:25279719

Turkovic, Vida; Engmann, Sebastian; Tsierkezos, Nikos; Hoppe, Harald; Ritter, Uwe; Gobsch, Gerhard

2014-11-12

58

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

59

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

60

Long-term change in the organization of inventive activity  

PubMed Central

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

Lamoreaux, Naomi R.; Sokoloff, Kenneth L.

1996-01-01

61

Wnt pathway activation in long term remnant rat model.  

PubMed

Progression of chronic kidney disease (CKD) is characterized by deposition of extracellular matrix. This is an irreversible process that leads to tubulointerstitial fibrosis and finally loss of kidney function. Wnt/ ?-catenin pathway was reported to be aberrantly activated in the progressive damage associated with chronic organ failure. Extensive renal ablation is an experimental model widely used to gain insight into the mechanisms responsible for the development of CKD, but it was not evaluated for Wnt/ ?-catenin pathway. This study aimed to elucidate if the rat 5/6 renal mass reduction model (RMR) is a good model for the Wnt/ ?-catenin activation and possible next modulation. RMR model was evaluated at 12 and 18 weeks after the surgery, when CKD is close to end-stage kidney disease demonstrated by molecular and histological studies. Wnt pathway components were analyzed at mRNA and protein level. Our results demonstrate that Wnt pathway is active by increase of ?-catenin at mRNA level and nuclear translocation in tubular epithelium as well as some target genes. These results validate the RMR model for future modulation of Wnt pathway, starting at shorter time after the surgery. PMID:24995284

Banon-Maneus, E; Rovira, J; Ramirez-Bajo, M J; Moya-Rull, D; Hierro-Garcia, N; Takenaka, S; Diekmann, F; Eickelberg, O; Königshoff, M; Campistol, J M

2014-01-01

62

A Long-Term Evaluation of Sensing Modalities for Activity Recognition  

E-print Network

A Long-Term Evaluation of Sensing Modalities for Activity Recognition Beth Logan1 , Jennifer Healey but highly instrumented home. Our experiment studied a married couple living for 10 weeks in this home. We

63

Positions for post-doctoral and/or senior researchers are available at the University of Oulu, Finland, within the Centre of Excellence in "Research on Solar Long-term  

E-print Network

SoLVE studies the long-term (multidecadal to centennial) magnetic evolution of the Sun magnetic fields, solar corona, solar wind and the heliospheric magnetic field, geomagnetic activity and geomagnetic storms, energizing magnetospheric particles

Kaski, Samuel

64

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

65

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

66

Long-term effects of language intensity in preventive messages on planned family solar protection.  

PubMed

A series of sun safety messages containing highly intense language and deductive logical style achieved the most immediate compliance by parents, particularly when they intended to improve protection. Inductive messages were more successful when no intentions existed (D. B. Buller, Borland, & Burgoon, 1998; D. B. Buller et al., 2000). Interviewers recontacted 568 parents during the winter following message dissemination and assessed solar protection. A 2 (language intensity) x 2 (logical style) x 3 (behavioral intention) x 2 (person) mixed-model analysis of variance showed that parents receiving high-intensity, deductive messages reported the most improved solar protection and improvement was greatest when parents intended to improve protection. Over the long term, high language intensity may reinforce decisions to take preventive action and does not appear to provoke psychological reactance or resistance to these highly directive messages. PMID:10938916

Buller, D B; Burgoon, M; Hall, J R; Levine, N; Taylor, A M; Beach, B; Buller, M K; Melcher, C

2000-01-01

67

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

68

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

69

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

70

SeaWiFS long-term solar diffuser reflectance and sensor noise analyses  

NASA Astrophysics Data System (ADS)

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

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

2007-02-01

71

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

PubMed

Tibial stress fractures are a common overuse injury among military recruits. The purpose of this study was to determine what, if any, long-term effects that tibial stress fractures have on military personnel with respect to physical activity level, completion of military training, recurrence of symptoms, and active duty service. Twenty-six military recruits included in a previous tibial stress fracture study were contacted 10 years after initial injury and asked a series of questions related to any long-term consequences of their tibial stress fracture. Of the 13 patients available for contact, no patients reported any necessary limited duty while on active duty, and no patient reported being separated or discharged from the military as a result of stress fracture. Tibial stress fractures in military recruits are most often an isolated injury and do not affect ability to complete military training or reflect a long-term need for decreased physical activity. PMID:23449055

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

2013-01-01

72

Long-Term Results of TPMT Activity Monitoring in Azathioprine-Treated Renal Allograft Recipients  

Microsoft Academic Search

Thiopurine methyltransferase (TPMT) is implicated in the metabolism of azathioprine. The consequences of dif- ferential TPMT activity induction by azathioprine on the long- term results after renal transplantation were investigated. The erythrocyte TPMT activity in 82 patients on days 0, 7, and 30 was prospectively evaluated. Because various patterns of TPMT activity variation were noted, the population was sub- sequently

ERIC THERVET; DANY ANGLICHEAU; NATHALIE TOLEDANO; ANNE-MARIE HOULLIER; LAURE-HÉLÈNE NOEL; HENRI KREIS; PHILIPPE BEAUNE; CHRISTOPHE LEGENDRE

2001-01-01

73

The mid-term and long-term solar quasi-periodic cycles and the possible relationship with planetary motions  

NASA Astrophysics Data System (ADS)

This work investigates the solar quasi-periodic cycles with multi-timescales and the possible relationships with planetary motions. The solar cycles are derived from long-term observations of the relative sunspot number and microwave emission at frequency of 2.80 GHz. A series of solar quasi-periodic cycles with multi-timescales are registered. These cycles can be classified into three classes: (1) the strong PLC (PLC is defined as the solar cycle with a period very close to the ones of some planetary motions, named as planetary-like cycle) which is related strongly with planetary motions, including nine periodic modes with relatively short period ( P<12 yr), and related to the motions of the inner planets and of Jupiter; (2) the weak PLC, which is related weakly to planetary motions, including two periodic modes with relatively long period ( P>12 yr), and possibly related to the motions of outer planets; (3) the non-PLC, for which so far there has been found no clear evidence to show the relationship with any planetary motions. Among the planets, Jupiter plays a key role in most periodic modes due to its sidereal motion or spring tidal motions associated with other planets. Among planetary motions, the spring tidal motion of the inner planets and of Jupiter dominates the formation of most PLCs. The relationships between multi-timescale solar periodic modes and the planetary motions will help us to understand the essential nature and prediction of solar activities.

Tan, Baolin; Cheng, Zhuo

2013-02-01

74

Long-Term Dynamics of Small Bodies in the Solar System  

NASA Technical Reports Server (NTRS)

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

Holman, Matthew J.

2004-01-01

75

Long-Term Dynamics of Small Bodies in the Solar System  

NASA Technical Reports Server (NTRS)

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

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

2002-01-01

76

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

77

A grounded theory of successful long-term physical activity behaviour change  

Microsoft Academic Search

This paper presents a grounded theory of successful long-term physical activity (PA) behaviour change. Currently, a range of theoretical frameworks are available to guide researchers and practitioners in the development and implementation of PA behaviour change interventions. However, none of these theoretical approaches are specifically intended to account for PA-related behaviours. In addition, there is limited evidence to support the

A. J. Hutchison; L. H. Johnston; J. D. Breckon

2012-01-01

78

The Task Rule Congruency Effect in Task Switching Reflects Activated Long-Term Memory  

ERIC Educational Resources Information Center

Reaction time task rule congruency effects (RT-TRCEs) reflect faster responses to stimuli for which the competing task rules indicate the same correct response than to stimuli indicating conflicting responses. The authors tested the hypothesis that RT-TRCE reflects activated overlearned response category codes in long-term memory (such as up or…

Meiran, Nachshon; Kessler, Yoav

2008-01-01

79

Analysis of Utterance in Long-Term Robot Assisted Activity for Elderly People  

Microsoft Academic Search

A long-term experiment of robot assisted activity for elderly people has been conducted at a health service facility for the aged since Aug. 2003. Three therapeutic seal robots, Paro, were introduced there. This paper describes the results of the experiment for one year. Face scales that consist of illustrations of person's faces were used to evaluate person's moods. In addition,

Kazuyoshi Wada; Takanori Shibata; Kayoko Sakamoto; Tomoko Saito; Kazuo Tanie

2005-01-01

80

Quantitative analysis of utterance of elderly people in long-term robot assisted activity  

Microsoft Academic Search

A long-term experiment of robot assisted activity for elderly people has been conducted at a health service facility for the aged since Aug. 2003. Three therapeutic seal robots, Paro, were introduced there. This paper describes the results of the experiment for one year. Face scales that consist of illustrations of person's faces were used to evaluate a person's moods. In

Kazuyoshi Wada; Takanori Shibata; Kayoko Sakamoto; Kazuo Tanie

2005-01-01

81

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

Microsoft Academic Search

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

Jun Il Kang; Elvire Vaucher; Teresa Serrano-Gotarredona

2009-01-01

82

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

E-print Network

Cholinergic Pairing with Visual Activation Results in Long-Term Enhancement of Visual Evoked´bec, Canada Abstract Acetylcholine (ACh) contributes to learning processes by modulating cortical plasticity) receptor antagonists before carbachol infusion. Stimulation of the cholinergic system paired with visual

83

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

84

PAMSys: long-term physical activity monitoring with single wearable motion sensor  

Microsoft Academic Search

In this demo, we present PAMSys#8482;(physical activity monitoring system), a single body sensor solution for long-term and continuous monitoring of a person's daily activities. PAMSys#8482; requires only a single light-weight sensor unit that can be integrated unobtrusively into a comfortable shirt (or directly to a subject's shirt) without hindering daily-living activities. The use of large flash storage and low power

Bor-rong Chen; Bryan Kate

2011-01-01

85

Long-term middle atmospheric influence of very large solar proton events  

E-print Network

short-lived (days). The long-term stratospheric ozone effects were caused by the NOy enhancements. Very variations. Some statistically significant long-term effects on mesospheric ozone were caused by the HOx impact on ozone [World Meteorological Organization, 2007]. The SPE-caused impacts are largest

Jackman, Charles H.

86

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

87

The impact of materials selection on long-term activation in fusion power plants  

Microsoft Academic Search

Neutron-induced transmutation of materials in a D–T fusion power plant will give rise to the potential for long-term activation. To ensure that the attractive safety and environmental characteristics of fusion power are not degraded, careful design choices are necessary. An aim of optimising power plant design must be to minimise both the level of activation and the total volume of

N. P. Taylor; C. B. A. Forty; D. A. Petti; K. A. McCarthy

2000-01-01

88

Accuracy of the European solar water heater test procedure. Part 2: Prediction of long-term performance  

Microsoft Academic Search

This paper continues the evaluation of the European test procedure for solar water heaters, by considering what consequences the errors of the parameters (derived in Part 1, the companion paper) will have for the prediction of the long-term performance. A simple criterion is derived for the required length of the test period, as a function of climatic variables and desired

A. Rabl; M. J. Carvalho; M. Collares-Pereira; B. Bourges

1991-01-01

89

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

PubMed

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

Leuenberger, Kaspar; Gassert, Roger

2011-01-01

90

Long-term patterns of solar irradiance forcing in model experiments and proxy based surface temperature reconstructions  

Microsoft Academic Search

Comparisons are made of long-term empirical and model-estimated patterns of solar irradiance forcing during a 200-year period (1650-1850), which precedes any apparent anthropogenic influence on climate. This interval encompasses a considerable range (approxi- mately 4 W\\/m2) of estimated variation in solar output, including the ''Maunder'' and ''Dalton'' Minima of so- lar irradiance, and an intervening interval of relatively high values

A. M. Waple; R. S. Bradley; M. E. Mann

2002-01-01

91

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

92

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

93

Activity and Composition of the Denitrifying Bacterial Community Respond Differently to Long-Term Fertilization  

Microsoft Academic Search

The objective of this study was to explore the long-term effects of different organic and inorganic fertilizers on activity and composition of the denitrifying and total bacterial communities in arable soil. Soil from the following six treatments was analyzed in an experimental field site established in 1956: cattle manure, sewage sludge, Ca(NO3)2, (NH4)2SO4, and unfertilized and unfertilized bare fallow. All

Karin Enwall; Laurent Philippot; Sara Hallin

2005-01-01

94

Involvement of Mitogen-Activated Protein Kinase in Hippocampal Long-Term Potentiation  

Microsoft Academic Search

Mitogen-activated protein kinase (MAPK) cascade classically is thought to be involved in cellular transformation, including proliferation and differentiation. Recent behavioral studies suggest that MAPK may also have a role in learning and memory. Long-term potentiation (LTP), a candidate mechanism for learning and memory, has at least two distinct temporal phases: an early phase (E-LTP) which lasts for 1–2 h and

Shang-Peng Wu; Kwok-Tung Lu; Wen-Chang Chang; Po-Wu Gean

1999-01-01

95

Soil microbial biomass and activity in long-term grassland: Effects of management changes  

Microsoft Academic Search

The effects of long-term N fertilizer management history and field drainage on soil microbial biomass N and C and its activity in the surface soil of a poorly-drained pasture soil in S.W. England were examined periodically for 1 year. The immediate effects of changes in N fertilizer inputs were also determined. In general, there were few differences in the trends

R. D. Lovell; S. C. Jarvis; R. D. Bardgett

1995-01-01

96

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

97

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

98

Long-term total solar irradiance variability during sunspot cycle 22  

NASA Technical Reports Server (NTRS)

Total solar irradiance measurements from the 1984-1993 Earth Radiation Budget Satellite (ERBS) active cavity radiometer and 1978-1993 Nimbus 7 transfer cavity radiometer spacecraft experiments are analyzed to detect the presence of 11-, 22-, and 80-year irradiance variability components. The analyses confirmed the existence of a significant 11-year irradiance variability component, associated with solar magnetic activity and the sunspot cycle. The analyses also suggest the presence of a 22- or 80-year variability component. The earlier Nimbus 7 and Solar Maximum Mission (SMM) spacecraft irradiance measurements decreased approximately 1.2 and 1.3 W/sq m, respectively, between 1980 and 1986. The Nimbus 7 values increased 1.2 W/sq m between 1986 and 1989. The ERBS irradiance measurements increased 1.3 W/sq m during 1986-1989, and then decreased 0.4 W/sq m (at an annual rate of 0.14 W/sq. m/yr) during 1990-1993. Considering the correlations between ERBS, Nimbus 7, and SMM irradiance trends and solar magnetic activity, the total solar irradiance should decrease to minimum levels by 1997 as solar activity decreases to minimum levels, and then increase to maximum levels by the year 2000 as solar activity rises. The ERBS measurements yielded 165.4 +/- 0.7 W/sq m as the mean irradiance value with measurement accuracies and precisions of 0.2% and 0.02%, respectively. The ERBS mean irradiance value is within 0.2% of the 1367.4, 1365.9, and 1366.9 W/sq m mean values for the SMM, Upper Atmosphere Research Satellite (UARS), and Space Shuttle Atmospheric Laboratory for Applications and Science (ATLAS 1) Solar Constant (SOLCON) active cavity radiometer spacecraft experiments, respectively. The Nimbus 7 measurements yielded 1372.1 W/sq m as the mean value with a measurement accuracy of 0.5%. Empirical irradiance model fits, based upon 10.7 -cm solar radio flux (F10) and photometric sunspot index (PSI), were used to assess the quality of the ERBS, Numbus 7, SMM, and the UARS irradiance data sets and to identify irradiance variability trends which may be caused by drifts or shifts in the spacecraft sensor responses. Comparisons among the fits and measured irradiances indicate that the Nimbus 7 radiometer response shifted by a total of 0.8 W/sq m between September 1989 and April 1990 and that the ERBS and UARS radiometers each drifted approximately 0.5 W/sq m during the first 5 months in orbit.

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

1995-01-01

99

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

100

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

101

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

102

Solar origin of long-term variations of the interplanetary magnetic field strength  

Microsoft Academic Search

Spacecraft measurements over the past two sunspot cycles have shown that the average strength of the interplanetary magnetic field (IMF) undergoes surprisingly modest long-term variation, unlike the total magnetic flux observed on the Sun. Our attempt to model the IMF during sunspot cycle 21, based on a current-free extrapolation of the observed photospheric field out to a fixed source surface

Y.-M. Wang; Sheeley N. R. Jr

1988-01-01

103

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

PubMed Central

OBJECTIVE—To analyse the long term results of mechanical prostheses for treating active infective endocarditis.?DESIGN—Prospective cohort study of a consecutive series of patients diagnosed with infective endocarditis and operated on in the active phase of the infection for insertion of a mechanical prosthesis.?SETTING—Tertiary referral centre in a metropolitan area.?RESULTS—Between 1975 and 1997, 637 cases of infective endocarditis were diagnosed in the centre. Of these, 436 were left sided (with overall mortality of 20.3%). Surgical treatment in the active phase of the infection was needed in 141 patients (72% native, 28% prosthetic infective endocarditis). Mechanical prostheses were used in 131 patients. Operative mortality was 30.5% (40 patients). Ninety one survivors were followed up prospectively for (mean (SD)) 5.4 (4.5) years. Thirteen patients developed prosthetic valve dysfunction. Nine patients suffered reinfection: four of these (4%) were early and five were late. The median time from surgery for late reinfection was 1.4 years. During follow up, 12 patients died. Excluding operative mortality, actuarial survival was 86.6% at five years and 83.7% at 10 years; actuarial survival free from death, reoperation, and reinfection was 73.1% at five years and 59.8% at 10 years.?CONCLUSIONS—In patients surviving acute infective endocarditis and receiving mechanical prostheses, the rate of early reinfection compares well with reported results of homografts. In addition, prosthesis dysfunction rate is low and long term survival is good. These data should prove useful for comparison with long term studies, when available, using other types of valve surgery in active infective endocarditis.???Keywords: infective endocarditis; surgery; mechanical prosthesis PMID:11410564

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

2001-01-01

104

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

105

Tissue plasminogen activator is required for corticostriatal long-term potentiation.  

PubMed

Several experimental data indicate that tissue plasminogen activator (tPA) is involved in memory formation and synaptic plasticity in different brain areas. In the attempt to highlight the role of this serine protease in striatal neuron activity, mice lacking tPA have been used for electrophysiological, immunohistochemical and Western blot experiments. Disruption of tPA gene prevented corticostriatal long-term potentiation, an NMDA-dependent form of synaptic plasticity requiring the stimulation of both dopamine and acetylcholine receptors. Spontaneous and evoked glutamatergic transmission was intact in the striatum of tPA-deficient mice, as was the nigrostriatal dopamine innervation and the expression of dopamine D1 receptors. Conversely, the sensitivity of striatal cholinergic interneurons to dopamine D1 receptor stimulation was lost in these mutants, suggesting that tPA facilitates long-term potentiation (LTP) induction in the striatum by favouring the D1 receptor-mediated excitation of acetylcholine-producing interneurons. The demonstration that tPA ablation interferes with the induction of corticostriatal LTP and with the dopamine receptor-mediated control of cholinergic interneurons might help to explain the altered striatum-dependent learning deficits observed in tPA-deficient mice and provides new insights into the molecular mechanisms underlying synaptic plasticity in the striatum. PMID:12270047

Centonze, Diego; Napolitano, Maddalena; Saulle, Emilia; Gubellini, Paolo; Picconi, Barbara; Martorana, Alessandro; Pisani, Antonio; Gulino, Alberto; Bernardi, Giorgio; Calabresi, Paolo

2002-08-01

106

Physical activity level and quality of life in long term lung cancer survivors  

PubMed Central

Purpose Lung cancer is associated with a multitude of challenges, and lung cancer survivors report significantly lower quality of life (QOL) than other cancer survivors. Methods This study aimed to examine the relationship between physical activity level and QOL in a large sample of long term lung cancer survivors (N = 1937). Average age at diagnosis was 65 years, 92% were Caucasian, and 51% male. Surveys were completed at lung cancer diagnosis and then average 4.2 years post-diagnosis. Results Most survivors reported having a sedentary lifestyle at both timepoints. However, 256 survivors reported a change in physical activity level from diagnosis to follow-up. Decreased physical activity (n = 140) was associated with decreased overall, mental, physical, emotional, social, and spiritual QOL (all ps < .001) and decreased symptom control as seen in reported pain, dry coughing, coughing with phlegm, shortness of breath, and level of fatigue (all ps < .05). In contrast, increased physical activity (n = 116) was associated with improved QOL (all ps < .05), and improved symptom control as seen in frequency and severity of pain (p < .01). For all participants, those engaging in regular physical activity (30 min or more per day, at least five days per week) reported significantly higher QOL scores (all ps < .001), and better symptom control than more sedentary survivors. Conclusions Results indicate a significant association between change in physical activity and QOL and symptom control for long term lung cancer survivors, and research exploring interventions designed to improve activity level for lung cancer survivors is further warranted. PMID:22681871

Nes, Lise Solberg; Liu, Heshan; Patten, Christi A.; Rausch, Sarah M.; Sloan, Jeff A.; Garces, Yolanda I.; Cheville, Andrea L; Yang, Ping; Clark, Matthew M.

2013-01-01

107

Diurnal tide in the low-latitude troposphere and stratosphere: Long-term trends and role of the extended solar minimum  

NASA Astrophysics Data System (ADS)

In the present study, long-term trends in the diurnal tide in the troposphere and stratosphere over a tropical station Gadanki (13.5°N, 79.2°E) are investigated using ERA-Interim wind and temperature products available since 1979. Suitability of the ERA-Interim data for the present study is ascertained using simultaneous radiosonde and MST radar observations over Gadanki and good consistency was found between the two. In general, diurnal tide amplitudes are found to increase from troposphere to stratosphere, as expected. Amplitude of the diurnal tide shows a long-term linear increasing trend, which becomes prominent in the stratosphere. Interestingly, convection over Gadanki also exhibits an increasing trend suggesting that they are related. Role of solar cycle on the diurnal tide is investigated by separating the tidal amplitudes during minimum and maximum of solar cycles 21, 22 and 23. Significantly higher amplitudes in the recent extended solar minimum are noticed though no consistent relation is found between solar activity and tides, in general. These results are discussed in the light of role of convection on the generation of the diurnal tide and their propagation to the higher altitudes, coupling lower and middle atmospheres. Special emphasis is made on the observed large amplitudes of the diurnal tide in the extended solar minimum while relating the observed changes to the background circulation.

Ratnam, M. Venkat; Rao, N. Venkateswara; Vedavathi, C.; Murthy, B. V. Krishna; Bhaskara Rao, S. Vijaya

2014-12-01

108

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

109

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

NASA Technical Reports Server (NTRS)

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

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

1999-01-01

110

PICARD SOL mission, a ground-based facility for long-term solar radius measurement  

NASA Astrophysics Data System (ADS)

For the last thirty years, ground time series of the solar radius have shown different variations according to different instruments. The origin of these variations may be found in the observer, the instrument, the atmosphere and the Sun. These time series show inconsistencies and conflicting results, which likely originate from instrumental effects and/or atmospheric effects. A survey of the solar radius was initiated in 1975 by F. Laclare, at the Calern site of the Observatoire de la Cˆote d'Azur (OCA). PICARD is an investigation dedicated to the simultaneous measurements of the absolute total and spectral solar irradiance, the solar radius and solar shape, and to the Sun's interior probing by the helioseismology method. The PICARD mission aims to the study of the origin of the solar variability and to the study of the relations between the Sun and the Earth's climate by using modeling. These studies will be based on measurements carried out from orbit and from the ground. PICARD SOL is the ground segment of the PICARD mission to allow a comparison of the solar radius measured in space and on ground. PICARD SOL will enable to understand the influence of the atmosphere on the measured solar radius. The PICARD Sol instrumentation consists of: SODISM II, a replica of SODISM (SOlar Diameter Imager and Surface Mapper), a high resolution imaging telescope, and MISOLFA (Moniteur d'Images SOLaires Franco-Al?erien), a seeing monitor. Additional instrumentation consists in a Sun photometer, which measures atmospheric aerosol properties, a pyranometer to measure the solar irradiance, a visible camera, and a weather station. PICARD SOL is operating since March 2011. First results from the PICARD SOL mission are briefly reported in this paper.

Meftah, M.; Irbah, A.; Corbard, T.; Morand, F.; Thuillier, G.; Hauchecorne, A.; Ikhlef, R.; Rouze, M.; Renaud, C.; Djafer, D.; Abbaki, S.; Assus, P.; Chauvineau, B.; Cissé, E. M.; Dalaudier, F.; D'Almeida, Eric; Fodil, M.; Laclare, F.; Lesueur, P.; Lin, M.; Marcovici, J. P.; Poiet, G.

2012-09-01

111

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

PubMed

The long-term effect of various temperature (4°C, 12°C, 20°C, 25°C and 34°C) on nitrous oxide (N2O) emission from lab-scale denitrifying activated sludge was studied in terms of activation energy, abundance of functional gene nosZ and its transcription. Results showed that temperature had a positive effect on N2O emissions as well as the maximum biomass-specific reduction rates of N2O and NO3(-), ranging from 0.006% to 0.681% of (N2O + N2), 17.3-116.2 and 5.2-66.2 mg N g(-1) VSS h(-1), respectively. The activation energies (Ea) for N2O and NO3(-) reduction of 44.1 kJ mol(-1) and 54.9 kJ mol(-1), shed light on differences in denitrifying rate variation. The maximum NO3(-) reduction rates were more sensitive to temperature variation than the corresponding N2O reduction rates under long-term acclimation. As a result, the ratio between N2O and NO3(-) reduction rates declined to 1.87 at 34°C from 3.31 at 4°C, suggesting great potential capacity for N2O losses at high temperature. The copy numbers of denitrifiers as nosZ gene (×10(8) copies mL(-1)) and total bacteria as 16S rRNA gene (×10(10) copies mL(-1)) did not show obvious relationship with temperature, having relative abundance of 0.42% on average. The transcriptional regulation of nosZ gene, in the range of 10(8)-10(5) copies mL(-1), was affected by reductase activity, substrate concentration as well as its duration. The active nosZ gene expression was accompanied with low reductase capacity, high dissolved N2O and the duration of N2O accumulation. These results provide insights into activation energy and gene expression responsible for N2O emission. PMID:24480748

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

2014-03-01

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

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

114

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

115

Persistence and activation of malaria hypnozoites in long-term primary hepatocyte cultures.  

PubMed

Malaria relapses, resulting from the activation of quiescent hepatic hypnozoites of Plasmodium vivax and Plasmodium ovale, hinder global efforts to control and eliminate malaria. As primaquine, the only drug capable of eliminating hypnozoites, is unsuitable for mass administration, an alternative drug is needed urgently. Currently, analyses of hypnozoites, including screening of compounds that would eliminate them, can only be made using common macaque models, principally Macaca rhesus and Macaca fascicularis, experimentally infected with the relapsing Plasmodium cynomolgi. Here, we present a protocol for long-term in vitro cultivation of P. cynomolgi-infected M. fascicularis primary hepatocytes during which hypnozoites persist and activate to resume normal development. In a proof-of-concept experiment, we obtained evidence that exposure to an inhibitor of histone modification enzymes implicated in epigenetic control of gene expression induces an accelerated rate of hypnozoite activation. The protocol presented may further enable investigations of hypnozoite biology and the search for compounds that kill hypnozoites or disrupt their quiescence. PMID:24509527

Dembélé, Laurent; Franetich, Jean-François; Lorthiois, Audrey; Gego, Audrey; Zeeman, Anne-Marie; Kocken, Clemens H M; Le Grand, Roger; Dereuddre-Bosquet, Nathalie; van Gemert, Geert-Jan; Sauerwein, Robert; Vaillant, Jean-Christophe; Hannoun, Laurent; Fuchter, Matthew J; Diagana, Thierry T; Malmquist, Nicholas A; Scherf, Artur; Snounou, Georges; Mazier, Dominique

2014-03-01

116

Effects on winter circulation of short and long term solar wind changes  

NASA Astrophysics Data System (ADS)

Indices of the North Atlantic Oscillation and the Arctic Oscillation show correlations on the day-to-day timescale with the solar wind speed (SWS). Minima in the indices were found on days of SWS minima during years of high stratospheric aerosol loading. The spatial distribution of surface pressure changes during 1963-2011 with day-to-day changes in SWS shows a pattern resembling the NAO. Such a pattern was noted for year-to-year variations by Boberg and Lundstedt (2002), who compared NAO variations with the geo-effective solar wind electric field (the monthly average SWS multiplied by the average southward component, i.e., negative Bz component, of the interplanetary magnetic field). The spatial distribution of the correlations of geopotential height changes in the troposphere and stratosphere with the SWS; the geo-effective electric field (SWS?Bz); and the solar 10.7 cm flux suggests that solar wind inputs connected to the troposphere via the global electric circuit, together with solar ultraviolet irradiance acting on the stratosphere, affect regional atmospheric dynamics.

Zhou, Limin; Tinsley, Brian; Huang, Jing

2014-12-01

117

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

118

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

PubMed

Synaptic activation of central neurons is often evoked by electrical stimulation leading to post-tetanic potentiation, long-term potentiation or long-term depression. Even a brief electrical tetanus can induce changes in as many as 100 proteins. Since climbing fibre activity is often associated with cerebellar behavioural plasticity, we used horizontal optokinetic stimulation (HOKS) to naturally increase synaptic input to floccular Purkinje cells in mice for hours, not minutes, and investigated how this activity influenced the transcription of microRNAs, small non-coding nucleotides that reduce transcripts of multiple, complementary mRNAs. A single microRNA can reduce the translation of as many as 30 proteins. HOKS evoked increases in 12 microRNA transcripts in floccular Purkinje cells. One of these microRNAs, miR335, increased 18-fold after 24 h of HOKS. After HOKS stopped, miR335 transcripts decayed with a time constant of approximately 2.5 h. HOKS evoked a 28-fold increase in pri-miR335 transcripts compared with an 18-fold increase in mature miR335 transcripts, confirming that climbing fibre-evoked increases in miR335 could be attributed to increases in transcription. We used three screens to identify potential mRNA targets for miR335 transcripts: (i) nucleotide complementarity, (ii) detection of increased mRNAs following microinjection of miR335 inhibitors into the cerebellum, and (iii) detection of decreased mRNAs following HOKS. Two genes, calbindin and 14-3-3-?, passed these screens. Transfection of N2a cells with miR335 inhibitors or precursors inversely regulated 14-3-3-? transcripts. Immunoprecipitation of 14-3-3-? co-immunoprecipitated PKC-? and GABAA?2. Knockdown of either 14-3-3-? or PKC-? decreased the serine phosphorylation of GABAA?2, suggesting that 14-3-3-? and PKC-? under the control of miR335 homeostatically regulate the phosphorylation and insertion of GABAA?2 into the Purkinje cell post-synaptic membrane. PMID:25135969

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

2014-09-26

119

Moderate-vigorous physical activity improves long-term clinical outcomes without worsening pain in fibromyalgia  

PubMed Central

Objective To evaluate the relationship between long-term maintenance of moderate-vigorous physical activity (MVPA) and clinical outcomes in fibromyalgia (FM). Methods Patients with FM (n=170) received individualized exercise prescriptions and completed baseline and follow-up physical activity assessments using the Community Health Activities Model Program for Seniors (CHAMPS) questionnaire at weeks 12, 24, and 36. The primary outcome was the change in the Fibromyalgia Impact Questionnaire-Physical Impairment (FIQ-PI) score. Secondary outcomes included improvements in overall well-being (FIQ-Total), pain severity ratings, and depression. Results Using a threshold increase in MVPA of ?10 metabolic equivalent hours per week (MET h/wk) above usual activities, 27 subjects (15.9%) increased and sustained (SUS-PA), 68 (40%) increased, but then declined (UNSUS-PA), and 75 (44.1%) did not achieve this benchmark (LO-PA). Compared to LO-PA subjects, both SUS-PA and UNSUS-PA subjects reported greater improvement in FIQ-PI (p<0.01) and FIQ-Total (p<0.05). Additionally, the SUS-PA group reported greater improvement in pain severity compared to the LO-PA group (p<0.05). However, there were no significant group differences between SUS-PA and UNSUS-PA for any primary or secondary outcome measure. Conclusion Increased participation in MVPA for at least 12 weeks improves physical function and overall well-being in patients with FM. Although sustained physical activity was not associated with greater clinical benefit compared to unsustained physical activity, these findings also suggest that performing greater volumes of physical activity is not associated with worsening pain in FM. Future research is needed to determine the relationship between sustained MVPA participation and subsequent improvement in patient outcomes. PMID:23401486

Kaleth, Anthony S.; Saha, Chandan K.; Jensen, Mark P.; Slaven, James E.; Ang, Dennis C.

2013-01-01

120

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

Microsoft Academic Search

Organic solar cells based on conductive polymers exhibit a unique combination of properties which include low cost, flexibility and large surface processability. Organic photovoltaic could then prevail for some applications alongside silicon, such as nomad or indoor. To achieve this objective, the sustainability of the initial properties in conditions of use of the cell is required, since it could be

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

2010-01-01

121

Long-term drift of the coronal source magnetic flux and the total solar irradiance  

Microsoft Academic Search

We test the method of Lockwood et al. [1999] for deriving the coronal source flux from the geomagnetic aa index and show it to be accurate to within 12% for annual means and 4.5% for averages over a sunspot cycle. Using data from four solar constant monitors during 1981-1995, we find a linear relationship between this magnetic flux and the

M. Lockwood; R. Stamper

1999-01-01

122

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

123

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

124

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

125

Long-term active antimicrobial coatings for surgical sutures based on silver nanoparticles and hyperbranched polylysine.  

PubMed

The goal of this study was to develop a long-term active antimicrobial coating for surgical sutures. To this end, two water-insoluble polymeric nanocontainers based on hyperbranched polylysine (HPL), hydrophobically modified by either using glycidyl hexadecyl ether, or a mixture of stearoyl/palmitoyl chloride, were synthesized. Highly stabilized silver nanoparticles (AgNPs, 2-5?nm in size) were generated by dissolving silver nitrate in the modified HPL solutions in toluene followed by reduction with L-ascorbic acid. Poly(glycolic acid)-based surgical sutures were dip-coated with the two different polymeric silver nanocomposites. The coated sutures showed high efficacies of more than 99.5% reduction of adhesion of living Staphylococcus aureus cells onto the surface compared to the uncoated specimen. Silver release experiments were performed on the HPL-AgNP modified sutures by washing them in phosphate buffered saline for a period of 30?days. These coatings showed a constant release of silver ions over more than 30?days. After this period of washing, the sutures retained their high efficacies against bacterial adhesion. Cytotoxicity tests using L929 mouse fibroblast cells showed that the materials are basically non-cytotoxic. PMID:23574366

Ho, Chau Hon; Odermatt, Erich K; Berndt, Ingo; Tiller, Joerg C

2013-01-01

126

Polygalasaponin F induces long-term potentiation in adult rat hippocampus via NMDA receptor activation  

PubMed Central

Aim: To investigate the effect and underlying mechanisms of polygalasaponin F (PGSF), a triterpenoid saponin isolated from Polygala japonica, on long-term potentiation (LTP) in hippocampus dentate gyrus (DG) of anesthetized rats. Methods: Population spike (PS) of hippocampal DG was recorded in anesthetized male Wistar rats. PGSF, the NMDAR inhibitor MK801 and the CaMKII inhibitor KN93 were intracerebroventricularly administered. Western blotting analysis was used to examine the phosphorylation expressions of NMDA receptor subunit 2B (NR2B), Ca2+/calmodulin-dependent kinase II (CaMKII), extracellular signal-regulated kinase (ERK), and cAMP response element-binding protein (CREB). Results: Intracerebroventricular administration of PGSF (1 and 10 ?mol/L) produced long-lasting increase of PS amplitude in hippocampal DG in a dose-dependent manner. Pre-injection of MK801 (100 ?mol/L) or KN93 (100 ?mol/L) completely blocked PGSF-induced LTP. Furthermore, the phosphorylation of NR2B, CaMKII, ERK, and CREB in hippocampus was significantly increased 5–60 min after LTP induction. The up-regulation of p-CaMKII expression could be completely abolished by pre-injection of MK801. The up-regulation of p-ERK and p-CREB expressions could be partially blocked by pre-injection of KN93. Conclusion: PGSF could induce LTP in hippocampal DG in anesthetized rats via NMDAR activation mediated by CaMKII, ERK and CREB signaling pathway. PMID:22286914

Sun, Feng; Sun, Jian-dong; Han, Ning; Li, Chuang-jun; Yuan, Yu-he; Zhang, Dong-ming; Chen, Nai-hong

2012-01-01

127

Reduction of K+ uptake in glia prevents long-term depression maintenance and causes epileptiform activity.  

PubMed

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

Janigro, D; Gasparini, S; D'Ambrosio, R; McKhann, G; DiFrancesco, D

1997-04-15

128

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

PubMed Central

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

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

2014-01-01

129

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

130

Evidence for a long-term variation of the dynamo action responsible for the solar magnetic cycle  

NASA Astrophysics Data System (ADS)

By using the sunspot time series as a proxy, we have made a detailed analysis of the mean solar magnetic field over the last two and half centuries, by means of a reconstruction of its phase space. We find evidence of a long-term trend variation of some of the solar physical processes (over a few decades) that might be responsible for the apparent erratic behaviour of the solar magnetic cycle. The analysis is done by means of a careful study of the axisymmetric dynamo model equations, where we show that the temporal counterpart of the magnetic field can be described by a self-regulated two-dimensional dynamic system, usually known as a Van der Pol-Duffing oscillator. Our results suggest that during the last two and half centuries, the velocity of the meridional flow, vp, and the efficiency of the ? mechanism responsible for the conversion of toroidal magnetic field into poloidal magnetic field might have suffered variations that can explain the observed variability in the solar cycle.

Lopes, I.; Passos, D.

2009-07-01

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 stability of amorphous silicon solar cells and modules  

Microsoft Academic Search

The thermal stability of the Al-a-Si:H and Al-SnO2 interfaces in the hydrogenated amorphous silicon (a-Si:H) solar cells and submodules and the photostability of the a-Si:H in these cells were investigated. The kinetics of thermal degradation was studied by heat-treating Al\\/a-Si\\/Mo\\/Cr\\/glass and Al\\/SNO2 samples at various temperatures, and then analyzing them by Auger depth profiling. The rapid diffusion of Si through

E. Eser; K. R. Ramaprasad; H. Volltrauer; F. Ramos; S. C. Gau; R VOS

1987-01-01

133

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

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 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

136

Long-term recording of external urethral sphincter EMG activity in unanesthetized, unrestrained rats.  

PubMed

The external urethral sphincter muscle (EUS) plays an important role in urinary function and often contributes to urinary dysfunction. EUS study would benefit from methodology for longitudinal recording of electromyographic activity (EMG) in unanesthetized animals, but this muscle is a poor substrate for chronic intramuscular electrodes, and thus the required methodology has not been available. We describe a method for long-term recording of EUS EMG by implantation of fine wires adjacent to the EUS that are secured to the pubic bone. Wires pass subcutaneously to a skull-mounted plug and connect to the recording apparatus by a flexible cable attached to a commutator. A force transducer-mounted cup under a metabolic cage collected urine, allowing recording of EUS EMG and voided urine weight without anesthesia or restraint. Implant durability permitted EUS EMG recording during repeated (up to 3 times weekly) 24-h sessions for more than 8 wk. EMG and voiding properties were stable over weeks 2-8. The degree of EUS phasic activity (bursting) during voiding was highly variable, with an average of 25% of voids not exhibiting bursting. Electrode implantation adjacent to the EUS yielded stable EMG recordings over extended periods and eliminated the confounding effects of anesthesia, physical restraint, and the potential for dislodgment of the chronically implanted intramuscular electrodes. These results show that micturition in unanesthetized, unrestrained rats is usually, but not always, associated with EUS bursting. This methodology is applicable to studying EUS behavior during progression of gradually evolving disease and injury models and in response to therapeutic interventions. PMID:24990895

LaPallo, Brandon K; Wolpaw, Jonathan R; Chen, Xiang Yang; Carp, Jonathan S

2014-08-15

137

Long-term variations of North Atlantic tropical cyclone activity downscaled from a coupled model simulation of the last millennium  

NASA Astrophysics Data System (ADS)

observed historical record of North Atlantic tropical cyclones (TCs) is relatively short and is subject to potential biases owing to a lack of observation platforms such as aircraft reconnaissance and satellite imagery in earlier decades. Therefore, studies of long-term variability in TC activity are hindered by the limitations and uncertainty within the historical data. An alternative approach is to study long-term Atlantic TC variability within the framework of a coupled ocean-atmosphere climate model simulation. We have taken such an approach using a simulation of the National Center for Atmospheric Research Climate System Model 1.4 forced with estimated natural and anthropogenic forcing over the past millennium. Atmospheric variables from the long-term model simulation are used to drive a recently developed downscaling relationship that simulates TC genesis and tracking over the course of the 1150 year model simulation. This downscaling process generates a long-term synthetic TC track data set, free of observational biases, though subject to limitations in the model climatology. The synthetic TC data are used to perform an analysis of long-term variability in Atlantic TCs, specifically focusing on TC landfalls, within the context of the coupled model simulation. Ultimately, analysis of various TC time series reveals that counts of landfalling TCs and even landfalling hurricanes track relatively well with the total basin-wide TC activity on multidecadal and longer timescales.

Kozar, Michael E.; Mann, Michael E.; Emanuel, Kerry A.; Evans, Jenni L.

2013-12-01

138

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

139

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

140

Metabotropic glutamate receptor activation and blockade: their role in long-term potentiation, learning and neurotoxicity  

Microsoft Academic Search

Metabotropic glutamate receptors represent a fairly recent addition to the family of glutamate receptors. These receptors have the distinguishing feature of being coupled to G-proteins rather than ion channels and they appear to have a variety of functional characteristics. These receptors play a vital role, for example, in the induction and maintenance of long-term potentiation, the most popular current model

Christian Hölscher; John Gigg; Shane M. O'Mara

1999-01-01

141

Cellular/Molecular Activity Pattern-Dependent Long-Term Potentiation in  

E-print Network

in the expression of long-term potentiation (LTP) and memory formation. Mice lacking this subunit possess a profound spatial working memory deficit. We investigated the influenceoftheGluA1subunitontheexpressionofLTPinpyramidalneuronsofthehippocampusCA1regionandsomatosensorycortex layer 2/3 for different cellular LTP protocols in adult mice. We found

Bern, Universität

142

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

PubMed

An appropriate approach to assess the effect of toxicants on aquatic animals is to monitor behavioral endpoints, as they are a link between physiological and ecological processes. A group that can be exposed long-term to low toxic concentrations is benthic macroinvertebrates, as their mobility in aquatic ecosystems is relatively limited. Therefore, the study of behavioral long-term effects in this group is suitable from an ecological point of view, as behavioral effects can appear before mortality. During the last decades there has been an increase in ammonia concentrations in freshwater ecosystems, threatening aquatic animals. The present study focuses on the long-term effects (40 days) of nonionized ammonia on the behavioral activity of the aquatic snail Potamopyrgus antipodarum. One control and three ammonia concentrations (0.02, 0.07, and 0.13 mg N-NH(3)/L) were used in triplicate, and the activity of snails (as mean time to start normal movement) and immobility were recorded for each treatment after 0, 10, 20, 30, and 40 days of continuous exposure to nonionized ammonia. The results show that P. antipodarum presented a high tolerance to lethal long-term effects of nonionized ammonia, as no animal died during the bioassay. However, the behavioral activity of snails was a very sensitivity endpoint, as a mean nonionized ammonia concentration of 0.07 mg N-NH(3)/L affected P. antipodarum. The results are discussed and compared with the available literature on long-term effects of ammonia on freshwater macroinvertebrates. Additionally, the ammonia water quality criteria, NOECs, LOECs, and long-term LCs are discussed on the basis of the current available data for freshwater macroinvertebrates. PMID:19039513

Alonso, Alvaro; Camargo, Julio A

2009-05-01

143

The detection and interpretation of long-term atmospheric change: Tasks in association with the shuttle solar backscatter ultraviolet spectral radiometer  

NASA Technical Reports Server (NTRS)

The objectives are to develop techniques to detect and remove long-term instrument drifts from the operational Solar Backscatter Ultraviolet (SBUV/2) data base using periodic measurements made by the Shuttle Solar Backscatter Ultraviolet Spectral Radiometer and to evaluate the potential effects of scattering by atmospheric aerosols on our ability to detect trends in ozone using SBUV-class instruments.

Frederick, John E.

1987-01-01

144

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.

145

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

146

Learning and Behavioral-Long-Term Controlling for Motor Activity Potentiation: Importance of  

Microsoft Academic Search

A series of brief, high-frequency trains of electrical stimu- lation delivered to the perforant-path results in long-term potentiation (LTP) of the dentate gyrus as measured by av- erage evoked potentials (EPs). Similar increases in dentate evoked potentials have been reported after natural learning. Previous studies of this behavioral LTP have not adequately controlled for ongoing behavior at the time of

E. L. Hargreaves; D. P. Cain; C. H. Vanderwolf

147

Tissue-plasminogen activator is induced as an immediate-early gene during seizure, kindling and long-term potentiation  

Microsoft Academic Search

THE requirement of protein and messenger RNA synthesis for long-term memory1,2 suggests that neural activity induced by learning initiates a cascade of gene expression3. Here we use differential screening to identify five immediate-early genes induced by neuronal activity. One of these is tissue-plasminogen activator (tPA), an extracellular serine protease, which is induced with different spatial patterns in the brain by

Zhuo Qian; Mary E. Gilbert; Michael A. Colicos; Eric R. Kandel; Dietmar Kuhl

1993-01-01

148

Erythrocyte PAF-acetylhydrolase activity in various stages of chronic kidney disease: Effect of long-term therapy with erythropoietin  

Microsoft Academic Search

Erythrocyte PAF-acetylhydrolase activity in various stages of chronic kidney disease: Effect of long-term therapy with erythropoietin.BackgroundErythrocytes represent an important component of the antioxidant capacity of blood, comprising, in particular, intracellular enzymes, including platelet-activating factor acetylhydrolase (PAF-AH) and glutathione peroxidase (Gpx). We evaluated the erythrocyte PAF-AH and Gpx activities in various stages of chronic kidney disease (CKD), and further investigated whether

ELENI C PAPAVASILIOU; CHARIKLIA GOUVA; KOSTAS C SIAMOPOULOS; ALEXANDROS D TSELEPIS

2005-01-01

149

Long-term coordinated changes in the convective activity of the North Atlantic  

NASA Astrophysics Data System (ADS)

The North Atlantic is a peculiarly convective ocean. The convective renewal of intermediate and deep waters in the Labrador Sea and Greenland/Iceland Sea both contribute significantly to the production and export of North Atlantic Deep Water, thus helping to drive the global thermohaline circulation, while the formation and spreading of 18-Degree Water at shallow-to-intermediate depths off the US eastern seaboard is a major element in the circulation and hydrographic character of the west Atlantic. For as long as time-series of adequate precision have been available to us, it has been apparent that the intensity of convection at each of these sites, and the hydrographic character of their products have been subject to major interannual change, as shown by AAGAARD (1968), CLARKE, SWIFT, REID and KOLTERMANN (1990), and MEINCKE, JONSSON and SWIFT (1992) for the Greenland Sea, in the OWS BRAVO record from the Labrador Sea, (eg LAZIER, 1980 et seq.), and at the Panulirus / Hydrostation “S” site in the Northern Sargasso off Bermuda (eg JENKINS, 1982, TALLEY and RAYMER, 1982). This paper reviews the recent history of these changes showing that the major convective centres of the Greenland and Labrador Seas are currently at opposite convective extrema in our postwar record, with vertical exchange at the former site limited to 1000 m or so, but with Labrador Sea convection reaching deeper than previously observed, to over 2300 m. As a result, the deep water of the Greenland Sea has become progressively warmer and more saline since the early '70s as a result of increased horizontal exchange with the Arctic Ocean through Fram Strait, while the Labrador Sea Water has become progressively colder and fresher over the same period through increased vertical exchange; most recently, convection has become deep enough there to reach into the more saline NADW which underlies it, so that cooler, but now saltier and denser LSW has resulted. The horizontal spreading of these changing watermasses in the northern gyre is described from the hydrographic record. The theory is advanced that the scales of atmospheric forcing have imposed a degree of synchrony on convective behaviour at all three sites over the present century, with ventilation at the Sargasso and Greenland Sea sites undergoing a parallel multi-decadal evolution to reach a long term maximum in the 1960s, driven by the twin cells of the North Atlantic Oscillation (NAO). During the NAO minimum of the 1960s, with an extreme Greenland ridge feeding record amounts of fresh water into the northern gyre in the form of the Great Salinity Anomaly, and its partner cell over the Southeast USA causing a southwestward retraction of storm activity ( DICKSON and NAMIAS, 1976), the surface freshening and postwar minimum in storm activity in the intervening area of the Labrador Sea also brought a progressive reduction, and ultimately a cessation, of wintertime convection there during the 1960s. In other words, the evolution of winter convective activity during the century was in phase but of different sign at the three sites. In these events, we see strong evidence of a direct impact of the shifting atmospheric circulation on the ocean; while this certainly does not rule out either feedbacks from anomalous ice and SST conditions on the atmosphere, or autonomous oscillations of the ocean's overturning circulation, it does tend to minimise them.

Dickson, Robert; Lazier, John; Meincke, Jens; Rhines, Peter; Swift, James

150

Genetic Activation of ERK5 MAP Kinase Enhances Adult Neurogenesis and Extends Hippocampus-Dependent Long-Term Memory  

PubMed Central

Recent studies have shown that inhibition of adult neurogenesis impairs the formation of hippocampus-dependent memory. However, it is not known whether increasing adult neurogenesis affects the persistence of hippocampus-dependent long-term memory. Furthermore, signaling mechanisms that regulate adult neurogenesis are not fully defined. We recently reported that the conditional and targeted knock-out of ERK5 MAP kinase in adult neurogenic regions of the mouse brain attenuates adult neurogenesis in the hippocampus and disrupts several forms of hippocampus-dependent memory. Here, we developed a gain-of-function knock-in mouse model to specifically activate endogenous ERK5 in the neurogenic regions of the adult brain. We report that the selective and targeted activation of ERK5 increases adult neurogenesis in the dentate gyrus by enhancing cell survival, neuronal differentiation, and dendritic complexity. Conditional ERK5 activation also improves the performance of challenging forms of spatial learning and memory and extends hippocampus-dependent long-term memory. We conclude that enhancing signal transduction of a single signaling pathway within adult neural stem/progenitor cells is sufficient to increase adult neurogenesis and improve the persistence of hippocampus-dependent memory. Furthermore, activation of ERK5 may provide a novel therapeutic target to improve long-term memory. PMID:24501354

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

2014-01-01

151

The long-term suppressive effect of prior activation of synaptic inputs by low-frequency stimulation on induction of long-term potentiation in CA1 neurons of guinea pig hippocampal slices  

Microsoft Academic Search

We have investigated the effects of prior activation of afferent inputs by a train of low-frequency stimulation (LFS) on the induction of long term potentiation (LTP) induced by highfrequency stimulation (tetanus, 100 Hz, 100 pulses) in CA1 neurons of guinea pig hippocampal slices. The parameters of the LFS were altered systematically: the frequency (1 or 5 Hz); the number of

Fujii Satoshi; Kuroda Yoichiro; Miura Masami; Furuse Hidekazu; Sasaki Hiroshi; Ken-ichi Ito; Chen Zhixiong; Kato Hiroshi

1996-01-01

152

The effects of long term nitrogen deposition on extracellular enzyme activity in an Acer saccharum forest soil  

Microsoft Academic Search

Anthropogenic N deposition affects litter decomposition and soil organic matter (SOM) storage through multiple mechanisms. Microbial community responses to long-term N deposition were investigated in a sugar maple-dominated forest in northern Michigan during the 1998–2000 growing seasons. Litter and soil were collected from three fertilized plots (30kg N ha?1y?1) and three control plots. The activities of 10 extracellular enzymes (EEA)

K. R. Saiya-Cork; R. L. Sinsabaugh; D. R. Zak

2002-01-01

153

QCM study of microbiological activity during long-term exposure to atmosphere—aluminium colonisation by Aspergillus Niger  

Microsoft Academic Search

The study demonstrated a possibility to sense the activity of microorganisms on metals in situ under atmosphere conditions\\u000a using a quartz crystal microbalance (QCM) as a sensitive mass change detector. Other innovative aspects of the QCM application\\u000a include long-term monitoring (over month), taking count of the influence of atmospheric pressure and application of Al-glued\\u000a foil electrodes. The research subject was

Povilas Mie?inskas; Konstantinas Leinartas; Virginija Uksien?; Eimutis Juzeli?nas

2007-01-01

154

Calcium-Stimulated Adenylyl Cyclase Activity Is Critical for Hippocampus-Dependent Long-Term Memory and Late Phase LTP  

Microsoft Academic Search

It is hypothesized that Ca2+ stimulation of calmodulin (CaM)–activated adenylyl cyclases (AC1 or AC8) generates cAMP signals critical for late phase LTP (L-LTP) and long-term memory (LTM). However, mice lacking either AC1 or AC8 exhibit normal L-LTP and LTM. Here, we report that mice lacking both enzymes (DKO) do not exhibit L-LTP or LTM. To determine if these defects are

Scott T Wong; Jaime Athos; Xavier A Figueroa; Victor V Pineda; Michele L Schaefer; Charles C Chavkin; Louis J Muglia; Daniel R Storm

1999-01-01

155

Communication activity in a social network: relation between long-term correlations and inter-event clustering  

PubMed Central

Human communication in social networks is dominated by emergent statistical laws such as non-trivial correlations and temporal clustering. Recently, we found long-term correlations in the user's activity in social communities. Here, we extend this work to study the collective behavior of the whole community with the goal of understanding the origin of clustering and long-term persistence. At the individual level, we find that the correlations in activity are a byproduct of the clustering expressed in the power-law distribution of inter-event times of single users, i.e. short periods of many events are separated by long periods of no events. On the contrary, the activity of the whole community presents long-term correlations that are a true emergent property of the system, i.e. they are not related to the distribution of inter-event times. This result suggests the existence of collective behavior, possibly arising from nontrivial communication patterns through the embedding social network. PMID:22876339

Rybski, Diego; Buldyrev, Sergey V.; Havlin, Shlomo; Liljeros, Fredrik; Makse, Hernan A.

2012-01-01

156

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

157

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

PubMed

Magnetic activity cycles are indirect traces of magnetic fields and can provide an insight on the nature and action of stellar dynamos and stellar magnetic activity. This, in turn, can determine local space weather and activity effects on stellar habitable zones. Using photometric monitoring of low-mass stars, we study the presence and properties of their magnetic activity cycles. We introduce long-term light curves of our sample stars, and discuss the properties of the observed trends, especially at spectral types where stars are fully convective (later than M3). PMID:22729352

Kafka, Stella

2012-06-01

158

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

159

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

PubMed

This study examined the long-term and mediation effects of a need-supportive coaching programme on physical activity. Sedentary employees (n = 92) of the university of Leuven received 4 months of physical activity coaching, based on the self-determination theory, by coaches with a bachelor's degree in kinesiology who are specializing in health-related physical activity (n = 30). The programme consisted of a limited number of individual contact moments (i.e. an intake session, three follow-up contacts and an out-take session), either face-to-face, by phone or by e-mail. Self-reported physical activity, social support, self-efficacy and autonomous motivation were assessed in the coaching group (n = 92) and a control group (n = 34) at three moments: before the intervention (i.e. pre-test), after the intervention (i.e. post-test) and 1 year after pre-test measurements (i.e. follow-up test). Results revealed significant 3 (time) × 2 (groups) interaction effects on strenuous and total physical activity. Moreover, whereas the control group remained stable from pre- to post-test, the coaching group increased significantly in moderate, strenuous and total physical activity. Additionally, the coaching group increased significantly in mild, moderate, strenuous and total physical activity from pre- to follow-up tests, whereas the control group did not change. Bootstrapping analyses indicated that self-efficacy and autonomous motivation significantly mediated the intervention effect on physical activity from pre- to post-test, while social support significantly mediated the long-term effect. This study provides evidence for the long-term effectiveness of a need-supportive physical activity programme that might be efficient at the community level. PMID:22752105

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

2013-09-01

160

Antitumor activity, growth, and phenotype of long-term IL-2 cultures of human NK and T lymphocytes.  

PubMed

We have studied growth, function, and phenotype of purified NK and T cells in long-term cultures and compared these parameters to those of conventionally prepared interleukin-2-activated lymphocytes with killer cell activity (LAK). Enrichment of NK and T cells was achieved by Percoll density gradient. Growth was analyzed by cell counts and [3H]TdR uptake. Cytotoxicity and tumor-binding efficacy were assessed in a 3-h 51Cr and single cell agarose assay, respectively, against K-562, Daudi, human ovarian cell line Ovcar-3, and fresh leukemic blasts. We found that long-term proliferation and lytic activity were highest in NK-enriched and lowest in T-enriched cultures. Conventional LAK cultures generated medium cytotoxicity levels. Lytic activity declined within 3 weeks in cultures not enriched for NK cells, while NK-enriched cultures showed high levels of cytotoxicity up to 6 weeks. No change was found in binding activity within 3 weeks with the exception of T cell-enriched fraction. A number of changes in the phenotypic patterns was observed in IL-2 cultures; the CD56+/CD3-/+ and CD56+/CD8+ subset increased in most cultures, whereas the CD56-/CD3+ subset decreased over time. The highly enriched NK cell culture maintained its NK cell phenotype over 5-6 weeks. We also delineated the most cytotoxic lymphocyte subset in long-term IL-2 cultures by complement dependent cytotoxic assays and fluorescence-activated cell sorting (FACS). Lytic activity in conventional LAK as well as in T and NK cell-enriched IL-2 cultures was mediated primarily by CD56+, CD16+, CD3- NK cells. The clinical implication of these studies is discussed. PMID:1651770

Fuchshuber, P R; Lotzová, E; Pollock, R E

1991-04-01

161

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

NASA Astrophysics Data System (ADS)

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

Frohlich, C.

2004-12-01

162

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

163

Effect of short- and long-term salinity on the activities of antioxidative enzymes and lipid peroxidation in tomato roots  

Microsoft Academic Search

Changes in the antioxidative enzyme activities (SOD, CuZnSOD, GSH-Px, GST), as well as TBARS content in 5-week-old tomato\\u000a (Lycopersicon\\u000a esculentum Mill. cv “Perkoz”) roots were examined 1, 3 h (short-term stress) and 1–14 days (long-term stress) after a single application\\u000a of 50 mM (mild stress) and 150 mM NaCl (severe stress). The severe stress caused an increase in GST, GSH-Px and SODs activities\\u000a from

Magdalena Gapi?ska; Maria Sk?odowska; Barbara Gabara

2008-01-01

164

Fate and toxicity of melamine in activated sludge treatment systems after a long-term sludge adaptation.  

PubMed

Melamine is a nitrogen-rich (67% nitrogen by mass) heterocyclic aromatic compound that could significantly increase effluent total nitrogen concentrations. In this study, we investigated the degradation of melamine and its impact on activated sludge operations by employing two common activated sludge processes, namely the Modified Ludzack-Ettinger (MLE) process and the continuous stirred tank reactor (CSTR) process. Melamine was dosed continuously from day 125 in both activated sludge treatment systems at an influent concentration of 3 mg/L for about 100 days. Even after such a long period of sludge adaptation, melamine appeared not to be easily biodegradable. The average melamine removal efficiencies in the CSTR and MLE systems were 14 ± 10% and 20 ± 15%, respectively. There was no significant difference in melamine removal between the two different activated sludge processes. The long-term input of melamine resulted in a decrease in the nitrifying bacterial activities (by 82 ± 8%) and population in both systems. Short-term microtiter assay results also showed that melamine reduced activated sludge growth by 80% when supplied at a concentration of 75.6 mg/L. These results suggest that sludge adaptation plays a minimal role in melamine degradation, as the enzymes responsible for hydrolytic deamination of melamine in activated sludge are not easily induced. The insignificant biodegradation of melamine is also attributed to bacterial growth inhibition under long-term dosing conditions with melamine, resulting in a significant decrease in effluent water quality. PMID:23466035

Xu, Shengnan; Zhang, Yanyan; Sims, Atreyee; Bernards, Matthew; Hu, Zhiqiang

2013-05-01

165

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

166

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

167

Peer Volunteers Improve Long-term Maintenance of Physical Activity with Older Adults: A Randomized Controlled Trial  

PubMed Central

Background Using peer volunteers as delivery agents may improve translation of evidence-based physical activity promotion programs for older adults. This study examined whether tailored support from older peer volunteers could improve initiation and long-term maintenance of physical activity behavior. Methods Participants were randomized to two 16-week, group-based programs: (1) peer-delivered, theory-based support for physical activity behavior change; or (2) an intervention typically available in community settings (basic education, gym membership, and pedometer for self-monitoring), attention-matched with health education. Moderate-to-vigorous physical activity (MVPA) was assessed via daily self-report logs at baseline, at the end of the intervention (16 weeks), and at follow-up (18 months), with accelerometry validation (RT3) in a random subsample. Results Seven peer volunteers and 81 sedentary adults were recruited. Retention at the end of the trial was 85% and follow-up at 18 months was 61 %. Using intent-to-treat analyses, at 16 weeks, both groups had similar significant improvements in MVPA. At 18 months, the group supplemented with peer support had significantly more MVPA. Conclusions Trained peer volunteers may enhance long-term maintenance of physical activity gains from a community-based intervention. This approach has great potential to be adapted and delivered inexpensively in community settings. PMID:21918240

2011-01-01

168

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

169

Evaluation of Voltage-Sensitive Dyes for Long-Term Recording of Neural Activity in the Hippocampus  

Microsoft Academic Search

.   We searched for an optimal voltage-sensitive dye for optical measurements of neural activity in the hippocampal slice by\\u000a evaluating several merocyanine-rhodanine and oxonol dyes. The wavelength dependence (action spectra), pharmacological effects\\u000a of staining, signal size, signal-to-noise ratio, and the utility of the dyes for long-term continuous recording were examined\\u000a for four merocyanine-rhodanine dyes (NK2761, NK2776, NK3224 and NK3225), which

Y. Momose-Sato; K. Sato; Y. Arai; I. Yazawa; H. Mochida; K. Kamino

1999-01-01

170

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

NASA Astrophysics Data System (ADS)

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

Plass-Dülmer, Christian; Reimann, Stefan

2013-04-01

171

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

172

Long-term stratospheric carbon tetrafluoride (CF4) increase inferred from 1985-2004 infrared space-based solar occultation measurements  

Microsoft Academic Search

The long-term stratospheric carbon tetrafluoride (CF4) increase has been determined from infrared high spectral resolution solar occultation Fourier transform spectrometer measurements between 3 and 50 hPa (~20 to 40 km altitude) and latitudes from 50°N to 50°S during 1985, 1992, 1993, 1994, and 2004. The 1985 to 1994 measurements were recorded from the ATMOS (Atmospheric Trace MOlecule Spectroscopy) instrument at

C. P. Rinsland; E. Mahieu; R. Zander; R. Nassar; P. Bernath; C. Boone; L. S. Chiou

2006-01-01

173

Long-term stratospheric carbon tetrafluoride (CF4) increase inferred from 1985–2004 infrared space-based solar occultation measurements  

Microsoft Academic Search

The long-term stratospheric carbon tetrafluoride (CF4) increase has been determined from infrared high spectral resolution solar occultation Fourier transform spectrometer measurements between 3 and 50 hPa (?20 to 40 km altitude) and latitudes from 50°N to 50°S during 1985, 1992, 1993, 1994, and 2004. The 1985 to 1994 measurements were recorded from the ATMOS (Atmospheric Trace MOlecule Spectroscopy) instrument at

C. P. Rinsland; E. Mahieu; R. Zander; R. Nassar; P. Bernath; C. Boone; L. S. Chiou

2006-01-01

174

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

175

Increasing small conductance Ca(2+) -activated potassium channel activity reverses ischemia-induced impairment of long-term potentiation.  

PubMed

Global cerebral ischemia following cardiac arrest and cardiopulmonary resuscitation (CA/CPR) causes injury to hippocampal CA1 pyramidal neurons and impairs cognition. Small conductance Ca(2+) -activated potassium channels type 2 (SK2), expressed in CA1 pyramidal neurons, have been implicated as potential protective targets. Here we showed that, in mice, hippocampal long-term potentiation (LTP) was impaired as early as 3 h after recovery from CA/CPR and LTP remained impaired for at least 30 days. Treatment with the SK2 channel agonist 1-Ethyl-2-benzimidazolinone (1-EBIO) at 30 min after CA provided sustained protection from plasticity deficits, with LTP being maintained at control levels at 30 days after recovery from CA/CPR. Minimal changes in glutamate release probability were observed at delayed times after CA/CPR, implicating post-synaptic mechanisms. Real-time quantitative reverse transcriptase-polymerase chain reaction indicated that CA/CPR did not cause a loss of N-methyl-D-aspartate (NMDA) receptor mRNA at 7 or 30 days after CA/CPR. Similarly, no change in synaptic NMDA receptor protein levels was observed at 7 or 30 days after CA/CPR. Further, patch-clamp experiments demonstrated no change in functional synaptic NMDA receptors at 7 or 30 days after CA/CPR. Electrophysiology recordings showed that synaptic SK channel activity was reduced for the duration of experiments performed (up to 30 days) and that, surprisingly, treatment with 1-EBIO did not prevent the CA/CPR-induced loss of synaptic SK channel function. We concluded that CA/CPR caused alterations in post-synaptic signaling that were prevented by treatment with the SK2 agonist 1-EBIO, indicating that activators of SK2 channels may be useful therapeutic agents to prevent ischemic injury and cognitive impairments. PMID:25080203

Orfila, J E; Shimizu, K; Garske, A K; Deng, G; Maylie, J; Traystman, R J; Quillinan, N; Adelman, J P; Herson, P S

2014-10-01

176

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

177

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

178

Long-term home cage activity scans reveal lowered exploratory behaviour in symptomatic female Rett mice?  

PubMed Central

Numerous experimental models have been developed to reiterate endophenotypes of Rett syndrome, a neurodevelopmental disorder with a multitude of motor, cognitive and vegetative symptoms. Here, female Mecp2Stop mice [1] were characterised at mild symptomatic conditions in tests for anxiety (open field, elevated plus maze) and home cage observation systems for food intake, locomotor activity and circadian rhythms. Aged 8–9 months, Mecp2Stop mice presented with heightened body weight, lower overall activity in the open field, but no anxiety phenotype. Although home cage activity scans conducted in two different observation systems, PhenoMaster and PhenoTyper, confirmed normal circadian activity, they revealed severely compromised habituation to a novel environment in all parameters registered including those derived from a non-linear decay model such as initial exploration maximum, decay half-life of activity and span, as well as plateau. Furthermore, overall activity was significantly reduced in nocturnal periods due to reductions in both fast ambulatory movements, but also a slow lingering. In contrast, light-period activity profiles during which the amount of sleep was highest remained normal in Mecp2Stop mice. These data confirm the slow and progressive development of Rett-like symptoms in female Mecp2Stop mice resulting in a prominent reduction of overall locomotor activity, while circadian rhythms are maintained. Alterations in the time-course of habituation may indicate deficiencies in cognitive processing. PMID:23643691

Robinson, Lianne; Plano, Andrea; Cobb, Stuart; Riedel, Gernot

2013-01-01

179

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

180

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

181

Long-term cycling behavior of asymmetric activated carbon\\/MnO 2 aqueous electrochemical supercapacitor  

Microsoft Academic Search

Activated carbon–MnO2 hybrid electrochemical supercapacitor cells have been assembled and characterized in K2SO4 aqueous media. A laboratory cell achieved 195,000 cycles with stable performance. The maximal cell voltage was 2V associated with 21±2Fg?1 of total composite electrode materials (including activated carbon and MnO2, binder and conductive additive) and an equivalent serie resistance (ESR) below 1.3?cm2. Long-life cycling was achieved by

Thierry Brousse; Pierre-Louis Taberna; Olivier Crosnier; Romain Dugas; Philippe Guillemet; Yves Scudeller; Yingke Zhou; Frédéric Favier; Daniel Bélanger; Patrice Simon

2007-01-01

182

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

183

A mathematical model of long-term renal sympathetic nerve activity inhibition during an increase in sodium intake.  

PubMed

It is well known that renal nerves directly affect renal vascular resistance, tubular sodium reabsorption, and renin secretion. Inhibition of renal sympathetic nerve activity (RSNA) decreases renal vascular resistance, tubular sodium reabsorption, and renin secretion, leading to an increase in sodium excretion. Although several studies show that inhibition of RSNA promotes sodium excretion during an acute blood volume expansion, there is limited research relating to the importance of RSNA inhibition that contributes to sodium homeostasis during a long-term increase in sodium intake. Therefore, to dissect the underlying mechanisms of sodium excretion, a mathematical model of a cardiovascular system consisting of two kidneys, each with an independent RSNA, was developed. Simulations were performed to determine the responses of RSNA and sodium excretion to an increased sodium intake. In these simulations, RSNA in the left kidney was fixed at its normal steady-state value, while RSNA in the contralateral kidney was allowed to change normally in response to the increased sodium intake. The results demonstrate that the fixed-RSNA kidney excretes less sodium than the intact-RSNA collateral kidney. Because each kidney is exposed to the same arterial pressure and circulatory hormones, the impaired sodium excretion in the absence of RSNA inhibition supports the hypothesis that RSNA inhibition contributes to natriuresis in response to a long-term increase in sodium intake. PMID:24285363

Karaaslan, Fatih; Denizhan, Yagmur; Hester, Robert

2014-02-15

184

Region-Specific Activation of CRTC1-CREB Signaling Mediates Long-Term Fear Memory.  

PubMed

CREB is a pivotal mediator of activity-regulated gene transcription that underlies memory formation and allocation. The contribution of a key CREB cofactor, CREB-regulated transcription coactivator 1 (CRTC1), has, however, remained elusive. Here we show that several constitutive kinase pathways and an activity-regulated phosphatase, calcineurin, converge to determine the nucleocytoplasmic shuttling of CRTC1. This, in turn, triggered an activity-dependent association of CRTC1 with CREB-dependent regulatory elements found on IEG promoters. Forced expression of nuclear CRTC1 in hippocampal neurons activated CREB-dependent transcription, and was sufficient to enhance contextual fear memory. Surprisingly, during contextual fear conditioning, we found evidence of nuclear recruitment of endogenous CRTC1 only in the basolateral amygdala, and not in the hippocampus. Consistently, CRTC1 knockdown in the amygdala, but not in the hippocampus, significantly attenuated fear memory. Thus, CRTC1 has a wide impact on CREB-dependent memory processes, but fine-tunes CREB output in a region-specific manner. PMID:25277455

Nonaka, Mio; Kim, Ryang; Fukushima, Hotaka; Sasaki, Kazuki; Suzuki, Kanzo; Okamura, Michiko; Ishii, Yuichiro; Kawashima, Takashi; Kamijo, Satoshi; Takemoto-Kimura, Sayaka; Okuno, Hiroyuki; Kida, Satoshi; Bito, Haruhiko

2014-10-01

185

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

186

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

187

Regulation of hippocampal long-term potentiation by p21-activated protein kinase 1 (PAK1)  

Microsoft Academic Search

The Rho family small GTPases are critically involved in the regulation of spine and synaptic properties, but the underlying mechanisms are poorly defined. We took genetic approaches to create and analyze knockout mice deficient in the expression of the protein kinase PAK1 that is directly associated with and activated by the Rho GTPases. We demonstrated that while these knockout mice

Suhail Asrar; Yanghong Meng; Zikai Zhou; Zarko Todorovski; Wayne Wenyin Huang; Zhengping Jia

2009-01-01

188

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

189

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

PubMed

The long-term outcome of athletes with frequent ventricular premature complexes (VPCs) and apparently normal heart has not been fully clarified. To evaluate the clinical and prognostic significance of VPCs and the influence of continuing sports activity during follow-up, we studied 120 healthy athletes (96 men; median age 16 years) in whom frequent VPCs (>100 VPCs/24 hours) were discovered by chance during preparticipation screening. All athletes were followed up for a median of 84 months. During follow-up, 96 underwent serial 24-hour Holter recording and 62 underwent serial echocardiography. The median number of VPCs/24 hours on basal Holter was 3,760. During follow-up, 81 athletes continued sports activity, whereas 39 did not. No athlete died or developed overt heart disease. The median number of VPCs/24 hours decreased in both athletes who continued sports activity and those who did not (from 3,805 to 1,124, p <0.0001 and from 5,787 to 1,298, p <0.0001, respectively). During follow-up, left ventricular ejection fraction slightly decreased to <55% in 9 of 62 athletes who, in respect to the remaining 53, had more VPCs/24 hours both in the basal state (12,000 vs 3,880) and during follow-up (10,702 vs 1,368), and a longer follow-up (95 vs 36 months). In conclusion, (1) frequent VPCs in athletes without heart disease have a long-term benign prognostic significance, (2) sporting activity does not modify this benign outcome, (3) during follow-up, the burden of VPCs decreases whether or not subjects continue sports activity, and (4) in 14.5% of athletes, ejection fraction slightly decreases over time. PMID:24135302

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

2013-11-01

190

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

191

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

NASA Technical Reports Server (NTRS)

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

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

2004-01-01

192

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.

193

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

194

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

PubMed

Bodily injury in mammals often produces persistent pain that is driven at least in part by long-lasting sensitization and spontaneous activity (SA) in peripheral branches of primary nociceptors near sites of injury. While nociceptors have been described in lower vertebrates and invertebrates, outside of mammals there is limited evidence for peripheral sensitization of primary afferent neurons, and there are no reports of persistent SA being induced in primary afferents by noxious stimulation. Cephalopod molluscs are the most neurally and behaviorally complex invertebrates, with brains rivaling those of some vertebrates in size and complexity. This has fostered the opinion that cephalopods may experience pain, leading some governments to include cephalopods under animal welfare laws. It is not known, however, if cephalopods possess nociceptors, or whether their somatic sensory neurons exhibit nociceptive sensitization. We demonstrate that squid possess nociceptors that selectively encode noxious mechanical but not heat stimuli, and that show long-lasting peripheral sensitization to mechanical stimuli after minor injury to the body. As in mammals, injury in squid can cause persistent SA in peripheral afferents. Unlike mammals, the afferent sensitization and SA are almost as prominent on the contralateral side of the body as they are near an injury. Thus, while squid exhibit peripheral alterations in afferent neurons similar to those that drive persistent pain in mammals, robust changes far from sites of injury in squid suggest that persistently enhanced afferent activity provides much less information about the location of an injury in cephalopods than it does in mammals. PMID:23761897

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

2013-06-12

195

Long-term starspot activity of short-period RS Canum Venaticorum stars. II - RT Andromedae  

NASA Astrophysics Data System (ADS)

The photometric distortion waves in the light curves of the short-period RS CVn system RT And are parameterized by means of a dark, circular starspot model. The light curves are drawn from archival sources and 1987 and 1989 observations. The longitudes, latitudes, and areas of the active regions are inferred and the information content of the archival data is evaluated. It is concluded that one large starspot region on the primary star at high latitude and near quadrature longitudes can account for the major maculation effects since 1920. The temperature difference between the spotted region and the photosphere is 1100 to 1200 K. Good quality light curves result in an eccentricity (e = 0.026) and major axis orientation consistent with those reported by others using different procedures.

Zeilik, M.; Cox, D. A.; de Blasi, C.; Rhodes, M.; Budding, E.

1989-10-01

196

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

197

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

NASA Technical Reports Server (NTRS)

An extensive body of research this quarter is documented. Further methodical analysis of temperature residuals in Cryogenic Limb Array Etalon Spectrometer (CLAES) Version 8 level 3AT data show signatures during December 1992 at middle and high northern latitudes that, when compared to Naval Research Laboratory/Mountain Wave Forecast Model (NRL)/(MWFM) mountain wave hindcasts, reveal evidence of long mountain waves in these data over Eurasia, Greenland, Scandinavia and North America. The explicit detection of gravity waves in limb-scanned Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) temperatures is modeled at length, to derive visibility functions. These insights are used to convert CRISTA gravity wave temperature residuals into data that more closely resemble gravity wave fluctuations detected in data from other satellite instruments, such as Microwave Limb Sounder (MLS), Limb Infrared Monitor of the Stratosphere (LIMS) and Global Positioning System/Meteorology (GPS)/(MET). Finally, newly issued mesospheric temperatures from inversion of CRISTA 15gin emissions are analyzed using a new method that uses separate Kalman fits to the ascending and descending node data. This allows us to study global gravity wave amplitudes at two local times, 12 hours apart. In the equatorial mesosphere, where a large diurnal tidal temperature signal exists, we see modulations of gravity wave activity that are consistent with gravity wave-tidal interactions produced by tidal temperature variability.

Eckermann, Stephen D.; Jackman, C. (Technical Monitor)

2000-01-01

198

Overnight transduction with foamyviral vectors restores the long-term repopulating activity of Fancc?/? stem cells  

PubMed Central

Fanconi anemia (FA) is a complex genetic disorder characterized by congenital abnormalities, bone marrow failure, and myeloid malignancies. Identification of 13 FA genes has been instrumental to explore gene transfer technologies aimed at correction of autologous FA-deficient stem cells. To date, 3 human FA stem cell gene therapy trials with standard 4-day transduction protocols using gammaretroviral vectors failed to provide clinical benefit. In addition, 2- to 4 day ex vivo manipulation of bone marrow from mice containing a disruption of the homologue of human FANCC (Fancc) results in a time-dependent increase in apoptosis and a risk for malignant transformation of hematopoietic cells. Here, we show that a 14-hour transduction period allows a foamyviral vector construct expressing the human FANCC cDNA to efficiently transduce murine FA stem cells with 1 to 2 proviral integrations per genome. Functionally, the repopulating activity of Fancc?/? stem cells from reconstituted mice expressing the recombinant FANCC transgene was comparable with wild-type controls. Collectively, these data provide evidence that short-term transduction of c-kit+ cells with a foamyviral vector is sufficient for functional correction of a stem cell phenotype in a murine FA model. These data could have implications for future gene therapy trials for FA patients. PMID:18684868

Si, Yue; Pulliam, Anna C.; Linka, Yvonne; Ciccone, Samantha; Leurs, Cordula; Yuan, Jin; Eckermann, Olaf; Fruehauf, Stefan; Mooney, Sean

2008-01-01

199

Permafrost and Active Layer Modeling in the Northern Hemisphere using AVHRR Long- Term Records  

NASA Astrophysics Data System (ADS)

High latitude environments such as those over northern Eurasia and North America are particularly vulnerable to climate change which is expected to be pronounced in these areas. Climate warming is likely to cause a permafrost thawing with subsequent effects on surface albedo, soil organic matter degradation, hydrology and greenhouse gas emissions. Recently, there have been a number of experiments to simulate soil temperature and permafrost dynamics on regional and global scales. In these simulations that employ some stand-alone equilibrium or transient permafrost models, the upper boundary conditions are usually the air temperature from observations or climate forcing from available Global or Regional Climate Models. In this research we used the GIPL-1.1 model, which is a spatially distributed model of permafrost based on an approximate analytical solution of soil freezing and thawing, which includes an estimation of thermal offset due to the difference in frozen and thawed soil thermal properties. The GIPL-1.1 model also accounts effectively for the effects of snow cover, vegetation, soil moisture, and soil thermal properties. Two decades of satellite clear sky thermal infrared data from 1981 to 2000 was used as an upper boundary conditions in order to simulate the distribution and temperatures of permafrost and active layer thickness in the entire Arctic and sub-Arctic permafrost domain. Under cloud-free conditions, infrared data provide skin depth (surface) temperatures and are shown to be generally consistent with surface air temperatures. The key source of historical surface temperature data is the Advanced Very High Resolution Radiometer (AVHRR) onboard National Oceanic and Atmospheric Administration satellites (Comiso, 2000, 2001, 2003). The results of permafrost modeling using GIPL-1.1 model show a very good agreement between calculated distribution of permafrost temperatures, observed data, and the distribution of permafrost derived from the International Permafrost Association (IPA) permafrost map.

Marchenko, S.; Romanovsky, V.; Comiso, J. C.

2008-12-01

200

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

201

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

202

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

203

Activation of Presynaptic and Postsynaptic Ryanodine-Sensitive Calcium Stores Is Required for the Induction of Long-Term  

E-print Network

transmission, which are held responsible for memory formation or neuronal network development. LTP and LTD can lead to a calcium-dependent long-term potentiation (LTP) or long-term depression (LTD) of synaptic synapses, several recent studies have reported that both LTP and LTD at GABAergic synapses can occur

Paris-Sud XI, Université de

204

Pain in long-term breast cancer survivors: The role of body mass index, physical activity, and sedentary behavior  

PubMed Central

Although pain is common among post-treatment breast cancer survivors, studies that are longitudinal, identify a case definition of clinically meaningful pain, or examine factors contributing to pain in survivors are limited. This study describes longitudinal patterns of pain in long-term breast cancer survivors, evaluating associations of body mass index [BMI], physical activity, sedentary behavior with mean pain severity and above-average pain. Women newly diagnosed with stages 0–IIIA breast cancer (N=1183) were assessed, on average, 6 months (demographic/clinical characteristics), 30 months (demographics), 40 months (demographics, pain), 5 years (BMI, physical activity, and sedentary behavior) and 10 years (demographics, pain, BMI, physical activity, and sedentary behavior) post-diagnosis. This analysis includes survivors who completed pain assessments 40 months post-diagnosis (N=801), 10 years post-diagnosis (N=563), or both (N=522). Above-average pain was defined by SF-36 bodily pain scores ?1/2 standard deviation worse than age-specific population norms. We used multiple regression models to test unique associations of BMI, physical activity, and sedentary behavior with pain adjusting for demographic and clinical factors. The proportion of survivors reporting above-average pain was higher at 10 years than at 40 months (32.3% vs. 27.8%, p<0.05). Approximately one-quarter of survivors reported improved pain, while 9.0% maintained above-average pain and 33.1% reported worsened pain. Cross-sectionally at 10 years, overweight and obese survivors reported higher pain than normal-weight survivors and women meeting physical activity guidelines were less likely to report above-average pain than survivors not meeting these guidelines (p<0.05). Longitudinally, weight gain (>5%) was positively associated, while meeting physical activity guidelines was inversely associated, with above-average pain (OR, 95% CI= 1.76, 1.03–3.01 and 0.40 (0.20–0.84, respectively) (p<0.05). Weight gain and lack of physical activity place breast cancer survivors at risk for pain long after treatment ends. Weight control and exercise interventions should be tested for effects on long-term pain in these women. PMID:23242613

Forsythe, Laura P; Alfano, Catherine M; George, Stephanie M; McTiernan, Anne; Baumgartner, Kathy B; Bernstein, Leslie; Ballard-Barbash, Rachel

2014-01-01

205

Earth magnetic field and geomagnetic activity effects on long-term trends in the F2 layer at mid-high latitudes  

Microsoft Academic Search

It is well known that the Earth magnetic field, as well as geomagnetic activity, presents long-term variations. Both phenomena affect the height of the F2 layer peak, hmF2, and the maximum electron concentration estimated by foF2. Experimental data of three mid-high latitude stations (Argentine Islands, Slough and Uppsala) were used to estimate foF2 long-term trends. These trends were compared with

Ana G. Elias; Nieves Ortiz de Adler

2006-01-01

206

General Surgery among Long-Term Residents with and without Active Epilepsy at the Kork Epilepsy Centre – A Prospective Comparative One-Year Survey  

Microsoft Academic Search

Background\\/Aims: We prospectively assessed the frequency, type, severity and cause of treatment among the long-term residents of the Kork Epilepsy Centre in the year 2005. Methods: All long-term residents were exclusively referred to the general surgeon practicing on the campus. Patients were divided into 2 groups comprising 285 patients with active epilepsy and 53 controls who either never had epileptic

Bernhard J. Steinhoff; Ralph Hartmann; Matthias Luy; Angelika Rombach; Gerhard Ziegler; Jürgen Schulte-Mönting; Frank G. Gilliam

2010-01-01

207

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

208

An exploration of the effectiveness of artificial mini-magnetospheres as a potential Solar Storm shelter for long term human space missions  

E-print Network

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 bombard...

Bamford, Ruth; Bradford, John; Todd, Tom N; Stafford-Allen, Robin; Alves, E Paulo; Silva, Luis; Collingwood, Cheryl; Crawford, Ian A; Bingham, Robert

2014-01-01

209

Testing Promotes Long-Term Learning via Stabilizing Activation Patterns in a Large Network of Brain Areas.  

PubMed

The testing effect refers to the phenomenon that repeated retrieval of memories promotes better long-term retention than repeated study. To investigate the neural correlates of the testing effect, we used event-related functional magnetic resonance imaging methods while participants performed a cued recall task. Prior to the neuroimaging experiment, participants learned Swahili-German word pairs, then half of the word pairs were repeatedly studied, whereas the other half were repeatedly tested. For half of the participants, the neuroimaging experiment was performed immediately after the learning phase; a 1-week retention interval was inserted for the other half of the participants. We found that a large network of areas identified in a separate 2-back functional localizer scan were active during the final recall of the word pair associations. Importantly, the learning strategy (retest or restudy) of the word pairs determined the manner in which the retention interval affected the activations within this network. Recall of previously restudied memories was accompanied by reduced activation within this network at long retention intervals, but no reduction was observed for previously retested memories. We suggest that retrieval promotes learning via stabilizing cue-related activation patterns in a network of areas usually associated with cognitive and attentional control functions. PMID:23796945

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

2014-11-01

210

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.

211

Trend and abrupt changes in long-term geomagnetic indices  

NASA Astrophysics Data System (ADS)

Advanced statistical methods are employed to analyze three long-term time series of geomagnetic activity indices (aa, IHV, and IDV) together with sunspot number (Rz) to examine whether or not the aa index can realistically represent long-term variations of geomagnetic activity. We make use of a decomposition method called STL, which is a time domain filtering procedure that decomposes a time series into trend, cyclic, and residual components using nonparametric regression. A Bayesian change point analysis is also applied to the geomagnetic indices, as well as to sunspot number, to detect abrupt changes that may be caused by either instrumental changes, calibration errors, or sudden changes in solar activity. Our analysis shows that all three long-term geomagnetic indices share a similar centennial-scale variation that resembles the long-term trend of sunspot number Rz. The amplitude ratio between the centennial-scale variation and 11-year cycle of aa and IHV are closely comparable. Overall, our analysis suggests that the majority of the changes in the aa index are controlled by solar activity. Instrumental change or site relocation has only a limited effect on the long-term trend of aa. This is in good agreement with those previous studies which have shown aa to be a reliable long-term index.

Lu, Hua; Li, Yun; Clilverd, Mark A.; Jarvis, Martin J.

2012-05-01

212

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

213

Long-Term Effects of Ammonia on the Behavioral Activity of the Aquatic Snail Potamopyrgus antipodarum (Hydrobiidae, Mollusca)  

Microsoft Academic Search

An appropriate approach to assess the effect of toxicants on aquatic animals is to monitor behavioral endpoints, as they are\\u000a a link between physiological and ecological processes. A group that can be exposed long-term to low toxic concentrations is\\u000a benthic macroinvertebrates, as their mobility in aquatic ecosystems is relatively limited. Therefore, the study of behavioral\\u000a long-term effects in this group

Álvaro Alonso; Julio A. Camargo

2009-01-01

214

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

215

Signatures of Marsili seamount activity from the ORION-GEOSTAR3 long-term seafloor multiparametric observatory experiment  

NASA Astrophysics Data System (ADS)

ORION-GEOSTAR3 (EC- 6th FP) has been the first long-term continuous geophysical and oceanographic experiment on the Marsili Seamount, Europe's largest underwater volcano of Plio-Pleistocenic age. The main scientific objective of this experiment was to detect specific signatures of Marsili activity. A deep sea multiparametric observatory was deployed on the seafloor at the base of the seamount at 3320 m b.s.l., in the period December 2003-May 2005. Among the instruments on board the observatory were: broadband seismometer, hydrophone, gravity meter, magnetometer, water sampler for laboratory analyses, 3D single point current meter, ADCP, CTD and Ph sensor, with a common accurate time reference. Multiparametric analysis shows that data are generally of good quality, showing continuous time series with only a very few gaps. Seismic, chemical, oceanographic, magnetic, and gravity data were analysed both in the time and frequency domains. This presentation will show some examples of analyses and comparisons. For instance, both the analysis of individual time series and their comparison have already shown interesting results: estimation of the lithospheric depth under the Marsili, lateral attenuation distribution of recorded seismic body waves and indications for possible existence of a hydrothermal circuit. Significant correlations between recorded time series could be related to activity and structure of the Marsili seamount revealing interesting and unknown characteristics of this submarine volcano.

de Santis, Angelo

2010-05-01

216

Dynamics of nascent and active zone ultrastructure as synapses enlarge during long-term potentiation in mature hippocampus.  

PubMed

Nascent zones and active zones are adjacent synaptic regions that share a postsynaptic density, but nascent zones lack the presynaptic vesicles found at active zones. Here dendritic spine synapses were reconstructed through serial section electron microscopy (3DEM) and EM tomography to investigate nascent zone dynamics during long-term potentiation (LTP) in mature rat hippocampus. LTP was induced with theta-burst stimulation, and comparisons were made with control stimulation in the same hippocampal slices at 5 minutes, 30 minutes, and 2 hours post-induction and to perfusion-fixed hippocampus in vivo. Nascent zones were present at the edges of ?35% of synapses in perfusion-fixed hippocampus and as many as ?50% of synapses in some hippocampal slice conditions. By 5 minutes, small dense-core vesicles known to transport active zone proteins moved into more presynaptic boutons. By 30 minutes, nascent zone area decreased, without significant change in synapse area, suggesting that presynaptic vesicles were recruited to preexisting nascent zones. By 2 hours, both nascent and active zones were enlarged. Immunogold labeling revealed glutamate receptors in nascent zones; however, average distances from nascent zones to docked presynaptic vesicles ranged from 170?±?5 nm in perfusion-fixed hippocampus to 251?±?4 nm at enlarged synapses by 2 hours during LTP. Prior stochastic modeling suggests that decrease in glutamate concentration reduces the probability of glutamate receptor activation from 0.4 at the center of release to 0.1 just 200 nm away. Thus, conversion of nascent zones to functional active zones likely requires the recruitment of presynaptic vesicles during LTP. J. Comp. Neurol. 522:3861-3884, 2014. © 2014 Wiley Periodicals, Inc. PMID:25043676

Bell, Maria Elizabeth; Bourne, Jennifer N; Chirillo, Michael A; Mendenhall, John M; Kuwajima, Masaaki; Harris, Kristen M

2014-12-01

217

A tectonic pressure pulse and increased geodynamic activity recorded from the long-term monitoring of faults in Europe  

NASA Astrophysics Data System (ADS)

This paper presents the results of a long-term monitoring study undertaken during the period 2002-2007. The study recorded the displacement of various widely-distributed tectonic structures along the generally aseismic Bohemian Massif (Czech Republic) and specifically along the Sudeten Marginal Fault Zone. The derived results were compared with data recorded over the same time period in the Upper Rhine Graben (Germany), Central Apennines (Italy), and the Gulf of Corinth (Greece). It is clear that a tectonic pressure pulse initiated a period of increased geodynamic activity across central and southern Europe during the course of our monitoring. Within the Bohemian Massif, the pressure pulse was first recorded in mid 2003 and the ensuing period of increased geodynamic activity lasted for nearly three years. This period is associated with compression along the Sudeten Marginal Fault Zone. The southern flank was repeatedly downthrust beneath the northern flank, which caused the latter to continually uplift and subside. The period of increased geodynamic activity was terminated by two strong local earthquakes. Consequently, it is considered that this period induced earthquake activity within the Bohemian Massif. When taken together, the presented data provides robust evidence for the reconfiguration of stress and strain relationships within central and southern Europe. Whilst it is possible that tectonic activity in the Alps produced a north-verging pressure pulse that affected central Europe (e.g. in the Bohemian Massif and Upper Rhine Graben), it cannot account for the pressure pulse recognised to the south (e.g. in the Central Apennines and the Gulf of Corinth). Due to the predominance of vertical movements, it is suggested that this reconfiguration results from deep seated processes within the lithosphere-asthenosphere. However, the influence of horizontal movements transmitted from the compressional zone between Africa and Europe cannot be discounted.

Stemberk, Josef; Koš?ák, Blahoslav; Caco?, Stefan

2010-05-01

218

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.

Cooper, Scott

219

Long Term Prognosis  

MedlinePLUS

... TERM PROGNOSIS The long-term outlook of pediatric cardiomyopathy continues to be unpredictable because it occurs with ... a child also depends on the type of cardiomyopathy and the stage the disease is first diagnosed. ...

220

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

221

A Randomized Controlled Trial of an Activity Specific Exercise Program for Individuals With Alzheimer Disease in Long-term Care Settings  

PubMed Central

Objective To determine whether an activity specific exercise program could improve ability to perform basic mobility activities in long-term care residents with Alzheimer disease (AD). Design Randomized, controlled, single-blinded clinical trial. Setting Residents of 7 long-term care facilities. Participants Eighty-two long-term care residents with mild to severe AD. Intervention An activity specific exercise program was compared to a walking program and to an attention control. Measurements Ability to perform bed mobility and transfers were assessed using the subscales of the Acute Care Index of Function; functional mobility was measured using the 6-Minute Walk test. Results Subjects receiving the activity specific exercise program improved in ability to perform transfers, whereas subjects in the other 2 groups declined. PMID:21937893

Roach, Kathryn E.; Tappen, Ruth M.; Kirk-Sanchez, Neva; Williams, Christine L.; Loewenstein, David

2011-01-01

222

Contrasting radon background levels in volcanic settings: Clues from radon activity concentrations measured during long-term deformation experiments  

NASA Astrophysics Data System (ADS)

To better understand the mechanisms leading to different radon background levels in volcanic settings, we have performed two long-term deformation experiments of 16 days using a real-time set-up that enables us to monitor any variation of radon activity concentration during rock compression. Our measurements demonstrate that, in the case of highly porous volcanic rocks, the emanating power of the substrate changes as a function of the volcanic stress conditions. Constant magmatic pressures, such as those observed during dike intrusions and hydrothermal fluid injections, can result in pervasive pore collapse that is mirrored by a significant radon decrease until a constant emanation is achieved. Conversely, repeated cycles of stress due to, for example, volcano inflation/deflation cycles, cause a progressive radon increase a few days (but even weeks and months) before rupture. After rock failure, however, the formation of new emanation surfaces leads to a substantial increase of the radon signal. Our results suggest that surface deformation in tectonic and volcanic settings, such as inflation/deflation or constant magmatic pressures, have important repercussions on the emanating power of volcanic substrates.

Scarlato, P.; Tuccimei, P.; Mollo, S.; Soligo, M.; Castelluccio, M.

2013-12-01

223

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

224

MAP1B-dependent Rac activation is required for AMPA receptor endocytosis during long-term depression  

PubMed Central

The microtubule-associated protein 1B (MAP1B) plays critical roles in neurite growth and synapse maturation during brain development. This protein is well expressed in the adult brain. However, its function in mature neurons remains unknown. We have used a genetically modified mouse model and shRNA techniques to assess the role of MAP1B at established synapses, bypassing MAP1B functions during neuronal development. Under these conditions, we found that MAP1B deficiency alters synaptic plasticity by specifically impairing long-term depression (LTD) expression. Interestingly, this is due to a failure to trigger AMPA receptor endocytosis and spine shrinkage during LTD. These defects are accompanied by an impaired targeting of the Rac1 activator Tiam1 at synaptic compartments. Accordingly, LTD and AMPA receptor endocytosis are restored in MAP1B-deficient neurons by providing additional Rac1. Therefore, these results indicate that the MAP1B-Tiam1-Rac1 relay is essential for spine structural plasticity and removal of AMPA receptors from synapses during LTD. This work highlights the importance of MAPs as signalling hubs controlling the actin cytoskeleton and receptor trafficking during plasticity in mature neurons. PMID:23881099

Benoist, Marion; Palenzuela, Rocío; Rozas, Carlos; Rojas, Patricio; Tortosa, Elena; Morales, Bernardo; González-Billault, Christian; Ávila, Jesús; Esteban, José A

2013-01-01

225

MAP1B-dependent Rac activation is required for AMPA receptor endocytosis during long-term depression.  

PubMed

The microtubule-associated protein 1B (MAP1B) plays critical roles in neurite growth and synapse maturation during brain development. This protein is well expressed in the adult brain. However, its function in mature neurons remains unknown. We have used a genetically modified mouse model and shRNA techniques to assess the role of MAP1B at established synapses, bypassing MAP1B functions during neuronal development. Under these conditions, we found that MAP1B deficiency alters synaptic plasticity by specifically impairing long-term depression (LTD) expression. Interestingly, this is due to a failure to trigger AMPA receptor endocytosis and spine shrinkage during LTD. These defects are accompanied by an impaired targeting of the Rac1 activator Tiam1 at synaptic compartments. Accordingly, LTD and AMPA receptor endocytosis are restored in MAP1B-deficient neurons by providing additional Rac1. Therefore, these results indicate that the MAP1B-Tiam1-Rac1 relay is essential for spine structural plasticity and removal of AMPA receptors from synapses during LTD. This work highlights the importance of MAPs as signalling hubs controlling the actin cytoskeleton and receptor trafficking during plasticity in mature neurons. PMID:23881099

Benoist, Marion; Palenzuela, Rocío; Rozas, Carlos; Rojas, Patricio; Tortosa, Elena; Morales, Bernardo; González-Billault, Christian; Ávila, Jesús; Esteban, José A

2013-08-14

226

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.1080/01431160902882645. _________________________________________________________________________________________ Corresponding author, Mossad El-Metwally, Email: melmetwally@yahoo.com Assessing surface solar irradiance, France Short title: Assessing solar irradiance in Northern Africa from Meteosat images Abstract Two

Paris-Sud XI, Université de

227

PICARD SOL, a new ground-based facility for long-term solar radius measurements: first results  

E-print Network

or a combination of both effects. Atmospheric hal-00835418,version1-18Jun2013 Author manuscript, published Laboratoire Atmosph`eres, Milieux et Observations Spatiales, UMR 8190, CNRS, Universit´e de Versailles Saint solar radius measured in space and on ground and to better understand and calibrate atmospheric effects

Boyer, Edmond

228

Peroxisome Proliferator-Activated Receptor-? in Capillary Endothelia Promotes Fatty Acid Uptake by Heart During Long-Term Fasting  

PubMed Central

Background Endothelium is a crucial blood–tissue interface controlling energy supply according to organ needs. We investigated whether peroxisome proliferator?activated receptor?? (PPAR?) induces expression of fatty acid–binding protein 4 (FABP4) and fatty acid translocase (FAT)/CD36 in capillary endothelial cells (ECs) to promote FA transport into the heart. Methods and Results Expression of FABP4 and CD36 was induced by the PPAR? agonist pioglitazone in human cardiac microvessel ECs (HCMECs), but not in human umbilical vein ECs. Real?time PCR and immunohistochemistry of the heart tissue of control (Ppargfl/null) mice showed an increase in expression of FABP4 and CD36 in capillary ECs by either pioglitazone treatment or 48 hours of fasting, and these effects were not found in mice deficient in endothelial PPAR? (Pparg?EC/null). Luciferase reporter constructs of the Fabp4 and CD36 promoters were markedly activated by pioglitazone in HCMECs through canonical PPAR?responsive elements. Activation of PPAR? facilitated FA uptake by HCMECs, which was partially inhibited by knockdown of either FABP4 or CD36. Uptake of an FA analogue, 125I?BMIPP, was significantly reduced in heart, red skeletal muscle, and adipose tissue in Pparg?EC/null mice as compared with Ppargfl/null mice after olive oil loading, whereas those values were comparable between Ppargfl/null and Pparg?EC/null null mice on standard chow and a high?fat diet. Furthermore, Pparg?EC/null mice displayed slower triglyceride clearance after olive oil loading. Conclusions These findings identified a novel role for capillary endothelial PPAR? as a regulator of FA handing in FA?metabolizing organs including the heart in the postprandial state after long?term fasting. PMID:23525438

Goto, Kosaku; Iso, Tatsuya; Hanaoka, Hirofumi; Yamaguchi, Aiko; Suga, Toshihiro; Hattori, Akinari; Irie, Yasunori; Shinagawa, Yuji; Matsui, Hiroki; Syamsunarno, Mas Rizky A. A.; Matsui, Miki; Haque, Anwarul; Arai, Masashi; Kunimoto, Fumio; Yokoyama, Tomoyuki; Endo, Keigo; Gonzalez, Frank J.; Kurabayashi, Masahiko

2013-01-01

229

Activation of group II metabotropic glutamate receptors induces long-term depression of synaptic transmission in the rat amygdala.  

PubMed

An animal model most sensitive for measuring anticipatory anxiety is fear conditioning, which is expressed by an enduring increase in synaptic strength in the amygdala. A converse view predicts that agents that induce long-term depression (LTD) of synaptic efficacy in the amygdala may be useful in the amelioration of stress disorders. In the present study, we show that activation of group II metabotropic glutamate receptor (mGluR II) by (2S,3S, 4S)-2-(carboxycyclopropyl) glycine (l-ccg) induces an LTD in the basolateral amygdala neurons. The effect was concentration-dependent with a maximal inhibition of approximately 30%. The induction of l-CCG LTD required concurrent synaptic activity, required presynaptic but not postsynaptic Ca(2+) increases, and was independent of NMDA receptors. l-CCG LTD was associated with an increase in the ratio of paired-pulse facilitation and was not occluded by low-frequency stimulation-induced LTD, suggesting that these two forms of LTD did not share a common underlying mechanism. After eliciting LTD with l-CCG, application of isoproterenol increased the synaptic responses back to its original baseline, demonstrating that chemically depressed synapses could be potentiated by another chemical. A selective PKA inhibitor, KT 5720, by its own caused a depression of synaptic transmission and blocked l-CCG LTD, presumably by mimicking and thereby occluding any further depression. Together, these results suggest that l-CCG LTD is induced by presynaptically mGluR II-mediated inhibition of Ca(2+)-sensitive adenylyl cyclase, resulting in a decrease in cAMP formation and PKA activation, which leads to a long-lasting decrease in transmitter release. PMID:11124977

Lin, H C; Wang, S J; Luo, M Z; Gean, P W

2000-12-15

230

Regeneration-associated WNT Signaling Is Activated in Long-term Reconstituting AC133bright Acute Myeloid Leukemia Cells12  

PubMed Central

Acute myeloid leukemia (AML) is a genetically heterogeneous clonal disorder characterized by two molecularly distinct self-renewing leukemic stem cell (LSC) populations most closely related to normal progenitors and organized as a hierarchy. A requirement for WNT/?-catenin signaling in the pathogenesis of AML has recently been suggested by a mouse model. However, its relationship to a specific molecular function promoting retention of self-renewing leukemia-initiating cells (LICs) in human remains elusive. To identify transcriptional programs involved in the maintenance of a self-renewing state in LICs, we performed the expression profiling in normal (n = 10) and leukemic (n = 33) human long-term reconstituting AC133+ cells, which represent an expanded cell population in most AML patients. This study reveals the ligand-dependent WNT pathway activation in AC133bright AML cells and shows a diffuse expression and release of WNT10B, a hematopoietic stem cell regenerative-associated molecule. The establishment of a primary AC133+ AML cell culture (A46) demonstrated that leukemia cells synthesize and secrete WNT ligands, increasing the levels of dephosphorylated ?-catenin in vivo. We tested the LSC functional activity in AC133+ cells and found significant levels of engraftment upon transplantation of A46 cells into irradiated Rag2-/-?c-/- mice. Owing to the link between hematopoietic regeneration and developmental signaling, we transplanted A46 cells into developing zebrafish. This system revealed the formation of ectopic structures by activating dorsal organizer markers that act downstream of the WNT pathway. In conclusion, our findings suggest that AC133bright LSCs are promoted by misappropriating homeostatic WNT programs that control hematopoietic regeneration. PMID:23308055

Beghini, Alessandro; Corlazzoli, Francesca; Del Giacco, Luca; Re, Matteo; Lazzaroni, Francesca; Brioschi, Matteo; Valentini, Giorgio; Ferrazzi, Fulvia; Ghilardi, Anna; Righi, Marco; Turrini, Mauro; Mignardi, Marco; Cesana, Clara; Bronte, Vincenzo; Nilsson, Mats; Morra, Enrica; Cairoli, Roberto

2012-01-01

231

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

232

Photovoltaic performance and long-term stability of quasi-solid-state fluoranthene dyes-sensitized solar cells  

Microsoft Academic Search

Two new fluoranthene-based organic dye sensitizers (I and II), in which 7, 12-diphenylbenzo[k]fluoranthene moiety is acted as electron donor, thiophene and phenylethynyl units as electron spacers and carboxylic acid as electron acceptor were successfully applied in quasi-solid-state dye-sensitized solar cells. The quasi-solid-state DSSCs based on the dye I showed the better photovoltaic performance: a maximum monochromatic incident photon-to-current conversion efficiency

Wenjun Wu; Jing Li; Fuling Guo; Lei Zhang; Yitao Long; Jianli Hua

2010-01-01

233

Short- and long-term theory-based predictors of physical activity in women who participated in a weight-management program.  

PubMed

This study analyzed psychosocial predictors of the Theory of Planned Behavior (TPB) and Self-Determination Theory (SDT) and evaluated their associations with short- and long-term moderate plus vigorous physical activity (MVPA) and lifestyle physical activity (PA) outcomes in women who underwent a weight-management program. 221 participants (age 37.6 ± 7.02 years) completed a 12-month SDT-based lifestyle intervention and were followed-up for 24 months. Multiple linear regression analyses tested associations between psychosocial variables and self-reported short- and long-term PA outcomes. Regression analyses showed that control constructs of both theories were significant determinants of short- and long-term MVPA, whereas affective and self-determination variables were strong predictors of short- and long-term lifestyle PA. Regarding short-term prediction models, TPB constructs were stronger in predicting MVPA, whereas SDT was more effective in predicting lifestyle PA. For long-term models, both forms of PA were better predicted by SDT in comparison to TPB. These results highlight the importance of comparing health behavior theories to identify the mechanisms involved in the behavior change process. Control and competence constructs are crucial during early adoption of structured PA behaviors, whereas affective and intrinsic sources of motivation are more involved in incidental types of PA, particularly in relation to behavioral maintenance. PMID:25274719

Wasserkampf, A; Silva, M N; Santos, I C; Carraça, E V; Meis, J J M; Kremers, S P J; Teixeira, P J

2014-12-01

234

Dopamine D1/D5 receptor activation reverses NMDA receptor-dependent long-term depression in rat hippocampus.  

PubMed

Activation of dopamine D1/D5 receptors (D1/D5Rs) in area CA1 of the rat hippocampus modulates the expression of synaptic plasticity in a manner that is dependent on the timing of the D1/D5R activation. Here, we measured field EPSPs in rat hippocampal slices to examine the modulation of long-term depression (LTD) in CA1 by D1/D5Rs when activated immediately after the induction of LTD by low-frequency stimulation (LFS) or bath application of NMDA or the metabotropic glutamate receptor agonist DHPG [(RS)-3,5-dihydroxyphenylglycine]. Activation of D1/D5Rs by SKF 38393 [(+/-)-1-phenyl-2,3,4,5-tetrahydro-(1H)-3-benzazepine-7,8-diol hydrobromide] completely reversed a moderate LFS-induced LTD in a time-dependent manner, presumably through an adenylate cyclase/cAMP cascade. In support of this, general adenylate cyclase activation by forskolin ([3R-(3 alpha,4a beta,5 beta,6 beta,6a alpha,10 alpha,10a beta,10b alpha)]-5-(acetyloxy)-3-ethenyldodecahydro-6,10,10b-trihydroxy-3,4a,7,7,10a-pentamenthyl-1H-naphtho[2,1-b]pyran-1-one) immediately, but not 60 min, after LFS also reversed the LTD. Beta-adrenergic receptor activation by isoproterenol failed to reverse the LTD, indicating that reversal is specific to D1/D5R-mediated increased cAMP production. SKF 38393 only partially reversed a more robust LFS-induced LTD, indicating that some components of consolidated LTD are resistant to reversal. LTD induced by bath application of NMDA, but not DHPG, was also reversed by SKF 38393. Western blot analysis of postsynaptic density fractions after NMDA-induced LTD revealed that the LTD was attributable to dephosphorylation of the AMPA receptor subunit glutamate receptor 1 (GluR1) at serine 845, without a change in total GluR content. Reversal of the LTD by SKF 38393 was associated with rephosphorylation of this same residue. Together, these findings demonstrate a new role for dopamine in the neuromodulation of hippocampal LTD. PMID:17360914

Mockett, Bruce G; Guévremont, Diane; Williams, Joanna M; Abraham, Wickliffe C

2007-03-14

235

Long-term impact of farming practices on soil organic carbon and nitrogen pools and microbial biomass and activity  

Microsoft Academic Search

Conventional agriculture with intensive tillage and high inputs of synthetic chemicals has critically depleted the soil C pools. Alternative practices such as no-tillage and organic inputs have been shown to increase soil C content. However, the long-term impact of these practices on soil C pools was not fully understood under humid and warm climate conditions such as the southeast USA.

Yi Wang; Cong Tu; Lei Cheng; Chunyue Li; Laura F. Gentry; Greg D. Hoyt; Xingchang Zhang; Shuijin Hu

236

Activation of Group II Metabotropic Glutamate Receptors Induces Long-Term Depression of Synaptic Transmission in the Rat Amygdala  

Microsoft Academic Search

An animal model most sensitive for measuring anticipatory anx- iety is fear conditioning, which is expressed by an enduring increase in synaptic strength in the amygdala. A converse view predicts that agents that induce long-term depression (LTD) of synaptic efficacy in the amygdala may be useful in the ameliora- tion of stress disorders. In the present study, we show that

Hui-Ching Lin; Su-Jane Wang; Ming-Zen Luo; Po-Wu Gean

2000-01-01

237

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

238

Cosmic Ray Hysteresis as Evidence for Time-dependent Diffusive Processes in the Long Term Solar Modulation  

NASA Technical Reports Server (NTRS)

A simple one-dimensional time-dependent diffusion-convection model for the modulation of cosmic rays is presented. This model predicts that the observed intensity at a given time is approximately equal to the intensity given by the time independent diffusion convection solution under interplanetary conditions which existed a time iota in the past, (U(t sub o) = U sub s(t sub o - tau)) where iota is the average time spent by a particle inside the modulating cavity. Delay times in excess of several hundred days are possible with reasonable modulation parameters. Interpretation of phase lags observed during the 1969 to 1970 solar maximum in terms of this model suggests that the modulating region is probably not less than 10 a.u. and maybe as much as 35 a.u. in extent.

Ogallagher, J. J.

1973-01-01

239

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

240

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.

241

Long-term testing  

SciTech Connect

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.

1994-12-31

242

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

243

Exploring Behavioral Markers of Long-Term Physical Activity Maintenance: A Case Study of System Identification Modeling within a Behavioral Intervention  

ERIC Educational Resources Information Center

Efficacious interventions to promote long-term maintenance of physical activity are not well understood. Engineers have developed methods to create dynamical system models for modeling idiographic (i.e., within-person) relationships within systems. In behavioral research, dynamical systems modeling may assist in decomposing intervention effects…

Hekler, Eric B.; Buman, Matthew P.; Poothakandiyil, Nikhil; Rivera, Daniel E.; Dzierzewski, Joseph M.; Aiken Morgan, Adrienne; McCrae, Christina S.; Roberts, Beverly L.; Marsiske, Michael; Giacobbi, Peter R., Jr.

2013-01-01

244

Hypoprolactinemia Induced by Hypophysectomy and Long-Term Bromocriptine Treatment Decreases Tuberoinfundibular Dopaminergic Neuronal Activity and the Responsiveness of These Neurons to Prolactin  

Microsoft Academic Search

The effect of long-term decreases in circulating concentrations of prolactin was determined on the responsiveness of tuberoinfundibular dopamine (DA) neurons to this hormone. The activity of these neurons in ovariectomized rats was estimated by measuring the rate of DA synthesis (DOPA accumulation after the administration of a decarboxylase inhibitor) in the median eminence at various times after serum concentrations of

Keith T. Demarest; Gail D. Riegle; Kenneth E. Moore

1985-01-01

245

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

246

Long-term increase of fat mass after a four week intervention with fast food based hyper-alimentation and limitation of physical activity  

Microsoft Academic Search

BACKGROUND: A sedentary lifestyle and increased consumption of energy dense food have become more common in many parts of the world. The aim of this study was to study long term effects on body composition after a four week intervention with fast food based hyper-alimentation and limited physical activity in young normal weight subjects. METHODS: Eighteen subjects, mean age 26

Åsa Ernersson; Fredrik H Nystrom; Torbjörn Lindström

2010-01-01

247

Robot assisted activity at a health service facility for the aged for 17 months: an interim report of long-term experiment  

Microsoft Academic Search

A long-term experiment of robot assisted activity for elderly people has been conducted at a health service facility for the aged since Aug. 2003. Three therapeutic seal robots, Paro, were introduced there. This paper describes the results of the experiment for 17 months. Face scales that consist of illustrations of person's faces were used to evaluate person's moods. In addition,

Kazuyoshi Wada; Takanori Shibata; Tomoko Saito; Kayoko Sakamoto; Kazuo Tanie

2005-01-01

248

Psychological and social effects in long-term experiment of robot assisted activity to elderly people at a health service facility for the aged  

Microsoft Academic Search

A long-term experiment of robot assisted activity for elderly people has been conducted at a health service facility for the aged since Aug. 2003. Two therapeutic seal robots, Paro, were introduced there. This paper describes the first interim report of the experiment for three months. Face scales that consist of illustrations of person's faces were used to evaluate person's moods.

Kazuyoshi Wada; Takanori Shibata; Tomoko Saito; Kazuo Tanie

2004-01-01

249

An Initial Evaluation of a Long-Term, Sustainable, Integrated Community-Based Physical Activity Program for Adults with Intellectual Disability  

ERIC Educational Resources Information Center

Background: Physical activity (PA) programs for adults with intellectual disability (ID) have positive impacts, at least in the short term. No research has been reported on the effect of long-term engagement in PA programs for adults with ID. This paper explores the physical and psychosocial benefits gained by two individuals with mild ID who…

Lante, Kerrie A.; Walkley, Jeff W.; Gamble, Merrilyn; Vassos, Maria V.

2011-01-01

250

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

251

Differential response of wheat genotypes to long term salinity stress in relation to oxidative stress, antioxidant activity and osmolyte concentration  

Microsoft Academic Search

Effect of long term soil salinity was studied in wheat cvs, Kharchia 65 (tolerant) and KRL 19 (moderately tolerant) under control and two levels of salinity (ECe=5.4 and 10.6 dS m?1). Salinity stress decreased relative water content (RWC), chlorophyll (CHL), carotenoids (CAR), membrane stability index (MSI), biomass and grain yield, and increased hydrogen peroxide (H2O2), thiobarbituric acid reactive substances (TBARS),

Raj Kumar Sairam; K. Veerabhadra Rao; G. C Srivastava

2002-01-01

252

Long Term Effect of Curcumin in Regulation of Glycolytic Pathway and Angiogenesis via Modulation of Stress Activated Genes in Prevention of Cancer  

PubMed Central

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

253

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

254

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

PubMed

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

255

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.

Bohm, Stephan Karl; Kruis, Wolfgang

2014-01-01

256

Electrolytic and ibotenic acid lesions of the nucleus basalis magnocellularis interrupt long-term retention, but not acquisition of two-way active avoidance, in rats  

Microsoft Academic Search

.   Previous experiments on two-way active avoidance have shown conflicting results after nucleus basalis magnocellularis lesion:\\u000a disrupting effects with electrolytic lesions and facilitative effects with excitotoxic lesions. To resolve this issue, in\\u000a this experiment, Wistar rats received pre-training bilateral electrolytic or ibotenic acid lesions and were trained in a massed\\u000a two-way active avoidance conditioning. In order to test the long-term

Anna Vale-Martínez; Gemma Guillazo-Blanch; Margarita Martí-Nicolovius; Roser Nadal; Rosa Arévalo-García; Ignacio Morgado-Bernal

2002-01-01

257

Extracellular Signal-Regulated Protein Kinase Activation Is Required for Metabotropic Glutamate Receptor-Dependent Long-Term Depression in Hippocampal Area CA1  

Microsoft Academic Search

Activation of group 1 metabotropic glutamate receptors (mGluRs) induces long-term depression (LTD) of synaptic transmission that relies on dendritic protein synthesis. We investigated the signal transduction pathways required for mGluR-LTD to identify candidate mechanisms for mGluR regulation of synaptic protein synthesis. Our results demonstrate a role for extracellular signal-regulated protein kinase (ERK), a subclass of the mitogen-activated protein kinases (MAPKs),

Sean M. Gallagher; Christine A. Daly; Mark F. Bear; Kimberly M. Huber

2004-01-01

258

Thiopurine Methyltransferase (TPMT) Activity and Adverse Effects of Azathioprine in Inflammatory Bowel Disease: Long-Term Follow-Up Study of 394 Patients  

Microsoft Academic Search

AIM:To prospectively evaluate whether a relationship between thiopurine methyltransferase (TPMT) activity and incidence of adverse effects (especially myelotoxicity) exists, in a long-term follow-up study of a large group of patients with inflammatory bowel disease treated with azathioprine.METHODS:TPMT activity in red blood cells (RBC) was measured by a radiochemical method in 394 consecutive patients with Crohn's disease (238) or ulcerative colitis

Javier P. Gisbert; Pilar Niño; Luis Rodrigo; Carlos Cara; Luis G. Guijarro

2006-01-01

259

Requirement of extracellular signal-regulated kinase\\/mitogen-activated protein kinase for long-term potentiation in adult mouse anterior cingulate cortex  

Microsoft Academic Search

Long-term potentiation (LTP) in the anterior cingulate cortex (ACC) is believed to be critical for higher brain functions including emotion, learning, memory and chronic pain. N-methyl-D-aspartate (NMDA) receptor-dependent LTP is well studied and is thought to be important for learning and memory in mammalian brains. As the downstream target of NMDA receptors, the extracellular signal-regulated kinase (ERK) in the mitogen-activated

Hiroki Toyoda; Ming-Gao Zhao; Hui Xu; Long-Jun Wu; Ming Ren; Min Zhuo

2007-01-01

260

AT 4 receptor activation increases intracellular calcium influx and induces a non- N-methyl- d-aspartate dependent form of long-term potentiation  

Microsoft Academic Search

The angiotensin 4 receptor (AT4) subtype is heavily distributed in the dentate gyrus and CA1–CA3 subfields of the hippocampus. Neuronal pathways connecting these subfields are believed to be activated during learning and memory processing. ur laboratory previously demonstrated that application of the AT4 agonist, Norleucine1-angiotensin IV, enhanced baseline synaptic transmission and long-term potentiation, whereas perfusion with the AT4 antagonist, Norleucine1-Leu3-?(CH2-NH2)3-4-angiotensin

C. J. Davis; E. A. Kramár; A. De; P. C. Meighan; S. M. Simasko; J. W. Wright; J. W. Harding

2006-01-01

261

Activation of the Phosphoinositide 3-Kinase-Akt-Mammalian Target of Rapamycin Signaling Pathway Is Required for Metabotropic Glutamate Receptor-Dependent Long-Term Depression  

Microsoft Academic Search

Hippocampal long-term depression (LTD) is a long-lasting decrease in synaptic strength that is most commonly studied at glutamatergic inputs to pyramidal cells in hippocampal area CA1. Activation of G-protein-coupled group I (including types 1 and 5) metabotropic glutamate receptors (mGluRs) by the pharmacological agonist (RS)-3,5-dihydroxyphenylglycine (DHPG) elicits LTD in area CA1 of the hippocampus. Recent reports have shown that de

Lingfei Hou; Eric Klann

2004-01-01

262

Effects of ionic products from silicon-substituted hydroxyapatite on the rat brain activity: Morris water maze studies and long term potentiation in hippocampal CA1  

Microsoft Academic Search

This study sets to examine the effects of ionic products from silicon-substituted hydroxyapatite (Si-HA) on brain activity in Wistar rats. Animals were treated intraperitoneally with leaching liquor of Si-HA once a day for 2weeks. Morris water maze (MWM) test was employed to evaluate the spatial memory. The long term potentiation (LTP) of synaptic responses in the CA1 area was recorded.

Yi-Yi Wang; Ning Li; Jie Huang; Zhuo Yang; Tao Zhang

2011-01-01

263

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

264

Reassessment of the long-term trends in surface solar radiation over Europe by means of a homogenized dataset (1939-2011)  

NASA Astrophysics Data System (ADS)

A widespread reduction of surface solar radiation (SSR) has been well established and documented from the 1950s to the 1980s, and an opposite trend has been detected in many regions of the world since the 1980s. This decrease and increase in SSR has been defined as "global dimming" and "brightening" periods, respectively. Nevertheless, the importance of the availability of high-quality SSR data in order to estimate long-term trends is well known, particularly with respect to the quality and homogeneity of the databases. This work presents a reassessment and update until December 2011 of the trends in SSR over Europe, which is based on the 56 longest and homogenized series available at the Global Energy Balance Archive (GEBA). The mean annual SSR series show an increase from the late 1930s to the early 1950s, followed by a reduction until mid-1980s, and ending with an increase up to 2011. During the period 1939-2011 the trend is negative and significant on annual basis, with a decrease of 3.6 Wm-2 over the whole period. This implies that the trend in SSR cannot be at the origin of the warming over Europe observed during this time. Similar results are obtained in different regions, especially in Central and Eastern Europe. On the other hand, updated records until 2013 in Potsdam (Germany) confirm that the winter 2013 was the least sunny one since the beginning of measurements in the 1930s.

Sanchez-Lorenzo, Arturo; Wild, Martin; Guijarro, Jose; Brunetti, Michele; Mystakidis, Stefanos; Hakuba, Maria

2014-05-01

265

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

266

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

267

Properties of Hot Spots for Solar Activity  

Microsoft Academic Search

Hot spots for solar flares are areas of enhanced flare activity in a long term, which rotate rigidly at a certain rate. For example, a double-hot-spot system with a synodic period of 26.73 days persisted for three solar cycles (20 through 22) in the same locations in the northern hemisphere. This paper investigates properties of three hot- spot systems. The

T. A. Bai

2007-01-01

268

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

269

Evidence for distinct modes of solar activity  

E-print Network

Aims. The Sun shows strong variability in its magnetic activity, from Grand minima to Grand maxima, but the nature of the variability is not fully understood, mostly because of the insufficient length of the directly observed solar activity records and of uncertainties related to long-term reconstructions. Here we present a new adjustment-free reconstruction of solar activity over three millennia and study its different modes. Methods. We present a new adjustment-free, physical reconstruction of solar activity over the past three millennia, using the latest verified carbon cycle, 14C production, and archeomagnetic field models. This great improvement allowed us to study different modes of solar activity at an unprecedented level of details. Results. The distribution of solar activity is clearly bi-modal, implying the existence of distinct modes of activity. The main regular activity mode corresponds to moderate activity that varies in a relatively narrow band between sunspot numbers about 20 and 67. The exist...

Usoskin, I G; Gallet, Y; Roth, R; Licht, A; Joos, F; Kovaltsov, G A; Thebault, E; Khokhlov, A

2014-01-01

270

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

271

Long-term radical scavenging activity of AA-2G and 6-acyl-AA-2G against 1,1-diphenyl-2-picrylhydrazyl.  

PubMed

Stoichiometric evaluation of the radical scavenging activity of O-substituted derivatives at the C-2 position of ascorbic acid (AA) was conducted. Their reaction with a stable radical, 1,1-diphenyl-2-picrylhydrazyl (DPPH), under an acidic condition was assessed by the colorimetric method. 2-O-alpha-D-Glucopyranosyl-L-ascorbic acid (AA-2G) and a series of 6-O-acyl-2-O-alpha-D-glucopyranosyl-L-ascorbic acids (6-Acyl-AA-2G) had long-term radical scavenging activity against DPPH. The reaction of AA-2G or 6-Acyl-AA-2G with DPPH was very slow when compared with AA. However, one molecule of these derivatives consumed approximately three molecules of DPPH radicals at the end of the experiment (2 h). In contrast, one molecule of AA scavenged two molecules of DPPH radicals, and the reaction ended in the short time (<10 min). The quantity of radicals quenched by AA-2G and 6-Acyl-AA-2G was superior to that of AA in a long-term reaction. PMID:12419971

Takebayashi, Jun; Tai, Akihiro; Yamamoto, Itaru

2002-11-01

272

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. ...

273

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

Santruckova, Eva; Dolezal, Vladimir; El-Fakahany, Esam E.; Jakubik, Jan

2014-01-01

274

Long-Term Impacts of Fire and Mass Wasting on Solar Loading and Stream Heating in Mountain Streams of Central Idaho  

Microsoft Academic Search

The immediate impacts of watershed disturbances such as forest fires, debris flows, and hyperconcentrated flows to lotic systems can include the local decimation of fish, amphibian, and insect populations, but the long-term impacts to biota may have more to do with the trajectory of stream habitat recovery from disturbance. This highlights the importance of understanding the mechanisms of disturbance and

C. W. Welcker; J. M. Buffington; B. E. Rieman; C. H. Luce; J. McKean

2005-01-01

275

Workshop on Solar Activity, Solar Wind, Terrestrial Effects, and Solar Acceleration  

NASA Technical Reports Server (NTRS)

A summary of the proceedings from the workshop are presented. The areas covered were solar activity, solar wind, terrestrial effects, and solar acceleration. Specific topics addressed include: (1) solar cycle manifestations, both large and small scale, as well as long-term and short-term changes, including transients such as flares; (2) sources of solar wind, as identified by interplanetary observations including coronal mass ejections (CME's) or x-ray bright points, and the theory for and evolution of large-scale and small-scale structures; (3) magnetosphere responses, as observed by spacecraft, to variable solar wind and transient energetic particle emissions; and (4) origin and propagation of solar cosmic rays as related to solar activity and terrestrial effects, and solar wind coronal-hole relationships and dynamics.

1992-01-01

276

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

277

Cerebellar long-term synaptic depression requires PKC-mediated activation of CPI-17, a myosin/moesin phosphatase inhibitor.  

PubMed

Cerebellar LTD requires brief activation of PKC and is expressed as a functional downregulation of AMPA receptors. Modulation of vascular smooth-muscle contraction by G protein-coupled receptors (called Ca(2+) sensitization) also involves PKC phosphorylation and activation of a specific inhibitor of myosin/moesin phosphatase (MMP). This inhibitor, called CPI-17, is also expressed in brain. Here, we tested the hypothesis that LTD, like Ca(2+) sensitization, employs a PKC/CPI-17 cascade. Introduction of activated recombinant CPI-17 into cells produced a use-dependent attenuation of glutamate-evoked responses and occluded subsequent LTD. Moreover, the requirement for endogenous CPI-17 in LTD was demonstrated with neutralizing antibodies plus gene silencing by siRNA. These interventions had no effect on basal synaptic strength but blocked LTD induction. Thus, a biochemical circuit that involves PKC-mediated activation of CPI-17 modulates the distinct physiological processes of vascular contractility and cerebellar LTD. PMID:12495628

Eto, Masumi; Bock, Roland; Brautigan, David L; Linden, David J

2002-12-19

278

Long-term follow-up of 246 adults with juvenile idiopathic arthritis: social function, relationships and sexual activity  

Microsoft Academic Search

Objective. To examine social function, relationships and sexual activity in adults with juvenile idiopathic arthritis (JIA). Patients and methods. Two hundred and forty-six adults identified with long-standing JIA had an average disease duration of 28.3 yr. Specific information was sought on marital status, offspring, age at first sexual encounter, and problems related to disease in sexual activity and pregnancy. Results.

J. C. Packham; M. A. Hall

2002-01-01

279

Long-Term Antidepressant Treatments Result in a Tonic Activation of Forebrain 5HT1A Receptors  

Microsoft Academic Search

We report here the first direct functional evidence of an increase in the tonic activation of postsynaptic 5-HT1A receptors by antidepressant treatments. Because 5-HT1A receptor activation hyperpolarizes and inhibits CA3 pyramidal neurons in the dorsal hippocampus, we determined, using in vivo extracellular re- cording, whether the selective 5-HT1A receptor antagonist WAY 100635 could disinhibit these neurons. Unexpectedly, no disinhibition could

Nasser Haddjeri; Pierre Blier; Claude de Montigny

1998-01-01

280

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

281

On the long-term evolution of the PC index  

NASA Astrophysics Data System (ADS)

A number of geomagnetic indices have been designed to describe the evolution of various current systems developing in the magnetosphere and ionosphere as a consequence of the interaction of the solar wind and heliospheric magnetic field. The Polar Cap (PC) index, a proxy for the electric field and convection in the polar ionosphere, has been only recently introduced (1980). We attempt here to reconstruct the PC index back to 1870, based on a correlation comparison of several geomagnetic indices (aa, AE, Dst, PC) that show common long-term behaviour, characterised by solar activity signature at Hale and Gleissberg cycles time scales.

Demetrescu, C.; Dobrica, V.

2012-04-01

282

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

283

Simultaneous Monitoring of Presynaptic Transmitter Release and Postsynaptic Receptor Trafficking Reveals an Enhancement of Presynaptic Activity in Metabotropic Glutamate Receptor-Mediated Long-Term Depression  

PubMed Central

Although the contribution of postsynaptic mechanisms to long-term synaptic plasticity has been studied extensively, understanding the contribution of presynaptic modifications to this process lags behind, primarily because of a lack of techniques with which to directly and quantifiably measure neurotransmitter release from synaptic terminals. Here, we developed a method to measure presynaptic activity through the biotinylation of vesicular transporters in vesicles fused with presynaptic membranes during neurotransmitter release. This method allowed us for the first time to selectively quantify the spontaneous or evoked release of glutamate or GABA at their respective synapses. Using this method to investigate presynaptic changes during the expression of group I metabotropic glutamate receptor (mGluR1/5)-mediated long-term depression (LTD) in cultured rat hippocampal neurons, we discovered that this form of LTD was associated with increased presynaptic release of glutamate, despite reduced miniature EPSCs measured with whole-cell recording. Moreover, we found that specific blockade of AMPA receptor (AMPAR) endocytosis with a membrane-permeable GluR2-derived peptide not only prevented the expression of LTD but also eliminated LTD-associated increase in presynaptic release. Thus, our work not only demonstrates that mGluR1/5-mediated LTD is associated with increased endocytosis of postsynaptic AMPARs but also reveals an unexpected homeostatic/compensatory increase in presynaptic release. In addition, this study indicates that biotinylation of vesicular transporters in live cultured neurons is a valuable tool for studying presynaptic function. PMID:23536098

Dobie, Frederick A.; Baudry, Michel; Craig, Ann Marie; Wong, Tak Pan; Wang, Yu Tian

2014-01-01

284

Long-term degradation of resin-based cements in substances present in the oral environment: influence of activation mode  

PubMed Central

Indirect restorations in contact with free gingival margins or principally within the gingival sulcus, where the presence of organic acids produced by oral biofilm is higher, may present faster degradation of the resin-based cement pellicle. Objectives: To investigate the degradation of four resin-based cements: Rely X ARC (R), Variolink II (V), enforce (E) and All Cem (A), after immersion in distilled water (DW), lactic acid (LA) and artificial saliva (AS) and to analyze the influence of the activation mode on this response. Material and Methods: Two activation modes were evaluated: chemical (Ch) and dual (D). In the dual activation, a two-millimeter thick ceramic disk (IPS empress System) was interposed between the specimen and light-curing unit tip. Specimens were desiccated, immersed in distilled water, artificial saliva and lactic acid 0.1 M at 37ºC for 180 days, weighed daily for the first 7 days, and after 14, 21, 28, 90 and 180 days and were desiccated again. Sorption and solubility (µg/mm3) were calculated based on ISO 4049. The data were submitted to multifactor analysis of variance (MANOVA) and Tukey's HSD test for media comparisons (?=0.05). Results: Sorption was higher after immersion in LA (p<0.05) and increased significantly with time (p<0.05). Sorption was influenced by the activation mode: Ch>D (p<0.05). The lowest solubility was presented by R (p<0.05). Conclusions: Lactic acid increased the degradation of resin-based cements. Moreover, the physical component of activation, i.e., light-activation, contributed to a low degradation of resin-based cements. PMID:23857651

da SILVA, Eduardo Moreira; NORONHA-FILHO, Jaime Dutra; AMARAL, Cristiane Mariote; POSKUS, Laiza Tatiana; GUIMARAES, Jose Guilherme Antunes

2013-01-01

285

Passive vs. active virtual reality learning: the effects on short- and long-term memory of anatomical structures.  

PubMed

This pilot study compares the differences in learning outcomes when students are presented with either an active (student-centered) or passive (teacher-centered) virtual reality-based anatomy lesson. The "active" lesson used UCSD's Anatomic VisualizeR and enabled students to interact with 3D models and control presentation of learning materials. The "passive" lesson used a digital recording of an anatomical expert's tour of the same VR lesson played back as a QuickTime movie. Subsequent examination of the recall and retention of the studied anatomic objects were comparable in both groups. Issues underlying these results are discussed. PMID:15544293

Phelps, Andrew; Fritchle, Alicia; Hoffman, Helene

2004-01-01

286

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

287

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

288

Glucocorticoids interact with noradrenergic activation at encoding to enhance long-term memory for emotional material in women.  

PubMed

Evidence from the animal literature suggests that post-training glucocorticoids (GCs) interact with noradrenergic activation at acquisition to enhance memory consolidation for emotional stimuli. While there is evidence that GCs enhance memory for emotional material in humans, the extent to which this depends on noradrenergic activation at encoding has not been explored. In this study, 20-mg hydrocortisone was administered to healthy young women (18-35 yrs old) in a double-blind fashion 10 min prior to viewing a series of emotional and neutral images. Saliva samples were taken at baseline, 10 min after drug or placebo administration, immediately after viewing the images, 10, 20, and 30 min after viewing the images. Participants returned 1 week later for a surprise recall test. Results suggest that, hydrocortisone administration resulted in emotional memory enhancement only in participants who displayed an increase in endogenous noradrenergic activation, measured via salivary alpha-amylase at encoding. These results support findings in the animal literature, and suggest that GC-induced memory enhancement relies on noradrenergic activation at encoding in women. PMID:25010401

Segal, S K; Simon, R; McFarlin, S; Alkire, M; Desai, A; Cahill, L F

2014-09-26

289

Adhesion and tear energy of a long-term soft lining material activated by rapid microwave energy  

Microsoft Academic Search

Statement of Problem. Construction of dentures with permanent soft linings is time-consuming in the laboratory and extra costs are related to equipment and materials used. Purpose.The purpose of this in vitro study was to determine whether using microwave energy to activate the polymerization of a silicone rubber denture soft lining material affected its properties. Material and Methods. Tear energy and

Aylin Baysan; Sandra Parker; Paul S. Wright

1998-01-01

290

The Effect of Long-Term Storage on the Physiochemical and Bactericidal Properties of Electrochemically Activated Solutions  

PubMed Central

Electrochemically activated solutions (ECAS) are generated by electrolysis of NaCl solutions, and demonstrate broad spectrum antimicrobial activity and high environmental compatibility. The biocidal efficacy of ECAS at the point of production is widely reported in the literature, as are its credentials as a “green biocide.” Acidic ECAS are considered most effective as biocides at the point of production and ill suited for extended storage. Acidic ECAS samples were stored at 4 °C and 20 °C in glass and polystyrene containers for 398 days, and tested for free chlorine, pH, ORP and bactericidal activity throughout. ORP and free chlorine (mg/L) in stored ECAS declined over time, declining at the fastest rate when stored at 20 °C in polystyrene and at the slowest rate when stored at 4 °C in glass. Bactericidal efficacy was also affected by storage and ECAS failed to produce a 5 log10 reduction on five occasions when stored at 20 °C. pH remained stable throughout the storage period. This study represents the longest storage evaluation of the physiochemical parameters and bactericidal efficacy of acidic ECAS within the published literature and reveals that acidic ECAS retain useful bactericidal activity for in excess of 12 months, widening potential applications. PMID:23263673

Robinson, Gareth; Thorn, Robin; Reynolds, Darren

2013-01-01

291

Long-Term Monitoring of Soil Microbiological Activities in Two Forest Sites in South Tyrol in the Italian Alps  

PubMed Central

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.

Margesin, Rosa; Minerbi, Stefano; Schinner, Franz

2014-01-01

292

Long-term monitoring of microbial biomass, N mineralisation and enzyme activities of a Chernozem under different tillage management  

Microsoft Academic Search

We investigated the influence of tillage (conventional, minimum and reduced) on selected soil microbial properties of a fine-sandy\\u000a loamy Haplic Chernozem over a period of 8 years. The microbial biomass and soil microbial processes were affected mostly by\\u000a type of tillage and to a lesser extent by the date of soil sampling. Whereas xylanase activity was significantly higher in\\u000a the

E. Kandeler; D. Tscherko; H. Spiegel

1999-01-01

293

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

294

Long-term sulphur starvation of Arabidopsis thaliana modifies mitochondrial ultrastructure and activity and changes tissue energy and redox status.  

PubMed

Sulphur, as a constituent of amino acids (cysteine and methionine), iron-sulphur clusters, proteins, membrane sulpholipids, glutathione, glucosinolates, coenzymes, and auxin precursors, is essential for plant growth and development. Absence or low sulphur concentration in the soil results in severe growth retardation. Arabidopsis thaliana plants grown hydroponically for nine weeks on Knop nutrient medium without sulphur showed morphological symptoms of sulphur deficiency. The purpose of our study was to investigate changes that mitochondria undergo and the role of the highly branched respiratory chain in survival during sulphur deficiency stress. Ultrastructure analysis of leaf mesophyll cells of sulphur-deficient Arabidopsis showed heterogeneity of mitochondria; some of them were not altered, but the majority had swollen morphology. Dilated mitochondria displayed a lower matrix density and fewer cristae compared to control mitochondria. Disintegration of the inner and outer membranes of some mitochondria from the leaves of sulphur-deficient plants was observed. On the contrary, chloroplast ultrastructure was not affected. Sulphur deficiency changed the respiratory activity of tissues and isolated mitochondria; Complex I and IV capacities and phosphorylation rates were lower, but external NAD(P)H dehydrogenase activity increased. Higher external NAD(P)H dehydrogenase activity corresponded to increased cell redox level with doubled NADH/NAD ratio in the leaf and root tissues. Sulphur deficiency modified energy status in the tissues of Arabidopsis plants. The total concentration of adenylates (expressed as ATP+ADP), measured in the light, was lower in the leaves and roots of sulphur-deficient plants than in the controls, which was mainly due to the severely decreased ATP levels. We show that the changes in mitochondrial ultrastructure are compensated by the modifications in respiratory chain activity. Although mitochondria of Arabidopsis tissues are affected by sulphur deficiency, their metabolic and structural features, which readily reach new homeostasis, make these organelles crucial for adaptation of plants to survive sulphur deficiency. PMID:24655391

Ostaszewska, Monika; Juszczuk, Izabela M; Ko?odziejek, Izabella; Rychter, Anna M

2014-04-15

295

Proliferative Activity as Measured by MIB1 Labeling Index and Long-term Outcome of Visual Pathway Astrocytomas in Children  

Microsoft Academic Search

Although most visual pathway tumors are low-grade gliomas their biologic behavior is highly unpredictable. In order to determine whether assessment of proliferative activity can assist in predicting tumor behavior, we studied the MIB-1 labeling indices (MIB-1 LIs) in surgical specimens and monitored tumor growth in 31 consecutive children operated on between 1978 and 1997. The MIB-1 LIs at diagnosis varied

Thomas Czech; Irene Slavc; Martin Aichholzer; Christine Haberler; Wolfgang Dietrich; Karin Dieckmann; Wolfgang Koos; Herbert Budka

1999-01-01

296

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

297

Adapting and implementing a long-term nutrition and physical activity curriculum to a rural, low-income, biethnic community.  

PubMed

This study adapted an urban-based school nutrition program for delivery in a rural community. Specific aims were to adapt the curriculum; expand it to include physical activity; determine effectiveness on students' attitudes, knowledge, and self-efficacy; and assess teachers' impressions. Three cohorts were established: 173 students taught by a resource teacher, 170 students taught by classroom teachers, and 187 students who did not receive the curriculum. Pre- and posttest surveys measured outcomes, and classroom teachers were observed and interviewed. The curriculum was shown to be effective in enhancing student outcomes for both the resource teacher and classroom teacher cohorts. Teachers reported that lessons needed to be simplified and that children enjoyed them. Findings support the transferability of an urban-based nutrition curriculum to a rural community and the need for students to receive health education annually. PMID:16595289

Belansky, Elaine S; Romaniello, Catherine; Morin, Catherine; Uyeki, Terry; Sawyer, Rebecca L; Scarbro, Sharon; Auld, Garry W; Crane, Lori; Reynolds, Kim; Hamman, Richard F; Marshall, Julie A

2006-01-01

298

The role of antigenic stimulation and cytotoxic T cell activity in regulating the long-term immunopathogenesis of HIV: mechanisms and clinical implications.  

PubMed Central

This paper develops a predictive mathematical model of cell infection, host immune response and viral replication that reproduces observed long-term trends in human immunodeficiency virus (HIV) pathogenesis. Cell activation induced by repeated exposure to many different antigens is proposed as the principal mechanism of providing target cells for HIV infection and, hence, of CD4+ T cell depletion, with regulation of the overall T cell pool size causing concomitant CD8 pool increases. The model correctly predicts the cross-patient variability in disease progression, the rate of which is found to depend on the efficacy of anti-HIV cytotoxic T lymphocyte responses, overall viral pathogenicity and random effects. The model also predicts a variety of responses to anti-viral therapy, including episodic residual viral replication and discordant responses and we find that such effects can be suppressed by increasing the potency of treatment. PMID:11600072

Fraser, C.; Ferguson, N. M.; de Wolf, F.; Anderson, R. M.

2001-01-01

299

Long-term corrosion studies  

SciTech Connect

The scope of this activity is to assess the long-term corrosion properties of metallic materials under consideration for fabricating waste package containers. Three classes of metals are to be assessed: corrosion resistant, intermediate corrosion resistant, and corrosion allowance. Corrosion properties to be evaluated are general, pitting and crevice corrosion, stress-corrosion cracking, and galvanic corrosion. The performance of these materials will be investigated under conditions that are considered relevant to the potential emplacement site. Testing in four aqueous solutions, and vapor phases above them, and at two temperatures are planned for this activity. (The environmental conditions, test metals, and matrix are described in detail in Section 3.0.) The purpose and objective of this activity is to obtain the kinetic and mechanistic information on degradation of metallic alloys currently being considered for waste package containers. This information will be used to provide assistance to (1) waste package design (metal barrier selection) (E-20-90 to E-20-92), (2) waste package performance assessment activities (SIP-PA-2), (3) model development (E-20-75 to E-20-89). and (4) repository license application.

Gdowski, G.

1998-05-29

300

The flavonoid, eriodictyol, induces long-term protection in ARPE-19 cells through its effects on Nrf2 activation and phase II gene expression  

PubMed Central

Purpose Eriodictyol, a flavonoid found in citrus fruits, is among the most potent compounds reported to protect human RPE cells from oxidative stress-induced cell death. In the present study, we determined whether eriodictyol-induced phase II protein expression further enhances the resistance of human ARPE-19 cells to oxidative stress. Methods We analyzed the ability of eriodictyol to activate Nrf2 and induce the phase II proteins, heme-oxygenase (HO-1), NAD(P)H: quinone oxidoreductase 1 (NQO-1), and the cellular antioxidant glutathione, (GSH). We performed cytoprotection assays in ARPE-19 cells that were overexpressing HO-1 or NQO-1. We compared cell survival after short-term and long-term eriodictyol treatment and tested the mechanism of protection using a dominant negative Nrf2 and an shRNA specific for HO-1. Results We demonstrate that eriodictyol induces the nuclear translocation of Nrf2, enhances the expression of HO-1 and NQO-1, and increases the levels of intracellular glutathione. We show that ARPE-19 cells that overexpress HO-1 or NQO-1 are more resistant to oxidative stress-induced cell death than control cells. We demonstrate that eriodictyol induces long-term protection that is significantly greater than its short-term protection, and this effect is correlated temporally with both the activation of Nrf2 and the induction of phase II enzymes. We demonstrate that this effect can be blocked with the use of a dominant negative to Nrf2 and an shRNA specific to HO-1. Conclusions These findings indicate the greatest benefit from eriodictyol may be its ability to regulate gene expression and enhance multiple cellular defenses to oxidative injury. PMID:19117929

Johnson, Jennifer; Maher, Pamela

2009-01-01

301

Long-term fish oil supplementation attenuates seizure activity in the amygdala induced by 3-mercaptopropionic acid in adult male rats.  

PubMed

Several studies have provided evidence of significant effects of omega-3 fatty acids on brain functionality, including seizures and disorders such as epilepsy. Fish oil (FO) is a marine product rich in unsaturated omega-3 fatty acids. Considering that the amygdala is one of the brain structures most sensitive to seizure generation, we aimed to evaluate the effect of long-term chronic FO supplementation (from embryonic conception to adulthood) on the severity of seizures and amygdaloid electroencephalographic activity (EEG) in a 3-mercaptopropionic acid (3-MPA)-induced seizure model using adult rats. Female Wistar rats were fed a commercial diet supplemented daily with FO (300mg/kg) from puberty through mating, gestation, delivery, and weaning of the pups. Only the male pups were then fed daily with a commercial diet supplemented with the same treatment as the dam up to the age of 150days postpartum, when they were bilaterally implanted in the amygdala to record behavior and EEG activity before, during, and after seizures induced by administering 3-MPA. Results were compared with those obtained from rats supplemented with palm oil (PO) and rats treated with a vehicle (CTRL). The male rats treated with FO showed longer latency to seizure onset, fewer convulsive episodes, and attenuated severity compared those in the PO and CTRL groups according to the Racine scale. Moreover, long-term FO supplementation was associated with a reduction of the absolute power (AP) of the fast frequencies (12-25Hz) in the amygdala during the seizure periods. These findings support the idea that chronic supplementation with omega-3 of marine origin may have antiseizure properties as other studies have suggested. PMID:24657504

Flores-Mancilla, L E; Hernández-González, M; Guevara, M A; Benavides-Haro, D E; Martínez-Arteaga, P

2014-04-01

302

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

303

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

304

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

305

Long-term apoptotic cell death process with increased expression and activation of caspase-3 and -6 in adult rat germ cells exposed in utero to flutamide.  

PubMed

Although it is established that in utero exposure to antiandrogenic compounds such as flutamide induces hypospermatogenesis in adult male rat offspring, the cellular and molecular mechanisms remain to be investigated. By using adult rats exposed in utero to flutamide (0.4, 2, 10 mg/kg.d) as a model, we show that the hypospermatogenesis could be related to a chronic apoptotic cell death process associated with a long-term increase in caspase-3 and -6 expression and activation in germ cells. The number of apoptotic (terminal deoxynucleotidyl transferase-mediated deoxyuridine positive) adult germ cells was dependent on the dose of flutamide. The apoptotic germ cell death process could be related to an increased expression and activation of effector caspases-3 and -6. Procaspases-3 and -6 were immunodetected in germ cells from both untreated or flutamide-treated rats, whereas cleaved active caspase-3 was detected exclusively in germ cells from adult rat exposed in utero to flutamide. Exposure to the antiandrogen increased in a dose-dependent manner as caspase-3 and -6 mRNA (in RT-PCR approaches) as well as procaspase-3 and -6 protein (in Western blotting analyses) levels in the adult rat testis. Flutamide also activates procaspases. Indeed, whereas cleaved active caspase-3 and -6 proteins were absent in control animals, they were detected in adult rat testes exposed in utero to flutamide. Our results show that whereas the apoptotic germ cell death process associated with the increased caspase expression and activation in adult rat germ cells was chronic and nonreversible when exposure to flutamide occurred in utero, it was transient when such an exposure occurred during adulthood. Indeed, although an increase in caspase-3 and -6 mRNA and procaspase-3 and -6 protein levels was observed in germ cells after 3 d of exposure to flutamide, 1-2 wk after the cessation of the antiandrogen exposure, the caspase mRNA and procaspase protein levels were back to control. Active cleaved caspase-3 and -6 protein appeared following the exposure to the antiandrogen, whereas they disappeared at cessation of exposure to flutamide. In summary, the present findings indicate that in utero exposure to the antiandrogen induced in the adult rat testes a chronic apoptotic germ cell death associated with a long-term increase in the expression and activation in germ cells of caspases-3 and -6, two key components in the death machinery. PMID:12538628

Omezzine, Asma; Chater, Sonia; Mauduit, Claire; Florin, Anne; Tabone, Eric; Chuzel, Franck; Bars, Remi; Benahmed, Mohamed

2003-02-01

306

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

307

A model of synaptic plasticity: activation of mGluR I induced long-term theta oscillations in medial septal diagonal band of rat brain slice.  

PubMed

This study aimed to establish a model of synaptic plasticity by the activation of metabotropic glutamate receptor (mGluR) I in rat medial septal diagonal band (MSDB). Electrophysiological experiment was performed to record the theta frequency oscillation activities in rat MSDB slices. The data were recorded and analyzed with Spike 2 (CED, Cambridge, UK). Application of aminocyclopentane-1, 3-dicarboxylic acid (ACPD) to MSDB slices produced theta frequency oscillations (4-12 Hz) which persisted for hours after ACPD washout, suggesting the existence of a form of synaptic plasticity in long-term oscillations (LTOs). Addition of NMDA receptor antagonist AP5 (50 ?M) caused no significant change in area power. In contrast, AMPA/Kainate receptor antagonist NBQX administration partially reduced the area power. Infusion of ZD7288, a hyperpolarization-activated channel (Ih) inhibitor, caused additional reduction to control level. Comparable effects were also observed with administration of DHPG (3, 5-dihydroxyphenylglycine) which also elicited LTOs. mGluR I activation induced theta oscillation and this activity maintained hours after drug washout. Both AMPA and hyperpolarization-activated channel make an essential contribution to LTO. Our study herein established a model of synaptic plasticity. PMID:24057118

Li, Chengzhang; Guo, Zhiyue; Wang, Yali; Li, Xiaojuan; Henderson, Zainb; Lu, Cheng B

2014-04-01

308

Active immunization to tumor necrosis factor-? is effective in treating chronic established inflammatory disease: a long-term study in a transgenic model of arthritis  

PubMed Central

Introduction Passive blockade of tumor necrosis factor-alpha (TNF-?) has demonstrated high therapeutic efficiency in chronic inflammatory diseases, such as rheumatoid arthritis, although some concerns remain such as occurrence of resistance and high cost. These limitations prompted investigations of an alternative strategy to target TNF-?. This study sought to demonstrate a long-lasting therapeutic effect on established arthritis of an active immunotherapy to human (h) TNF-? and to evaluate the long-term consequences of an endogenous anti-TNF-? response. Methods hTNF-? transgenic mice, which spontaneously develop arthritides from 8 weeks of age, were immunized with a heterocomplex (TNF kinoid, or TNF-K) composed of hTNF-? and keyhole limpet hemocyanin after disease onset. We evaluated arthritides by clinical and histological assessment, and titers of neutralizing anti-hTNF-? antibody by enzyme-linked immunosorbent assay and L929 assay. Results Arthritides were dramatically improved compared to control mice at week 27. TNF-K-treated mice exhibited high levels of neutralizing anti-hTNF-? antibodies. Between weeks 27 and 45, all immunized mice exhibited symptoms of clinical deterioration and a parallel decrease in anti-hTNF-? neutralizing antibodies. A maintenance dose of TNF-K reversed the clinical deterioration and increased the anti-hTNF-? antibody titer. At 45 weeks, TNF-K long-term efficacy was confirmed by low clinical and mild histological scores for the TNF-K-treated mice. Injections of unmodified hTNF-? did not induce a recall response to hTNF-? in TNF-K immunized mice. Conclusions Anti-TNF-? immunotherapy with TNF-K has a sustained but reversible therapeutic efficacy in an established disease model, supporting the potential suitability of this approach in treating human disease. PMID:20030816

2009-01-01

309

Long-term change in thermospheric temperature above Saint Santin  

NASA Astrophysics Data System (ADS)

The 1966-1987 Saint Santin/Nançay incoherent scatter radar database is analyzed to determine long-term trends beyond those associated with the "natural" variations of solar and magnetic activity, season, and time of day. Trends averaging some -3 K/yr are found in the F region. Positive trends in the E region may be explained by the subsidence of an overlying warmer regime of air. The trend line seems to change slope around the "breakpoint" year 1979, with the cooling changing from -0.8 K/yr before that time to -5.5 K/yr afterward at 350 km altitude. These trends greatly exceed those predicted by model simulations for increases in greenhouse gas concentrations. Further, carbon dioxide shows no such breakpoint year, but ozone does, near the time of the change in thermospheric trend, and a surface climatic regime shift has also been reported near this time. It is not clear that greenhouse gases are driving the long-term trend in thermospheric temperature. Restriction of analysis to a particular time of day results in greatly different trends, from near zero at midnight to -6 K/yr at noon at 350 km altitude. A separate analysis to determine the long-term trend in the amplitude of the 24 h tide at 350 km altitude shows a large change, with the amplitude diminishing from 136 K in 1966 to 89 K in 1988. Our results show the great need to remove all other natural variations from long-term data sets in determining long-term trends to avoid great ambiguity in trend interpretation.

Donaldson, J. K.; Wellman, T. J.; Oliver, W. L.

2010-11-01

310

Fusion energy in context: its fitness for the long term  

Microsoft Academic Search

Long-term limits to growth in energy will be imposed not by inability to expand supply, but by the rising environmental and social costs of doing so. These costs will therefore be cental issues in choosing long-term options. Fusion, like solar energy, is not one possibility but many, some with very attractive environmental characteristics and others perhaps little better in these

J. P. Holdren

1978-01-01

311

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

312

Myosin II ATPase Activity Mediates the Long-Term Potentiation-Induced Exodus of Stable F-Actin Bound by Drebrin A from Dendritic Spines  

PubMed Central

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) Ca2+ 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

313

Effects of long-term oxygen treatment on ?-ketoglutarate dehydrogenase activity and oxidative modifications in mitochondria of the guinea pig heart  

PubMed Central

Objective Oxygen therapy is used for the treatment of various diseases, but prolonged exposure to high concentrations of O2 is also associated with formation of free radicals and oxidative damage. Methods In the present study we compared ?-ketoglutarate dehydrogenase (KGDH) activity and mitochondrial oxidative damage in the hearts of guinea pigs after long-term (17 and 60 h) oxygenation with 100% normobaric O2 and with partially negatively (O2 neg) or positively (O2 posit) ionized oxygen. Results Inhalation of O2 led to significant loss in KGDH activity and thiol group content and accumulation of bityrosines. Inhalation of O2 neg was accompanied by more pronounced KGDH inhibition, possibly due to additional formation of protein-lipid conjugates. In contrast, O2 posit prevented loss in KGDH activity and diminished mitochondrial oxidative damage. Conclusions These findings suggest that oxygen treatment is associated with impairment of heart energy metabolism and support the view that inhalation of O2 posit optimizes the beneficial effects of oxygen therapy. PMID:20156740

2009-01-01

314

Long-term effect of cyclic AMP on N-glycosylation is caused by an increase in the activity of the cis-prenyltransferase.  

PubMed

Previously we have shown that long-term pretreatment of JEG-3 choriocarcinoma cells with 8-bromo-cAMP increases the capacity for N-glycosylation that was caused by an 8-10-fold enlargement of the dolichol pyrophosphoryl oligosaccharide (Dol-PP-oligosaccharide) pool [Konrad and Merz (1994) J. Biol. Chem. 269, 8659-8666]. The factors involved in the effect of cAMP on synthesis of Dol-PP-oligosaccharide are investigated here. The GlcNAc transfer to dolichol phosphate (Dol-P) was found to be unaffected by pretreatment with 8-bromo-cAMP. By measuring the uptake of [3H]mevalonate, a 20-fold increase in the incorporation of the label into Dol-P was observed in the cells treated with 8-bromo-cAMP. Under the same conditions, the synthesis of dolichol was enhanced 60-fold. However, the incorporation of the radioactivity into cholesterol was not increased in the JEG-3 cells pretreated with 8-bromo-cAMP, which suggests a specific stimulation of the dolichol/Dol-P pathway by cAMP. The cis-prenyltransferase activity was found to be increased 10-fold in cells pretreated with 8-bromo-cAMP. Dolichol kinase activity was unaffected by stimulation with 8-bromo-cAMP. The present study suggests that the larger glycosylation capacity in JEG-3 cells treated with 8-bromo-cAMP is caused by an increase in the microsomal cis-prenyltransferase activity. PMID:8687403

Konrad, M; Merz, W E

1996-06-01

315

Long-term increase of fat mass after a four week intervention with fast food based hyper-alimentation and limitation of physical activity  

PubMed Central

Background A sedentary lifestyle and increased consumption of energy dense food have become more common in many parts of the world. The aim of this study was to study long term effects on body composition after a four week intervention with fast food based hyper-alimentation and limited physical activity in young normal weight subjects. Methods Eighteen subjects, mean age 26 (6.6) years, increased their energy intake with in average 70% and physical activity were not to exceed 5000 steps/day. Body composition was measured by Dual energy x-ray (DXA) at baseline, after the intervention and after 12 months. A matched control group was also included. ANOVA and Student's paired and unpaired t-test were used. Results During the intervention body weight increased with 6.4 (2.8) kg and DXA measurements showed increases of both fat free mass and fat mass. Six months after the intervention the subjects had lost most of the weight gain, - 4.7 (3.1) kg. Twelve months after the intervention body weight had increased with 1.5 (2.4) kg compared to baseline (p = 0.018). DXA measurements at 12 months showed unchanged fat free mass compared to baseline but higher fat mass, + 1.4 (1.9) kg (p = 0.01). After 2.5 years the increase of body weight was 3.1 (4.0) kg (p = 0.01) while there was no change in controls compared to baseline, + 0.1(2.5) kg (p = 0.88). Conclusion One year after a short term intervention with increased fast food based hyper-alimentation there was an increase of fat mass but unchanged fat free mass. As the change of fat mass was larger than expected from prospective epidemiological studies and as there was no increase of body weight in controls it raises the issue whether there is a long-term effect to increase fat mass of a short period of hyper-alimentation. PMID:20738843

2010-01-01

316

Human papillomavirus E2 protein with single activation domain initiates HPV18 genome replication, but is not sufficient for long-term maintenance of virus genome.  

PubMed

The papillomavirus life cycle is regulated by a family of proteins encoded by the E2 open reading frame; E2 proteins regulate viral gene expression, DNA replication and genome maintenance. We have previously shown that the bovine papillomavirus (BPV1) full-length E2 protein forms heterodimers with repressor forms of E2, and these E2 heterodimers serve as activators of transcription and replication during the viral life cycle. In the present study, using the single-chain E2 heterodimer as a model, we show that human papillomavirus (HPV) 11 and 18 E2 heterodimers with single activation domain are able to initiate replication of URR-containing plasmid in transient assay. Single-chain E2 heterodimer in the context of HPV18 genome initiates genome replication, but is not sufficient for long-term replication of HPV18 genome. We also show that HPV18 genome has a capacity to encode truncated E2 repressor E8/E2 which acts as a negative regulator of HPV18 genome replication. PMID:20940072

Kurg, Reet; Uusen, Piia; Võsa, Liisi; Ustav, Mart

2010-12-20

317

Long-term fungal inhibitory activity of water-soluble extract from Amaranthus spp. seeds during storage of gluten-free and wheat flour breads.  

PubMed

This study aimed at investigating the use of the water-soluble extract of amaranth seeds for extending the shelf-life of gluten-free and wheat flour breads. The antifungal activity of the amaranth water-soluble extract was shown by agar diffusion, conidia germination and dry biomass assays, using Penicillium roqueforti DPPMAF1 as the indicator fungus. The crude water-soluble extract had minimal inhibitory concentration (MIC) of 5 mg of peptides/ml and showed inhibition towards a large number of fungal species isolated from bakeries. Four novel antifungal peptides, encrypted in amaranth agglutinin sequences, were identified from the water-soluble extract by nano-Liquid Chromatography-Electrospray Ionisation-Mass Spectra/Mass Spectra (nano-LC-ESI-MS/MS). The water-soluble extract of amaranth was used as an ingredient for the manufacture of gluten-free and wheat flour breads and the inhibitory activity was confirmed during long-term shelf-life under pilot plant conditions. The effect of the water-soluble extract on gluten-free bread rheology and sensory properties was also shown. PMID:19328576

Giuseppe Rizzello, Carlo; Coda, Rossana; De Angelis, Maria; Di Cagno, Raffaella; Carnevali, Paola; Gobbetti, Marco

2009-05-31

318

Long-term trends in Antarctic winter hydroxyl temperatures  

Microsoft Academic Search

Fifteen year observational record of hydroxyl temperatures in AntarcticaMeasurement of solar cycle response and long-term linear trendExamination of the influence of planetary waves and other dynamical indices

W. John R. French; A. R. Klekociuk

2011-01-01

319

Long-term forecast of space weather in real-time  

Microsoft Academic Search

The scaling character of the cosmic ray fluctuation dynamics detected in a wide interval of the scales of inten- sity decreases assumes the long-term (2-3 Bartel's rotations) forecast of the solar sporadic activity. It is achieved by using the cosmic ray scintillation index 5-min values averaged by Bartels rotations.

V. I. Kozlov; S. A. Starodubtsev; A. A. Turpanov; V. G. Grigoryev; V. S. Nikolaev; A. N. Prikhodko

2001-01-01

320

Long-term ethanol exposure-induced hepatocellular carcinoma cell migration and invasion through lysyl oxidase activation are attenuated by combined treatment with pterostilbene and curcumin analogues.  

PubMed

Ethanol consumption induces hepatocellular carcinoma (HCC) cell metastasis by changing the extracellular matrix (ECM). Lysyl oxidase (LOX) catalyzes the cross-linkage of collagen or elastin in the ECM. LOX protein and mRNA overexpression (>21-fold compared with controls, n = 6) was detected in cirrhotic HCC patients with a history of alcoholism. LOX protein expression was induced in HCC cells after long-term treatment with ethanol (10 mM) for 20-40 passages (denoted E20-E40 cells). Pterostilbene (PSB, 1 ?M) displayed significant potency to reduce LOX-mediated activity in E40 cells when combined with curcumin and its analogues. The ability of E40 cells to form colonies in soft agar was reduced by both genetic depletion of LOX and by chemical inhibitors of LOX expression. This study suggests that targeting LOX expression with food components such as PSB and curcumin may be a novel strategy to overcome ethanol-induced HCC cell metastasis in liver cancer patients. PMID:23560895

Huang, Ching-Shui; Ho, Chi-Tang; Tu, Shih-Hsin; Pan, Min-Hsiung; Chuang, Chien-Hui; Chang, Hui-Wen; Chang, Chien-Hsi; Wu, Chih-Hsiung; Ho, Yuan-Soon

2013-05-01

321

Cost-effectiveness of a long-term Internet-delivered worksite health promotion programme on physical activity and nutrition: a cluster randomized controlled trial  

PubMed Central

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 standard programme consisting of a physical health check with face-to-face advice and personal feedback on a website. The intervention consisted of several additional website functionalities: action-oriented feedback, self-monitoring, possibility to ask questions and monthly e-mail messages. Primary outcomes were meeting the guidelines for PA and fruit and vegetable intake. Secondary outcomes were self-perceived health, obesity, elevated blood pressure, elevated cholesterol level and maximum oxygen uptake. Direct and indirect costs were calculated from a societal perspective, and a process evaluation was performed. Of the 924 participants, 72% participated in the first and 60% in the second follow-up. No statistically significant differences were found on primary and secondary outcomes, nor on costs. Average direct costs per participant over the 2-year period were €376, and average indirect costs were €9476. In conclusion, no additional benefits were found in effects or cost savings. Therefore, the programme in its current form cannot be recommended for implementation. PMID:22350194

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

2012-01-01

322

Long-term monitoring and modeling of the mass transfer of polychlorinated biphenyls in sediment following pilot-scale in-situ amendment with activated carbon  

NASA Astrophysics Data System (ADS)

The results of five years of post-treatment monitoring following in-situ activated carbon (AC) placement for stabilization of polychlorinated biphenyls (PCBs) at an inter-tidal mudflat adjacent to Hunters Point Shipyard, San Francisco Bay, CA, USA are reported in this paper. After five years, AC levels of the sediment cores were comparable to those at earlier sampling times. Passive sampler uptake validated the benefit of the AC amendment with a strong local sorbent dose-response relationship. The PCB uptakes in passive samplers decreased up to 73% with a 3.7 dry wt.% AC dose after five years, confirming the temporal enhancement of the amendment benefit from a 19% reduction with a 4.4% dose observed within one month. The long-term effectiveness of AC, the local AC dose response, the impact of fouling by NOM, the spatial heterogeneity of AC incorporation, and the effects of advective sediment pore-water movement are discussed with the aid of a PCB mass transfer model. Modeling and experimental results indicated that the homogeneous incorporation of AC in the sediment will significantly accelerate the benefit of the treatment.

Cho, Yeo-Myoung; Werner, David; Choi, YongJu; Luthy, Richard G.

2012-03-01

323

Bidirectional and Multi-User Telerehabilitation System: Clinical Effect on Balance, Functional Activity, and Satisfaction in Patients with Chronic Stroke Living in Long-Term Care Facilities  

PubMed Central

Background The application of internet technology for telerehabilitation in patients with stroke has developed rapidly. Objective The current study aimed to evaluate the effect of a bidirectional and multi-user telerehabilitation system on balance and satisfaction in patients with chronic stroke living in long-term care facilities (LTCFs). Method This pilot study used a multi-site, blocked randomization design. Twenty-four participants from three LTCFs were recruited, and the participants were randomly assigned into the telerehabilitation (Tele) and conventional therapy (Conv) groups within each LTCF. Tele group received telerehabilitation but the Conv group received conventional therapy with two persons in each group for three sessions per week and for four weeks. The outcome measures included Berg Balance Scale (BBS), Barthel Index (BI), and the telerehabilitation satisfaction of the participants. Setting A telerehabilitation system included “therapist end” in a laboratory, and the “client end” in LTCFs. The conventional therapy was conducted in LTCFs. Results Training programs conducted for both the Tele and Conv groups showed significant effects within groups on the participant BBS as well as the total and self-care scores of BI. No significant difference between groups could be demonstrated. The satisfaction of participants between the Tele and the Conv groups also did not show significant difference. Conclusions This pilot study indicated that the multi-user telerehabilitation program is feasible for improving the balance and functional activity similar to conventional therapy in patients with chronic stroke living in LTCFs. PMID:25019632

Lin, Kwan-Hwa; Chen, Chin-Hsing; Chen, You-Yin; Huang, Wen-Tzeng; Lai, Jin-Shin; Yu, Shang-Ming; Chang, Yuan-Jen

2014-01-01

324

Geochemical changes and microbial activities during CO2 storage - Long-term experiments under in situ conditions within the frame of CO2SINK  

NASA Astrophysics Data System (ADS)

Within the frame of the CO2SINK project, CO2 is injected into a saline aquifer of the Stuttgart formation (Triassic, Middle Keuper) at a depth of about 640 m below surface near Ketzin (Northeast German Basin, about 40 km west of Berlin) (Schilling et al., 2009). The injection of CO2 may induce a variety of geochemical changes in the reservoir system. Inorganic components may be dissolved from mineral phases (Wigand et al., 2008) and mineral precipitation from fluid components (Ketzer et al., 2009) may occur. In addition, organic molecules may be relocated, since supercritical CO2 is an excellent solvent for organic components. These geochemical shifts probably affect the microbial community composition and activity. The dissolution and precipitation of minerals, as well as corresponding microbial processes (Bennet et al., 2001) can affect reservoir permeability. In order to detect and quantify changes in geochemical characteristics and microbial processes during CO2storage and to estimate their impact on storage efficiency long-term experiments under in situ P-T conditions are performed. Freshly drilled sandstone sections from the target reservoir at Ketzin from a depth of about 630 m were incubated together with synthetic brine (20 % lower total dissolved solids than the Ketzin reservoir fluid) in high pressure vessels at 5.5 MPa and 40 ° C since September 2007. Since outer core sections were contaminated with drilling mud, as shown with fluorescein tracer detection (Wandrey et al., 2010), only clean inner core sections were used for long-term experiments to avoid contamination with microorganisms, as well as organic and inorganic mud components. After 15, 21 and 24 month fluid and rock samples were taken for chemical, microbial, mineralogical and petrophysical analyses. In fluid samples the concentrations of Ca2+, Mg2+, and K+ were found to exceed those of the Ketzin reservoir fluid. Assuming chemical equilibrium between mineral and formation brine, observed effects are probably caused by mineral dissolution in response to CO2 exposure. In consistence with inorganic concentration declines, XRD, SEM and EMP analyses suggest feldspar dissolution (Fischer et al., EGU GA 2010). A shift to larger pore radii was observed as well (Zemke et al., 2010). Organic acids are a marker for the presence of active microorganisms. They are intermediate products of the bacterial metabolism. Furthermore, if excreted, organic acids can locally decrease the pH at the bacterial attachment site and may support mineral dissolution (Welch and McPhail et al., 2003). After 15 month organic acid concentrations in vessel fluids were 2 to 7 times lower than the expected concentration (based on pore water analysis). To investigate the concentration trend during CO2 exposure, the analysis of further samples is in progress. In order to characterise the microbial community of the reservoir sandstone, initial 16S taxonomic studies were performed. So fare 16S rRNA gene sequences of chemoheterotrophic bacteria (Methylophilales bacterium, Rhizobium radiobacter, Arthrobacter, Sphingomonas), and hydrogen oxidizing bacteria (Ralstonia, Hydrogenophaga) were obtained. During the long-term exposure experiment only minor changes of the microbial community composition were observed, reflecting the adaptation of the microorganisms to the modified conditions. The quantification of metabolic groups and relevant microbial activities, e.g. metal and sulfate reduction, using Real-Time PCR and FISH in untreated and CO2 exposed samples will help to quantify bacterial processes and to assess their long-term influence on storage efficiency. Bennet P.C., Rogers J.R., Choi W.J. (2001) Geomicrobiol J 18, pp. 3 Fischer S., Zemke K., Liebscher A., Wandrey M., CO2SINK Group, EGU General Assembly 2010, Vienna Ketzer J.M., Iglesias R., Einloft S., Dullius J., Ligabue R., de Lima V. (2009) Appl Geochem 24(5), pp. 760 Schilling F., Borm G., Würdemann H., Möller F., Kühn M., CO2SINK Group (2009) Energy Procedia 1, 2029-2035 Wandrey M., Morozova D., Zettlitzer M., Würdemann H., CO2

Wandrey, Maren; Scherf, Ann-Kathrin; Vieth, Andrea; Zettlitzer, Michael; Würdemann, Hilke

2010-05-01

325

Long Term Illness and Wages  

ERIC Educational Resources Information Center

Long-term illness (LTI) is a more prevalent workplace risk than fatal accidents but there is virtually no evidence for compensating differentials for a broad measure of LTI. In 1990 almost 3.4 percent of the U.K. adult population suffered from a LTI caused solely by their working conditions. This paper provides the first estimates of compensating…

Sandy, Robert; Elliott, Robert R.

2005-01-01

326

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

327

A long-term record of photosynthetically available radiation (PAR) and total solar energy at 38.6°N, 78.2°W  

Microsoft Academic Search

Photosynthetically available radiation (PAR; 400–700 nm, E m?2 d?1) is the fraction of the total solar energy (Mjoules m?2 d?1) that is used by organisms for photosynthesis and vision. We present a statistical summary of a 17-yr time series of PAR\\u000a data (1982–1998) collected near Chesapeake Bay as well as a second set of data on PAR and total solar

Thomas R. Fisher; Anne B. Gustafson; Gregory M. Radcliffe; Karen L. Sundberg; J. Court Stevenson

2003-01-01

328

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

329

Forecasting the solar activity cycle: new insights  

NASA Astrophysics Data System (ADS)

Having advance knowledge of solar activity is important because the Sun's magnetic output governs space weather and impacts technologies reliant on space. However, the irregular nature of the solar cycle makes solar activity predictions a challenging task. This is best achieved through appropriately constrained solar dynamo simulations and as such the first step towards predictions is to understand the underlying physics of the solar dynamo mechanism. In Babcock-Leighton type dynamo models, the poloidal field is generated near the solar surface whereas the toroidal field is generated in the solar interior. Therefore a finite time is necessary for the coupling of the spatially segregated source layers of the dynamo. This time delay introduces a memory in the dynamo mechanism which allows forecasting of future solar activity. Here we discuss how this forecasting ability of the solar cycle is affected by downward turbulent pumping of magnetic flux. With significant turbulent pumping the memory of the dynamo is severely degraded and thus long term prediction of the solar cycle is not possible; only a short term prediction of the next cycle peak may be possible based on observational data assimilation at the previous cycle minimum.

Nandy, Dibyendu; Karak, Bidya Binay

2013-07-01

330

Long-term selenium supplementation in HaCaT cells: importance of chemical form for antagonist (protective versus toxic) activities.  

PubMed

The beneficial effect of selenium (Se) on cancer is known to depend on the chemical form, the dose and the duration of the supplementation. The aim of this work was to explore long term antagonist (antioxidant versus toxic) effects of an inorganic (sodium selenite, Na2SeO3) and an organic (seleno-L-methionine, SeMet) forms in human immortalized keratinocytes HaCaT cells. HaCaT cells were supplemented with Na2SeO3 or SeMet at micromolar concentrations for 144 h, followed or not by UVA radiation. Se absorption, effects of UVA radiation, cell morphology, antioxidant profile, cell cycle processing, DNA fragmentation, cell death triggered and caspase-3 activity were determined. At non-toxic doses (10 ?M SeMet and 1 ?M Na2SeO3), SeMet was better absorbed than Na2SeO3. The protection of HaCaT from UVA-induced cell death was observed only with SeMet despite both forms increased glutathione peroxidase-1 (GPX1) activities and selenoprotein-1 (SEPW1) transcript expression. After UVA irradiation, malondialdehyde (MDA) and SH groups were not modulated whatever Se chemical form. At toxic doses (100 ?M SeMet and 5 ?M Na2SeO3), Na2SeO3 and SeMet inhibited cell proliferation associated with S-G2 blockage and DNA fragmentation leading to apoptosis caspase-3 dependant. SeMet only led to hydrogen peroxide production and to a decrease in mitochondrial transmembrane potential. Our study of the effects of selenium on HaCaT cells reaffirm the necessity to take into account the chemical form in experimental and intervention studies. PMID:23771685

Hazane-Puch, Florence; Champelovier, Pierre; Arnaud, Josiane; Garrel, Catherine; Ballester, Bruno; Faure, Patrice; Laporte, François

2013-08-01

331

Hypoprolactinemia induced by hypophysectomy and long-term bromocriptine treatment decreases tuberoinfundibular dopaminergic neuronal activity and the responsiveness of these neurons to prolactin.  

PubMed

The effect of long-term decreases in circulating concentrations of prolactin was determined on the responsiveness of tuberoinfundibular dopamine (DA) neurons to this hormone. The activity of these neurons in ovariectomized rats was estimated by measuring the rate of DA synthesis (DOPA accumulation after the administration of a decarboxylase inhibitor) in the median eminence at various times after serum concentrations of prolactin had been reduced by hypophysectomy or the chronic administration of a DA agonist (bromocriptine, 3 mg/kg/day). The concentration of DA in the median eminence, but not in striatum, declined progressively up to 12 days after hypophysectomy, but did not change at any time during bromocriptine treatment. On the other hand, norepinephrine concentrations in the median eminence were increased 12 days after both treatments. Within 24 h after hypophysectomy or the first injection of bromocriptine the rate of DA synthesis in the median eminence was decreased; this decrease was maintained for at least 12 days suggesting that tuberoinfundibular DA neuronal activity is normally maintained by endogenous prolactin. Intracerebroventricular (ICV) injections of prolactin (10 micrograms, 12 h prior to sacrifice) increased the rate of DA synthesis in the median eminence of control, 24-hour hypophysectomized and 24-hour bromocriptine-treated rats. After longer periods (6-12 days) of bromocriptine treatment or after hypophysectomy the responsiveness of tuberoinfundibular DA neurons to prolactin was reduced. Dose-response studies revealed that the sensitivity and magnitude of response to ICV prolactin was markedly reduced in 12-day hypophysectomized rats.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3925360

Demarest, K T; Riegle, G D; Moore, K E

1985-05-01

332

The small-conductance calcium-activated potassium channel is a key modulator of firing and long-term depression in the dorsal striatum  

PubMed Central

The striatum is considered to be critical for the control of goal-directed action, with the lateral dorsal striatum (latDS) being implicated in modulation of habits and the nucleus accumbens thought to represent a limbic–motor interface. Although medium spiny neurons from different striatal subregions exhibit many similar properties, differential firing and synaptic plasticity could contribute to the varied behavioral roles across subregions. Here, we examined the contribution of small-conductance calcium-activated potassium channels (SKs) to action potential generation and synaptic plasticity in adult rat latDS and nucleus accumbens shell (NAS) projection neurons in vitro. The SK-selective antagonist apamin exerted a prominent effect on latDS firing, significantly decreasing the interspike interval. Furthermore, prolonged latDS depolarization increased the interspike interval and reduced firing, and this enhancement was reversed by apamin. In contrast, NAS neurons exhibited greater basal firing rates and less regulation of firing by SK inhibition and prolonged depolarization. LatDS neurons also had greater SK currents than NAS neurons under voltage-clamp. Importantly, SK inhibition with apamin facilitated long-term depression (LTD) induction in the latDS but not the NAS, without alterations in glutamate release. In addition, SK activation in the latDS prevented LTD induction. Greater SK function in the latDS than in the NAS was not secondary to differences in sodium or inwardly rectifying potassium channel function, and apamin enhancement of firing did not reflect indirect action through cholinergic interneurons. Thus, these data demonstrate that SKs are potent modulators of action potential generation and LTD in the dorsal striatum, and could represent a fundamental cellular mechanism through which habits are regulated. PMID:20497469

Hopf, F. Woodward; Seif, Taban; Mohamedi, Maysha L.; Chen, Billy T.; Bonci, Antonello

2011-01-01

333

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

334

The small-conductance calcium-activated potassium channel is a key modulator of firing and long-term depression in the dorsal striatum.  

PubMed

The striatum is considered to be critical for the control of goal-directed action, with the lateral dorsal striatum (latDS) being implicated in modulation of habits and the nucleus accumbens thought to represent a limbic-motor interface. Although medium spiny neurons from different striatal subregions exhibit many similar properties, differential firing and synaptic plasticity could contribute to the varied behavioral roles across subregions. Here, we examined the contribution of small-conductance calcium-activated potassium channels (SKs) to action potential generation and synaptic plasticity in adult rat latDS and nucleus accumbens shell (NAS) projection neurons in vitro. The SK-selective antagonist apamin exerted a prominent effect on latDS firing, significantly decreasing the interspike interval. Furthermore, prolonged latDS depolarization increased the interspike interval and reduced firing, and this enhancement was reversed by apamin. In contrast, NAS neurons exhibited greater basal firing rates and less regulation of firing by SK inhibition and prolonged depolarization. LatDS neurons also had greater SK currents than NAS neurons under voltage-clamp. Importantly, SK inhibition with apamin facilitated long-term depression (LTD) induction in the latDS but not the NAS, without alterations in glutamate release. In addition, SK activation in the latDS prevented LTD induction. Greater SK function in the latDS than in the NAS was not secondary to differences in sodium or inwardly rectifying potassium channel function, and apamin enhancement of firing did not reflect indirect action through cholinergic interneurons. Thus, these data demonstrate that SKs are potent modulators of action potential generation and LTD in the dorsal striatum, and could represent a fundamental cellular mechanism through which habits are regulated. PMID:20497469

Hopf, F Woodward; Seif, Taban; Mohamedi, Maysha L; Chen, Billy T; Bonci, Antonello

2010-06-01

335

Increased long-term recreational physical activity is associated with older age at natural menopause among heavy smokers: the California Teachers Study  

PubMed Central

Objective Although physical activity modulates the hypothalamic-ovarian-pituitary axis, the few studies investigating whether physical activity is associated with age at natural menopause have had mixed results. We set out to determine whether physical activity is associated with the timing of natural menopause in a large cohort of California women, overall, and by smoking history. Methods We investigated the association between long-term physical activity (hours/week/year) and age at natural menopause among 97,945 women in the California Teachers Study. Multivariable Cox proportional hazards regression methods were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). The impact of cigarette smoking (never smoker, former-light smoker, former-heavy smoker, current-light smoker, current-heavy smoker) as an effect modifier was evaluated. Results In a multivariable model adjusting for body mass index at age 18, age at menarche, race/ethnicity, and age at first full-term pregnancy, increased physical activity was statistically significantly associated with older age at natural menopause (ptrend=0.005). Higher body mass index at age 18 (ptrend=0.0003) and older age at menarche (ptrend=0.0003) were also associated with older age at natural menopause. Hispanic ethnicity (vs. non-Hispanic whites, HR 1.17, 95% CI 1.09–1.26), current smokers (vs. never smokers, HR 1.68, 95% CI 1.60–1.75 for current-light smokers; HR 1.38, 95% CI 1.33–1.44 for current-heavy smokers) and older age at first full-term pregnancy (HR?29, 2+ full-term pregnancies vs. <29, 2+ full-term pregnancies 1.10, 95% CI 1.06–1.14) were associated with earlier age at natural menopause. Upon stratification by smoking history, increased physical activity was statistically significantly associated with older natural menopause among heavy smokers only (HRHighest vs. Lowest quartile 0.88, 95% CI 0.81–0.97, ptrend=0.02 for former-heavy smokers; HRHighest vs. Lowest quartile 0.89, 95% CI 0.80–0.99, ptrend=0.04 for current-heavy smokers). Conclusion Age at natural menopause is a complex trait; the determinants of age at natural menopause, including physical activity, may differ by smoking status. PMID:23435025

Emaus, Aina; Dieli-Conwright, Christina; Xu, Xinxin; Lacey, James V.; Ingles, Sue A.; Reynolds, Peggy; Bernstein, Leslie; Henderson, Katherine D.

2012-01-01

336

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

337

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

338

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

339

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

340

PKMf Maintains Spatial, Instrumental, and Classically Conditioned Long-Term  

Microsoft Academic Search

How long-term memories are stored is a fundamental question in neuroscience. The first molecular mechanism for long-term memory storage in the brain was recently identified as the persistent action of protein kinase Mzeta (PKMf), an autonomously active atypical protein kinase C (PKC) isoform critical for the maintenance of long-term potentiation (LTP). PKMf maintains aversively conditioned associations, but what general form

Eugenia L. Friedman; Jana Kenney; Stephen M. Taubenfeld; Joshua M. Zimmerman; John Hanna; Cristina Alberini; Ann E. Kelley; Stephen Maren; Jerry W. Rudy; Jerry C. P. Yin; Todd C. Sacktor; Andre A. Fenton

341

Assessment of Economic Losses to Recreational Activities from 1988 Marine Pollution Events and Assessment of Economic Losses from Long-Term Contamination of Fish within the New York Bight to New Jersey  

Microsoft Academic Search

In this paper economic losses from recent marine pollution events associated with recreational activities to New Jersey are examined. In addition, assessment of economic losses from long-term contamination of fish from the New York Bight to New Jersey are presented. During the 1987 and 1988 summer season, marine pollution and debris wash-ups occurred almost simultaneously in New York and New

Douglas D Ofiara; Bernard Brown

1999-01-01

342

Long term effect of reduced pack sizes of paracetamol on poisoning deaths and liver transplant activity in England and Wales: interrupted time series analyses  

PubMed Central

Objective To assess the long term effect of United Kingdom legislation introduced in September 1998 to restrict pack sizes of paracetamol on deaths from paracetamol poisoning and liver unit activity. Design Interrupted time series analyses to assess mean quarterly changes from October 1998 to the end of 2009 relative to projected deaths without the legislation based on pre-legislation trends. Setting Mortality (1993-2009) and liver unit activity (1995-2009) in England and Wales, using information from the Office for National Statistics and NHS Blood and Transplant, respectively. Participants Residents of England and Wales. Main outcome measures Suicide, deaths of undetermined intent, and accidental poisoning deaths involving single drug ingestion of paracetamol and paracetamol compounds in people aged 10 years and over, and liver unit registrations and transplantations for paracetamol induced hepatotoxicity. Results Compared with the pre-legislation level, following the legislation there was an estimated average reduction of 17 (95% confidence interval ?25 to ?9) deaths per quarter in England and Wales involving paracetamol alone (with or without alcohol) that received suicide or undetermined verdicts. This decrease represented a 43% reduction or an estimated 765 fewer deaths over the 11¼ years after the legislation. A similar effect was found when accidental poisoning deaths were included, and when a conservative method of analysis was used. This decrease was largely unaltered after controlling for a non-significant reduction in deaths involving other methods of poisoning and also suicides by all methods. There was a 61% reduction in registrations for liver transplantation for paracetamol induced hepatotoxicity (?11 (?20 to ?1) registrations per quarter). But no reduction was seen in actual transplantations (?3 (?12 to 6)), nor in registrations after a conservative method of analysis was used. Conclusions UK legislation to reduce pack sizes of paracetamol was followed by significant reductions in deaths due to paracetamol overdose, with some indication of fewer registrations for transplantation at liver units during the 11 years after the legislation. The continuing toll of deaths suggests, however, that further preventive measures should be sought. PMID:23393081

2013-01-01

343

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

344

On the Possibility to Simultaneously Determine the Long-Term Average Fluxes of Solar pp-NEUTRINOS and Cosmic Ray Muons  

NASA Astrophysics Data System (ADS)

The Allchar mine in the southern FYR Macedonia contains the world's largest known concentration of thallium bearing minerals. LOREX (acronym for the geo-chemical LORandite EXperiment) is an international collaboration exploring the opportunity to use the rare mineral lorandite (TlAsS2) for the determination of the solar pp-neutrino flux, averaged over the 4.3 million year age of the deposit. Here we discuss the possibility to determine simultaneously both the solar neutrino and the cosmic ray muon flux, averaged over the same period of time. Cosmic-ray muons participate in the reaction 205Tl(?p, n)205Pb, whereas the neutrinos induce the capture reaction 205Tl(?e, e)205Pb* ? 205Pb. Both fluxes can in principle be determined by counting the number of atoms of the long-lived 205Pb present in the mineral, produced by both muons and neutrinos in the reactions with the most abundant stable isotope, 205Tl.

Anicin, I. V.; Pejovi?, V.; Pavi?evi?, M. K.; Amthauer, G.; Boev, B.; Bosch, F.; Brüchle, W.; Djurci?, Z.; Henning, W. F.; Faestermann, T.; Jelenkovi?, R.; Niedermann, S.; Weiss, A.

345

Microbial functional diversity, metabolic quotient, and invertase activity of a sandy loam soil as affected by long-term application of organic amendment and mineral fertilizer  

Microsoft Academic Search

Purpose  Organic and inorganic fertilizers are used primarily to increase nutrient availability to plants. Monitoring balanced versus\\u000a unbalanced fertilization effects on soil microbes could improve our understanding of soil biochemical processes and thus help\\u000a us to develop sound management strategies. The objective of this study was to investigate the effects of long-term fertilization\\u000a regimes on soil microbial community functional diversity, metabolic

Junli Hu; Xiangui Lin; Junhua Wang; Jue Dai; Ruirui Chen; Jiabao Zhang; Ming Hung Wong

2011-01-01

346

Long-term Safety and Efficacy Results of Once-Daily Emtricitabine-Based Highly Active Antiretroviral Therapy Regimens in Human Immunodeficiency Virus-Infected Pediatric Subjects  

Microsoft Academic Search

OBJECTIVES.The purpose of this work was to obtain long-term safety and efficacy data for antiretroviral regimens containing emtricitabine in HIV-infected pediatric sub- jects and confirm that a pediatric dose of 6 mg\\/kg once daily would provide steady- state emtricitabine concentrations comparable to those observed in adults given 200 mg of emtricitabine once daily. PATIENTS AND METHODS.HIV-infected subjects between 3 months

Xavier Saez-Llorens; Avy Violari; Ram Yogev; Andrew Wiznia; Greg Chittick; John Hinkle; M. Robert Blum; Nathalie Adda; Franck Rousseau; Federico Gomez

2008-01-01

347

Effect of long-term continuous consumption of fermented milk containing probiotic bacteria on mucosal immunity and the activity of peritoneal macrophages  

Microsoft Academic Search

The effect of the long-term administration of commercial fermented milk containing probiotic bacteria in the mucosal immune response and peritoneal macrophages was analyzed. BALB\\/c mice were fed with fermented milk for 98 consecutive days. Small and large intestines were removed for histology; IgA, CD4, CD8 cells and cytokines-producing cells were counted. The influence on the immune cells associated with bronchus

A. de Moreno de LeBlanc; S. Chaves; E. Carmuega; R. Weill; J. Antóine; Gabriela Perdigón

2008-01-01

348

The Sun's Role in Long-Term Climate Change  

Microsoft Academic Search

Evidence suggests that changes of solar irradiance in recent centuries have provided a significant climate forcing and that the sun has been one of the principal causes of long-term climate change. During the past two decades the solar forcing has been much smaller than the climate forcing caused by increasing greenhouse gases. But it is incorrect to assume that the

James E. Hansen

2000-01-01

349

Links between short and long term tectonics  

NASA Astrophysics Data System (ADS)

In the quest for understanding the rheology of the lithosphere a central question that can be addressed is the existence of a parameterisation of the rheology, which could reflect both the response of the lithosphere over the large time scale (10's Myr) and the time scale of earthquakes and faulting. The gap existing between these observational time scales is mainly due to modelling approximations which in each separate fields permit to fit the data but which rely on simplification of the physics, the rheology and set of boundary conditions which are not always compatible one with each other. The long-term community, i.e. the geodynamics community, tend to use Mohr-Coulomb non-associated plasticity to model self-consistent shear zone localisation. This type of rheology corresponds, in the limit of a discrete fault plan, to a slip weakening/hardening formulation in which weakening rate depends on fault plan orientation. The short term community, i.e. the earthquake community, has stopped using this kind of formulation and rather uses the rate and state formulation to model the activity of faults. Rate and State is limited because it cannot self-consistently generate an earthquake, the triggering, i.e. the initial slip acceleration must be imposed. This contribution is a synthesis of several geological case studies at different length-scale, in which we suspects a strong link between long term geodynamic processes and current seismological and geodetic observations. We make use of these case studies together with quantitative numerical models to understand how the seismic and inter-seismic behaviour reflects the rather long-term geodynamic setting than the internal rheological properties of faults. After briefly revisiting the different modelling approaches from geodynamic seismologic and geodetic communities, we show how modelling results obtained with the long term modelling approach brings new insights and alternative models for both the seismological and geodetic behaviour of active faults. The first example will concern the seismic activity on low angle normal faults focussing on the case of the Gulf of Corinth. Then focusing on strike slip tectonic, I will compare data from active and exhumed strike slip faults and discuss how a single model can explain their behaviour. The last example will focus on the creeping segment of the San Andreas Fault to discuss how heterogeneities in the long-term tectonic loading (in that instance flexure of the lithosphere) may influence the seismic behaviour of strike slip fault.

Le Pourhiet, Laetitia; Traoré, Nafissatou; Lecomte, Emmanuel; Saleeby, Jason

2013-04-01

350

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

351

Long-term consequences of anorexia nervosa.  

PubMed

Anorexia nervosa (AN) is a psychiatric disorder that occurs mainly in female adolescents and young women. The obsessive fear of weight gain, critically limited food intake and neuroendocrine aberrations characteristic of AN have both short- and long-term consequences for the reproductive, cardiovascular, gastrointestinal and skeletal systems. Neuroendocrine changes include impairment of gonadotropin releasing-hormone (GnRH) pulsatile secretion and changes in neuropeptide activity at the hypothalamic level, which cause profound hypoestrogenism. AN is related to a decrease in bone mass density, which can lead to osteopenia and osteoporosis and a significant increase in fracture risk in later life. Rates of birth complications and low birth weight may be higher in women with previous AN. The condition is associated with fertility problems, unplanned pregnancies and generally negative attitudes to pregnancy. During pregnancy, women with the condition have higher rates of hyperemesis gravidarum, anaemia and obstetric complications, as well as impaired weight gain and compromised intrauterine foetal growth. It is reported that 80% of AN patients are affected by a cardiac complications such as sinus bradycardia, a prolonged QT interval on electrocardiography, arrythmias, myocardial mass modification and hypotension. A decrease in bone mineral density (BMD) is one of the most important medical consequences of AN. Reduced BMD may subsequently lead to a three- to seven-fold increased risk of spontaneous fractures. Untreated AN is associated with a significant increase in the risk of death. Better detection and sophisticated therapy should prevent the long-term consequences of this disorder. The aims of treatment are not only recovery but also prophylaxis and relief of the long-term effects of this disorder. Further investigations of the long-term disease risk are needed. PMID:23706279

Meczekalski, Blazej; Podfigurna-Stopa, Agnieszka; Katulski, Krzysztof

2013-07-01

352

Long-term continuous production of optically active 2-(4-chlorophenoxy)propanoic acid by yeast lipase in an organic solvent system  

Microsoft Academic Search

Long-term continuous optical resolution of 2-(4-chlorophenoxy)propanoic acid was carried out by stereoselective esterification with Celite-adsorbed lipase OF 360 from Candida cylindracea using n-tetradecanol as the second substrate in organic solvent systems. The water content of the Celite-adsorbed lipase affected productivity, 1.0 µl water·mg lipase-1 being optimal for preparation of the adsorbed lipase. Water-saturated carbon tetrachloride-isooctane (8:2, v\\/v) was found to

Toshiaki Fukui; Takuo Kawamoto; Kenji Sonomoto; Atsuo Tanaka

1990-01-01

353

Long-term oxygen therapy.  

PubMed

This article provides an overview of the status of long-term oxygen therapy (LTOT). In the United States, payment cutbacks are occurring as a result of congressionally mandated competitive bidding and capped rental programs. These Medicare programs are discussed. These legislative and regulatory changes may result in reduced patient access to appropriate oxygen-delivery systems that meet medical needs, including optimal ambulation. Prescribing LTOT is addressed in this article, as is the need for adequate patient education. The importance of appropriate monitoring and reassessment is presented. The use of an LTOT collaborative care model is discussed. Although the new intermittent flow oxygen-delivery systems have potential benefits, there is consensus that each patient should be tested on the specific device because of variability in delivery and patient response. Feasible locations for patient education and monitoring are identified. PMID:21285057

Christopher, Kent L; Porte, Phillip

2011-02-01

354

Long-term potentiation and long-term depression: a clinical perspective  

PubMed Central

Long-term potentiation and long-term depression are enduring changes in synaptic strength, induced by specific patterns of synaptic activity, that have received much attention as cellular models of information storage in the central nervous system. Work in a number of brain regions, from the spinal cord to the cerebral cortex, and in many animal species, ranging from invertebrates to humans, has demonstrated a reliable capacity for chemical synapses to undergo lasting changes in efficacy in response to a variety of induction protocols. In addition to their physiological relevance, long-term potentiation and depression may have important clinical applications. A growing insight into the molecular mechanisms underlying these processes, and technological advances in non-invasive manipulation of brain activity, now puts us at the threshold of harnessing long-term potentiation and depression and other forms of synaptic, cellular and circuit plasticity to manipulate synaptic strength in the human nervous system. Drugs may be used to erase or treat pathological synaptic states and non-invasive stimulation devices may be used to artificially induce synaptic plasticity to ameliorate conditions arising from disrupted synaptic drive. These approaches hold promise for the treatment of a variety of neurological conditions, including neuropathic pain, epilepsy, depression, amblyopia, tinnitus and stroke. PMID:21779718

Bliss, Timothy V.P.; Cooke, Sam F

2011-01-01

355

Long-term plasticity may be manifested as reduction or expansion of cortical representations of actively used muscles in motor skill specialists.  

PubMed

Our aim was to study long-term plasticity in the organization of cortical muscle representations due to extensive motor training for different skills. We were especially interested in whether skill-specific demands on independent hand muscle movements and synchronous leg muscle movements are reflected differently in the reorganization of muscle representations. We used navigated transcranial magnetic stimulation to estimate the size of cortical representations of opponens pollicis, abductor digiti minimi, and tibialis anterior muscles in five string instrument players, five figure skaters, and five controls. The extent of the representation area was presented as an amplitude-area curve showing the spatial distribution of motor evoked potentials. The size of representation areas was compared between the dominant and nondominant hemispheres and between the groups. The representation area of the left abductor digiti minimi (critical for reaching right tones) in the right, nondominant hemisphere was smaller in string players and the representation area of the tibialis anterior in the dominant hemisphere (critical for jumps) was larger in figure skaters when compared with controls. Reorganization in the motor cortex may differ depending upon the skill and an individual muscle's role in the skill. A smaller representation area of the independently used hand muscle in masters of fine motor skills may reflect long-term plasticity toward more focused representation, which may be beneficial in accurate and discrete cortical control of the muscle. Larger cortical representations are related to skill demanding coactivation of proximal and distal lower limb muscles. PMID:23719022

Vaalto, Selja; Julkunen, Petro; Säisänen, Laura; Könönen, Mervi; Määttä, Sara; Karhu, Jari

2013-08-01

356

Mark I containment long-term program safety evaluation report, resolution of generic technical activity A-7. Report for February 1977-December 1979  

SciTech Connect

During testing for an advanced Boiling Water Reactor (BWR) containment system design (Mark III), suppression pool hydrodynamic loads were identified which had not been considered in the original design of the Mark I containment system. To address this issue, a Mark I Owners Group was formed and the assessment was divided into a short-term and long-term program. The results of the NRC staff's review of the Mark I Containment Short Term Program are described in NUREG-0408. This report describes the results of the NRC staff's review of the generic Mark I Containment Long Term Program (LTP). The LTP was conducted to provide a generic basis to define suppression pool hydrodynamic loads and the related structural acceptance criteria, such that a comprehensive reassessment of each Mark I containment system would be performed. A series of experimental and analytical programs were conducted by the Mark I Owners Group to provide the necessary bases for the generic load definition and structural assessment techniques. The generic methods proposed by the Mark I Owners Group, as modified by the NRC staff's requirements, will be used to perform plant-unique analyses, which will identify the plant modifications, if any, that will be needed to restore the originally intended margin of safety in the Mark I containment designs.

Not Available

1980-07-01

357

Techniques for Active Learning in CS Courses Studies show that active learning promotes improved long-term retention of course material  

E-print Network

· Visual and Verbal · Sequential and Global Active learners prefer an environment that enables them, and relationships. Visual learners prefer learning from material they can see: charts, figures, and demonstrations students tend to be active and visual learners, then one of the most effective learning environments is one

Briggs, Tom

358

Asthma Medicines: Long-Term Control  

MedlinePLUS

... Control Health Issues Listen Asthma Medicines: Long-term Control Article Body Corticosteroids Synthetic versions of hormones produced ... form, they are used exclusively for long-term control; they are not very effective for acute symptoms. ...

359

Long-Term Effects of 6Weeks Whole-Body Vibration on Balance Recovery and Activities of Daily Living in the Postacute Phase of Stroke A Randomized, Controlled Trial  

Microsoft Academic Search

Background and Purpose—The long-term effects of 6-weeks whole-body vibration, as a novel method of somatosensory stimulation, on postural control and activities of daily living were compared with those of 6 weeks of exercise therapy on music of the same intensity in the postacute phase of stroke. Methods—Fifty-three patients with moderate to severe functional disabilities were randomized within 6 weeks poststroke

Ilse J. W. van Nes; Hilde Latour; Fanny Schils; Ronald Meijer; Annet van Kuijk; Alexander C. H. Geurts

360

Long-term effects of 6-week whole-body vibration on balance recovery and activities of daily living in the postacute phase of stroke: a randomized, controlled trial  

Microsoft Academic Search

BACKGROUND AND PURPOSE: The long-term effects of 6-weeks whole-body vibration, as a novel method of somatosensory stimulation, on postural control and activities of daily living were compared with those of 6 weeks of exercise therapy on music of the same intensity in the postacute phase of stroke. METHODS: Fifty-three patients with moderate to severe functional disabilities were randomized within 6

I. J. W. van Nes; H. Latour; F. Schils; R. Meijer; A. van Kuijk; A. C. H. Geurts

2006-01-01

361

Asymmetric relationships between homosynaptic long-term potentiation and heterosynaptic long-term depression  

Microsoft Academic Search

All synaptically-based neuropsychological theories of learning postulate that there are changes resulting from neural activity which are long-lasting and confined to specific sets of synapses1-3. In the past decade a form of synaptic strengthening known as long-term potentiation (LTP) has been found which results from high-frequency neural activity and is of sufficient duration to model as a learning mechanism4,5. Some

W. C. Abraham; G. V. Goddard

1983-01-01

362

CREB and the formation of long-term memory.  

PubMed

Cyclic AMP response element binding protein (CREB)-responsive transcription plays a central role in the formation of long-term memory in Drosophila, Aplysia and mice. Agents that disrupt the activity of CREB specifically block the formation of long-term memory, whereas agents that increase the amount or activity of the transcription factor accelerate the process. These results have led to the recent hypothesis that CREB is pivotal in the switch from short-term (protein synthesis independent) to long-term (protein synthesis dependent) memory. PMID:8725970

Yin, J C; Tully, T

1996-04-01

363

Long-term variation of Saturn H2 emission  

NASA Technical Reports Server (NTRS)

The goal of this research effort was to analyze the long-term IUE database of Saturn images for the possible presence of diffuse H2 emissions, using techniques originally developed for analysis of Jupiter images. The poor S/N ratio in many of the Saturn images proved to be a significant limitation to the possible detection of H2 emission. The creation of a satisfactory background atmosphere model was also limited by difficulties in reproducing the observed C2H2 band structure at long wavelengths. The results currently available suggest that diffuse H2 emission is present on Saturn on some occasions. However, the IUE data are not able to indicate whether H2 emission is present at all times with a magnitude proportional to solar activity, as was shown for Jupiter.

DeLand, Matthew T.; McGrath, Melissa

1995-01-01

364

Intracellular delivery of 2-deoxy-D-glucose into tumor cells by long-term cultivation and through swelling-activated pathways: implications for radiation treatment.  

PubMed

2-Deoxy-D-glucose (2DG), a well-known inhibitor of anaerobic glycolysis, is expected to exert cytotoxic and radiosensitizing effects. In order to test this hypothesis, the response of four tumor cell lines (U87-MG, GaMG, A549 and HT1080) to 2DG was analyzed for cell proliferation, changes in cell volume and nucleus size, as well as for radiation-induced DNA fragmentation, measured by the alkaline Comet assay. Two methods were used for loading cells with 2DG. The long-term method included cell cultivation in the presence of 5 mM 2DG for 24 h, while rapid intracellular delivery of 2DG was achieved by exposing the cells for 20 min to a hypotonic solution containing 100 mM 2DG. Irrespective of the loading method, 2DG inhibited the growth of HT1080 and A549 cells. In contrast, two glioblastoma lines (U87 and GaMG) were resistant to 2DG. In three of the four cell lines (all except HT1080), long-term treatment with 2DG reduced radiation-induced DNA fragmentation in conjunction with 2DG-mediated nucleus shrinkage (probably via chromatin condensation) in non-irradiated cells. Complementary volumetric experiments revealed the avid hypotonic uptake of 2DG by all tumor lines. Nonetheless, only HT1080 cells exhibited a significant increase in radiation-induced DNA fragmentation upon hypotonic loading with 2DG, associated with marked nucleus expansion in non-irradiated samples. Our data suggest that, dependant on cell type as well as on medium composition and tonicity, sugar treatment can induce the compaction or expansion of chromatin, thus decreasing or increasing radiation-induced DNA fragmentation. These results raise interesting questions for further studies on the mechanistic links between the sugar-modulated cell volume changes, chromatin structure and radiosensitivity of tumor and normal cells. PMID:21475878

Djuzenova, Cholpon S; Krasnyanska, Julia; Kiesel, Martin; Stingl, Lavinia; Zimmermann, Ulrich; Flentje, Michael; Sukhorukov, Vladimir L

2009-01-01

365

Long-term environmental exposure to metals (Cu, Cd, Pb, Zn) activates the immune cell stress response in the common European sea star (Asterias rubens).  

PubMed

The common sea star Asterias rubens represents a key-species of the North-Eastern Atlantic macro benthic community. The cells of their immune system, known as coelomocytes, are the first line of defence against environmental hazards. Here, we report the results of investigations on the immune cells response of sea stars exposed to marine environmental pollution for long periods. We show that levels of the heat shock cognate protein 70 (HSC70) in coelomocytes from A. rubens, which were collected during a field study in the S?rfjord (North Sea, SW coast of Norway) along a contamination gradient, are directly associated with the long-term accumulation of Cd, Cu heavy metals exclusively in the tegument. Conversely, Pb and Zn accumulation in the tegument did not relate to HSC70 levels and none of the metals were found accumulated in the pyloric coeca. In addition the coelomocytes from A. rubens, collected in high and low metal impacted stations were examined by a proteomic approach using two-dimensional electrophoresis (2DE). By comparison of the proteomic maps, we observed that 31 protein spots differed in their relative abundance, indicating a gene expression response to the metal mixture exposure. All together, our results confirm that the echinoderm immune cells are a suitable model for the assessment of long-term exposure to environmental pollution, moreover that the increased level of HSC70 can be considered a signal of an acquired tolerance within a large spectrum of protein profile changes occurring in response to metal contamination. PMID:22000270

Matranga, V; Pinsino, A; Randazzo, D; Giallongo, A; Dubois, P

2012-05-01

366

Long Term Surface Salinity Measurements  

NASA Technical Reports Server (NTRS)

Our long-term goal is to establish a reliable system for monitoring surface salinity around the global ocean. Salinity is a strong indicator of the freshwater cycle and has a great influence on upper ocean stratification. Global salinity measurements have potential to improve climate forecasts if an observation system can be developed. This project is developing a new internal field conductivity cell that can be protected from biological fouling for two years. Combined with a temperature sensor, this foul-proof cell can be deployed widely on surface drifters. A reliable in-situ network of surface salinity sensors will be an important adjunct to the salinity sensing satellite AQUARIUS to be deployed by NASA in 2009. A new internal-field conductivity cell has been developed by N Brown, along with new electronics. This sensor system has been combined with a temperature sensor to make a conductivity - temperature (UT) sensor suitable for deployment on drifters. The basic sensor concepts have been proven on a high resolution CTD. A simpler (lower cost) circuit has been built for this application. A protection mechanism for the conductivity cell that includes antifouling protection has also been designed and built. Mr. A.Walsh of our commercial partner E-Paint has designed and delivered time-release formulations of antifoulants for our application. Mr. G. Williams of partner Clearwater Instrumentation advised on power and communication issues and supplied surface drifters for testing.

Schmitt, Raymond W.; Brown, Neil L.

2005-01-01

367

Examining Long-Term Global Climate Change on the Web.  

ERIC Educational Resources Information Center

Describes a web-based, inquiry-oriented activity that enables students to examine long-term global climate change. Supports instruction in other topics such as population growth. (Contains 34 references.) (DDR)

Huntoon, Jacqueline E.; Ridky, Robert K.

2002-01-01

368

Long term evolution of photogravitational N-body problem  

NASA Astrophysics Data System (ADS)

Abstract: We consider Photogravitational N-body problem and find long term integration using symplectic map method. The first and higher order symplectic codes in CUDA C are used for long term evolution for fix and variable time steps in High Performance Computing(HPC) Workstation with an NVIDIA Tesla K20 C Graphics Processing Unit(GPU). It is seen that error in total energy remains bounded for long time, whereas, variable time steps take less number of steps for integration which increases the performance. We also obtain long term evolution of our inner and outer solar systems by taking actual initial conditions (masses, positions and velocities) and found that whole solar systems is chaotic. Keywords: Photogravitational; N-Body Problem; Symplectic map;CUDA C; GPU; HPC.

Kushvah, Badam Singh

369

NMDA Receptor-Dependent Long-Term Potentiation and Long-Term Depression (LTP/LTD)  

PubMed Central

Long-term potentiation and long-term depression (LTP/LTD) can be elicited by activating N-methyl-d-aspartate (NMDA)-type glutamate receptors, typically by the coincident activity of pre- and postsynaptic neurons. The early phases of expression are mediated by a redistribution of AMPA-type glutamate receptors: More receptors are added to potentiate the synapse or receptors are removed to weaken synapses. With time, structural changes become apparent, which in general require the synthesis of new proteins. The investigation of the molecular and cellular mechanisms underlying these forms of synaptic plasticity has received much attention, because NMDA receptor–dependent LTP and LTD may constitute cellular substrates of learning and memory. PMID:22510460

Luscher, Christian; Malenka, Robert C.

2012-01-01

370

Long-Term Changes in Physical Activity Following a One-Year Home-Based Physical Activity Counseling Program in Older Adults with Multiple Morbidities  

PubMed Central

This study assessed the sustained effect of a physical activity (PA) counseling intervention on PA one year after intervention, predictors of sustained PA participation, and three classes of post-intervention PA trajectories (improvers, maintainers, and decliners) in 238 older Veterans. Declines in minutes of PA from 12 to 24 months were observed for both the treatment and control arms of the study. PA at 12 months was the strongest predictor of post-intervention changes in PA. To our surprise, those who took up the intervention and increased PA levels the most, had significant declines in post-intervention PA. Analysis of the three post-intervention PA trajectories demonstrated that the maintenance group actually reflected a group of nonresponders to the intervention who had more comorbidities, lower self-efficacy, and worse physical function than the improvers or decliners. Results suggest that behavioral counseling/support must be ongoing to promote maintenance. Strategies to promote PA appropriately to subgroups of individuals are needed. PMID:21234104

Hall, Katherine S.; Sloane, Richard; Pieper, Carl F.; Peterson, Matthew J.; Crowley, Gail M.; Cowper, Patricia A.; McConnell, Eleanor S.; Bosworth, Hayden B.; Ekelund, Carola C.; Morey, Miriam C.

2011-01-01

371

A long-term solution to fossil fuel depletion  

Microsoft Academic Search

It is argued that the only long-term practical alternative to sustaining a national economy on organic fuels is to convert a major source of continuously renewable nonfossil carbon to synfuels that are interchangeable with fossil fuels. The most promising source of this carbon is land- and water-based biomass produced from solar energy by photosynthesis. This paper presents an assessment of

D. L. Klass

1976-01-01

372

Search for long term variations of the interplanetary magnetic field  

Microsoft Academic Search

A statistical study is made of the long term variations of the interplanetary magnetic field parameters collected in the years 1964 to 1973 by 12 spacecraft (IMP's, Pioneers and HEOS). Although temporal fluctuations are observed on field components and magnitudes no clear solar cycle variation is found. The same conclusion holds for the statistical distributions and variances of these parameters.

F. Mariani; L. Diodato; G. Moreno

1975-01-01

373

The fall and rise of V854 Centauri: long-term ultraviolet spectroscopy of a highly-active R Coronae Borealis star  

E-print Network

We examine long-term low-dispersion IUE, SWP and LWP spectroscopy of the R Coronae Borealis (RCB) star V854 Cen, obtained across the deep 1991, 1992-1993 and 1994 declines. We also report the optical light curve for the star in the interval 1987-1998, including multi-color photometry obtained during 1989-1998. Analysis of the UV emission line spectra indicates most lines decay during the deep declines on characteristic timescales comparable to that reported for optical features. Fe, Mg and neutral C lines decay on timescales of typically 50-100 d. Other lines, notably ionized C lines, decay on longer timescales (> 200 d) or appear to be unaffected by the declines. The general nature of the UV emission lines and other UV features during the declines is consistent with the E1/E2/BL line-region model developed from the behavior of optical spectral features during declines. However, the detailed line-behavior indicates large intrinsic variability between decline events inconsistent with the simple E1/E2/BL model. Limited temporal coverage prevents detailed examination of the geometry of the emission line region or the obscuring dust. We also report the first detection of the transition-region line C IV 1550 in the spectrum of an RCB star.

W. A. Lawson

1999-05-15

374

The fall and rise of V854 Centauri long-term ultraviolet spectroscopy of a highly-active R Coronae Borealis star  

E-print Network

We examine long-term low-dispersion IUE, SWP and LWP spectroscopy of the R Coronae Borealis (RCB) star V854 Cen, obtained across the deep 1991, 1992-1993 and 1994 declines. We also report the optical light curve for the star in the interval 1987-1998, including multi-color photometry obtained during 1989-1998. Analysis of the UV emission line spectra indicates most lines decay during the deep declines on characteristic timescales comparable to that reported for optical features. Fe, Mg and neutral C lines decay on timescales of typically 50-100 d. Other lines, notably ionized C lines, decay on longer timescales (> 200 d) or appear to be unaffected by the declines. The general nature of the UV emission lines and other UV features during the declines is consistent with the E1/E2/BL line-region model developed from the behavior of optical spectral features during declines. However, the detailed line-behavior indicates large intrinsic variability between decline events inconsistent with the simple E1/E2/BL model....

Lawson, W A; Clayton, G C; Valencic, L A; Jones, A F; Kilkenny, J D; Van Wyk, C J; Roberts, G; Marang, F

1999-01-01

375

The neuronal response at extended timescales: long-term correlations without long-term memory  

PubMed Central

Long term temporal correlations frequently appear at many levels of neural activity. We show that when such correlations appear in isolated neurons, they indicate the existence of slow underlying processes and lead to explicit conditions on the dynamics of these processes. Moreover, although these slow processes can potentially store information for long times, we demonstrate that this does not imply that the neuron possesses a long memory of its input, even if these processes are bidirectionally coupled with neuronal response. We derive these results for a broad class of biophysical neuron models, and then fit a specific model to recent experiments. The model reproduces the experimental results, exhibiting long term (days-long) correlations due to the interaction between slow variables and internal fluctuations. However, its memory of the input decays on a timescale of minutes. We suggest experiments to test these predictions directly. PMID:24744724

Soudry, Daniel; Meir, Ron

2014-01-01

376

Effects of Long-Term Acid-Mine Drainage Contamination on Diversity and Activity of Sulfate-Reducing Bacteria in a Natural Salt Marsh.  

NASA Astrophysics Data System (ADS)

Constructed wetlands have been studied as sites or analogs for in situ bioremediation of metal contaminants from acid mine drainage (AMD) or industrial sources (e.g. Webb et al. 1998). Wetlands bioremediation necessarily invokes the ubiquity and robustness of sulfate-reducing bacteria (SRB) to sequester dissolved metals into various poorly soluble metal-sulfides (e.g. PbS, CdS). However, few studies of natural wetlands under long-term ecological forcing by AMD or other contaminant sources are available for context. We are investigating the microbial diversity, mineralogy and geochemistry of a highly contaminated salt marsh along the East Central San Francisco Bay. For nearly a half-century, areas within this marsh have received acidic and/or metal-rich groundwaters from near-surface pyrite tailings (transported there from Iron Mountain Mine, near Redding, CA) and local industrial sources (e.g. paint and explosives manufacturers). Sediment cores (30-40 cm long) were taken from six contaminated sites in the marsh with pH range of ˜2 to ˜8. Previous analyses (URS Corp. 2001) reported As, Cd, Cu, Se, Zn, and Pb present in sediments at extremely high concentrations (100s of ppm), yet our ICP-AES analyses of pore waters showed only As present at concentrations of 10-50 ppb. We infer, from high-resolution transmission electron microscope (HRTEM) studies of biogenic (SRB biofilm) ZnS (Moreau et al. 2003, in review) and marsh sediments, that contaminant metals have been sequestered into aggregates of nanocrystalline metal-sulfides. Continuous-flow isotope ratio mass spectrometer (CF-IRMS) analyses of pore-water sulfate and sedimentary sulfides allow resolution of contributions to dissolved sulfate and sulfide from tailings oxidation and dissimilatory sulfate reduction. Sulfate analyses from subsections of three cores (pH 2-3, 6-7, 7-8, respectively) all yield ? 34S values consistent with bacterial sulfate reduction. We note that all three cores also contain very fine-grained black muds that are distinguishable from coarser pyrite cinders, and exhibit a noticeably strong sulfide odor. Aero- and halo-tolerant SRB were enriched from circumneutral pH cores, and we hypothesize that acido-tolerant SRB may also be present. Analysis of restriction fragment length polymorphism of whole community 16S rDNA extracted from each core shows an expected increase in diversity between acidic and circumneutal sediments, and clone libraries from both contaminated and uncontaminated marsh sediments are being compared to assess the impact of long-term contamination. References: Webb et al. 1998, J. Appl. Microbio., 84, 240-248; Moreau et al. 2003, Amer. Min., in review; URS Corp. 2001, Report 51.09967067.00.

Moreau, J. W.; Banfield, J. F.

2003-12-01

377

Exposure to Ionizing Radiation Causes Long-Term Increase in Serum Estradiol and Activation of PI3K-Akt Signaling Pathway in Mouse Mammary Gland  

SciTech Connect

Purpose: Exposure to ionizing radiation is an established risk factor for breast cancer. Radiation exposure during infancy, childhood, and adolescence confers the highest risk. Although radiation is a proven mammary carcinogen, it remains unclear where it acts in the complex multistage process of breast cancer development. In this study, we investigated the long-term pathophysiologic effects of ionizing radiation at a dose (2 Gy) relevant to fractionated radiotherapy. Methods and Materials: Adolescent (6-8 weeks old; n = 10) female C57BL/6J mice were exposed to 2 Gy total body {gamma}-radiation, the mammary glands were surgically removed, and serum and urine samples were collected 2 and 12 months after exposure. Molecular pathways involving estrogen receptor-{alpha} (ER{alpha}) and phosphatidylinositol-3-OH kinase (PI3K)-Akt signaling were investigated by immunohistochemistry and Western blot. Results: Serum estrogen and urinary levels of the oncogenic estrogen metabolite (16{alpha}OHE1) were significantly increased in irradiated animals. Immunostaining for the cellular proliferative marker Ki-67 and cyclin-D1 showed increased nuclear accumulation in sections of mammary glands from irradiated vs. control mice. Marked increase in p85{alpha}, a regulatory sub-unit of the PI3K was associated with increase in Akt, phospho-Akt, phospho-BAD, phospho-mTOR, and c-Myc in irradiated samples. Persistent increase in nuclear ER{alpha} in mammary tissues 2 and 12 months after radiation exposure was also observed. Conclusions: Taken together, our data not only support epidemiologic observations associating radiation and breast cancer but also, specify molecular events that could be involved in radiation-induced breast cancer.

Suman, Shubhankar [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, DC (United States)] [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, DC (United States); Johnson, Michael D. [Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC (United States)] [Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC (United States); Fornace, Albert J. [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, DC (United States) [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, DC (United States); Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC (United States); Datta, Kamal, E-mail: kd257@georgetown.edu [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, DC (United States)] [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, DC (United States)

2012-10-01

378

Long-term kidney transplant survival  

Microsoft Academic Search

With improvements in short-term kidney graft survival, focus has shifted towards long-term survival. There has also been a substantial improvement in long-term survival as measured by kidney half-life. Long-term graft failure is secondary to chronic allograft nephropathy (CAN), recurrent disease, and death with a functioning graft. CAN is secondary to a combination of chronic rejection, chronic cyclosporine toxicity, and\\/or donor

Sundaram Hariharan

2001-01-01

379

National Nuclear Security Administration Service Center Environmental Programs. Long Term Environmental Stewardship Baseline Handbook.  

National Technical Information Service (NTIS)

As environmental restoration (ER) projects move toward completion, the planning, integration, and documentation of long-term environmental stewardship (LTES) activities is increasingly important for ensuring smooth transition to LTES. The Long-Term Enviro...

D. D. Grisworld, K. Rohde

2003-01-01

380

Correlation of Far Ultraviolet Lunar Albedo with Solar Activity  

NASA Technical Reports Server (NTRS)

We present a correlative analysis between the variability of the lunar albedo in the far ultraviolet wavelength range (130- 190 nm) and various solar activity indices for a two-week period. We also report lunar albedo measurements in four separate wavelength ranges, corresponding to four filters on the Polar Ultraviolet Imager. To our knowledge this is the first reported long term measurements of the lunar albedo in this wavelength range.

Maddox, Will; Spann, James F.; Germany, Glynn

2004-01-01

381

Long-term correlations in earth sciences  

NASA Astrophysics Data System (ADS)

In this article we review the occurrence and consequences of long-term memory in geophysical records like climate and seismic records, and describe similarities with financial data sets. We review several methods to detect linear and nonlinear long-term correlations, also in the presence of external trends, and show how external trends can be detected in data with long-term memory. We show as well that long-term correlations lead to a natural clustering of extreme events and discuss the implications for several geophysical data sets.

Bunde, Armin; Lennartz, Sabine

2012-06-01

382

Effects of Coronal Mass Ejections on the Long Term Cosmic Ray Modulation  

NASA Astrophysics Data System (ADS)

Recently we have proposed that the long term solar modulation of galactic cosmic rays (CR) is influenced by coronal mass eyection (CME) activity. In this work, we analyze the effect of CMEs number and latitudinal changes on the CR flux during positive and negative magnetic cycles. For CME data, we use both, recent observations by the Large Angle and Spectrometric Coronagraph (LASCO) experiment on board of SOHO and past observations by Solar Maximum Mission (SMM) and Solarwind spacecrafts. For CR we use data from IMP-8 and Voyager 1/2 spacecrafts. We discuss our results in terms of the magnetic irregularities transported by CMEs in to the heliosphere.

Lara, Alejandro; Caballero-López, Rogelio

383

A search for long-term periodicities in large earthquakes of southern and coastal central California  

SciTech Connect

It has been occasionally suggested that large earthquakes may follow the 8.85-year and 18.6-year lunar-solar tidal cycles and possibly the {approximately} 11-year solar activity cycle. From a new study of earthquakes with magnitudes {ge} 5.5 in southern and coastal central California during the years 1855-1983, it is concluded that, at least in this selected area of the world, no statistically significant long-term periodicities in earthquake frequency occur. The sample size used is about twice that used in comparable earlier studies of this region which concentrated on large earthquakes.

Stothers, R.B. (NASA, Goddard Space Flight Center, Greenbelt, MD (USA))

1990-10-01

384

A search for long-term periodicities in large earthquakes of southern and coastal central California  

NASA Technical Reports Server (NTRS)

It has been occasionally suggested that large earthquakes may follow the 8.85-year and 18.6-year lunar-solar tidal cycles and possibly the approximately 11-year solar activity cycle. From a new study of earthquakes with magnitudes greater than 5.5 in southern and coastal central California during the years 1855-1983, it is concluded that, at least in this selected area of the world, no statistically significant long-term periodicities in earthquake frequency occur. The sample size used is about twice that used in comparable earlier studies of this region, which concentrated on large earthquakes.

Stothers, Richard B.

1990-01-01

385

Solar activity and transformer failures in the Greek national electric grid  

NASA Astrophysics Data System (ADS)

Aims: We study both the short term and long term effects of solar activity on the large transformers (150 kV and 400 kV) of the Greek national electric grid. Methods: We use data analysis and various statistical methods and models. Results: Contrary to 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 summarised 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 (GICs). Explicit cases are briefly presented. For the long term effects, again for the same period 1989-2010, we have two main results: The annual number of transformer failures seems to follow the solar activity pattern. Yet the maximum number of transformer failures occurs about half a solar cycle 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 the geomagnetic station 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.

Panayiotis Zois, Ioannis

2013-11-01

386

Grand minima and maxima of solar activity: New observational constraints  

E-print Network

Using a reconstruction of sunspot numbers stretching over multiple millennia, we analyze the statistics of the occurrence of grand minima and maxima and set new observational constraints on long-term solar and stellar dynamo models. We present an updated reconstruction of sunspot number over multiple millennia, from $^{14}$C data by means of a physics-based model, using an updated model of the evolution of the solar open magnetic flux. A list of grand minima and maxima of solar activity is presented for the Holocene (since 9500 BC) and the statistics of both the length of individual events as well as the waiting time between them are analyzed. The occurrence of grand minima/maxima is driven not by long-term cyclic variability, but by a stochastic/chaotic process. The waiting time distribution of the occurrence of grand minima/maxima deviates from an exponential distribution, implying that these events tend to cluster together with long event-free periods between the clusters. Two different types of grand minima are observed: short (30--90 years) minima of Maunder type and long ($>$110 years) minima of Sp\\"orer type, implying that a deterministic behaviour of the dynamo during a grand minimum defines its length. The duration of grand maxima follows an exponential distribution, suggesting that the duration of a grand maximum is determined by a random process. These results set new observational constraints upon the long-term behaviour of the solar dynamo.

I. G. Usoskin; S. K. Solanki; G. A. Kovaltsov

2007-06-04

387

PKA-activated ApAF-ApC/EBP heterodimer is a key downstream effector of ApCREB and is necessary and sufficient for the consolidation of long-term facilitation  

PubMed Central

Long-term memory requires transcriptional regulation by a combination of positive and negative transcription factors. Aplysia activating factor (ApAF) is known to be a positive transcription factor that forms heterodimers with ApC/EBP and ApCREB2. How these heterodimers are regulated and how they participate in the consolidation of long-term facilitation (LTF) has not, however, been characterized. We found that the functional activation of ApAF required phosphorylation of ApAF by PKA on Ser-266. In addition, ApAF lowered the threshold of LTF by forming a heterodimer with ApCREB2. Moreover, once activated by PKA, the ApAF–ApC/EBP heterodimer transactivates enhancer response element–containing genes and can induce LTF in the absence of CRE- and CREB-mediated gene expression. Collectively, these results suggest that PKA-activated ApAF–ApC/EBP heterodimer is a core downstream effector of ApCREB in the consolidation of LTF. PMID:16966424

Lee, Jin-A; Lee, Sue-Hyun; Lee, Changhoon; Chang, Deok-Jin; Lee, Yong; Kim, Hyoung; Cheang, Ye-Hwang; Ko, Hyoung-Gon; Lee, Yong-Seok; Jun, Heejung; Bartsch, Dusan; Kandel, Eric R.; Kaang, Bong-Kiun

2006-01-01

388

Common Calibration Source for Monitoring Long-term Ozone Trends  

NASA Technical Reports Server (NTRS)

Accurate long-term satellite measurements are crucial for monitoring the recovery of the ozone layer. The slow pace of the recovery and limited lifetimes of satellite monitoring instruments demands that datasets from multiple observation systems be combined to provide the long-term accuracy needed. A fundamental component of accurately monitoring long-term trends is the calibration of these various instruments. NASA s Radiometric Calibration and Development Facility at the Goddard Space Flight Center has provided resources to minimize calibration biases between multiple instruments through the use of a common calibration source and standardized procedures traceable to national standards. The Facility s 50 cm barium sulfate integrating sphere has been used as a common calibration source for both US and international satellite instruments, including the Total Ozone Mapping Spectrometer (TOMS), Solar Backscatter Ultraviolet 2 (SBUV/2) instruments, Shuttle SBUV (SSBUV), Ozone Mapping Instrument (OMI), Global Ozone Monitoring Experiment (GOME) (ESA), Scanning Imaging SpectroMeter for Atmospheric ChartographY (SCIAMACHY) (ESA), and others. We will discuss the advantages of using a common calibration source and its effects on long-term ozone data sets. In addition, sphere calibration results from various instruments will be presented to demonstrate the accuracy of the long-term characterization of the source itself.

Kowalewski, Matthew

2004-01-01

389

Long-Term Care Ombudsman Program  

MedlinePLUS

Long-Term Care Ombudsman Program (OAA, Title VII, Chapter 2, Sections 711/712) The Purpose of the Program and How it ... Services Provided to Persons Living in Long-Term Care Facilities Program data for FY 2011 indicate that ...

390

Referral from primary care to a physical activity programme: establishing long-term adherence? A randomized controlled trial. Rationale and study design  

Microsoft Academic Search

BACKGROUND: Declining physical activity is associated with a rising burden of global disease. There is little evidence about effective ways to increase adherence to physical activity. Therefore, interventions are needed that produce sustained increases in adherence to physical activity and are cost-effective. The purpose is to assess the effectiveness of a primary care physical activity intervention in increasing adherence to

Maria Giné-Garriga; Carme Martin; Carlos Martín; Anna Puig-Ribera; Juan José Antón; Agustí Guiu; Ana Cascos; Rafel Ramos

2009-01-01

391

The Permanent Seismo-Acoustic-Thermal Station at the Summit of Stromboli: Insights Into the Long-Term Dynamics of Explosive Activity  

Microsoft Academic Search

Stromboli volcano is characterized by a persistent, moderately explosive activity. This behavior is interrupted once or twice a year by stroger explosions that present a serious risk to turists who gather to watch the activity. Simultaneous thermal, infrasonic and seismic measurements have revealed strong temporal links between variations in degassing and explosive activity. These results indicate that degassing, and thus

M. Ripepe; A. J. Harris; D. A. Rothery; E. Marchetti

2002-01-01

392

Intracellular thiols and photo-illumination sequentially activate doubly locked molecular probes for long-term cell highlighting and tracking with precise spatial accuracy.  

PubMed

A novel photoconvertible fluorescent probe, which can be activated by intracellular thiols, has been synthesized. Such a molecular probe comprises three parts: a 7-aminocoumarin phototrigger, a thiol-removable energy acceptor, and a caged fluorescein scaffold with intracellular thiols reactivity as the fluorescent reporter. Extracellularly, the energy acceptor blocks the emission of the coumarin that regulates the photocleavage and photoactivation of the fluorescein. Intracelluarly, the high concentration of thiols releases the energy acceptor, thus activating the S1 state of the phototrigger, which emits coumarin blue fluorescence for pre-visualization and liberates the caged green-fluorescent fluorescein to highlight the specific cell upon illumination. Compared to traditional photoactivated organic dyes, the intracellular thiols activated probe requires double activations: one by intracellular thiols and the other by light activation. The dual activations restrict fluorescence precisely inside live cells and at the particular spatial region of light activation, thus a probe with precise spatial accuracy in live cells. PMID:25308070

Lin, Qiuning; Du, Zengmin; Yang, Yunlong; Fang, Qian; Bao, Chunyan; Yang, Yi; Zhu, Linyong

2014-12-01

393

Stratospheric ozone, solar activity and volcanism  

NASA Astrophysics Data System (ADS)

The aim of this study is to investigate the long-term (multiannual) variations of the total ozone content (TOC) on the base of TOMS instrument measurements on the board of Nimbus-7 satellite for the period 1979 -- 1993 AD. The total effects of the solar activity influence over stratosphere ozone has been investigated by using multiple regression analysis. The monthly radio-index F10.7, the cosmic rays neutron flux, the geomagnetic index Ap and the number of GOES x-ray X-class flares have been used as solar or solar-modulated parameters as predictors in the model. The global mean-monthly TOC-parameter has been used as a predictant. It has been found that the coefficient of correlation of the model between TOC and above-mentioned solar and geomagnetic factors is about 0.544. Thus the corresponding factor variance is about 37%. The results calculated by the model have been removed from the original TOC data. It has been found out that during the first 12 years since 1979 the downward trend is predominantly caused by the solar and solar-modulated processes. However during the remaining 3 years after 1990 the slope of the negative trend has been essentially increased. This phenomenon could only be explained by some catastrophic event. Most probably such one is the Pinatubo volcano eruption in June, 1991. An evidence for the possibility that the last one is caused by trigger effect from the extremely high solar flare activity in May -- June 1991, is given.

Komitov, Boris; Stoychev, Konstantin