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1

Long-term ionospheric cooling: Dependency on local time, season, solar activity, and geomagnetic activity  

NASA Astrophysics Data System (ADS)

Ionospheric ion temperature Ti is an excellent approximation to neutral temperature Tn in the thermosphere, especially for altitudes below 300 km. This analysis of long?term Ti trends in the F region over different local times is based on a database of incoherent scatter radar (ISR) observations spanning more than three solar cycles during 1968-2006 at Millstone Hill and represents an extended effort to a prior study focusing on noon?time only. This study provides important information for understanding the difference between the ISR and other results. A gross average of the Ti trend at heights of Ti ˜ Tn (200-350 km) is ˜ -4 K/decade, a cooling trend close to the Tn estimation based on the satellite neutral density data. However, there exists considerable variability in the cooling: it is strong during the day and very weak during the night with a large apparent warming at low altitudes (200-350 km); it is strong at solar minimum for both daytime and nighttime. The strongest cooling for altitudes below 375 km occurs around 90-120 solar flux units of the 10.7 cm solar flux, not at the lowest solar flux. There appears more cooling toward high magnetic activity, but this dependency is very weak. No consistent and substantial seasonal dependency across different heights was found. We speculate that a fraction of the observed cooling trend may be contributed by a gradual shifting away from the sub?auroral region at Millstone Hill, as part of the secular change in the Earth's magnetic field. In this 39 year long series of data record, two anomalous Ti drops were noticed, and we speculate on their connection to volcano eruptions in 1982 and 1991.

Zhang, Shun-Rong; Holt, John M.

2013-06-01

2

Long-term trends in the ionospheric F2 region with different solar activity indices  

NASA Astrophysics Data System (ADS)

A new comprehensive data collection by Damboldt and Suessmann (2012a) with monthly foF2 and M(3000)F2 median values is an excellent basis for the derivation of long-term trends in the ionospheric F2 region. Ionospheric trends have been derived only for stations with data series of at least 22 years (124 stations with foF2 data and 113 stations with M(3000)F2 data) using a twofold regression analysis depending on solar and geomagnetic activity. Three main results have been derived: Firstly, it could be shown that the solar 10.7 cm radio flux F10.7 is a better index for the description of the solar activity than the relative solar sunspot number R as well as the solar EUV proxy E10.7. Secondly, the global mean foF2 and hmF2 trends derived for the interval between 1948 and 2006 are in surprisingly good agreement with model calculations of an increasing atmospheric greenhouse effect (Rishbeth and Roble, 1992). Thirdly, during the years 2007 until 2009, the hmF2 values and to a smaller amount the foF2 values strongly decrease. The reason for this effect is a reduction of the thermospheric density and ionization due to a markedly reduced solar EUV irradiation and extremely small geomagnetic activity during the solar cycle 23/24 minimum.

Mielich, J.; Bremer, J.

2013-02-01

3

Long-term variations of the coronal rotation and solar activity  

NASA Astrophysics Data System (ADS)

Recently, Chandra and Vats have obtained the yearly period length of the solar coronal rotation cycle by analysing the daily adjusted solar radio flux at the 10.7-cm wavelength for the years 1947-2009. In this paper, we use the time series (series I) of the yearly period length to investigate the long-term variation of the rotation of radio emission corona, and we find a weak decreasing trend in the time series. We use the empirical mode decomposition to decompose both the yearly mean value (series II) of the solar radio flux at the 10.7-cm wavelength and series I into different periodical components. There is a secular trend for each of the two series, and we find a negative correlation in the two trends. The decomposed 11-yr-cycle components of the two series show different and complicated periods and there is a phase relation between them. We investigate the cycle-related variation of the coronal rotation length, and we find that there is no Schwable cycle of statistical significance for the long-term variation of the rotation cycle length.

Li, K. J.; Shi, X. J.; Feng, W.; Xie, J. L.; Gao, P. X.; Zhan, L. S.; Liang, H. F.

2012-07-01

4

Magnetic activity of six young solar analogues II. Surface Differential Rotation from long-term photometry  

NASA Astrophysics Data System (ADS)

The present paper is the second of a series dedicated to the study of the magnetic activity in a selected sample of young solar analogues. The sample includes five single G0-G5V stars with ages between =~ 130 Myr and 700 Myr: EK Dra, pi 1 UMa, HN Peg, k1 Cet and BE Cet. In this study we also include the Pleiades-age ( =~ 130 Myr) K0V star DX Leo. Our analysis is based on high precision photometric observations carried out as part of The Sun in Time project, aimed at a multiwavelength study of stars with solar-like global properties, but with different ages and thus at different stages of evolution. In the first paper of this series we presented the photometric observations and determined the existence of starspot cycles and their correlation with the global stellar properties. In the present paper we investigate the surface differential rotation (SDR). The periodogram analysis of the photometric data time series has allowed us to determine the rotational periods and to derive the following results: i) all the selected stars show variations of the rotational period. Such variations are definitely periodic and in phase with the starspot cycle for BE Cet and DX Leo. They are likely periodic and in phase also for pi 1 UMa, EK Dra and HN Peg, but still need confirmation. By analogy with the solar butterfly diagram, the rotational period variations are interpretable in terms of surface differential rotation, that is, they are attributable to the existence of active latitude belts migrating during the activity cycle on a differentially rotating star; ii) BE Cet, pi 1 UMa and EK Dra show a solar-like pattern of SDR, that is the rotational period steadily decreases along the activity cycle, jumping back to higher values at the beginning of the next cycle; on the contrary, DX Leo, k1 Cet and HN Peg show an antisolar pattern; iii) the amplitude of the rotational period variations shows a power law dependence on the rotational period similar to that found in previous studies. Contrary to theoretical predictions, the cycle length is not correlated to the Dynamo number, it is indeed positively correlated to the SDR amplitude. More precisely, stars tend to concentrate along three different branches with the cycle length increasing with increasing Delta Omega /Omega . Moreover, we found that the SDR amplitude changes from cycle to cycle, which is reminiscent of a wave of excess rotation propagating in latitude; iiii) the apparently different solar and antisolar behaviours are probably due to different inclinations of the stellar rotation axis under which the star is seen. The long-term photometry of the young single star LQ Hya, although not included in the initial project, is also used in the present analysis to enlarge the investigated sample. We determined for LQ Hya three different starspot cycles and an antisolar pattern of SDR.

Messina, S.; Guinan, E. F.

2003-10-01

5

Long term variability in solar wind velocity and IMF intensity and the relationship between solar wind parameters & geomagnetic activity  

Microsoft Academic Search

A study is carried out on the mean monthly values of in situ observations of solar wind velocity (V) and the intensity of interplanetary magnetic field, Bto elucidate their long term variations using the technique of singular spectrum analysis. It is shown that Bexhibits a clear solar cycle signal with progressively deepening minimum and a well-defined longer period variation but

G. K. Rangarajan; L. M. Barreto

2000-01-01

6

Long term variability in solar wind velocity and IMF intensity and the relationship between solar wind parameters & geomagnetic activity  

Microsoft Academic Search

A study is carried out on the mean monthly values of in situ observations of solar wind velocity ( V ) and the intensity of interplanetary magnetic field, B to elucidate their long term variations using the technique of singular spectrum analysis. It is shown that B exhibits a clear solar cycle signal with progressively deepening minimum and a well-defined

G. K. Rangarajan; L. M. Barreto

2000-01-01

7

Long-term solar-terrestrial observations.  

National Technical Information Service (NTIS)

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-ter...

1988-01-01

8

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

Microsoft Academic Search

Six-month and yearly averages of solar wind speed from 1962 to 1975 are shown to be highly correlated with geomagnetic activity as measured by averages of the AP index. On the same time scale the correlation between the southward component of the interplanetary magnetic field and geomagnetic activity is poor. Previous studies with hourly averages give opposite results. The better

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

1977-01-01

9

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

NASA Astrophysics Data System (ADS)

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

Mehravani Behrouz, Masoud; Ajabshirizadeh, Ali

10

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

Microsoft Academic Search

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

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

1999-01-01

11

The role of energy exchange between the eddies and the mean flow for the long-term modulation of the solar activity  

NASA Astrophysics Data System (ADS)

The variability of the magnetic features observed in the outer layers of the solar atmosphere is determined by the energetic coupling between the circulation in the convection zone and the solar magnetic field. The 11-year cycle variability is remarkable and was identified few cycles after systematic telescopic observations of sunspots became available. These quasi-periodic oscillations are registered in several parameters such as the total solar irradiance, which is the main external source of energy of the highly coupled Earth's atmospheric/oceanic system. The long-term evolution of the solar activity is also clearly observed in direct and indirect proxies of the solar activity. Periods of low (grand minima) and high (grand maxima) solar activity occurred during the Holocene. However, the precise mechanism that drives the long-term evolution of the solar activity is unknown. Here we show that large storms at the bottom of the convection zone can drive the long-term evolution of the solar activity. We found that the exchange of energy between the mean flow and perturbations of the velocity fields imposed by large cyclonic/anti-cyclonic activity at the bottom of the convection zone is mapped to the outer layers of the solar atmosphere. We anticipate that the relationships found will allow us to model the long-term evolution of the solar cycle activity through the Holocene. We point out that this mechanism requires much less energy them the one based on changes of the meridional circulation. This approach will also help us to constrain the long-term evolution of key solar cycle parameters that are employed to model the long-term evolution of the total and spectral solar irradiance, which are needed to untangle the natural and anthropogenic drivers of the present climate change.

Vieira, L. A.; Dudok de Wit, T.; Da Silva, L. A.

2011-12-01

12

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

NASA Astrophysics Data System (ADS)

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

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

2009-09-01

13

Long-Term Solar Irradiance Variability: 1984-1989 Observations.  

National Technical Information Service (NTIS)

Long-term variability in the total solar irradiance has been observed in the Earth Radiation Budget Experiment (ERBE) solar monitor measurements. The monitors have been used to measure the irradiance from the Earth Radiation Budget Satellite (ERBS) and th...

R. B. Lee

1990-01-01

14

Long-term reconstructions of total solar irradiance  

NASA Astrophysics Data System (ADS)

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

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

2012-07-01

15

Going Solar Yields Long-Term Economical, Educational Benefits  

ERIC Educational Resources Information Center

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

von Moos, Brian

2009-01-01

16

The Long-Term Hemispheric Sunspot Activity  

NASA Astrophysics Data System (ADS)

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

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

2009-01-01

17

Long-term storage of solar energy in native rock  

Microsoft Academic Search

Long-term storage (annual or seasonal storage) of solar-collected thermal energy in native rock or sandstone appears to be both technically feasible and economically attractive. In this storage concept, a large bed of crushed or naturally formed porous rock is heated by hot air flowing from a central manifold to two cold manifolds; on discharge, the flow is reversed and cold

M. Riaz

1978-01-01

18

Long-term solar activity and its implications to the heliosphere, geomagnetic activity, and the Earth's climate. Preface to the Special Issue on Space Climate  

NASA Astrophysics Data System (ADS)

The Sun's long-term magnetic variability is the primary driver of space climate. This variability is manifested not only in the long-observed and dramatic change of magnetic fields on the solar surface, but also in the changing solar radiative output across all wavelengths. The Sun's magnetic variability also modulates the particulate and magnetic fluxes in the heliosphere, which determine the interplanetary conditions and impose significant electromagnetic forces and effects upon planetary atmospheres. All these effects due to the changing solar magnetic fields are also relevant for planetary climates, including the climate of the Earth. The ultimate cause of solar variability, at time scales much shorter than stellar evolutionary time scales, i.e., at decadal to centennial and, maybe, even millennial or longer scales, has its origin in the solar dynamo mechanism. Therefore, in order to better understand the origin of space climate, one must analyze different proxies of solar magnetic variability and develop models of the solar dynamo mechanism that correctly produce the observed properties of the magnetic fields. This Preface summarizes the most important findings of the papers of this Special Issue, most of which were presented in the Space Climate-4 Symposium organized in 2011 in Goa, India.

Mursula, Kalevi; Manoharan, Periasamy; Nandy, Dibyendu; Tanskanen, Eija; Verronen, Pekka

2013-06-01

19

Solar cycle and long term variations of mesospheric ice layers  

NASA Astrophysics Data System (ADS)

Ice layers in the summer mesosphere at middle and polar latitudes, frequently called `noctilucent clouds' (NLC) or `polar mesosphere clouds'(PMC), are considered to be sensitive indicators of long term changes in the middle atmosphere. We present a summary of long term observations from the ground and from satellites and compare with results from the LIMA model (Leibniz Institute Middle Atmosphere Model). LIMA nicely reproduces mean conditions of the summer mesopause region and also mean characteristics of ice layers. LIMA nudges to ECMWF data in the troposphere and lower stratosphere which influences the background conditions in the mesosphere and thereby the morphology of ice clouds. A strong correlation between temperatures and PMC altitudes is observed. Applied to historical measurements this give s negligible temperature trends at PMC altitudes (approximately 0.01-0.02 K/y). Trace gas concentrations are kept constant in LIMA except for water vapor which is modified by variable solar radiation. Still, long term trends in temperatures and ice layer parameters are observed, consistent with observations. As will be shown, these trends originate in the stratosphere. Solar cycle effects are expected in ice layers due to variations in background temperatures and water paper. We will present results from LIMA regarding solar cycle variations and compare with NLC observations at our lidar stations in Kühlungsborn (54°N) and ALOMAR (69°N), and also with satellite measurements.

Lübken, Franz-Josef; Berger, Uwe; Kiliani, Johannes; Baumgarten, Gerd; Fiedler, Jens; Gerding, Michael

2010-05-01

20

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

21

Possible associations between long term anomalous geomagnetic variations, Vrancea (Romania) intermediate depths earthquakes and the solar activity for the last 15 years  

NASA Astrophysics Data System (ADS)

Geomagnetic variations associated with earthquakes are widely accepted and several anomalous geomagnetic observations have been interpreted as a result of changing rock magnetic properties under varying tectonic stress (piezomagnetic effect). During the last 15 years of geomagnetic investigations conducted in Vrancea seismogenic zone, period covering more than a complete solar cycle, the solar-terrestrial perturbations have fluctuated from very low to very large values, providing the ideal medium to observe the correlation between the long and short term geomagnetic field perturbations, solar activity and earthquakes. The October 2004 intermediate depth earthquake (Mw=6.0) offered us the opportunity to investigate possible connections between the local geomagnetic field behavior and the occurrence of moderate magnitude Vrancea earthquakes. The comparison between the geomagnetic data obtained at a station inside the epicentral zone with other remote reference stations (outside the epicenter) considers an effective technique to detect the anomalous variation of a lithospheric origin. The working data are: (i) the geomagnetic field records made at Muntele Rosu Observatory (MLR), Surlari (SUA) and/or Tihany (THY) INTERMAGNET Observatories; (ii) the seismic data for Vrancea source zone; (iii) the daily geomagnetic index from NOAA/Space Weather. The one minute and daily averaged geomagnetic data were calculated at these stations for the whole period 1996-2011. The geomagnetic components: X, Y (horizontal North-South and East-West) and Z (vertical) and the normalized vertical component (Bz/Bx and Bz/By) were used in the data analysis processes and also in the comparison of the geomagnetic data between the selected stations. Our results indicate the presence of long term anomalous variations (weeks or months) in the geomagnetic components and in the magnetic impedance at MLR Observatory (close to the epicenter) and no magnetic modifications in the SUA and THY recordings (far from the epicenter) preceding the occurrence of earthquakes with Mw>4.0. Moreover, in the periods of anomalous behavior, the geomagnetic components recorded at MLR show no correlation with those recorded at the other two stations, as they do in the rest of the time. The observed anomalous variations may be explained as a result of the tectonic stress variations and the enhancement of the lithospheric conductivity in the Vrancea region during the preparation period of earthquakes.

Moldovan, I. A.; Moldovan, A. S.; Placinta, A. O.; Takla, E. M.; Constantin, A. P.; Popescu, E.

2012-04-01

22

Long term evolution of super active regions  

NASA Astrophysics Data System (ADS)

In the solar cycle 23, there were some active regions (ARs) which produced energetic events, e.g. flares, CMEs, of unprecedented magnitudes during their disc passes, termed as super active regions (SARs). For example, NOAA 10486 stood unrivaled as it produced flares of unprecedented magnitude, such as X17/4B, X10/2B and X28 in quick succession. Occurrence of flares of such magnitude at this rate evidently requires extremely rapid energy buildup mechanism. Therefore, from their energetic considerations, these SARs are expected to possess distinctly different sup-photospheric flows as compared to less productive ARs. Study of such SARs is expected to provide important insights in our understanding of flare productivity, characterization of ARs, and in space-weather predictions. We derived sup-photospheric flows beneath these SARs using ring diagram technique, one of the local helioseismic techniques. We found strong and largely twisted sub-photospheric flows in the interior of SARs as compared to ARs. We present maps of sub-photospheric flows beneath some SARs and their evolution from one to next Carrington rotation.

Maurya, Ram Ajor

23

Long-term goals for solar thermal technology  

NASA Astrophysics Data System (ADS)

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

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

1985-05-01

24

Long-term goals for solar thermal technology  

SciTech Connect

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

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

1985-05-01

25

Montessori-Based Dementia Activities in Long-Term Care  

Microsoft Academic Search

This article describes Montessori-based activities for use with persons with dementia in long-term care settings. An overview of the Montessori method of education is presented, with emphasis on its application to geriatric populations. Individual and group activities are detailed, along with techniques for adapting Montessori materials and procedures for use in long-term care settings. A description is provided of training

Silvia Orsulic-Jeras; Nicole M. Schneider; Cameron J. Camp; Pam Nicholson; Michael Helbig

2001-01-01

26

The long-term variations of ozone, UV-radiation and temperature in tropostratosphere and their connection with solar variability  

Microsoft Academic Search

The long-term variations of the total column ozone amount, temperature in tropostratophere, UV-radiation above Kyrgyzstan and solar activity are analyzed. The deviations of monthly average meanings of UV-radiation from norm are presented, the anomaly periods are allocated. These data are analyzed for 22 and 23 cycles of 11-year solar activity. The parameters of solar activity such as the variations of

K. A. Karimov; R. D. Gainutdinova

2007-01-01

27

Experimental evidence for solar cycle and long-term change in the low-latitude MLT region  

Microsoft Academic Search

There is a great deal of interest in long-term change in the upper atmosphere and its possible relationship with human activities, but it is clear that we do not yet have a consistent picture of solar cycle and long-term trends in the MLT region. The long series of rocket measurements made from the early 1960s through to the mid-1990s, over

Barclay Clemesha; Hisao Takahashi; Dale Simonich; Delano Gobbi; Paulo Batista

2005-01-01

28

A repetitive day method for predicting the long-term thermal performance of passive solar buildings  

Microsoft Academic Search

The long-term thermal performance of passively-heated solar buildings is predicted by a single repetitive meteorological day which contains judiciously chosen solar radiation and ambient temperature functions. These are used as the driving functions of the governing equations that describe the passive solar building under study. The solar radiation and ambient temperature functions are chosen such that they include, both qualitatively

D. Feuermann

1990-01-01

29

Long-term perspective on the development of solar energy  

Microsoft Academic Search

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

Yacov Tsur; Amos Zemel

2000-01-01

30

Effects of solar and geomagnetic activity in long-term variations in the ionospheric parameters of the auroral zone in 1963-1986  

NASA Astrophysics Data System (ADS)

A stable linear relation between foF2 and W with a correlation coefficient of 0.68-0.96 has been revealed as a result of a joint analysis of the foF2 critical frequencies and the virtual minimal heights ( h’ F) obtained from the data of vertical sounding (VS) of the ionosphere at Dixon Island auroral station, Wolf numbers ( W), and PC geomagnetic index from 1963 to 1986. A significant linear relation exists between foF2 and the PC index with a correlation coefficient of r = 0.18-0.67. The correlation between the PC index and W is low in winter and autumn and is r = 0.50 and 0.74 at a significance level of ss = 0.96-0.99 in spring and summer. When the correlation between PC and foF2 is analyzed, it is necessary to consider the effect of solar activity (SA) on both parameters. The multiple correlation coefficients between these parameters have been calculated with regard to the effect of W. They were R = 0.75-0.98; however, the standardized regression coefficients ? W and ? PC indicated that W and PC considerably and insignificantly affect multiple correlation with foF2, respectively, and this effect depends on the season and time of day. It has been detected that the cyclic variations in foF2 and h’ F are asymmetric. The amplitudes of these parameters in cycle 20 are smaller than in cycle 21.

Vovk, V. Ya.; Egorova, L. V.

2010-08-01

31

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

NASA Astrophysics Data System (ADS)

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 to ozone variations. Some statistically significant long-term effects on mesospheric ozone were caused by the HOx increases due to a very active time period for SPEs (years 2000-2004), even though the HOx increases were short-lived (days). The long-term stratospheric ozone effects were caused by the NOy enhancements. Very large NOy enhancements lasted for months in the middle and lower stratosphere after a few of the largest SPEs. SPE-caused NOy increases computed with WACCM3 were statistically significant at the 95% level throughout much of the polar stratosphere and mesosphere in the recent solar maximum 5-year period (2000-2004). WACCM3-computed SPE-caused polar stratospheric ozone decreases of >10% continued for up to 5 months past the largest events; however, statistically significant ozone decreases were computed for only a relatively small fraction of this time in relatively limited altitudes in the lower mesosphere and upper stratosphere. Annually averaged model output showed statistically significant (to 95%) stratospheric ozone loss in the polar Northern Hemisphere for years 2000-2002. The computed annually averaged temperature and total ozone change in these years were not statistically significant.

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

2009-06-01

32

A new approach to the long-term reconstruction of the solar irradiance leads to large historical solar forcing  

NASA Astrophysics Data System (ADS)

Context. The variable Sun is the most likely candidate for the natural forcing of past climate changes on time scales of 50 to 1000 years. Evidence for this understanding is that the terrestrial climate correlates positively with the solar activity. During the past 10 000 years, the Sun has experienced the substantial variations in activity and there have been numerous attempts to reconstruct solar irradiance. While there is general agreement on how solar forcing varied during the last several hundred years - all reconstructions are proportional to the solar activity - there is scientific controversy on the magnitude of solar forcing. Aims: We present a reconstruction of the total and spectral solar irradiance covering 130 nm-10 ?m from 1610 to the present with an annual resolution and for the Holocene with a 22-year resolution. Methods: We assume that the minimum state of the quiet Sun in time corresponds to the observed quietest area on the present Sun. Then we use available long-term proxies of the solar activity, which are 10Be isotope concentrations in ice cores and 22-year smoothed neutron monitor data, to interpolate between the present quiet Sun and the minimum state of the quiet Sun. This determines the long-term trend in the solar variability, which is then superposed with the 11-year activity cycle calculated from the sunspot number. The time-dependent solar spectral irradiance from about 7000 BC to the present is then derived using a state-of-the-art radiation code. Results: We derive a total and spectral solar irradiance that was substantially lower during the Maunder minimum than the one observed today. The difference is remarkably larger than other estimations published in the recent literature. The magnitude of the solar UV variability, which indirectly affects the climate, is also found to exceed previous estimates.We discuss in detail the assumptions that lead us to this conclusion. Appendix is only available in electronic form at http://www.aanda.org

Shapiro, A. I.; Schmutz, W.; Rozanov, E.; Schoell, M.; Haberreiter, M.; Shapiro, A. V.; Nyeki, S.

2011-05-01

33

The long-term millimeter activity of active galactic nuclei  

NASA Astrophysics Data System (ADS)

We analyze the long-term evolution of the fluxes of six active galactic nuclei (AGN) - 0923+392, 3C 111, 3C 273, 3C 345, 3C 454.3, and 3C 84 - in the frequency range 80-267 GHz using archival calibration data of the IRAM Plateau de Bure Interferometer. Our dataset spans a long timeline of ?14 years with 974-3027 flux measurements per source. We find strong (factors ?2-8) flux variability on timescales of years for all sources. The flux density distributions of five out of six sources show clear signatures of bi- or even multimodality. Our sources show mostly steep (? ? 0.5-1), variable spectral indices that indicate outflow dominated emission; the variability is most probably due to optical depth variations. The power spectra globally correspond to red-noise spectra with five sources being located between the cases of white and flicker noise and one source (3C 111) being closer to the case of random walk noise. For three sources the low-frequency ends of their power spectra appear to be upscaled in spectral power by factors ?2-3 with respect to the overall powerlaws. In two sources, 3C 454.3 and 3C 84, the 1.3-mm emission preceeds the 3-mm emission by ?55 and ?300 days, respectively, probably due to (combinations of) optical depth and emission region geometry effects. We conclude that the source emission cannot be described by uniform stochastic emission processes; instead, a distinction of "quiescent" and (maybe multiple) "flare" states of the source emission appears to be necessary. This study is based on observations carried out with the IRAM Plateau de Bure Interferometer. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain).

Trippe, S.; Krips, M.; Piétu, V.; Neri, R.; Winters, J. M.; Gueth, F.; Bremer, M.; Salome, P.; Moreno, R.; Boissier, J.; Fontani, F.

2011-09-01

34

Long term storage of relativistic particles in the solar corona  

Microsoft Academic Search

A model is presented which shows that large numbers of energetic electrons (0.3-> 10 MeV) and protons (1–30 MeV) can be stored in the solar corona at altitudes around 3 × 105 km for periods in excess of 5 days. Specific reference is made to the time period July 6–16 1968 as an excellent example of energetic solar particle storage.

George M. Simnett; Stephen S. Holt

1971-01-01

35

Long-Term Variability of the Polytropic Index of Solar Wind Protons at 1 AU  

NASA Astrophysics Data System (ADS)

Spacecraft data from the OMNI database were used to calculate the value of the polytropic index of the solar wind by fitting the logarithms of proton density and temperature in selected time intervals from 1 January 1995 to 30 June 2012. Bernoulli's integral and the correlation coefficient were used to filter the results. An alternative method based on the maximization of the correlation coefficient was employed to confirm our results. The long-term behavior of the polytropic index we obtained is found to be virtually identical for both methods. We noticed a characteristic behavior of the estimated polytropic index values, particularly from 1995 to 2006, which tends to have a periodicity of about one year. The distribution of the polytropic index is best described by a ?-Gaussian distribution with mean ? 1.8 and standard deviation ? 2.4. We finally examined the possible correlation between the polytropic index values and solar activity.

Nicolaou, G.; Livadiotis, G.; Moussas, X.

2013-10-01

36

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

Microsoft Academic Search

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

Jaein Jeong; David Culler

37

Downregulation of platelet activation markers during long-term immobilization.  

PubMed

Immobilization and sedentary lifestyle are risk factors for venous thromboembolism and cardiovascular disease, yet little is known about platelet function during long-term physical inactivity. Our aim was to investigate platelet activation markers and their coupling to standardized immobilization: platelet-derived growth factor (PDGF-BB) and P-selectin. We studied 15 healthy females participating in the Women International Space simulation for Exploration study. Following a 20-day ambulatory control period, the subjects underwent 60 days of bed rest in head-down tilt position (-6°) 24 hours a day, finalized by 20 days of recovery. The subjects were randomized into two groups during bed rest: a control group (n?=?8) that remained physically inactive and an exercise group (n?=?7) that participated in both supine resistance and aerobic exercise training. Blood samples for the analysis of platelet activation markers were collected at baseline (5 days before bed rest), after 44 days of bed rest and 8 days into the recovery period. Compared to baseline, the levels of P-selectin and PDGF-BB decreased after bed rest (by 55%, p?=?0.01 and 73%, p?long-term immobilization, a known risk factor for thrombosis, the levels of P-selectin and PDGF-BB decreased. Our findings indicate downregulation of platelet activation during immobilization. PMID:22931233

Arinell, Karin; Fröbert, Ole; Blanc, Stéphane; Larsson, Anders; Christensen, Kjeld

2012-08-29

38

The long-term dynamical evolution and stability of the solar system  

Microsoft Academic Search

The question of the long-term stability of the solar system is one of the oldest unsolved problems in Newtonian physics. Although the general solution remains elusive, several recent theoretical and numerical advances suggest that the simple 'clockwork' model of the solar system envisaged by early workers must be replaced by one incorporating the deterministic chaos recently found in many nonlinear

Martin J. Duncan; Thomas Quinn

1993-01-01

39

Solar cycle dependence and long-term trends in the wind field of the mesosphere\\/lower thermosphere  

Microsoft Academic Search

Ground-based observations of the wind field in the mesosphere\\/lower thermosphere have been used to investigate long-lasting wind variations at mid-latitudes. Besides small solar activity induced variations (11 yr cycle), non-solar induced long-term trends were clearly detected, which could be a hint of anthropogenically caused variations in the wind field near the mesopause region. Comparisons with other observations qualitatively confirm the

J. Bremer; R. Schminder; K. M. Greisiger; P. Hoffmann; D. Kürschner; W. Singer

1997-01-01

40

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

Microsoft Academic Search

It has long been hypothesized that a significant fraction of observed Northern Hemisphere (NH) temperature variability at multi-decadal to centennial time scales can be attributed to variations in solar activity. This argument has been supported by some modeling experiments that used long-term changes in solar irradiance, explosive volcanism, and anthropogenic trace gases to model temperature changes over the past 1,000

E. R. Cook

2004-01-01

41

Estimation of solar radiation over Cambodia from long-term satellite data  

Microsoft Academic Search

In this work, monthly average daily global solar irradiation over Cambodia was estimated from a long-term satellite data. A 14-year period (1995–2008) of visible channel data from GMS5, GOES9 and MTSAT-1R satellites were used to provide earth-atmospheric reflectivity. A satellite-based solar radiation model developed for a tropical environment was used to estimate surface solar radiation. The model relates the satellite-derived

S. Janjai; P. Pankaew; J. Laksanaboonsong; P. Kitichantaropas

2011-01-01

42

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

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

43

Two-Dimensional Assimilation Of Solar Occultation Satellite Data To Study Long-Term Ozone Trends  

NASA Astrophysics Data System (ADS)

The methodology of two-dimensional chemistry-transport model driven data assimilation is used to evaluate atmospheric ozone changes for several decades. The SUNY-SPb two-dimensional transport-chemistry model, using the same mathematical framework, has been used to assimilate atmospheric composition data from two different solar occultation satellite instruments. The associated errors of the satellite observations are objectively calculated based on estimation theory. Two-dimensional data assimilation results for ozone are shown for SAGE II Version 6.2 and for HALOE Version 19 data. SAGE II was launched in October of 1984, and HALOE was launched on September of 1991. The SAGE II data spans two periods of high stratospheric aerosol loading (from El Chichon and Mt. Pinatubo), almost 10 QBO periods, 4 major ENSO events, and almost two complete solar cycles. The HALOE data spans one period of high stratospheric aerosol loading, almost 6 QBO periods, 3 major ENSO events, and about 1 1/2 solar cycles. HALOE and SAGE II results will be compared for the same periods. Assimilated satellite data are used to study the role of solar activity variations, atmospheric dynamics, and aerosol effects for long-term ozone variability in the lower and upper stratosphere and mesosphere.

Geller, M. A.; Zhou, X.; Smyshlyaev, S.

44

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

NASA Astrophysics Data System (ADS)

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

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

2004-12-01

45

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

SciTech Connect

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, Jr., P. W.; Cox, S. J.; Chandler, W. S.; Hoell, J. M.; Zhang, T.; Westberg, D.; Perez, R.; Hemker, C.; Schlemmer, J.; Renne, D.; Sengupta, M; Bates, J.; Knapp, K.

2011-01-01

46

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

47

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

National Technical Information Service (NTIS)

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 gra...

M. J. Holman

2002-01-01

48

Solar energy can be self-supporting long-term energy storage  

Microsoft Academic Search

The problem of long-term storage of collected solar energy is considered. Storage media discussed include water, graded rock or gravel, and salt hydrates (for latent-heat storage). It is suggested that the scale of storage be increased so that energy collected during the favorable summer months can be used in winter. Applications to individual houses are evaluated along with the possibility

R. F. Benseman

1977-01-01

49

Very Long-term Numerical Integrations of Solar System Planetary Orbits  

Microsoft Academic Search

The results of long-term numerical integrations of solar system planetary motions are presented. The numerical data show that planetary motion, at least in our solar system, seems to be stable over a 109-yr timespan. A closer look at the low-frequency oscillations shows a potentially diffusive character of terrestrial planetary motion, especially that of Mercury. We have also performed a couple

T. Ito; K. Tanikawa

2002-01-01

50

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

Microsoft Academic Search

The consequences of the shear-induced alpha effect to the long-term modulation of magnetic activity are examined with the help of the axisymmetric numerical dynamo model that includes the self-consistent description of the angular momentum balance, heat transport and magnetic field generation in the spherical shell. We find that the shear contributions to alpha effect can complicate the long-term behaviour of

V. V. Pipin

2007-01-01

51

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

Microsoft Academic Search

The consequences of the shear-induced alpha eect to the long-term modulation of magnetic activity are examined with the help of the axisymmetric numerical dynamo model that includes the self-consistent description of the angular momentum balance, heat transport and magnetic eld generation in the spherical shell. We nd that the shear contributions to alpha eect can complicate the long-term behaviour of

V. V. Pipin

52

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

53

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

SciTech Connect

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

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

1997-06-01

54

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

Microsoft Academic Search

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

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

2011-01-01

55

Persistent protein kinase activity underlying long-term potentiation  

Microsoft Academic Search

Long-term potentiation (LTP) of synaptic transmission in the hippocampus is a much-studied example of synaptic plasticity1,2. Although the role of N-methyl-D-aspartate (NMDA) receptors in the induction of LTP is well established3-5, the nature of the persistent signal underlying this synaptic enhancement is unclear. Involvement of protein phosphorylation in LTP has been widely proposed6-15, with protein kinase C (PKC)6-8,10-12,14 and calcium-calmodulin

Roberto Malinow; Daniel V. Madison; Richard W. Tsien

1988-01-01

56

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

57

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

58

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

NASA Astrophysics Data System (ADS)

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

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

2010-11-01

59

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

60

NMDA receptor-mediated long-term alterations in epileptiform activity in experimental chronic epilepsy  

Microsoft Academic Search

When epileptiform activity is acutely induced in vitro, transient partial blockade of N-methyl-d-aspartic acid (NMDA) receptor-mediated calcium influx leads to selective long-term depotentiation of the synapses involved in the epileptic activity as well as a reduction in the probability of further epileptiform activity. If such selective depotentiation occurred within foci of epileptic activity in vivo, the corresponding long-term reduction in

Jennifer L. Hellier; Andrew White; Philip A. Williams; F. Edward Dudek; Kevin J. Staley

2009-01-01

61

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

62

Long-Term Change in the Organization of Inventive Activity  

Microsoft Academic Search

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

Naomi R. Lamoreaux; Kenneth L. Sokoloff

1996-01-01

63

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.

Lamoreaux, Naomi R.; Sokoloff, Kenneth L.

1996-01-01

64

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

NASA Astrophysics Data System (ADS)

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

Fodroci, M. P.; Gafka, G. K.; Lutomski, M. G.; Maher, J. S.

2012-01-01

65

Long-Term Solar and Cosmic Radiation Data Bases. (Reannouncement with New Availability Information).  

National Technical Information Service (NTIS)

The cosmic radiation that reaches the earth is inversely correlated with solar activity as represented by the sunspot number. Thus one of the longest solar-terrestrial data records (solar data) has been combined with one of the shortest data records (cosm...

M. A. Shea D. F. Smart

1991-01-01

66

Long-term calibration monitoring of medium resolution spectral imager (MERSI) solar bands onboard FY-3  

NASA Astrophysics Data System (ADS)

Medium Resolution Spectral Imager (MERSI) is a keystone instrument onboard Fengyun-3 (FY-3), the second generation of polar-orbiting meteorological satellites in China. This paper summarizes the knowledge of MERSI instrument in terms of sensor design, calibration algorithm, and long term calibration monitoring. The calibration monitoring of its reflective solar bands (RSBs) is conducted using China Radiometric Calibration Sites (CRCS) vicarious calibration (VC), global multi-site calibration tracking, visible onboard calibrator (VOC) monitoring and deep convective cloud (DCC) monitoring. All these methods provide results with good consistency . It is found that there is significant degradation over 10% in the shorter RSB bands (<500 nm), with the largest in band 8 (412 nm) of approximately 35% during the past four years. The performance in the red and near-infrared (600 to 900 nm) is relatively stable. The overall uncertainty of the MERSI top-of-the-atmosphere (TOA) reflectance is less than 5% verified through several methods.

Sun, Ling; Hu, Xiuqing; Chen, Lin

2012-11-01

67

Long-term geomagnetic indices and their use in inferring solar wind parameters in the past  

NASA Astrophysics Data System (ADS)

We discuss three new geomagnetic indices [the Inter-Hour Variability ( IHV), the Inter-Diurnal Variability ( IDV), Svalgaard, L., Cliver, E.W. The IDV index: its derivation and use in inferring long-term variations of the interplanetary magnetic field strength. J. Geophys. Res. 110, A12103. doi:10.1029/2005JA011203, 2005; and the Polar Cap Potential ( PCP) index, Le Sager, P., Svalgaard, L. No increase of the interplanetary electric field since 1926. J. Geophys. Res. 109 (A7), A07106. doi:10.1029/2004JA010411, 2004], that are derivable from data available for a century or more. Each of these indices responds directly to either the solar wind magnetic field strength ( B) or to different combinations of B and the solar wind speed ( V). This over-determined system permits a reconstruction of these parameters for the past ˜150 years. The variation of yearly averages of B can be described as a constant value (4.6 nT) plus a component varying with the square root of the sunspot number. Because the latter seems to exhibit a ˜100 year Gleissberg cycle, B does as well. Since 1890, annual averages of V range from a low of ˜300 km/s in 1902 to 545 km/s in 2003. The IHV-index fords a way to check the calibration of other long-term geomagnetic indices. We find that the ap-index tracks the variation of IHV, back to 1932 but that the aa-index (extended back to 1844) is systematically too low (3-6 nT) before 1957, relative to modern values.

Svalgaard, L.; Cliver, E. W.

68

Salt Gradient Solar Pond for Solar Heat Collection and Long Term Storage.  

National Technical Information Service (NTIS)

The solar pond project at the University of Sussex aims to study the design, construction, filling, and operation of salt gradient solar ponds, and to develop instrumentation for monitoring behavior and performance. The paper describes the construction, f...

P. J. Unsworth N. Al-Saleh V. Phillips B. Butlin

1985-01-01

69

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

ERIC Educational Resources Information Center

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

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

2011-01-01

70

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

ERIC Educational Resources Information Center

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

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

2009-01-01

71

Long-term variability of solar direct and global radiation derived from ISCCP data and comparison with reanalysis data  

Microsoft Academic Search

Annual variations of solar radiation at the Earth’s surface may be strong and could seriously harm the return of investment for solar energy projects. This paper analyzes the long-term variability of broadband surface solar radiation based on 18 years of three-hourly satellite observations from the International Satellite Cloud Climatology Project (ISCCP). Direct normal irradiance (DNI) and global horizontal irradiance (GHI)

S. Lohmann; C. Schillings; B. Mayer; R. Meyer

2006-01-01

72

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

SciTech Connect

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

Zhang, Yabei; Smith, Steven J.

2007-08-16

73

Long-term changes in rainfall and tropical cyclone activity over South and Southeast Asia  

NASA Astrophysics Data System (ADS)

Long-term changes in rainfall and associated tropical cyclone (TC) activity in transition seasons between the wet and dry seasons in South and Southeast Asia, namely boreal spring and fall, were examined, using gridded rainfall, TC tracks, and reanalysis datasets, the focus of discussion being the long-term changes in coastal regions. It was found that long-term changes in rainfall during the transition seasons in South and Southeast Asia were closely associated with those in TC activity over the north Indian Ocean and South China Sea. Rainfall in May increased in the last 40 years over and around Myanmar, which indicates an earlier monsoon onset over the western Indochina Peninsula. Rainfall over and around northern Vietnam also increased in the last 40 years during October, which is known as the monsoon retreat period. These increases were associated with the long-term changes in TC activity. Furthermore, although linear trends have been previously suggested, monotonically increasing or decreasing trends in these long-term changes were not found over the last 60 years.

Takahashi, H. G.

2011-05-01

74

Long-term low do enriches and shifts nitrifier community in activated sludge.  

PubMed

In the activated sludge process, reducing the operational dissolved oxygen (DO) concentration can improve oxygen transfer efficiency, thereby reducing energy use. The low DO, however, may result in incomplete nitrification. This research investigated the long-term effect of low DO on the nitrification performance of activated sludge. Results indicated that, for reactors with 10 and 40 day solids retention times (SRTs), complete nitrification was accomplished after a long-term operation with a DO of 0.37 and 0.16 mg/L, respectively. Under long-term low DO conditions, nitrite oxidizing bacteria (NOB) became a better oxygen competitor than ammonia oxidizing bacteria (AOB) and, as a result, no nitrite accumulated. Real-time PCR assays indicated that the long-term low DO enriched both AOB and NOB in activated sludge, increasing the sludge nitrification capacity and diminishing the adverse effect of low DO on the overall nitrification performance. The increase in the population size of nitrifiers was likely resulted from the reduced nitrifier endogenous decay rate by a low DO. Under long-term low DO conditions, Nitrosomonas europaea/eutropha remained as the dominant AOB, whereas the number of Nitrospira-like NOB became much greater than Nitrobacter-like NOB, especially for the 40 day SRT sludge. The enrichment and shift of the nitrifier community reduced the adverse effect of low DO on nitrification; therefore, low DO operation of a complete nitrification process is feasible. PMID:23631354

Liu, Guoqiang; Wang, Jianmin

2013-05-13

75

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

PubMed Central

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

Ludmer, Rachel; Dudai, Yadin; Rubin, Nava

2012-01-01

76

80 120 yr Long-term solar induced effects on the earth, past and predictions  

NASA Astrophysics Data System (ADS)

The 80 120 year solar Wolf-Gleissberg cycles have wide effects on the Earth’s environment. Studying past effects can throw light on future predictions of solar terrestrial relations at similar solar activity levels. Solar induced climate changes do happen at the turning points of such cycles when changes in solar spin rates occur. Reversing of North Atlantic Oscillations can be interpreted in terms of solar stimuli. The sudden abrupt rises of lakes levels and closed seas are solar forced. It is anticipated that the Aral and the Dead Sea will recover in the near future. Following drought conditions in African Equatorial lakes by the end of cycle 23 around 2008 ± 2 yr, cyclic rises and falls of lakes level are expected to be coherent with the weak cycles 24 to perhaps 26 when solar forcings will reverse or cease to exist. The Atlanto Canadian fish disappearance dilemma is a natural Wolf-Gleissberg cycle induced effect and is expected to recover in due time.

Yousef, Shahinaz Moustafa

77

Stellar activity and the long-term use of robotic telescopes  

Microsoft Academic Search

A number of automated and robotic telescopes are nowadays devoted to the systematic monitoring of magnetically active stars and binary systems at several astronomical institutions, all over the world, and their number is steadily increasing. Standard equipments include wide- and narrow-band photometers and, more recently, spectroscopic capabilities. The long-term time series that those telescopes are providing turn out to be

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

2004-01-01

78

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

79

Expression of interferon-? by stromal cells inhibits murine long-term repopulating hematopoietic stem cell activity  

Microsoft Academic Search

Several lines of evidence suggest that overexpression of interferon ? (IFN-?) in the marrow microenvironment may play a role in the pathogenesis of marrow suppression in aplastic anemia. We previously showed that overexpression of IFN-? by marrow stromal cells inhibits human long-term culture initiating cell activity assayed in vitro to a much greater degree than the addition of soluble IFN-?.

Jian-Mei Yu; Robert V. B Emmons; Yutaka Hanazono; Stephanie Sellers; Neal S Young; Cynthia E Dunbar

1999-01-01

80

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

Microsoft Academic Search

The aim of this study was to determine if episodic hypoxia evokes persistent increases of genioglossus muscle (GG) activity, termed long-term facilitation (LTF), in neonatal rats in vivo. Experiments were performed on anaesthetized, spontaneously breathing, intubated neonatal rats (postnatal days (P) 3-7), divided into three groups. The first group (n = 8) was subjected to three 5-min periods of hypoxia

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

2004-01-01

81

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

82

A Framework for Supervising Lifestyle Diseases Using Long-Term Activity Monitoring  

PubMed Central

Activity monitoring of a person for a long-term would be helpful for controlling lifestyle associated diseases. Such diseases are often linked with the way a person lives. An unhealthy and irregular standard of living influences the risk of such diseases in the later part of one's life. The symptoms and the initial signs of these diseases are common to the people with irregular lifestyle. In this paper, we propose a novel healthcare framework to manage lifestyle diseases using long-term activity monitoring. The framework recognizes the user's activities with the help of the sensed data in runtime and reports the irregular and unhealthy activity patterns to a doctor and a caregiver. The proposed framework is a hierarchical structure that consists of three modules: activity recognition, activity pattern generation and lifestyle disease prediction. We show that it is possible to assess the possibility of lifestyle diseases from the sensor data. We also show the viability of the proposed framework.

Han, Yongkoo; Han, Manhyung; Lee, Sungyoung; Jehad Sarkar, A. M.; Lee, Young-Koo

2012-01-01

83

A New Approach to the Long-Term Activity Behavior of DM UMa  

NASA Astrophysics Data System (ADS)

A long-term activity character of DM UMa (K0-1 IV-III), which is one of the most active members of the RS CVn type variables, is examined using the multicolor photometric observations which spread to the time interval between 1980 and 2009. In this work, we present a new approximation for the long-term light and color variation of DM UMa using data obtained by combining our own observations obtained in the Johnson broad-band U,B,V,R filters between the years 1997 and 2008 and data published in literature. Available light and color data were examined for the long-term and seasonal variations using PERIOD04 program. The period analysis of the V-band data reveals the period estimations of 51.2 ± 2.8 years and 15.1 ± 0.7 years superposed on it. The U--B, B--V and V--R colors do not show correlation with the longer period, but they show variations with a period similar to the shorter one, except for B--V color. The amplitude variation also does not exhibit any correlation with the V light and color curves. It is found that the movement of the spot minima phases in years also indicates the migration period of nearly 15 years, similar to the period derived from the analysis of the long-term photometric observations in V-band.

Ta?, G.; Evren, S.

84

Bistable MAP kinase activity: a plausible mechanism contributing to maintenance of late long-term potentiation.  

PubMed

Bistability of MAP kinase (MAPK) activity has been suggested to contribute to several cellular processes, including differentiation and long-term synaptic potentiation. A recent model (Markevich NI, Hoek JB, Kholodenko BN. J Cell Biol 164: 353-359, 2004) predicts bistability due to interactions of the kinases and phosphatases in the MAPK pathway, without feedback from MAPK to earlier reactions. Using this model and enzyme concentrations appropriate for neurons, we simulated bistable MAPK activity, but bistability was present only within a relatively narrow range of activity of Raf, the first pathway kinase. Stochastic fluctuations in molecule numbers eliminated bistability for small molecule numbers, such as are expected in the volume of a dendritic spine. However, positive-feedback loops have been posited from MAPK up to Raf activation. One proposed loop in which MAPK directly activates Raf was incorporated into the model. We found that such feedback greatly enhanced the robustness of both stable states of MAPK activity to stochastic fluctuations and to parameter variations. Bistability was robust for molecule numbers plausible for a dendritic spine volume. The upper state of MAPK activity was resistant to inhibition of MEK activation for >1 h, which suggests that inhibitor experiments have not sufficed to rule out a role for persistent MAPK activity in the maintenance of long-term potentiation (LTP). These simulations suggest that persistent MAPK activity and consequent upregulation of translation may contribute to LTP maintenance and to long-term memory. Experiments using a fluorescent MAPK substrate may further test this hypothesis. PMID:18057118

Smolen, Paul; Baxter, Douglas A; Byrne, John H

2007-12-05

85

Long-Term Caffeine Inhibits Ehrlich Ascites Carcinoma Cell-Induced Induction of Central GABAergic Activity  

Microsoft Academic Search

Long-term administration (for 22–27 consecutive days) of caffeine (20 mg\\/kg\\/day p.o) developed tolerance to this drug by upregulating the central GABAergic activity. Development of Ehrlich ascites carcinoma (EAC) cell induced the whole brain GABAergic activity. But pre-treatment of caffeine and continuation of its treatment in the course of development of EAC cells restored the EAC cell-induced change of GABAergic activity

M. K. Poddar

2000-01-01

86

Longitudinal study of the long-term relation between physical activity and obesity in adults  

Microsoft Academic Search

BACKGROUND: Earlier observational studies of the relation between physical activity and obesity are inconsistent and ambiguous, showing a clear cross-sectional inverse relation, and a prospective association only when physical activity at the time of follow-up is included.OBJECTIVE: To examine the long-term effect of leisure time physical activity (LTPA) on subsequent development of obesity and the effect of body weight on

L Petersen; P Schnohr; T I A Sørensen; TIA Sørensen

2004-01-01

87

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

88

Long-term global hurricane activity record shows periodic highs and lows  

NASA Astrophysics Data System (ADS)

In the long-record of hurricane activity, which stretches back roughly 7500 years, the frequency of large tropical cyclones has varied, with distinct periods of elevated or depressed activity lasting hundreds to thousands of years. Of the 12 sites that provide the basis for this record, 6 measure the activity in the tropical North Atlantic, 1 serves as a history of the northwestern Pacific, and 5 sites around Australia represent the southwestern Pacific Ocean and the Indian Ocean. In previous research, scientists used the individual records from northern hemispheric sites to investigate the connection between long-term tropical cyclone activity and climate systems such as the El Niño Southern Oscillation (ENSO). Nott and Forsyth, however, used the records from all 12 sites to ascertain a measure of long-term global hurricane activity.

Schultz, Colin

2012-09-01

89

Long-Term Variation of the Rotation of the Solar Corona  

NASA Astrophysics Data System (ADS)

Synoptic photoelectric observations of the coronal Fe XIV and Fe X emission lines at 530.3 nm and 637.4 nm, respectively, are analyzed to study the rotational behavior of the solar corona as a function of latitude, height and time. The data used are measurements made with the Sacramento Peak 40-cm coronagraph and Emission-Line Coronal Photometer of the intensity of these lines observed at 1.15 to 1.45 solar radii (Ro) between 1973 (1984 for Fe X) and 2000. An earlier similar temporal-correlation analysis of the Fe XIV data at 1.15 Ro over only one 11-year solar activity cycle (Sime, Fisher and Altrock 1989, Astrophys. J. 336, 454) found suggestions of solar-cycle variations in the differential-rotation and latitude-averaged-rotation patterns that combined the effects of large-scale patterns seen in the white-light corona and smaller-scale patterns seen in chromospheric and photospheric rotation. These results will be tested over the longer epoch now available. In addition, the new 1.15 Ro Fe XIV results will be compared with those at greater heights and with results from the Fe X line and radio frequencies (Vats et al. 2001, Astrophys. J., 548, L87) to form a global picture of solar rotation throughout the corona and over more than two solar cycles.

Altrock, R. C.

2001-05-01

90

Long-Term Variation of the Rotation of the Solar Corona  

NASA Astrophysics Data System (ADS)

Synoptic photoelectric observations of the coronal Fe XIV and Fe X emission lines at 530.3 nm and 637.4 nm, respectively, are analyzed to study the rotational behavior of the solar corona as a function of latitude, height and time. The data used are measurements made with the Sacramento Peak 40-cm coronagraph and Emission-Line Coronal Photometer of the intensity of these lines observed at 1.15 to 1.45 solar radii (Ro) between 1973 (1984 for Fe X) and 2000. An earlier similar temporal-correlation analysis of the Fe XIV data at 1.15 Ro over only one 11-year solar activity cycle (Sime, Fisher and Altrock 1989, Astrophys. J. 336, 454) found suggestions of solar-cycle variations in the differential-rotation and latitude-averaged-rotation patterns that combined the effects of large-scale patterns seen in the white-light corona and smaller-scale patterns seen in chromospheric and photospheric rotation. These results will be tested over the longer epoch now available. In addition, the new 1.15 Ro Fe XIV results will be compared with those at greater heights and with results from the Fe X line and radio frequencies (Vats et al. 2001, Astrophys. J., 548, L87) to form a global picture of solar rotation throughout the corona and over more than two solar cycles.

Altrock, R. C.

2002-01-01

91

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

Microsoft Academic Search

OBJECTIVETo analyse the long term results of mechanical prostheses for treating active infective endocarditis.DESIGNProspective 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.SETTINGTertiary referral centre in a metropolitan area.RESULTSBetween 1975 and 1997, 637 cases of infective endocarditis were diagnosed in the

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

2001-01-01

92

Activity Measures in Rhesus Monkeys on Long-Term Calorie Restriction  

Microsoft Academic Search

Weed, J. L., M. A. Lane, G. S. Roth, D. Speer and D. K. Ingram. Activity measures in rhesus monkeys on long-term calorie restriction. Physiol Behav 62(1) 97–103, 1997—Calorie restriction (CR), undernutrition without malnutrition, extends the mean and maximal lifespan of several ecologically diverse species. Rodents on CR demonstrate increased activity measured as spontaneous locomotion, wheel running, open field behavior

J. L Weed; G. S Roth; D. L Speer; D. K Ingram

1997-01-01

93

Endogenous Serine Protease Inhibitor Modulates Epileptic Activity and Hippocampal Long-Term Potentiation  

Microsoft Academic Search

Protease nexin-1 (PN-1), a member of the serpin superfamily, controls the activity of extracellular serine proteases and is expressed in the brain. Mutant mice overexpressing PN-1 in brain under the control of the Thy-1 promoter (Thy 1\\/PN-1) or lacking PN-1 (PN-12\\/2) were found to develop epileptic activ- ity in vivo and in vitro. Theta burst-induced long-term potenti- ation (LTP) and

Andreas Luthi; Herman van der Putten; Florence M. Botteri; Isabelle M. Mansuy; Marita Meins; Uwe Frey; Gilles Sansig; Chantal Portet; Markus Schmutz; Markus Schroder; Cordula Nitsch; Jean-Paul Laurent; Denis Monard

1997-01-01

94

Tremorlytic activity of budipine: a quantitative study with long-term tremor recordings.  

PubMed

The tremorlytic activity of the novel antiparkinson agent budipine was quantified in an open trial. Eleven patients with Parkinson's disease (PD) were treated with individual doses of budipine added to stable conventional antiparkinsonian medication. Tremor activity was measured using long-term electromyogram (EMG) recordings. Tremor intensity was reduced by 25%, tremor occurrence by 34%, and conventional "Unified Parkinson's Disease Rating Scale" (UPDRS) scores improved by 20% with this medication. There were two dropouts because of side effects. One dropout appeared not to be related to budipine. Apart from those, the drug was well tolerated by all patients. We conclude that budipine is an effective and well-tolerated tremorlytic drug and that the method of long-term EMG recording is suitable for tremor quantification in clinical studies. PMID:8635185

Spieker, S; Löschmann, P; Jentgens, C; Boose, A; Klockgether, T; Dichgans, J

1995-06-01

95

Long term outcome of patients with active Crohn's disease exhibiting extensive and deep ulcerations at colonoscopy  

Microsoft Academic Search

OBJECTIVE:Prediction of the clinical course of Crohn's disease (CD) is difficult in the long term. Our aim was to determine whether the presence of severe endoscopic lesions (SELs) may predict a higher risk of colectomy and penetrating complications.METHODS:All patients at our institution with active ileocolonic CD who had colonoscopies between 1990 and 1996 were included in the study. SELs were

Matthieu Allez; Marc Lemann; Joëlle Bonnet; Pierre Cattan; Raymond Jian; Robert Modigliani

2002-01-01

96

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

Microsoft Academic Search

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

R. Marchetti

1995-01-01

97

Long-term efficacy and safety of etanercept after readministration in patients with active ankylosing spondylitis  

Microsoft Academic Search

Objectives. Treatment of ankylosing spondylitis (AS) with the tumour necrosis factor a (TNF-a) receptor fusion protein etanercept has shown efficacy in patients with active disease in randomized controlled trials (RCTs) for limited periods. The objective of the study was to assess the long-term efficacy and safety of etanercept over 1 yr, including discontinuation and readministration. Methods. In this 54-week open

J. Brandt; J. Listing; H. Haibel; H. Sorensen; A. Schwebig; M. Rudwaleit; J. Sieper; J. Braun

2005-01-01

98

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

Microsoft Academic Search

Context: The IUE database provides several UV high and low-resolution spectra of RS CVn-type stars from 1978 to 1996. In particular, many of these stars were monitored continuously during several seasons by IUE. Aims: Our main purpose is to study the short and long-term chromospheric activity of the RS CVn systems most observed by IUE: HD 22 468 (V711 Tau,

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

2009-01-01

99

Phrenic Long-Term Facilitation Requires Spinal Serotonin Receptor Activation and Protein Synthesis  

Microsoft Academic Search

Respiratory long-term facilitation (LTF) is a form of serotonin- dependent plasticity induced by intermittent hypoxia. LTF is manifested as a long-lasting increase in respiratory amplitude (and frequency) after the hypoxic episodes have ended. We tested the hypotheses that LTF of phrenic amplitude requires spinal serotonin receptor activation and spinal protein synthe- sis. A broad-spectrum serotonin receptor antagonist (methy- sergide) or

L. Baker-Herman; Gordon S. Mitchell

2002-01-01

100

Long-term trends in solar irradiance in Ireland and their potential effects on gross primary productivity  

Microsoft Academic Search

Long-term trends in total solar irradiance (Rs), diffuse irradiance (Rd) and pan evaporation (Epan), from various sites in Ireland, were examined over the last 20–50 years. This information was used to estimate the impact of changes in Rs and Rd on gross primary productivity (GPP) of forest, arable and grassland ecosystems. Analysis of the data indicated a significant (P<0.0001) reduction

Kevin Black; Phill Davis; Peter Lynch; Mike Jones; Michael McGettigan; Bruce Osborne

2006-01-01

101

Search for long-term periodicity in the Pleiades active dwarf stars from photographic sky surveys  

NASA Astrophysics Data System (ADS)

A program for searching for long-term periodicity of the Pleiades active dwarf stars is presented. As a basis the Pleiades flare stars (or UV Cet type stars) from the Flare Stars Database, which are identified in the USNO A2.0 catalogue are used. The investigation for long-term variability will be made by the usage of European astronomical plate archives, included in the Wide-Field Plate Database (http://www.skyarchive.org), whose time distribution covers more than 100 years. Among these plate archives are those of Rozhen Observatory (Bulgaria), Konkoly Observatory (Hungary), Byurakan (Armenia), Potsdam (Germany), Royal Observatory of Edinburgh (UK), Bamberg (Germany), etc. Limited number of the existing plates in the Pleiades region are already digitized with different scaning machines as PDS 1010 (Sofia), PDS 2020 (Muenster), SUPER COSMOS (Edinburgh) and some flatbed scanners.

Borisova, A. P.; Tsvetkov, M. K.; Tsvetkova, K. P.; Hambly, N.; Kalaglarsky, D. G.

2002-07-01

102

Solar cycle 24: Implications for energetic particles and long-term space climate change  

NASA Astrophysics Data System (ADS)

The recent solar minimum was the longest and deepest of the space age, with the lowest average sunspot numbers for nearly a century. The Sun appears to be exiting a grand solar maximum (GSM) of activity which has persisted throughout the space age, and is headed into a significantly quieter period. Indeed, initial observations of solar cycle 24 (SC24) continue to show a relatively low heliospheric magnetic field strength and sunspot number (R), despite the average latitude of sunspots and the inclination of the heliospheric current sheet showing the rise to solar maximum is well underway. We extrapolate the available SC24 observations forward in time by assuming R will continue to follow a similar form to previous cycles, despite the end of the GSM, and predict a very weak cycle 24, with R peaking at ˜65-75 around the middle/end of 2012. Similarly, we estimate the heliospheric magnetic field strength will peak around 6nT. We estimate that average galactic cosmic ray fluxes above 1GV rigidity will be ˜10% higher in SC24 than SC23 and that the probability of a large SEP event during this cycle is 0.8, compared to 0.5 for SC23. Comparison of the SC24 R estimates with previous ends of GSMs inferred from 9300 years of cosmogenic isotope data places the current evolution of the Sun and heliosphere in the lowest 5% of cases, suggesting Maunder Minimum conditions are likely within the next 40 years.

Owens, M. J.; Lockwood, M.; Barnard, L.; Davis, C. J.

2011-10-01

103

An Approach for Long Term Forecasting with an Application to Solar Electric Energy  

Microsoft Academic Search

An approach is proposed that is useful for long term forecasting of market penetration of new technologies, fuel price and availability, business performance, etc. The central idea is to systematically solicit experts' opinion in the form of subjective probability distributions in making future projections. The approach has two basic ingredients. One is the decomposition of the problem so that each

Rakesh K. Sarin

1979-01-01

104

Long-term variations in the properties of large solar energetic particle events.  

NASA Astrophysics Data System (ADS)

The occurrence of large solar energetic particle SEP events 30MeV fluence 2x10 9 cm -2 is reviewed using data obtained by satellites ground based instrumentation and from the glaciological record It is shown that the frequency of occurrence of large fluence events during the space era 1960 et seq was one of the lowest in the past 400 years Large SEP were up to 6 to 8-times more frequent during periods of low solar activity such as the Gleissberg minimum circa 1890-1900 The possibility that the frequency of occurrence of SEP is inversely related to the strength of the magnetic fields near the Sun is discussed and advanced as a working hypothesis that allows the occurrence of SEP during the 11-year solar cycle and over centennial scales to be better understood The energy dependence of the particle spectra at high energies the occurrence of large ephemeral anisotropies and the dependence of the particle intensities upon heliographic longitude are summarized The Carrington white light flare of 1859 resulted in the greatest 30MeV fluence 18 8x10 9 cm -2 near Earth in the past 400 years however evidence from the 10 Be record might indicate a significantly greater event during the Spoerer grand minimum of the Sun 1420-1540 A cumulative probability curve for the occurrence of very large SEP events is presented In closing a prediction is made regarding the occurrence of large SEP events until 2050AD

McCracken, K. G.

105

Long-term integrations and stability of planetary orbits in our Solar system  

Microsoft Academic Search

We present the results of very long-term numerical integrations of planetary orbital motions over 109 -yr time-spans including all nine planets. A quick inspection of our numerical data shows that the planetary motion, at least in our simple dynamical model, seems to be quite stable even over this very long time-span. A closer look at the lowest-frequency oscillations using a

Takashi Ito; Kiyotaka Tanikawa

2002-01-01

106

DNA Nanoparticles: Detection of Long-Term Transgene Activity in Brain Using Bioluminescence Imaging  

PubMed Central

In this study, we used bioluminescence imaging (BLI) to track long-term transgene activity following the transfection of brain cells using a nonviral gene therapy technique. Formulations of deoxyribonucleic acid (DNA) combined with 30-mer lysine polymers (substituted with 10 kDa polyethylene glycol) form nanoparticles that transfect brain cells in vivo and produce transgene activity. Here we show that a single intracerebral injection of these DNA nanoparticles (DNPs) into the rat cortex, striatum, or substantia nigra results in long-term and persistent luciferase transgene activity over an 8- to 11-week period as evaluated by in vivo BLI analysis, and single injections of DNPs into the mouse striatum showed stable luciferase transgene activity for 1 year. Compacted DNPs produced in vivo signals 7- to 34-fold higher than DNA alone. In contrast, ex vivo BLI analysis, which is subject to less signal quenching from surrounding tissues, demonstrated a DNP to DNA alone ratio of 76- to 280-fold. Moreover, the ex vivo BLI analysis confirmed that signals originated from the targeted brain structures. In summary, BLI permits serial analysis of luciferase transgene activity at multiple brain locations following gene transfer with DNPs. Ex vivo analysis may permit more accurate determination of relative activities of gene transfer vectors.

Yurek, David M.; Fletcher, Anita M.; McShane, Matthew; Kowalczyk, Tomasz H.; Padegimas, Linas; Weatherspoon, Marcy R.; Kaytor, Michael D.; Cooper, Mark J.; Ziady, Assem G.

2011-01-01

107

Long-Term Tracking of Physical Activity Behaviors in Women: The WIN Study  

PubMed Central

Purpose Interest lies in the prevalence of community-living women meeting 2008 Department of Health and Human Services physical activity guidelines across time. The purpose was to report prevalence and stability of long-term (up to 125 weeks) tracking of physical activity behaviors and compare self-reported physical activity behaviors using different measures. Methods The WIN study tracks nearly real-time physical activity behaviors in community-living women. At baseline, 918 women began weekly Internet reporting of physical activity behaviors, accessing a secure Internet site and answering 8 questions about physical activity behaviors for the previous week. Measures included days and minutes of moderate, vigorous, walking, and strengthening activities, and pedometer steps recorded weekly. Results Prevalence of meeting physical activity guidelines depended on the criterion used. Weekly averages across the surveillance period indicated 25% reported ?150 mins of moderate physical activity, 47% reported ?75 mins of vigorous physical activity, 57% reported ?150 mins of moderate-to-vigorous physical activity, 63% conducted ?500 MET-mins of physical activity, 15% reported ?2 days of strengthening activities per week, and 39% reported ?7500 steps per week. Alpha coefficients (?.97) indicated stable physical activity behaviors across all measures. Conclusion Across reporting methods, it is estimated that approximately 50% or more of these community-living women engage in sufficient physical activity for health benefits weekly across long-term follow-up. Self-report physical activity behaviors are stable across long periods in these community-living women not participating in a specific physical activity intervention.

Morrow, James R.; Bain, Tyson M.; Frierson, Georita M.; Trudelle-Jackson, Elaine; Haskell, William L.

2010-01-01

108

Repeated solarization and long-term effects on soil microbiological parameters and agronomic traits  

Microsoft Academic Search

Innovative methods less invasive for man and environment are needed to solve the problem of weeds, pests and diseases in cropping systems. Soil solarization is one practice that involves passively heating soil covered by a thin clear plastic film for several weeks during the periods of high solar radiation before the crop is planted. Soil solarization treatments were repeated to

Antonio Scopa; Vincenzo Candido; Stefano Dumontet; Vincenzo Pasquale; Vito Miccolis

2009-01-01

109

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

PubMed Central

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

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

2012-01-01

110

Long-term changes to incoming solar energy on the Canadian Prairie  

Microsoft Academic Search

Many regions of the earth experienced a steady decline in solar radiation (global dimming) from the late 1950s to the late 1980s–early 1990s and a steady brightening thereafter. To determine trends in solar energy across the agricultural region of the Canadian Prairie, we analyzed incoming solar radiation, sunshine, and climate data gathered between 1951 and 2005 from 7 locations on

H. W. Cutforth; D. Judiesch

2007-01-01

111

Activation of CaMKII in single dendritic spines during long-term potentiation.  

PubMed

Calcium/calmodulin-dependent kinase II (CaMKII) plays a central part in long-term potentiation (LTP), which underlies some forms of learning and memory. Here we monitored the spatiotemporal dynamics of CaMKII activation in individual dendritic spines during LTP using two-photon fluorescence lifetime imaging microscopy, in combination with two-photon glutamate uncaging. Induction of LTP and associated spine enlargement in single spines triggered transient ( approximately 1 min) CaMKII activation restricted to the stimulated spines. CaMKII in spines was specifically activated by NMDA receptors and L-type voltage-sensitive calcium channels, presumably by nanodomain Ca(2+) near the channels, in response to glutamate uncaging and depolarization, respectively. The high degree of compartmentalization and channel specificity of CaMKII signalling allow stimuli-specific spatiotemporal patterns of CaMKII signalling and may be important for synapse-specificity of synaptic plasticity. PMID:19295602

Lee, Seok-Jin R; Escobedo-Lozoya, Yasmin; Szatmari, Erzsebet M; Yasuda, Ryohei

2009-03-19

112

Constitutive ?-opioid receptor activity leads to long-term endogenous analgesia and dependence.  

PubMed

Opioid receptor antagonists increase hyperalgesia in humans and animals, which indicates that endogenous activation of opioid receptors provides relief from acute pain; however, the mechanisms of long-term opioid inhibition of pathological pain have remained elusive. We found that tissue injury produced ?-opioid receptor (MOR) constitutive activity (MOR(CA)) that repressed spinal nociceptive signaling for months. Pharmacological blockade during the posthyperalgesia state with MOR inverse agonists reinstated central pain sensitization and precipitated hallmarks of opioid withdrawal (including adenosine 3',5'-monophosphate overshoot and hyperalgesia) that required N-methyl-D-aspartate receptor activation of adenylyl cyclase type 1. Thus, MOR(CA) initiates both analgesic signaling and a compensatory opponent process that generates endogenous opioid dependence. Tonic MOR(CA) suppression of withdrawal hyperalgesia may prevent the transition from acute to chronic pain. PMID:24052307

Corder, G; Doolen, S; Donahue, R R; Winter, M K; Jutras, B L; He, Y; Hu, X; Wieskopf, J S; Mogil, J S; Storm, D R; Wang, Z J; McCarson, K E; Taylor, B K

2013-09-20

113

The inner heliosphere from solar minimum to solar maximum Short- and long-term variations in the energetic particle population  

NASA Astrophysics Data System (ADS)

Between 1975 and 1983 Helios 1 scanned the interplanetary medium between 0.3 and 1 AU 31 times. The observed variations in the differential and integral flux of protons and helium nuclei in the energy range from 4 to over 50 MeV/n are characterized by large temporal changes in the intensities, moderate changes in the energy spectrum, and changes in the gradient below the detection level (60 percent). During solar minimum conditions, recurrent disturbances are caused mainly by corotating interaction regions. The onset of solar activity near the end of 1977, characterized by a large number of solar events, is accompanied by a monotonous decrease of galactic cosmic radiation. The successive reduction of the cosmic ray intensity to the level of solar maximum is discussed in view of the role of large transient disturbances, as compared to such processes as diffusion, convection, adiabatic energy losses, and drifts.

Mueller-Mellin, R.; Wibberenz, G.

114

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

Microsoft Academic Search

Artificial Neural Networks (ANN) are efficient tools to derive solar UV radiation from measured meteorological parameters such as global radiation, aerosol optical depths and atmospheric column ozone. The ANN model has been tested with different combinations of data from the two sites Potsdam and Lindenberg, and used to reconstruct solar UV radiation at eight European sites by more than 100

U. Feister; J. Junk; M. Woldt

2008-01-01

115

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 Côote 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

116

Effects of long-term administration of clonidine on plasma renin activity.  

PubMed Central

Plasma renin activity (PRA) was studied before and during long-term treatment with moderate oral doses (0.2 or 0.3 mg/d) of clonidine. Nine outpatients with essential hypertension received clonidine for 12 weeks; a significant decrease in blood pressure was evident in all patients. Except for a nonsignificant increase after 12 weeks of treatment, PRA values were not notably changed by clonidine therapy. No correlation was found between individual blood pressure changes and PRA variation during the study. The absence of a net effect on PRA in this study does not exclude more complex interactions of clonidine with the renin-angiotensin system. Nonetheless, clonidine cannot generally be classified as a "renin-inhibiting" drug.

De Wurstemberger, B.; Gysling, E.

1976-01-01

117

Daily life physical activity in long-term survivors of nephroblastoma and neuroblastoma.  

PubMed

The risk of metabolic late effects after childhood cancer, such as obesity, hypertension, and diabetes, can be positively influenced by a healthy lifestyle with sufficient physical activity. Nevertheless, studies on physical activity in adult survivors of childhood cancer are scarce and involve different and often nonvalidated questionnaires. We used the Short QUestionnaire to ASsess Health-enhancing physical activity (SQUASH), which was developed and validated to assess daily life physical activity in the Dutch adult population. The aim of the study was to assess daily life physical activity in Dutch adult long-term nephroblastoma and neuroblastoma survivors. Sixty-seven nephroblastoma and 36 neuroblastoma survivors (median age, 30 y; range, 18 to 51 y) and 60 sociodemographically similar healthy control subjects (median age, 32 y; range, 18 to 62 y) were asked to complete the SQUASH during their regular follow-up visit. The adjusted mean physical activity score in male neuroblastoma survivors (mean, 7155; P=0.004) was significantly lower than in male controls (mean, 10,574), whereas it was not significantly lower in male nephroblastoma survivors (mean, 9122; P=0.108). Adjusted means for physical activity scores in females were not different from their controls. In conclusions, male neuroblastoma survivors were identified as performing less daily physical activity. PMID:23389502

van Waas, Marjolein; Wijnen, Mark; Hartman, Annelies; de Vries, Andrica C H; Pieters, Rob; Neggers, Sebastian J C M M; van den Heuvel-Eibrink, Marry M

2013-07-01

118

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

NASA Astrophysics Data System (ADS)

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

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

2013-03-01

119

Towards a long-term record of solar total and spectral irradiance  

NASA Astrophysics Data System (ADS)

The variation of total solar irradiance (TSI) has been measured since 1978 and that of the spectral irradiance for an even shorter amount of time. Semi-empirical models are now available that reproduce over 80% of the measured irradiance variations. An extension of these models into the more distant past is needed in order to serve as input to climate simulations. Here we review our most recent efforts to model solar total and spectral irradiance on time scales from days to centuries and even longer. Solar spectral irradiance has been reconstructed since 1947. Reconstruction of solar total irradiance goes back to 1610 and suggests a value of about 1-1.5W/m2 for the increase in the cycle-averaged TSI since the end of the Maunder minimum, which is significantly lower than previously assumed but agrees with other modern models. First steps have also been made towards reconstructions of solar total and spectral irradiance on time scales of millennia.

Krivova, N. A.; Solanki, S. K.; Unruh, Y. C.

2011-02-01

120

Long-Term Exposure to High Corticosterone Levels Inducing a Decrease of Adenylate Kinase 1 Activity  

Microsoft Academic Search

Corticosterone, a principal glucocorticoid synthesized in the rodent adrenal cortex, can be cumulatively toxic to hippocampal neurons, the cause of which is not known. The present study determined whether the cytosol adenylate kinase (AK) system was involved in the neuronal damage induced by long-term exposure to high corticosterone levels. We investigated the effects of long-term exposure to high corticosterone levels

Yu'nan Zhao; Jia Shen; Hui Su; Yufang Huang; Dongming Xing; Lijun Du

2009-01-01

121

Soil biological activity and their seasonal variations in response to long-term application of organic and inorganic fertilizers  

Microsoft Academic Search

The objectives of this study were to explore the effects of long-term and continued application of fertilizers and manures\\u000a on microbial biomass, soil biological activity and their seasonal variations in surface and subsurface soils in relation to\\u000a soil fertility. For this, soils were sampled in spring, summer and autumn from Shenyang Long-term Experimental Station, northeastern\\u000a China. The results showed that

Gaofei Ge; Zhaojun Li; Fenliang Fan; Guixin Chu; Zhenan Hou; Yongchao Liang

2010-01-01

122

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

ERIC Educational Resources Information Center

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

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

2009-01-01

123

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

ERIC Educational Resources Information Center

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

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

2009-01-01

124

Activation of ?-adrenergic receptors facilitates heterosynaptic translation-dependent long-term potentiation  

PubMed Central

Abstract Noradrenaline critically modulates the ability of synapses to undergo long-term plasticity on time scales extending well beyond fast synaptic transmission. Noradrenergic signalling through ?-adrenergic receptors (?-ARs) enhances memory consolidation and can boost the longevity of long-term potentiation (LTP). Previous research has shown that stimulation of one synaptic pathway with a protocol that induces persistent, translation-dependent LTP can enable the induction of LTP by subthreshold stimulation at a second, independent synaptic pathway. This heterosynaptic facilitation depends on the regulation and synthesis of proteins. Recordings taken from area CA1 in mouse hippocampal slices showed that induction of ?-AR-dependent LTP at one synaptic pathway (S1) can facilitate LTP at a second, independent pathway (S2) when low-frequency, subthreshold stimulation is applied after a 30 min delay. ?-AR-dependent heterosynaptic facilitation requires protein synthesis as inhibition of mammalian target of rapamycin (mTOR), extracellular signal-regulated kinase (ERK), or translation, prevented homo- and heterosynaptic LTP. Shifting application of a translational repressor, emetine, to coincide with S2 stimulation did not block LTP. Heterosynaptic LTP was prevented in the presence of the cell-permeable cAMP-dependent protein kinase inhibitor, PKI. Conversely, the time window for inter-pathway transfer of heterosynaptic LTP was extended through inhibition of GluR2 endocytosis. Our data show that activation of ?-ARs boosts the heterosynaptic expression of translation-dependent LTP. These results suggest that engagement of the noradrenergic system may extend the associative capacity of hippocampal synapses through facilitation of intersynaptic crosstalk.

Connor, Steven A; Wang, Yu Tian; Nguyen, Peter V

2011-01-01

125

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

NASA Astrophysics Data System (ADS)

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

Napoli, Christian; Bonanno, Francesco; Capizzi, Giacomo

2011-06-01

126

Long-term variations in the properties of large solar energetic particle events  

Microsoft Academic Search

The occurrence of large solar energetic particle SEP events 30MeV fluence 2x10 9 cm -2 is reviewed using data obtained by satellites ground based instrumentation and from the glaciological record It is shown that the frequency of occurrence of large fluence events during the space era 1960 et seq was one of the lowest in the past 400 years Large

K. G. McCracken

2006-01-01

127

Long-term Solar Forcing of the Arctic Oscillation\\/North Atlantic Oscillation  

Microsoft Academic Search

We examine the climate response to solar irradiance changes between the late 17th century Maunder Minimum and the late 18th century. Global average temperature changes are small (≈0.3--0.4 K) in both a climate model including stratospheric ozone feedbacks and in empirical reconstructions. Regional temperature changes, however, are quite large. In the model, these occur primarily through a forced decrease in

D. Shindell; G. Schmidt; M. Mann; D. Rind; A. Waple

2001-01-01

128

Long-term culture of hepatocytes: effect of hormones on enzyme activities and metabolic capacity.  

PubMed

(i) Hepatocytes isolated from adult rats were cultured for 2 to 3 weeks on collagen in a modified, serum-free Waymouth medium containing fatty acids and varying concentrations of glucocorticoid, insulin and glucagon. (ii) In the presence of all three hormones, it was possible to maintain the content of DNA, the activity of glucokinase, pyruvate kinase, hexokinase and lactate dehydrogenase at initial levels for 2 to 3 weeks. The activity of glucokinase and pyruvate kinase was affected by the concentration of insulin. (iii) The activity of alcohol dehydrogenase was stable for 3 days and declined to about 25% of the initial level after 2 weeks of culture, irrespective of the presence of hormones. (iv) Maintenance of albumin secretion was dependent on the presence of glucocorticoid, and glucocorticoid and insulin showed an additive or, at some time points, a synergistic effect on its secretion. (v) The content of cytochrome P-450 could be kept at 65% of the initial level, provided that a relatively high concentration of dexamethasone was present (10(-6) M). (vi) In the absence of hormones, urea synthesis was 70% of initial levels throughout the experimental period. With insulin and glucocorticoid present, a high concentration of glucagon (10(-8) M) was required to maintain the synthesis of urea at this level. (vii) It is concluded that hepatocyte cultures as described in the present study may be a useful, well-defined system for long-term metabolic, pharmacologic and toxicologic studies. PMID:3276589

Dich, J; Vind, C; Grunnet, N

129

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

130

Vestibular stimulation enhances hippocampal long-term potentiation via activation of cholinergic septohippocampal cells.  

PubMed

Vestibular stimulation induced acetylcholine release in the hippocampus, and acetylcholine is known to facilitate long-term potentiation (LTP) in the hippocampus. Thus, we hypothesize that vestibular stimulation enhances LTP in CA1 in freely behaving rats, and this enhancement depends on the activation of septohippocampal cholinergic neurons. Field excitatory postsynaptic potentials were recorded in CA1 area of behaving rats following stimulation of the basal dendritic afferents. LTP was induced by a single stimulation train (100 pulses at 200 Hz) during passive whole-body rotation or during awake-immobility. LTP induced during rotation was significantly larger than that induced during immobility. Pretreatment with cholinergic antagonist atropine sulfate (50mg/kg i.p.) abolished the facilitation of LTP during rotation as compared to immobility. Selective lesion of cholinergic cells in the medial septum (MS) with 192 IgG-saporin (0.49 ?g in 1.4 ?l) also abolished the difference in LTP induced during rotation and immobility, which was found in sham-lesion rats. 192 IgG-saporin lesioned rats, as compared to sham-lesion rats, revealed a depletion of MS cells immunopositive to choline acetyltransferase and paling of acetylcholinesterase staining in the hippocampus, without significant change in the number of parvalbumin-immunopositive cells. We conclude that enhancement of LTP during vestibular stimulation is mediated by the activation of cholinergic septohippocampal cells. This is the first direct evidence that vestibular stimulation facilitates hippocampal synaptic plasticity via a cholinergic input. PMID:22521836

Tai, Siew Kian; Leung, L Stan

2012-04-13

131

NADPH oxidase activity is necessary for acute intermittent hypoxia-induced phrenic long-term facilitation  

PubMed Central

Phrenic long-term facilitation (pLTF) following acute intermittent hypoxia (AIH) is a form of spinal, serotonin-dependent synaptic plasticity that requires reactive oxygen species (ROS) formation. We tested the hypothesis that spinal NADPH oxidase activity is a necessary source of ROS for pLTF. Sixty minutes post-AIH (three 5-min episodes of 11% O2, 5 min intervals), integrated phrenic and hypoglossal (XII) nerve burst amplitudes were increased from baseline, indicative of phrenic and XII LTF. Intrathecal injections (?C4) of apocynin or diphenyleneiodonium chloride (DPI), two structurally and functionally distinct inhibitors of the NADPH oxidase complex, attenuated phrenic, but not XII, LTF. Immunoblots from soluble (cytosolic) and particulate (membrane) fractions of ventral C4 spinal segments revealed predominantly membrane localization of the NADPH oxidase catalytic subunit, gp91phox, whereas membrane and cytosolic expression were both observed for the regulatory subunits, p47phox and RAC1. Immunohistochemical analysis of fixed tissues revealed these same subunits in presumptive phrenic motoneurons of the C4 ventral horn, but not in neighbouring astrocytes or microglia. Collectively, these data demonstrate that NADPH oxidase subunits localized within presumptive phrenic motoneurons are a major source of ROS necessary for AIH-induced pLTF. Thus, NADPH oxidase activity is a key regulator of spinal synaptic plasticity, and may be a useful pharmaceutical target in developing therapeutic strategies for respiratory insufficiency in patients with, for example, cervical spinal injury.

MacFarlane, P M; Satriotomo, I; Windelborn, J A; Mitchell, G S

2009-01-01

132

Long-term health-enhancing physical activity in rheumatoid arthritis - the PARA 2010 study  

PubMed Central

Background People with rheumatoid arthritis (RA) suffer increased risk of disability andpremature mortality. Health-enhancing physical activity (HEPA) could be one importantfactor to reduce this risk. Rising health care costs call for the development and evaluation ofnew modes of rehabilitation, including physical activity in settings outside the health caresystem. Methods/Design This cohort study targets 450 patients with RA that do not currently meet HEPA recommendations, recruited from six hospitals reporting to the Swedish Rheumatology Quality Registers (SRQ). We have developed a two-year real-life intervention program including a minimum of twice-weekly circuit training, moderately intense physical activity the remaining days of the week and group meetings to support behavior change every other week. Our hypothesis is that increased physical activity and exercise will improve perceived health, reduce pain and fatigue, increase muscle function and aerobic capacity, impact psychosocial factors and prevent future cardiovascular events. Research questions regard outcomes, retention rates, dose–response matters and the exploration of responder characteristics. This protocol outlines recruitment procedure, design, assessment methods and the intervention program of the study. Discussion The PARA 2010 project is designed to expand the knowledge on HEPA in RA by a progressive approach regarding population, setting, intervention, time frames and outcome measures. To our knowledge this is the first long-term HEPA program based on Social Cognitive Theory, and performed in a real life environment to demonstrate if this new setting can promote increased and maintained physical activity in people with RA. Trial registration number ISRCTN25539102

2012-01-01

133

Long-term health-enhancing physical activity in rheumatoid arthritis - the PARA 2010 study.  

PubMed

ABSTRACT: BACKGROUND: People with rheumatoid arthritis (RA) suffer increased risk of disability and premature mortality. Health-enhancing physical activity (HEPA) could be one important factor to reduce this risk. Rising health care costs call for the development and evaluation of new modes of rehabilitation, including physical activity in settings outside the health care system. METHODS: This cohort study targets 450 patients with RA that do not currently meet HEPA recommendations, recruited from six hospitals reporting to the Swedish Rheumatology Quality Registers (SRQ). We have developed a two-year real-life intervention program including a minimum of twice-weekly circuit training, moderately intense physical activity the remaining days of the week and group meetings to support behavior change every other week. Our hypothesis is that increased physical activity and exercise will improve perceived health, reduce pain and fatigue, increase muscle function and aerobic capacity, impact psychosocial factors and prevent future cardiovascular events. Research questions regard outcomes, retention rates, dose-response matters and the exploration of responder characteristics. This protocol outlines recruitment procedure, design, assessment methods and the intervention program of the study. DISCUSSION: The PARA 2010 project is designed to expand the knowledge on HEPA in RA by a progressive approach regarding population, setting, intervention, time frames and outcome measures. To our knowledge this is the first long-term HEPA program based on Social Cognitive Theory, and performed in a real life environment to demonstrate if this new setting can promote increased and maintained physical activity in people with RA. Trial registration number ISRCTN25539102. PMID:22656861

Nordgren, Birgitta; Fridén, Cecilia; Demmelmaier, Ingrid; Bergström, Gunnar; Opava, Christina H

2012-06-01

134

Long-Term Dosimetry of Solar UV Radiation in Antarctica with Spores of Bacillus subtilis  

PubMed Central

The main objective was to assess the influence of the seasonal stratospheric ozone depletion on the UV climate in Antarctica by using a biological test system. This method is based on the UV sensitivity of a DNA repair-deficient strain of Bacillus subtilis (TKJ 6321). In our field experiment, dried layers of B. subtilis spores on quartz discs were exposed in different seasons in an exposure box open to solar radiation at the German Antarctic Georg von Neumayer Station (70°37?S, 8°22?W). The UV-induced loss of the colony-forming ability was chosen as the biological end point and taken as a measure for the absorbed biologically harmful UV radiation. Inactivation constants were calculated from the resulting dose-response curves. The results of field experiments performed in different seasons indicate a strongly season-dependent trend of the daily UV-B level. Exposures performed at extremely depleted ozone concentrations (October 1990) gave higher biologically harmful UV-B levels than expected from the calculated season-dependent trend, which was determined at normal ozone values. These values were similar to values which were measured during the Antarctic summer, indicating that the depleted ozone column thickness has an extreme influence on the biologically harmful UV climate on ground.

Puskeppeleit, Monika; Quintern, Lothar E.; el Naggar, Saad; Schott, Jobst-Ulrich; Eschweiler, Ute; Horneck, Gerda; Bucker, Horst

1992-01-01

135

Review: the long-term consequences of microglial activation following acute traumatic brain injury.  

PubMed

The brain is vulnerable to a number of acute insults, with traumatic brain injury being among the commonest. Neuroinflammation is a common response to acute injury and microglial activation is a key component of the inflammatory response. In the acute and subacute phase it is likely that this response is protective and forms an important part of the normal tissue reaction. However, there is considerable literature demonstrating an association between acute traumatic brain injury to the brain and subsequent cognitive decline. This article will review the epidemiological literature relating to both single and repetitive head injury. It will focus on the neuropathological features associated with long-term complications of a single blunt force head injury, repetitive head injury and blast head injury, with particular reference to chronic traumatic encephalopathy, including dementia pugilistica. Neuroinflammation has been postulated as a key mechanism linking acute traumatic brain injury with subsequent neurodegenerative disease, and this review will consider the response to injury in the acute phase and how this may be detrimental in the longer term, and discuss potential genetic factors which may influence this cellular response. Finally, this article will consider future directions for research and potential future therapies. PMID:23206160

Smith, C

2013-02-01

136

Physical activity and fitness in adolescent and young adult long-term survivors of childhood acute lymphoblastic leukaemia  

Microsoft Academic Search

Introduction  There is a lack of data on physical activity (PA) and fitness of adolescent and young adult very long-term survivors of childhood\\u000a acute lymphoblastic leukemia (ALL).\\u000a \\u000a \\u000a \\u000a \\u000a Methods  We studied 21 childhood ALL long-term survivors (aged 16–30 years, median time since diagnosis 15.9y), diagnosed in 1986–1996,\\u000a with age- and sex-matched controls. Peak oxygen uptake (VO2peak) and muscle strength were measured and physical activity

Liisa S. Järvelä; Harri Niinikoski; Päivi M. Lähteenmäki; Olli J. Heinonen; Jukka Kapanen; Mikko Arola; Jukka Kemppainen

2010-01-01

137

Long-term lithium treatment in rats attenuates m -chlorophenylpiperazine-induced decreases in food intake but not locomotor activity  

Microsoft Academic Search

Administration of various doses of m-chlorophenylpiperazine (m-CPP, a 5-HT agonist) to rats produced dose-related decreases in food intake and locomotor activity. Long-term (21–25 days) but not short-term (3–7 days) lithium treatment attenuated m-CPP-induced decreases in food intake. However, neither short-term nor long-term lithium treatment had any significant effect on m-CPP-induced decreases in locomotor activity. These findings suggest development of functional

Charanjit S. Aulakh; Joseph Zohar; Krystyna M. Wozniak; James L. Hill; Dennis L. Murphy

1989-01-01

138

Long-term superiority of steroid elution in atrial active fixation platinum leads.  

PubMed

Steroid elution reduces the acute increase in stimulation threshold particularly in active fixation leads. The aim of this study was to investigate the long-term efficacy of steroid elution in atrial screw-in leads compared to conventional lead design. Two different bipolar active fixation platinum lead designs were implanted. Leads were similar except for the presence (group S, n = 66) or absence (group N, n = 68) of steroid elution. Patients received dual chamber pacemakers with the following atrial leads in consecutive order: Medtronic 4058 M (group N, n = 30), Medtronic 4068 (group S, n = 40), Vitatron IMS 13 (identical to 4058 M, group N, n = 38), and Vitatron IMX 13 (identical to 4068, group S, n = 26). The mean follow-up period was 40.7 +/- 16.1 months (range 10 to 84 months). Stimulation thresholds, pacing impedances, P wave potentials, and sensing threshold were assessed for both groups immediately, 10 days, 6 weeks, and 3 months after implantation followed by 6-months intervals. Energy thresholds, chronaxie-rheobase products, and energy consumption of atrial pacing were calculated. Chronic values were deduced from the most recent measurement performed in an individual patient. Within the first 10 days after implantation, atrial voltage threshold at pulse duration of 0.4 ms increased from 0.91 +/- 0.42 to 2.06 +/- 0.45 V in group N (P < 0.001). Less increase was observed in group S (0.83 +/- 0.39 to 1.08 +/- 0.53 V, P = 0.003). Atrial voltage thresholds remained markedly lower in steroid-eluting leads during whole follow-up (1.12 +/- 0.49 V in group S vs 1.58 +/- 0.71 V in group N, P < 0.001). Chronic energy consumption was markedly reduced in group S (4.0 +/- 2.7 microJ) compared to group N (9.8 +/- 7.5 microJ, P < 0.001). An atrial voltage threshold below 1.25 V at 0.4 ms was achieved in 92.3% of patients of group S allowing programming of an output of 2.5 V. Such low outputs were feasible in only 49.3% of patients in group N (P < 0.001). Chronic P wave amplitudes did not differ significantly between groups (3.27 +/- 1.81 mV in group N vs 3.24 +/- 1.18 mV in group S, P = 0.91). Steroid elution diminishes the increase of stimulation thresholds of nonsteroid atrial active fixation platinum leads resulting in a long-term reduction of energy consumption. Thus, use of steroids can be recommended for general use in atrial active fixation lead designs. PMID:10879386

Wiegand, U K; Potratz, J; Bonnemeier, H; Bode, F; Panik, R; Haase, H; Peters, W; Katus, H A

2000-06-01

139

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

NASA Astrophysics Data System (ADS)

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

Kim, Mi-Jeong; Park, Nam-Gyu

2012-09-01

140

Temporal Sensitivity of Protein Kinase A Activation in Late-Phase Long Term Potentiation  

PubMed Central

Protein kinases play critical roles in learning and memory and in long term potentiation (LTP), a form of synaptic plasticity. The induction of late-phase LTP (L-LTP) in the CA1 region of the hippocampus requires several kinases, including CaMKII and PKA, which are activated by calcium-dependent signaling processes and other intracellular signaling pathways. The requirement for PKA is limited to L-LTP induced using spaced stimuli, but not massed stimuli. To investigate this temporal sensitivity of PKA, a computational biochemical model of L-LTP induction in CA1 pyramidal neurons was developed. The model describes the interactions of calcium and cAMP signaling pathways and is based on published biochemical measurements of two key synaptic signaling molecules, PKA and CaMKII. The model is stimulated using four 100 Hz tetani separated by 3 sec (massed) or 300 sec (spaced), identical to experimental L-LTP induction protocols. Simulations show that spaced stimulation activates more PKA than massed stimulation, and makes a key experimental prediction, that L-LTP is PKA-dependent for intervals larger than 60 sec. Experimental measurements of L-LTP demonstrate that intervals of 80 sec, but not 40 sec, produce PKA-dependent L-LTP, thereby confirming the model prediction. Examination of CaMKII reveals that its temporal sensitivity is opposite that of PKA, suggesting that PKA is required after spaced stimulation to compensate for a decrease in CaMKII. In addition to explaining the temporal sensitivity of PKA, these simulations suggest that the use of several kinases for memory storage allows each to respond optimally to different temporal patterns.

Kim, MyungSook; Huang, Ted; Abel, Ted; Blackwell, Kim T.

2010-01-01

141

Cholinergic activity enhances hippocampal long-term potentiation in CA1 during walking in rats.  

PubMed

Long-term potentiation (LTP) at the basal-dendritic synapses of CA1 pyramidal cells was induced by a single 200 Hz stimulation train (0.5-1 sec duration) in freely behaving rats during one of four behavioral states: awake-immobility (IMM), walking, slow-wave sleep (SWS), and rapid eye movement sleep (REM). Field EPSPs generated by basal-dendritic excitation of CA1 were recorded before and up to 1 d after the tetanus. After a tetanus during any behavioral state, basal-dendritic LTP was >170% of the baseline for the first hour after the tetanus and decayed to approximately 120% 1 d after. LTP induced during walking was significantly larger than that induced during IMM, SWS, or REM, which had similar LTP magnitudes. To test the hypothesis that septohippocampal cholinergic activity enhanced LTP during walking as compared with IMM, rats were either pretreated with muscarinic cholinergic antagonist scopolamine or injected with IgG192-saporin in the medial septum to selectively lesion cholinergic septohippocampal neurons. Pretreatment with scopolamine decreased the LTP induced during walking but did not affect that induced during IMM, such that the difference between the LTP induced during walking and IMM was abolished after scopolamine. Rats injected with IgG192-saporin showed no difference in the LTP induced during walking and IMM, and scopolamine did not reduce the LTP during walking. In contrast, sham-lesion rats showed larger LTP induced during walking than IMM, and the LTP induced during walking was attenuated by scopolamine. This is the first demonstration of an enhancement of hippocampal LTP by physiologically activated cholinergic inputs. PMID:14561856

Leung, L Stan; Shen, Bixia; Rajakumar, Nagalingam; Ma, Jingyi

2003-10-15

142

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

143

Evidence for Human Fronto-Central Gamma Activity during Long-Term Memory Encoding of Word Sequences  

Microsoft Academic Search

Although human gamma activity (30–80 Hz) associated with visual processing is often reported, it is not clear to what extend gamma activity can be reliably detected non-invasively from frontal areas during complex cognitive tasks such as long term memory (LTM) formation. We conducted a memory experiment composed of 35 blocks each having three parts: LTM encoding, working memory (WM) maintenance

Esther Berendina Meeuwissen; Atsuko Takashima; Guillén Fernández; Ole Jensen; Thomas Koenig

2011-01-01

144

Long-term changes in indices of geomagnetic activity at the auroral station Sodankylä  

NASA Astrophysics Data System (ADS)

Here we compare the traditional analog measure of geomagnetic activity, Ak, with the more recent digital indices of IHV and Ah based on hourly mean data, and their derivatives at the auroral station Sodankylä. By this selection of indices we study the effects of (i) analog vs. digital technique, and (ii) full local-time vs. local night-time coverage on quantifying local geomagnetic activity. We find that all other indices are stronger than Ak during the low-activity cycles 15-16 suggesting an excess of very low scalings in Ak at this time. The full-day indices consistently depict stronger correlation with the interplanetary magnetic field strength, while the night-time indices have higher correlation with solar wind speed. The Ak index correlates better with the digital indices of full-day coverage than with any night-time index. However, Ak depicts somewhat higher activity levels than the digital full-day indices in the declining phase of the solar cycle, indicating that, due to their different sampling rates, the latter indices are less sensitive to high-frequency variations driven by the Alfvén waves in high-speed streams. On the other hand, the night-time indices have an even stronger response to solar wind speed than Ak. The results strongly indicate that at auroral latitudes, geomagnetic indices with different local time coverage reflect different current systems, which, by an appropriate choice of indices, allows studying the century-scale dynamics of these currents separately.

Martini, D.; Mursula, K.; Ulich, T.; Pandey, V. S.; Kim, K.-H.; Lee, D.-H.

2012-09-01

145

Influence of long term physical activity on selected skinfold variables of national level male sports persons  

Microsoft Academic Search

The aim of present investigation were: (1) to describe the selected skinfold variables of male students of University of Delhi that is, national level sports persons; and (2) to study the effect of long term physical training programme on selected skinfold variables of national level sports persons that is, male volunteers from University of Delhi. The sample size for the

Dhananjoy Shaw; Seema Kaushik

2010-01-01

146

Long term CO2 trapping and associated leakage efficiency: the role of active faults  

NASA Astrophysics Data System (ADS)

Geological CO2 storage is viewed as a possible solution for the mitigation of increasing on-going global warming. Several pilot injection sites are already in place and numerous numerical scenarios are modeled. However, the remaining question is how effective the different kind of traps, caprocks and associated leakages are in the long term. One of the best keys to answer this question is to investigate natural CO2 fields. Here, we present the study of a CO2-reservoir, located upon the Colorado Plateau, leaking for thousands of years along normal faults. We are currently investigating i) the CO2-leakage processes from the deep to the surface, ii) the CO2 and the fluid origins, the reaction mechanisms during the transfer and finally iii) the fluid circulation time by datation. Fieldworks across a fractured zone lead us to rebuild the architecture of the CO2 path from the depth to the surface: from bleached fractures through the reservoir/caprock pile to calcium carbonate mineralization. The CO2 leaking zone migrated along the faults: traces of past and actual leakages are obvious at different points of faults evidenced by travertine occurrences. Furthermore, at a same location, proofs of episodic CO2 circulation had been found at different scales, from outcrop to thin-section scales. Detailed petrographic and isotopic analysis confirmed this result and characterized the change in fluid source. Dedicated studies on carbonated mineralization (travertine) at the surface, revealed a complex mode of formation. The travertine can be subdivided into three main types of carbonated rocks: 1) a "classical" travertine built on surface 2) horizontal and 3) vertical crosscutting veins through the first occurrence. Each of theses units is characterized by different crystallization modes and processes. Petrographic observations indicates that the travertine and the veins are mainly built of aragonite and calcite: their partition and mineral morphology can be considered as a tool to understand the paragenesis and the evolution of thermodynamic and chemical properties - P, PCO2, T, calcium saturation - of the fluids during the leakage, through mineralization time-step at the surface. In parallel, preliminary paleomagnetic studies and U/Th datating on the various cross-cutting veins constrain the laps-time of each mineralization event, leading to an estimation of flow rate evolution of one opening/sealing event. Based on these results, we will propose a numerical modeling of CO2-leakage through a faulted zone which links episodic variations of CO2-circulation to fault opening and sealing: a Dirac of CO2-input corresponding to the opening of the fault during earthquake is followed by an exponential decrease rate of the CO2 flow related to the post-seismic fault sealing by the mineralization of calcium carbonate. The model allows to evaluate the cumulative flow of CO2 releases by successive earthquakes or pressure drop linked to the long-term fault activity.

Frery, E.; Gratier, J.; Ellouz, N.; Swennen, R.; Blamart, D.; Aubourg, C.; Deschamps, P.; Faure, J.; Battani, A.

2010-12-01

147

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.

148

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

ERIC Educational Resources Information Center

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

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

2011-01-01

149

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

ERIC Educational Resources Information Center

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

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

2011-01-01

150

Long-term stability of Angle Class II, Division 1 malocclusions with successful occlusal results at end of active treatment  

Microsoft Academic Search

The purpose of this study was to examine long-term stability of Angle Class II, Division 1 malocclusions with successful occlusal results at the end of active appliance therapy, search for predictors of relapse, and look for characteristics associated with successful treatment. Records taken before and after treatment and a mean of 14.0 years postretention of adolescent patients treated for a

Brett C. Fidler; Jon Årtun; Donald R. Joondeph; Robert M. Little

1995-01-01

151

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

ERIC Educational Resources Information Center

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

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

2009-01-01

152

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

Microsoft Academic Search

The present study used functional magnetic resonance imaging to delineate cortical networks that are activated when objects or spatial locations encoded either visually (visual encoding group, n = 10) or haptically (haptic encoding group, n = 10) had to be retrieved from long-term memory. Participants learned associations between auditorily presented words and either meaningless objects or locations in a 3-D

Oliver Stock; Michael Burke; Siegfried Bien; Frank Rosler

2008-01-01

153

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

Microsoft Academic Search

The present study used functional magnetic resonance imaging to delineate cortical networks that are activated when objects or spatial locations encoded either visually (visual encoding group, n = 10) or haptically (haptic encoding group, n = 10) had to be retrieved from long-term memory. Participants learned associations between auditorily presented words and either meaningless objects or locations in a 3-D

Oliver Stock; Brigitte Röder; Michael Burke; Siegfried Bien; Frank Rösler

2009-01-01

154

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

ERIC Educational Resources Information Center

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

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

2009-01-01

155

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

Microsoft Academic Search

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

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

2006-01-01

156

Long-Term Variations of the Solar Supergranulation Size According to the Observations in CaIIK Line  

NASA Astrophysics Data System (ADS)

This work contains analysis of distinctive size of chromospheric cells Kodaikanal (1907-1999) and Medon (1983-2010). At first the contrast of chromospheric grid was enlarged on image, by means of subtraction of the gradient from the solar disc intensity. This analysis was performed with the help of balanced wavelet transformation. It was discovered that distinctive size of chromospheric cells is close to 36Mm but it has variations,in the phase of solar activity ˜1, 2Mm maximal size of the cell can be seen as a rule, in ˜1, 5 year after maximum of the solar activity. There is a positive correlation (R = 0, 83) between the size of the chromospheric cells in maximum and the amplitude of the following activity cycle. Thus, the size of the supergranulation is connected with the solar activity and is ahead of it ˜8, 8 of a year.

Tlatov, A. G.

157

Midlatitude long-term temperature trend deduced from 17 years of Na lidar observations and its relationships to solar cycle effects and an observed episodic response  

NASA Astrophysics Data System (ADS)

The Colorado State University (CSU) sodium lidar, first light in August 1989, has conducted regular observations of nocturnal mesopause region temperature and Na density continuously for more than 18 years since May 1991. The long-term nocturnal temperature record (1990-2007) has been used to reveal an episodic response after Mt. Pinatubo eruption, 11-year (and 27-day) solar cycle effect and temperature trend. Though the observed cooling reported in the literature from different instruments at different geographic locations is inconclusive, ranging between 0 and 10 K per decade, when all 3 long-term effects are included, the CSU data deduced a temperature trend with maximum cooling of ~ 1.5 K/decade at 91 km and a profile in general agreement with recent model predictions. The effect of solar flux variations and observed episodic response on the deduced long-term temperature trend will be discussed.

She, C.; Krueger, D. A.

2009-12-01

158

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

Microsoft Academic Search

Context. The IUE database provides a large number of UV high and\\u000alow-resolution spectra of RS CVn-type stars from 1978 to 1996. In particular,\\u000amany of these stars were monitored continuously during several seasons by IUE.\\u000aAims. Our main purpose is to study the short and long-term chromospheric\\u000aactivity of the RS CVn systems most observed by IUE: HD 22468

Andrea P. Buccino; Pablo J. D. Mauas

2008-01-01

159

Copper Speciation and Microbial Activity in Long-Term Contaminated Soils  

Microsoft Academic Search

.   Most soil quality guidelines do not distinguish among the various forms of metals in soils; insoluble, nonreactive, and\\u000a nonbioavailable forms are deemed as hazardous as highly soluble, reactive, and toxic forms. The objective of this study was\\u000a to better understand the long-term effects of copper on microorganisms in relation to its chemical speciation in the soil\\u000a environment. Carbon mineralization

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

1999-01-01

160

ACUTE DEVI ATIONS FROM LONG-TERM TRAIT DEPRESSIVE SYMPTOMS PREDICT SYSTEMIC INFLAMM ATO RY ACTIVITY  

Microsoft Academic Search

Objective. Depressive symptoms increase morbidity and mortality from coronary heart disease and systemic inflammation has been proposed as the underlying mechanism. While higher levels of inflammatory mediators have been found in dysphoric individuals, it is not known whether long-term or short-term mood changes are responsible for this phenomenon. Methods. A sample of 65 young women provided weekly web-based self-ratings of

Nicolas Rohleder; Gregory E. Miller

161

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

USGS Publications Warehouse

Forest managers often seek to balance economic benefits from timber harvesting with maintenance of habitat for wildlife, ecosystem function, and human uses. Most research on the relationship between avian abundance and active timber management has been short-term, lasting one to two years, creating the need to investigate long-term avian responses and to identify harvest thresholds when a small change in habitat results in a disproportionate response in relative abundance and nest success. Our objectives were to identify trends in relative abundance and nest success and to identify landscape-scale disturbance thresholds for avian species and habitat guilds in response to a variety of harvest treatments (clear-cuts, heavy and light partial harvests) over 14 years. We conducted point counts and monitored nests at an industrial forest in the central Appalachians of West Virginia during 1996-1998, 2001-2003, and 2007-2009. Early successional species increased in relative abundance across all three time periods, whereas interior-edge and forest-interior guilds peaked in relative abundance mid-study after which the forest-interior guild declined. Of 41 species with >10 detections, four (10%) declined significantly, 13 (32%) increased significantly (only three species among all periods), and 9 (22%) peaked in abundance mid-study (over the entire study period, four species had no significant change in abundance, four declined, and one increased). Based on piecewise linear models, forest-interior and interior-edge guilds' relative abundance harvest thresholds were 28% total harvests (all harvests combined), 10% clear-cut harvests, and 18% light partial harvests, after which abundances declined. Harvest thresholds for the early successional guild were 42% total harvests, 11% clear-cut harvest, and 10% light partial harvests, and relative abundances increased after surpassing thresholds albeit at a reduced rate of increase after the clear-cut threshold. Threshold confidence intervals for individual species overlapped their guild threshold intervals 91% of the time. Even though relative abundance of most species (80%) did not decline as the area affected by timber management increased, implementing management at or below our approximate forest-interior and interior-edge harvest thresholds would reduce the number of declining species by half, maintain higher relative abundances of four species with a net decline in abundance but that peaked in abundance mid-study, and maintain higher relative abundances of ten additional species. In contrast, this management strategy also would prevent the increase in relative abundance of seven species and limit the increase in abundance of three species that increased throughout the study. ?? 2011 Elsevier B.V.

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

2011-01-01

162

?-Galactosidase activity of Escherichia coli under long-term starvation, alterations in temperature, and different nutrient conditions in lake water  

Microsoft Academic Search

.   ?-Galactosidase activity of Escherichia coli was investigated in response to long-term starvation, changes in temperature and the presence of certain nutrient sources\\u000a in lake water. ?-Galactosidase activity decreased markedly in filtered-autoclaved lake water at 25 °C and 37 °C, whereas it\\u000a remained almost constant at 4 °C and 15 °C for 60 days. Increases in ?-galactosidase activity were observed in response to\\u000a the following

R. Özkanca

2002-01-01

163

Naringin Enhances CaMKII Activity and Improves Long-Term Memory in a Mouse Model of Alzheimer's Disease.  

PubMed

The Amyloid-? (A?)-induced impairment of hippocampal synaptic plasticity is an underlying mechanism of memory loss in the early stages of Alzheimer's disease (AD) in human and mouse models. The inhibition of the calcium/calmodulin-dependent protein kinase II (CaMKII) autophosphorylation plays an important role in long-term memory. In this study, we isolated naringin from Pomelo peel (a Citrus species) and studied its effect on long-term memory in the APPswe/PS1dE9 transgenic mouse model of AD. Three-month-old APPswe/PS1dE9 transgenic mice were randomly assigned to a vehicle group, two naringin (either 50 or 100 mg/kg body weight/day) groups, or an Aricept (2 mg/kg body weight/day) group. After 16 weeks of treatment, we observed that treatment with naringin (100 mg/kg body weight/day) enhanced the autophosphorylation of CaMKII, increased the phosphorylation of the ?-amino-3-hydroxy-5-methyl-4-isoxazolepropionic (AMPA) receptor at a CaMKII-dependent site and improved long-term learning and memory ability. These findings suggest that the increase in CaMKII activity may be one of the mechanisms by which naringin improves long-term cognitive function in the APPswe/PS1dE9 transgenic mouse model of AD. PMID:23478434

Wang, Dong-Mei; Yang, Ya-Jun; Zhang, Li; Zhang, Xu; Guan, Fei-Fei; Zhang, Lian-Feng

2013-03-11

164

Increase in posterior alpha activity during rehearsal predicts successful long-term memory formation of word sequences  

Microsoft Academic Search

It is becoming increasingly clear that demanding cognitive tasks rely on an extended network engaging task-relevant areas and, importantly, disengaging task-irrelevant areas. Given that alpha activity (8-12 Hz) has been shown to reflect the disengagement of task-irrelevant regions in attention and working memory tasks, we here ask if alpha activity plays a related role for long-term memory formation. Subjects were

E. B. Meeuwissen; A. Takashima; G. S. E. Fernandez; O. Jensen

2011-01-01

165

Long-term Exposure of Variable Dietary Protein-to-Carbohydrate Ratio: Effect on Brain Regional Glutamatergic Activity with Age  

Microsoft Academic Search

Glutamatergic activity of hypothalamus and hippocampus of young (3 months) male albino rats having normal diet [protein (20%)–carbohydrate\\u000a (68%)] was increased with the increase of age. Long-term (60 consecutive days) feeding of low protein (8%)–high carbohydrate\\u000a (80%) diet (LP–HC) increased glutamatergic activity in these brain regions of young rats and decreased that in aged (18 months).\\u000a On the contrary, supplementation of high

Sudipta Pal; Mrinal K. Poddar

2008-01-01

166

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

Microsoft Academic Search

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

Z. Franic; G. Marovic

2007-01-01

167

Long-term investigations of radiocaesium activity concentrations in carp in North Croatia after the Chernobyl accident  

Microsoft Academic Search

Long-term investigations of radiocaesium activity concentrations in carp in the Republic of Croatia are presented. The radiocaesium levels in carp decreased exponentially and the effective ecological half-life of 137Cs was estimated to be about 1 year during 1987–2002 and 5 years during 1993–2005.The observed 134Cs:137Cs activity ratio in carp was found to be similar to the ratio observed in other

Zdenko Frani?; Gordana Marovi?

2007-01-01

168

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

NASA Astrophysics Data System (ADS)

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

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

2011-10-01

169

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

170

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

NASA Astrophysics Data System (ADS)

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

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

1994-05-01

171

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

Microsoft Academic Search

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

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

2000-01-01

172

Potentiation of d -amphetamine and l-dopa-induced acoustic startle activity after long-term exposure to amphetamine  

Microsoft Academic Search

The startle response to an auditory atimulus was potentiated by treatment with d-amphetamine sulfate. Administration of l-dopa after pretreatment with the extracerebral decarboxylase inhibitor MK-486 also increased startle activity. After long-term exposure to amphetamine the startle response to l-dopa and d-amphetamine was enhanced. These findings are consistent with the consequences of longterm amphetamine administration on other amphetamine-induced behaviors (e.g. stereotypy),

Larry Kokkinidis; Ellen P. MacNeill

1982-01-01

173

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.

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

2012-01-01

174

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

PubMed

In July 2001, the National Museum of Marine Biology and Aquarium, co-sponsored by the Kenting National Park Headquarters and Taiwan's National Science Council, launched a Long-Term Ecological Research (LTER) program to monitor anthropogenic impacts on the ecosystems of southern Taiwan, specifically the coral reefs of Kenting National Park (KNP), which are facing an increasing amount of anthropogenic pressure. We found that the seawater of the reef flats along Nanwan Bay, Taiwan's southernmost embayment, was polluted by sewage discharge at certain monitoring stations. Furthermore, the consequently higher nutrient and suspended sediment levels had led to algal blooms and sediment smothering of shallow water corals at some sampling sites. Finally, our results show that, in addition to this influx of anthropogenically-derived sewage, increasing tourist numbers are correlated with decreasing shallow water coral cover, highlighting the urgency of a more proactive management plan for KNP's coral reefs. PMID:22534409

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

2012-04-23

175

A Semi-Quantitative Method to Denote Generic Physical Activity Phenotypes from Long-Term Accelerometer Data - The ATLAS Index  

PubMed Central

Background Physical activity is inversely correlated to morbidity and mortality risk. Large cohort studies use wearable accelerometer devices to measure physical activity objectively, providing data potentially relevant to identify different activity patterns and to correlate these to health-related outcome measures. A method to compute relevant characteristics of such data not only with regard to duration and intensity, but also to regularity of activity events, is necessary. The aims of this paper are to propose a new method – the ATLAS index (Activity Types from Long-term Accelerometric Sensor data) – to derive generic measures for distinguishing different characteristic activity phenotypes from accelerometer data, to propose a comprehensive graphical representation, and to conduct a proof-of-concept with long-term measurements from different devices and cohorts. Methods The ATLAS index consists of the three dimensions regularity (reg), duration (dur) and intensity (int) of relevant activity events identified in long-term accelerometer data. It can be regarded as a 3D vector and represented in a 3D cube graph. 12 exemplary data sets of three different cohort studies with 99,467 minutes of data were chosen for concept validation. Results Five archetypical activity types are proposed along with their dimensional characteristics (insufficiently active: low reg, int and dur; busy bee: low dur and int, high reg; cardio-active: medium reg, int and dur, endurance athlete: high reg, int and dur; and weekend warrior: high int and dur, low reg). The data sets are displayed in one common graph, indicating characteristic differences in activity patterns. Conclusion The ATLAS index incorporates the relevant regularity dimension apart from the widely-used measures of duration and intensity. Along with the 3D representation, it allows to compare different activity types in cohort study populations, both visually and computationally using vector distance measures. Further research is necessary to validate the ATLAS index in order to find normative values and group centroids.

Marschollek, Michael

2013-01-01

176

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

177

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

2012-06-23

178

Comparison of two voltage-sensitive dyes and their suitability for long-term imaging of neuronal activity.  

PubMed

One of the key approaches for studying neural network function is the simultaneous measurement of the activity of many neurons. Voltage-sensitive dyes (VSDs) simultaneously report the membrane potential of multiple neurons, but often have pharmacological and phototoxic effects on neuronal cells. Yet, to study the homeostatic processes that regulate neural network function long-term recordings of neuronal activities are required. This study aims to test the suitability of the VSDs RH795 and Di-4-ANEPPS for optically recording pattern generating neurons in the stomatogastric nervous system of crustaceans with an emphasis on long-term recordings of the pyloric central pattern generator. We demonstrate that both dyes stain pyloric neurons and determined an optimal concentration and light intensity for optical imaging. Although both dyes provided sufficient signal-to-noise ratio for measuring membrane potentials, Di-4-ANEPPS displayed a higher signal quality indicating an advantage of this dye over RH795 when small neuronal signals need to be recorded. For Di-4-ANEPPS, higher dye concentrations resulted in faster and brighter staining. Signal quality, however, only depended on excitation light strength, but not on dye concentration. RH795 showed weak and slowly developing phototoxic effects on the pyloric motor pattern as well as slow bleaching of the staining and is thus the better choice for long-term experiments. Low concentrations and low excitation intensities can be used as, in contrast to Di-4-ANEPPS, the signal-to-noise ratio was independent of excitation light strength. In summary, RH795 and Di-4-ANEPPS are suitable for optical imaging in the stomatogastric nervous system of crustaceans. They allow simultaneous recording of the membrane potential of multiple neurons with high signal quality. While Di-4-ANEPPS is better suited for short-term experiments that require high signal quality, RH795 is a better candidate for long-term experiments since it has only minor effects on the motor pattern. PMID:24124505

Preuss, Stephanie; Stein, Wolfgang

2013-10-04

179

Comparison of Two Voltage-Sensitive Dyes and Their Suitability for Long-Term Imaging of Neuronal Activity  

PubMed Central

One of the key approaches for studying neural network function is the simultaneous measurement of the activity of many neurons. Voltage-sensitive dyes (VSDs) simultaneously report the membrane potential of multiple neurons, but often have pharmacological and phototoxic effects on neuronal cells. Yet, to study the homeostatic processes that regulate neural network function long-term recordings of neuronal activities are required. This study aims to test the suitability of the VSDs RH795 and Di-4-ANEPPS for optically recording pattern generating neurons in the stomatogastric nervous system of crustaceans with an emphasis on long-term recordings of the pyloric central pattern generator. We demonstrate that both dyes stain pyloric neurons and determined an optimal concentration and light intensity for optical imaging. Although both dyes provided sufficient signal-to-noise ratio for measuring membrane potentials, Di-4-ANEPPS displayed a higher signal quality indicating an advantage of this dye over RH795 when small neuronal signals need to be recorded. For Di-4-ANEPPS, higher dye concentrations resulted in faster and brighter staining. Signal quality, however, only depended on excitation light strength, but not on dye concentration. RH795 showed weak and slowly developing phototoxic effects on the pyloric motor pattern as well as slow bleaching of the staining and is thus the better choice for long-term experiments. Low concentrations and low excitation intensities can be used as, in contrast to Di-4-ANEPPS, the signal-to-noise ratio was independent of excitation light strength. In summary, RH795 and Di-4-ANEPPS are suitable for optical imaging in the stomatogastric nervous system of crustaceans. They allow simultaneous recording of the membrane potential of multiple neurons with high signal quality. While Di-4-ANEPPS is better suited for short-term experiments that require high signal quality, RH795 is a better candidate for long-term experiments since it has only minor effects on the motor pattern.

Preuss, Stephanie; Stein, Wolfgang

2013-01-01

180

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

NASA Astrophysics Data System (ADS)

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

Özdarcan, O.; Evren, S.; Henry, G. W.

2012-02-01

181

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

2012-07-02

182

Montessori-based activities for long-term care residents with advanced dementia: effects on engagement and affect.  

PubMed

Sixteen residents in long-term care with advanced dementia (14 women; average age = 88) showed significantly more constructive engagement (defined as motor or verbal behaviors in response to an activity), less passive engagement (defined as passively observing an activity), and more pleasure while participating in Montessori-based programming than in regularly scheduled activities programming. Principles of Montessori-based programming, along with examples of such programming, are presented. Implications of the study and methods for expanding the use of Montessori-based dementia programming are discussed. PMID:10750318

Orsulic-Jeras, S; Judge, K S; Camp, C J

2000-02-01

183

Long-term scenarios for energy and environment: Energy from the desert with very large solar plants using liquid hydrogen and superconducting technologies  

Microsoft Academic Search

Among the long-term energy scenarios identified by major international organizations in order to drastically reduce fossil fuels consumption and to develop a sustainable energy system within the 21st century, the exploitation of desert areas for large-scale renewable energy production, must be seriously considered. Desert areas are characterized by large land availability, with high levels of solar radiation and wind. However,

L. Trevisani; M. Fabbri; F. Negrini

2006-01-01

184

Midlatitude long-term temperature trend deduced from 17 years of Na lidar observations and its relationships to solar cycle effects and an observed episodic response  

Microsoft Academic Search

The Colorado State University (CSU) sodium lidar, first light in August 1989, has conducted regular observations of nocturnal mesopause region temperature and Na density continuously for more than 18 years since May 1991. The long-term nocturnal temperature record (1990-2007) has been used to reveal an episodic response after Mt. Pinatubo eruption, 11-year (and 27-day) solar cycle effect and temperature trend.

C. She; D. A. Krueger

2009-01-01

185

Long-term exercise increases the DNA binding activity of peroxisome proliferator-activated receptor gamma in rat adipose tissue.  

PubMed

The aim of the present study was to examine the effect of 8 weeks of voluntary wheel running on the gene expression, at the protein level, of 2 enzymes involved in lipogenesis (fatty acid synthase [FAS] and diacylglycerol acyl transferase 1), 2 proteins involved in lipolysis (hormone-sensitive lipase [HSL] and perilipin), and 3 transcription factors mediating the induction of genes involved in lipid metabolism (the alpha, gamma, and delta members of the peroxisome proliferator-activated receptor, or PPAR, family) in rat liver, gastrocnemius muscle, epididymal fat, and subcutaneous fat. Proteins were measured through Western blot analysis in the tissues of 11 trained and 14 untrained rats. The trained rats had lower FAS in the liver; higher FAS, HSL, and perilipin in epididymal fat; and higher HSL in subcutaneous fat. In addition, the trained rats had higher total protein concentrations in both fat depots. No significant differences in the liver, muscle, or adipose tissue PPAR contents were found between groups. However, the DNA binding activity of PPARgamma, measured through an enzyme immunoassay-based method, was higher in both fat depots of the trained rats. Our findings suggest that long-term wheel running had significant effects on the concentrations of proteins playing key roles in lipogenesis and lipolysis in rat liver and adipose tissue. These effects may be due to PPAR activation rather than induction, rendering the transcriptional regulation of target genes more economical and flexible. The activation of PPARgamma with exercise may mediate its beneficial effect on insulin sensitivity. PMID:17618946

Petridou, Anatoli; Tsalouhidou, Sofia; Tsalis, George; Schulz, Thorsten; Michna, Horst; Mougios, Vassilis

2007-08-01

186

Long-term effects of Ni(II) on the performance and activity of activated sludge processes.  

PubMed

The long-term effects of Ni(II) on substrate removal and microorganism activities were investigated by operating sequencing batch reactors (SBRs). Compared to the control system lacking Ni(II), the removal efficiencies of total organic carbon (TOC) and ammonium nitrogen (NH4(+)-N) in SBR system loading with 10mgL(-1) Ni(II) decreased drastically from 90.2±3.6 percent to 75.0±8.9 percent, and 99.2±0.6 percent to 50.8±11.5 percent, respectively. As compared to the control system, a inhibitory rate of more than 50 percent for the 2,3,5-triphenyltetrazolium chloride electron transport system (TTC-ETS) and the 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyltetrazolium chloride electron transport system (INT-ETS), and 43 percent for the specific oxygen uptake rate (sOUR) were detected in SBR system loading with 20mgL(-1) Ni(II). TTC-ETS, INT-ETS, and sOUR were significantly correlated with substrate removal efficiencies, suggesting that they could all serve as effective indicators of the performance of activated sludge processes. Additionally, INT-ETS is superior to sOUR and TTC-ETS in detecting the toxic effects of Ni(II) on sludge microorganism activity. PMID:23590764

Wang, Wei; Li, Xiaochen; Wang, Peifang; Song, Xuedong; Jiang, Dandan; Wang, Kai

2013-04-13

187

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.

2011-01-01

188

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.

189

Long-term effects of postnatal aluminium exposure on acetylcholinesterase activity and biogenic amine neurotransmitters in rat brain.  

PubMed

The long-term effects of early postnatal exposure to aluminium on acetyl choline esterase (AChE) activity and on biogenic amines were studied in different brain regions. The subjects were eight days old male Wistar rat pups. They were grouped into normal control and aluminium exposed groups. For aluminium exposure, the pups were gastric intubated with aluminium chloride (40 mg/Kg body weight) for two weeks. Control rats were given equal volumes of distilled water. After the treatment, they were rehabilitated for forty days. On the sixtieth day, the rats from both the groups were sacrificed and AChE activity, levels of dopamine, noradrenaline and serotonin were estimated in the cerebral cortex, hippocampus, septum, brainstem and striatum. In the aluminium exposed group: the AChE activity was significantly decreased in the hippocampus, septum, striatum and brainstem; serotonin levels were reduced by 20% in the cortex, hippocampus, septum and striatum; in brain stem, the serotonin level was decreased by 40%. A 60% reduction in noradrenaline levels was observed in the striatum whereas it was reduced by 25% in other regions except in hippocampus. Though dopamine levels were not altered in the cortex, septum and brainstem, they were reduced by 40% in the striatum. The study documents the long-term consequences of exposure to aluminium during the developmental periods. PMID:11214504

Ravi, S M; Prabhu, B M; Raju, T R; Bindu, P N

2000-10-01

190

Local technicians in long-term research projects: evaluation of 25 years experience in an active tropical research station.  

PubMed

Most field ecology is conceived and financed by scientists from urban areas but is actually carried out in rural areas. Field staff can either be imported from urban areas or recruited from local residents. We evaluated the advantages and disadvantages of involving rural residents as local technicians over a 25- year period at active field research site in Costa Rica. We defined "local technicians" as local residents with no university education who acquired significant experience in field data collection, data management and/or laboratory work. We analyzed the experiences of incorporating these technicians into field research in developing countries from the points of view of scientist and of the local technicians themselves. Primary data were written responses from to a standardized survey of 19 senior scientists and Ph.D. students,and results from standardized personal interviews with 22 local technicians. Researchers highlighted the advantages of highly-skilled technicians with minimal staff turnover, as well as the technicians' knowledge of local ecological conditions. Local technicians considered the primary advantages of their jobs to be opportunities for continuing education training in science as well as cultural enrichment through interactions with people of different cultures. The main challenges identified by researchers were the lack of long-term funding for projects and extended training required for local technicians. Local technicians can be of great benefit to research projects by providing high-quality data collection at reasonable costs with low staff turnover. Over the last 25 years the research model at the field station we studied has evolved to the point that most long-term projects now depend heavily on local technicians. This model of involving local technicians in long-term research has multiple benefits for the researchers, the technicians and the local community, and could be adapted to a variety of settings in rural areas of developing countries. PMID:22208064

Hurtado, Johanna; Clark, David B

2011-12-01

191

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

PubMed

Although physical limitations associated with transfemoral amputation (TFA) have been studied in laboratory settings, little is known about habitual activity within free-living environments. A retrospective analysis of 12 mo of step activity data was performed to quantify activity levels, variations, and patterns in 17 adults with unilateral TFA. Yearly, seasonal, and monthly average daily step counts and coefficients of variation (CoVs) were examined to characterize mobility. Analysis by Medicare Functional Classification Level (MFCL) was performed to explore relationships between clinical classification and performance. Subjects averaged 1,540 prosthetic steps/day, and activity generally increased with MFCL. Activity between MFCL-2 and -3 subjects was not significantly different, suggesting that ability to engage in habitual physical activity may be similar for these groups. Relative variation (CoV) was 0.65 across subjects but was lower for those with higher activity levels. No significant differences in CoV by group were detected. Marked seasonal and monthly patterns in activity were identified. Warmer seasons and months generally promoted higher activity, but peak temperatures and humidity depressed activity. Results suggest that persons with TFA are greatly limited in regards to activity. Further, large variations within and between subjects may challenge the interpretation of step activity gathered over short periods of time. PMID:23934872

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

2013-07-01

192

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

PubMed Central

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

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

2007-01-01

193

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

PubMed

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

2011-10-01

194

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.

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

2011-01-01

195

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…

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

2012-01-01

196

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

PubMed Central

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

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

2009-01-01

197

Interferon-beta-1b-induced short- and long-term signatures of treatment activity in multiple sclerosis.  

PubMed

Interferon beta (IFN?) reduces disease burden in relapsing-remitting multiple sclerosis (MS) patients. In this study, IFN?-1b-treated MS patient gene expression profiles and biological knowledgebases were integrated to study IFN?'s pleiotropic mechanisms of action. Genes involved in immune regulation, mitochondrial fatty acid metabolism and antioxidant activity were discovered. Plausible mediators of neuronal preservation included NRF2, downregulation of OLA1, an antioxidant suppressor, and the antioxidant gene ND6, implicated in optic neuropathy and MS-like lesions. Network analysis highlighted IKBKE, which likely has a role in both viral response and energy metabolism. A comparative analysis of therapy-naive MS- and IFN?-associated gene expression suggests an IFN? insufficiency in MS. We observed more gene expression changes in long-term treatment than during acute dosing. These distinct short- and long-term effects were driven by different transcription factors. Multi-gene biomarker signatures of IFN? treatment effects were developed and subsequently confirmed in independent IFN?-1b-treated MS studies, but not in glatiramer acetate-treated patients. PMID:22711062

Croze, E; Yamaguchi, K D; Knappertz, V; Reder, A T; Salamon, H

2012-06-19

198

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

NASA Astrophysics Data System (ADS)

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

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

2002-05-01

199

[The activity of the carbon metabolism enzymes in Chromatium minutissimum after long-term preservation].  

PubMed

The activity of the enzymes of the tricarboxylic acid cycle and glyoxylate shunt, as well as of some enzymes involved in carbohydrate metabolism, were determined in the purple sulfur bacterium Chromatium minutissimum, either maintained by subculturing in liquid medium or stored in the lyophilized state for 36 years. In cultures stored in the lyophilized state, the activities of the key enzymes of the tricarboxylic acid cycle, glyoxylate shunt, and Embden-Meyerhof-Parnas pathway were higher, whereas the activities of glucose-6-phosphate dehydrogenase, pyruvate kinase, and ribulose bisphosphate carboxylase were somewhat lower than in cultures maintained by regular transfers. PMID:10920800

Krasil'nikova, E N; Zakharchuk, L M

200

Long-term starspot activity of short-period RS Canum Venaticorum stars. III - BH Virginis  

SciTech Connect

The photometric distortion waves in the light curves of the short-period RS CVn system BH Vir by a dark, circular spot model for the active regions on the primary star is parameterized. Recent observations and archival sources are used to infer the positions and areas of the active regions. For light curves with simultaneous B and R or V and I data, the temperatures of the spotted regions relative to the photospheres can be evaluated. For BH Vir in 1986, T(spot) = 4900 + or - 500 K. The active regions tend to occur at high latitudes and at preferred longitudes near 90 and 270 deg. 32 refs.

Zeilik, M.; Ledlow, M.; Rhodes, M.; Arevalo, M.J.; Budding, E. (New Mexico Univ., Albuquerque (USA) Air Force Academy, Colorado Springs, CO (USA) Instituto de Astrofisica de Canarias, La Laguna (Spain) Carter Observatory, Wellington (New Zealand))

1990-05-01

201

SWIFT Observations of the Long Term Activity of Comet C/2009 P1 (Garradd)  

NASA Astrophysics Data System (ADS)

We report on space-borne observations of comet C/2009 P1 (Garradd) using Swift’s UV-Optical Telescope (UVOT). C/2009 P1 is a dynamically new comet and this is likely its first journey to the inner solar system since its emplacement in the Oort cloud. It was discovered in 2009 and clearly exhibited a dust coma as far as 8.5 AU from the Sun. We observed the comet on part of its inbound trajectory and found that at a distance of 3.5 AU from the Sun it produced several tons of gas and dust per second. Between 3.5 and 2.5 AU the comet’s dust production rate steadily increased with the heliocentric distance as rh-2, but at the same time we noted a steep increase in the comet’s OH production rate, suggesting the onset of a new source of OH. Swift/UVOT observed comet C/2009 P1 (Garradd) at regular intervals at heliocentric distances between 3.5 and 1.7 AU on its inbound trajectory, and will continue to do as the comet is moves away from the Sun. We used the UV grism on Swift-UVOT to quantitatively measure gas and dust content in the coma (Bodewits et al., AJ 141, p12, 2011). Broadband UVW1 and V-filter observations provide context to our grism observations and allow for independent measures of the OH and dust content in the coma. The sensitivity of Swift’s grisms permits the observation of a comet far away from the Earth and the Sun when it is outside the grasp of most ground based observatories.

Bodewits, Dennis; Farnham, T. L.; A'Hearn, M. F.

2012-10-01

202

Long-term starspot activity of short-period RS Canum Venaticorum stars. IV - WY CANCRI  

NASA Astrophysics Data System (ADS)

The photometric distortion waves in the short-period RS CVn system WY CnC are parametrized by a dark, circular spot model for the active regions on the primary star. From recent observations and archival sources, the changes in positions and areas of the active regions are inferred. For light curves with simultaneous visual and red or infrared data, the average temperatures of the spotted regions relative to the photosphere are evaluated. In 1989, it is found that T(spot) = 3970 + or - 300 K for a primary star temperature of 5520 K. Some indication is found of a nonuniform temperature distribution in longitude across the spotted area at this time. The active regions tend to occur at low latitudes, in contrast to the high latitudes previously found for SV Cam, RT And, and BH Vir. It is found again that the active regions fall into preferred longitudes near 90 and 270 deg.

Zeilik, M.; Cox, D. A.; Ledlow, M. J.; Rhodes, M.; Heckert, P. A.; Budding, E.

1990-11-01

203

Long-term starspot activity of short-period RS Canum Venaticorum stars. IV. WY Cancri  

SciTech Connect

The photometric distortion waves in the short-period RS CVn system WY CnC are parametrized by a dark, circular spot model for the active regions on the primary star. From recent observations and archival sources, the changes in positions and areas of the active regions are inferred. For light curves with simultaneous visual and red or infrared data, the average temperatures of the spotted regions relative to the photosphere are evaluated. In 1989, it is found that T(spot) = 3970 + or - 300 K for a primary star temperature of 5520 K. Some indication is found of a nonuniform temperature distribution in longitude across the spotted area at this time. The active regions tend to occur at low latitudes, in contrast to the high latitudes previously found for SV Cam, RT And, and BH Vir. It is found again that the active regions fall into preferred longitudes near 90 and 270 deg. 27 refs.

Zeilik, M.; Cox, D.A.; Ledlow, M.J.; Rhodes, M.; Heckert, P.A. (New Mexico Univ., Albuquerque (USA) U.S. Air Force Academy, Colorado Springs, CO (USA) Western Carolina Univ., Cullowhee, NC (USA))

1990-11-01

204

The activity of the carbon metabolism enzymes in chromatium minutissimum after long-term storage  

Microsoft Academic Search

The activity of the enzymes of the tricarboxylic acid cycle and glyoxylate shunt, as well as of some enzymes involved in carbohydrate\\u000a metabolism, were determined in the purple sulfur bacteriumChromatium minutissimum either maintained by subculturing in liquid medium or stored in the lyophilized state for 36 years. In cultures stored in\\u000a the lyophilized state, the activities of the key enzymes

E. N. KrasH’nikova; L. M. Zakharchuk

2000-01-01

205

Maintenance of alcohol dehydrogenase activity in long-term culture of hepatocytes from female rat.  

PubMed

Conditions for maintaining the activity of alcohol dehydrogenase in cultures of hepatocytes isolated from female rats were studied. The activity of alcohol dehydrogenase in freshly isolated cells was 1.7 U/mg DNA. When cultured, the activity declined 20% after one day of culture, irrespective of the culture conditions. In a conventional medium with 5 mM glucose the activity after one week of culture was only 30% of that initially measured in culture. Addition of 25 mM glucose or a high concentration of amino acids delayed the decrease. When these compounds were added together it was possible to maintain the initial activity for one week, but the activity declined during the following week. Addition of growth hormone had no effect during the first week of culture but abolished the fall during the second week. The initial metabolism of ethanol was 0.65 mumol/min x mg DNA and declined to two-thirds during the 2 weeks of culture. PMID:2646972

Grunnet, N; Vind, C; Dich, J

1989-02-01

206

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

207

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

208

The Relationship Between Active Learning and Long-Term Retention in an Introductory Statistics Course  

Microsoft Academic Search

In statistics, active learning (AL) methods include projects with class participation and hands-on experiments. Projects might involve sampling, regression analysis, experimental design and the analysis of variance. Cooperative learning is a form of AL in which small group interaction leads learning via peer instruction. Johnson and Johnson (1975) discuss various situations in which cooperative learning helps to create an environment

Paul H. Kvam

1999-01-01

209

Deciphering Long-Term Photospheric and Chromospheric Activity on VW Cep  

Microsoft Academic Search

VW Cep is one of the brightest and best observed short period W UMa binaries. It consists of G5V and K0V components in contact with their Roche limiting surfaces. Because of its long history of ground based and satellite observations VW Cep can serve as the prototype for understanding this important class of active close binaries. The scientific aims of

Edward F. Guinan

1991-01-01

210

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

PubMed

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

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

2013-05-28

211

Short and long-term effects of heavy metals on urease activity in soils  

Microsoft Academic Search

The inhibitory effects of cadmium, chromium, copper, lead, nickel and zinc on urease activity of five different soils during two different periods were investigated, in order to obtain information on the change in heavy metal toxicity with time. The results are presented graphically as logistic dose-response curves. When the ecological dose range was used as a measure of toxicity this

P. Doelman; L. Haanstra

1986-01-01

212

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

213

Immediate and Long-Term Effects of Hippotherapy on Symmetry of Adductor Muscle Activity and Functional Ability in Children With Spastic Cerebral Palsy  

Microsoft Academic Search

McGibbon NH, Benda W, Duncan BR, Silkwood-Sherer D. Immediate and long-term effects of hippotherapy on symmetry of adductor muscle activity and functional ability in children with spastic cerebral palsy.

Nancy H. McGibbon; William Benda; Burris R. Duncan; Debbie Silkwood-Sherer

2009-01-01

214

Physical activity, skeletal health and fractures in a long term perspective.  

PubMed

Exercise during adolescence, especially during the pre-pubertal years, builds a skeleton with a high bone mineral density (BMD) and possibly a larger skeleton with a different skeletal architecture. This would lead to a stronger skeleton more resistant to trauma. These changes could be of biological significance for fracture reduction, if they were maintained into old age where fragility fractures exponentially rise. The Achilles heel of exercise is its cessation. Most BMD benefits achieved by exercise appear to be eroded with cessation of exercise. Reduced exercise intensity after a period of high activity, may maintain some residual BMD benefits into old age. A decreased fracture rate in the population could perhaps be achieved by promoting a physically active life style with lifelong high activity. But what happens if the activity in former athletes is reduced to the same level as in individuals who never exercised? The null hypothesis that exercise has no effect on fracture rates in old age cannot be rejected on the basis of any published, randomised, prospective data. Instead we have to rely on retrospective observational and case control studies, all hypothesis-generating, not hypothesis-testing. Existing data suggest that there could be a reduced fracture risk in former athletes. This notion may be correct, but consistently replicated sampling bias may produce the same observation and any biological explanation for this fracture reduction is unclear. Residual structural skeletal benefits, improved muscle strength, coordination and balance are all traits possibly maintained in former athletes after their active career. These traits may possibly reduce the number of fractures in later life. PMID:15615074

Karlsson, M K

2004-03-01

215

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

Microsoft Academic Search

A multi-temporal scheme of satellite data analysis, named RST (Robust Satellite Techniques), already successfully used to study and monitor several active volcanoes, has recently been tested on a long time series of NOAA-AVHRR records acquired over Mount Etna area for a full assessment of its performances. Satellite records acquired at different time of pass (e.g. day\\/night, winter\\/summer), from 1995 to

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

2010-01-01

216

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

Microsoft Academic Search

We present the results of multicolor photometry of the two spotted, short-period, late-type RS CVn stars BH Vir and WY Cnc.\\u000a We have derived the parameters of the binaries’ components, and refined their masses, radii, and luminosities. A strong flare\\u000a of WY Cnc was detected for the first time, and pre-flare variations of the star’s activity studied. Our observations and

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

2007-01-01

217

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

Microsoft Academic Search

We present the results of multicolor photometry of the two spotted, short-period, late-type RS CVn stars BH Vir and WY Cnc. We have derived the parameters of the binaries' components, and refined their masses, radii, and luminosities. A strong flare of WY Cnc was detected for the first time, and pre-flare variations of the star's activity studied. Our observations and

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

2007-01-01

218

Long-term repeatability of force, endurance time and muscle activity during isometric contractions  

Microsoft Academic Search

We determined the repeatability and correlations between force, endurance and muscle activity during isometric contractions over three years. Twenty-six subjects, with and without complaints of the shoulder and neck, performed standardized maximal and submaximal shoulder-abduction contractions and wrist extension-contractions at yearly intervals from 1997 to 1999. Peak forces developed during maximal contraction and the endurance times of submaximal contractions during

C. Røe; Ó. A. Steingrímsdóttir; S. Knardahl; E. S. Bakke; N. K. Vøllestad

2006-01-01

219

Long-term course and cardiac sympathetic nerve activity in patients with hypertrophic cardiomyopathy  

Microsoft Academic Search

OBJECTIVE--To investigate the relation between regional myocardial sympathetic nerve activity and the electrocardiographic and cardiac functional changes in hypertrophic cardiomyopathy. DESIGN--A retrospective study to compare the findings of myocardial scintigraphy with iodine-123 metaiodobenzylguanidine (MIBG) and the serial electrocardiographic changes. SETTING--Myocardial scintigraphy was performed with iodine-123 MIBG and thallium-201 and single photon emission computed tomography (SPECT) in the division of nuclear

M Shimizu; N Sugihara; Y Kita; K Shimizu; Y Horita; K Nakajima; J Taki; R Takeda

1992-01-01

220

Long-term carvedilol therapy increases parasympathetic nervous system activity in chronic congestive heart failure.  

PubMed

To determine the effect of beta blockade on parasympathetic nervous system activity, we assessed RR variability during 24-hour Holter monitoring in 10 patients with congestive heart failure before and after 3 to 4 months of treatment with the beta blocker carvedilol. High-frequency power increased from 26 to 64 ms2, root-mean-square of successive differences in RR interval increased from 14.3 to 23.7 ms2, and percentage of absolute differences >50 ms between successive normal RR intervals increased from 0.8% to 4.7%, all p <0.01, indicating a substantial increase in parasympathetic modulation of RR intervals. PMID:9352991

Goldsmith, R L; Bigger, J T; Bloomfield, D M; Krum, H; Steinman, R C; Sackner-Bernstein, J; Packer, M

1997-10-15

221

Long-term intermittent hypoxia increases sympathetic activity and chemosensitivity during acute hypoxia in humans  

PubMed Central

We determined the effects of 10 daily exposures of intermittent hypoxia (IH; 1 h day?1; oxyhaemoglobin saturation = 80%) on muscle sympathetic nerve activity (MSNA, peroneal nerve) and the hypoxic ventilatory response (HVR) before, during and after an acute 20 min isocapnic hypoxic exposure. We also assessed the potential parallel modulation of the ventilatory and sympathetic systems following IH. Healthy young men (n = 11; 25 ± 1 years) served as subjects and pre- and post-IH measures of MSNA were obtained on six subjects. The IH intervention caused HVR to significantly increase (pre-IH = 0.30 ± 0.03; post-IH = 0.61 ± 0.12 l min?1 %SaO2?1). During the 20 min hypoxic exposure sympathetic activity was significantly greater than baseline and remained above baseline after withdrawal of the hypoxic stimulus, even though oxyhaemoglobin saturation had normalized and ventilation and blood pressure had returned to baseline levels. When compared to the pre-IH trial, burst frequency increased (P < 0.01), total MSNA trended towards higher values (P = 0.06), and there was no effect on burst amplitude (P = 0.82) during the post-IH trial. Following IH the rise in MSNA burst frequency was strongly related to the change in HVR (r = 0.79, P < 0.05) suggesting that these sympathetic and ventilatory responses may have common central control.

Lusina, Sarah-Jane C; Kennedy, Paul M; Inglis, J Timothy; McKenzie, Donald C; Ayas, Najib T; Sheel, A William

2006-01-01

222

Long-term repeatability of force, endurance time and muscle activity during isometric contractions.  

PubMed

We determined the repeatability and correlations between force, endurance and muscle activity during isometric contractions over three years. Twenty-six subjects, with and without complaints of the shoulder and neck, performed standardized maximal and submaximal shoulder-abduction contractions and wrist extension-contractions at yearly intervals from 1997 to 1999. Peak forces developed during maximal contraction and the endurance times of submaximal contractions during shoulder abduction and wrist extension were measured. Electromyography (EMG) of muscle activity was recorded bilaterally from the upper trapezius, middle deltoid, and forearm extensor muscles. Root mean square EMG amplitudes were calculated. We found statistically significant associations between peak forces developed during wrist extension and shoulder abduction, and between endurance times of submaximal wrist extension and shoulder abduction. No statistically significant changes in peak force and EMG(peak) were found over the measurement years. The responses were not statistically significantly influenced by gender, or neck and shoulder pain. However, we observed considerable intra-individual variation in the inter-year measurements particularly for the responses to submaximal contraction. Such large variations represent a challenge when attempting to use the responses to interpret the effects of therapies. PMID:15939629

Røe, C; Steingrímsdóttir, O A; Knardahl, S; Bakke, E S; Vøllestad, N K

2005-06-06

223

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.

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

2011-01-01

224

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

SciTech Connect

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. 36 refs.

Zeilik, M.; Cox, D.A.; De Blasi, C.; Rhodes, M.; Budding, E. (New Mexico Univ., Albuquerque (USA) Carter Observatory, Wellington (New Zealand))

1989-10-01

225

Long-Term Physical Activity and Inflammatory Biomarkers in Older Adults  

PubMed Central

Purpose To determine the effects of a 12-month physical activity intervention on inflammatory biomarkers in elderly men and women. Methods 424 elderly (aged 70–89 years), nondisabled, community-dwelling men and women at risk for physical disability were enrolled in a multicenter, single-blind, randomized controlled-trial. Participants were randomized to participate in either a 12-month moderate-intensity physical activity (PA) intervention or a successful aging (SA) health education intervention. Biomarkers of inflammation (IL-6sR, IL-1sRII, sTNFRI, sTNFRII, IL-8, IL-15, adiponectin, IL-1ra, IL-2sR?, and TNF-?) were measured at baseline, 6 and 12 months. Results A baseline blood sample was successfully collected from 368 participants. After adjustment for gender, clinic site, diabetes status, and baseline outcome measure, IL-8 was the only inflammatory biomarker affected by the PA intervention (p=0.03). The adjusted mean IL-8 at month 12 was 9.9% (0.87 pg/mL) lower in the PA compared to the SA group. Secondary interaction analyses between baseline biomarker status and treatment showed one significant interaction (p=0.02) such that the PA intervention reduced IL-15 concentrations in participants with a baseline IL-15 above the median value of 1.67 pg/mL. However, these associations were no longer significant after consideration for multiple comparisons. Conclusions Overall, this study does not provide definitive evidence for an effect of regular exercise for altering systemic concentrations of the measured inflammatory biomarkers in older adults.

Beavers, Kristen M.; Hsu, Fang-Chi; Isom, Scott; Kritchevsky, Stephen B.; Church, Timothy; Goodpaster, Bret; Pahor, Marco; Nicklas, Barbara J.

2010-01-01

226

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.

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

2008-01-01

227

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

Microsoft Academic Search

Artificial Neural Networks (ANN) are efficient tools to derive solar UV radiation from measured meteorological parameters such as global radiation, aerosol optical depths and atmospheric column ozone. The ANN model has been tested with different combinations of data from the two sites Potsdam and Lindenberg, and used to reconstruct solar UV radiation at eight European sites by more than 100

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

2008-01-01

228

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

Microsoft Academic Search

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

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

1979-01-01

229

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

NASA Astrophysics Data System (ADS)

Torrential processes present a serious hazard in alpine regions. Especially sediment transport is responsible for most torrent related damages. The material incorporated in torrents is inherently complex, varying from clay sized solids to boulders of several meters of diameter. For geoscientists it is important to predict possible triggering zones and deposition areas or run out lengths. Run out analysis is an especially important component for hazard assessment in alpine watersheds, which includes prediction of potential hazard areas and mapping the distribution of hazard intensity parameters such as the thickness of the deposit. In this study terrestrial laser scanning has been applied to investigate the spatial distribution of erosion and deposition of bed load material over a 4000 m long reach of a torrent. Within the monitoring period a new open check dam was built at the study site after removing the old one. Due to the open construction it was expected, that during flood events sediment is stored behind the check dam, but during smaller flood events the deposition area should be self-emptied again. The measurements were carried out to investigate if the new check dam functioned as expected. Therefore the reach has been scanned 6 times during the last 3 years. Several monitoring activities before and after torrent events required global data registration using differential GPS. Tachymetry connected areas with missing GPS reception to GPS measured ones. Terrestrial laser scanning provided dense 3d-data. The RIEGL LMS-Z420i was chosen due to its long range, high accuracy and high scanning speed of the measurements. The accuracy of the measurement was in a range of 8 cm. The objectives of the TLS survey of the torrent deposit were to determine the volume of the deposited mass as well as to detect zones of erosion and deposition of material by the creation of high resolution DEM's. The results of the measurements taken at the test site in Carinthia, Austria are presented and the geomorphologic changes of the channel bed caused by the new check dam are discussed.

Prokop, A.; Chiari, M.

2012-04-01

230

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

231

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

PubMed

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

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

2012-07-28

232

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

NASA Astrophysics Data System (ADS)

Over the last couple of decades we have been carrying out a study of stellar magnetic activity, dynamos, atmospheric physics, and spectral irradiances from a sample of solar-type G0-5 V stars with different ages. One of the major goals of this program is to study the evolution of the Sun's X-ray through NUV spectral irradiances with age. Of particular interest is the determination of the young Sun's elevated levels of high-energy fluxes because of the critical roles that X-ray (coronal) through FUV (transition region (TR), chromospheric) emissions play on the photochemical and photoionization evolution (and possible erosion) of early, young planetary atmospheres and ionospheres. Motivated by the current exoplanetary search missions (such as Kepler and CoRoT, along with the planned Space Interferometry Mission and Darwin/Terrestrial Planet Finder missions) that are hunting for Earth-size planets in the habitable zones (liquid water) of nearby main-sequence G-M stars, we are expanding our program to cooler, less luminous, but very importantly, much more numerous main-sequence K-type stars, such as ? Centauri B. The long life (2-3× longer than the Sun) and slow evolution of K stars provide nearly constant energy sources for possible hosted planets. This program parallels our "Sun in Time" program, but extends the study to stars with deeper convective zone depths. Presented here are X-ray (coronal; ROSAT, Chandra, XMM-Newton), UV (TR; International Ultraviolet Explorer (IUE)), NUV (chromospheric; IUE), and recently acquired FUV (TR/chromospheric; FUSE Cycles 7/8) observations of the K1 V star ? Cen B (HD 128621; V = 1.33; (B - V) = +0.88; ? = 5.6 ± 0.6 Gyr). These combined high-energy measures provide a more complete look into the nature of ? Cen B's magnetic activity and X-ray-UV radiances. We find that ? Cen B has exhibited significant long-term variability in X-ray through NUV emission fluxes, indicating a solar-like long-term activity cycle of P cycle = 8.84 ± 0.4 years. In addition, analysis of the short-term rotational modulation of mean light due to the effects of magnetically active regions has yielded a well-determined rotation period of P rotation = 36.2 ± 1.4 days. ? Cen B is the only old main-sequence K star with a reliably determined age and rotation period, and for early K stars, as in the case of the Sun for G2 V stars, is an important calibrator for stellar age/rotation/activity relations.

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

2010-10-01

233

Constitutive Caspase Activation and Impaired Death-Inducing Signaling Complex Formation in CD95Resistant, Long-Term Activated, Antigen-Specific T Cells  

Microsoft Academic Search

Elimination of T cells during an immune response is mediated by activation-induced cell death (AICD) and CD95-mediated apoptosis. Chronic graft-vs-host disease and T cell-mediated autoimmune diseases are caused by the persistence of activated T cells that escaped tolerance induction by deletion or silencing. To mimic the in vivo situation of long-term activated T cells, we generated an in vitro system

Gudrun Strauss; Ingrid Knape; Ingo Melzner; Klaus-Michael Debatin

234

Effect of ascorbic Acid on long-term cold exposure induced changes in thyroid activity in sprague dawley rats.  

PubMed

Objective: To determine the effect of ascorbic acid supplementation on long-term cold exposure induced changes in thyroid activity in Sprague-Dawley rats. Study Design: Experimental study. Place and Duration of Study: Physiology Department of Islamic International Medical College, Rawalpindi, National Institute of Health, Islamabad and Railway Hospital, Rawalpindi, from January to December 2009. Methodology: Ninety Sprague-Dawley rats were randomly divided into three groups of control, cold exposed and cold exposed along with ascorbic acid supplementation. After one month, their thyroid levels were analyzed by using chemiluminescent immunometric Assay on Siemens Immulite 2000 Analyzer. Results: After 4 weeks of cold exposure to experimental animals, the thyroid activity was raised significantly in the cold exposed group as compared to the control group (p-value for T3 difference = 0.004, T4 difference = 0.002 and TSH difference < 0.001). Supplementation with ascorbic acid in the third group normalized the thyroid hormone activity with p-value for difference in levels of T3 being 0.6661, T4 = 0.027 and TSH = 0.0028. Conclusion: Ascorbic acid prevented the cold induced changes in thyroid hormone levels in rodents. PMID:24034191

Rashid, Aneeqa; Khan, Umar Ali

2013-09-01

235

Sustained Dorsal Hippocampal Activity is Not Obligatory for Either the Maintenance or Retrieval of Long-Term Spatial Memory  

PubMed Central

Memories are initially stored in a labile state and are subject to modification by a variety of treatments, including disruption of hippocampal function. We infused a sodium channel blocker (or CNQX) to inactivate the rat dorsal hippocampus reversibly for 1 week following training on a task of spatial memory (the water maze). Previous work with conventional lesions has established that the dorsal hippocampus is essential for both the acquisition and expression of memory in this task. The question in the present study was whether chronic disruption of neuronal activity in the dorsal hippocampus after training would abolish memory or whether memory would survive extended disruption of hippocampal activity. As expected from earlier work, we found that performance was impaired during the infusion period. The critical test occurred 1 week after the lesion was reversed. We found that retention of the water maze recovered to control levels. Accordingly, sustained hippocampal activity following training is not obligatory for either the maintenance of long-term spatial memory or its subsequent retrieval.

Broadbent, Nicola J.; Squire, Larry R.; Clark, Robert E.

2011-01-01

236

Long-term depression of nociceptive synapses by non-nociceptive afferent activity: role of endocannabinoids, Ca²+, and calcineurin.  

PubMed

Activity in non-nociceptive afferents is known to produce long-lasting decreases in nociceptive signaling, often referred to as gate control, but the cellular mechanisms mediating this form of neuroplasticity are poorly understood. In the leech, activation of non-nociceptive touch (T) mechanosensory neurons induces a heterosynaptic depression of nociceptive (N) synapses that is endocannabinoid-dependent. This heterosynaptic, endocannabinoid-dependent long-term depression (ecLTD) is observed where the T- and N-cells converge on a common postsynaptic target, in this case the motor neuron that innervates the longitudinal muscles (L-cells) that contributes to a defensive withdrawal reflex. Depression in the nociceptive synapse required both presynaptic and postsynaptic increases in intracellular Ca²?. Activation of the Ca²?-sensitive protein phosphatase calcineurin was also required, but only in the presynaptic neuron. Heterosynaptic ecLTD was unaffected by antagonists for NMDA or metabotropic glutamate receptors, but was blocked by the 5-HT? receptor antagonist ritanserin. Depression was also blocked by the CB1 receptor antagonist rimonabant, but this is thought to represent an effect on a TRPV-like receptor. This heterosynaptic, endocannabinoid-dependent modulation of nociceptive synapses represents a novel mechanism for regulating how injury-inducing or painful stimuli are transmitted to the rest of the central nervous system. PMID:22578358

Yuan, Sharleen; Burrell, Brian D

2012-04-24

237

Long-term effects of dietary glycemic index on adiposity, energy metabolism, and physical activity in mice  

PubMed Central

A high-glycemic index (GI) diet has been shown to increase adiposity in rodents; however, the long-term metabolic effects of a low- and high-GI diet have not been examined. In this study, a total of 48 male 129SvPas mice were fed diets high in either rapidly absorbed carbohydrate (RAC; high GI) or slowly absorbed carbohydrate (SAC; low GI) for up to 40 wk. Diets were controlled for macronutrient and micronutrient content, differing only in starch type. Body composition and insulin sensitivity were measured longitudinally by DEXA scan and oral glucose tolerance test, respectively. Food intake, respiratory quotient, physical activity, and energy expenditure were assessed using metabolic cages. Despite having similar mean body weights, mice fed the RAC diet had 40% greater body fat by the end of the study and a mean 2.2-fold greater insulin resistance compared with mice fed the SAC diet. Respiratory quotient was higher in the RAC group, indicating comparatively less fat oxidation. Although no differences in energy expenditure were observed throughout the study, total physical activity was 45% higher for the SAC-fed mice after 38 wk of feeding. We conclude that, in this animal model, 1) the effect of GI on body composition is mediated by changes in substrate oxidation, not energy intake; 2) a high-GI diet causes insulin resistance; and 3) dietary composition can affect physical activity level.

Scribner, Kelly B.; Pawlak, Dorota B.; Aubin, Cristin M.; Majzoub, Joseph A.; Ludwig, David S.

2008-01-01

238

Membrane-associated glucocorticoid activity is necessary for modulation of long-term memory via chromatin modification  

PubMed Central

Glucocorticoid hormones enhance the consolidation of long-term memory of emotionally arousing training experiences. This memory enhancement requires activation of the cAMP-dependent kinase pathway and the subsequent phosphorylation of cAMP response-element binding (CREB) protein. Here, we demonstrate that glucocorticoids enhance the consolidation of hippocampus-dependent and hippocampus-independent aspects of object recognition memory via chromatin modification. More specifically, systemic corticosterone increases histone acetylation, a form of chromatin modification, in both the hippocampus and insular cortex following training on an object recognition task. This led us to examine whether increasing histone acetylation via histone deacetylase (HDAC) inhibition enhances memory in a similar manner as corticosterone. We found a double dissociation between posttraining HDAC inhibitor infusion into the insular cortex and hippocampus on the enhancement of object recognition and object location memory, respectively. In determining the molecular pathway upstream of glucocorticoids’ effects on chromatin modification, we found that activation of membrane-associated glucocorticoid receptors (GRs) and the subsequent interaction between phospho-CREB and CREB-binding protein (CBP) appear to be necessary for glucocorticoids to enhance memory consolidation via chromatin modification. In contrast, mineralocorticoid receptors (MRs) do not appear to be involved. The findings also indicate that glucocorticoid activity has differential influences on hippocampus-dependent and hippocampus-independent components of memory for objects.

Roozendaal, Benno; Hernandez, Angelina; Cabrera, Sara M.; Hagewoud, Roelina; Malvaez, Melissa; Stefanko, Daniel P.; Haettig, Jakob; Wood, Marcelo A.

2010-01-01

239

Long-term investigations of radiocaesium activity concentrations in carp in North Croatia after the Chernobyl accident.  

PubMed

Long-term investigations of radiocaesium activity concentrations in carp in the Republic of Croatia are presented. The radiocaesium levels in carp decreased exponentially and the effective ecological half-life of (137)Cs was estimated to be about 1 year during 1987-2002 and 5 years during 1993-2005. The observed (134)Cs:(137)Cs activity ratio in carp was found to be similar to the ratio observed in other environmental samples. The concentration factor for carp (wet weight) was estimated to be 128+/-74 Lkg(-1), which is in reasonable agreement with model prediction based on K(+) concentrations in water. Estimated annual effective dose received by adult members of the Croatian population due to consumption of carp contaminated with (134)Cs and (137)Cs are small: per capita dose from this source during 1987-2005 was estimated to be 0.5+/-0.2 microSv. Due to minor freshwater fish consumption in Croatia and low radiocaesium activity concentrations in carp, it can be concluded that carp consumption was not a critical pathway for the transfer of radiocaesium from fallout to humans after the Chernobyl accident. PMID:17343962

Frani?, Zdenko; Marovi?, Gordana

2007-03-06

240

Long-term effects of the PPAR gamma activator pioglitazone on cardiac inflammation in stroke-prone spontaneously hypertensive rats.  

PubMed

We investigated the long-term effects of the thiazolidinedione PPARgamma activator pioglitazone on cardiac inflammation in stroke-prone spontaneously hypertensive rats (SHRSP), a model of malignant of hypertension. Six-week-old SHRSP were treated with pioglitazone (10 mg/kg per day p.o.) for 20 weeks. The rise in systolic blood pressure (SBP) in SHRSP was only transiently and slightly attenuated by pioglitazone (P < 0.05). On one hand, cardiac hypertrophy was little affected by the pioglitazone treatment, and there was only a reduction of subepicardial interstitial fibrosis. On the other hand, left ventricular NFkappaB and AP-1 binding activities, the expression of TNFalpha, and the adhesion of molecule PECAM were significantly decreased by pioglitazone treatment. Expression of the pro-apoptotic proteins p53 and bax was significantly increased by pioglitazone. Thus, pioglitazone-attenuated cardiac inflammation in SHRSP had little effect on BP or cardiac hypertrophy. PPARgamma activation may play a preventive cardiovascular role by offsetting the cardiac inflammatory response as demonstrated in this genetic model of malignant hypertension. PMID:15644937

Diep, Quy N; Amiri, Farhad; Benkirane, Karim; Paradis, Pierre; Schiffrin, Ernesto L

2004-11-01

241

Low-flow, long-term air sampling under normal domestic activity to measure house dust mite and cockroach allergens.  

PubMed

Successful applications of air sampling for the quantification of exposure to indoor allergens have been reported, but its efficiency is still controversial. We evaluated whether the low-flow, long-term air sampling in normal domestic activity conditions can quantify the exposure of house dust mites (HDM) and cockroaches (CR) allergens or not. Airborne Der f 1 and Bla g 1 were captured with a personal air sampler in 25 bedrooms during normal domestic activity. Quantification of the major allergens in the reservoir dust and the extraction of the air sampler filters were done with two-site ELISA kits. Airborne Der f 1 was measured above the threshold level of detection in 15 houses (60%). Detection rate of airborne Der f 1 was significantly higher in those houses where D. farinae was microscopically found in the reservoir dusts (76.5% vs. 25%, chi 2 = 6.0, p = 0.014). Airborne Der f 1 was more frequently detected in the houses with higher Der f 1 (> or = 10 micrograms/g dust) in bedding reservoir dust than the other group (91% vs. 35.7%, chi 2 = 7.819, p = 0.005), and the median value of airborne Der f 1 was also significantly higher in that group (14.0 pg/m3 vs. below detection limit, p = 0.002). Airborne Der f 1 was significantly correlated with Der f 1 in bedding reservoir dust (r = 0.591, p < 0.01). Airborne Bla g 1 was measured with ELISA in 16 houses (64%), and it was more frequently detected in the houses where the CRs were captured by adhesive traps (91% vs. 57%, chi 2 = 3,484, p = 0.06). The median concentration of Bla g 1 in the filter was also higher in the houses with captured CRs (0.12 vs. 0.05 mU/m3, p = 0.06), but the level of Bla g 1 did not correlate with that of the bedding dusts or the floor dusts of kitchen. These results suggested that airborne HDM or CR allergens could be measured by low-flow, long-term air sampling, and that it might be one of appropriate modalities for evaluating personal exposure to HDM and CR allergens. PMID:12926189

Park, Jung Won; Kim, Cheol Woo; Kang, Dae Bong; Lee, In Young; Choi, Soo Young; Yong, Tai-Soon; Shin, Dong Cheon; Kim, Kyu Earn; Hong, Chein-Soo

2002-01-01

242

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

PubMed Central

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

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

2010-01-01

243

Parallel instabilities of long-term potentiation, place cells, and learning caused by decreased protein kinase A activity.  

PubMed

To further elucidate the links among synaptic plasticity, hippocampal place cells, and spatial memory, place cells were recorded from wild-type mice and transgenic "R(AB)" mice with reduced forebrain protein kinase A (PKA) activity after introduction into a novel environment. Place cells in both strains were similar during the first exposure and were equally stable for recording sessions separated by 1 hr. Place cell stability in wild-type mice was unchanged for sessions separated by 24 hr but was reduced in R(AB) mice over the longer interval. This stability pattern parallels both the reduced late-phase long-term potentiation in hippocampal slices from R(AB) mice and the amnesia for context fear conditioning seen in R(AB) mice 24 but not 1 hr after training. The similar time courses of synaptic, network, and behavioral instability suggest that the genetic reduction of PKA activity is responsible for the defects at each level and support the idea that hippocampal synaptic plasticity is important in spatial memory. PMID:11050131

Rotenberg, A; Abel, T; Hawkins, R D; Kandel, E R; Muller, R U

2000-11-01

244

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

245

Long-term recordings of networks of immortalized GnRH neurons reveal episodic patterns of electrical activity.  

PubMed

The CNS controls reproduction through pulsatile secretion of gonadotropin-releasing hormone (GnRH). Episodic increases in the firing rate of unidentified hypothalamic neurons have been associated with downstream markers of GnRH secretion. Whether this episodic electrical activity is intrinsic to GnRH neurons, intrinsic to other "pulse generator" neurons that drive GnRH neurons, or a combination of these is unknown. To determine if GnRH neurons display episodic firing patterns in isolation from other cell types, immortalized GnRH neurons (GT1-7 cells) were cultured on multiple microelectrode arrays. Long-term, multi-site recordings of GT1-7 cells revealed repeated episodes of increased firing rate with an interval of 24.8 +/- 1.3 (SE) min that were completely eliminated by tetrodotoxin, a sodium channel blocker. This pattern was comprised of active units that fired independently as well as coincidentally, suggesting the overall pattern of electrical activity in GT1-7 cells emerges as a network property. The A-type potassium-channel antagonist 4-aminopyridine (1 mM) increased both firing rate and GnRH secretion, demonstrating the presence of A-type currents in these cells and supporting the hypothesis that electrical activity is associated with GnRH release. Physiologically relevant episodic firing patterns are thus an intrinsic property of immortalized GnRH neurons and appear to be associated with secretion. The finding that overall activity is derived from the sum of multiple independent active units within a network may have important implications for the genesis of the GnRH secretory pattern that is delivered to the target organ. Specifically, these data suggest not every GnRH neuron participates in each secretory pulse and provide a possible mechanism for the variations in GnRH-pulse amplitude observed in vivo. PMID:11431490

Nunemaker, C S; DeFazio, R A; Geusz, M E; Herzog, E D; Pitts, G R; Moenter, S M

2001-07-01

246

Differential Roles of Ca21\\/Calmodulin-Dependent Protein Kinase II and Mitogen-Activated Protein Kinase Activation in Hippocampal Long-Term Potentiation  

Microsoft Academic Search

The roles of Ca 21\\/calmodulin-dependent protein kinase II (CaM kinase II) and mitogen-activated protein kinase (MAPK) in long- term potentiation (LTP) were investigated in the CA1 area of hippocampal slices, using electrophysiological and biochemi- cal approaches. A brief high-frequency stimulation, but not low-frequency stimulation, delivered to Schaffer collateral\\/com- missural afferents produced a stable LTP and activated both CaM kinase II

Jie Liu; Kohji Fukunaga; Hideyuki Yamamoto; Katsuhide Nishi; Eishichi Miyamoto

247

Enhanced prolylhydroxylase activity in the posterior annulus fibrosus of canine intervertebral discs following long-term running exercise.  

PubMed

The effect of long-term excercise on the intervertebral disc collagen concentration (hydroxyproline), collagen-synthesizing enzymes (prolyl-4-hydroxylase, PH, and galactosyl-hydroxylysyl glucosyltransferase, GGT) and hydroxypyridinium crosslinks was studied in ten female beagle dogs. The dogs were run on a treadmill for 1 year starting at the age of 15 weeks. The daily running distance was gradually increased to 40km, which distance the dogs ran for the final 15 weeks. Ten untrained dogs from the same breeding colony served as controls. The nucleus pulposus and anterior and posterior halves of the annulus fibrosus of C2-3, T10-12, L4-5 disc segments were analysed. Crosslinks were measured from the anterior annulus fibrosus of the T10-11 disc. Hydroxyproline and hydroxypyridinium concentrations remained similar in both groups. PH and GGT were significantly elevated by running in the posterior annulus fibrosus of the thoracic and lumbar discs and in the lumbar nucleus pulposus. In the thoracic nucleus pulposus GGT was reduced significantly. The results suggest activated collagen metabolism in the posterior annulus fibrosus of the thoracic and lumbar discs as a result of locally increased strains on the spine. PMID:20058463

Puustjärvi, K; Takala, T; Wang, W; Tammi, M; Helminen, H J; Kovanen, V

1993-10-01

248

Synapse-specific protein kinase C activation enhances maintenance of long-term potentiation in rat hippocampus.  

PubMed Central

1. Protein kinase C (PKC) stimulators, 12-O-tetradecanoyl-phorbol-13-acetate (TPA) or cis-unsaturated fatty acid (UFA), have been shown to prolong synaptic enhancement induced by long-term potentiation (LTP). This observation suggests a role for PKC in the biochemical mechanisms underlying maintained enhancement. 2. To determine if PKC stimulators prolong LTP by acting selectively at synapses given high-frequency stimulation or by actions that are not synapse-specific (e.g. increased postsynaptic excitability) we examined the effect of TPA or UFA on input-selective enhancement. Population EPSPs, evoked in the same granule cell population by either the medial (MPP) or lateral (LPP) perforant path, can be selectively enhanced leaving the other perforant path input which receives only low-frequency stimulation as an internal control for PKC stimulator effects not specific to enhanced synapses. 3. Synapse-specific effects were in fact observed, as UFA or TPA selectively prolonged MPP enhancement following two trains of high-frequency MPP stimulation, without affecting responses evoked by the LPP. A similar synapse selectivity of PKC stimulator action was seen following high-frequency LPP stimulation. 4. These findings suggest that PKC stimulators prolong enhancement by acting specifically at high-frequency-stimulated synapses. PKC stimulators do not appear to affect either postsynaptic neurone excitability or synapses given only low-frequency stimulation. This provides further evidence that PKC acts synergistically with the consequences of repetitive synaptic activation to maintain enhancement.

Lovinger, D M; Routtenberg, A

1988-01-01

249

Contrasting radon background levels in volcanic settings: clues from 220Rn 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 setup 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, Piergiorgio; Tuccimei, Paola; Mollo, Silvio; Soligo, Michele; Castelluccio, Mauro

2013-09-01

250

The rat model of tardive dyskinesia: relationship between vacuous chewing movements and gross motor activity during acute and long-term haloperidol treatment.  

PubMed

Tardive dyskinesia (TD) is a serious side-effect of neuroleptic treatment. In order to describe and analyse more thoroughly the rat model of TD, the behavior of the rats during cage testing was studied after acute and during long-term haloperidol (HAL) treatment. Rats were injected with HAL i.p. in an acute experiment, and in a long-term experiment, rats were treated for 4-12 months with HAL decanoate IM. Control rats received saline or sesame oil. The behavior was videotaped one h after the i.p. injection in the acute experiment, and at intervals during the long-term experiment. The putative TD analogue vacuous chewing movements (VCM), the general behavior and the type of behavior occurring simultaneously with VCM, were scored. Long-term ( > 4 months) HAL treatment increased VCM but did not change the general behavior. The single i.p. injection of HAL markedly reduced locomotion in addition to increasing VCM. Both in the acute and in the long-term experiment, VCM appeared more frequently when the gross motor activity was low, indicating an intrinsic incompatibility between gross motor activity and VCM. However, in the long-term experiment, the distribution of VCM in the different categories of behavior was the same in OIL and HAL treated rats. This shows that cage-observed VCM in rats induced by long-term HAL treatment cannot be an artifact due to reduced locomotion. Thereby, an important argument against cage-observed VCM as a rat model of TD seems to be disproved. PMID:7475980

Andreassen, O A; Jørgensen, H A

1995-01-01

251

Our changing atmosphere: evidence based on long-term infrared solar observations at the Jungfraujoch since 1950.  

PubMed

The Institute of Astrophysics of the University of Liège has been present at the High Altitude Research Station Jungfraujoch, Switzerland, since the late 1940s, to perform spectrometric solar observations under dry and weakly polluted high-mountain conditions. Several solar atlases of photometric quality, extending altogether from the near-ultra-violet to the middle-infrared, were produced between 1956 and 1994, first with grating spectrometers then with Fourier transform instruments. During the early 1970s, scientific concerns emerged about atmospheric composition changes likely to set in as a consequence of the growing usage of nitrogen-containing agricultural fertilisers and the industrial production of chlorine-bearing compounds such as the chlorofluorocarbons and hydro-chlorofluorocarbons. Resulting releases to the atmosphere with ensuing photolysis in the stratosphere and catalytic depletion of the protective ozone layer prompted a worldwide consortium of chemical manufacturing companies to solicit the Liège group to help in clarifying these concerns by undertaking specific observations with its existing Jungfraujoch instrumentation. The following pages evoke the main steps that led from quasi full sun-oriented studies to priority investigations of the Earth's atmosphere, in support of both the Montreal and the Kyoto Protocols. PMID:18067951

Zander, R; Mahieu, E; Demoulin, P; Duchatelet, P; Roland, G; Servais, C; De Mazière, M; Reimann, S; Rinsland, C P

2007-12-18

252

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

NASA Astrophysics Data System (ADS)

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 the timing of recovery to evaluate the full implications of disturbance to streams. Our work in the Idaho Batholith focuses on stream temperature because the distribution of cold water habitat is a key determinant of the presence of salmonids and because previous work has shown that recently disturbed streams are significantly warmer than undisturbed streams. The present study builds upon this work by looking at the effects of fire and mass wasting separately and in combination, as compared to undisturbed reference streams. We also studied different ages of disturbance from recent (1995-2003) to older (1964). Solar radiation is expected to dominate the heat budgets of these stream reaches, so the key variables of solar loading, stream width and depth, shading (measured with hemispherical photo analysis), and estimated velocity, were compared to the reach-scale stream heating to understand the mechanisms of thermal disturbance and recovery. Preliminary results indicate that mass-wasting has a stronger impact on stream heating than fires, and that while streams return to pre-disturbance conditions after 40 years, there is little sign of recovery 10 years after fires or fires and mass wasting. These results can be used to assess the long term risks to salmonid habitat due to watershed disturbances.

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

2005-12-01

253

Regeneration-associated WNT signaling is activated in long-term reconstituting AC133bright acute myeloid leukemia cells.  

PubMed

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 AC133(bright) 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 AC133(bright) 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

2012-12-01

254

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.

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

255

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

SciTech Connect

An impurity migration model for systems with material interfaces is applied to Cu migration in CdTe solar cells. In the model, diffusion fluxes are calculated from the Cu chemical potential gradient. Inputs to the model include Cu diffusivities, solubilities, and segregation enthalpies in CdTe, CdS and contact materials. The model yields transient and equilibrium Cu distributions in CdTe devices during device processing and under field-deployed conditions. Preliminary results for Cu migration in CdTe PV devices using available diffusivity and solubility data from the literature show that Cu segregates in the CdS, a phenomenon that is commonly observed in devices after back-contact processing and/or stress conditions.

Teeter, G.; Asher, S.

2008-05-01

256

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

SciTech Connect

An impurity migration model for systems with material interfaces is applied to Cu migration in CdTe solar cells. In the model, diffusion fluxes are calculated from the Cu chemical potential gradient. Inputs to the model include Cu diffusivities, solubilities, and segregation enthalpies in CdTe, CdS and contact materials. The model yields transient and equilibrium Cu distributions in CdTe devices during device processing and under field-deployed conditions. Preliminary results for Cu migration in CdTe photovoltaic devices using available diffusivity and solubility data from the literature show that Cu segregates in the CdS, a phenomenon that is commonly observed in devices after back-contact processing and/or stress conditions.

Teeter, G.; Asher, S.

2008-05-01

257

Long-term trend of CH4 at northern mid-latitudes: Comparison between ground-based infrared solar and surface sampling measurements  

NASA Astrophysics Data System (ADS)

We report average tropospheric CH4 volume mixing ratios retrieved from a 27 year time series of high spectral resolution infrared solar absorption measurements recorded between May 1977 and July 2004 at the US National Solar Observatory station on Kitt Peak (31.9N,111.6W, 2.09 km altitude) and their comparison with surface in situ sampling measurements recorded between 1983 and 2004 at the Climate Monitoring and Diagnostics Laboratory (CMDL) station at Niwot Ridge, Colorado (40.0N,105.5W, 3013 m altitude). The two measurement sets therefore overlap for the 1983 2004 time period. An average tropospheric volume mixing ratios of 1814±48ppbv (1ppbv=10 per unit volume) has been derived from the solar absorption time series with a best-fit increase rate trend equal to 8.26±2.20 ppbv yr in 1983 decreasing to 1.94±3.69 ppbv yr in 2003. The CMDL measurements also show a continuous long-term CH4 volume mixing ratio rise, with subsequent slowing down. A mean ratio of the retrieved average tropospheric volume mixing ratio to the CMDL volume mixing ratio for the overlapping time period of 1.038±0.034 indicates agreement between both data sets within the quantified experimental errors.

Rinsland, Curtis P.; Goldman, Aaron; Elkins, James W.; Chiou, Linda S.; Hannigan, James W.; Wood, Stephen W.; Mahieu, Emmanuel; Zander, Rodolphe

2006-02-01

258

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

Microsoft Academic Search

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

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

2008-01-01

259

Constancy and variability of Strombolian eruptive activity: long-term analysis of infrared surveillance videos from Stromboli Volcano  

NASA Astrophysics Data System (ADS)

Persistent Strombolian activity characterizes open-conduit volcanoes worldwide. Among these, Stromboli (Italy) is one of the best monitored by permanent networks that include visible and infrared cameras. Continuous surveillance videos from the INGV archive allow us to parameterize the dynamics of explosive events in the period 2005-2009. Here we focus on three consecutive days per each year, by analyzing a total of 4275 explosive events from the different active vents. Via image analysis of the video frames, we obtained the time lapse among consecutive events, and duration and geometrical parameters (maximum height, width, and ejection angle) of individual jets. Long-term average values of the above parameters quantitatively define the activity baseline, as follows: inter-event time lapse 5 minutes (standard deviation 5 minutes); jet duration 15 s (5 s); jet height 70 m (24 m); jet width 33 m (10 m); jet axis at angle of 3° (16°) to the vertical. Significant deviations from these baseline values are observed over different (minute to year) time-scales, e.g.: peak jet durations and heights may reach up to 120 s and 251 m, respectively. The analysis of the mutual relationships among the eruptive parameters, and their temporal variation patterns at the different vents, provide a statistically based groundwork to define the dynamics of Strombolian activity. In this regard, a higher aspect ratio (height over width) of the jet seems to reflect increasing depth of the bubble burst beneath the magma free surface in the conduit, to be compared with seismic- and acoustic-derived information. Also, the remarkable constancy of jet angles at specific vents, notwithstanding the occurrence of a significant collapse of the whole crater area during the 2007 eruptive crisis, reveals self-similar resumption of the branching, shallow conduit system and provides insights into its connection to the feeder dike. The robust statistically based definition of the Stromboli behaviour can be helpful to determine the intensity thresholds of the activity and the areas prone to ejecta dispersal, relevant for hazard assessment.

Taddeucci, J.; Palladino, D. M.; Bernini, D.; Sottili, G.; Andronico, D.; Cristaldi, A.

2012-04-01

260

Effect of long-term highly active antiretroviral therapy (HAART) on some haematological parameters of HIV-infected Nigerians  

Microsoft Academic Search

Haematologic abnormalities are among the most common manifestations of advanced HIV infection and AIDS. The aim of this case controlled study was to examine the long-term effect of HAART on the haematological profile of HIV-infected Nigerians. One hundred consecutive patients were randomized to take a fixed drug combination of stavudine, lamivudine and nevirapine. Haematological parameters were analyzed at baseline and

Osaro Erhabor; Emmanuel Kufre Uko; Osekhuiemen Adebayo Ejele; Confidence Wachukwu

261

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…

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

2008-01-01

262

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.

263

Long Term Quadrotor Stabilization.  

National Technical Information Service (NTIS)

The work of this thesis focuses on the IMU and getting the best performance possible out of the IMU to achieve better long term stability and a better navigation solution. This is done in two ways. First, the IMU accelerometer output is examined to determ...

N. Hamilton

2011-01-01

264

Ionospheric Effects of Solar Activity.  

National Technical Information Service (NTIS)

The effects of solar flares on the ionsophere are reviewed in a brief and qualitative fashion. Individual phenomena described include the long-term solar-cycle variability of the ionosphere, sudden ionospheric disturbances, polar-cap absorption events, an...

G. C. Reid

1972-01-01

265

Long-Term Trend of Carbon Tetrachloride (CCl4) from Ground-based High Resolution Infrared Solar Spectra recorded at the Jungfraujoch  

NASA Astrophysics Data System (ADS)

The long-term trend of carbon tetrachloride (CCl4) has been retrieved from infrared high resolution solar absorption spectra encompassing the 1999 to 2010 time period. The measurements were recorded with a Fourier transform spectrometer at the northern mid-latitude, high altitude Jungfraujoch station in Switzerland (46.5° N latitude, 8.0° E longitude, 3580 m altitude). Total columns were derived from the region of the strong CCl4 ?3 band at 794 cm-1 accounting for all interfering molecules (e.g. H2O, O3) with significant improvement in the residuals obtained by also taking into account the line mixing in a nearby CO2 Q branch, a procedure not implemented in previous remote sensing CCl4 retrievals though its importance has been noted in several papers. The time series shows a statistically-significant long-term decrease in the CCl4 total atmospheric burden of -1.18±0.10 %/yr, at the 95% confidence level, using 2005 as reference. Furthermore, fit to the total column data set also reveals a seasonal cycle with a peak-to-peak amplitude of 10.2%, with minimum and maximum values found in mid-February and early August, respectively. This seasonal modulation can however be attributed to tropopause height changes throughout the season. The results quantify the continued impact of the regulations implemented by the Montreal Protocol and its strengthening amendments and adjustments for a molecule with high global warming potential. Although a statistically significant decrease in the total column is inferred, the CCl4 molecule remains an important contributor to the stratospheric chlorine budget and burden.

Rinsland, Curtis; Mahieu, Emmanuel; Demoulin, Philippe; Chiou, Linda; Zander, Rodolphe; Hartmann, Jean-Michel

2010-05-01

266

Long-Term Trend of Carbon Tetrachloride (CCl4) from Ground-Based High Resolution Infrared Solar Spectra Recroded at the Jungfraujoch  

NASA Astrophysics Data System (ADS)

The long-term trend of carbon tetrachloride (CCl4) has been retrieved from infrared high resolution solar absorption spectra encompassing the 1999 to 2010 time period. The measurements were recorded with a Fourier transform spectrometer at the northern mid-latitude, high altitude Jungfraujoch station in Switzerland (46.5°N latitude, 8.0°E longitude, 3580 m altitude). Total columns were derived from the region of the strong CCl4 \\upsilon3 band at 794 cm-1 accounting for all interfering molecules (e.g. H2O, O3) with significant improvement in the residuals obtained by also taking into account the line mixing in a nearby CO2 Q branch, a procedure not implemented in previous remote sensing CCl4 retrievals though its importance has been noted in several papers. The time series shows a statistically-significant long-term decrease in the CCl4 total atmospheric burden of (-1.18 ±0.10 %/yr), at the 95% confidence level, using 2005 as reference. Furthermore, fit to the total column data set also reveals a seasonal cycle with a peak-to-peak amplitude of 10.2%, with minimum and maximum values found in mid-February and early August, respectively. This seasonal modulation can however be attributed to tropopause height changes throughout the season. The results quantify the continued impact of the regulations implemented by the Montreal Protocol and its strengthening amendments and adjustments for a molecule with high global warming potential. Although a statistically significant decrease in the total column is inferred, the CCl4 molecule remains an important contributor to the stratospheric chlorine budget and burden.

Rinsland, C.; Mahieu, E.; Demoulin, P.; Zander, R.; Chiou, L.; Hartmann, J.-M.

2010-06-01

267

Modulation of Long-Term Potentiation and Epileptiform Activity in the Rat Dentate Gyrus by the Group II Metabotropic Glutamate Receptor Subtype mGluR3.  

National Technical Information Service (NTIS)

We are the first to report involvement of group II metabotropic glutamate receptors (mGluRs; specifically mGluR3) in modulation of epileptiform activity and long-term potentiation (LTP) in the hippocampal dentate gyrus. By stimulation and/or inhibition of...

P. M. Lea

2000-01-01

268

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

269

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

270

Correlates of Long-Term Participation in a Physical Activity-Based Positive Youth Development Program for Low-Income Youth: Sustained Involvement and Psychosocial Outcomes  

ERIC Educational Resources Information Center

This study examined correlates of long-term participation in a positive youth development (PYD) program. Low-income youth (N = 215) age 8-13 of diverse ethnicity participating in a summer physical activity-based PYD program completed questionnaires at the beginning and end of the program (year 1) and at the beginning of year 2. Those with lower…

Ullrich-French, Sarah; McDonough, Meghan H.

2013-01-01

271

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

272

Short- and Long-Term Regulation of Intestinal Na+/H+ Exchange Activity Associated with TLR2 Receptor Activation Is Independent of Nuclear Factor-?B Signaling.  

PubMed

Type 2 Toll-like receptors (TLR2s) are expressed in cell membranes and recognize a wide range of pathogen-associated molecular patterns derived from bacteria, such as lipoteichoic acid (LTA). The aim of this study was to evaluate the effect of TLR2 activation by LTA on the activity of type 1 Na(+)/H(+) exchanger (NHE) in T84 intestinal epithelial cells. Short-term (0.5 hour) and long-term (18 hours) TLR2 activation significantly inhibited NHE1 activity in a concentration-dependent manner (0.01-100 µg/ml; -7 ± 3 to -21 ± 3% and 3 ± 3 to -21 ± 3% of control values, respectively). S3226 [3-[2-(3-guanidino-2-methyl-3-oxopropenyl)-5-methyl-phenyl]-N-isopropylidene-2-methyl-acrylamide dihydrochloride], an NHE3-selective inhibitor, did not affect the inhibitory effect on NHE activity. LTA-induced NHE inhibition did not occur in the presence ofethylisopropylamiloride (an NHE1 inhibitor). Long-term TLR2 activation decreased NHE1 affinity for Na(+) (Km= 64.98 ± 1.67 mM) compared with control (Km= 20.44 ± 0.54 mM) without changes in Vmax values. After TLR2 activation, we observed tyrosine-protein kinase (SRC) activation, phosphatidylinositol 3-kinase (PI3K) recruitment, and adenylyl cyclase (AC3) phosphorylation. The total amount of AC3 increased (23 ± 8% of control) after long-term treatment with LTA. Anti-AC3 small interfering RNA prevented LTA-induced NHE1 inhibition, similar to that observed with the AC3 inhibitor KH7 [(±)-2-(1H-benzimidazol-2-ylthio)propanoic acid 2-[(5-bromo-2-hydroxyphenyl)methylene]hydrazide]. A significant increase in cAMP levels (32 ± 3% and 14 ± 2% after short- and long-term stimulation, respectively) was detected, and inhibition of protein kinase A (PKA), phospholipase C (PLC), and downregulation of protein kinase C (PKC) prevented NHE1 inhibition. Inhibition of nuclear factor-?? (NF-?B) failed to revert NHE1 inhibition. We concluded that activation of TLR2 reduces NHE1 activity in epithelial cells through an alternative pathway that is unrelated to NF-?B, which involves SCR, PI3K, AC3, PKA, PLC, and PKC. PMID:23845891

Cabral, José Miguel; Soares-da-Silva, Patrício; Magro, Fernando

2013-07-11

273

Mitogen-Activated Protein Kinase Regulates Early Phosphorylation and Delayed Expression of Ca2\\/Calmodulin-Dependent Protein Kinase II in Long-Term Potentiation  

Microsoft Academic Search

Activation of mitogen-activated protein kinase (MAPK) and Ca 2\\/calmodulin-dependent protein kinase II (CaMKII) are re- quired for numerous forms of neuronal plasticity, including long-term potentiation (LTP). We induced LTP in rat hippocam- pal area CA1 using theta-pulse stimulation (TPS) paired with -adrenergic receptor activation (isoproterenol (ISO)), a proto- col that may be particularly relevant to normal patterns of hippocampal activity

Maria Grazia Giovannini; Robert D. Blitzer; Tony Wong; Kichiemon Asoma; Panayiotis Tsokas; John H. Morrison; Ravi Iyengar; Emmanuel M. Landau

274

Oxygen Deprivation Produces Delayed Inhibition of Long-Term Potentiation by Activation of NMDA Receptors and Nitric Oxide Synthase  

Microsoft Academic Search

The acute and delayed effects of anoxia on synaptic transmission and long-term potentiation (LTP) were examined in the CA1 region of rat hippocampal slices. Oxygen deprivation for 20 minutes completely but reversibly depressed excitatory postsynaptic potentials mediated by both N-methyl-D-aspartate receptors (NMDAR) and non-NMDAR. Although LTP was reliably produced by a single tetanus delivered 30 minutes after reoxygenation, LTP could

Yukitoshi Izumi; Hiroshi Katsuki; Ann M. Benz; Charles F. Zorumski

1998-01-01

275

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

Microsoft Academic Search

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

CYRIL PETIBOIS; HENRI GIN; GERARD DELERIS

276

Reduction of K1 Uptake in Glia Prevents Long-Term Depression Maintenance and Causes Epileptiform Activity  

Microsoft Academic Search

Extracellular cesium causes synchronous, interictal-like burst- ing 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)

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

277

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

278

Acute Stress, But not Corticosterone, Disrupts Short- and Long-Term Synaptic Plasticity in Rat Dorsal Subiculum Via Glucocorticoid Receptor Activation.  

PubMed

The subiculum (SUB) serves as the major output structure of the hippocampus; therefore, exploring synaptic plasticity within this region is of great importance for understanding the dynamics of hippocampal circuitry and hippocampal-cortical interactions. Previous research has shown exposure to acute stress dramatically alters synaptic plasticity within the hippocampus proper. Using in vivo electrophysiological recordings in urethane-anesthetized adult male Sprague-Dawley rats, we tested the effects of either acute restraint stress (30 min) or corticosterone (CORT) injections (3 mg/kg; s.c.) on short- and long-term forms of synaptic plasticity in the Cornu Ammonis 1-SUB pathway. Paired-pulse facilitation and two forms of long-term plasticity (long-term potentiation and late-developing potentiation) were significantly reduced after exposure to acute stress but not CORT treatment. Measurements of plasma CORT confirmed similar levels of circulating hormone in animals exposed to either acute stress or CORT treatment. The disruptive effects of acute stress on both short- and long-term forms of synaptic plasticity are mediated by glucocorticoid receptor (GR) activation as these disruptions were blocked by pre-treatment with the selective GR antagonist RU38486 (10 mg/kg; s.c.). The present results highlight the susceptibility of subicular plasticity to acute stress and provide evidence that GR activation is necessary but not sufficient for mediating these alterations. PMID:22918985

Macdougall, Matthew J; Howland, John G

2012-08-23

279

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

2011-06-20

280

Long-term administering low anticoagulant activity heparin can lessen rat hepatic fibrosis induced by either CCl 4 or porcine serum injection  

Microsoft Academic Search

Background\\/aimHeparin or heparin-derived molecules have been demonstrated to have a renoprotective activity in a number of experimental nephropathies and anti-fibrotic effect on pulmonary fibrosis induced by Bleomycin. However, the effectiveness of low anticoagulant activity heparin (LAAH) in the treatment of liver fibrosis has not been well defined. We are here demonstrating by both biochemical and morphological methods that long term

Wencai Li; Jinsheng Zhang; Quangcun Huang; Hongguang Zhu; Xuerong Zhang

2006-01-01

281

Autophagosomal I?B? Degradation Plays a Role in the Long Term Control of Tumor Necrosis Factor-?-induced Nuclear Factor-?B (NF-?B) Activity*  

PubMed Central

Transcription factor NF-?B is persistently activated in many chronic inflammatory diseases and cancers. The short term regulation of NF-?B is well understood, but little is known about the mechanisms of its long term activation. We studied the effect of a single application of TNF-? on NF-?B activity for up to 48 h in intestinal epithelial cells. Results show that NF-?B remained persistently activated up to 48 h after TNF-? and that the long term activation of NF-?B was accompanied by a biphasic degradation of I?B?. The first phase of I?B? degradation was proteasome-dependent, but the second was not. Further investigation showed that TNF-? stimulated formation of autophagosomes in intestinal epithelial cells and that I?B? co-localized with autophagosomal vesicles. Pharmacological or genetic blockade of autophagosome formation or the inhibition of lysosomal proteases decreased TNF-?-induced degradation of I?B? and lowered NF-?B target gene expression. Together, these findings indicate a role of autophagy in the control of long term NF-?B activity. Because abnormalities in autophagy have been linked to ineffective innate immunity, we propose that alterations in NF-?B may mediate this effect.

Colleran, Amy; Ryan, Aideen; O'Gorman, Angela; Mureau, Coralie; Liptrot, Catherine; Dockery, Peter; Fearnhead, Howard; Egan, Laurence J.

2011-01-01

282

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

Microsoft Academic Search

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

Jean-MiChel Heard; Serge Fichelson; Bruno Varet

1982-01-01

283

Long-Term Effects of a Standardized Complex Mixture of Urban Dust Particulate on the Metabolic Activation of Carcinogenic Polycyclic Aromatic Hydrocarbons in Human Cells in Culture  

Microsoft Academic Search

Humans are exposed to complex mixtures of polycyclic aromatic hydrocarbons in the atmosphere. We examined the long term effects of a standard reference material (SRM) 1649a over time on the metabolic activation and DNA adduct formation by two carcinogenic PAHs, benzo(a)pyrene (BP) and dibenzo(a,l)pyrene (DBP) in the human mammary carcinoma derived cell line MCF-7. PAH-DNA adduct analysis, cytochrome P450 (CYP)

Tamara Musafia-Jeknic; Brinda Mahadevan; Clifford Pereira; William M Baird

2005-01-01

284

Long-term trends in concentrations of halocarbons and radiatively active trace gases in atlantic and european air masses monitored at mace head, Ireland from 1987–1994  

Microsoft Academic Search

Long-term trends in trace gas concentrations over the period 1987–1994 are reported here for air masses advected to the Mace Head monitoring station on the remote west coast of Ireland. The trace gases covered include the principal halocarbons: CFC-11, CFC-12, CFC-113, CCl4 and methyl chloroform; the radiatively active trace gases: carbon dioxide, methane, nitrous oxide and ozone; together with carbon

P. G. Simmonds; R. G. Derwent; A. McCulloch; S. O'Doherty; A. Gaudry

1996-01-01

285

TLR-2 activation induces regulatory T cells and long-term suppression of asthma manifestations in mice.  

PubMed

Asthma is a chronic inflammatory disease of the airways characterized by variable airway obstruction and airway hyperresponsiveness (AHR). The T regulatory (Treg) cell subset is critically important for the regulation of immune responses. Adoptive transfer of Treg cells has been shown to be sufficient for the suppression of airway inflammation in experimental allergic asthma. Intervention strategies aimed at expanding the Treg cell population locally in the airways of sensitized individuals are therefore of high interest as a potential therapeutic treatment for allergic airway disease. Here, we aim to test whether long-term suppression of asthma manifestations can be achieved by locally expanding the Treg cell subset via intranasal administration of a TLR-2 agonist. To model therapeutic intervention aimed at expanding the endogenous Treg population in a sensitized host, we challenged OVA-sensitized mice by OVA inhalation with concomitant intranasal instillation of the TLR-2 agonist Pam3Cys, followed by an additional series of OVA challenges. Pam3Cys treatment induced an acute but transient aggravation of asthma manifestations, followed by a reduction or loss of AHR to methacholine, depending on the time between Pam3Cys treatment and OVA challenges. In addition, Pam3Cys-treatment induced significant reductions of eosinophils and increased numbers of Treg cells in the lung infiltrates. Our data show that, despite having adverse acute effects, TLR2 agonist treatment as a therapeutic intervention induces an expansion of the Treg cell population in the lungs and results in long-term protection against manifestation of allergic asthma upon subsequent allergen provocation. Our data indicate that local expansion of Tregs in allergic airway disease is an interesting therapeutic approach that warrants further investigation. PMID:23393567

Nawijn, Martijn C; Motta, Alexandre C; Gras, Renée; Shirinbak, Soheila; Maazi, Hadi; van Oosterhout, Antoon J M

2013-02-05

286

TLR-2 Activation Induces Regulatory T Cells and Long-Term Suppression of Asthma Manifestations in Mice  

PubMed Central

Asthma is a chronic inflammatory disease of the airways characterized by variable airway obstruction and airway hyperresponsiveness (AHR). The T regulatory (Treg) cell subset is critically important for the regulation of immune responses. Adoptive transfer of Treg cells has been shown to be sufficient for the suppression of airway inflammation in experimental allergic asthma. Intervention strategies aimed at expanding the Treg cell population locally in the airways of sensitized individuals are therefore of high interest as a potential therapeutic treatment for allergic airway disease. Here, we aim to test whether long-term suppression of asthma manifestations can be achieved by locally expanding the Treg cell subset via intranasal administration of a TLR-2 agonist. To model therapeutic intervention aimed at expanding the endogenous Treg population in a sensitized host, we challenged OVA-sensitized mice by OVA inhalation with concomitant intranasal instillation of the TLR-2 agonist Pam3Cys, followed by an additional series of OVA challenges. Pam3Cys treatment induced an acute but transient aggravation of asthma manifestations, followed by a reduction or loss of AHR to methacholine, depending on the time between Pam3Cys treatment and OVA challenges. In addition, Pam3Cys-treatment induced significant reductions of eosinophils and increased numbers of Treg cells in the lung infiltrates. Our data show that, despite having adverse acute effects, TLR2 agonist treatment as a therapeutic intervention induces an expansion of the Treg cell population in the lungs and results in long-term protection against manifestation of allergic asthma upon subsequent allergen provocation. Our data indicate that local expansion of Tregs in allergic airway disease is an interesting therapeutic approach that warrants further investigation.

Gras, Renee; Shirinbak, Soheila; Maazi, Hadi; van Oosterhout, Antoon J. M.

2013-01-01

287

Long-Term Memory Improvement?  

ERIC Educational Resources Information Center

Tests Piaget's interpretation of long-term memory improvement among 82 five- and six-year-old children. Concludes that there is little evidence for long-term memory improvement or for Piaget's theory of memory. (Author/RH)

Maurer, Daphne; And Others

1979-01-01

288

Long-Term Effects of Irrigation with Waste Water on Soil AM Fungi Diversity and Microbial Activities: The Implications for Agro-Ecosystem Resilience  

PubMed Central

The effects of irrigation with treated urban wastewater (WW) on the arbuscular mycorrhizal fungi (AMF) diversity and soil microbial activities were assayed on a long-term basis in a semiarid orange-tree orchard. After 43 years, the soil irrigated with fresh water (FW) had higher AMF diversity than soils irrigated with WW. Microbial activities were significantly higher in the soils irrigated with WW than in those irrigated with FW. Therefore, as no negative effects were observed on crop vitality and productivity, it seems that the ecosystem resilience gave rise to the selection of AMF species better able to thrive in soils with higher microbial activity and, thus, to higher soil fertility.

del Mar Alguacil, Maria; Torrecillas, Emma; Torres, Pilar; Garcia-Orenes, Fuensanta; Roldan, Antonio

2012-01-01

289

[Responses of enzyme activities in different particle-size aggregates of paddy soil in Taihu Lake region of China to long-term fertilization].  

PubMed

Taking a long-term fertilized paddy soil in Taihu Lake region as research object, the enzyme activities in <2, 2-20, 20-200, and 200-2000 microm aggregates under no fertilization (NF), chemical fertilization (CF), chemical fertilization plus straw return (CFS), and chemical fertilization plus pig manure (CFM) were investigated. Fertilization promoted the formation of 200-2000 microm aggregates significantly. The enzyme activities differed with aggregates' particle-size. Urease and invertase activities were the highest in <2 microm aggregates, whereas the activities of cellulase, polyphenoloxidase and FDA hydrolase were the highest in 200-2000 microm aggregates. Fertilization, especially the combined fertilization of inorganic and organic fertilizers, increased the activities of urease, invertase, cellulase and FDA hydrolase in 200-2000 microm aggregates significantly. With the geometric mean (GMea) of the five test enzyme activities as the integrative index of soil enzyme activities, it was found that under fertilization, the GMea was significantly higher in 200-2000 microm aggregates, suggesting the high sensitivity of enzyme activities in larger particle-size aggregates to fertilization practices. Long-term inorganic plus organic fertilization could enhance the soil bio-function via the promotion of the formation of larger particle-size aggregates and the enzyme activities in these aggregates. PMID:20030140

Niu, Wen-jing; Li, Lian-qing; Pan, Gen-xing; Song, Xiang-yun; Li, Zhi-peng; Liu, Xiao-yu; Liu, Yong-zhuo

2009-09-01

290

Activation of de novo GSH synthesis pathway in mouse spleen after long term low-dose ?-ray irradiation.  

PubMed

Glutathione (GSH) is an important cellular antioxidant and has a critical role in maintaining the balance of cellular redox. In this study, we investigated the GSH biosynthesis genes involved in the elevation of endogenous GSH levels using an irradiation system with an irradiation dose rate of 1.78 mGy/h, which was about 40,000 times less than the dose rates used in other studies. The results showed that GSH levels were significantly increased in the low-dose (0.02 and 0.2 Gy) irradiated group compared to those in the non-irradiated group, but enzymatic antioxidants such as superoxide dismutase and catalase were not induced at any doses tested. The elevation in GSH was accompanied by elevated expression of glutamate-cysteine ligase modifier subunit, but no changes were observed in the expression of glutamate-cysteine ligase catalytic subunit and thioredoxin in de novo GSH synthesis. In the case of genes involved in the GSH regeneration cycle, the expression of glutathione reductase was not changed after irradiation, whereas glutathione peroxidase was only increased in the 0.2 Gy irradiated group. Collectively, our results suggest that the de novo pathway, rather than the regeneration cycle, may be mainly switched on in response to stimulation with long-term low-dose radiation in the spleen. PMID:23136969

Lee, E K; Kim, J A; Kim, J S; Park, S J; Heo, K; Yang, K M; Son, T G

2012-11-27

291

Comparison of Long-term Activity of Comet Hale-Bopp at Visible and Mm-wavelengths  

NASA Astrophysics Data System (ADS)

Here we compare the long-term behavior of comet Hale-Bopp at visual wavelengths with the production rates of CO and HCN. Absolute visual magnitudes were calculated from over 2000 entries selected from a group of 16 experienced observers who reported their observations to the Comet Quarterly. We further restricted the sample to to select the best set of visible observations of this comet from 7 - 1 AU to date. The data were first searched by independent observer to search for outbursts and conformity of the observations, then normalized to the average reliable reported magnitude and then saved as a final corrected dataset. The data were then studied as a group to study the overall behavior of the comet pre-vs. post- perihelion. Although the overall visual magnitude (which arises primarily from reflection off dust particles) is not expected to be well-correlated with CO and HCN gaseous production, the behavior of the gas and dust were compared to search for possible relationships. This work was supported by a grant from the NSF CAREER Program and a grant from the joint NASA/NSF Hale-Bopp program.

Womack, M.; Homich, A.

1999-09-01

292

Sustainable development and next generation's health: a long-term perspective about the consequences of today's activities for food safety.  

PubMed

Development is defined sustainable when it meets the needs of the present without compromising the ability of future generations to meet their own needs. Pivoting on social, environmental and economic aspects of food chain sustainability, this paper presents the concept of sustainable food safety based on the prevention of risks and burden of poor health for generations to come. Under this respect, the assessment of long-term, transgenerational risks is still hampered by serious scientific uncertainties. Critical issues to the development of a sustainable food safety framework may include: endocrine disrupters as emerging contaminants that specifically target developing organisms; toxicological risks assessment in Countries at the turning point of development; translating knowledge into toxicity indexes to support risk management approaches, such as hazard analysis and critical control points (HACCP); the interplay between chemical hazards and social determinants. Efforts towards the comprehensive knowledge and management of key factors of sustainable food safety appear critical to the effectiveness of the overall sustainability policies. PMID:19567981

Frazzoli, Chiara; Petrini, Carlo; Mantovani, Alberto

2009-01-01

293

The Long Term Care Questionnaire and Report.  

National Technical Information Service (NTIS)

The purpose of this report is to describe an experimental data gathering activity designed to provide information on the utilization of long-term care facilities in western South Dakota. The report describes Western Health Systems, the organization doing ...

D. O. Mueller

1974-01-01

294

The Exogenous Application of Brassinosteroids to Zea mays (L.) Stressed by Long-Term Chilling Does Not Affect the Activities of Photosystem 1 or 2  

Microsoft Academic Search

The effect of various concentrations of exogenously applied 24-epibrassinolide (E) and 2?,3?,17?-trihydroxy-5?-androstan-6-one\\u000a (A) on the activities of Photosystem 1 and the Hill reaction, the contents of photosynthetic pigments, and the growth of plants\\u000a was examined in young maize (Zea mays L.) plants subjected to long-term chilling stress or grown in normal-temperature conditions. Neither the activity of Photosystem\\u000a 1 nor the

Jana Honnerová; Olga Rothová; Dana Holá; Marie Ko?ová; Ladislav Kohout; Miroslav Kvasnica

2010-01-01

295

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

NASA Astrophysics Data System (ADS)

Shortage of water is one of the most important environmental problem in the Mediterranean areas that implicates the search for strategies for saving good quality water. The use of treated waste water for the irrigation of agricultural land can be a good solution for this problem because it reduces the utilization of fresh water and potentially could improve soil key parameters, but can modify physical-chemical and biological properties of the same. The aim of this work was to study the effect of long-term irrigation with treated waste water on microbial diversity, mainly arbuscular mycorrhizal fungi (AMF) of the soil and other properties related with the microbial community. The experiment was developed in an agricultural area with Citrus orchard, located in Alicante in the southeast Spain. Here, we tested whether the communities of AMF as well as soil microbial properties were affected by irrigation with water coming from sewage treatment plant during 40 years in a soil. To carry out this study the soil properties (dehydrogenase, urease, protease-BAA, acid phosphatase, ?-glucosidase, glomalin related soil protein, microbial biomass C and aggregate stability) and AMF diversity (the AM fungal small sub-unit (SSU) rRNA genes were subjected to PCR, cloning, sequencing and phylogenetic analyses) were analysed in the soil from two different plots with the same soil but with different type of irrigation (irrigated with fresh water and irrigated with treated water). The first results did not show significant differences in some soil properties between soil irrigated with water treated or not.

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

2012-04-01

296

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

NASA Astrophysics Data System (ADS)

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

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

2005-12-01

297

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

PubMed Central

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

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

2008-01-01

298

Evi1 is essential for hematopoietic stem cell self-renewal, and its expression marks hematopoietic cells with long-term multilineage repopulating activity  

PubMed Central

Ecotropic viral integration site 1 (Evi1), a transcription factor of the SET/PR domain protein family, is essential for the maintenance of hematopoietic stem cells (HSCs) in mice and is overexpressed in several myeloid malignancies. Here, we generate reporter mice in which an internal ribosome entry site (IRES)-GFP cassette is knocked-in to the Evi1 locus. Using these mice, we find that Evi1 is predominantly expressed in long-term HSCs (LT-HSCs) in adult bone marrow, and in the hematopoietic stem/progenitor fraction in the aorta-gonad-mesonephros, placenta, and fetal liver of embryos. In both fetal and adult hematopoietic systems, Evi1 expression marks cells with long-term multilineage repopulating activity. When combined with conventional HSC surface markers, sorting according to Evi1 expression markedly enhances purification of cells with HSC activity. Evi1 heterozygosity leads to marked impairment of the self-renewal capacity of LT-HSCs, whereas overexpression of Evi1 suppresses differentiation and boosts self-renewal activity. Reintroduction of Evi1, but not Mds1-Evi1, rescues the HSC defects caused by Evi1 heterozygosity. Thus, in addition to documenting a specific relationship between Evi1 expression and HSC self-renewal activity, these findings highlight the utility of Evi1-IRES-GFP reporter mice for the identification and sorting of functional HSCs.

Kataoka, Keisuke; Sato, Tomohiko; Yoshimi, Akihide; Goyama, Susumu; Tsuruta, Takako; Kobayashi, Hiroshi; Shimabe, Munetake; Arai, Shunya; Nakagawa, Masahiro; Imai, Yoichi; Kumano, Keiki; Kumagai, Katsuyoshi; Kubota, Naoto; Kadowaki, Takashi

2011-01-01

299

Particle-in-cell, self-consistent electromagnetic wave emission simulations of solar type III radio bursts: parameter space investigation and electron beam long-term evolution  

NASA Astrophysics Data System (ADS)

A recent work by Tsiklauri, Physics of Plasmas 18, 052903 (2011), presented the first attempt to produce synthetic (simulated) dynamical spectrum of the solar type III radio bursts in the fully kinetic plasma model. The latter was based on 1.5D non-zero pitch angle (non-gyrotropic) electron beam, that is an alternative to the plasma emission classical mechanism for which two spatial dimensions are needed. High-resolution, 1.5D Particle-in-Cell, relativistic, fully electromagnetic simulations were used to model electromagnetic wave emission generation in the context of solar type III radio bursts. The model studied generation of electromagnetic waves by a super-thermal, hot beam of electrons injected into a plasma thread that contains uniform longitudinal magnetic field and a parabolic density gradient. In effect, a single magnetic line connecting Sun to earth was considered, for which several cases were studied. Tsiklauri (2011) established the following: (i) The physical system without a beam is stable and only low amplitude level electromagnetic drift waves (noise) are excited. (ii) The beam injection direction is controlled by setting either longitudinal or oblique electron initial drift speed, i.e. by setting the beam pitch angle (the angle between the beam velocity vector and the direction of background magnetic field). In the case of zero pitch angle i.e. when ?c vb \\cdot ?c E?=0, the beam excites only electrostatic, standing waves, oscillating at local plasma frequency, in the beam injection spatial location, and only low level electromagnetic drift wave noise is also generated. (iii) In the case of oblique beam pitch angles, i.e. when ?c vb \\cdot ?c E? ¬ =0, again electrostatic waves with same properties are excited. However, now the beam also generates the electromagnetic waves with the properties commensurate to type III radio bursts. The latter is evidenced by the wavelet analysis of transverse electric field component, which shows that as the beam moves to the regions of lower density and hence lower plasma frequency, frequency of the electromagnetic waves drops accordingly. (iv) When the density gradient is removed, an electron beam with an oblique pitch angle still generates the electromagnetic radiation. However, in the latter case no frequency decrease is seen. Here we extend the previous analysis of Tsiklauri (2011) by presenting a full parameter space investigation and the beam's long-term time evolution. We study how the generated radio burst emission varies as a function of beam pitch angle and its temperature (which is normally different from the background plasma temperature). We established that: (i) there is an optimal angle for which the maximal radio emission occurs and (ii) in the plausible range of beam temperatures, their variation does not produce a significant effect on the generated radio emission.

Pechhacker, R.; Tsiklauri, D.

2011-12-01

300

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

2013-06-14

301

Simultaneous, long-term monitoring of valve and cardiac activity in the blue mussel Mytilus edulis exposed to copper  

Microsoft Academic Search

Valve and cardiac activity were simultaneously measured in the blue mussel (Mytilus edulis) in response to 10?d copper exposure. Valve movements, heart rates and heart-rate variability were obtained non-invasively\\u000a using a Musselmonitor® (valve activity) and a modified version of the Computer-Aided Physiological Monitoring system (CAPMON; cardiac activity).\\u000a After 2?d exposure of mussels (4 individuals per treatment group) to a range

T. M. Curtis; R. Williamson; M. H. Depledge

2000-01-01

302

Effects of long term polyarthritis and subsequent NSAID treatment on activity with disassociation of tactile allodynia in the mouse  

PubMed Central

Chronic pain has profound effects on activity. Previous reports indicate chronic inflammatory conditions result in reduced activity which normalizes upon pain treatment. However, there is little systematic investigation of this process. Rheumatoid arthritis is an autoimmune disorder that causes significant joint pain. The K/BxN serum transfer mouse has been characterized as a model for rheumatoid arthritis and chronic pain. We investigated the activity of mice following K/BxN serum transfer vs. control serum and observed the activity changes following delivery of an NSAID, ketorolac. Previous studies have used running wheels and laser beams to monitor activity; we chose to validate a model using cost-effective infrared sensors on individual cages. Each mouse had its baseline activity obtained, which showed significant variation between individual C57Bl/6 mice. Arthritic mice had significantly decreased activity for only the first 11 nights. Conversely, previous work has shown that these animals display tactile allodynia that persists for at least 45 days. Mice were treated with ketorolac in their drinking water (10mg/kg, 15mg/kg, or 20mg/kg) for nights 6–8. The two highest doses showed significant normalization of activity levels. Four nights after ketorolac was stopped, treated animals were still significantly more active than control. The reversal of the reduced activity provides support that the depression relates to the arthritic pain state of the animal. These results indicate the efficacy of activity monitoring to better investigate behavior in persistent pain states. However, insofar as depressed activity reflects pain and disability, the present work raises questions as to the relevance of the tactile thresholds in defining behaviorally relevant pain states.

Suhail, Mohammed S A; Christianson, Christina; Koehrn, Fred; Malkmus, Shelle A; Mitchell, William; Corr, Maripat; Yaksh, Tony L.

2012-01-01

303

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

PubMed

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

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

2003-06-01

304

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

Microsoft Academic Search

When monkeys perform a delayed match-to-sample task, some neurons in the anterior inferotemporal cortex show sustained activity following the presentation of specific visual stimuli, typically only those that are shown repeatedly. When sample stimuli are shown in a fixed temporal order, the few images that evoke delay activity in a given neuron are often neighboring stimuli in the sequence, suggesting

Volodya Yakovlev; Stefano Fusi; Elisha Berman; Ehud Zohary

1998-01-01

305

Weather-induced changes in moth activity bias measurement of long-term population dynamics from light trap samples  

Microsoft Academic Search

Interpretation of light trap catches of moths is complicated by daily variation in weather that alters flight activity and numbers caught. Light trap efficiency is also modified by wind and fog, and daily weather may effect absolute abundance (numbers actually present). However, actograph experiments and other sampling methods suggest that changes in daily activity are large by comparison to changes

M. Holyoak; V. Jarosik; I. Novak

1997-01-01

306

Age Differences and Social Stratification in the Long-Term Trajectories of Leisure-Time Physical Activity  

PubMed Central

Objectives. This study assessed how and why the social stratification of leisure-time physical activity changes as adults at different points in the life course, and from different birth cohorts, grow older. Methods. A series of multilevel models were estimated using longitudinal data from a national sample of more than 3,000 adults from the Americans’ Changing Lives study. Results. On average, rates of leisure-time physical activity increased within younger adults and decreased within middle-aged and older adults, throughout the study period. Initial Black–White differences in activity converged over time, whereas initial men advantages over women widened, particularly among older adults. Gender-based differences did not remain after accounting for differences in health; however, significant age and race differences in the trajectories of physical activity persisted, even after accounting for the effects of health and social relationships on leisure-time physical activity. Discussion. American adults appear to be reducing their levels of physical activity relatively early in the life course and at increasingly steep rates among older age groups. The changing patterns of stratification in physical activity, as well as the associations between several time-varying predictors and physical activity, provide insight into the forces that may be responsible for these declines.

Liang, Jersey; Krause, Neal; Gallant, Mary; McGeever, Kelly

2010-01-01

307

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. ...

308

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

Microsoft Academic Search

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

Asl? Seyhan Ç??g?n; Derin Orhon; Simona Rossetti; Mauro Majone

2011-01-01

309

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

310

Presynaptic long-term plasticity  

PubMed Central

Long-term synaptic plasticity is a major cellular substrate for learning, memory, and behavioral adaptation. Although early examples of long-term synaptic plasticity described a mechanism by which postsynaptic signal transduction was potentiated, it is now apparent that there is a vast array of mechanisms for long-term synaptic plasticity that involve modifications to either or both the presynaptic terminal and postsynaptic site. In this article, we discuss current and evolving approaches to identify presynaptic mechanisms as well as discuss their limitations. We next provide examples of the diverse circuits in which presynaptic forms of long-term synaptic plasticity have been described and discuss the potential contribution this form of plasticity might add to circuit function. Finally, we examine the present evidence for the molecular pathways and cellular events underlying presynaptic long-term synaptic plasticity.

Yang, Ying; Calakos, Nicole

2013-01-01

311

Tissue-Plasminogen Activator Is Induced as an Immediate-Early Gene During Seizure, Kindling and Long-Term Potentiation.  

National Technical Information Service (NTIS)

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 a...

Z. Qian M. E. Gilbert M. A. Colicos E. R. Kandel D. Kuhl

1993-01-01

312

Long-term culture of hepatocytes: ethanol oxidation and effect of ethanol on enzyme activities and albumin secretion.  

PubMed

Rat hepatocytes were cultured in a modified HI-WO/BA medium for 13 days, and the combined effect of dexamethasone, 10(-7) M, insulin, 10(-8) M, and glucagon, 10(-9) M on the DNA-content, and on the activity of several enzymes, the secretion of albumin and the rate of ethanol oxidation was investigated. The effect of ethanol on these parameters was also studied. All parameters measured declined with time in the hormone-free cultures. In hormone-supplemented cultures, the DNA-content, the activity of glucokinase, pyruvate kinase, hexokinase and lactate dehydrogenase and the secretion of albumin was maintained at reasonable levels throughout the 13 days, whereas both the activity of alcohol dehydrogenase and the rate of ethanol oxidation fell significantly, although less than in hormone-free cultures. Addition of 50 mM ethanol to the hormone-supplemented culture medium caused a ca. 20% fall in the activity of glucokinase and pyruvate kinase and a 20% increase in alcohol dehydrogenase activity. No effect of ethanol was observed on the activity of hexokinase and lactate dehydrogenase or on the secretion of albumin. PMID:3322306

Dich, J; Vind, C; Grunnet, N

1987-01-01

313

Physical activity in relation to long-term weight maintenance after intentional weight loss in premenopausal women.  

PubMed

The type and amount of physical activity (PA) needed for prevention of weight regain are not well understood. We prospectively examined the associations between patterns of discretionary PA and 6-year maintenance of intentional weight loss among 4,558 healthy premenopausal women who were 26-45 years old in 1991 and had lost >5% of their body weight in the previous 2 years. Participants reported their PA and weight in 1991 and 1997. The outcome was weight regain, defined as regaining in 1997 >30% of the lost weight between 1989 and 1991. Between 1991 and 1997, 80% of women regained >30% of their previous intentional weight loss. An increase of 30 min/day in total discretionary activity between 1991 and 1997 was associated with less weight regain (-1.36 kg, 95% confidence interval (CI) = -1.61, -1.12), particularly among overweight women (BMI >/=25) (-2.45 kg, -3.12 to -1.78). Increased jogging or running was associated with less weight regain (-3.26 kg; -4.41 to -2.10) than increased brisk walking (-1.69 kg; -2.15 to -1.22) or other activities (-1.26 kg; -1.65 to -0.87). Compared to women who remained sedentary, women were less likely to regain >30% of the lost weight if they maintained 30+ min/day of discretionary PA (odds ratio (OR) = 0.69, 0.53 to 0.89) or increased to this activity level (OR = 0.48, 0.39 to 0.60). Conversely, risk was elevated in women who decreased their activity. Increased PA, particularly high intensity activities, is associated with better maintenance of weight loss. The benefits of activity were greater among overweight/obese than normal weight women. PMID:19498346

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

2009-06-04

314

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

315

Optimal warm-up stimuli of muscle activation to enhance short and long-term acute jumping performance  

Microsoft Academic Search

The aim of this study was to determine the effect of different types of active warm-up stimuli of muscle activation on explosive\\u000a jumping performance after short (5 min postwarm-up) and long (6 h postwarm-up) recovery periods following warm-up. Twelve\\u000a trained volleyball players (21-24 years) performed different types of specific warm-up stimuli (WP) after baseline measurements\\u000a [e.g., countermovement jump (CMJ) without and with extra

Eduardo Saez Saez de Villarreal; Juan J. González-Badillo; Mikel Izquierdo

2007-01-01

316

Leisure-time activity is an important determinant of long-term weight maintenance after weight loss in the Sibutramine Trial on Obesity Reduction and Maintenance (STORM trial)  

Microsoft Academic Search

Background: The success rate of long-term maintenance of weight loss in obese patients is usually low. To improve the success rate, determinants of long-term weight maintenance must be identified. Objective: The objective of the study was to identify determinants of long-term success in weight maintenance in obese subjects who completed the Sibutramine Trial on Obesity Reduction and Main- tenance (n

Marleen A van Baak; Edgar van Mil; V. Vastrup; Nick Finer; W. Saris

2003-01-01

317

Exercise slips in high-risk situations and activity patterns in long-term exercisers: An application of the relapse prevention model  

Microsoft Academic Search

Background: Key factors in successful long-term exercise maintenance are not well understood. The Relapse Prevention Model (RPM) may\\u000a provide a framework for this process.Purpose: The purpose of this study was to examine the relationships among characteristics of exercise high-risk situations, components\\u000a of the RPM relevant to exercise slips, and follow-up exercise outcomes in long-term community exercisers.Methods: We obtained long-term exercisers’

Barbara A. Stetson; Abbie O. Beacham; Stephen J. Frommelt; Kerri N. Boutelle; Jonathan D. Cole; Craig H. Ziegler; Stephen W. Looney

2005-01-01

318

Characterisation of eye-lens DNases: long term persistence of activity in post apoptotic lens fibre cells.  

PubMed

Fibre cells in the ocular lens exhibit a constitutive apoptotic process of nuclear degradation that includes chromatin breakage, generating a ladder pattern of DNA fragments. This process is intrinsic to the normal terminal differentiation program. Despite the loss of nucleus and cytoplasmic organelles, the terminal differentiated fibre cells remain in the lens during the whole life span of the individual. The lens cells thus provide a unique system in which to determine the presence and fate of endonucleases once the chromatin has been cleaved. We report here on the presence of DNase activity in nucleated and anucleated lens cells. Using a nuclease gel assay and double-stranded DNA as substrate, we found active 30 and 60 kDa DNases. The enzymatic activities were Ca(2+), Mg(2+) dependent, and active at neutral pH. The relative amount of these forms changed during development and aging of the lens fibre cells. Both forms were inhibited by Zn(2+), aurintricarboxylic acid, and G-actin. The proteins were also separated by SDS-PAGE, renatured after removing SDS and incubated in the presence of native DNA adsorbed to a membrane. Therefore it was possible to demonstrate, by means of a nick translation reaction, that the enzymes produced single strand cuts. Based on these findings we propose that these chick lens nucleases are probably related to DNase I. PMID:17180015

Arruti, C; Chaudun, E; De Maria, A; Courtois, Y; Counis, M F

1995-01-01

319

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.

Robinson, Gareth; Thorn, Robin; Reynolds, Darren

2013-01-01

320

Rac1 activity changes are associated with neuronal pathology and spatial memory long-term recovery after global cerebral ischemia  

Microsoft Academic Search

Excitotoxicity is the main event during neurological disorders producing drastic morphological and functional changes. Rac-GTPase is involved in cytoskeletal remodeling and survival. However, the role of Rac1 after cerebral ischemia has not been completely understood yet. In this study, we evaluated the activity of Rac1 and its immunoreactivity associated to neuropathological hallmarks and behavioral task analyses after global cerebral ischemia

Gutiérrez-Vargas Johanna; Castro-Álvarez John Fredy; Velásquez-Carvajal David; Montañez-Velásquez Maria Natalia; Céspedes-Rubio Ángel; Cardona-Gómez Gloria Patricia

2010-01-01

321

Powdered activated carbon and membrane bioreactors (MBRPAC) for tannery wastewater treatment: long term effect on biological and filtration process performances  

Microsoft Academic Search

This paper describes the findings of an experimental investigation carried out on a pilot scale membrane bioreactor (MBR) with the addition of powdered activated carbon (PAC) to analyze improvements in effluent quality and in the filtration process. The results refer to a pilot plant monitoring stretched over a period of 594 days: 380 without PAC, 123 with a PAC concentration

G. Munz; R. Gori; G. Mori; C. Lubello

2007-01-01

322

Early warning for volcanic activity investigated from the 2008 Chaiten eruption based on long-term observation by microwave radiometer  

Microsoft Academic Search

A microwave radiometer can observe thermal emission from the ground with less contamination by clouds than an infrared radiometer. However, because its spatial resolution is large, if an analysis method to compensate the disadvantage is developed, it should be more suitable to issue an alert for a volcanic activity in the early stage before an eruption. We have investigated an

Takashi Maeda; Tadashi Takano

2011-01-01

323

A metallic multisite recording system designed for continuous long-term monitoring of electrophysiological activity in slice cultures  

Microsoft Academic Search

This paper describes a flexible, metallic multielectrode array, made on kapton to fit in a recording chamber for interface-type organotypic cultures. This multisite recording system is designed for continuous multisite monitoring of electrophysiological activity in rat brain organotypic slice cultures. The system is composed of a signal conditioning set-up, which also masters electrical stimulation paradigms and a card containing the

S Duport; C Millerin; D Muller; P Corrèges

1999-01-01

324

Adapting and Implementing a Long-Term Nutrition and Physical Activity Curriculum to a Rural, Low-Income, Biethnic Community  

Microsoft Academic Search

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

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

2006-01-01

325

[The effect of preparations with nootropic action when used long-term on the brain bioelectrical activity in rats].  

PubMed

The impact of prolonged injection of piracetam (2 months), meclophenoxate (5 months), and mexidole (5 months) on the bioelectrical activity of the sensomotor cortex and dorsal hippocamp was studied in rats who behaved freely. The injects increased and stabilized the predominant peak of EEC spectra power by the Fourier method. Discontinuation (24 hours) of piracetam failed to impair EEG spectra and bioelectrical activity. Increasing the basic effects of nootropic drugs given chronically versus acutely suggests that chronic injection enhanced their action. The drugs under study elevated the level of wakefulness and excitability of the animals, which is likely to underlie the neurophysiological mechanisms responsible for behaviour optimization under the influence of these agents. PMID:8324481

Krapivin, S V; Sopyev, Zh A

326

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

PubMed Central

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 physical activity in the general population seen in primary care. Method and design Randomized controlled trial with systematic random sampling. A total of 424 subjects of both sexes will participate; all will be over the age of 18 with a low level of physical activity (according to the International Physical Activity Questionnaire, IPAQ), self-employed and from 9 Primary Healthcare Centres (PHC). They will volunteer to participate in a physical activity programme during 3 months (24 sessions; 2 sessions a week, 60 minutes per session). Participants from each PHC will be randomly allocated to an intervention (IG) and control group (CG). The following parameters will be assessed pre and post intervention in both groups: (1) health-related quality of life (SF-12), (2) physical activity stage of change (Prochaska's stages of change), (3) level of physical activity (IPAQ-short version), (4) change in perception of health (vignettes from the Cooperative World Organization of National Colleges, Academies, and Academic Associations of Family Physicians, COOP/WONCA), (5) level of social support for the physical activity practice (Social Support for Physical Activity Scale, SSPAS), and (6) control based on analysis (HDL, LDL and glycated haemoglobin). Participants' frequency of visits to the PHC will be registered over the six months before and after the programme. There will be a follow up in a face to face interview three, six and twelve months after the programme, with the reduced version of IPAQ, SF-12, SSPAS, and Prochaska's stages. Discussion The pilot study showed the effectiveness of an enhanced low-cost, evidence-based intervention in increased physical activity and improved social support. If successful in demonstrating long-term improvements, this randomised controlled trial will be the first sustainable physical activity intervention based in primary care in our country to demonstrate long-term adherence to physical activity. Trial Registration A service of the U.S. National Institutes of Health. Developed by the National Library of Medicine. ClinicalTrials.gov ID: NCT00714831.

Gine-Garriga, Maria; Martin, Carme; Martin, Carlos; Puig-Ribera, Anna; Anton, Juan Jose; Guiu, Agusti; Cascos, Ana; Ramos, Rafel

2009-01-01

327

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

328

Effects of tranylcypromine stereoisomers, clorgyline and deprenyl on open field activity during long term lithium administration in rats  

Microsoft Academic Search

Locomotor activity of male rats was stutied in an open field after an i.p. injection (15 mg\\/kg) of thed- orl-isomers of tranylcypromine (d-Tc andl-Tc, respectively) or after s.c. injection of either clorgyline (0.5, 1 or 5 mg\\/kg) which selectively inhibits Type A MAO or deprenyl (0.5, 5 or 10 mg\\/kg) which selectively inhibits Type B MAO. The rats were fed

Donald F. Smith

1976-01-01

329

The acute and the long-term effects of nigral lipopolysaccharide administration on dopaminergic dysfunction and glial cell activation.  

PubMed

Sustained reactive microgliosis may contribute to the progressive degeneration of nigral dopaminergic neurons in Parkinson's disease (PD), in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) exposed human and in non-human primates. However, the temporal relationship between glial cell activation and nigral cell death is relatively unexplored. Consequently, the effects of acute (24 h) and chronic (30 days) glial cell activation induced by unilateral supranigral lipopolysaccharide (LPS) administration were studied in rats. At 24 h, LPS administration caused a marked reduction in the number of tyrosine hydroxylase-immunoreactive (TH-ir) neurons in the substantia nigra (SN) but striatal TH-ir was unaffected. By 30 days, the loss of TH-positive neurons in the LPS-treated nigra was no greater than at 24 h although a heterogeneous loss of striatal TH-ir was present. The loss of nigrostriatal neurons was of functional significance, as at 30 days, LPS-treated rats exhibited ipsiversive circling in response to (+)-amphetamine administration. At 24 h, there was a moderate increase in glial fibrillary acidic protein (GFAP)-ir astrocytes in the SN but a marked elevation of p47phox positive OX-42-ir microglia, and intense inducible nitric oxide synthase (iNOS)-ir and 3-nitrotyrosine (3-NT)-ir was present. However, by 30 days the morphology of OX-42-ir microglia returned to a resting state, the numbers were greatly reduced and no 3-NT-ir was present. At 30 days, GFAP-ir astrocytes were markedly increased in number and iNOS-ir was present in fibrillar astrocyte-like cells. This study shows that acute glial activation leading to dopaminergic neuron degeneration is an acute short-lasting response that does not itself perpetuate cell death or lead to prolonged microglial activation. PMID:16045485

Iravani, Mahmoud M; Leung, Clement C M; Sadeghian, Mona; Haddon, Claire O; Rose, Sarah; Jenner, Peter

2005-07-01

330

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

331

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

SciTech Connect

The synthesis and accumulation of nitrite has been suggested as a causative factor in the inhibition of legume nodules supplied with nitrate. Plants were grown in sand culture with a moderate level of nitrate (2.1 to 6.4 millimolar) supplied continuously from seed germination to 30 to 50 days after planting. In a comparison of nitrate treatments, a highly significant negative correlation between nitrite concentration in soybean (Glycine max (L.) Merr.) nodules and nodule fresh weight per shoot dry weight was found even when bacteroids lacked nitrate reductase (NR). However, in a comparison of two Rhizobium japonicum strains, there was only 12% as much nitrite in nodules formed by NR/sup -/ R. japonicum as in nodules formed by NR/sup +/ R. japonicum, and growth and acetylene reduction activity of both types of nodules was about equally inhibited. The very small concentration of nitrite found in P. vulgaris nodules was probably below that required for the inhibition of nitrogenase based on published in vitro experiments, and yet the specific acetylene reduction activity was inhibited 83% by nitrate. The overall results do not support the idea that nitrite plays a role in the inhibition of nodule growth and nitrogenase activity by nitrate.

Streeter, J.G.

1985-02-01

332

Argon ion laser and halogen lamp activation of a dark and light resin composite: microhardness after long-term storage  

Microsoft Academic Search

The objective of this study was to evaluate in vitro light activation of the nano-filled resin composite Vita shade A1 and\\u000a A3 with a halogen lamp (QTH) and argon ion laser by Knoop microhardness profile. Materials and methods: Specimens of nanofilled\\u000a composite resin (Z350-3 M-ESPE) Vita shade A1 and A3 were prepared with a single increment inserted in 2.0-mm-thick and 3-mm

Alessandra Cassoni; Juliana de Oliveira Ferla; Luis Gustavo Barrotte Albino; Michel Nicolau Youssef; Jamil Awad Shibli; José Augusto Rodrigues

2010-01-01

333

Long-Term Consumption of Platycodi Radix Ameliorates Obesity and Insulin Resistance via the Activation of AMPK Pathways  

PubMed Central

This study was designed to evaluate the effects and mechanism of Platycodi radix, having white balloon flower (Platycodon grandiflorum for. albiflorum (Honda) H. Hara) on obesity and insulin resistance. The extracts of Platycodi radix with white balloon flower were tested in cultured cells and administered into mice on a high-fat diet. The Platycodi radix activated the AMPK/ACC phosphorylation in C2C12 myotubes and also suppressed adipocyte differentiation in 3T3-L1 cells. In experimental animal, it suppressed the weight gain of obese mice and ameliorated obesity-induced insulin resistance. It also reduced the elevated circulating mediators, including triglyceride (TG), T-CHO, leptin, resistin, and monocyte chemotactic protein (MCP)-1 in obesity. As shown in C2C12 myotubes, the administration of Platycodi radix extracts also recovered the AMPK/ACC phosphorylation in the muscle of obese mice. These results suggest that Platycodi radix with white balloon flower ameliorates obesity and insulin resistance in obese mice via the activation of AMPK/ACC pathways and reductions of adipocyte differentiation.

Lee, Chae Eun; Hur, Haeng Jeon; Hwang, Jin-Taek; Sung, Mi Jeong; Yang, Hye Jeong; Kim, Hyun-Jin; Park, Jae Ho; Kwon, Dae Young; Kim, Myung-Sunny

2012-01-01

334

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

335

Long-term regulation of AMP-activated protein kinase and acetyl-CoA carboxylase in skeletal muscle.  

PubMed

Evidence is accumulating for roles of AMP-activated protein kinase (AMPK) in controlling glucose uptake, fatty acid oxidation and gene expression in skeletal muscle. Relatively little is known, however, about the control of expression of the AMPK subunit isoforms. Marked differences are noted in subunit expression as a function of muscle fibre type. Expression of the gamma3 subunit isoform increases in fast-twitch red fibres of the rat in response to training. All subunit isoforms are expressed to a lesser extent in rats treated with propylthiouracil (PTU; an inhibitor of thyroid hormone synthesis) for 3 weeks compared with rats given excess thyroid hormones for 3 weeks. An approx. 2-fold increase in acetyl-CoA carboxylase was observed in gastrocnemius of hyperthyroid rats compared with experimentally hypothyroid rats. Thyroid state therefore appears to be one important factor controlling expression of these proteins in skeletal muscle. PMID:12546681

Winder, W W; Hardie, D G; Mustard, K J; Greenwood, L J; Paxton, B E; Park, S H; Rubink, D S; Taylor, E B

2003-02-01

336

Similar neutralizing activity in the HIV-1 infected long term non-progressors(LTNPs) and typical progressors(TPs).  

PubMed

Neutralizing antibodies are considered to be an important protective parameter used in HIV-1 vaccine evaluation. However, the exact role that neutralizing antibodies plays in controlling the disease progression of HIV-1 infected peoples is still undetermined. In this paper, we compared the protective function of the neutralizing antibody response in the plasma from LTNP and TP against clade B and clade C pseudoviruses. No difference in the neutralizing activities between the plasma from LTNP and TP was found, which was consistent with the most recent reports. In addition, no correlations between the titer or breadth and CD(4+) or viral load in HIV-1 infected individuals were found. The protective roles played by neutralizing antibodies in controlling disease progression of HIV-1 infected people need to be considered in a new viewpoint. PMID:22684470

Wang, Zheng; Li, Tian-yi; Li, Jing-yun; Chen, Li-li; Liu, Yong-jian; Li, Han-ping; Bao, Zuo-yi; Wang, Xiao-lin; Zhuang, Dao-min; Liu, Si-yang; Li, Lin

2012-06-09

337

The content and activity of cytochrome P-450 in long-term culture of hepatocytes from male and female rats.  

PubMed

The content of cytochrome P-450 and the capacity for O-demethylation have been measured in cultures of hepatocytes from male and female rats for a period of 21 days. The effect of dexamethasone, insulin, glucagon, phenobarbital and hemin was investigated. In hepatocytes from female rats the content of cytochrome P-450 was unchanged after one day of culture. From day 1 to day 3 the content of cytochrome P-450 decreased by 65% and only the combined addition of dexamethasone, phenobarbital and hemin diminished the fall. After the initial fall, addition of 0.1 microM dexamethasone resulted in a stable value. Addition of 1 microM dexamethasone or 1 mM phenobarbital gave rise to an induction of cytochrome P-450 (285%). The high level of cytochrome P-450 was maintained for 3 weeks. In hepatocytes from male rats the content of cytochrome P-450 decreased by 40% after one day of culture. From day 1 to day 3 the content decreased by 45% and the decrease continued irrespective of the presence of hormones and/or phenobarbital. The O-demethylase activity in cultures of hepatocytes from female rats correlated to the cytochrome P-450 content independent of medium composition and age of the cultures, whereas no correlation was found in cultures from male rats. The present study demonstrates that hepatocytes from female rats in cultures retain O-demethylase activity for at least 3 weeks and that, with the experimental conditions used, the response to the hormones and inducers is different for hepatocytes from male and female rats. PMID:3355606

Vind, C; Dich, J; Grunnet, N

1988-04-01

338

Anti-anhedonic activity of long-term lithium treatment in rats exposed to repeated unavoidable stress.  

PubMed

Behavioural and neurochemical responses to palatable food exposure represent an index of hedonic competence. In rats, a palatable meal increases extra-neuronal dopamine levels in the nucleus accumbens shell (NAcS) that confers to it incentive salience and reinforcing value. Repeated stress exposure decreases dopamine output and impairs the NAcS dopaminergic response to palatable food and the competence to acquire a vanilla sugar (VS)-reinforced instrumental behaviour [VS-sustained appetitive behaviour (VAB)]. Moreover, chronic stress exposure disrupts reactivity to aversive stimuli. A 3-wk treatment with lithium, the gold-standard treatment in bipolar disorder, tonically reduces NAcS dopamine output and the reactivity to aversive stimuli. However, it does not affect the dopaminergic response to VS and the competence to acquire VAB. This study investigated whether repeated lithium administration is endowed with anti-anhedonic activity. The NAcS dopaminergic response to VS and the competence to acquire VAB and sucrose self-administration (SA), in terms of fixed-ratio (FR)1, FR5 and progressive ratio schedules of reinforcement, were studied in saline or lithium-treated groups of non-food-deprived rats exposed or not to repeated unavoidable stress. Chronic stress exposure impaired the NAcS dopaminergic response to VS, acquisition of VAB and sucrose SA, in terms of FR1 and FR5 schedules of reinforcement and breaking point score. Repeated lithium treatment restored these parameters to control group values, even when treatment began in rats already showing an anhedonia-like condition. Since the breaking point defines the reinforcement efficacy of a hedonic stimulus, the present data suggest that lithium treatment is endowed with anti-anhedonic activity in rats. PMID:23363811

Marchese, Giovanna; Scheggi, Simona; Secci, Maria Elena; De Montis, Maria Graziella; Gambarana, Carla

2013-08-01

339

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

340

Input\\/output test results and long-term performance prediction of a domestic thermosiphon solar water heater in Algiers, Algeria  

Microsoft Academic Search

Experimental tests have been conducted following the recommended CSTG guidelines in outdoor conditions, in order to evaluate a thermosiphon Solar Domestic Hot Water (SDHW) system. This thermosiphonic solar system tested represents a good sample of various characteristics for SDHW systems manufactured by the Algerian industry. Heating of water utilising solar energy is a well-known and established technology in many parts

A. Zerrouki; A. Boumedien; N. Said; B. Tedjiza

2002-01-01

341

Solar Activity and PMC Response  

NASA Astrophysics Data System (ADS)

Ground-based noctilucent cloud (NLC) observations have been analyzed for the existence of a long-term relationship with solar activity for many years. Physical processes such as upper atmospheric heating by solar EUV radiation or photodissociation of water vapor suggest that an anti-correlation between solar activity and NLC occurrence should be observed. However, different studies found inconsistent results depending on the data set and time period considered. The availability of satellite polar mesospheric cloud (PMC) data sets beginning in the late 1970s improved our ability to address this question with uniform geographic coverage, data from both Northern and Southern Hemispheres, and quantitative brightness information. The merged PMC data sets from the SBUV and SBUV/2 instruments now cover more than two solar cycles, and show a clear solar cycle anti- correlation between solar Lyman alpha flux and both PMC occurrence frequency and brightness. The solar cycle response in occurrence frequency is significantly larger than the corresponding secular change over an 11-year period, whereas these two effects are more comparable in PMC brightness. Variations in amplitude between different latitudes and hemispheres are observed in the SBUV data. Consistent results have also been obtained from long single instrument PMC data sets acquired by SAGE II and UARS HALOE. The best statistical fit between solar activity and PMC behavior typically requires a phase lag between 0-1 years. Modeling of the PMC response to solar activity has evolved with time. Initial predictions suggested that there would be direct photochemical control through water vapor photodissociation, but later work shows that freeze-drying and phase changes of mesospheric H2O must also be considered. Recent analysis of PMC data from the SCIAMACHY and SBUV/2 instruments also demonstrates the presence of a 27-day solar rotational modulation signal in PMC occurrence frequency. Coordinated observations from the suite of instruments on the AIM spacecraft during the rising phase of solar cycle 24 will provide new insight into the connection between solar forcing and PMC variability.

Deland, M. T.

2008-05-01

342

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

PubMed

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

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

2012-01-14

343

Long-term activation of semicarbazide-sensitive amine oxidase lowers circulating levels of uric acid in diabetic conditions.  

PubMed

Uric acid is involved in nitrogenous waste in animals, together with ammonia and urea. Uric acid has also antioxidant properties and is a surrogate marker of metabolic syndrome. We observed that the elevated plasma uric acid of high-fat fed mice was normalized by benzylamine treatment. Indeed, benzylamine is the reference substrate of semicarbazide-sensitive amine oxidase (SSAO), an enzyme highly expressed in fat depots and vessels, which generates ammonia when catalysing oxidative deamination. Ammonia interferes with uric acid metabolism/solubility. Our aim was therefore to investigate whether the lowering action of benzylamine on uric acid was related to an improvement of diabetic complications, or was connected with SSAO-dependent ammonia production. First, we observed that benzylamine administration lowered plasma uric acid in diabetic db/db mice while it did not modify uric acid levels in normoglycemic and lean mice. In parallel, benzylamine improved the glycemic control in diabetic but not in normoglycemic mice, while plasma urea remained unaltered. Then, uric acid plasma levels were measured in mice invalidated for AOC3 gene, encoding for SSAO. These mice were unable to oxidize benzylamine but were not diabetic and exhibited unaltered plasma uric levels. Therefore, activated or abolished ammonia production by SSAO was without influence on uric acid in the context of normoglycemia. Our observations confirm that plasma uric acid increases with diabetes and can be normalized when glucose tolerance is improved. They also show that uric acid, a multifunctional metabolite at the crossroads of nitrogen waste and of antioxidant defences, can be influenced by SSAO, in a manner apparently related to changes in glucose homeostasis. PMID:22480418

Carpéné, C; Desquesnes, A; Gomez-Ruiz, A; Iffiú-Soltész, Z; Le Gonidec, S; Mercader, J

2012-04-05

344

A History of Solar Activity over Millennia  

NASA Astrophysics Data System (ADS)

Presented here is a review of present knowledge of the long-term behavior of solar activity on a multi-millennial timescale, as reconstructed using the indirect proxy method. The concept of solar activity is discussed along with an overview of the special indices used to quantify different aspects of variable solar activity, with special emphasis upon sunspot number. Over long timescales, quantitative information about past solar activity can only be obtained using a method based upon indirect proxies, such as the cosmogenic isotopes 14C and 10Be in natural stratified archives (e.g., tree rings or ice cores). We give an historical overview of the development of the proxy-based method for past solar-activity reconstruction over millennia, as well as a description of the modern state. Special attention is paid to the verification and cross-calibration of reconstructions. It is argued that this method of cosmogenic isotopes makes a solid basis for studies of solar variability in the past on a long timescale (centuries to millennia) during the Holocene. A separate section is devoted to reconstructions of strong solar energetic-particle (SEP) events in the past, that suggest that the present-day average SEP flux is broadly consistent with estimates on longer timescales, and that the occurrence of extra-strong events is unlikely. Finally, the main features of the long-term evolution of solar magnetic activity, including the statistics of grand minima and maxima occurrence, are summarized and their possible implications, especially for solar/stellar dynamo theory, are discussed.

Usoskin, Ilya G.

2013-03-01

345

Commission 10: Solar Activity  

Microsoft Academic Search

Commission 10 aims at the study of various forms of solar activity, including net- works, plages, pores, spots, fibrils, surges, jets, filaments\\/prominences, coronal loops, flares, coronal mass ejections (CMEs), solar cycle, microflares, nanoflares, coronal heating etc., which are all manifestation of the interplay of magnetic fields and solar plasma. Increasingly important is the study of solar activities as sources of

Donald B. Melrose; Lidia van Driel-Gesztelyi; Carolus J. Schrijver; Lyndsay Fletcher; Natchimuthuk Gopalswamy; Richard A. Harrison; Cristina H. Mandrini; K. J. Schrijver; Bojan Vršnak; Jing-Xiu Wang

2005-01-01

346

Long-term measurement of tremor.  

PubMed

To account for the fluctuating and context-dependent nature of tremor, the method of ambulatory long-term electromyography (EMG) was developed for quantification of this symptom. It is based on successive evaluation of 15-s intervals by using a fast Fourier transformation (FFT). The standard results obtained are (a) tremor occurrence, a measure of how many intervals contain tremor; (b) mean tremor intensity; and (v) mean tremor frequency. This new method fulfills the so-called "test criteria" such as reliability, validity, sensitivity, and specificity for tremor quantification in essential tremor (ET) and Parkinson's disease (PD). In addition, we developed a method of determining the antagonist activation pattern by using cross-correlation analysis, also based on the long-term approach. This allows differentiation between ET and PD with a high sensitivity and a high interrater reliability. We conclude that long-term EMG is useful for both quantification and differentiation of tremor. PMID:9827600

Spieker, S; Boose, A; Breit, S; Dichgans, J

1998-01-01

347

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

PubMed Central

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

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

2002-01-01

348

IL-2 and long-term T cell activation induce physical and functional interaction between STAT5 and ETS transcription factors in human T cells.  

PubMed

Activation of Stat5 by many cytokines implies that it cannot alone insure the specificity of the regulation of its target genes. We have evidenced a physical and functional interaction between members of two unrelated transcription factor families, Ets-1, Ets-2 and Stat5, which could contribute to the proliferative response to interleukin 2. Competition with GAS- and EBS-specific oligonucleotides and immunoassays with a set of anti-Stat and anti-Ets families revealed that the IL-2-induced Stat5-Ets complex recognizes several GAS motifs identified as target sites for activated Stat5 dimers. Coimmunoprecipitation experiments evidenced that a Stat5/Ets-1/2 complex is formed in vivo in absence of DNA. GST-pull down experiments demonstrated that the C-terminal domain of Ets-1 is sufficient for this interaction in vitro. Cotransfection experiments in Kit225 T cells resulted in cooperative transcriptional activity between both transcription factors in response to a combination of IL-2, PMA and ionomycin. A Stat5-Ets protein complex was the major inducible DNA-binding complex bound to the human IL-2rE GASd/EBSd motif in long-term proliferating normal human T cells activated by CD2 and CD28. These results suggest that the inducible Stat5-Ets protein interaction plays a role in the regulation of gene expression in response to IL-2 in human T lymphocytes. PMID:10815800

Rameil, P; Lécine, P; Ghysdael, J; Gouilleux, F; Kahn-Perlès, B; Imbert, J

2000-04-20

349

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

PubMed

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

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

2008-07-01

350

Long-term variations of the oxygen red 630 nm line nightglow intensity  

NASA Astrophysics Data System (ADS)

The long-term data set of total nightglow intensity of the oxygen red 630.0 nm line observed at Abastumani (41.8 degrees N, 42.8 degrees E) between 1957-1993 is investigated. The long-term trend and characteristic variations in solar radiation during an 11 year cycle of the red-line intensity are different after astronomical twilight (premidnight) and at midnight. The amplitude of deviation of the red-line intensity from its mean value at solar maximum and (or) minimum phase is greatest after astronomical twilight and decreases toward midnight. The long-term trend of these variations changes from its value about 0.74 R/year premidnight to its minimum negative value of about -1.92 R/year at and after midnight. This behavior of the long-term trend is considered as a possible result of an increase in electron density below the peak height (h(m)F2) of the ionospheric F2 layer and lowering of the height h(m)F2 after midnight predicted by the TIME-GCM model on the assumption of an increase in density of greenhouse gases in the lower atmosphere. The third-order regression equation (with different solar activity indices) is considered to be convenient for describing long-term variations in the mean annual red-line intensity.

Gudadze, N. B.; Didebulidze, G. G.; Javakhishvili, G. Sh.; Shepherd, M. G.; Vardosanidze, M. V.

2007-02-01

351

Long Term Variability of the Sun and Climate Change  

Microsoft Academic Search

We explore the linkage between the long term variability of the Sun and earth's climate change by analysing periodicities of time series of solar proxies and global temperature anomalies. We apply the power spectral estimation method named as the periodgram to solar proxies and global temperature anomalies. We also decompose global temperature anomalies and reconstructed total solar irradiance into each

Il-Hyun Cho; Heon-Young Chang

2008-01-01

352

Exploring behavioral markers of long-term physical activity maintenance: a case study of system identification modeling within a behavioral intervention.  

PubMed

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 and identifying key behavioral patterns that may foster behavioral maintenance. The Active Adult Mentoring Program was a 16-week randomized controlled trial of a group-based, peer-delivered physical activity intervention targeting older adults. Time-intensive (i.e., daily) physical activity reports were collected throughout the intervention. We explored differential patterns of behavior among participants who received the active intervention (N = 34; 88% women, 64.1 ± 8.3 years of age) and either maintained 150 minutes/week of moderate to vigorous intensity physical activity (MVPA; n = 10) or did not (n = 24) at 18 months following the intervention period. We used dynamical systems modeling to explore whether key intervention components (i.e., self-monitoring, access to an exercise facility, behavioral initiation training, behavioral maintenance training) and theoretically plausible behavioral covariates (i.e., indoor vs. outdoor activity) predicted differential patterns of behavior among maintainers and nonmaintainers. We found that maintainers took longer to reach a steady-state of MVPA. At week 10 of the intervention, nonmaintainers began to drop whereas maintainers increased MVPA. Self-monitoring, behavioral initiation training, percentage of outdoor activity, and behavioral maintenance training, but not access to an exercise facility, were key variables that explained patterns of change among maintainers. Future studies should be conducted to systematically explore these concepts within a priori idiographic (i.e., N-of-1) experimental designs. PMID:24084400

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

2013-10-01

353

Influence of polymer–metal interface on the photovoltaic properties and long-term stability of nc-TiO 2-P3HT hybrid solar cells  

Microsoft Academic Search

The role played by the interface between light harvesting polymer poly(3-hexylthiophene) (P3HT) and thermally evaporated metal electrodes such as Au, Ag, and Cu on the photovoltaic performance and stability of nc-TiO2-P3HT (nc refers to nanocrystalline) ordered heterojunction hybrid solar cells has been systematically investigated. These hybrid solar cells with Cu films as positive electrode have been fabricated for the first

B. Reeja-Jayan; A. Manthiram

2010-01-01

354

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.

2010-01-01

355

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

2009-03-09

356

Diversity and activity of cellulose-decomposing bacteria, isolated from a sandy and a loamy soil after long-term manure application.  

PubMed

The community of culturable cellulolytic bacteria was analyzed in two long-term experimental field sites on Albic Luvisol (silty sand) and Haplic Phaeozem (loam), with and without farmyard manure treatment. Against the backdrop of significant differences in soil properties, the bacterial community structure differed clearly between sites and was affected by manure application as analyzed by T-RFLP of 16S rDNA. The population densities of cellulolytic bacteria were significantly increased by manure application in Phaeozem. Cellulose decomposing potentials of 537 isolates were tested on soluble, colloidal, and crystalline cellulose. The results showed some evidence of a greater proportion of isolates with high decomposition activity in Luvisol, but no impact from manure application could be observed in both soils. Restriction analysis and sequencing of 16S rDNA of isolates revealed a rather simple community composition that was dominated by Streptomyces (67%). The composition of the RFLP groups was affected by manure application, which was most evident in Luvisol, whereas an effect of the soil type could not be found. Although abundant RFLP groups were assigned to phylogenetically different bacterial classes (Actinobacteria, Betaproteobacteria, and Gammaproteobacteria), cellulolytic activity could not consistently be differentiated. All in all, cellulolytic capabilities of the isolates were highly variable and did not map to phylogenetic affiliation. PMID:17665240

Ulrich, Andreas; Klimke, Gabriele; Wirth, Stephan

2007-07-31

357

Long-Term Hepatitis B Virus (HBV) Response to Lamivudine-Containing Highly Active Antiretroviral Therapy in HIV-HBV Co-Infected Patients in Thailand  

PubMed Central

Background Approximately 4 million of people are co-infected with HIV and Hepatitis B virus (HBV). In resource-limited settings, the majority of HIV-infected patients initiate first-line highly active antiretroviral therapy containing lamivudine (3TC-containing-HAART) and long-term virological response of HBV to lamivudine-containing HAART in co-infected patients is not well known. Methodology/Principal Finding HIV-HBV co-infected patients enrolled in the PHPT cohort (ClinicalTrials.gov NCT00433030) and initiating a 3TC-containing-HAART regimen were included. HBV-DNA, HIV-RNA, CD4+ T-cell counts and alanine transaminase were measured at baseline, 3 months, 12 months and then every 6 months up to 5 years. Kaplan-Meier analysis was used to estimate the cumulative rates of patients who achieved and maintained HBV-DNA suppression. Of 30 co-infected patients, 19 were positive for HBe antigen (HBeAg). At initiation of 3TC-containing-HAART, median HBV DNA and HIV RNA levels were 7.35 log10 IU/mL and 4.47 log10 copies/mL, respectively. At 12 months, 67% of patients achieved HBV DNA suppression: 100% of HBeAg-negative patients and 47% of HBeAg-positive. Seventy-three percent of patients had HIV RNA below 50 copies/mL. The cumulative rates of maintained HBV-DNA suppression among the 23 patients who achieved HBV-DNA suppression were 91%, 87%, and 80% at 1, 2, and 4 years respectively. Of 17 patients who maintained HBV-DNA suppression while still on 3TC, 4 (24%) lost HBsAg and 7 of 8 (88%) HBeAg-positive patients lost HBeAg at their last visit (median duration, 59 months). HBV breakthrough was observed only in HBeAg-positive patients and 6 of 7 patients presenting HBV breakthrough had the rtM204I/V mutations associated with 3TC resistance along with rtL180M and/or rtV173L. Conclusions All HBeAg-negative patients and 63% of HBeAg-positive HIV-HBV co-infected patients achieved long-term HBV DNA suppression while on 3TC-containing-HAART. This study provides information useful for the management of co-infected patients in resource-limited countries where the vast majority of co-infected patients are currently receiving 3TC.

Khamduang, Woottichai; Gaudy-Graffin, Catherine; Ngo-Giang-Huong, Nicole; Jourdain, Gonzague; Moreau, Alain; Luekamlung, Nuananong; Halue, Guttiga; Buranawanitchakorn, Yuwadee; Kunkongkapan, Sura; Buranabanjasatean, Sudanee; Lallemant, Marc; Sirirungsi, Wasna; Goudeau, Alain

2012-01-01

358

Long term virological, immunological and mortality outcomes in a cohort of HIV-infected female sex workers treated with highly active antiretroviral therapy in Africa  

PubMed Central

Background Concerns have been raised that marginalised populations may not achieve adequate compliance to antiretroviral therapy. Our objective was to describe the long-term virological, immunological and mortality outcomes of providing highly active antiretroviral therapy (HAART) with strong adherence support to HIV-infected female sex workers (FSWs) in Burkina Faso and contrast outcomes with those obtained in a cohort of regular HIV-infected women. Methods Prospective study of FSWs and non-FSWs initiated on HAART between August 2004 and October 2007. Patients were followed monthly for drug adherence (interview and pill count), and at 6-monthly intervals for monitoring CD4 counts and HIV-1 plasma viral loads (PVLs) and clinical events. Results 95 women, including 47 FSWs, were followed for a median of 32 months (interquartile range [IQR], 20-41). At HAART initiation, the median CD4 count was 147 cells/?l (IQR, 79-183) and 144 cells/?l (100-197), and the mean PVLs were 4.94 log10copies/ml (95% confidence interval [CI], 4.70-5.18) and 5.15 log10 copies/ml (4.97-5.33), in FSWs and non-FSWs, respectively. Four FSWs died during follow-up (mortality rate: 1.7 per 100 person-years) and none among other women. At 36 months, the median CD4 count increase was 230 cells/?l (IQR, 90-400) in FSWs vs. 284 cells/?l (193-420) in non-FSWs; PVL was undetectable in 81.8% (95% CI, 59.7-94.8) of FSWs vs. 100% (83.9-100) of non-FSWs; and high adherence to HAART (> 95% pills taken) was reported by 83.3% (95% CI, 67.2-93.6), 92.1% (95% CI, 78.6-98.3), and 100% (95% CI, 54.1-100) of FSWs at 6, 12, and 36 months after HAART initiation, respectively, with no statistical difference compared to the pattern observed among non-FSWs. Conclusions Clinical and biological benefits of HAART can be maintained over the long term among FSWs in Africa and could also lead to important public health benefits.

2011-01-01

359

Hippocampal network activity is transiently altered by induction of long-term potentiation in the dentate gyrus of freely behaving rats.  

PubMed

A role for oscillatory activity in hippocampal neuronal networks has been proposed in sensory encoding, cognitive functions and synaptic plasticity. In the hippocampus, theta (5-10 Hz) and gamma (30-100 Hz) oscillations may provide a mechanism for temporal encoding of information, and the basis for formation and retrieval of memory traces. Long-term potentiation (LTP) of synaptic transmission, a candidate cellular model of synaptic information storage, is typically induced by high-frequency tetanisation (HFT) of afferent pathways. Taking into account the role of oscillatory activity in the processing of information, dynamic changes may occur in hippocampal network activity in the period during HFT and/or soon after it. These changes in rhythmic activity may determine or, at least, contribute to successful potentiation and, in general, to formation of memory. We have found that short-term potentiation (STP) and LTP as well LTP-failure are characterised with different profiles of changes in theta and gamma frequencies. Potentiation of synaptic transmission was associated with a significant increase in the relative theta power and mean amplitude of theta cycles in the period encompassing 300 seconds after HFT. Where LTP or STP, but not failure of potentiation, occurred, this facilitation of theta was accompanied by transient increases in gamma power and in the mean amplitude of gamma oscillations within a single theta cycle. Our data support that specific, correlated changes in these parameters are associated with successful synaptic potentiation. These findings suggest that changes in theta-gamma activity associated with induction of LTP may enable synaptic information storage in the hippocampus. PMID:18958189

Bikbaev, Arthur; Manahan-Vaughan, Denise

2007-12-30

360

Solar Activity, Lightning and Climate  

Microsoft Academic Search

The physics of solar forcing of the climate and long term climate change is summarized, and the role of energetic charged particles (including cosmic rays) on cloud formation and their effect on climate is examined. It is considered that the cosmic ray-cloud cover hypothesis is not supported by presently available data and further investigations (during Forbush decreases and at other

Devendraa Siingh; R. P. Singh; Ashok K. Singh; M. N. Kulkarni; A. S. Gautam; Abhay K. Singh

2011-01-01

361

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

362

? Carinae long-term variability  

NASA Astrophysics Data System (ADS)

We present preliminary results of our analysis on the long-term variations observed in the optical spectrum of the LBV star ? Carinae. Based on the hydrogen line profiles, we conclude that the physical parameters of the primary star did not change in the last 15 years.

Damineli, Augusto; Teodoro, Mairan; Corcoran, Michael F.; Groh, Jose H.

2011-07-01

363

Correlates of long-term participation in a physical activity-based positive youth development program for low-income youth: sustained involvement and psychosocial outcomes.  

PubMed

This study examined correlates of long-term participation in a positive youth development (PYD) program. Low-income youth (N = 215) age 8-13 of diverse ethnicity participating in a summer physical activity-based PYD program completed questionnaires at the beginning and end of the program (year 1) and at the beginning of year 2. Those with lower BMI and higher attendance and leader support perceptions were more likely to return to the program the following year. Self-worth and leader support perceptions at time 2 were higher for returners compared to non-returners. Among returners, hope increased from year 1 to year 2 and increases in global self-worth across the first year were maintained over one year. Social support is linked to continued PYD participation. Returners had increased and/or sustained positive perceptions of self-worth and hope. Programs are encouraged to foster staff-participant relationships and self-worth, and minimize barriers associated with weight status. PMID:23267750

Ullrich-French, Sarah; McDonough, Meghan H

2012-12-23

364

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

PubMed

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

2012-02-20

365

Energetic Solar activities during cycle 22, 23  

NASA Astrophysics Data System (ADS)

Energetic Solar particles and Geomagnetic Indices during the last two cycles were given. The data of the grouped flares and 10.7 cm radio flux were obtained from Solar Geophysical data reports by the US Department of Commerce, during the solar cycle 22 and 23. Power spectrum analyses method were used for the data treatments, to find the intermediate-term periodicities, 14, 28, 35 are significant. Long-term periodicities periodicity 154 days appeared, and confirmed with the other results. Halloween storms during Nov. 2003 and its effects on the geomagnetic storms have been studied analytically. The data of amplitude and phase of most common indicators of geomagnetic activities during solar cycle 23 has been analyzed.

Hady, Ahmed A.; Samweel, Susan W.

2010-03-01

366

Colocalization of Protein Kinase A with Adenylyl Cyclase Enhances Protein Kinase A Activity during Induction of Long-Lasting Long-Term-Potentiation  

PubMed Central

The ability of neurons to differentially respond to specific temporal and spatial input patterns underlies information storage in neural circuits. One means of achieving spatial specificity is to restrict signaling molecules to particular subcellular compartments using anchoring molecules such as A-Kinase Anchoring Proteins (AKAPs). Disruption of protein kinase A (PKA) anchoring to AKAPs impairs a PKA-dependent form of long term potentiation (LTP) in the hippocampus. To investigate the role of localized PKA signaling in LTP, we developed a stochastic reaction-diffusion model of the signaling pathways leading to PKA activation in CA1 pyramidal neurons. Simulations investigated whether the role of anchoring is to locate kinases near molecules that activate them, or near their target molecules. The results show that anchoring PKA with adenylyl cyclase (which produces cAMP that activates PKA) produces significantly greater PKA activity, and phosphorylation of both inhibitor-1 and AMPA receptor GluR1 subunit on S845, than when PKA is anchored apart from adenylyl cyclase. The spatial microdomain of cAMP was smaller than that of PKA suggesting that anchoring PKA near its source of cAMP is critical because inactivation by phosphodiesterase limits diffusion of cAMP. The prediction that the role of anchoring is to colocalize PKA near adenylyl cyclase was confirmed by experimentally rescuing the deficit in LTP produced by disruption of PKA anchoring using phosphodiesterase inhibitors. Additional experiments confirm the model prediction that disruption of anchoring impairs S845 phosphorylation produced by forskolin-induced synaptic potentiation. Collectively, these results show that locating PKA near adenylyl cyclase is a critical function of anchoring.

Kim, Myungsook; Park, Alan Jung; Havekes, Robbert; Chay, Andrew; Guercio, Leonardo Antonio; Oliveira, Rodrigo Freire; Abel, Ted; Blackwell, Kim T.

2011-01-01

367

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

368

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.

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

369

Dynamic medium containing kit ligand and follicle-stimulating hormone promotes follicular survival, activation, and growth during long-term in vitro culture of caprine preantral follicles.  

PubMed

The aim of this study was to evaluate the effects of a dynamic medium containing kit ligand (KL) and follicle-stimulating hormone (FSH) on the in vitro culture of caprine preantral follicles for 16 days. Ovarian fragments were cultured in ?-MEM(+) containing or not containing KL (50 ng/ml) and/or FSH (50 ng/ml) added during the first (days 0-8) and/or second half (days 8-16) of the culture period. Noncultured (control) and cultured fragments were processed for histological and ultrastructural evaluation. After 1 day of culture, only the treatments performed with KL or FSH maintained a percentage of normal follicles similar to that of the control. After 16 days, all treatments using KL until day 8 (KL/KL, KL/FSH, and KL/FSH+KL) and only FSH during the entire culture period (FSH/FSH) showed higher rates of follicular survival compared to ?-MEM(+) alone. After 1 and 8 days, the treatments initially cultured with KL increased the percentage of follicular activation in comparison to ?-MEM(+) alone and other treatments. The highest follicular diameter after 16 days was observed in follicles cultured with KL until day 8 followed by FSH (KL/FSH). Furthermore, this treatment promoted, as early as after 1 day of culture, an increase in oocyte growth compared to ?-MEM(+) alone. Ultrastructural analysis confirmed the integrity of follicles cultured in KL/FSH after 16 days. In conclusion, a dynamic medium containing KL and FSH maintained follicular integrity and promoted follicular activation and growth during the long-term in vitro culture of caprine preantral follicles. PMID:21494023

Lima, I M T; Celestino, J J H; Faustino, L R; Magalhães-Padilha, D M; Rossetto, R; Brito, I R; Donato, M A M; Lopes, C A P; Campello, C C; Peixoto, C A; Figueiredo, J R; Rodrigues, A P R

2011-04-14

370

Is there a planetary influence on solar activity?  

NASA Astrophysics Data System (ADS)

Context. Understanding the Sun's magnetic activity is important because of its impact on the Earth's environment. Direct observations of the sunspots since 1610 reveal an irregular activity cycle with an average period of about 11 years, which is modulated on longer timescales. Proxies of solar activity such as 14C and 10Be show consistently longer cycles with well-defined periodicities and varying amplitudes. Current models of solar activity assume that the origin and modulation of solar activity lie within the Sun itself; however, correlations between direct solar activity indices and planetary configurations have been reported on many occasions. Since no successful physical mechanism was suggested to explain these correlations, the possible link between planetary motion and solar activity has been largely ignored. Aims: While energy considerations clearly show that the planets cannot be the direct cause of the solar activity, it remains an open question whether the planets can perturb the operation of the solar dynamo. Here we use a 9400 year solar activity reconstruction derived from cosmogenic radionuclides to test this hypothesis. Methods: We developed a simple physical model for describing the time-dependent torque exerted by the planets on a non-spherical tachocline and compared the corresponding power spectrum with that of the reconstructed solar activity record. Results: We find an excellent agreement between the long-term cycles in proxies of solar activity and the periodicities in the planetary torque and also that some periodicities remain phase-locked over 9400 years. Conclusions: Based on these observations we put forward the idea that the long-term solar magnetic activity is modulated by planetary effects. If correct, our hypothesis has important implications for solar physics and the solar-terrestrial connection.

Abreu, J. A.; Beer, J.; Ferriz-Mas, A.; McCracken, K. G.; Steinhilber, F.

2012-12-01

371

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

372

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.

373

Both Protein Kinase A and Mitogen-Activated Protein Kinase Are Required in the Amygdala for the Macromolecular Synthesis Dependent Late Phase of Long-Term Potentiation  

Microsoft Academic Search

The lateral amygdala (LA) is thought to be critical for the specific acquisition of conditioned fear, and the emotionally charged memories related to fear are thought to require a form of synaptic plasticity related to long-term potentiation (LTP). Is LTP in the lateral amygdala enduring, and, if so, does it require gene ex- pression and the synthesis of new protein?

Yan-You Huang; Kelsey C. Martin; Eric R. Kandel

2000-01-01

374

CREB1 Encodes a Nuclear Activator, a Repressor, and a Cytoplasmic Modulator that Form a Regulatory Unit Critical for Long-Term Facilitation  

Microsoft Academic Search

Although CREB seems to be important for memory formation, it is not known which of the isoforms of CREB, CREM, or ATF1 are expressed in the neurons that undergo long-term synaptic changes and what roles they have in memory formation. We have found a single Aplysia CREB1 gene homologous to both mammalian CREB and CREM and have characterized in the

Dusan Bartsch; Andrea Casadio; Kevin A Karl; Paulo Serodio; Eric R Kandel

1998-01-01

375

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

376

Long-term photometry of three active red giants in close binary systems: V2253 Oph, IT Com and IS Vir  

NASA Astrophysics Data System (ADS)

We present and analyze long-term optical photometric measurements of the three active stars V2253 Oph, IT Com and IS Vir. All three systems are single-lined spectroscopic binaries with an early K giant as primary component but in different stages of orbital-rotational synchronization. Our photometry is supplemented by 2MASS and WISE near-IR and mid-IR magnitudes and then used to obtain more accurate effective temperatures and extinctions. For V2253 Oph and IT Com, we found their spectral energy distributions consistent with pure photospheric emission. For IS Vir, we detect a marginal mid-IR excess which hints towards a dust disk. The orbital and rotational planes of IT Com appear to be coplanar, contrary to previous findings in the literature. We apply a multiple frequency analysis technique to determine photometric periods, and possibly changes of periods, ranging from days to decades. New rotational periods of 21.55±0.03 d, 65.1±0.3 d, and 23.50±0.04 d were determined for V2253 Oph, IT Com, and IS Vir, respectively. Splitting of these periods led to tentative detections of differential surface rotations of ? P/P?0.02 for V2253 Oph and 0.07 for IT Com. Using a time-frequency technique based on short-term Fourier transforms we present evidence of cyclic light variations of length ? 10 yr for V2253 Oph and 5-6 yr for IS Vir. A single flip-flop event has been observed for IT Com of duration 2-3 yr. Its exchange of the dominant active longitude had happened close to a time of periastron passage, suggesting some response of the magnetic activity from the orbital dynamics. The 21.55-d rotational modulation of V2253 Oph showed phase coherence also with the orbital period, which is 15 times longer than the rotational period, thus also indicating a tidal feedback with the stellar magnetic activity.

Oláh, K.; Moór, A.; Strassmeier, K. G.; Borkovits, T.; Granzer, T.

377

Solar activity forecast for solar cycle 23  

Microsoft Academic Search

In this paper, we predict the next cycle's activity and improve the timing of solar cycle predictions. Dynamo-based solar activity prediction techniques rely upon two properties inherent in the solar cycle: that solar magnetism oscillates between poloidal and toroidal components; and that there is a degree of ``magnetic persistence'' in dynamos, which in the case of the Sun, results in

Kenneth Schatten; Daniel J. Myers; Sabatino Sofia

1996-01-01

378

Statistical Properties of Extreme Solar Activity Intervals  

NASA Astrophysics Data System (ADS)

A study of long-term solar variability reflected in indirect indices of past solar activity leads to stimulating results. We compare the statistics of intervals of very low and very high solar activity derived from two cosmogenic radionuclide records and look for consistency in their timing and physical interpretation. According to the applied criteria, the numbers of minima and of maxima are 61 and 68, respectively, from the 10Be record, and 42 and 46 from the 14C record. The difference between the enhanced and depressed states of solar activity becomes apparent in the difference in their statistical distributions. We find no correlation between the level or type (minimum or maximum) of an extremum and the level or type of the predecessor. The hypothesis of solar activity as a periodic process on the millennial time scale is not supported by the existing proxies. A new homogeneous series of 10Be measurements in polar ice covering the Holocene would be of great value for eliminating the existing discrepancy in the available solar activity reconstructions.

Lioznova, A. V.; Blinov, A. V.

2013-06-01

379

Solar dynamo and geomagnetic activity  

NASA Astrophysics Data System (ADS)

The correlation between geomagnetic activity and the sunspot number in the 11-year solar cycle exhibits long-term variations due to the varying time lag between the sunspot-related and non-sunspot related geomagnetic activity, and the varying relative amplitude of the respective geomagnetic activity peaks. As the sunspot-related and non-sunspot related geomagnetic activity peaks are caused by different solar agents, related to the solar toroidal and poloidal fields, respectively, we use their variations to derive the parameters of the solar dynamo transforming the poloidal field into toroidal field and back. We find that in the last 12 cycles the solar surface meridional circulation varied between 5 and 20 m/s (averaged over latitude and over the sunspot cycle), the deep circulation varied between 2.5 and 5.5 m/s, and the diffusivity in the whole of the convection zone was ˜108 m2/s. In the last 12 cycles solar dynamo has been operating in moderately diffusion dominated regime in the bulk of the convection zone. This means that a part of the poloidal field generated at the surface is advected by the meridional circulation all the way to the poles, down to the tachocline and equatorward to sunspot latitudes, while another part is diffused directly to the tachocline at midlatitudes, “short-circuiting” the meridional circulation. The sunspot maximum is the superposition of the two surges of toroidal field generated by these two parts of the poloidal field, which is the explanation of the double peaks and the Gnevyshev gap in sunspot maximum. Near the tachocline, dynamo has been operating in diffusion dominated regime in which diffusion is more important than advection, so with increasing speed of the deep circulation the time for diffusive decay of the poloidal field decreases, and more toroidal field is generated leading to a higher sunspot maximum. During the Maunder minimum the dynamo was operating in advection dominated regime near the tachocline, with the transition from diffusion dominated to advection dominated regime caused by a sharp drop in the surface meridional circulation which is in general the most important factor modulating the amplitude of the sunspot cycle.

Georgieva, Katya; Kirov, Boian

2011-02-01

380

Long-term outcome of low-activity radioiodine administration preceded by adjuvant recombinant human TSH pretreatment in elderly subjects with multinodular goiter  

PubMed Central

Background Large multinodular goiter (MNG) in elderly people is a common finding which can require intervention. The long-term effect of radioiodine therapy on thyroid volume (TV) and function after recombinant human (rh) TSH pre-treatment was evaluated. Methods After baseline evaluation, 40 subjects over 60 years old with a large MNG were treated with 131I up to the activity of 600 MBq. Nineteen patients were pretreated with rhTSH (0.1 mg on 2 consecutive days; group 1) while 21 subjects underwent treatment without rhTSH pretreatment (group 2). TV was monitored every 6–12 months by ultrasonography. The median follow-up period was 36 months. Results At the baseline, the groups matched in terms of TV, 24-h radioiodine uptake (RAIU), urinary iodine and neck complaints. The number of subjects pretreated with anti-thyroid drugs was significantly (P = 0.01) greater in group 2 than in group 1; TSH was more suppressed (P = 0.003) and f-T3 was more elevated (P = 0.005) in group 2 than in group 1 patients. RhTSH increased 24-h RAIU in group 1 up to the baseline level observed in group 2. The 131I activity administered was similar in both groups. Adverse events were slight and similar in both groups. A permanent post-radioiodine toxic condition was reported only in 2 patients in group 2. After radioiodine therapy, hypothyroidism was observed in significantly more group 1 patients than group 2 patients (P = 0.002). While TV was reduced in both groups, the percentage TV reduction recorded at the last examination was significantly higher (P = 0.03) in group 1 than in group 2. MNG-related complaints were significantly reduced in both group 1 (P = 0.0001 vs baseline) and group 2 (P = 0.001) patients. Conclusion Low radioiodine activities after pretreatment with low-dosage rhTSH are able to reduce TV and improve MNG-related symptoms in elderly subjects.

Giusti, Massimo; Caputo, Mauro; Calamia, Iolanda; Bagnara, Mariaclaudia; Ceresola, Enrica; Schiavo, Mara; Mussap, Michele; Ferone, Diego; Minuto, Francesco; Bagnasco, Marcello

2009-01-01

381

Long term survival in primary pulmonary hypertension.  

PubMed

The mean survival of patients with severe primary pulmonary hypertension (PPH) is < 3 years without appropriate treatment. There are no long term reports on the spontaneous course of mild PPH over a longer period. Stable long term follow up is described of a 39 year old patient with PPH without treatment over a 30 year period. PPH had been diagnosed 30 years previously after right heart catheterisation (mean pulmonary artery pressure 35 mm Hg) and 30 years later, repeated measurements showed nearly unchanged haemodynamic parameters. Further examinations confirmed the diagnosis of PPH. It is suggested that PPH with modestly limited physical activity (New York Heart Association functional class II) does not always seem to coincide with progression of the disease and, therefore, it may be feasible to withhold treatment while closely monitoring these patients. PMID:15201266

Halank, M; Marx, C; Hoeffken, G

2004-07-01

382

Soil organic carbon (SOC) accumulation in rice paddies under long-term agro-ecosystem experiments in southern China - VI. Changes in microbial community structure and respiratory activity  

NASA Astrophysics Data System (ADS)

Biological stabilization within accumulated soil organic carbon (SOC) has not been well understood, while its role in physical and chemical protection as well as of chemical recalcitrance had been addressed in Chinese rice paddies. In this study, topsoil samples were collected and respiratory activity measured in situ following rice harvest under different fertilization treatments of three long-term experimental sites across southern China in 2009. The SOC contents, microbial biomass carbon (SMBC) and nitrogen (SMBN) were analysed using chemical digestion and microbial community structure assessment via clony dilute plate counting methods. While SOC contents were consistently higher under compound chemical fertilization (Comp-Fert) or combined organic and inorganic fertilization (Comb-Fert) compared to N fertilization only (N-Fert), there was significantly higher fungal-bacterial ratio under Comb-Fert than under N-Fert and Comp-Fert. When subtracting the background effect under no fertilization treatment (Non-Fert), the increase both in SMBC and SMBN under fertilization treatment was found very significantly correlated to the increase in SOC over controls across the sites. Also, the ratio of culturable fungal to bacterial population numbers (F/B ratio) was well correlated with soil organic carbon contents in all samples across the sites studied. SOC accumulation favoured a build-up the microbial community with increasing fungal dominance in the rice paddies under fertilization treatments. While soil respiration rates were high under Comb-Fert as a result of enhanced microbial community build-up, the specific soil respiratory activity based on microbial biomass carbon was found in a significantly negatively correlation with the SOC contents for overall samples. Thus, a fungal-dominated microbial community seemed to slow SOC turnover, thereby favouring SOC accumulation under Comp-Fert or under Comb-Fert in the rice paddies. Therefore, the biological stabilization process is of importance in SOC sequestration in the rice paddies, operating with physical and chemical protection and chemical recalcitrance. However, sufficient understanding and prediction of SOM dynamics needs further quantitative characterization of the simultaneous operation of several mechanisms.

Liu, D.; Liu, X.; Liu, Y.; Li, L.; Pan, G.; Crowley, D.; Tippkötter, R.

2011-02-01

383

Susceptibility to the long-term anxiogenic effects of an acute stressor is mediated by the activation of the glucocorticoid receptors  

Microsoft Academic Search

The specificity of the response of an organism is an important variable influencing stress-related parameters and psychopathological states. We have shown that trait anxiety in C57BL\\/6 mice, determined by their emergence latencies in the free choice open field test, positively correlates with the long-term behavioral and neuroendocrinological changes induced by a stressor. Here, we show that this interindividual variability is

Mira Jakovcevski; Melitta Schachner; Fabio Morellini

2011-01-01

384

Spreading of HIV-specific CD8 + T-cell repertoire in long-term nonprogressors and its role in the control of viral load and disease activity  

Microsoft Academic Search

Long-term non-progressors (LTNP) represent a minority of human immunodeficiency virus (HIV) infected individuals characterized by stable or even increasing CD4+ T-cell count and by stronger immune responses against HIV than progressors. In this study, HIV-specific effector CD8+ T cells, as detected by both a sensitive ex vivo enzyme-linked immunospot (ELISPOT) assay and specific major histocompatibility complex (MHC) peptide tetramers, were

Antonella Propato; Enrico Schiaffella; Elisa Vicenzi; Vittorio Francavilla; Letizia Baloni; Marino Paroli; Luigi Finocchi; Nobuyuki Tanigaki; Silvia Ghezzi; Rosa Ferrara; Robert Chesnut; Brian Livingston; Alessandro Sette; Roberto Paganelli; Fernando Aiuti; Guido Poli; Vincenzo Barnaba

2001-01-01

385

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

386

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

2013-05-21

387

Solar Activity, Lightning and Climate  

Microsoft Academic Search

The physics of solar forcing of the climate and long term climate change is summarized, and the role of energetic charged\\u000a particles (including cosmic rays) on cloud formation and their effect on climate is examined. It is considered that the cosmic\\u000a ray-cloud cover hypothesis is not supported by presently available data and further investigations (during Forbush decreases\\u000a and at other

Devendraa Siingh; R. P. Singh; Ashok K. Singh; M. N. Kulkarni; A. S. Gautam; Abhay K. Singh

388

Long Term Care: Early Planning Pays Off  

MedlinePLUS

... reprinted for personal, noncommercial use only. Long term care: Early planning pays off By Mayo Clinic staff ... your e-mail address Sign up Long term care: Early planning pays off It's best to talk ...

389

Long-Term Care Ombudsman Program  

MedlinePLUS

... shortly. Unable to Share This Page Long-Term Care Ombudsman Program (OAA, Title VII, Chapter 2, Sections ... Services Provided to Persons Living in Long-Term Care Facilities Program data for FY 2011 indicate that ...

390

Solar activity and the mean global temperature  

NASA Astrophysics Data System (ADS)

The variation with time from 1956 to 2002 of the globally averaged rate of ionization produced by cosmic rays in the atmosphere is deduced and shown to have a cyclic component of period roughly twice the 11 year solar cycle period. Long term variations in the global average surface temperature as a function of time since 1956 are found to have a similar cyclic component. The cyclic variations are also observed in the solar irradiance and in the mean daily sun spot number. The cyclic variation in the cosmic ray rate is observed to be delayed by 2-4 years relative to the temperature, the solar irradiance and daily sun spot variations suggesting that the origin of the correlation is more likely to be direct solar activity than cosmic rays. Assuming that the correlation is caused by such solar activity, we deduce that the maximum recent increase in the mean surface temperature of the Earth which can be ascribed to this activity is {\\lesssim }14% of the observed global warming.

Erlykin, A. D.; Sloan, T.; Wolfendale, A. W.

2009-01-01

391

Activities for Teaching Solar Energy.  

ERIC Educational Resources Information Center

Plans and activities are suggested for teaching elementary children about solar energy. Directions are included for constructing a flat plate collector and a solar oven. Activities for a solar field day are given. (SA)

Mason, Jack Lee; Cantrell, Joseph S.

1980-01-01

392

Activities for Teaching Solar Energy.  

ERIC Educational Resources Information Center

|Plans and activities are suggested for teaching elementary children about solar energy. Directions are included for constructing a flat plate collector and a solar oven. Activities for a solar field day are given. (SA)|

Mason, Jack Lee; Cantrell, Joseph S.

1980-01-01

393

Solar activity prediction studies and services in NAOC  

NASA Astrophysics Data System (ADS)

Solar activity prediction services started in 1960’s in National Astronomical Observatories, Chinese Academy of Sciences (NAOC). As one of the members of the International Space Environment Service (ISES), Regional Warning Center of China (RWC-China) was set up in 1990’s. Solar Activity Prediction Center (SAPC), as one of the four sub-centers of RWC-China, is located in NAOC. Solar activity prediction studies and services in NAOC cover short-term, medium-term, and long-term forecast of solar activities. Nowadays, certain prediction models, such as solar X-ray flare model, solar proton event model, solar 10 cm radio flux model, have been established for the practical prediction services. Recently, more and more physical analyses are introduced in the studies of solar activity prediction, such as the magnetic properties of solar active regions and magnetic structure of solar atmosphere. Besides traditional statistics algorithms, Machine Learning and Artificial Intelligence techniques, such as Support Vector Machine (SVM) method, are employed in the establishment of forecast models. A Web-based integrated platform for solar activity data sharing and forecast distribution is under construction.

He, Han; Wang, Huaning; Du, Zhanle; Li, Rong; Cui, Yanmei; Zhang, Liyun; He, Yulin

2008-11-01

394

Solar activity prediction studies and services in NAOC  

NASA Astrophysics Data System (ADS)

Solar activity prediction services started in 1960 s in National Astronomical Observatories Chinese Academy of Sciences NAOC As one of the members in International Space Environment Service ISES Regional Warning Center of China RWC-China was set up in 1990 s Solar Activity Prediction Center SAPC as one of the four sub-centers of RWC-China is located in NAOC Solar activity prediction studies and services in NAOC cover short-term medium-term and long-term forecast of solar activities Nowadays certain prediction models such as solar X-ray flare solar proton event solar 10cm radio flux model have been established in practical prediction services Recently more and more physical analyses are introduced in the studies of solar activity prediction such as the magnetic properties of solar active regions and magnetic structure of solar atmosphere Besides traditional statistics algorithms Machine Learning and Artificial Intelligence techniques such as Support Vector Machine SVM method are employed in the establishment of forecast models The daily solar activity prediction services can be found on the web site http rwcc bao ac cn

He, H.; Wang, H.; Du, Z.; Li, R.; Cui, Y.; Zhang, L.; He, Y.

395

Solar Thermal Manufacturing Activities  

EIA Publications

This report, Solar Thermal Collector Manufacturing Activities, providesan overview and tables with historical data spanning 2000-2009. These tables willcorrespond to similar tables to be presented in the Renewable Energy Annual 2009 andare numbered accordingly.

Michele Simmons

2010-12-01

396

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

397

Long term outcome of patients with active Crohn’s disease exhibiting extensive and deep ulcerations at colonoscopy 1 1 Some of these data have been presented in abstract form ( Gastroenterology 1996;110:A853)  

Microsoft Academic Search

OBJECTIVE:Prediction of the clinical course of Crohn’s disease (CD) is difficult in the long term. Our aim was to determine whether the presence of severe endoscopic lesions (SELs) may predict a higher risk of colectomy and penetrating complications.METHODS:All patients at our institution with active ileocolonic CD who had colonoscopies between 1990 and 1996 were included in the study. SELs were

Matthieu Allez; Marc Lemann; Joëlle Bonnet; Pierre Cattan; Raymond Jian; Robert Modigliani

2002-01-01

398

Systemic Administration of Atipamezole, a Selective Antagonist of Alpha2 Adrenoceptors, Facilitates Behavioural Activity but does not Influence Short-term or Long-term Memory in Trimethyltin-intoxicated and Control Rats  

Microsoft Academic Search

NIITTYKOSKI M., R. LAPPALAINEN, J. JOLKKONEN, A. HAAPALINNA, P. RIEKKINEN Sr and J. SIRVIÖ. Systemic administration of atipamezole, a selective antagonist of alpha-2 adrenoceptors, facilitates behavioural activity but does not influence short-term or long-term memory in trimethyltin-intoxicated and control rats. NEUROSCI BIOBEHAV REV 22(6) 735–750, 1998.—The present study used trimethyltin (TMT)-intoxicated rats as a model for the behavioural syndrome seen

M Niittykoski; R Lappalainen; J Jolkkonen; A Haapalinna; P Riekkinen; J Sirviö

1998-01-01

399

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

400

Medium to long term results of the Exeter bipolar hemiarthroplasty for femoral neck fractures in active, independent patients. 5-13 year follow-up.  

PubMed

We present the clinical and radiographic outcome of 49 Exeter bipolar hemiarthroplasties for femoral neck fractures in 49 patients with a median age of 71 years at the time of operation. Median length of follow-up was 7.1 years (5 to 13). There was one dislocation, and one peri-prosthetic fracture. There were no revisions for infection, acetabular erosion or stem loosening. Twenty-six patients had died by the time of final follow-up with an overall 5 year cumulative survival of 60.2%. Thirty day mortality was 36% in patients with an ASA score of 3. We present excellent clinical and radiological medium to long term results with no evidence of acetabular erosion. However, careful patient selection is necessary to avoid high early mortality rates. PMID:19097008

Miller, D; Choksey, A; Jones, P; Perkins, R

401

Long-term changes of (polar) mesosphere summer echoes  

NASA Astrophysics Data System (ADS)

Strong VHF radar echoes have been observed not only during summer months at polar latitudes (polar mesosphere summer echoes, PMSE) but also at middle latitudes (mesosphere summer echoes, MSE). These echoes are closely connected with small ice particles, thus containing information about mesospheric temperature and water vapour content. But the (P)MSE also depend on the ionisation due to solar wave radiation and precipitating high energetic particles. Observations with VHF radars at Andenes (69.3°N; 16.0°E) since 1994 and at Kühlungsborn (54.6°N; 11.8°E) since 1998 are used for investigations of the solar and geomagnetic control of the (P)MSE as well as of possible long-term changes. The (P)MSE are positively correlated with the solar Lyman [alpha] radiation and the geomagnetic activity and have slightly positive trends. Due to the limited measuring period, the significance levels of the detected (P)MSE trends are small. Positive trends in noctilucent clouds (NLC) and polar mesospheric clouds (PMC) are in general agreement with (P)MSE trends.

Bremer, J.; Hoffmann, P.; Latteck, R.; Singer, W.; Zecha, M.

2009-10-01

402

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

2011-09-28

403

Long-term energy resources  

Microsoft Academic Search

Papers presented at this conference cover some 45 different energy sources as well as the energy policies and issues of a number of countries, both developed and developing. The papers are grouped into sections dealing with a world energy overview, energy policy and planning, coal, petroleum, shale oil, tar sands, heavy oil, enhanced oil recovery, unconventional natural gas, solar energy,

R. F. Meyer; J. C. Olson

1981-01-01

404

Induction of system A amino acid transport activity through long-term treatment with ouabain: possible correlation with enhanced (Na/sup +//K/sup +/)ATPase activity  

SciTech Connect

Mouse embryo fibroblast cells (C3H-10T1/2) and the methylcholanthrene-transformed derivative (MCA-10T1/2) were treated with basal modified Eagles medium at varying ouabain concentrations ranging from 0.05 mM to 0.5 mM for 16 h in culture. After replacing the ouabain-containing medium with BME, System A (/sup 3/H-AlB uptake) and the (Na/sup +//K/sup +/)ATPase pump activity (ouabain-sensitive /sup 86/Rb/sup +/ uptake) was increased 10-fold and 3-fold, respectively (at 0.4 mM ouabain) in confluent C3H-10T1/2 cells. System A and the (Na/sup +//K/sup +/)ATPase activity was increased 15-fold and 5-fold, respectively in confluent MCA-10T1/2 cells but the increase was maximal at 0.2 mM ouabain. This treatment with ouabain increased the (Na/sup +/)/sub i//(K/sup +/)/sub i/ as measured by atomic absorption, and thereby decreased the Na/sup +/ and K/sup +/ electrochemical gradients. Their data show that the transformed cells were more sensitive to the internal ion inversion by ouabain than the C3H-10T1/2 cells. It appears, from data on hypertonicity and lipophilic cations that neither the chemical Na/sup +/ gradient nor the negative membrane potential are the primary driving forces of System A transport.

Schenerman, M.A.; Leister, K.J.; Wang, S.Y.; Racker, E.

1987-05-01

405

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.

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

406

Challenges and Opportunities for Improving Mental Health Services in Rural Long-Term Care.  

National Technical Information Service (NTIS)

Over 10 million Americans with chronic disabilities require long-term services to assist them with activities of daily living. Mental health comorbidities are common among members of the United States long-term care population. Inadequately treated, these...

A. F. Coburn J. A. Talbot

2013-01-01

407

Multistage Optimization for Long-term Investors  

Microsoft Academic Search

Multi-stage simulation and optimization models are effective for solving long-term financial planning problems. Prominent examples include: asset-liability management for pension plans, integrated risk management for